Effect Of Silencing EGFR Gene Expression By RNA Interference On The Growth And Chemosensitivity Of Ovarian Cancer Cell Line Skov3

Objective To construct expression vector of EGFR specific siRNA and transfect it into human ovarian cancer cell line skov3. To investigate the effect of RNA interference on the target gene expression, cell growth and the chemosensitivity of the cell line.Methods According to EGFR mRNA sequence, we designed and synthesized shRNA targeted EGFR which were directly cloned into pSilencer^TM 2.1-U6 neo plasmid. DNA sequencing confirmed whether the insertion sequence was correct or not. Then transfected the recombinant plasmid into human ovarian cancer cell line skov3 with Hifectin II. There were three groups: normal control; non-specific transfect and EGFR shRNA transfect. The inhibitive effect of RNAi on mRNA level and protein level were respectively detected by RT-PCR and immunocytochemistry. Cell growth and the chemosensitivity to cisplatin were detected by MTT method.Results DNA sequencing confirmed that the insertion sequence was completely correct. Sequence specific shRNA targeting EGFR obviously down-regulated the expression of EGFR mRNA (F= 87.73, q=1.50～16.81, P<0.01) and protein (F=69.29, q=1.14～14.71, P <0.01), The growth of EGFR shRNA specific transfect cell was significantly slower than the other two groups. It was 30% decreased on the fifth day. And the chemosensitivity to cisplatin increased by 3 times.Conclusion The EGFR specific shRNA expression vector can effectively suppress the expression level of EGFR gene and protein of skov3 cells. Also it can suppress the cell growth and increase the chemosensitivity to cisplatin.