title: Proteolytic inactivation of anti-angiogenic vasohibin-1 by cancer cells.
abstract: Vasohibin-1 (VASH1) is an angiogenesis inhibitor synthesized by endothelial cells (ECs) under conditions associated with physiological and pathological angiogenesis including cancers. VASH1, which is a 44-kDa protein, is processed after its translation and secretion, and a 29 kDa product cleaved both N-terminal and C-terminal end loses its anti-angiogenic activity. Here, we tested whether cancer cells modulate the processing of VASH1. When mouse EC line MS1 stably overexpressing the human VASH1 gene (MS1-hVASH1) and various cancer cell lines were co-cultured, there was an increased processing of hVASH1 protein in the culture media. This augmented processing was abrogated by a general cysteine protease inhibitor, E-64, and also by a specific calpain inhibitor, MDL28170. Recombinant hVASH1 protein was degraded by µ-calpain in vitro, which degradation was blocked by calpeptin. Conditioned media from co-cultures had little effect on the migration of human umbilical vein endothelial cells, but exhibited an inhibitory effect on their migration when collected in the presence of MDL28170; and this inhibitory effect was blocked by neutralizing anti-hVASH1 mAb. These results indicate that cancer cells proteolytically inactivate VASH1 protein secreted by ECs in the tumour microenvironment.
authors.affiliation: Department of Vascular Biology, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, Aoba-ku, Sendai 980-8575, Japan.
authors.forename: Megumu
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Vascular Biology, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, Aoba-ku, Sendai 980-8575, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Division of Medical Oncology, Cancer Research Institute, Kanazawa University, 13-1 Takara-Machi, Kanazawa, Ishikawa 920-0934, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Yano
authors.affiliation: Department of Biochemistry, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-Ku, Tokyo 142-8555, Japan.
authors.forename: Takuro
authors.initials: T
authors.lastname: Miyazaki
authors.affiliation: Department of Vascular Biology, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, Aoba-ku, Sendai 980-8575, Japan yasufumi.sato.b3@tohoku.ac.jp.
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Sato
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D006801:Humans; D051379:Mice; D009363:Neoplasm Proteins / Q000378:metabolism*; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology; D011480:Protease Inhibitors / Q000494:pharmacology; D059748:Proteolysis; D059016:Tumor Microenvironment
chemical_list: D014151:Anti-Anxiety Agents; D018797:Cell Cycle Proteins; D009363:Neoplasm Proteins; D011480:Protease Inhibitors; C493181:VASH1 protein, human; C510089:Vash1 protein, mouse