Extracellular signal-regulated kinases 1 and 2 and TRPC1 channels are required for calcium-sensing receptor-stimulated MCF-7 breast cancer cell proliferation.
The calcium-sensing receptor (CaR), is a G protein-dependent receptor that responds to increments in extracellular Ca(2+) ([Ca(2+)](o)). We previously reported that an increase in [Ca(2+)](o) induced a release of intracellular calcium and Ca(2+) entry via store operated channels (SOCs). We also demonstrated that MCF-7 cells express Transient Receptor Potential canonical 1 (TRPC1) channels. Herein, we investigated CaR intracellular signaling pathways and examined the role of TRPC1 in CaR-induced cell proliferation, through the extracellular signal-regulated Kinases 1 & 2 (ERK1/2) pathways. Treatment by [Ca(2+)](o) increased both MCF-7 cell proliferation and TRPC1 expression. Both the [Ca(2+)](o) proliferative effect and TRPC1 protein levels were abolished by the ERK1/2 inhibitors. Moreover, [Ca(2+)](o) failed to increase cell proliferation either in the presence of CaR or TRPC1 siRNAs. Both [Ca(2+)](o) and the selective CaR activator spermine, elicited time and dose-dependent ERK1/2 phosphorylation. ERK1/2 phosphorylation was almost completely inhibited by treatment with the phospholipase C and the protein kinase C inhibitors. Treatment with 2-aminoethoxydiphenyl borate (2-APB), and SKF-96365 or by siTRPC1 diminished both [Ca(2+)](o)- and spermine-stimulated ERK1/2 phosphorylation. Moreover, down-regulation of TRPC1 by siRNA reduced the Ca(2+) entry induced by CaR activation. We conclude that the CaR activates ERK1/2 via a PLC/PKC-dependent pathway. Moreover, TRPC1 is required for the ERK1/2 phosphorylation, Ca(2+) entry and the CaR-proliferative effect.
El Hiani
Yassine
Y
Laboratoire de Physiologie Cellulaire et Moléculaire, Faculté des Sciences, Université de Picardie Jules Verne, Amiens, France.
Ahidouch
Ahmed
A
Lehen'kyi
V'yacheslav
V
Hague
Frédéric
F
Gouilleux
Fabrice
F
Mentaverri
Romuald
R
Kamel
Said
S
Lassoued
Kaiss
K
Brûlé
Gérard
G
Ouadid-Ahidouch
Halima
H
D001943:Breast Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D002118:Calcium / Q000378:metabolism; D049109:Cell Proliferation; D015536:Down-Regulation; D005260:Female; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D010766:Phosphorylation; D034741:RNA, Small Interfering / Q000378:metabolism; D044169:Receptors, Calcium-Sensing / Q000378:metabolism*; D015398:Signal Transduction; D050052:TRPC Cation Channels / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000378:metabolism
D034741:RNA, Small Interfering; D044169:Receptors, Calcium-Sensing; D050052:TRPC Cation Channels; C096351:transient receptor potential cation channel, subfamily C, member 1; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D010738:Type C Phospholipases; D002118:Calcium