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Objective To examine the role of c-Src activation in hepatitis B virus X (HBx) protein induced epithelial-mesenchymal transition (EMT) in liver cancer.Methods SMMC-7721 liver cancer cells were transfected with HBx gene to induce EMT and the activated c-Src expression was evaluated by Western blot.Both the morphological changes and the epithelial and mesenchymal markers expression (real-time PCR,western blot and immunocytochemistry) of HBx-transfected SMMC-7721 cell treated by c-Src kinase inhibitor PP2 and negative control PP3 were observed and compared,respectively.Results The activated c-Src expression in HBx gene transfected SMMC-7721 cells was significantly increased compared to that in mock transfected cells,c-Src kinase inhibitor PP2 could enable the HBx-transfected SMMC-7721 cells to transmit from spindle-like shape to original epithelial morphology.Western blot and immunocytochemistry confirmed that the expression of epithelial markers and mesenchymal markers almost returned to the levels of parental cells,indicating the mesenchymal-epithelial transition.Conclusions c-Src activation plays a key role in the process of EMT induced by HBx protein in SMMC-7721 cells.
RESUMO
Objective To determine whether HBx gene can directly induce hepatocellular carcinoma in vivo, and to explore the mechanism of transplantation tumor in nude mice.Methods pCMVX/QSG7701 cell lines were vaccinated into subcutaneous tissue of nude mice. pRcCMV2/QSG7701 and QSG7701 cell lines were used as controls. The sections of transplantation tumor were observed microscopically by HE staining. RT-PCR was used to detect the expression of mutant p53 and c-Myc mRNA in transplant tumor and an other 3 cell lines. Results The transplant tumor occurred within the subcutaneous tissue of the nude mice inoculated with pCMVX/QSG7701 cell lines at 2nd week after the vaccination. No metastatic tumor was found in other organs. Transplant tumor was not formed in all the controls. HE staining confirmed that the transplant tumor was hepatocellular carcinoma. The mutant p53 mRNA and c-Myc mRNA expression level of transplant tumor and pCMVX/QSG7701 cells was significantly higher than that of pRcCMV2/QSG7701 and QSG7701 cells, respectively (P＜0.01).Conclusion HBx gene can up-regulate the expression of mutant p53 and c-Myc genes, and directly induce hepatocellular carcinoma in vivo.