Androgen receptor assays in specimens of prostatic tissue obtained by transurethral resection and transvesical adenomectomy

Androgen receptor status in nontumoral and malignant human colorectal tissues

Data on androgen receptor (AR) status of nontumoral and malignant human colorectal tissues are compared using ligand binding assay in 22 patients who underwent surgery for colorectal cancer at the "M. Ascoli" Cancer Hospital Centre in Palermo, Sicily. In nontumoral tissues, ARs were predominantly (67%) positive, with 25% of cases having a 0/+ status. Conversely, malignant tissues showed only 32% of cases with a positive (+/+) AR status, with a proportional increase of 0/+ cases (from 25% to 55%); the extent of AR-negative (0/0) cases remained fairly constant (8-9%). Overall, our evidence indicates that nontumoral colorectal tissues have a predominantly positive (+/+) AR status and that this condition shifts towards a significant decrease of AR-positive cases in cancer tissues. Studies on the relation between status of sex steroid receptors and specific biomolecular markers in human colorectal tumors are currently being carried out in our laboratories.

Endocrine end-points in rheumatoid arthritis

Our previous studies are reviewed and at the same time preliminary experimental observation to the topic of endocrine end-points in autoimmune disease is introduced. To this end, we have used rheumatoid arthritis (RA), including synovial fluids and primary cultures of synovial macrophages, as a model system in order to investigate (a) expression and subcellular localization of high-affinity sites of steroid binding in immune effector cells; (b) steroid metabolic profiles in both male and female RA patients, as compared to healthy subjects; and (c) activities of key steroid enzymes that govern intratissue accumulation of sex hormones. In RA tissues and cells, the concurrent evidence for (1) androgen and/or estrogen receptors, (2) high concentrations of biologically active steroids, (3) key enzymes of steroid metabolism, and (4) significant changes of estrogen to androgen ratio, all strongly suggests that individual immune cells, including synovial macrophages, may behave as steroid-sensitive cells, namely, they may represent a target for sex steroids, supporting the hypothesis of a potential endocrine regulation of the immune response also in RA disease. In this respect, definition of several endocrine end-points may have important implications for the treatment of rheumatic disease and other immunological disorders.

Steroid-growth factor interaction in human prostate cancer. 1. Short-term effects of transforming growth factors on growth of human prostate cancer cells

In order to better define potential mechanisms of growth regulation in human prostate cancer cells, we have compared biological responses (such as short-term response to both transforming growth factor alpha and beta; TFG alpha and TFG beta) in relation to hormone sensitivity of LNCaP, DU145, and PC3 cells. Androgen receptor (AR) and epidermal growth factor receptor (EGF-R) content of each cell line was also investigated. In addition, expression of EGF, TGF alpha, and TGF beta was evaluated through immunofluorescent staining. Growth of androgen non-responsive PC3 cells was stimulated by TGF alpha (about 35%) and inhibited by TGF beta (more than 50%), with respect to controls, after 48 h exposure. Conversely, AR-positive, hormone-responsive LNCaP cells proved to be poorly sensitive, at least short-term, to either growth factor. Furthermore, high levels of both EGF-R and TGF alpha, and a fairly high amount of EGF, were found in DU145 cells and, to a lesser extent, in LNCaP cells; in contrast, PC3 cells exhibited low expression levels of both receptors (EGF-R) and ligands (EGF, TGF alpha), but displayed remarkable TGF beta binding and relatively high levels of endogenous TGF beta. Overall, these results suggest a differential sensitivity to TGF alpha and TGF beta by prostate cancer cells; TGF alpha response seems not to be proportional to the EGF-R content of individual cell lines.

Presence of estrogen-binding sites on macrophage-like synoviocytes and CD8+, CD29+, CD45RO+ T lymphocytes in normal and rheumatoid synovium

OBJECTIVE

To study the presence of estrogen-binding sites (EBS) in the synovial tissues of male and female patients with rheumatoid arthritis (RA) and in age- and sex-matched healthy controls.

METHODS

Both type 1 (high affinity, low binding capacity) and type 2 (reduced affinity, higher binding capacity) EBS were investigated in both soluble and nuclear fractions of homogenized synovial tissue samples by a dextran-coated charcoal method. To determine what type of synovial cell was positive for EBS, cryosections of synovial tissues were immunostained with a specific monoclonal anti-estrogen receptor antibody (anti-ER MAb) using both immunofluorescence and immunoperoxidase techniques. Double immunostaining with the anti-ER MAb and with specific MAb to detect different macrophage antigens (Ber-MAC3, MAC387, CD68) and CD8+ T cell subsets (CD29+, CD45RO+ and CD29-, CD45RO-) was performed.

RESULTS

Higher affinity EBS were found mostly in nuclear cell fractions of either RA or control synovial tissues (28 of the 33). These EBS were present to a lesser extent in soluble cell fractions (11 of the 33). Immunostaining showed the estrogen receptor-positive cells to be the macrophage-like synoviocytes and the CD8+, CD29+ T cells both in RA and in control synovial tissues. Higher nuclear content of EBS was consistent with more intense nuclear staining of synoviocytes and T cells.

CONCLUSION

It is conceivable that the immunomodulatory activity exerted by estrogens is at least partly mediated through their interaction with EBS that are present on macrophage-like synoviocytes, functioning as antigen-processing and antigen-presenting cells, and on antigen-experienced (memory) CD8+ T lymphocytes (CD29+, CD45RO+).

Evidence for the presence of androgen receptors in the synovial tissue of rheumatoid arthritis patients and healthy controls

OBJECTIVE

To study the presence of androgen receptors in the synovial tissue of male and female patients with rheumatoid arthritis (RA) and matched healthy controls.

METHODS

Both site I (high affinity, low binding capacity) and site II (reduced affinity, higher binding capacity) androgen receptors were investigated in soluble and nuclear fractions of homogenized synovial samples, using the dextran-coated charcoal method. The finding of pure, high-affinity site I receptors in both fractions was considered indicative of androgen receptor positivity. In order to determine what type of synovial cell was positive for androgen receptors, cryosections of synovial tissues were immunostained with a specific monoclonal anti-androgen receptor antibody (MAb), using both immunofluorescence and immunoperoxidase techniques. Double immunostaining with this MAb and specific MAb directed toward different macrophage/granulocyte antigens was also performed.

RESULTS

Remarkable differences were found between male and female controls: Most males were positive for androgen receptors, and most females were negative. The fetomolar content of androgen receptor in the nuclear fraction was fairly constant, but the soluble fraction showed a higher femtomolar concentration in female RA patients than in controls of either sex, as well as in male RA patients compared with female RA patients. The androgen receptor-positive cells in both RA and control synovial cryosections were found by immunostaining to be macrophage-like synoviocytes, and were also found to be HLA-DR positive.

CONCLUSIONS

The immunosuppressive action exerted by androgens might, at least in part, be mediated through their interaction with macrophage-like synoviocytes functioning as antigen-processing and antigen-presenting cells in rheumatoid synovia.

Soluble and nuclear type I and II androgen-binding sites in benign hyperplasia and cancer of the human prostate

This paper presents an approach for the assessment of the androgen receptor (AR) status in benign prostatic hyperplasia (BPH) and prostate cancer (PCa) tissues. Evaluation of AR was carried out in both soluble and nuclear fractions by a standard competition method, using tritiated mibolerone as radioligand. Based on our experience with breast and endometrial cancer, this approach focused on both type I (high affinity, low capacity) and type II (reduced affinity, higher capacity) binding sites, aiming mainly at establishing a putative "functional" receptor mechanism, i.e., the presence of type I AR in both cytosol and nucleus. Ancillary studies were carried out to exclude a potential overestimation of the AR content by interference with other steroid receptors, namely, progesterone (PgR) or glucocorticoid (GcR) receptors. Results showed that the interaction by PgR or GcR upon AR measurement was not relevant. The distribution of AR, namely the percent of positivity either in a single or in both cell compartments, was not significantly different in BPH (N = 32) or PCa (N = 24) tissues. For type I binding, the percent of positivity in both soluble and nuclear fractions (i.e., the "functional" AR status) was very close to that observed for other endocrine-related tumors, like breast cancer. Concentrations of type I AR appeared significantly higher in PCa than in BPH tissues; this was true for both soluble and nuclear fractions. In contrast, no significant difference was found in type II AR concentrations in either cell fraction.(ABSTRACT TRUNCATED AT 250 WORDS)