Angiostatic activity of human plasminogen fragments is highly dependent on glycosylation.
To assess the importance of carbohydrate moieties to the anti-angiogenic activity of plasminogen fragments, we cloned the fragment corresponding to amino acids Val(79) to Thr(346) (Kint3-4) that presents the three glycosylation sites. The activity of glycosylated and unglycosylated Kint3-4 was tested in murine sponge implant model. We observed a significant decrease in the neovascularization on the sponge after treatment with Kint3-4 by histological examination and determination of the hemoglobin levels. The effects were more intense with the glycosylated than the unglycosylated protein. (99m)Technecium-labeled red blood cells confirmed the inhibition of cell infiltration in the implanted sponge. Studies using melanoma B16F1 implanted in a mouse demonstrated that treatment with glycosylated Kint3-4 (0.15 nmol/48 h) during 14 days suppresses tumor growth by 80%. The vascular endothelial growth factor mRNA levels on the tumor were reduced after treatment. Kint3-4 is a potent plasminogen fragment that has been found to inhibit tumor growth.
Santos
Ivan Carlos
IC
Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Silbiger
Vivian Nogueira
VN
Higuchi
Débora Ayame
DA
Gomes
Maria Aparecida
MA
Barcelos
Lucíola Silva
LS
Teixeira
Mauro Martins
MM
Lopes
Mirian Teresa Paz
MT
Cardoso
Valbert Nascimento
VN
Lima
Mercia Paula
MP
Araujo
Ronaldo Carvalho
RC
Pesquero
João Bosco
JB
Pesquero
Jorge Luiz
JL
D000595:Amino Acid Sequence; D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D006031:Glycosylation; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000494:pharmacology*; D010958:Plasminogen / Q000737:chemistry / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics
D020533:Angiogenesis Inhibitors; D039302:Integrin alphaVbeta3; D010446:Peptide Fragments; D042461:Vascular Endothelial Growth Factor A; D010958:Plasminogen