TRPC3 Regulates the Proliferation and Apoptosis Resistance of Triple Negative Breast Cancer Cells through the TRPC3/RASA4/MAPK Pathway
TRPC3 Regulates the Proliferation and Apoptosis Resistance of Triple Negative Breast Cancer Cells through the TRPC3/RASA4/MAPK Pathway
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DOI：
10.3390/cancers11040558
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发表时间：
2019-04-01
期刊：
影响因子：
5.2
通讯作者：
Tsang, Suk-Ying
中科院分区：
文献类型：
--
作者：
Wang, Yan;Qi, Yan-Xiang;Tsang, Suk-Ying
目前，对于三阴性乳腺癌（TNBC）没有有效的基于分子的疗法。与正常乳腺组织相比，经典瞬时受体电位亚型3（TRPC 3）先前显示在乳腺癌活检组织中上调。然而，TRPC 3在乳腺癌中的生物学作用仍有待阐明。在这项研究中，亚细胞分级分离，然后进行蛋白质印迹和免疫细胞化学显示，TRPC 3在TNBC系MDA-MB-231的质膜上过表达，与雌激素受体阳性细胞系MCF-7相比。TRPC 3阻断剂Pyr 3和TRPC 3的显性阴性减弱MDA-MB-231中的增殖，诱导细胞凋亡和对化疗剂敏感的细胞死亡，如通过增殖测定所测量的。有趣的是，Ras GTP酶激活蛋白4（RASA 4），一个Ca 2+促进的Ras-MAPK通路抑制剂，被发现位于MDA-MB-231的质膜上。阻断TRPC 3降低了位于质膜上的RASA 4的量，伴随着MAPK途径的激活。我们的研究结果表明，在TNBC MDA-MB-231细胞中，通过TRPC 3通道的Ca 2+内流维持质膜上RASA 4的存在，RASA 4抑制Ras-MAPK通路，导致增殖和凋亡抗性。我们的研究揭示了TNBC细胞中新的TRPC 3-RASA 4-MAPK信号级联，并表明TRPC 3可能被开发为TNBC的潜在治疗靶点。
Currently, there is no effective molecular-based therapy for triple-negative breast cancer (TNBC). Canonical transient receptor potential isoform 3 (TRPC3) was previously shown to be upregulated in breast cancer biopsy tissues when compared to normal breast tissues. However, the biological role of TRPC3 in breast cancer still remains to be elucidated. In this study, subcellular fractionation followed by Western blot and immunocytochemistry showed that TRPC3 was over-expressed on the plasma membrane of TNBC line MDA-MB-231 when compared to an estrogen receptor-positive cell line MCF-7. TRPC3 blocker Pyr3 and dominant negative of TRPC3 attenuated proliferation, induced apoptosis and sensitized cell death to chemotherapeutic agents in MDA-MB-231 as measured by proliferation assays. Interestingly, Ras GTPase-activating protein 4 (RASA4), a Ca2+-promoted Ras-MAPK pathway suppressor, was found to be located on the plasma membrane of MDA-MB-231. Blocking TRPC3 decreased the amount of RASA4 located on the plasma membrane, with concomitant activation of MAPK pathways. Our results suggest that, in TNBC MDA-MB-231 cells, Ca2+ influx through TRPC3 channel sustains the presence of RASA4 on the plasma membrane where it inhibits the Ras-MAPK pathway, leading to proliferation and apoptosis resistance. Our study reveals the novel TRPC3-RASA4-MAPK signaling cascade in TNBC cells and suggests that TRPC3 may be exploited as a potential therapeutic target for TNBC.