分割剂量电离辐射对卵巢癌耐药细胞自噬性死亡的影响  

Role of fractionated ionizing radiation in autophagy in drug resistance of ovarian cancer

作　　者：梁冰[1] 刘晓冬[1] 刘欣[2] 贾立立[1] 孔德娟[1] 徐慧英[1] 贺梦子[1] 宋志恒[1] 刘明博[1] 马淑梅[1] 

机构地区：[1]吉林大学公共卫生学院卫生部放射生物学重点实验室,吉林长春130021 [2]吉林大学公共卫生学院流行病与卫生统计学教研室,吉林长春130021

出　　处：《吉林大学学报（医学版）》2011年第6期971-975,964,共6页Journal of Jilin University：Medicine Edition

基　　金：国家自然科学基金资助课题(30970682;30770649)

摘　　要：目的:研究不同电离辐射方式对卵巢癌耐药细胞株SKVCR自噬性细胞死亡的影响,并探讨其相关机制。方法:实验分为假照组、分割照射组(2Gy·d-1×5)及单次照射组(10Gy·d-1×1)。采用MTT法检测各组细胞对长春新碱(VCR)、依托泊苷(VP-16)及顺铂(DDP)的药物敏感性,MDC染色及流式细胞术检测自噬发生率的变化,实时荧光定量PCR方法检测自噬特异基因MAPLC3B和Akt1mRNA水平,Western blotting法检测自噬相关蛋白MAPLC3B表达和蛋白激酶B(PKB,Akt1)/哺乳动物雷帕霉素靶蛋白(mTOR)及其下游基因P70S6K、磷酸化AKT1/mTOR/P70S6K表达的变化。结果:与假照组比较,电离辐射使SKVCR细胞对VCR、VP-16的药物敏感性提高,分割照射组更明显(P<0.05)。与假照组比较,电离辐射使细胞自噬发生率升高,尤其以分割照射组升高更明显(P<0.05);与假照组比较,照射后MAPLC3B mRNA升高、Akt1mRNA下降(P<0.05);照射后MAPLC3B蛋白表达升高,Akt1、mTOR、p-mTOR、P70S6K、p-P70S6K蛋白表达均不同程度下降,分割照射组较单次照射组下降更明显(P<0.05)。结论:不同的电离辐射作用方式可以引起卵巢癌细胞发生自噬性死亡,其机制主要涉及Akt1/mTOR/S6K通路。Objective To detect the effects of different subtypes of fractionated ionizing radiation(IR) on autophagy in ovarian cancer cell line and to explore the relevant mechanisms.Methods The cells were divided into control group,fractionated IR group(2 Gy perfraction·d-1×5) and single IR group(10 Gy perfraction·d-1×1).MTT assay was used to detect the drug sensitivities of the cells in three groups to VCR,VP-16 and DDP.MDC staining was used to examine the incidence of autophagy,Real-time fluorescence quantitative PCR was used to detect the expression levels of autophagy-relative genes MAPLC3B and Akt1 mRNA.Western blotting was applied to detect the expressions of autophagy-related protein MAPLC3B,protein kinase B(PKB,Akt1)/mammalian target of rapamycin(mTOR) and its downstream gene P70 S6K.Results Compared with control group,IR increased the drug sensitivities of SKVCR cells to VCR and VP-16,which was more significant in fractionated group(P<0.05).Compared with control group,IR increased the incidence of autophagy,particularly in fractionated IR group.Compared with control group,MAPLC3B was increased and Akt1 was decreased(P<0.05) after irradiation both at mRNA level and protein level,the expressions of mTOR,p-mTOR,P70 S6K,p-P70 S6K were decreased,the changes in fractionated IR group were more significant compared with single IR group.Conclusion Different subtypes of IR can induce the cell death of ovarian cancer,the Akt1/mTOR/S6K signal pathway and autophagy might be involved in the regulation mechanism.

关 键 词：分割剂量 卵巢肿瘤 自噬 

分 类 号：R737[医药卫生—肿瘤]