25855

BRMS1

breast cancer metastasis suppressor 1;BRMS1;breast cancer metastasis suppressor 1

breast cancer metastasis-suppressor 1

11q13.2

protein-coding

We have recently characterized a human bladder cancer cell line T24 and a more aggressive lineage related variant of it, T24T. To gain further insights, we have studied their metastatic ability in an in vivo model system. Results show that T24 forms significantly fewer [4/12 (1/11) mice had metastases with 1-2 lesions/mouse] metastasis in SCID/bg mice than T24T [14/14 (6/6) mice had metastases with a mean of 24-28 lesions/mouse]. To begin exploring the mechanisms underlying this difference, we evaluated the mRNA and protein expression levels of metastasis-suppressor genes, known to be important in the progression of other cancers, in our model of bladder cancer progression. A higher mRNA expression of BRMS1, a metastasis suppressor in breast cancer, was observed in T24 cells. In addition, RhoGDI2 mRNA expression was only observed in T24 when compared to T24T, suggesting that Rho activation might play a significant role in the metastatic cascade. However, a basal level mRNA expression of KISS1, described as metastasis suppressor in melanoma and breast, was observed in both the lines and had slightly higher expression in T24T. No difference of Nm23-H1, KAI1, MKK4/SEK1 and E-Cadherin protein levels were noted between these two lines. In summary, it appears that the T24/T24T paired cell lines constitute a useful model for the study of human bladder cancer metastasis that will allow both the discovery and mechanistic evaluation of genes potentially involved in this process.

Mechanisms by which cancer cells communicate with the host organism to regulate lung colonization/metastasis are unclear. We show that this communication occurs via sphingosine 1-phosphate (S1P) generated systemically by sphingosine kinase 1 (SK1), rather than via tumour-derived S1P. Modulation of systemic, but not tumour SK1, prevented S1P elevation, and inhibited TRAMP-induced prostate cancer growth in TRAMP(+/+) SK1(-/-) mice, or lung metastasis of multiple cancer cells in SK1(-/-) animals. Genetic loss of SK1 activated a master metastasis suppressor, Brms1 (breast carcinoma metastasis suppressor 1), via modulation of S1P receptor 2 (S1PR2) in cancer cells. Alterations of S1PR2 using pharmacologic and genetic tools enhanced Brms1. Moreover, Brms1 in S1PR2(-/-) MEFs was modulated by serum S1P alterations. Accordingly, ectopic Brms1 in MB49 bladder cancer cells suppressed lung metastasis, and stable knockdown of Brms1 prevented this process. Importantly, inhibition of systemic S1P signalling using a novel anti-S1P monoclonal antibody (mAb), Sphingomab, attenuated lung metastasis, which was prevented by Brms1 knockdown in MB49 cells. Thus, these data suggest that systemic SK1/S1P regulates metastatic potential via regulation of tumour S1PR2/Brms1 axis.

We previously showed that introduction of a normal, neomycin-tagged human chromosome 11 reduces the metastatic capacity of MDA-MB-435 (435) human breast carcinoma cells by 70-90% without affecting tumorigenicity, suggesting the presence of one or more metastasis suppressor genes encoded on human chromosome 11. To identify the gene(s) responsible, differential display comparing chromosome 11-containing (neo11/ 435) and parental, metastatic cells was done. We describe the isolation and functional characterization of a full-length cDNA for one of the novel genes, designated breast-cancer metastasis suppressor 1 (BRMS1), which maps to human chromosome 11q13.1-q13.2. Stably transfected MDA-MB-435 and MDA-MB-231 breast carcinoma cells still form progressively growing, locally invasive tumors when injected into mammary fat pads but are significantly less metastatic to lungs and regional lymph nodes. These data provide compelling functional evidence that breast-cancer metastasis suppressor 1 is a novel mediator of metastasis suppression in human breast carcinoma.

Breast cancer progresses toward increasingly malignant behavior in tumorigenic and metastatic stages. In the series of events in the metastatic stage, tumor cells leave the primary tumor in breast and travel to distant sites where they establish secondary tumors, or metastases. In this report, we demonstrate that cell-cell communication via gap junctions is restored in the metastatic human breast carcinoma cell line MDA-MB-435 when it is transfected with breast metastasis suppressor 1 (BRMS1) cDNA. Furthermore, the expression profile of connexins (Cxs), the protein subunits of gap junctions, changes. Specifically, the expression of BRMS1 in MDA-MB-435 cells increases Cx43 expression and reduces Cx32 expression, resulting in a gap junction phenotype more similar to normal breast tissue. Taken together, these results suggest that gap junctional communication and the Cx expression profile may contribute to the metastatic potential of these breast cancer cells.

We have recently characterized a human bladder cancer cell line T24 and a more aggressive lineage related variant of it, T24T. To gain further insights, we have studied their metastatic ability in an in vivo model system. Results show that T24 forms significantly fewer [4/12 (1/11) mice had metastases with 1-2 lesions/mouse] metastasis in SCID/bg mice than T24T [14/14 (6/6) mice had metastases with a mean of 24-28 lesions/mouse]. To begin exploring the mechanisms underlying this difference, we evaluated the mRNA and protein expression levels of metastasis-suppressor genes, known to be important in the progression of other cancers, in our model of bladder cancer progression. A higher mRNA expression of BRMS1, a metastasis suppressor in breast cancer, was observed in T24 cells. In addition, RhoGDI2 mRNA expression was only observed in T24 when compared to T24T, suggesting that Rho activation might play a significant role in the metastatic cascade. However, a basal level mRNA expression of KISS1, described as metastasis suppressor in melanoma and breast, was observed in both the lines and had slightly higher expression in T24T. No difference of Nm23-H1, KAI1, MKK4/SEK1 and E-Cadherin protein levels were noted between these two lines. In summary, it appears that the T24/T24T paired cell lines constitute a useful model for the study of human bladder cancer metastasis that will allow both the discovery and mechanistic evaluation of genes potentially involved in this process.

tumor metastasis is one of the most important clinical aspects of neoplastic disease because patient mortality is frequently attributable to disseminated rather than primary tumors. However, it still is not possible to definitively distinguish those individuals at high risk for disseminated disease, who would benefit from aggressive adjuvant therapy, from the low-risk patients who might be spared the side effects of additional anticancer therapy. To identify factors that predispose toward metastatic disease, we have used a genetic approach. Using a highly metastatic model of mammary cancer, we identified previously inbred mouse strains (DBA/2J, NZB/B1NJ, and I/LnJ) that harbor genetic factors that significantly suppress metastatic efficiency. In this study, we report the results of four experiments to localize the genetic map locations of the metastasis efficiency modifier genes. One statistically significant locus was identified on proximal Chr 19 designated Mtes1. Secondary candidate intervals were detected on Chrs 6, 9, 13, and 17. Interestingly, Mtes1 colocalizes with the murine orthologue of the human breast cancer metastasis suppressor gene Brms1, suggesting that allelic variants of Brms1 might be responsible for the metastasis suppression observed.

Transmembrane 4 superfamily (TM4SF) is a recently described gene family, and TM4SF members are known to play roles in the signal transduction pathways and to regulate cell activation, development, proliferation, and motility. MRP-1/CD9, KAI1/CD82, and ME491/CD63, members of the TM4SF, have been reported to suppress tumor progression or metastasis. Previously, we showed that MRP-1/CD9 suppressed cell motility and metastatic potential to lungs. Moreover, reduction of MRP-1/CD9 and KAI1/CD82 gene expression was found to be a factor in a poor prognosis for patients with non-small cell lung cancer. However, among TM4SF, CD151 is identical to an existing gene, PETA-3, which may promote tumor metastasis of malignant cells, and its expression may be involved in the malignant progression of cancer. The function of CD151 is opposite that of the metastasis suppressor genes, MRP-1/CD9 and KAI1/CD82. On the basis of these results, we used reverse transcription-PCR and immunohistochemical techniques for a retrospective study of CD151 gene expression in tumor tissues from 145 lung cancer patients; 72 tumors were stage I, 29 stage II, 27 stage IIIA, and 17 stage IIIB. Whereas 86 patients had tumors positive for the CD151 gene, 59 had tumors that were negative for the CD151 gene. The overall survival rate of patients with CD151-positive tumors was much lower than that of CD151-negative patients (51.9% versus 73.1%; P = 0.013). Our findings suggest that high CD151 gene expression in lung cancer may be associated with a poor prognosis. Assessment of CD151 could be instrumental for improvements in lung cancer diagnosis and therapies.

We have cloned a novel metastasis-suppressor gene (BRMS1) by differential display, comparing metastatic human breast carcinoma cell line MDA-MB-435 to its metastasis-suppressed human chromosome 11 microcell hybrid. Screening of a murine cDNA library led to the identification of a 1.4 kb cDNA with a sequence revealing 85% homology to human BRMS1 within the open reading frame. The predicted protein sequence for the murine ortholog is 95% identical, suggesting that it is strongly conserved across these 2 species. The cloned cDNA was used to screen a murine strain SV129 BAC library to obtain brms1 genomic DNA. Three BAC clones [226(I4), 226(H4) and 239(N7)] were confirmed to encode the entire brms1 gene. Detailed analysis of BAC clone 226(I4) shows that the gene spans 8.5 kb and, like the human gene, is organized into 10 exons and 9 introns. While the exons share a high degree of homology, there are greater differences when comparing intron structures between the human and murine genes. The 5' upstream region shares about 64% homology with its human counterpart, retaining several of the many putative regulatory elements. Like the human genomic BRMS1, the murine ortholog of the iGnT gene is found upstream of brms1 and the murine ortholog of the RIN1 gene is found downstream of brms1. brms1 was then tested for suppression of metastasis of mouse mammary carcinoma cell line 66cl4 in syngeneic BALB/c mice. Transfection with brms1 did not inhibit 66cl4 primary tumor formation but significantly suppressed its metastatic capability. This suggests that the murine ortholog functions similarly to BRMS1.

We recently identified a novel metastasis suppressor gene, BRMS1, in breast cancer. Since the BRMS1 gene maps to chromosome 11q13.1-q13.2 and since chromosome 11q defects have been described in various stages of human melanoma progression, we hypothesized that BRMS1 may function as a tumor or metastasis suppressor in melanomas as well. Quantitative real-time RT-PCR revealed that BRMS1 mRNA expression was high in melanocytes, considerably reduced in early melanoma-derived cell lines, and barely detectable in advanced/metastatic cell lines. Stable transfectants of BRMS1 in the human melanoma cell lines MelJuSo and C8161.9 did not alter the tumorigenicity of either cell line, but significantly suppressed metastasis compared to vector-only transfectants. Orthotopic tumors continued to express BRMS1, but expression was lost in lung metastases. In vitro morphology, growth rate, and histology of BRMS1 transfectants were similar to controls. BRMS1 transfectants were less invasive in a collagen sandwich assay and had restored homotypic gap junctional intercellular communication (GJIC). Thus, BRMS1 functions as a metastasis suppressor in more than one tumor type (i.e., breast carcinoma and cutaneous melanoma) by modifying several metastasis-associated phenotypes.

BRMS1 (breast cancer metastasis suppressor 1) was recently identified as a novel breast cancer metastasis suppressor gene. To further characterize BRMS1-mediated metastasis suppression, we applied two-dimensional proteomic and mass spectrometry (LC-tandem MS and MALDI-TOF) analysis to identify proteins differentially expressed between highly metastatic MDA-MB-435 cells and metastasis-suppressed BRMS1-transfected MDA-MB-435 cells. Quadruplicate independent 2D gels were run and analyzed under identical conditions. Following in-gel trypsin digestion of seven differentially expressed proteins, amino acid sequence and mass profiles of the peptides were generated. Proteins were identified from the NCBI non-redundant database using the search program TurboSequest. Differential expression was confirmed for five proteins, including annexin I and alpha B-crystallin, by Northern blot analysis and immunostaining. Furthermore, we showed that both proteins were expressed in vivo in lungs containing metastasized MDA-MB-435 cells but not expressed in normal lung tissue of athymic mice. Our results suggest that annexin I and alpha B-crystallin are important cellular proteins that are down regulated through BRMS1 mediated metastasis suppression.

The breast cancer metastasis-suppressor gene BRMS1 is downregulated in metastatic breast cancer cells. Previous reports have shown restoration of gap junctional intercellular communication (GJIC) in the metastatic human breast carcinoma cell line MDA-MB-435 (435) transfected with BRMS1 cDNA. metastasis, to a large extent in most breast cancers, occurs to bone. However, the reason for this preferential metastasis is not known. We explored cell-to-cell communication between 435 carcinoma cells and a human osteoblastic cell line, hFOB1.19, to determine whether carcinoma cells can form gap junctions with bone cells and to explore the role of these heterotypic gap junctions and the BRMS1 gene in breast cancer metastasis to bone. 435 cells displayed greater cell-to-cell communication with hFOB 1.19 cells than with themselves. Transfection of BRMS1 into 435 cells increased homotypic gap junctional communication but did not significantly affect heterotypic communication with hFOBs. However, heterotypic communication of BRMS1 transfectants with hFOB cells was reduced relative to homotypic communication. In contrast, parental 435 cells displayed greater heterotypic communication with hFOBs relative to homotypic communication. Our results suggest that there are differences in the relative homotypic and heterotypic GJIC of metastasis-capable and -suppressed cell lines.

Repression of gene transcription is mediated by histone deacetylases containing repressor-co-repressor complexes, which are recruited to promoters of target genes via interactions with sequence-specific transcription factors. The mammalian Sin3A co-repressor complex contains a core of at least seven proteins including the pRb-interacting protein RBP1 and a putative tumor suppressor p33(ING1b). By biochemical purification and mass spectrometry, we have identified a novel component p40 from this complex. p40 bears homology to both yeast Sds3, a component of yeast histone deacetylase complexes, and its mammalian homologue mSds3. The p40-associated complex purified from human cells shows a strong histone deacetylase activity. When tethered to a Gal-DNA binding domain, the Gal-p40 is able to significantly repress transcription of a Gal-luciferase promoter. Interestingly, database analysis reveals that p40 is also highly homologous to BRMS1, a breast carcinoma metastasis suppressor, and overexpression of p40 in human cells can significantly inhibit cell growth. Thus, our data indicate that p40 may be critically involved in transcription repression of cell growth-associated gene expression by recruiting the HDAC1 deacetylase complex.

PURPOSE: Brain metastases are an increasingly common complication in breast cancer patients. The metastasis Suppressor Genes (MSG) Nm23, KISS1, KAI1, BRMS1, and Mkk4 have been associated with the metastatic potential of breast cancer in vitro and in vivo. METHODS: The mRNA expression of Nm23, KISS1, KAI1, BRMS1, and Mkk4 in fresh frozen tissue samples of brain metastases from ductal invasive breast cancer specimens was examined in relation to primary tumors. In a first step, mRNA expression screening was carried out using a semi-quantitative RT-PCR approach, in a second step quantitative real-time RT-PCR was performed on selected specimens. By immunohistochemical staining, gene products were visualized on the protein level. RESULTS: Semi-quantitative RT-PCR revealed reduced mRNA expression of Nm23, KISS1, KAI1, BRMS, and Mkk4 in brain metastases. Results for KISS1, KAI1, BRMS, and Mkk4 were confirmed by real-time RT-PCR. In detail, mRNA expression reduction in breast cancer brain metastases was tenfold. expression of MSG could be confirmed by immunohistochemical staining on protein level. CONCLUSIONS: Our investigations revealed significantly reduced mRNA expression of metastases suppressor genes KISS1, KAI1, BRMS1, and Mkk4 in breast cancer brain metastasis. Particularly, in the case of KISS1 and Mkk4, an important role for future treatment of patients with breast cancer brain metastatic lesions can be assumed.

The BRMS1 (breast cancer metastasis suppressor 1) gene has been found to suppress metastasis in animal models without inhibiting primary tumor growth. The aim of this study was to measure expression of BRMS1 mRNA in a panel of human breast carcinomas and compare its expression with parameters of local dissemination such as tumor size and lymph node metastasis. We also compared expression of BRMS1 mRNA in normal breast tissue, fibroadenomas, primary breast cancers and axillary nodal metastases from primary breast cancers. BRMS1 mRNA was detected in 10/11 (90%) specimens of normal breast tissue, 12/16 (75%) fibroadenomas, 64/82 (78%) primary breast cancer and 11/15 (64%) lymph node metastases (p, NS). In the primary cancer, expression was independent of tumor size, tumor grade, metastasis to axillary nodes and hormone receptor status. Furthermore, similar levels of BRMS1 were found in normal breast tissue, primary breast carcinomas and lymph node metastases from primary breast cancer. Our results do not suggest a role for BRMS1 in suppressing metastasis to local lymph nodes in patients with breast cancer.

metastasis-suppressor genes, by definition, suppress metastasis without affecting tumorigenicity and, hence, present attractive targets as prognostic or therapeutic markers. BRMS1 (breast cancer metastasis suppressor) has recently been identified as a metastasis-suppressor gene for human breast cancer and melanoma. expression of BRMS1 messenger RNA (mRNA) in multitissue including normal prostate, ovarian, testis, and colon has been detected by northern blot analysis. We hypothesize that the role of BRMS1 in tumor progression may not be limited to breast cancer and melanoma. We previously found that BRMS1 mRNA levels in primary ovarian epithelial carcinomas were significantly lower than that in normal ovarian and benign tumors (P < 0.05), and statistical analysis of BRMS1 mRNA levels revealed that BRMS1 mRNA levels were significantly higher in early tumor stages (I, II) compared with advanced tumor stages (III, IV) in which lymph node or distant metastases were present (P < 0.01). Our data showed that reduced BRMS1 mRNA seems to influence ovarian carcinoma metastatic ability. Therefore, we transfected BRMS1 plasmid into highly malignant ovarian carcinoma cell line, HO-8910PM, and examined cell biologic behaviors including proliferation, adhesion, invasion, and metastasis in vitro and in vivo. BRMS1 expression did not alter the proliferation of HO-8910PM cells in vitro and primary tumor formation in vivo. But, BRMS1 expression significantly suppressed the cell adhesion to extracellular matrix components and in vitro cell invasion in BRMS1-transfected HO-8910PM cells compared to parental HO-8910PM and vector-only transfectants (HO-8910PM-vect). Furthermore, motility of BRMS1 transfectants was inhibited. lung colony formation of intravenously injected BRMS1 transfectants in nude mice was significantly reduced. Also, BRMS1 transfectants form significantly less metastatic to organs of peritoneal cavity in orthotopically implanted ovarian tumor nude models. We further discovered that BRMS1 expression did downregulate expression of an actin-bundling protein associated with cell motility -fascin, which perhaps is the mechanism underlying BRMS1 suppression of metastasis. These data suggested that in addition to its already described role in breast cancer and melanoma, BRMS1 functions as a metastasis-suppressor gene in ovarian carcinoma by modifying several metastatic-associated phenotypes, offering a new target for therapeutic intervention.

tumour metastasis is a significant contributor to death in cancer patients. So studies on the molecular mechanism of tumor metastasis can provide new prognostic and therapeutic methods. tumor metastasis suppressor gene is a kind of genes that only suppresses metastasis without affecting tumorigenicity and tumor growth. BRMS1 is a tumor metastasis suppressor gene discovered in breast carcinoma cells in 2000. Its protein product was found to also suppress metastasis of melanoma cells and murine mammary carcinoma cells. BRMS1 is located in the nucleus,and interacts with mSin3-HDAC complex, and can alter the connexin expression profile of breast carcinoma cells, thereby restoring cell-cell communication via gap junctions. This review highlights some recent progress in the study of BRMS1, gives a brief introduction of related genes, and predicts its possible mechanism of action.

PURPOSE: It is well established that breast cancer metastasis suppressor 1 (BRMS1) suppresses metastasis of breast cancer in animal models without affecting the growth of the primary tumor. It has also been shown to suppress the metastasis of tumors derived from breast and melanoma cell lines. However, its clinical importance for breast cancer patients remains undetermined. This prompted us to investigate its expression level in breast cancer patients to clarify its clinical significance. EXPERIMENTAL DESIGN: The level of expression of BRMS1 mRNA was assessed by LightCycler quantitative real-time reverse transcription-PCR in 161 cases of invasive carcinoma of the breast. Associations between BRMS1 mRNA expression and various clinicopathologic factors were sought. RESULTS: It was found that BRMS1 mRNA was expressed at significantly higher levels in patients>50 years of age, with tumor size<2 cm, or with progesterone receptor-positive and HER2-negative tumors. No differences were found between BRMS1 mRNA expression and axillary lymph node metastasis and histologic grade groups. Patients with high levels of expression of BRMS1 mRNA have a better prognosis than those with low expression. Univariate and multivariate prognostic analysis showed that BRMS1 mRNA is an independent prognostic factor for disease-free survival in breast cancer. CONCLUSIONS: These results provide clinical evidence to support the notion that BRMS1 is a breast carcinoma metastasis suppressor gene. Our results also suggest that measuring BRMS1 expression will help to identify those breast cancer patients with worse disease-free survival.

PURPOSE: This study aims to determine the effect of loss of breast cancer metastasis suppressor 1 (BRMS1) protein expression on disease-free survival in breast cancer patients stratified by estrogen receptor (ER), progesterone receptor (PR), or HER2 status, and to determine whether loss of BRMS1 protein expression correlated with genomic copy number changes. EXPERIMENTAL DESIGN: A tissue microarray immunohistochemical analysis was done on tumors of 238 newly diagnosed breast cancer patients who underwent surgery at the Cleveland Clinic between January 1, 1995 and December 31, 1996, and a comparison was made with 5-year clinical follow-up data. Genomic copy number changes were determined by array-based comparative genomic hybridization in 47 breast cancer cases from this population and compared with BRMS1 staining. RESULTS: BRMS1 protein expression was lost in nearly 25% of cases. Patients with tumors that were PR negative (P=0.006) or HER2 positive (P=0.039) and <50 years old at diagnosis (P=0.02) were more likely to be BRMS1 negative. No overall correlation between BRMS1 staining and disease-free survival was observed. A significant correlation, however, was seen between loss of BRMS1 protein expression and reduced disease-free survival when stratified by either loss of ER (P=0.008) or PR (P=0.029) or HER2 overexpression (P=0.026). Overall, there was poor correlation between BRMS1 protein staining and copy number status. CONCLUSIONS: These data suggest a mechanistic relationship between BRMS1 expression, hormone receptor status, and HER2 growth factor. BRMS1 staining could potentially be used in patient stratification in conjunction with other prognostic markers. Further, mechanisms other than genomic deletion account for loss of BRMS1 gene expression in breast tumors.

BRMS1 is regarded as a metastasis suppressor gene for its ability to reduce metastatic potential of human and murine breast cancer cells as well as human melanoma cells. However, BRMS1 association to human tumor progression is not clearly understood. In the present study we analyzed BRMS1 mRNA expression in tumor progression and its potential prognostic value for breast carcinoma. BRMS1 mRNA expression level was quantified by real-time PCR in 47 tumoral, in 14 peritumoral and in 15 metastatic microdissected cellular populations from 47 breast cancer patients with 10-year follow up. We found BRMS1 expression to be higher in carcinoma cells than in matching normal epithelial cell populations in 10 out of 14 cases (p = 0.0005), while lymph-nodal carcinoma cells showed lower BRMS1 expression in 9 out of 15 cases (p = 0.001). Using both in vivo (human mammary breast carcinomas) and in vitro systems (breast cancer cell lines) we were able to demonstrate that BRMS1 overexpression was not a bias effect induced by cell proliferation rate. BRMS1 expression levels did not correlate with standard breast cancer prognostic factors but BRMS1 higher expression was associated with patient shorter disease-free and overall survival. Our findings are apparently inconsistent with the concept of BRMS1 as a metastasis suppressor gene. One possible explanation is that epithelial cells increase their BRMS1 expression as a compensatory response to tumor formation or metastasis progression, which is elevated in proportion to tumor aggressiveness, whereas those cells of the primary tumor that cannot upregulate BRMS1 escape to form metastasis.

We used Affymetrix microarrays to compare gene expression profiles of the metastatic parental breast cancer cell line MDA-MB-435 (435) and the non-metastatic daughter cell line created by the stable expression of the BReast cancer metastasis Suppressor 1 (BRMS1) gene in 435 cells, MDA-MB-435-BRMS1 (435/BRMS1). Analysis of microarray data provided insight into some of the potential mechanisms by which BRMS1 inhibits tumor formation at secondary sites. Furthermore, due to the importance of the microenvironment, we also examined gene expression under different growth conditions (i.e., plus or minus serum). expression of 565 genes was significantly (adjusted P-value <0.05) altered regardless of in vitro growth conditions. BRMS1 expression significantly increased multiple major histocompatability complex (MHC) genes and significantly decreased expression of several genes associated with protein localization and secretion. The pattern of gene expression associated with BRMS1 expression suggests that metastasis suppression may be mediated by enhanced immune recognition, altered transport, and/or secretion of metastasis-associated proteins.

Breast cancer metastasis suppressor 1 (BRMS1) inhibits formation of macroscopic lung metastases in breast, ovary, and melanoma xenograft models. Because it is unclear which step(s) of the metastatic cascade are affected by BRMS1, the major aim of this study was to determine when and how BRMS1 acts to suppress metastasis. We also examined whether BRMS1 expression globally blocks metastasis or selectively inhibits metastatic outgrowths in specific tissues. metastatic human breast carcinoma cell lines MDA-MB-231 and -435 expressing enhanced green fluorescent protein (GFP; 231 GFP and 435 GFP) and cell lines transduced with the BRMS1 gene (231 GFP-BRMS1 and 435 GFP-BRMS1) were injected into the left cardiac ventricle to achieve the widest possible cellular distribution, by minimizing first-pass clearance in the lungs. Compared with parental cells, BRMS1-expressing clones formed significantly fewer metastases in all organs tested. When cells were injected directly into the vasculature, fewer of the BRMS1-expressing cells reached lungs or bone compared with parental cells, suggesting that restoration of BRMS1 expression increased cell death during transit. Susceptibility to anoikis was verified in vitro by demonstrating decreased survival on poly-hydroxyethyl methacrylate-coated dishes. Most of the BRMS1-expressing cells reaching secondary sites failed to proliferate, suggesting that BRMS1 also inhibits colonization. Coupled with previous reports showing modest effects of BRMS1 on adhesion and invasion, our results indicate that BRMS1 inhibits metastases in multiple organs by blocking several steps in the metastatic cascade.

Breast cancer metastasis Suppressor 1 (BRMS1) suppresses metastasis of human breast cancer, ovarian cancer and melanoma in athymic mice. Studies have also shown that BRMS1 is significantly downregulated in some breast tumors, especially in metastatic disease. However, the mechanisms which regulate BRMS1 expression are currently unknown. Upon examination of the BRMS1 promoter region by methylation specific PCR (MSP) analysis, we discovered a CpG island (-3477 to -2214), which was found to be hypermethylated across breast cancer cell lines. A panel of 20 patient samples analyzed showed that 45% of the primary tumors and 60% of the matched lymph node metastases, displayed hypermethylation of BRMS1 promoter. Furthermore, we found a direct correlation between the methylation status of the BRMS1 promoter in the DNA isolated from tissues, with the loss of BRMS1 expression assessed by immunohistochemistry. There are several studies investigating the mechanism by which BRMS1 suppresses metastasis; however thus far there is no study that reports the cause(s) of loss of BRMS1 expression in aggressive breast cancer. Here we report for the first time that BRMS1 is a novel target of epigenetic silencing; and aberrant methylation in the BRMS1 promoter may serve as a cause of loss of its expression.

That metastatic tumor cells grow in selective non-native environments suggests an ability to differentially respond to local microenvironments. BRMS1, like other metastasis suppressors, halts ectopic growth (metastasis) without blocking orthotopic tumor formation. BRMS1-expressing tumor cells reach secondary sites but do not colonize distant tissues, compelling the hypothesis that BRMS1 selectively restricts the ability of tumor cells to respond to exogenous regulators in different tissues. Here we report that BRMS1 expression in metastatic human breast cancer cells leads to a selective reduction in epidermal growth factor receptor expression and downstream (AKT) signaling. Signaling through another receptor tyrosine kinase, hepatocyte growth factor receptor (c-Met), remains unaltered despite reduced levels of the signaling intermediate phosphatidylinositol (4,5)-bisphosphate. Interestingly, reduced downstream calcium signaling is observed following treatment with platelet-derived growth factor, consistent with decreased phosphatidylinositol (4,5)-bisphosphate. However, platelet-derived growth factor receptor expression is unaltered. Thus, BRMS1 differentially attenuates cellular responses to mitogenic signals, not only dependent upon the specific signal received, but at varying steps within the same signaling cascade. Specific modulation of signaling responses received from the microenvironment may ultimately dictate which environments are permissive/restrictive for tumor cell growth and provide insights into the biology underlying metastasis.

Clinical studies evaluating the mRNA expression level of the BRMS1 metastasis suppressor in the progression of breast cancer have not been consistent. The purpose of this study was to characterize endogenous BRMS1 mRNA and protein in a model of the progression of breast cancer. BRMS1 protein expression was evaluated in the genetically related MCF10 cell lines representing 'normal' breast epithelial cells (MCF10A), pre-malignant breast disease (MCF10AT), comedo ductal carcinoma in situ (MCF10DCIS.com), and metastatic carcinoma (MCF10CAa.1 and MCF10CAd.1alpha) with two antibodies that recognize distinct epitopes in the BRMS1 protein. Nuclear expression of the characteristic *35 kDa BRMS1 protein was detected in all cell lines. Because BRMS1 was expressed in the metastatic MCF10 variants, the BRMS1 exons were sequenced to scan for possible genetic mutations. BRMS1 was wild-type with the exception of a synonymous T/C transition in exon 7. However, alternatively spliced variants were detected by RT-PCR. Two variants, BRMS1.v2 and BRMS1.v4 were only detected in the MCF10A and AT cell lines, while BRMS1 and BRMS1.v3 were detected in all lines. These results demonstrate that expression of the characteristic *35 kDa BRMS1 protein is not sufficient to prevent metastasis. The differential expression of alternative splice variants suggests caution should be taken when evaluating BRMS1 mRNA in clinical samples.

The Breast cancer metastasis Suppressor 1 (BRMS1) belongs to an expanding category of proteins called metastasis suppressors that demonstrate in vivo metastasis suppression while still allowing growth of the orthotopic tumor. Since BRMS1 decreases either the expression or function of multiple mediators implicated in resistance to chemotherapy (NF-kappaB, AKT, EGFR), we asked whether breast carcinoma cells expressing BRMS1 could be sensitized upon exposure to commonly used therapeutic agents that inhibit some of these same cellular mediators as BRMS1. In this report, we demonstrate that chemosensitivity of breast cancer cells is preserved in the presence of BRMS1. Further, BRMS1 does not change expression of AKT isoforms or PTEN, implicated in chemoresistance to common drug agents. Overall, our data with two different metastatic breast cancer cell lines indicates that BRMS1 expression status may not interfere with the response to commonly used chemotherapeutic agents in the management of solid tumors such as breast cancer. Since tumor protein expression analysis increasingly guides therapy decisions, our data may be of clinical benefit in disease management including profiling for BRMS1 expression before start of therapy.

The breast cancer metastasis suppressor 1 (BRMS1) is a member of a family of proteins that actively suppress tumour metastasis. Understanding BRMS1 mediated metastasis suppression is critical to the development of new therapies designed to prevent and treat patients with late stage breast cancer. To aid research into the functional aspects that underpin BRMS1 mediated metastasis suppression we have expressed and purified recombinant BRMS1 and produced BRMS1 polyclonal antibodies. Using these antibodies to immunoprecipitate endogenous BRMS1 containing complexes from MCF7 breast cancer cell lines we have identified, by mass spectrometry, the small heat shock protein Hsp27 in complex with BRMS1. We also show that the expression of both BRMS1 and Hsp27 are inversely correlated with metastatic potential.

RhoBTB2, or Deleted in Breast cancer 2 (DBC2), identified as a candidate tumor suppressor gene for breast cancer and other human malignancies, is an atypical member of a novel gene family encoding small GTPases. In this study, we found that ectopic expression of RhoBTB2 inhibits the migration and invasion of the human metastatic breast cancer cell lines MDA-MB-231 and MDA-MB-435 in a dose-dependent manner. Western blotting analysis revealed that ectopic expression of RhoBTB2 induces a significant increase in the breast cancer metastasis suppressor, BRMS1. siRNA suppression of BRMS1 expression markedly reversed the inhibitory effects of RhoBTB2 on the migration and invasion abilities of both cell lines. Ezrin is a member of the ezrin-radixin-moesin cytoskeleton-associated protein family and is a key signaling molecule that regulates cancer migration and invasion. Western blotting analysis demonstrated that ectopic expression of RhoBTB2 results in decreased phosphorylation of ezrin and Akt2 in both MDA-MB-231 and MDA-MB-435 cells. Therefore, we conclude that up-regulation of the breast cancer metastasis suppressor BRMS1 and down-regulation of the phosphorylation of the cancer metastasis-related gene, ezrin, contributed to RhoBTB2-induced inhibition of metastatic breast carcinoma cell migration and invasion. Our findings suggest that understanding RhoBTB2-mediated migration and suppression of invasion is critical to the development of new therapies designed to prevent and treat patients with breast cancer metastasis.

Breast cancer metastasis suppressor 1 (BRMS1) has been reported to suppress metastasis without significantly affecting tumorigenicity in breast cancer and ovarian cancer. To investigate the role of BRMS1 in human melanoma progression and prognosis, we established tissue microarray and BRMS1 expression was evaluated by immunohistochemistry in 41 dysplastic nevi, 90 primary melanomas and 47 melanoma metastases. We found that BRMS1 expression was significantly decreased in metastatic melanoma compared with primary melanoma or dysplastic nevi (P=0.021 and 0.001, respectively, chi(2) test). In addition, reduced BRMS1 staining was significantly correlated with American Joint Committee on cancer stages (P=0.011, chi(2) test), but not associated with tumor thickness, tumor ulceration and other clinicopathological parameters. Furthermore, BRMS1 expression was significantly correlated with disease-specific 5-year survival of melanoma patients (P=0.007, log-rank test). Multivariate Cox regression analysis revealed that BRMS1 staining was an independent prognostic factor for melanoma patients (relative risk=0.51; confidence interval=0.29-0.91; P=0.022). Moreover, we demonstrated that BRMS1 overexpression inhibited endothelial cell growth and tube formation ability by suppressing NF-kappaB activity and IL-6 expression in vitro. We also showed that knockdown of BRMS1 increased IL-6 expression and promoted endothelial cell growth and tube formation. In addition, our data revealed that the BRMS1-mediated IL-6 expression is dependent on NF-kappaB. Strikingly, our in vivo studies using nude mice confirmed that BRMS1 inhibited blood vessel formation and the recruitment of CD31-positive cells in matrigel plugs. Taken together, BRMS1 expression was decreased in metastatic melanomas, which resulted in deficient suppression of angiogenesis and contributed to melanoma progression. BRMS1 may serve an important prognostic marker and therapeutic target for melanoma patients.

metastasis is a complex process divided into a number of steps including detachment of tumor cells from the primary tumor, invasion, migration, intravasation, survival in the vasculature, extravasation, and colonization of the secondary site. Proteins that block metastasis without inhibiting primary tumor formation are known as metastasis suppressors; examples are NM23, Maspin, KAI1, KISS1, and MKK4. Breast cancer metastasis suppressor 1 (BRMS1) was identified as a suppressor of breast cancer metastasis in the late 1990s. In vitro and in vivo studies have confirmed that BRMS1 is a potent metastasis suppressor not limited to breast cancer. However, conflicting clinical observations regarding its role as a metastasis suppressor and its validity as a diagnostic biomarker warrant more in-depth clinical study. In this review, the authors provide an overview of its biology, function, action mechanism and pathological significance.

Breast cancer metastasis suppressor-1 (BRMS1) is a putative antimetastatic gene. However, results relating its expression to the prognosis of breast cancer are still controversial, and all studies carried out to date have failed to show a relationship between the expression of BRMS1 and axillary lymph node metastasis in breast cancer. It has been recently suggested that BRMS1 may exert its physiological role through the modulation of apoptosis. In order to test this hypothesis, we studied the expression of BRMS1 and genes known to be directly related with apoptosis in human breast carcinoma. The expression of mRNA corresponding to BRMS1, BCL2, BAX, CASP3 and the apoptosis-related X-chromosome RNA binding motif (RBM) genes (RBMX, RBM3, RBM10 small and large variant) was studied by means of differential RT-PCR in 94 samples obtained from previously untreated patients with breast carcinoma. A significant (p=0.03) inverse correlation between BRMS1 mRNA expression and expression of the mRNA corresponding to the large variant of the X-chromosome RBM10 gene was found. The degree of direct correlation with another member of the X-chromosome RBM gene family, RBMX, almost attained statistical significance (p=0.06). These results point towards a possible link between BRMS1 expression and apoptosis in human breast cancer through a relationship with the expression of genes belonging to the X-chromosome RBM family.

Morbidity and mortality of breast cancer patients are drastically increased when primary tumor cells are able to spread to distant sites and proliferate to become secondary lesions. Effective treatment of metastatic disease has been limited; therefore, an increased molecular understanding to identify biomarkers and therapeutic targets is needed. Breast cancer metastasis suppressor 1 (BRMS1) suppresses development of pulmonary metastases when expressed in a variety of cancer types, including metastatic mammary carcinoma. Little is known of Brms1 function throughout the initiation and progression of mammary carcinoma. The goal of this study was to investigate mechanisms of Brms1-mediated metastasis suppression in transgenic mice that express Brms1 using polyoma middle T oncogene-induced models. Brms1 expression did not significantly alter growth of the primary tumors. When expressed ubiquitously using a beta-actin promoter, Brms1 suppressed pulmonary metastasis and promoted apoptosis of tumor cells located in the lungs but not in the mammary glands. Surprisingly, selective expression of Brms1 in the mammary gland using the MMTV promoter did not significantly block metastasis nor did it promote apoptosis in the mammary glands or lung, despite MMTV-induced expression within the lungs. These results strongly suggest that cell type-specific over-expression of Brms1 is important for Brms1-mediated metastasis suppression.

Breast cancer metastasis suppressor 1 (BRMS1) was originally identified as an active metastasis suppressor in human breast cancer. Loss of BRMS1 expression correlates with tumor progression, and BRMS1 suppresses several steps required for tumor metastasis. However, the role of BRMS1 in hepatocellular carcinoma (HCC) remains elusive. In this study, we found that the expression level of BRMS1 was significantly down-regulated in HCC tissues. expression of BRMS1 in SK-Hep1 cells did not affect cell growth under normal culture conditions, but sensitized cells to apoptosis induced by serum deprivation or anoikis. Consistently, knockdown of endogenous BRMS1 expression in Hep3B cells suppressed cell apoptosis. We identified that BRMS1 suppresses osteopontin (OPN) expression in HCC cells and that there is a negative correlation between BRMS1 and OPN mRNA expression in HCC tissues. Moreover, knockdown of endogenous OPN expression reversed the anti-apoptosis effect achieved by knockdown of BRMS1. Taken together, our results show that BRMS1 sensitizes HCC cells to apoptosis through suppressing OPN expression, suggesting a potential role of BRMS1 in regulating HCC apoptosis and metastasis.

The breast cancer metastasis suppressor 1 (BRMS1) gene suppresses metastasis without affecting the primary tumor growth. Cellular localization of BRMS1 appears to be important for exerting its effects on metastasis inhibition. We recently described a nucleo-cytoplasmic shuttling for BRMS1 and identified a nuclear export signal within the N-terminal coiled coil. The structure of these regions shows an antiparallel coiled coil capable of oligomerizing, which compromises the accessibility to the nuclear export signal consensus residues. We have studied the structural and biophysical features of this region to further understand the contribution of the N-terminal coiled coil to the biological function of BRMS1. We have observed that residues 85 to 98 might be important in defining the oligomerization state of the BRMS1 N-terminal coiled coil. The fragments are mainly disordered in solution, with evidence of residual structure. In addition, we report the presence of a conformational dynamic equilibrium (oligomeric folded species <--> oligomeric unfolded) in solution in the BRMS1 N-terminal coiled coil that might facilitate the nuclear export of BRMS1 to the cytoplasm.

Inactivation of tumor suppressor and metastasis suppressor genes via epigenetic silencing is a frequent event in human cancers. Recent work has shown new mechanisms of epigenetic silencing, based on the occurrence of long noncoding promoter-spanning antisense and/or sense RNAs (lncRNAs), which constitute part of chromatin silencing complexes. Using reverse transcription polymerase chain reaction (RT-PCR), we have started to scan "triple negative" and Her2-overexpressing breast cancer cell lines for directional/bidirectional transcription through promoters of tumor suppressor and metastasis suppressor genes known to be epigenetically silenced in vivo. Surprisingly, we found that RT-PCR-amplified products were obtained at high frequency in the absence of exogenous primers. These amplified products resulted from RT priming via transcripts originating from promoter or upstream spanning regions. Consequently, this priming overruled directionality determination and led to false detection-identification of such lncRNAs. We show that this prevalent "no primer" artifact can be eliminated by treating the RNA preparations with periodate, performing RT reactions at highly elevated temperatures, or a combination of both. These experimental improvements enabled determination of the presence and directionality of individual promoter-spanning long noncoding RNAs with certainty. Examples for the BRMS1 metastasis suppressor gene, as well as RAR-beta2 and CST6 human tumor suppressor genes, in breast carcinoma cell lines are presented.

Purinergic signaling may represent an effective target in cancer therapy because the expression of purinergic receptors is altered in many forms of cancer and extracellular nucleotides modulate cancer cell growth. We examined the effect of extracellular ATP on the growth of the metastatic breast carcinoma cell line MDA-MB-435 relative to an immortalized breast epithelial cell line, hTERT-HME1. We also investigated whether the metastasis suppressor gene BRMS1 alters the sensitivity of breast cancer cells to ATP. Exposure to ATP for 24 h decreased proliferation and induced apoptosis in hTERT-HME1. However, exposure to ATP did not decrease proliferation or induce apoptosis in MDA-MD-435 cells until 48 h of exposure and only at higher doses than were effective with hTERT-HME1, suggesting MDA-MB-435 cells were resistant to the antiproliferative and apoptosis-inducing effects of ATP. Exposure to ATP for 24 h induced a decrease in proliferation of MDA-MB-435 cells expressing BRMS1, similar to hTERT-HME1, but did not induce an increase in apoptosis. MDA-MB-435 cells expressed low levels of the purinergic receptor P2Y2, as well as decreased ATP-induced cytosolic calcium mobilization, relative to hTERT-HME1. However, expressing BRMS1 in MDA-MB-435 cells restored P2Y2 levels and ATP-induced cytosolic calcium mobilization such that they were similar to hTERT-HME1. These data suggest that BRMS1 increases the sensitivity of breast cancer cells to the antiproliferative, but not apoptosis-inducing effects of ATP and that this is at least partly mediated by increased expression of the P2Y2 receptor.

metastatic dissemination is a multi-step process that depends on cancer cells' ability to respond to microenvironmental cues by adapting adhesion abilities and undergoing cytoskeletal rearrangement. Breast cancer metastasis Suppressor 1 (BRMS1) affects several steps of the metastatic cascade: it decreases survival in circulation, increases susceptibility to anoikis, and reduces capacity to colonize secondary organs. In this report, BRMS1 expression is shown to not significantly alter expression levels of integrin monomers, while time-lapse and confocal microscopy revealed that BRMS1-expressing cells exhibited reduced activation of both beta1 integrin and focal adhesion kinase, and decreased localization of these molecules to sites of focal adhesions. Short-term plating of BRMS1-expressing cells onto collagen or fibronectin markedly decreased cytoskeletal reorganization and formation of cellular adhesion projections. Under 3D culture conditions, BRMS1-expressing cells remained rounded and failed to reorganize their cytoskeleton and form invasive colonies. Taken together, BRMS1-expressing breast cancer cells are greatly attenuated in their ability to respond to microenvironment changes. (c) 2013 Wiley Periodicals, Inc.

OBJECTIVE: To study the effect of the transfected Breast cancer metastasis suppressor 1 (BRMS1) gene on the migration of breast cancer cells and the possible mechanisms involved. METHODS: MDA-MB-231HM cells which have a high propensity of metastasize to lung was sieved from MDA-MB-231 and its derivative cells stable transfected with BRMS1 were used to study in vitro. Cell migratory ability was observed. The cellular cyclic adenylic acid (cAMP) concentration was tested by radioimmunoassay (RIA). The activity of adenylate cyclase (AC), phosphodiesterase (PDE) and protein kinase A (PKA) were measured by enzyme immunoassay (EIA) and (gamma-(32)P) ATP incorporation. The effect of BRMS1 on connexins (Cx) expression was analyzed by by RT-PCR and Western blot. RESULTS: Overexpression of BRMS1 significantly inhibited cell migration in MDA-MB-231HM cells in vitro. However, BRMS1's effect on cell migration could be eliminated after pretreating with pertussis toxin (PTX). BRMS1 overexpression increased cellular cAMP and PKA activity by activating the activity of AC. Furthermore, BRMS1 overexpression up-regulated Cx26 expression, whereas Cx32, Cx43 expressions did not changed. CONCLUSION: The present study indicated G-protein-coupled cAMP signaling pathway was involved in BRMS1 related MDA-MB-231HM cells migration, and BRMS1 could change connexins (Cx) expression profiles through increasing expression of Cx26 in cells.

Breast cancer metastasis suppressor-1 (BRMS1) is a candidate metastasis-suppressing gene and has been shown to potentially inhibit tumor progression without blocking the growth of orthotopic tumors, in different tumor types including non-small cell lung cancer, ovarian, melanoma and breast cancers. MATERIALS AND METHODS: BRMS-1 gene transcript was quantified in breast cancer sample tissues and analyzed against histological and clinical patient outcome. Human breast cancer cell lines, MDA MB-231 and MCF-7 were used to genetically-modify the expression of BRMS-1 and test for biological responses following BRMS-1 modifications. Key candidate signal pathways, influenced by BRMS-1 were also explored. RESULTS: BRMS1 was present in MDA MB-231 and MCF-7 cell lines. Using anti-BRMS1 transgenes, we knocked-down the transcripts of BRMS1 in both cells at the mRNA and protein levels. Knockdown of BRMS1 gave both cells a faster cell growth rate, rapid pace of cellular migration and invasion, compared to respective wild-type and control cells (p<0.05). Blocking phospholipase-Cgamma (PLCgamma) had a significant influence on the BRMS-1-induced cell migration. Finally, significantly low levels of BRMS1 were observed in patients with high-grade tumors (p=0.12), in patients with distant metastasis (p=0.05) and those who died of breast cancer (p=0.0037). In addition, patients with low levels of BRMS1 had a significantly shorter overall survival (p=0.035). CONCLUSION: BRMS-1 is aberrantly expressed in human breast cancer and is inversely-correlated with disease progression and patient survival. This is likely to be occurring via its influence on invasion and migration of breast cancer cells.

BACKGROUND: Breast cancer metastasis suppressor 1 (BRMS1) is a potent metastasis suppressor of various types of malignancies, including melanoma and ovarian cancer. Unfortunately, the clinical data regarding its role as a true metastatic suppressor and its efficacy as a prognostic marker and therapeutic target remain controversial. This study was designed to investigate the effect of BRMS1 on the invasion and metastasis of human ovarian cancer cells and its potential underlying mechanisms. MATERIALS AND METHODS: BRMS1 small interfering RNAs (siRNAs) or control siRNAs were transfected into the OVCAR3 human ovarian cancer cell line. Invasion and migration activities were assessed using the Transwell invasion and migration assay. Protein levels of nuclear factor-kappaB (NF-kappaB) subunit p65, osteopontin (OPN) and urokinase-type plasminogen activator (uPA) were evaluated by Western blot, immunofluorescence and immunocytochemistry methods. RESULTS: Successful knockdown of BRMS1 was verified by quantitative real-time RT-PCR and Western blot. The invasion and migration capacities of OVCAR3 cells were significantly enhanced in the BRMS1-silenced group, compared to controls (p < 0.05). Silencing of BRMS 1 significantly induced the expression of NF-kappaB subunit, p65, uPA, and OPN proteins. CONCLUSIONS: BRMS1 inhibits expression of p65, uPA and OPN protein. In turn, this leads to inhibition of ovarian cancer cell invasion and metastasis. This study unveils a potential novel mechanism by which BRMS1 inhibits metastasis of ovarian cancer cells.

Epidermal growth factor receptor (EGFR) is widely used as a biomarker for pathological grading and therapeutic targeting of human cancers. This study investigates expression, spatial distribution as well as the endocytosis of EGFR in single breast cancer cells using surface-enhanced Raman spectroscopy (SERS). By incubating anti-EGFR antibody conjugated SERS nanoprobes with an EGFR-over-expressing cancer cell line, A431, EGFR localization was measured over time and found to be located primarily at the cell surface. To further validate the constructed SERS probes, we applied this SERS probes to detect the EGFR expression on breast cancer cells (MDA-MB-435, MDA-MB-231) and their counterpart cell lines in which EGFR expression was down-regulated by breast cancer metastasis suppressor 1 (BRMS1). The results showed that SERS method not only confirms immunoblot data measuring EGFR levels, but also adds new insights regarding EGFR localization and internalization in living cells which is impossible in immunoblot method. Thus, SERS provides a powerful new tool to measure biomarkers in living cancer cells.

Breast cancer metastasis suppressor 1 (BRMS1) was originally identified as a metastasis suppressor gene in human breast cancer. Previous studies have reported that loss of BRMS1 expression correlates with tumor progression, and poor prognosis in NSCLC. However, the role of BRMS1 in NSCLC is not fully understood. In this study, we found that expression of BRMS1 in A549 cells did not affect cell growth under normal culture conditions but sensitized cells to apoptosis induced by serum deprivation. Consistently, knockdown of endogenous BRMS1 expression in H1299 cells suppressed cell apoptosis. We identified that BRMS1 regulate apoptosis in NSCLC cells by modulating Stat3 activation. Taken together, our results show that BRMS1 sensitizes NSCLC cells to apoptosis through Stat3 signaling pathway, suggesting a potential role of BRMS1 in regulating NSCLC apoptosis and metastasis.

Computational tools occupy the prime position in the analysis of large volume of post-genomic data. These tools have advantage over the wet lab experiments in terms of high coverage, cost and time. Breast cancer is the most common cancer in females worldwide. It is a genetically heterogeneous disorder and many genes are involved in the pathway of the disease. mutations in metastasis suppressor gene are the major cause of the disease. In this study, the effects of mutations in breast cancer metastasis suppressor 1gene upon protein structure and function were examined by means of computational tools and information from databases.This study can be useful to predict the potential effect of every allelic variant, devise new biological experiments and to interpret and predict the patho-physiological impact of new mutations or non-synonymous polymorphisms.

Breast cancer metastasis suppressor gene-1 (BRMS1) is newly discovered tumor metastasis gene, which has been reported to play an important role in the progression of human tumor. However, its role in rectal cancer has never been investigated. In this present study, we evaluated the associated of BRMS1 with colorectal cancer, its value in prognosis, and its role in metastasis of rectal cancer. BRMS1 expression examined in 80 patients and the role of BRMS1 in metastasis was studied using mice model. Our results showed that BRMS1 expression was significantly associated with clinicopathological parameters in rectal cancer patients and overexpression of BRMS1 in rectal cancer xenograft led to decreased growth, invasiveness and metastasis. Our findings indicate that high expression of BRSM1 in rectal cancer plays an essential role in tumor progression.

We recently identified a novel metastasis suppressor gene, BRMS1, in breast cancer. Since the BRMS1 gene maps to chromosome 11q13.1-q13.2 and since chromosome 11q defects have been described in various stages of human melanoma progression, we hypothesized that BRMS1 may function as a tumor or metastasis suppressor in melanomas as well. Quantitative real-time RT-PCR revealed that BRMS1 mRNA expression was high in melanocytes, considerably reduced in early melanoma-derived cell lines, and barely detectable in advanced/metastatic cell lines. Stable transfectants of BRMS1 in the human melanoma cell lines MelJuSo and C8161.9 did not alter the tumorigenicity of either cell line, but significantly suppressed metastasis compared to vector-only transfectants. Orthotopic tumors continued to express BRMS1, but expression was lost in lung metastases. In vitro morphology, growth rate, and histology of BRMS1 transfectants were similar to controls. BRMS1 transfectants were less invasive in a collagen sandwich assay and had restored homotypic gap junctional intercellular communication (GJIC). Thus, BRMS1 functions as a metastasis suppressor in more than one tumor type (i.e., breast carcinoma and cutaneous melanoma) by modifying several metastasis-associated phenotypes.

Breast cancer metastasis suppressor 1 (BRMS1) was originally identified as an active metastasis suppressor in human breast cancer. Loss of BRMS1 expression correlates with tumor progression, and BRMS1 suppresses several steps required for tumor metastasis. However, the role of BRMS1 in hepatocellular carcinoma (HCC) remains elusive. In this study, we found that the expression level of BRMS1 was significantly down-regulated in HCC tissues. expression of BRMS1 in SK-Hep1 cells did not affect cell growth under normal culture conditions, but sensitized cells to apoptosis induced by serum deprivation or anoikis. Consistently, knockdown of endogenous BRMS1 expression in Hep3B cells suppressed cell apoptosis. We identified that BRMS1 suppresses osteopontin (OPN) expression in HCC cells and that there is a negative correlation between BRMS1 and OPN mRNA expression in HCC tissues. Moreover, knockdown of endogenous OPN expression reversed the anti-apoptosis effect achieved by knockdown of BRMS1. Taken together, our results show that BRMS1 sensitizes HCC cells to apoptosis through suppressing OPN expression, suggesting a potential role of BRMS1 in regulating HCC apoptosis and metastasis.

Breast cancer metastasis suppressor 1 (BRMS1) is able to suppress tumor metastasis without affecting primary tumor growth in various cancers. Here, we report a novel transcript variant of human BRMS1, termed BRMS1.vh. BRMS1.vh is identical to the major BRMS1 variant (BRMS1.v1) except for missing base pairs 683-775, encoding a 215-amino acid protein lacking a functional nuclear localization sequence. expression of BRMS1.vh in hepatocellular carcinoma (HCC) cells suppressed NF-kappaB signaling pathway, sensitized cells to apoptotic stimuli, leading to suppressed tumor growth. Taken together, our results suggest a potential role for BRMS1.vh in regulating cell apoptosis and tumor growth in HCC.

The mechanisms through which the metastasis suppressor gene BRMS1 functions are poorly understood. Herein, we report the identification of a previously undescribed E3 ligase function of BRMS1 on the histone acetyltransferase p300. BRMS1 induces polyubiquitination of p300, resulting in its proteasome-mediated degradation. We identify BRMS1 as the first eukaryote structural mimic of the bacterial IpaH E3 ligase family and establish that the evolutionarily conserved CXD motif located in BRMS1 is responsible for its E3 ligase function. mutation of this E3 ligase motif not only abolishes BRMS1-induced p300 polyubiquitination and degradation, but importantly, dramatically reduces the metastasis suppressor function of BRMS1 in both in vitro and in vivo models of lung cancer metastasis.

We recently identified a novel metastasis suppressor gene, BRMS1, in breast cancer. Since the BRMS1 gene maps to chromosome 11q13.1-q13.2 and since chromosome 11q defects have been described in various stages of human melanoma progression, we hypothesized that BRMS1 may function as a tumor or metastasis suppressor in melanomas as well. Quantitative real-time RT-PCR revealed that BRMS1 mRNA expression was high in melanocytes, considerably reduced in early melanoma-derived cell lines, and barely detectable in advanced/metastatic cell lines. Stable transfectants of BRMS1 in the human melanoma cell lines MelJuSo and C8161.9 did not alter the tumorigenicity of either cell line, but significantly suppressed metastasis compared to vector-only transfectants. Orthotopic tumors continued to express BRMS1, but expression was lost in lung metastases. In vitro morphology, growth rate, and histology of BRMS1 transfectants were similar to controls. BRMS1 transfectants were less invasive in a collagen sandwich assay and had restored homotypic gap junctional intercellular communication (GJIC). Thus, BRMS1 functions as a metastasis suppressor in more than one tumor type (i.e., breast carcinoma and cutaneous melanoma) by modifying several metastasis-associated phenotypes.

This article reviews information related to the BRMS1 (BReast metastasis Suppressor 1) metastasis suppressor gene. BRMS1 was identified by differential display comparing metastasis-suppressed chromosome 11 hybrids with metastatic, parental MDA-MB-435 human breast carcinoma cells. BRMS1 has subsequently been shown to suppress metastasis, but not tumorigenicity of human melanoma cells. The murine version, Brms1, also suppresses metastasis and exhibits a high level of homology to the human gene at the structure, nucleotide and amino acid levels. The mechanisms of action remain to be determined; however, BRMS1 transfectant cells have restored gap junctional intercellular communication. Recent data suggest that BRMS1 is part of the mSin3A histone deacetylase complex.

metastasis is the most lethal attribute of cancer, which severely affects the effectiveness and prognosis of cancer patients. The discovery of metastasis suppressor genes will provide important clues for the predictive diagnosis and interferential therapies of metastasis. However, there have been few metastasis suppressor genes discovered till now. And this kind of research has not been reported domestically yet. In order to promote this research, this paper reviewed the theoretical principles and technical approaches for the functional localization and cloning strategy for metastasis suppressor genes, which mainly include microcell mediated chromosome transfer, PCR analysis of site tagged sites, and spontaneous metastasis analysis. The metastasis suppressor genes, KAI-1, KiSS-1, MKK4, and BRMS1, discovered by this technique and the application of this technique in prostate cancer, melanoma, and liver cancer are also reviewed.

metastasis-suppressor genes, by definition, suppress metastasis without affecting tumorigenicity and, hence, present attractive targets as prognostic or therapeutic markers. BRMS1 (breast cancer metastasis suppressor) has recently been identified as a metastasis-suppressor gene for human breast cancer and melanoma. expression of BRMS1 messenger RNA (mRNA) in multitissue including normal prostate, ovarian, testis, and colon has been detected by northern blot analysis. We hypothesize that the role of BRMS1 in tumor progression may not be limited to breast cancer and melanoma. We previously found that BRMS1 mRNA levels in primary ovarian epithelial carcinomas were significantly lower than that in normal ovarian and benign tumors (P < 0.05), and statistical analysis of BRMS1 mRNA levels revealed that BRMS1 mRNA levels were significantly higher in early tumor stages (I, II) compared with advanced tumor stages (III, IV) in which lymph node or distant metastases were present (P < 0.01). Our data showed that reduced BRMS1 mRNA seems to influence ovarian carcinoma metastatic ability. Therefore, we transfected BRMS1 plasmid into highly malignant ovarian carcinoma cell line, HO-8910PM, and examined cell biologic behaviors including proliferation, adhesion, invasion, and metastasis in vitro and in vivo. BRMS1 expression did not alter the proliferation of HO-8910PM cells in vitro and primary tumor formation in vivo. But, BRMS1 expression significantly suppressed the cell adhesion to extracellular matrix components and in vitro cell invasion in BRMS1-transfected HO-8910PM cells compared to parental HO-8910PM and vector-only transfectants (HO-8910PM-vect). Furthermore, motility of BRMS1 transfectants was inhibited. lung colony formation of intravenously injected BRMS1 transfectants in nude mice was significantly reduced. Also, BRMS1 transfectants form significantly less metastatic to organs of peritoneal cavity in orthotopically implanted ovarian tumor nude models. We further discovered that BRMS1 expression did downregulate expression of an actin-bundling protein associated with cell motility -fascin, which perhaps is the mechanism underlying BRMS1 suppression of metastasis. These data suggested that in addition to its already described role in breast cancer and melanoma, BRMS1 functions as a metastasis-suppressor gene in ovarian carcinoma by modifying several metastatic-associated phenotypes, offering a new target for therapeutic intervention.

PURPOSE: It is well established that breast cancer metastasis suppressor 1 (BRMS1) suppresses metastasis of breast cancer in animal models without affecting the growth of the primary tumor. It has also been shown to suppress the metastasis of tumors derived from breast and melanoma cell lines. However, its clinical importance for breast cancer patients remains undetermined. This prompted us to investigate its expression level in breast cancer patients to clarify its clinical significance. EXPERIMENTAL DESIGN: The level of expression of BRMS1 mRNA was assessed by LightCycler quantitative real-time reverse transcription-PCR in 161 cases of invasive carcinoma of the breast. Associations between BRMS1 mRNA expression and various clinicopathologic factors were sought. RESULTS: It was found that BRMS1 mRNA was expressed at significantly higher levels in patients>50 years of age, with tumor size<2 cm, or with progesterone receptor-positive and HER2-negative tumors. No differences were found between BRMS1 mRNA expression and axillary lymph node metastasis and histologic grade groups. Patients with high levels of expression of BRMS1 mRNA have a better prognosis than those with low expression. Univariate and multivariate prognostic analysis showed that BRMS1 mRNA is an independent prognostic factor for disease-free survival in breast cancer. CONCLUSIONS: These results provide clinical evidence to support the notion that BRMS1 is a breast carcinoma metastasis suppressor gene. Our results also suggest that measuring BRMS1 expression will help to identify those breast cancer patients with worse disease-free survival.

BRMS1 is regarded as a metastasis suppressor gene for its ability to reduce metastatic potential of human and murine breast cancer cells as well as human melanoma cells. However, BRMS1 association to human tumor progression is not clearly understood. In the present study we analyzed BRMS1 mRNA expression in tumor progression and its potential prognostic value for breast carcinoma. BRMS1 mRNA expression level was quantified by real-time PCR in 47 tumoral, in 14 peritumoral and in 15 metastatic microdissected cellular populations from 47 breast cancer patients with 10-year follow up. We found BRMS1 expression to be higher in carcinoma cells than in matching normal epithelial cell populations in 10 out of 14 cases (p = 0.0005), while lymph-nodal carcinoma cells showed lower BRMS1 expression in 9 out of 15 cases (p = 0.001). Using both in vivo (human mammary breast carcinomas) and in vitro systems (breast cancer cell lines) we were able to demonstrate that BRMS1 overexpression was not a bias effect induced by cell proliferation rate. BRMS1 expression levels did not correlate with standard breast cancer prognostic factors but BRMS1 higher expression was associated with patient shorter disease-free and overall survival. Our findings are apparently inconsistent with the concept of BRMS1 as a metastasis suppressor gene. One possible explanation is that epithelial cells increase their BRMS1 expression as a compensatory response to tumor formation or metastasis progression, which is elevated in proportion to tumor aggressiveness, whereas those cells of the primary tumor that cannot upregulate BRMS1 escape to form metastasis.

The breast cancer metastasis suppressor 1 (BRMS1) gene has been shown to suppress metastasis without affecting the growth of the primary tumor in mouse models. It has also been shown to suppress the metastasis of tumors derived from breast, melanoma, and, more recently, ovarian carcinoma (see ref 1). However, how BRMS1 exerts its metastasis suppressor function remains unknown. To shed light into its metastatic mechanism of action, the sensitive 2D-DIGE analysis coupled with MS has been used to identify proteins differentially expressed by either overexpressing (Mel-BRMS1) or silencing BRMS1 (sh635) in a melanoma cell line. After comparison of the protein profiles from WT, Mel-BRMS1, and sh635 cells, 79 spots were found to be differentially expressed. Mass spectrometry analysis allowed the unambiguous identification of 55 polypeptides, corresponding to 43 different proteins. Interestingly, more than 75% of the identified proteins were down-regulated in Mel-BRMS1 cells compared to WT. In contrast, all the identified proteins in sh635 cells extracts were up-regulated compared to WT. Most of the deregulated proteins are involved in cell growth/maintenance and signal transduction among other cell processes. Six differentially expressed proteins (Hsp27, Alpha1 protease inhibitor, Cofilin1, Cathepsin D, Bone morphogenetic protein receptor2, and Annexin2) were confirmed by immunoblot and functional assays. Excellent correlation was found between DIGE analysis and immunoblot results, indicating the reliability of the analysis. Available evidence on the reported functions of the identified proteins supports the emerging role of BRMS1 as negative regulator of the metastasis development. This work opens an avenue for the molecular mechanisms' characterization of metastasis suppressor genes with the aim to understand their roles.

Breast cancer metastasis suppressor 1 (BRMS1) inhibits formation of macroscopic lung metastases in breast, ovary, and melanoma xenograft models. Because it is unclear which step(s) of the metastatic cascade are affected by BRMS1, the major aim of this study was to determine when and how BRMS1 acts to suppress metastasis. We also examined whether BRMS1 expression globally blocks metastasis or selectively inhibits metastatic outgrowths in specific tissues. metastatic human breast carcinoma cell lines MDA-MB-231 and -435 expressing enhanced green fluorescent protein (GFP; 231 GFP and 435 GFP) and cell lines transduced with the BRMS1 gene (231 GFP-BRMS1 and 435 GFP-BRMS1) were injected into the left cardiac ventricle to achieve the widest possible cellular distribution, by minimizing first-pass clearance in the lungs. Compared with parental cells, BRMS1-expressing clones formed significantly fewer metastases in all organs tested. When cells were injected directly into the vasculature, fewer of the BRMS1-expressing cells reached lungs or bone compared with parental cells, suggesting that restoration of BRMS1 expression increased cell death during transit. Susceptibility to anoikis was verified in vitro by demonstrating decreased survival on poly-hydroxyethyl methacrylate-coated dishes. Most of the BRMS1-expressing cells reaching secondary sites failed to proliferate, suggesting that BRMS1 also inhibits colonization. Coupled with previous reports showing modest effects of BRMS1 on adhesion and invasion, our results indicate that BRMS1 inhibits metastases in multiple organs by blocking several steps in the metastatic cascade.

Breast cancer metastasis Suppressor 1 (BRMS1) suppresses metastasis of human breast cancer, ovarian cancer and melanoma in athymic mice. Studies have also shown that BRMS1 is significantly downregulated in some breast tumors, especially in metastatic disease. However, the mechanisms which regulate BRMS1 expression are currently unknown. Upon examination of the BRMS1 promoter region by methylation specific PCR (MSP) analysis, we discovered a CpG island (-3477 to -2214), which was found to be hypermethylated across breast cancer cell lines. A panel of 20 patient samples analyzed showed that 45% of the primary tumors and 60% of the matched lymph node metastases, displayed hypermethylation of BRMS1 promoter. Furthermore, we found a direct correlation between the methylation status of the BRMS1 promoter in the DNA isolated from tissues, with the loss of BRMS1 expression assessed by immunohistochemistry. There are several studies investigating the mechanism by which BRMS1 suppresses metastasis; however thus far there is no study that reports the cause(s) of loss of BRMS1 expression in aggressive breast cancer. Here we report for the first time that BRMS1 is a novel target of epigenetic silencing; and aberrant methylation in the BRMS1 promoter may serve as a cause of loss of its expression.

OBJECTIVE: Breast cancer metastasis suppressor 1 (BRMS1) has been shown to functionally reduce the metastatic potential of melanoma. We also previously reported that BRMS1 negatively regulates the expression of the oncoprotein osteopontin (OPN). This study was carried out to assess the clinical relevance of BRMS1 and OPN in melanoma. METHODS: Epigenetic regulation of BRMS1 was assessed by treating clinically derived melanoma cell lines with the demethylating agent 5-aza-2'-deoxycytidine (DAC) and the histone deacetylase inhibitor trichostatin A (TSA), followed by sodium bisulfite modification and methylation-specific PCR. Assessments of BRMS1 and OPN levels were performed using immunoblotting, quantitative real-time RT-PCR or reporter assays. RNA silencing was employed to abrogate the expression of OPN in melanoma-derived cell lines. The in vivo relevance of our findings was determined with experiments using athymic nude mice. RESULTS: The reduced expression of BRMS1 in surgically excised melanoma specimens correlated with increased OPN expression during the progression from primary to metastatic melanoma. Treatment with DAC and TSA elevated BRMS1 levels, but caused an inconsistent change in OPN gene expression. Abrogating the expression of OPN in BRMS1-deficient metastatic melanoma-derived cell lines retarded the growth of melanoma tumor xenografts in athymic nude mice. CONCLUSION: While treatment with DAC and TSA may not be a universally applicable treatment alternative in melanoma, silencing the expression of OPN in metastatic melanomas that have lost expression of BRMS1 is a potential option for therapeutic intervention.

BACKGROUND/AIMS: Breast cancer metastasis suppressor 1 (BRMS1) blocks metastasis in melanoma xenografts; however, its usefulness as a biomarker in human melanomas has not been widely studied. The goal was to measure BRMS1 expression in benign nevi, primary and metastatic melanomas and evaluate its impact on disease progression and prognosis. METHODS: Paraffin-embedded tissue from 155 primary melanomas, 69 metastases and 15 nevi was examined for BRMS1 expression using immunohistochemistry. siRNA mediated BRMS1 down-regulation was used to study impact on invasion and migration in melanoma cell lines. RESULTS: A significantly higher percentage of nevi (87%), compared to primary melanomas (20%) and metastases (48%), expressed BRMS1 in the nucelus (p < 0.0001). Strong nuclear staining intensity was observed in 67% of nevi, and in 9% and 24% of the primary and metastatic melanomas, respectively (p < 0.0001). Comparable cytoplasmic expression was observed (nevi; 87%, primaries; 86%, metastases; 72%). However, a decline in cytoplasmic staining intensity was observed in metastases compared to nevi and primary tumors (26%, 47%, and 58%, respectively, p < 0.0001). Score index (percentage immunopositive celles multiplied with staining intensity) revealed that high cytoplasmic score index (>/= 4) was associated with thinner tumors (p = 0.04), lack of ulceration (p = 0.02) and increased disease-free survival (p = 0.036). When intensity and percentage BRMS1 positive cells were analyzed separately, intensity remained associated with tumor thickness (p = 0.024) and ulceration (p = 0.004) but was inversely associated with expression of proliferation markers (cyclin D3 (p = 0.008), cyclin A (p = 0.007), and p21Waf1/Cip1 (p = 0.009)). Cytoplasmic score index was inversely associated with nuclear p-Akt (p = 0.013) and positively associated with cytoplasmic p-ERK1/2 expression (p = 0.033). Nuclear BRMS1 expression in >/= 10% of primary melanoma cells was associated with thicker tumors (p = 0.016) and decreased relapse-free period (p = 0.043). Nuclear BRMS1 was associated with expression of fatty acid binding protein 7 (FABP7; p = 0.011), a marker of invasion in melanomas. In line with this, repression of BRMS1 expression reduced the ability of melanoma cells to migrate and invade in vitro. CONCLUSION: Our data suggest that BRMS1 is localized in cytoplasm and nucleus of melanocytic cells and that cellular localization determines its in vivo effect. We hypothesize that cytoplasmic BRMS1 restricts melanoma progression while nuclear BRMS1 possibly promotes melanoma cell invasion.Please see related article: http://www.biomedcentral.com/1741-7015/10/19.

AIMS: To determine the expression of breast metastasis suppressor 1 (BRMS1) in human uveal melanoma (UM) tissues and cell lines. In addition, we intend to establish a possible association between BRMS1 expression and the presence of metastatic disease. METHODS: Thirty-one formalin-fixed paraffin-embedded tissues from enucleated eyes of patients with UM were immunostained. Clinical-pathological data were obtained, including age, tumour location, largest dimension, cell type, and occurrence of metastasis. The expression of BRMS1 mRNA in four human UM cell lines was determined by real-time reverse transcriptase polymerase chain reaction, and protein expression was assessed by immunocytochemistry and western blot. The association between BRMS1 immunostaining and location, largest tumour dimension, and tumour cell type was determined using the correlation coefficient test. The association between BRMS1 immunostaining and the incidence of metastasis was assessed using Kaplan-Meier analysis. RESULTS: Of the 31 cases of UM, 24 (77.42%) stained positive and seven (22.58%) negative for BRMS1. From the positively stained tumours, 21 (87.50%) showed cytoplasmatic staining. Macrophages were usually positive when present in the tumour and staining intensity was generally higher than in UM cells. BRMS1 mRNA was present in all four human UM cell lines, as well as cytoplasmatic immunoexpression of BRMS1. Immunoblotting showed variable BRMS1 protein levels between the different cell lines. No statistically significant correlation was found between BRMS1 protein expression and survival (P = 0.69), tumour cell type (P = 0.68), largest tumour dimension (P = 0.75), and tumour location (P = 0.11). CONCLUSIONS: BRMS1 is expressed in UM both at the mRNA and protein level; however, neither was associated with any of the prognosticor outcome parameters that we tested.

BACKGROUND: Breast cancer metastasis suppressor 1 (BRMS1) is a potent metastasis suppressor of various types of malignancies, including melanoma and ovarian cancer. Unfortunately, the clinical data regarding its role as a true metastatic suppressor and its efficacy as a prognostic marker and therapeutic target remain controversial. This study was designed to investigate the effect of BRMS1 on the invasion and metastasis of human ovarian cancer cells and its potential underlying mechanisms. MATERIALS AND METHODS: BRMS1 small interfering RNAs (siRNAs) or control siRNAs were transfected into the OVCAR3 human ovarian cancer cell line. Invasion and migration activities were assessed using the Transwell invasion and migration assay. Protein levels of nuclear factor-kappaB (NF-kappaB) subunit p65, osteopontin (OPN) and urokinase-type plasminogen activator (uPA) were evaluated by Western blot, immunofluorescence and immunocytochemistry methods. RESULTS: Successful knockdown of BRMS1 was verified by quantitative real-time RT-PCR and Western blot. The invasion and migration capacities of OVCAR3 cells were significantly enhanced in the BRMS1-silenced group, compared to controls (p < 0.05). Silencing of BRMS 1 significantly induced the expression of NF-kappaB subunit, p65, uPA, and OPN proteins. CONCLUSIONS: BRMS1 inhibits expression of p65, uPA and OPN protein. In turn, this leads to inhibition of ovarian cancer cell invasion and metastasis. This study unveils a potential novel mechanism by which BRMS1 inhibits metastasis of ovarian cancer cells.

The breast cancer metastasis suppressor 1 (BRMS1) gene has been shown to suppress metastasis without affecting the growth of the primary tumor in mouse models. It has also been shown to suppress the metastasis of tumors derived from breast, melanoma, and, more recently, ovarian carcinoma (see ref 1). However, how BRMS1 exerts its metastasis suppressor function remains unknown. To shed light into its metastatic mechanism of action, the sensitive 2D-DIGE analysis coupled with MS has been used to identify proteins differentially expressed by either overexpressing (Mel-BRMS1) or silencing BRMS1 (sh635) in a melanoma cell line. After comparison of the protein profiles from WT, Mel-BRMS1, and sh635 cells, 79 spots were found to be differentially expressed. Mass spectrometry analysis allowed the unambiguous identification of 55 polypeptides, corresponding to 43 different proteins. Interestingly, more than 75% of the identified proteins were down-regulated in Mel-BRMS1 cells compared to WT. In contrast, all the identified proteins in sh635 cells extracts were up-regulated compared to WT. Most of the deregulated proteins are involved in cell growth/maintenance and signal transduction among other cell processes. Six differentially expressed proteins (Hsp27, Alpha1 protease inhibitor, Cofilin1, Cathepsin D, Bone morphogenetic protein receptor2, and Annexin2) were confirmed by immunoblot and functional assays. Excellent correlation was found between DIGE analysis and immunoblot results, indicating the reliability of the analysis. Available evidence on the reported functions of the identified proteins supports the emerging role of BRMS1 as negative regulator of the metastasis development. This work opens an avenue for the molecular mechanisms' characterization of metastasis suppressor genes with the aim to understand their roles.

Mechanisms by which cancer cells communicate with the host organism to regulate lung colonization/metastasis are unclear. We show that this communication occurs via sphingosine 1-phosphate (S1P) generated systemically by sphingosine kinase 1 (SK1), rather than via tumour-derived S1P. Modulation of systemic, but not tumour SK1, prevented S1P elevation, and inhibited TRAMP-induced prostate cancer growth in TRAMP(+/+) SK1(-/-) mice, or lung metastasis of multiple cancer cells in SK1(-/-) animals. Genetic loss of SK1 activated a master metastasis suppressor, Brms1 (breast carcinoma metastasis suppressor 1), via modulation of S1P receptor 2 (S1PR2) in cancer cells. Alterations of S1PR2 using pharmacologic and genetic tools enhanced Brms1. Moreover, Brms1 in S1PR2(-/-) MEFs was modulated by serum S1P alterations. Accordingly, ectopic Brms1 in MB49 bladder cancer cells suppressed lung metastasis, and stable knockdown of Brms1 prevented this process. Importantly, inhibition of systemic S1P signalling using a novel anti-S1P monoclonal antibody (mAb), Sphingomab, attenuated lung metastasis, which was prevented by Brms1 knockdown in MB49 cells. Thus, these data suggest that systemic SK1/S1P regulates metastatic potential via regulation of tumour S1PR2/Brms1 axis.

BACKGROUND: Breast cancer metastasis suppressor 1 (BRMS1) is a metastasis suppressor gene. This study aimed to investigate the impact of BRMS1 on metastasis in nasopharyngeal carcinoma (NPC) and to evaluate the prognostic significance of BRMS1 in NPC patients. METHODS: BRMS1 expression was examined in NPC cell lines using quantitative reverse transcription-polymerase chain reaction and Western blotting. NPC cells stably expressing BRMS1 were used to perform wound healing and invasion assays in vitro and a murine xenograft assay in vivo. Immunohistochemical staining was performed in 274 paraffin-embedded NPC specimens divided into a training set (n = 120) and a testing set (n = 154). RESULTS: BRMS1 expression was down-regulated in NPC cell lines. Overexpression of BRMS1 significantly reversed the metastatic phenotype of NPC cells in vitro and in vivo. Importantly, low BRMS1 expression was associated with poor distant metastasis-free survival (DMFS, P < 0.001) and poor overall survival (OS, P < 0.001) in the training set; these results were validated in the testing set and overall patient population. Cox regression analysis demonstrated that low BRMS1 expression was an independent prognostic factor for DMFS and OS in NPC. CONCLUSIONS: Low expression of the metastasis suppressor BRMS1 may be an independent prognostic factor for poor prognosis in NPC patients.

This report shows that over-expression of BRMS1 reduces SDF-induced chemotaxis and suppresses nuclear factor-kappaB (NF-kappaB) activity in NSCLC cell line. Inhibition of NF-kappaB activity impairs SDF-1alpha-dependent migration and NF-kappaB can directly bind to the chemokine (C-X-C motif) receptor 4 (CXCR4) promoter invivo. However, knockdown of BRMS1 promotes NSCLC cell migration and CXCR4 expression. Furthermore, BRMS1 and CXCR4 expression levels are inversely correlated in the NSCLC cases. The level of BRMS1 mRNA is found to be markedly lower in the distant metastasis group than in the non-distant metastasis group (P=0.003). However, CXCR4 mRNA was higher in the distant metastasis group than in the non-distant metastasis group (P=0.032). These results indicate that BRMS1 regulates metastatic potential at least in part through the down-regulation of CXCR4, to be indirectly regulated by BRMS1 through nuclear factor-kappaB activation.

Breast cancer metastasis suppressor 1 (BRMS1) is a metastasis suppressor gene in several solid tumors. The role of BRMS1 in non-small cell lung cancer (NSCLC) is not well established. To assess in vitro and in vivo metastatic behavior H1299 NSCLC cells stably expressing BRMS1 or a vector control were created. BRMS1 expression significantly decreases both migration and invasion of NSCLC cells in vitro. Importantly, in flank xenografts, BRMS1 suppresses the formation of pulmonary and hepatic metastases but does not significantly affect primary tumor growth. To evaluate whether BRMS1 is related to the progression of NSCLC, we examined BRMS1 expression in human NSCLC. Both BRMS1 mRNA and protein levels are diminished in NSCLC compared to adjacent non-cancerous lung. BRMS1 expression is also lower in squamous cell carcinoma compared to adenocarcinoma. Moreover, preservation of tumor BRMS1 expression is associated with improved patient survival. Thus, BRMS1 functions as a metastasis suppressor and may be a prognostic indicator for human NSCLC.

Breast cancer metastasis suppressor gene-1 (BRMS1) mRNA and protein expression are significantly decreased in non-small cell lung cancer (NSCLC) and this is a poor prognostic indicator. Given that the BRMS1 promoter region contains a promoter-associated CpG island (CGI) that encompasses the transcriptional start site, we hypothesized that decreased BRMS1 mRNA and protein levels in NSCLC was secondary to increased BRMS1 promoter methylation. Methylation-specific PCR (MSP) of the two known CGIs (-3477 to - 2214 and - 531 to + 608) in the BRMS1 genome was performed in NSCLC cells. This demonstrated a robust increase in methylation of the promoter-associated CGI (-531 to + 608) but not of the upstream CGI (-3477 to - 2214). To experimentally verify that methylation contributes to BRMS1 transcriptional repression, we cloned the BRMS1 promoter region, including the promoter-associated CGI, into a luciferase reporter gene and found that BRMS1 promoter activity was dramatically inhibited under methylated conditions. We then assessed the BRMS1 methylation profile with MSP and bisulphite-sequencing PCR in human NSCLC adenocarcinoma (n = 20) and squamous cell carcinoma (n = 20) relative to adjacent non-cancerous bronchial epithelium. There was a significant increase in BRMS1 promoter methylation in all NSCLC specimens relative to non-cancerous tissues, with the most dramatic difference in squamous cell cancer histology. Subsequent immunostaining demonstrated that nuclear BRMS1 expression is reduced in lung cancer specimens compared to normal bronchial epithelium. The association between BRMS1 promoter methylation and specific clinical and histopathological variables was examined using a general linear model. Pathological tumour stage was associated with increased BRMS1 methylation in squamous cell cancers. These observations demonstrate that methylation of the promoter-associated CGI in BRMS1 results in its transcriptional repression, and highlight the potential clinical relevance of this methylation event with respect to NSCLC tumour histology and pathological stage.

Breast cancer metastasis suppressor-1 (BRMS1) is a candidate metastasis-suppressing gene and has been shown to potentially inhibit tumor progression without blocking the growth of orthotopic tumors, in different tumor types including non-small cell lung cancer, ovarian, melanoma and breast cancers. MATERIALS AND METHODS: BRMS-1 gene transcript was quantified in breast cancer sample tissues and analyzed against histological and clinical patient outcome. Human breast cancer cell lines, MDA MB-231 and MCF-7 were used to genetically-modify the expression of BRMS-1 and test for biological responses following BRMS-1 modifications. Key candidate signal pathways, influenced by BRMS-1 were also explored. RESULTS: BRMS1 was present in MDA MB-231 and MCF-7 cell lines. Using anti-BRMS1 transgenes, we knocked-down the transcripts of BRMS1 in both cells at the mRNA and protein levels. Knockdown of BRMS1 gave both cells a faster cell growth rate, rapid pace of cellular migration and invasion, compared to respective wild-type and control cells (p<0.05). Blocking phospholipase-Cgamma (PLCgamma) had a significant influence on the BRMS-1-induced cell migration. Finally, significantly low levels of BRMS1 were observed in patients with high-grade tumors (p=0.12), in patients with distant metastasis (p=0.05) and those who died of breast cancer (p=0.0037). In addition, patients with low levels of BRMS1 had a significantly shorter overall survival (p=0.035). CONCLUSION: BRMS-1 is aberrantly expressed in human breast cancer and is inversely-correlated with disease progression and patient survival. This is likely to be occurring via its influence on invasion and migration of breast cancer cells.

BACKGROUND: Breast-cancer metastasis suppressor 1 (BRMS1) gene encodes for a predominantly nuclear protein that differentially regulates the expression of multiple genes, leading to suppression of metastasis without blocking orthotropic tumour growth. The aim of the present study was to evaluate for the first time the prognostic significance of BRMS1 promoter methylation in cell-free DNA (cfDNA) circulating in plasma of non-small cell lung cancer (NSCLC) patients. Towards this goal, we examined the methylation status of BRMS1 promoter in NSCLC tissues, matched adjacent non-cancerous tissues and corresponding cfDNA as well as in an independent cohort of patients with advanced NSCLC and healthy individuals. METHODS: Methylation of BRMS1 promoter was examined in 57 NSCLC tumours and adjacent non-cancerous tissues, in cfDNA isolated from 48 corresponding plasma samples, in cfDNA isolated from plasma of 74 patients with advanced NSCLC and 24 healthy individuals. RESULTS: The BRMS1 promoter was highly methylated both in operable NSCLC primary tissues (59.6%) and in corresponding cfDNA (47.9%) but not in cfDNA from healthy individuals (0%), while it was also highly methylated in cfDNA from advanced NSCLC patients (63.5%). In operable NSCLC, Kaplan-Meier estimates were significantly different in favour of patients with non-methylated BRMS1 promoter in cfDNA, concerning both disease-free interval (DFI) (P=0.048) and overall survival (OS) (P=0.007). In advanced NSCLC, OS was significantly different in favour of patients with non-methylated BRMS1 promoter in their cfDNA (P=0.003). Multivariate analysis confirmed that BRMS1 promoter methylation has a statistical significant influence both on operable NSCLC patients' DFI time and OS and on advanced NSCLC patients' PFS and OS. CONCLUSIONS: Methylation of BRMS1 promoter in cfDNA isolated from plasma of NSCLC patients provides important prognostic information and merits to be further evaluated as a circulating tumour biomarker.

expression of the breast cancer metastasis suppressor 1 (BRMS1) protein is dramatically reduced in non-small cell lung cancer (NSCLC) cells and in primary human tumors. Although BRMS1 is a known suppressor of metastasis, the mechanisms through which BRMS1 functions to regulate cell migration and invasion in response to specific NSCLC driver mutations are poorly understood. To experimentally address this, we utilized immortalized human bronchial epithelial cells in which p53 was knocked down in the presence of oncogenic K-RasV12 (HBEC3-p53KD-K-RasV12). These genetic alterations are commonly found in NSCLC and are associated with a poor prognosis. To determine the importance of BRMS1 for cytoskeletal function, cell migration and invasion in our model system we stably knocked down BRMS1. Here, we report that loss of BRMS1 in HBEC3-p53KD-K-RasV12 cells results in a dramatic increase in cell migration and invasion compared to controls that expressed BRMS1. Moreover, the loss of BRMS1 resulted in additional morphological changes including F-actin re-distribution, paxillin accumulation at the leading edge of the lamellapodium, and cellular shape changes resembling mesenchymal phenotypes. Importantly, re-expression of BRMS1 restores, in part, cell migration and invasion; however it does not fully reestablish the epithelial phenotype. These finding suggests that loss of BRMS1 results in a permanent, largely irreversible, mesenchymal phenotype associated with increased cell migration and invasion. Collectively, in NSCLC cells without p53 and expression of oncogenic K-Ras our study identifies BRMS1 as a key regulator required to maintain a cellular morphology and cytoskeletal architecture consistent with an epithelial phenotype.

metastasis-suppressor genes, by definition, suppress metastasis without affecting tumorigenicity and, hence, present attractive targets as prognostic or therapeutic markers. BRMS1 (breast cancer metastasis suppressor) has recently been identified as a metastasis-suppressor gene for human breast cancer and melanoma. expression of BRMS1 messenger RNA (mRNA) in multitissue including normal prostate, ovarian, testis, and colon has been detected by northern blot analysis. We hypothesize that the role of BRMS1 in tumor progression may not be limited to breast cancer and melanoma. We previously found that BRMS1 mRNA levels in primary ovarian epithelial carcinomas were significantly lower than that in normal ovarian and benign tumors (P < 0.05), and statistical analysis of BRMS1 mRNA levels revealed that BRMS1 mRNA levels were significantly higher in early tumor stages (I, II) compared with advanced tumor stages (III, IV) in which lymph node or distant metastases were present (P < 0.01). Our data showed that reduced BRMS1 mRNA seems to influence ovarian carcinoma metastatic ability. Therefore, we transfected BRMS1 plasmid into highly malignant ovarian carcinoma cell line, HO-8910PM, and examined cell biologic behaviors including proliferation, adhesion, invasion, and metastasis in vitro and in vivo. BRMS1 expression did not alter the proliferation of HO-8910PM cells in vitro and primary tumor formation in vivo. But, BRMS1 expression significantly suppressed the cell adhesion to extracellular matrix components and in vitro cell invasion in BRMS1-transfected HO-8910PM cells compared to parental HO-8910PM and vector-only transfectants (HO-8910PM-vect). Furthermore, motility of BRMS1 transfectants was inhibited. lung colony formation of intravenously injected BRMS1 transfectants in nude mice was significantly reduced. Also, BRMS1 transfectants form significantly less metastatic to organs of peritoneal cavity in orthotopically implanted ovarian tumor nude models. We further discovered that BRMS1 expression did downregulate expression of an actin-bundling protein associated with cell motility -fascin, which perhaps is the mechanism underlying BRMS1 suppression of metastasis. These data suggested that in addition to its already described role in breast cancer and melanoma, BRMS1 functions as a metastasis-suppressor gene in ovarian carcinoma by modifying several metastatic-associated phenotypes, offering a new target for therapeutic intervention.

OBJECTIVE: To study the inhibition effects of breast cancer metastasis suppressor l (BRMS1) gene on metastasis of human ovarian cancer cell in vivo and in vitro. METHODS: BRMS1 gene was transfected into human ovarian cancer cell line A2780 by liposome transfection method. The cells were divided into 3 groups: transfected group with pcDNA3-BRMS1, negative control group with empty plasmid pcDNA3, blank control group without any transfection. Proliferation, apoptosis, growth rate, capability of colony formation, gap junctional intercellular communication (GJIC), capability of adhesion, changes of surface and internal structures of cells were observed in vitro. The cells were injected into athymic mice to establish animal tumor models, and inhibition of the tumorigenicity and metastasis were observed in vivo. RESULTS: BRMS1 gene was transfected into A2780 cell line successfully. There were no significant differences in the growth rate among transfected group, negative control group and blank control group (P > 0.05). The amounts of cell clones per well were 40 +/- 4 in transfected group, 42 +/- 7 in blank control group and 39 +/- 4 in negative control group (P > 0.05 between each two groups). The ratios of S vs G(2)/M and G(0)/G(1) were not significantly different in three groups (P > 0.05). The ultramicrostructure of cells detected by electron microscope showed that GJIC function in transfected group was higher than that in the other two groups. While in migration assay, the numbers of cells in lower chamber passing through the membrane in transfected group, blank control group and negative control group were 112 +/- 23, 306 +/- 49 and 322 +/- 91, respectively; with significant differences among 3 groups (P < 0.01). CONCLUSION: BRMS1 gene could suppress metastasis of ovarian cancer in vitro and in vivo.

The breast cancer metastasis suppressor 1 (BRMS1) gene has been shown to suppress metastasis without affecting the growth of the primary tumor in mouse models. It has also been shown to suppress the metastasis of tumors derived from breast, melanoma, and, more recently, ovarian carcinoma (see ref 1). However, how BRMS1 exerts its metastasis suppressor function remains unknown. To shed light into its metastatic mechanism of action, the sensitive 2D-DIGE analysis coupled with MS has been used to identify proteins differentially expressed by either overexpressing (Mel-BRMS1) or silencing BRMS1 (sh635) in a melanoma cell line. After comparison of the protein profiles from WT, Mel-BRMS1, and sh635 cells, 79 spots were found to be differentially expressed. Mass spectrometry analysis allowed the unambiguous identification of 55 polypeptides, corresponding to 43 different proteins. Interestingly, more than 75% of the identified proteins were down-regulated in Mel-BRMS1 cells compared to WT. In contrast, all the identified proteins in sh635 cells extracts were up-regulated compared to WT. Most of the deregulated proteins are involved in cell growth/maintenance and signal transduction among other cell processes. Six differentially expressed proteins (Hsp27, Alpha1 protease inhibitor, Cofilin1, Cathepsin D, Bone morphogenetic protein receptor2, and Annexin2) were confirmed by immunoblot and functional assays. Excellent correlation was found between DIGE analysis and immunoblot results, indicating the reliability of the analysis. Available evidence on the reported functions of the identified proteins supports the emerging role of BRMS1 as negative regulator of the metastasis development. This work opens an avenue for the molecular mechanisms' characterization of metastasis suppressor genes with the aim to understand their roles.

Breast cancer metastasis Suppressor 1 (BRMS1) suppresses metastasis of human breast cancer, ovarian cancer and melanoma in athymic mice. Studies have also shown that BRMS1 is significantly downregulated in some breast tumors, especially in metastatic disease. However, the mechanisms which regulate BRMS1 expression are currently unknown. Upon examination of the BRMS1 promoter region by methylation specific PCR (MSP) analysis, we discovered a CpG island (-3477 to -2214), which was found to be hypermethylated across breast cancer cell lines. A panel of 20 patient samples analyzed showed that 45% of the primary tumors and 60% of the matched lymph node metastases, displayed hypermethylation of BRMS1 promoter. Furthermore, we found a direct correlation between the methylation status of the BRMS1 promoter in the DNA isolated from tissues, with the loss of BRMS1 expression assessed by immunohistochemistry. There are several studies investigating the mechanism by which BRMS1 suppresses metastasis; however thus far there is no study that reports the cause(s) of loss of BRMS1 expression in aggressive breast cancer. Here we report for the first time that BRMS1 is a novel target of epigenetic silencing; and aberrant methylation in the BRMS1 promoter may serve as a cause of loss of its expression.

Breast cancer metastasis suppressor 1 (BRMS1) has been reported to suppress metastasis without significantly affecting tumorigenicity in breast cancer and ovarian cancer. To investigate the role of BRMS1 in human melanoma progression and prognosis, we established tissue microarray and BRMS1 expression was evaluated by immunohistochemistry in 41 dysplastic nevi, 90 primary melanomas and 47 melanoma metastases. We found that BRMS1 expression was significantly decreased in metastatic melanoma compared with primary melanoma or dysplastic nevi (P=0.021 and 0.001, respectively, chi(2) test). In addition, reduced BRMS1 staining was significantly correlated with American Joint Committee on cancer stages (P=0.011, chi(2) test), but not associated with tumor thickness, tumor ulceration and other clinicopathological parameters. Furthermore, BRMS1 expression was significantly correlated with disease-specific 5-year survival of melanoma patients (P=0.007, log-rank test). Multivariate Cox regression analysis revealed that BRMS1 staining was an independent prognostic factor for melanoma patients (relative risk=0.51; confidence interval=0.29-0.91; P=0.022). Moreover, we demonstrated that BRMS1 overexpression inhibited endothelial cell growth and tube formation ability by suppressing NF-kappaB activity and IL-6 expression in vitro. We also showed that knockdown of BRMS1 increased IL-6 expression and promoted endothelial cell growth and tube formation. In addition, our data revealed that the BRMS1-mediated IL-6 expression is dependent on NF-kappaB. Strikingly, our in vivo studies using nude mice confirmed that BRMS1 inhibited blood vessel formation and the recruitment of CD31-positive cells in matrigel plugs. Taken together, BRMS1 expression was decreased in metastatic melanomas, which resulted in deficient suppression of angiogenesis and contributed to melanoma progression. BRMS1 may serve an important prognostic marker and therapeutic target for melanoma patients.

OBJECTIVE: To study the expression and clinical significance of SATB1, BRMS1 in Ovarian serous adenocarcinoma. METHODS: Immanohistochemistrical SP method was used to detect the expression of SATB1, BRMS1 in 11 cases of normal ovarian tissue and 11 cases of benign ovarian tumor and 10 cases of ovarian borderline tumor and 53 cases ovarian serous adenocarcinoma. RESULTS: The expression of SATB1 in ovarian serous adenocarcinoma (86.8%) was significantly higher than those of normal ovarian tissues (0) and benign ovarian tumor tissues (36.4%), P < 0.05, and there was no difference between ovarian borderline tumor (70%) and ovarian serous adenocarcinoma, P > 0.05. The expression of BRMS1 in ovarian serous adenocarcinoma (28. 3%) was significantly lower than those in normal ovarian tissues (100%) and benign ovarian tumor tissues (81.8%), P < 0. 05, and there was no difference between ovarian borderline tumor (60%) and ovarian serous adenocarcinoma, P > 0.05. The inverse correlation between the expression of SATB1 and BRMS1 was observed (r = -0.387, P < 0.05). The expression of SATB1 was correlated with surgical stage and lymph node metastasis (P < 0.05), BRMS1 was correlated with surgical stage, lymph node metastasis and tumor size (P < 0.05); SATB1 and BRMS1 had no correlation with the patients whether menopause or not, histopathological grading, ascites (P > 0.05). CONCLUSION: SATB1 and BRMS1 might play an important role in the development and lymph node metastasis of ovarian cancer.

Breast cancer metastasis suppressor 1 (BRMS1) is a predominantly nuclear protein that differentially regulates the expression of multiple genes, leading to suppression of metastasis without affecting orthotopic tumor growth. It has been demonstrated that BRMS1 may be correlated with advanced ovarian cancer. The aim of this study was to investi-gate the mechanisms of BRMS1 involvement in ovarian cancer metastasis. We constructed a plasmid containing a short hairpin RNA (shRNA) against BRMS1 and transfected it into the ovarian cancer cell line OVCAR3. Real-time reverse transcription polymerase chain reaction (real-time PCR) and Western blot analyses demonstrated that BRMS1 expression was efficiently downregulated. Stable suppression of BRMS1 significantly enhanced cell adhesion, migration, invasion and angiogenesis. We also found that chemokine receptor 4 (CXCR4) was upregulated at both the mRNA and protein levels. When approaching for the mechanism, we discovered that activation of the nuclear factor-kappaB (NF-kappaB) signaling pathway mediated CXCR4 upregulation, as demonstrated by the electrophoretic mobility shift assay (EMSA). Collectively, these results suggest that attenuation of BRMS1 may play a critical role in promoting migration, invasion and angiogenesis of ovarian cancer cells and BRMS1 may regulate the metastatic potential at least in part through upregulation of CXCR4 via NF-kappaB activation. Restoration of BRMS1 function is thus a potential new strategy for treating human ovarian cancer.

Breast cancer metastasis suppressor-1 (BRMS1) is a candidate metastasis-suppressing gene and has been shown to potentially inhibit tumor progression without blocking the growth of orthotopic tumors, in different tumor types including non-small cell lung cancer, ovarian, melanoma and breast cancers. MATERIALS AND METHODS: BRMS-1 gene transcript was quantified in breast cancer sample tissues and analyzed against histological and clinical patient outcome. Human breast cancer cell lines, MDA MB-231 and MCF-7 were used to genetically-modify the expression of BRMS-1 and test for biological responses following BRMS-1 modifications. Key candidate signal pathways, influenced by BRMS-1 were also explored. RESULTS: BRMS1 was present in MDA MB-231 and MCF-7 cell lines. Using anti-BRMS1 transgenes, we knocked-down the transcripts of BRMS1 in both cells at the mRNA and protein levels. Knockdown of BRMS1 gave both cells a faster cell growth rate, rapid pace of cellular migration and invasion, compared to respective wild-type and control cells (p<0.05). Blocking phospholipase-Cgamma (PLCgamma) had a significant influence on the BRMS-1-induced cell migration. Finally, significantly low levels of BRMS1 were observed in patients with high-grade tumors (p=0.12), in patients with distant metastasis (p=0.05) and those who died of breast cancer (p=0.0037). In addition, patients with low levels of BRMS1 had a significantly shorter overall survival (p=0.035). CONCLUSION: BRMS-1 is aberrantly expressed in human breast cancer and is inversely-correlated with disease progression and patient survival. This is likely to be occurring via its influence on invasion and migration of breast cancer cells.

BACKGROUND: Breast cancer metastasis suppressor 1 (BRMS1) is a potent metastasis suppressor of various types of malignancies, including melanoma and ovarian cancer. Unfortunately, the clinical data regarding its role as a true metastatic suppressor and its efficacy as a prognostic marker and therapeutic target remain controversial. This study was designed to investigate the effect of BRMS1 on the invasion and metastasis of human ovarian cancer cells and its potential underlying mechanisms. MATERIALS AND METHODS: BRMS1 small interfering RNAs (siRNAs) or control siRNAs were transfected into the OVCAR3 human ovarian cancer cell line. Invasion and migration activities were assessed using the Transwell invasion and migration assay. Protein levels of nuclear factor-kappaB (NF-kappaB) subunit p65, osteopontin (OPN) and urokinase-type plasminogen activator (uPA) were evaluated by Western blot, immunofluorescence and immunocytochemistry methods. RESULTS: Successful knockdown of BRMS1 was verified by quantitative real-time RT-PCR and Western blot. The invasion and migration capacities of OVCAR3 cells were significantly enhanced in the BRMS1-silenced group, compared to controls (p < 0.05). Silencing of BRMS 1 significantly induced the expression of NF-kappaB subunit, p65, uPA, and OPN proteins. CONCLUSIONS: BRMS1 inhibits expression of p65, uPA and OPN protein. In turn, this leads to inhibition of ovarian cancer cell invasion and metastasis. This study unveils a potential novel mechanism by which BRMS1 inhibits metastasis of ovarian cancer cells.

Breast cancer metastasis suppressor gene-1 (BRMS1) is newly discovered tumor metastasis gene, which has been reported to play an important role in the progression of human tumor. However, its role in rectal cancer has never been investigated. In this present study, we evaluated the associated of BRMS1 with colorectal cancer, its value in prognosis, and its role in metastasis of rectal cancer. BRMS1 expression examined in 80 patients and the role of BRMS1 in metastasis was studied using mice model. Our results showed that BRMS1 expression was significantly associated with clinicopathological parameters in rectal cancer patients and overexpression of BRMS1 in rectal cancer xenograft led to decreased growth, invasiveness and metastasis. Our findings indicate that high expression of BRSM1 in rectal cancer plays an essential role in tumor progression.

OBJECTIVE: To investigate the expression of breast cancer metastasis suppressor 1 (BRMS1) mRNA in supraglottic cancer and to evaluate its clinical significance. METHOD: The expression of BRMS1 mRNA was examined by using RT-PCR method which take beta-actin mRNA as reference template in 66 cases of supraglottic cancer tissues and their adjacent normal mucosa tissues (ANT). RESULT: The expression of BRMS1 mRNA in the tissues of supraglottic cancer is lower significantly than that in the tissues of ANT ( P<0.05). There is correlation between BRMS1 mRNA expression and the clinical stage, differentiation and cervical lymph node metastasis in the laryngeal supraglottic cancers (P<0.05). There is no correlation between BRMS1 mRNA expression and sex and age. CONCLUSION: expression of BRMS1 mRNA in supraglottic cancer is lower than that in adjacent normal mucosa. The decrease of BRMS1 mRNA expression may be related to clinical stage and low differentiation and lymph node metastasis of supraglottic laryngeal cancer.

OBJECTIVE: To investigate the expression of breast cancer metastasis suppressor 1 (BRMS1) and CD44v6 protein in supraglottic cancer and to evaluate its clinical significance. METHOD: The expression of BRMS1 protein and CD44v6 protein were examined by using immunohistochemical method in 70 cases of paraffin-embedded supraglottic cancer tissues and their surrounding laryngeal normal mucosa tissues (LNT). RESULT: The expression of BRMS1 protein in LNT of supraglottic cancer was positive, and the positive rate was 85.7% (60/70); in tumor tissue was negative or lower expression, and the positive rate was 35.7% (25/70). The expression of CD44v6 protein in tumor tissue of supraglottic cancer was positive, the positive rate was 82.9% (58/70), in LNT was negative. There was a significant difference in BRMS1 and CD44v6 protein expression between the supraglottic cancer tissue and LNT (P<0.01). The expression of BRMS1 and CD44v6 protein had correlation with clinical stage and pathologic differentiation and cervical lymph node metastasis of supraglottic cancer (P<0.01). No correlation was found between the two proteins expression and sex and age (P>0.05). The expression of BRMS1 protein was related to the expression of CD44v6 protein (r = -0.9042, P<0.01). Calculated by Kaplan-Meier method, there is no survival difference at 3-year between the group with positive BRMS1 protein expression and the group with negative BRMS1 protein expression in tumor tissues (P>0.05), there is a significant survival difference at 3-year between the group with positive CD44v6 protein expression and the group with negative CD44v6 protein expression in tumor tissues (P<0.05). CONCLUSION: The expression of BRMS1 protein in supraglottic cancer is significantly decreased and the expression of CD44v6 protein in supraglottic cancer is significantly increased. The expression of BRMS1 protein and CD44v6 protein has a close relationship with pathologic differentiation and clinical stage and cervical lymph node metastasis of supraglottic cancer. Combined detection of the expression of them in supraglottic cancer may provide a significant parameter to judge the cervical lymph node metastasis of supraglottic cancer.

OBJECTIVE: To investigate the expression of breast cancer metastasis suppressor 1 (BRMS1) gene protein and the expression of BRMS1 gene promotor area methylation in supraglottic cancer and to evaluate its clinical significance. METHOD: The expression of BRMS1 protein and BRMS1 gene promotor area methylation were examined by using Western blotting method and methylation-specific polymerase chain reaction(MSP) method in 70 cases of supraglottic cancer tissues and 60 cases of their surrounding laryngeal normal mucosa tissues (LNT) and 44 cases of cervical lymph node metastasis of supraglottic cancer. RESULT: Western blot results indicate that BRMS1 protein expression is declined expression level in supraglottic cancer tissue than the expression of BRMS1 protein in LNT of supraglottic cancer. Compared with para carcinoma normal laryngeal mucous tissue, BRMS1 gene protein in supraglottic cancer tissue primary lesion decreased obviously, and it is decreased more obviously in cervical lymph node metastasis lesion, the discrepancy is notable (P < 0.05). MSP results indicate BRMS1 gene promotor methylation is coordinated with its down-expression in supraglottic cancer tissue. BRMS1 promotor area methylation analysis reveal that there were 34 patients with methylation in 70 patients' supraglottic cancer tumor primary lesion, hold 48.6% (34/70); 32 patients have methylation in 44 patients' cervical metastasis lymph node tissue, hold 72.7% (32/44); however, there is no methylation in 60 para carcinoma tissue (r(s) = 0.66, P < 0.05). CONCLUSION: The expression of BRMS1 protein in supraglottic cancer is significantly decreased. It had correlation with clinical stage and pathologic differentiation and cervical lymph node metastasis of supraglottic cancer. BRMS1 gene promotor methylation is related with down-expression of BRMS1 gene protein of supraglottic cancer. Maybe BRMS1 gene promotor methylation is one of the reasons of its down-expression.