Hairpin ribozyme targeted vascular endothelial growth factor (VEGF) inhibited the expression of VEGF and the growth of xenografted tumors / 肿瘤

ABSTRACT

Objective: Hepatocarcinoma cell line was transfected with anti-vascular endothelial growth factor (VEGF) hairpin ribozyme gene to observe the effect of hairpin ribozyme on VEGF expression and the growth of the xenografted tumors. Methods: The artificial anti-VEGF hairpin ribozyme gene was transfected into hepatocarcinoma SMMC-7721 cells via lipofectin mediation. The blank vector and the cell controls were prepared simultaneously. Then, positive clones were screened by genticin (G418). The transcription of ribozyme was confirmed by RT-PCR. The effects of the ribozyme on VEGF expression of SMMC-7721 cells were detected by semi-quantitative RT-PCR and immunohistochemical method. Cells in each group were inoculated into nude mice. The tumor volume and weight were recorded. The change in microvessel density and expression of VEGF was determined by immunohistochemistry. Results: Ribozyme gene was successfully transferred into tumor cells. The proliferation rate of ribozyme-transfected SMMC-7721 cells was significantly slower (P < 0.01). The expression of VEGF significantly decreased in ribozyme-transfected SMMC-7721 cells. After rebozyme transfection, the tumor formation rate significantly decreased and the growth speed of xenografted hepatocarcinoma markedly slowed down. The microvessel density and angiogenesis of the xenografted hepatocarcinoma were obviously reduced. Conclusion: Anti-VEGF hairpin ribozyme gene significantly inhibited the VEGF expression of hepatocarcinoma in vitro and in vivo by inhibiting angiogenesis of tumor cells. This study provided an experimental evidence for anti-angiogenesis gene therapy for hepatocarcinoma.