The Effect Of RNA Interfence-mediated ERCC1 Gene On Cisplatin Resistance In A549/DDP Cells

Objective :To investigate the effect of excision repair cross-complementing group 1(ERCC1)silencing on the chemosensitivity to cisplatin(DDP)of human lung cancer cells A549/DDP.Methods:The si RNA sequence targeting ERCC1 gene were designed and synthesized.The si RNA were transfected to A549/DDP cells with lipofectamine 2000.The interference effect of ERCC1 was detected by reverse transcription-polymerase chain reaction(RT-PCR)and Western blot.The chemosensitivity to DDP was analyzed by MTT assay.Results:1,The expression of ERCC1 mRNA after ERCC1-siRNA interference was detected by reverse transcription-polymerase chain reaction(RT-PCR),the results show that the transfection after 48 hours,the transfection group of m RNA expression quantity of 0.39 ±0.11,compared with non-transfection group(0.82 ± 0.26),the expression of ERCC1 m RNA were cut(P=0.002);compared with the negative control group(0.90 ± 0.17),the expression of ERCC1 m RNA were cut(P=0.000),the difference was statistically significant;while the difference between the negative control group and the non-transfection group was not statistically significant(P=0.460).2,The protein expression of ERCC1 after ERCC1-si RNA interference was detected by Western Blotting,the results show that the transfection group of protein expression quantity was 0.65 ±0.15,compared with non-transfection group(1.16 ± 0.44),the expression of ERCC1 protein were cut(P=0.025);compared with the negative control group(1.17 ± 0.40),the expression of ERCC1 protein was cut(P=0.0024),the difference was statistically significant;while the difference between the negative control group and the non-transfection group was not statistically significant(P=0.972).3,MTT assay indicated that the inhibitory rate of cell proliferation was obvious higher and the values of IC50 was significantly decreased in the cells treated by ERCC1-si RNA.There were statistical significance among different groups(P=0.000).the values of IC50(the transfection group)was 8.63±2.03ug/ml,compared with non-transfection group(16.71 ± 2.33ug/m),the difference was statistically significant(P =0.000);when compared with the negative control group(16.69 ± 1.69ug/m),the difference was statistically significant(P =0.000);while the difference between the negative control group and the non-transfection group was not statistically significant(P=0.972).Conclusion:The expression of ERCC1 gene is inhibited by RNA interference technique.Selective silencing of ERCC1 gene promotes the sensitivity to cisplatin in A549/DDP cell and can partly reverse the cisplatin resistance in A549/DDP cell line in vitro.