Novel role of cold/menthol-sensitive transient receptor potential melastatine family member 8 (TRPM8) in the activation of store-operated channels in LNCaP human prostate cancer epithelial cells
Novel role of cold/menthol-sensitive transient receptor potential melastatine family member 8 (TRPM8) in the activation of store-operated channels in LNCaP human prostate cancer epithelial cells
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DOI：
10.1074/jbc.m503544200
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发表时间：
2005-11-25
影响因子：
4.8
通讯作者：
Prevarskaya, N
中科院分区：
文献类型：
--
作者：
Thebault, S;Lemonnier, L;Prevarskaya, N
最近从啮齿动物感觉神经元中克隆了一个冷/薄荷醇敏感的TRPM8通道(瞬时受体电位Melastatine家族成员8)，为冷感提供了分子基础。令人惊讶的是，啮齿动物TRPM8的人类同源基因似乎也在前列腺和前列腺癌衍生的上皮细胞系LNCaP中强烈表达。在这项研究中，我们发现，尽管有这种表达，LNCaP细胞还是通过膜电流(I-COLD/薄荷醇)对冷/薄荷醇刺激做出反应的，这种电流表现出向内整流和高钙选择性，这与“经典”TRPM8介导的I-冷/薄荷醇的性质截然不同。然而，通过反义或siRNA策略沉默内源性TRPM8 mRNA可以抑制LNCaP细胞中的I-冷/薄荷醇和TRPM8蛋白。我们证明，这些令人费解的结果是由于TRPM8不是在血浆中定位，而是在LNCaP细胞的内质网(ER)膜上定位，在内质网(ER)中，TRPM8支持冷/薄荷醇/尼可林诱导的内质网钙释放，同时激活质膜(PM)储存操作通道(SOC)。相反，在HEK-293细胞中异源表达的GFP标记的TRPM8靶向PM我们还证明了TRPM8的表达和与其相关的SOC电流的大小是雄激素依赖的。我们的结果提示，TRPM8可能是一个重要的新的内质网钙释放通道，可能参与了前列腺癌上皮细胞中许多钙离子和钙库依赖的过程，包括那些对前列腺癌的发生具有重要作用的过程，如增殖和凋亡。
Recent cloning of a cold/menthol-sensitive TRPM8 channel ( transient receptor potential melastatine family member 8) from rodent sensory neurons has provided the molecular basis for the cold sensation. Surprisingly, the human orthologue of rodent TRPM8 also appears to be strongly expressed in the prostate and in the prostate cancer-derived epithelial cell line, LNCaP. In this study, we show that despite such expression, LNCaP cells respond to cold/ menthol stimulus by membrane current (I-cold/menthol) that shows inward rectification and high Ca2+ selectivity, which are dramatically different properties from "classical" TRPM8-mediated I-cold/menthol. Yet, silencing of endogenous TRPM8 mRNA by either antisense or siRNA strategies suppresses both I-cold/menthol and TRPM8 protein in LNCaP cells. We demonstrate that these puzzling results arise from TRPM8 localization not in the plasma, but in the endoplasmic reticulum ( ER) membrane of LNCaP cells, where it supports cold/menthol/icilin-induced Ca2+ release from the ER with concomitant activation of plasma membrane ( PM) store-operated channels ( SOC). In contrast, GFP-tagged TRPM8 heterologously expressed in HEK-293 cells target the PM. We also demonstrate that TRPM8 expression and the magnitude of SOC current associated with it are androgen-dependent. Our results suggest that the TRPM8 may be an important new ER Ca2+ release channel, potentially involved in a number of Ca2+- and store-dependent processes in prostate cancer epithelial cells, including those that are important for prostate carcinogenesis, such as proliferation and apoptosis.