Transient receptor potential melastatin 4 channel contributes to migration of androgen-insensitive prostate cancer cells

// Christian Holzmann 1,* , Sven Kappel 1,2,* , Tatiana Kilch 1,2 , Marcus Martin Jochum 2,3 , Sabine Katharina Urban 2,4 , Volker Jung 3 , Michael Stöckle 3 , Karen Rother 2,4 , Markus Greiner 2,4 and Christine Peinelt 1,2 1 Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany 2 Center of Human and Molecular Biology, Saarland University, Homburg, Germany 3 Clinics of Urology and Pediatric Urology, Saarland University, Homburg, Germany 4 Department of Medical Biochemistry and Molecular Biology, Saarland University, Homburg, Germany * These authors have contributed equally to this work Correspondence to: Christine Peinelt, email: // Keywords : prostate cancer, cancer driver gene, transient receptor potential melastatin 4 channel (TRPM4), cell migration, Ca2+ signaling Received : July 17, 2015 Accepted : September 30, 2015 Published : October 19, 2015 Abstract Impaired Ca 2+ signaling in prostate cancer contributes to several cancer hallmarks, such as enhanced proliferation and migration and a decreased ability to induce apoptosis. Na + influx via transient receptor potential melastatin 4 channel (TRPM4) can reduce store-operated Ca 2+ entry (SOCE) by decreasing the driving force for Ca 2+ . In patients with prostate cancer, gene expression of TRPM4 is elevated. Recently, TRPM4 was identified as a cancer driver gene in androgen-insensitive prostate cancer. We investigated TRPM4 protein expression in cancer tissue samples from 20 patients with prostate cancer. We found elevated TRPM4 protein levels in prostatic intraepithelial neoplasia (PIN) and prostate cancer tissue compared to healthy tissue. In primary human prostate epithelial cells (hPEC) from healthy tissue and in the androgen-insensitive prostate cancer cell lines DU145 and PC3, TRPM4 mediated large Na + currents. We demonstrated significantly increased SOCE after siRNA targeting of TRPM4 in hPEC and DU145 cells. In addition, knockdown of TRPM4 reduced migration but not proliferation of DU145 and PC3 cells. Taken together, our data identify TRPM4 as a regulator of SOCE in hPEC and DU145 cells, demonstrate a role for TRPM4 in cancer cell migration and suggest that TRPM4 is a promising potential therapeutic target.