DNA pol ζ Inhibitors

DNA pol ζ inhibitors encompass a diverse array of chemical compounds that interface with cellular pathways to modulate the activity of DNA polymerase zeta (pol ζ). The chemical classes of these inhibitors are not unified under a singular mechanism of action due to the indirect nature of their effects on pol ζ. However, they share a common thread in their ability to influence DNA synthesis and repair processes within the cell. Inhibitors such as aphidicolin, hydroxyurea, and 5-Fluorouracil function primarily by disrupting nucleotide pools or mimicking nucleotides, thereby challenging the fidelity and function of DNA polymerases, including pol ζ, during DNA replication and translesion synthesis. Aphidicolin, for instance, impedes DNA polymerases α and δ, which are crucial for normal DNA synthesis, subsequently affecting pol ζ's role in the bypass of lesions during replication stress.

Other compounds like etoposide, camptothecin, and cisplatin work by inducing DNA damage, which can elevate the need for pol ζ's translesion synthesis activity, as this enzyme specializes in replicating across damaged DNA. Cisplatin, in particular, creates DNA crosslinks that stall replication forks, necessitating the recruitment of translesion synthesis polymerases to resolve these barriers. In the context of DNA damage response, inhibitors such as olaparib, mirin, and VE-821 disrupt the cellular repair machinery by inhibiting enzymes like PARP, the Mre11-Rad50-Nbs1 complex, and ATR kinase. This disruption can indirectly necessitate the engagement of pol ζ to bypass the accruing DNA damage that these inhibited pathways would normally resolve. Compounds like N-Ethylmaleimide and UCN-01 exhibit their modulatory effects by altering enzyme activities through covalent modifications of key residues or by broadly targeting protein kinases that signal for DNA repair and synthesis, thus having the capacity to alter pol ζ activity within those contexts.