A novel association of neuropilin-1 and MUC1 in pancreatic ductal adenocarcinoma: role in induction of VEGF signaling and angiogenesis.. Oncogene, January 25, 2016. R Zhou 1, JM Curry 1, LD Roy 1, P Grover 1, J Haider 2, LJ Moore 1, S-t Wu 1, A Kamesh 1, M Yazdanifar 1, WA Ahrens 3, T Leung 2, and P Mukherjee 1.
1 Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
2 Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, Kannapolis, NC, USA
3 Section of Hepatobiliary and Pancreas Surgery, Department of Surgery, Carolinas Medical Center, Charlotte, NC, USA
We report that Mucin1 (MUC1), a transmembrane glycoprotein that is overexpressed in >80% of pancreatic ductal adenocarcinoma (PDA), induced a pro-angiogenic tumor microenvironment by increasing the levels of neuropilin-1 (NRP1, a co-receptor of vascular endothelial growth factor (VEGF)) and its ligand VEGF. Expression of tumor-associated MUC1 (tMUC1) positively correlated with NRP1 levels in human and mouse PDA. Further, tMUC1hi PDA cells secreted high levels of VEGF and expressed high levels of VEGF receptor 2 (VEGFR2) and its phosphorylated forms as compared with tMUC1low/null PDA. This enabled the tMUC1hi/NRP1hi PDA cells to (a) induce endothelial cell tube formation, (b) generate long ectopic blood vessels and (c) enhance distant metastasis in a zebrafish xenograft model. Concurrently, the proteins associated with epithelial-to-mesenchymal transition, N-cadherin and Vimentin, were highly induced in these tMUC1/NRP1hi PDA cells. Hence, blocking signaling via the NRP1–VEGF axis significantly reduced tube formation, new vessel generation and metastasis induced by tMUC1hi PDA cells. Finally, we show that blocking the interaction between VEGF165 and NRP1 with a NRP1 antagonist significantly reduced VEGFR signaling and PDA tumor growth in vivo. Taken together, our data suggest a novel molecular mechanism by which tMUC1 may modulate NRP1-dependent VEGFR signaling in PDA cells.