Lack of influence of dyspareunia on the beneficial effect of intravaginal prasterone (dehydroepiandrosterone, DHEA) on sexual dysfunction in postmenopausal women.

INTRODUCTION: We have previously observed that intravaginal prasterone (dehydroepiandrosterone, DHEA) improved all domains of female sexual dysfunction (FSD). AIM: Investigate the influence of moderate/severe pain at sexual activity (dyspareunia) (MSD) at baseline on FSD following prasterone administration. METHODS: The effect of daily administration of prasterone (0, 3.25 mg, 6.5 mg or 13 mg) for 12 weeks on FSD in 215 postmenopausal women with or without MSD at baseline was evaluated in a prospective, randomized, double-blind, and placebo-controlled phase III clinical trial. MAIN OUTCOME MEASURES: Differences were examined on desire, arousal and orgasm. RESULTS: Comparable benefits were observed in women not having MSD (n = 56) vs. those having MSD (n = 159). The benefits over placebo in prasterone-treated women for desire, avoiding intimacy and vaginal dryness as well as for the total sexual domain of the MENQOL (Menopause Specific Quality of Life) questionnaire, ranged between 18.0% and 38.2% with P values of <0.05 or <0.01 except in one out of 12 subgroups. For the arousal/sensation, arousal/lubrication and summary score of the ASF (Abbreviated Sexual Function) questionnaire, in the MSD+ group, improvements of 64.2% (P = 0.01), 118% (P = 0.001) and 31.1% (P = 0.03) were observed over placebo, respectively, while similar differences (58.0%, 67.6% and 32.1%) did not reach statistical significance in the MSD- group having up to only 44 prasterone-treated women compared with 119 in the MSD+ group. CONCLUSIONS: No MSD at baseline does not apparently affect the effects of intravaginal prasterone on sexual dysfunction. Knowing the absence of significant effects of estrogens on FSD, the present data suggest that vulvovaginal atrophy (VVA) and vulvovaginal sexual dysfunction (VVSD) are two different consequences of sex steroid deficiency at menopause which can respond independently. In addition, the present data seriously question the justification of pain being part of FSD as well as the separation of FSD into separate domains.

High internal consistency and efficacy of intravaginal DHEA for vaginal atrophy.

Following the compelling data obtained in a pivotal phase III clinical trial performed in 218 postmenopausal women suffering from vaginal atrophy who received daily intravaginal 0.25, 0.5 or 1.0% DHEA (dehydroepiandrosterone) ovules for 12 weeks, we have performed analysis of the four co-primary objectives at each site of that multicentre U.S. and Canadian trial. Comparison was made of the change in percentage of parabasal and superficial cells, vaginal pH and severity of the most bothersome symptom. The site-by-site (seven sites) analysis has shown that 10-13 women per group are generally sufficient to obtain a significant or highly statistically significant decrease in vaginal pH and percentage of parabasal cells and increased percentage of superficial cells at p values ranging from 0.02 to <0.0001. For vaginal pain as the most bothersome symptom, a statistically significant difference from baseline was found at six out of seven sites. The exceptionally high consistency between all sites in this phase III study and high potency of the compound permit to obtain a clinically and statistically significant to highly significant effect of treatment on all parameters of vaginal atrophy with the 0.5% DHEA daily intravaginal dose which does not significantly affect the serum levels of oestrogens, thus avoiding systemic risks.

Gonadotropin-releasing hormone agonists in the treatment of prostate cancer.

In 1979, the first prostate cancer patient was treated with a GnRH agonist at the Laval University Medical Center in Quebec City, Canada, thus rapidly leading to the worldwide replacement of surgical castration and high doses of estrogens. The discovery of medical castration with GnRH agonists was soon followed by fundamental changes in the endocrine therapy of prostate cancer. Most importantly, the excellent tolerance accompanying the treatment with GnRH agonists has been a key factor that permitted a series of studies demonstrating a major reduction in the death rate from prostate cancer ranging from 31 to 87% at 5 yr of follow-up in patients with localized or locally advanced prostate cancer. In fact, a one third reduction in prostate cancer deaths has been calculated in the metaanalysis of all available studies. The general acceptance of this discovery by patients and physicians is illustrated by world sales above 3.0 billion U.S. dollars in 2003. Although extremely efficient in achieving complete medical castration and well tolerated, with no other side effects than the expected hypoandrogenicity, GnRH agonists should not be administered alone. In fact, shortly after discovery of the castration effects of GnRH agonists, we observed that approximately 50% of androgens remain in the prostate after castration, thus leading to the recognition of the role of adrenal dehydroepiandrosterone as an important source of the androgens synthesized locally in the prostate and in many peripheral target tissues. We therefore developed combined androgen blockade (CAB), whereby the androgens of both testicular and adrenal origins are blocked simultaneously at start of treatment with the combination of a GnRH agonist to block the testis and a pure antiandrogen to block the action of the androgens produced locally. CAB, first used in advanced metastatic disease, has been the first treatment shown to prolong life in prostate cancer. Most interestingly, in 2002, we made the observation that CAB alone given continuously for 6.5 yr or more leads to cure of the disease in at least 90% of cases, thus suggesting that androgen blockade combining a GnRH agonist and a pure antiandrogen could well be the most efficient treatment of localized prostate cancer, and thus offering the possibility of practically eliminating death from prostate cancer.

Endocrine and intracrine sources of androgens in women: inhibition of breast cancer and other roles of androgens and their precursor dehydroepiandrosterone.

Serum androgens as well as their precursors and metabolites decrease from the age of 30-40 yr in women, thus suggesting that a more physiological hormone replacement therapy at menopause should contain an androgenic compound. It is important to consider, however, that most of the androgens in women, especially after menopause, are synthesized in peripheral intracrine tissues from the inactive precursors dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) of adrenal origin. Much progress in this new area of endocrine physiology called intracrinology has followed the cloning and characterization of most of the enzymes responsible for the transformation of DHEA and DHEA-S into androgens and estrogens in peripheral target tissues, where the locally produced sex steroids are exerting their action in the same cells in which their synthesis takes place without significant diffusion into the circulation, thus seriously limiting the interpretation of serum levels of active sex steroids. The sex steroids made in peripheral tissues are then inactivated locally into more water-soluble compounds that diffuse into the general circulation where they can be measured. In a series of animal models, androgens and DHEA have been found to inhibit breast cancer development and growth and to stimulate bone formation. In clinical studies, DHEA has been found to increase bone mineral density and to stimulate vaginal maturation without affecting the endometrium, while improving well-being and libido with no significant side effects. The advantage of DHEA over other androgenic compounds is that DHEA, at physiological doses, is converted into androgens and/or estrogens only in the specific intracrine target tissues that possess the appropriate physiological enzymatic machinery, thus limiting the action of the sex steroids to those tissues possessing the tissue-specific profile of expression of the genes responsible for their formation, while leaving the other tissues unaffected and thus minimizing the potential side effects observed with androgens or estrogens administered systemically.

Androgen-regulated transcription factor AIbZIP in prostate cancer.

Androgen-induced bZIP (AIbZIP/CREB3L4) is a transcription factor of the bZIP family that associates with the membrane of the endoplasmic reticulum (ER). In humans, AIbZIP RNA is most abundant in the prostate gland where the protein is produced in luminal cells of the glandular epithelium. AIbZIP could play an important role in prostate cancer because its expression is up-regulated by androgens in LNCaP prostate cancer cells and the protein is more abundant in cancerous than in non-cancerous prostate cells. We recently added 74 adenocarcinomas and 43 specimens of prostatic intraepithelial neoplasia (PIN) to our survey of AIbZIP expression in prostate tumours. This study showed that AIbZIP is expressed in all grades of adenocarcinoma and that it is more abundant in high-grade PIN and in adenocarcinoma than in normal prostate. The physiological function of AIbZIP remains unknown but its association with the ER and its structural homology to transcription factors such as ATF6 suggest that AIbZIP could be activated by regulated intramembrane proteolysis during the cellular response to ER stress. This review will describe the characteristics of human and mammalian AIbZIP, its relationship to prostate cancer, and our recent efforts to characterize the transcriptional properties and targets of AIbZIP.

Effect of intravaginal DHEA on serum DHEA and eleven of its metabolites in postmenopausal women.

The primary objective of this study was measurement of the systemic bioavailability of DHEA and its metabolites following daily intravaginal application of the sex steroid precursor. Forty postmenopausal women were randomized to receive a daily dose of one ovule of the following DHEA concentrations: 0.0%, 0.5%, 1.0% or 1.8%. After only 7 days of treatment, the maturation value of the vaginal epithelial cells was significantly increased while the vaginal pH was significantly decreased at all DHEA doses. These important local effects were observed while the serum concentrations of estradiol and testosterone remained within the values found in normal postmenopausal women at all DHEA doses. Similar observations were made for serum androstenedione, estrone, estrone-sulfate and DHEA-sulfate. Even at the highest 1.8% DHEA dose, serum DHEA was increased at the levels found in normal premenopausal women. The present data show that the intravaginal administration of DHEA permits to rapidly achieve the local beneficial effects against vaginal atrophy without significant changes in serum estrogens, thus avoiding the increased risk of breast cancer associated with the current intravaginal or systemic estrogenic formulations. In addition, the recent observation that DHEA is transformed into both androgens and estrogens in the vagina permits to exert benefits on all the three layers of the vaginal wall.

Transcriptional profiling of genes that are regulated by the endoplasmic reticulum-bound transcription factor AIbZIP/CREB3L4 in prostate cells.

The androgen-regulated protein androgen-induced bZIP (AIbZIP) is a bZIP transcription factor that localizes to the membrane of the endoplasmic reticulum (ER). The physiological role of AIbZIP is unknown, but other ER-bound transcription factors such as ATF6 and SREBPs play a crucial role in the regulation of protein processing and lipid synthesis, respectively. In response to alterations in the intracellular milieu, ATF6 and SREBPs are processed to their transcriptionally active forms by regulated intramembrane proteolysis. In humans, AIbZIP mRNA is expressed in several organs including the pancreas, liver, and gonads, but it is especially abundant in prostate epithelial cells. We therefore used LNCaP human prostate cancer cells as a model to identify stimuli that lead to AIbZIP activation and define the transcriptional targets of AIbZIP. In LNCaP cells, AIbZIP was processed to its transcriptionally active form by drugs that deplete ER calcium stores (i.e., A23187 and caffeine), but it was unaffected by an inhibitor of protein glycosylation (tunicamycin). To identify AIbZIP-regulated genes, we generated LNCaP cell lines that conditionally express the processed form of AIbZIP and used Affymetrix microarrays to screen for AIbZIP-regulated transcripts. Selected genes (n = 48) were validated by Northern blot hybridization. The results reveal that the downstream targets of AIbZIP include genes that are implicated in protein processing (e.g., BAG3, DNAJC12, KDELR3). Strikingly, a large number of AIbZIP-regulated transcripts encode proteins that are involved in transcriptional regulation, small molecule transport, signal transduction, and metabolism. These results suggest that AIbZIP plays a novel role in cell homeostasis.

Dehydroepiandrosterone (DHEA) is an anabolic steroid like dihydrotestosterone (DHT), the most potent natural androgen, and tetrahydrogestrinone (THG).

We have recently taken advantage of the unique power of DNA microarrays to compare the genomic expression profile of tetrahydrogestrinone (THG) with that of dihydrotestosterone (DHT), the most potent natural androgen, thus clearly demonstrating that THG is an anabolic steroid. In 2004, the U.S. Controlled Substances Act has been modified to include androstenedione (4-dione) as an anabolic steroid. However, despite the common knowledge that dehydroepiandrosterone (DHEA) is the precursor of testosterone, DHEA has been excluded from the list of anabolic steroids. We thus used the same DNA microarray technology to analyze the expression profile of practically all the 30,000 genes of the mouse genome modulated by DHEA and DHT in classical androgen-sensitive tissues. Daily subcutaneous injections of DHT (0.1mg) or DHEA (3mg) for 1 month in gonadectomized C57BL6/129 SV mice increased ventral prostate, dorsal prostate, seminal vesicle and preputial gland weight (p<0.01 for all tissues). As early as 24h after single injection of the two steroids, 878, 2681 and 14 probe sets were commonly stimulated or inhibited (p<0.01, change> or =30%), in the prostate (ventral+dorsal), seminal vesicles and preputial glands, respectively, compared to tissues from gonadectomized control animals. After 7 days of daily treatment with DHEA and DHT, 629, 919 and 562 probe sets were commonly modulated in the same tissues while after 27 days of treatment, 1195, 5127 and 2883 probe sets were modulated, respectively. In analogy with the data obtained with THG, the present microarray data provide an extremely precise and unquestionable genomic signature and proof of the androgenic/anabolic activity of DHEA. Such data add to the literature showing that DHEA is transformed into androgens in the human peripheral tissues as well as in laboratory animal species, including the monkey, thus exerting potent androgenic/anabolic activity. The present microarray approach to identify anabolic compounds is applicable to all potential androgenic/anabolic compounds.

Stage-specific expression of the Atce1/Tisp40alpha isoform of CREB3L4 in mouse spermatids.

The maturation of haploid spermatids into spermatozoa relies on the timely production of proteins required for spermatid differentiation. The mammalian CREB3L4 (cAMP responsive element binding protein 3-like 4) gene encodes a bZIP transcription factor that associates with the membrane of the endoplasmic reticulum. CREB3L4 is presumed to play an important role in protein maturation via its involvement in the cellular response to endoplasmic reticulum stress. In mice, the Creb3l4 gene gives rise to 2 distinct classes of mRNAs through the use of alternate promoters. Transcripts that initiate upstream of the first coding exon encode a 370-amino acid (aa) protein designated Tisp40beta, whereas transcripts that initiate downstream of the first coding exon encode Atce1/Tisp40alpha, a truncated (315-aa) form of Tisp40beta. In the mouse testis, Creb3l4 transcripts are known to be expressed exclusively in postmeiotic spermatids but the presence of CREB3L4 protein in spermatids has not been formally demonstrated. We produced an antibody directed against the carboxy terminus of mouse CREB3L4 and used it in immunostaining experiments to document that CREB3L4 protein accumulates in post-meiotic spermatids in a stage-specific manner. Moreover, we show that Atce1/Tisp40alpha is the major form of CREB3L4 in mouse testis. These findings suggest that testis-specific isoforms of Creb3l4 could play an important role in spermatid differentiation.

Overexpression of a dominant negative type II bone morphogenetic protein receptor inhibits the growth of human breast cancer cells.

Bone morphogenetic proteins (BMPs) exert cell type-specific effects on cell proliferation. To clarify the role of the BMP pathway in human breast cancer cells, we used a dominant negative strategy with a truncated human type II BMP receptor (DN-BMPRII; amino acid 1-172) fused to the NH2 terminus of enhanced green fluorescent protein. Transient overexpression of DN-BMPRII interfered with BMP-2-induced Smad1 transcriptional activity and caused cells to accumulate in G1. Stable cell lines that constitutively overexpressed DN-BMPRII were resistant to BMP-2-induced Smad1 phosphorylation and proliferated much more slowly than control stable cell lines. These results suggest that BMPs interacting with type II BMP receptors contribute to the proliferation and/or survival of human breast cancer cells.

AIbZIP, a novel bZIP gene located on chromosome 1q21.3 that is highly expressed in prostate tumors and of which the expression is up-regulated by androgens in LNCaP human prostate cancer cells.

Androgens play an important role in the development and physiology of the normal prostate as well as in prostate cancer cell proliferation. Comparison of the mRNA expression profiles of control and R1881-treated cultures of LNCaP human prostate cancer cells using cDNA subtraction led to the identification of a novel transcription factor that we named Androgen-Induced bZIP (AIbZIP) protein. AIbZIP is a 395 aa protein with homology to cyclic AMP-responsive element binding protein/activating transcription factor transcription factors. It contains an NH(2)-terminal activation domain, a central bZIP domain, and a COOH-terminal transmembrane domain. The AIbZIP gene is localized on chromosome 1q21.3 and consists of 10 exons. A major 1.7-kb transcript was detected exclusively in the prostate as well as in breast and prostate cancer cell lines. Androgens up-regulate AIbZIP mRNA and protein levels in a dose-dependent manner. The kinetics of AIbZIP mRNA up-regulation and the results of experiments with cycloheximide suggest that AIbZIP may be a delayed response gene. Immunoreactive AIbZIP protein was primarily detected in the cytoplasm of prostatic luminal epithelial cells. Similarly, full-length AIbZIP-green fluorescent protein fusion proteins were localized in the cytoplasm of LNCaP cells, whereas a truncated form of AIbZIP lacking the putative transmembrane domain was exclusively nuclear. Examination of AIbZIP protein and mRNA expression in a series of transurethral resection of the prostate and needle biopsy specimens indicated that AIbZIP is expressed at higher levels in cancerous prostate cells compared with noncancerous prostate cells. The highly tissue-specific expression profile, androgen regulation, chromosomal localization, and expression profile of AIbZIP in prostate tumors suggest that AIbZIP may play an important role in prostate cancer and in androgen receptor signaling in prostate cells. Future studies will confirm a possible relationship between AIbZIP and prostate cancer.

Activity and safety of the antiestrogen EM-800, the orally active precursor of acolbifene, in tamoxifen-resistant breast cancer.

PURPOSE: To determine the efficacy and safety of EM-800 (SCH-57050), the precursor of acolbifene, a new, highly potent, orally active, pure antiestrogen in the mammary gland and endometrium, for the treatment of tamoxifen-resistant breast cancer. PATIENTS AND METHODS: Forty-three post menopausal/ovariectomized women with breast cancer who had received tamoxifen, either for metastatic disease or as adjuvant to surgery for > or = 1 year, and had relapsed were treated in a prospective, multicenter, phase II study with EM-800 (20 mg/d [n = 21] or 40 mg/d [n = 22] orally). Results Thirty-seven patients had estrogen receptor (ER)-positive tumors (>10 fmol/mg; mean, 146 fmol/mg cytosolic protein), three patients had ER-negative/progesterone receptor-positive tumors, and three patients had undetermined ER status. The objective response rate to EM-800 was 12%, with one complete response and four partial responses. Ten patients (23%) had stable disease for > or = 3 months, and 7 patients (16%) had stable disease for > or = 6 months. With a median follow-up of 29 months, median duration of response was 8 months (range, 7 to 71+ months). Treatment with EM-800 was well tolerated. No significant adverse events related to the study drug were observed clinically or biochemically. CONCLUSION: EM-800 produced responses in a significant proportion of patients with tamoxifen-resistant breast cancer, thus showing that this highly potent, selective estrogen receptor modulator, which lacks estrogenic activity in the mammary gland and endometrium, has incomplete cross-resistance with tamoxifen, thus suggesting additional benefits in the treatment of breast cancer.

Tetrahydrogestrinone induces a genomic signature typical of a potent anabolic steroid.

Tetrahydrogestrinone (THG) is a recently identified compound having the greatest impact in the world of sports. In order to obtain a highly accurate and sensitive assessment of the potential anabolic/androgenic activity of THG, we have used microarrays to identify its effect on the expression of practically all the 30,000 genes in the mouse genome and compared it with the effect of dihydrotestosterone (DHT), the most potent natural androgen. Quite remarkably, we found that 671 of the genes modulated by THG in the mouse muscle levator ani are modulated in a similar fashion by DHT, while in the gastrocnemius muscle and prostate, 95 and 939 genes respectively, are modulated in common by the two steroids. On the other hand, THG is more potent than DHT in binding to the androgen receptor, while, under in vivo conditions, THG possesses 20% of the potency of DHT in stimulating prostate, seminal vesicle and levator ani muscle weight in the mouse. The present microarray data provide an extremely precise and unquestionable signature of the androgenic/anabolic activity of THG, an approach which should apply to the analysis of the activity of any anabolic steroid.

Treatment of pain at sexual activity (dyspareunia) with intravaginal dehydroepiandrosterone (prasterone).

OBJECTIVE: This study aims to confirm the local effects of intravaginal prasterone on moderate to severe dyspareunia, a symptom of vulvovaginal atrophy (VVA) associated with menopause. METHODS: In a prospective, randomized, double-blind, placebo-controlled phase III clinical trial, we examined the effects of daily intravaginal prasterone (6.5 mg) on four co-primary objectives, namely, percentage of vaginal parabasal cells, percentage of vaginal superficial cells, vaginal pH, and moderate to severe dyspareunia identified by women as the most bothersome VVA symptom. RESULTS: After daily intravaginal prasterone administration for 12 weeks, the percentage of parabasal cells decreased by 45.8% compared with placebo (P < 0.0001), the percentage of superficial cells increased by 4.7% over placebo (P < 0.0001), and vaginal pH decreased by 0.83 pH units compared with placebo (P < 0.0001). The severity of most bothersome dyspareunia decreased by 46% over placebo (P = 0.013) at 12 weeks, whereas moderate to severe vaginal dryness decreased by 0.43 severity score units (or 42%) compared with placebo (P = 0.013). On gynecologic evaluation, a 14.4% to 21.1% improvement in vaginal secretions, epithelial integrity, epithelial surface thickness, and color over placebo (P = 0.0002 to P < 0.0001) was observed. Serum steroids, in agreement with the physiology of intracrinology and menopause, remained well within reference postmenopausal concentrations. All endometrial biopsies at 12 weeks have shown atrophy. CONCLUSIONS: Daily intravaginal prasterone (0.50%; 6.5 mg) treatment has clinically and statistically significant beneficial effects on the four co-primary objectives of VVA, according to US Food and Drug Administration guidelines. No significant drug-related adverse effect in line with the strictly local action of treatment has been reported, thus providing a high benefit-to-risk ratio for intravaginal prasterone.

Prasterone has parallel beneficial effects on the main symptoms of vulvovaginal atrophy: 52-week open-label study.

OBJECTIVE: An objective was to analyze the time course of efficacy of daily intravaginal administration of 0.5% (6.5mg) DHEA (prasterone) for 52 weeks on the moderate to severe (MS) symptoms and signs of vulvovaginal atrophy (VVA). METHOD: Five hundred twenty-one postmenopausal women were enrolled and received daily intravaginal administration of 0.5% DHEA in an open-label phase III study. The severity of the VVA symptoms examined in detail in the different groups. RESULTS: A parallel improvement of pain at sexual activity was observed in women who had moderate to severe (MS) dyspareunia as their most bothersome symptom (MBS) (n=183) or not MBS (n=240) and MS without being MBS (n=57) with a 1.70 severity unit change in the MBS group for a decrease of 66.1% from baseline (p<0.0001 versus baseline) over 52 weeks. A further improvement of dyspareunia, namely 0.33 severity unit (19.4%), was observed with continuing treatment from 12 weeks to 52 weeks. Similar results were observed on vaginal dryness and irritation/itching. Highly significant beneficial effects (p<0.0001 versus baseline for all) were observed at gynecological examination on vaginal secretions, color, epithelial integrity and epithelial surface thickness. CONCLUSION: The present study shows, in addition to the parallel benefits on the three symptoms of VVA, that the choice of any of the MS symptoms as being or not being MBS by women has no influence on the observed therapeutic effect (NCT01256671).

Isolation of the novel human guanine nucleotide exchange factor Src homology 3 domain-containing guanine nucleotide exchange factor (SGEF) and of C-terminal SGEF, an N-terminally truncated form of SGEF, the expression of which is regulated by androgen in prostate cancer cells.

In searching for androgen-responsive genes in human prostate cancer cells, we have isolated two cDNAs that encode alternate forms of a novel Src homology 3 domain-containing guanine nucleotide exchange factor (SGEF). The SGEF mRNA is widely expressed in human tissues, and the predicted 871-amino acid SGEF protein contains Dbl homology and pleckstrin homology domains as well as an N-terminal proline-rich domain, a C-terminal Src homology 3 domain, and two nuclear localization signals. The second cDNA encodes a 139-amino acid N-terminally truncated form of SGEF designated C-terminal SGEF (CSGEF). In contrast to SGEF, CSGEF mRNA expression is restricted to prostate and liver. Moreover, CSGEF expression is up-regulated by androgens in LNCaP cells, whereas that of SGEF is not. Up-regulation of CSGEF was sensitive to actinomycin D but did not require new protein synthesis. The SGEF gene is located on chromosome 3q25.2 and consists of at least 15 exons. Based on the structure of the SGEF and CSGEF cDNAs, we deduced that CSGEF expression is controlled by an alternate androgen-responsive promoter of the SGEF gene. We hypothesize that SGEF is a ubiquitous regulator of Rho guanosine triphosphatases, whereas CSGEF may function as an androgen-induced regulator of Rho guanosine triphosphatase activity in epithelial cells of the human prostate.

The combination of a novel selective estrogen receptor modulator with an estrogen protects the mammary gland and uterus in a rodent model: the future of postmenopausal women's health?

The Women's Health Initiative Study and other reports have created major uncertainty among postmenopausal women and physicians concerning hormone replacement therapy. We have thus investigated the possibility of replacing the progestin in hormone replacement therapy by a novel selective estrogen receptor (ER) modulator having potent and pure antiestrogenic activity in the mammary gland and uterus. As measured by changes in histology and Cdc47 labeling in the rat model, the present study shows that the stimulatory effect of estradiol in the mammary gland and uterus is efficiently blocked by simultaneous administration of the novel selective ER modulator EM-652, but bone mineral density is preserved and serum cholesterol is decreased. After the administration of 14C-labeled EM-652, we observed that there is no detectable radioactivity in the brain. Moreover, ER alpha immunoreactivity remained constant in the hypothalamus after EM-652 treatment, whereas ER alpha became almost undetectable in the mammary gland and uterus. The present data show the poor or absent access of EM-652 to the brain, whereas the effects of estrogens are efficiently neutralized in the mammary gland and uterus. Such data support the exciting possibility of a novel approach that could meet most of the needs of women's health at menopause, namely control of hot flushes and prevention of breast, uterine, and ovarian cancer as well as osteoporosis and potentially helping brain function and preventing Alzheimer's disease with no identifiable risk or negative effect.

Bioavailability and pharmacokinetics of dehydroepiandrosterone in the cynomolgus monkey.

We have studied the pharmacokinetics of dehydroepiandrosterone (DHEA) administered orally (PO), i.v., and during a continuous i.v. infusion in ovariectomized cynomolgus monkeys under suppression of adrenal DHEA secretion with dexamethasone. The glucocorticoid induced a rapid suppression of serum cortisol, DHEA, and DHEA-sulfate (DHEA-S) as well as their metabolites, thus permitting to use this model to study the pharmacokinetic parameters of DHEA and its metabolites without significant interference by endogenous steroid levels. After a single 10 mg i.v. dose of DHEA, the metabolic clearance rate and terminal half-life of DHEA were 99.9 +/- 9.1 liter/d and 4.5 +/- 0.3 h, respectively. Following a 50-mg DHEA PO dose, systemic availability was only 3.1 +/- 0.4%. As shown by their high conversion ratios, the major circulating metabolites of DHEA are DHEA-S, androsterone glucuronide, and androstane-3 alpha,17 beta-diol-glucuronide. The conversion ratios of androst-5-ene-3 beta,17 beta-diol, testosterone, dihydrotestosterone, and androstenedione are, in comparison, small. No transformation to estrogens could be detected in the circulation after either i.v. or PO DHEA administration. The present data indicate that DHEA is transformed predominantly into androgens in peripheral tissues in ovariectomized cynomolgus monkeys with minimal (androgens) or no (estrogens) release of the bioactive steroids in the circulation. Furthermore, the present study supports the importance of measuring circulating androgen glucuronide derivatives to assess hormonal exposure of peripheral tissues to androgens after DHEA administration.

Plasma lipoprotein profile in the male cynomolgus monkey under normal, hypogonadal, and combined androgen blockade conditions.

In men, orchiectomy (GDX) produces an atherogenic lipid profile, whereas combined androgen blockade (CAB) induces a favorable lipid pattern. To better understand the opposite effects of GDX and CAB on lipid metabolism, we have compared the changes in plasma lipoproteins, mesenteric fat metabolism, as well as serum and intratissular sex steroid concentrations in intact, GDX, and GDX+FLU [GDX male cynomolgus monkeys treated for 3 months with flutamide (FLU)]. Serum concentrations of dehydroepiandrosterone, dehydroepiandrosterone sulfate (DHEA-S), and androstenediol remained stable after GDX. Serum androstenedione (-40%), testo (-97%), dihydrotestosterone (-89%), androsterone-glucuronide (-75%), and androstane-3alpha,17beta-diol-glucuronide (-80%) levels decreased similarly in both GDX and GDX+FLU animals. Intratissular dihydrotestosterone (-59 to -99%), estradiol (-31 to -53%), and androsterone-glucuronide (-28 to -85%) concentrations also decreased after GDX. GDX induced significant increases in plasma low-density lipoprotein (LDL) (+78%) and high-density lipoprotein (+34%) cholesterol as well as in LDL-apoB (+58%) and high-density lipoprotein-apoAI (+32%). In the GDX+FLU group, except for the LDL-apoB that showed a tendency to decrease, lipid and apoprotein parameters remained unchanged compared with baseline values measured in intact animals. It is worth noting that these differences in the lipid profile could not be explained by changes in the metabolism of mesenteric adipose tissue. In summary, in the cynomolgus monkey, GDX and CAB induced opposite effects on the plasma lipoprotein profile. These differences possibly result from differences in the specific activity of the androgens and estrogens derived from adrenal precursors. Such data support the suggestion that androgens and estrogens produced from adrenal precursors in peripheral intracrine tissues could have important, but so-far unsuspected, effects on the homeostasis of lipid and lipoprotein metabolism.

Gene expression profiling by DNA microarray analysis in mouse embryonic fibroblasts transformed by rasV12 mutated protein and the E1A oncogene.

BACKGROUND: Ras is an area of intensive biochemical and genetic studies and characterizing downstream components that relay ras-induced signals is clearly important. We used a systematic approach, based on DNA microarray technology to establish a first catalog of genes whose expression is altered by ras and, as such, potentially involved in the regulation of cell growth and transformation. RESULTS: We used DNA microarrays to analyze gene expression profiles of rasV12/E1A-transformed mouse embryonic fibroblasts. Among the approximately 12,000 genes and ESTs analyzed, 815 showed altered expression in rasV12/E1A-transformed fibroblasts, compared to control fibroblasts, of which 203 corresponded to ESTs. Among known genes, 202 were up-regulated and 410 were down-regulated. About one half of genes encoding transcription factors, signaling proteins, membrane proteins, channels or apoptosis-related proteins was up-regulated whereas the other half was down-regulated. Interestingly, most of the genes encoding structural proteins, secretory proteins, receptors, extracellular matrix components, and cytosolic proteins were down-regulated whereas genes encoding DNA-associated proteins (involved in DNA replication and reparation) and cell growth-related proteins were up-regulated. These data may explain, at least in part, the behavior of transformed cells in that down-regulation of structural proteins, extracellular matrix components, secretory proteins and receptors is consistent with reversion of the phenotype of transformed cells towards a less differentiated phenotype, and up-regulation of cell growth-related proteins and DNA-associated proteins is consistent with their accelerated growth. Yet, we also found very unexpected results. For example, proteases and inhibitors of proteases as well as all 8 angiogenic factors present on the array were down-regulated in transformed fibroblasts although they are generally up-regulated in cancers. This observation suggests that, in human cancers, proteases, protease inhibitors and angiogenic factors could be regulated through a mechanism disconnected from ras activation. CONCLUSIONS: This study established a first catalog of genes whose expression is altered upon fibroblast transformation by rasV12/E1A. This catalog is representative of the genome but not exhaustive, because only one third of expressed genes was examined. In addition, contribution to ras signaling of post-transcriptional and post-translational modifications was not addressed. Yet, the information gathered should be quite useful to future investigations on the molecular mechanisms of oncogenic transformation.