MDR1基因RNA干扰逆转喉癌细胞多药耐药性的研究

Reverse multidrug resistance in the laryngeal cancer cells by RNA interference of MDR1 gene

目的采用RNA干扰（RNA interference，RNAi）技术通过敲减MDR1基因编码的P糖蛋白的表达，逆转人喉癌耐药细胞系（LSC-1，WⅨ）对于化疗药物的多药耐药性（multidrugresistance，MDR）。方法采用表达MDR1shRNA（smallhairpinRNA）的慢病毒载体转染LSC-1/TAX细胞，干扰MDR1mRNA。体外MTT实验观察其对各种化疗药物敏感性，裸鼠荷瘤试验在体检测其对TAX的敏感性，通过免疫组化方法在蛋白水平检测体内外细胞中MDR1基因的表达。结果体外逆转LSC-1／TAX喉癌细胞对多种化疗药物的MDR，裸鼠荷瘤试验显示细胞化疗药物的敏感性被成功回复。免疫组化方法证实MDR1shRNA可以在体内外有效地敲减MDRl基因的表达。结论表达MDR1shRNA的慢病毒载体可以在转录后明显降低MDR1基因的表达，从而提高喉癌细胞对常用化疗药物的敏感性。

OBJECTIVE To reverse multidrug resistance （MDR） to chemotherapeutic agents in human laryngeal cancer cells （LSC-1/TAX） by knockdown the expression of P-glycoprotein （P-GP） , the MDR1 gene product, using RNA interference （RNAi） technique. METHODS LSC-1/TAX cells were transfected with lenUvirus vector that contains the shRNA construct targeting MDR1 mRNA. The drug resistance was measured by MTT assay in vitro, and sensitivity of the laryngeal cancer cells to various anti-neoplasm agents was quantified in vivo. The knockdown of MDR1 gene expression was assessed by immunocytochemistry in vitro and vivo. RESULTS Mul＇ddrug resistance phenotype in human laryngeal cancer cell line （LSC-1/TAX） was reversed in vitro. Tumor growth assay in vivo revealed a reverse of MDR in the laryngeal cancer cells. Immunocytochemistry showed that P-GP expression was significantly inhibited.CONCLUSION MDR1 shRNA lentivirus vectors can significantly inhibited MDR1 expression. Inhibition of MDR1 gene expression conferred an increased sensitivity of drug-resistant in laryngeal cancer cells to conventional chemotherapeutic agents.