X irradiation induces the proapoptotic state independent of the loss of clonogenic ability in Chinese hamster V79 cells
X irradiation induces the proapoptotic state independent of the loss of clonogenic ability in Chinese hamster V79 cells
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DOI：
10.1667/rr3393
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发表时间：
2005-07-01
影响因子：
3.4
通讯作者：
Kuwabara, M
中科院分区：
文献类型：
--
作者：
Iizuka, D;Inanami, O;Kuwabara, M
本文测定了中国仓鼠V79细胞经X射线和新药1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine(ECYD，TAS106)处理后的克隆形成能力(生殖细胞死亡)。与仅暴露于X射线的细胞相比，克隆形成能力丧失的扩增被观察到。加入广谱半胱氨酸氨基转移酶抑制剂benzyloxycarbonyl-val-ala-asp-fluoromethylketone(Z-VADFMK)可减弱增加的致死率，但所获得的剂量-反应曲线仅恢复到仅暴露于X射线的细胞的剂量-反应曲线。流式细胞仪分析显示，与TAS106共同作用后，X射线照射引起的G(2)/M期细胞数减少，而亚G_1期细胞数增加。Western印迹分析证明，TAS106处理下调了G(2)/M期阻滞相关蛋白Cyclin B1、磷酸化CDC2和WEE1的表达。根据这些结果，我们得出结论：(1)单纯X射线照射的细胞的剂量-效应曲线中没有包括细胞凋亡；(2)X射线照射诱导细胞处于潜在的凋亡(促凋亡)状态，而不依赖于其克隆形成能力的丧失；(3)TAS106通过消除G2/M期的停滞而将促凋亡细胞转化为凋亡细胞，从而增强了其克隆形成能力的丧失。(C)2005年，由辐射研究学会提供。
The clonogenic ability (reproductive cell death) of Chinese hamster V79 cells was measured after treatment with X radiation and a newly developed anti-cancer drug, 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine (ECyd, TAS106). Amplification in the loss of clonogenicity was observed compared to that obtained for cells exposed to X rays alone. Addition of benzyloxycarbonyl-val-ala-asp-fluoromethylketone (Z-VADFMK), a broad-spectrum caspase inhibitor, attenuated the increased lethality, but the dose-response curve obtained was found to merely revert to that obtained for cells exposed to X rays alone. Flow cytometric analysis showed that the number of cells arrested at the G(2)/M phase by X irradiation was decreased by co-treatment with TAS106, and instead the number of cells in the sub-G, phase increased. Western blot analysis proved that TAS106 treatment down-regulated the expression of the G(2)/M arrest-related proteins cyclin B1, phospho-CDC2 and WEE1. From these results, it was concluded that (1) no apoptosis was included in the dose-response curve obtained from cells exposed to X rays alone, (2) X radiation induced a potentially apoptotic (proapoptotic) state in cells independent of the loss of their clonogenic ability, and (3) TAS106 enhanced the loss of their clonogenic ability by converting the proapoptotic cells to apoptotic cells through the abrogation of arrest at the G2/M phase. (c) 2005 by Radiation Research Society.