Suppression of MDR1 gene by RNA interference in multidrug-resistant cancer cells / 中国病理生理杂志

ABSTRACT

AIM: To explore the feasibility of using vector-based small interfereing RNA(siRNA) to inhibit the expression of MDR1 mRNA and P-glycoprotein and to reverse the multidrug resistance of drug-resistant ovarian cancer cell line.METHODS: An adriamycin-resistant human ovarian cancer cell subline OVCAR/AR was established by stepwise inducement.Another mutidrug-resistant human ovarian cancer cell subline OVCAR/MDR was established by transfecting multidrug resistant gene 1(MDR1) into ovarian carcinoma cell line OVCAR-3.Transfection of MDR1 mRNA specific siRNA expressing plasmids(pSN/mdr1a and pSN/mdr1b) into OVCAR/AR and OVCAR/MDR cells was performed using liposome transfection reagents.MDR1 mRNA expression level was quantified using real time reverse transcription polymerase chain reaction(real time RT-PCR).Flow cytometry(FCM) was performed to assess the expression of p-glycoprotein(P-gp).Multidrug resistant to anticancer agents was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide(MTT) assay.RESULTS: Basal MDR1 mRNA expression level in drug-resistant cell line OVCAR/MDR was higher than that in OVCAR/AR cell line,and was both higher than that in its parent cell line OVCAR-3.The expression of MDR1 mRNA and P-gp protein in both OVCAR/AR and OVCAR/MDR cells was inhibited dramatically by transfecting with pSN/mdr1a and pSN/mdr1b.The reversal rate of chemoresistance to adriamycin in OVCAR/AR and OVCAR/MDR transfected with pSN/mdr1a and pSN/mdr1b was 79.5% and 93.9%,compared with control group.CONCLUSION: MDR1 expression in the drug-resistant cell lines is partially inhibited by treatment with vector-based MDR1 specific small interference RNAs at the mRNA and protein level,which increases the chemotherapy sensitivity of these drug resistant ovarian carcinoma cell sublines.