Fig. 1. Effect of daily treatment with DHT (100 nM) on levels of M₁dG (A) or 8-oxo-dG (B) in DU145, PC3 and LNCaP cells grown in medium. Open bars denote untreated cells and closed bars denote treated cells. Cells (approximately 10⁶) were seeded in flasks and grown for 3 days in medium containing 10% foetal calf serum. DHT was then added daily for 7 days. Results (mean + SD) are presented from three separate experiments. Asterisks indicate that the difference is significant compared to control cells (P < 0.05 by ANOVA in A; P < 0.01 by Mann–Whitney test in B). For details of cell culture and measurement of M₁dG and 8-oxo-dG, see Section 2.

Fig. 2. Concentration dependence of effect of DHT on levels of M₁dG (A) or 8-oxo-dG (B) in LNCaP cells. Oxidative DNA adduct levels in incubations of cells omitting DHT are denoted “control” (open bars). Cells (approximately 10⁶) were seeded in flasks and grown for 3 days in medium containing 10% foetal calf serum. DHT was then added daily for 7 days. Results (mean + SD) are from three experiments. Stars indicate that the difference to respective control cells is significant (P < 0.05 by ANOVA). For details of cell culture and M₁dG or 8-oxo-dG measurements, see Section 2.

Fig. 3. Effect of flutamide (10 μM) on increase in M₁dG (A) or 8-oxo-dG (B) caused by DHT (100 nM) in LNCaP cells. Oxidative DNA adduct levels in incubations of cells omitting DHT are denoted “control” (“C”, open bars). Cells (10⁶) were seeded in flasks and grown for 3 days in medium containing 10% foetal calf serum. Unlike the data shown in Fig. 1 and Fig. 2, cells were then grown in serum-free medium with or without the daily addition of flutamide and/or DHT for 4 days. Results (mean + SD) are from three experiments. Stars indicate that difference to control cells is significant, crosses indicate that the difference to cells incubated with DHT alone is significant (P < 0.05 by ANOVA). C, control; Flut, flutamide. For details of cell culture and M₁dG and 8-oxo-dG measurements, see Section 2.

Fig. 4. Effect of treatment with flutamide (50 mg/kg ig) daily for 7 days on tumour volume and serum PSA in athymic MF1 mice bearing the LNCaP tumour. Open bars: control mice. Closed bars: treated mice. Results are presented as percentage change from pre-dosing volume/levels. In untreated animals, the mean terminal tumour volumes and PSA concentrations were 506 ± 476 mm³ and 57 ± 31 ng/mL (mean ± SD, n = 12), respectively. When original pre- and post-dose values were compared, the difference was statistically significant (P < 0.001 by ANOVA) for both types of measurements. For details of tumour implantation and analyses of tumour volume and PSA, see Section 2.

Fig. 5. Representative photomicrographs of LNCaP tumours from control mice (A) and mice that received flutamide (50 mg/kg ig) daily for 7 days (B). Haematoxylin and eosin stain, magnification 250×. Areas of focal necrosis and cell debris are demonstrated by arrows in B.

Fig. 6. Effect of treatment with flutamide (50 mg/kg ig) daily for 7 days on M₁dG levels in xenografted prostate tumour, normal prostate tissue and blood leukocytes from non-tumour-bearing mice or mice bearing LNCaP tumours. Open bars: control tumour-bearing mice (treated with vehicle only). Hatched bars: non-tumour-bearing mice (treated with vehicle only). Closed bars: tumour-bearing mice treated with flutamide. Results are mean ± SD from 12 mice. Stars indicate that the difference to control mice is significant (P < 0.001 by Mann–Whitney test). For details of tumour implantation and measurement of M₁dG levels, see Section 2.