Modulation of Drug Resistance in Ovarian Cancer Cells by Inhibition of Protein Kinase C-alpha (PKC-α) with Small Interference RNA (siRNA) Agents

Li-Jun Zhao,Jin-Hua Wang,Heng Xu,Jun-Wei Qu,Wan-Zhou Zhao,Yi-Bing Zhao

doi:10.7314/apjcp.2012.13.8.3631

Abstract

To determine whether silence of PKC-α expression by small interference RNA (siRNA) might regulate MDR1 expression and reverse chemoresistance of ovarian cancer. We measured gene and protein expression of MDR1 and PKC-α in ovarian cancer cells and assessed their correlation with cell drug resistance. We also examined whether blocking PKC-α by RNA interference (RNAi) affected MDR1 expression and reversed drug resistance in drug sensitivity tests. The drug resistance cell lines, OV1228/DDP and OV1228/Taxol, had higher gene and protein expression of MDR1 and PKC-α than their counterpart sensitive cell line, OV1228. SiRNA depressed PKC-α gene protein expression, as well as MDR1 and protein expression and improved the drug sensitivity in OV1228/DDP and OV1228/Taxol cells. These results indicated that decreasing PKC-α expression with siRNA might be an effective method to improve drug sensitivity in drug resistant cells with elevated levels of PKC-α and MDR1. A new siRNA-based therapeutic strategy targeting PKC-α gene could be designed to overcome the chemoresistance of ovarian cancer.

Highlights

Ovarian carcinomas (OC) are the leading cause of death from gynecologic neoplasia (Ozols, 2002)
We examined whether blocking Protein kinase C (PKC)-α by RNA interference (RNAi) affected MDR1 expression and reversed drug resistance in drug sensitivity tests
Transfected with the PKC-α small interference RNA (siRNA) interference plasmid The effect of RNA interference on the expression of PKC-α The uptake of PKC-α siRNA interference plasmid and MDR1 genes transfected with Lipofectamine 2000, FuGENE 6, The expression of PKC-α and MDR1 genes in EnoGeneFec 2000 were shown in Supplemental Figure 2

Summary

Introduction

Ovarian carcinomas (OC) are the leading cause of death from gynecologic neoplasia (Ozols, 2002). Up to 13,850 of women with OC had died in United State in 2010 (Jemal et al, 2010). The efficacy of chemotherapy is hampered by multidrug resistance (MDR), which is either present initially or is induced during treatment (Persidis, 1999). One of the major causes of MDR is the over-expression of P-glycoprotein (P-gp), 170KDa plasma membrane glycoprotein (P-gp170), which function as an ATP-dependent efflux pump for structurally different drugs (Rao et al, 2010). P-gp is coded by MDR1 gene, high which has been detected in many human malignancies (Mayur et al, 2009)

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Conclusion