Fig. 2.

Impact of repeated exposure to chemotherapy on the chemosensitivity of endothelial cells. a–c Histograms showing the IC₅₀ values of vinblastine (a), etoposide (b) and paclitaxel (c) in the 6 BMH29L subclones as determined by 72 h growth inhibition assay. d–f Percentage of vascular structure formation following 8 h incubation on Matrigel with 5 nM vinblastine (d), 10 μM etoposide (e) and 10 nM paclitaxel (f). Columns means of at least four individual experiments, bars SE. Statistics were calculated by comparing drug-treated cells with control cells, unless indicated otherwise; *p < 0.05; **p < 0.01; ***p < 0.001