Editorial PARP inhibitors and the treatment of breast cancer: beyond BRCA1/2?

Poly(ADP-ribose) polymerase (PARP) inhibitors have been explored as therapeutic agents for the treatment of hereditary breast and ovarian cancers harboring mutations in BRCA1 or BRCA2. In a new study, Inbar-Rozensal and colleagues show that phenanthridine-derived PARP inhibitors promote cell cycle arrest and cell death in breast cancer cells lacking BRCA1 and BRCA2 mutations and prevent the growth of tumors from xenografts of these cells in immunocompromised mice. These results suggest a potential broader utility of PARP-1 inhibitors in the treatment of breast cancer, although further mechanistic studies are needed. Recent studies have suggested that chemical inhibitors of poly(ADP-ribose) polymerases (PARPs) might be effective as therapeutic agents for the treatment of hereditary breast and ovarian cancers harboring mutations in BRCA1 or BRCA2. In a recent article from the Cohen-Armon group published in Breast Cancer Research, Inbar-Rozensal and colleagues [1] provide evidence that certain PARP inhibitors might also inhibit the growth and promote the death of non-hereditary breast cancer cells lacking mutations in BRCA1 or BRCA2. These intriguing results might lead the way to new approaches for treating a broad spectrum of breast cancer subtypes.