DNA damage and toxicity caused by ARTIK-52 treatment are replication dependent. A. Immunofluorescent staining of cells treated with 1 μM of ARTIK-52 for 6 hours with antibodies to RPA1, XRCC1 and DAPI. B. Immunofluorescent images of MCF7 cells incubated with ARTIK-52 (1 µM) and EdU for 16 hours followed by Click-IT assay, and staining with γH2AX antibody and DAPI. C, D. E. Cytotoxicity assay on CWR22R (C) and MCF7 (D) cells and either pre-treated with nutlin (CWR22R −10 µ M, MCF7 −5 µM) or not for 24 hours before addition of ARTIK-52. Nutlin was left with cells untill the end of experiment, but diluted twice due to addition of ARTIK-52 solutions. E, F. Cytotoxicity assays on arrested or growing CWR22R cells with ARTIK-52 or HU. Error bars on C-F are standard deviation between 3 replicates in one experiment.