OBJECTIVETo investigate the regulatory effect of cholesterol depletion on the proliferation inhibition and apoptosis of human prostate cancer PC-3 cells.

METHODSWe cultured PC-3 cells in cholesterol depletion media (CDM) or normal media (NM), and added to the media platelet-derived growth factor (PDGF) and epidermal growth factor (EGF), respectively. Then we observed cell morphology under the inverse microscope, detected cell growth inhibition by MTT assay, and analyzed cell apoptosis and cycle phase by flow cytometry.

RESULTSAfter treated with CDM for 48 hours, the PC-3 cells obviously grew rounder and smaller, with more detached ones, and their proliferation remarkably inhibited in a dose-dependent manner, while their apoptosis rate not significantly increased, as compared with those treated with NM. After exposure to PDGF or EGF, the number of cells was increased in the NM group, but there were more detached and apoptotic cells in the CDM group than in the former (P < 0.05). Cell cycle analysis showed an increase in the number of G0/G1-phase cells and a decrease in that of S- and G2/M-phase cells in the CDM group compared with the NM group.

CONCLUSIONCholesterol depletion could significantly inhibit the growth of PC-3 cells without obvious induction of their apoptosis, which is probably one of the self-regulating mechanisms of the cells avoiding apoptosis.