Effect of plasmid-mediated stable interferon-γ expression on proliferation and cell death in the SKOV-3 human ovarian cancer cell line

Introduction: High interferon-gamma (IFN-gamma) expression in tumors has been reported to be a favorable prognostic marker. Continuous exposure of ovarian cancer cells to IFN-gamma was previously shown to result in significant growth inhibition and apoptosis. Our goal in this study was to evaluate the effect of plasmid-mediated stable IFN-gamma expression on the SKOV-3 human ovarian carcinoma cell line. Methods: SKOV-3 cells were stably transfected with the pEGFP-IFN-gamma plasmid. IFN-gamma mRNA was detected by RT-PCR and IFN-gamma protein expression was measured by ELISA. Proliferation and cell death in transfected SKOV-3 cells were measured by methyl-thiazolyl tetrazolium (MTT) assay and Hoechst 33258 staining, respectively and compared with untransfected and empty vector-transfected cells. Results: pEGFP-IFN-gamma SKOV-3 cells efficiently expressed and secreted IFN-gamma. They exhibited significantly decreased cellular proliferation when compared with control untransfected or empty vector-transfected cells (P < 0.05). The mode of cell death was primarily apoptosis. Conclusions: Stable expression of IFN-gamma significantly inhibits the proliferation of ovarian carcinoma cells and has the potential to be used in clinical applications to treat ovarian carcinoma in the future.