Basal and estrogen-stimulated hormone receptor profiles in four R3327 rat prostatic carcinoma sublines in relation to histopathology and androgen sensitivity.

Four sublines (H, HI, G, and AT) of the R3327 (Dunning) rat prostatic carcinoma have different androgen sensitivities and histopathological characteristics. In order to investigate whether these characteristics were associated with differences in the hormone receptor profile and its response to estrogen, we carried out Scatchard analysis on the cytosolic (C) and high-salt nuclear-associated (N) androgen (AR), estrogen (ER), and progesterone (PgR) receptor in each line, carried in control and diethylstilbestrol (DES)-treated animals. In the H line (androgen sensitive, well differentiated) DES treatment resulted in significant increases in total cellular AR and ER, in redistribution of both receptors between the C and N fractions, and in a marked increased of PgR (greater than 10-fold). The hormone receptor profile and its response to DES was similar in the HI line (androgen insensitive, well differentiated), except that total cellular ER was not increased after treatment. The G line (androgen sensitive, poorly differentiated) contained higher basal concentrations of AR and PgR than the H line, but the concentrations were not increased by DES treatment, although treatment promoted association of ER with the nuclear fraction. The AT line (androgen insensitive, anaplastic) contained no ER and negligible PgR, but AR was present, although in lower concentrations than in the other lines. Diethylstilbestrol treatment had no effect on the concentration, although redistribution of AR between C and N fractions did occur. Some characteristics of the AR in the AT line differed qualitatively from that in the H line, but injection of testosterone into castrated animals bearing the AT tumor promoted association of AR with the nuclear fraction, indicating normal activation. The data suggest that the ability of DES treatment to increase AR and PgR concentrations is associated with differentiation and/or the presence of stroma and that it is unrelated to androgen sensitivity.