Wang X, Liu Y, Chow L S, Wong S C, Tsao G S, Kwong D L, Sham J S, Nicholls J M
Department of Pathology, University of Hong Kong, Queen Mary Hospital, Hong Kong.
Anticancer Res. 2000 Jan-Feb;20(1A):433-7.
Since telomerase has been suggested to play a role in radiation response, the effect of radiation on the regulation of telomerase activity was studied on two NPC cell lines, CNE1 and 915. In order to investigate the correlation between cell survival and telomerase activity, three low doses (0.25, 0.5 and 1 Gy) and three high doses (2, 4 and 8 Gy) of gamma-radiation were used. We found that low doses of radiation induced telomerase activity (up to 250% of untreated controls) followed by a cell cycle G1 arrest, suggesting that the up-regulation of telomerase may play a role in initiating radiation induced cell cycle arrest. High doses of radiation resulted in decreased telomerase activity (down to 30% of untreated controls) and this was followed by an increased cell death. Our results indicate that the up-regulation of telomerase activity is an important response to radiation induced sub-lethal DNA damage. Our results also suggest that inhibition of telomerase activity by high doses of radiation may play a role radiation-induced cell death.
由于端粒酶被认为在辐射反应中起作用，因此研究了辐射对两种鼻咽癌（NPC）细胞系CNE1和915中端粒酶活性调节的影响。为了研究细胞存活与端粒酶活性之间的相关性，使用了三种低剂量（0.25、0.5和1 Gy）和三种高剂量（2、4和8 Gy）的γ射线辐射。我们发现低剂量辐射诱导端粒酶活性（高达未处理对照的250%），随后细胞周期G1期停滞，这表明端粒酶的上调可能在启动辐射诱导的细胞周期停滞中起作用。高剂量辐射导致端粒酶活性降低（低至未处理对照的30%），随后细胞死亡增加。我们的结果表明，端粒酶活性的上调是对辐射诱导的亚致死性DNA损伤的重要反应。我们的结果还表明，高剂量辐射对端粒酶活性的抑制可能在辐射诱导的细胞死亡中起作用。
