Fig. 5. (a) Clonogenic survival of OE21, OE33 or FLO-1 cells pre-treated with Ru1 (2 μM, 24 h) before irradiation with 0–8 Gy 137Cs-γ-rays. Mean ± SEM of two or three independent experiments. Data were fit to a second order polynomial function (R2 values > 0.99). Data for sub-cytotoxic doses of cisplatin (Cis) (500 nM OE21 and OE33, 300 nM FLO-1 cells) included (dashed lines). (b) CLSM images of OE21 cells treated with Ru1 (10 μM, 24 h), IR (2 Gy), or both, where IR was applied at the end of Ru1 treatment. Samples were fixed 1 h after irradiation. Immunofluorescence staining with anti-γH2AX antibody (white) provides visualisation of DSB damage. DNA (DAPI) staining included for reference. Scale bars = 10 μm. (c) Quantification of γH2AX foci/nucleus for OE21 cells treated as in (b). Data mean of two independent experiments ± S.D. (d) Immunoblotting (top) and corresponding densitometry (bottom) of γH2AX levels in OE21 cells treated with Ru1 (24 h) with or without 8 Gy IR after treatment. Whole-cell extracts were prepared 1 h after irradiation and γH2AX levels were measured relative to β-actin loading controls by densitometry. Data normalised to untreated cells and are the mean ± S.D. of two independent experiments.
