辛伐他汀通过调控PI3K/AKT通路介导的EMT参与放疗诱导的食管癌细胞耐受  

Simvastatin is involved in radioresistance of esophageal cancer cells by regulating the PI3K/AKT pathway-mediated epithelial-mesenchymal transition

作　　者：金迎迎[1] 包兴[1] 柯悦 何赟[1] 贾辉[1] 孟鑫 安雷 罗恒[1] JIN Ying-ying;BAO Xing;KE Yue;HE Yun;JIA Hui;MENG Xin;AN Lei;LUO Heng(Department of Oncology Radiotherapy,The Second Affiliated Hospital of Xi'an Jiaotong University,Xi'an 710004,China)

机构地区：[1]西安交通大学第二附属医院肿瘤放疗科,陕西西安710004

出　　处：《西安交通大学学报（医学版）》2019年第1期32-37,共6页Journal of Xi’an Jiaotong University（Medical Sciences）

基　　金：陕西省科学技术研究与发展计划项目(No.2016SF-089)~~

摘　　要：目的明确辛伐他汀对食管癌细胞放疗耐受性、上皮间充质细胞转化(epithelialmesenchymal transition,EMT)发生的影响及其作用机制。方法食管癌细胞经辛伐他汀(5μmol/L)预处理8h后进行X线放射处理,克隆平板形成实验测定细胞生存分数;MTT检测放疗后细胞增殖能力;流式细胞术检测细胞凋亡;试剂盒检测caspase-3活性;Western blot检测对PI3K/AKT通路的影响。结果辛伐他汀预处理降低放疗细胞的克隆存活分数(P<0.05),放疗后细胞的增殖能力进一步降低(P<0.05),而细胞的凋亡率及caspase-3活性上调(P<0.05)。此外,辛伐他汀增加6Gy细胞处理组中上皮标记物E-cadherin的表达,同时抑制间充质标记物N-cadherin及Vimentin的表达,差异有统计学意义(P<0.05)。机制分析证实,放疗后细胞中p-AKT的表达水平明显增加,而辛伐他汀预处理可明显抑制p-AKT的表达。当用PI3K/AKT通路激动剂IGF-1预处理后,辛伐他汀介导的放疗细胞增敏效应及逆转放疗细胞EMT发生的能力明显减弱(P<0.05)。结论辛伐他汀可以阻断PI3K/AKT通路的活化,抑制放疗引发的食管癌细胞EMT发生,从而增加食管癌细胞的放疗敏感性,提示本研究将为食管癌放疗增敏的临床研究提供新的策略。Objective To explore the role and mechanism of simvastatin in radioresistance and epithelial-mesenchymal transition(EMT)of esophageal cancer.Methods Esophageal cancer cells were preconditioned with simvastatin(5μmol/L)for 8 h,prior to exposure to x-ray irradiation.Clonogenic cell survival assay was performed to detect cell survival fraction.Cell proliferation was evaluated by MTT assay.Cell apoptosis was determined by flowcytometry.The activity of caspase-3 was detected by the common commercial kit.Additionally,Western blot assay was performed to analyze the activation of the PI3K/AKT pathway.Results Pretreatment with simvastatin dramatically decreased the survival fraction(P<0.05)and proliferation(P<0.05)of the radiated cells,but aggravated cell apoptosis rate and caspase-3 activity(P<0.05).Furthermore,simvastatin stimulation significantly increased the expression of epithelial marker E-cadherin in 6 Gy-treated cells,but down-regulated the expression of mesenchymal marker N-cadherin and Vimentin(P<0.05).Mechanism analysis corroborated the activation of the PI3K/AKT pathway in cells after irradiation by elevating the expression of p-AKT,which was abrogated by simvastatin pre-treatment.More importantly,administration with IGF-1,an activator of PI3K/AKTpathway,attenuated the inhibitory effect of simvastatin on radioresistance and radiation-evoked EMT(P<0.05).Conclusion Simvastatin inhibits radiation-induced EMT of esophageal cancer cells by blocking the PI3K/AKT pathway,and ultimately elevates the radiosensitivity,indicating a promising therapeutic avenue for treatment of esophageal cancer radioresistance.

关 键 词：辛伐他汀 食管癌 放疗耐受 上皮间充质细胞转化(EMT) PI3K/AKT 

分 类 号：R735.1[医药卫生—肿瘤]