小干扰RNA抑制bcl-xL表达对食管癌细胞化疗敏感性的影响

Effect of bcl-xL down-regulation mediated by siRNA on chemosensitivity of esophageal cancer cells

目的探讨凋亡抑制分子bcl-xL表达下调对食管癌细胞化疗敏感性的影响。方法根据人bcl-xL基因序列设计和合成3对小干扰RNA,将其转染于体外培养的人食管癌细胞株Eca-109,通过RT-PCR和Western-blotting检测bcl-xL的表达情况,筛选出对bcl-xL表达抑制作用最强的小干扰RNA,通过MTT法检测小干扰RNA转染细胞和对照细胞在不同浓度顺铂和紫杉醇作用下的细胞增殖抑制率,计算出半数抑制浓度IC50值并进行对比分析。结果食管癌细胞转染靶向bcl-xL的3种小干扰RNA后,bcl-xL mRNA和蛋白表达均显示出不同程度下调,其中siRNA1对癌细胞bcl-xL表达的抑制作用最强。siRNA1转染食管癌细胞后可使顺铂和紫杉醇对癌细胞的IC50值由转染前的(31.4±4.3)μmol/L和(35.3±6.1)μmol/L下降至转染后的(8.4±3.3)μmol/L和(15.1±4.7)μmol/L(P<0.01)。结论小干扰RNA抑制bcl-xL表达可增强食管癌细胞对顺铂和紫杉醇化疗的敏感性。

Objective To analyze the effect of bcl-xL down-regulation mediated by small interference RNA（siRNA） on the chemosensitivity of esophageal cancer cells to cisplatin and paclitaxel.Methods Three pairs of siRNA targeted at bcl-xL were designed and synthesized.Esophageal cancer cells were transfected with siRNA by using Lipofectamine 2000.bcl-xL expressions in the transfected cells and the control cells were determined by RT-PCR and Western blot.Cell proliferation inhibition rates of esophageal cancer cells treated with cisplatin and paclitaxel were detected by MTT assay.The IC50 values were calculated and compared.Results bcl-xL was down-regulated in esophageal cancer cells transfected with specific siRNA.The down-regulation of bcl-xL decreased the IC50 values of esophageal cancer cells treated with cisplatin or paclitaxel.Conclusion the down-regulation of bcl-xL mediated by siRNA can increase the chemosensitivity of esophageal cancer cells to cisplatin and paclitaxel.