靶向survivin反义寡核苷酸对MCF-7乳腺癌细胞系survivin mRNA及紫杉醇药物敏感性的影响

Effects of the survivin antisense oligonucleotide on survivin mRNA expression and chemosensitivity to Paclitaxel in human breast cancer cells MCF-7

目的探讨靶向survivin基因的反义寡核苷酸(ASODN)对MCF-7细胞的增殖、凋亡及药物敏感性等生物学行为的影响。方法采用脂质体介导survivin-ASODN转染MCF-7乳腺癌细胞系,RT-PCR检测survivin mRNA的表达,MTT法检测细胞增殖能力及对药物的敏感性,流式细胞术检测细胞周期及细胞凋亡。结果survivin-ASODN可有效下调survivin表达水平,抑制细胞的生长,并呈时间剂量依赖关系;流式细胞术示,24 h反义转染组细胞周期被阻滞于G2/M期,细胞凋亡率增加到15.23%。紫杉醇作用早期(6 h),survivin mRNA表达增高,利于肿瘤细胞逃避紫杉醇诱导的细胞凋亡,增加肿瘤耐药机会;反义转染组中细胞早期survivin mRNA表达上调受到抑制,对药物的敏感性增加。结论survivin基因ASODN转染细胞后,下调survivin的表达,细胞凋亡增加,提高了对药物的敏感性。

Objective To investigate the effects of the survivin antisense oligonucleotide（ASODN） on cell proliferation, apoptosis and chemosensitivity to paclitaxel in human breast cancer cells MCF-7. Methods Survivin-ASODN was transfected into MCF- 7cells mediated by Lip reagent. The expression of survivin mRNA was determined by RT-PCR, cell proliferation and chemosensitivity to paclitaxel in MCF-7 were determined by MTT assay, and apoptosis and cell cycle were determined by flow cytometry. Results The antisense compound efficiently down-regulated survivin mRNA expression in a time-dependent manner. The growth inhibition rate of MCF-7 was decreased in a dose- and time-independent manner. The cell cycle was arrested at G2/M phase; apoptosis was obviously found. Paclitaxel could enhance the expression of survivin at an early time, and this effect might play a critical role in the escape to apoptosis induced by paclitaxel, which may promote the resistance of paclitaxel. The antisense compound efficiently down-regulated this induction by paclitaxel, and enhanced the chemosensitivity to paclitaxel in MCF-7. Conclusion Survivin antisense oligonucleotide effectively suppresses the expression of survivin mRNA, increases apoptosis and enhances the chemosensitivity to paclitaxel in MCF-7.