[Experimental study of anti-VEGF hairpin ribozyme gene inhibiting expression of VEGF and proliferation of ovarian cancer cells].

Background & Objective: Growth of solid tumor metastases are critically dependent on angiogenesis. Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, has been identified as one of the most potent inducers of tumor associated angiogenesis, studies have shown that VEGF plays an important role in angiogenesis which is associated with epithelial ovarian cancer. Until now, many strategies for gene therapy have been developed. Among them is Ribozyme-based therapeutics for cancer which might be devised to inhibit tumor growth or prevent metastases. Angiogenesis is required for sustained tumor growth, making the VEGF pathway another promising target for either small molecule or nucleic acid-based therapeutics. Little is known about the role of VEGF in ovarian tumorigenecity. We propose to block the autocrine and/or paracrine pathway of VEGF in ovarian cancer using anti-VEGF hairpin ribozyme gene to see whether the growth of tumor cells could be inhibited and to further exploit its mechanisms.

Methods: Anti-VEGF hairpin ribozyme gene eukaryotic expression vector was introduced into ovarian cancer SKOV3 cells by lipofectin mediation and positive clones were screened by G418; Ribozyme expression was confirmed by RNA dot blot; The VEGF expression of SKOV3 cells before or after transfection were detected by immunohistochemical and immunofluorescence and flow cytometer immunofluorescence methods, MTT, colony forming, soft agar colony forming, and FCM were used to observe the effect of proliferation to ovarian cancer cells.

Results: VEGF expression decreased distinctly in SKOV3-RZ cells. The growth of transfected SKOV3-RZ cells were slower, The average colony forming efficiency and soft agar colony forming efficiency of SKOV3-RZ cells(12.7 +/- 1.4 and 9.4 +/- 2.0, respectively) decreased distinctly (P < 0.001). The SKOV3-RZ cells of G1 stage increased(P < 0.01), the SKOV3-RZ cells of S stage were reduced(P < 0.01).

Conclusions: Anti-VEGF hairpin ribozyme gene can inhibit the proliferation of ovarian cancer SKOV3 cells. This provides a experimental basis for cure human ovarian cancer with antiangiogenesis method.