TSA caused G2-M phase cell cycle arrest and apoptosis in breast cancer cells.

<p>(<b>A</b>) Histograms depict cell cycle distributions in MCF-10A, MDA-MB-231 and MCF-7 cells after a 24 h treatment with DMSO (control) or TSA (1000 nmol/L, 500 nmol/L or 500 nmol/L). (<b>B</b>) Western blot of CyclinB1, Phospho-cdc2 (Thr161) and H3P in MCF-10A, MDA-MB-231 and MCF-7. Representative of 3 experiments. (<b>C</b>) Cell cycle distribution in MDA-MB-231 cells after exposure to 500 nmol/L of TSA at the indicated time points. (<b>D</b>) A time-course study of the effects of 1000 nmol/L, 500 nmol/L and 500 nmol/L TSA on the percentages of apoptotic cells in the MCF-10A, MDA-MB-231 and MCF-7 cell lines, respectively. Apoptosis was determined by flow cytometric analysis of the PI-positive and Annexin-V-positive cells. Values were shown as the means ± SD, n = 3. **P<0.01 versus the 0 h group using Student's t-test. A pan-caspase inhibitor, zVAD-fmk, was used to protect MDA-MB-231 cells from apoptosis; graphs showed the percentage of apoptotic cells under different treatments (<b>E</b>) and the cell cycle distributions (<b>F</b>). **P<0.01 compared to the TSA-treated alone group using Student's t-test.