BACKGROUND AND OBJECTIVES: E-cadherin and catenins (alpha, beta, gamma, p120cat) are important epithelial adhesion molecules in normal epithelial cells. Loss of E-cadherin-catenin adhesion is an important step in the progression of epithelial cancers such as tongue cancer. E-cadherin and catenins expression in carcinoma of human tongue was evaluated in relation to their clinicopathological features and prognostic values. SUBJECTS AND METHOD: Thirty-nine specimens of tongue squamous cell carcinoma were examined in this study. These patients were all treated by primary surgery without prior radiotherapy or chemotherapy. The specimens of formalin-fixed and paraffin-embedded tumor tissues were investigated by immunohistochemical analysis using E-cadherin and catenin (alpha, beta, gamma, p120cat) monoclonal antibodies. RESULTS: The expressions of E-cadherin, alpha-catenin, beta-catenin, gamma-catenin and p120cat in cell membranes were reduced or absent in 71.8%, 74.4%, 76.9%, 59.0% and 82.1% of the tumors examined, respectively. The reduced expressions of alpha-catenin and gamma-catenin in the cell membranes was cor-related with tumore differentiation (p=0.018, p=0.004, respectively). There were significant correlations between E-cadherin and expressions of the four cantenins in the cell membranes of tongue cancer. There were no correlations between beta-catenin and p120cat expression in the cytoplasm, cell nucleus and clinicopathological features. There was significant correlation between E-cadherin expression and Kaplan-Meier survival curves. CONCLUSION: These results suggest that E-cadherin and catenins (alpha, beta, gamma, p120cat) can be used as prognostic markers of human tongue squamous cell carninoma. The result of beta-catenin and p120cat absence in the nucleus suggests that Wnt/Wingless signaling or Kaiso transcription did not occur in the human tongue squamous cell carcinoma.
alpha Catenin ; Antibodies, Monoclonal ; beta Catenin ; Cadherins* ; Carcinoma, Squamous Cell ; Catenins ; Cell Membrane ; Cell Nucleus ; Cytoplasm ; Drug Therapy ; Epithelial Cells ; gamma Catenin ; Humans ; Kaplan-Meier Estimate ; Prognosis ; Radiotherapy ; Tongue Neoplasms* ; Tongue*

N,N-Diethylnitrosamine (DEN) has been proved to have carcinogenic potential in the initiation or promotion stage and the transformed cells proliferate to form preneoplastic nodules which are positive for placental form of glutathione S-transferase (GST-P). E-Cadherin, a member of the cadherin family, is expressed in epithelial cells. To evaluate the role of adhesion molecules (E-Cadherin, alpha-catenin, and beta-catenin), which have not been well understood in carcinogenesis, we investigated the changes of E-cadherin, alpha-Catenin and beta-Catenins by immunohistochemistry and immunoblotting in DEN-induced hepatocarcinogenesis of rat liver. In addition, the sequential analysis of histopathology and the expression of GST-P were also examined. Immunoreactive areas for GST-P were gradually increased from early period of carcinogenesis and strong GST-P positive foci were noted in various lesions, especially in the clear cell and eosinophilic cell nodules. Immunohistochemically, the E-Cadherin expression was increased in DEN-treated preneoplastic nodules in 4 and 10 weeks and hepatocellular carcinomas displayed relatively reduced expression compared with the hyperplastic nodules. But alpha- and beta-catenin expression was increased in hyperplastic nodules and hepatocellular carcinomas. Immunoblotting studies revealed that the level of alpha-catenin (cytosol and membranous fraction) was overexpressed in hyperplastic nodules as well as hepatocellular carcinomas, which showed markedly increased expression. The membranous fraction of beta-catenin was markedly increased in 10 weeks of DEN treatment and slightly reduced in hepatocellular carcinomas. These findings suggest that during DEN-induced hepatocarcinogenesis, the clear cell and eosinophilic cell nodules expressing GST-P in their cytoplasm are early transformed cell nodules. The altered expression of E-Cadherin and catenins is closely related with tumor propagation. Loss or reduced expression of E-cadherin may play a role in the progression of late hyperplastic nodule to hepatocellular carcinoma in DEN-induced rat hepato carcinogenesis.
alpha Catenin ; Animals ; beta Catenin ; Cadherins* ; Carcinogenesis ; Carcinoma, Hepatocellular ; Catenins* ; Cytoplasm ; Eosinophils ; Epithelial Cells ; Glutathione Transferase* ; Glutathione* ; Humans ; Immunoblotting ; Immunohistochemistry ; Liver* ; Rats*

To investigate the relationship and significance of Wnt/b-catenin signaling pathway with caspase-3, XIAP, HSP27and Grp-78. The HCC cell line HepG2 was transfected with small interfering RNA (siRNA) directed against b-catenin. After 72 and 96 h, protein was extracted and the protein expressions of b-catenin, caspase-3, XIAP, Grp-78 and HSP27 were detected by Western blot. b-catenin protein expression was inhibited at both time points and the expression at 96 h was higher than that at 72 h (F = 160.72, P is less than to 0.01). Interestingly, Caspase-3 protein expression was decreased at 72 h and increased to normal at 96 h (F = 136.10, P is less than to 0.01), while p-caspase-3 protein expression increased at 72 h and decreased to normal at 96 h (F = 98.65, P is less than to 0.01). XIAP protein expression decreased at 72 h (F = 37.29, P is less than to 0.01) and increased at 96 h. Grp-78 protein expression increased at 72 h and decreased to normal at 96 h ( F = 58.72, P is less than to 0.01). HSP27 protein expression showed no change following transfection ( F = 1.91, P is more than to 0.05). Wnt/b-catenin signaling pathway is related to the protein expressions of caspase-3, XIAP and Grp-78, but not related to HSP27 protein expression in HCC. Wnt/b-catenin signaling pathway may participate in the regulation of HCC apoptosis, proliferation and differentiation through affecting these factors.
Carcinoma, Hepatocellular ; Caspase 3 ; Catenins ; Humans ; Liver Neoplasms ; Wnt Signaling Pathway ; beta Catenin ; metabolism

This study was aimed to investigate the expressions of E-cadherin, p120ctn, &beta;-catenin and NF-κB in ulcerative colitis (UC) tissues and the implications of their expressions in the pathogenesis of UC. The expressions of E-cadherin, p120ctn, &beta;-catenin and NF-κB were detected by immunohistochemistry, and those of p120ctn and NF-κB by Western blotting in 23 cases of UC and 17 cases of normal colonic tissues. The relationship between the expression of E-cadherin or NF-κB and that of p120ctn was analyzed by Spearman rank correlation analysis. The results showed that in UC and normal colonic groups, the abnormal expression rate of E-cadherin, p120ctn, &beta;-catenin, and NF-κB was 52.2% vs. 0 (P<0.05), 73.9% vs. 23.5% (P<0.05), 65.2% vs. 17.6% (P<0.05) and 78.4% vs. 23.5% (P<0.05), respectively. p120ctn expression was positively correlated with E-cadherin expression (r=0.404, P<0.05), but negatively with nuclear NF-κB expression (r= - 0.347, P<0.05). Western blotting showed that as compared with the normal controls, the p120ctn protein level was significantly decreased (P<0.05), whereas the NF-κB protein level was increased (P<0.05) in UC tissues. It was concluded that in the colonic tissues of UC patients, the expressions of E-cadherin, p120ctn and &beta;-catenin are decreased, suggesting the mucosal barrier is impaired in UC. Moreover, NF-κB is increased and activated in the UC tissues, resulting in the inflammation in UC. p120ctn may influence the UC development through modulating intercellular adhesion and inflammatory response.
Adolescent ; Adult ; Cadherins ; metabolism ; Catenins ; metabolism ; Colitis, Ulcerative ; metabolism ; pathology ; Down-Regulation ; Female ; Humans ; Male ; Middle Aged ; NF-kappa B ; metabolism ; Statistics, Nonparametric ; Young Adult ; beta Catenin ; metabolism

OBJECTIVES: E-cadherin is a transmembrane protein that is one of the key players involved in cell to cell adhesion. Loss of E-cadherin expression is suggested to promote tumor invasion and distant metastasis in tumor development. Recently, it has been proposed E-cadherin function requires its linkage to the cytoskeleton through catenins. So defects in catenins may cause defective E-cadherin function and promote tumor invasion. We intend to evaluate the expression of E-cadherin and alpha-, beta-, gamma- catenin in tissues of human endometrial carcinoma to analyze the patterns of cell adhesion molecules' expression in endometrial carcinoma and to investigate the relationship between status of cell adhesion molecules and various clinicopathological factors. MATERIALS AND METHODS: The present study investigated the immunohistochemical expression of E-cadherin and alpha-, beta-, gamma- catenin in 33 paraffin embedded formalin fixed tissues of endometrial carcinomas. RESULTS: Aberrant E-cadherin, alpha-, beta-, gamma- catenin expression was observed in 33.3(11 of 33), 27.3(9 of 33), 18.2 (6 of 33), and 51.5(17 of 33) % of the specimens, respectively. Statistically significant correlation was found between aberrant expression of E-cadherin and lymph node metastasis and cell types other than endometrioid adenocarcinoma. Aberrant pattern of gamma- catenin expression also correlated with deep myometrial invasion. But alpha-, beta- catenin expression were not correlated with any clinicopathological parameters. Using Kaplan-Meier curves, abnormal expression of E-cadherin correlated closely with poor survival (p<0.05). CONCLUSION: We revealed aberrant expression of these cell adhesion molecules in part of patients with endometrial carcinoma. Aberrant expression of E-cadherin was correlated with lymph node metastasis and cell types other than endometrioid adenocarcinoma and aberrant expression of gamma-catenin was related with deep myometrial invasion.
Cadherins* ; Carcinoma, Endometrioid ; Catenins* ; Cell Adhesion ; Cell Adhesion Molecules ; Cytoskeleton ; Endometrial Neoplasms* ; Female ; Formaldehyde ; gamma Catenin ; Humans ; Lymph Nodes ; Neoplasm Metastasis ; Paraffin

OBJECTIVETo explore the effects of K-ras gene mutation on colon cancer cell line Caco-2 metastasis by regulating E-cadherin/beta-catenin/p120 protein complex formation and RhoA protein activity.

METHODSK-ras wild-type colon cancer cell line Caco-2 was transiently transfected by phr-GFP vector (control group), transfected by mutant K-ras gene phr-K-ras (Val12) vector (transfection group), transfected by mutant K-ras gene phr-K-ras (Val12) vector and treated by specific MAPK pathway inhibitor PD98059 (MAPK inhibition group), or transfected by mutant K-ras gene phr-K-ras (Val12) vector and treated by specific PI-3K pathway inhibitor LY294002 (PI-3K inhibition group), respectively. Cell migration was tested by Transwell experiment. E-cadherin and beta-catenin protein expression and intracellular location were detected by cell immunofluorescence method. Intracellular p120 protein expression was detected by Western blot. beta-catenin protein level which combined with E-cadherin was detected by immunoprecipitation. RhoA activity was analyzed by Pull-down assay.

RESULTSThe Caco-2 cell migration rate was (19.8 +/- 5.6) % in transfection group, which was significantly higher than that in control group [(14.0 +/- 4.2) %] (P = 0.001) and in MAPK inhibition group [(15.8 +/- 1.2) %] (P = 0.044), but was not significantly different from that in PI-3K inhibition group [(17.5 +/- 2.8) %] (P = 0.095). Immunofluorescence method showed that the E-cadherin and beta-catenin stain located in the cell membrane decreased in transfection group. Western blot showed that the total intracellular p120 protein decreased in transfection group and PI-3K inhibition group. Immunoprecipitation data showed that beta-catenin protein level combined with E-cadherin decreased in transfection group and PI-3K group. Pull-down test showed that RhoA protein activity was up-regulated in transfection group.

CONCLUSIONK-ras gene mutation stimulates the migration of colon cancer cell Caco-2, which may be achieved by decreasing the E-cadherin/beta-catenin/p120 protein complex formation via MAPK pathway and increasing the RhoA protein activity.

Caco-2 Cells ; Cadherins ; metabolism ; Catenins ; metabolism ; Cell Movement ; Colonic Neoplasms ; metabolism ; pathology ; Genes, ras ; genetics ; Humans ; Multiprotein Complexes ; metabolism ; Mutation ; Neoplasm Metastasis ; Transfection ; beta Catenin ; metabolism ; rhoA GTP-Binding Protein ; metabolism

BACKGROUND: Catenins are the associated protein with E-cadherin in the formation of adhesion complexes in normal and tumor cells related with epithelial differentiation and development of organ formation as well as in the tumor spread. The present study was aimed to find the distribution of alpha- and gamma-catenins in fetal skin development. OBJECTIVE: The purpose of this study was to observe the distribution of above two adhesion related proteins in the fetal skin during development, and to find its relationship by expression and their distribution pattern. METHODS: Skin was obtained from the scalp, chest, and sole of 21 human fetuses, ranging from 13 to 37 weeks of gestational age. Immunohistochemical staining was performed by the avidin biotin peroxidase complex method on paraffin embedded tissue using the anti-human monoclonal antibody against the human alpha- and gamma-catenins. RESULTS: alpha- and gamma-catenins were expressed strongly in basal cells of the epidermis and germ cells of skin adnexa, such as hair and eccrine glands at 13th week, followed by decreased basal cell expression. Increase in the suprabasal epithelium and differentiated adnexal epithelium, such as outer root sheath cells and eccrine ducts and glands at 18th week, and adult pattern in 23th week of gestation. Both showed similar distribution pattern in skin though gamma-catenin appeared two or three weeks later. alpha- and gamma-catenins are expressed not only in the epithelium of the skin, but also in the mesenchymal cells such as endothelial cells and fibroblasts. Though both catenins are more strongly expressed in the membrane portion, cytoplasmic expression is also noted. CONCLUSION: Both alpha- and gamma-catenin showed basically the same expression distribution pattern in the fetal skin developmental stage, suggesting that both adhesion molecules are highly related to each other in function and development of epidermis and adnexae of the skin in fetal stage.
Adult ; Avidin ; Biotin ; Cadherins ; Catenins ; Cytoplasm ; Eccrine Glands ; Endothelial Cells ; Epidermis ; Epithelium ; Fetus ; Fibroblasts ; gamma Catenin* ; Germ Cells ; Gestational Age ; Hair ; Humans ; Membranes ; Paraffin ; Peroxidase ; Pregnancy ; Scalp ; Skin* ; Thorax

This study examined the possible role of p120ctn in the pathogenesis and development of pancreatic cancer. PANC-1 cells, a kind of human pancreatic carcinoma cell line, were cultured in this study. p120ctn was immunocytochemically detected in PANC-1 cells. The recombinant lentivirus vector was constructed to knock down the p120ctn expression of PANC-1 cells. Real-time quantitative PCR (RQ-PCR) and Western blotting were used to determine the expression of p120ctn and E-cadherin in PANC-1 cells after p120ctn knockdown. The adhesion, invasion and migration capacity of PANC-1 cells after p120ctn knockdown was detected by cell adhesion, invasion and migration assays. Cell growth was measured by the MTT method. Cell cycle and apoptosis were analyzed by fluorescence-activated cell sorting. The results showed that p120ctn knockdown led to significantly down-regulated E-cadherin and a reduced cell-to-cell adhesion ability in PANC-1 cells. shRNA-mediated knockdown of p120ctn reduced invasion and migration capacity of PANC-1 cells, inhibited cell growth, caused a significant decrease in the percentage of cells in G(1), an increase in S, and promoted apoptosis of PANC-1 cells. It was concluded that p120ctn plays a pivotal role in the proliferation and metastasis of pancreatic carcinoma, suggesting that p120ctn is a novel target for pancreatic carcinoma treatment.
Catenins ; genetics ; Cell Line, Tumor ; Gene Silencing ; Humans ; Pancreatic Neoplasms ; genetics

OBJECTIVETo investigate the effect of catenin p120 (p120ctn) translocation on the malignant features of hepatocellular carcinoma and its interrelation with beta-catenin in E-cadherin-mediated cell signaling.

METHODSExpression and translocation of p120ctn, tyrosine phosphorylation, and its binding capacity to E-cadherin were detected by DNA transfection, immunoblotting and immunoprecipitation. Cellular localization of p120ctn and beta-catenin was detected by immunofluorescent microscopy. Cell adhesion, cell migration and cell proliferation were also studied.

RESULTSExpression of p120ctn increased after cells transfected with p120ctn isoform 3A, and it was located mainly at cell-cell contact region. Its binding to E-cadherin was enhanced. After EGF stimulation, tyrosine phosphorylation of p120ctn was increased, membrane expression of p120ctn and beta-catenin was decreased while cytosol expression was increased. It was translocated into the nucleus, cell adhesiveness was increased but mobility decreased. With over-expression of p120ctn, beta-catenin was recruited by nucleus export. Cell proliferation was reduced but it was increased after EGF treatment.

CONCLUSIONp120tn plays an important role in cell adhesion, migration and proliferation of hepatocellular carcinoma, and its tyrosine phosphorylation might contribute to this mechanism. There might be a competitive relationship between p120ctn and beta-catenin.

Cadherins ; metabolism ; Carcinoma, Hepatocellular ; metabolism ; pathology ; Catenins ; Cell Adhesion ; Cell Adhesion Molecules ; metabolism ; Cell Line, Tumor ; Cell Membrane ; metabolism ; Cell Movement ; Cell Nucleus ; metabolism ; Cell Proliferation ; Cytoskeletal Proteins ; metabolism ; Cytosol ; metabolism ; Epidermal Growth Factor ; pharmacology ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Phosphoproteins ; metabolism ; Phosphorylation ; Protein Transport ; Trans-Activators ; metabolism ; Tyrosine ; metabolism ; beta Catenin

Animals ; Cadherins ; metabolism ; Catenins ; metabolism ; Estradiol ; pharmacology ; Estrogen Receptor Modulators ; pharmacology ; Female ; Ovariectomy ; Rats ; Uterus ; drug effects ; metabolism