1499

CTNNB1

catenin (cadherin-associated protein), beta 1, 88kDa;CTNNB1;catenin (cadherin-associated protein), beta 1, 88kDa

catenin beta-1

3p21

protein-coding

BACKGROUND: Adrenocortical carcinoma (ACC) liver metastases (LM) represent a therapeutic challenge, and it is unclear whether resection is justified. This study assesses long-term outcome and prognostic factors after liver resection for metastatic ACC. METHODS: Patients who underwent resection of ACC LM were identified from institutional databases. Recurrence, survival, and tumor characteristics, including beta-catenin and TP53 status based on immunohistochemistry and sequencing, were reviewed. The prognostic value of variables was assessed with log-rank test for univariate analysis and Cox proportional hazard models for multivariate analysis. RESULTS: From 1978 to 2009, 28 patients (20 females; median age, 45 years), including 11 with synchronous metastasis and 3 with extrahepatic metastasis, underwent resection for ACC LM (major hepatectomy in 61%). Postoperative mortality was nil and morbidity 55%. On pathological examination, tumors were multiple in 68%, with a median size of 43 mm, and resections were R0, 1, and 2 in 59%, 33%, and 7%, respectively. All 28 patients developed recurrent disease, which was treated surgically in 11, including repeat hepatectomy in 4. Of the 15 patients with adequate tissue for analysis, beta-catenin immunostaining was positive in 7, with 4 corresponding CTNNB1 mutations associated with decreased survival; p53 staining was positive in 5 (4 with corresponding TP53 mutations). The median disease-free and overall survival after hepatectomy was 7 and 31.5 months, respectively, with a 5-year survival of 39%. In multivariate analysis, nonfunctional tumor and surgical treatment of recurrence were independent predictors of good outcome. CONCLUSIONS: In selected patients with ACC LM, resection is associated with long-term survival and is, therefore, justified but rarely curative.

BACKGROUND: The Wnt signaling pathway has been implicated in colon and other cancers. Nevertheless, few or no mutations of CTNNB1 (beta-catenin) have so far been described in brain cancer. We therefore examined the prevalence of constitutive activation of the Wnt signaling pathway in brain cancer specimens as well as cancer cell lines. METHOD: We used polymerase chain reaction PCR and direct sequencing methods to investigate whether mutations in the CTNNB1 phosphorylation sites S33, S37, S41 and T45 were present in 68 brain tumours, including meningioma, astrocytoma, pituitary adenoma, neuroblastoma, metastasis to the brain, and cell lines. FINDINGS: CTNNB1 gene mutations were not found in either the original brain tumour specimens or the cell lines. However, a missense mutation of CTNNB1 was identified at residue 33, TCT (Ser) --> TGT (Cys) in a patient with lung metastasis to brain. In addition, in vitro functional assay showed that the S33C mutant of beta-catenin did affect transcriptional activity in a TCF-4-luciferase reporter construct. CONCLUSIONS: These results indicate that the mutation of exon 3 of the CTNNB1 gene in brain tumours may be a rare event and yet may be required for a small subset of human metastatic brain tumours.

MUC1 is aberrantly expressed in greater than 90% of all breast carcinomas, yet its function as a tumor antigen is not fully understood. Recently, studies have shown that MUC1 interacts with beta-catenin, erbB receptors, src, GSK-3beta and protein kinase Cdelta, possibly in a complex that promotes the disassembly of adherens junctions and the invasion of cells. Here we show that the deletion of Muc1 expression from MMTV-Wnt-1 transgenic mice results in a significant increase in the time to mammary gland tumor onset. Analysis of MMTV-Wnt-1 tumors on a wild-type Muc1 background shows a tumor-specific complex formation between Muc1 and beta-catenin that can be observed in both the membrane and the cytoplasm of transformed epithelium. Analysis of primary human adenocarcinomas revealed that this MUC1/beta-catenin interaction occurs in both primary and metastatic tumors, but is dramatically increased in metastatic lesions. Addition of MUC1-cytoplasmic domain peptides to the invasive MDA-MB-468 and MDA-MB-231 cell lines increases their invasive capability, and these peptides colocalize with both beta-catenin and the focal adhesion protein vinculin, primarily at sites of membrane invasion into a collagen matrix. These data indicate a potential mechanism for MUC1 promotion of invasive tumorigenesis in the breast through the modulation of beta-catenin localization and subsequent cytoskeletal dynamics.

BACKGROUND: Very low density lipoprotein receptor (VLDLR) has been considered as a multiple function receptor due to binding numerous ligands, causing endocytosis and regulating cellular signaling. Our group previously reported that enhanced activity of type II VLDLR (VLDLR II), one subtype of VLDLR, promotes adenocarcinoma SGC7901 cells proliferation and migration. The aim of this study is to explore the expression levels of VLDLR II in human gastric, breast and lung cancer tissues, and to investigate its relationship with clinical characteristics and beta-catenin expression status. METHODS: VLDLR II expression was examined using immunohistochemistry (IHC) and Western blot in tumor tissues from 213 gastric, breast and lung cancer patients, tumor adjacent noncancerous tissues by same methods. Correlations between VLDLR II and clinical features, as well as beta-catenin expression status were evaluated by statistical analysis. RESULTS: The immunohistochemical staining of VLDLR II showed statistical difference between tumor tissues and tumor adjacent noncancerous tissues in gastric, breast and lung cancers (P = 0.034, 0.018 and 0.043, respectively). Moreover, using Western, we found higher VLDLR II expression levels were associated with lymph node and distant metastasis in gastric and breast cancer (P < 0.05). Furthermore, highly significant positive correlations were found between VLDLR II and beta-catenin in gastric cancer (r = 0.689; P < 0.001)breast cancer (r = 0.594; P < 0.001). CONCLUSIONS: According to the results of the current study, high VLDLR II expression is correlated with lymph node and distant metastasis in gastric and breast cancer patients, the data suggest that VLDLR II may be a clinical marker in cancers, and has a potential link with beta-catenin signaling pathway. This is the first to reveal the closer relationship of VLDLR II with clinical information.

BACKGROUND AND PURPOSE: beta-catenin has crucial roles in cell-cell adhesion as well as Wingless (Wnt) signaling pathway, which is closely associated with carcinogenesis. The aim of this study was to evaluate the expression of beta-catenin in invasive ductal breast carcinomas and investigate its associations with known clinicopathological parameters, estrogen receptor (ER), progesterone receptor (PR) and tumor proliferative activity then, to explore betacatenin expressional differences in primary tumors and corresponding axillary lymph node metastasis (ALNM). MATERIAL AND METHODS: Immunohistochemistry using streptavidin biotin immunoperoxidase method was applied on 65 formalin-fixed paraffin-embedded primary invasive ductal breast carcinomas. Among them, 39 primary tumors (showing LN metastasis) and their corresponding ALNM were further evaluated for differential expression of Betacatenin. Cases were diagnosed during the time period between 2005 to 2007 and retrieved from the archival material of the Pathology Department, Minia University Hospital. RESULTS: Of the 65 primary tumors, positive staining for beta-catenin was observed in 60 (92.3%) cases with membrane and /or cytoplasmic localization in the examined tumor cells. Reduced membrane expression was significantly associated with advanced stage, lymph node metastasis and negative ER. On the contrary, cytoplasmic localization seemed to be related to an aggressive tumor phenotype where significant associations were identified between high cytoplasmic expression and a large tumor size, a high grade, advanced stage, lymph node positivity, high Ki-67 proliferation index and poor Nottingham Prognostic Index. Membrane betacatenin expression was significantly higher in ALNM compared to their primary where it was significantly reduced with re-expression in ALNM. CONCLUSION: beta-catenin seemed to have different roles in invasive ductal breast carcinomas, based on its expression levels and subcellular distribution. Altered beta-catenin expression in primary tumors with re-expression in nodal metastases is a common event in breast ductal carcinomas and may play a central role in establishing metastasis. These results may offer new insights regarding the role of beta-catenin in breast cancer.

A role of WNT signaling for primary breast cancers of the basal-like subtype and as a predictor of brain metastasis has been described. However, a responsible WNT ligand has not been identified. To further clarify this question, we comparatively investigated 22 human breast cancer brain metastases as well as the highly invasive human breast cancer cell line MDA-MB-231 and the weakly motile MCF-7 as models for the basal-like and the luminal A subtype. WNT5A and B were found overexpressed in MDA-MB-231 cells as compared with MCF-7. This corresponded to reduction of MDA-MB-231 invasiveness by WNT inhibitors, whereas MCF-7 invasion was enhanced by recombinant WNT5B and abolished by WNT and Jun-N-terminal kinase antagonists. expression and subcellular distribution of beta-catenin remained uninfluenced. Consistently, beta-catenin was not localized in the nuclei of brain metastases while there was strong nuclear c-Jun staining. Similar to MDA-MB-231, metastases showed expression of WNT5A/B and the alternative WNT receptors ROR1 and 2. These findings were validated using external gene expression datasets (Gene expression Omnibus) of different breast cancer subtypes and brain metastases. Hierarchical cluster analysis yielded a close relation between basal-like cancers and brain metastases. Gene set enrichment analyses confirmed WNT pathway enrichment not only in basal-like primaries but also in cerebral metastases of all subtypes. In conclusion, WNT signaling seems highly relevant for basal-like and other subtypes of breast cancers metastasizing into the brain. beta-catenin-independent WNT signaling, presumably via ROR1-2, plays a major role in this context.

Wnt/beta-catenin signalling has been suggested to be active in basal-like breast cancer. However, in highly aggressive metastatic triple-negative breast cancers (TNBC) the role of beta-catenin and the underlying mechanism(s) for the aggressiveness of TNBC remain unknown. We illustrate that WNT10B induces transcriptionally active beta-catenin in human TNBC and predicts survival-outcome of patients with both TNBC and basal-like tumours. We provide evidence that transgenic murine Wnt10b-driven tumours are devoid of ERalpha, PR and HER2 expression and can model human TNBC. Importantly, HMGA2 is specifically expressed during early stages of embryonic mammogenesis and absent when WNT10B expression is lost, suggesting a developmentally conserved mode of action. Mechanistically, ChIP analysis uncovered that WNT10B activates canonical beta-catenin signalling leading to up-regulation of HMGA2. Treatment of mouse and human triple-negative tumour cells with two Wnt/beta-catenin pathway modulators or siRNA to HMGA2 decreases HMGA2 levels and proliferation. We demonstrate that WNT10B has epistatic activity on HMGA2, which is necessary and sufficient for proliferation of TNBC cells. Furthermore, HMGA2 expression predicts relapse-free-survival and metastasis in TNBC patients.

tumor metastasis involves a series of biological steps during which the tumor cells acquire the ability to invade surrounding tissues and survive outside the original tumor site. During the early stages, the cancer cells undergo an epithelial-mesenchymal transition (EMT). Wnt/beta-catenin signaling is known to drive EMT and metastasis. Here we report that Wnt/beta-catenin signaling is hyperactivated in metastatic breast cancer cells that express microRNA 374a (miR-374a). In breast cancer cell lines, ectopic overexpression of miR-374a promoted EMT and metastasis both in vitro and in vivo. Furthermore, miR-374a directly targeted and suppressed multiple negative regulators of the Wnt/beta-catenin signaling cascade, including WIF1, PTEN, and WNT5A. Notably, miR-374a was markedly upregulated in primary tumor samples from patients with distant metastases and was associated with poor metastasis-free survival. These results demonstrate that miR-374a maintains constitutively activated Wnt/beta-catenin signaling and may represent a therapeutic target for early metastatic breast cancer.

BACKGROUND: Insulin like growth factor binding proteins modulate the mitogenic and pro survival effects of IGF. Elevated expression of IGFBP2 is associated with progression of tumors that include prostate, ovarian, glioma among others. Though implicated in the progression of breast cancer, the molecular mechanisms involved in IGFBP2 actions are not well defined. This study investigates the molecular targets and biological pathways targeted by IGFBP2 in breast cancer. METHODS: Transcriptome analysis of breast tumor cells (BT474) with stable knockdown of IGFBP2 and breast tumors having differential expression of IGFBP2 by immunohistochemistry was performed using microarray. Differential gene expression was established using R-Bioconductor package. For validation, gene expression was determined by qPCR. Inhibitors of IGF1R and integrin pathway were utilized to study the mechanism of regulation of beta-catenin. Immunohistochemical and immunocytochemical staining was performed on breast tumors and experimental cells, respectively for beta-catenin and IGFBP2 expression. RESULTS: Knockdown of IGFBP2 resulted in differential expression of 2067 up regulated and 2002 down regulated genes in breast cancer cells. Down regulated genes principally belong to cell cycle, DNA replication, repair, p53 signaling, oxidative phosphorylation, Wnt signaling. Whole genome expression analysis of breast tumors with or without IGFBP2 expression indicated changes in genes belonging to Focal adhesion, Map kinase and Wnt signaling pathways. Interestingly, IGFBP2 knockdown clones showed reduced expression of beta- catenin compared to control cells which was restored upon IGFBP2 re-expression. The regulation of beta-catenin by IGFBP2 was found to be IGF1R and integrin pathway dependent. Furthermore, IGFBP2 and beta-catenin are co-ordinately overexpressed in breast tumors and correlate with lymph node metastasis. CONCLUSION: This study highlights regulation of beta-catenin by IGFBP2 in breast cancer cells and most importantly, combined expression of IGFBP2 and beta-catenin is associated with lymph node metastasis of breast tumors.

PURPOSE: Presence of pelvic lymph node metastases is the main prognostic factor in early-stage cervical cancer patients, primarily treated with surgery. Aim of this study was to identify cellular tumor pathways associated with pelvic lymph node metastasis in early-stage cervical cancer. EXPERIMENTAL DESIGN: Gene expression profiles (Affymetrix U133 plus 2.0) of 20 patients with negative (N(0)) and 19 with positive lymph nodes (N(+)), were compared with gene sets that represent all 285 presently available pathway signatures. Validation immunostaining of tumors of 274 consecutive early-stage cervical cancer patients was performed for representatives of the identified pathways. RESULTS: Analysis of 285 pathways resulted in identification of five pathways (TGF-beta, NFAT, ALK, BAD, and PAR1) that were dysregulated in the N(0), and two pathways (beta-catenin and Glycosphingolipid Biosynthesis Neo Lactoseries) in the N(+) group. Class comparison analysis revealed that five of 149 genes that were most significantly differentially expressed between N(0) and N(+) tumors (P < 0.001) were involved in beta-catenin signaling (TCF4, CTNNAL1, CTNND1/p120, DKK3, and WNT5a). Immunohistochemical validation of two well-known cellular tumor pathways (TGF-beta and beta-catenin) confirmed that the TGF-beta pathway (positivity of Smad4) was related to N(0) (OR: 0.20, 95% CI: 0.06-0.66) and the beta-catenin pathway (p120 positivity) to N(+) (OR: 1.79, 95%CI: 1.05-3.05). CONCLUSIONS: Our study provides new, validated insights in the molecular mechanism of lymph node metastasis in cervical cancer. pathway analysis of the microarray expression profile suggested that the TGF-beta and p120-associated noncanonical beta-catenin pathways are important in pelvic lymph node metastasis in early-stage cervical cancer.

AIMS: A decreased expression of beta-catenin has been known to be associated with tumour metastasis. The prognostic value of beta-catenin expression in colorectal cancer (CRC) patients with liver metastasis was evaluated. MATERIALS AND METHODS: Seventy patients who underwent curative resection for CRC with liver metastasis were included. Tissue samples from normal colon mucosa, primary CRC and metastatic liver lesions were prepared in tissue microarrays, and were stained by immunohistochemistry with beta-catenin antibody. The beta-catenin expression of primary CRC tissues and metastatic liver tissues was analysed. RESULTS: A high expression of beta-catenin (score > 6) was observed in 42.0% and 21.9% of primary colorectal tissues and metastatic liver tissues, respectively. The beta-catenin expression in metastatic liver tissues was significantly lower than in primary CRC tissues (P = 0.022). The patients were classified into two groups according to the difference in the beta-catenin expression score between the primary CRC and the liver metastasis. Group A was defined as patients showing a remarkably decreased expression of beta-catenin in their metastatic liver tissue and group B was defined as patients showing a maintained or increased beta-catenin expression in their metastatic liver tissue in comparison with their primary CRC. The overall survival and disease-free survival rates were better in group B than in group A, and this was statistically significant (P = 0.02, P = 0.002). CONCLUSION: The decreased expression of beta-catenin in a metastatic liver lesion may be a poor prognostic marker in CRC with liver metastasis and further investigation is necessary.

Serum response factor (SRF) is a transcription factor that controls cell growth, differentiation, and tumor progression as well as muscle development and function. Reduced expression of cell adhesion molecules has been reported to be associated with tumor metastasis. The aim of this study was to evaluate the expression and a role of SRF in liver metastasis of primary colorectal carcinomas. We examined the expression of SRF, E-cadherin, and beta-catenin by the use of immunochemical staining in 43 cases as a set of primary colorectal carcinomas and liver metastases. We also examined the role of SRF in colorectal carcinoma by overexpression of SRF in a colon cancer cell line. In metastatic carcinoma surgical samples, there was a marked increased expression of SRF as compared to expression in primary colorectal carcinoma surgical samples (P<0.05). E-cadherin expression was significantly decreased in metastatic liver carcinoma samples as compared to primary colorectal carcinoma samples (P<0.001). Frequent nuclear translocation of beta-catenin protein in primary and metastatic carcinoma cells was observed. Overexpression of SRF in SW480 cells resulted in a decreased expression of E-cadherin and an increased expression of non-phosphorylated nuclear beta-catenin. Overexpression of SRF in colorectal carcinoma cells enhanced cell motility and invasiveness. These results indicate that overexpression of SRF in colorectal carcinoma cells is associated with modulation of E-cadherin/beta-catenin expression and may play an important role in colorectal cancer metastasis.

The role of expression of markers (beta-catenin, matrix metalloproteinase 9, collagen IV, and laminin) in primary colorectal adenocarcinomas and their metastases in the liver and lymph nodes of patients with colorectal cancer was studied. High level of matrix metalloproteinase 9 expression in zones of invasive growth of colorectal cancer was associated with high accumulation of beta-catenin in cancer cell nuclei in the peripheral zones of 30% studied tumors. The presence of nuclear beta-catenin and high content of matrix metalloproteinase 9 in the tumor were associated with abnormal accumulation of laminin in the cytoplasm and with the absence of basal membranes containing collagen IV. These changes were characteristic of colorectal cancer with high invasive metastatic potential. It was found that beta-catenin, matrix metalloproteinase 9, laminin, and collagen IV were important markers for prediction of the clinical course of colorectal cancer. The expression of proteins associated with risk of metastases in the liver was coordinated and most pronounced in zone of invasive front-line of tumors.

Beta-catenin and p53 play key roles in tumorigenesis. The relationships between these 2 signaling pathways and their contribution to colorectal cancer metastatic progression have not been completely elucidated. We analyzed 141 cases of primary sporadic colorectal cancer, 45 matched metastases, and 80 samples of normal mucosa by immunohistochemistry on paraffin-embedded specimens. The expression profiles were also related to patients clinicopathologic features and 5-year survival. In primary tumors, beta-catenin immunoreactivity was nuclear (27%), predominantly membrane/cytosolic (46.0%) or negative (27%). This latter subgroup was strongly related to microsatellite instability, in particular to MLH-1 deficiency. Remarkably, beta-catenin membrane/cytosolic expression in primary tumors was reduced in the corresponding matched metastases. p53 showed a significant increase in immunoreactivity in (66.7%), whereas it was negative in (33.3%) of tumors. When we considered the expression of both genes, the combination of negative beta-catenin and positive p53 nuclear staining (21%) was strongly related to a higher frequency of liver metastases. Such an association was significantly related to a worse prognosis than any other combination. In a multivariate analysis, beta-catenin and distant metastases were independent prognostic markers. We suggest that a combination of low beta-catenin and high p53 expression in primary colorectal cancers may be a prognostic factor in predicting the progression of the disease, the occurrence of metastasis, and a more severe outcome.

BACKGROUND: beta-catenin plays an important role in colorectal tumorigenesis. Relatively little is known about the relationship between beta-catenin overexpression and liver metastasis. The purpose of this study was to investigate whether nuclear beta-catenin overexpression in colorectal cancer is associated with synchronous liver metastasis. METHODS: The beta-catenin expression in tumor tissue from 486 patients with colorectal cancer was examined by immunohistochemistry. The relationship between nuclear beta-catenin expression in colorectal cancers and liver metastatic lesions and other clinicopathological characteristics was analyzed. Univariate analysis and logistic multivariate regression analysis were adopted to discriminate risk factors of liver metastasis. RESULTS: Nuclear beta-catenin overexpression at the invasive front of the primary tumor in patients with liver metastasis is more evident than that in patients without liver metastasis (71.5% vs. 29.3%; P < 0.001). Nuclear beta-catenin expression in primary tumors had a positive correlation with that in the matched metastatic lesions (r = 0.499, P < 0.001). Univariate and multivariate analyses indicated that overexpression of nuclear beta-catenin at the invasive front in colorectal cancer correlated with liver metastasis. CONCLUSIONS: Overexpression of nuclear beta-catenin at the invasive front in colorectal cancer is strongly associated with liver metastasis and may be a promising predictor of liver metastasis.

beta-catenin and E cadherin are both membrane-associated proteins which are essential regulators and providers of cellular adhesion. In the metastatic cascade of malignant tumours, detachment of tumour cells from each other is a very important step. It has been shown in several tumour types, that reduced expression of these proteins is important. The aim of our study was to clarify the expression profile of these proteins, and correlate the findings with the metastasizing potential of early stage colon and rectal cancers. Formalin fixed and paraffin embedded samples from 79 Dukes B2 stage colorectal cancer were examined using a tissue microarray approach. The expression of beta-catenin and E-cadherin proteins was determined immunohistochemically. Our findings indicated that there is a tendency for metastatic spread in cases when membranous expression of beta-catenin is lost (p = 0.062). Similarly metastases in negative cases developed more rapidly, than in positive ones (p = 0.05). Survival rate was worse in the negative cases. The risk of metastasis in rectal cancer was significantly higher in the beta-catenin membranously negative than positive groups (p = 0.024) and in case of beta-catenin nuclear expression the risk was also higher (p = 0.047). Reduced E-cadherin expression also correlated with development of metastatic disease, but this association was statistically not significant. The immunohistochemical analysis of 79 cases shows that in Dukes B2 stage colorectal tumours clarification of beta-catenin and E-cadherin expression patterns is reliable for predicting the metastatic potential of early stage rectal cancer and hence the method may have relevant implications in the therapeutic management of these cancers.

BACKGROUND: Beta-catenin, a component of the Wingless/Wnt signaling pathway, can activate target genes linking with the adenomatous polyposis coli (APC) gene in colorectal cancer. The purpose of this study is to investigate whether nuclear beta-catenin overexpression in metastatic sentinel lymph node(s) [SLN(s)] is associated with synchronous liver metastasis. METHODS: Clinicopathological data from 355 patients (93 cases with liver metastasis and 262 cases without liver metastasis) were reviewed. Beta-catenin expression in metastatic SLN(s) and liver metastatic lesions was examined by immunohistochemistry. The association of nuclear beta-catenin expression in metastatic SLN(s) and liver metastatic lesions was evaluated, and the relationship between nuclear beta-catenin expression and clinicopathological characteristics was analyzed. Finally, univariate and logistic multivariate regression analyses were adopted to discriminate the risk factors of liver metastasis. RESULTS: Nuclear beta-catenin overexpression in metastatic SLN(s) was observed in 70 patients with liver metastasis and 31 patients without liver metastasis (75.3% vs. 11.8%; P < 0.001). Nuclear beta-catenin expression was noted in all the metastatic lesions. Spearman rank correlation analysis demonstrated that nuclear beta-catenin expression in metastatic SLN(s) had a positive correlation with that in metastatic lesions (r = 0.425, P < 0.001). Univariate and multivariate analyses indicated that nuclear beta-catenin overexpression in metastatic SLN(s) correlated with liver metastasis. CONCLUSIONS: Nuclear beta-catenin overexpression in metastatic SLN(s) is strongly associated with liver metastasis and may contribute to predict liver metastasis.

BACKGROUND: The wingless-type MMTV integration site family of proteins (WNT) pathway is highly involved in colorectal cancer development. The aim of this study was to explore the prognostic significance and clinicopatological correlations of this pathway in a cohort of surgically-treated patients with non-metastatic colorectal cancer in relation to the site of expression of pathway proteins. MATERIALS AND METHODS: Immunohistochemical expression of nuclear cyclin D1, membranous E-cadherin and P-cadherin, membranous and nuclear beta-catenin in the invasive front (IF), the tumor center (TC), as well as their mean, were assessed in 106 paraffin-embedded tissue samples. Adenomatous Polyposis Coli (APC), Axin-2 (AXIN2), cyclin-D1 (CCND1), Matrix Metalloproteinase-7 (MMP7), Secreted Frizzled Related Protein (SFRP) 1, 2 and 4 and WNT5A were evaluated by RT PCR. RESULTS: Membranous beta-catenin expression was statistically reduced in the IF. Cyclin-D1 was reduced in tumors arising closer to the rectum. Reduced nuclear expression of cyclin-D1 in the IF was associated with lymphatic, venous and perineural invasion. Loss of membranous beta-catenin in the TC was more common among N2 tumors. Higher SFRP4 mRNA was associated with advanced T stage. In univariate analysis, membranous expression of beta-catenin in TC and IF, and their mean, was associated with longer disease-free survival (DFS). In multivariate analysis, tumor stage and mean beta-catenin expression were prognostic for longer DFS (hazard ratio=0.33; p=0.01). beta-Catenin expression in the IF remained significant when the mean expression was not included in the multivariate analysis (hazard ratio=0.41; p=0.028). CONCLUSION: Mean membranous expression of beta-catenin, as well as that in the IF, is prognostic for longer DFS in patients with non metastatic colorectal cancer.

We determined whether active PI3K signaling together with nuclear accumulation of beta-Catenin is necessary to fully activate canonical WNT signaling and examined the association of both signaling pathways with colon cancer progression. Using reporter gene assays we examined the activation of beta-Catenin mediated transcription upon PI3K inhibition with or without beta-Catenin nuclear accumulation. Ectopically induced as well as constitutively active WNT signaling strictly required PI3K activity whereas PI3K inhibition had no effect on beta-Catenin subcellular localization but impaired beta-Catenin binding to WNT target gene promoters and decreased WNT target gene expression. Transcriptional activity of nuclear beta-Catenin depended on active PI3K signaling as nuclear accumulation of beta-Catenin failed to induce WNT reporter gene transcription upon PI3K inhibition. PI3K dependend transcriptional transactivation of beta-Catenin relies on events beyond phosphorylation at the AKT target site serine 552, as S552D-phosphomimetic beta-Catenin mutants were unable to restore WNT signaling when inhibiting PI3K. To study the prognostic value of PI3K pathway activation (activating PIK3CA mutations or loss of PTEN expression) and nuclear beta-Catenin expression, both variables were determined in 55 matched pairs of primary right sided colon cancer cases with or without distant metastasis. Activating mutations in the PIK3CA gene or loss of PTEN expression did not correlate with distant metastasis while high nuclear beta-Catenin expression combined with activation of the PI3K pathway identified cases in which distant metastasis had occurred. Activation of the PI3K pathway was not associated with nuclear beta-Catenin expression. We conclude that the transcriptional activity of nuclear beta-Catenin depends on PI3K activity. However, PI3K on its own does not affect beta-Catenin subcellular localization. Both factors synergize for full WNT signaling activity and are associated with distant metastasis in colon cancer. Thus, the detection of high nuclear beta-Catenin expression and simultaneous PI3K pathway activation identifies colon cancer patients with a high risk for distant metastasis.

BACKGROUND & OBJECTIVE: Many reports have characterized the aberrant expression of beta-catenin in diverse types of human cancer. To determine whether beta-catenin has possible roles in esophageal carcinogensis, we designed this study to detect the expression pattern of beta-catenin in normal esophageal epithelium and esophageal cancer tissue, then to study the relevance of its expression and localization to tumor differetiation degree and lymph node metastasis. METHODS: By using immunohistochemical staining(SP method), the expression of beta-catenin was detected in 22 normal esophageal tissue slides and 52 esophageal carcinomas. RESULTS: In the 22 normal esophageal tissue, beta-catenin showed high intense expression at the membrane and low intense expression at the cytoplasm. In contrast to the normal tissue, beta-catenin was expressed in the cytoplasma in carcinoma with varied degrees, accompanied by less, or even lost expression at the membrane in cancer samples. In some cases, beta-catenin could be detected in the nucleus. Moreover, the positive rate of beta-catenin expression in cytoplasm was significantly higher in those patients with lymph node metastasis than patients without(P < 0.05). CONCLUSIONS: The aberrant expression of beta-catenin occurred frequently in the esophageal carcinoma, mainly including the translocation of beta-catenin protein from membrane to the cytoplasm and nucleus, and the accumulation of beta-catenin in cytoplasma was overt. And the aberrant expression of beta-catenin protein was statistically correlated to the lymph node metastasis in esophageal cancer.

The aim of this study was to investigate the correlation between Wnt1/beta-catenin expression and the clinicopathologic features and prognosis of patients with esophageal squamous cell carcinoma (ESCC). The mRNA and protein expression levels of Wnt1/beta-catenin genes in 70 ESCC and 15 adjacent noncancerous paraffin-embedded samples were determined by real-time quantitative polymerase chain reaction and immunohistochemical staining. The mRNA expression level of Wnt1/beta-catenin in ESCC was significantly higher than that in the adjacent noncancerous tissues (1.9934 +/- 1.9888 vs. 0.8863 +/- 0.665, p = 0.0184; 0.2854 +/- 0.1298 vs. 0.0128 +/- 0.0158, p = 0.0000, respectively), and the overexpression of Wnt1/beta-catenin mRNA was aggressively associated with lymph node metastasis and advanced pathological stage (p < 0.0001). The protein expression level of Wnt1/beta-catenin was also significantly higher than that in the adjacent noncancerous tissues (0.3830 +/- 0.0947 vs. 0.2721 +/- 0.1474, p = 0.0002; 0.2835 +/- 0.0844 vs. 0.2352 +/- 0.0670, p = 0.0210, respectively); however, the overexpression was not associated with clinicopathologic characteristics. Meanwhile, the protein expression level of Wnt1 had no relevance with that of beta-catenin. The overexpression of Wnt1/beta-catenin might be an important molecular marker to predict the clinicopathologic stage and prognosis of ESCC, and the level of Wnt1/beta-catenin mRNA was conversely correlated with lymph node metastasis and advanced pathological stage. The overexpression of Wnt1/beta-catenin mRNA should also predict poor prognosis of ESCC; however, it might not be an independent prognostic factor.

Upregulated gene 11 (URG11), a new gene upregulated by Hepatitis B Virus X protein (HBx), was previously shown to activate beta-catenin and promote hepatocellular growth and tumourigenesis. Although the oncogenic role of URG11 in the development of hepatocellular carcinoma has been well documented, its relevance to other human malignancies and the underlying molecular mechanisms remain largely unknown. Here we reported a novel function of URG11 to promote gastric cancer growth and metastasis. URG11 was found to be highly expressed in gastric cancer tissues compared with adjacent nontumourous ones by immunohistochemical staining and western blot. Knockdown of URG11 expression by small interfering RNA (siRNA) effectively attenuated the proliferation, anchorage-independent growth, invasiveness and metastatic potential of gastric cancer cells. URG11 inhibition led to decreased expression of beta-catenin and its nuclear accumulation in gastric cancer cells and extensive costaining between URG11 and beta-catenin was observed in gastric cancer tissues. Transient transfection assays with the beta-catenin promoter showed that it was inhibited by URG11-specific small inhibitory RNA. Moreover, suppression of endogenous URG11 expression results in decreased activation of beta-catenin/TCF and its downstream effector genes, cyclinD1 and membrane type 1 matrix metallopeptidase (MT1-MMP), which are known to be involved in cell proliferation and invasion, respectively. Taken together, our data suggest that URG11 contributes to gastric cancer growth and metastasis at least partially through activation of beta-catenin signalling pathway. These findings also propose a promising target for gene therapy in gastric cancer.

The interaction between tumor cells and the stroma environment has crucial effects on tumor cell invasive behavior. As a major component of the stroma, collagen plays a key role on cellular adhesion and epithelial-mesenchymal transition (EMT). Recently, we found that collagen type I is significantly up-regulated in gastric cancer tissues compared with their adjacent non-neoplastic tissues. However, whether collagen type I contributes to gastric cancer invasion and metastasis is not clear. Herein we show that, collagen type I induces cell scattering and cytoskeleton rearrangement, prompts cell migration and proliferation, which indicates that collagen type I is involved in promoting gastric cancer invasion and metastasis. Collagen type I is able to reduce cell-cell adhesion and enhance migration by inducing disassembly of the E-cadherin/catenin complex in gastric carcinoma cells, which is related to tyrosine phosphorylation of beta-catenin. Tyrosine phosphorylation of beta-catenin dissociates it from E-cadherin and actin cytoskeleton and facilitates its entry into the nucleus, where beta-catenin acts as a transcriptional activator inducing genes involved in cell proliferation. In conclusion, collagen type I contributes to invasion and metastasis by regulating beta-catenin tyrosine phosphorylation and nuclear translocation to promote migration and proliferation of gastric carcinoma cells.

The E-cadherin-catenin complex plays an important role in the process of cell adhesion. Its dysfunction is associated with a decrease in cell differentiation and with increased invasiveness and metastasis. Our aim was to evaluate the expression of E-cadherin and B-catenin in advanced gastric cancer in relation to selected clinico-pathomorphological parameters. Formalin-fixed, paraffin-embedded tissue specimens were immunohistochemically stained with monoclonal antibodies E-cadherin (NCL-E-Cad, Novocastra Laboratiries Ltd; dilution 1:50), beta-catenin (NCL-B-CAT, Novocastra Laboratories Ltd; dilution 1:100), alpha-catenin (alpha-E-caten, Santa Cruz Biotechnology; dilution 1:300) and gamma-catenin (gamma-catenin, Santa Cruz Biotechnology; dilution 1:100). The expressions of E-cadherin and alpha-, beta-, gamma-catenins in the main mass of tumor and lymph node metastasis were investigated in 91 patients with gastric cancer. No statistically significant correlation was observed between the expressions of E-cadherin, alpha-, beta-catenins and histological differentiation and between the expressions of E-cadherin, alpha-, gamma-catenins and location or depth of invasion. Moreover, the expression of alpha-, gamma-catenins in the main mass of tumor was not associated with lymph node metastasis. However, we found a relationship between the expression of beta-catenin in the main mass of tumor and lymph node metastasis and tumor location. The depth of invasion was correlated with positive expression of beta-catenin in the main mass of gastric cancer. A statistically significant association was observed between the expressions of E-cadherin and beta-catenin in the main mass of tumor and lymph node involvement. The expression of alpha-catenin in the main mass of tumor was also associated with histological differentiation and Laurens classification. Statistical analysis showed an association between the expression of E-cadherin and postoperative survival time. No significant correlation was found between the expression of alpha-, beta-, gamma-catenins and survival time. Our results may suggest that the E-cadherin-catenin complex is the factor indicative of metastasis and disease progression in gastric cancer. Also the expression of E-cadherin may play a role as a prognostic factor.

Heat shock protein 60 (HSP60) plays an essential role in assisting many newly synthesized proteins to reach their native forms. Increased HSP60 expression is observed in different types of human cancers with metastasis (e.g. pancreatic cancer and large bowel carcinoma). However, the role of HSP60 in metastasis remains little known. Aberrant activation of beta-catenin plays a key role in tumorigenesis and metastasis. Here, we show that overexpression of HSP60 induces metastatic phenotypes in vitro and in vivo. HSP60 interacts with beta-catenin, increases beta-catenin protein levels through the apical domain and enhances its transcriptional activity. Short-interference RNA-mediated repression of beta-catenin reverts metastatic activity caused by HSP60 overexpression. Proteosomal activity is not required for the induction of beta-catenin by HSP60. Coexpression of HSP60 and nuclear beta-catenin predicts a worse prognosis of metastatic head and neck cancer patients. These results implicate a novel role of HSP60 in metastasis.

OBJECTIVE: To investigate the roles of E-cadherin and beta-catenin play in the carcinogenesis and progression of laryngeal carcinoma. METHOD: Immunohistochemistry staining (PicTure two steps method) was used to detect E-cadherin and beta-catenin proteins expression in laryngeal carcinomas and normal epithelia around tumors. RESULT: In 60 laryngeal carcinomas, the abnormal expression rates of E-cadherin and beta-catenin were 55.00% and 66.67% respectively. The significant relationship was observed between abnormal E-cadherin and beta-catenin expression and differentiation, clinical stage and lymph node metastasis. There was a positive relationship between the expression of beta-catenin and E-cadherin in same sample. CONCLUSION: The abnormal expression of E-cadherin and beta-catenin were closely related with differentiation, clinical stage, metastasis in laryngeal carcinoma.

BACKGROUND: p130Cas (p130Crk-associated substance) is a junction protein that is important to the adhesion between cytoskeleton and extracellular matrix. Also, the adhesion molecules E-cadherin and beta-catenin play important roles in the invasiveness of carcinoma. This study was undertaken to investigate the effects of p130Cas, E-cadherin and beta-catenin on the invasion, metastasis and prognosis of hepatocellular carcinoma (HCC). METHODS: Immunohistochemistry was used to evaluate the expression of p130Cas, E-cadherin, and beta-catenin in 40 patients with HCC. All patients were followed up postoperatively, and the relationship between expression and clinicopathological prognostic parameters was analyzed. RESULTS: The positive expression rates of p130Cas and E-cadherin in HCC tissue (n=40) were 62.50% and 55.00%, but in normal liver tissue 10%, and 100%, respectively (P<0.05). The abnormal expression rate of beta-catenin in HCC tissue was 70%, while in normal liver tissue it was 13.33% (P<0.05). The positive rate of p130Cas was correlated with lymph node invasion, pathological stage, TNM stage, and a worse prognosis, but not with gender, age, HBV infection, hepatic cirrhosis, alpha-fetoprotein (AFP) level before operation, and tumor diameter. Similarly, the expression of E-cadherin and beta-catenin was correlated with lymph node invasion, pathological stage, TNM stage, and worse prognosis, but not with gender, age, HBV infection, hepatic cirrhosis, AFP level before operation, and tumor size. Correlations were found between p130Cas and abnormal E-cadherin/beta-catenin expression (P<0.001 and <0.05, respectively). CONCLUSIONS: In HCC, there is a negative correlation between the positive expression of p130Cas and the normal expression of the adhesion molecules E-cadherin/beta-catenin, and p130Cas plays important roles in the invasion, metastasis and prognosis of HCC. p130Cas may be involved in alterating the structure and function of E-cadherin/beta-catenin, by regulating tyrosine phosphorylation via the p130Cas-Src signal pathway.

PURPOSE: To investigate the role of CD24 in tumor invasion and prognostic significance in hepatocellular carcinoma (HCC). EXPERIMENTAL DESIGN: CD24 expression was measured in stepwise metastatic HCC cell lines, tumor, peritumoral tissues, and normal liver tissues by quantitative real-time PCR and Western blot. The role of CD24 in HCC was investigated by CD24 depletion using small interfering RNA. tumor tissue microarrays of 314 HCC patients who underwent resection between 1997 and 2000 were used to detect expression of CD24, beta-catenin, and proliferating cell nuclear antigen. Prognostic significance was assessed using Kaplan-Meier survival estimates and log-rank tests. RESULTS: CD24 was overexpressed in the highly metastatic HCC cell line and in tumor tissues of patients with recurrent HCC. Depletion of CD24 caused a notable decrease in cell proliferation, migration, and invasiveness in vitro. Univariate and multivariate analyses revealed that CD24 was a significant predictor for overall survival and relapse-free survival. CD24 expression was correlated with poor prognosis independent of alpha-fetoprotein, tumor-node-metastasis stage, and Edmondson stage. High CD24 expression was significantly associated with cytoplasmic and nuclear accumulation of beta-catenin (P = 0.023), high tumor proliferative status (P = 0.018), and diffused intrahepatic recurrence and distant metastasis (P = 0.026). Adjuvant transcatheter arterial chemoembolization after surgery reduced the rate of early recurrence (expression of CD24 in HCC was associated with high invasiveness and metastatic potential, high tumor proliferation status, and activation of the Wnt/beta-catenin pathway. CD24 may be a novel predictor for poor prognosis of HCC patients after surgery.

PURPOSE: Aberrant activation of beta-catenin contributes to the malignant phenotype in hepatocellular carcinoma (HCC). Hypoxia is also known to promote HCC invasion and metastasis. However, the association between beta-catenin and the proinvasive role of hypoxia remains unclear. We investigated the role of beta-catenin in the proinvasive consequences of hypoxia in HCC. EXPERIMENTAL DESIGN: We established in vitro and in vivo hypoxic models to investigate the expression of beta-catenin in hypoxic HCC cells and its role in hypoxia-induced aggressiveness. The clinical significance of beta-catenin and/or hypoxia-induced factor-1alpha (HIF-1alpha) was evaluated using HCC tissue microarrays. RESULTS: Hypoxia induced beta-catenin overexpression and/or intracellular accumulation in four HCC cell lines through downregulating the endogenous degradation machinery, and promoted in vitro invasion and in vivo metastasis of MHCC97 and Hep3B cells. Besides morphologic changes, hypoxic MHCC97 and Hep3B cells exhibited molecular alterations consistent with epithelial-mesenchymal transition, characterized by the loss of epithelial cell markers (E-cadherin and plakoglobin) and upregulation of mesenchymal markers (vimentin and N-cadherin), as well as the increase of matrix metalloproteinase 2. However, silencing beta-catenin in these hypoxic cells reversed epithelial-mesenchymal transition and repressed metastatic potential. Positive expression of beta-catenin in HCC tissue microarray was associated with the expression of HIF-1alpha (P=0.034), and coexpression of beta-catenin and HIF-1alpha in HCC was correlated with shorter overall survival and time to recurrence. CONCLUSION: beta-Catenin in HCC is activated by hypoxia and contributes to hypoxia-induced metastatic potential.

Although evidence has shown that both the mammalian target of rapamycin and beta-catenin are involved in hepatocellular carcinoma, little is known about their relationship in pathogenesis of hepatocellular carcinoma. To investigate the expression of phosphorylated mammalian target of rapamycin and beta-catenin and their prognostic impacts, as well as their relationship in hepatocellular carcinoma, we analyzed 63 human hepatocellular carcinoma samples by immunohistochemistry. Phosphorylated mammalian target of rapamycin cytoplasmic and beta-catenin cytoplasmic/nuclear-positive immunoreactivities were observed in 63.5% (40/63) and 55.6% (35/63) of the hepatocellular carcinoma specimens, respectively. Significant associations were found between cytoplasmic beta-catenin and phosphorylated mammalian target of rapamycin expression and tumor size (both P < .01) and metastasis (P < .01 and P < .05, respectively). In addition, beta-catenin expression in the cytoplasm was closely associated with the expression of phosphorylated mammalian target of rapamycin. To further explore the relationship between mammalian target of rapamycin and beta-catenin, hepatocellular carcinoma HepG2 and Hep3B cells were treated with beta-catenin siRNA and mammalian target of rapamycin inhibitor, rapamycin; and the expression of phosphorylated mammalian target of rapamycin and beta-catenin in cells was then measured by Western blot. The activity of Wnt/beta-catenin signaling pathway was also assessed by luciferase reporter assay. The cell viability and proliferation were evaluated by thiazolyl blue tetrazolium bromide assay and [(3)H]-thymidine incorporation assay. The results showed that the level of beta-catenin protein expression was markedly decreased by rapamycin in HepG2 and Hep3B cells. The reduction of beta-catenin and mammalian target of rapamycin resulted in inhibition of cell viability proliferation, but the combination of reduction of beta-catenin and mammalian target of rapamycin did not show a synergistic effect on the inhibition of cell viability and proliferation in HepG2 and Hep3B cells. In conclusion, the present study showed that, for the first time, mammalian target of rapamycin regulated the expression level of beta-catenin in hepatocellular carcinoma. Both mammalian target of rapamycin and beta-catenin play important roles in the growth, metastasis, and prognosis of hepatocellular carcinoma.

The canonical Wnt signalling pathway induces the beta-catenin/lymphoid enhancer factor transcription factors. It is activated in various cancers, most characteristically carcinomas, in which it promotes metastatic spread by increasing migration and/or invasion. The Wnt/beta-catenin signalling pathway is frequently activated in melanoma, but the presence of beta-catenin in the nucleus does not seem to be a sign of aggressiveness in these tumours. We found that, unlike its positive role in stimulating migration and invasion of carcinoma cells, beta-catenin signalling decreased the migration of melanocytes and melanoma cell lines. In vivo, beta-catenin signalling in melanoblasts reduced the migration of these cells, causing a white belly-spot phenotype. The inhibition by beta-catenin of migration was dependent on MITF-M, a key transcription factor of the melanocyte lineage, and CSK, an Src-inhibitor. Despite reducing migration, beta-catenin signalling promoted lung metastasis in the NRAS-driven melanoma murine model. Thus, beta-catenin may have conflicting roles in the metastatic spread of melanoma, repressing migration while promoting metastasis. These results highlight that metastasis formation requires a series of successful cellular processes, any one of which may not be optimally efficient.

OBJECTIVE: To study the mechanism of invasion and metastasis in early nasopharyngeal carcinoma (NPC) in relation to E-cadherin promoter methylation and mutation in exon 3 of beta-catenin. METHODS: Methylation of E-cadherin promoter, mutation in exon 3 of beta-catenin and differential expression of beta-catenin in the primary lesion of 21 NPC and the metastatic lymph node of 21 NPC were investigated by DNA Methylation-Specific PCR, direct sequencing and immunohistochemical method. RESULTS: Methylation on E-cadherin promoter was showed in 23.8% (5/21) primary lesions and 61.9% (13/21) metastatic lymph nodes (P < 0.01). mutation in exon 3 of beta-catenin was showed in 3 of 42 tissues: codon 37 (TCT-->GCT), codon 41 (ACC-->GCC) and codon 47 (AGT-->ACT). However, there was no relation between these mutations and invasion or metastasis (P > 0.05). High beta-catenin expression on the membrane without nuclear expression was observed in 42 tissues (P > 0.05). CONCLUSION: 1. In NPC, methylation of promoter is a major cause of down-regulation of E-cadherin which may finally lead to detachment and metastasis of neoplastic cells, 2. mutation in exon 3 of beta-catenin is a rare event in NPC. It may be an early event in the carcinogenesis of NPC but have no significant role in invasion and metastasis and 3. High expression of beta-catenin, as one of NPC characteristics, is not a key factor for invasion or metastasis.

Abnormal Wnt signaling and impaired cell-cell adhesion due to abnormal E-cadherin and beta-catenin function have been implicated in many cancers, but have not been fully explored in nasopharyngeal carcinoma. The aim of this study was to analyze beta-Catenin cellular location and E-cadherin expression levels in nasopharyngeal carcinoma. E-cadherin expression levels were also correlated with clinical data and underlying pathology. beta-Catenin and E-cadherin expression were examined in 18 nasopharyngeal carcinoma and 7 non-tumoral inflammatory pharynx tissues using immunohistochemical methods. Patient clinical data were collected, and histological evaluation was performed by hematoxylin/eosin staining. beta-catenin was detected in membrane and cytoplasm in all cases of nasopharyngeal carcinoma, regardless of histological type; in non-tumoral tissues, however, beta-catenin was observed only in the membrane. As for E-cadherin expression levels, strong staining was observed in most non-tumoral tissues, but staining was only moderate in nasopharyngeal carcinoma tissues. E-cadherin expression was associated with beta-catenin localization, study group, metastatic disease, and patient outcomes. Reduced levels of E-cadherin protein observed in nasopharyngeal carinoma may play an important role in invasion and metastasis. Cytoplasmic beta-catenin in nasopharyngeal carcinoma may impair cell-cell adhesion, promoting invasive behavior and a metastatic tumor phenotype.

expression of vimentin and the epithelial to mesenchymal transition (EMT) markers E-cadherin, beta-catenin is essential for the progression of various human cancers. Our study aimed to investigate the aberrant localization E-cadherin, beta-catenin and vimentin, and their prognostic significance in 122 nasopharyngeal carcinoma (NPC) patients by immunohistochemistry and immunofluorescence. Our results showed that both membranous and cytoplasmic localization of E-cadherin staining were associated with lymph node metastasis (p = 0.000 and 0.005, respectively) and clinical stage (p = 0.000 and 0.007, respectively). High cytoplasmic beta-catenin correlated significantly with larger tumor size (p = 0.020), lymph node metastasis (p = 0.000) and advanced clinical stage (p = 0.036). However, no significant difference was observed between membranous beta-catenin and clinicopathologic features (p >/= 0.05). High nuclear vimentin expression correlated significantly with positive lymph node metastasis (p = 0.000) and advanced clinical stage (p = 0.000). Multivariate analysis showed that nuclear vimentin and cytoplasmic E-cadherin were independent prognostic factors (p = 0.016 and 0.001, respectively), as well as M classification (p = 0.001). More importantly, patients with high coexpression of nuclear vimentin and cytoplasmic E-cadherin had shorter survival time (p = 0.000). Furthermore, high coexpression of these two proteins was closely associated with lymph node metastasis (p = 0.000) and advanced clinical stage (p = 0.000). Our studies provide convincing evidence that EMT may play an important role in the biological progression of NPC, and nuclear vimentin and cytoplasmic E-cadherin might have independent prognostic value in NPC patients and serve as novel targets for prognostic therapeutics.

OBJECTIVE: To evaluate the expression of N-cadherin and beta-catenin protein and their relationship with clinicopathological characteristics of osteosarcoma. METHODS: The expressions of N-cadherin and beta-catenin at protein level were detected by immunohistochemical staining in 54 cases of osteosarcoma, 11 cases of osteoid osteoma, 7 cases of osteoblastoma and 8 cases of newly formed bone in nonmalignant bone diseases. The relationship between the two indexes and clinicopathological characteristics of osteosarcoma was analyzed. RESULTS: In newly formed bone, osteoblastoma, osteoid osteoma and osteosarcoma, the positive expression rate of N-cadherin protein was 75.0%, 71.4%, 63.6% and 35.2%, respectively. The positive expression rate of N-cadherin protein in osteosarcoma was significantly lower than that in osteoid osteoma, osteoblastoma and newly formed bone in nonmalignant bone diseases (P = 0.035). The positive expression rate of N-cadherin protein in osteosarcoma cases with pulmonary metastasis was lower than that in cases without (21.7% vs. 56.3%, P = 0.027). The positive expression rate of N-cadherin protein in osteosarcoma cases died in two years was lower than that in cases lived for more than two years (18.2% vs. 50.0%, P = 0.024). In newly formed bone, osteoblastoma, osteoid osteoma and osteosarcoma, the aberrant expression rate of beta-catenin protein was 12.5%, 28.6%, 27.3% and 66.7%, respectively. The aberrant expression rate of beta-catenin protein in osteosarcoma was significantly higher than that in osteoid osteoma, osteoblastoma and newly formed bone (P = 0.002). Aberrant expression rate of beta-catenin in osteosarcoma cases with pulmonary metastasis was higher than that without (82.6% vs. 43.8%, P = 0.011). An inverse correlation was found between the aberrant expression of beta-catenin and N-cadherin expression in osteosarcoma(r = -0.302, P = 0.027). CONCLUSION: The positive expression rate of N-cadherin is decreased in osteosarcoma while aberrant expression rate of beta-catenin increased. The expression of N-cadherin protein is closely correlated with the metastasis and prognosis of osteosarcoma, but the expression of beta-catenin protein is merely correlated with the metastasis of osteosarcoma.

Ovarian cancer takes a fourth place as cause of death from all cancers and a first place from gynecologic malignancies in Poland. Up to now, relatively little is known about immunohistochemical markers accepted as prognostic indicators for ovarian cancers. Recent investigations took a note of prognostic significance of catenin-cadherin adhesion complex and Ki-67 proliferation protein in serous ovarian cancers. The aim of the study was to evaluate the immunoexpression of beta-catenin and E-cadherin in metastatic and nonmetastatic serous ovarian tumors, as well as to find possible relationships between this immunoexpression and tumor proliferation activity. The analysis comprised of 66 women diagnosed and treated for epithelial ovarian tumors. On immunohistochemical examinations it was found a significantly lower immunoexpression of beta-catenin and E-cadherin in invasive serous ovarian cancers than in cystadenomas. Additionally, in metastatic group the immunoexpression of both beta-catenin and E-cadherin was significantly decreased as compared with patients without metastases. Moreover, the significant inverse correlations have been shown between immunoexpression of Ki-67 and beta-catenin as well as Ki-67 and E-cadherin. In conclusion, our data suggest that decreased immunoexpression of beta-catenin and E-cadherin in serous ovarian tumors may be helpful in identifying the cases of higher metastatic potential and infiltration ability.

The membrane mucin MUC4 is aberrantly expressed in multiple cancers and is of clinical significance to diagnosis and prognosis in pancreatic cancer. However, the role of MUC4 in angiogenesis and the potential association among these malignant capabilities have not been explored. In this study, we investigated the collective signaling mechanisms associated with MUC4-induced growth, metastasis and angiogenesis in pancreatic cancer. Knockdown of MUC4 in two pancreatic cancer cell lines led to downregulation of lysosomal degradation of E-cadherin by Src kinase through downregulation of pFAK and pSrc pathway. The downregulation of lysosomal degradation of E-cadherin in turn induced the formation of E-cadherin/beta-catenin complex and membrane translocation of beta-catenin, resulting in the downregulation of Wnt/beta-catenin signaling pathway. Thus, the Wnt/beta-catenin target genes c-Myc, Cyclin D1, CD44 and VEGF were down-regulated and their malignant functions proliferation, metastasis and angiogenesis were reduced. Taken together, MUC4-induced nuclear translocation of beta-catenin is a novel mechanism for growth, metastasis and angiogenesis of pancreatic cancer.

BACKGROUND: The expression of E-cadherin in the intercellular adhesion of metastatic prostate cancer cells in bone, which is the most prevalent site of metastatic growth, remains elusive. METHODS: The aim of the study was to compare the concurrent membranous expression of E-cadherin and beta-catenin proteins, the state which is known to be associated with the cellular adhesion function of E-cadherin, in prostate biopsy tissue specimens by immunohistochemical staining method. The expression patterns of E-cadherin or beta-catenin were classified as homogeneous (most cells exhibiting positively), heterogeneous (a few scattered patches of cells with positivity) or negative. RESULTS: Benign prostate hyperplasia cells exhibited homogeneous expression of both E-cadherin and beta-catenin in 9 of 11 (82%), whereas the primary prostate cancer cells were homogeneously positive for both proteins only in 4 of 22 (18%) of the cases. The results are similar to those reported in literature. However, in contrast to the primary cancer, a significantly increased frequency of the metastatic prostate cancer cells in bone exhibited homogeneous expression of E-cadherin and beta-catenin in 12 of 17 (71%) of the cases. A statistically significant association was observed between the overexpression of both proteins and the metastatic prostate cancer cells in bone (Fisher's exact P < 0.001). CONCLUSIONS: The result of the study demonstrated for the first time that the membranous overexpression of E-cadherin and beta-catenin are significantly associated with the metastatic prostate cancer cells in bone and that the high frequency of expression suggest their involvement in the intercellular adhesion of the metastatic cells in bone.

OBJECTIVES: E-cadherin and beta-catenin are adhesion molecules responsible for the maintenance of normal epithelial cell phenotype. A disturbance in epithelial cell adhesion, which leads to a more invasive and metastatic phenotype, is a hallmark of tumor progression. Several immunohistochemical studies have reported a strong correlation between loss of their expression to higher stage and grade in prostate carcinoma, but their influence in metastatic process is not yet known. The aim of this study is to verify the role of adhesion molecules in the progression of prostate cancer (PC), assessing the expression of E-cadherin and beta-catenin in bone metastasis. MATERIALS AND METHODS: Twenty-eight bone metastases of prostate carcinoma were submitted to immunohistochemistry analysis for E-cadherin and beta-catenin expression. In 6 patients, we were able to assess the expression of the adhesion molecules in the primary tumors and their respective metastases. The definition of normal expression for both antibodies was strong and diffuse expression in more than 70% of tumor cells. RESULTS: In bone metastases, there was loss of expression of E-cadherin and beta-catenin in 86% and 82%, respectively. Among the primary tumors, E-cadherin and beta-catenin expression was normal in 83% and 50% cases, respectively. Considering the 6 patients with paired primary and bone metastasis, we found loss of expression for both E-cadherin and beta-catenin in most of the cases. CONCLUSIONS: Comparing primary PC and its metastasis, we showed persistent loss of E-cadherin and beta-catenin expression. This phenomenon may be related to metastatic potential in PC, because we have shown underexpression for E-cadherin and beta-catenin in 86% and 82% of bone metastases.

BACKGROUND: Currently available methods for diagnosis and staging of prostate cancer lack the sensitivity to distinguish between patients with indolent prostate cancer and those requiring radical treatment. Alterations in key adherens (AJ) and tight junction (TJ) components have been hailed as potential biomarkers for prostate cancer progression but the majority of research has been carried out on individual molecules. OBJECTIVE: To elucidate a panel of biomarkers that may help distinguish dormant prostate cancer from aggressive metastatic disease. METHODS: We analysed the expression of 7 well known AJ and TJ components in cell lines derived from normal prostate epithelial tissue (PNT2), non-invasive (CAHPV-10) and invasive prostate cancer (LNCaP, DU145, PC-3) using gene expression, western blotting and immunofluorescence techniques. RESULTS: Claudin 7, alpha -catenin and beta-catenin protein expression were not significantly different between CAHPV-10 cells and PNT2 cells. However, in PC-3 cells, protein levels for claudin 7, alpha -catenin were significantly down regulated (-1.5 fold, p = <.001) or undetectable respectively. Immunofluoresence showed beta-catenin localisation in PC-3 cells to be cytoplasmic as opposed to membraneous. CONCLUSION: These results suggest aberrant Claudin 7, alpha - and beta-catenin expression and/or localisation patterns may be putative markers for distinguishing localised prostate cancer from aggressive metastatic disease when used collectively.

The aims of this study were to investigate the expression levels of beta-catenin, Pin1 and cyclin D1 in salivary adenoid cystic carcinomas (SACC ) and to evaluate its clinical importance, furthermore, to elucidate whether beta-catenin expression was aberrant in SACC and whether Pin1 was involved in aberrant beta-catenin and cyclin D1 expression. The expression of Pin1, beta-catenin and cyclin D1 were examined in the specimens of 65 patients with SACC by immunohistochemistry, protein and mRNA expressions were detected by western blotting and RT-PCR in four SACC cell lines. Pin1 was overexpressed in 51 cases of SACC (78%), and high levels of Pin1 expression correlated with cyclin D1 positive expression (p = 0.02). Fourteen (22%) cases showed positive immunoreactivity for beta-catenin protein in the nuclear/cytoplasmic fraction in tumor tissues, which was defined as cytoplasm/nucleus staining, among which quite evident nuclear expression of beta-catenin was detected in six cases (9%), while cyclin D1 positive expression was detected in 41 cases of SACC (63%). Reduced membranous expression of beta-catenin was detected in the cases with metastasis (11/14). Theses results suggest that Pin1 and Wnt signalling pathway are activated in SACC and may play a pivotal role in SACC carcinogenesis and metastasis.

We analyzed promoter methylation of RASSF1A, CTNNB1, CDH1, LAMB3, LAMC2, RUNX3, NORE1A, and CAV1 using methylation-specific PCR in 33 cases of small bowel carcinoid with both matched primary and metastatic tumors. The methylation status of RASSF1A and CTNNB1 were also determined in six primary appendiceal carcinoid tumors. Two neuroendocrine cell lines, NCI-H727 and HTB-119, were analyzed for promoter methylation. Immunohistochemical analyses for RASSF1A and beta-catenin were performed in 28 matched primary and metastatic tumors. Western blot analysis for RASSF1A and beta-catenin was also performed. Normal enterochromaffin cells were unmethylated in all eight genes examined. RASSF1A and CTNNB1 were unmethylated in appendiceal carcinoids. Methylation of RASSF1A and CTNNB1 promoters was more frequent in metastatic compared to primary tumors (p = 0.013 and 0.004, respectively). The NCI-H727 and HTB-119 cells lines were methylated in the RASSF1A promoter region, and after treatment with 5-aza-2-deoxycytidine (5-AZA), RASSF1A mRNA was expressed in both cell lines. Western blot results for RASSF1A and beta-catenin supported the methylation-specific PCR findings. The other six genes did not show significant differences. These results suggest that increased methylation of RASSF1A and CTNNB1 may play important roles in progression and metastasis of small bowel carcinoid tumors.

The RET receptor tyrosine kinase has essential roles in cell survival, differentiation, and proliferation. Oncogenic activation of RET causes the cancer syndrome multiple endocrine neoplasia type 2 (MEN 2) and is a frequent event in sporadic thyroid carcinomas. However, the molecular mechanisms underlying RET's potent transforming and mitogenic signals are still not clear. Here, we show that nuclear localization of beta-catenin is frequent in both thyroid tumors and their metastases from MEN 2 patients, suggesting a novel mechanism of RET-mediated function through the beta-catenin signaling pathway. We show that RET binds to, and tyrosine phosphorylates, beta-catenin and show that the interaction between RET and beta-catenin can be direct and independent of cytoplasmic kinases, such as SRC. As a result of RET-mediated tyrosine phosphorylation, beta-catenin escapes cytosolic down-regulation by the adenomatous polyposis coli/Axin/glycogen synthase kinase-3 complex and accumulates in the nucleus, where it can stimulate beta-catenin-specific transcriptional programs in a RET-dependent fashion. We show that down-regulation of beta-catenin activity decreases RET-mediated cell proliferation, colony formation, and tumor growth in nude mice. Together, our data show that a beta-catenin-RET kinase pathway is a critical contributor to the development and metastasis of human thyroid carcinoma.