Higher androgen levels induce growth inhibition and G1 arrest in LNCaP cells. LNCaP cells were treated for 72 h with 1 pM R1881 defined as low androgen levels (LAL) and 1 nM R1881 as supraphysiological androgen levels (SAL). A. SAL treatment inhibits growth of LNCaP cells. Cells were treated with the indicted concentrations of R1881 for three days. Cell number was determined and plotted against the untreated control. For each time point n = 4, the errors are shown in SEM. B. Viability analysis of treated cells was measured by the MTT assay. LNCaP cells were treated for 72 h with DMSO or with the indicated concentrations of R1881 following spectrometrical measurement to analyze the relative cell viability. Data represent the mean from triplets and show the cell viability in percent. C. To analyze the irreversibility of androgen-induced cellular senescence LNCaP cells were treated with SAL or LAL as well as DMSO for 72 h. Afterwards compounds were removed and cells were cultured for additional 72 h, followed by fixation and determination of the SA β-gal activity level via light microscopy at a 200x magnification. 3x 200 cells from triplets were counted and their means in percent diagramed. D. FACS analysis was performed to analyze the cell cycle state of R1881 treated cells. LNCaP cells were incubated for 72 h with solvent control or R1881 (SAL or LAL) and stained with propidium iodide followed by cell sorting analysis. The acquired FACS data were analyzed by Cylchred (Ormerod, Hoy). Counts of the different cell cycle phases were represented in percent.