MDR1反义RNA降低细胞KB_(v200)的耐药性

Reduction of the Multidrug Resistance of KBv200 Cellsby MDR1 Antisense RNA

由ＭＤＲ１基因过度表达所引起的肿瘤细胞对化疗药物的耐药性，是导致化疗失败的主要原因之一．针对ＭＤＲ１中一段包含转录启始位点、翻译启始位点和转录正调控区的序列，设计了反义ＲＮＡ并将其克隆到逆转录病毒载体ｐＬＸＳＮ上．用脂质体包裹载体导入ＭＤＲ１高表达的耐药细胞ＫＢｖ２００中，在反义ＲＮＡ转染的细胞中，ＭＤＲ１在ｍＲＮＡ和蛋白水平的表达都有下降，细胞内药物的浓度有所提高，对长春新碱、阿霉素的耐药性分别下降了６５％和４７％．实验结果表明，反义ＲＮＡ对ＭＤＲ１的表达有抑制作用，从而使肿瘤细胞内的药物浓度升高，其耐药程度下降．

Acquisition of resistance to multiple drugs of tumor cells caused by overexpression of MDR1 gene is one of the major obstacles in cancer chemotherapy.A plasmid expressing antisense MDR1 cDNA segment was transduced into KBv200,which was selected for resistance to anticancer drug VCR(vincristine) and ADM(adriamycin)resulting from overexpression of MDR1.In the antisense RNA expressing cells,a stable expression of antisense MDR1 RNA and a reduction of MDR1 mRNA were detected by RTPCR,and a reduction of MDR1 specific permeabilityglycoprotein(Pgp)was detected by Western blot,which led to the increase of the concentration of ADM.The IC50 of transfected cells to VCR and ADM was reduced by 65% and 47%,respectively as compared with that of the control.This study showed that MDR1 antisense RNA expression could increase the sensibility of KBv200 tumor cells to anticancer drugs by reducing the expression of Pgp,and it might be applicable to cancer patients as a specific means to reverse tumors with Pgpmediated MDR phenotype.