Abstract: To investigate the effects of HER2/neu gene silencing on SKOV3 ovarian cancer cells by RNA interference. Methods： Design and synthesize two siRNAs based on the sequence of HER2/neu mRNA. They were separately subcloned into the plasmid of pGenesil1 containing U6 promoter. The pGenesil1 vectors of the RNA interference eukaryotic expression specific to HER2/neu gene were constructed. The pGenesil1 vectors were transfected into SKOV3 ovarian cancer cells with METAFECTENE in vitro. The positive cell clones were obtained after being screened with 250?μg/ml G418. Then the effects of RNAi on the expression of HER2/neu gene were detected by RTPCR and Western Blot. The cellular growth activities were assayed by CCK8 colorimetry and flow cytometry in vitro. Results： DNA sequencing of the plasmids verified the successful construction of the HER2/neu siRNA vectors. Compared with the blank and the control group, the expressions of HER2/neu mRNA and protein 185 were remarkably downregulated in the RNAi groups; and the cell proliferations decreased in the RNAi groups. Conclusion： We successfully construct the recombinant plasmids of siRNAs specific to HER2/neu gene and transfect them into the SKOV3 ovarian cancer cells in vitro. The RNAi inhibits the expression of HER2/neu mRNA and protein 185, and subsequently suppresses the proliferation of SKOV3 cells.

Key words: RNA interference, HER2/neu gene, Ovarian cancer cell, Gene therapy