Difference In E-cadherin Expression Research Articles

Insights into E-Cadherin Impairment in CDH1-Unaltered Invasive Lobular Carcinoma: A Comprehensive Bioinformatic Study.

Invasive lobular carcinoma exhibits unique morphological features frequently associated with alterations in CDH1. Although some studies have identified abnormalities in adhesion factors other than E-cadherin, the molecular mechanisms underlying E-cadherin abnormalities in CDH1-unaltered invasive lobular carcinoma remain poorly understood. In this study, we investigated the molecular underpinnings of E-cadherin dysregulation in invasive lobular carcinoma in the absence of CDH1 gene alterations, using comprehensive bioinformatic analyses. We conducted a comparative study of CDH1-mutated and non-mutated invasive lobular carcinoma and evaluated the differences in mRNA levels, reverse-phase protein array, methylation, and miRNAs. We observed that invasive lobular carcinoma cases without CDH1 alterations exhibited a significantly higher incidence of the Claudin-low subtype (p < 0.01). The results of the reverse-phase protein array indicate no significant difference in E-cadherin expression between CDH1-mutated and non-mutated cases. Therefore, abnormalities in E-cadherin production also exist in CDH1 non-mutated invasive lobular carcinoma. Considering that there are no differences in mRNA levels and methylation status, post-translational modifications are the most plausible explanation for the same. Hence, future studies should focus on elucidating the mechanism underlying E-cadherin inactivation via post-translational modifications in CDH1 non-mutated invasive lobular carcinoma.

English

BACKGROUND Early diagnosis of colorectal cancer is associated with a good prognosis and uncovering the biological mechanisms underlying pathogenesis and progression of this cancer form the recent focus of research. E-cadherin is one of the strong intercellular adhesion molecules in epithelial cells and one of the best characterized markers of epithelial-mesenchymal transition. The objectives of this study were to assess the pattern of expression of E-cadherin in colorectal cancer in patients from a medical college in Kerala, India and also determine the association between the expression of E-cadherin and different morphological parameters as well as the grade and stage of the tumour. METHODS All specimens of histologically diagnosed colorectal cancers received in the department were included in the study. Immunohistochemical staining of formalinfixed paraffin-embedded tissue was done. The intensity of E-cadherin staining was scored and analyzed for different tissues. Frequency tables of different variables were analyzed using the chi-square test. The significance of the correlation between different variables was assessed using Fischer’s exact test. P-value &lt; 0.05 was considered statistically significant. RESULTS A total of 43 specimens of histologically diagnosed colorectal cancers were analyzed for the study. The mean age of the participants was 58 years. Majority of the tumours were &lt; 5 cm in size. Both homogenous (55.8 %) and heterogeneous staining (44.2 %) were noted in the E-cadherin staining pattern among the participants. In patients with low E-cadherin index, 12 of them showed a heterogeneous pattern of expression. E-cadherin expression was not statistically associated with tumour differentiation in the patients. CONCLUSIONS There is a significant difference in E-cadherin expression between low and highgrade tumours of colorectal cancer. High-grade tumours showed a more heterogeneous staining pattern correlating with increased invasiveness of the tumour. The heterogeneous pattern of staining in E-cadherin among adjacent cells of tumour results from reduced expression of the protein in the tumour. KEY WORDS E cadherin, Colorectal Cancer, Cancer Marker.

Propolin C Inhibited Migration and Invasion via Suppression of EGFR-Mediated Epithelial-to-Mesenchymal Transition in Human Lung Cancer Cells.

Controlling lung cancer cell migration and invasion via epithelial-to-mesenchymal transition (EMT) through the regulation of epidermal growth factor receptor (EGFR) signaling pathway has been demonstrated. Searching biological active phytochemicals to repress EGFR-regulated EMT might prevent lung cancer progression. Propolis has been used as folk medicine in many countries and possesses anti-inflammatory, antioxidant, and anticancer activities. In this study, the antimigration and anti-invasion activities of propolin C, a c-prenylflavanone from Taiwanese propolis, were investigated on EGFR-regulated EMT signaling pathway. Cell migration and invasion activities were dose-dependently suppressed by noncytotoxic concentration of propolin C. Downregulations of vimentin and snail as well as upregulation of E-cadherin expressions were through the inhibition of EGFR-mediated phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) and extracellular signal-regulated kinase (ERK) signaling pathway in propolin C-treated cells. In addition, EGF-induced migration and invasion were suppressed by propolin C-treated A549 lung cancer cells. No significant differences in E-cadherin expression were observed in EGF-stimulated cells. Interestingly, EGF-induced expressions of vimentin, snail, and slug were suppressed through the inhibition of PI3K/Akt and ERK signaling pathway in propolin C-treated cells. Inhibition of cell migration and invasion by propolin C was through the inhibition of EGF/EGFR-mediated signaling pathway, followed by EMT suppression in lung cancer.

FGFR3 silencing by siRNA inhibits invasion of A549 cells.

The present study identified that fibroblast growth factor receptor 3 (FGFR3) was significantly upregulated in bone metastasis of lung adenocarcinoma. RNA interference (RNAi) is a powerful approach for treating a wide range of human diseases, including cancer, through downregulating the expression of selected genes. In the present study, the invasiveness of A549 cells cultured in vitro was altered by small interfering (si)RNA targeting FGFR3, and the regulatory effect of silencing FGFR3 on the expression levels of E-cadherin and matrix metalloproteinase (MMP)9 was investigated. Human lung adenocarcinoma A549 cells were transfected with synthetic specific siRNAs targeting a fragment of the FGFR3 gene (namely, siRNA-855, siRNA-1447 and siRNA-2076) or with negative control (NC) siRNA. Cells were divided into five groups (A, siRNA-855 group; B, siRNA-1447 group; C, siRNA-2076 group; D, NC-siRNA group; and E, blank control group). The effect of the above siRNAs targeting FGFR3 on the invasion capacity of A549 cells was detected by Transwell assay. siRNAs against FGFR3 were transfected into A549 cells with by Lipofectamine® 2000, and the expression levels of FGFR3, E-cadherin and MMP9 were measured by reverse transcription-quantitative polymerase chain reaction and western blot assay. The experimental findings indicated that the expression levels of FGFR3 and MMP9 were significantly reduced in the siRNA-FGFR3-transfected groups (A-C groups), compared with those in the D and E groups (P<0.01). In addition, the expression levels of E-cadherin were markedly elevated in the A-C groups, compared with those in the D and E groups (P<0.01). There was no significant difference in E-cadherin expression between the A-C groups, or between the D and E groups (P>0.05). These results indicated that siRNA-FGFR3 was able to decrease the invasiveness of A549 cells, inhibit the expression of MMP9 and increase the expression of E-cadherin by downregulating the expression of FGFR3. Taken together, the results of the present study indicated that the upregulation of E-cadherin expression and the downregulation of MMP9 expression are able to inhibit the migration of A549 cells, and siRNA silencing FGFR3 acts as a tumor suppressor in these cells.

Pleomorphic adenoma and adenoid cystic carcinoma of salivary glands: E-cadherin immunoexpression and analysis of the CDH1 -160C/A polymorphism

ObjectiveDespite their similar cellular origin, pleomorphic adenomas (PA) and adenoid cystic carcinomas (ACC) present distinct behaviors. This study aimed to analyze the immunoexpression of E-cadherin in PA and ACC of salivary glands, and to investigate differences in its expression in relation to E-cadherin gene (CDH1) -160C/A polymorphism. DesignTwenty-four PA (15 cell-rich and 9 cell-poor tumors) and 24 ACC (10 tubular, 8 cribriform and 6 solid tumors) were selected for the analysis of pattern of distribution, and cellular localization of E-cadherin. In addition, E-cadherin expression was evaluated using the H-score scoring system. The CDH1 -160C/A polymorphism was investigated by PCR-RFLP. ResultsNo significant differences in pattern of distribution (p=0.181) and cellular localization (p=0.192) of E-cadherin were observed between PA and ACC. Comparison of PA and ACC cases revealed a higher median H-score in the latter (p=0.036). Cell-rich PA presented a higher H-score than cell-poor tumors (p=0.013), whereas no significant differences in E-cadherin expression were observed between ACC subtypes (p=0.254). The heterozygous genotype of the CDH1 -160C/A polymorphism was detected in only one PA and one ACC. H-scores for tumors carrying the polymorphism were below the lower quartile of their respective groups. ConclusionsThe results suggest that E-cadherin expression in PA and ACC is mainly related to cellular composition (epithelial cells versus myoepithelial cells) and degree of differentiation of myoepithelial cells in these tumors. The CDH1 -160C/A polymorphism does not seem to significantly influence the expression of E-cadherin in PA and ACC of salivary glands.

Abstract 3451: Breast cancer risk factor associations by loss of E-cadherin tumor tissue expression: A pooled analysis of 5,896 cases in 12 studies from the Breast Cancer Association Consortium (BCAC)

Abstract Purpose: Expression of the tumor suppressor gene E-cadherin is diminished in lobular breast cancers and has been implicated in epithelial mesenchymal transition. We assessed risk factor associations for breast cancer stratified by low vs. high E-cadherin protein expression in a pooled analysis within the Breast Cancer Association Consortium (BCAC) studies. Methods: E-cadherin tumor tissue staining was performed centrally at the NCI on formalin-fixed paraffin-embedded tissue microarray (TMA) sections representing 6,010 breast cancer patients from 12 US and European BCAC studies. TMAs were digitally scanned and scored using the SlidePath Digital Image Hub (Leica Biosystems, Wetzlar, Germany). For 5,896 cancers with evaluable tumors, E-cadherin was visually scored as estimated percent of positive cells times stain intensity (0, 1+, 2+, 3+) (score range 0-300). E-cadherin low was defined as tumors with a score &amp;lt; 100. Risk factor associations for low vs. high E-cadherin expressing tumors were evaluated by logistic regression, adjusted for age and study site, and stratified by ER status and histologic subtype. To assess the consistency in results by study, meta-analyses were performed using the random-effects model. All statistical tests were two-sided. Results: E-cadherin low cancers comprised 20% of tumors and were associated with lobular histology, well/moderately differentiated cancers, &amp;gt; 2cm in size, and HER2-negative status (χ2, P &amp;lt; 0.003 for all factors). E-cadherin low status was associated with family history of breast cancer (FH) (OR = 1.32, 95% CI = 1.09-1.60, P-het = 0.005) and ever use of menopausal hormones (OR = 1.26, 95% CI = 1.02-1.56, P-het = 0.03). Study specific meta-plots showed consistent effects across studies for menopausal hormone therapy (I2 = 0.0%, p = 0.64); however, E-cadherin loss by FH did show evidence of heterogeneity by study (I2 = 54%, P = 0.03). Differences in E-cadherin expression remained significant for FH, and menopausal hormone use when further adjusted for ER (P &amp;lt; 0.05). We also found relationships with E-cadherin loss to vary by BMI, number of live births, age at first birth, and oral contraceptive use in stratified analysis by ER status and histologic subtype. Conclusion: This large pooled analysis shows that breast cancer risk factor associations may differ by E-cadherin expression independent of ER status, suggesting that it may represent a marker of etiologic heterogeneity. Citation Format: Hisani N. Horne, Hannah Oh, Mark E. Sherman, Maya Palakal, Stephen H. Hewitt, Marjanka Schmidt, Javier Benitez, Roger Milne, Hermann Brenner, Heli Nevanlinna, Arto Mannermaa, Georgia Chenevix-Trench, Fergus Couch, Peter Devilee, Diana Eccles, Maartje Hooning, Anthony J. Swerdlow, Nick Orr, Melissa A. Troester, Renata Cora, Paul D. Pharoah, Montserrat Garcia-Closas, Jonine D. Figueroa. Breast cancer risk factor associations by loss of E-cadherin tumor tissue expression: A pooled analysis of 5,896 cases in 12 studies from the Breast Cancer Association Consortium (BCAC). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3451.

E-cadherin expression in obesity-associated, Kras-initiated pancreatic ductal adenocarcinoma in mice

The epithelial-mesenchymal transition (EMT) is critical in the development of invasive epithelial malignancies. EMT is accelerated by inflammation and results in decreased E-cadherin expression. Diet-induced obesity is an inflammatory state that accelerates pancreatic carcinogenesis; its effect on EMT and E-cadherin expression in the development of pancreatic ductal adenocarcinoma is unclear. Conditional Kras(G12D) mice were fed a control diet or a high-fat, high-calorie diet for 3 or 9 months (n = 10 each). Immunohistochemistry with anti-E-cadherin antibody was performed. E-cadherin expression was characterized by staining intensity, location, and proportion of positive cells. In vitro expression of E-cadherin and Slug in primary pancreatic intraepithelial neoplasia (PanIN) and cancer cells was determined by Western blot. The HFCD led to increased weight gain in both 3- (15.8 vs 5.6 g, P < .001) and 9-month (19.8 vs 12.9 g, P = .007) mice. No differences in E-cadherin expression among various stages of preinvasive PanIN lesions were found--regardless of age or diet. In invasive cancer, E-cadherin expression was aberrant, with loss of membranous staining and prominent cytoplasmic staining, associated with strong, cytoplasmic expression of β-catenin. In vitro expression of E-cadherin was greatest in primary PanIN cells, accompanied by absent Slug expression. Cancer cell lines demonstrated significantly decreased E-cadherin expression in the presence of upregulated Slug. Despite increased pancreatic inflammation and accelerated carcinogenesis, the high-fat, high-calorie diet did not induce changes in E-cadherin expression in PanIN lesions of all stages. Invasive lesions demonstrated aberrant cytoplasmic E-cadherin staining. Loss of normal membranous localization may reflect a functional loss of E-cadherin.

Colorectal adenocarcinoma with mucinous component: relation of MMP-13, EGFR, and E-cadherin expressions to clinicopathological features and prognosis.

The aim of this study was to compare colorectal adenocarcinoma with mucinous component, ordinary adenocarcinoma (OA) and mucinous adenocarcinoma (MA) regarding clinicopathological parameters, survival, EGFR, MMP-13, and E-cadherin. We studied tumor tissue specimens from 28 patients with adenocarcinoma with mucinous component, 47 with OA, and 56 with MA, who underwent radical surgery from January 2007 to January 2012 at the Gastroenterology Centre, Mansoura University, Egypt. High density manual tissue microarrays were constructed and immunohistochemistry for EGFR, MMP-13, and E-cadherin was done. Colorectal adenocarcinoma with mucinous component (AWMC) was significantly associated with more perineural invasion, lower EGFR, and MMP-13 expressions than OA, with no difference in E-cadherin expression. Conversely, only microscopic abscess formation was significantly more with colorectal AWMC than MC with no difference in EGFR, MMP-13 and E-cadherin expression between both groups. Colorectal AWMC showed a better survival than MA with no difference with OA. In a univariate analysis, EGFR, MMP-13, and E-cadherin expressions did not show a significant impact on disease-free or overall survival in patients with colorectal AWMC. Colorectal AWMC remains a vague entity that resembles OA in some clinicopathological and molecular respects as well as MA.

E-cadherin as a potential biomarker of malignant transformation in oral leukoplakia: a retrospective cohort study.

BackgroundNumerous attempts have been made to establish and develop tumor markers that could determine the susceptibility of normal tissues to transform into cancerous ones. To determine whether altered expression patterns of E-cadherin could be an early event in the progression of potentially malignant disorders to oral squamous cell carcinoma, this study aimed to assess the relationship between the immunoexpression of E-cadherin and the different degrees of epithelial dysplasia in oral leukoplakia.MethodsSurgically excised specimens from patients with oral leukoplakia (n = 31), oral cavity squamous cell carcinoma with cervical lymph node metastasis (n = 12) and normal oral mucosa (n = 9) were immunostained for E-cadherin. Oral leukoplakia samples were distributed into low and high risk group according to a binary system for grading oral epithelial dysplasia. Comparative analyses between E-cadherin expression and microscopic features (WHO histological grading and epithelial dysplasia) were performed by Pearson Chi-square test (P < 0.05).ResultsDifferences in E-cadherin expression were observed between normal oral mucosa and low risk oral leukoplakia (P = 0.006), low and high risk oral leukoplakia (P = 0.019), and high risk oral leukoplakia and oral cavity squamous cell carcinoma with cervical lymph node metastasis (P = 0.0001). In addition, as epithelia undergo dysplastic changes, the risk of malignant transformation increases, and there is a reduction or loss of E-cadherin expression by keratinocytes. Reduced E-cadherin expression was an early phenomenon and it was observed in moderate-severe dysplasia, showing that the loss of epithelial cohesion may be an indicator of progression to oral cavity squamous cell carcinoma.ConclusionsE-cadherin could be used as a novel biomarker to identify lesions with potential risk for malignant transformation, which may provide opportunities for prophylactic interventions in high risk patient groups.

37-kDa laminin receptor precursor promotes lung adenocarcinoma cell invasion and metastasis by epithelial-to-mesenchymal transition.

37-kDa laminin receptor precursor (37LRP) has a crucial role in migration of some human cancers. Epithelial-to-mesenchymal transition (EMT) has received much attention in invasion and metastasis of lung cancer. Nevertheless, the role of 37LRP is not entirely clear in EMT promotion of lung cancer at present. In this study, we firstly examined the possible role of 37LRP in the invasiveness and metastasis process of lung cancer using immunohistochemistry of 80 lung adenocarcinoma cases, western blot and real-time PCR of 12 fresh lung adenocarcinoma tissues. The results showed that 37LRP significantly correlated with clinical stage and were highly expressed in metastatic lung adenocarcinomas compared with nonmetastatic ones. In vitro, we observed that 37LRP significantly increased the adhesive, invasive and metastatic abilities of human lung adenocarcinoma cell lines A549 by 37LRP-lentivirus interference. Furthermore, inoculation of A549 cells transduced with 37LRP-lentivirus in nude mice resulted in multi-metastases including the lung. In addition, western blotting and immunofluorescence were used to detect the significant difference in expression of E-cadherin and fibronectin in A549 by 37LRP-lentivirus interference compared with 37LRP-small interference RNA-lentivirus interference in vitro and vivo. The data indicated that A549 cells of epithelial cell characteristics might be induced to undergo EMT by 37LRP. A549 cells transduced with 37LRP-lentivirus showed marked morphological changes, accompanied by the decrease of epithelial marker E-cadherin and the increase of mesenchymal marker fibronectin. These results indicated that 37LRP may promote lung adenocarcinoma invasion and metastasis via the mechanism of EMT.

Colorectal adenocarcinoma with mucinous activity: relation of EGFR, MMP-13 and E-cadherin expressions to clinicopathological features and prognosis

Colorectal adenocarcinoma with mucinous activity (AWMA) is an entity of ordinary adenocarcinoma that shows mucin secretion less than 50% of the tumor. Whether it resembles ordinary adenocarcinoma (OA) or mucoid adenocarcinoma (MA) is still questionable. We aimed to compare AWMA, OA and MA regarding clinicopathological, histological parameters, survival, EGFR, MMP-13 and E-cadherin expressions. We studied tumor tissue specimens from 28 patients with AWMA, 47 patients with OA and 56 patients with MA. High density manual tissue microarrays were constructed using modified mechanical pencil tips technique. AWMA was significantly associated with more perineural invasion, lower EGFR and MMP-13 expressions than O A, with no difference in E-cadherin expression. Conversely, only microscopic abscess formation was significantly more with AWMA than MA with no difference in EGFR, MMP-13 or E-cadherin expressions. AWMA showed a better survival than MA with no difference with OA. EGFR, MMP-13 and E-cadherin expressions did not show a significant impact on disease-free or overall survival in patients with AWMA. In summary, based on the clinicopathological and molecular findings, AWMA resembles MA more than OA. The contrary is true regarding survival. AWMA remains a vague entity that needs further molecular studies to be grouped with either OA or MA.

Epithelial-to-Mesenchymal Transition Leads to Docetaxel Resistance in Prostate Cancer and Is Mediated by Reduced Expression of miR-200c and miR-205

Docetaxel is a standard chemotherapy for patients with metastatic prostate cancer. However, the response is rather limited and not all of the patients benefit from this treatment. To uncover key mechanisms of docetaxel insensitivity in prostate cancer, we have established docetaxel-resistant sublines. In this study, we report that docetaxel-resistant cells underwent an epithelial-to-mesenchymal transition during the selection process, leading to diminished E-cadherin levels and up-regulation of mesenchymal markers. Screening for key regulators of an epithelial phenotype revealed a significantly reduced expression of microRNA (miR)-200c and miR-205 in docetaxel-resistant cells. Transfection of either microRNA (miRNA) resulted in re-expression of E-cadherin. Functional assays confirmed reduced adhesive and increased invasive and migratory abilities. Furthermore, we detected an increased subpopulation with stem cell-like properties in resistant cells. Tissue microarray analysis revealed a reduced E-cadherin expression in tumors after neoadjuvant chemotherapy. Low E-cadherin levels could be linked to tumor relapse. The present study uncovers epithelial-to-mesenchymal transition as a hallmark of docetaxel resistance. Therefore, we suggest that this mechanism is at least in part responsible for chemotherapy failure, with implications for the development of novel therapeutics.

CDH1 promoter polymorphism (-347G→GA) is a possibleprognostic factor in sporadic colorectal cancer

To investigate the role of the -347G-->GA polymorphism in the progression of colorectal cancer (CRC). We designed a case-control study based on a population of CRC patients in China and normal healthy controls with no history of tumors or inherited diseases. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses were used to genotype the variants, and immunohistochemical staining was performed to measure the expression of E-cadherin in different allele cases among the CRC patients and normal controls. The GA-allele (G/GA heterozygous and GA/GA homozygous) did not increase the risk of CRC compared with the G-allele (OR=1.232, 95% CI=0.898-1.691). However, the frequencies of the GA-allele were higher in poorly differentiated (P=0.002) and proximal (P=0.019) CRC patients than in normal controls. We also observed that E-cadherin expression was lower in poorly differentiated CRC patients than in well differentiated CRC patients (P=0.001). Furthermore, E-cadherin expression was lower for the GA-allele than for the G-allele (G/G heterozygous) in CRC patients (P=0.018). In contrast, there was no significant difference in E-cadherin expression for the G-allele and GA-allele in normal controls (P=0.292). The -347G-->GA promoter polymorphism in E-cadherin gene is associated with specific CRC features, and may be a prognostic factor rather than a susceptibility factor during the progression of CRC.

E-cadherin but not β-catenin expression is decreased in laryngeal biopsies from patients with laryngopharyngeal reflux

Abnormal exposure of acid refluxate on the esophageal mucosa has been shown to decrease the epithelial barrier function through an alteration in the intercellular junctional complex. However, only few studies have examined the molecular effects caused by abnormal exposure of gastric refluxate on the laryngeal epithelium. E-cadherin and beta-catenin are cell membrane-associated proteins playing a major role in the maintenance of cell-cell adhesion in epithelial tissues. In this study we tried to analyse the molecular effect of laryngopharyngeal reflux (LPR) on the cellular expression of these proteins. Therefore, we compared the expression of E-caherin and beta-catenin in laryngeal biopsies from patients with and without pH-documented laryngopharyngeal reflux. Paraffin-embedded archival laryngeal biopsies taken from 21 patients, who had undergone rigid laryngoscopy under general anaesthesia and postoperative 24-h pH monitoring, were evaluated immunohistochemically with antibodies to E-cadherin and beta-catenin. The membrane expression of the two proteins was categorized in no expression, mild, moderate and strong (grade 0-3). In LPR patients (n=14) the mean grade of E-cadherin and beta-catenin expression was 1.57 and 1.21, while in specimens of patients without pH-documented LPR it was 2.57 and 1.29. The difference in E-cadherin expression was statistically significant (P=0.011). From our findings we conclude that LPR can cause a decrease in the laryngeal expression of E-cadherin but not of beta-catenin. The reduction of E-cadherin-mediated adhesion could contribute to the development of laryngeal neoplasms. E-cadherin immunostaining of laryngeal biopsies could be a further diagnostic tool to confirm the diagnosis in patients with suspected LPR.

Expression of adhesion proteins E-cadherin, α-catenin, β-catenin and γ-catenin is different in T1 and T2 breast tumours

Breast cancer is the most common malignancy in women. Although an increasing number of patients with breast cancer are being cured by surgery, a considerable number of patients suffer relapse in the form of metastases after surgery. E-cadherin and catenins have documented roles in breast cancer progression. Mammography is supposed to decrease breast cancer mortality by detecting tumours while they are small and before they have reached a clinically detectable stage. In the present study, we wanted to evaluate whether there are differences in expression patterns of adhesion proteins, shown to be crucial in the metastatic process, between small tumours detected by mammography and clinically detected large tumours. Expression of E-cadherin, alpha-catenin, beta-catenin and gamma-catenin was analysed using immunohistochemistry methods in 86 invasive breast carcinomas detected by mammography and compared with 90 clinically palpable invasive breast carcinomas. In the group of tumours detected by mammography (86 samples), reduced expression of E-cadherin was observed in 12 (14%) samples. Reduced expression of alpha-catenin was observed in four (4.6%) samples, and three (3.5%) samples showed reduced expression of beta-catenin. All samples showed strong expression of gamma-catenin. When expression patterns of these proteins were evaluated in 90 clinically detected tumours, we observed reduced expression of E-cadherin in 58 (64.4%) samples, 12 (13.3%) samples showed reduced expression of alpha-catenin, while nine (10%) samples showed reduced expression of beta-catenin. Strong expression of gamma-catenin was detected in all tumours also in this group.Statistical analyses revealed a highly significant difference in expression of E-cadherin (p<0.001). However, no statistically significant differences were observed in expression of alpha-catenin (p = 0.081) and beta-catenin (p = 0.092) between the two groups of tumours. Results indicate that T1 breast tumours harbour less alterations in E-cadherin-catenin complexes and therefore are probably less likely to disseminate, and patients probably have a better prognosis than if tumours are diagnosed as T2.

Reduced E-cadherin and α-catenin expressions have no prognostic role in bladder carcinoma

In various human cancers, dysfunction of the E-cadherin-catenin complex is associated with a decrease in cellular and tissue differentiation, and with higher invasive and metastatic potentials. The objective of this study was to investigate E-cadherin and alpha-catenin expression in superficial noninvasive papillary TCC and invasive TCC, and correlate these results with pathological and clinical parameters. We have used immunohistochemistry to localize Ecadherin and alpha-catenin in 56 formalin-fixed, paraffin-embedded tissue blocks from 41 patients with superficial bladder cancer and 15 with invasive bladder cancer. The 46 male and 10 female patients had a mean age of 67 years, with range of 40 to 82 years. The mean follow-up time was 33.4 (range 5-120) months. Tumor grade 1:2:3 ratios were 5:32:19. In superficial bladder tumor, abnormal expression of E-cadherin and alpha-catenin was demonstrated in 37 and 71% of the tumors, respectively. In advanced bladder tumor, abnormal expression of E-cadherin and alpha-catenin was demonstrated in 80 and 100% of the tumors, respectively. Differences in expression of E-cadherin and alpha-catenin could be discerned between superficial and advanced bladder tumors (p=0.004, p=0.024, respectively). However, the association between E-cadherin and alpha-catenin expression and tumor grade was not statistically significant (p>0.05). In addition, the expression of E-cadherin and alpha-catenin did not correlate with tumor number and size (p>0.05). We have demonstrated that abnormal expression of E-cadherin and/or alpha-catenin occurs in more than 85% of bladder carcinomas and correlates significantly only with advanced stage. Nevertheless, these observations need to be confirmed in larger prospective clinical studies.

Disordered beta-catenin expression and E-cadherin/CDH1 promoter methylation in gastric carcinoma

To investigate the distribution of beta-catenin in nuclei or membrane/cytoplasm of gastric carcinoma cells, the relationship between E-cadherin gene methylation and its expression, and the role of beta-catenin and E-cadherin as potential molecular markers in predicting tumor infiltration. Twenty-nine cases of gastric carcinoma, classified as diffuse and intestinal variants, were selected for study. Nuclear and cytoplasmic proteins were purified and beta-catenin content was detected by ELISA. DNA methylation of E-cadherin/CDH1 gene promoter was studied by methylation-specific PCR and compaired with E-cadherin expression detected by immunohistochemistry. In 27 cases of gastric carcinoma, the ratio of beta-catenin content between nuclei and membrane/cytoplasm was correlated with the T-classification (r = 0.392, P = 0.043). The significance was present between T2 and T3 groups. No correlation was detected between diffuse and intestinal variants in terms of their beta-catenin distribution. In 21 cases of diffuse variants of gastric carcinoma, there was a difference in E-cadherin expression between CDH1 gene-methylated group and non-methylated group (29 % vs 71 %, P = 0.027). No correlation between CDH1 gene methylation and T-classification was found, neither was the significance between E-cadherin expression and tumor infiltration grade. Comparative analysis of nuclear and membrane/cytoplasmic beta-catenin can predict local tumor infiltration. E-cadherin/CDH1 gene methylation is an important cause for its gene silence in diffuse variant gastric carcinoma. Methylation of CDH1 gene in the absence of E-cadherin is an early event in gastric carcinogenesis.

Reciprocal altered expression of T-cadherin and P-cadherin in psoriasis vulgaris.

The most characteristic change in psoriasis vulgaris is markedly increased, persistent keratinocyte proliferation. The underlying mechanism of excessive epidermal growth is controversial. We previously found and reported that T-cadherin was expressed in keratinocytes and confined to the basal layer of mouse and human skin. Invasive cutaneous squamous cell carcinoma showed a loss of T-cadherin expression. Another study showed that T-cadherin was a negative growth regulator of epidermal growth factor in T-cadherin transfectant neuroblastoma cells. To obtain insight into the role of T-cadherin in keratinocyte proliferation and to investigate further the pathogenesis of psoriasis vulgaris, we examined the expression of T-cadherin, as well as E- and P-cadherin, in psoriasis vulgaris. Four untreated active psoriatic skin samples from psoriasis vulgaris patients and four normal human skin samples from plastic surgery were collected, cryosectioned and immunohistochemically stained by antihuman T-, P- and E-cadherin antibodies. Further, the immunofluorescence intensities of T- and P-cadherin on the basal layer of the epidermis were quantitatively measured by the histogram function of LSM 510 software installed in a Zeiss laser scanning confocal microscope. The data were statistically analysed by Student's t-test. It was observed that T-cadherin was weakly and discontinuously expressed on the basal layer of psoriatic skin, while it was intensively expressed on all basal keratinocytes in normal human skin. In contrast, P-cadherin was strongly expressed throughout the entire epidermal layer in psoriatic skin samples, although its expression is restricted to the basal cell layer in normal human skin. There were no obvious differences in E-cadherin expression between normal human skin and psoriatic skin. Statistical analyses showed that the immunofluorescence intensity of T-cadherin in the basal cell layer of psoriatic skin (35 +/- 9.08) was significantly decreased compared with that in normal human skin (131.75 +/- 3.49, P = 2.46 x 10(-6)). There was a significant increase (P = 0.00139) in the immunofluorescence intensity of P-cadherin in the basal layer of psoriatic skin (68.25 +/- 12.13) compared with normal human skin (26 +/- 4.90). The present study demonstrates that there is downregulation of T-cadherin expression and upregulation of P-cadherin expression in psoriatic skin, which are considered to be involved in the hyperproliferation of keratinocytes in psoriasis vulgaris.

Cutaneous breast cancer deposits show distinct growth patterns with different degrees of angiogenesis, hypoxia and fibrin deposition.

We postulated that skin metastases and cutaneous local recurrences from breast adenocarcinoma show different growth patterns with distinct angiogenic profiles. Fifty-one surgically resected dermal breast cancer deposits were evaluated for growth pattern, E-cadherin expression, presence of necrosis and a fibrotic focus, fibrin deposition, carbonic anhydrase IX expression (CA IX), microvessel density, endothelial cell proliferation and blood vessel immaturity. Growth patterns were infiltrative, with carcinoma cells infiltrating the dermis without significant disturbance of the pre-existing architecture, expansive, meaning that a nodule of carcinoma cells and desmoplastic tissue pushed aside the pre-existing dermal structures, or mixed. All lobular carcinomas showed an infiltrative growth and lacked membranous E-cadherin expression. Different growth patterns in the ductal carcinomas were not correlated with differences in E-cadherin expression. The presence of necrosis and/or a fibrotic focus and the expression of the hypoxia marker CA IX were significantly associated with an expansive growth. Fibrin was present in all expansive deposits and less frequently in the other growth patterns. There was a positive association between fibrin deposition, CA IX expression and microvessel density. The latter was significantly higher in the expansive and mixed growth patterns than in the infiltrative pattern. Endothelial cell proliferation was highest in the expansive growth pattern and was positively correlated with the presence of a fibrotic focus and with fibrin deposition. The maximum percentage of immature blood vessels was higher in the expansive and mixed growth patterns than in the infiltrative one. The recognition of different subgroups of cutaneous breast cancer deposits with different degrees of hypoxia-driven angiogenesis may have important implications for the usefulness of anti-angiogenic therapy.

Transfection of E-cadherin cDNA in human lung tumor cells reduces invasive potential of tumors.

Lung cancer is a major health-care problem in industrialized countries. With reference to its therapeutic consequences and major histological variations, it is divided into two subgroups - SCLC (small-cell lung cancer) and NSCLC (non-small-cell lung cancer). As an important factor of cell-cell and cell-substratum interaction, cell adhesion molecules (CAMs) seem to play a key role in tumor-cell migration and invasion that lead to metastases. We investigated human lung tumor cell lines established from histologically documented neoplastic lesions taken in our operating theater. Immunohistological screening showed differences in E-cadherin expression with no clear predominance of SCLC or NSCLC cell lines. Using an invasion model with Matrigel Matrix and a migration assay, we could demonstrate a more aggressive behavior pattern in E-cadherin-negative cell lines. We transfected E-cadherin cDNA into a formerly negative cell line showing strong invasive behavior in the initial tests in order to investigate the role of E-cadherin in this process. In this study, we examined E-cadherin cDNA transfection in human bronchial carcinoma cells. At present, transfection is stable with a follow-up time of one year. We could demonstrate that cell lines were remarkably less invasive after transfection of E-cadherin in the invasion model with Matrigel Matrix. These results indicate that the E-cadherin CAM plays an important role in lung tumor invasion and metastasis. Further studies are in progress to confirm these findings and to describe a possible role of this CAM in tumor therapy.