5,8,11,14-eicosatetraynoic acid inhibits PC3 DNA synthesis and cellular proliferation, in part due to its 5'-lipoxygenase activity.

5,8,11,14-eicosatetraynoic acid (ETYA), a competitive analogue of arachidonic acid reversibly inhibited human prostate PC3 DNA synthesis at 4 h. This was not due to reduced cellular viability, as judged by several criteria, and resulted in reduced cell numbers at 72 h. Several less specific inhibitors of 5'-lipoxygenase, and A63162, a highly specific inhibitor, reduced labeling of DNA with 3H-thymidine. A23187, a calcium ionophore, reduced DNA synthesis, and ETYA rapidly increased [Ca2+]i measured with the Fura II technique. Comparison of the biochemical events evoked by ETYA and A63162 should identify those required for the downregulation of DNA synthesis.