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Dive into the research topics where Angela E. Taylor is active.

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Featured researches published by Angela E. Taylor.


Cancer Research | 2012

Interactions of abiraterone, eplerenone and prednisolone with wild-type and mutant androgen receptor: a rationale for increasing abiraterone exposure or combining with MDV3100

Juliet Richards; Ai Chiin Lim; Colin W. Hay; Angela E. Taylor; Anna Wingate; Karolina Nowakowska; Carmel Pezaro; Suzanne Carreira; Jane Goodall; Wiebke Arlt; Iain J. McEwan; Johann S. de Bono; Gerhardt Attard

Prostate cancer progression can be associated with androgen receptor (AR) mutations acquired following treatment with castration and/or an antiandrogen. Abiraterone, a rationally designed inhibitor of CYP17A1 recently approved for the treatment of docetaxel-treated castration-resistant prostate cancer (CRPC), is often effective, but requires coadministration with glucocorticoids to curtail side effects. Here, we hypothesized that progressive disease on abiraterone may occur secondary to glucocorticoid-induced activation of mutated AR. We found that prednisolone plasma levels in patients with CRPC were sufficiently high to activate mutant AR. Mineralocorticoid receptor antagonists, such as spironolactone and eplerenone that are used to treat side effects related to mineralocorticoid excess, can also bind to and activate signaling through wild-type or mutant AR. Abiraterone inhibited in vitro proliferation and AR-regulated gene expression of AR-positive prostate cancer cells, which could be explained by AR antagonism in addition to inhibition of steroidogenesis. In fact, activation of mutant AR by eplerenone was inhibited by MDV3100, bicalutamide, or greater concentrations of abiraterone. Therefore, an increase in abiraterone exposure could reverse resistance secondary to activation of AR by residual ligands or coadministered drugs. Together, our findings provide a strong rationale for clinical evaluation of combined CYP17A1 inhibition and AR antagonism.


The Journal of Clinical Endocrinology and Metabolism | 2011

Urine Steroid Metabolomics as a Biomarker Tool for Detecting Malignancy in Adrenal Tumors

Wiebke Arlt; Michael Biehl; Angela E. Taylor; Stefanie Hahner; Rossella Libé; Beverly Hughes; Petra Schneider; David J. Smith; Han Stiekema; Nils Krone; Emilio Porfiri; Giuseppe Opocher; Jérôme Bertherat; Franco Mantero; Bruno Allolio; Massimo Terzolo; Peter Nightingale; Cedric Shackleton; Xavier Bertagna; Martin Fassnacht; Paul M. Stewart

Context: Adrenal tumors have a prevalence of around 2% in the general population. Adrenocortical carcinoma (ACC) is rare but accounts for 2–11% of incidentally discovered adrenal masses. Differentiating ACC from adrenocortical adenoma (ACA) represents a diagnostic challenge in patients with adrenal incidentalomas, with tumor size, imaging, and even histology all providing unsatisfactory predictive values. Objective: Here we developed a novel steroid metabolomic approach, mass spectrometry-based steroid profiling followed by machine learning analysis, and examined its diagnostic value for the detection of adrenal malignancy. Design: Quantification of 32 distinct adrenal derived steroids was carried out by gas chromatography/mass spectrometry in 24-h urine samples from 102 ACA patients (age range 19–84 yr) and 45 ACC patients (20–80 yr). Underlying diagnosis was ascertained by histology and metastasis in ACC and by clinical follow-up [median duration 52 (range 26–201) months] without evidence of metastasis in ACA. Steroid excretion data were subjected to generalized matrix learning vector quantization (GMLVQ) to identify the most discriminative steroids. Results: Steroid profiling revealed a pattern of predominantly immature, early-stage steroidogenesis in ACC. GMLVQ analysis identified a subset of nine steroids that performed best in differentiating ACA from ACC. Receiver-operating characteristics analysis of GMLVQ results demonstrated sensitivity = specificity = 90% (area under the curve = 0.97) employing all 32 steroids and sensitivity = specificity = 88% (area under the curve = 0.96) when using only the nine most differentiating markers. Conclusions: Urine steroid metabolomics is a novel, highly sensitive, and specific biomarker tool for discriminating benign from malignant adrenal tumors, with obvious promise for the diagnostic work-up of patients with adrenal incidentalomas.


The Journal of Clinical Endocrinology and Metabolism | 2014

Hyperandrogenemia Predicts Metabolic Phenotype in Polycystic Ovary Syndrome: The Utility of Serum Androstenedione

Michael O'Reilly; Angela E. Taylor; Nicola Crabtree; Beverly Hughes; Farfia Capper; Rachel Crowley; Paul M. Stewart; Jeremy W. Tomlinson; Wiebke Arlt

Context: Polycystic ovary syndrome (PCOS) is a triad of anovulation, insulin resistance, and hyperandrogenism. Androgen excess may correlate with metabolic risk and PCOS consensus criteria define androgen excess on the basis of serum T. Here we studied the utility of the androgen precursor serum androstenedione (A) in conjunction with serum T for predicting metabolic dysfunction in PCOS. Patients and Methods: Eighty-six PCOS patients fulfilling Rotterdam diagnostic consensus criteria and 43 age- and body mass index-matched controls underwent measurement of serum androgens by tandem mass spectrometry and an oral glucose tolerance test with homeostatic model assessment of insulin resistance and insulin sensitivity index calculation. We analyzed 24-hour urine androgen excretion by gas chromatography/mass spectrometry. Results: PCOS patients had higher levels of serum androgens and urinary androgen metabolites than controls (all P < .001). Within the PCOS cohort, both serum A and T were positively correlated with the free androgen index (T × 100/SHBG) and total androgen metabolite excretion (all P < .001). All subjects with T above the normal reference range [high T (HT)] also had high A (HA/HT group, n = 56). However, the remaining 30 patients had normal T levels, either in the presence of HA (HA/NT; n = 20) or normal A (NA/NT; n = 10). The groups did not differ in age or BMI. The HA/HT and HA/NT groups had higher total androgen excretion than NA/NT (P < .01 and P < .05, respectively). Multiple linear regression showed a strong negative association between serum androstenedione and insulin sensitivity. The incidence of dysglycemia according to an oral glucose tolerance test increased with the severity of androgen phenotype (NA/NT, 0%; HA/NT, 14%; HA/HT, 25%, P = .03). Conclusion: Simultaneous measurement of serum T and A represents a useful tool for predicting metabolic risk in PCOS women. HA levels are a sensitive indicator of PCOS-related androgen excess.


Cell Reports | 2014

Single-Cell RNA Sequencing Reveals T Helper Cells Synthesizing Steroids De Novo to Contribute to Immune Homeostasis

Bidesh Mahata; Xiuwei Zhang; Aleksandra A. Kolodziejczyk; Valentina Proserpio; Liora Haim-Vilmovsky; Angela E. Taylor; Daniel Hebenstreit; Felix A. Dingler; Victoria Moignard; Berthold Göttgens; Wiebke Arlt; Andrew N. J. McKenzie; Sarah A. Teichmann

Summary T helper 2 (Th2) cells regulate helminth infections, allergic disorders, tumor immunity, and pregnancy by secreting various cytokines. It is likely that there are undiscovered Th2 signaling molecules. Although steroids are known to be immunoregulators, de novo steroid production from immune cells has not been previously characterized. Here, we demonstrate production of the steroid pregnenolone by Th2 cells in vitro and in vivo in a helminth infection model. Single-cell RNA sequencing and quantitative PCR analysis suggest that pregnenolone synthesis in Th2 cells is related to immunosuppression. In support of this, we show that pregnenolone inhibits Th cell proliferation and B cell immunoglobulin class switching. We also show that steroidogenic Th2 cells inhibit Th cell proliferation in a Cyp11a1 enzyme-dependent manner. We propose pregnenolone as a “lymphosteroid,” a steroid produced by lymphocytes. We speculate that this de novo steroid production may be an intrinsic phenomenon of Th2-mediated immune responses to actively restore immune homeostasis.


The Journal of Clinical Endocrinology and Metabolism | 2013

Mitotane Therapy in Adrenocortical Cancer Induces CYP3A4 and Inhibits 5α-Reductase, Explaining the Need for Personalized Glucocorticoid and Androgen Replacement

Vasileios Chortis; Angela E. Taylor; Petra Schneider; Jeremy W. Tomlinson; Beverly Hughes; Donna M. O'Neil; Rossella Libé; Bruno Allolio; Xavier Bertagna; Jérôme Bertherat; Felix Beuschlein; Martin Fassnacht; Niki Karavitaki; Massimo Mannelli; Franco Mantero; Giuseppe Opocher; Emilio Porfiri; Marcus Quinkler; Mark Sherlock; Massimo Terzolo; Peter Nightingale; Cedric Shackleton; Paul M. Stewart; Stefanie Hahner; Wiebke Arlt

CONTEXT Mitotane [1-(2-chlorophenyl)-1-(4-chlorophenyl)-2,2-dichloroethane] is the first-line treatment for metastatic adrenocortical carcinoma (ACC) and is also regularly used in the adjuvant setting after presumed complete removal of the primary tumor. Mitotane is considered an adrenolytic substance, but there is limited information on distinct effects on steroidogenesis. However, adrenal insufficiency and male hypogonadism are widely recognized side effects of mitotane treatment. OBJECTIVE Our objective was to define the impact of mitotane treatment on in vivo steroidogenesis in patients with ACC. SETTING AND DESIGN At seven European specialist referral centers for adrenal tumors, we analyzed 24-h urine samples (n = 127) collected from patients with ACC before and during mitotane therapy in the adjuvant setting (n = 23) or for metastatic ACC (n = 104). Urinary steroid metabolite excretion was profiled by gas chromatography/mass spectrometry in comparison with healthy controls (n = 88). RESULTS We found a sharp increase in the excretion of 6β-hydroxycortisol over cortisol (P < 0.001), indicative of a strong induction of the major drug-metabolizing enzyme cytochrome P450 3A4. The contribution of 6β-hydroxycortisol to total glucocorticoid metabolites increased from 2% (median, interquartile range 1-4%) to 56% (39-71%) during mitotane treatment. Furthermore, we documented strong inhibition of systemic 5α-reductase activity, indicated by a significant decrease in 5α-reduced steroids, including 5α-tetrahydrocortisol, 5α-tetrahydrocorticosterone, and androsterone (all P < 0.001). The degree of inhibition was similar to that in patients with inactivating 5α-reductase type 2 mutations (n = 23) and patients receiving finasteride (n = 5), but cluster analysis of steroid data revealed a pattern of inhibition distinct from these two groups. Longitudinal data showed rapid onset and long-lasting duration of the observed effects. CONCLUSIONS Cytochrome P450 3A4 induction by mitotane results in rapid inactivation of more than 50% of administered hydrocortisone, explaining the need for doubling hydrocortisone replacement in mitotane-treated patients. Strong inhibition of 5α-reductase activity is in line with the clinical observation of relative inefficiency of testosterone replacement in mitotane-treated men, calling for replacement by 5α-reduced androgens.


Molecular Endocrinology | 2010

Dehdyroepiandrosterone sulfate directly activates protein kinase C-β to increase human neutrophil superoxide generation

David J. Radford; Keqing Wang; Joanne McNelis; Angela E. Taylor; Georg Hechenberger; Johann Hofmann; Hema Chahal; Wiebke Arlt; Janet Lord

Dehydroepiandrosterone sulfate (DHEAS) is the most abundant steroid in the human circulation and is secreted by the adrenals in an age-dependent fashion, with maximum levels during the third decade and very low levels in old age. DHEAS is considered an inactive metabolite, whereas cleavage of the sulfate group generates dehydroepiandrosterone (DHEA), a crucial sex steroid precursor. However, here we show that DHEAS, but not DHEA, increases superoxide generation in primed human neutrophils in a dose-dependent fashion, thereby impacting on a key bactericidal mechanism. This effect was not prevented by coincubation with androgen and estrogen receptor antagonists but was reversed by the protein kinase C inhibitor Bisindolylmaleimide 1. Moreover, we found that neutrophils are unique among leukocytes in expressing an organic anion-transporting polypeptide D, able to mediate active DHEAS influx transport whereas they did not express steroid sulfatase that activates DHEAS to DHEA. A specific receptor for DHEAS has not yet been identified, but we show that DHEAS directly activated recombinant protein kinase C-beta (PKC-beta) in a cell-free assay. Enhanced PKC-beta activation by DHEAS resulted in increased phosphorylation of p47(phox), a crucial component of the active reduced nicotinamide adenine dinucleotide phosphate complex responsible for neutrophil superoxide generation. Our results demonstrate that PKC-beta acts as an intracellular receptor for DHEAS in human neutrophils, a signaling mechanism entirely distinct from the role of DHEA as sex steroid precursor and with important implications for immunesenescence, which includes reduced neutrophil superoxide generation in response to pathogens.


Vaccine | 2016

Morning vaccination enhances antibody response over afternoon vaccination: a cluster-randomised trial

Joanna E. Long; Mark T. Drayson; Angela E. Taylor; K.M. Toellner; Janet M. Lord; Anna C. Phillips

Highlights • Early small studies provide mixed evidence for effects of time of vaccination on antibody response.• This is the first large scale randomised trial of different times of vaccination.• Morning vaccination enhances the antibody response to the influenza vaccine.• This simple manipulation is cost neutral and may improve protection from influenza in older adults.


The Journal of Clinical Endocrinology and Metabolism | 2011

A novel entity of clinically isolated adrenal insufficiency caused by a partially inactivating mutation of the gene encoding for P450 side chain cleavage enzyme (CYP11A1).

Silvia Parajes; Clemens Kamrath; Ian T. Rose; Angela E. Taylor; Christiaan F. Mooij; Vivek Dhir; Joachim Grötzinger; Wiebke Arlt; Nils Krone

CONTEXT Cytochrome P450 side-chain cleavage enzyme (CYP11A1) facilitates the first and rate-limiting step of steroidogenesis. Only nine patients with CYP11A1 deficiency have been described. All patients presented with adrenal insufficiency (AI) and disorder of sex development in 46,XY individuals. OBJECTIVE Our objective was to define the pathogenic consequences of a novel CYP11A1 mutation (p.R451W) found in two brothers with isolated adrenal insufficiency. PATIENTS The two brothers (46,XY) presented with AI and normal male genital development. The older boy first presented with signs and symptoms suggestive of AI at the age of 2.8 yr but was only diagnosed at the age of 4.1 yr during an adrenal crisis. The younger brother was diagnosed with AI at the age of 2.5 yr while being clinically asymptomatic. Both boys had entirely normal appearance of their external genitalia. RESULTS The novel p.R451W mutation and five published missense CYP11A1 mutations were characterized employing two in vitro approaches using the natural substrate cholesterol and the intermediate 22R-hydroxycholesterol, respectively. Pregnenolone generation was measured by highly specific liquid chromatography tandem mass spectrometry. p.R451W had 30% of wild-type activity consistent with the clinical phenotype in our patients. Two previously published mutations (p.L222P and p.A359V) had 2- to 3-fold higher in vitro activities than originally reported, correlating better with the associated phenotypes. CONCLUSIONS We provide the first evidence that partial CYP11A1 deficiency has to be considered as a differential diagnosis in clinically isolated adrenal insufficiency. Our assays demonstrate a tighter genotype-phenotype correlation in CYP11A1 deficiency than previous in vitro studies.


The Journal of Clinical Endocrinology and Metabolism | 2015

PAPSS2 deficiency causes androgen excess via impaired DHEA sulfation-in vitro and in vivo studies in a family harboring two novel PAPSS2 mutations

Wilma Oostdijk; Jan Idkowiak; Jonathan W. Mueller; Philip J. House; Angela E. Taylor; Michael O'Reilly; Beverly Hughes; Martine C. de Vries; Sarina G. Kant; Gijs W.E. Santen; Annemieke J. M. H. Verkerk; André G. Uitterlinden; Jan M. Wit; Monique Losekoot; Wiebke Arlt

Context: PAPSS2 (PAPS synthase 2) provides the universal sulfate donor PAPS (3′-phospho-adenosine-5′-phosphosulfate) to all human sulfotransferases, including SULT2A1, responsible for sulfation of the crucial androgen precursor dehydroepiandrosterone (DHEA). Impaired DHEA sulfation is thought to increase the conversion of DHEA toward active androgens, a proposition supported by the previous report of a girl with inactivating PAPSS2 mutations who presented with low serum DHEA sulfate and androgen excess, clinically manifesting with premature pubarche and early-onset polycystic ovary syndrome. Patients and Methods: We investigated a family harboring two novel PAPSS2 mutations, including two compound heterozygous brothers presenting with disproportionate short stature, low serum DHEA sulfate, but normal serum androgens. Patients and parents underwent a DHEA challenge test comprising frequent blood sampling and urine collection before and after 100 mg DHEA orally, with subsequent analysis of DHEA sulfation and androgen metabolism by mass spectrometry. The functional impact of the mutations was investigated in silico and in vitro. Results: We identified a novel PAPSS2 frameshift mutation, c.1371del, p.W462Cfs*3, resulting in complete disruption, and a novel missense mutation, c.809G>A, p.G270D, causing partial disruption of DHEA sulfation. Both patients and their mother, who was heterozygous for p.W462Cfs*3, showed increased 5α-reductase activity at baseline and significantly increased production of active androgens after DHEA intake. The mother had a history of oligomenorrhea and chronic anovulation that required clomiphene for ovulation induction. Conclusions: We provide direct in vivo evidence for the significant functional impact of mutant PAPSS2 on DHEA sulfation and androgen activation. Heterozygosity for PAPSS2 mutations can be associated with a phenotype resembling polycystic ovary syndrome.


Clinical Chemistry | 2015

Comparison of 7 Published LC-MS/MS Methods for the Simultaneous Measurement of Testosterone, Androstenedione, and Dehydroepiandrosterone in Serum

Rahel M. Büttler; Frans Martens; Flaminia Fanelli; Hai T. Pham; Marcel J.W. Janssen; Laura Owen; Angela E. Taylor; Tue Søeborg; Marinus A. Blankenstein; Annemieke C. Heijboer

BACKGROUND Recently, LC-MS/MS was stated to be the method of choice to measure sex steroids. Because information on the mutual agreement of LC-MS/MS methods is scarce, we compared 7 published LC-MS/MS methods for the simultaneous measurement of testosterone, androstenedione, and dehydroepiandrosterone (DHEA). METHODS We used 7 published LC-MS/MS methods to analyze in duplicate 55 random samples from both men and women. We performed Passing-Bablok regression analysis and calculated Pearson correlation coefficients to assess the agreement of the methods investigated with the median concentration measured by all methods, and we calculated the intraassay CV of each method derived from duplicate results and the CVs between the methods. RESULTS Median concentrations of testosterone were 0.22-1.36 nmol/L for women and 8.27-27.98 nmol/L for men. Androstenedione and DHEA concentrations were 0.05-5.53 and 0.58-18.04 nmol/L, respectively. Intraassay CVs were 2.9%-10%, 1.2%-8.8%, 2.7%-13%, and 4.3%-16% for testosterone in women, testosterone in men, androstenedione, and DHEA. Slopes of the regression lines calculated by Passing-Bablok regression analysis were 0.92-1.08, 0.92-1.08, 0.90-1.13, and 0.91-1.41 for all testosterone values, testosterone in women, androstenedione, and DHEA. Intermethod CVs were 14%, 8%, 30%, and 22% for testosterone in women, testosterone in men, androstenedione, and DHEA. CONCLUSIONS In general, the LC-MS/MS methods investigated show reasonable agreement. However, some of the assays show differences in standardization, and others show high variation.

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Wiebke Arlt

Queen Elizabeth Hospital Birmingham

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Beverly Hughes

University of Birmingham

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Carl Jenkinson

University of Birmingham

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Nils Krone

University of Sheffield

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Silvia Parajes

University of Birmingham

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