Androgen receptors detected by autoradiography in prostatic carcinoma and benign prostatic hyperplastic tissue

Monoclonal anti-androgen receptor antibodies: production, characterization and potential diagnostic applications

Several monoclonal antibodies (mAbs) and novel mAb-based assays for the androgen receptors (AR) have been developed. Large amounts of the recombinant human AR protein produced by a baculovirus expression system were used as an antigen to produce mAbs. Twenty-nine AR-specific mAbs were first confirmed by Western blot analysis and were then characterized for their immunoglobulin isotypes, epitopes, and epitope localization in AR. Novel assays using flow cytometry and sandwich enzyme-linked immunosorbent assays (ELISA) were established to detect AR-expressing cells and to quantify soluble AR protein, respectively. Using immunostaining, we identified several anti-AR mAbs exclusively recognizing AR within the nuclei of the prostate cancer cell line LNCaP and of prostate tissues in both frozen and paraffin-embedded sections, whereas other mAbs could detect AR in both nuclear and cytoplasmic compartments. Interestingly, certain mAbs, such as G122-25 and G122-77, could distinguish the androgen-bound AR from the unoccupied AR. In sum, many purified AR protein and anti-AR mAbs, together with the assays developed, could be powerful tools for the study of functional AR and for the diagnosis of prostatic cancers.

Histochemistry of the prostate

Histochemistry, including immunohistochemistry, is helpful to the practicing pathologist in the diagnosis of prostatic carcinoma. Of equal importance, histochemistry is being increasingly used to study the pathobiology of the prostate. This article reviews these histochemical techniques and their applications.

Androgen receptor heterogeneity in human prostatic carcinomas visualized by immunohistochemistry

Expression of the human androgen receptor was examined in 26 primary prostatic carcinomas by immunohistochemical staining with a polyclonal antibody reactive with the N-terminal domain of the human androgen receptor. Eighteen carcinomas showed homogeneous staining for the androgen receptor, whereas in seven cases a considerable heterogeneity in expression of the receptor was found. In one case, only a very limited number of immunoreactive tumour cells were detected. Comparison of androgen receptor expression with the tumour grading score, according to the MD Anderson grading system, revealed that the proportion of immunostained tumour cells and--to a lesser extent--the intensity of immunostaining were decreased in the more aggressive (grade III) tumours. The use of immunohistochemistry for detection of expression of androgen receptor in prostatic carcinomas may become a new and sensitive method for predicting prostatic tumour behaviour under hormonal therapy and prognosis.

Benign prostatic hyperplasia in a patient castrated in his youth

We report a case of benign prostatic hyperplasia in a 60-year-old patient who had been castrated when he was 30 years old. The prostatic tissue, which consisted of cystic and fibromuscular hyperplasia, contained no significant concentration of androgen receptors. Only 1 such case was reported previously in the literature.

Serum hormone levels among patients with prostatic carcinoma or benign prostatic hyperplasia and clinic controls

This study sought to identify differences in serum hormone levels between prostatic cancer (CaP) patients, benign prostatic hyperplasia (BPH) patients, and clinic controls (CC). Serum testosterone, estradiol, and prolactin values were obtained from 35 CaP, 42 BPH, and 161 CC patients attending a single medical center between January 1984 and April 1985. Relative risk estimates adjusted for age and race were calculated to compare hormone values between each case group and the CC. The distributions of hormone values and the testosterone to estradiol (T/E) ratios were grouped into thirds with the lowest third forming the reference category. The relative risk estimates for BPH in the middle and high thirds of testosterone were greater than unity (1.26 and 2.10, respectively), whereas the relative risk estimates in the middle and high thirds of estradiol were less than unity (0.63 and 0.35, respectively). For the middle and high thirds of the T/E ratio, the relative risk estimates for BPH showed statistically significant three- to fourfold increases. Modest depression of serum testosterone and estradiol was noted for CaP patients compared to CC, although the differences were not statistically significant. This depression was interpreted to be a likely result of the malignant process rather than a cause of it, whereas the development of clinically evident BPH was felt to be a biologically plausible response to an elevated T/E ratio.