RNA干扰抑制端粒酶对受照后端粒长度的影响  

Effect of RNAi inhibiting telomerase on telomere lengths after irradiation

作　　者：邹跃 李志韧 周湘艳[2] 杜维霞[2] 胡海兰 

机构地区：[1]解放军二炮总医院,北京100088 [2]中国疾病预防控制中心辐射防护与核安全医学所

出　　处：《中华放射医学与防护杂志》2006年第5期453-455,共3页Chinese Journal of Radiological Medicine and Protection

基　　金：全军"十五"卫生科研规划资助项目(01MB054)

摘　　要：目的探索RNA干扰体内表达质粒抑制端粒酶表达的作用,以及端粒酶抑制后射线对端粒长度的影响。方法构建RNA干扰体内表达质粒,脂质体介导转染A549细胞系,TRAP-ELISA法检测端粒酶活性,RT-PCR法检测hTERTmRNA表达,端粒限制性片段平均长度分析法检测端粒长度。结果pPUR/hTERT质粒在A549转染株内表达可下调hTERTmRNA表达,抑制端粒酶活性;A549照射后端粒明显延长,而pPUR/hTERT表达株照射后未见端粒延长,抑制了射线诱导端粒延长作用。结论RNA干扰体内表达质粒可抑制端粒酶表达及照射后端粒延长,表明射线诱导端粒延长可能是端粒酶在端粒断裂端合成端粒序列的结果。Objective To investigate the effect of expression vector of RNAi on inhibiting expression of telomerase, and its influence on telomere lengths in human cell line exposed to ionizing radiation. Methods Expression vector of pPUR/hTERT interfering with hTERT mRNA was constructed by inserting oligodeoxynucleotide into pPUR/U6 vector. Transfecied A549 line was mediated by Lipofectamine. Telomerase activities were measured by TRAP-ELISA, expression of hTERT mRNA by RT-PCR, and telomere lengths by mean length of terminal restriction fragment （TRF） analysis. Results An expression of the vector inhibited telomerase activities in transferred A549 and the expression of hTERT mRNA was down-regulated. After irradiation with coblat-60 γ-rays, length of telomere of A549 increased significantly, however, telomere lengthening did not occur in pPUR/hTERT line. Conclusions The expression vector of RNAi could inhibit expression of telomerase and telomere lengthening after radiation, suggesting that telomere lengthening induced by irradiation may be attributed to telomerase de novo composition of telomere sequences.

关 键 词：RNA干扰 端粒酶 端粒 放射线 

分 类 号：R346[医药卫生—基础医学]