Lycorine induces cell-cycle arrest in the G0/G1 phase in K562 cells via HDAC inhibition

Li, Lv; Dai, Hong-Juan; Ye, Mao; Wang, Shu-Ling; Xiao, Xiao-Juan; Zheng, Jie; Chen, Hui-Yong; Luo, Yu-hao; Liu, Jing

Several studies have shown that inhibitors of HDAC block cell cycle progression at the G0/G1 or G2/M phase [17] depending on the cell type and type of drugs. Similar to the effect of HDAC inhibitors in other tumor types, lycorine inhibits cell cycle progression and induces cell-cycle arrest in the G0/G1 phase in K562 cells. Progress in the eukaryotic cell cycle is driven by protein kinase complexes consisting of a cyclin and a CDK. During G1-phase progression, the complexes cyclin D-CDK4, cyclin D-CDK6, and cyclin E-CDK2 are activated and move the cell cycle from the G1 phase to the S phase. We found that cyclin D1, CDK4 and CDK2 are significantly downregulated in K562 cells after lycorine treatment. By contrast, the expression patterns of cyclin E, CDK2, and CDK6 were not significantly altered after lycorine treatment. This finding suggests that inhibition of cyclin D1 and CDK4 expression is involved in lycorine-induced G0/G1 arrest in K562 cells.