Effect of ECM proteins on cancer cell proliferation. (A) U87 cells, (B) U251N cells, (C) MDA-MB-231, (D) MCF-7, (E) HeLa cells. Cells (5,000) were seeded in 96 well-plates coated with various ECM proteins. XTT solution was added to cells at different times in culture, i.e. 24 h, 48 h and 72 h. The metabolic activity of the cells was measured at 450 nm using Ascent software. Values represent the mean for three replicates. Data shown are representative of three independent experiments.