Jardin Isaac, Diez-Bello Raquel, Lopez Jose J, Redondo Pedro C, Salido Ginés M, Smani Tarik, Rosado Juan A
Cellular Physiology Research Group, Department of Physiology, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain.
Department of Medical Physiology and Biophysic, Institute of Biomedicine of Sevilla, 41013 Sevilla, Spain.
Cancers (Basel). 2018 Sep 14;10(9):331. doi: 10.3390/cancers10090331.
Transient receptor potential channels convey signaling information from a number of stimuli to a wide variety of cellular functions, mainly by inducing changes in cytosolic Ca concentration. Different members of the TRPC, TRPM and TRPV subfamilies have been reported to play a role in tumorigenesis. Here we show that the estrogen receptor positive and triple negative breast cancer cell lines, MCF7 and MDA-MB-231, respectively, exhibit enhanced expression of the TRPC6 channel as compared to the non-tumoral MCF10A cell line. In vitro TRPC6 knockdown using shRNA impaired MCF7 and MDA-MB-231 cell proliferation, migration and invasion detected by BrdU incorporation, wound healing and Boyden chamber assays, respectively. Using RNAi-mediated TRPC6 silencing as well as overexpression of the pore-dead dominant-negative TRPC6 mutant we have found that TRPC6 plays a relevant role in the activation of store-operated Ca entry in the breast cancer cell lines but not in non-tumoral breast cells. Finally, we have found that TRPC6 interacts with Orai1 and Orai3 in MCF7 and MDA-MB-231 cells and is required for the translocation of Orai1 and Orai3 to the plasma membrane in MDA-MB-231 and MCF7 cells, respectively, upon Ca store depletion. These findings introduce a novel mechanism for the modulation of Ca influx and the development of different cancer hallmarks in breast cancer cells.
瞬时受体电位通道主要通过诱导胞质钙浓度变化，将多种刺激的信号信息传递给广泛的细胞功能。据报道，TRPC、TRPM和TRPV亚家族的不同成员在肿瘤发生中起作用。在这里，我们表明，雌激素受体阳性和三阴性乳腺癌细胞系MCF7和MDA-MB-231分别与非肿瘤性MCF10A细胞系相比，TRPC6通道表达增强。使用shRNA在体外敲低TRPC6分别通过BrdU掺入、伤口愈合和博伊登小室试验检测到损害了MCF7和MDA-MB-231细胞的增殖、迁移和侵袭。使用RNAi介导的TRPC6沉默以及孔道失活的显性负性TRPC6突变体的过表达，我们发现TRPC6在乳腺癌细胞系中储存-操作性钙内流的激活中起相关作用，但在非肿瘤性乳腺细胞中不起作用。最后，我们发现TRPC6在MCF7和MDA-MB-231细胞中与Orai1和Orai3相互作用，并且在MCF7和MDA-MB-231细胞中分别在钙储存耗竭时Orai1和Orai3向质膜的转运中是必需的。这些发现引入了一种调节钙内流和乳腺癌细胞中不同癌症特征发展的新机制。
