Anthracycline-induced DNA breaks and resealing in doxorubicin-resistant murine leukemic P388 cells.
Anthracycline-induced DNA breaks and resealing in doxorubicin-resistant murine leukemic P388 cells.
复制标题
蒽环类药物诱导的多柔比星耐药小鼠白血病 P388 细胞中的 DNA 断裂和重新封闭。
DOI：
10.1016/0006-2952(88)90440-6
复制
发表时间：
1988
影响因子：
5.8
通讯作者：
Samy,TS
中科院分区：
文献类型：
--
作者：
Maniar,N;Krishan,A;Israel,M;Samy,TS
能量依赖性药物外排被认为是细胞对阿霉素（DOX）耐药的主要因素。然而，最近的研究表明，减少保留单独不能解释蒽环类抗生素耐药性，并可能涉及其他因素，如药物代谢，自由基清除剂，改变DNA损伤/修复。本实验观察了阿霉素（DOX）诱导的P388细胞DNA损伤及其修复。我们的研究表明，与类似处理的P388/S细胞相比，P388/R细胞中的DNA损伤（以蛋白质相关的单链DNA断裂测量）减少2至5倍。P388/R在4小时内完成了整个细胞的DNA修复，表示为DNA重新连接的百分比，而P388/S细胞直到20小时才看到修复。当细胞核用于修复实验时，观察到DNA损伤修复没有差异。在敏感的全细胞中缺乏修复可能是由于高保留或缓慢的药物流出。三氟拉嗪（TFP）或维拉帕米（VPL）处理细胞增加DOX滞留并不导致P388/R细胞DNA损伤的增加。在耐药细胞中，DOX类似物AF-三氟乙酰阿霉素-14-戊酸酯（AD 32）、4′-O-四氢吡喃阿霉素（THP-阿霉素）和N-苄基阿霉素-14-戊酸酯（AD 198）诱导的DNA损伤比DOX高2- 4倍。P388/S和P388/R细胞暴露于DOX或AD 32后，聚（ADP-核糖）合成无差异。由于ADP-核糖聚合物的合成与自由基诱导的DNA损伤有关，并通过切除修复机制指示DNA修复，这些研究的数据表明，蒽环类药物暴露的细胞中的DNA断裂可能不是由于自由基的产生，而是由于其他机制，如DNA拓扑异构酶II活性的抑制。目前的研究，除了强调DNA损伤在耐药性中的作用外，还强调DNA拓扑异构酶II功能在蒽环类药物细胞毒性中的相对重要性。
Energy-dependent drug efflux is believed to be a major factor in cellular resistance to doxorubicin (DOX). However, recent studies have shown that decreased retention alone cannot account for anthracycline resistance, and possibly other factors, such as drug metabolism, free radical scavengers, and altered DNA damage/repair, may be involved. We have measured DOX-induced DNA damage and its repair in P388 cells sensitive (P388/S) and resistant (P388/R) to DOX. Our studies show 2- to 5-fold less DNA damage, measured as protein-associated single-strand DNA breaks, in P388/R cells when compared to similarly treated P388/S cells. The repair of DNA in whole cells, expressed as percent DNA rejoined, was complete in 4 hr in P388/R, whereas no repair was seen in P388/S cells until 20 hr. No difference in repair of DNA lesions was observed when nuclei were used in repair experiments. The absence of repair in sensitive whole cells may be due to high retention or slow drug efflux. Increase of cellular DOX retention by exposure of cells to trifluoperazine (TFP) or verapamil (VPL) did not result in the increase of DNA damage in P388/R cells. DOX analogs, Af-trifluoroacetyladriamycin-14-valerate (AD 32), 4′-O-tetrahydropyranyladriamycin (THP-adriamycin), andN-benzyladriamycin-14-valerate (AD 198), induced 2- to 4-fold more DNA damage than DOX in resistant cells. There was no difference in the poly(ADP-ribose) synthesis of P388/S and P388/R cells exposed to DOX or AD 32. Since ADP-ribose polymer synthesis is associated with free radical-induced DNA damage and is indicative of DNA repair by an excision-repair mechanism, data from these studies suggest that DNA breaks in anthracycline-exposed cells may not be due to free radical production but rather to other mechanisms, such as inhibition of DNA topoisomerase II activity. The present studies, in addition to emphasizing the role of DNA damage in resistance, also underscore the relative importance of DNA topoisomerase II function in anthracycline cytotoxicity.