mTOR抑制剂RAD001通过c-Raf/ERK1/2通路介导胰腺癌耐药的机制  

Mechanism underlying pancreatic cancer cell resistance to mTOR inhibitor RAD001 via c-Raf/ERK1/2 activation

作　　者：魏锋[1] 张平[1] 綦俊[1] 王蒙[1] 王广义[1] 

机构地区：[1]吉林大学第一医院肝胆胰外科,吉林长春130021

出　　处：《细胞与分子免疫学杂志》2014年第1期23-27,共5页Chinese Journal of Cellular and Molecular Immunology

基　　金：国家自然科学基金(81201711)

摘　　要：目的研究哺乳动物雷帕霉素靶蛋白(mTOR)抑制剂RAD001介导胰腺癌细胞耐药的分子机制,探索逆转该耐药性的可行性方案。方法 Western blot法检测RAD001对胰腺癌细胞中相关蛋白的影响;Western blot法验证RAD001与c-Raf抑制剂索拉菲尼联合用药对相关信号通路蛋白的抑制;磺酰罗丹明B(SRB)比色法、平板克隆形成实验观察RAD001与索拉菲尼联合用药时对细胞增殖和生长的影响;构建胰腺癌荷瘤裸鼠模型,验证联合用药对肿瘤生长的抑制作用。结果 RAD001可有效抑制mTOR下游效应蛋白,但同时诱导c-Raf的激活;RAD001与索拉菲尼联合用药可以有效抑制c-Raf/ERK1/2的激活;同时可有效逆转胰腺癌细胞的耐药,与RAD001单独用药组相比较,具有明显的协同抑制作用;体内抑瘤实验进一步证实该联合用药方案可有效抑制移植瘤的生长。结论 c-Raf的激活上调参与胰腺癌对mTOR抑制剂RAD001的耐药,以c-Raf为靶点可改善RAD001对胰腺癌的靶向治疗效果。Objective To investigate the molecular mechanism of pancreatic cancer cell resistance to mammalian target of rapamycin （mTOR） inhibitor RADOOI, and explore a feasible therapeutic strategy to overcome the resistance in patients with pancreatic cancer. Methods Western blotting was conducted to find out whether RADO0I induced c-Raf-ERK feedback activation and to identify whether RADO0] in combination with c-Raf inhibitor sorafenib could effectively block the feedback activation of c-Raf and downstream proteins. Sulphorhodamine B （SRB） colorimetdc assay and colony formation were used to detect the effect of the combination treatment on cell growth and proliferation; finally, the effect on mouse subcutaneous xenografts was examined to confirm the efficacy of the combination treatment in vivo. Results RAD001 effectively inhibited the expressions of mTORCI and its downstream proteins, and induced the feedback activation of c-Raf. Whereas, RAD001 combined with c-Raf inhibitor sorafenib eliminated RAD001-induced activation of c-Raf-ERK pathway and reversed pancreatic cancer cell resistance to RAD001; compared with the RADO01 alone, sorafenib had a synergistical inhibitory effect with RADO01. And the tumor growth inhibitory effect of the combination was also proved in mouse subcutaneous xenografts in vivo. Conclusion RADOOl-induced c-Raf-ERK feedback activation contributes to pancreatic cancer cell resistance to RAD001. Targeting of c-Raf may improve the therapeutic efficacy of RADOOI in patients with pancreatic cancer.

关 键 词：MTOR抑制剂 胰腺癌 耐药性 c—Raf通路 

分 类 号：R735.9[医药卫生—肿瘤] R392-33[医药卫生—临床医学]