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 <i>CDC20</i> and <i>CDK1</i> 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 <i>p</i>-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.