MVL-PLA2 blocks in vitro angiogenesis.

(A) Representative visualization of tubulogenesis assay after pre-treatment of HMEC-1 cells without (control) or with 50, 100 or 500 nM MVL-PLA2 for 30 min at room temperature. Cells were then added to Matrigel™ in the presence of the enzyme and allowed to form capillary-like structures for 5 h at 37°C. Scale bar: 70 µm. (B) Dose-effect of native MVL-PLA2 or catalytically inactive MVL-PLA2 (MVL-PLA2+BPB), at the indicated concentration, on tubulogenesis on Matrigel™. Quantification of tubulogenesis was done as described in experimental section. Data shown (±S.D.) are from at least 3 independent experiments. (C) Tubulogenesis on Matrigel™ was performed as above in the presence of the indicated anti-integrin antibodies (10 µg/ml). Data shown (±SD) are from 3 independent experiments.