Small Molecule Inhibitor Targeting CDT1/Geminin Protein Complex Promotes DNA Damage and Cell Death in Cancer Cells

Abstract

DNA replication initiation requires the loading of MCM2-7 complexes at the origins of replication during G1. Replication licensing renders chromatin competent for DNA replication and its tight regulation is essential to prevent aberrant DNA replication and genomic instability. CDT1 is a critical factor of licensing and its activity is controlled by redundant mechanisms, including Geminin, a protein inhibitor of CDT1. Aberrant CDT1 and Geminin expression have been shown to promote tumorigenesis in vivo and are also evident in multiple human tumors. In this study, we developed an in vitro AlphaScreen™ high-throughput screening (HTS) assay for the identification of small-molecule inhibitors targeting the CDT1/Geminin protein complex. Biochemical characterization of the most potent compound, AF615, provided evidence of specific, dose-dependent inhibition of Geminin binding to CDT1 both in-vitro and in cells. Moreover, compound AF615 induces DNA damage, inhibits DNA synthesis and reduces viability selectively in cancer cell lines, and this effect is CDT1-dependent. Taken together, our data suggest that AF615 may serve as a useful compound to elucidate the role of CDT1/Geminin protein complex in replication licensing and origin firing as well as a scaffold for further medicinal chemistry optimisation.

Cdt1 overexpression drives colorectal carcinogenesis through origin overlicensing and DNA damage

“…Notably, stabilizing CDT1 activity or inactivating Geminin has been shown to induce genotoxic stress in cancer‐derived cell lines, in contrast to non‐transformed cells [28]. Therefore, the development of inhibitors stabilizing CDT1 activity, like the neddylation inhibitor MLN4924 [31], or chemical compounds inhibiting Geminin, or its interaction with CDT1 [32], may lead to specific anti‐cancer agents in CRC. Interestingly, it has recently been reported that mismatch repair‐deficient stage II or III rectal adenocarcinomas are highly sensitive to single‐agent programmed death 1 (PD‐1) blockade [33].…”

Construction of exosome-related genes risk model in kidney cell carcinoma predicts prognosis and immune therapy response

“…For CDC6, evidence has been accumulated that it acts as an oncogene promoting tumour progression and as a potential driver of tumourigenesis [ 40 ]. Aberrant CDT1 expression has been reported to promote tumourigenesis, and its small molecular inhibitor showed an obvious tumour-inhibition function by inducing DNA damage [ 41 ]. In addition, we also found that these two genes show a highly positive correlation with multiple tumour-related pathways, such as E2F targets and G2M checkpoint pathways.…”