Cynaroside Induces G1 Cell Cycle Arrest by Downregulating Cell Division Cycle 25A in Colorectal Cancer

Natural chemicals derived from herbal plants have recently been recognized as potentially useful treatment alternatives owing to their ability to target a wide range of important biological molecules. Cynaroside is one of these natural compounds with promising anticancer activity for numerous tumor types. Nevertheless, the anticancer effects and molecular mechanisms of action of cynaroside on colorectal cancer (CRC) remain unclear. In this study, cynaroside was found to markedly inhibit CRC cell proliferation and colony formation in vitro. Cynaroside also inhibited cell proliferation in vivo and decreased the expression of KI67, a cell nuclear antigen. RNA sequencing revealed 144 differentially expressed genes (DEGs) in HCT116 cells and 493 DEGs in RKO cells that were enriched in the cell cycle signaling pathway. Cell division cycle 25A (CDC25A), a DEG widely enriched in the cell cycle signaling pathway, is considered a key target of cynaroside in CRC cells. Cynaroside also inhibited DNA replication and arrested cells in the G1/S phase in vitro. The expression levels of CDC25A and related G1-phase proteins were significantly elevated after CDC25A overexpression in CRC cells, which partially reversed the inhibitory effect of cynaroside on CRC cell proliferation and G1/S-phase arrest. In summary, cynaroside may be used to treat CRC as it inhibits CDC25A expression.