Modulation Of Drug Resistance In Ovarian Cancer Cells By Inhibition Of Protein Kinase C-alpha (PKC-α) With Small Interference RNA (siRNA) Agents

Objective: To determine whether silence of PKC-α expression by small interferenceRNA (siRNA) might regulate MDR1expression and reverse chemoresistance ofhuman ovarian cancer.Methods: Effective and specific siRNA oligo targeting PKC-α was designed andcompounded. Three different transfection reagents were used to test transfectionefficiency, the best transfection one could be selected as the transfection tool in ourstudies. The experiment was divided into7groups: cell control group (drug-resistancecell line and parent cell line), trancfection group (pEGFP-iLenti-PKC-α492,746,1114and1676) and negative control group. The expression of PKC-α and MDR1mRNA and protein in ovarian cancer cells were detected by reverse transcriptionpolymerase chain reaction (RT-PCR) and western blot. Drug sensitivity ofOV1228/DDP and OV1228/Taxol after trancfection by specific siRNA wasperformed by MTT assay.Results: Both OV1228/DDP and OV1228/Taxol cells transfected with EnoGeneFec2000had the strongest fluorescence signals. Therefore, we choose the EnoGeneFec2000as the transfection tool in our studies. The drug resistance cell lines,OV1228/DDP and OV1228/Taxol, had higher gene and protein expression of MDR1and PKC-α than their counterpart sensitive cell line, OV1228. SiRNA depressed PKC-α gene protein expression, as well as MDR1and protein expression andimproved the drug sensitivity in OV1228/DDP and OV1228/Taxol cells.Conclusion: These results indicated that decreasing PKC-α expression with siRNAmight be an effective method to improve drug sensitivity in drug resistant cells withelevated levels of PKC-α and MDR1. A new siRNA-based therapeutic strategytargeting PKC-α gene could be designed to overcome the chemoresistance of ovariancancer.