p,p'-DDE increases G0/G1-S transition of CAMA-1 cells in the presence of 17β-estradiol (E2) and dihydrotestosterone (DHT). Treatment-related changes are shown for the percentage of cells in S (a), G0/G1 (b), and G2/M (c) phases. Synchronization of the cells – 90% of cells in G0/G1 and less than 3% in S phase – was induced by a 48-hour serum deprivation period. Cells were subsequently treated during 24 hours with hormones and antiandrogens (or their vehicles). Each bar represents the mean ± standard error of the mean of four independent experiments in duplicate. Single asterisk indicates P < 0.05, double asterisk P < 0.01, and triple asterisk P < 0.001 versus control, † indicates P < 0.05 versus E2 treatment, and ‡ indicates P < 0.05 versus E2+DHT treatment as determined by an analysis of variance with specific contrasts. OHF, hydroxyflutamide; p,p'-DDE, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene.