Coupling of mitochondria to store-operated Ca2+-signaling sustains constitutive activation of protein kinase B/Akt and augments survival of malignant melanoma cells
Coupling of mitochondria to store-operated Ca2+-signaling sustains constitutive activation of protein kinase B/Akt and augments survival of malignant melanoma cells
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DOI：
10.1016/j.ceca.2010.05.002
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发表时间：
2010-06-01
期刊：
影响因子：
4
通讯作者：
Fishman, Daniel
中科院分区：
文献类型：
--
作者：
Feldman, Ben;Fedida-Metula, Shlomit;Fishman, Daniel
线粒体正在成为细胞内钙信号的主要枢纽，尽管它们在癌症中钙离子驱动的生长和生存促进事件中的作用鲜为人知。在这里，我们使用流式细胞术监测线粒体和胞浆钙离子，我们评估了恶性和非恶性B16BL6黑色素瘤克隆的跨线粒体钙转运和存储操作钙内流(存储操作通道(SOC))。值得注意的是，与非恶性克隆相比，恶性克隆在整个细胞或分离的线粒体中测得的线粒体钙通量都加快了。这与SOC介导的钙内流增加和高水平的结构性活性蛋白激酶B/Akt(PKB)相一致。线粒体Na~+/Ca~(2+)交换拮抗剂CGP-37157阻断恶性细胞跨线粒体Ca~(2+)转运，代谢SOC介导的Ca~(2+)内流，使蛋白激酶B失活，细胞生长受阻，易发生凋亡。同样，通过沉默STIM1直接阻断SOC可以抑制PKB，这表明SOC和线粒体之间的串扰对于保持PKB处于结构性激活状态是必不可少的。最后，Fis1过表达导致线粒体从亚质膜微区收回，抑制了SOC偶联的跨线粒体钙通量、通过SOC的钙内流和PKB活性。综上所述，我们的数据表明，在恶性黑色素瘤细胞中，上调的线粒体Ca~(2+)转运到SOC的功能和空间关系支持了强大的Ca~(2+)反应和下游信号，这些信号对抗凋亡和增殖至关重要。(C)2010爱思唯尔有限公司。保留所有权利。
Mitochondria are emerging as a major hub for cellular Ca2+-signaling, though their contribution to Ca2+-driven growth- and survival-promoting events in cancer is poorly understood. Here employing flow cytometry to monitor mitochondrial and cytosolic Ca2+, we assessed trans-mitochondrial Ca2+-transport and store-operated Ca2+-influx (store-operated channels (SOC)) in malignant vs. non-malignant B16BL6 melanoma clones. Remarkably, mitochondrial Ca2+-fluxes measured in whole cells or in isolated mitochondria were accelerated in the malignant clones compared to their non-malignant counterpart clones. This coincided with enhanced SOC-mediated Ca2+-influx and high levels of constitutively active protein kinase B/Akt (PKB). Interruption of trans-mitochondrial Ca2+-transport in the malignant cells with an antagonist of the mitochondrial Na+/Ca2+ exchanger, CGP-37157, abolsihed SOC-mediated Ca2+-influx, inactivated PKB, retarded cell growth and increased vulnerability to apoptosis. Similarly, direct SOC blockade by silencing Stim1 inhibited PKB, indicating that the crosstalk between SOC and mitochondria is essential to preserve PKB in constitutively active state. Finally, the retraction of mitochondria from sub-plasmalemmal micro-domains triggered by Fis1 over-expression inhibited SOC-coupled trans-mitochondrial Ca2+-flux, Ca2+-entry via SOC and PKB activity. Taken together, our data show that in the malignant melanoma cells, the functional and spatial relationship of up-regulated mitochondrial Ca2+-transport to the SOC sustains the robust Ca2+-responses and down-stream signaling critical for apoptosis-resistance and proliferation. (C) 2010 Elsevier Ltd. All rights reserved.