Control of angiogenesis by inhibitor of phospholipase A₂

Objective: To investigate the potential effects of angiogenic process by secretory phospholipase A₂ (sPLA₂) inhibitor-HyPE (linking N-derivatized phosphatidyl-ethanolamine to hyaluronic acid) on human bone marrow endothelial cell line (HBME-1). Methods: In order to examine the suppressing effects of HyPE on HBME-1 proliferation, migration, and capillary-like tube formation, HBME-1 were activated by angiogenic factor, specifically by basic fibroblast growth factor (b-FGF), vascular endothelial growth factor (VEGF), and oncostatin M (OSM) (at a final concentration of 25, 20, and 2.5 ng/mL, respectively), then HBME-1 proliferation, migration, and tube formation were studied in the absence or presence of HyPE. HBME-1 tube formation was specially analyzed in fibrin gel. Results: HyPE effectively inhibited HBME-1 proliferation and migration as a dose-dependent manner, whatever HBME-1 were grown in the control culture medium or stimulated with b-FGF, VEGF, or OSM. In fibrin, the formations of HBME-1 derived tube-like structures were enhanced by all angiogenic factors, but these were strongly suppressed by HyPE. Conclusions: The results support the involvement of sPLA₂ in angiogenesis. It is proposed that sPLA₂ inhibitor introduces a novel approach in the control of cancer development.