Potential conflict of interest: Dr. Colledan advises Novartis.
Platelet-derived growth factor-D and Rho GTPases regulate recruitment of cancer-associated fibroblasts in cholangiocarcinoma
Article first published online: 22 JUL 2013
Copyright © 2013 by the American Association for the Study of Liver Diseases
Volume 58, Issue 3, pages 1042–1053, September 2013
How to Cite
Cadamuro, M., Nardo, G., Indraccolo, S., Dall'Olmo, L., Sambado, L., Moserle, L., Franceschet, I., Colledan, M., Massani, M., Stecca, T., Bassi, N., Morton, S., Spirli, C., Fiorotto, R., Fabris, L. and Strazzabosco, M. (2013), Platelet-derived growth factor-D and Rho GTPases regulate recruitment of cancer-associated fibroblasts in cholangiocarcinoma. Hepatology, 58: 1042–1053. doi: 10.1002/hep.26384
This work was supported by the Associazione Scientifica Gastroenterologica di Treviso (to L.F. and I.F.), the Telethon (grant no.: GGP09189) and Fondazione Amici Dell' Epatologia (to L.F.), the Progetto di Ricerca Ateneo 2008 (grant no.: CPDA083217) and 2011 (grant no.: CPD113799/11) (to L.F. and M.C.), the National Institutes of Health (grant no.: DK34989: Silvio O. Conte Digestive Diseases Research Core Centers – 5P30DK034989), and a grant from PSC partners for a care (to M.S.). R.F is a recipient of a Liver Scholar Award (American Liver Foundation). The support of Fondazione San Martino (Bergamo, Italy) is gratefully acknowledged.
See Editorial on Page 853
- Issue published online: 29 AUG 2013
- Article first published online: 22 JUL 2013
- Accepted manuscript online: 15 MAR 2013 07:49AM EST
- Manuscript Accepted: 8 MAR 2013
- Manuscript Received: 16 NOV 2012
Cholangiocarcinoma (CCA) is characterized by an abundant stromal reaction. Cancer-associated fibroblasts (CAFs) are pivotal in tumor growth and invasiveness and represent a potential therapeutic target. To understand the mechanisms leading to CAF recruitment in CCA, we studied (1) expression of epithelial-mesenchymal transition (EMT) in surgical CCA specimens and CCA cells, (2) lineage tracking of an enhanced green fluorescent protein (EGFP)-expressing human male CCA cell line (EGI-1) after xenotransplantation into severe-combined-immunodeficient mice, (3) expression of platelet-derived growth factors (PDGFs) and their receptors in vivo and in vitro, (4) secretion of PDGFs by CCA cells, (5) the role of PDGF-D in fibroblast recruitment in vitro, and (6) downstream effectors of PDGF-D signaling. CCA cells expressed several EMT biomarkers, but not alpha smooth muscle actin (α-SMA). Xenotransplanted CCA masses were surrounded and infiltrated by α-SMA-expressing CAFs, which were negative for EGFP and the human Y-probe, but positive for the murine Y-probe. CCA cells were strongly immunoreactive for PDGF-A and -D, whereas CAFs expressed PDGF receptor (PDGFR)β. PDGF-D, a PDGFRβ agonist, was exclusively secreted by cultured CCA cells. Fibroblast migration was potently induced by PDGF-D and CCA conditioned medium and was significantly inhibited by PDGFRβ blockade with Imatinib and by silencing PDGF-D expression in CCA cells. In fibroblasts, PDGF-D activated the Rac1 and Cdc42 Rho GTPases and c-Jun N-terminal kinase (JNK). Selective inhibition of Rho GTPases (particularly Rac1) and of JNK strongly reduced PDGF-D-induced fibroblast migration. Conclusion: CCA cells express several mesenchymal markers, but do not transdifferentiate into CAFs. Instead, CCA cells recruit CAFs by secreting PDGF-D, which stimulates fibroblast migration through PDGFRβ and Rho GTPase and JNK activation. Targeting tumor or stroma interactions with inhibitors of the PDGF-D pathway may offer a novel therapeutic approach. (Hepatology 2013;53:1042–1053)