Effects of tetramethylpyrazine on apoptosis of human leukemia cells and the expressions of apoptotic-relevant proteins / 肿瘤

ABSTRACT

Objective: To explore the effects of tetramethylpyrazine injection on apoptosis of human leukemia cells and the expressions of apoptotic-relevant proteins. Methods: Leukemia cell line U937 cells were treated with different concentrations (0.5, 1.0, 1.5, 2.0 and 2.5 mg/mL) of tetramethylpyrazine for 24, 48 and 72 h. Then the proliferation inhibitory rate of U937 cells was detected by CCK-8 (cell counting kit-8) method. The cell cycle distribution and the apoptosis of U937 cells were detected by flow cytometry. The expressions of apoptotic-relevant proteins survivin, Bcl-2, Bax and caspase-3 in U937 cells were measured by Western blotting. Results: Tetramethylpyrazine significantly inhibited the cell growth of U937 cells in a time- and dose-dependent manner (P 2/M phase decreased (P < 0.05), as well as the apoptosis rate increased significantly in a dose-dependent fashion (P < 0.05). The expression levels of survivin and Bcl-2 proteins were reduced (P < 0.05), and the expression levels of Bax and caspase-3 proteins were elevated (P < 0.05) in a dose-dependent fashion in U937 cells after tetramethylpyrazine treatment. Conclusion: Tetramethylpyrazine injection can significantly induce apoptosis of U937 cells resulting in antineoplastic effect. Its mechamism may be related to down-regulation of survivin and Bcl-2 protein expressions and up-regulation of Bax and caspase-3 protein expressions.