Abstract
PURPOSE: To study effects of trophinin on the metastatic potential of human gallbladder cancer cells and its potential mechanism. MATERIALS AND METHODS: Expression of trophinin in the highly metastatic GBC-SDH(i) cells was investigated by real time RT-PCR and western blot. Recombinant expression plasmid vector of the human trophinin gene was constructed and transfected into GBC-SD cells. Effects of trophinin on the invasion of GBC-SD cells were investigated by adhesion assay and invasion assay in vitro. The siRNA was used to down-regulate the expression of trophinin. Some genes related to the invasion and metastasis of cancer were determined by real time RT-PCR and western blot. The pulmonary metastasis regulated by trophinin was determined in the nude mice. RESULTS: Overexpression of trophinin in GBC-SDH(i) cells was confirmed compared with its parental counterparts. Up-regulation of trophinin enhanced the in vitro invasion in the GBC-SD/TRO cells. The enhancement was associated with increasing integrin alpha3, MMP-7, MMP-9, and Ets-1 expression. The results were further demonstrated by RNA interference experiment in vitro. In in vivo study, we also demonstrated that trophinin-transfected gallbladder cancer cells had more pulmonary metastases than the vector-transfected one or its parental counterparts. CONCLUSION: Overexpression of trophinin leads to a more invasive phenotype and metastatic potential in human gallbladder cancer, at least in part, through regulating integrin alpha3, MMP-7, MMP-9, and Ets-1 expression.