Pan-Cdk inhibitor ZK304709 suppresses Cdc20 expression and potentiates the anticancer activity of apcin in HeLa cervical cancer cells.

Cell division cycle 20 homologue (Cdc20), a key regulator of the anaphase-promoting complex/cyclosome (APC/C), is frequently overexpressed in human cancers and represents a promising therapeutic target. However, monotherapy targeting Cdc20 has shown limited efficacy, partly due to compensatory activation of cyclin-dependent kinase 1 (Cdk1). In this study, we investigated the combinatorial potential of the pan-Cdk inhibitor ZK304709 with the Cdc20 inhibitor apcin in HeLa cervical cancer cells. Transcriptomic analysis revealed that both CDC20 and CDK1 are upregulated in cervical cancer tissues. Mechanistically, apcin treatment induced cyclin B1 accumulation and enhanced Cdk1 phosphorylation at Thr161, suggesting feedback activation. In contrast, ZK304709 reduced p-Cdk1(T161) levels and suppressed Cdc20 expression at both protein and mRNA levels. Functionally, the combination of apcin and ZK304709 synergistically inhibited cell proliferation and induced G2/M phase arrest in HeLa cells. These findings demonstrate that dual inhibition of Cdk1 and Cdc20 disrupts compensatory signalling pathways and enhances antitumour efficacy in HeLa cells, providing a rational strategy for combination therapy in cervical cancer.