Peg-IFNα 2b联合伊马替尼对耐伊马替尼胃肠间质瘤细胞株的抑制作用

Inhibitory effects of Peg-IFNα 2b and imatinib,alone or in combination,on imatinibresistant gastrointestinal stromal tumor cell line PC9/GR

目的:探讨聚乙二醇(polyethylene glycol,Peg)修饰重组人干扰素α2b[Peg-(interferonα,I F Nα)2b]联合伊马替尼对耐伊马替尼胃肠道间质瘤(gastrointestinal stromal tumors,GISTs)细胞株的增殖和凋亡的影响及其可能机制.方法:培养C-kit二次突变所致继发性耐药的G I S Ts患者的原代细胞株G I S T-R和对伊马替尼敏感GIST-T1细胞株模拟临床胃肠间质瘤获得性耐药过程;Peg-IFNα2b和伊马替尼单独或联合组处理细胞;MTT法检测细胞的增殖并计算耐药指数、联合指数,FCM法检测细胞凋亡率,Western blot检测p-mT OR和Bcl-2蛋白表达水平.结果:GIST-R细胞株对伊马替尼高度耐药,其耐药指数(RI=46.14),Peg-IFNα2b单独用药对GISTs细胞株均无明显增殖抑制作用;I N F-α与伊马替尼联合用药组对G I S T-R抑制率明显高于伊马替尼单独用药,耐药指数下降(RI=14.79),表现明显的协同增敏效应(CI=0.79).FCM检测结果表明,Peg-IFNα2b与伊马替尼联合用药具有明显的促细胞凋亡的作用.与单药组比较,Peg-IFNα2b与伊马替尼联合用药可明显下调耐伊马替尼细胞p-m TOR和Bcl-2蛋白表达水平(P<0.01).结论:Peg-IFNα2b可以提高GISTs耐药细胞株细胞对伊马替尼的敏感性,这一协同增敏效应可能与下调p-m TOR蛋白表达水平以及诱导细胞凋亡有关.

AIM： To investigate the inhibition effects of polyethylene glycol interferon α 2b （Peg-IFNα 2b） and imatinib, alone or in combination, on imatinib-resistant gastrointestinal stromal tumor （GIST） cell line （GIST-R）, and to explore the possible mechanism. IFNα 2b and imatinib, alone or in combination. The rate of reduced proliferation and the combination index （CI） in different treatment groups were detected by MTT assay. The apoptotic rate was detected by flow cytometry. The expression of phosphorylated mammalian target of rapamycin （p-mTOR） and Bcl-2 was analyzed by Western blot. RESULTS： GIST-R cells presented remarkable resistance to imatinib, and the resistance index （RI） was 46.14. The rate of reduced proliferation in the combination group was significantly higher than those in the Peg-IFNα 2b or imatinib alone groups （P 〈 0.05）. The calculated CI values in the combination group suggested a synergistic effect. Compared with non-treated GIST-R cells, the expression levels of p-roTOR and Bcl-2 proteins in GIST-R cells treated with Peg-IFNα 2b and imatinib significantly decreased （P 〈 0.01）. CONCLUSION： The combination of Peg-IFNα 2b and imatinib generates a synergistic effect in GIST-R cells. This effect may be related with apoptosis and the down-regulation of the expression of p-roTOR.