Chemicals classified as indirect FANCG inhibitors primarily target the DNA repair mechanisms and cell cycle regulation processes, thereby influencing the function of the FANCG protein. The FA pathway, where FANCG plays a key role, is crucial for repairing DNA interstrand crosslinks. Compounds like Mitomycin C and various platinum-based compounds (Cisplatin, Carboplatin, Oxaliplatin) introduce DNA crosslinks, thereby challenging the FA pathway and indirectly impacting FANCG's role in DNA repair. The PARP inhibitors (Olaparib, Veliparib, Rucaparib, Niraparib, Talazoparib) represent another significant class of indirect FANCG inhibitors. These compounds inhibit the enzyme poly (ADP-ribose) polymerase (PARP), which is essential for repairing single-strand breaks in DNA. By inhibiting PARP, these chemicals increase the incidence of single-strand breaks, which can escalate to double-strand breaks during DNA replication. These breaks necessitate the intervention of more complex DNA repair pathways, including the FA pathway. Therefore, PARP inhibitors can indirectly affect FANCG by increasing the burden on the FA pathway.
Other chemicals like ATR inhibitor (VE 821), CHK1 inhibitor (AZD7762), and WEE1 inhibitor (2-allyl-1-(6-(2-hydroxypropan-2-yl)pyridin-2-yl)-6-(4-(4-methylpiperazin-1-yl)phenylamino)-1,2-dihydropyrazolo[3,4-d]pyrimidin-3-one) target various kinases involved in the DNA damage response. ATR kinase, CHK1, and WEE1 play critical roles in cell cycle checkpoint control and in orchestrating the DNA repair processes. Inhibiting these kinases can lead to a disruption in the proper functioning of DNA damage response, thereby indirectly impacting the FA pathway and FANCG's role in it. Overall, the indirect inhibition of FANCG through these chemicals sheds light on the interconnected nature of DNA repair mechanisms and the ability to modulate the FA pathway for research.