反义survivin核酸增强胃癌细胞对多西他赛敏感性及其逆转耐药机制的探讨

目的探讨反义survivin核酸(anti-pcDNA3-svv)对胃癌细胞系SGC7901的凋亡诱导和化疗增敏作用,及其与多药耐药基因(mdr-1)的相关性。方法采用电转染法转染胃癌细胞系SGC7901,并筛选阳性克隆。以Western blot法检测survivin蛋白的表达,用透射电镜观察转染后对SGC7901的凋亡诱导作用,RT-PCR检测mdr-1 mRNA的表达,MTT法检测转染细胞对多西他赛的敏感性。诱导SGC7901细胞耐药,检测耐药mdr-1和survivin的表达。结果转染anti-pcDNA3-svv的SGC7901细胞中,survivin蛋白表达较未转染组明显降低;透射电镜下,转染组细胞呈凋亡晚期变化;转染组的mdr-1 mRNA较未转染组明显降低,转染组与未转染组的MDR指数分别为0.196±0.013和3.126±O.019;转染组多西他赛的IC50值为(16.7±1.98)μg/L,而未转染组为(55.7±1.89)μg/L,差异有统计学意义。耐药SGC7901细胞的survivin mRNA表达随着mdr-1 mRNA表达增加而明显增强。结论反义survivin核酸可诱导SGC7901细胞凋亡,增强多西他赛化疗敏感性,其逆转耐药的机制与mdr-1低表达有关。

Exploration on the increased sensitivity to docetaxel and reversing mechanism of drug resistance of antisense survivin RNA in gastric cancer cell line SGC7901 cells

OBJECTIVE: To explore the effects of survivin antisense RNA on apoptosis and chemosensitivity to docetaxel in gastric cancer line SGC7901 cells, and its relation to mdr-1. METHODS: survivin antisense eukaryotic vector anti-pcDNA3-svv was transfected into SGC7901 cells by electorporation and positive clone was screened out. survivin protein and mdr-1 mRNA were determined by Western blot and RT-PCR. Apoptosis-inducing effect was examined by electron microscopy. Sensitivity to docetaxel was examined by MTT. Expression of mdr-1 and survivin mRNA were detected in the SGC7901 cells after drug-resisitance induction. RESULTS: The expression of survivin protein of SGC7901 cells after transfection reduced significantly than that of non-transfected cells. MDR indexes of transfection group and non-transfection group were 0.196 +/- 0.013 and 3.126 +/- 0.019, respectively. The IC50 of transfection group to docetaxel was (16.7 +/- 1.98) microg/L and non-transfection group was (55.7 +/- 1. 89) microg/L, with a statistically significant difference. Expression of survivin mRNA in drug-resistant cells decreased along with the decreasing of mdr-1. CONCLUSION: Antisense surivivin RNA can induce apoptosis in gastric cancer cells and increase sensitivity to docetaxel. The reversing mechanism of drug resistance is related with decreasing of mdr-1.