title: Plasminogen Kringle 5 blocks tumor progression by antiangiogenic and proinflammatory pathways.
abstract: Proteolytic processing of human plasminogen generates potent antiangiogenic peptides such as angiostatin. The plasminogen kringle 5 (K5) domain, which is distinct from angiostatin, possesses potent antiangiogenic properties on its own, which can be exploited in cancer therapy. It has been recently observed that antiangiogenic agents promote leukocyte-vessel wall interaction as part of their antitumor effect. Although we have previously shown that K5 suppresses cancer growth in tumor xenograft models, its modulation of inflammation in experimental mice with intact immune systems is unknown. To determine whether K5 possesses immune proinflammatory properties, we investigated the effects of K5 in an immune competent model of breast cancer and observed that tumor rejection is substantially reduced in nonobese diabetic/severe combined immunodeficient and BALB/c nude when compared with wild-type BALB/c mice, suggesting an important role for T-lymphoid cells in the antitumor effect of K5. Tumor explant analysis shows that K5 enhances tumor recruitment of CD3(+) lymphoid cells, in particular, the NKT phenotype. We also observed a significant decrease in tumor-associated microvessel length and density consistent with antiangiogenic activity. Histologic analysis of K5 tumors also revealed a robust neutrophilic infiltrate, which may be explained by the neutrophil chemotactic activity of K5 as well as its ability to promote CD64 up-regulation within the CD11b(+) adhesive neutrophil population. In sum, our findings confirm that the K5 protein acts as a potent angiostatic agent and possesses a novel proinflammatory role via its ability to recruit tumor-associated neutrophils and NKT lymphocytes, leading to a potent antitumor response.
authors.affiliation: Lady Davis Institute for Medical Research, 3755 Cote-Ste-Catherine Road, Montreal, Quebec, Canada H3T 1E2.
authors.forename: Sabrina R
authors.initials: SR
authors.lastname: Perri
authors.forename: Daniel
authors.initials: D
authors.lastname: Martineau
authors.forename: Moïra
authors.initials: M
authors.lastname: François
authors.forename: Laurence
authors.initials: L
authors.lastname: Lejeune
authors.forename: Louis
authors.initials: L
authors.lastname: Bisson
authors.forename: Yves
authors.initials: Y
authors.lastname: Durocher
authors.forename: Jacques
authors.initials: J
authors.lastname: Galipeau
mesh_terms: D000230:Adenocarcinoma / Q000098:blood supply / Q000276:immunology / Q000628:therapy; D020533:Angiogenesis Inhibitors / Q000378:metabolism*; D000818:Animals; D017252:CD3 Complex / Q000378:metabolism; D003094:Collagen / Q000378:metabolism; D018450:Disease Progression; D004338:Drug Combinations; D005805:Genes, MHC Class I / Q000502:physiology; D006801:Humans; D007111:Immunity, Cellular; D007249:Inflammation / Q000378:metabolism; D007797:Laminin / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D016246:Lymphocytes, Tumor-Infiltrating / Q000473:pathology; D008325:Mammary Neoplasms, Experimental / Q000098:blood supply / Q000276:immunology / Q000628:therapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000517:prevention & control; D009504:Neutrophils / Q000378:metabolism; D010446:Peptide Fragments / Q000502:physiology*; D010958:Plasminogen / Q000502:physiology*; D011509:Proteoglycans / Q000378:metabolism; D012190:Retroviridae; D015398:Signal Transduction; D015996:Survival Rate; D023041:Xenograft Model Antitumor Assays
chemical_list: D020533:Angiogenesis Inhibitors; D017252:CD3 Complex; D004338:Drug Combinations; D007797:Laminin; D010446:Peptide Fragments; D011509:Proteoglycans; C491499:plasminogen kringle 5; C059485:matrigel; D010958:Plasminogen; D003094:Collagen