Department of Pharmacology and The Center for Lung and Vascular Biology, The University of Illinois College of Medicine, Chicago, IL 60612, USA
Mumtaz Anwar
Department of Pharmacology and The Center for Lung and Vascular Biology, The University of Illinois College of Medicine, Chicago, IL 60612, USA
Md Zahid Akhter
Department of Pharmacology and The Center for Lung and Vascular Biology, The University of Illinois College of Medicine, Chicago, IL 60612, USA
Alejandra Chavez
Department of Pharmacology and The Center for Lung and Vascular Biology, The University of Illinois College of Medicine, Chicago, IL 60612, USA
De Yu Mao
Department of Physiology, The University of Illinois College of Medicine, Chicago, IL 60612, USA
Viswanathan Natarajan
Department of Pharmacology and The Center for Lung and Vascular Biology, The University of Illinois College of Medicine, Chicago, IL 60612, USA; Department of Medicine, The University of Illinois College of Medicine, Chicago, IL 60612, USA
Sribalaji Lakshmikanthan
Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA
Magdalena Chrzanowska-Wodnicka
Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA
Arkadiusz Z. Dudek
Department of Medicine, The University of Illinois College of Medicine, Chicago, IL 60612, USA
Lena Claesson-Welsh
Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Science for Life Laboratory, Uppsala University, 751 85 Uppsala, Sweden
Jan K. Kitajewski
Department of Physiology, The University of Illinois College of Medicine, Chicago, IL 60612, USA
Kishore K. Wary
Department of Pharmacology and The Center for Lung and Vascular Biology, The University of Illinois College of Medicine, Chicago, IL 60612, USA
Asrar B. Malik
Department of Pharmacology and The Center for Lung and Vascular Biology, The University of Illinois College of Medicine, Chicago, IL 60612, USA
Dolly Mehta
Department of Pharmacology and The Center for Lung and Vascular Biology, The University of Illinois College of Medicine, Chicago, IL 60612, USA; Corresponding author
Summary: The vascular endothelial growth factor-A (VEGF-A)-VEGFR2 pathway drives tumor vascularization by activating proangiogenic signaling in endothelial cells (ECs). Here, we show that EC-sphingosine-1-phosphate receptor 1 (S1PR1) amplifies VEGFR2-mediated angiogenic signaling to enhance tumor growth. We show that cancer cells induce S1PR1 activity in ECs, and thereby, conditional deletion of S1PR1 in ECs (EC-S1pr1−/− mice) impairs tumor vascularization and growth. Mechanistically, we show that S1PR1 engages the heterotrimeric G-protein Gi, which amplifies VEGF-VEGFR2 signaling due to an increase in the activity of the tyrosine kinase c-Abl1. c-Abl1, by phosphorylating VEGFR2 at tyrosine-951, prolongs VEGFR2 retention on the plasmalemma to sustain Rac1 activity and EC migration. Thus, S1PR1 or VEGFR2 antagonists, alone or in combination, reverse the tumor growth in control mice to the level seen in EC-S1pr1−/− mice. Our findings suggest that blocking S1PR1 activity in ECs has the potential to suppress tumor growth by preventing amplification of VEGF-VEGFR2 signaling. : Vijay Avin et al. demonstrate an essential role of endothelial cell (EC)-S1PR1 signaling in amplifying VEGFR2-mediated tumor growth. S1PR1 by Gi and c-Abl1 phosphorylates VEGFR2 at Y951, which retains VEGFR2 at EC plasmalemma, thus enabling EC migration, tumor angiogenesis, and growth. Keywords: angiogenesis, VEGF-A, VEGFR2 phosphorylation, S1P, S1PR1, tumor growth, tumor vascularization, Rac1, endothelial cells, c-Abl1