Background & objective: Drug resistance is a major obstacle to the successful chemotherapy of ovarian cancer. Recent studies have shown overexpression of Survivin in ovarian cancer tissues and cell lines, which may play an important role in the drug resistance of ovarian cancer. This study was to explore the effects of Survivin short hairpin RNA (shRNA) on Survivin expression, apoptosis, and chemosensitivity of human ovarian cancer cell line OVCAR3.
Methods: OVCAR3 cells were transfected with Survivin shRNA. Untransfected, lip-transfected, and mU6-transfected cells were set as controls. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of Survivin mRNA. Flow cytometry was applied to examine the expression of Survivin protein and cell apoptosis. MTT assay was used to examine the effect of Survivin shRNA on chemosensitivity of OVCAR3 cells.
Results: The mRNA and protein levels of Survivin were obviously lower in Survivin shRNA-transfected OVCAR3 cells than in untransfected cells, lip-transfected cells, and mU6-transfected cells 24 h after transfection. The apoptotic rates of OVCAR3 cells 12 h, 24 h, 36 h, 48 h after Survivin shRNA transfection were 20.7%, 31.9%, 39.0%, and 46.7%, respectively, that showed a time-dependent manner. The 50% inhibitory concentrations (IC50) of paclitaxel were (0.305+/-0.032) micromol/L for untransfected cells, (0.157+/-0.031) micromol/L for lip-transfected cells, (0.175+/-0.010) micromol/L for mU6-transfected cells, and (0.019+/-0.001) micromol/L for Survivin shRNA-transfected cells; and the IC50 of cisplatin were (9.410+/-0.796) micromol/L, (6.675+/-1.739) micromol/L, (6.930+/-1.273) micromol/L, and (7.862+/-0.081) micromol/L, respectively. Survivin shRNA increased the sensitivity of OVCAR3 cells to paclitaxel by 16 folds (P<0.01), but had no significant effect on the sensitivity to cisplatin (P>0.05).
Conclusion: Sequence-specific shRNA targeting Survivin can suppress the expression of Survivin gene effectively in OVCAR3 cells, and sensitize OVCAR3 cells to paclitaxel, but has no significant effect on the sensitivity to cisplatin.