c-met and VE-cadherin protein levels vary in cultured HUVECs in relation to cell density. (A) HUVECs grown as a confluent monolayer or as a sparse monolayer were fixed and double-stained with anti–c-met C-28, and with anti–VE-cadherin antibodies, followed by immunofluorescent-labeled secondary antibodies. Original magnification for all images in panel A, × 400. In parallel, 5 μg protein extracted from confluent (c) or sparse (s) HUVECs was resolved by 8% SDS-PAGE and analyzed by Western blotting. Blots probed with anti–c-met C-28 (B), or with anti–VE-cadherin antibody (C) are shown, along with the corresponding scanning densitometry results. Arrows indicate the positions of the unprocessed 170-kDa c-met precursor and the 140-kDa c-met β-chain. In panels B-C, relative density is reported in arbitrary units. (D) Filters were stripped and reprobed with an antiactin antibody. Data are representative of 6 independent experiments.