This study identifies TP53RK as a key regulator of colorectal cancer (CRC) cell survival by stabilizing CDC7 for proper DNA replication. Its loss causes replication stress, apoptosis, and cell cycle arrest, making TP53RK a promising therapeutic target for CRC.

Colorectal cancer (CRC) is a leading cause of cancer-related mortality, necessitating the development of novel therapeutic strategies. In the present study, we identified TP53RK as a critical regulator of CRC cell survival and proliferation using a custom CRISPR/Cas9 library screen targeting serine/threonine kinase-related genes. TP53RK was significantly overexpressed in CRC tissues and was correlated with copy number amplification. Functional validation revealed that TP53RK depletion induced DNA replication stress, apoptosis, and cell cycle arrest, independent from p53 status. Mechanistically, TP53RK stabilized CDC7, a key kinase regulating DNA replication origin activation, ensuring proper MCM phosphorylation and replication fork progression. Disruption of the TP53RK-CDC7 axis led to reduced MCM2 enrichment at replication origins and impaired DNA replication dynamics. Moreover, TP53RK overexpression sensitized cells to DNA replication stress (aphidicolin) and CDC7 inhibition (XL413), highlighting its potential as a therapeutic strategy. These findings establish TP53RK as a pivotal regulator of DNA replication fidelity and genomic stability, thereby providing a promising therapeutic target for CRC.