OBJECTIVETo explore a new approach in gene therapy of ovarian cancer, we used RNAi to inhibit survivin gene expression, and explore the effect of survivin and neu RNAi on growth, apoptosis and chemosensitivity of ovarian cancer cell line SKOV3/DDP cells.

METHODSExpression vector of survivin gene-targeting siRNA was constructed using pSilencer 1.0-U6 vector containing U6 promotor (pSilencer-survivin) and transfected into SKOV3/DDP cells by lipofectamine. The untransfected group and pSilencer-control group were used as control. The expressions of survivin mRNA and protein were identified by RT-PCR and Western blot assay. The proliferation of SKOV3/DDP cells was determined by MTT assay. The apoptosis rate and cell cycle distribution were analyzed by flow cytometry. Cisplatin (DDP) resistance experiment was performed in SKOV3/DDP cells with RNAi.

RESULTSSurvivin RNAi plasmid knocked-down survivin expression in SKOV3/DDP cells obviously, arrested the cells at G(1)/G(0) phase, inhibited the cell proliferation and promoted cell apoptosis. The IC(50) of DDP to SKOV3/DDP cells transfected with survivin siRNA was dropped.

CONCLUSIONSurvivin RNAi can partly suppress the expression of survivin in SKOV3/DDP cells, inhibit the cell proliferation and promote cell apoptosis. Survivin RNAi can enhance the cell sensitivity to apoptosis induced by cisplatin, which implies that survivin RNAi may partly reverse the drug resistance of ovarian cancer. RNAi could be a new approach for gene therapy of cancer.