γ射线照射后造血细胞端粒酶活性变化  

Change of telomerase activity in gamma irradiated hematopoietic cells.

作　　者：李夏新[1,2,3] 洪平 程少杰[1,2,3] 

机构地区：[1]第一军医大学附属南方医院 [2]广州军区第一五七医院儿科 [3]法国巴黎圣-路易医院血研所

出　　处：《中华放射医学与防护杂志》1998年第6期377-380,共4页Chinese Journal of Radiological Medicine and Protection

基　　金：军队"八.五"青年基金

摘　　要：以ＫＧｌａ和ＣＥＭ两个白血病细胞株为模型，探讨γ射线照射后造血细胞中端粒酶的变化。方法细胞经照射后用３Ｈ－胸腺嘧啶渗入法测定细胞增殖能力，Ｋｉｍ氏ＴＲＡＰ方法分析端粒酶活性，并采用２次胸腺嘧啶使细胞同步化，ＢｒｄＵ渗入法分析细胞同步化结果及照射后细胞周期分布。结果γ射线照射后造血细胞能增加端粒酶活性，在０～３Ｇｙ照射后酶活性逐渐上升，３Ｇｙ达高峰，在时间动态变化上，照射后８～２４小时酶活性最高，此后开始下降，此时在细胞周期分布上有Ｇ２／Ｍ期细胞堆积，然而使细胞同步化后端粒酶活性在细胞各期无明显变化。结论造血细胞的端粒酶活性在照射后的上调反应，可能与ＤＮＡ的修复、稳定断裂染色体有关。Objective\ Using two hematopoietic cell lines, KGla and CEM, to investigate the variation of telomerase activity after γ irradiation.Methods\ After irradiation, cell proliferation was measured by thymidine incorporation and telomerase activity of cells was analysed by Kim's TRAP assay. Cell synchronization was achieved after two step thymidine blocks, and cell cycle was examined by BrdU incorporation technique for verifying cell cycle distribution after irradiation and cell synchronization.Results\ Telomerase activity increased after irradiation of between 0 and 3Gy in a dose dependent manner, reaching the maximum at 3 Gy. The increase of telomerase activity was nearly to its maximum 8h after irradiation, the peak being observed at around 24h. Although this kinetics partly correlated with cell redistribution into the G 2/M phase of the cell cycle, telomerase activity did not show significant variation over the cell cycle.Conclusion\ The up regulation of telomerase in hematopoietic cell lines after γ irradiation may suggest the involvement of telomerase in DNA repair and chromosome healing.

关 键 词：Γ射线 造血细胞 端粒酶 细胞周期 

分 类 号：R818.023[医药卫生—放射医学]