Fig. 5

DNA damage signalling and APOBEC3 activity in breast cancer cell lines. a MCF10A cells were treated with ATM or ATR inhibitors for 24 h after which cells were treated with hydroxyurea (HU) for a further 48 h prior to lysis and cytidine deamination assay for APOBEC3 activity. b MDA-MB-453 cells were treated for 48 h with the indicated doses of Chk1 inhibitor CCT244747 followed by APOBEC3 cytidine deamination assay. c MCF10A cells were treated for 48 h with the indicated doses of Chk1 inhibitor CCT244747 and with 2 mM hydroxyurea for the last 24 h. Following lysis, western blots were probed with the indicated antibodies. d MCF10A cells were treated as in c before lysis and cytidine deamination assay to determine APOBEC3 activity. e Model illustrating mechanisms of APOBEC3 regulation by replication stress. CTRL control, UNT untreated