DMP1 induces the adhesion, migration, and differentiation of HUVECs in vitro but decreases their proliferation. (A) Cells were plated onto DMP1 (50 nmol/L) or incubated for 1 hour in the presence of 50 nmol/L of RGD peptide and then plated onto DMP1 (50 nmol/L). Vitronectin (50 nmol/L) and BSA 1% were used as positive and negative controls, respectively. Cells were allowed to adhere for 2 hours at 37°C and were quantified as described in “Adhesion assay.” Error bars represent the means ± SD of 6 replicates of a representative experiment (n = 2). **P ≤ .005 vs control; n.s., not significant. (B) Modified Boyden chamber chemotaxis assays were performed on HUVECs with DMP1 (100 nmol/L) placed in the bottom chamber (DMP1 bottom), in the top chamber with the cells (DMP1 top), or in both the top and bottom chambers (DMP1 both). Each bar represents the mean ± SD of the total number of migrated cells within 4 replicates (n = 2). (C) HUVECs were treated with DMP1 (1-100 nmol/L) and proliferation was followed for 24 and 48 hours and scattered as described in “Methods.” Error bars represent the means ± SD of 3 replicates of a representative experiment (n = 3). **P ≤ .001, ***P ≤ .0001 vs control; n.s., not significant. (D) Capillary tube–like assay using HUVECs treated with DMP1 (50 nmol/L) for 24 hours and then cultured on Matrigel for 1, 4, 8 (100×), and 24 hours (40×). Phase-contrast microscopy photomicrographs were taken for each culture time. The quantification of the assay is shown and was realized by counting the number of vessels from 2 representative fields from 2 replicates (n = 3). **P ≤ .005 vs control; n.s., not significant.