P120ctn overexpression enhances beta-catenin-E-cadherin binding and down regulates expression of survivin and cyclin D1 in BEL-7404 hepatoma cells.

AIM: To understand the role of P120ctn in E-cadherin-mediated cell-cell adhesion and signaling as well as in hepatoma cell biological function.
METHODS: We stably overexpressed p120ctn isoform 3A in BEL-7404 human hepatoma cells and studied the effect of p120ctn on beta-catenin and E-cadherin binding as well as p120ctn and beta-catenin subcellular localization using immunoprecipitation, Western blotting and confocal microscopy. We also investigated the inhibitory effect of p120ctn transfection on the expression of apoptotic protein survivin survivin and cell cycle regulator cyclin D1 in the cells.
RESULTS: Western blotting indicated that p120ctn expression increased after cells were transfected with p120ctn isoform 3A. The protein was located mainly at membrane under immunofluorescent microscope. Beta-catenin nuclear expression was reduced after overexpression of p120ctn isoform 3A. The p120ctn-E-cadherin binding increased after transfection of p120ctn isoform 3A. Furthermore, overexpression of p120ctn down regulated the expression of apoptotic protein survivin and cell cycle regulator cyclin D1. These effects led to reduction of cell proliferation.
CONCLUSION: Our results indicate that p120ctn plays an important role in regulating the formation of E-cadherin and -catenin complex, cell apoptosis, cell cycle and cancer cell biological function.