The Orphan Nuclear Receptors Steroidogenic Factor-1 and Liver Receptor Homolog-1: Structure, Regulation, and Essential Roles in Mammalian Reproduction.

Nuclear receptors are intracellular proteins that act as transcription factors. Proteins with classic nuclear receptor domain structure lacking identified signaling ligands are designated orphan nuclear receptors. Two of these, steroidogenic factor-1 (NR5A1, also known as SF-1) and liver receptor homolog-1 (NR5A2, also known as LRH-1), bind to the same DNA sequences, with different and nonoverlapping effects on targets. Endogenous regulation of both is achieved predominantly by cofactor interactions. SF-1 is expressed primarily in steroidogenic tissues, LRH-1 in tissues of endodermal origin and the gonads. Both receptors modulate cholesterol homeostasis, steroidogenesis, tissue-specific cell proliferation, and stem cell pluripotency. LRH-1 is essential for development beyond gastrulation and SF-1 for genesis of the adrenal, sexual differentiation, and Leydig cell function. Ovary-specific depletion of SF-1 disrupts follicle development, while LRH-1 depletion prevents ovulation, cumulus expansion, and luteinization. Uterine depletion of LRH-1 compromises decidualization and pregnancy. In humans, SF-1 is present in endometriotic tissue, where it regulates estrogen synthesis. SF-1 is underexpressed in ovarian cancer cells and overexpressed in Leydig cell tumors. In breast cancer cells, proliferation, migration and invasion, and chemotherapy resistance are regulated by LRH-1. In conclusion, the NR5A orphan nuclear receptors are nonredundant factors that are crucial regulators of a panoply of biological processes, across multiple reproductive tissues.

ß-Catenin alterations in testicular Leydig cell tumour: a immunohistochemical and molecular analysis.

BACKGROUND: Testicular Leydig cell tumours (LCTs) are the most common type of sex cord-stromal tumour in men, representing 1%-3% of all testicular neoplasms. Among testicular sex cord-stromal tumours, CTNNB1 mutations and nuclear expression of ß-catenin have been typically associated with Sertoli cell tumour. Recent genomic analyses have shown that CTNNB1 variants are also identified in a subset of LCTs; however, the frequency and clinicopathologic associations of ß-catenin alterations remain incompletely understood in this tumour type. METHODS: In this study, we evaluated 32 LCTs (five malignant/metastasizing, 27 nonmetastasizing) using ß-catenin immunohistochemistry and DNA sequencing. RESULTS: Immunohistochemistry revealed focal or multifocal nuclear ß-catenin expression in 47% of the tumours. Diffuse nuclear ß-catenin expression (in >50% of the tumour cells) was not detected in any of the cases analysed herein. Comparison of ß-catenin-positive and ß-catenin-negative cases did not show significant differences in the frequency of adverse histopathologic findings or malignant clinical behaviour. DNA sequencing performed de novo on a subset of seven cases revealed the presence of exon 3 CTNNB1 variants in four of them (4/7, 57%), with variant allele frequencies (VAF) ranging from 7 to 33%. Two additional ß-catenin-positive cases that had been sequenced as part of a previous study harboured exon 3 CTNNB1 variants at VAF of 28% and 7%, respectively. CONCLUSION: These results demonstrate that ß-catenin alterations are relatively common in LCT, most likely occurring as subclonal events that are not enriched in cases with aggressive features. Further studies are needed to clarify the oncogenic role of ß-catenin in this tumour type.

Comparative molecular analysis of testicular Leydig cell tumors demonstrates distinct subsets of neoplasms with aggressive histopathologic features.

Testicular Leydig cell tumor (LCT), the most common sex-cord stromal tumor in men, represents a small fraction of all testicular tumors (~1 to 3%). Although most testicular LCTs are indolent and cured by radical orchiectomy, 5-10% have aggressive biology and metastatic potential. In primary LCTs, large size, cytologic atypia, necrosis, increased mitotic activity, and vascular invasion have been associated with clinically aggressive tumors. From a molecular perspective, the characteristics of aggressive LCTs and the differences between aggressive and nonaggressive LCTs remain largely unexplored. This study compares the genomic landscape of aggressive and nonaggressive testicular LCTs. Twenty-six cases were analyzed using next-generation DNA sequencing (NGS) and immunohistochemistry. Cases were classified as aggressive LCT if they met published criteria for malignancy in primary (i.e., testicular) tumors or if they had pathology-proven metastatic disease; otherwise, cases were considered nonaggressive. This multi-institutional series included 18 aggressive LCTs (14 primary/testicular, 4 metastatic) and 8 nonaggressive LCTs. Two cases (2/26, 8%; both aggressive LCTs) failed sequencing and had negative (i.e., uninformative) FH immunohistochemistry results. One additional primary aggressive LCT failed sequencing but had informative FH immunohistochemistry results. Combined NGS and immunohistochemical analysis demonstrated FH inactivation in 5/26 cases (19%). In addition, NGS demonstrated CTNNB1 mutations or biallelic APC inactivation in 9/23 cases (39%), copy number changes without recurrent mutations in 6/23 (26%) cases, and no alterations in 4/23 cases (17%). CTNNB1 mutations were present in both aggressive and nonaggressive LCTs. In contrast, FH inactivation and multiple copy number changes were only identified in aggressive LCTs. In conclusion, three distinct subgroups of aggressive LCTs were characterized by FH inactivation, Wnt pathway activation, and copy number changes without recurrent mutations, respectively. Nuclear translocation of ß-catenin and Wnt pathway activation appear to be early driver events that provide an environment conducive for progression to aggressive biology in a subset of LCTs.

The Leydig cell tumour Scaled Score (LeSS): a method to distinguish benign from malignant cases, with additional correlation with MDM2 and CDK4 amplification.

AIMS: To investigate the morphological and molecular characteristics of Leydig cell tumours (LCTs) of the testis for the identification of cases that may metastasise. METHODS AND RESULTS: Six parameters for a predictive model of the metastatic risk were evaluated in 37 benign and 14 malignant LCTs of the testis [LCT Scaled Score (LeSS)]. The tumour size (benign LCTs, mean 13.3 mm; malignant LCTs, mean 44 mm) (P < 0.001) and five other parameters (infiltrative margins, necrosis, vascular invasion, mitotic count, and nuclear atypia) showed significant differences (Wilcoxon's test, P < 0.001). Eight metastatic LCTs and one benign LCT had infiltrative margins. Foci of coagulative necrosis occurred in 10 metastatic LCTs, whereas vascular invasion was identified in nine of 14 metastatic LCTs and none of 37 benign LCTs. Benign LCTs showed <2 mitoses/10 high-power fields (HPFs), whereas a high mitotic count (range, 3-50 mitoses/10 HPFs) was a feature of malignant LCTs. These parameters were selected by use of an inferential analysis based on univariate logistic regression models to develop a score. A LeSS of <4 correctly identified all histologically and clinically benign LCTs. A LeSS of ≥4 correctly identified all malignant LCTs. MDM2 and CDK4 immunostains were applied in all 51 cases: benign LCTs were negative; three of 11 malignant LCTs (27%) showed strong and diffuse immunopositivity and high levels of MDM2 and CDK4 amplification as determined with fluorescence in-situ hybridisation analysis and next-generation sequencing. CONCLUSION: We provide a new tool, the LeSS, for the prediction of malignant behaviour in LCTs.

Occult symptomatic bilateral pure Leydig cell tumors in a postmenopausal woman: a case report.

BACKGROUND: Pure Leydig cell tumors (LCTs) represent 0.1% of ovarian masses. Postmenopausal patients typically present with virilization. Although LCTs can be challenging to locate on conventional imaging, positron emission tomography (PET) has been demonstrated to be effective. CASE: A 64-year-old postmenopausal woman presented with alopecia, facial hirsutism, and clitoromegaly. Laboratory findings included elevated testosterone and androstenedione. Ultrasound, computed tomography, and magnetic resonance imaging showed no adnexal masses. PET did not demonstrate ovarian fludeoxyglucose-avidity. Histopathology after bilateral salpingo-oophorectomy revealed bilateral Leydig cell tumors. Her testosterone normalized 2 weeks postoperatively. CONCLUSION: We describe the occult, symptomatic, bilateral ovarian Leydig cell tumors, an occurrence that has not been described in the literature. Virilizing tumors must be considered in patients with evidence of hyperandrogenism, even without pelvic masses on imaging.

Testis-sparing surgery for testicular tumors in children: a 20 year single center experience and systematic review of the literature.

PURPOSE: Although surgical therapy for testicular tumors (TT) is often radical orchidectomy, tumor resection with preservation of healthy testicular parenchyma has been proposed. This study herein reports a 20 year single center experience applying testicular sparing surgery (TSS) as a primary operative strategy in pediatric patients. A systematic literature review summarizes the utility and outcomes of TSS in appropriately selected patients. METHODS: Pediatric patients with TT who underwent TSS between 1997 and 2018 were studied. TSS was indicated if patients presented evidence of adequately spared healthy testicular parenchyma on preoperative ultrasound and negative serum tumor markers. A systematic review of the literature was also performed. RESULTS: 12 cases met full inclusion criteria with 10 of 12 subjects in the prepubertal age group. Follow-up was 73 months (range 18-278 months). Only a single male patient (GSCCT) presented with early recurrence and orchidectomy was then performed. No cases of postoperative testicular atrophy were identified. Sexual maturation (Tanner stage) expected for age in each patient was documented. Review of the literature identified 34 published studies including 269 patients (94% prepubertal). Pathologic lesions here were mainly mature teratoma(s)-(62%) with a follow-up period of 4 years. Recurrent tumors were observed in only three patients (1.1%) notably two Leydig Cell Tumors and one Teratoma. Testicular atrophy reportedly occurred in only one single case (0.37%). DISCUSSION: TSS is a feasible alternative to radical orchidectomy in pediatric male patients with localized TT and negative tumor markers. Long term follow-up is essential to monitor testicular growth, puberty with sexual development and psychological male health.

Postmenopausal androgen-secreting ovarian tumors: challenging differential diagnosis in two cases.

Postmenopausal hyperandrogenism constitutes a very rare condition of tumoral or non-tumoral origin primarily residing either in the ovary or in the adrenal glands. We present herein two cases with this condition; one with abnormal postmenopausal genital bleeding and mild increase in facial hair, and the second with slow-developing hirsutism and virilization. Both cases shared a notorious increase in libido. The laboratory tests showed high levels of testosterone (>100 ng/ml). A normal value of dehydroepiandrosterone sulfate and a normal cortisol level at 9 am after 1 mg of dexamethasone administered at midnight (Nugent test) made an adrenal etiology very unlikely. On the other hand, a high level of inhibine B oriented to an ovarian source. Transvaginal sonography failed to demonstrate an ovarian tumor, but an abdominal and pelvic computed tomography scan or magnetic resonance imaging detected an ovarian tumor and normal adrenal glands. A laparoscopic oophorectomy was performed, and the histological study demonstrated a steroidal cell tumor in the first case and a Leydig cell tumor in the second.

Malignant leydig cell tumor in a 91-year-old man: Case report.

Testicle tumors are a rare entity among men population, accounting for only 1-1.5% of all can-cers among men. The stromal tumors of the sexual cord correspond just 4% of all testicular cancers. Only 10% of them are malignant. The major representative of the sex cord-stromal tumors is the Leydig cell tumor, corresponding to 75 to 80% of the total. It has bimodal age incidence, involving children and adults between 30 and 60 years. We report the caso of a 91-year-old man with malignant Leydig cell tumor, presenting increase of the volume of scrotum, local pain and hyperemia. The are few cases in the literature, only 1 with pacient above 85 years old.

Diagnostic pitfalls in ovarian androgen-secreting (Leydig cell) tumours: case series.

Leydig cell tumours of the ovary are rare and represent a diagnostic challenge not only due to their sporadic incidence but also due to the seemingly normal imaging. We present three cases of pre- and postmenopausal women who were presented with severe clinical signs of hyperandogenism where modern imaging modalities (including computed tomography (CT), magnetic resonance imaging (MRI) and positron-emission tomography combined with computed tomography (PET-CT)) failed to identify the tumour. Two patients underwent non-expert ultrasound, CT and MRI examination with uniform conclusion that ovaries are of normal appearance. One of the two patients even had a PET-CT performed, which was inconclusive. Our case reports show the importance of examination by specialists with established skills in gynaecologic ultrasonography in the diagnosis of the Leydig cell tumours. The most useful diagnostic tool seems to be the combination of age (postmenopause), symptoms (onset of hirsutism and virilisation), high total testosterone plasma values and expert sonography. On ultrasound, these tumours are unilateral, usually small, solid intraovarian nodules of a slightly increased echogenicity in contrast to the surrounding ovarian tissue, delineated by abundant perfusion with an enhanced vascularity. The appropriate setting of the sensitive colour Doppler is crucial for the detection of intraovarian Leydig cell tumour. Impact statement What is already known on this subject? A diagnosis of Leydig cell tumours is based on ultrasound performed by a trained examiner or by MRI. CT or PET/CT are not among the primary methods of choice. According to the results of imaging investigations surgical treatment is planned. Because these tumours are usually benign and have a good prognosis the unilateral salpingo-oophorectomy is a standard procedure. What do the results of this study add? Our case series show how difficult it can be to establish the diagnosis of Leydig cell tumours by imaging, including transvaginal ultrasound, the most frequently recommended diagnostic tool. We demonstrate in three cases how easily a small hyperechogenic tumour can be overseen or interchanged for a different gynaecological pathology if transvaginal scan is not performed by an experienced examiner trained in sonographic features of gynaecologic neoplasms. What are the implications of these findings for clinical practice and/or further research? This case series demonstrate how important it is to see the patient in the whole complexity with their medical history, proper clinical symptoms evaluation, laboratory test and not to rely solely just on sophisticated high-end investigations, such as the PET-CT, a CT and an MRI. It also emphasises the importance of specialists with established skills in gynaecologic ultrasonography. Further effort should be made to define the resources for the appropriate training of such sonographers.

Testis Sparing Surgery for Benign Testicular Masses: Diagnostics and Therapeutic Approaches.

PURPOSE: Small benign testicular masses are often misinterpreted as germ cell tumors and immediate inguinal orchiectomy is performed. We analyzed the diagnostic and therapeutic workup of testicular masses to improve preoperative stratification algorithms. MATERIALS AND METHODS: We performed a retrospective, single center analysis of the records of 522 patients diagnosed with primary testicular masses of unknown malignant potential. RESULTS: A total of 28 patients (5%) showed a primary benign tumor after resection, including Leydig cell tumors in 9 (32%), epidermoid cysts in 9 (32%), adenomatoid tumors in 8 (29%) and Sertoli cell tumors in 2 (7%). The median volume of benign tumors was significantly less than that of malignant tumors (0.75 cm3, range 0.1 to 2.1 vs 15, range 4.5-39.9, p ≤0.001). At a cutoff of 2.8 cm3 tumor volume most accurately differentiated between benign and malignant disease, and it was a predictor of malignancy with 83% sensitivity and 89% specificity (OR 1.389, 95% CI 1.035-1.864, p = 0.029). Symptom duration in patients with benign tumors was significantly longer (365 days, range 25.5 to 365 vs 20, range 7 to 42, p ≤0.001). Also, tumor markers were unaltered in benign lesions. In patients with benign tumors significantly more fertility disorders or cryptorchidism were found (p ≤0.001) as well as a tendency toward lower testosterone (3.9 µg/l, range 0.9 to 4.9 vs 5.3, range 3.5 to 6.8, p = 0.084). Testis sparing surgery was performed in 22 of all patients (79%) with benign tumors. There was no case of relapse during followup. CONCLUSIONS: Nongerm cell tumors should be considered when small testicular masses have a volume of less than 2.8 cm3 and there are hormone disorders or normal tumor markers. Immediate orchiectomy should be avoided, favoring testis sparing surgery.

Testicle-sparing surgery versus radical orchiectomy in the management of Leydig cell tumors: results from a multicenter study.

OBJECTIVE: To compare the oncological outcomes of testicle-sparing surgery (TSS) and radical orchiectomy (RO) in patients with Leydig cell tumor (LCT) of the testis. PATIENTS AND METHODS: A multicenter retrospective clinical study was conducted in 12 centers in France. All the patients with histologically proven LCT were included and analyzed according to treatment (organ-sparing surgery or radical orchiectomy). Patients underwent preoperative clinical, biological and imaging assessment. Demographic, clinical, and pathological variables were collected at baseline and compared between groups according to surgical treatment. Follow-up was calculated using the reverse Kaplan-Meier estimation and was updated at the end of 2015. RESULTS: Between 1986 and 2014, 56 patients presented with LCT were identified and included in the study. Twenty-one patients (37.5%) underwent TSS and 35 (62.5%) RO. Demographics and tumor characteristics were not significantly different between the groups. Median follow-up was 62 months after TSS, but only 35 months after RO. Two patients (9.5%) developed local recurrence 15 and 34 months after TSS and underwent secondary RO. No local recurrence or metastasis was observed after complementary treatment. No recurrence was observed after RO. Disease-free survival did not differ between the groups (95.2% in TSS versus 77.1% in the RO group, p = 0.23). No patient died in the TSS group, but three patients (8.6%) in the RO group died from other diseases without evidence of relapse. One patient (4.8%) in the TSS group versus five (14.3%) in the RO group were lost to follow-up. CONCLUSION: Long-term follow-up suggests that testicle-sparing surgery does not compromise relapse-free survival in the treatment of Leydig cell tumor of the testis.

Dynamic contrast-enhanced and diffusion-weighted MR imaging in the characterisation of small, non-palpable solid testicular tumours.

OBJECTIVES: To explore the role of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI), using semiquantitative and quantitative parameters, and diffusion-weighted (DW) MRI in differentiating benign from malignant small, non-palpable solid testicular tumours. METHODS: We calculated the following DCE-MRI parameters of 47 small, non-palpable solid testicular tumours: peak enhancement (PE), time to peak (TTP), percentage of peak enhancement (Epeak), wash-in-rate (WIR), signal enhancement ratio (SER), volume transfer constant (Ktrans), rate constant (Kep), extravascular extracellular space volume fraction (Ve) and initial area under the curve (iAUC). DWI signal intensity and apparent diffusion coefficient (ADC) values were evaluated. RESULTS: Epeak, WIR, Ktrans , Kep and iAUC were higher and TTP shorter in benign compared to malignant lesions (p < 0.05). All tumours had similar ADC values (p > 0.07). Subgroup analysis limited to the most frequent histologies - Leydig cell tumours (LCTs) and seminomas - replicated the findings of the entire set. Best diagnostic cutoff value for identification of seminomas: Ktrans ≤0.135 min-1, Kep ≤0.45 min-1, iAUC ≤10.96, WIR ≤1.11, Epeak ≤96.72, TTP >99 s. CONCLUSIONS: DCE-MRI parameters are valuable in differentiating between benign and malignant small, non-palpable testicular tumours, especially when characterising LCTs and seminomas. KEY POINTS: • DCE-MRI may be used to differentiate benign from malignant non-palpable testicular tumours. • Seminomas show lower Ktrans, Kep and iAUC values. • ADC values are not valuable in differentiating seminomas from LCTs. • Semiquantitative DCE-MRI may be used to characterise small, solid testicular tumours.

Determination of temperature distribution in tissue for interstitial cancer photothermal therapy.

BACKGROUND: Temperature increase in tumour tissue during photothermal therapy (PTT) is a significant factor in determining the outcomes of the treatment. Therefore, controlling and optimising temperature distribution in target tissue is crucial for PTT. In this study, we developed a unique ex vivo device to study the temperature distribution during PTT to be used as a guide for the desired photothermal effects for cancer treatment. METHODS: Bovine liver tissue buried inside agarose gel served as a phantom tumour surrounded by normal tissue. A thermostatic incubator was used to simulate tissue environment in live animals. The temperature distributions were measured by thermocouples with needle probes at different locations inside the target tissue, during laser irradiation using an 805-nm laser. RESULTS: The results obtained using the ex vivo device were verified by comparing the tissue temperature directly measured in animal tumours irradiated under the same conditions. With this model, the spatial distribution of temperature in target tissue can be monitored in real time. A two-dimensional temperature distribution in target tissue allows us to establish the correlations among laser parameters, temperature distribution and tumour size. In addition, the optimal temperature range for tumour destruction and immunological stimulation was determined using metastatic rat mammary tumour model. CONCLUSION: The device and method developed in this study can provide guidance for choosing the appropriate treatment parameters for optimal photothermal effects, particularly when combined with immunotherapy, for cancer treatment.

Retroperitoneal Leydig cell tumor recurrence presenting 14 years after orchiectomy.

Malignant Leydig cell tumor is a rare entity that has been previously described as rapidly progressive and uniformly fatal. We present the case of a malignant Leydig cell tumor that presented 14 years after orchiectomy with an isolated retroperitoneal metastasis. Our patient underwent a retroperitoneal lymph node dissection and has been free of recurrence or progression at 12 months of follow up. Additionally, we describe the symptomatic hormone dysfunction experienced by our patient as a result of his tumor.

Mechanism of bisphenol AF-induced progesterone inhibition in human chorionic gonadotrophin-stimulated mouse Leydig tumor cell line (mLTC-1) cells.

Bisphenol AF (BPAF) has been shown to inhibit testicular steroidogenesis in male rats. However, the precise mechanisms related to the toxic effects of BPAF on reproduction remain poorly understood. In the present study, a mouse Leydig tumor cell line (mLTC-1) was used as a model to investigate the mechanism of steroidogenic inhibition and to identify the molecular target of BPAF. Levels of progesterone and the concentration of cyclic adenosine monophosphate (cAMP) in cells exposed to BPAF were detected, and expression of key genes and proteins in steroid biosynthesis was assessed. The results showed that BPAF exposure decreased human chorionic gonadotrophin (hCG)-stimulated progesterone production in a dose-dependent manner. The 24-h IC50 (half maximal inhibitory concentration) value for BPAF regarding progesterone production was 70.2 µM. A dramatic decrease in cellular cAMP concentration was also observed. Furthermore, BPAF exposure inhibited expression of genes and proteins involved in cholesterol transport and progesterone biosynthesis. Conversely, the protein levels of steroidogenic acute regulatory protein (StAR) were not altered, and those of progesterone were still decreased upon 22R-hydroxycholesterol treatment of cells exposed to higher doses of BPAF. Together, these data indicate that BPAF exposure inhibits progesterone secretion in hCG-stimulated mLTC-1 cells by reducing expression of scavenger receptor class B type I (SR-B1) and cytochrome P450 (P450scc) due to the adverse effects of cAMP. However, StAR might not be the molecular target in this process.

Constitutive luteinizing hormone receptor signaling causes sexual dysfunction and Leydig cell adenomas in male mice.

The luteinizing hormone receptor (LHCGR) is necessary for fertility, and genetic mutations cause defects in reproductive development and function. Activating mutations in LHCGR cause familial male-limited precocious puberty (FMPP). We have previously characterized a mouse model (KiLHRD582G) for FMPP that exhibits the same phenotype of precocious puberty, Leydig cell hyperplasia, and elevated testosterone as boys with the disorder. We observed that KiLHRD582G male mice became infertile by 6 months of age, although sperm count and motility were normal. In this study, we sought to determine the reason for the progressive infertility and the long-term consequences of constant LHCGR signaling. Mating with superovulated females showed that infertile KiLHRD582G mice had functional sperm and normal accessory gland function. Sexual behavior studies revealed that KiLHRD582G mice mounted females, but intromission was brief and ejaculation was not achieved. Histological analysis of the reproductive tract showed unique metaplastic changes resulting in pseudostratified columnar epithelial cells with cilia in the ampulla and chondrocytes in the penile body of the KiLHRD582G mice. The infertile KiLHRD582G exhibited enlarged sinusoids and a decrease in smooth muscle content in the corpora cavernosa of the penile body. However, collagen content was unchanged. Leydig cell adenomas and degenerating seminiferous tubules were seen in 1-year-old KiLHRD582G mice. We conclude that progressive infertility in KiLHRD582G mice is due to sexual dysfunction likely due to functional defects in the penis.

Glucocorticoid Receptor as a Potential Target to Decrease Aromatase Expression and Inhibit Leydig Tumor Growth.

Leydig cell tumors are the most frequent interstitial neoplasms of the testis with increased incidence in recent years. They are hormonally active and are considered one of the steroid-secreting tumors. Although usually benign, the malignant phenotype responds poorly to conventional chemotherapy or radiation, highlighting the need to identify new therapeutic targets for treatment. Here, we identified a novel glucocorticoid-mediated mechanism that controls cell growth in Leydig cell tumors. We found that a synthetic glucocorticoid receptor agonist, dexamethasone, reduces cell proliferation in rat Leydig tumor cells by decreasing the expression and the enzymatic activity of the estrogen-producing enzyme aromatase. This inhibitory effect relies on the ability of activated glucocorticoid receptor to regulate the aromatase gene transcriptional activity through the recruitment of nuclear receptor corepressor protein and silencing mediator of retinoid and thyroid hormone receptors to a newly identified putative glucocorticoid responsive element within the aromatase promoter II. Our in vivo studies reveal a reduction of tumor growth, after dexamethasone treatment, in animal xenografts. Tumors from dexamethasone-treated mice exhibit a decrease in the expression of the proliferation marker Ki-67 and the aromatase enzyme. Our data demonstrate that activated glucocorticoid receptor, decreasing aromatase expression, induces Leydig tumor regression both in vitro and in vivo, suggesting that glucocorticoid receptor might be a potential target for the therapy of Leydig cell tumors.

Naloxegol, an opioid antagonist with reduced CNS penetration: Mode-of-action and human relevance for rat testicular tumours.

Naloxegol is an opioid antagonist which has been developed for the treatment of patients with opioid induced constipation. In the nonclinical safety program naloxegol was shown to have a very benign toxicity profile. In the rat, but not the mouse, 2-year carcinogenicity study a change in tumour pattern with an increase in testicular Leydig cell tumours (LCT) was observed after dosing at high (supra-pharmacological) concentrations. To establish the basis of the increase in LCT and to assess its potential relevance to humans, studies to exclude and potentially identify mode-of-action (MoA) were performed. A genotoxic mechanism was ruled out following negative results in the Ames, mouse lymphoma, and micronucleus assays. An effect on androgen metabolism was excluded since the treatment of rats with naloxegol for 14days did not result in any induction of CYP protein levels. It was demonstrated that administration of centrally restricted opioid antagonists naloxegol or methylnaltrexone at high doses induced an increase in LH release with no clear increase in testosterone, in contrast to the centrally acting opioid antagonist naloxone, which showed marked increases in both LH and testosterone. LCT due to increased LH stimulation is common in rats but not documented in humans. Collectively, the lack of genotoxicity signal, the lack of androgen effect, the increase in LH secretion in rats, which is no considered to be relevant for LCT formation in humans, and high margins to clinical exposures, the observed increase in LCT in the rat is not expected to be clinically relevant.

Confounder factors masking a Leydig-cell ovarian tumor in a post-menopausal woman treated for androgen-positive receptor breast cancer.

Post-menopause hyperandrogenism is a condition that needs careful evaluation. Aromatase inhibitors (AI), which are important in the management of positive estrogen breast cancer, and chronic kidney disease (CKD) can puzzle the evaluation of this condition. A postmenopause female with type-2 diabetes and advanced CKD was attended due to progressive virilization, which has started after the introduction of an AI for breast cancer 5 years earlier. Clinical and radiological investigation has confirmed a pure Leydig cell tumor as source of hyperandrogenism. Re-evaluation of the breast tumor immunohistochemistry has shown positive androgen receptor expression and negative expression for estrogen, progesterone and HER-2 receptors. Even though an ovarian tumor was the source of androgen excess, we discuss that AI could exert a slight contribution to patient's virilization by reducing estradiol counterbalance. Also, although the onset of hyperandrogenic symptoms was unclear, we could not exclude that the ovarian tumor had produced enough androgens to play a role in breast tumor progression. This case report supports the literature regarding the possible association between Leydig cell tumor and androgen-receptor-positive breast cancer development. Finally, progressive hyperandrogenic symptoms in postmenopause, even under AI therapy or the presence of advanced CKD, impose a more detailed investigation.