A quantitative analysis of total and free 11-oxygenated androgens and its application to human serum and plasma specimens using liquid-chromatography tandem mass spectrometry

Simultaneous measurement of 17 endogenous steroid hormones in human serum by liquid chromatography-tandem mass spectrometry without derivatization

Mass spectrometric-based steroidomics is a valuable analytical approach that gives a comprehensive understanding of the interlinked steroid biosynthetic pathways. Here, we describe a rapid and versatile liquid chromatography-tandem mass spectrometry (LC-MS/MS) method designed to accurately quantify endogenous steroids in human serum. Sample preparation involved liquid-liquid extraction with methyl tert-butyl ether (MTBE) from 180 µL serum. The targeted steroids for quantification included androgens: dehydroepiandrosterone (DHEA), androstenedione (A4), testosterone (T), dihydrotestosterone (DHT), 11-oxyandrogens: 11β-hydroxy-androstenedione (11OHA4), 11-keto-androstenedione (11KA4), 11β-hydroxy-testosterone (11OHT), 11-keto-testosterone (11KT), progestogens: 17α-hydroxy-progesterone (17OHP4), progesterone (P4), 11β-hydroxy-progesterone (11OHP4), 11-keto-progesterone (11KP4), mineralocorticoids: aldosterone, corticosterone, and glucocorticoids: 11-deoxycortisol, cortisol, and cortisone. The lower limits of quantification (LLOQ) were 0.05 ng/mL for A4, T, 11KA4, P4, and cortisone, 0.1 ng/mL for DHT, 11OHA4, 11OHT, 11KT, 17OHP4, 11OHP4, 11KP4, corticosterone, aldosterone, 11-deoxycortisol, and cortisol, and 0.5 ng/mL for DHEA. Accuracy, precision, reproducibility, and recovery fell within acceptable limits for bioanalytical method validation. Using serum samples from 29 premenopausal women in different menstrual phases, we demonstrated the clinical utility of our method, which showed sufficient sensitivity to reliably quantify all targeted steroids at levels typically found in circulation, except for 11OHP4 and 11KP4.

Pre-receptor regulation of 11-oxyandrogens differs between normal and cancerous endometrium and across endometrial cancer grades and molecular subtypes

Background

Endometrial cancer (EC) is a prevalent gynecological malignancy globally, with a rising incidence trend. While classic androgens have been implicated with EC risk, the role of their 11-oxygenated metabolites is poorly understood. Here, we studied 11-oxyandrogen formation from steroid precursors in EC for the first time.

Methods

We performed in vitro studies on a panel of four EC cell lines of varying differentiation degree and molecular subtype and a control cell line of normal endometrium to assess 11-oxyandrogen formation from steroid precursors. We also characterized the transcriptomic effects of dihydrotestosterone (DHT) and 11-keto-DHT on Ishikawa and RL95-2. Key molecular players in 11-oxyandrogen metabolism and action were explored in endometrial tumors using public transcriptomic datasets.

Results

We discovered that within endometrial tumors, the formation of 11-oxyandrogens does not occur from classic androgen precursors. However, we observed distinct regulatory mechanisms at a pre-receptor level in normal endometrium compared to cancerous tissue, and between low- and high-grade tumors. Specifically, in vitro models of low-grade EC formed higher levels of bioactive 11-keto-testosterone from 11-oxyandrogen precursors compared to models of noncancerous endometrium and high-grade, TP53-mutated EC. Moreover, the potent androgen, DHT and its 11-keto homologue induced mild transcriptomic effects on androgen receptor (AR)-expressing EC model, Ishikawa. Finally, using public transcriptomic datasets, we found HSD11B2 and SRD5A2, coding for key enzymes in steroid metabolism, to be associated with better disease-specific survival, whereas higher intra-tumoral AR expression correlated with lower recurrence in TP53-wt tumors.

Conclusions

The intra-tumoral metabolism of 11-oxyandrogen precursors is characteristic for low-grade EC of non-TP53-alt molecular subtypes. Our findings support further exploration of circulating 11-oxyandrogens as prognostic biomarkers in EC.

Quantitative analysis of 34 sex (pro)hormones, conjugates and bioactive oxidation products thereof in human plasma by GC- and LC-MS/MS and systematic investigation of overestimations of analyte concentrations not accounted for by method validation

When investigating endocrine disorders, it is essential to assess a comprehensive quantitative profile of sex (pro)hormones in plasma including conjugates. Thus, the present study aimed to develop and validate a comprehensive mass spectrometry-based multimethod combining the direct analysis of unconjugated sex (pro)hormones and oxidation products thereof (by GC), as well as their sulfates and glucuronides present in higher concentrations (by LC) with the indirect quantification of glucuronides present in lower concentrations after selective glucuronide hydrolysis (by GC) and its application to plasma derived from ten pre- and postmenopausal women and men each. Even guideline-compliant validation experiments cannot completely reflect overestimation of analyte concentrations due to effects depending on the individual ratio of analytes (i.e. chemical formation of analytes or incomplete removal of interfering analytes). Thus, the extent of processes not accounted for by the calibration strategy were investigated and maximum over- or underestimations of analyte concentrations were assessed for each plasma sample individually. 34 analytes were successfully calibrated, validated (median accuracy 101.1 %, median inter-day precision 8.1 %) and 31 were detected above the detection limit in plasma samples. The sporadic maximum individual over- or underestimation of analyte concentrations amounted to less than 20 %.

Circulating adrenal and gonadal steroid hormones heterogeneity in active young males and the contribution of 11-oxy androgens

The classical androgens, testosterone and dihydrotestosterone, together with dehydroepiandrosterone, the precusrsor to all androgens, are generally included in diagnostic steroid evaluations of androgen excess and deficiency disorders and monitored in androgen replacement and androgen suppressive therapies. The C11-oxy androgens also contribute to androgen excess disorders and are still often excluded from clinical and research-based steroids analysis. The contribution of the C11-oxy androgens to the androgen pool has not been considered in androgen deficiency. An exploratory investigation into circulating adrenal and gonadal steroid hormones in men was undertaken as neither the classical androgens nor the C11-oxy androgens have been evaluated in the context of concurrent measurement of all adrenal steroid hormones. Serum androgens, mineralocorticoids, glucocorticoids, progesterones and androgens were assessed in 70 healthy young men using ultra high performance supercritical fluid chromatography and tandem mass spectrometry. Testosterone, 24.5 nmol/L was the most prominent androgen detected in all participants while dihydrotestosterone, 1.23 nmol/L, was only detected in 25% of the participants. The 11-oxy androgens were present in most of the participants with 11-hydroxyandrostenedione, 3.37 nmol, in 98.5%, 11-ketoandrostenedione 0.764 in 77%, 11-hydroxytestosterone, 0.567 in 96% and 11-ketotestosterone: 0.440 in 63%. A third of the participants with normal testosterone and comparable 11-ketotestosterone, had significantly lower dehydroepiandrosterone (p < 0.001). In these males 11-hydroxyandrostenedione (p < 0.001), 11-ketoandrostenedione (p < 0.01) and 11-hydroxytestosterone (p < 0.006) were decreased. Glucocorticoids were also lower: cortisol (p < 0.001), corticosterone (p < 0.001), cortisone (p < 0.006) 11-dehydrocorticosterone (p < 0.001) as well as cortisol:cortisone (p < 0.001). The presence of dehydroepiandrosterone was associated with 16-hydroxyprogesterone (p < 0.001), which was also significantly lower. Adrenal and gonadal steroid analysis showed unexpected steroid heterogeneity in normal young men. Testosterone constitutes 78% of the circulating free androgens with the 11-oxy androgens abundantly present in all participants significantly contributing 22%. In addition, a subset of men were identified with low circulating dehydroepiandrosterone who showed altered adrenal steroids with decreased glucocorticoids and decreased C11-oxy androgens. Analysis of the classical and 11-oxy androgens with the additional measurement of dehydroepiandrosterone and 16-hydroxyprogesterone may allow better diagnostic accuracy in androgen excess or deficiency.

Automated sample preparation for electrospray ionization mass spectrometry based on CLOCK-controlled autonomous centrifugal microfluidics

We report a centrifugal microfluidic device that automatically performs sample preparation under steady-state rotation for clinical applications using mass spectrometry. The autonomous microfluidic device was designed for the control of liquid operation on centrifugal hydrokinetics (CLOCK) paradigm. The reported device was highly stable, with less than 7% variation with respect to the time of each unit operation (sample extraction, mixing, and supernatant extraction) in the preparation process. An agitation mechanism with bubbling was used to mix the sample and organic solvent in this device. We confirmed that the device effectively removed the protein aggregates from the sample, and the performance was comparable to those of conventional manual sample preparation procedures that use high-speed centrifugation. In addition, probe electrospray ionization mass spectrometry (PESI-MS) was performed to compare the device-treated and manually treated samples. The obtained PESI-MS spectra were analyzed by partial least squares discriminant analysis, and the preparation capability of the device was found to be equivalent to that of the conventional method.

C11-hydroxy and C11-oxo C19 and C21 Steroids: Pre-Receptor Regulation and Interaction with Androgen and Progesterone Steroid Receptors

C11-oxy C19 and C11-oxy C21 steroids have been identified as novel steroids but their function remains unclear. This study aimed to investigate the pre-receptor regulation of C11-oxy steroids by 11β-hydroxysteroid dehydrogenase (11βHSD) interconversion and potential agonist and antagonist activity associated with the androgen (AR) and progesterone receptors (PRA and PRB). Steroid conversions were investigated in transiently transfected HEK293 cells expressing 11βHSD1 and 11βHSD2, while CV1 cells were utilised for agonist and antagonist assays. The conversion of C11-hydroxy steroids to C11-oxo steroids by 11βHSD2 occurred more readily than the reverse reaction catalysed by 11βHSD1, while the interconversion of C11-oxy C19 steroids was more efficient than C11-oxy C21 steroids. Furthermore, 11-ketodihydrotestosterone (11KDHT), 11-ketotestosterone (11KT) and 11β-hydroxydihydrotestosterone (11OHDHT) were AR agonists, while only progestogens, 11β-hydroxyprogesterone (11βOHP4), 11β-hydroxydihydroprogesterone (11βOHDHP4), 11α-hydroxyprogesterone (11αOHP4), 11α-hydroxydihydroprogesterone (11αOHDHP4), 11-ketoprogesterone (11KP4), 5α-pregnan-17α-diol-3,11,20-trione (11KPdione) and 21-deoxycortisone (21dE) exhibited antagonist activity. C11-hydroxy C21 steroids, 11βOHP4, 11βOHDHP4 and 11αOHP4 exhibited PRA and PRB agonistic activity, while only C11-oxo steroids, 11KP4 and 11-ketoandrostanediol (11K3αdiol) demonstrated PRB agonism. While no steroids antagonised the PRA, 11OHA4, 11β-hydroxytestosterone (11OHT), 11KT and 11KDHT exhibited PRB antagonism. The regulatory role of 11βHSD isozymes impacting receptor activation is clear-C11-oxo androgens exhibit AR agonist activity; only C11-hydroxy progestogens exhibit PRA and PRB agonist activity. Regulation by the downstream metabolites of active C11-oxy steroids at the receptor level is apparent-C11-hydroxy and C11-oxo metabolites antagonize the AR and PRB, progestogens the former, androgens the latter. The findings highlight the intricate interplay between receptors and active as well as "inactive" C11-oxy steroids, suggesting novel regulatory tiers.

The use of liquid chromatography-tandem mass spectrometry in newborn screening for congenital adrenal hyperplasia: improvements and future perspectives

Newborn screening for congenital adrenal hyperplasia using 17-hydroxyprogesterone by immunoassay remains controversial despite screening been available for almost 40 years. Screening is confounded by poor immunoassay specificity, fetal adrenal physiology, stress, and illness which can result in a large number of false positive screening tests. Screening programmes apply higher screening thresholds based on co-variates such as birthweight or gestational age but the false positive rate using immunoassay remains high. Mass spectrometry was first applied to newborn screening for congenital adrenal hyperplasia over 15 years ago. Elevated 17-hydroxprogesterone by immunoassay can be retested with a specific liquid chromatography tandem mass spectrometry assay that may include additional steroid markers. Laboratories register with quality assurance programme providers to ensure accurate steroid measurements. This has led to improvements in screening but there are additional costs and added laboratory workload. The search for novel steroid markers may inform further improvements to screening. Studies have shown that 11-oxygenated androgens are elevated in untreated patients and that the adrenal steroidogenesis backdoor pathway is more active in babies with congenital adrenal hyperplasia. There is continual interest in 21-deoxycortisol, a specific marker of 21-hydroxylase deficiency. The measurement of androgenic steroids and their precursors by liquid chromatography tandem mass spectrometry in bloodspots may inform improvements for screening, diagnosis, and treatment monitoring. In this review, we describe how liquid chromatography tandem mass spectrometry has improved newborn screening for congenital adrenal hyperplasia and explore how future developments may inform further improvements to screening and diagnosis.

Androgen signalling in the ovaries and endometrium

Currently, our understanding of hormonal regulation within the female reproductive system is largely based on our knowledge of estrogen and progesterone signalling. However, while the important functions of androgens in male physiology are well known, it is also recognized that androgens play critical roles in the female reproductive system. Further, androgen signalling is altered in a variety of gynaecological conditions, including endometriosis and polycystic ovary syndrome, indicative of regulatory roles in endometrial and ovarian function. Co-regulatory mechanisms exist between different androgens, estrogens, and progesterone, resulting in a complex network of steroid hormone interactions. Evidence from animal knockout studies, in vitro experiments, and human data indicate that androgen receptor expression is cell-specific and menstrual cycle stage-dependent, with important regulatory roles in the menstrual cycle, endometrial biology, and follicular development in the ovaries. This review will discuss the expression and co-regulatory interactions of androgen receptors, highlighting the complexity of the androgen signalling pathway in the endometrium and ovaries, and the synthesis of androgens from additional alternative pathways previously disregarded as male-specific. Moreover, it will illustrate the challenges faced when studying androgens in female biology, and the need for a more in-depth, integrative view of androgen metabolism and signalling in the female reproductive system.

Circulating adrenal 11-oxygenated androgens are associated with clinical outcome in endometrial cancer

Context

Recent evidence support that androgens play an important role in the etiology of endometrial cancer (EC). Adrenal-derived 11-oxygenated androgens are highly potent agonists of the androgen receptor (AR), comparable to testosterone (T) and dihydrotestosterone (DHT) that have not been studied in the context of EC.

Methodology

We studied a cohort of 272 newly diagnosed postmenopausal EC cases undergoing surgical treatment. Circulating concentrations of seven 11-oxygenated androgens including precursors, potent androgens and their metabolites were established in serum samples collected before and 1 month after surgery using a validated liquid chromatography tandem mass spectrometry method (LC-MS/MS). Free (unconjugated) and total (free + sulfate and glucuronide conjugates following enzymatic hydrolysis) were analyzed in relation to clinicopathological features, recurrence and disease-free survival (DFS).

Results

Levels of 11-oxygenated androgens were weakly correlated to those of canonical androgens such as testosterone (T) and dihydrotestosterone (DHT), with no evidence of their association with clinicopathological features. Levels of 11-oxygenated androgens declined after surgery but remained higher in overweight and obese compared to normal weight cases. Higher levels of preoperative free 11-ketoandrosterone (11KAST) were associated with an increased risk of recurrence (Hazard ratio (HR) of 2.99 (95%CI=1.09-8.18); P=0.03). Postoperative free 11β-hydroxyandrosterone (11OHAST) levels were adversely associated with recurrence and DFS (HR = 3.23 (1.11-9.40); P=0.03 and 3.27 (1.34-8.00); P=0.009, respectively).

Conclusion

11-oxygenated androgen metabolites emerge as potential prognostic markers of EC.

Extensive metabolic consequences of human glycosyltransferase gene knockouts in prostate cancer

BACKGROUND

Naturally occurring germline gene deletions (KO) represent a unique setting to interrogate gene functions. Complete deletions and differential expression of the human glycosyltransferase UGT2B17 and UGT2B28 genes are linked to prostate cancer (PCa) risk and progression, leukaemia, autoimmune and other diseases.

METHODS

The systemic metabolic consequences of UGT deficiencies were examined using untargeted and targeted mass spectrometry-based metabolomics profiling of carefully matched, treatment-naive PCa cases.

RESULTS

Each UGT KO differentially affected over 5% of the 1545 measured metabolites, with divergent metabolic perturbations influencing the same pathways. Several of the perturbed metabolites are known to promote PCa growth, invasion and metastasis, including steroids, ceramides and kynurenine. In UGT2B17 KO, reduced levels of inactive steroid-glucuronides were compensated by sulfated derivatives that constitute circulating steroid reservoirs. UGT2B28 KO presented remarkably lower levels of oxylipins paralleled by reduced inflammatory mediators, but higher ceramides unveiled as substrates of the enzyme in PCa cells.

CONCLUSION

The distinctive and broad metabolic rewiring caused by UGT KO reinforces the need to examine their unique and divergent functions in PCa biology.

Sensitive HPLC-DMS/MS/MS method coupled with dispersive magnetic solid phase extraction followed by in situ derivatization for the simultaneous determination of multiplexing androgens and 17-hydroxyprogesterone in human serum and its application to patients with polycystic ovarian syndrome

BACKGROUND AND AIMS

Androgens play important roles in polycystic ovarian syndrome (PCOS). However, measures of androgens based on mass spectrometry (MS) remain complex due to endogenous inferences of isomers or compounds with similar structures. Lack of sensitivity can also affect the accurate quantification of androgens, especially for very low level of 11-oxygenated androgens.

MATERIALS AND METHODS

We developed a fast and sensitive high-performance liquid chromatography-differential mobility spectrometry tandem mass spectrometry (HPLC-DMS/MS/MS) method for the simultaneous determination of seven androgens and 17-hydroxyprogesterone. Dispersive magnetic solid phase extraction (DMSPE) was conducted with core-shell structured nanoparticles of magnetic graphene oxide (Fe₃O₄@GO). In situ derivatization was performed using Girard's Reagent P.

RESULTS

Linear ranges of the eight analytes were set in terms of clinical use. Intra- and inter-run precisions were < 16.7 % and 12.9 % for all the analytes and relative error was - 14.7-13.3 % and - 9.3-11.0 %, respectively. Extraction recoveries were 54.0-92.7 % for different analytes. The method was validated and was applied to assay 432 clinical samples.

CONCLUSION

The developed method is green, fast, sensitive and accurate for the determination of endogenous androgens. It can be readily implemented in medical laboratories to provide superior analytical performance over the traditional electrochemiluminescence immunoassay method.

Inclusion of 11-Oxygenated Androgens in a Clinical Routine LC-MS/MS Setup for Steroid Hormone Profiling

11-Oxygenated androgens (11-OAs) are being discussed as potential biomarkers in diagnosis and therapy control of disorders with androgen excess such as congenital adrenal hyperplasia and polycystic ovary syndrome. However, quantification of 11-OAs by liquid chromatography-tandem mass spectrometry (LC-MS/MS) still relies on extensive sample preparation including liquid-liquid extraction, derivatization and partial long runtimes, which is unsuitable for high-throughput analysis under routine laboratory settings. For the first time, an established online-solid-phase extraction-LC-MS/MS (online-SPE-LC-MS/MS) method for the quantitation of seven serum steroids in daily routine use was extended and validated to include 11-ketoandrostenedione, 11-ketotestosterone, 11β-hydroxyandrostenedione and 11β-hydroxytestosterone. Combining a simple protein precipitation step with fast chromatographic separation and ammonium fluoride-modified ionization resulted in a high-throughput method (6.6 min run time) featuring lower limits of quantification well below endogenous ranges (63-320 pmol/L) with recoveries between 85% and 117% (CVs ≤ 15%). Furthermore, the ability of this method to distinguish between adrenal and gonadal androgens was shown by comparing 11-OAs in patients with hyperandrogenemia to healthy controls. Due to the single shot multiplex design of the method, potential clinically relevant ratios of 11-OAs and corresponding androgens were readily available. The fully validated method covering endogenous concentration levels is ready to investigate the diagnostic values of 11-OAs in prospective studies and clinical applications.

Rapid Derivatization of Phenolic and Oxime Hydroxyl with Isonicotinoyl Chloride under Aqueous Conditions and Its Application in LC-MS/MS Profiling Multiclass Steroids

Quantification of steroids possesses a crucial clinical value in early diagnosis and prognosis evaluation of various endocrine diseases. However, it is still challenging to realize feasible analysis of estrogens, androgens, progestogens, and corticoids within one single workflow. In this study, two derivatization reactions were newly designed for improvement: (1) acylation of phenolic hydroxyl on estrogens with isonicotinoyl chloride (INC) under the catalysis of 4-dimethylaminopyridine and (2) post-modification of oxime hydroxyl on hydroxylamine-pretreated ketosteroids with INC. Both reactions could conduct instantaneously at room temperature under aqueous conditions. Moreover, the resulting phenolic-INC and oxime-INC esters exhibited favorable MS responses. Through integrating these derivatization strategies with cold-induced phase separation technology, a feasible LC-MS/MS method was developed for simultaneous quantification of 15 multiclass steroids with proper sample consumption (50 μL serum), satisfying sensitivity (lower limit of quantitation at 0.01-5.00 ng/mL) and high throughput (40 min for sample-preparation). The practical applicability was tested by detecting 30 real samples from pregnant and non-pregnant women. The obtained results showed a good agreement with a previous validated methodology.

The Roles of Androgens in Humans: Biology, Metabolic Regulation and Health

Androgens are an important and diverse group of steroid hormone molecular species. They play varied functional roles, such as the control of metabolic energy fate and partition, the maintenance of skeletal and body protein and integrity and the development of brain capabilities and behavioral setup (including those factors defining maleness). In addition, androgens are the precursors of estrogens, with which they share an extensive control of the reproductive mechanisms (in both sexes). In this review, the types of androgens, their functions and signaling are tabulated and described, including some less-known functions. The close interrelationship between corticosteroids and androgens is also analyzed, centered in the adrenal cortex, together with the main feedback control systems of the hypothalamic-hypophysis-gonads axis, and its modulation by the metabolic environment, sex, age and health. Testosterone (T) is singled out because of its high synthesis rate and turnover, but also because age-related hypogonadism is a key signal for the biologically planned early obsolescence of men, and the delayed onset of a faster rate of functional losses in women after menopause. The close collaboration of T with estradiol (E2) active in the maintenance of body metabolic systems is also presented Their parallel insufficiency has been directly related to the ravages of senescence and the metabolic syndrome constellation of disorders. The clinical use of T to correct hypoandrogenism helps maintain the functionality of core metabolism, limiting excess fat deposition, sarcopenia and cognoscitive frailty (part of these effects are due to the E2 generated from T). The effectiveness of using lipophilic T esters for T replacement treatments is analyzed in depth, and the main problems derived from their application are discussed.

Integration of androgen hormones in endometrial cancer biology

Endometrial cancer (EC) is a gynecological pathology that affects the uterine inner lining. In recent years, genomic studies revealed continually evolving mutational landscapes of endometrial tumors that hold great potential for tailoring therapeutic strategies. This review aims to broaden our knowledge of EC biology by focusing on the role of androgen hormones. First, we discuss epidemiological evidence implicating androgens with EC pathogenesis and cover their biosynthesis and metabolism to bioactive 11-oxyandrogens. Next, we explore the endometrial tumor tissue and the altered microbiota as alternative sources of androgens and their 11-oxymetabolites in EC patients. Finally, we discuss the biological significance of androgens' genomic and nongenomic signaling as part of a medley of pathways ultimately deciding the fate of cells.

Basics of androgen synthesis and action

Androgens are essential sex steroid hormones for both sexes. Testosterone (T) is the predominant androgen in males, while in adult females, T concentrations are about 15-fold lower and androgen precursors are converted to estrogens. T is produced primarily in testicular Leydig cells in men, while in women precursors are biosynthesised in the adrenal cortex and ovaries and converted into T in the periphery. The biosynthesis of T occurs via a series of enzymatic reactions in steroidogenic organs. Notably, the more potent androgen, dihydrotestosterone, may be synthesized from T in the classic pathway, however, alternate metabolic pathways also exist. The classic action of androgens on target organs is mediated through the androgen receptor, which regulates nuclear receptor gene transcription. However, the androgen-androgen receptor complex may also interact directly with membrane proteins or signaling molecules to exert more rapid effects. This review summarizes the current knowledge of androgen biosynthesis, mechanisms of action and endocrine effects in human biology, and relates these effects to respective human congenital and acquired disorders.