Dual PARP/BRD4 inhibitor D6 curbs tumor growth in breast cancer xenograft
- Because BRD4 inhibition weakens homologous recombination repair, the authors built dual PARP/BRD4 inhibitors to make cancer cells more vulnerable to PARP blockade.
- SAR optimization yielded D6, which inhibits both PARP1 and BRD4 in the low-nanomolar range and suppresses proliferation, colony formation and metastasis-related phenotypes in breast and pancreatic cancer cells.
- D6 downregulates the BRD4-cJUN-CCL2 axis, reducing macrophage recruitment and macrophage-driven invasion.
- In a breast cancer xenograft, D6 slowed tumor growth without evident toxicity.
💡 Points
Two targets in one molecule looks elegant on paper, but balance is the hard part. Can one exposure hold both PARP1 and BRD4 engaged at tolerable doses, or does BRD4 occupancy drive toxicity? Before calling the pharmacophore merge a win, I need D6 compared with a PARP inhibitor plus BET inhibitor combination, and its selectivity across other bromodomains.