Hepatic myofibroblasts promote the progression of human cholangiocarcinoma through activation of epidermal growth factor receptor

Abstract

Intrahepatic cholangiocarcinoma (CCA) is characterized by an abundant desmoplastic environment. Poor prognosis of CCA has been associated with the presence of alpha‐smooth muscle actin (α‐SMA)‐positive myofibroblasts (MFs) in the stroma and with the sustained activation of the epidermal growth factor receptor (EGFR) in tumor cells. Among EGFR ligands, heparin‐binding epidermal growth factor (HB‐EGF) has emerged as a paracrine factor that contributes to intercellular communications between MFs and tumor cells in several cancers. This study was designed to test whether hepatic MFs contributed to CCA progression through EGFR signaling. The interplay between CCA cells and hepatic MFs was examined first in vivo, using subcutaneous xenografts into immunocompromised mice. In these experiments, cotransplantation of CCA cells with human liver myofibroblasts (HLMFs) increased tumor incidence, size, and metastastic dissemination of tumors. These effects were abolished by gefitinib, an EGFR tyrosine kinase inhibitor. Immunohistochemical analyses of human CCA tissues showed that stromal MFs expressed HB‐EGF, whereas EGFR was detected in cancer cells. In vitro, HLMFs produced HB‐EGF and their conditioned media induced EGFR activation and promoted disruption of adherens junctions, migratory and invasive properties in CCA cells. These effects were abolished in the presence of gefitinib or HB‐EGF‐neutralizing antibody. We also showed that CCA cells produced transforming growth factor beta 1, which, in turn, induced HB‐EGF expression in HLMFs. Conclusion: A reciprocal cross‐talk between CCA cells and myofibroblasts through the HB‐EGF/EGFR axis contributes to CCA progression. (Hepatology 2013; 58:2001–2011)

Epithelial-mesenchymal transition in cholangiocarcinoma: From clinical evidence to regulatory networks

“…CAFs have a crucial role in favoring CCA progression, and more particularly in promoting EMT, through interactive autocrine and paracrine signaling pathways [68,131]. We have recently shown that CAFs from human iCCA synthesize HB-EGF, which activates EGFR in CCA cells leading to the disruption of cell-cell junctions and an increase of invasiveness [68]. Furthermore, we described a paracrine reciprocal loop in which CCA cells produced TGF-β1 that stimulates HB-EGF expression by CAF.…”

“…TGF-β1-3 and their receptors TGF-β RI and RII were found expressed in both CCA tumor cells and surrounding stroma cells [65][66][67][68][69][70] while no data on TGF-β RIII expression is available. Regarding TGF-β1, it is expressed not only by invading malignant cholangiocytes, but also by stroma cells (e.g.…”

“…Interestingly, E-cadherin also displayed a cytoplasmic pattern in xenografted tumors, whereas the mice treatment with gefitinib restored the membranous expression of E-cadherin. In vitro, EGF and HB-EGF, two EGFR ligands, induced scattering of CCA cells that resulted from the disruption of adherens junctions [29,68]. In EGFstimulated CCA cells, EMT-TFs (SLUG and ZEB1) and mesenchymal markers (N-cadherin and α-SMA) were induced, favoring cell invasiveness through cytoskeleton remodeling [29,89].…”

“…The possibility that cholangiocytes could also feed the pool of stroma myofibroblasts has been refuted in different models of fibrosis [132] and more recently in a murine model of xenografted tumors [133]. CAFs have a crucial role in favoring CCA progression, and more particularly in promoting EMT, through interactive autocrine and paracrine signaling pathways [68,131]. We have recently shown that CAFs from human iCCA synthesize HB-EGF, which activates EGFR in CCA cells leading to the disruption of cell-cell junctions and an increase of invasiveness [68].…”

Cholangiocarcinoma: current knowledge and future perspectives consensus statement from the European Network for the Study of Cholangiocarcinoma (ENS-CCA)

“…CAFs, which express α-smooth muscle actin, are able to modulate several processes (that is, prolifer ation, migration, invasion and EMT) in CCA tumour cells 139,[175][176][177][178][179][180] . Accordingly, patients with high levels of α-smooth muscle actin expression in CCA tissue samples exhibit worse prognosis 181,182 .…”