FIGURE 1.
Wogonin, apigenin, and chrysin inhibit c-FLIP expression in HTLV-1-associated ATL cells. A, ATL cells expressing elevated levels of c-FLIP mRNA. HTLV-1-associated ATL cell lines SP and MT-2 and the non-HTLV-1-infected leukemic T cell line Jurkat were subjected to quantitative PCR analysis to determine the expression levels of c-FLIPL and c-FLIPS. Data are representative of three independent experiments performed in triplicate. Means ± S.D. (error bars) are shown. Numbers on columns of SP and MT-2 represent -fold expression compared with Jurkat. B, kinetic analysis of wogonin-, apigenin-, and chrysin-mediated inhibition of c-FLIP mRNA expression. MT-2 cells were treated with different flavones at 50 μm as indicated for 3 h, 6 h, and 9 h. The c-FLIP mRNA expression levels were monitored by quantitative PCR. Data are representative of two independent experiments performed in triplicate. Means ± S.D. are shown. C, c-FLIP expression levels down-regulated by wogonin, apigenin, and chrysin. MT-2 cells were treated with different concentrations of flavones for 8 h. The protein expression levels of various pro- and antiapoptotic proteins were analyzed by Western blotting. Tubulin was used to control for equal protein loading. The results are representative of two independent experiments. D, kinetic analysis of wogonin-mediated down-regulation of c-FLIPs. SP cells were treated with 50 μm wogonin for different time periods as indicated. The protein expression levels of c-FILPL and c-FLIPS were determined by Western blotting. The results are representative of two independent experiments.