Cell cycle perturbations induced by HB-19 treatment.

<p>(A) Analysis of cell cycle parameters in HB-19 treated cells. MDA-MB-231 cells were cultured for 48 hours in medium without FBS (starvation) or in medium containing 10% FBS supplemented or not with 10 µM HB-19. DNA synthesis was quantified after BrdU incorporation and staining with anti-BrdU antibody and 7-AAD, by FACScan analysis. The histograms indicate the relative amount of cells in G1, S and G2/M cell phases. (B) HB-19 treatment inhibits serum-induced phosphorylation of ERK1/2. Serum starved MDA-MB-231 cells were stimulated with 10% FBS in the absence or presence of 2, 5, and 10 µM of HB-19. Five minutes after serum stimulation, cells were lysed directly in electrophoresis sample buffer and processed for immunoblotting using anti-phospho-p42/44 ERK1/2 and anti-p42/44 ERK antibodies. NS stands for non-stimulated cells.