中文摘要：

目的筛选高效dsRNA／mdr1，以备研究RNA干扰逆转肝细胞癌多药耐药之用。方法首先根据siRNA设计原则，以多药耐药基因（mdr1）为靶基因，设计并选择4～5条siRNA／mdr1，经BLAST后体外转录法合成dsRNA／mdr1，用Oligofectamine试剂分别转染HepG2／mdr1，然后从mRNA、蛋白（P-gP）表达水平和细胞功能变化评价HepG2／mdr1耐药性被逆转的程度，比较各个dsRNA／mdr1的逆转效率，筛选出有效的siRNA／mdr1。结果成功合成5条dsRNA／mdr1（其中1条为阴性对照），dsRNA／mdr1-4mRNA表达（18．73±1．33）％、蛋白表达变化（79．1±1．6）％～（16．8±0．4）％与其他各组细胞比较，有显著性差异；细胞内柔红霉素（DNR）累积量也较其他组明显增加（平均荧光强度79．58，阳性率84．25％，P〈0．05）。结论体外转录法结合脂质体转染适用于筛选高效siRNA，肯定了siRNA干扰序列能够有效阻抑mdrl基因编码蛋白p170的功能。

英文摘要：

Objective To screen effective dsRNA/mdr1 for studying the reversal of muhidrug resistance of hepatocellular carcinoma （HCC） by RNA interference （RNAi）. Methods dsRNA/mdr1 targeting muhidrug resistance gene （mdr1） was designed and synthesized by in vitro transcription. HepG2/mdr1 in 6 groups was transfected with the complex of different dsRNA/mdrl （dsRNA/mdr1-1, dsRNA/mdr1-2, dsRNA/mdr1-3, dsRNA/mdr1-4, dsRNA/mdr1-5 ） using Oligofectamine. Then the cells were collected to measure the expression of mRNA/mdr1, P-glycoprotein and the accumulation of DNR. Results Five dsRNA/mdr1 were successfully synthesized including one negative. The expression of mRNA/mdr1 [ （ 18.73 ±1.33 ）% ] and P-glycoprotein [ from （79.1 ± 1.6） % before transfection down to （ 16.8 ±0.4） % ] in dsRNA/mdr1-4 was significantly lower than that of other groups （ P 〈 0.05 ）. Accumulation of DNR in dsRNA/mdr1-4 was higher than that in other groups （P 〈 0.05 ）. Conclusion In vitro transcription combined with liposome is fit to screen the effective dsRNA/mdr1, siRNA/mdr1 could suppress the expression of P-glycoprotein coded by mdrl gene.