外源表达miR-34a对H1299细胞辐射敏感性的影响  

Effects of exogenetic miR-34a on radiosensitivity of H1299 cells

作　　者：陈雪[1] 高刚[1] 阮健磊[1] 刘建香[1] 

机构地区：[1]中国疾病预防控制中心辐射防护与核安全医学所辐射防护与核应急中国疾病预防控制中心重点实验室,北京100088

出　　处：《中华放射医学与防护杂志》2013年第2期128-130,共3页Chinese Journal of Radiological Medicine and Protection

基　　金：国家自然科学基金（31100606）;卫生行业科研专项（201002009）

摘　　要：目的 研究miR-34a对H1299细胞辐射敏感性的影响.方法 采用pre-miR-34a瞬时转染H1299细胞,接受不同剂量（0、2、4、6和8 Gy）γ射线照射后,利用CCK-8试剂盒检测细胞活性.流式细胞术检测细胞凋亡及细胞周期,real-time PCR检测miR-34a靶基因bcl-2、bax、CDK4、CDK6及cyclinD1的表达水平.结果 不同剂量（0、2、4、6和8 Gy）γ射线照射后,与阴性对照转染组相比,pre-miR-34a转染组各剂量点细胞活力明显降低（t=-2.39、-3.12、-4.98、-4.03、-3.06,P＜0.05）,并与阴性对照转染组的差值呈剂量依赖性的增加.6 Gyγ射线照射后,与阴性对照转染组相比,pre-miR-34a转染组细胞凋亡率明显增加（t=7.06,P＜0.05）,细胞G0/G1期阻滞（t =3.94,P＜0.05）,S期细胞减少（t=6.23,P＜0.05）,bcl-2、CDK4及CDK6明显下调（t=3.39、12.88、6.21,P＜0.05）,cyclinD1有下降趋势,但差异无统计学意义,而bax明显上调（t=-4.35,P＜0.05）,是阴性对照转染组的1.94倍,bcl-2/bax比值下降.结论 miR-34促进H1299细胞凋亡,诱导细胞G0/G1期阻滞,抑制细胞活性,进而提高H1299细胞的辐射敏感性.Objective To investigate the influences of miR-34a on the radiosensitivity of H1299 cells. Methods CCK-8 kit was used to examine the viability of H1299 cells which were exposed to different doses （0, 2, 4, 6 and 8 Gy） of 60Co r-rays after transient transfection of pre-miR-34a. Apoptosis rate and cell cycle were measured with flow cytometry. The expression levels of miR-34a target genes, bcl-2, bax, CDK4, CDK6 and cyclinD1 were analyzed by real-time PCR. Results Compared to the control group of negative transfection, the cell viability in pre-miR-34a transfection group decreased significantly after irradiation at0, 2, 4, 6, 8 Gy （t= -2.39, -3.12, -4.98, -4.03, -3.06, P〈 0. 05 ） in a dose-dependent manner. After being irradiated with 6 Gy r-rays, the apoptotie rate in pre-miR- 34a transfeetion group was significantly increased （ t = 7.06, P 〈 0. 05 ） together with an aeeumulation of G0/Gl phase （ t ＂= 3.94, P 〈 0. 05 ） and a reduction of S phase （ t = 6. 23, P 〈 0. 05 ）. The gene expression levels of bel-2, CDK4 and CDK6 in pre-miR-34a transfeetion group were respectively decreased （ t = 3.39, 12. 88, 6. 21, P 〈0. 05） of negative eontrol, eyclinD1 was also decreased but no signifieanee, while bax was increased to 1.94 times of negative control （ t = - 4.35, P 〈 0.05） together with a decrease of bel-2/ bax. Conclusions miR-34a could promote cell apoptosis, induce G0/Gt phase accumulation, suppress cell activity, and in turn increase the radiosensitivity of H1299 cells.

关 键 词：MIR-34A H1299细胞 辐射敏感性 细胞凋亡 细胞周期 

分 类 号：R734.2[医药卫生—肿瘤]