Zinc inhibition of caspase-3 activation does not protect HeLa cells from apoptotic cell death
Zinc inhibition of caspase-3 activation does not protect HeLa cells from apoptotic cell death
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DOI：
10.1006/taap.2001.9239
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发表时间：
2001-08-15
影响因子：
3.8
通讯作者：
Kang, YJ
中科院分区：
文献类型：
--
作者：
Lambert, JC;Wang, GW;Kang, YJ
锌被认为是抗细胞凋亡的，因为它已被证明可以抑制细胞凋亡途径的晚期事件，如染色质DNA的Ca 2 +/Mg-2+依赖性核酸内切酶切割，聚ADP核糖聚合酶切割和caspase-3活性。由于caspase-3是凋亡中的关键执行者caspase，因此进行本研究以专门检查锌抑制caspase-3活化与HeLa细胞凋亡之间的相关性。培养的HeLa细胞在用1.0 μ M阿霉素（DOX）处理12小时之前暴露于100 μ M ZnCl 2 1小时，阿霉素是一种重要的抗癌剂，其在多种肿瘤细胞中引起凋亡。用DOX处理HeLa细胞12 h的Western印迹分析显示，DOX引起caspase-3的蛋白水解活化，锌抑制这种活化。有趣的是，锌并没有抑制DOX诱导的细胞凋亡所测量的末端脱氧核苷酸转移酶介导的dUTP缺口末端标记试验。此外，微量培养四唑测定证实，在锌的存在下发生细胞死亡。这些结果表明，锌特异性抑制HeLa细胞中DOX诱导的半胱天冬酶-3活化，但不抑制DOX诱导的细胞凋亡或其他细胞死亡，因此表明DOX诱导的半胱天冬酶-3活化可能在整体细胞死亡中不起主要作用和/或非半胱天冬酶-3途径参与HeLa细胞中DOX诱导的细胞凋亡。(C)北京：科学出版社.
Zinc is proposed to be antiapoptotic for it has been shown to inhibit late events of apoptotic pathways such as Ca2+/Mg-2+-dependent endonuclease cleavage of chromatin DNA, poly-ADP ribose polymerase cleavage, and caspase-3 activity. Because caspase-3 is a critical executioner caspase in apoptosis, this study was undertaken to examine specifically a correlation between zinc inhibition of caspase-3 activation and apoptosis in HeLa cells. Cultured HeLa cells were exposed to 100 rhoM ZnCl2 for 1 h prior to 12 h treatment with 1.0 muM doxorubicin (DOX), an important anticancer agent that causes apoptosis in a wide variety of tumor cells. Western blot analysis of HeLa cells treated with DOX for 12 h revealed that DOX caused proteolytic activation of caspase-3 and zinc inhibited this activation. Interestingly, zinc did not inhibit DOX-induced apoptosis as measured by a terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. Furthermore, a microculture tetrazolium assay confirmed that cell death occurred in the presence of zinc. These results demonstrate that zinc specifically inhibits DOX-induced activation of caspase-3 in HeLa cells, but does not suppress DOX-induced apoptosis or otherwise cell death, thus suggesting DOX-induced caspase-3 activation may not play a major role in overall cell death and/or non-caspase-3 pathways are involved in DOX-induced apoptosis in HeLa cells. (C) 2001 Academic Press.