The present disclosure provides methods of determining the levels of BRCA1 in a cell, altering the levels of BRCA1 in a cell, determining the likelihood of developing cancer, and determining the prognosis of a patient with cancer using miR-182 and analogs thereof. Importantly, the invention also provides methods of determining whether a patient should be treated with PARP inhibitors, improving PARP therapy in cancer, as well as methods for selecting and improving genotoxic therapies. Also featured are methods of treating patients with cancers based on the expression levels of miR-182. The invention also features compositions comprising miR-182 and analogs thereof, antagomirs of mIR-182 and analogs thereof, in combination with PARP inhibitors and genotoxic agents.