Measurement of sex steroids in murine blood and reproductive tissues by liquid chromatography–tandem mass spectrometry

McNamara, Keely May; Harwood, D. Tim; Simanainen, Ulla; Walters, Kirsty A; Jimenez, Mark; Handelsman, David J.

doi:10.1016/j.jsbmb.2010.02.001

Cited by 102 publications

(92 citation statements)

References 57 publications

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“…Hence, increased androgen sensitivity in the testis of the NTNKO mice could support the maintenance of normal spermatogenesis despite markedly lowered circulating and intratesticular levels. Although E 2 can induce murine spermatogenesis (Ebling et al 2000) in gonadotrophin-deficient hpg mice by a mechanism requiring a functional AR (Lim et al 2008) and stimulation of pituitary FSH secretion (Allan et al 2010), serum E 2 was not detectable in either the WT or KO mice by LC-MS/MS consistent with our previous findings (McNamara et al 2010). Hence, the remarkable maintenance of spermatogenesis in this study is unlikely to involve E 2 due to the absence of sufficiently increased circulating FSH and E 2 levels involved in E 2 induction of spermatogenesis.…”

Section: Discussionsupporting

confidence: 91%

“…Serum levels of testosterone, DHT, 3a-diol and 3b-diol were measured in extracts of 100 ml of mouse serum by liquid chromatography-tandem mass spectrometry (LC-MS/MS; Harwood & Handelsman 2009) as adapted for mouse serum (McNamara et al 2010). The quantitation limits for testosterone, DHT, 3a-diol and 3b-diol were 20, 100, 400 and 400 pg/ml respectively.…”

Section: Hormone Assaysmentioning

confidence: 99%

“…Testis Intratesticular testosterone was analysed by stable isotope dilution LC-MS/MS (Harwood & Handelsman 2009) as adapted for mouse serum and reproductive tissue (McNamara et al 2010). Briefly, whole frozen testis was homogenised in 500 ml PBS buffer (containing 0.5% BSA (w/v) and 5 mM EDTA, pH 7.4) and centrifuged (2000 g 10 min, 4 8C) to separate insoluble debris, and then 200 ml of supernatant were extracted with 1 ml hexane:ethyl acetate (3:2 ratio) fortified with testosterone-1,2,3-d 3 (d 3 -T) as the internal standard.…”

Section: Hormone Assaysmentioning

confidence: 99%

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Evidence for increased tissue androgen sensitivity in neurturin knockout mice

Simanainen

Gao

Desai

et al. 2013

Journal of Endocrinology

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Neurturin (NTN) is a member of the glial cell line-derived neurotrophic factor (GDNF) family and signals through GDNF family receptor alpha 2 (GFRa2). We hypothesised that epithelial atrophy reported in the reproductive organs of Ntn (Nrtn)-and Gfra2 (Gfra2)-deficient mice could be due to NTN affecting the hormonal environment. To investigate this, we compared the reproductive organs of Ntn-and Gfra2-deficient male mice in parallel with an analysis of their circulating reproductive hormone levels. There were no significant structural changes within the organs of the knockout mice; however, serum and intratesticular testosterone and serum LH levels were very low. To reconcile these observations, we tested androgen sensitivity by creating a dihydrotestosterone (DHT) clamp (castration plus DHT implant) to create fixed circulating levels of androgens, allowing the evaluation of androgen-sensitive endpoints. At the same serum DHT levels, serum LH levels were lower and prostate and seminal vesicle weights were higher in the Ntn knockout (NTNKO) mice than in the wild-type mice, suggesting an increased response to androgens in the accessory glands and hypothalamus and pituitary of the NTNKO mice. Testicular and pituitary responsiveness was unaffected in the NTNKO males, as determined by the response to the human chorionic gonadotrophin or GNRH analogue, leuprolide, respectively. In conclusion, our results suggest that NTN inactivation enhances androgen sensitivity in reproductive and neuroendocrine tissues, revealing a novel mechanism to influence reproductive function and the activity of other androgen-dependent tissues. Key Words" glial cell line-derived neurotrophic factor (GDNF) family " TGFb family " neurotrophic " hypothalamic-pituitarytesticular axis " urogenital tract

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Section: Discussionsupporting

confidence: 91%

Section: Hormone Assaysmentioning

confidence: 99%

Section: Hormone Assaysmentioning

confidence: 99%

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Evidence for increased tissue androgen sensitivity in neurturin knockout mice

Simanainen

Gao

Desai

et al. 2013

Journal of Endocrinology

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“…relevant levels in the circulation of women (Burger 2002, McNamara et al 2010 and play important biological roles in females. There are several species of androgenic hormones in the circulation including, in the order of high to low concentration, dehydroepiandrosterone-sulphate (DHEAS), DHEA, androstenedione (A 4 ), testosterone and 5a-dihydrotestosterone (DHT).…”

Section: Introductionmentioning

confidence: 99%

Complexities of androgen receptor signalling in breast cancer

McNamara¹,

Moore²,

Hickey³

et al. 2014

Endocrine-Related Cancer

123

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While the clinical benefit of androgen-based therapeutics in breast cancer has been known since the 1940s, we have only recently begun to fully understand the mechanisms of androgen action in breast cancer. Androgen signalling pathways can have either beneficial or deleterious effects in breast cancer depending on the breast cancer subtype and intracellular context. This review discusses our current knowledge of androgen signalling in breast cancer, including the relationship between serum androgens and breast cancer risk, the prognostic significance of androgen receptor (AR) expression in different breast cancer subtypes and the downstream molecular pathways mediating androgen action in breast cancer cells. Intracrine androgen metabolism has also been discussed and proposed as a potential mechanism that may explain some of the reported differences regarding dichotomous androgen actions in breast cancers. A better understanding of AR signalling in this disease is critical given the current resurgence in interest in utilising contemporary AR-directed therapies for breast cancer and the need for biomarkers that will accurately predict clinical response.

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“…Testosterone, E 2 , and P 4 levels were measured in extracts of 100 ml mouse serum and ovarian homogenates by liquid chromatography tandem mass spectrometry (LC-MS/MS; Harwood & Handelsman 2009) as modified for mouse serum and ovary (McNamara et al 2010). The lowest limits of quantification (defined as detectable with a coefficient of variation !20%) were 25 pg/ml for testosterone, 2.5 pg/ml for E 2 , and 50 pg/ml for P 4 .…”

Section: Hormone Assaysmentioning

confidence: 99%

Androgen actions via androgen receptor promote PTEN inactivation induced uterine cancer

Choi

Desai

Zheng

et al. 2015

Endocrine-Related Cancer

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Haploinsufficient inactivating phosphatase and tensin homolog (Pten) mutations cause Cowden syndrome, an autosomal dominant risk genotype for hormone dependent reproductive cancers. As androgen actions mediated via the androgen receptor (AR) supports uterine growth and may modify uterine cancer risk, we hypothesized that a functional AR may increase PTEN inactivation induced uterine cancer. To test the hypothesis, we compared the PTEN knockout (PTENKO) induced uterine pathology in heterozygous PTENKO and combined heterozygous PTEN and complete AR knockout (PTENARKO) female mice. PTENKO induced uterine pathology was significantly reduced by AR inactivation with severe macroscopic uterine pathology present in 21% of PTENARKO vs 46% of PTENKO at a median age of 45 weeks. This could be due to reduced stroma ERa expression in PTENARKO compared to PTENKO uterus, while AR inactivation did not modify PTEN or P-AKT levels. Unexpectedly, while progesterone (P 4 ) is assumed protective in uterine cancers, serum P 4 was significantly higher in PTENKO females compared to WT, ARKO, and PTENARKO females consistent with more corpora lutea in PTENKO ovaries. Serum testosterone and ovarian estradiol were similar between all females. Hence, our results demonstrated AR inactivation mediated protection against PTENKO induced uterine pathology and suggests a potential role for antiandrogens in uterine cancer prevention and treatment.

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Measurement of sex steroids in murine blood and reproductive tissues by liquid chromatography–tandem mass spectrometry

Cited by 102 publications

References 57 publications

Evidence for increased tissue androgen sensitivity in neurturin knockout mice

Evidence for increased tissue androgen sensitivity in neurturin knockout mice

Complexities of androgen receptor signalling in breast cancer

Androgen actions via androgen receptor promote PTEN inactivation induced uterine cancer

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