PARP inhibition sensitizes p53-deficient breast cancer cells to doxorubicin-induced apoptosis
PARP inhibition sensitizes p53-deficient breast cancer cells to doxorubicin-induced apoptosis
复制标题
DOI：
10.1042/bj20040776
复制
发表时间：
2005-02-15
影响因子：
4.1
通讯作者：
Oliver, FJ
中科院分区：
文献类型：
--
作者：
Muñoz-Gámez, JA;Martín-Oliva, D;Oliver, FJ
p53缺陷导致对多柔比星（doxorubicin）的抗性，多柔比星是一种临床上有活性且广泛使用的抗肿瘤蒽环类抗生素。本研究的目的是研究p53缺陷型乳腺癌细胞系EVSA-T和MDA-MB-231中强效PARP [poly（ADPribose）polymerase]抑制剂ANI（4-amino-1，8-naphthalimide）对doxo耐药的逆转机制。与单独的doxo相比，ANI对doxo诱导的细胞凋亡的影响在EVSA-T或MDA-MB-231的配对中进行了研究，有或没有ANI共处理。Doxo引起PARP活化，通过蛋白质印迹法和免疫荧光法测定聚（ADP-核糖），ANI增强Doxo的细胞毒活性2.3倍，并以半胱天冬酶依赖的方式。通过集落形成试验研究了长期细胞毒性作用。使用该测定，ANI还显著增强了相对于单独用doxo治疗的长期细胞毒性作用。在ANI的存在下，还观察到线粒体电位的降低以及细胞色素c释放的增加、Bax与线粒体的关联以及半胱天冬酶3的活化。因此，PARP抑制可能代表了一种选择性靶向p53缺陷乳腺癌细胞的新方法。潜在的机制可能是未修复的DNA损伤的增强，由于PARP活性的有效抑制而从DNA修复转变为凋亡。
p53 deficiency confers resistance to doxo (doxorubicin), a clinically active and widely used antitumour anthracycline antibiotic. The purpose of the present study was to investigate the reversal mechanism of doxo resistance by the potent PARP [poly(ADPribose) polymerase] inhibitor ANI (4-amino-1,8-naphthalimide) in the p53-deficient breast cancer cell lines EVSA-T and MDA-MB-231. The effects of ANI, in comparison with doxo alone, on doxo-induced apoptosis, were investigated in matched pairs of EVSA-T or MDA-MB-231 with or without ANI co-treatment. Doxo elicited PARP activation as determined by Western blotting and immunofluorescence of poly(ADP-ribose), and ANI enhanced the cytotoxic activity of doxo 2.3 times and in a caspase-dependent manner. The long-term cytotoxic effect was studied by a colony-forming assay. Using this assay, ANI also significantly potentiates the long-term cytotoxic effect with respect to treatment with doxo alone. Decrease in mitochondrial potential together with an increase in cytochrome c release, association of Bax with the mitochondria and caspase 3 activation were also observed in the presence of ANI. Therefore PARP inhibition may represent a novel way of selectively targeting p53-deficient breast cancer cells. The underlying mechanism is probably a potentiation of unrepaired DNA damage, shifting from DNA repair to apoptosis due to the effective inhibition of PARP activity.