IBR2 is a specific RAD51 inhibitor.
IBR2 shows interesting RAD51 inhibition activities. RAD51 is rapidly degraded in IBR2-treated cancer cells, and the homologous recombination repair is impaired, subsequently leading to cell death. The IC50 values of the original IBR2 are in the range of 12-20 µM for most tested cancer cell lines. IBR2 can inhibit the growth of triple-negative human breast cancer cell line MBA-MD-468 with an IC50 of 14.8 µM[1].
[1]. Zhu J, et al. Synthesis, molecular modeling, and biological evaluation of novel RAD51 inhibitors. Eur J Med Chem. 2015;96:196-208.