Referenced in: none

Automatically associated channels: TRP , TRPM , TRPM7

Title: Transient receptor potential melastatin-related 7 channel is overexpressed in human pancreatic ductal adenocarcinomas and regulates human pancreatic cancer cell migration.

Authors: Pierre Rybarczyk, Mathieu Gautier, Frédéric Hague, Isabelle Dhennin-Duthille, Denis Chatelain, Julie Kerr-Conte, François Pattou, Jean-Marc Regimbeau, Henri Sevestre, Halima Ouadid-Ahidouch

Journal, date & volume: Int. J. Cancer, 2012 Sep 15 , 131, E851-61

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22323115

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive forms of cancer with a tendency to invade surrounding healthy tissues, leading to a largely incurable disease. Despite many advances in modern medicine, there is still a lack of early biomarkers as well as efficient therapeutical strategies. The melastatin-related transient receptor potential 7 channel (TRPM7) is a nonselective cation channel that is involved in maintaining Ca(2+) and Mg(2+) homeostasis. It has been recently reported to regulate cell differentiation, proliferation and migration. However, the role of TRPM7 in PDAC progression is far to be understood. In our study, we show that TRPM7 is 13-fold overexpressed in cancer tissues compared to the healthy ones. Furthermore, TRPM7 staining is stronger in tumors with high grade, suggesting a correlation between TRPM7 expression and PDAC progression. Importantly, TRPM7 expression is inversely related to patient survival. In BxPC-3 cell line, dialyzing the cytoplasm during the patch-clamp whole-cell recording with a 0-Mg(2+) solution activated a nonselective current with a strong outward rectification. This cation current is inhibited by intracellular Mg(2+) and by TRPM7 silencing. The downregulation of TRPM7 by small interference RNA dramatically inhibited intracellular Mg(2+) fluorescence and cell migration without affecting cell proliferation, suggesting that TRPM7 contributes to Mg(2+) entry and cell migration. Moreover, external Mg(2+) following TRPM7 silencing fully restored the cell migration. In summary, our results indicate that TRPM7 is involved in the BxPC-3 cell migration via a Mg(2+)-dependent mechanism and may be a potential biomarker of poor prognosis of PDAC.