Inhibition of angiogenesis and angiogenesis-dependent tumor growth by the cryptic kringle fragments of human apolipoprotein(a).
Apolipoprotein(a) (apo(a)) contains tandemly repeated kringle domains that are closely related to plasminogen kringle 4, followed by a single kringle 5-like domain and an inactive protease-like domain. Recently, the anti-angiogenic activities of apo(a) have been demonstrated both in vitro and in vivo. However, its effects on tumor angiogenesis and the underlying mechanisms involved have not been fully elucidated. To evaluate the anti-angiogenic and anti-tumor activities of the apo(a) kringle domains and to elucidate their mechanism of action, we expressed the last three kringle domains of apo(a), KIV-9, KIV-10, and KV, in Escherichia coli. The resultant recombinant protein, termed rhLK68, exhibited a dose-dependent inhibition of basic fibroblast growth factor-stimulated human umbilical vein endothelial cell proliferation and migration in vitro and inhibited the neovascularization in chick chorioallantoic membranes in vivo. The ability of rhLK68 to abrogate the activation of extracellular signal-regulated kinases appears to be responsible for rhLK68-mediated anti-angiogenesis. Furthermore, systemic administration of rhLK68 suppressed human lung (A549) and colon (HCT-15) tumor growth in nude mice. Immunohistochemical examination and in situ hybridization analysis of the tumors showed a significant decrease in the number of blood vessels and the reduced expression of vascular endothelial growth factor, basic fibroblast growth factor, and angiogenin, indicating that suppression of angiogenesis may have played a significant role in the inhibition of tumor growth. Collectively, these results suggest that a truncated apo(a), rhLK68, is a potent anti-angiogenic and anti-tumor molecule.
Mogam Biotechnology Research Institute, Yongin-city, Kyonggi-do 449-910, Korea.
Jang-Seong
JS
Kim
Ji-Hoon
JH
Chang
Hyun-Kyung
HK
Yu
Jin-Hyung
JH
Ahn
Jung-Sun
JS
Yum
Suk-Keun
SK
Lee
Kyung-Hwan
KH
Jung
Doo-Hong
DH
Park
Yeup
Y
Yoon
Si-Myung
SM
Byun
Soo-Il
SI
Chung
D000482:Allantois / Q000098:blood supply; D000818:Animals; D001054:Apolipoproteins A / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D002645:Chickens; D002823:Chorion / Q000098:blood supply; D003110:Colonic Neoplasms / Q000098:blood supply / Q000737:chemistry / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D016228:Endothelial Growth Factors / Q000032:analysis / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000032:analysis / Q000235:genetics / Q000494:pharmacology; D015870:Gene Expression; D006801:Humans; D017403:In Situ Hybridization; D036341:Intercellular Signaling Peptides and Proteins / Q000032:analysis / Q000235:genetics; D018082:Kringles / Q000502:physiology*; D008175:Lung Neoplasms / Q000098:blood supply / Q000737:chemistry / Q000473:pathology; D008222:Lymphokines / Q000032:analysis / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000098:blood supply* / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000517:prevention & control*; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D010766:Phosphorylation; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000494:pharmacology; D012259:Ribonuclease, Pancreatic / Q000032:analysis / Q000235:genetics; D014407:Tumor Cells, Cultured; D014471:Umbilical Veins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D001054:Apolipoproteins A; D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D010446:Peptide Fragments; D012333:RNA, Messenger; D011994:Recombinant Proteins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D016222:Fibroblast Growth Factor 2; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; C046366:angiogenin; D012259:Ribonuclease, Pancreatic