Effect of Fatty Acids and Prostaglandin on Androgen Receptor Binding in Human Prostatic Cancer Cells

The effect of fatty acids and delta 12 prostaglandin J2 (PGJ) on androgen ([3H]R1881) binding to human prostatic cancer cytosol was investigated with glycerol density gradient analysis and dextran-charcoal assay. The binding of androgen to the prostatic cancer cytosol receptor proteins was not modulated by saturated fatty acids such as palmitic acid (C16:0) or stearic acid (C18:0). Unsaturated fatty acids (UFAs) such as palmitoleic acid (C16:1), linoleic acid (C18:2) and arachidonic acid (C20:4) showed concentration dependent inhibition on androgen binding to the receptor. The inhibitory potency of UFAs did not parallel to the number of cis double bonds and carbon; however, C20:4 had a marked inhibitory effect on the binding. PGJ at a low concentration (9.0nM) stimulated androgen binding to the receptor up to 130% of the control value. At a higher PGJ concentration (30nM), the androgen binding was markedly reduced. The inhibitory effect of PGJ on the androgen binding was more potent than that of UFAs. The results suggest that modulation of steroid hormone action by UFAs is a general characteristic of steroid hormone target cells regardless of species differences or malignant transformation of the cells