Dissecting the Mechanisms of Drug Resistance in BRCA1/2-Mutant Breast Cancers
Abstract
Poly(ADP-ribose) polymerase (PARP) inhibition provides a promising therapeutic modality for targeting homologous recombination (HR) deficient tumors such as BRCA1 and BRCA2-mutated triple negative breast cancers (TNBCs). Although PARP inhibitors have shown activity in the BRCA-associated TNBCs, several of these tumors develop de novo as well as acquired PARP inhibitor (PARPi) resistance. Besides attenuation in intracellular uptake of drugs, the only known mechanism that drives chemotherapy resistance of BRCA1/2-deficient cancers is through the restoration of HR. Recent studies from our laboratories (Nussenzweig and DAndrea) indicate that deregulation of pathways that promote extensive degradation of nascent DNA strands and alternative end-joining (Alt-EJ) can render BRCA1/2-deficient cells resistant to PARPi in a HR-independent manner. The objective of our project is to collaboratively test the hypothesis that complex processes involving Alt-EJ or replication fork stability promote survival and drives resistance to chemotherapy. A detailed assessment of the critical mediators that regulate the balance between HR, Alt-EJ and replication fork degradation should identify novel means to overcome acquired chemoresistance in BRCA1/2-mutated breast cancers. During the first year of the DOD funding, we have made progress in identifying the proteins which contribute to the replication fork stability and we have identified new mechanisms of chemoresistance in BRCA2-deficient tumors.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2017
- Accession Number
- AD1050845
Entities
People
- Andre Nussenzweig
Organizations
- Geneva Foundation