Muscarinic receptor agonists stimulate human colon cancer cell migration and invasion

A Belo, K Cheng, A Chahdi, J Shant… - American Journal …, 2011 - journals.physiology.org
A Belo, K Cheng, A Chahdi, J Shant, G Xie, S Khurana, JP Raufman
American Journal of Physiology-Gastrointestinal and Liver …, 2011journals.physiology.org
Muscarinic receptors (CHRM) are overexpressed in colon cancer. To explore a role for
muscarinic receptor signaling in colon cancer metastasis, we used human H508 and HT29
colon cancer cells that coexpress epidermal growth factor (ERBB) and CHRM3 receptors. In
a wound closure model, following 8-h incubation of H508 cells with 100 μM ACh we
observed a threefold increase in cell migration indistinguishable from the actions of
epidermal growth factor (EGF). Atropine blocked the actions of ACh but not of EGF. In SNU …
Muscarinic receptors (CHRM) are overexpressed in colon cancer. To explore a role for muscarinic receptor signaling in colon cancer metastasis, we used human H508 and HT29 colon cancer cells that coexpress epidermal growth factor (ERBB) and CHRM3 receptors. In a wound closure model, following 8-h incubation of H508 cells with 100 μM ACh we observed a threefold increase in cell migration indistinguishable from the actions of epidermal growth factor (EGF). Atropine blocked the actions of ACh but not of EGF. In SNU-C4 colon cancer cells that express ERBB but not CHRM, EGF caused a threefold increase in migration; ACh had no effect. ACh-induced cell migration was attenuated by chemical inhibitors of ERBB1 activation, by anti-ERBB1 antibody, and by inhibitors of ERK and phosphatidylinositol 3-kinase (PI3K) signaling. Consistent with matrix metalloproteinase-7 (MMP7)-mediated release of an ERBB1 ligand, heparin binding epidermal growth factor-like growth factor (HBEGF), ACh-induced migration was inhibited by an MMP inhibitor and by anti-MMP7 and -HBEGF antibodies. ACh-induced cell migration was blocked by inhibiting RhoA and ROCK, key proteins that interact with the actin cytoskeleton. ACh-induced RhoA activation was attenuated by agents that inhibit ERBB1, ERK, and PI3K activation. Collectively, these findings indicate that ACh-induced cell migration is mediated by MMP7-mediated release of HBEGF, an ERBB ligand that activates ERBB1 and downstream ERK and PI3K signaling. In a cell invasion model, ACh-induced HT29 cell invasion was blocked by atropine. In concert with previous observations, these findings indicate that muscarinic receptor signaling plays a key role in colon cancer cell proliferation, survival, migration, and invasion.
American Physiological Society