title: Pyrazolo-pyrimidine-derived c-Src inhibitor reduces angiogenesis and survival of squamous carcinoma cells by suppressing vascular endothelial growth factor production and signaling.
abstract: Src tyrosine kinase family cooperates with activated growth factor receptors to regulate growth, invasion and metastasis. The authors examined the influence of a novel c-Src inhibitor, 1l, derived from 4-amino-substituted-pyrazolo-pyrimidines, on tumor angiogenesis and on the angiogenic output of squamous carcinoma cells, A431 and SCC-4. The effect of 1l was assessed on growth and microvessel density in A431 tumors and its effect compared with the established c-Src inhibitor PP-1. The effects of c-Src inhibition were investigated on vascular endothelial growth factor (VEGF) expression and activity in tumor cells grown in vivo and in vitro, as well as on VEGF mediated signaling and on endothelial cell functions. Nanomolar concentrations of 1l decreased tumor volume promoted by A431 implanted in nude mice, without affecting in vitro cell tumor survival. This effect was related to 1l inhibition of VEGF production, and secondary to an effect on tumor microvessel density. The rabbit cornea assay confirmed that 1l markedly decreased neovessel growth induced by VEGF. In cultured endothelial cells, 1l inhibited the VEGF-induced phosphorylation on tyr416 of c-Src, resulting in a reduced cell proliferation and invasion. Consistently, 1l dowregulated endothelial nitric oxide synthase, MAPK-extracellular receptor kinase 1-2 (ERK1-2) activity and matrix metalloproteinases (MMP-2/MMP-9), while the tissue inhibitors of metalloproteinases (TIMP2/TIMP-1) were upregulated. These results demonstrate that nM concentrations of c-Src kinase inhibitors (1l and PP-1), by reducing the production of VEGF released by tumor cell and its endothelial cell responses, have a highly selective antiangiogenesis effect, which might be useful in combination therapies.
authors.affiliation: Dipartimento di Biologia Molecolare, Università degli Studi di Siena, Via Aldo Moro, 2, 53100, Siena, Italy.
authors.forename: Sandra
authors.initials: S
authors.lastname: Donnini
authors.forename: Martina
authors.initials: M
authors.lastname: Monti
authors.forename: Cinzia
authors.initials: C
authors.lastname: Castagnini
authors.forename: Raffaella
authors.initials: R
authors.lastname: Solito
authors.forename: Maurizio
authors.initials: M
authors.lastname: Botta
authors.forename: Silvia
authors.initials: S
authors.lastname: Schenone
authors.forename: Antonio
authors.initials: A
authors.lastname: Giachetti
authors.forename: Marina
authors.initials: M
authors.lastname: Ziche
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000098:blood supply* / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D061965:Matrix Metalloproteinase Inhibitors; D051379:Mice; D008819:Mice, Nude; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors; D009389:Neovascularization, Pathologic / Q000201:enzymology* / Q000473:pathology; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000037:antagonists & inhibitors*; D011720:Pyrazoles / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D011817:Rabbits; D015398:Signal Transduction / Q000187:drug effects; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism; D014407:Tumor Cells, Cultured; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors*; D023041:Xenograft Model Antitumor Assays
chemical_list: C108123:4-amino-5-(4-methylphenyl)-7-(tert-butyl)pyrazolo(3,4-d)pyrimidine; D061965:Matrix Metalloproteinase Inhibitors; C517891:N-benzyl-1-(2-chloro-2-phenylethyl)-1H-pyrazolo(3,4-d)pyrimidine-4-amine; D047428:Protein Kinase Inhibitors; D011720:Pyrazoles; D011743:Pyrimidines; D019715:Tissue Inhibitor of Metalloproteinase-1; D042461:Vascular Endothelial Growth Factor A; D019716:Tissue Inhibitor of Metalloproteinase-2; D052250:Nitric Oxide Synthase Type III; D016392:Proto-Oncogene Proteins pp60(c-src); D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3