Matrix metalloproteinase-7-catalyzed release of HB-EGF mediates deoxycholyltaurine-induced proliferation of a human colon cancer cell line

Abstract

Prior evidence indicates that bile acids stimulate colon cancer cell proliferation by muscarinic receptor-induced transactivation of epidermal growth factor receptors (EGFR). To explore further the mechanism underlying this action, we tested the hypothesis that bile acids activate a matrix metalloproteinase (MMP) that catalyzes release of an EGFR ligand. Initial studies showed that nonselective MMP inhibitors blocked the actions of deoxycholyltaurine (DCT), thereby indicating a role for MMP-catalyzed release of an EGFR ligand. DCT-induced cell proliferation was reduced by increasing concentrations of EGFR kinase inhibitors, by antibodies to the ligand-binding domain of EGFR, by neutralizing antibodies to heparin binding-EGF-like growth factor (HB-EGF) and by CRM197, an inhibitor of HB-EGF release. These findings and our observations with more selective MMP inhibitors suggested that MMP-7, an enzyme known to release HB-EGF, plays a key role in mediating bile acid-induced H508 colon cancer cell proliferation. We observed that recombinant HB-EGF and MMP-7 mimicked both the signaling and proliferative actions of bile acids. Strikingly, reducing MMP-7 expression with either neutralizing antibody or small interfering RNA attenuated the actions of DCT. MMP-7 expression in H508 cells was confirmed using quantitative reverse transcription PCR. DCT stimulated a greater than 10-fold increase in MMP-7 gene transcription. Colocalization of pro-MMP-7 and pro-HB-EGF at the cell surface (immunofluorescence microscopy) was demonstrated, indicating proximity of the enzyme to its substrate. These findings provide strong evidence that in H508 human colon cancer cells, DCT-induced transactivation of EGFR is mediated by MMP-7-catalyzed release of the EGFR ligand HB-EGF.

Genetic Ablation of M3 Muscarinic Receptors Attenuates Murine Colon Epithelial Cell Proliferation and Neoplasia

“…This observation is consistent with our in vitro observations in human colon cancer cells that post-M 3 R/EGFR signaling is mediated primarily by the proproliferative ERK pathway and that blocking ERK signaling abolishes M 3 R-agonist-induced cell proliferation (8,(11)(12)(13).…”

“…These actions of acetylcholine are blocked by muscarinic receptor inverse agonists, calcium chelators, and inhibitors of mitogen-activated protein/ERK kinase (the regulatory protein just upstream of ERK), and they do not occur in SNU-C4 human colon cancer cells that do not express M 3 R (9). Moreover, recent studies support the hypothesis that luminal bile acids, long associated with the development of colon cancer (10), also stimulate colon cancer cell proliferation by M 3 R-and epidermal growth factor receptor-dependent mechanisms (11)(12)(13). In these in vitro cell systems, proliferative actions of muscarinic agonists require both M 3 R expression and activation of post-M 3 R signaling.…”

Acetylcholine-induced activation of M3 muscarinic receptors stimulates robust matrix metalloproteinase gene expression in human colon cancer cells

“…Conjugated secondary bile acids induce proliferation of colon cancer cells by a mechanism involving MMP7-catalyzed release of an EGFR ligand, HBEGF (9). Because bile acids interact functionally with muscarinic receptors and induce transactivation of EGFR (7,9,26), we hypothesized that the actions of ACh were mediated by a similar mechanism.…”

“…Hence, there is great interest in identifying key colon cancer growth factors and their receptors. Increasing evidence indicates that muscarinic receptors and ligands play key roles in intestinal neoplasia (8,9,14,15,17,27). The muscarinic cholinergic family of G proteincoupled receptors (GPCRs) consists of five muscarinic receptor subtypes designated M 1 R, M 2 R, M 3 R, M 4 R, and M 5 R (for reviews see Refs.…”

Matrilysin (MMP-7) Inhibition of BMP-7 Induced Renal Tubular Branching Morphogenesis Suggests a Role in the Pathogenesis of Human Renal Dysplasia

“…Matrilysin is tightly associated with cell surface heparan sulfated proteoglycans (Yu and Woessner 2000), and this interaction localizes the proteinase with heparin-binding matrilysin substrates such as heparin-binding epidermal growth factor and C type lectin member family member 3A (Yu et al 2002;Cheng et al 2007;Lynch et al 2007;Tsunezumi et al 2009). Bone morphogenetic protein (BMP-7) and hepatocyte growth factor (HGF) are heparin-binding proteins that are critical in normal renal development (Davies and Fisher 2002;Irie et al 2003;Takada et al 2003), and our prior microarray study demonstrated that BMP7 gene expression and BMP-7 tissue levels were reduced in dysplastic kidneys compared to normal controls (Jain et al 2007).…”