汉防己甲素通过促进HIF-1α降解增强p53缺陷型非小细胞肺癌的放疗敏感性  

Tetrandrine enhances the radiosensitivity of p53-deficient non-small cell lung cancer by promoting HIF-1αdegradation

作　　者：金磊[1] 郭洁[2] 刘昊[1] 康云帆 吴翔 Lei Jin;Jie Guo;Hao Liu;YunfanKang;Xiang Wu(Department of Cardiothoracic Surgery,First Affiliated Hospital of Xi'an Medical College,Xi'an 710077,China;Emergency Department,First Affiliated Hospital of Xi'an Medical College,Xi'an 710077,China;Basic Medical College of Xi'an Jiaotong University Medical College,Xi'an 710061,China)

机构地区：[1]西安医学院第一附属医院心胸外科,西安市710077 [2]西安医学院第一附属医院急诊科,西安市710077 [3]西安交通大学医学院基础医学院

出　　处：《中国肿瘤临床》2020年第20期1044-1050,共7页Chinese Journal of Clinical Oncology

摘　　要：目的:探讨汉防己甲素(tetrandrine,TET)增强非小细胞肺癌(non-small cell lung cancer,NSCLC)放疗敏感性的作用机制。方法:通过CCK-8法检测H1299和Calu-1细胞活力,并结合克隆形成实验检测在常规或缺氧条件下,TET对NSCLC放疗敏感性的影响。研究TET对NSCLC中由辐射和缺氧诱导的缺氧诱导因子-1α(hypoxia inducible factor-1,HIF-1α)及血管内皮生长因子(vascular endothelial growth factor,VEGF)表达的影响,并敲低HIF-1α基因进一步验证。通过逆转录聚合酶链反应(reverse tran⁃scription-polymerase chain reaction,RT-PCR)、环己酰亚胺(cycloheximide,CHX)追踪及免疫沉淀法检测TET对HIF-1α降解的影响,并探讨p53在TET放疗增敏中的作用。结果:TET可显著增强p53缺陷型NSCLC细胞的放疗敏感性,而对p53野生型的细胞作用不明显。辐射和缺氧暴露后,TET明显抑制HIF-1α及VEGF的表达。TET可通过蛋白泛素化降解系统加速HIF-1α的降解。野生型p53基因转染到H1299细胞中可减弱TET抑制HIF-1α表达的作用。结论:TET通过促进HIF-1α降解抑制HIF-1α通路,使p53缺陷型NSCLC细胞对辐射敏感,而p53在TET诱导的HIF-1α降解中发挥抑制作用。Objective:To explore the specific mechanisms by which tetrandrine(TET)enhances the radiosensitivity of non-small cell lung cancer(NSCLC).Methods:Cell viability was assessed via CCK-assay,combined with the colony formation experiment to detect the effect of TET on the radiosensitivity of NSCLC under conventional or hypoxic conditions.The effect of TET on hypoxia inducible factor-1(HIF-1α)and vascular endothelial growth factor(VEGF)in NSCLC induced by ionising radiation(IR)and hypoxia was investigated.To investigate the impact of decreased HIF-1αexpression on radiosensitivity,HIF-1αwas knocked down.The effect of TET on HIF-1αdegradation was investigated via reverse transcription-polymerase chain reaction(RT-PCR),cycloheximide(CHX)tracking,and immunoprecipitation.The role of p53 in TET-induced radiosensitization was also explored.Results:While TET significantly enhances the radiosensitivity of p53-deficient NSCLC cells,it has no significant impact on the radiosensitivity of cells expressing normal level of p53.Exposure to TET after IR and hypoxia significantly inhibits HIF-1αand VEGF expression.This effect is attributable to TET-induced HIF-1αubiquitination,which accelerates HIF-1αdegradation via the ubiquitin proteasomal system.Transfection of wild-type p53 into H1299 cells attenuates the impact of TET on HIF-1αexpression.Conclusions:Inhibition of the HIF-1αpathway by TET is achieved via promoting HIF-1αdegradation,which sensitizes p53-deficient NSCLC cells to IR.The presence of p53 inhibits TET-induced HIF-1αdegradation.

关 键 词：汉防己甲素放疗增敏HIF-1α P53 非小细胞肺癌 

分 类 号：R734.2[医药卫生—肿瘤]