Figure 5: Isorhamnetin arrests K562 cells at G2/M phase via Src.
(a) The effects of isorhamnetin on cell-cycle progression determined by flow cytometry. Representative cell-cycle distributions after exposure to 0, 12.5, 25 and 50 μ M isorhamnetin for 24 h. (b) Western blotting analysis of whole cell extracts of K562 cells treated for 24 hours with different doses of isorhamnetin, showing the dose-dependent down-regulation of pSrc416, CDK1, Cyclin B1 and up-regulation of ATR and Wee 1. pSrc416 indicates the phosphoryl-specific antibody targeting activated Src phosphorylated at Y416. (c) K562 cells were transfected with Src siRNA or negative control siRNA for 48 hours, then K562 cells were treated with different doses of isorhamnetin. Western blotting analysis of whole cell extracts showed the dose-dependent down-regulation of Cyclin B1 and CDK1 in negative control group. These two proteins displayed no remarkable change in Src siRNA group. (d) The K562 cells were pre-treated with 8 nM dasatinib (the first line is control) for 12 h, then the K562 cells were treated with different doses of isorhamnetin for 24 h. The protein levels are shown in the above picture. (The typical full blot of the western blot is shown in Supplementary material).
