In vitro effects of prostaglandins on human retinoblastoma cell line, Y-79 cells.

Prostaglandins (PGs) and their derivatives have been reported to modulate or inhibit a variety of tumor cells in vitro and in vivo. In the present study, an established retinoblastoma cell line, Y-79, was investigated for 1) its capacity to synthesize PGs and 2) its susceptibility to PGs and their derivative, 64E, exogenously given. The capacity of Y-79 cells to produce PGs was estimated by thin layer chromatography using [1-14C] arachidonic acid as a substrate, and it was found that no detectable amounts of PGD2, PGE2, PGF2 alpha, thromboxane B2, or 6-keto PGF1 alpha were produced by Y-79 cells. Furthermore, the effects of exogenously given PGs (PGA1, A2, D2, E1, E2, F2 alpha, and J2) and 64E on the cell proliferation of Y-79 cells in culture were examined. PGE1, E2, and F2 alpha showed no significant effects on the cell growth of Y-79 cells at all tested doses (1-20 micrograms/ml). On the other hand, PGA1, A2, D2, and J2, and 64E remarkably inhibited the cell growth of Y-79 cells. A dose-response study indicated that 64E was the most effective among these drugs, followed by PGJ2. PGD2, A1, and A2 were less effective than PGJ2. The present data demonstrate that Y-79 cells do not produce endogenous PGs, and that these cells are highly susceptible to exogenous PGs (PGJ2, D2, A1, and A2) as well as 64E.