Figure 2.

Endostatin mediates endothelial cell adhesion through α₅- and α_v-integrins. (A) Dose dependence of cell adhesion to endostatin. Huvec cells were plated onto microtiter wells coated with the indicated concentrations of endostatin, and cell attachment was analyzed as described in Materials and Methods. (B) Effect of EDTA and RGD-peptides on cell attachment to endostatin. Huvec cells were incubated on wells coated with endostatin for 50 min in the absence (Left) or presence of 10 mM EDTA (Middle) or 0.8 mM of RGD-peptides (Right). Wells were washed with PBS, and cells were photographed. (C) Cell adhesion to endostatin is α₅- and α_v-integrin-dependent. Huvec cells were incubated with the indicated antibodies before plating on wells coated with 30 μg/ml of endostatin. Anti-integrin antibodies used were: anti-α_v (L230, VNR147), anti-α_vβ₃ (LM609), anti-α_vβ₅ (P1F6), anti-β₁ (P4C10) and anti-α₅ (P1D6). Cell attachment was analyzed as above. Error bars represent SD.