Androgen antagonists in androgen target tissues

Do high-dose progestins impair sexual function in women treated for endometriosis? A prospective observational longitudinal study

INTRODUCTION

High-dose progestins are used as an effective therapy for painful symptoms of endometriosis but their impact on sexual function has been poorly studied. The study aims to assess the impact of high-dose progestin on sexual function among women treated for endometriosis.

MATERIAL AND METHODS

In this bicenter prospective observational study, women with endometriosis who received medical or surgical treatment for endometriosis and who were sexually active were included. They completed the Sexual Activity Questionnaire (SAQ, a validated tool) before (T0) and 12 months after (T1) endometriosis treatment. We classified patients into two groups according to whether they were using high-dose progestins at T1: a high-dose progestin group and a control group. The main outcome was sexual function measured by the SAQ score (from 0 to 30) at T1. The secondary outcomes were each individual SAQ item, the dyspareunia 100-mm visual analog scale (VAS) and the quality of life assessed with EuroQoL Group 5D Index (EQ-5D) at T1. We also assessed the change in dyspareunia VAS and quality of life between T0 and T1. The Ethics Committee of Ile-de-France (Act 2004-806, 9 August 2004) approved the study.

RESULTS

Among 214 women included, 25 (12%) were exposed to high-dose progestins at T1. The SAQ score of women exposed to high-dose progestins was significantly lower compared with the control group, with or without adjustment for covariates (15.5 ± 6.3 vs 18.3 ± 6.2, P = .03, adjusted effect size -0.44 [95% CI -0.86 to -0.02], P = .04). High-dose progestin intake at T1 was associated with a lower subscore on two SAQ items: pleasure (1.8 ± 0.8 vs 2.2 ± 0.9, P = .02), and satisfaction with frequency of intercourse (1.2 ± 1.2 vs 1.8 ± 1.1, P = .02). In the overall population, dyspareunia VAS and quality of life assessed by EQ-5D improved between T0 and T1 (45 ± 29 at T0 vs 28 ± 29 at T1, P < .001; 0.78 ± 0.14 at T0 vs 0.86 ± 0.14 at T1, P < .001, respectively). At T1, the groups did not differ significantly for dyspareunia VAS (effect size 0.36 [95% CI -0.06 to 0.78], P = .10) and quality of life (EQ-5D, effect size 0.02 [95% CI -0.40 to 0.44], P = .91).

CONCLUSION

In this observational study, high-dose progestins impair the sexual function of women treated for endometriosis even though they improved dyspareunia.

Establishment of adult mouse Sertoli cell lines by using the starvation method

Sertoli cells were isolated from the testes of 6-week-old mice and stable Sertoli cell lines with higher proliferation rates were subcloned after starvation of primary cultured cells. After two rounds of this subcloning, 33 subcloned lines were selected on the basis of their proliferation rates. In addition, these subclones were screened according to their phagocytic activity and the characteristics of mature Sertoli cells, such as the expression of androgen receptors (ARs) and progesterone receptors, by using western blotting and immunocytochemical analysis, in addition to their morphology and proliferation rates. After the third round of subcloning, 12 subclones were selected for the final selection using RT-PCR for identification of genes specifically expressed by various testicular cells. Three clones were selected that expressed Sertoli-cell-specific genes, i.e. stem cell factor, clusterin, AR, α-inhibin, transferrin, Wilms' tumour-1, Müllerian inhibitory substance, sex-determining region Y-box 9, FSH receptor (Fshr) and occludin; however, these clones did not express globulin transcription factor 1, steroidogenic factor or androgen-binding protein. These clones also expressed growth and differentiation factors that act on germ cells, such as leukaemia inhibitory factor, transforming growth factor β1 and basic fibroblast growth factor 2, but did not express c-kit (specific for germ cells), LH receptor and 3β-hydroxyl-dehydrogenase (specific for Leydig cells). Immunocytochemical data confirmed the expression of clusterin in these clones. Furthermore, the Bromodeoxyuridine incorporation assay confirmed the proliferation activity of these clones throughFshrafter treatment with FSH. These clones are considered to be valuable tools for the study of Sertoli cell-specific gene expression and function.

QSAR models for anti-androgenic effect--a preliminary study

Three modelling systems (MultiCase®, LeadScope® and MDL® QSAR) were used for construction of androgenic receptor antagonist models. There were 923-942 chemicals in the training sets. The models were cross-validated (leave-groups-out) with concordances of 77-81%, specificity of 78-91% and sensitivity of 51-76%. The specificity was highest in the MultiCase® model and the sensitivity was highest in the MDL® QSAR model. A complementary use of the models may be a valuable tool when optimizing the prediction of chemicals for androgenic receptor antagonism. When evaluating the fitness of the model for a particular application, balance of training sets, domain definition, and cut-offs for prediction interpretation should also be taken into account. Different descriptors in the modelling systems are illustrated with hydroxyflutamide and dexamethasone as examples (a non-steroid and a steroid anti-androgen, respectively). More research concerning the mechanism of anti-androgens would increase the possibility for further optimization of the QSAR models. Further expansion of the basis for the models is in progress, including the addition of more drugs.

Discovery and biological characterization of a novel series of androgen receptor modulators

BACKGROUND AND PURPOSE

Selective androgen receptor modulators are of great value in the treatment of prostate cancer. The purpose of this study was to provide a preliminary characterization of a new class of non-steroidal androgen receptor modulators discovered in a high-throughput screening campaign.

EXPERIMENTAL APPROACH

Competitive receptor binding, luciferase-based reporter methods, cell proliferation and in vivo assays were employed to evaluate an initial set of compounds from chemistry efforts.

KEY RESULTS

Forty-nine analogues from the chemistry efforts showed high affinity binding to androgen receptors, agonist and/or antagonist activities in both CV-1 and MDA-MB-453 transfection assays. A proliferation assay in LNCaP cells also exhibited this profile. A representative of these non-steroidal compounds (compound 21) was devoid of activity at other nuclear receptors (oestrogen, progesterone, glucocorticoid and mineralocorticoid receptors) in the CV-1 co-transfection assay. At the same time, in an immature castrated rat model, it behaved as an androgen receptor antagonist against the growth of prostate, seminal vesicles and levator ani induced by exogenous androgen. Separation of compound 21 into its enantiomers showed that nearly all the androgen receptor modulating activity and binding resided in the dextrorotatory compound (23) while the laevorotatory isomer (22) possessed weak or little effect depending on the cell type studied.

CONCLUSIONS AND IMPLICATIONS

These non-steroidal compounds may represent a new class of androgen receptor modulators for the treatment of not only prostate cancer but other clinical conditions where androgens and androgen receptors are involved in the pathological processes.

Effects of dihydrotestosterone and hydroxyflutamide on androgen receptors in cultured human breast cancer cells (EVSA-T)

The purpose of our study was to evaluate the effects of 5 alpha-dihydrotestosterone (DHT) and hydroxyflutamide (HF), alone or in combination, on androgen receptor (AR) dynamics and on cellular growth in cultured breast cancer cells (EVSA-T). The incubation of cells with DHT increased the concentration of nuclear AR after 24 and 48 h. HF was also able to promote the nuclear accumulation of AR after 24 and 48 h of treatment. When HF-treated cells are incubated with DHT, the nuclear AR concentration is lower than that found in cells treated with DHT alone. We conclude that HF acts by increasing nuclear accumulation of receptor-antiandrogen complexes. Moreover, DHT stimulates cell growth while HF has an inhibitory effect. Thymidine incorporation in cells also increased after DHT treatment and decreased after HF incubation. The HF-induced inhibition of cell growth persisted both after renewal of the medium and after the addition of DHT to cultures. It may be hypothesized that either DHT is converted to inactive metabolites or that HF exerts a persistent inhibitory effect. In the latter case, the antiandrogen action of HF could be exerted by retention of high levels of antiandrogen in cells or by such a depressed protein synthesis that the renewal of growth is slower than the 48 h period studied.

[Hydroxy substituted phenyltetralines: compounds with affinity for estrogen and androgen receptors]

Among nonsteroidal antiandrogens, mostly compounds of the Flutamide-type are described. For the development of new compounds with affinity to androgen receptors and antiandrogenic activity five new hydroxy-substituted phenyltetralines were prepared and tested. Synthesis was achieved by reaction of the respective 1-tetralones with phenyl magnesium bromides, dehydration of the carbinols, hydrogenation and ether cleavage. In addition to the expected affinity to estrogen receptors, especially the 6-OH, 4'-OH-substituted compound 11 showed an affinity to androgen receptors, too. Whereas none of the tested compounds had a marked estrogenicity, 11 and 15 (6-OH, 3'-OH) exerted antiestrogenic effects. Androgenic properties were not given. In the adult, intact mouse, 11 and 15 exhibited a pronounced inhibition of seminal vesicle weights concomitant with a reduction of the testosterone level. Since in castrated, androgen-substituted animals only relatively weak direct antiandrogenic effects were demonstrable, the antiandrogenic activity of these new phenyltetralines is more due to an inhibition of testosterone biosynthesis than to a direct, receptor-mediated effect.

Studies on the mechanism of action of danazol and gestrinone (R2323) in the rat: evidence for a masked estrogen component

The effects of androgen and estrogen receptor antagonists on the action of danazol and gestrinone (R2323) were investigated. The tropic effect of danazol and gestrinone on sex accessory tissues of castrated, immature male rats was inhibited by the antiandrogen flutamide, whereas the uterotropic action of these steroids in immature female and adult ovariectomized rats was not inhibited by flutamide. In contrast, the uterotropic effect of danazol was reduced by the antiestrogen, LY156758. The estrogen-sensitive endpoints, vaginal keratinization and uterine progesterone receptor concentration, were enhanced by treatment with a combination of flutamide and either danazol or gestrinone. These data indicate that danazol and gestrinone have estrogenic activity that is masked by the androgenic component of these drugs.

How the study of the biological activities of antiandrogens can be oriented towards the clinic

Antiandrogens can be used in various androgen-dependent diseases. Depending upon the therapeutic indication, they can be administered systemically or topically. Systemic treatment with an antiandrogen will inhibit androgen action not only in the desired target site but also in all other target tissues; thus, it will block the androgen-dependent feedback regulating the secretion (hypothalamo-pituitary-testis axis) or the action (protein factors) of androgens. In contrast, topical treatment (acting through cutaneous receptors or local metabolism) should not produce systemic side effects especially in man. Pharmacological assays which can select antiandrogens irrespective of the mechanism measure changes in the final androgenic response, but they consume a great deal of time and test compound and bear little relation to therapeutic activity. Therefore, the biological strategy that we report here and which, at Roussel-Uclaf, has led to the selection of a systemic and a topical antiandrogen (RU 23908 and RU 38882) has consisted in successively performing: (1) in vitro assays which measure an effect at a specific level in the mechanism of antiandrogen action, e.g. interaction with the androgen receptor. Assessing interactions with other classes of steroid hormone receptor can be used to predict possible hormonal side-effects, (2) in vitro determinations of agonist or antagonist activity, e.g. in pituitary cells (LH response to LHRH) or mammary tumor cells (induction of androgen-dependent proteins), (3) in vivo antiandrogen assays after a single treatment (induction of mouse kidney proteins, rat prostatic binding protein) or after repeated treatment (inhibition of the growth of rat accessory glands or of hamster sebaceous glands), to determine the active dose of the compound and possibly the absence of systemic effects by the topical route, (4) assays in animal models designed to mimic a therapeutic context e.g. for prostate cancer: inhibition of the "flare-up" effect of LHRH-A or of the trophic effect of perfused adrenal androgens on rat prostate, antitumoral activity in experimental cancer models. For hyperseborrhoea and acne: histological and stereological analysis of rat skin biopsies to measure the volume density of the smooth endoplasmic reticulum vesicles of the differentiating cells of the sebaceous gland.

Properties of an intermediate-sized androgen receptor: association with RNA

This study identifies an intermediate-sized androgen receptor and characterizes its relationship with the 9.1S and 4.4S receptor forms. Under low ionic conditions, at 2-4 degrees C, there exists a 9.1S (+/- 0.17) (n = 30) oligomeric form which does not bind to DNA. Under high ionic conditions, this form dissociates to a 4.4S (+/- 0.08) (n = 18) monomeric form. When the salt concentration is lowered, the 4.4S monomer converts to a species with an intermediate sedimentation coefficient of 7.7S (+/- 0.15) (n = 17) which binds to DNA. Unlike the 9.1S oligomer the 7.7S form is not maintained by sodium molybdate under high ionic conditions but rather dissociates to the 4.4S monomer. To determine whether these forms were associated with RNA, the 7.7S form was incubated with RNase A and analyzed by density gradient centrifugation. The 7.7S form was digested fully by RNase to the 4.4S monomer. The 7.7S form demonstrated a buoyant density of 1.2459 +/- 0.014 g/cm3 (n = 6) in metrizamide gradients, suggesting a ribonucleoprotein component. The sedimentation coefficient of the 9.1S form was unaffected by RNase. These data suggest that the intermediate 7.7S receptor form is composed of 4.4S monomer associated with a ribonucleoprotein molecule(s).

Physicochemical characterization of the androgen receptor from hyperplastic human prostate

In this manuscript we have characterized the androgen receptor from human benign prostatic hypertrophied (BPH) tissue. BPH tissue was obtained fresh from surgery, ground, and frozen in liquid nitrogen. Tissue was homogenized in 10 mM Tes buffer (pH 7.4 at 25 degrees C) containing 0.25 M sucrose, 20 mM Na2MoO4, 12 mM monothioglycerol, and 1.5 mM EDTA. Cytosol was labeled with (3H)-R1881 (0.5-10 nM) +/- a 100-fold excess of R1881 and a 500-fold excess of triamcinolone acetonide to identify specific androgen receptor sites. An exchange assay was developed, whereby maximum binding was achieved by raising the temperature to 30 degrees C for 15 min. A high-affinity binding protein was detected (Kd = 1.3 +/- 0.8 nM) which had a binding capacity of 15 +/- 7 fmol/mg protein. Binding was specific for androgens with the following Ki (nM) values: R1881 (0.09), dihydrotestosterone (6), testosterone (50), progesterone (92), estradiol (100), epitestosterone (860), and cortisol (greater than 1,000). Under high ionic conditions the sedimentation coefficient of the receptor was 4.1 S. Higher S values were not observed in the presence of the following protein inhibitors: leupeptin (20 or 150 microM), iodoacetamide (10 mM), DFP (5 mM), PMSF (1 mM), bacitracin (0.1 mM), antipain (0.1 mM), aprotinin (1 TIU/ml). Gel filtration analysis revealed a Stokes radius of 6.5 nm. These data indicate a Mr of 120,000 and a f/fo of 2.01. The receptor eluted from a chromatofocusing column at a pH of 6.8. The receptor bound to phosphocellulose and DNA cellulose after being heat-treated for 15 min at 30 degrees C. These results suggest that BPH tissue contains an androgen receptor which is similar to receptors in other androgen-responsive tissues.