Autoradiographic localization of estrogen and androgen target cells in human and rat prostate carcinoma

The distribution of estrogen target cells within the Dunning R3327-H rat prostate tumor following intravenous injection of tritiated estradiol into rat hosts was compared to the distribution obtained following incubation of a 2 mm. sample of the tumor with tritiated estradiol in organ culture. No difference was observed, indicating that the in vitro method was an effective approach for autoradiographic analysis of tumor biopsy samples. Subsequently, tumor samples were excised from solid tumors of R3327-H and R3327-MAT LyLu tumors growing in Copenhagen rats. These tumor models were chosen as representatives of hormone sensitive (R3327-H) and hormone insensitive (R3327-MAT LyLu) tumors. Normal rat dorsal prostate and human tumor biopsy samples were also studied. Autoradiographic studies were performed in vitro utilizing tritiated estradiol and tritiated dihydrotestosterone to compare the distribution of estrogen and androgen target cells. The present research demonstrated that 1) similar patterns of nuclear uptake of steroids are obtained with in vivo and in vitro autoradiographic techniques, 2) estradiol receptors occur primarily in extra-acinar epitheloid cells in both rat and human prostate carcinomas, 3) these epithelioid cells are not characteristic of the normal rat dorsal prostate, 4) androgen receptors occur in both acinar and stromal epithelioid cells in rat and primarily in acinar epithelial cells in human tumors and 5) in vitro autoradiographic methods can provide insight into differences in sensitivity to steroids which may be of diagnostic importance in the treatment of cancer.