Inhibition of transient receptor potential canonical channels impairs cytokinesis in human malignant gliomas
Inhibition of transient receptor potential canonical channels impairs cytokinesis in human malignant gliomas
复制标题
DOI：
10.1111/j.1365-2184.2007.00504.x
复制
发表时间：
2008-02-01
影响因子：
8.5
通讯作者：
Sontheimer, H. W.
中科院分区：
文献类型：
--
作者：
Bomben, V. C.;Sontheimer, H. W.
目的：胶质源性原发脑瘤是生长最快的恶性肿瘤之一，临床上面临巨大挑战。研究表明，离子通道在正常和恶性细胞的生长控制中发挥着重要的作用，但人们对此知之甚少。在这项研究中，我们试图从功能上表征瞬时受体潜势通道(TRPC)在胶质瘤细胞增殖中的作用。TRPC通道形成非选择性的阳离子通道，被认为是影响细胞生长的钙离子内流途径。材料和方法：结合分子、生化和生物物理技术，我们研究了胶质瘤细胞中的TRPC通道。结果：我们发现4个通道家族成员(TRPC-1、-3、-5、-6)在胶质瘤细胞系和急性患者来源的组织中表达一致。这些通道产生小的、不依赖于电压的阳离子电流，这些电流被TRPC抑制剂GdCl3、2-APB或SKF96365阻断。重要的是，TRPC通道参与了胶质瘤细胞的静息电导，其急性药物抑制导致细胞静息电位出现类似于10 mV的超极化。此外，长期应用TRPC抑制剂SKF96365导致近乎完全的生长停滞。荧光激活的细胞分选和时间推移显微镜的详细分析表明，细胞周期的G(2)+M期出现生长抑制，并有胞质缺陷。细胞分裂不完全，变成多核、增大的细胞。结论：核异型性和细胞增大是最高级别的多形性胶质母细胞瘤的组织病理学特征，提示TRPC通道功能缺陷可能是这些肿瘤细胞异常的原因之一。
Objectives: Glial-derived primary brain tumours, gliomas, are among the fastest growing malignancies and present a huge clinical challenge. Research suggests an important, yet poorly understood, role of ion channels in growth control of normal and malignant cells. In this study, we sought to functionally characterize Transient Receptor Potential Canoncial (TRPC) channels in glioma cell proliferation. TRPC channels form non-selective cation channels that have been suggested to represent a Ca2+ influx pathway impacting cellular growth. Materials and Methods: Employing a combination of molecular, biochemical and biophysical techniques, we characterized TRPC channels in glioma cells. Results: We showed consistent expression of four channel family members (TRPC-1, -3, -5, -6) in glioma cell lines and acute patient-derived tissues. These channels gave rise to small, non-voltage-dependent cation currents that were blocked by the TRPC inhibitors GdCl3, 2-APB, or SKF96365. Importantly, TRPC channels contributed to the resting conductance of glioma cells and their acute pharmacological inhibition caused an similar to 10 mV hyperpolarization of the cells' resting potential. Additionally, chronic application of the TRPC inhibitor SKF96365 caused near complete growth arrest. A detailed analysis, by fluorescence-activated cell sorting and time-lapse microscopy, showed that growth inhibition occurred at the G(2) + M phase of the cell cycle with cytokinesis defects. Cells underwent incomplete cell divisions and became multinucleate, enlarged cells. Conclusions: Nuclear atypia and enlarged cells are histopathological hallmarks for glioblastoma multiforme, the highest grade glioma, suggesting that a defect in TRPC channel function may contribute to cellular abnormalities in these tumours.