ETOPOSIDE (VP-16-213)-INDUCED GENE ALTERATIONS - POTENTIAL CONTRIBUTION TO CELL-DEATH
ETOPOSIDE (VP-16-213)-INDUCED GENE ALTERATIONS - POTENTIAL CONTRIBUTION TO CELL-DEATH
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DOI：
10.1073/pnas.88.19.8740
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发表时间：
1991-10-01
影响因子：
11.1
通讯作者：
HELMS, SR
中科院分区：
文献类型：
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作者：
BERGER, NA;CHATTERJEE, S;HELMS, SR
我们以前已经证明了依托泊苷诱导的姐妹染色单体交换(SCE)和细胞毒性之间有很好的相关性。依托泊苷是鬼臼毒素的半合成衍生物，也称为Vepesid(Bristol；代码为VP-16-213，缩写为VP-16)。由于SCE代表DNA重组事件，我们推测VP-16诱导的SCE可能导致非同源重组，其中DNA片段要么缺失，要么增加，导致负责细胞必需蛋白的基因序列改变。这些必需基因的改变以及由此对其产物形成的干扰可能会导致细胞死亡。为了评估VP-16处理是否引起足够水平的DNA序列改变以干扰基因产物的形成，我们从有或没有VP-16的中国仓鼠V79细胞中分离到次黄嘌呤(鸟嘌呤)磷酸核糖基转移酶(HPRT)缺陷突变株。将3个自发突变株和10个VP-16诱导突变株的DNA与仓鼠HPRT全长cDNA探针进行Southern杂交。大多数VP-16诱导的突变体表现出HPRT基因的部分缺失和/或重排。相比之下，自发突变的缺失或重排可以忽略不计。这些结果有力地支持了我们的假设，即基因序列的缺失可能是VP-16诱导细胞死亡机制的重要组成部分。
We have shown previously a good correlation between etoposide-induced sister chromatid exchanges (SCE) and cytotoxicity. A semisynthetic derivative of podophyllotoxin, etoposide is also called Vepesid (Bristol; code designation VP-16-213, abbreviated VP-16). Since SCE represent DNA recombinational events, we hypothesized that VP-16-induced SCE might result in nonhomologous recombination in which segments of DNA were either deleted or added, leading to an alteration of gene sequences responsible for essential cell proteins. Alterations of such essential genes and consequent interference with formation of their products could consequently lead to cell death. To evaluate whether VP-16 treatment caused sufficient levels of DNA sequence alterations to interfere with gene product formation, we isolated hypoxanthine (guanine) phosphoribosyltransferase (HPRT)-deficient mutants from Chinese hamster V79 cells grown in the presence or absence of VP-16. DNA from 3 spontaneous mutants and 10 VP-16-induced mutants was analyzed by Southern blot hybridization to a full-length hamster HPRT cDNA probe. Most of the VP-16-induced mutants showed partial deletions and/or rearrangements of the HPRT gene. In contrast, spontaneous mutants showed negligible deletions or rearrangements. These results provide strong support for our hypothesis that deletion of genetic sequences may constitute an important component of the mechanism of VP-16-induced cell death.