New RAD51 Inhibitors to Target Homologous Recombination in Human Cells

Area of Science:

• Oncology
• Molecular Biology
• Medicinal Chemistry

Background:

• Small-molecule inhibitors targeting DNA repair proteins are a validated anti-cancer strategy.
• Homologous recombination (HR) is a critical DNA repair pathway.
• RAD51 is a key protein in HR, and its inhibitor B02 has shown promise.

Purpose of the Study:

• To enhance the potency of the RAD51 inhibitor B02 through medicinal chemistry.
• To evaluate the efficacy of a novel B02 analog, B02-isomer, in inhibiting HR.
• To assess the sensitizing effect of B02-isomer on triple-negative breast cancer cells treated with a PARP inhibitor.

Main Methods:

• Medicinal chemistry approach to design and synthesize B02 analogs.
• In vitro assessment of HR inhibition in human cells.
• Evaluation of drug sensitization in MDA-MB-231 triple-negative breast cancer cells.

Main Results:

• Identification of B02-isomer, a potent analog of B02.
• B02-isomer demonstrated significantly higher efficiency in inhibiting HR compared to B02.
• B02-isomer sensitized MDA-MB-231 cells to the PARP inhibitor olaparib.

Conclusions:

• B02-isomer represents a more potent inhibitor of homologous recombination.
• The enhanced HR inhibition by B02-isomer can sensitize triple-negative breast cancer cells to PARP inhibitors like olaparib.
• This study provides a promising lead for developing novel cancer therapeutics targeting DNA repair pathways.