EFFECTS OF INTERFERON-BETA ON STEROID-RECEPTORS, PROSTAGLANDINS AND ENZYMATIC-ACTIVITIES IN HUMAN ENDOMETRIAL CANCER

Steroid receptors, prostaglandin output and enzymatic activities were determined in explants derived from human endometrium exposed to natur al interferon-beta (TFN-beta). Receptors and cell metabolism were eval uated before culturing the tissue fragments and after a 3-day treatmen t with varying concentrations of IFN-beta. Total steroid receptor leve ls were unchanged when explants were set up, but there was a redistrib ution of both estrogen and progesterone receptors (ER and PR). A decre ase in cytoplasmic receptors corresponded to an increase in receptor m olecules within the nucleus. Treatment with low concentrations of IFN- beta caused a significant enhancement (p < 0.05) of ER and PR in neopl astic endometrium. In basal conditions the ratio between prostaglandin F2 alpha (PgF2 alpha) and prostaglandin E2 (PgE2) was higher in norma l than in neoplastic endometrium. The addition of low concentrations o f IFN-beta to the culture medium determined a significant increase (p < 0.02) in PgF2 alpha and a parallel increase in the above ratio in ne oplastic tissue, whilst no variation was found in normal endometrium. Analysis of the results concerning the variations in hormone-related e nzymatic activities due to IFN-beta revealed a significant increase (p < 0.05) in 17 beta-Hydroxy-steroid-dehydrogenase (17 beta-HSD) activi ty. The data presented here indicate that treatment with IFN-beta modi fies those biological characteristics of neoplastic cells which are in volved in hormone-responsiveness.