The development of new blood vessels (angiogenesis) is required for many physiological processes including embryogenesis, wound healing and corpus luteum formation. Blood vessel neoformation is also important in the pathogenesis of many disorders, particularly rapid growth and metastasis of solid tumours. There are several potential mediators of tumour angiogenesis, including basic and acidic fibroblast growth factors, tumour necrosis factor-alpha and transforming factors-alpha and -beta. But it is unclear whether any of these agents actually mediates angiogenesis and tumour growth in vivo. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen and an angiogenesis inducer released by a variety of tumour cells and expressed in human tumours in situ. To test whether VEGF may be a tumour angiogenesis factor in vivo, we injected human rhabdomyosarcoma, glioblastoma multiforme or leiomyosarcoma cell lines into nude mice. We report here that treatment with a monoclonal antibody specific for VEGF inhibited the growth of the tumours, but had no effect on the growth rate of the tumour cells in vitro. The density of vessels was decreased in the antibody-treated tumours. These findings demonstrate that inhibition of the action of an angiogenic factor spontaneously produced by tumour cells may suppress tumour growth in vivo.

Inhibition of vascular endothelial growth factor-induced angiogenesis suppresses tumour growth in vivo

Angiostatin: A novel angiogenesis inhibitor that mediates the suppression of metastases by a lewis lung carcinoma

Angiogenesis depends on the adhesive interactions of vascular cells. The adhesion receptor integrin alpha v beta 3 was identified as a marker of angiogenic vascular tissue. Integrin alpha v beta 3 was expressed on blood vessels in human wound granulation tissue but not in normal skin, and it showed a fourfold increase in expression during angiogenesis on the chick chorioallantoic membrane. In the latter assay, a monoclonal antibody to alpha v beta 3 blocked angiogenesis induced by basic fibroblast growth factor, tumor necrosis factor-alpha, and human melanoma fragments but had no effect on preexisting vessels. These findings suggest that alpha v beta 3 may be a useful therapeutic target for diseases characterized by neovascularization.

https://science.sciencemag.org/content/sci/264/5158/569.full.pdf

Requirement of vascular integrin alpha v beta 3 for angiogenesis

Clinical and experimental studies suggest that angiogenesis is a prerequisite for solid tumour growth. Several growth factors with mitogenic or chemotactic activity for endothelial cells in vitro have been described, but it is not known whether these mediate tumour vascularization in vivo. Glioblastoma, the most common and most malignant brain tumour in humans, is distinguished from astrocytoma by the presence of necroses and vascular proliferations. Here we show that expression of an endothelial cell-specific mitogen, vascular endothelial growth factor (VEGF), is induced in astrocytoma cells but is dramatically upregulated in two apparently different subsets of glioblastoma cells. The high-affinity tyrosine kinase receptor for VEGF, flt, although not expressed in normal brain endothelium, is upregulated in tumour endothelial cells in vivo. These observations strongly support the concept that tumour angiogenesis is regulated by paracrine mechanisms and identify VEGF as a potential tumour angiogenesis factor in vivo.

Vascular endothelial growth factor is a potential tumour angiogenesis factor in human gliomas in vivo.

Integrin alpha v beta 3 antagonists promote tumor regression by inducing apoptosis of angiogenic blood vessels

Neovascularization is critical for the growth of tumours and is a dominant feature in a variety of angiogenic diseases such as diabetic retinopathy, haemangiomas, arthritis and psoriasis. Recognition of the potential therapeutic benefit of controlling unabated capillary growth has led to a search for safe and effective angiogenesis inhibitors. We report here the synthesis of a family of novel inhibitors that are analogues of fumagillin, a naturally secreted antibiotic of Aspergillus fumigatus fresenius. We first isolated this fungus from a contaminated culture of capillary endothelial cells. Purified fumagillin inhibited endothelial cell proliferation in vitro and tumour-induced angiogenesis in vivo; it also inhibited tumour growth in mice, but prolonged administration was limited because it caused severe weight loss. Synthesis of fumagillin analogues yielded potent angiogenesis inhibitors ('angioinhibins') which suppress the growth of a wide variety of tumours with relatively few side-effects.

Synthetic analogues of fumagillin that inhibit angiogenesis and suppress tumour growth.

Potent anti-angiogenic action of AGM-1470 : comparison to the fumagillin parent

Effects of 5-[4-(1-methylcyclohexylmethoxy)benzyl]-thiazolidine-2,4-dione (ADD-3878, U-63,287, Ciglitazone) on glucose and lipid metabolism were examined in various animal models. ADD-3878, administered as a dietary admixture (30-186 mg/kg/day) to obese-diabetic yellow KK (KK-Ay) mice, markedly suppressed the diabetic syndromes (hyperglycemia, hypertriglyceridemia, and hyperinsulinemia), accompanied by the reduction of insulin resistance as manifested by improvement of overall insulin sensitivity in either the insulin tolerance test or the steady-state blood glucose test. Chronic administration of ADD-3878 for as long as 12 wk to young yellow KK mice, which were in the early stage of diabetes and obesity, depressed age-dependent rises in blood glucose, plasma triglyceride, and insulin without exerting any effect on obesity. When orally administered to obese Zucker-fatty rats, ADD-3878 decreased plasma insulin and triglyceride in a dose-dependent manner (5-100 mg/kg/day). The treated rats showed increased tolerance and decreased insulin secretion in response to oral glucose. The glycemic response to insulin and the steady-state plasma glucose were also normalized in the treated rats. Chronic administration of ADD-3878 to young fatty rats for as long as 12 wk decreased the dose-dependent rises in blood glucose, plasma triglyceride, and insulin without exerting any effect on body weight. ADD-3878 had no effect on glucose and lipid metabolism of young Sprague-Dawley rats and mild streptozotocin-diabetic rats. However, in old Sprague-Dawley rats that were moderately insulin resistant and hyperlipidemic compared with young ones, ADD-3878 decreased plasma triglyceride and insulin and improved insulin sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduction of Insulin Resistance in Obese and/or Diabetic Animals by 5-[4-(1-Methylcyclohexylmethoxy)benzyl]-thiazolidine-2,4-dione (ADD-3878, U-63,287, Ciglitazone), a New Antidiabetic Agent

Thiazolidinedione derivatives of the formula: ##STR1## and pharmacologically acceptable salts thereof are novel compounds, which exhibit in mammals blood sugar- and lipid-lowering activity, and are of value as a therapeutic agent for treatment of diabetes and hyperlipemia.

Thiazolidinedione derivatives, useful as antidiabetic agents

The effect of the potent angiogenesis inhibitor O-(chloroacetyl-carbamoyl)fumagillol (TNP-470), a semisynthetic analogue of fumagillin, on tumor growth and metastasis was studied using rodent tumors. Injection of TNP-470 s.c. inhibited tumor growth in a dose-dependent manner, and the tumor sizes of B16BL6 melanoma, M5076 reticulum cell sarcoma, Lewis lung carcinoma, and Walker 256 carcinoma were maximally reduced to 16, 10, 17, and 4% of that in the respective control. The activity of TNP-470 upon i.v. injection was slightly weaker than that following s.c. injection. This tendency was observed for all the tumors tested. Injection i.v. (infusion) of TNP-470 increased the life span of Walker 256 carcinoma-bearing rats by 183% over the control, while bolus i.v. injection increased the life span by only 47%. TNP-470 reduced the number of pulmonary metastatic foci of i.v. inoculated B16BL6 melanoma in a dose-dependent manner, and the number of metastatic foci was reduced to 10% of that in the control by treatment with TNP-470 at 60 mg/kg, 3 times/week. The mean survival time of B16BL6 tumor-bearing mice treated with TNP-470 using this regimen was extended by 56% over that of control mice. TNP-470 at 10 mg/kg every day also reduced the number of metastatic foci of M5076 sarcoma in the liver after resection of the tumor from the primary site. Adriamycin at the same dose only slightly reduced the number of metastatic foci, even though TNP-470 and Adriamycin showed roughly equal inhibitory activity against M5076 sarcoma growth. TNP-470 extended the mean survival time of M5076 tumor-bearing mice by more than 100% over that of control mice at 30 mg/kg every 3 days, while Adriamycin extended mean survival times by maximally 20% at 10 mg/kg. These results show that the angiogenesis inhibitor TNP-470 has strong inhibitory activities against in vivo growth and metastasis of a wide variety of tumors.

https://cancerres.aacrjournals.org/content/canres/53/18/4262.full.pdf

Takeshi Fujita

Papers

Synthetic analogues of fumagillin that inhibit angiogenesis and suppress tumour growth.

Potent anti-angiogenic action of AGM-1470 : comparison to the fumagillin parent

Reduction of Insulin Resistance in Obese and/or Diabetic Animals by 5-[4-(1-Methylcyclohexylmethoxy)benzyl]-thiazolidine-2,4-dione (ADD-3878, U-63,287, Ciglitazone), a New Antidiabetic Agent

Thiazolidinedione derivatives, useful as antidiabetic agents

Inhibition of Tumor Growth and Metastasis of Rodent Tumors by the Angiogenesis Inhibitor O-(Chloroacetyl-carbamoyl)fumagillol (TNP-470; AGM-1470)