An N-terminal 80 kDa recombinant fragment of human thrombospondin-2 inhibits vascular endothelial growth factor induced endothelial cell migration in vitro and tumor growth and angiogenesis in vivo.
We have previously shown that stable overexpression of the thrombospondin-2 (TSP-2) gene inhibited the tumor growth and angiogenesis of human squamous cell carcinoma xenotransplants. To investigate the potential antitumoral efficacy of systemic TSP-2 therapy, we expressed a recombinant 80 kDa fragment of human TSP-2 (TSP-2/NTF), encompassing the N-terminal globular region through the three type 1 repeats, in human kidney 293 EBNA cells, using a modified pCEP4 expression vector. Daily intraperitoneal injections of TSP-2/NTF resulted in a significant inhibition of the growth of human A431 squamous cell carcinomas in vivo and in reduced tumor vascularization. To further investigate possible mechanisms of the antiangiogenic activity of TSP-2/NTF, several in vitro angiogenesis assays were performed in human dermal microvascular endothelial cells. TSP-2/NTF inhibited vascular endothelial growth factor induced migration of human dermal microvascular endothelial cells and inhibited tube formation on Matrigel in vitro. TSP-2/NTF also inhibited vascular endothelial growth factor induced angiogenesis in an in vivo Matrigel assay. Moreover, TSP-2/NTF potently induced human dermal microvascular endothelial cell apoptosis in vitro but did not affect A431 tumor cell proliferation or apoptosis. These findings identify TSP-2/NTF as a potent systemic inhibitor of tumor growth and angiogenesis, acting by direct inhibition of several endothelial cell functions involved in neovascularization.
Noh
Yun-Hee
YH
Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA.
Matsuda
Kant
K
Hong
Young-Kwon
YK
Kunstfeld
Rainer
R
Riccardi
Lucia
L
Koch
Manuel
M
Oura
Hajimu
H
Dadras
Soheil S
SS
Streit
Michael
M
Detmar
Michael
M
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002294:Carcinoma, Squamous Cell / Q000098:blood supply / Q000188:drug therapy*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects* / Q000502:physiology; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology; D005260:Female; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D007668:Kidney / Q000166:cytology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000188:drug therapy* / Q000503:physiopathology; D011994:Recombinant Proteins / Q000235:genetics / Q000494:pharmacology; D012878:Skin Neoplasms / Q000098:blood supply / Q000188:drug therapy*; D019699:Thrombospondins / Q000235:genetics / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology; D023041:Xenograft Model Antitumor Assays; D000099262:Thrombospondin 2
D011994:Recombinant Proteins; D019699:Thrombospondins; D042461:Vascular Endothelial Growth Factor A; D000099262:Thrombospondin 2