Fig. 5

Loss of NUDT5 induces oxidative 8-oxoG and DNA damage response. A 8-oxoG lesions were stained in TNBC (MDA-MB-231) and ER-positive (MCF-7) cells treated with siLuc or siNUDT5, and nuclei were counterstained with DAPI after 4 days. The data is shown as nuclear intensity for siLuc- or siNUDT5-treated cells. B γH₂AX was stained in MDA-MB-231 and MCF-7 cells treated with siLuc or siNUDT5, and nuclei were counterstained with DAPI after 7 days. The data is shown as γH₂AX positivity, and was compared between the different treatments. Statistical significance was analyzed by the Student’s t test. C Representative DNA fibers from MDA-MB-231 and MCF-7 cells treated with siLuc or siNUDT5. Cells were first labelled with 30 min treatment with 50 µM IdU, followed by 30 min treatment with 100 µM CIdU. DNA fiber length was imaged by an Andor Revolution XDi WD Spinning disk confocal microscope and analyzed with Imaris software. The fork speed = (the length of IdU labeled DNA fiber + the length of CdU labeled DNA fiber)/total labeling time (1 h). The difference between siLuc- and siNDUT5-treated DNA fibers is shown graphically and compared using a Student’s t test. Additional TNBC (MDA-MB-436, MDA-MB-468) and ER-positive (ZR-75-1 and MDA-MB-361) cell lines are shown in Additional file 7, 8: Figures S7 and S8. Proof of effective knockdown is shown via Western blot and qPCR in Additional file 2: Figure S2A