Extracellular Ca(2+) Selectively Enhances Adriamycin-induced Cell Death in Human Hepatoma Cells.
Extracellular Ca(2+) Selectively Enhances Adriamycin-induced Cell Death in Human Hepatoma Cells.
复制标题
细胞外 Ca(2) 选择性增强人肝癌细胞中阿霉素诱导的细胞死亡。
DOI：
10.2174/156800961506150805151905
复制
发表时间：
2015-06
期刊：
影响因子：
--
通讯作者：
Wu, Zhigang
中科院分区：
文献类型：
--
作者：
Liu, Yanyi;Xie, Hong;Wang, Jiachun;Wu, Zhigang
研究表明，肿瘤细胞和正常细胞之间Ca（2+）信号的调控机制不同，为抗癌药物的药理学调控提供了新的思路。然而，肝癌细胞和正常肝细胞对细胞外Ca（2+）的反应是否存在差异尚不清楚。本研究采用MTT法和Annexin V/PI法分别检测了钙离子（[Ca（2+）]a）和阿霉素（ADM）对人正常胚胎肝细胞L02和人肝癌细胞HepG 2的生长抑制、凋亡和坏死率的影响。结果表明，[Ca（2+）]e对HepG 2细胞的生长抑制、坏死率、凋亡率及细胞内Ca（2+）浓度（[Ca（2+）]i）均高于L02细胞。此外，[Ca（2+）]e能选择性地增强ADM对HepG 2细胞的生长抑制、凋亡和坏死，而对L02细胞无此作用。ADM和[Ca（2+）]a联合处理对两种细胞的[Ca（2+）]i均有显著的交互作用，但两种细胞的[Ca（2+）]i无显著差异。为进一步阐明[Ca（2+）] a选择性促进HepG 2和L02细胞[Ca（2+）]e的作用机制，本研究观察了ADM或/和[Ca（2+）]a处理HepG 2和L02细胞后，凋亡调节蛋白bcl-2、bax和caspase-3的水平以及caspase-3的活性。结果表明，与ADM单独作用组相比，[Ca（2+）]a和ADM联合作用组Bax蛋白水平和caspase-3活性均升高，bcl-2蛋白水平降低。而L02细胞则无明显变化。上述结果表明，肝癌细胞HepG 2对[Ca（2+）] a比正常肝细胞L02更敏感，[Ca（2+）]a可选择性地增强ADM诱导的HepG 2细胞死亡。这种强烈的促凋亡作用的机制可以归因于bax的上调和bcl-2的同时下调，随后从procaspase-3到caspase-3的转换，从而执行凋亡。目前的数据表明钙离子作为ADM增强剂的效力。
It has been shown that the regulatory mechanisms of Ca(2+) signaling between tumor and normal cells are different, providing new insight into the pharmacological modulation of anticancer drugs. However, it remains unclear whether there is any difference between hepatoma and normal hepatic cells in their response to extracellular Ca(2+) ([Ca(2+)]e). In the present study, the growth inhibition, apoptosis and necrosis rates of human normal embryo hepatic L02 and human hepatoma HepG2 cells exposed to additional calcium ([Ca(2+)]a)and adriamycin (ADM), a chemotherapeutic agent to treat hepatocellular carcinoma, were measured by MTT and annexin V/PI assays, respectively. The results showed that the growth inhibition, necrosis and apoptosis rates, as well as intracellular Ca(2+) concentrations ([Ca(2+)]i) induced by [Ca(2+)]e in HepG2 cells were higher than those in L02 cells. Moreover, [Ca(2+)]e was able to selectively enhance ADM-induced growth inhibition, apoptosis and necrosis in HepG2 cells, but not in L02 cells. ADM and [Ca(2+)]a co-treatment had a significant interaction effect to increase [Ca(2+)]i in both cell lines, although there was no significant difference in [Ca(2+)]i between the two cells. To further elucidate the mechanisms involved in the selective promotion of [Ca(2+)]e in HepG2 and L02 cells, the levels of these apoptosis regulatory proteins (bcl-2, bax and procaspase-3) and the caspase-3 activity following treatment of HepG2 and L02 cells with ADM or/and [Ca(2+)]a were investigated. The results showed that treating HepG2 cells with [Ca(2+)]a and ADM increased the level of bax protein and caspase-3 activity while decreasing the level of bcl-2 protein, compared with treatment with ADM alone. However, no significant change was noted in L02 cells. These results indicate that hepatoma HepG2 cells are more sensitive to [Ca2+]e than normal hepatic L02 cells and that [Ca(2+)]a can selectively enhance ADM-induced cell death in HepG2 cells. The mechanism of this intensive pro-apoptotic effect can be ascribed to up-regulation of bax and the simultaneous down-regulation of bcl-2, followed by the switch from procaspase-3 to caspase-3, which executed apoptosis. The present data suggest the potency of the calcium ion as an enhancer of ADM.