Effects of 2-methoxyestradiol on proliferation, apoptosis and PET-tracer uptake in human prostate cancer cell aggregates.

The purpose of this study was to investigate the potential use of PET in vivo to record cytotoxic effects of 2-methoxyestradiol (2-ME), an endogenous metabolite of 17beta-estradiol. The anti-proliferative and pro-apoptotic effects of 2-ME on human prostate cancer cell (PC3) aggregates in vitro, were correlated with the uptake of fluoro-deoxy-D-glucose, FMAU and choline labelled with 18F, 11C, or 3H. 2-ME clearly reduced growth of PC3 aggregates and induced apoptosis in a dose-dependent manner. However, the uptake of the putative proliferation markers 11C-FMAU or 3H-choline failed to record the growth inhibitory effects of 2-ME on PC3 cell aggregates. The uptake of 18F-FDG was used as a marker for effects on cellular metabolism and also failed to show any dose-dependent effects in PC3 aggregates. The use of these PET-tracers in vivo is therefore not recommended in order to evaluate the cytotoxic effects of 2-ME on human prostate cancer cells.