Angiogenesis has been identified as an important target for antineoplastic therapy. The use of pu... more Angiogenesis has been identified as an important target for antineoplastic therapy. The use of purine analogue antimetabolites in combination chemotherapy of solid tumors has been proposed. To assess the possibility that selected purine analogues may affect tumor neovascularization, 6-methylmercaptopurine riboside (6-MMPR), 6-methylmercaptopurine, 2-aminopurine, and adenosine were evaluated for the capacity to inhibit angiogenesis in vitro and in vivo. 6-MMPR inhibited fibroblast growth factor-2 (FGF2)-induced proliferation and delayed the repair of mechanically wounded monolayer in endothelial GM 7373 cell cultures. 6-MMPR also inhibited the formation of solid sprouts within fibrin gel by FGF2-treated murine brain microvascular endothelial cells and the formation of capillary-like structures on Matrigel by murine aortic endothelial cells transfected with FGF2 cDNA. 6-MMPR affected FGF2-induced intracellular signaling in murine aortic endothelial cells by inhibiting the phosphorylat...
Basic fibroblast growth factor (bFGF) is expressed in the vascular endothelium of human brain tum... more Basic fibroblast growth factor (bFGF) is expressed in the vascular endothelium of human brain tumors. To investigate the biological consequences of a possible autocrine modality of microvascular endothelial cell activation by endogenous bFGF in these tumors, mouse brain microvascular endothelial cells were stably transfected with a retroviral expression vector harboring a human bFGF cDNA. When grown on tissue culture plastic, bFGF-transfected clones show a transformed morphology and increased saturation density. bFGF-transfectants have an invasive behavior when seeded on three-dimensional fibrin gel and originate endothelial cell sprouts when embedded within fibrin. Also, bFGF-transfected cells undergo morphogenetic organization and produce a complex network of branching cord-like structures connecting foci of infiltrating cells when seeded on Matrigel, a laminin-rich extracellular matrix material. In contrast, parental and mock-transfected cells do not invade fibrin gels nor organize on Matrigel. These findings demonstrate that bFGF overexpression induces an angiogenic phenotype in brain microvascular endothelial cells characterized by an invasive behavior and morphogenic potential. They support the notion that neovascularization of brain tumors can be triggered by stimuli that induce vascular endothelium to produce its own autocrine factor(s).
Angiogenesis has been identified as an important target for antineoplastic therapy. The use of pu... more Angiogenesis has been identified as an important target for antineoplastic therapy. The use of purine analogue antimetabolites in combination chemotherapy of solid tumors has been proposed. To assess the possibility that selected purine analogues may affect tumor neovascularization, 6-methylmercaptopurine riboside (6-MMPR), 6-methylmercaptopurine, 2-aminopurine, and adenosine were evaluated for the capacity to inhibit angiogenesis in vitro and in vivo. 6-MMPR inhibited fibroblast growth factor-2 (FGF2)-induced proliferation and delayed the repair of mechanically wounded monolayer in endothelial GM 7373 cell cultures. 6-MMPR also inhibited the formation of solid sprouts within fibrin gel by FGF2-treated murine brain microvascular endothelial cells and the formation of capillary-like structures on Matrigel by murine aortic endothelial cells transfected with FGF2 cDNA. 6-MMPR affected FGF2-induced intracellular signaling in murine aortic endothelial cells by inhibiting the phosphorylat...
Basic fibroblast growth factor (bFGF) is expressed in the vascular endothelium of human brain tum... more Basic fibroblast growth factor (bFGF) is expressed in the vascular endothelium of human brain tumors. To investigate the biological consequences of a possible autocrine modality of microvascular endothelial cell activation by endogenous bFGF in these tumors, mouse brain microvascular endothelial cells were stably transfected with a retroviral expression vector harboring a human bFGF cDNA. When grown on tissue culture plastic, bFGF-transfected clones show a transformed morphology and increased saturation density. bFGF-transfectants have an invasive behavior when seeded on three-dimensional fibrin gel and originate endothelial cell sprouts when embedded within fibrin. Also, bFGF-transfected cells undergo morphogenetic organization and produce a complex network of branching cord-like structures connecting foci of infiltrating cells when seeded on Matrigel, a laminin-rich extracellular matrix material. In contrast, parental and mock-transfected cells do not invade fibrin gels nor organize on Matrigel. These findings demonstrate that bFGF overexpression induces an angiogenic phenotype in brain microvascular endothelial cells characterized by an invasive behavior and morphogenic potential. They support the notion that neovascularization of brain tumors can be triggered by stimuli that induce vascular endothelium to produce its own autocrine factor(s).
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Papers by M. Belleri