siRNA干扰MDR1逆转口腔舌癌耐药性表型的实验研究

Effect of MDR1 siRNA on drug resistance of human carcinoma of the tongue cell line TCA8113

目的:探讨MDR1siRNA对人舌癌耐药细胞株TCA8113多药耐药性的影响。方法:以人舌癌耐药细胞株TCA8113/DDP为靶细胞,将针对MDR1基因合成,并已鉴定和测序后的siRNA分子利用脂质体介导转染TCA8113/DDP细胞,采用G418筛选克隆细胞,RT-PCR检测MDR1基因mRNA表达,免疫组织化学法测定P-糖蛋白(P-gp)表达;MTT比色法检测TCA8113/DDP细胞对顺铂(DDP)、卡铂(CBP)、平阳霉素(PYM)的敏感性。结果:经转染成功的阳性克隆细胞TCA8113/DDP的MDR1mRNA和P-gp的表达均被抑制。TCA8113人舌癌耐药细胞顺铂(DDP)、卡铂(CBP)、平阳霉素(PYM)的IC50分别降至3.43μmol/L,1.72μmol/L和1.05μmol/L(P<0.01)。结论:稳定转染含编码MDR1siRNA的质粒载体能特异性地阻抑人舌癌多药耐药细胞TCA8113细胞MDR1基因的表达,逆转其对抗癌药物的耐受性。

Objective：To investigate the effect of MDR1 siRNA on multidrug resistance（MDR1）of Human carcinoma of the tongue cells.Method：Human multidrug-resistant Human carcinoma of the tongue cell line TCA8113 over expressing mdr1 gene was used as the target.The siRNA speciafically targeting mdr1 gene was chemically synthesized and identified,then was transfected into TCA8113 cells with RNAi-MATE.Clone cells were screened by G418.The silencing efficiency of siRNA was evaluated by the inhibition of mdr1 mRNA expression measured with RT-PCR and the inhabition of P-glycoprotein（P-gp）expression with immunohistochemical analysis.The sensitivity of the cells to PYM,Cisplatin（DDP）and Carboplatin（CBP）was detected with a MTT colorimetric assay.Result：The expression of MDR1 mRNA and P-gp in positive clone cells（TCA8113）were all inhibited.IC50 of DDP,CBP and PYM for TCA8113 cells were 3.43 μmol/L,1.72 μmol/L and 1.05 μmol/L,respectively（P 0.01）.Conclusion：Stable trasfection of plasmid vector encoding MDR1 siRNA can speciafically depress the expression of mdr1 gene and its product P-gp in drug-resistant TCA8113 cells and reverse multidrug resistance to chemotherapeutical agents.