Effects of reduced intracellular copper by knocking-down CTR1 or TEPA copper chelation on HMEC-1 angiogenic activity. (a) Representative western blot for CTR-1 protein (35 kDa cropped band) on whole-cell extracts from HMEC-1 cells. GAPDH (37 kDa cropped band) expression was used as a protein loading control. (b) Representative photographs of HMEC-1 cells in Matrigel™ assays. Photographs were taken after knockdown of CTR-1 using 20 nM CTR-1 siRNA B or 8 h incubation with TEPA. Non-silencing siRNA (NSsiRNA) was use as control. Inset, % of inhibition as compared to untreated control cells; N.S. non-significant; Scale bar 200 µM. (c) Total surface area of vascular structure. Columns, n = 3, bars, SEM (****p < 0.0001).