Single-cell ATAC and RNA sequencing reveal pre-existing and persistent cells associated with prostate cancer relapse.

Prostate cancer is heterogeneous and patients would benefit from methods that stratify those who are likely to respond to systemic therapy. Here, we employ single-cell assays for transposase-accessible chromatin (ATAC) and RNA sequencing in models of early treatment response and resistance to enzalutamide. In doing so, we identify pre-existing and treatment-persistent cell subpopulations that possess regenerative potential when subjected to treatment. We find distinct chromatin landscapes associated with enzalutamide treatment and resistance that are linked to alternative transcriptional programs. Transcriptional profiles characteristic of persistent cells are able to stratify the treatment response of patients. Ultimately, we show that defining changes in chromatin and gene expression in single-cell populations from pre-clinical models can reveal as yet unrecognized molecular predictors of treatment response. This suggests that the application of single-cell methods with high analytical resolution in pre-clinical models may powerfully inform clinical decision-making.

Altered levels of Smad2 and Smad4 are associated with human prostate carcinogenesis.

Alterations have been demonstrated in ligand and cognate receptor system of the transforming growth factor beta (TGF-beta) pathway in prostate cancer (PC). Still, little is known about changes in the activity of the intracellular Smad cascade of TGF-beta signaling during prostate carcinogenesis. We used immunohistochemistry to analyze phosphorylated Smad2 (p-Smad2), nuclear Smad4 and inhibitory-Smad7 in epithelial cells of normal, hyperplastic and malignant prostate. Specimens comprised 49 tissue cores of PC, 10 benign prostate hypertrophies and three normal prostates. Nuclear p-Smad2 (P<0.001) and nuclear Smad4 (P=0.023) were significantly decreased in PC with remarkable variations in cytoplasmic Smad7 levels. Substantial decreases in p-Smad2 and Smad4 levels were found in specimens with primary Gleason grades 3 and 4, whereas in grade 5, levels were markedly higher. Our results provide the first evidence for changes and reversible attenuation in the Smad system of the TGF-beta pathway during prostate carcinogenesis.

Location of androgen receptor in human skin.

The distribution of androgen receptor (AR) in human skin was studied by an immunohistochemical method using a polyclonal antibody against the human AR. Skin samples of preputial skin and male and female nongenital skin were examined. The possible correlation of AR location to acne was studied in skin biopsies from skin areas affected or unaffected by acne. In preputial skin, AR was expressed in epidermal cells as well as in fibroblasts, smooth muscle cells, and endothelial cells of blood vessels in the dermal area. AR was found located also in the flat fibroblast-like cells of Pacinian corpuscles. In nongenital skin, AR was also expressed in the basal cells and glandular cells of sebaceous glands, in the outer root sheath of hair follicles, and in eccrine sweat glands. The presence of AR in different cell types in the skin reflects the numerous direct effects androgens may have on this target tissue. The distribution of AR was similar in male and female skin.

Activin beta A- and beta B-subunit expression in the developing chicken bursa of fabricius.

The bursa of Fabricius (BF) is a site for B-lymphocyte maturation in birds. The BF is also known to function as an endocrine organ, with regulatory effects on steroid-secreting glands (testes, ovaries, and adrenal glands) during embryonic development. To study the possible involvement of the growth and differentiation factors, inhibins and activins, in bursal differentiation and function, the expression of inhibin/activin subunits in chicken BF was examined using specific antibodies against inhibin/activin alpha-, beta A-, and beta B-subunits. Bursae from chickens from 11 days of embryonic development until 22 weeks after hatching were studied. Immunoreactive beta A- and beta B-subunits were demonstrated in bursal epithelial cells throughout the time period studied. Immunoreactivities for both subunits were most intense and widespread from day 18 of embryonation until 1 week after hatching. Inhibin alpha-subunits were not detected. Partially different locations were shown for beta A- and beta B-subunits, suggesting different roles for activin-A (beta A beta A homodimer) and activin-B (beta B beta B homodimer) in bursal development and function. As activin beta A-subunit immunoreactivity was predominantly localized in medullary epithelia, it may be assumed that the developing B-cells within follicular medullae might be the target for activin-A action in the chicken BF. The most conspicuous site for activin-B production, on the other hand, was the follicle-associated epithelium, which is able to take up antigens from the cloacal environment and pass them to medullary cells. The data suggest that activin-A and -B may have different roles in modulating bursal microenvironment during B-lymphocyte differentiation. The possible role of bursal activins in the regulation of steroidogenesis in birds is discussed.

Change in location and processing of inhibin alpha-subunit precursors during sexual maturation of the Djungarian hamster testis.

Immunohistochemical location and immunoblot of inhibin alpha-subunit peptides were analyzed in the testis of the Djungarian hamster from days 0-31 of postnatal development using a specific antibody. An intense immunoreaction was observed in the centrally located T1 prespermatogonia at day 0. The staining intensity decreased gradually in the spermatogonia when they make contact with the basal lamina at days 8-10. At days 13 and 15 there is no staining. Thereafter the immunoreactivity in Sertoli cells as well as in A spermatogonia gradually increased, being highest in sexually mature animals. The intensity of alpha-subunit staining in the seminiferous tubules was stage specific, being strongest at stages III and IV. Immunoblot analysis of testis homogenates with the anti-INH alpha 1-32 antibody showed several bands: 88K, 80K, and 43K in immature hamster testis (0-, 2-, 6-, 8-, or 10-day-old). In the adult hamster (31-day-old) 88K, 80K, 28K, and 20K bands were seen, but no 43K band. Dimeric inhibin was not detected. The 43-44K band most likely corresponds to the pro-alpha N alpha C, the 28K band to intermediate forms between alpha N alpha C and alpha C (alpha I alpha C), and the 20K band to mature alpha-subunit (alpha C). The shift from the immature pattern to mature occurs at about 20 days of age. Freezing of the samples was deleterious to alpha C, since it could be detected only in freshly homogenized samples. The results suggest that prespermatogonia produce predominantly monomeric alpha-subunit precursor pro-alpha N alpha C, whereas the mature Sertoli cells as well as A spermatogonia contain mainly monomeric alpha I alpha C. The alpha-inhibin precursors may act as auto-/paracrine regulators of spermatogenesis. Our results suggest that different alpha-subunit precursors, pro-alpha N alpha C and alpha I alpha C, might be involved in the differentiation and maintenance of spermatogenesis, respectively. The posttranslational processing of alpha-subunit precursors seems to play an important role in the physiology of reproduction.

Estrogen and prolactin regulation of rat dorsal and lateral prostate in organ culture.

Besides androgens, estrogen (E) and PRL are thought to have important roles in the regulation of the growth and function of the prostate. We have established organ cultures of rat dorsolateral prostate for the analysis of the multiple hormone actions. Explants of dorsal prostate (DP) and lateral prostate (LP) were cultured in a serum-free basal medium containing insulin and corticosterone with or without the hormones studied. The viability and overall integrity of the tissues were maintained for at least 14 days. The morphology of the explants showed castration-like changes in the basal medium, but the addition of testosterone (T) prevented them. Androgen receptors in the prostate cultured with T were demonstrated by immunohistochemistry. When the explants were grown with E the epithelium became stratified, and the cells were flat. The epithelium was also layered when the explants were grown with PRL, but the epithelial cells were hypersecretory and large. The glandular morphology of the cultured prostate was, however, best preserved if T was added along with E or PRL. The wet weights and DNA contents of the explants declined during the culture, but they were better maintained if T, E, or PRL were added to the medium. The rate of DNA labeling with [3H]thymidine was activated in the cultured explants, but it was higher in those grown with T, E, or PRL than in those grown in the basal medium. The tissue specific functions were evaluated by measuring the expression of the genes RWB and M-40.3 encoding androgen-regulated secretory proteins. The steady state levels of RWB and M-40.3 mRNA were low in the explants grown in the basal medium but in the presence of T they were high. E and PRL also increased the expression of RWB and M-40.3 messenger RNA, although the responses in DP and LP were somewhat different. The antihormones cyproterone and toremifene opposed the increase of M-40.3 messenger RNA by T and E, respectively. The results show that the cultured DP and LP of the rat maintain the androgen responsiveness and tissue-specific functions in vitro. In addition, E and PRL have androgen-independent, direct effects in them. Rat dorsolateral prostate in culture thus provides a useful model for the studies on the mechanisms of hormone regulation of the prostate.

Development and evaluation of an immunoenzymometric assay for the chicken progesterone receptor.

A specific and sensitive immunoenzymometric assay (IEMA) was developed for measuring the quantity of chicken progesterone receptor (PR) in tissue cytosol. The assay uses two monoclonal antibodies to the PR. One is used to capture the PR. The second (labelled with biotin) reacts first with the captured receptor and subsequently with avidin-labelled horseradish peroxidase to provide an enzymatic end-point. The method has a determination range from 0.3 to 60 pmol/l. Intra- and interassay coefficients of variation were 3.7% and 9.0% respectively. The assay can be performed with equal results as a rapid (3 h) or an overnight procedure. The IEMA is convenient, especially for signal measurement and the calculation of results. No ultracentrifugation of samples is needed, since the IEMA can be performed on low-speed cytosol samples. Assay results correlated well (r = 0.927) with those obtained by the conventional ligand-binding assay used in our laboratory. Similar results were obtained with the IEMA and the ligand-binding assay after exposure of cytosol samples to increased temperatures: at 20 degrees C the PR remained stable for the 4-h period examined, whereas at 37 degrees C almost complete degradation of the PR was observed in 30 min. Being more than 100 times as sensitive as the ligand-binding assay, the IEMA enabled the quantification of PR for the first time in such tissues as the bursa and small intestine even of immature animals.

Inhibin A, B and pro-alphaC in serum and peritoneal fluid in postmenopausal patients with ovarian tumors.

OBJECTIVE: To compare serum and peritoneal fluid concentrations of inhibin A, B, and pro-alphaC in women with ovarian tumors. METHODS: Serum and peritoneal fluid samples were taken from 41 postmenopausal women operated on for an ovarian tumor. Twenty-one patients with endometrial cancer formed a control group. Serum and peritoneal fluid inhibin A, B, and pro-alphaC concentrations, and serum FSH and tumor marker CA 125 (study group only) concentrations were analyzed. RESULTS: Inhibin A was found in low concentrations (median 4.1pg/ml, range <2-29pg/ml) in serum in most postmenopausal patients with epithelial ovarian carcinoma, whereas inhibin B was not measurable. Inhibin pro-alphaC circulated in high concentrations (median 125pg/ml, range 37->1000pg/ml). All inhibins were found in clearly greater concentrations in the peritoneal fluid than in serum. International Federation of Gynecology and Obstetrics (FIGO) stage III-IV and poor differentiation grade were associated with significantly lower concentrations of inhibin A and pro-alphaC in the peritoneal fluid compared with stages I-II or low grade. This correlation was not found in the serum concentrations of inhibin A or pro-alphaC. In the control group, no dimeric inhibins were found in serum, and pro-alphaC circulated in median concentrations of 47pg/ml (range 12-174pg/ml). CONCLUSIONS: Postmenopausal patients with epithelial ovarian tumors had low concentrations of inhibin A and relatively high concentrations of inhibin pro-alphaC in serum. The peritoneal fluid concentrations of all inhibins far exceeded those in the serum. Relatively low concentrations of inhibin A and pro-alphaC in the peritoneal fluid of patients with ovarian cancer seem to be associated with high stage and grade and, to a lesser degree, with positive peritoneal cytology.

Subcellular location of androgen receptor in rat prostate, seminal vesicle and human osteosarcoma MG-63 cells.

Location of the androgen receptor (AR) before and after dihydrotestosterone (DHT) administration was studied in 6 castrated and 2 normal male rats, as well as in MG-63 human osteosarcoma cell culture. Two days after castration, rats were injected with DHT and sacrificed 0, 6 and 24 h later. Cryosections of ventral prostate and seminal vesicle were stained with a polyclonal anti-AR antibody. Cultured MG-63 cells were also stained similarly. The intensity of immunoreaction was measured semiquantitatively by computer-assisted image analysis. In both normal and castrated rats, a positive reaction was seen mainly in the nuclei of epithelial cells and stromal cells of the prostate and seminal vesicle, as well as in those of smooth muscle cells of the seminal vesicle. AR immunoreactivity was up-regulated by DHT, it decreased clearly in both organs after castration. Nuclear AR and its up-regulation by androgen were also seen in MG-63 cells. At the immunoelectron microscopy, silver enhanced gold particles were predominantly found in the heterochromatin of cell nuclei. Treatment with DHT caused a decondensation of the heterochromatin and AR was more dispersed. Thus, AR appears to be nuclear independently of the ligand.

The effect of dihydrotestosterone on the estrogen-induced cytodifferentiation of the chick oviduct.

The androgenic effects on the estrogen-induced cytodifferentiation of the chick oviduct epithelium were investigated. Dihydrotestosterone was shown to have an effect on the organization of stromal cells. Since these cells contained androgen receptor (AR), it is reasonable to assume an involvement of androgens in the differentiation and functioning of these cells through a direct action. Immunohistochemical analysis revealed a wide distribution of AR. AR was shown to be expressed in both the endothelial and smooth muscle cells of blood vessels. In the immature oviduct AR was located in the epithelial, mesenchymal and mesothelial cells. In the differentiating oviduct, whether induced by exogenous estrogen or normally by endogenous hormones, AR was also expressed by the tubular gland cells. Dihydrotestosterone alone had no effect on the morphology of the immature oviduct, suggesting the involvement of the determinants of differentiation in the action of androgen together with estrogen.

Spermatogenesis in the vitamin A-deficient rat: possible interplay between retinoic acid receptors, androgen receptor and inhibin alpha-subunit.

In order to understand the mechanisms of retinol action on the testis, testicular retinoic acid receptor alpha, beta(RAR alpha and beta), androgen receptor (AR) and inhibin alpha-subunit were studied in normal, vitamin A-deficient (VAD) and vitamin A-supplemented rats by immunohistochemistry and immunoblotting. Compared to the normal testis, expression of 110 K AR was up-regulated by vitamin A withdrawal, whereas 51 K RAR alpha remained unchanged. An additional 55 K RAR alpha signal was observed. Readministration of retinol caused a marked decrease of AR in the VAD testis. By 24 h, AR declined to below the normal level. Although the 51 K RAR alpha signal remained unchanged, the 55 K band was slightly up-regulated at 6 h after retinol administration. A 51 K RAR beta protein was seen in the VAD but in not the normal testis. The intensity of the 51 K RAR beta band remained constant before and after the administration of retinol, but it had a slight up-shift at 6 h after retinol injection, suggesting post-translational modification of the receptor. The inhibin alpha-subunit of 18 K protein was undetectable in the VAD testis and increased to above normal level at 24 h after retinol administration. Immunohistochemically, nuclear AR immunostaining was more intense in the VAD testis than in the normal testis. The intensity of immunostaining declined in all AR-positive cells after the injection of retinol, but the decrease was more evident in Sertoli than in other cells. At 24 h after retinol the immunostaining was undetectable in most Sertoli cells. The regulation of the inhibin alpha-subunit by retinol in the cytoplasm of Sertoli cells detected by immunohistochemistry was correlated to the results in immunoblotting. These results suggest a possible interplay between retinoids, androgen and inhibin signalling systems in Sertoli cells in the regulation of spermatogenesis during retinol action.

Localization of 1,25-dihydroxyvitamin D3 receptor (VDR) expression in human prostate.

1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has been found to have a variety of physiological functions, including effects on growth and differentiation in normal and malignant cells. The antiproliferative effects of 1,25(OH)2D3 are reported to be mediated through the genomic signaling pathway by binding to a specific high affinity receptor protein, the 1,25-dihydroxyvitamin D3 receptor (VDR). VDR has been localized in a variety of tissues, but little is known about VDR distribution in human prostate. In this study, we raised an antibody against a synthetic peptide corresponding to amino acids 10-24 of human vitamin D receptor. The sequence selected for immunization is identical in human, rat and mouse VDR. Based on this antibody, we developed an immunohistochemical method suitable for studying VDR expression in paraffin-embedded tissue. The immunohistochemical staining was verified using classical target organs for vitamin D (kidney, intestine, skin). With this method, we studied VDR localization on paraffin-embedded human prostatic tissue obtained from 8 patients undergoing radical prostatectomy for urinary bladder cancer and demonstrate VDR expression in the secretory epithelial and few stromal cells of human prostate. The nuclear staining in the secretory epithelial cells was concentrated near the nuclear membrane and in discrete foci in the nucleoplasm. This suggests that effects of 1,25-dihydroxyvitamin D3 are mediated through VDR in these cells. Moreover our result indicates that there are strong variations in VDR expression between prostatic samples.

Hormone-dependent changes in A and B forms of progesterone receptor.

The influence of different estrogen and/or progesterone treatments on concentrations of A and B forms of progesterone receptor (PR-A and PR-B) in the different cell types of chick oviduct was studied. A semiquantitative immunohistochemical assay for cellular PR concentrations was developed using a computer-assisted image analysis system. The staining intensity of nuclear PR in the basal layer of epithelial cells, glandular, smooth muscle and mesothelial cells was analysed separately using two monoclonal antibodies, PR6 and PR22. The measured concentrations of PR varied between different cell types and from cell to cell. A significant decrease in PR concentration, as noted by a decrease in staining intensity, was observed in all cell types studied 2 or 6 h after a single injection of progesterone with or without simultaneous estrogen administration. The decrease was also verified with immunoblotting and an immunoenzymometric assay (IEMA) for chicken PR. After down-regulation the concentration of PR recovered to the control level within 48 h after progesterone or estrogen administration. Estrogen administration alone was observed to cause changes in the concentration of PR-A only, having little or no effect on PR-B concentration depending on the cell type studied. These findings indicate that estrogen and progesterone cause cell-specific changes not only to the total concentration of PR but also to the cellular ratio of PR-A and PR-B.

Characterization of human 1,25-dihydroxyvitamin D3 receptor anti-peptide antibodies.

Rabbit and chicken antibodies were raised against two peptides synthesized according to the structure of human 1,25-dihydroxyvitamin D3 receptor (hVDR): rabbit alpha hVDR-103 against the N-terminal amino acids 5-18 and alpha hVDR-104 against the amino acids 172-186 in the hinge region and chicken alpha hVDR-cab11 against the amino acids 172-186, respectively. The specificity of the antibodies was tested by peptide saturation, SDS-PAGE immunoblotting, gel shift assay and sucrose gradient centrifugation. Immunoblotting of a soluble extract (cytosol) from osteosarcoma cell line MG-63 showed a single band with an M(r) of about 48,000 and human intestine cytosol a broad band (50-63,000) for both antibodies. The antibodies recognized activated (3.2S) hVDR by shifting the centrifugation sedimentation profile to 5-6S. The antibodies showed nuclear immunostaining of unoccupied VDR in human osteosarcoma cells MG-63, U2-Os and SaOs-2. The immunoreaction could be saturated with the corresponding synthetic peptide. In immunoblot alpha hVDR-103 reacted with human and rat VDR, whereas alpha hVDR-104 recognized human VDR only. Similarly in immunohistochemistry, alpha hVDR-103 showed staining with hVDR and rVDR, whereas alpha hVDR-104 reacted only with hVDR. All antibodies recognized the native hVDR as verified with sucrose gradient centrifugation or immunoprecipitation but only alpha hVDR-103 and alpha hVDR-cab11 in gel shift assay of hVDR associated with the vitamin D-responsive element of human osteocalcin gene promoter.

Vitamin D and prostate cancer.

Our recent epidemiological study (Ahonen et al., Cancer Causes Control 11(2000) (847-852)) suggests that vitamin D deficiency may increase the risk of initiation and progression of prostate cancer. The nested case-control study was based on a 13-year follow-up of about 19000 middle-aged men free of clinically verified prostate cancer. More than one-half of the serum samples had 25OH-vitamin D (25-VD) levels below 50 nmol/l, suggesting VD deficiency. Prostate cancer risk was highest among the group of younger men (40-51 years) with low serum 25-VD, whereas low serum 25-VD appeared not to increase the risk of prostate cancer in older men (>51 years). This suggests that VD has a protective role against prostate cancer only before the andropause, when serum androgen concentrations are higher. The lowest 25-VD concentrations in the younger men were associated with more aggressive prostate cancer. Furthermore, the high 25-VD levels delayed the appearance of clinically verified prostate cancer by 1.8 years. Since these results suggest that vitamin D has a protective role against prostate cancer, we tried to determine whether full spectrum lighting (FSL) during working hours could increase serum 25-VD concentrations. After 1-month exposure, there was no significant increase in the serum 25-VD level, although there was a bias towards slightly increasing values in the test group as opposed to decreasing values in controls. There was no significant change in the skin urocanic acid production. The possibility to use FSL in cancer prevention is discussed. In order to clarify the mechanism of VD action on cell proliferation and differentiation, we performed studies with the rat and human prostates as well prostate cancer cell lines. It is possible that 25-VD may have a direct role in the host anticancer defence activity, but the metabolism of vitamin D in the prostate may also play an important role in its action. We raised antibodies against human 1alpha-hydroxylase and 24-hydroxylase. Our preliminary results suggest that vitamin D is actively metabolised in the prostate. Vitamin D appears to upregulate androgen receptor expression, whereas androgens seem to upregulate vitamin D receptor (VDR). This may at least partially explain the androgen dependence of VD action. VD alone or administered with androgen causes a suppression of epithelial cell proliferation. VD can activate mitogen-activated kinases, erk-1 and erk-2, within minutes and p38 within hours. Also, auto/paracrine regulation might be involved, since keratinocyte growth factor (mRNA and protein) was clearly induced by VD. Based on these studies, a putative model for VD action on cell proliferation and differentiation is presented.

Prognostic factors in controlled ovarian hyperstimulation.

OBJECTIVE: To determine whether the number of retrieved oocytes and the required amount of gonadotropins per oocyte in IVF treatment can be predicted with use of the following independent predictive variables: age, parity, cause of infertility, body mass index, day 3-5 FSH, E2, inhibin B, ovarian volume, the number of follicles, and intraovarian and uterine artery vascular resistance measured by ultrasonography before ovarian hyperstimulation. DESIGN: A retrospective analysis. SETTING: University hospital infertility clinic. PATIENT(S): Seventy-four consecutive women attending the university hospital infertility clinic for IVF treatment. INTERVENTION(S): The investigated factors were measured on day 3-5 of the cycle, in which luteal phase suppression was begun before ovarian hyperstimulation preparatory to IVF. MAIN OUTCOME MEASURE(S): The amount of gonadotropins required per oocyte and the number of retrieved oocytes were correlated with the predictive factors in stepwise regression analysis. RESULT(S): The best predictive factors for the number of oocytes retrieved were FSH, inhibin B, and parity, explaining 25% of the ovarian response. Intraovarian vascular resistance, parity, FSH, and inhibin B best predicted the amount of gonadotropins needed, explaining 44% of the variation. CONCLUSION(S): FSH, inhibin B, and parity were the independent predictive factors for the number of retrieved oocytes. The same factors and intraovarian vascular resistance predicted the required amount of gonadotropins per oocyte. The main part of the ovarian response cannot be predicted using the factors investigated.

Ovarian cancer and gonadotropins in vitro: new evidence in favor of independence.

BACKGROUND: The aim of this study was to investigate whether newly established epithelial ovarian carcinoma cell lines secrete inhibins, and whether their proliferative and secretory activity can be regulated by gonadotropins. MATERIALS AND METHODS: Three recently characterized human epithelial ovarian carcinoma cell lines were exposed to human choriongonadotropin hCG and follicle stimulating hormone FSH. Cell proliferation was determined by counting. Secretory activity of the cell lines was studied by analyzing inhibin A, inhibin B, inhibin pro-aC, estradiol, progesterone, testosterone, and CA 125 concentrations from the medium. The expression of gonadotropin receptors was studied by RT-PCR. RESULTS: None of the cell lines were found to secrete any of the inhibins, progesterone or testosterone. Only UT-OC-4 cells secreted low levels of estradiol. Gonadotropin receptors were not expressed by any of the cell lines, and accordingly neither FSH nor hCG stimulated the growth of these cells. However, hCG had some dose dependent growth inhibitory effect on UT-OC-3. Passage 42 cells of UT-OC-3 secreted significantly more CA 125 than passages 8 cells (P = 0.000). CONCLUSIONS: The present results suggest that the carcinomatous epithelial cells of the ovary do not secrete inhibins. The serum inhibin levels previously detected in patients with epithelial ovarian carcinoma may therefore reflect an ovarian stromal response to carcinoma. The findings are also in favor of an independence of ovarian cancer of gonadotropins.

Inhibin A and B in peri- and postmenopause.

OBJECTIVE: The aim of the study was to investigate the origin of inhibin A and B during the last years of the reproductive age and after menopause by measuring their levels in the ovarian and peripheral venous blood. METHODS: The study population consisted of 43 women, aged 42-69 years (mean 50), who underwent hysterectomy with ovarian removal for a benign disease. A total of 24 of them were in follicular phase, 11 in luteal phase, and eight were postmenopausal. Peripheral and ovarian venous blood was collected for measurement of inhibin A and B. In addition, sex steroid hormone and gonadotropin levels were measured. RESULTS: Ovarian venous inhibin B correlated significantly with ovarian estradiol secretion (r = 0.5, P = 0.001). The levels of inhibin B were significantly higher in the ovarian vein than in the peripheral vein (P = 0.006). The highest inhibin B concentrations were detected in the mid-proliferative (mid-follicular) phase (median 31.6 pg/ml range 25.9-47.9). In postmenopausal women, inhibin B was not detectable. No correlation between FSH and ovarian inhibin B was found. Inhibin A rose rapidly in late proliferative (late follicular) phase (median 28.5, range < 2-51.8) and dominated in the circulation throughout the luteal phase (median 20.9, range 8.8-60). For inhibin A, no concentration gradient existed between the ovarian and peripheral vein. Unlike inhibin B, inhibin A was detectable in ovarian and peripheral blood in postmenopausal women. A significant negative correlation between ovarian and peripheral inhibin A and FSH was found (r = -0.386, P = 0.015; r = -0.345, P = 0.034, respectively). CONCLUSION: Inhibin B correlates with ovarian estradiol secretion and seems to reflect follicular function. Inhibin A dominates in circulation during the luteal phase but is detectable at low concentrations both in follicular phase and even in postmenopause. Our findings suggest that inhibin A may play a role in FSH suppression in the female reproduction. In addition to the ovary, there may be extragondal source(s) of inhibin A.

Mechanisms of action of sex steroid hormones: basic concepts and clinical correlations.

The review deals with the clinically important aspects of the basic mechanisms of sex steroid hormones. Steroids can act through two basic mechanisms: genomic and non-genomic. The classical genomic action is mediated by specific intracellular receptors, whereas the primary target for the non-genomic one is the cell membrane. Many clinical symptoms seem to be mediated through the non-genomic route. Furthermore, membrane effects of steroid and other factors can interfere with the intranuclear receptor system inducing or repressing steroid-and receptor-specific genomic effects. These signalling pathways may lead to unexpected hormonal or anti-hormonal effects in patients treated with certain drugs. Steroid receptors (SRs) are members of a large family of nuclear transcription factors that regulate gene expression by binding to their cognate steroid ligands, to the specific enhancer sequences of DNA (steroid response elements) and to the basic transcription machinery. SRs are phosphoproteins, which are further phosphorylated after ligand binding. The role of phosphorylation in receptor transaction is complex and may not be uniform to all SRs. However, phosphorylation/dephosphorylation is believed to be a key event regulating the transcriptional activity of steroid receptors. SR activities can be affected by the amount of SR in the cell nuclei, which is modified by the rate of transcription and translation of the SR gene as well as by proteolysis of the SR protein. There is an auto- and heteroregulation of receptor levels. Some of the SRs appear to bind specific protease inhibitors and exhibit protease activity. The physiological significance of this weak proteolytic activity is not clear. Some SRs are expressed as two or more isoforms, which may have different effects on transcription. Receptor isoforms are different translation or transcription products of a single gene. Isoform A of the progesterone receptor is a truncated form of PR isoform B originating from the same gene, but it is able to suppress not only the gene enhancing activity of PR-B but also that of other steroid receptors. From the clinical point of view, it is important to note that the final hormonal effect in a target tissue is dependent on the cross talk between different nuclear steroid receptors and on expression of receptor isoforms.

Immunohistochemical demonstration of androgen receptors in human salivary glands.

Androgen receptors were demonstrated in human salivary glands by immunohistochemistry using polyclonal antibodies. Fresh, clinically healthy salivary gland samples (two from minor, seven from parotid and eight from submandibular glands) of both sexes were used. Frozen tissue sections were incubated with the antibody against human androgen receptor and visualized by an indirect immunoperoxidase technique. Androgen receptors could be detected in all salivary tissues studied. Positive staining was confined to nuclei of almost all acinar cells as well as to the majority of nuclei in ductal cells. Very few of the nuclei of connective tissue and endothelial cells stained positively. The presence of androgen receptors in human salivary glands suggests possible direct effects of androgens on these tissues.