G1T28 inhibits cell-cycle progression in models of prostate cancer. A, LNCaP, VCaP, or 22Rv1 cells were plated in media containing 10% FBS and treated with increasing concentrations of enzalutamide, docetaxel, palbociclib, or G1T28 (10−10-10−4.3 mol/L) and measured for cell viability by Hoechst staining after 5 to 7 days of treatment. B and C, LNCaP, VCaP, or 22Rv1 cells were plated in media containing 10% FBS with increasing concentrations of G1T28 (10−9.5-10−6 mol/L) for 24 hours and then stained with PI for cell-cycle analysis (B) or fixed, permeabilized, and stained for phospho (Ser 807/811) and total Rb using a LI-COR Odyssey Clx imager (C). Dose–response curves were generated from densitometry of the phospho and total retinoblastoma expression using LI-COR Image Studio software. Data are representative of at least three independent experiments.