Immunoelectron microscopic localization of 3beta-hydroxysteroid dehydrogenase and type 5 17beta-hydroxysteroid dehydrogenase in the human prostate and mammary gland

Evidence on Statins, Omega-3, and Prostate Cancer: A Narrative Review

Dietary intake selections might play a crucial role in prostate cancer (PCa) occurrence and progression. Several studies have investigated whether statin use could reduce PCa risk but with conflicting results. Nevertheless, a significantly decreased incidence of advanced PCa has been consistently noted. Statins may also reduce the risk of biochemical recurrence (BCR) in men with PCa after receiving active treatment. However, the influence of statin usage on BCR and PCa progression in men with high prostate-specific antigen levels has been found to be insignificant. In contrast, the combined use of a statin and metformin was significantly related to the survival status of PCa patients. However, some studies have revealed that the intake of long-chain omega-3 fatty acid (ω-3) from fish or fish oil supplements may elevate PCa risk. Several meta-analyses on ω-3 consumption and PCa have shown controversial results for the relationship between PCa and ω-3 consumption. However, studies with positive results for various genotypes, fatty acid intake or levels, and PCA risk are emerging. This review highlights the association among statins, ω-3, and PCa. The findings summarized here may be helpful for clinicians counseling patients related to PCa.

The role of 17βHSDs in breast tissue and breast cancers

The family of seventeen beta hydroxysteroid dehydrogenase enzymes has a long and diverse history in breast and breast cancer research. Given the known dependence of the breast on steroid signalling and intracrine steroid metabolism these enzymes are considered to be essential local fine tuners of overall steroid balance in the tissue. This review will cover the current state of knowledge regarding the expression, clinical effect and biological regulation of enzymes in both cancerous and normal states. In addition we will also cover the current state of knowledge regarding 17βHSD actions in the often neglected adipose and stromal components of tumours.

Study of the association of DHEAS, testosterone and cortisol with S-Klotho plasma levels in healthy sedentary middle-aged adults

BACKGROUND

α-Klotho is a recently discovered gene that accelerates ageing when disrupted and extends lifespan when overexpressed. The age-related decline in DHEAS and testosterone secretion and the increase in cortisol are associated with a rise of frailty and mortality.

OBJECTIVE

To investigate the association of DHEAS, cortisol and testosterone plasma levels with S-Klotho plasma levels in healthy sedentary middle-aged adults.

METHODS

73 (39 women) healthy middle-aged sedentary adults (45-65 years old) were recruited for the present study. The blood samples were collected in the morning after fasting for 12 h.

RESULTS

DHEAS was positively associated with S-Klotho in men (β = 0.521, R² = 0.248, P = 0.002), whereas no association was observed in women (P ≥ 0.201). Testosterone was positively associated with S-Klotho in both men and women (β = 0.360, R² = 0.099, P = 0.047; β = 0.431, R² = 0.161, P = 0.010, respectively). No association was found between cortisol and S-Klotho neither in men nor in women (all P ≥ 0.141). The association between DHEAS and testosterone with S-Klotho in men disappeared after adjusting by age (all P ≥ 0.151). Nevertheless, the association between testosterone (β = 0.397, R² = 0.423, P = 0.011) and S-Klotho in women remained after adjusting by age.

CONCLUSIONS

DHEAS and testosterone were positively associated with S-Klotho in healthy sedentary middle-aged men while only testosterone was positively associated in women.

Berberine inhibits androgen synthesis by interaction with aldo-keto reductase 1C3 in 22Rv1 prostate cancer cells

Aldo-keto reductase family 1 member C3 has recently been regarded as a potential therapeutic target in castrate-resistant prostate cancer. Herein, we investigated whether berberine delayed the progression of castrate-resistant prostate cancer by reducing androgen synthesis through the inhibition of Aldo-keto reductase family 1 member C3. Cell viability and cellular testosterone content were measured in prostate cancer cells. Aldo-keto reductase family 1 member C3 mRNA and protein level were detected by RT-PCR and Western bolt analyses, respectively. Computer analysis with AutoDock Tools explored the molecular interaction of berberine with Aldo-keto reductase family 1 member C3. We found that berberine inhibited 22Rv1 cells proliferation and decreased cellular testosterone formation in a dose-dependent manner. Berberine inhibited Aldo-keto reductase family 1 member C3 enzyme activity, rather than influenced mRNA and protein expressions. Molecular docking study demonstrated that berberine could enter the active center of Aldo-keto reductase family 1 member C3 and form p-p interaction with the amino-acid residue Phe306 and Phe311. In conclusion, the structural interaction of berberine with Aldo-keto reductase family 1 member C3 is attributed to the suppression of Aldo-keto reductase family 1 member C3 enzyme activity and the inhibition of 22Rv1 prostate cancer cell growth by decreasing the intracellular androgen synthesis. Our result provides the experimental basis for the design, research, and development of AKR1C3 inhibitors using berberine as the lead compound.

The current evidence on statin use and prostate cancer prevention: are we there yet?

An increasing amount of data supports an inverse association between statin use and cancer risk. The findings for prostate cancer, particularly advanced disease, are the most promising of all cancers studied. Use of these agents seems to also be associated with improved prostate- cancer-specific survival, particularly in men undergoing radiotherapy, suggesting usefulness of statins in secondary and tertiary prevention. Some study results might be influenced by increased PSA screening and health-conscious behaviour in statin users but these factors are unlikely to completely account for observed beneficial effects. The epidemiological evidence is supported by preclinical studies that show that statins directly inhibit prostate cancer development and progression in cell-based and animal-based models. The antineoplastic effect of statins might arise from a number of cholesterol-mediated and non-cholesterol-mediated mechanisms that affect pathways essential for cancer formation and progression. Understanding these mechanisms is instrumental in drug discovery research for the development of future prostate cancer therapeutics, as well as in designing clinical trials to test a role for statins in prostate cancer prevention. Currently, sufficient data are lacking to support the use of statins for the primary prevention of prostate cancer and further research is clearly warranted. Secondary and tertiary prevention trials in men who have been diagnosed with prostate cancer might soon be performed.

Progesterone induces progesterone receptor gene (PGR) expression via rapid activation of protein kinase pathways required for cooperative estrogen receptor alpha (ER) and progesterone receptor (PR) genomic action at ER/PR target genes

Progesterone Receptors (PRs) are critical effectors of estrogen receptor (ER) signaling required for mammary gland development and reproductive proficiency. In breast and reproductive tract malignancies, PR expression is a clinical prognostic marker of ER action. While estrogens primarily regulate PR expression, other factors likely contribute to a dynamic range of receptor expression across diverse tissues. In this study, we identified estrogen-independent but progestin (R5020)-dependent regulation of ER target genes including PGR in ER+/PR+ cancer cell lines. R5020 (10nM-10μM range) induced dose-dependent PR mRNA and protein expression in the absence of estrogen but required both PR and ERα. Antagonists of either PR (RU486, onapristone) or ERα (ICI 182,780) attenuated R5020 induction of TFF1, CTSD, and PGR. Chromatin immunoprecipitation (ChIP) assays performed on ER+/PR+ cells demonstrated that both ERα and PR were recruited to the same ERE/Sp1 site-containing region of the PGR proximal promoter in response to high dose progestin (10μM). Recruitment of ERα and PR to chromatin and subsequent PR mRNA induction were dependent upon rapid activation of MAPK/ERK and AKT; inhibition of these kinase pathways via U0126 or LY294002 blocked these events. Overall, we have identified a novel mechanism of ERα activation initiated by rapid PR-dependent kinase pathway activation and associated with phosphorylation of ERα Ser118 for estrogen-independent but progestin-dependent ER/PR cross talk. These studies may provide insight into mechanisms of persistent ER-target gene expression during periods of hormone (i.e. estrogen) ablation and suggest caution following prolonged treatment with aromatase or CYP17 inhibitors (i.e. contexts when progesterone levels may be abnormally elevated).

Human 3β-hydroxysteroid dehydrogenase type 1 in human breast cancer: clinical significance and prognostic associations

Active sex steroids including estrogens and androgens are locally produced from circulating inactive steroids by various steroid-metabolizing enzymes, and play pivotal roles in the progression of hormone-dependent breast cancers. Human 3β-hydroxysteroid dehydrogenase type 1 (3β-HSD type 1) is a critical enzyme in the formation of all classes of active steroid hormones, and is also involved in the inactivation of potent androgen dihydrotestosterone (DHT). Therefore, this enzyme is suggested to modulate active sex steroid production or inactivation, with a role in hormone-dependent breast cancer. The purpose of this study was to investigate the clinical significance of 3β-HSD type 1 in human breast cancer. Using immunohistochemistry (IHC), we evaluated 3β-HSD type 1 expression in 161 human breast cancers and analyzed correlations of 3β-HSD type 1 expression with various clinicopathological factors. Of 161 breast cancer cases, 3β-HSD type 1 expression in cancer cells was detected in 119 cases (73.9%), and was positively correlated with estrogen receptor (ER)-positivity but not HER-2 status. In ER-positive cases (n = 130), 3β-HSD type 1 expression was inversely correlated with invasive tumor size (P = 0.0009), presence of invasive region (P = 0.0107), and lymphatic involvement (P = 0.0004). 3β-HSD type 1 expression was significantly associated with decreased risk of recurrence or improved prognosis by both univariate (P = 0.0003 and P = 0.009, respectively) and multivariate (P = 0.027 and P = 0.023, respectively) analyses. Our findings indicate that this enzyme is a prognostic factor in hormone-dependent breast cancer.

Reconsideration of progression to CRPC during androgen deprivation therapy

Androgen blockade-naïve prostate cancer (PCa) develops into CRPC during androgen deprivation therapy (ADT) by various genetic actions. The androgen-AR signaling axis plays a key role in this development. PCa cells mainly adapt themselves to the environment of lower androgen concentrations and change into androgen-hypersensitive cells or androgen-independent cells. Androgens of adrenal origin and their metabolites synthesized in the microenvironment in an intracrine/paracrine fashion act on surviving PCa cells and secrete prostate specific antigen (PSA). Total androgen deprivation (TAD) (castration, antiandrogen, and CYP17A1 inhibitor) can become an effective therapeutic strategy concerning the androgen signaling axis-related pathway. However, it is important to ascertain whether elevation of serum PSA results from AR activation or from an androgen-independent tumor volume effect. Then, clinicians can judge it adequately using the imaging studies such as CT or bone scan as well as PSA and bone metabolic markers, an approach which is necessary to judge which treatment is most suitable for the CRPC patients. This article is part of a Special Issue entitled 'Essential role of DHEA'.

The intracrinology of breast cancer

The importance of intracrinology, or in situ production of steroids from circulating precursors, in breast cancer has been firmly established in estrogen actions on postmenopausal patients. Expression levels of various steroid synthesizing and/or metabolizing enzymes have been examined in human breast cancer tissues by a number of groups. The enzymes examined include those capable of converting circulating DHEA-S to sex steroids (STS and 3βHSDΔ4-5 isomerase), the group of enzymes that modulate the strength of both androgens and estrogens (17βHSD family) as well as the androgenic 5αR enzymes and the estrogenic aromatase enzyme. In addition to these DHEA-related metabolism pathways, other intracrine pathways involving progesterone and cholesterol have also been examined. Some risk factors of breast cancer development, including obesity, have also been postulated to interact with steroid metabolising pathways. In this review, we aimed to summarise the current state of knowledge regarding intracrine metabolism including expression levels of various enzymes and receptors, focusing particularly upon the importance of the production of biologically potent steroids from circulating sulfated precursors such as DHEA-S. In addition, we attempted to summarise the factors, both steroidal and non-steroidal, involved in the regulation of these enzymes and propose future directions for research in this particular field. The concept of intracrinology was first proposed over 20 years ago but there still remain many unanswered questions which could open new horizons for the understanding of intracrine metabolism in the breast. This article is part of a Special Issue entitled 'Essential role of DHEA'.

Adrenal hypoplasia congenita presenting as congenital adrenal hyperplasia

We report on a patient with genetically confirmed adrenal hypoplasia congenita (AHC) whose presentation and laboratory abnormalities were consistent with the more common condition, congenital adrenal hyperplasia (CAH). The patient presented with failure to thrive and salt wasting. General appearance showed marked hyperpigmentation and normal male genitalia. He displayed mildly elevated 17-hydroxyprogesterone and markedly elevated 11-deoxycortisol levels at baseline and with ACTH stimulation testing. Results were consistent with 11 β -hydroxylase deficiency. He required glucocorticoids and high doses of mineralocorticoids. The marked elevation in 11-deoxycortisol directed our clinical reasoning away from a hypoplastic condition and towards a hyperplasic adrenal condition. Sequencing of the DAX1 gene (named for dosage-sensitive sex reversal (DSS) locus and the AHC locus on the X chromosome) revealed a missense mutation. A review of the literature revealed that elevated 11-deoxycortisol levels have been noted in kindreds with DAX1 mutations, but only when measured very early in life. A mouse model has recently been described that displays elevated 11-deoxycorticosterone levels and evidence for hyperplasia of the zona glomerulosa of the adrenal gland. We conclude that DAX1 testing may be considered in patients with laboratory evidence of 11 β -hydroxylase deficiency, especially in those with severe salt wasting.

Transforming growth factor β1 increase of hydroxysteroid dehydrogenase proteins is partly suppressed by red clover isoflavones in human primary prostate cancer-derived stromal cells

Transforming growth factor β1 (TGF-β1) increases dehydro-epiandrosterone (DHEA) metabolism to androgens and prostate-specific antigen (PSA) in a prostate tissue model where stromal (6S) cells and epithelial (LAPC-4) cells are cocultured. Red clover (RC) isoflavones inhibits transforming growth factor (TGF)-β-induced androgenicity. Mechanisms controlling those activities were explored. Three hydroxysteroid dehydrogenases (HSDs), 3β-HSD, HSD-17β1 and HSD-17β5 involved in metabolizing DHEA to testosterone (TESTO) were investigated. Individual depletion of HSDs in 6S cells significantly reduced TGF-β1/DHEA-induced PSA in LAPC-4 cells in cocultures. Monomer amounts of 3β-HSD were similar without or with TGF-β1 in both cell types but aggregates of 3β-HSD in 6S cells were much higher than those in LAPC-4 cells and were upregulated by TGFβ in 6S cells. Basal and TGF-β1-treated levels of HSD-17β1 and HSD-17β5 in LAPC-4 cells were significantly lower than in 6S cells, whereas levels of HSD-17β1 but not HSD-17β5 were TGFβ inducible. 6S cell HSD genes expression induced by TGFβ or androgen signaling was insignificant to contribute TGF-β1/DHEA-upregulated protein levels of HSDs. RC decreased TGF-β1- upregulation of aggregates of 3β-HSD but not HSD-17β1. Depletion of TGFβ receptors (TGFβ Rs) reduced TGF-β1/DHEA-upregulated HSDs and TESTO. Immunoprecipitation studies demonstrated that TGF-β1 disrupted associations of TGFβ Rs/HSDs aggregates, whereas RC suppressed the dissociations of aggregates of 3β-HSD but not HSD-17β1 from the receptors. Given that TGFβ Rs are recycled with or without ligand, TGF-β1-induced disassociation of the HSDs from TGFβ Rs may increase stability and activity of the HSDs. These data suggest a pathway connecting overproduction of TGFβ with increased PSA in prostate cancer.

Chinese red yeast rice inhibition of prostate tumor growth in SCID mice

Prostate cancer is a slowly developing but very common cancer in males that may be amenable to preventive strategies that are not toxic. Chinese red yeast rice (RYR), a food herb made by fermenting Monascus purpureus Went yeast on white rice, contains a mixture of eight different monacolins that inhibit cholesterogenesis in addition to red pigments with antioxidant properties. Monacolin K is identical to lovastatin (LV), but LV unlike RYR can be used in individuals intolerant to statins due to muscle pain. Both LV and RYR inhibit de novo cholesterogenesis, which is critical to the growth of tumor cells. Long-term use of statin drugs has been associated with a reduced risk of prostate cancer. We have previously shown that RYR inhibited androgen-dependent and androgen receptor-overexpressing androgen-independent prostate cancer cell proliferation in vitro. This study was designed to determine whether RYR and LV inhibit prostate tumor growth in SCID mice. RYR significantly reduced tumor volumes of androgen-dependent and androgen-independent prostate xenograft tumors compared with animals receiving vehicle alone (P < 0.05). Inhibition by RYR was greater than that observed with LV at the dose found in RYR, showing that other compounds in RYR contributed to the antiproliferative effect. There was a significant correlation of tumor volume to serum cholesterol (P < 0.001). RYR decreased gene expression of androgen synthesizing enzymes (HSD3B2, AKR1C3, and SRD5A1) in both type of tumors (P < 0.05). Clinical studies of RYR for prostate cancer prevention in the increasing population of men undergoing active surveillance should be considered.

Integrated view on 17beta-hydroxysteroid dehydrogenases

17beta-Hydroxysteroid dehydrogenases (17beta-HSDs) are important enzymes in steroid metabolism. Long known members of the protein family seemed to be well characterised concerning their role in the regulation of the biological potency of steroid hormones, but today more and more evidence points to pivotal contributions of these enzymes in a variety of other metabolic pathways. Therefore, studies on 17beta-HSDs develop towards metabolomic survey. Latest research results give new insights into the complex metabolic interconnectivity of the 17beta-HSDs. In this paper metabolic activities of 17beta-HSDs will be compared, their interplay with endogenous substrates summarised, and interlacing pathways depicted. Strategies on deciphering the physiological role of 17beta-HSDs and the genetic predisposition for associated diseases will be presented.

Chinese red yeast rice versus lovastatin effects on prostate cancer cells with and without androgen receptor overexpression

Chinese red yeast rice (RYR), a food herb made by fermenting Monascus purpureus Went yeast on white rice, contains a mixture of eight different monacolins that inhibit cholesterogenesis and also red pigments with antioxidant properties. Monacolin K (MK) is identical to lovastatin (LV). Both LV and RYR contain statins, which could inhibit de novo cholesterogenesis, which is critical to the growth of tumor cells. Dysregulation of the cholesterol biosynthetic pathway has been demonstrated during progression to androgen independence in xenograft models, and it has been proposed that cholesterogenesis and androgen receptor (AR) up-regulation are essential to androgen-independent cell survival. This study was designed to examine the differences between the effects of RYR and LV on androgen-dependent LNCaP cells and androgen-independent cells overexpressing AR (LNCaP-AR). RYR showed more potent inhibition effect on prostate cancer cell growth compared to LV. Both the pigment and monacolin-enriched fractions purified from RYR inhibited proliferation (P < .001) to a lesser extent than intact RYR. While mevalonate, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), restored proliferation in LV-treated cells, it failed to do so in RYR-treated cells. Expression of the HMGCR gene was up-regulated by LV (P < .001) but not RYR in both LNCaP and LNCaP-AR cells. These results suggest that the RYR matrix beyond MK alone may be bioactive in inhibiting androgen-dependent and -independent prostate cancer growth. In vivo studies are needed to further establish the potential advantages of RYR over LV in prostate cancer chemoprevention and in the prevention of the emergence of androgen independence.

Steroid hormone transforming aldo-keto reductases and cancer

Prostate and breast cancer are hormone-dependent malignancies of the aging male and female and require the local production of androgens and estrogens to stimulate cell proliferation. Aldo-keto reductases (AKR) play key roles in this process. In the prostate, AKR1C3 (type 5 17beta-HSD) reduces Delta(4)-androstene-3,17-dione to yield testosterone while AKR1C2 (type 3 3alpha-HSD) eliminates 5alpha-dihydrotestosterone (5alpha-DHT), and AKR1C1 forms 3beta-androstanediol (a ligand for ERbeta). In the breast, AKR1C3 forms testosterone, which is converted to 17beta-estradiol by aromatase or reduces estrone to 17beta-estradiol directly. AKR1C3 also acts as a prostaglandin (PG) F synthase and forms PGF(2alpha) and 11beta-PGF(2alpha), which stimulate the FP receptor and prevent the activation of PPARgamma by PGJ(2) ligands. This proproliferative signaling may stimulate the growth of hormone-dependent and -independent prostate and breast cancer.

The Role of Androgens in Normal and Malignant Breast Tissue

Androgens, like estrogens, can be synthesized in the breast. As both active androgens and their corresponding receptors are present in breast tissue, we conclude that they play a role in breast physiology. This is supported by the fact that insufficient androgen production or sensitivity results in the development of gynecomastia. Complete androgen insensitivity due to receptor defects leads to normal female breast development in these XY women. While breast development is completely inhibited by male testosterone levels, partial but not total degradation of a developed breast by androgen treatment appears to be possible. Breast cancer in early stages seems to fulfill the prerequisites of androgen responsiveness. Androgen treatment of advanced breast cancer has shown similar effectiveness as anti-estrogen or estrogen-ablative therapy, but also considerable side effects. It has been speculated that the use of selective androgen modulators (SARMs), either alone or preferably in addition to anti-estrogens or aromatase inhibitors, may be a promising alternative to current therapy modalities in hormone-dependent breast cancer. In addition, future studies on the use of SARMs in prophylactic settings seem to be justified.

Expression of steroidogenic enzymes and sex-steroid receptors in human prostate

Identification of the cell types expressing the steroidogenic enzymes and sex steroid receptors in the human prostate has recently been performed using immunocytochemistry and in-situ hybridization. The enzymes 3beta-hydroxysteroid dehydrogenase (3beta-HSD), which converts dehydroepiandrosterone (DHEA) into androstenedione, and type 5 17beta-HSD, which catalyzes the reduction of androstenedione to testosterone, have been localized in basal cells of alveoli as well as in stromal cells and endothelial cells of blood vessels. On the other hand, type-2 5alpha-reductase, which converts testosterone into the most potent androgen dihydrotestosterone (DHT), has been mostly observed in the luminal cells in alveoli. Aromatase, which converts testosterone into estradiol, has also been found to be expressed in the luminal cells of the alveoli as well as in stromal cells. Androgen receptor (AR) has been localized in luminal cell nuclei of alveoli and a large number of stromal cells, while estrogen receptor beta has been detected in both basal and luminal cells in alveoli and also in stromal cells.

Do Statins Affect Androgen Levels in Men? Results from the Boston Area Community Health Survey

BACKGROUND

In 2005, statins were among the most commonly used prescription medications in the United States. Some data suggest statins may affect cancer risk and/or disease severity. Because cholesterol is a required intermediate in sex steroid synthesis, it is possible that statins influence prostate cancer risk through effects on steroid hormone metabolism. We investigated whether levels of circulating androgens and their carrier protein, sex hormone-binding globulin (SHBG), varied by statin exposure among a sample of 1,812 men from a population-based epidemiologic study, the Boston Area Community Health Survey.

METHODS

We measured serum total testosterone, free testosterone, dehydroepiandrosterone sulfate, luteinizing hormone, and SHBG. Statin exposure was collected through participant self-report and/or interviewer-recorded information. Multivariate linear models were constructed to account for potential confounding.

RESULTS

The prevalence of statin use was 12.4% [95% confidence interval (95% CI), 10.3-14.9]. On average, statin users were older, had larger body mass index and more chronic illnesses, and used more medications. We found no relationship between statin use and free testosterone, dehydroepiandrosterone sulfate, or luteinizing hormone. A significant association between statin use and total testosterone was initially observed but was not robust to covariate control in a multivariate model that included age, body mass index, time since awakening, and history of cardiovascular disease and diabetes (-5.5%; 95% CI, -13.2 to 2.9%). In multivariate models adjusted similarly, SHBG levels among statin users were statistically significantly lower compared with nonusers (-10.6%; 95% CI, -18.8 to -1.6%).

CONCLUSION

In this sample, it is unlikely that statins affect circulating androgens and prostate cancer risk through a hormonal mechanism.

Transcript profiling of the androgen signal in normal prostate, benign prostatic hyperplasia, and prostate cancer

Human prostate adenocarcinoma (CaP) and benign prostatic hyperplasia (BPH) have epithelial and stromal cell origins, respectively. To determine whether the androgen signal is processed differently in these cell types the expression of transcripts for enzymes that control ligand access to the androgen receptor (AR) were measured. Transcripts for type 2 5alpha-reductase, ketosteroid reductases [aldo-keto reductase (AKR)1C1-AKR1C4], the major oxidative 3alpha-hydroxysteroid dehydrogenase (HSD) retinol dehydrogenase (RODH)-like 3alpha-HSD (RL-HSD) and nuclear receptors [AR, estrogen receptor (ER)alpha, and ERbeta] were determined in whole human prostate and in cultures of primary epithelial cells (PEC) and primary stromal cells (PSC) from normal prostate, CaP and BPH by real-time RT-PCR. Normal PEC (n=14) had higher levels of AKR1C1 (10-fold, P<0.001), AKR1C2 (115-fold, P<0.001) and AKR1C3 (6-fold, P<0.001) than normal PSC (n=15), suggesting that reductive androgen metabolism occurs. By contrast, normal PSC had higher levels of AR (8-fold, P<0.001) and RL-HSD (21-fold, P<0.001) than normal PEC, suggesting that 3alpha-androstanediol is converted to 5alpha-dihydrotestosterone to activate AR. In CaP PEC (n=14), no significant changes in transcript levels vs. normal PEC were observed. In BPH PSC (n=21) transcripts for AR (2-fold, P<0.001), AKR1C1 (4-fold, P<0.001), AKR1C2 (10-fold P<0.001), AKR1C3 (4-fold, P<0.001) and RL-HSD (3-fold, P<0.003) were elevated to increase androgen response. Differences in the AR:ERbeta transcript ratios (eight in normal PEC vs. 280 in normal PSC) were maintained in PEC and PSC in diseased prostate. These data suggest that CaP may be more responsive to an ERbeta agonist and BPH may be more responsive to androgen ablation.

Aldo-keto reductase (AKR) 1C3: role in prostate disease and the development of specific inhibitors

Human aldo-keto reductases (AKR) of the 1A, 1B, 1C and 1D subfamilies are involved in the pre-receptor regulation of nuclear (steroid hormone and orphan) receptors by regulating the local concentrations of their lipophilic ligands. AKR1C3 is one of the most interesting isoforms. It was cloned from human prostate and the recombinant protein was found to function as a 3-, 17- and 20-ketosteroid reductase with a preference for the conversion of Delta4-androstene-3,17-dione to testosterone implicating this enzyme in the local production of active androgens within the prostate. Using a validated isoform specific real-time RT-PCR procedure the AKR1C3 transcript was shown to be more abundant in primary cultures of epithelial cells than stromal cells, and its expression in stromal cells increased with benign and malignant disease. Using a validated isoform specific monoclonal Ab, AKR1C3 protein expression was also detected in prostate epithelial cells by immunoblot analysis. Immunohistochemical staining of prostate tissue showed that AKR1C3 was expressed in adenocarcinoma and surprisingly high expression was observed in the endothelial cells. These cells are a rich source of prostaglandin G/H synthase 2 (COX-2) and vasoactive prostaglandins (PG) and thus the ability of recombinant AKR1C enzymes to act as PGF synthases was compared. AKR1C3 had the highest catalytic efficiency (kcat/Km) for the 11-ketoreduction of PGD2 to yield 9alpha,11beta-PGF2 raising the prospect that AKR1C3 may govern ligand access to peroxisome proliferator activated receptor (PPARgamma). Activation of PPARgamma is often a pro-apoptotic signal and/or leads to terminal differentiation, while 9alpha,11beta-PGF2 is a pro-proliferative signal. AKR1C3 is potently inhibited by non-steroidal anti-inflammatory drugs suggesting that the cancer chemopreventive properties of these agents may be mediated either by inhibition of AKR1C3 or COX. To discriminate between these effects we developed potent AKR1C inhibitors based on N-phenylanthranilic acids that do not inhibit COX-1 or COX-2. These compounds can now be used to determine the role of AKR1C3 in producing two proliferative signals in the prostate namely testosterone and 9alpha,11beta-PGF2.

Immunolocalization of 3beta-hydroxysteroid dehydrogenase in normal and hyperplastic ram prostates

The enzyme 3beta-hydroxysteroid dehydrogenase (3beta-HSD) is essential in the synthesis of all steroids by cleaving dehydroepiandrosterone to androstenedione. In the present study, 3beta-HSD immunoreactivity was investigated in the prostate of Akkaraman breed rams aged older than 3 years. Five normal and five hyperplastic ram prostates were processed for immunohistochemistry. Prostate hyperplasia was determined by histopathological evaluation of 375 ram prostate and confirmed with significantly (P<0.01) increased number of cells expressing proliferating cell nuclear antigen (PCNA) immunoreactivity in the glandular epithelia. The 3beta-HSD immunoreactivity with a variable intensity and pattern of distribution was present in the glandular epithelia and endothelia of blood vessels in normal and hyperplastic ram prostates. While immunoreactivity was focally present in some glands, some sections had a homogenous distribution. The presence of 3beta-HSD immunoreactivity indicates that steroids are locally synthesized in the ram prostate. No differences in the distribution pattern of 3beta-HSD immunoreactivity and the percentage of immunoreactive cells were observed between normal and hyperplastic prostates (P>0.05), suggesting that locally produced steroids have little or no effect on the pathogenesis of the ram prostate hyperplasia which affects a very small proportion of the ram population (5 out of 375).

Comparison of hormone levels in nipple aspirate fluid of pre- and postmenopausal women: effect of oral contraceptives and hormone replacement

The effects of ovarian suppression by oral contraceptives as well as hormone replacement therapy were studied on hormone levels and on products of hormone action in nipple aspirate fluid (NAF) from breasts of pre- and postmenopausal women. Multiple samples per subject revealed high consistency (intraclass correlation coefficients) for all products measured. Compared with premenopausal women, NAF progesterone was much lower in postmenopausal women, but NAF androstenedione, dehydroepiandrosterone, and dehydroepiandrosterone sulfate concentrations were not different. With oral contraceptive use, estradiol, estrone sulfate, and progesterone levels were similarly lower in serum and NAF. In postmenopausal women, NAF estradiol and estrone sulfate were not significantly less than those in premenopausal women, nor were epidermal growth factor or cathepsin D levels, but IL-6 was elevated. Despite corresponding changes in hormones in serum and NAF over time, correlations based on simultaneous sampling were not significant. It is concluded that: 1) potential precursors of estradiol remain at comparable levels in the breast after menopause; 2) local synthesis is important for maintenance of estradiol levels in NAF of postmenopausal women but less important for progesterone; and 3) changes in the serum parameters are accurately reflected in NAF, but only after a matter of days. These findings provide additional validation for the physiological relevance of NAF hormone levels as potential breast cancer risk markers.

Major impact of hormonal therapy in localized prostate cancer--death can already be an exception

For about 50 years, androgen blockade in prostate cancer has been limited to monotherapy (surgical castration) or high doses of estrogens in patients with advanced disease and bone metastases. The discovery of medical castration with LHRH agonists has led to fundamental changes in the endocrine therapy of prostate cancer. In 1979, the first prostate cancer patient treated with an LHRH agonist received such treatment at the Laval University Medical Center. A long series of studies have clearly demonstrated that medical castration with an LHRH agonist has inhibitory effects on prostate cancer equivalent to those of surgical castration. The much higher acceptability of LHRH agonists has been essential to permit a series of studies in localized disease. Based upon the finding that the testicles and adrenals contribute approximately equal amounts of androgens in the human prostate, the combination of medical (LHRH agonist) or surgical castration associated with a pure antiandrogen (flutamide, nilutamide or bicalutamide) has led to the first demonstration of a prolongation of life in prostate cancer, namely a 10-20% decreased risk of death according to the various metaanalyses of all the studies performed in advanced disease. In analogy with the other types of advanced cancers, the success of combined androgen blockade in metastatic disease is limited by the development of resistance to treatment. To avoid the problem of resistance to treatment while taking advantage of the relative ease of diagnosis of prostate cancer at an "early" stage, the much higher acceptability of LHRH agonists has permitted a series of studies which have demonstrated a major reduction in deaths from prostate cancer ranging from 31% to 87% at 5 years of follow-up in patients with localized or locally advanced prostate cancer. Most importantly, recent data show that the addition of a pure antiandrogen to an LHRH agonist in order to block the androgens made locally in the prostate leads to a 90% long-term control or probable cure of prostate cancer.

Characterization of a monoclonal antibody for human aldo-keto reductase AKR1C3 (type 2 3alpha-hydroxysteroid dehydrogenase/type 5 17beta-hydroxysteroid dehydrogenase); immunohistochemical detection in breast and prostate

Human aldo-keto reductase AKR1C3 (type 2 3alpha-hydroxysteroid dehydrogenase/type 5 17beta-hydroxysteroid dehydrogenase) catalyzes the reduction of Delta(4)-androstene-3,17-dione to yield testosterone, the reduction of 5alpha-dihydrotestosterone to yield 3alpha- and 3beta-androstanediol, and the reduction of estrone to yield 17beta-estradiol. Relatively, high mRNA expression of AKR1C3 was found in human prostate and mammary gland where it is implicated in regulating ligand access to the androgen and estrogen receptor, respectively. AKR1C3 shares high sequence identity >86% with related plastic human 20alpha-hydroxysteroid dehydrogenases (AKR1C1), type 3 3alpha-hydroxysteroid dehydrogenase (AKR1C2) and type 1 3alpha-hydroxysteroid dehydrogenase (AKR1C4), and reagents are urgently needed to discriminate between these enzymes at the mRNA, protein and functional level. We describe the characterization of a high-titer isoform specific monoclonal antibody (Ab) for AKR1C3. It does not cross react with human AKR1C1, AKR1C2 or AKR1C4, human aldehyde reductase AKR1A1 or rat 3alpha-hydroxysteroid dehydrogenase (AKR1C9) on immunoblot analysis. The monoclonal Ab can be used to detect AKR1C3 expression by immunohistochemistry in sections of paraffin-embedded mammary gland and prostate. In the breast enzyme staining was detected in ductal carcinoma in situ where the cancerous cells were strongly immunoreactive. In normal prostate immunoreactivity was limited to stromal cells with only faint staining in the epithelial cells. In adenocarcinoma of the prostate elevated staining was observed in the endothelial cells and carcinoma cells. The reagent thus has utility to access the localized expression of AKR1C3 in hormonal dependent malignancies of the breast and prostate.

Development of nonsteroidal anti-inflammatory drug analogs and steroid carboxylates selective for human aldo-keto reductase isoforms: potential antineoplastic agents that work independently of cyclooxygenase isozymes

Human aldo-keto reductases (AKRs) regulate nuclear receptors by controlling ligand availability. Enzymes implicated in regulating ligand occupancy and trans-activation of the nuclear receptors belong to the AKR1C family (AKR1C1-AKR1C3). Nuclear receptors regulated by AKR1C members include the steroid hormone receptors (androgen, estrogen, and progesterone receptors) and the orphan peroxisome proliferator-activated receptor (PPARgamma). In human myeloid leukemia (HL-60) cells, ligand access to PPARgamma is regulated by AKR1C3, which diverts PGD(2) metabolism away from J-series prostanoids (Desmond et al., 2003). Inhibition of AKR1C3 by indomethacin, a nonsteroidal anti-inflammatory drug (NSAID), caused PPARgamma-mediated terminal differentiation of the HL-60 cells. To discriminate between antineoplastic effects of NSAIDs that are mediated by either AKR1C or cyclooxygenase (COX) isozymes, selective inhibitors are required. We report a structural series of N-phenylanthranilic acid derivatives and steroid carboxylates that selectively inhibit recombinant AKR1C isoforms but do not inhibit recombinant COX-1 or COX-2. The inhibition constants, IC(50), K(I) values, and inhibition patterns were determined for the NSAID analogs and steroid carboxylates against AKR1C and COX isozymes. Lead compounds, 4-chloro-N-phenylanthranilic acid and 4-benzoyl-benzoic acid for the N-phenylanthranilic acid analogs and most steroid carboxylates, exhibited IC(50) values that had greater than 500-fold selectivity for AKR1C isozymes compared with COX-1 and COX-2. Crystallographic and molecular modeling studies showed that the carboxylic acid of the inhibitor ligand was tethered by the catalytic Tyr55-OH(2)(+) and explained why A-ring substituted N-phenylanthranilates inhibited only AKR1C enzymes. These compounds can be used to dissect the role of the AKR1C isozymes in neoplastic diseases and may have cancer chemopreventive roles independent of COX inhibition.

Racial differences in prostate androgen levels in men with clinically localized prostate cancer

PURPOSE

We sought to determine whether there are racial differences in androgenic stimulation within the prostate tissue microenvironment.

MATERIALS AND METHODS

Steroid hormones were extracted from snap frozen tissue obtained intraoperatively from radical prostatectomy specimens of 36 black and 59 white Americans. Testosterone, dihydrotestosterone (DHT), androstenedione (ASD), dehydroepiandrosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin (SHBG) and prostate specific antigen (PSA) were measured using radioimmunoassay. The Wilcoxon 2 group test was performed to compare clinical characteristics and tissue steroid levels between white and black Americans. Nonparametric rank ANOVA was used to consider race and other clinical factors in a multivariable way.

RESULTS

Black and white American men were similar with respect to serum PSA, and pathological grade and stage. However, black men were younger (p = 0.01) and had a significantly higher body mass index (p = 0.02). Black and white men had similar testosterone and DHT. However, black men had higher ASD (p = 0.006) and SHBG (p = 0.009). Racial differences in ASD (p = 0.015) and SHBG (p = 0.008) persisted after controlling for age, body mass index, PSA, and pathological Gleason sum and stage.

CONCLUSIONS

Tissue levels of testosterone and DHT did not differ by race. However, black men had higher tissue ASD and SHBG than white men. Higher tissue ASD did not result in a greater conversion of ASD to testosterone in the prostate of black men. Higher tissue SHBG may activate the androgen receptor through cyclic adenosine monophosphate dependent pathways.

Inactivation of androgens by UDP-glucuronosyltransferase enzymes in humans

In humans, 3beta-hydroxysteroid dehydrogenase (3beta-HSD), 17beta-HSD and 5alpha-reductase activities in androgen target tissues, such as the prostate and skin, convert dehydroepiandrosterone, androstenedione and testosterone into the most potent natural androgen dihydrotestosterone (DHT). This androgen is converted mainly in situ into two phase I metabolites, androsterone (ADT) and androstane-3alpha,17beta-diol (3alpha-DIOL), which might be back converted to DHT. Here, we discuss the recent findings regarding the characterization of specific UDP-glucuronosyltransferases (UGTs), UGT2B7, B15 and B17, responsible for the glucuronidation of these metabolites. The tissue distribution and cellular localization of the UGT2B transcripts and proteins in humans clearly indicate that these enzymes are synthesized in androgen-sensitive tissues. It is postulated that the conjugating activity of UGT enzymes is the main mechanism for modulating the action of steroids and protecting the androgen-sensitive tissues from deleteriously high concentrations of DHT, ADT and 3alpha-DIOL.

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.

Incidentally detected giant oncocytoma arising in retroperitoneal heterotopic adrenal tissue

A nonfunctional retroperitoneal oncocytoma incidentally discovered in a 40-year-old woman is described. The tumor, which was 17 cm in largest dimension, was completely separated from the kidneys and adrenal glands and consisted of nests of polygonal cells with large, granular, eosinophilic cytoplasm. Significant nuclear atypia, necrosis, and mitosis were absent. Ultrastructural analysis confirmed the oncocytic nature of the neoplastic cells. Since neoplastic cells were not immunoreactive for chromogranin and did not contain dense-core secretory granules, the diagnosis of oncocytic paraganglioma was excluded. Cells immunoreactive for 3beta-hydroxysteroid dehydrogenase, the enzyme catalyzing the conversions of pregnenolone to progesterone and dehydroepiandrosterone to androstenedione, were identified in the tumor, thus strongly indicating adrenocortical tissue origin. Multiple nests of 3beta-hydroxysteroid dehydrogenase-positive cells were detected in the loose retroperitoneal connective tissue. These findings strongly support the origin of the tumor from heterotopic retroperitoneal rests of the adrenal gland. To our knowledge, only 1 similar case has been described in the literature to date.

Roles of androgens in the development, growth, and carcinogenesis of the mammary gland

Androgens influence the development and growth of the mammary gland in women. Treatment of animals and cultured cells with androgens has either inhibitory or stimulatory effects on the proliferation of mammary epithelia and cancer cells; the mechanisms for these dual functions are still not very clear and are discussed in this review. Epidemiological data suggest that, similar to increased estrogens, elevated androgens in serum may be associated with the development of breast cancer. Experiments in rodents have also shown that simultaneous treatment of androgen and estrogen synergizes for mammary gland carcinogenesis. Similar synergistic effects of both hormones have been observed for carcinogenesis of the uterine myometrium of female animals and for carcinogenesis of the prostate and deferens of males. There are also clinical and experimental indications for a possible association of elevated levels of both androgens and estrogens with the development of ovarian and endometrial cancers. A hypothesis is thus proposed that concomitant elevation in both androgens and estrogens may confer a greater risk for tumorigenesis of the mammary gland, and probably other female reproductive tissues than an elevation of each hormone alone.