RNA Interference Gene Therapy Targeting The Epidermal Growth Factor Receptor In Human Ovarian Cancer

Aim: Ovarian cancer is common in gynecological tumors. It has high mortality and poor therapeutic efficacy. So a new treatment is needed. The epidermal growth factor receptors(EGFR) which mediate cell growth, vessel formation and DNA repair are found to overexpress in epidermal tumors, including ovarian cancer and carcinoma vulvae. RNA interference(RNAi) is a recently observed process to inhibit cellular proliferation, induce apoptosis and down-regulate or silence the gene expression. The aim of the study is to investigate the biological features of SKOV3 cells(ovarian cancer) and A431 cells(carcinoma vulvae) in which epidermal growth factor receptors expression were suppressed by RNAi.Methods: SKOV3 cells and A431 cells were transfected using short hairpin RNAs (shRNAs) targeting EGFR formulated with Liposome. The antiproliferative effects of siRNA-EGFR were assessed using MTT assays. The effects of inducing apoptosis were assessed by flowcytometry and hoechst staining assays. The antitumor activity was detected using mouse models with ovarian cancer by intravenous injection. The treatment was carried on twice a week, ten times in total. The length and width of the tumor was recorded to calculate the tumor volume. Immunohistochemical staining was used to assess the microvessel density of the tumor tissue. HE staining was used to analyze the morphous of the tumour issue and the side effects of each organ.Results: 1. In the trial of using the general negative control- pGPU6-shNC, the results of MTT assays, flowcytometry and hoechst staining assays showed that the antiproliferative effects of siRNA-EGFR had significance with the control group(p<0.05),but no significance with negative control siRNA-NC (p>0.05 ) .The siRNA-EGFR had antitumor activity when administered intravenously in the mouse model of ovarian cancer compared with the control group, but there was no statistic significance between siRNA-EGFR and siRNA-NC (p>0.05) . 2. In the second trial of using reconstructed carrier as negative control, however, siRNA-EGFR suppressed the proliferation and induced apoptosis of SKOV3 cells and A431 cells and showed significance with the control group and the carrier group (p<0.05) .Conclusions: siRNA-EGFR combining liposome were capable of inhibiting cellular proliferation and induce cell apoptosis in vitro, but the efficacy need to be reconfirmed in vivo. Nevertheless it may help extend the list of available therapeutic modalities in the treatment of ovarian cancer.