Effects of Taspine on Proliferation and Apoptosis by Regulating Caspase-3 Expression and the Ratio of Bax/Bcl-2 in A431 Cells

Taspine is an active component isolated from Radix et Rhizoma Leonticis. It has been shown that taspine can inhibit tumour angiogenesis. However, how it inhibits the proliferation of, and induces apoptosis in, A431 cells is unknown. The study investigated the effects of taspine on the proliferation and apoptosis in the A431 cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, transmission electron microscopy (TEM), western blotting (WB) and real-time reverse transcription-polymerase chain reaction (PCR). Changes in microstructure, cell cycle and protein expressions of caspase-3, cleaved caspase-3, cyclin-dependent kinase 2 (CDK2), cyclin-dependent kinase 4 (CDK4), Bcl-2 and Bax were observed after treatment of A431 cells with taspine. Taspine could inhibit the growth of, and induce apoptosis in, A431 cells in a dose-dependent manner. The cell cycle was significantly stopped at S phase. Nuclear karyopyknosis, chromatin agglutination and typical apoptotic bodies were found in A431 cells. There was a decrease in the expression of Bcl-2, whereas the expression of caspase-3, cleaved caspase-3, CDK2, CDK4 and Bax increased. These data demonstrated that taspine can inhibit the proliferation of, and induce apoptosis in, A431 cells by activating caspase-3 expression and up-regulating the ratio of Bax/Bcl-2 in A431 cells. Copyright (c) 2010 John Wiley & Sons, Ltd.