果蝇zeste基因增强子的人类同源物2促进小细胞肺癌化疗耐药的作用及其分子机制  

The effect of EZH2 on the chemoresistance in small cell lung cancer and its mechanism

作　　者：华倩 刘方文 骆珍玉 李强[3] 邱振纲[3] HUA Qian;LIU Fang-wen;LUO Zhen-yu;LI Qiang;QIU Zhen-gang(Postgraduate student of Grade 2020,Gannan Medical University;The People's Hospital of Shangyou;The First Affiliated Hospital of Gannan Medical University,Ganzhou,Jiangxi 341000)

机构地区：[1]赣南医学院 [2]上犹县人民医院 [3]赣南医学院第一附属医院,江西赣州341000

出　　处：《赣南医学院学报》2023年第1期5-9,共5页JOURNAL OF GANNAN MEDICAL UNIVERSITY

基　　金：国家自然科学基金项目(82260546);江西省自然科学基金项目(20224BAB206062);赣州市指导性科技计划项目(GZ2021SF002);希思科-豪森肿瘤研究基金项目(Y-HS2019/2-015);赣南医学院科研课题(YB201909)。

摘　　要：目的:观察果蝇zeste基因增强子的人类同源物2(Enhancer of zeste homologue 2,EZH2)对小细胞肺癌(Small cell lung cancer,SCLC)化疗耐药的影响并研究其潜在分子机制。方法:首先使用RT-PCR和蛋白印迹方法检测SCLC初治和耐药患者组织标本、敏感细胞株(H446)和耐药细胞株(H446DDP)的EZH2表达差异;再通过CCK8方法检测敲低EZH2后的耐药SCLC细胞株对化疗药物半抑制浓度(Half maximal inhibitory concentration,IC50)值变化;最后通过RNA测序和验证方法筛查EZH2的下游靶基因以及CHIP-qPCR方法检测EZH2敲低后其靶基因启动子区的EZH2表达变化。结果:SCLC化疗耐药患者EZH2阳性表达水平(80%)高于化疗敏感患者,耐药细胞株(H446DDP)的EZH2 mRNA和蛋白表达水平均高于敏感细胞株(H446)(P<0.01,P<0.001);敲低EZH2表达后,耐药SCLC细胞株对化疗药物IC50值降低;细胞周期蛋白依赖性激酶抑制剂-1A(Cyclin-Dependent Kinase Inhibitor 1A,CDKN1A)表达增加,且CDKN1A基因启动子EZH2蛋白沉积显著减少。结论:EZH2促进SCLC化疗耐药,其分子机制与EZH2靶向调控CDKN1A基因表达相关。Objective:To investigate the effect of enhancer of zeste homologue 2(EZH2)on the chemoresistance in small cell lung cancer and its mechanism.Methods:The expressions of EZH2 in small cell lung cancer(SCLC)patients,drug-resistant SCLC cell line(H446DDP)and its parental cell line(H446)were detected by RT-PCR and Western blot.The half maximal inhibitory concentration(IC50)values for chemotherapy drugs was detected after EZH2 was downregulated.Further,we determine the target genes of EZH2 by RNA-sequence and verification method.Finally,the methylation level of target genes was detected by CHIP-qPCR method.Results:The positive expression of EZH2 in drug-resistant patients(80%)was higher than that in untreated patients(30%);the expression of EZH2 in H446DDP drug-resistance cell line was higher than that in drug-sensitive group(P<0.01,P<0.001).EZH2 knockdown decreases IC50 to chemotherapy drugs in chemoresistant SCLC cell lines.Cyclin-dependent kinase inhibitor 1A(CDKN1A)expressionincreased,and the deposition of EZH2 in the promoter of CDKN1A genewas significantly reduced.Conclusion:EZH2 promotes the chemoresistance in SCLC cells,which may be related to the methylation of CDKN1A gene promoter.

关 键 词：小细胞肺癌 化疗耐药 果蝇zeste基因增强子的人类同源物2 细胞周期蛋白依赖性激酶抑制剂-1A 

分 类 号：R734.2[医药卫生—肿瘤]