Heparin Octasaccharides Inhibit Angiogenesis In vivo

• Published in: Clinical cancer research Vol. 11; no. 22; pp. 8172 - 8179
• Main Authors: Hasan, Jurjees, Shnyder, Steven D., Clamp, Andrew R., McGown, Alan T., Bicknell, Roy, Presta, Marco, Bibby, Michael, Double, John, Craig, Steven, Leeming, David, Stevenson, Kenneth, Gallagher, John T., Jayson, Gordon C.
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 15.11.2005
• Subjects: Angiogenesis; Angiogenesis Inhibitors - pharmacology; Animals; Anticoagulants - pharmacology; Antineoplastic agents; Biological and medical sciences; Cell Line, Tumor; Female; FGF; Fibroblast Growth Factor 2 - pharmacology; Heparin; Heparin - chemistry; Heparin - pharmacology; Humans; Lung Neoplasms - blood supply; Lung Neoplasms - pathology; Lung Neoplasms - prevention & control; Male; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Nude; Neovascularization, Pathologic - prevention & control; Neovascularization, Physiologic - drug effects; Oligosaccharides - pharmacology; Partial Thromboplastin Time; Pharmacology. Drug treatments; Xenograft Model Antitumor Assays - instrumentation; Xenograft Model Antitumor Assays - methods; Angiogenesis; In vivo; Glycosaminoglycan; Anticoagulant; Inhibitor; Heparin; Neovascularization
• DOI: 10.1158/1078-0432.CCR-05-0452
• ISSN: 1078-0432

Background: In previous experiments, we showed that heparin oligosaccharides inhibit the angiogenic cytokine fibroblast growth factor-2. Here, we present the first in vivo study of size-fractionated heparin oligosaccharides in four models of angiogenesis that are progressively less dependent on fibroblast growth factor-2. Experimental Design: Heparin oligosaccharides were prepared using size-exclusion gel filtration chromatography and characterized through depolymerization and strong anion exchange high-performance liquid chromatography. Size-defined oligosaccharides (20 mg/kg/d) were given to mice bearing s.c. sponges that were injected with fibroblast growth factor-2 (100 ng/d). After 14 days, octasaccharides and decasaccharides reduced the microvessel density to levels below control. In a second experiment, HEC-FGF2 human endometrial cancer cells that overexpress fibroblast growth factor-2 were implanted in a hollow fiber placed s.c. in vivo . Oligosaccharides were given at 20 mg/kg/d for 2 weeks and the data again showed that octasaccharides significantly reduced microvessel density around the fiber ( P = 0.03). In a more complex model, where angiogenesis was induced by a broad spectrum of growth factors, including vascular endothelial growth factor, we implanted H460 lung carcinoma cells in hollow fibers and treated the animals with oligosaccharides at 20 mg/kg/d over 3 weeks. Octasaccharides reduced the microvessel density to that of control. Preliminary investigation of 6- O -desulfated heparins showed that these also had antiangiogenic activity. Results: Finally, we examined the inhibitory potential of hexasaccharides and octasaccharides given at 20 mg/kg/d and these inhibited the growth of H460 lung carcinoma in vivo . At clinically attainable concentrations, significant anticoagulation (activated partial thromboplastin time, anti–factor Xa, and anti–factor IIa) was not observed in vitro unless species containing ≥16 saccharide residues were investigated. Conclusions: Thus, our preclinical data show that heparin octasaccharides represent novel antiangiogenic compounds that can be given without the anticoagulant effects of low molecular weight heparin.