PARP inhibitors work by blocking the PARP enzyme's ability to repair single-strand DNA breaks. When PARP is inhibited, these single-strand breaks become double-strand breaks during DNA replication. Normally, cells repair double-strand breaks through homologous recombination, a process requiring proteins like BRCA1 and BRCA2. Cancer cells with mutations in these genes are unable to repair the damage, leading to cell death and making PARP inhibitors particularly effective against BRCA-mutated cancers.
