Fig. 4
Effect of T-type Ca2+ channel antagonists, mibefradil (Mib) and NNC-55-0396 (NNC), on the cell cycle distribution and cell apoptosis of Jurkat and MOLT-4 cells. a-c Each cell was treated with different concentrations (0, 5 or 10 μM) of mibefradil or NNC-55-0396 for 48 h. To acquire enough cells for cell cycle analysis, Jurkat cells were treated with 8 μM NNC-55-0396. Cell cycle phase was determined using flow cytometry (FACS). d-e Cells were stained with Annexin V -FITC and propidium iodide (PI) after treatment with 10 μM mibefradil or NNC-55-0396 for 48 h (except Jurkat cells subjected to NNC-55-0396 for 24 h). Flow cytometry profiles represent annexin V-FITC staining in x-axis and PI in y-axis for the three experimental conditions. Percentage of each LR and UR area represents Annexin V-positive/PI-negative (early apoptotic) and Annexin V-positive/PI-positive cells (late apoptotic), respectively. Mibefradil and NNC-55-0396 had a dual effect on cell viability: (a) reducing the proliferation rate; and (b) increasing cell apoptosis. c and e Histogram bars representing the mean ± SEM of three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001 versus control group. Statistical significances were determined using one factor ANOVA and Student-Newman-Keuls post-test