title: VEGF-A/NRP1 stimulates GIPC1 and Syx complex formation to promote RhoA activation and proliferation in skin cancer cells.
abstract: Neuropilin-1 (NRP1) has been identified as a VEGF-A receptor. DJM-1, a human skin cancer cell line, expresses endogenous VEGF-A and NRP1. In the present study, the RNA interference of VEGF-A or NRP1 suppressed DJM-1 cell proliferation. Furthermore, the overexpression of the NRP1 wild type restored shNRP1-treated DJM-1 cell proliferation, whereas NRP1 cytoplasmic deletion mutants did not. A co-immunoprecipitation analysis revealed that VEGF-A induced interactions between NRP1 and GIPC1, a scaffold protein, and complex formation between GIPC1 and Syx, a RhoGEF. The knockdown of GIPC1 or Syx reduced active RhoA and DJM-1 cell proliferation without affecting the MAPK or Akt pathway. C3 exoenzyme or Y27632 inhibited the VEGF-A-induced proliferation of DJM-1 cells. Conversely, the overexpression of the constitutively active form of RhoA restored the proliferation of siVEGF-A-treated DJM-1 cells. Furthermore, the inhibition of VEGF-A/NRP1 signaling upregulated p27, a CDK inhibitor. A cell-penetrating oligopeptide that targeted GIPC1/Syx complex formation inhibited the VEGF-A-induced activation of RhoA and suppressed DJM-1 cell proliferation. In conclusion, this new signaling pathway of VEGF-A/NRP1 induced cancer cell proliferation by forming a GIPC1/Syx complex that activated RhoA to degrade the p27 protein.
authors.affiliation: Division of Engineering (Biotechnology), Graduate School of Engineering, Kyoto Sangyo University, Kyoto 603-8555, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Yoshida
authors.affiliation: Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8047, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Shimizu
authors.affiliation: Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8047, Japan.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Asano
authors.affiliation: Biofunctional Engineering, Graduate School of Bioscience & Biotechnology, Tokyo Institute of Technology, Tokyo 226-8503, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kadonosono
authors.affiliation: Biofunctional Engineering, Graduate School of Bioscience & Biotechnology, Tokyo Institute of Technology, Tokyo 226-8503, Japan.
authors.forename: Shinae Kizaka
authors.initials: SK
authors.lastname: Kondoh
authors.affiliation: Vascular Biology Program, Boston Children's Hospital, Departments of Surgery and Pathology and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Geretti
authors.affiliation: Vascular Biology Program, Boston Children's Hospital, Departments of Surgery and Pathology and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Akiko
authors.initials: A
authors.lastname: Mammoto
authors.affiliation: Vascular Biology Program, Boston Children's Hospital, Departments of Surgery and Pathology and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Klagsbrun
authors.affiliation: Division of Engineering (Biotechnology), Graduate School of Engineering, Kyoto Sangyo University, Kyoto 603-8555, Japan Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8047, Japan mseo@cc.kyoto-su.ac.jp.
authors.forename: Misuzu Kurokawa
authors.initials: MK
authors.lastname: Seo
keywords: Cancer; Neuropilin; RhoA; Syx; VEGF-A