Fig 1: CuET induces replication stress. (A) RPA32 foci detection in pre-extracted U2OS cells treated with CuET (250 nM) or hydroxyurea (HU, 2 mM) for 5 h. (B) Quantification of cells with more than 10 RPA32 foci treated as in (A) (mean, SD from three independent experiments). (C) Formation of single-stranded DNA (ssDNA) visualized by BrdU detected under non-denaturating conditions in U2OS cells treated by CuET (250 nM) and HU (2 mM) for 5 h. (D) Quantification of bromodeoxyuridine (BrdU) foci in U2OS and H1299 cells treated as in C. (E) Detection of RAD51 foci in pre-extracted H1299 cells treated by CuET (250 nM) for 5 h. (F) Quantification of RAD51 foci in cyclin A positive H1299 and MDA-MB-231 cells treated by CuET (250 nM) for 5 h. (G) Quantification of Rad51 foci in BRCA2 proficient and deficient H1299 cells after 5-h treatment with 250 nM CuET or 4 Gray (Gy) irradiation. (H) FIGE analysis of DSBs in H1299 cells exposed to CuET or HU.Box plot represents 25–75 quartiles, median, and whiskers non-outlier range. Scale bars = 10 µm.