ERCC1 targeted RNA interference reversing cisplatin resistance in human lung adeno-carcinoma cells

Objective: To explore the feasibility of using ERCC1-targeted RNA interference for reversing cisplatin resistance in human lung adeno-carcinoma.Methods: Cisplatin-resistant cell line A549/CDDP was routinely cultured with RPMI 1640 medium.ERCC1-siRNA(at 100,200,300 nmol/L) was used to transfect A549/CDDP cells by Lipofectamine.The expression of ERCC1 protein was measured by immunohistochemical SABC assay;reverse transcription-polymerase chain reaction(RT-PCR) was used to detect the expression of ERCC1 mRNA;MTT assay was performed to detect the cell half-maximum inhibitory concentration(IC_50) for calculation of the cisplatin resistant index.The cisplatin resistance-reversing effect of ERCC1-targeted siRNA was observed.Results: The transfection rates of lip,siRNA-neg,siRNA-ERCC1①,siRNA-ERCC1②and siRNA-ERCC1③ groups were(56.38±9.82)%,(63.54±4.87)%,(43.62±6.08)%,(65.85±9.61)% and(78.93±4.86)%,respectively.After transfection with siRNA-ERCC1 of different concentrations,expression of ERCC1 mRNA and protein were both downregulated in A549/CDDP cells.The most severe downregulation was observed when the concentration of siRNA-ERCC1 was 300 nmol/L,with ERCC1 mRNA and protein expression down regulated to(11.19±6.82)% and(20.88±6.57)%,respectively(P0.01).After treatment with siRNA-ERCC1 at 100 nmol/L,200 nmol/L and 300 nmol/L,the resistant indices of A549/CDDP cells were reduced to 6.05,4.64,and 2.94,respectively,Treatment with blank vector resulted in a resistant index of 9.6.Conclusion: ERCC1-targeted siRNA can,to a great extent,reverse the resistance to cisplatin in human lung adeno-carcinoma cell line A549/CDDP in vitro in a rough concentration-dependent manner,indicating that ERCC1 gene can be an effective target for reversing cisplatin resistance in lung cancer.