Cell experiment:

U2OS reporter cell lines (DR-GFP or EJ5-GFP) are pretreated in triplicate with varying concentrations of YU238259 for 24 h, after which 4 μg of SCE-I plasmid is transfected into 1 × 106 cells/replicate using an Amaxa Nucleofector. Transfected cells are reseeded on 6-well plates and cultured with YU238259 for an additional 72 h. The percentage of GFP-positive cells is quantified by flow cytometry. Data analysis is performed using FlowJo software. Error bars represent the standard deviation[1].

Animal experiment:

069(nu)/070(nu/+) athymic nude mice, at 4-5 weeks age, are injected subcutaneously with 3 × 106 DLD-1 or DLD-1 BRCA2-KO cells suspended in 100 μL PBS. Tumor take rate is >80%. When tumors reach 100 mm3 geometric mean volume, the mice are injected with 3 mg/kg YU238259 or its 3:1 DMSO:PBS vehicle, or 5 mg/kg YU128440 or its 1:19 DMSO:PBS vehicle (IP, 100 μL total in each case). Treatment is repeated 3×/week (Mon/Wed/Fri) for a total of 12 doses of YU238259 and 4 doses of YU128440. Tumor growth is assessed by external caliper. Mice are euthanized when individual tumor volumes exceed 1000 mm3[1].

YU238259 is an inhibitor of homology-dependent DNA repair (HDR), used for cancer research.

YU238259 is an inhibitor of homology-dependent DNA repair, with no effect on PARP activity. YU238259 shows cytotoxicity in BRCA2-deficient cells, with a low LD50 of 8.5 uM. YU238259 (0-5 uM) causes a potent, dose-dependent decrease in HDR efficiency in U2OS DR-GFP or U2OS EJ5-GFP cells, but with no effect on NHEJ frequency. YU238259 (0-10 uM) exhibits synthetic lethality with loss of frequently mutated tumor suppressors, and shows synergism with radiotherapy (IR) and DNA-damaging chemotherapy that is potentiated by BRCA2 loss[1].

YU238259 (3 mg/kg, i.p.) inhibits the growth of BRCA2-deficient tumor xenografts in nude mice[1].

References:
[1]. Stachelek GC, et al. YU238259 Is a Novel Inhibitor of Homology-Dependent DNA Repair That Exhibits Synthetic Lethality and Radiosensitization in Repair-Deficient Tumors. Mol Cancer Res. 2015 Oct;13(10):1389-97.