The NCX1/TRPC6 Complex Mediates TGFβ-Driven Migration and Invasion of Human Hepatocellular Carcinoma Cells

Abstract TGFβ plays an important role in the progression and metastasis of hepatocellular carcinoma (HCC), yet the cellular and molecular mechanisms underlying this role are not completely understood. In this study, we investigated the roles of Na+/Ca2+ exchanger 1 (NCX1) and canonical transient receptor potential channel 6 (TRPC6) in regulating TGFβ in human HCC. In HepG2 and Huh7 cells, TGFβ-stimulated intracellular Ca2+ increases through NCX1 and TRPC6 and induced the formation of a TRPC6/NCX1 molecular complex. This complex-mediated Ca2+ signaling regulated the effect of TGFβ on the migration, invasion, and intrahepatic metastasis of human HCC cells in nude mice. TGFβ upregulated TRPC6 and NCX1 expression, and there was a positive feedback between TRPC6/NCX1 signaling and Smad signaling. Expression of both TRPC6 and NCX1 were markedly increased in native human HCC tissues, and their expression levels positively correlated with advancement of HCC in patients. These data reveal the role of the TRPC6/NCX1 molecular complex in HCC and in regulating TGFβ signaling, and they implicate TRPC6 and NCX1 as potential targets for therapy in HCC. Significance: TGFβ induces the formation and activation of a TRPC6/NCX1 molecular complex, which mediates the effects of TGFβ on the migration, invasion, and intrahepatic metastasis of HCC. Cancer Res; 78(10); 2564–76. ©2018 AACR.