Overexpression of amplified genes is often associated with the acquisition of resistance to cancer therapeutic agents in vitro. We have identified a similar molecular mechanism in vivo for endocrine treatment failure in human prostate cancer which involves amplification of the androgen receptor (AR) gene. Comparative genomic hybridization shows that amplification of the Xq11-q13 region (the location), is common in tumours recurring during androgen deprivation therapy. We found high-level AR amplification in seven of 23 (30%) recurrent tumours, but in none of the specimens taken from the same patients prior to therapy. Our results suggest that AR amplification emerges during androgen deprivation therapy by facilitating tumour cell growth in low androgen concentrations.

CD44 is a multifunctional protein involved in cell adhesion and signaling. The role of CD44 in prostate cancer (PCa) development and progression is controversial with studies showing both tumor-promoting and tumor-inhibiting effects. Most of these studies have used bulk-cultured PCa cells or PCa tissues to carry out correlative or overexpression experiments. The key experiment using prospectively purified cells has not been carried out. Here we use FACS to obtain homogeneous CD44(+) and CD44(-) tumor cell populations from multiple PCa cell cultures as well as four xenograft tumors to compare their in vitro and in vivo tumor-associated properties. Our results reveal that the CD44(+) PCa cells are more proliferative, clonogenic, tumorigenic, and metastatic than the isogenic CD44(-) PCa cells. Subsequent molecular studies demonstrate that the CD44(+) PCa cells possess certain intrinsic properties of progenitor cells. First, BrdU pulse-chase experiments reveal that CD44(+) cells colocalize with a population of intermediate label-retaining cells. Second, CD44(+) PCa cells express higher mRNA levels of several 'stemness' genes including Oct-3/4, Bmi, beta-catenin, and SMO. Third, CD44(+) PCa cells can generate CD44(-) cells in vitro and in vivo. Fourth, CD44(+) PCa cells, which are AR(-), can differentiate into AR(+) tumor cells. Finally, a very small percentage of CD44(+) PCa cells appear to undergo asymmetric cell division in clonal analyses. Altogether, our results suggest that the CD44(+) PCa cell population is enriched in tumorigenic and metastatic progenitor cells.

Chromosomal rearrangements fusing the androgen-regulated gene TMPRSS2 to the oncogenic ETS transcription factor ERG occur in approximately 50% of prostate cancers, but how the fusion products regulate prostate cancer remains unclear. Using chromatin immunoprecipitation coupled with massively parallel sequencing, we found that ERG disrupts androgen receptor (AR) signaling by inhibiting AR expression, binding to and inhibiting AR activity at gene-specific loci, and inducing repressive epigenetic programs via direct activation of the H3K27 methyltransferase EZH2, a Polycomb group protein. These findings provide a working model in which TMPRSS2-ERG plays a critical role in cancer progression by disrupting lineage-specific differentiation of the prostate and potentiating the EZH2-mediated dedifferentiation program.

Mammalian genomes are populated with thousands of transcriptional enhancers that orchestrate cell-type-specific gene expression programs, but how those enhancers are exploited to institute alternative, signal-dependent transcriptional responses remains poorly understood. Here we present evidence that cell-lineage-specific factors, such as FoxA1, can simultaneously facilitate and restrict key regulated transcription factors, exemplified by the androgen receptor (AR), to act on structurally and functionally distinct classes of enhancer. Consequently, FoxA1 downregulation, an unfavourable prognostic sign in certain advanced prostate tumours, triggers dramatic reprogramming of the hormonal response by causing a massive switch in AR binding to a distinct cohort of pre-established enhancers. These enhancers are functional, as evidenced by the production of enhancer-templated non-coding RNA (eRNA) based on global nuclear run-on sequencing (GRO-seq) analysis, with a unique class apparently requiring no nucleosome remodelling to induce specific enhancer-promoter looping and gene activation. GRO-seq data also suggest that liganded AR induces both transcription initiation and elongation. Together, these findings reveal a large repository of active enhancers that can be dynamically tuned to elicit alternative gene expression programs, which may underlie many sequential gene expression events in development, cell differentiation and disease progression.

The distribution of cells that express mRNA encoding the androgen (AR) and estrogen (ER) receptors was examined in adult male and female rats by using in situ hybridization. Specific labeling appeared to be largely, if not entirely, localized to neurons. AR and ER mRNA-containing neurons were widely distributed in the rat brain, with the greatest densities of cells in the hypothalamus, and in regions of the telencephalon that provide strong inputs in the medial preoptic and ventromedial nuclei, each of which is thought to play a key role in mediating the hormonal control of copulatory behavior, as well as in the lateral septal nucleus, the medial and cortical nuclei of the amygdala, the amygdalohippocampal area, and the bed nucleus of the stria terminalis. Heavily labeled ER mRNA-containing cells were found in regions known to be involved in the neural control of gonadotropin release, such as the anteroventral periventricular and the arcuate nuclei, but only a moderate density of labeling for AR mRNA was found over these nuclei. In addition, clearly labeled cells were found in regions with widespread connections throughout the brain, including the lateral hypothalamus, intralaminar thalamic nuclei, and deep layers of the cerebral cortex, suggesting that AR and ER may modulate a wide variety of neural functions. Each part of Ammon's horn contained AR mRNA-containing cells, as did both parts of the subiculum, but ER mRNA appeared to be less abundant in the hippocampal formation. Moreover, AR and ER mRNA-containing cells were also found in olfactory regions of the cortex and in both the main and accessory olfactory bulbs. AR and ER may modulate nonolfactory sensory information as well since labeled cells were found in regions involved in the central relay of somatosensory information, including the mesencephalic nucleus of the trigeminal nerve, the ventral thalamic nuclear group, and the dorsal horn of the spinal cord. Furthermore, heavily labeled AR mRNA-containing cells were found in the vestibular nuclei, the cochlear nuclei, the medial geniculate nucleus, and the nucleus of the lateral lemniscus, which suggests that androgens may alter the central relay of vestibular and auditory information as well. However, of all the regions involved in sensory processing, the heaviest labeling for AR and ER mRNA was found in areas that relay visceral sensory information such as the nucleus of the solitary tract, the area postrema, and the subfornical organ. We did not detect ER mRNA in brainstem somatic motoneurons, but clearly labeled AR mRNA-containing cells were found in motor nuclei associated with the fifth, seventh, tenth, and twelfth cranial nerves. Similarly, spinal motoneurons contained AR but not ER mRNA.(ABSTRACT TRUNCATED AT 400 WORDS)

OBJECTIVE

To develop a standardized nomenclature system for the neuropsychiatric syndromes of systemic lupus erythematosus (NPSLE).

METHODS

An international, multidisciplinary committee representing rheumatology, neurology, psychiatry, neuropsychology, and hematology developed case definitions, reporting standards, and diagnostic testing recommendations. Before and after the meeting, clinician committee members assigned diagnoses to sets of vignettes randomly generated from a pool of 108 NPSLE patients. To assess whether the nomenclature system improved diagnostic agreement, a consensus index was developed and pre- and postmeeting scores were compared by t-tests.

RESULTS

Case definitions including diagnostic criteria, important exclusions, and methods of ascertainment were developed for 19 NPSLE syndromes. Recommendations for standard reporting requirements, minimum laboratory evaluation, and imaging techniques were formulated. A short neuropsychological test battery for the diagnosis of cognitive deficits was proposed. In the postmeeting exercise, a statistically significant improvement in diagnostic agreement was observed.

CONCLUSIONS

The American College of Rheumatology (ACR) Nomenclature for NPSLE provides case definitions for 19 neuropsychiatric syndromes seen in SLE, with reporting standards and recommendations for laboratory and imaging tests. It is intended to facilitate and enhance clinical research, particularly multicenter studies, and reporting. In clinical settings, consultation with other specialists may be required. It should be useful for didactic purposes but should not be used uncritically or as a substitute for a clinical diagnosis. The complete case definitions are available on the ACR World Wide Web site: http://www.rheumatology .org/ar/ar.html.

BACKGROUND

Schizophrenia is associated with immune system dysfunction, including aberrant cytokine levels. We performed a meta-analysis of these associations, considering effects of clinical status and antipsychotic treatment following an acute illness exacerbation.

METHODS

We identified articles by searching PubMed, PsychInfo, and Institute for Scientific Information and the reference lists of identified studies.

RESULTS

Forty studies met the inclusion criteria. Effect sizes were similar for studies of acutely relapsed inpatients (AR) and first-episode psychosis (FEP). Interleukin (IL)-1β, IL-6, and transforming growth factor-β (TGF-β) appeared to be state markers, as they were increased in AR and FEP (p < .001 for each) and normalized with antipsychotic treatment (p < .001, p = .008, and p = .005, respectively). In contrast, IL-12, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and soluble IL-2 receptor (sIL-2R) appeared to be trait markers, as levels remained elevated in acute exacerbations and following antipsychotic treatment. There was no difference in IL-6 levels between stable medicated outpatients and control subjects (p = .69). In the cerebrospinal fluid, IL-1β was significantly decreased in schizophrenia versus controls (p = .01).

CONCLUSIONS

Similar effect sizes in AR and FEP suggest that the association between cytokine abnormalities and acute exacerbations of schizophrenia is independent of antipsychotic medications. While some cytokines (IL-1β, IL-6, and TGF-β) may be state markers for acute exacerbations, others (IL-12, IFN-γ, TNF-α, and sIL-2R) may be trait markers. Although these results could provide the basis for future hypothesis testing, most studies did not control for potential confounding factors such as body mass index and smoking.

Genome-wide association studies (GWAS) of longitudinal birth cohorts enable joint investigation of environmental and genetic influences on complex traits. We report GWAS results for nine quantitative metabolic traits (triglycerides, high-density lipoprotein, low-density lipoprotein, glucose, insulin, C-reactive protein, body mass index, and systolic and diastolic blood pressure) in the Northern Finland Birth Cohort 1966 (NFBC1966), drawn from the most genetically isolated Finnish regions. We replicate most previously reported associations for these traits and identify nine new associations, several of which highlight genes with metabolic functions: high-density lipoprotein with NR1H3 (LXRA), low-density lipoprotein with AR and FADS1-FADS2, glucose with MTNR1B, and insulin with PANK1. Two of these new associations emerged after adjustment of results for body mass index. Gene-environment interaction analyses suggested additional associations, which will require validation in larger samples. The currently identified loci, together with quantified environmental exposures, explain little of the trait variation in NFBC1966. The association observed between low-density lipoprotein and an infrequent variant in AR suggests the potential of such a cohort for identifying associations with both common, low-impact and rarer, high-impact quantitative trait loci.

The androgen receptor (AR) plays a key role in progression to incurable androgen ablation-resistant prostate cancer (PCA). We have identified three novel AR splice variants lacking the ligand-binding domain (designated as ARARARARARARARARAR level) in hormone-resistant PCA cells attenuates their growth under androgen-depleted conditions in both cell culture and xenograft models, suggesting an indispensable role of ARARAR. Our data suggest that aberrant expression of AR splice variants may be a novel mechanism underlying ablation independence during PCA progression, and ARAR splice variants are not inhibited by currently available antiandrogen drugs, development of new drugs targeting these AR isoforms may potentially be effective for treatment of ablation-resistant PCA.

The standard systemic treatment for prostate cancer (PCa) is androgen ablation, which causes tumor regression by inhibiting activity of the androgen receptor (AR). Invariably, PCa recurs with a fatal androgen-refractory phenotype. Importantly, the growth of androgen-refractory PCa remains dependent on the AR through various mechanisms of aberrant AR activation. Here, we studied the 22Rv1 PCa cell line, which was derived from a CWR22 xenograft that relapsed during androgen ablation. Three AR isoforms are expressed in 22Rv1 cells: a full-length version with duplicated exon 3 and two truncated versions lacking the COOH terminal domain (CTD). We found that CTD-truncated AR isoforms are encoded by mRNAs that have a novel exon 2b at their 3' end. Functionally, these AR isoforms are constitutively active and promote the expression of endogenous AR-dependent genes, as well as the proliferation of 22Rv1 cells in a ligand-independent manner. AR mRNAs containing exon 2b and their protein products are expressed in commonly studied PCa cell lines. Moreover, exon 2b-derived species are enriched in xenograft-based models of therapy-resistant PCa. Together, our data describe a simple and effective mechanism by which PCa cells can synthesize a constitutively active AR and thus circumvent androgen ablation.

Progression of prostate cancer following castration is associated with increased androgen receptor (AR) expression and signaling despite AR blockade. Recent studies suggest that these activities are due to the generation of constitutively active AR splice variants, but the mechanisms by which these splice variants could mediate such effects are not fully understood. Here we have identified what we believe to be a novel human AR splice variant in which exons 5, 6, and 7 are deleted (ARv567es) and demonstrated that this variant can contribute to cancer progression in human prostate cancer xenograft models in mice following castration. We determined that, in human prostate cancer cell lines, ARv567es functioned as a constitutively active receptor, increased expression of full-length AR (ARfl), and enhanced the transcriptional activity of AR. In human xenografts, human prostate cancer cells transfected with ARv567es cDNA formed tumors that were resistant to castration. Furthermore, the ratio of ARv567es to ARfl expression within the xenografts positively correlated with resistance to castration. Importantly, we also detected ARv567es frequently in human prostate cancer metastases. In summary, these data indicate that constitutively active AR splice variants can contribute to the development of castration-resistant prostate cancers and may serve as biomarkers for patients who are likely to suffer from early recurrence and are candidates for therapies directly targeting the AR rather than ligand.

Alizarin red S (ARS) staining has been used for decades to evaluate calcium-rich deposits by cells in culture. It is particularly versatile in that the dye can be extracted from the stained monolayer and assayed. This study describes a sensitive method for the recovery and semiquantification of ARS in a stained monolayer by acetic acid extraction and neutralization with ammonium hydroxide followed by colorimetric detection at 405 nm. This method was three times more sensitive than an older method involving cetylpyridinium chloride (CPC) extraction and resulted in a better signal to noise ratio, especially for weakly stained monolayers. The assay facilitates detailed inspection of mineralization by phase microscopy and semiquantification of the entire monolayer by extraction and quantification. The sensitivity of the assay is improved by the extraction of the calcified mineral at low pH and, since the mineral is already stained in a quantitative manner, there is no requirement for an additional colorimetric quantification step. Furthermore, the linear range is much wider than those of conventional assays for calcium, making dilutions of mineral extracts prior to measurement unnecessary. It has a wide range of potential uses including tumor characterization, mesenchymal stem cell evaluation, and osteogenic compound screening. Although more labor intensive than CPC extraction, the protocol is more sensitive and yields more reliable results for weakly mineralizing samples.

The relationship of the classical receptors and their transcriptional activity to nongenotropic effects of steroid hormones is unknown. We demonstrate herein a novel paradigm of sex steroid action on osteoblasts, osteocytes, embryonic fibroblasts, and HeLa cells involving activation of a Src/Shc/ERK signaling pathway and attenuating apoptosis. This action is mediated by the ligand binding domain and eliminated by nuclear targeting of the receptor protein; ERalpha, ERbeta, or AR can transmit it with similar efficiency irrespective of whether the ligand is an estrogen or an androgen. This antiapoptotic action can be dissociated from the transcriptional activity of the receptor with synthetic ligands, providing proof of principle for the development of function-specific-as opposed to tissue-selective-and gender-neutral pharmacotherapeutics.

The traditional receptor-stimulus model of agonism began with a description of drug action based on the law of mass action and has developed by a series of modifications, each accounting for new experimental evidence. By contrast, in this paper an approach to modelling agonism is taken that begins with the observation that experimental agonist-concentration effect, E/[A], curves are commonly hyperbolic and develops using the deduction that the relation between occupancy and effect must be hyperbolic if the law of mass action applies at the agonist-receptor level. The result is a general model that explicitly describes agonism by three parameters: an agonist-receptor dissociation constant, KA; the total receptor concentration, [R0]; and a parameter, KE, defining the transduction of agonist-receptor complex, AR, into pharmacological effect. The ratio, [R0]/KE, described here as the 'transducer ratio', tau, is a logical definition for the efficacy of an agonist in a system. The model may be extended to account for non-hyperbolic E/[A] curves with no loss of meaning. Analysis shows that an explicit formulation of the traditional receptor-stimulus model is one particular form of the general model but that it is not the simplest. An alternative model is proposed, representing the cognitive and transducer functions of a receptor, that describes agonist action with one fewer parameter than the traditional model. In addition, this model provides a chemical definition of intrinsic efficacy making this parameter experimentally accessible in principle. The alternative models are compared and contrasted with regard to their practical and conceptual utilities in experimental pharmacology.

Androgen receptor (AR) is a ligand-dependent transcription factor that plays a key role in prostate cancer. Little is known about the nature of AR cis-regulatory sites in the human genome. We have mapped the AR binding regions on two chromosomes in human prostate cancer cells by combining chromatin immunoprecipitation (ChIP) with tiled oligonucleotide microarrays. We find that the majority of AR binding regions contain noncanonical AR-responsive elements (AREs). Importantly, we identify a noncanonical ARE as a cis-regulatory target of AR action in TMPRSS2, a gene fused to ETS transcription factors in the majority of prostate cancers. In addition, through the presence of enriched DNA-binding motifs, we find other transcription factors including GATA2 and Oct1 that cooperate in mediating the androgen response. These collaborating factors, together with AR, form a regulatory hierarchy that governs androgen-dependent gene expression and prostate cancer growth and offer potential new opportunities for therapeutic intervention.

Activation of G protein-coupled receptors upon agonist binding is a critical step in the signaling cascade for this family of cell surface proteins. We report the crystal structure of the A(2A) adenosine receptor (A(2A)AR) bound to an agonist UK-432097 at 2.7 angstrom resolution. Relative to inactive, antagonist-bound A(2A)AR, the agonist-bound structure displays an outward tilt and rotation of the cytoplasmic half of helix VI, a movement of helix V, and an axial shift of helix III, resembling the changes associated with the active-state opsin structure. Additionally, a seesaw movement of helix VII and a shift of extracellular loop 3 are likely specific to A(2A)AR and its ligand. The results define the molecule UK-432097 as a "conformationally selective agonist" capable of receptor stabilization in a specific active-state configuration.

Resveratrol, trans-3,5,4'-trihydroxystilbene, was first isolated in 1940 as a constituent of the roots of white hellebore (Veratrum grandiflorum O. Loes), but has since been found in various plants, including grapes, berries and peanuts. Besides cardioprotective effects, resveratrol exhibits anticancer properties, as suggested by its ability to suppress proliferation of a wide variety of tumor cells, including lymphoid and myeloid cancers; multiple myeloma; cancers of the breast, prostate, stomach, colon, pancreas, and thyroid; melanoma; head and neck squamous cell carcinoma; ovarian carcinoma; and cervical carcinoma. The growth-inhibitory effects of resveratrol are mediated through cell-cycle arrest; upregulation of p21Cip1/WAF1, p53 and Bax; down-regulation of survivin, cyclin D1, cyclin E, Bcl-2, Bcl-xL and clAPs; and activation of caspases. Resveratrol has been shown to suppress the activation of several transcription factors, including NF-kappaB, AP-1 and Egr-1; to inhibit protein kinases including IkappaBalpha kinase, JNK, MAPK, Akt, PKC, PKD and casein kinase II; and to down-regulate products of genes such as COX-2, 5-LOX, VEGF, IL-1, IL-6, IL-8, AR and PSA. These activities account for the suppression of angiogenesis by this stilbene. Resveratrol also has been shown to potentiate the apoptotic effects of cytokines (e.g., TRAIL), chemotherapeutic agents and gamma-radiation. Phamacokinetic studies revealed that the target organs of resveratrol are liver and kidney, where it is concentrated after absorption and is mainly converted to a sulfated form and a glucuronide conjugate. In vivo, resveratrol blocks the multistep process of carcinogenesis at various stages: it blocks carcinogen activation by inhibiting aryl hydrocarbon-induced CYP1A1 expression and activity, and suppresses tumor initiation, promotion and progression. Besides chemopreventive effects, resveratrol appears to exhibit therapeutic effects against cancer. Limited data in humans have revealed that resveratrol is pharmacologically quite safe. Currently, structural analogues of resveratrol with improved bioavailability are being pursued as potential therapeutic agents for cancer.

Platelets have a crucial role in the maintenance of normal haemostasis, and perturbations of this system can lead to pathological thrombus formation and vascular occlusion, resulting in stroke, myocardial infarction and unstable angina. ADP released from damaged vessels and red blood cells induces platelet aggregation through activation of the integrin GPIIb-IIIa and subsequent binding of fibrinogen. ADP is also secreted from platelets on activation, providing positive feedback that potentiates the actions of many platelet activators. ADP mediates platelet aggregation through its action on two G-protein-coupled receptor subtypes. The P2Y1 receptor couples to Gq and mobilizes intracellular calcium ions to mediate platelet shape change and aggregation. The second ADP receptor required for aggregation (variously called P2Y(ADP), P2Y(AC), P2Ycyc or P2T(AC)) is coupled to the inhibition of adenylyl cyclase through Gi. The molecular identity of the Gi-linked receptor is still elusive, even though it is the target of efficacious antithrombotic agents, such as ticlopidine and clopidogrel and AR-C66096 (ref. 9). Here we describe the cloning of this receptor, designated P2Y12, and provide evidence that a patient with a bleeding disorder has a defect in this gene. Cloning of the P2Y12 receptor should facilitate the development of better antiplatelet agents to treat cardiovascular diseases.

Although systemic androgen deprivation prolongs life in advanced prostate cancer, remissions are temporary because patients almost uniformly progress to a state of a castration-resistant prostate cancer (CRPC) as indicated by recurring PSA. This complex process of progression does not seem to be stochastic as the timing and phenotype are highly predictable, including the observation that most androgen-regulated genes are reactivated despite castrate levels of serum androgens. Recent evidence indicates that intraprostatic levels of androgens remain moderately high following systemic androgen deprivation therapy, whereas the androgen receptor (AR) remains functional, and silencing the AR expression following castration suppresses tumor growth and blocks the expression of genes known to be regulated by androgens. From these observations, we hypothesized that CRPC progression is not independent of androgen-driven activity and that androgens may be synthesized de novo in CRPC tumors leading to AR activation. Using the LNCaP xenograft model, we showed that tumor androgens increase during CRPC progression in correlation to PSA up-regulation. We show here that all enzymes necessary for androgen synthesis are expressed in prostate cancer tumors and some seem to be up-regulated during CRPC progression. Using an ex vivo radiotracing assays coupled to high-performance liquid chromatography-radiometric/mass spectrometry detection, we show that tumor explants isolated from CRPC progression are capable of de novo conversion of [(14)C]acetic acid to dihydrotestosterone and uptake of [(3)H]progesterone allows detection of the production of six other steroids upstream of dihydrotestosterone. This evidence suggests that de novo androgen synthesis may be a driving mechanism leading to CRPC progression following castration.

To study the mechanisms and kinetics underlying the development of increased airway responsiveness (AR) after allergic sensitization, animal models have been invaluable. Using barometric whole-body plethysmography and increases in enhanced pause (Penh) as an index of airway obstruction, we measured responses to inhaled methacholine in conscious, unrestrained mice after sensitization and airway challenge with ovalbumin (OVA). Sensitized and challenged animals had significantly increased AR to aerosolized methacholine compared with control animals. AR measured as Penh was associated with increased IgE production and eosinophil lung infiltration. In a separate approach we confirmed the involvement of the lower airways in the response to aerosolized methacholine using tracheotomized mice. Increases in Penh values after methacholine challenge were also correlated with increased intrapleural pressure, measured via an esophageal tube. Lastly, mice demonstrating AR using a noninvasive technique also demonstrated increased pulmonary resistance responses to aerosolized methacholine when measured using an invasive technique the following day in the same animals. The increases in Penh values were inhibited by pretreatment of the mice with a beta 2-agonist. These data indicate that measurement of AR to inhaled methacholine by barometric whole-body plethysmography is a valid indicator of airway hyperresponsiveness after allergic sensitization in mice. The measurement of AR in unrestrained, conscious animals provides new opportunities to evaluate the mechanisms and kinetics underlying the development and maintenance of airway hyperresponsiveness and to assess various therapeutic interventions.

OBJECTIVE

Studies indicate that castration-resistant prostate cancer (CRPC) remains driven by ligand-dependent androgen receptor (AR) signaling. To evaluate this, a trial of abiraterone acetate-a potent, selective, small-molecule inhibitor of cytochrome P (CYP) 17, a key enzyme in androgen synthesis-was pursued.

METHODS

Chemotherapy-naïve men (n = 21) who had prostate cancer that was resistant to multiple hormonal therapies were treated in this phase I study of once-daily, continuous abiraterone acetate, which escalated through five doses (250 to 2,000 mg) in three-patient cohorts.

RESULTS

Abiraterone acetate was well tolerated. The anticipated toxicities attributable to a syndrome of secondary mineralocorticoid excess-namely hypertension, hypokalemia, and lower-limb edema-were successfully managed with a mineralocorticoid receptor antagonist. Antitumor activity was observed at all doses; however, because of a plateau in pharmacodynamic effect, 1,000 mg was selected for cohort expansion (n = 9). Abiraterone acetate administration was associated with increased levels of adrenocorticotropic hormone and steroids upstream of CYP17 and with suppression of serum testosterone, downstream androgenic steroids, and estradiol in all patients. Declines in prostate-specific antigen>>or= 30%, 50%, and 90% were observed in 14 (66%), 12 (57%), and 6 (29%) patients, respectively, and lasted between 69 to>>or= 578 days. Radiologic regression, normalization of lactate dehydrogenase, and improved symptoms with a reduction in analgesic use were documented.

CONCLUSIONS

CYP17 blockade by abiraterone acetate is safe and has significant antitumor activity in CRPC. These data confirm that CRPC commonly remains dependent on ligand-activated AR signaling.

Androgen receptor (AR) is a member of the steroid hormone receptor family of molecules. AR primarily is responsible for mediating the physiologic effects of androgens by binding to specific DNA sequences that influence transcription of androgen-responsive genes. The three-dimensional structure of the AR ligand-binding domain has shown it is similar to other steroid hormone receptors and that ligand binding alters the protein conformation to allow binding of coactivator molecules that amplify the hormone signal and mediate transcriptional initiation. However, AR also undergoes intramolecular interactions that regulate its interactions with coactivators and influence its activity. A large number of naturally occurring mutations of the human AR gene have provided important information about AR molecular structure and intermolecular interactions. AR is also a critical mediator of prostate cancer promotion, conferring growth signals to prostate cancer cells throughout the natural history of the disease. Late-stage prostate cancer, unresponsive to hormonal deprivation, sustains AR signaling through a diverse array of molecular strategies. Variations in the AR gene may also confer genetic predisposition to prostate cancer development and severity. Further understanding of AR action and new strategies to interfere with AR signaling hold promise for improving prostate cancer therapy.

A shortened 10-item scale for clinical quantitation of the severity of the alcohol withdrawal syndrome has been developed. This scale offers an increase in efficiency while at the same time retaining clinical usefulness, validity and reliability. It can be incorporated into the usual clinical care of patients undergoing alcohol withdrawal and into clinical drug trials of alcohol withdrawal.

Previous microarray studies on breast cancer identified multiple tumour classes, of which the most prominent, named luminal and basal, differ in expression of the oestrogen receptor alpha gene (ER). We report here the identification of a group of breast tumours with increased androgen signalling and a 'molecular apocrine' gene expression profile. Tumour samples from 49 patients with large operable or locally advanced breast cancers were tested on Affymetrix U133A gene expression microarrays. Principal components analysis and hierarchical clustering split the tumours into three groups: basal, luminal and a group we call molecular apocrine. All of the molecular apocrine tumours have strong apocrine features on histological examination (P=0.0002). The molecular apocrine group is androgen receptor (AR) positive and contains all of the ER-negative tumours outside the basal group. Kolmogorov-Smirnov testing indicates that oestrogen signalling is most active in the luminal group, and androgen signalling is most active in the molecular apocrine group. ERBB2 amplification is commoner in the molecular apocrine than the other groups. Genes that best split the three groups were identified by Wilcoxon test. Correlation of the average expression profile of these genes in our data with the expression profile of individual tumours in four published breast cancer studies suggest that molecular apocrine tumours represent 8-14% of tumours in these studies. Our data show that it is possible with microarray data to divide mammary tumour cells into three groups based on steroid receptor activity: luminal (ER+ AR+), basal (ER- AR-) and molecular apocrine (ER- AR+).