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CD44

CD44 molecule (Indian blood group);CD44;CD44 molecule (Indian blood group)

CD44 antigen|GP90 lymphocyte homing/adhesion receptor|Hermes antigen|cell surface glycoprotein CD44|chondroitin sulfate proteoglycan 8|epican|extracellular matrix receptor III|hematopoietic cell E- and L-selectin ligand|heparan sulfate proteoglycan|homing

11p13

protein-coding

In this study we have examined the interaction between CD44 (a hyaluronan (HA) receptor) and the transforming growth factor beta (TGF-beta) receptors (a family of serine/threonine kinase membrane receptors) in human metastatic breast tumor cells (MDA-MB-231 cell line). Immunological data indicate that both CD44 and TGF-beta receptors are expressed in MDA-MB-231 cells and that CD44 is physically linked to the TGF-beta receptor I (TGF-betaRI) (and to a lesser extent to the TGF-beta receptor II (TGF-betaRII)) as a complex in vivo. Scatchard plot analyses and in vitro binding experiments show that the cytoplasmic domain of CD44 binds to TGF-betaRI at a single site with high affinity (an apparent dissociation constant (K(d)) of approximately 1.78 nm). These findings indicate that TGF-betaRI contains a CD44-binding site. Furthermore, we have found that the binding of HA to CD44 in MDA-MB-231 cells stimulates TGF-betaRI serine/threonine kinase activity which, in turn, increases Smad2/Smad3 phosphorylation and parathyroid hormone-related protein (PTH-rP) production (well known downstream effector functions of TGF-beta signaling). Most importantly, TGF-betaRI kinase activated by HA phosphorylates CD44, which enhances its binding interaction with the cytoskeletal protein, ankyrin, leading to HA-mediated breast tumor cell migration. Overexpression of TGF-betaRI by transfection of MDA-MB-231 cells with TGF-betaRIcDNA stimulates formation of the CD44.TGF-betaRI complex, the association of ankyrin with membranes, and HA-dependent/CD44-specific breast tumor migration. Taken together, these findings strongly suggest that CD44 interaction with the TGF-betaRI kinase promotes activation of multiple signaling pathways required for ankyrin-membrane interaction, tumor cell migration, and important oncogenic events (e.g. Smad2/Smad3 phosphorylation and PTH-rP production) during HA and TGF-beta-mediated metastatic breast tumor progression.

Cells with distinct phenotypes and stem cell-like properties have been reported to exist in breast cancer. The aim of the present study was to investigate the clinicopathologic and prognostic significance of the CD44(+)/CD24(-/low) and CD44(-)/CD24(+) tumor phenotypes' prevalence. Double immunohistochemistry was applied on a series of 155 paraffin-embedded breast tissue specimens to detect CD44 and CD24. Evaluation of the phenotypes was performed by image analysis. The prevalence of CD44(+)/CD24(-/low) and CD44(-)/CD24(+) tumor cells was 58.7% and 82.6%, respectively. The dominance of the CD44(+)/CD24(-/low) tumor cells was inversely associated with lymph node metastasis (P = .019) and tended to inversely associate with the stage of the disease (P = .068). Moreover, the prevalence of CD44(+)/CD24(-/low) was found to exert no significant impact on patients' prognosis although it displayed a tendency toward an increase in disease-free survival (P = .074). On the other hand, the prevalence of CD44(-)/CD24(+) tumor cells was found to have no clinicopathologic significance. However, it was found to exert an unfavorable impact on both relapse-free (P = .009) and overall survival (P = .046) of the patients with breast carcinomas of intermediate differentiation (grade 2). In breast tissue, CD44(+)/CD24(-/low) tumor cells seem to be associated with lack of lymph node metastasis and a tendency toward an increase of the relapse-free survival of the patients. On the contrary, tumor cells with the phenotype CD44(-)/CD24(+) seem to identify patients with worse disease-free and overall survival within the group of intermediate-grade differentiation patients whose prognosis is difficult to assess.

Evidence has accumulated on the role of reactive oxygen species (ROS) in metastasis since surgical removal of tumors generates oxidative stress promoting metastasis and cell growth. metastasis consists of a cascade of events which allow the cell to survive in target tissues and influence several processes such as dissemination from tumor tissue, transport in blood/lymphatic vessels, invasion and homing of malignant cells. A cDNA oligoarray was used to determine whether alterations of metastatic genes are associated with oxidative stress in breast cancer cell lines. The cell lines used for the experiments were derived from a pre-existent in vitro breast cancer progression model originated in our laboratory. The cDNA array showed alterations in functional gene groups related with cell-cell and cell-matrix interaction molecules, such as caveolin-1; metastasis suppressor genes, such as CD44; metastasis-associated proteases, such as cathepsin D and the protease inhibitor, plasminogen activator inhibitor type 1. The changes of the selected genes were validated by differential display-RT-PCR as well as by protein expression assessed by Western blot analysis. It was found that the cell line, called tumor2 with down-regulation of basal ROS and manganese superoxide dismutase (MnSOD) expression as a constitutive pattern of this cell line, presented alterations in genes that confer metastatic potential in comparison to the Alpha5 cell line, showing overexpression of basal MnSOD and high levels of ROS. Interesting, it was to found that CD44, considered a metastatic suppressor gene, was influenced by ROS, measured by hydrogen peroxide treatments, as seen by decreased CD44 protein expression in the Alpha5 cell line in a compensatory response to increased MnSOD protein expression. In conclusion, alterations of metastatic genes in malignant breast cancer cell lines were observed in relation to ROS and basal levels of antioxidant enzymes.

OBJECTIVE: Breast cancer cells with CD44+CD24-/low gene expression signature have been suggested to have stem cell-like tumor-initiating properties. The purpose of this study is to clarify the gene expression profiling of cells with CD44+CD24-/low gene expression signature in the luminal subtype. METHODS: Laser capture microdissection was used to select the isolation of cancer cells in 35 frozen tissues of breast cancer, and RNA extracted from these cells was examined by real-time RT-PCR to quantify CD44 and CD24 expressions. Human stem cell RT(2) Profiler PCR Array was used for gene expression analysis in the groups of CD44+CD24-/low and CD44+CD24+ gene expression signature. RESULTS: Thirty-five tumors were divided into 3 groups. Group A was composed of the CD44+CD24-/low type, in which the ratio of CD44/CD24 was >10.0. Group B was composed of the CD44+CD24+ type, in which the ratio was >0.1 and tumors in groups A, B, and C were 5, 28, and 2, respectively. Regarding the correlation of CD44/CD24 status with tumor characteristics, the tumors of group A were significantly associated with axillary lymph node metastasis compared with those of group B (p = 0.033). There were no significant differences in tumor size, nuclear grade, or HER2 status between the two groups. According to signaling pathways, the number of expression genes for the Notch pathway in group A was significantly greater than in group B (p = 0.028). Overexpressed genes for ALDH1 (p = 0.021) and SOX2 (p = 0.018) were noted in group A compared to group B. CONCLUSION: This study suggests that the Notch pathway may be an important signaling pathway in luminal subtype with CD44+CD24-/low gene expression signature. In addition, either ALDH1 or SOX2 may be a candidate marker for cancer stem cells in luminal subtype breast cancer.

The importance of non-coding RNA transcripts in regulating microRNA (miRNA) functions, especially the 3'-untranslated region (3' UTR), has been revealed in recent years. Genes encoding the extracellular matrix normally produce large mRNA transcripts including the 3' UTR. How these large transcripts affect miRNA functions and how miRNAs modulate extracellular matrix protein expression are largely unknown. Here, we demonstrate that the overexpression of the CD44 3' UTR results in enhanced cell motility, invasion and cell adhesion in human breast carcinoma cell line MDA-MB-231. Furthermore, we found that expression of the CD44 3' UTR enhances metastasis in vivo. We hypothesize that increased expression of the CD44 3' UTR affects miRNA binding and modulates synthesis of the extracellular matrix. Computational analysis indicated that miRNAs that interact with the CD44 3' UTR also have binding sites in other matrix-encoding mRNA 3' UTRs, including collagen type 1alpha1 (Col1alpha1) repressed by miR-328 and fibronectin type 1 (FN1) repressed by miR-512-3p, miR-491 and miR-671. Protein analysis demonstrated that expression of CD44, Col1alpha1 and FN1 were synergistically upregulated in vitro and in vivo upon transfection of the CD44 3' UTR. The non-coding 3' UTR of CD44 interacts with multiple miRNAs that target extracellular matrix properties and thus can be used to antagonize miRNA activities.

Hyaluronan (HA), a component of the extracellular matrix, plays an important role in cell-cell adhesion and cell migration. Membrane type 1-matrix metalloproteinase (MT1MMP) is often expressed in invasive cancer cells. CD44, a transmembrane receptor for HA, is implicated in various adhesion-dependent cellular processes including cell migration, tumor cell metastasis and invasion. Previous studies have shown that CD44 is highly expressed in cancer cells and may be proteolytically cleaved at the ectodomain by MT1-MMP; this process of inducing CD44 cleavage plays a critical role in cancer cell migration. We hypothesized that HA modulates MT1-MMP expression to facilitate breast cancer cell migration. Flow cytometry, real-time PCR, western blotting and immunofluorescence staining were used to quantify HA-induced MT1-MMP expression in breast cancer cells. In order to validate the relevance of cell migration and HA-induced MT1-MMP, we analyzed the cell migration via matrigel-coated transwell. We found that after HA oligosaccharide (6.5 kDA) stimulation, MT1-MMP expression in the membrane of breast cancer cells was increased. In response to HA oligosaccharide stimulation, significant upregulation of MT1-MMP mRNA occurred. Our data also provide evidence that HA oligosaccharide enhances MT1-MMP; the elevated expression of MT1-MMP confers enhanced CD44 cleavage and cell migration. In conclusion, we have identified a new function of HA in the induction of MT1-MMP expression in breast cancer cell lines and CD44 cleavage to increase cell migration during the invasion process. The HA oligosaccharide-induced MT1-MMP expression in breast cancer cells may be a critical step in the formation of metastatic colonies.

BACKGROUND: CD44, a transmembrane glycoprotein expressed in a variety of cells and tissues, has been implicated in tumour metastasis. But the molecular mechanisms of CD44-mediated tumour cell metastasis remain to be elucidated. METHODS: The downregulation of CD44 was determined by immunofluorescence. Moreover, the motility of breast cancer cells was detected by wound-healing and transwell experiments. Then the spontaneous metastasis of CD44-silenced MDA-MB-231 cells was tested by histology with BALB/c nude mice. RESULTS: A positive correlation between CD44 and Na(+)/H(+) exchanger isoform 1 (NHE1) was found in two breast cancer cells. CD44 downregulation could inhibit the metastasis of MDA-MB-231 cells and the expressions of Na(+)/H(+) exchanger 1. Moreover, CD44 overexpression upregulated the metastasis of MCF-7 cells, but the elevated metastatic ability was then inhibited by Cariporide. Interestingly, during these processes only the p-ERK1/2 was suppressed by CD44 downregulation and the expression of matrix metalloproteinases and metastatic capacity of MDA-MB-231 cells were greatly inhibited by the MEK1 inhibitor PD98059, which even had a synergistic effect with Cariporide. Furthermore, CD44 downregulation inhibits breast tumour outgrowth and spontaneous lung metastasis. CONCLUSIONS: Taken together, this work indicates that CD44 regulates the metastasis of breast cancer cells through regulating NHE1 expression, which could be used as a novel strategy for breast cancer therapy.

Breast cancer preferentially metastasizes to lung, lymph node, liver, bone, and brain. However, it is unclear whether properties of cancer cells, properties of organ microenvironments, or a combination of both is responsible for this observed organ tropism. We hypothesized that breast cancer cells exhibit distinctive migration/growth patterns in organ microenvironments that mirror common clinical sites of breast cancer metastasis and that receptor-ligand interactions between breast cancer cells and soluble organ-derived factors mediate this behavior. Using an ex vivo model system composed of organ-conditioned media (CM), human breast cancer cells (MDA-MB-231,MDA-MB-468, SUM149, and SUM159) displayed cell line-specific and organ-specific patterns of migration/proliferation that corresponded to their in vivo metastatic behavior. Notably, exposure to lung-CM increased migration of all cell lines and increased proliferation in two of four lines (P < .05). Several cluster of differentiation (CD) 44 ligands including osteopontin (OPN) and L-selectin (SELL) were identified in lung-CM by protein arrays. Immunodepletion of SELL decreased migration of MDA-MB-231 cells, whereas depletion of OPN decreased both migration and proliferation. Pretreatment of cells with a CD44-blocking antibody abrogated migration effects (P < .05). "Stemlike" breast cancer cells with high aldehyde dehydrogenase and CD44 (ALDH(hi)CD44(+)) responded in a distinct chemotactic manner toward organ-CM, preferentially migrating toward lung-CM through CD44 receptor-ligand interactions (P < .05). In contrast, organ-specific changes in migration were not observed for ALDH(low)CD44(-) cells. Our data suggest that interactions between CD44(+) breast cancer cells and soluble factors present in the lung microenvironment may play an important role in determining organotropic metastatic behavior.

The aim of this article was to evaluate the expression of E-cadherin and CD44 adhesion molecule in oral tongue squamous cell carcinoma (SCC) since inappropriate expression of adhesion molecules raises the metastatic ability of the tumor cells. Biopsy specimens from 92 patients with tongue SCC were examined for the expression of E-cadherin and CD44 by immunohistochemistry. The relationship of immunoreactivity with tumor stage and cervical lymph node metastasis was then analyzed. Sixty-one patients (66.3%) had reduced or negative staining for CD44. Weak or absent staining for E-cadherin was seen in 14 patients (15.21%). Cervical lymph node metastasis is associated with decreased or negative staining for CD44, but no association was found between E-cadherin immunoreactivity and nodal metastasis. Our study reveals that reduced expression of CD44 could be an indicator of high invasiveness of tumor by increasing cervical lymph node metastasis.

BACKGROUND: Late nodal metastases is a critical factor that worsens the prognosis of T1/T2N0 tongue cancer treated by interstitial brachytherapy. If we could better predict the patients at high risk for late nodal metastases developing before treatment, more appropriate choices of treatment could be selected. In recent studies of colon cancer, prostate cancer, and laryngeal cancer, CD44H has been postulated to be a metastasis suppressor. METHODS: On the basis of this phenomenon, we immunohistochemically evaluated the expression of CD44H in 38 cases of primary T1/T2N0 tongue cancer treated by interstitial brachytherapy. Formalin-fixed, paraffin-embedded biopsy specimens obtained before treatment were examined. RESULTS: The group that had late nodal metastases revealed a significantly lower (p =.0035) CD44H expression. CONCLUSIONS: A decreased CD44H expression may therefore be useful as a new predictor of late nodal metastases in patients with T1/T2N0 tongue carcinoma. For patients with a decreased CD44H expression, a partial glossectomy and an elective neck dissection may therefore be an appropriate treatment modality.

Although relatively little is known about the molecular mechanisms underlying tumor progression, recently CD44 glycoproteins and the c-Met receptor tyrosine kinase have been identified as potentially important components of the metastatic cascade. CD44 is a family of transmembrane receptors generated from a single gene by alternative splicing and differential glycosylation. Important biological processes involving CD44 glycoproteins include cell adhesion, lymphocyte homing, hematopoiesis, tumor progression and metastasis. The precise mechanism via which CD44 promotes tumorigenesis have not yet been elucidated. We evaluated the expression of adhesion molecule CD44 variant 6 in pulmonary metastases from colorectal carcinomas and its correlation with clinicopathological parameters. Twenty patients were randomly selected from the patients who had undergone a resection of pulmonary metastasis from colorectal cancer. Formalin-fixed, paraffin-embedded archival specimens of tumor tissues and adjacent normal mucosa from these patients were the subjects of the present study. Immunoreactivity for CD44 was quantified. Specimens were considered positive if almost 25% of the neoplastic cells were stained. CD44 v6 expression was related to the interval between colon resection and metastases diagnosis, the number of pulmonary metastases, and the survival after lung resection. No statistical correlation was found between CD44 v6 positivity and disease-free interval after colon resection, number of metastases or 2-year survival after lung resection. Probably CD44 v6 is necessary and sufficient to confer metastatic potential to carcinoma cells increasing the migration capacity and participating in invasion via changes in adhesion to the extracellular ligands, but is not necessary to modify the clinical history of the metastases. Therefore the evaluation of CD44 v6 expression in lung metastases does not influence the therapeutic scheme.

AIM: To investigate the expression of proliferating cell nuclear antigen (PCNA) and CD44mRNA in colorectal cancer with venous invasion and its relationship with liver metastasis. METHODS: Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect the expression of PCNA and CD44mRNA in 31 cases of colorectal cancer with venous invasion. RESULTS: Positive expression rates of PCNA and CD44mRNA in colorectal cancer were higher than those without liver metastasis (P<0.05 and P<0.01). In case of colorectal cancer with liver metastasis, strongly positive rates of PCNA and CD44mRNA were 94.1% and 70.6%, respectively, significantly higher than those without liver metastasis. There was a positive relationship between the expressions of PCNA and CD44mRNA (r=0.67, P<0.05). CONCLUSION: Detection of PCNA and CD44mRNA expression in colorectal cancer may be useful for evaluating liver metastasis of cancer cells.

Selectin-mediated binding of tumor cells to platelets, leukocytes, and vascular endothelium may regulate their hematogenous spread in the microvasculature. We recently reported that CD44 variant isoforms (CD44v) on LS174T colon carcinoma cells possess selectin binding activity. Here we extended those findings by showing that T84 and Colo205 colon carcinoma cells bind selectins via sialidase-sensitive O-linked glycans presented on CD44v, independent of heparan and chondroitin sulfate. To assess the functional role of CD44v in selectin-mediated binding, we quantified the adhesion to selectins of T84 cell subpopulations sorted based on their CD44 expression levels and stable LS174T cell lines generated using CD44 short hairpin RNA. High versus low CD44-expressing T84 cells tethered more efficiently to P- and L-selectin, but not E-selectin, and rolled more slowly on P- and E-selectin. Knocking down CD44 expression on LS174T cells inhibited binding to P-selectin and increased rolling velocities over P- and L-selectin relative to control-transfected cells, without affecting tethering and rolling on E-selectin, however. Blot rolling analysis revealed the presence of alternative sialylated glycoproteins with molecular masses of approximately 170 and approximately 130 kDa, which can mediate selectin binding in CD44-knockdown cells. Heparin diminishes the avidity of colon carcinoma cells for P- and L-selectin, which may compromise integrin-mediated firm adhesion to host cells and mitigate metastasis. Our finding that CD44v is a functional P-selectin ligand on colon carcinoma provides a novel perspective on the enhanced metastatic potential associated with tumor CD44v overexpression and the role of selectins in metastasis.

High expression of EpCAM and the tetraspanin CO-029 has been associated with colorectal cancer progression. However, opposing results have been reported on CD44 variant isoform v6 (CD44v6) expression. We recently noted in rat gastrointestinal tumors that EpCAM, claudin-7, CO-029, and CD44v6 were frequently coexpressed and could form a complex. This finding suggested the possibly that the complex, rather than the individual molecules, could support tumor progression. The expression of EpCAM, claudin-7, CO-029, and CD44v6 expression was evaluated in colorectal cancer (n = 104), liver metastasis (n = 66), and tumor-free colon and liver tissue. Coexpression and complex formation of the molecules was correlated with clinical variables and apoptosis resistance. EpCAM, claudin-7, CO-029, and CD44v6 expression was up-regulated in colon cancer and liver metastasis. expression of the four molecules did not correlate with tumor staging and grading. However, coexpression inversely correlated with disease-free survival. Coexpression was accompanied by complex formation and recruitment into tetraspanin-enriched membrane microdomains (TEM). Claudin-7 contributes to complex formation inasmuch as in the absence of claudin-7, EpCAM hardly associates with CO-029 and CD44v6 and is not recruited into TEMs. Notably, colorectal cancer lines that expressed the EpCAM/claudin-7/CO-029/CD44v6 complex displayed a higher degree of apoptosis resistance than lines devoid of any one of the four molecules. expression of EpCAM, claudin-7, CO-029, and CD44v6 by themselves cannot be considered as prognostic markers in colorectal cancer. However, claudin-7-associated EpCAM is recruited into TEM and forms a complex with CO-029 and CD44v6 that facilitates metastasis formation.

Selectins and fibrin(ogen) play key roles in the hematogenous dissemination of tumor cells, and especially of colon carcinomas. However, the fibrin(ogen) receptor(s) on colon carcinoma cells has yet to be defined along with its relative capacity to bind fibrinogen versus fibrin under flow. Moreover, the functional P-selectin ligand has yet to be validated using intact platelets rather than purified selectin substrates. Using human CD44-knockdown and control LS174T cells, we demonstrate the pivotal involvement of CD44 in the P-selectin-mediated binding to platelets in shear flow. Quantitative comparisons of the binding kinetics of LS174T versus P-selectin glycoprotein ligand-1 (PSGL-1)-expressing THP-1 cells to activated platelets reveal that the relative avidity of P-selectin-CD44 binding is more than sevenfold lower than that of P-selectin-PSGL-1 interaction. Using CD44-knockdown LS174T cells and microspheres coated with CD44 immunoprecipitated from control LS174T cells, and purified fibrin(ogen) as substrate, we provide the first direct evidence that CD44 also acts as the major fibrin, but not fibrinogen, receptor on LS174T colon carcinoma cells. Interestingly, binding of plasma fibrin to CD44 on the colon carcinoma cell surface interferes with the P-selectin-CD44 molecular interaction and diminishes platelet-LS174T heteroaggregation in the high shear regime. Cumulatively, our data offer a novel perspective on the apparent metastatic potential associated with CD44 overexpression on colon carcinoma cells and the critical roles of P-selectin and fibrin(ogen) in metastatic spread and provide a rational basis for the design of new therapeutic strategies to impede metastasis.

AIMS: To assess systematically the membranous expression of CD44v6 in colorectal cancer by immunohistochemistry to determine its prognostic impact, the differential expression between primary and metastatic tumours and expression differences between the tumour centre and invasive front. METHODS AND RESULTS: Immunohistochemistry was performed for CD44v6 on two tissue microarrays. The first included 1279 colorectal tumours with full clinicopathological data. The second consisted of 50 matched primary and metastatic tumours sampled from the tumour centre and the invasive margin. A scoring system was tested by multiple observers. Receiver-operating characteristic curve analysis was used for cut-off point determination. Loss of membranous CD44v6 was associated with pT stage (P = 0.016; sensitivity 85.8%, specificity 20.1%), lymph node metastasis (P = 0.015; sensitivity 52.8%, specificity 55%), an infiltrating tumour margin (P < 0.001; sensitivity 71.4%, specificity 40%) and adverse prognosis (P = 0.011; hazard ratio 0.79, 95% confidence interval 0.7, 0.9), but was not an independent prognostic factor on multivariable analysis. Loss of expression occurred at the invasive front in both primary and metastatic lesions (P < 0.001). CONCLUSIONS: This study outlines an approach to help standardize the immunohistochemical evaluation of CD44v6 and similar markers in colorectal cancer and highlights a significant role for loss of membranous CD44v6 expression in colorectal cancer progression and prognosis.

PURPOSE: The aim of the present study was to evaluate the standard CD44 (CD44s) expression in colorectal cancer (CRC) with invasion to the subserosal layer (T3), its relationship with clinicopathological characteristics, and its potential metastatic significance. MATERIALS AND METHODS: CD44s expression was measured on immunohistochemistry in tumors from 65 patients with primary colorectal carcinomas. CD44s expression was estimated at the deepest invaded area of the tumor in subserosal layer. RESULTS: CD44s was demonstrated in 35.4% (23/65). CD44s expression showed no significant relationship with the clinicopathological characteristics such as age, gender, tumor location, tumor size, and macroscopic/microscopic classification. However, the CD44s expression showed significantly adverse relationship with lymph node metastasis (p < 0.05) and liver metastasis (p < 0.01), respectively. CONCLUSION: The loss of CD44s expression in cancer cells in the deepest invaded area is a good marker for predicting potential metastasis to lymph nodes and liver in T3 CRC.

Histone deacetylase 1 (HDAC1) and metastasis-associated protein 1 (MTA1) form the nucleosome remodeling and histone deacetylation (NuRD) complex and may possibly play a central role in cancer development. However, limited data has been reported regarding the expression of both HDAC1 and MTA1. The aim of the present study was to clarify the clinical role of HDAC1 and MTA1 expression in colon cancer. Seventy-four patients with colon cancer, who underwent colectomy at our institution, were enrolled in this study. expression of HDAC1 and MTA1 was examined immunohistochemically. The patients were divided into four groups: HDAC1-positive group (n=58), HDAC1-negative group (n=16), MTA1-positive group (n=38) and MTA1-negative group (n=36). Clinicopathological factors and survival rates were compared between the groups. Regarding the clinicopathological factors, the depth of tumor invasion and stage correlated significantly with HDAC1 expression (p<0.05). Age, depth of tumor invasion and vascular invasion tended to correlate with MTA1 expression. The 5-year survival rate in the HDAC1-positive group (55.1%) was significantly worse compared to the HDAC1-negative group (86.5%) (p<0.05), and the 5-year survival rate of the MTA1-positive group (50.5%) was significantly worse than that of the MTA1-negative group (73.1%) (p=0.05). In patients with stages II-IV and curability A, B, the survival rate in those with HDAC1-positive expression was significantly worse than those with HDAC1-negative expression (p<0.05), and the survival rate of the MTA1-positive group tended to be worse than that of the MTA1-negative group (p=0.07). Overall survival in both the HDAC1 and MTA1-positive groups was significantly worse than overall survival of the other groups (p<0.05). Disease-free survival in both the HDAC1- and MTA1-positive groups, among patients with stages II-IV and curability A, B, was also significantly worse than that of the other groups (p<0.05). HDAC1 and MTA1 expression levels were significantly related to poorer prognosis. Therefore, HDAC1 and MTA1 expression levels are potential prognostic indicators for colon cancer.

Histone deacetylase 1 (HDAC1) and metastasis-associated protein 1 (MTA1) form the nucleosome remodeling and histone deacetylation (NuRD) complex and may possibly play a central role in cancer development. However, limited data has been reported regarding the expression of both HDAC1 and MTA1. The aim of the present study was to clarify the clinical role of HDAC1 and MTA1 expression in colon cancer. Seventy-four patients with colon cancer, who underwent colectomy at our institution, were enrolled in this study. expression of HDAC1 and MTA1 was examined immunohistochemically. The patients were divided into four groups: HDAC1-positive group (n=58), HDAC1-negative group (n=16), MTA1-positive group (n=38) and MTA1-negative group (n=36). Clinicopathological factors and survival rates were compared between the groups. Regarding the clinicopathological factors, the depth of tumor invasion and stage correlated significantly with HDAC1 expression (p<0.05). Age, depth of tumor invasion and vascular invasion tended to correlate with MTA1 expression. The 5-year survival rate in the HDAC1-positive group (55.1%) was significantly worse compared to the HDAC1-negative group (86.5%) (p<0.05), and the 5-year survival rate of the MTA1-positive group (50.5%) was significantly worse than that of the MTA1-negative group (73.1%) (p=0.05). In patients with stages II-IV and curability A, B, the survival rate in those with HDAC1-positive expression was significantly worse than those with HDAC1-negative expression (p<0.05), and the survival rate of the MTA1-positive group tended to be worse than that of the MTA1-negative group (p=0.07). Overall survival in both the HDAC1 and MTA1-positive groups was significantly worse than overall survival of the other groups (p<0.05). Disease-free survival in both the HDAC1- and MTA1-positive groups, among patients with stages II-IV and curability A, B, was also significantly worse than that of the other groups (p<0.05). HDAC1 and MTA1 expression levels were significantly related to poorer prognosis. Therefore, HDAC1 and MTA1 expression levels are potential prognostic indicators for colon cancer.

Fatty acid synthase (FASN) and ATP-citrate lyase, key enzymes of de novo lipogenesis, are significantly upregulated and activated in many cancers and portend poor prognosis. Even though the role of lipogenesis in providing proliferative and survival advantages to cancer cells has been described, the impact of aberrant activation of lipogenic enzymes on cancer progression remains unknown. In this study, we found that elevated expression of FASN is associated with advanced stages of colorectal cancer (CRC) and liver metastasis, suggesting that it may play a role in progression of CRC to metastatic disease. Targeted inhibition of lipogenic enzymes abolished expression of CD44, a transmembrane protein associated with metastases in several cancers including CRC. In addition, inhibition of lipogenic enzymes and reduced expression of CD44 attenuated the activation of MET, Akt, FAK, and paxillin, which are known to regulate adhesion, migration, and invasion. These changes were consistent with an observed decrease in migration and adhesion of CRC cells in functional assays and with reorganization of actin cytoskeleton upon FASN inhibition. Despite the modest effect of FASN inhibition on tumor growth in xenografts, attenuation of lipogenesis completely abolished establishment of hepatic metastasis and formation of secondary metastasis. Together, our findings suggest that targeting de novo lipogenesis may be a potential treatment strategy for advanced CRC.

Although relatively good therapeutic results are achieved in non-advanced cancer, the prognosis of the advanced colon cancer still remains poor, dependent on local or distant recurrence of the disease. One of the factors responsible for recurrence is supposed to be cancer stem cells (CSCs) or tumor-initiating cells, which are a population of cancer cells with ability to perpetuate themselves through self-renewal and to generate differentiated cells, thought to be responsible for tumor recurrence. This study globally approach the possible role of tissue-derived stem cells in the initiation of colon cancer and its metastatic process in the liver. Fresh surgical specimens from colon cancer, non-tumor tissue and liver metastasis were obtained directly from the operating room, examined, and immediately processed. CSCs were selected under serum-free conditions and characterized by CD44 and CD133 expression levels. CD133(+)/CD44(+) cell populations were then investigated in paraffin-embedded tissues and circulating tumor cells isolated from peripheral blood of the same group of colon cancer patients. Our data demonstrate that metastatic properties of cell populations from blood and liver metastasis, differently from primitive tumors, seem to be strictly related to the phenotype CD133 positive and CD44 positive.

BACKGROUND: CD44 is a transmembrane glycoprotein and is associated with cell-matrix and cell-cell interactions. CD44 expression was shown to be relevant to tumour progression in various types of human cancer. The objective of this study was to investigate the relationship between the expression levels of the standard form of CD44 (CD44s), and clinicopathological characteristics in a subset of colorectal carcinomas (CRC). PATIENTS AND METHODS: A total of 96 cases of CRC were retrieved from the archives at the Department of Pathology at King Abdulaziz University, Jeddah, KSA. Immunohistochemistry was performed using antibodies to CD44s. A cut-off of <10% of positive neoplastic cells was used to define low expression, 10-50% to define moderate expression and >50% to define extensive expression. Statistical tests were used to determine the association of CD44s with clinicopathological characteristics in a subset of colorectal carcinomas and survival. RESULTS: Immunostaining results showed that there was no association between C44 immunoexpression and age of patients, tumour grade, depth of invasion, vascular invasion, recurrence and survival. CD44s immunolabelling was found to have an association with nodal metastasis and to be an independent predictor of nodal metastasis. CONCLUSION: Loss of CD44s immunolabelling in CRC is an independent favourable predictor of regional lymph node metastasis. On the other hand, CD44s loss has no significant association with disease recurrence or survival. Extensive in vivo and in vitro molecular studies are required to elucidate the possible mechanistic association of CD44s with tumour initiation, progression, invasion and metastasis in primary CRC, and in nodal and distant metastases.

BACKGROUND: CD44 is considered as 'a' metastasis associated gene, despite the fact that it is an umbrella term for a group of molecules produced from a single gene by alternative splicing. However, little consideration is given to the above in the literature of colorectal carcinomas as well as other tumour types, leading to confusion and contradictory results about its possible role in tumour progression. METHODS: We compared the CD44 alternative splice pattern (ASP) of three genetically different human colorectal cancer cell lines (HT25, HT29, HCT116) using a series of PCR reactions and next- generation sequencing method, as well as identified a colorectal adenocarcinoma specific CD44 ASP. This ASP was further investigated in terms of its qualitative and quantitative stability in our experimental iso- and xenograft mouse models for colorectal cancer progression. A complex preclinical experimental set-up was established to separately test the different steps of tumour progression and the role of tumour microenvironment, respectively, focusing on the role of 'CD44' in this process. RESULTS: We managed to present a colorectal cancer-specific CD44 ASP, which remained unchanged from cell lines throughout primary tumour formation and metastatic progression. Furthermore, we report a unique roster of all expressed CD44 variant isoforms characteristic to colorectal cancer. Finally, on quantitative assessment of the variable exons v3 and v6, higher co-expression levels were found to be characteristic to metastatically potent tumour cells. CONCLUSION: Particular CD44 variant isoforms seem to act as "metastasis genes" via tumour microenvironment-driven shifts in v3 and v6 expressions. However, this function may just affect a minority of tumour subclones. This fact and the huge potential number of different CD44 splice variants that can contain v3 and v6 domains can explain incoherence of clinical studies regarding functional asessment of CD44 variants, as well as diminish the chances of using CD44 variants for predictive purpose.

OBJECTIVE: To evaluate the expression of ezrin and CD44-v6 in esophageal squamous cell carcinoma, and to evaluate its relationship with lymph node metastasis (LNM) and histological grading. METHODS: The expression of ezrin and CD44-v6 in 71 patients with esophageal squamous cell carcinoma was studied using immunohistochemical (SP) method. The correlation of their expression with relevant clinical data was statistically analyzed. RESULTS: In normal esophageal squamous epithelia, the expression of ezrin was found in 33 cases among 71 cases and the expression of CD44-v6 in 18 cases among 71 cases. In esophageal squamous cell carcinoma, the expression of ezrin was found in 64 cases among 71 cases and CD44-v6 in 58 cases among 71 cases. The expression of ezrin was closely related to LNM. The positive rate of ezrin expression in LNM cases was significantly higher than that in cases without LNM. The expression of CD44-v6 had a close relation to tumor differentiation and LNM. The positive rate of CD44-v6 expression in LNM cases was significantly higher than that in patients without LNM. The expression of ezrin in CD44-v6 positive cases was significantly higher than that of CD44-v6 negative cases. The LNM rate was 60.0% in 48 patients with positive expression of both ezrin and CD44-v6, while none of lymph node metastasis was found in the 6 patients with both negative. CONCLUSION: The test of CD44-v6 and ezrin expression may have significant prognostic value for assessing the degree of malignancy and potential LNM probability of ESCC. Ezrin may become a new target in evaluation of tumor prognosis.

AIM: To explore the expression of heparanase gene, CD44v6, MMP-7 and nm23 proteins in human gastric carcinoma as well as their relationship with the clinicopathological factors. METHODS: Reverse transcription polymerase chain reaction (RT-PCR) was used to measure the expressions of heparanase mRNA in 43 human gastric carcinomas and 10 adjacent normal gastric tissues. Streptavidin-peroxidase (S-P) two step method was used to measure the immunohistochemical expression of CD44v6, MMP-7 and nm23 protein in 43 human gastric carcinomas. RESULTS: The expression of heparanase gene was positive in 29 cases of gastric cancer with a positive rate of 67.4%, which was significantly higher than those in adjacent normal gastric tissues (P<0.05). The heparanase mRNA expression was significantly related to advanced stage of disease, serosal infiltration, lymph node metastasis and size of tumors (P<0.05), but not related to tumor location, gross and histological types of the cancer, peritoneal dissemination and liver metastasis (P>0.05). The positive rate of CD44v6, nm23 and MMP-7 proteins was 76.7%, 37.2% and 60.5%, respectively. The CD44v6 protein expression was significantly related to serosal infiltration, lymph node metastasis and TNM stage of disease (P<0.05). The nm23 protein expression was significantly related to the tumor gross appearance, lymph node and peritoneal metastasis (P<0.05). The MMP-7 protein expression was significantly related to serosal infiltration and TNM stage of disease (P<0.05). In an attempt to measure the association between these agents, we found that the expression of heparanase mRNA had significantly negative correlation with the expression of CD44v6 and MMP-7 protein (P<0.05), the expression of MMP-7 protein had significantly positive correlation with the expression of CD44v6 protein (r=0.568, P<0.05), the expression of MMP-7 protein had no correlation with the expression of nm23 protein (P>0.05), and the expression of nm23 protein had no correlation with the expression of CD44v6 protein (P>0.05). CONCLUSION: Despite their different mechanisms of action, heparanase, CD44v6 and nm23 may play important roles in the invasive infiltration and lymph node metastasis in gastric carcinomas. Instead of metastatic spreading, MMP-7 may be just related to the invasion of gastric carcinomas. However, co-detection of these factors may be important to predict metastatic spreading in such patients.

The aim of this study was to examine the expression of CD44v6, CD54, Cdx2, CXCL5, Cyclin B1, MMP-7, nm23, RCAS1 and Survivin in primary gastric cancer and to investigate whether these molecules were useful in predicting the lymph node status. They were selected as candidates for indicators of lymph node metastasis from various kinds of cancer-associated genes reported previously. In 135 cases of radically resected primary gastric adenocarcinoma, we investigated the association between the expression of these molecules and clinocopathologic factors by immunohistochemistry. The results revealed that the expression of CD44v6 and MMP-7 were significantly associated with lymph node status. By contrast, nuclear Cdx2 expression was found to be inversely correlated with lymph node metastasis. Moreover, multivariate analysis demonstrated that CD44v6, MMP-7 and nuclear Cdx2 were independent predictors for lymph node status. In conclusion, our results suggest that positive expression of both CD44v6 and MMP-7, and negative expression of nuclear Cdx2 may serve as powerful predictors of lymph node metastasis in gastric cancer. Combined evaluation of these markers could be further useful to predict lymph node status clinically.

AIM: To investigate the expression levels of lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), vascular endothelial growth factor receptor-3 (VEGFR-3) and CD44 genes and the relationship between their levels and clinicopathological parameters in gastric cancer. METHODS: Tissue samples were obtained from 33 patients (8 females) with gastric cancer. mRNA levels of LYVE-1, VEGFR-3 and CD44 in normal and tumor tissues were quantitatively measured using real time polymerase chain reaction. The results were correlated with lymph node metastasis, histological type and differentiation of the tumor, T-stage, and presence of vascular, perineural and lymphatic invasions. The distribution of molecules in the tissue was evaluated using immunohistochemistry. RESULTS: LYVE-1, CD44 and VEGFR-3 gene expression levels were significantly higher in gastric cancer than in normal tissue. While there was no correlation between gene expressions and clinicopathologic features such as histologic type, differentiation and stage, gene expression levels were found to be increased in conjunction with positive lymph node/total lymph node ratio and the presence of perineural invasion. A significant correlation was also found between LYVE-1 and CD44 over-expressions and perineural invasion and lymph node positivity in gastric cancers. When the distribution of LYVE-1 antibody-stained lymphatic vessels in tissue was evaluated, lymphatic vessels were located intra-tumorally in 13% and peri-tumorally in 27% of the patients. Moreover, lymph node metastases were also positive in all patients with LYVE-1-staining. CONCLUSION: LYVE-1, VEGFR-3 and CD44 all play an important role in lymphangiogenesis, invasion and metastasis. LYVE-1 is a perfectly reliable lymphatic vessel marker and useful for immunohistochemistry.

OBJECTIVE: To study the metastasis feature of the primary and metastatic lymph node lesions in supraglottic or hypopharyngeal cancer. METHODS: The expression of CD44 and nm23-H1 in specimens from the primary and metastatic lymph node lesions of the 41 cases with supraglottic or hypopharyngeal cancer were studied with immunohistochemistry method and flow cytometry. RESULTS: No correlation was found between the expression of CD44, nm23-H1 and the tumor differentiation of the supraglottic or hypopharyngeal cancer, but their expression related with the clinical staging. The CD44 and nm23-H1 positive expression rates in the primary and metastatic lymph node lesions were 75.6% (31/41), 85.4% (35/41) and 34.1% (14/41), 26.8% (11/41) respectively (P >0.05). The average fluorescence index of CD44 and nm23-H1 in the primary and metastatic lymph node lesions were 1.27 +/- 0.18, 1.33 +/- 0.16 and 1.11 +/- 0.19, 1.08 +/- 0.15 (x +/- s) respectively (P >0.05). CONCLUSIONS: The expressions of CD44 and nm23-H1 in the metastatic lymph node tumor had no difference compared with that in primary tumor of the supraglottic or hypopharyngeal cancer. The difference of metastasis potentials between the primary and metastatic lymph node lesions in the same patient was not proved in this study and should be further investigated from multiple oncogens markers.

To assess the expression of COX-2,CD44v6 and CD147 in hypopharyngeal squamous cell carcinomas and the three biomarkers correlation with tumor invasion and lymph node metastasis of Chinese people. 101 cases of surgically excised primary tumor were included in this study, and 40 tissues of epithelium adjacent to carcinoma were used as controls. We characterized the immunohistochemical expression of COX-2, CD44v6, and CD147 in 141 formalin-fixed, paraffin-embedded tissues, and measured the mean optical density (OD) of the positive area to identify the expression of the three bio-markers and relationship with tumor invasion and lymph node metastasis. Our study demonstrates that the expression of the COX-2 and CD147 were significantly increased in carcinoma tissues compared to the epithelium adjacent to carcinoma. We also observed that the expression of COX-2, CD44v6, and CD147 were significantly associated with T classification, lymph node metastasis and clinical stage. There was strong significant correlation among the three biomarkers as well. Additionally, we indicated that recurrence and >/= P50 level of COX-2 expression had an independent prognostic effect on prognosis. In conclusion, the three biomarkers play important roles in tumor invasion and lymph node metastases and might be valuable indicators of tumor metastasis in hypopharyngeal squamous cell carcinoma.

The intravessel microenvironment has significant effects on cancer metastasis. The aim of the present study was to determine how the morphologic and immunophenotypic features of cancer cells and infiltrating stromal cells within the permeated lymphatic vessels are associated with lymphogenic metastasis. A total of 137 primary lung adenocarcinoma patients with extratumoral lymphatic permeations were examined. Morphologically, the floating cancer nests within the permeated lymphatic vessels were divided into two types: Type A, consisting of a single large cancer nest; and Type B, consisting of multiple small cancer nests. We compared the clinicopathologic characteristics and the immunophenotypes of the cancer cells and infiltrating stromal cells between the Type A and Type B nests. Eleven of 54 Type A patients (20%) had intrapulmonary metastases, compared with 36 of 83 Type B patients (43%; P = 0.006). Immunohistochemically, Type B cancer cells expressed significantly higher levels of CD44 than Type A cancer cells (mean scoresAUTHOR: Scores - what is this score? Is it the number of cells expressing CD44 or the concentration of CD44 or some other type of scoring system? 43.0 vs 20.5, respectively) and E-cadherin (60.5 vs 31.5, respectively), but lower levels of Geminin (11.9% vs 20.3%, respectively) and cleaved caspase 3 (2.4% vs 7.8%AUTHOR: 11.9% vs 20.3%, respectively) and cleaved caspase 3 (2.4% vs 7.8%, - what do the percentages here refer to? The number of cells expressing geminin and caspase 3? The levels of these factors? Please clarify., respectively). Moreover, a significantly larger number of CD204-positive macrophages were present within the cancer-permeated lymphatic vessels in Type B patients than in Type A patients (mean number 9.5 vs 4.6, respectively). The present study reveals that intralymphatic cancer cell and stromal cell phenotypes are susceptible to lymphogenic metastasis, suggesting that lymphogenic metastasis may be affected by the intralymphatic microenvironment they create.

BACKGROUND: Late nodal metastases is a critical factor that worsens the prognosis of T1/T2N0 tongue cancer treated by interstitial brachytherapy. If we could better predict the patients at high risk for late nodal metastases developing before treatment, more appropriate choices of treatment could be selected. In recent studies of colon cancer, prostate cancer, and laryngeal cancer, CD44H has been postulated to be a metastasis suppressor. METHODS: On the basis of this phenomenon, we immunohistochemically evaluated the expression of CD44H in 38 cases of primary T1/T2N0 tongue cancer treated by interstitial brachytherapy. Formalin-fixed, paraffin-embedded biopsy specimens obtained before treatment were examined. RESULTS: The group that had late nodal metastases revealed a significantly lower (p =.0035) CD44H expression. CONCLUSIONS: A decreased CD44H expression may therefore be useful as a new predictor of late nodal metastases in patients with T1/T2N0 tongue carcinoma. For patients with a decreased CD44H expression, a partial glossectomy and an elective neck dissection may therefore be an appropriate treatment modality.

OBJECTIVE: To study the expression of CD44 and nm23-H1 gene proteins and their clinical significance in laryngeal carcinoma. METHOD: The expression of CD44 and nm23-H1 proteins were detected by immunohistochemistry method in 40 cases with laryngeal carcinoma, 20 adjacent carcinoma tissues and 12 cases normal laryngeal mucosa tissues. RESULT: The expression of CD44 and nm23-H1 proteins in laryngeal carcinoma were much higher than that in normal laryngeal mucosa. The expression of CD44 protein in laryngeal carcinoma with metastatic lymph node was higher than that in laryngeal carcinoma without metastatic lymph node, but nm23-H1 protein lower. The expression of CD44 protein was positively correlated with the metastasis, clinical staging and pathological classification but not correlated with T classification of laryngeal carcinoma. The expression of nm23-H1 protein was negative correlation with the metastasis and clinical staging of laryngeal carcinoma. CONCLUSION: CD44 and nm23-H1 gene proteins play an important coordinated regulation role in the carcinogenesis, development and metastasis of laryngeal carcinoma and will probably become the key biological marks in the judging and evaluating prognosis of laryngeal carcinoma.

OBJECTIVE: To investigate the expression and clinical significance of OPN, CD44v6 and MMP-9 in laryngeal squamous cell carcinomas (LSCC). METHOD: The expression of OPN, CD44v6 and MMP-9 in the 47 cases of LSCC and 10 cases normal mucosa were detected by immunohistochemical method. The correlation between OPN, CD44v6 and MMP-9 proteins expressions and the correlation between them and clinicopathological feature were also studied. RESULT: (1) The positive expression rates of OPN, CD44v6 and MMP-9 were 63.8%, 76.6% and 68.1% in LSCC of 47 cases and, and 10%, 30% and 0 in the tumor adjacent issue. (2) The positive rate of OPN and CD44v6 was significantly correlated with the clinical staging, the pathological grading and the metastasis of cervical lymph node (P < 0.05). The positive rate of MMP-9 was correlated with the clinical staging and the metastasis of cervical lymph node (P < 0.05). The positive rates of OPN, CD44v6 and MMP-9 were not correlated with patient's age, sex and tumor location (P > 0.05). (3) The expression of OPN was well correlated with the positive rate of CD44v6 and MMP-9 in LSCC (r = 0.421, P < 0.01, r = 0.340, P < 0.05). The expression of positive rate of CD44v6 and MMP-9 was well related in LSCC as well (r = 0.376, P < 0.01). CONCLUSION: There is a high level of expression of OPN, CD44v6 and MMP-9 in LSCC. OPN, CD44v6 and MMP-9 are positively related and involved in the invasion and metastasis of LSCC.

Pharyngolaryngeal cancer is one of the most common head and neck cancer worldwide, and the early diagnosis and prognosis prediction are still difficult because of lacking in reliable cell markers. Although the expression of CD44 has been reported to correlate with poor prognosis of pharyngolaryngeal cancer in most literatures, some controversies still exist. Since the limited patient numbers within independent studies, here we performed a meta-analysis to clarify the correlations between CD44 expression and clinicopathological features and prognosis in pharyngolaryngeal cancer. A search of PubMed, ISI Web of Science and China National Knowledge Infrastructure databases (up to June 2013) was performed. Nineteen studies with 1,405 patients met the inclusion criteria. The expression of pan-CD44, including all variant isoforms, was detected in 58.0% (14.1-79.2%) specimens, while CD44-v6 (variant isoform 6 of CD44) was expressed in 54.8% (12-79.2%). In pooled analysis, CD44 expression was significantly associated with larger tumor size (T category, RR (relative risk) = 1.21, 95% CI: 1.01-1.46), lymph nodes metastasis (N category, RR = 1.94, 95% CI: 1.38-2.73) and poor prognosis [3-year overall survival (OS): RR = 0.70, 95% CI: 0.53-0.91; 5-year OS: RR = 0.66, 95% CI: 0.66-0.94]. In the stratified analysis of CD44 isoforms, high expression of CD44-v6 was related with a poor 5-year OS rate (RR = 0.53, 95% CI: 0.37-077). We propose that CD44 expression is associated with tumor size, lymph node metastasis, and poor prognosis in pharyngolaryngeal cancer patients.

BACKGROUND/AIMS: We investigated the correlation between vascular endothelial growth factor (VEGF) and CD44 expression in hepatocellular carcinoma (HCC) and the frequency of extrahepatic metastasis, in order to evaluate the influence of vascular growth and adhesion molecules in facilitation of distant metastasis. METHODOLOGY: We obtained materials from primary lesions of HCC with no extrahepatic metastasis (control group) and primary lesions and metastatic lesions with extrahepatic metastasis (metastasis group). Immunohistochemical staining was performed using anti-human CD44v3 monoclonal antibodies and anti-human VEGF ab-3 monoclonal antibodies. Although pathological parameters such as tumor size, differentiation, capsule formation, and vascular invasion were analyzed, there was no marked difference among the groups. RESULTS: Percentages of nodules with VEGF-positive tumor and sinusoidal cells were low in primary lesions of the control and metastasis groups, while high in metastatic lesions in the metastasis group. On the other hand, percentages of nodules with CD44-positive tumor and sinusoidal cells were low in primary lesions of the control group, while high in primary lesions and metastatic lesions of the metastasis group. CONCLUSIONS: The present study demonstrated that CD44 expression in primary lesions is related to a higher frequency of extrahepatic metastasis, suggesting that this is a clinicopathologically useful parameter in predicting the occurrence of distant metastasis.

OBJECTIVE: To explore the relationship of CD44 expression or glycosylation and hepatocellular carcinoma (HCC) metastasis. METHODS: IHC, Quantum dots detection, RT-PCR, Western blot, Cellular immune fluorescence and MS-PCR were used to identify CD44 expression in HCC samples and a series of human HCC cell lines with different metastatic potentials. Lectin array was used to reveal the relationship of CD44v6 glycosylation and human HCC metastasis. RESULTS: Immunohistochemistry analysis showed that CD44v6 was mainly distributed on the cell membrane, while CD44S immunoreactivity was prominently in the cytoplasm, CD44v3 and CD44v4/5 were in cytoplasm on membrane. Among CD44S and those CD44 variants, only the expression of CD44v6 was higher in metastasis HCC samples as compared to that in non-metastasis group (x(2)=8.828, P less than 0.05). This result was also re-confirmed by the result of Quantum dots (t = 2.392, P < 0.05) and serum detection (t = 2.56, P < 0.05). We found completely methylation of CD44v6 gene in Hep3B and incomplete methylation in MHCC97H and MHCC97L cell lines with metastatic potentials. The lectin affinity assay indicated that lectin MAL, SNA and WGA showed more affinity to MHCC97H and MHCC97Lcell lines than that of the non-metastatic Hep3B cell lines. CONCLUSIONS: CD44v6 over-expression presents a positive correlation with HCC metastatic potential, which may be associated with DNA methylation level in promoter sequence. The increasing sialic acid modified glycan of CD44v6 might be related to HCC metastatic ability.

INTRODUCTION: Factors that emerge as crucial participants in tumour invasion and metastases are matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinase (TIMP) inhibitors and cellular adhesion molecules (CD44 and similar molecules). They play important roles in tumour invasion and metastasis in non-small-cell lung carcinomas (NSCLCs). MATERIALS AND METHODS: The study was performed using the data of 33 patients. MMP-2 from the metalloproteinase family, TIMP-2 from the metalloproteinase inhibitor family and the adhesion molecule CD44v6 expression were investigated immunohistochemically to search their role in the metastasis and the clinical outcome of the patients with NSCLCs. RESULTS: Twenty-three tumours (70%) were squamous cell carcinoma (SCC), 9 (27%) were adenocarcinoma (AC), and 1 (3%) was large cell carcinoma (LCC). MMP-2 and TIMP-2 were expressed in high rates in NSCLC but CD44v6 expression was about 50%. Lymphatic invasion was less frequent in TIMP-2- positive patients and this difference was statistically significant (P = 0.005). There was a statistically significant difference between SCCs and ACs with respect to CD44v6 tumoral expression (P = 0.004). Also, there was a negative correlation between lymphatic invasion and the extent of CD44v6; lymphatic invasion was significantly less in CD44v6-positive cases (P = 0.013). CONCLUSION: We found that TIMP-2 and CD44v6 can decrease the lymphatic invasion in NSCLCs. Also there was observed histiotype-related pattern of CD44v6 variant expression in SCCs.

In cancer metastasis, various environmental stressors attack the disseminating cells. The successful colonization of cancer cells in secondary sites therefore requires the ability of the cells to avoid the consequences of such exposure to the stressors. Here we show that orthotopic transplantation of a CD44 variant isoform-expressing (CD44v(+)) subpopulation of 4T1 breast cancer cells, but not that of a CD44v(-) subpopulation, in mice results in efficient lung metastasis accompanied by expansion of stem-like cancer cells. Such metastasis is dependent on the activity of the cystine transporter xCT, and the stability of this protein is controlled by CD44v. We find that epithelial splicing regulatory protein 1 regulates the expression of CD44v, and knockdown of epithelial splicing regulatory protein 1 in CD44v(+) cells results in an isoform switch from CD44v to CD44 standard (CD44s), leading to reduced cell surface expression of xCT and suppression of lung colonization. The epithelial splicing regulatory protein 1-CD44v-xCT axis is thus a potential therapeutic target for the prevention of metastasis.

cancer metastasis involves multistep adhesive interactions between tumor cells (TCs) and endothelial cells (ECs), but the molecular mechanisms of intercellular communication in the tumor microenvironment remain elusive. Using static and flow coculture systems in conjunction with flow cytometry, we discovered that certain receptors on the ECs are upregulated on melanoma cell adhesion. Direct contact but not separate coculture between human umbilical endothelial cells (HUVECs) and a human melanoma cell line (Lu1205) increased intercellular adhesion molecule 1 (ICAM-1) and E-selectin expression on HUVECs by 3- and 1.5-fold, respectively, compared with HUVECs alone. The nonmetastatic cell line WM35 failed to promote ICAM-1 expression changes in HUVECs on contact. Enzyme-linked immunosorbent assay (ELISA) revealed that EC-TC contact has a synergistic effect on the expression of the cytokines interleukin (IL)-8, IL-6, and growth-related oncogene alpha (Gro-alpha). By using E-selectin cross-linking and beads coated with CD44 immunopurified from Lu1205 cells, we showed that CD44/selectin ligation was responsible for the ICAM-1 up-regulation on HUVECs. Protein kinase Calpha (PKC-alpha) activation was found to be the downstream target of the CD44/selectin-initiated signaling, as ICAM-1 elevation was inhibited by siRNA targeting PKCalpha or a dominant negative form of PKCalpha (PKCalpha DN). Western blot analysis and electrophoretic mobility shift assays (EMSAs) showed that TC-EC contact mediated p38 phosphorylation and binding of the transcription factor SP-1 to its regulation site. In conclusion, CD44/selectin binding signals ICAM-1 up-regulation on the EC surface through a PKCalpha-p38-SP-1 pathway, which further enhances melanoma cell adhesion to ECs during metastasis.

CD44 is a cell adhesion molecule that was traditionally known as 'homing receptor'. This molecule is known to interact with the ezrin family (ERM family) members and form a complex that plays diverse roles within both normal and abnormal cells, particularly cancer cells. CD44 and ezrin and their respective complex have properties suggesting that they may be important in the process of tumour-endothelium interactions, cell migrations, cell adhesion, tumour progression and metastasis. This article reviews the role of CD44, ezrin family and the CD44/ezrin complex in cancer cells and their clinical impact in patients with cancer.

Despite great strides in our knowledge of the genetic and epigenetic changes underlying malignancy, we have limited information on the molecular basis of metastasis. Over 90% of cancer deaths are caused by spread of tumor cells from a primary site to distant organs and tissues, highlighting the pressing need to define the molecular effectors of cancer metastasis. Mounting evidence suggests that circulating tumor cells (CTCs) home to specific tissues by hijacking the normal leukocyte trafficking mechanisms. cancer cells characteristically express CD44, and there is increasing evidence that hematopoietic cell E-/L-selectin ligand (HCELL), a sialofucosylated glycoform of CD44, serves as the major selectin ligand on cancer cells, allowing interaction of tumor cells with endothelium, leukocytes, and platelets. Here, we review the structural biology of CD44 and of HCELL, and present current data on the function of these molecules in mediating organ-specific homing/metastasis of CTCs.

In cancer metastasis, various environmental stressors attack the disseminating cells. The successful colonization of cancer cells in secondary sites therefore requires the ability of the cells to avoid the consequences of such exposure to the stressors. Here we show that orthotopic transplantation of a CD44 variant isoform-expressing (CD44v(+)) subpopulation of 4T1 breast cancer cells, but not that of a CD44v(-) subpopulation, in mice results in efficient lung metastasis accompanied by expansion of stem-like cancer cells. Such metastasis is dependent on the activity of the cystine transporter xCT, and the stability of this protein is controlled by CD44v. We find that epithelial splicing regulatory protein 1 regulates the expression of CD44v, and knockdown of epithelial splicing regulatory protein 1 in CD44v(+) cells results in an isoform switch from CD44v to CD44 standard (CD44s), leading to reduced cell surface expression of xCT and suppression of lung colonization. The epithelial splicing regulatory protein 1-CD44v-xCT axis is thus a potential therapeutic target for the prevention of metastasis.

Increasing evidence indicates that several types of solid tumor are hierarchically organized and sustained by a distinct population of cancer stem cells (CSCs). CSCs possess enhanced mechanisms of protection from stress induced by reactive oxygen species (ROS) that render them resistant to chemo- and radiotherapy. expression of CD44, especially variant isoforms (CD44v) of this major CSC marker, contributes to ROS defense through upregulation of the synthesis of reduced glutathione (GSH), the primary intracellular antioxidant. CD44v interacts with and stabilizes xCT, a subunit of the cystine-glutamate transporter xc(-), and thereby promotes cystine uptake for GSH synthesis. Given that cancer cells are often exposed to high levels of ROS during tumor progression, the ability to avoid the consequences of such exposure is required for cancer cell survival and propagation in vivo. CSCs, in which defense against ROS is enhanced by CD44v are thus thought to drive tumor growth, chemoresistance and metastasis. Therapy targeted to the CD44v-xCT system may therefore impair the ROS defense ability of CSCs and thereby sensitize them to currently available treatments.

INTRODUCTION: Factors that emerge as crucial participants in tumour invasion and metastases are matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinase (TIMP) inhibitors and cellular adhesion molecules (CD44 and similar molecules). They play important roles in tumour invasion and metastasis in non-small-cell lung carcinomas (NSCLCs). MATERIALS AND METHODS: The study was performed using the data of 33 patients. MMP-2 from the metalloproteinase family, TIMP-2 from the metalloproteinase inhibitor family and the adhesion molecule CD44v6 expression were investigated immunohistochemically to search their role in the metastasis and the clinical outcome of the patients with NSCLCs. RESULTS: Twenty-three tumours (70%) were squamous cell carcinoma (SCC), 9 (27%) were adenocarcinoma (AC), and 1 (3%) was large cell carcinoma (LCC). MMP-2 and TIMP-2 were expressed in high rates in NSCLC but CD44v6 expression was about 50%. Lymphatic invasion was less frequent in TIMP-2- positive patients and this difference was statistically significant (P = 0.005). There was a statistically significant difference between SCCs and ACs with respect to CD44v6 tumoral expression (P = 0.004). Also, there was a negative correlation between lymphatic invasion and the extent of CD44v6; lymphatic invasion was significantly less in CD44v6-positive cases (P = 0.013). CONCLUSION: We found that TIMP-2 and CD44v6 can decrease the lymphatic invasion in NSCLCs. Also there was observed histiotype-related pattern of CD44v6 variant expression in SCCs.

BACKGROUND & OBJECTIVE: E-cadherin (E-cad), CD44v6 and proliferating cell nuclear antigen (PCNA) play important roles in invasion and metastasis of cancers. This study was to investigate the correlations of the expression of E-cad, CD44v6, and PCNA to the invasion, metastasis, and prognosis of non-small cell lung cancer (NSCLC). METHODS: The expression of E-cad, CD44v6 and PCNA in 86 specimens of NSCLC and 40 specimens of adjacent normal tissues were detected by EnVision immunohistochemistry. RESULTS: The high expression rate of E-cad was significantly lower in NSCLC than in adjacent normal tissues (53.5% vs. 80.0%, P<0.05). E-cad staining in NSCLC tissues was correlated to differentiation, lymph node metastasis and TNM stage (P<0.05). The high expression rate of CD44v6 was 44.2% in NSCLC, and 0 in adjacent normal tissues. CD44v6 staining in NSCLC tissues was correlated to classification, lymph node metastasis and TNM stage (P<0.05). The high expression rate of PCNA was 48.8% in NSCLC, and 0 in adjacent normal tissues. PCNA staining was correlated to lymph node metastasis (P<0.05). PCNA expression was negatively correlated to E-cad expression (r=-0.554, P<0.05), and positively correlated to CD44v6 expression (r=0.688, P<0.05). Univariate analysis indicated that E-cad, CD44v6, and PCNA were prognostic factors of NSCLC. Multivariate analysis showed that E-cad and TNM stage were independent prognostic indicators (P<0.05). CONCLUSIONS: E-cad, CD44v6 and PCNA play important roles in invasion and metastasis of NSCLC. The expression of E-cad, CD44v6 and PCNA may be of prognostic value in patients with NSCLC.

CD44 is an integral membrane glycoprotein that functions as a receptor for the extracellular matrix glycan, hyaluronan. It exists as standard (CD44s) and variant (CD44v) isoforms which have been shown to be associated with metastasis in a range of tumors. Both CD44s and CD44v are found in normal respiratory epithelium and in non small cell lung cancers (NSCLCs). However, there isn't much information regarding their role in the metastatic process of NSCLCs. We examined the expression of CD44s in 30 NSCLCs using immunohistochemical techniques. Ten were non-metastatic (N0, M0), 5 were metastases to lymph nodes (N1, M0) and 15 were excised brain metastases. We found CD44s positivity in all non-metastatic tumors with varying degrees of expression, whereas 10 out of 15 metastatic tumors in brain and 3 out of 5 lymph node metastases were negative for CD44s. There was a statistically significant inverse relation between the CD44s expression and metastatic potential (P < 0.05). Our results support the hypothesis that diminished or lack of CD44s is the functional equivalent of CD44v which may be an accompaniment of enhanced metastatic potential. The value of CD44 in predicting metastatic behavior of NSCLCs remains to be established in a larger series.

OBJECTIVE: To explore the relationship between expressions of cell adhesion molecules CD44 v6 and E-cadherin (E-cad) and lymphatic metastasis in non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Eighty- seven tissue samples obtained from patients with primary NSCLC were collected in our hospital from Dec., 2007 to Dec., 2012, and the expressions of CD44 v6 and E-cad gene proteins in these samples were detected by immunohistochemical method. RESULTS: In the tissue without lymphatic metastasis, the positive expression rate of CD44 v6 was significantly lower, whereas the normal expression rate of E-cad was notably higher than that with lymphatic metastasis (55.6% vs. 78.4%, 47.2% vs. 21.6%), and both differences had statistical significance (P<0.05). Besides, CD44 v6 and E-cad expressions had a significant correlation in the NSCLC tissue with lymphatic metastasis (P<0.05). CONCLUSIONS: The positive expression of CD44 v6 and abnormal expression of E-cad may play a very important role in promoting lymphatic metastasis of NSCLC, with synergistic effect. Hence, detection of CD44 v6 and E-cad expressions is conductive to judging the lymphatic metastasis in NSCLC.

The aim of this article was to evaluate the expression of E-cadherin and CD44 adhesion molecule in oral tongue squamous cell carcinoma (SCC) since inappropriate expression of adhesion molecules raises the metastatic ability of the tumor cells. Biopsy specimens from 92 patients with tongue SCC were examined for the expression of E-cadherin and CD44 by immunohistochemistry. The relationship of immunoreactivity with tumor stage and cervical lymph node metastasis was then analyzed. Sixty-one patients (66.3%) had reduced or negative staining for CD44. Weak or absent staining for E-cadherin was seen in 14 patients (15.21%). Cervical lymph node metastasis is associated with decreased or negative staining for CD44, but no association was found between E-cadherin immunoreactivity and nodal metastasis. Our study reveals that reduced expression of CD44 could be an indicator of high invasiveness of tumor by increasing cervical lymph node metastasis.

PURPOSE: To determine the prognostic value of the expression of Ezrin, CD44 and Six1 genes in osteosarcoma tissues of Chinese patients. METHODS: Fluorescent quantitative real-time PCR was applied to study the mRNA levels of Ezrin, CD44 and Six1 genes in 32 osteosarcoma patient samples and 10 adjacent normal tissues and MG63 osteosarcoma cell lines. The analysis of relationships between pulmonary metastasis and overall survival time were carried out based on the clinical data. RESULTS: mRNA levels of Ezrin and Six1 genes in osteosarcoma tissues were higher than those in adjacent normal tissues (P=0.015, 0.025). The mRNA levels of Ezrin, CD44 and Six1 genes were closely correlated with Enneking GTM clinical staging, while no correlations were demonstrated between the mRNA level of these genes with sex, age, location or pathological types. In addition, we demonstrated that the high mRNA level of Ezrin gene was related to shorter lung metastasis-free and overall survival time of the Chinese patients with osteosarcoma (P < 0.001). CONCLUSION: Our data suggest that Ezrin, but not CD44 and Six1, could be a prognostic factor and a predictor of potential lung metastasis in osteosarcoma. Further large sample studies need to be done to confirm the potential value of Ezrin as a new therapeutic target.

Osteosarcoma (OS) is the most frequent primary malignant bone cancer in children and adolescents with a high propensity for lung metastasis. Therefore, it is of great importance to identify molecular markers leading to increased metastatic potential in order to devise more effective therapeutic strategies that suppress metastasis, the major cause of death in OS. CD44, the principal receptor for the extracellular matrix component hyaluronan (HA), is frequently found overexpressed in tumor cells and has been implicated in metastatic spread in various cancer types. Here, we investigated the effects of stable shRNA-mediated silencing of CD44 gene products on in vitro and in vivo metastatic properties of the highly metastatic human 143-B OS cell line. In vitro, CD44 knockdown resulted in a 73% decrease in the adhesion to HA, a 57% decrease in the migration rate in a trans-filter migration assay, and a 28% decrease in the cells' capacity for anchorage-independent growth in soft agar compared to the control cells, implicating that CD44 expression contributes to the metastatic activity of 143-B cells. However, making use of an orthotopic xenograft OS mouse model, we demonstrated that reduced CD44 expression facilitated primary tumor growth and formation of pulmonary metastases. The enhanced malignant phenotype was associated with decreased adhesion to HA and reduced expression of the tumor suppressor merlin in vivo. In conclusion, our study identified CD44 as a metastasis suppressor in this particular experimental OS model.

BACKGROUND: Many previous studies demonstrated that cell adhesion molecules CD44v6 and integrin-beta1 had been extensively investigated as potential prognostic markers of various cancers. However, data in PC are scarce. METHODS: We now investigate CD44v6 and integrin-beta1 mRNA expression in PBMC by a triplex real-time RT-PCR assay and protein expression in plasma by ELISA. All specimens were collected from 54 PC patients who received the treatment of cryosurgery as well as 20 healthy individuals (control). RESULTS: The mRNA and protein expression levels of CD44v6 and integrin-beta1 in patients were significantly increased compared with control group (P<0.05). The high CD44v6 mRNA and protein expression were significantly correlated with clinical stage, tumor differentiation, LNM, liver metastasis and decreased median DFS (P<0.05), while the high integrin-beta1 mRNA and protein expression were significantly correlated with clinical stage, LNM, liver metastasis and decreased median DFS (P<0.05). Clinical stage, LNM, liver metastasis, CD44v6 mRNA and protein expression were the independent predictors of survival in PC patients (P<0.05). Moreover, CD44v6 and integrin-beta1 mRNA and protein expression levels were significantly decreased in patients in 3 months after cryosurgery (P<0.05). No significant difference was found in CD44v6 mRNA and protein expression between patients in 3 months after cryosurgery and control group (P>0.05). CONCLUSION: CD44v6 and integrin-beta1 mRNA and protein expression in blood may serve as biomarkers for the development and metastasis of PC, and as prognostic indicators for PC. They may become useful predictors in assessing outcome of PC patients after cryosurgery. VIRTUAL SLIDES: The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4035308681009006.

BACKGROUND & AIMS: CD44s is a surface marker of tumor-initiating cells (TICs); high tumor levels correlate with metastasis and recurrence, as well as poor outcomes for patients. Monoclonal antibodies against CD44s might eliminate TICs with minimal toxicity. This strategy is unclear for treatment of pancreatic cancer, and little is known about how anti-CD44s affect pancreatic cancer initiation or recurrence after radiotherapy. METHODS: One hundred ninety-two pairs of human pancreatic adenocarcinoma and adjacent nontumor pancreatic tissues were collected from patients undergoing surgery. We measured CD44s levels in tissue samples and pancreatic cancer cell lines by immunohistochemistry, real-time polymerase chain reaction, and immunoblot; levels were correlated with patient survival times. We studied the effects of anti-CD44s in mice with human pancreatic tumor xenografts and used flow cytometry to determine the effects on TICs. Changes in CD44s signaling were examined by real-time polymerase chain reaction, immunoblot, reporter assay, and in vitro tumorsphere formation assays. RESULTS: Levels of CD44s were significantly higher in pancreatic cancer than adjacent nontumor tissues. Patients whose tumors expressed high levels of CD44s had a median survival of 10 months compared with >43 months for those with low levels. Anti-CD44s reduced growth, metastasis, and postradiation recurrence of pancreatic xenograft tumors in mice. The antibody reduced the number of TICs in cultured pancreatic cancer cells and xenograft tumors, as well as their tumorigenicity. In cultured pancreatic cancer cell lines, anti-CD44s down-regulated the stem cell self-renewal genes Nanog, Sox-2, and Rex-1 and inhibited signal transducer and activator of transcription 3-mediated cell proliferation and survival signaling. CONCLUSIONS: The TIC marker CD44s is up-regulated in human pancreatic tumors and associated with patient survival time. CD44s is required for initiation, growth, metastasis, and postradiation recurrence of xenograft tumors in mice. Anti-CD44s eliminated bulk tumor cells as well as TICs from the tumors. Strategies to target CD44s cab be developed to block pancreatic tumor formation and post-radiotherapy recurrence in patients.

BACKGROUND AND PURPOSE: CD44 variants have been associated with tumor invasion and metastasis, but CD44 expression patterns have not been systematically investigated in pancreatic carcinoma. This study systematically investigated whether CD44 expression patterns are involved in pancreatic carcinoma metastasis and prognosis. METHODS: We applied primers specific for all CD44 variants and CD44s to analyze the expression patterns of CD44 (CD44v2-CD44v10 and CD44s) using quantitative real-time PCR (qRT-PCR). We then further evaluated their roles in pancreatic carcinoma metastasis and prognosis using clinical survival analysis. RESULTS: Increased CD44v expression and decreased CD44s expression were found in metastatic pancreatic carcinoma in three different cell lines and in human tumor tissue. Clinical analysis showed that CD44v6+ and CD44v9+ were correlated with lymph node metastasis, liver metastasis and TNM stage. However, CD44s- was associated with liver metastasis, tumor differentiation and TNM stage. Survival analysis showed that patients with CD44v6+/CD44s- or CD44v6+/CD44s- had lower overall survival (OS) rates, although the individual expression of CD44v6, CD44v9 and CD44s was also related to decreased OS rates. Univariate analysis showed that lymph node metastasis; vessel invasion; hepatic metastases; TNM stage; and individual or co-expression of CD44v6, CD44v9 and CD44s were risk factors affecting survival. Multivariate analysis showed that CD44v6+/CD44s- was an independent predictor of survival. CONCLUSIONS: We found that CD44v6+, CD44v9+ and CD44s- were associated with pancreatic carcinoma metastasis and progression and that CD44v6+/CD44s- was an independent risk factor affecting survival in pancreatic carcinoma. Therefore, the different expression patterns of CD44v/CD44s may determine pancreatic carcinoma prognosis. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1579257224116287.

The metastasis-related molecules CD133, CD44v6 and human tissue factor (TF) have been shown to be associated with tumor invasion and metastasis. This study aimed to determine whether co-expression of these three molecules was associated with metastasis and overall prognosis in pancreatic carcinoma. We analyzed the expression profiles of these three molecules by immunohistochemistry and evaluated the relationship of their expression profiles with metastasis and prognosis in 109 pancreatic carcinomas. The results showed that the expression levels of CD133, CD44v6 and TF were increased in pancreatic carcinoma. Co-expression of CD133, CD44v6 and TF (tri-expression) was also detected in pancreatic carcinoma. Clinical analysis showed that individual expression of CD133, CD44v6 or TF was associated with vessel invasion, lymph node metastasis and liver metastasis, while tri-expression was associated with lymph node metastasis. Survival analysis showed that patients with co-expression of CD133 and TF or tri-expression had lower and the lowest overall survival rates, respectively. Univariate analysis showed that T-factor, lymph node metastasis, TNM stage, and individual levels or tri-expression of CD133, CD44v6 and TF were survival risk factors. Multivariate analysis showed that tri-expression of CD133, CD44v6 and TF was an independent predictor of survival. These results suggest that overexpression of CD133, CD44v6 and TF is associated with pancreatic carcinoma metastasis. Tri-expression of these three molecules may be a useful predictor for pancreatic carcinoma prognosis.

Prostate cancers account for 43% of all cancers diagnosed in American men. It is estimated that in 1996, 317,000 new cases of prostate cancer were diagnosed and 41,000 men died of the disease. The challenge of treating prostate cancer lies in accurately distinguishing those histologically-localized cancers which will complete metastatic progression from those that will remain indolent. At this time, we lack appropriate histological markers to make such distinctions, therefore, it is often difficult to accurately predict the clinical course of an individual patient's disease. There is growing evidence that a critical event in the progression of a tumor cell from a non-metastatic to metastatic phenotype is the loss of function of metastasis-suppressor genes. These genes specifically suppress the ability of a cell to metastasize. Work from several groups has demonstrated that human chromosomes 8, 10, 11 and 17 encode prostate cancer metastasis suppressor activities. As a result of these efforts the first prostate cancer metastasis-suppressor gene, KAI1, was identified and mapped to the p11-2 region of chromosome 11. In subsequent studies, an additional gene encoded by the same region, CD44 was also determined to have metastasis-suppressor activity. Recent studies have shown a correlation between decreased expression of KAI1 and CD44 and an increased malignant potential of prostate cancers. It is anticipated that the identification of other metastasis suppressor genes may allow for the development of diagnostic markers useful in the clinical substaging of individual tumors. This manuscript is intended to present our perspective on the importance of these genes in the understanding of prostate cancer progression. More importantly, we present new findings from our laboratory's effort to identify the metastasis-suppressor genes encoded by human chromosome 17. Specifically we report the strategy currently being used to evaluate a series of candidate genes and the approach being utilized to pinpoint the metastasis-suppressor region on human chromosome 17.

Previous studies demonstrated that CD44 is a metastasis suppressor gene for prostate cancer and that the expression of CD44 both at mRNA and protein levels is down-regulated during prostate cancer progression, with down-regulation being correlated with higher tumor grade, aneuploidy, and distant metastasis. In this study, we evaluated DNA hypermethylation as a potential mechanism accompanying this decreased CD44 expression in human prostate cancer. Nucleotide sequence analysis revealed a CpG island in the CD44 transcriptional regulatory region. We found that cytosine methylation of CD44 promoter occurs in CD44-negative prostate cancer cell line (i.e., LNCaP) but not in prostate cancer cell lines (i.e., TSU, PC3, and DU145) expressing this gene. In addition, we examined methylation status of CD44 in 84 matched normal and cancer prostate specimens. Hypermethylation of the 5' CpG island of CD44 gene was observed in 31 of 40 primary prostate cancer specimens, 3 of 4 distant organ site metastases obtained at autopsy from men who died of prostate cancer, and 4 of the 40 matched normal tissues. These results demonstrated that methylation of the 5' CpG island of CD44 gene is closely associated with transcriptional inactivation, resulting in a decreased expression of CD44 in human prostate cancer.

BACKGROUND: Late nodal metastases is a critical factor that worsens the prognosis of T1/T2N0 tongue cancer treated by interstitial brachytherapy. If we could better predict the patients at high risk for late nodal metastases developing before treatment, more appropriate choices of treatment could be selected. In recent studies of colon cancer, prostate cancer, and laryngeal cancer, CD44H has been postulated to be a metastasis suppressor. METHODS: On the basis of this phenomenon, we immunohistochemically evaluated the expression of CD44H in 38 cases of primary T1/T2N0 tongue cancer treated by interstitial brachytherapy. Formalin-fixed, paraffin-embedded biopsy specimens obtained before treatment were examined. RESULTS: The group that had late nodal metastases revealed a significantly lower (p =.0035) CD44H expression. CONCLUSIONS: A decreased CD44H expression may therefore be useful as a new predictor of late nodal metastases in patients with T1/T2N0 tongue carcinoma. For patients with a decreased CD44H expression, a partial glossectomy and an elective neck dissection may therefore be an appropriate treatment modality.

BACKGROUND: CD44 is a metastasis suppressor gene for prostate cancer and the down-regulation of CD44 and its variants is associated with the progression of prostate cancer. Also, hypermethylation of the CpG islands of the CD44 gene is closely associated with transcriptional inactivation, resulting in the decreased expression of CD44. To clarify the exact role of methylation status of CpG islands of CD44 gene in the progression and metastasis of prostate cancer, we investigated the methylation status of this gene in primary and metastatic human prostate tumors obtained from surgery or autopsy. METHODS: We examined 97 samples from 40 Japanese patients with adenocarcinoma of the prostate. tumor tissues were obtained from radical prostatectomy specimens from eight patients with stage B, 12 patients with stage C and three patients with stage D1 and at autopsy from 17 hormone-refractory metastatic cases, who had initially responded to the therapy and thereafter relapsed. Distant metastatic tissues were also obtained at autopsy (i.e., liver, lung, kidney, mammary gland, and pelvic lymph nodes) from 10 of 17 hormone-refractory cases. We analyzed the hypermethylation status of CD44 promotor region by PCR using genomic DNAs digested with the m(5)C-sensitive restriction enzyme HpaII. RESULTS: The correlation between the methylation status of CD44 gene and the stage progression of prostate cancer was statistically significant (P = 0.0438). In two of 10 hormone-refractory cases, a comparison of the methylation status of the CD44 gene in metastases to that in primary tumors revealed interfocal heterogeneity of CD44 methylation status. CONCLUSIONS: These results indicate an important role of CD44 methylation in the progression and metastasis of prostate cancer, although the amount of methylational heterogeneity is substantial among metastatic sites within the same patient.

BACKGROUND AND PURPOSE: CD44 is an important metastasis-suppressor gene in prostate cancer. Downregulation of the CD44 gene is attributed to transcription repression by methylation of CpG islands in the promoter region. The feasibility of CD44 promoter methylation measurement as a diagnostic tool was assessed in the serum of patients with cancer of the prostate (CAP). MATERIALS AND METHODS: Seven serum samples of patients with CAP were investigated for CD44 promoter methylation by methylation-specific PCR. Three patients had proven metastatic disease, and four were free of metastases. Tissues from a variety of normal epithelia were assessed as well. RESULTS: Methylation of the CD44 promoter was readily detectable in all serum samples, although no distinction could be made between patients with and those without metastatic disease on the basis of the signal intensity of methylation-specific PCR products. Remarkably, tissue specimens from different normal epithelia, especially those of the colon and rectum, repeatedly showed aberrant methylation of the promoter region of CD44. CONCLUSIONS: In the serum of CAP patients, assessment of the methylation status of CpG islands in the promoter region of the CD44 gene is feasible using methylation-specific PCR. However, because of physiologic promoter methylation in normal tissues, including the colorectal mucosa, assessment of methylation of tumor-derived DNA in the serum of cancer patients lacks tissue specificity and seems not to be applicable in clinical settings.

PURPOSE: The prevention and treatment of prostate cancer metastasis continue to provide a significant clinical challenge. Identification of the rate limiting steps of metastasis and their underlying molecular mechanisms may lead to new therapeutic targets and also allow more accurate risk stratification for clinical metastases. We review the literature supporting growth of disseminated tumor cells at the secondary site as a key rate limiting step in metastasis. We also reviewed the definition, identification and characterization of metastasis suppressor genes, and discuss their evolving role in regulating this step. MATERIALS AND METHODS: We performed MEDLINE searches and manual bibliographic reviews on the specific steps of metastasis, including growth at the secondary site. In addition, we performed a comprehensive literature review to identify genes fitting the classic definition of a metastasis suppressor gene. The literature was also searched to assess the status of each gene in clinical cancer and evaluate functional support for the potential involvement of each gene in regulating growth at the secondary site. RESULTS: Clinical studies in prostate cancer and other cancer types suggest that dissemination to the secondary site is often an early clinical event. However, not all patients with tumor cells at the secondary site have overt metastatic lesions even in the absence of therapy, suggesting that growth at the secondary site may be highly inefficient. Complimentary approaches have allowed researchers to document and quantify the inefficiency of cancer cell growth at the secondary site. Regarding the mechanism of growth control, many studies support a role for the interaction of a cancer cell and the microenvironment at the secondary site influencing whether growth into metastasis may occur. The 7 genes that suppress metastasis without affecting primary tumor growth that have been identified are KAI1, CD44, mitogen activated protein kinase (MAPK) kinase 4, nm23-H1, nm23-H2, KiSS1 and BrMS1. Three of these genes (KAI1, CD44 and MAPK kinase 4) act as metastasis suppressor genes of prostate cancer, while the remainder have yet to be tested in this cancer type. Loss of expression has been demonstrated for most of these genes during the clinical progression of prostate cancer to metastasis. MAPK kinase 4 and KiSS1 appear to suppress metastasis by inhibiting cancer cell growth at the secondary site. Interestingly many metastasis suppressor genes have common roles in growth control, adhesion and cytoskeletal reorganization, suggesting a common mechanism of metastasis suppression. Proposed candidate pathways include signaling through Src kinase and Rac GTPase. CONCLUSIONS: The findings discussed support growth at the secondary site as a clinical target for metastasis treatment and prevention. metastasis suppressor genes may offer valuable mechanistic insight for guiding specific therapeutic strategies, which may include drug induced reactivation of metastasis suppressor genes and their signaling pathways. Clinical assessment of metastasis suppressor gene product status in disseminated cancer cells may improve the accuracy of predicting the prognosis in patients with clinically localized disease.

The standard form of cell adhesion glycoprotein CD44 is a metastasis suppressor in prostate cancer. However, we previously showed by RT-PCR and Western blotting that cancer overexpresses unique CD44 variant v7-v10 isoforms. Muc18 is another cell adhesion marker reportedly overexpressed by prostate cancer. Matched frozen section-confirmed tumor and benign tissues were harvested from 10 prostatectomy specimens and tumor was microdissected from two lymph node metastases. Tissues were homogenized for RNA preparations, and RT-PCR was performed for the CD44v7-v10 sequence. In cultured prostate cancer cells, we caused RNA interference against CD44v9 and/or Muc18. We used PC3M cells and a derivative cell line called G(s)alpha, that constitutively expresses this G-protein and is more invasive. Lipofection was performed for a green fluorescent protein plasmid and for two 22-mer DNA fragments, cloned into a plasmid expression vector to generate hairpin, interfering dsRNA. Assays for invasion into Matrigel, a basement membrane matrix, were performed in 4-5 experiments. RT-PCR demonstrated expression of a 608 bp band representing CD44v7-v10 or a 638 bp band of CD44v6-v10 in prostate cancer tissues and metastases but not benign tissue. Cultured G(s)alpha cells overexpressed CD44v9 by comparison with PC3M cells. At 90 h after 6-hour lipofection, protein silencing was evident by Western blots. Silencing the CD44v9 expression reduced invasiveness into Matrigel to 21.6+/-7.0% in PC3M cells (P<0.001) and 31.2+/-18.3% in G(s)alpha cells (P=0.001), compared to cells exposed to transfection vehicle alone. Silencing Muc18 expression reduced invasiveness to 76.9+/-13.5% of the control value in PC3M cells (P<0.05) and 84.8+/-29.9% in G(s)alpha cells (P=0.18). Prostate cancer invasion is facilitated more by its overexpression of CD44 variant 9 than by Muc18. Its relative overexpression by G(s)alpha cells is a novel finding, suggesting a link between signal transduction and cell adhesion marker expression.

CD44 and CD147 are associated with cancer metastasis and progression. Our purpose in the study was to investigate the effects of down-regulation of CD44 or CD147 on the metastatic ability of prostate cancer (CaP) cells, their docetaxel (DTX) responsiveness and potential mechanisms involved in vitro and in vivo. CD44 and CD147 were knocked down (KD) in PC-3M-luc CaP cells using short hairpin RNA (shRNA). expression of CD44, CD147, MRP2 (multi-drug resistance protein-2) and MCT4 (monocarboxylate tranporter-4) was evaluated using immunofluorescence and Western blotting. The DTX dose-response and proliferation was measured by MTT and colony assays, respectively. The invasive potential was assessed using a matrigel chamber assay. Signal transduction proteins in PI3K/Akt and MAPK/Erk pathways were assessed by Western blotting. An in vivo subcutaneous (s.c.) xenograft model was established to assess CaP tumorigenecity, lymph node metastases and DTX response. Our results indicated that KD of CD44 or CD147 decreased MCT4 and MRP2 expression, reduced CaP proliferation and invasive potential and enhanced DTX sensitivity; and KD of CD44 or CD147 down-regulated p-Akt and p-Erk, the main signal modulators associated with cell growth and survival. In vivo, CD44 or CD147-KD PC-3M-luc xenografts displayed suppressed tumor growth with increased DTX responsiveness compared to control xenografts. Both CD44 and CD147 enhance metastatic capacity and chemoresistance of CaP cells, potentially mediated by activation of the PI3K and MAPK pathways. Selective targeting of CD44/CD147 alone or combined with DTX may limit CaP metastasis and increase chemosensitivity, with promise for future CaP treatment.

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 relationship between expression of cell adhesion molecular CD44, epithelial cadherin (E-cad) and metastatic suppressor gene nm23-H1 as well as the clinicopathologic features including cell differentiation, invasion and metastasis of thyroid follicular-derived carcinoma. METHODS: Forty two (42) thyroid follicular carcinomas (FTC) and 54 papillary carcinomas (PTC) were collected for studying the expression of CD44, E-cad and nm23-H1 using immunohistochemical staining. RESULTS: Neoplastic epithelium and infiltrating lymphocyte expressed CD44 in an intense plasma membrane pattern. CD44 expression rates in poorly differentiated FTC (80%) and PTC cases with metastasis (78%) were significantly higher than those of well-differentiated FTC cases (64%) and PTC without metastasis cases (59%) respectively. Thyroid carcinoma tissue was positive for E-cad and nm23-H1 in a cytoplasm pattern. Well-differentiated FTC presented a higher E-cad and nm23-H1 expression rate than poorly-differentiated FTC, but both had a lower expression rate than that of PTC (70% and 76%, P < 0.01). The expression rate and intensity of E-cad and nm23-H1 were lower and less in metastatic PTC than those in primary PTC. expression rate of CD44 (72%) in thyroid follicular-derived carcinoma was higher than those of E-cad (54%, P < 0.01) and nm23-H1 (61%, P < 0.05). E-cad expression was adversely correlated with that of nm23-H1 (chi(2) = 15.75, P < 0.011, r = 0.522 2). There was a reverse relationship between expression of CD44 and E-cad or nm23 (P > 0.05). CONCLUSIONS: Cell differentiation degree in FTC and metastasis in PTC have positive correlation with the expression of E-cad and nm23, but have a reverse correlation with the expression of CD44. There was a relationship between expression of CD44, E-cad, nm23 and the characteristics of the degree of differentiation, metastatic potential and the prognosis of thyroid follicular-derived carcinoma.

OBJECTIVES: To investigate the ability of matrix metalloproteinase (MMP)-2 and CD44 variant 6 (CD44v6) protein levels to diagnose papillary thyroid cancer (PTC), compared with routine diagnostic methods using tissue sections; to explore the relationship between MMP-2 and CD44v6 protein levels and lymph node metastases (LNM) in PTC. METHODS: Archival PTC specimens from patients with PTC, with or without lateral cervical LNM, were included in this retrospective immunohistochemical study. MMP-2 and CD44v6 protein levels were analysed immunohistochemically using routinely prepared tissue sections. RESULTS: Specimens from 66 patients with PTC were reviewed retrospectively (35 patients with lateral cervical LNM; 31 patients without LNM). The percentages of samples with cells that demonstrated positive protein staining differed significantly between PTC specimens, benign thyroid nodules and adjacent normal follicular epithelium (MMP-2: 86.4%, 60.0%, and 25.7%, respectively; CD44v6: 80.3%, 37.1% and 22.9%, respectively). The level of CD44v6 protein staining was found to be significantly and positively correlated with the level of MMP-2 protein staining in PTC specimens. CONCLUSIONS: Both MMP-2 and CD44v6 might be useful tumour markers for predicting risk of lateral cervical LNM in patients with PTC.

BACKGROUND: Late nodal metastases is a critical factor that worsens the prognosis of T1/T2N0 tongue cancer treated by interstitial brachytherapy. If we could better predict the patients at high risk for late nodal metastases developing before treatment, more appropriate choices of treatment could be selected. In recent studies of colon cancer, prostate cancer, and laryngeal cancer, CD44H has been postulated to be a metastasis suppressor. METHODS: On the basis of this phenomenon, we immunohistochemically evaluated the expression of CD44H in 38 cases of primary T1/T2N0 tongue cancer treated by interstitial brachytherapy. Formalin-fixed, paraffin-embedded biopsy specimens obtained before treatment were examined. RESULTS: The group that had late nodal metastases revealed a significantly lower (p =.0035) CD44H expression. CONCLUSIONS: A decreased CD44H expression may therefore be useful as a new predictor of late nodal metastases in patients with T1/T2N0 tongue carcinoma. For patients with a decreased CD44H expression, a partial glossectomy and an elective neck dissection may therefore be an appropriate treatment modality.