Effect of Glibenclamide, a specific blocker of the K
channels, on cell growth. The figure shows the mRNA expression of KATP channels components and the effect of Gli and minoxidil (Min) on cell proliferation in MDA-MB-231 cells. Proliferation was evaluated by counting of colonies with 50 cells or more and expressed as percentage of values obtained with vehicle (means ± SEM of three experiments on parallel). Panel A: mRNA expression of KATP channels in MDA-MB-231 cells by RT-PCR analysis. Agarose gel electrophoresis of PCR products showed bands corresponding to: Kir6.1 (336 bp), Kir6.2 (301 bp), SUR2B (312 bp). No bands were detected for SUR2A (215 bp) or SUR1 (291 bp). CN: negative control Panel B: Inhibition of proliferation obtained with different concentrations of Gli (10, 20, 30 or 50 μM). Insert shows the dose–response curve used to determine IC50 (IC50 = 25 μM). Panel C: Increase of proliferation obtained with Min 0.05; 0.5 or 5 μM. Panel D: Results obtained with IC50 Gli plus different concentration of Min. Panel B and C: *p < 0.05 vs. control; **p < 0.01 vs control; ***p < 0.001 vs. control, One way ANOVA and Dunnet post test. Panel D: ***p < 0.01 vs. Min 0.05 μM; vs. Min 0.5 μM; vs. Min 5 μM. ###p < 0.001 vs. Min 0.05 μM; vs. Min 0.5 μM; vs. Min 5 μM. One way ANOVA and Tuckey post test.