Fig. 5.

TA induces cell cycle arrest and apoptosis. (A) U2OS cells were treated with TA (2 μM) for different periods and the cell cycle distribution was examined by flow cytometry. (B) The histogram represents the percentage of cells in each phase of the cell cycle. (C) Cells were treated with indicated concentrations and periods of TA and evaluated for the expression of CDK2/4/6, cyclin D1/D3/E1, p21, and p27 proteins. (D) The apoptotic rate of U2OS cells after treatment with indicated periods of TA (2 μM) was determined by Annexin V- FITC and PI staining. **P < 0.01, ***P < 0.001 versus 0 μM treatment group. (E) Cells were treated with indicated concentrations and times of TA, the proteolytic activation of procaspase-7, −9, −3, cleavage of PARP, Bcl-2, and Bax was detected.