Modulation of growth and apoptosis response in PC-3 and LNCAP prostate-cancer cell lines by Fas.

Fas/APO-1 is a cell-surface protein, a member of the TNF-receptor family, and it potentially induces apoptosis. In presence of an apoptosis-inducible anti-human Fas MAb, Fas-negative control PC-3 human prostate-cancer cells did not undergo morphological changes, while PC-3 human Fas transfectants showed apoptotic changes in vitro. However, LNCaP human Fas transfectants, as well as Fas-negative control LNCaP human prostate-cancer cells, were Fas-resistant. The growth of Fas-transfected PC-3 tumor was retarded compared with that of control PC-3 tumor in vivo without stimulation of anti-human Fas MAb. Anti-human Fas MAb administration in vivo caused macroscopic Fas-transfected PC-3 tumors formed in BALB/c nude mice to undergo apoptosis.