AIM:To evaluate the significance ofγ-catenin in clinical pathology,cellular function and signaling mechanism in esophageal squamous cell carcinoma(ESCC).METHODS:The mRNA expression ofγ-catenin was detected by real-time quantitative reverse transcription-polymerase chain reaction in 95 tissue specimens and evaluated for association with the clinicopathologic characteristics and survival time of patients with ESCC.siRNAs against humanγ-catenin were used to inhibitγ-catenin expression.Hanging drop aggregation assay and dispase-based dissociation assay were performed to detect the effect ofγ-catenin on ESCC cell-cell adhesion.Transwell assay was performed to determine cell migration.Luciferase-based transcriptional reporter assay(TOPflash)was used to measureβ-catenindependent transcription in cells with reducedγ-catenin expression.The expression and subcellular localizations ofβ-catenin and E-cadherin were examined using Western blot and immunofluorescence analysis.RESULTS:γ-catenin mRNA expression was significantly associated with tumor histological grade(P=0.017)in ESCC.Kaplan-Meier survival analysis showed thatγ-catenin expression levels had an impact on the survival curve,with lowγ-catenin indicating worse survival(P=0.003).The multivariate Cox regression analysis demonstrated thatγ-catenin was an independent prognostic factor for survival.Experimentally,silencingγ-catenin caused defects in cell-cell adhesion and a concomitant increase in cell migration in both KYSE150 and TE3 ESCC cells.Analysis of Wnt signaling revealed no activation event associated withγ-catenin expression.Totalβ-catenin and Triton X-100-insolubleβ-catenin were significantly reduced in theγ-catenin-specific siRNA-transfected KYSE150 and TE3 cells,whereas Triton X-100-solubleβ-catenin was not altered.Moreover,knocking downγ-catenin expression resulted in a significant decrease of E-cadherin and Triton X-100-insoluble desmocollin-2,along with reducedβ-catenin and E-cadherin membrane localization in ESCC cells.CONCLUSION:γ-catenin is a tumor suppressor in ESCC and may serve as a prognostic marker.Dysregulated expression ofγ-catenin may play important roles in ESCC progression. AIM: To evaluate the significance of γ-catenin in clinical pathology, cellular function and signaling mechanism in esophageal squamous cell carcinoma (ESCC). METHODS: The mRNA expression of γ-catenin was detected by real-time quantitative reverse transcription- polymerase chain reaction in 95 tissue specimens and evaluated for association with the clinicopathologic characteristics and survival time of patients with ESCC. siRNAs against human γ-catenin were used to inhibit γ-catenin expression. Huanging drop aggregation assay and dispase-based dissociation assay were performed to detect the effect of γ-catenin on ESCC cell-cell adhesion. Transwell assay was performed to determine cell migration. Luciferase-based transcriptional reporter assay (TOPflash) was used to measure β-catenindependent transcription in cells with reduced γ-catenin expression. The expression and subcellular localizations of β-catenin and E -cadherin were examined using Western blot and immunofluorescence analysis .RESULTS: γ-caten in mRNA expression was significantly associated with tumor histological grade (P = 0.017) in ESCC. Kaplan-Meier survival analysis showed that γ-catenin expression levels had an impact on the survival curve, with low γ-catenin indicating worse survival (P = 0.003). The multivariate Cox regression analysis demonstrated that γ-catenin was an independent prognostic factor for survival. Experimentally, silencing γ-catenin caused defects in cell-cell adhesion and a concomitant increase in cell migration in both KYSE150 and TE3 ESCC cells. Analysis of Wnt signaling revealed no activation event associated with γ-catenin expression.Total β-catenin and Triton X-100-insoluble β-catenin were significantly reduced in the γ-catenin-specific siRNA-transfected KYSE150 and TE3 cells, whereas Triton X-100-soluble β-catenin was not altered. Moreover, knocking down γ-catenin expression resulted in a significant decrease of E-cadherin and Triton X-100-insoluble desmocollin-2, along with reduced β-catenin and E-cadherin mem brane localization in ESCC cells. CONCLUSION: γ-catenin is a tumor suppressor in ESCC and may serve as a prognostic marker. Dysregulated expression of γ-catenin may play important roles in ESCC progression.