LOSS OF S-PHASE-DEPENDENT RADIORESISTANCE IN IRS-1 CELLS EXPOSED TO X-RAYS
LOSS OF S-PHASE-DEPENDENT RADIORESISTANCE IN IRS-1 CELLS EXPOSED TO X-RAYS
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DOI：
10.1016/0921-8777(94)90063-9
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发表时间：
1994-01-01
期刊：
影响因子：
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通讯作者：
ILIAKIS, G
中科院分区：
文献类型：
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作者：
CHEONG, N;WANG, XM;ILIAKIS, G
我们测量了亲本V79细胞和从它们分离的辐射敏感突变体IRS-1(Jones等人)在整个细胞周期中的辐射敏感性。(1987)突变研究，183,279-286)。我们观察到，在5或9GyX射线照射的亲本V79细胞中，辐射敏感性在整个细胞周期中都有很大的波动；在G1/S交界处照射的细胞一般是放射敏感的，而在S中期或晚期照射的细胞是放射抗性的。与此结果形成鲜明对比的是，IRS-1细胞在整个细胞周期中表现出相对平坦的辐射敏感性，这主要是由于在S期缺乏辐射抗性。一般来说，IRS-1细胞在V79细胞抵抗辐射的细胞周期阶段对辐射最敏感，而与V79细胞周期中最敏感的有丝分裂相比，IRS-1细胞对V79细胞的辐射敏感性同样高。结果表明，其修复受到IRS-1突变影响的辐射诱导损伤的子集类似于其修复或表达导致修复熟练细胞中整个细胞周期的放射敏感性波动的损伤子集。这些观察结果为IRS-1突变增加了另一个独特的表型特征。
We measured radiosensitivity throughout the cell cycle in parental V79 cells and a radiation-sensitive mutant isolated from them, irs-1 (Jones et al. (1987) Mutation Res., 183, 279-286). We observed, as expected, large fluctuations in radiosensitivity throughout the cell cycle in parental V79 cells exposed to 5 or 9 Gy X-rays; cells irradiated at the G1/S border were generally radiosensitive whereas cells irradiated in mid- or late-S phase were radioresistant. In sharp contrast to this result, irs-1 cells showed a relatively flat response of radiosensitivity throughout the cell cycle mainly due to a lack of radioresistance during S. In general, irs-1 cells were maximally radiosensitive in phases of the cell cycle where V79 cells were radioresistant, and equally radiosensitive to V79 cells when compared at mitosis, the most radiosensitive phase of the V79 cell cycle. The results suggest that the subset of radiation-induced lesions whose repair is compromised by the irs-1 mutation is similar to the subset of lesions whose repair or expression causes the fluctuations in radiosensitivity throughout the cell cycle in repair-proficient cells. These observations add another unique phenotypic characteristic to the irs-1 mutation.