Critical role of N-cadherin in myofibroblast invasion and migration in vitro stimulated by colon-cancer-cell-derived TGF-β or wounding

Abstract

Invasion of stromal host cells, such as myofibroblasts, into the epithelial cancer compartment may precede epithelial cancer invasion into the stroma. We investigated how colon cancer-derived myofibroblasts invade extracellular matrices in vitro in the presence of colon cancer cells. Myofibroblast spheroids invade collagen type I in a stellate pattern to form a dendritic network of extensions upon co-culture with HCT-8/E11 colon cancer cells. Single myofibroblasts also invade Matrigel™ when stimulated by HCT-8/E11 colon cancer cells. The confrontation of cancer cells with extracellular matrices and myofibroblasts, showed that cancer-cell-derived transforming growth factor-β (TGF-β) is required and sufficient for invasion of myofibroblasts. In myofibroblasts, N-cadherin expressed at the tips of filopodia is upregulated by TGF-β. Functional N-cadherin activity is implicated in TGF-β stimulated invasion as evidenced by the neutralizing anti-N-cadherin monoclonal antibody (GC-4 mAb), and specific N-cadherin knock-down by short interference RNA (siRNA). TGF-β1 stimulates Jun N-terminal kinase (also known as stress-activated protein kinase) (JNK) activity in myofibroblasts. Pharmacological inhibition of JNK alleviates TGF-β stimulated invasion, N-cadherin expression and wound healing migration. Neutralization of N-cadherin activity by the GC-4 or by a 10-mer N-cadherin peptide or by siRNA reduces directional migration, filopodia formation, polarization and Golgi-complex reorientation during wound healing. Taken together, our study identifies a new mechanism in which cancer cells contribute to the coordination of invasion of stromal myofibroblasts.

Global analysis of host tissue gene expression in the invasive front of colorectal liver metastases

“…These phenomena are reflected in our model by a very prominent overrepresentation of the GO terms ''cell communication,'' ''cell adhesion'' and ''cell adhesion molecule activity'' in the invasive front. Further localization and more mechanistic studies are required to pinpoint the specific roles of host cell adhesion molecules in our model, e.g., proangiogenic integrins on endothelial cells, 31 cadherins such as N-cadherin on myofibroblasts for interaction with and paving the way for cancer cells 29,47 or adhesion molecules for the initial attachment of circulating cancer cells. [48][49][50] Host cells in the invasion front are apparently intensively responding to the external stimuli initiated by tumor invasion since the GO terms ''response to external stimulus'' and ''response to biotic stimulus'' are overrepresented.…”

Cadherins in development: cell adhesion, sorting, and tissue morphogenesis

“…Expression of either exogenous Cadherin-6 or R-cadherin in cells located in the vicinity of the boundary induced strong preferential sorting of cells across the presumptive boundary into the Cadherin-6 or R-cadherin positive compartment, respectively (Inoue et al 2001). It has also been postulated that expression of N-cadherin in tumor cells acts as a targeting mechanism for endothelial and stromal tissue during metastasis (Hazan et al 2000;De Wever et al 2004;Qi et al 2005).…”

Stromal myofibroblasts are drivers of invasive cancer growth

“…A key question is to identify the efferent signals (cancer cellderived) that have an impact on myofibroblast attraction, differentiation, proliferation and production of proinvasive signals. Myofibroblasts infiltrate collagen matrices upon treatment with TGF-b 71 and invasion of myofibroblasts into subcutaneously implanted ovarian cancer spheroids mark the exit of tumors from dormancy. Ex vivo labeling of myofibroblasts with either magnetic resonance or near-infrared and fluorescent stains render them detectable for in vivo imaging and reveals the alignment of these invading myofibroblasts in the outer rim of the tumor, colocalizing with the angiogenic neovasculature.…”