Objective: In hepatocellular carcinoma cells, the tyrosine phosphorylation of p120(ctn) was stimulated by epidermal growth factor (EGF) to investigate the relationship between the tyrosine phosphorylation of p120(ctn) and the translocation of p120(ctn), also the relationship between the tyrosine phosphorylation of p120(ctn) and the biological behaviour of hepatocellular carcinoma cells. The role of p120(ctn) in the cell adhesion and signaling of hepatocellular carcinoma is to be investigated.
Methods: In BEL-7404 human hepatocellular carcinoma cells, the tyrosine phosphotyrosine of p120(ctn) stimulated by EGF were detected by immunoprecipitation (IP) and Immunoblotting (IB). The cellular distribution and translocation of p120(ctn) and beta-catenin were detected and examined by indirect intracellular immunofluorescence. Cell morphology and cell adhesion potential were also detected using correspondent methods. Antisense nucleotide of p120(ctn) was transfected into BEL-7404 cells.
Results: The tyrosine phosphorylation of p120(ctn) was enhanced after EGF treatment than control, especially at 20min after EGF treatment; When BEL-7404 cells were transfected with antiseuse nucleotide of p120(ctn) before EGF treatment, the tyrosine phosphorylation of p120(ctn) stimulated by EGF was obviously lowered. We also observed that the tyrosine phosphorylation of p120(ctn) stimulated by EGF was accompanied by the nuclear translocation of p120(ctn); the similar translocation was also observed in beta-catenin after EGF stimulation. At the meantime, cell adhesion potential was reduced after EGF treatment and cell morphology became thin, elongated and irregular, speudopods increased.
Conclusions: In BEL-7404 cells,the tyrosine phosphorylation of p120(ctn) could be stimulated by EGF, which was accompanied by the nuclear accumulation of p120(ctn). The tyrosine phosphorylation of p120(ctn) stimulated by EGF was also in correlation with the changes of cell adhesion and cell morphology. The results indicated that the tyrosine phosphorylation of p120(ctn) cell correlated with the translocation of p120(ctn) and the biological behavior of cells.