Androgen formation and metabolism in the pulmonary epithelial cell line A549: expression of 17beta-hydroxysteroid dehydrogenase type 5 and 3alpha-hydroxysteroid dehydrogenase type 3

Divergent androgenic modulation of SARS-CoV-2 infection cooperates with dysregulated immune response to dictate worse COVID-19 outcomes in men

BACKGROUND

Sex-determined differences are rarely addressed in the management of diseases, despite well-known contrasting outcomes between female and male patients. In COVID-19 there is a remarkable disparity, with higher rates of mortality and more severe acute disease in men compared to women, who are mostly affected by long COVID-19. Furthermore, whether androgens play a protective or detrimental role in COVID-19 is still a matter of debate. Hence, the adequate management of the disease, especially regarding men presenting acute disease aggravation, still needs important data to elucidate the interplay between sex hormones and host immune responses that drive the worse evolution in male patients.

METHODS

A cohort of 92 controls and 198 non-severe and severe COVID-19 patients, from both sexes, was assessed for clinical outcomes, plasma steroids, gonadotropins, sex hormone binding globulin (SHBG) and immune mediators, before vaccination. These data were correlated with the global gene expression of blood leukocytes. The androgen receptor (AR) signaling pathway was investigated by transcriptomics and tracheal aspirate was obtained from severe patients for SARS-COV-2 quantification in the respiratory tract. The interplay among clinical, endocrine and immunological data deciphered the sex differences in COVID-19. Importantly, statistical analyses, using 95% confidence interval, considered confounding factors such as age and comorbidities, to definitely parse the role of androgens in the disease outcome.

RESULTS

There were notable contrasting levels of testosterone and dihydrotestosterone (DHT) throughout the disease course in male but not female patients. Inflammatory mediators presented significant negative correlations with testosterone, which was partially dependent on age and diabetes in men. Male subjects with severe COVID-19 had a significant up regulation of the AR signaling pathway, including modulation of TMPRSS2 and SRD5A1 genes, which are related to the viral infection and DHT production. Indeed, men had a higher viral load in the tracheal aspirate and levels of DHT were associated with increased relative risk of death. In contrast, the testosterone hormone, which was notably reduced in severe disease, was significantly related with susceptibility to COVID-19 worsening in male patients. Secondary hypogonadism was ruled out in the male severe COVID-19 subjects, as FSH, LH, and SHBG levels were not significantly altered. Instead, these subjects tended to have increased gonadotropin levels. Most interestingly, in this study we identified, for the first time, combined sets of clinical and immunoendocrine parameters that together predicted progression from non-severe to severe COVID-19 in men. One of the limitations of our study was the low or undetectable levels of DHT in many patients. Then, the evaluation of enzymes related to biosynthesis and signaling by androgens was mandatory and reiterated our findings.

CONCLUSIONS

These original results unraveled the disease immunoendocrine regulation, despite vaccination or comorbidities and pointed to the fundamental divergent role of the androgens testosterone and DHT in the determination of COVID-19 outcomes in men. Therefore, sex-specific management of the dysregulated responses, treatments or public health measures should be considered for the control of COVID-19 pandemic.

Oroxin A ameliorates the oleic acid-induced A549 cell injury through the suppression of pyroptosis and degradation of alveolar surfactant

The destruction of the pulmonary epithelial barrier in acute respiratory distress syndrome is caused by the damage of the alveolar epithelial cells. Oroxin A is an effective flavonoid component derived from the medicinal plant Oroxylum indicum (L.) Kurz. In this study, the oleic acid (OA)-induced A549 cell injury model was established in vitro to explore the protective mechanism of Oroxin A. The experiment was divided into the following groups: control, OA and OA + Oroxin A group. The OA-induced A549 cell injury was dose (time)-dependent and was detected by the CCK-8 assay. The protein and mRNA expression levels associated with pyroptosis are detected by Western blotting and RT-qPCR. After Oroxin A treatment, the levels of IL-1β, IL-18 and LDH released were significantly lower than the OA group. In terms of pyroptosis, Oroxin A can inhibit the expression of pyroptosis-related protein and mRNA. Significantly, the surfactant protein C (SPC) level in the OA + Oroxin A group was significantly higher than that in the OA group. The treatment with Oroxin A alleviates the OA-induced injury in the A549 cells, and its mechanism may be related to the inhibition of A549 cells pyroptosis and prevention of the degradation of the SPC.

Y It Matters—Sex Differences in Fetal Lung Development

Within this review, sex-specific differences in alveolar epithelial functions are discussed with special focus on preterm infants and the respiratory disorders associated with premature birth. First, a short overview about fetal lung development, the challenges the lung faces during perinatal lung transition to air breathing and respiratory distress in preterm infants is given. Next, clinical observations concerning sex-specific differences in pulmonary morbidity of human preterm infants are noted. The second part discusses potential sex-specific causes of pulmonary complications, including pulmonary steroid receptors and local lung steroid metabolism. With regard to pulmonary steroid metabolism, it is important to highlight which steroidogenic enzymes are expressed at which stage during fetal lung development. Thereafter, we review the knowledge concerning sex-specific aspects of lung growth and maturation. Special focus is given to alveolar epithelial Na+ transport as a driver of perinatal lung transition and the sex differences that were noted in this process.

Sex-Steroid Signaling in Lung Diseases and Inflammation

Sex/gender difference exists in the physiology of multiple organs. Recent epidemiological reports suggest the influence of sex-steroids in modulating a wide variety of disease conditions. Sex-based discrepancies have been reported in pulmonary physiology and various chronic inflammatory responses associated with lung diseases like asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, and rare lung diseases. Notably, emerging clinical evidence suggests that several respiratory diseases affect women to a greater degree, with increased severity and prevalence than men. Although sex-specific differences in various lung diseases are evident, such differences are inherent to sex-steroids, which are major biological variables in men and women who play a central role to control these differences. The focus of this chapter is to comprehend the sex-steroid biology in inflammatory lung diseases and to understand the mechanistic role of sex-steroids signaling in regulating these diseases. Exploring the roles of sex-steroid signaling in the regulation of lung diseases and inflammation is crucial for the development of novel and effective therapy. Overall, we will illustrate the importance of differential sex-steroid signaling in lung diseases and their possible clinical implications for the development of complementary and alternative medicine to treat lung diseases.

Androgen Effects on the Adrenergic System of the Vascular, Airway, and Cardiac Myocytes and Their Relevance in Pathological Processes

INTRODUCTION

Androgen signaling comprises nongenomic and genomic pathways. Nongenomic actions are not related to the binding of the androgen receptor (AR) and occur rapidly. The genomic effects implicate the binding to a cytosolic AR, leading to protein synthesis. Both events are independent of each other. Genomic effects have been associated with different pathologies such as vascular ischemia, hypertension, asthma, and cardiovascular diseases. Catecholamines play a crucial role in regulating vascular smooth muscle (VSM), airway smooth muscle (ASM), and cardiac muscle (CM) function and tone.

OBJECTIVE

The aim of this review is an updated analysis of the role of androgens in the adrenergic system of vascular, airway, and cardiac myocytes. Body. Testosterone (T) favors vasoconstriction, and its concentration fluctuation during life stages can affect the vascular tone and might contribute to the development of hypertension. In the VSM, T increases α1-adrenergic receptors (α ₁-ARs) and decreases adenylyl cyclase expression, favoring high blood pressure and hypertension. Androgens have also been associated with asthma. During puberty, girls are more susceptible to present asthma symptoms than boys because of the increment in the plasmatic concentrations of T in young men. In the ASM, β ₂-ARs are responsible for the bronchodilator effect, and T augments the expression of β ₂-ARs evoking an increase in the relaxing response to salbutamol. The levels of T are also associated with an increment in atherosclerosis and cardiovascular risk. In the CM, activation of α _1A-ARs and β ₂-ARs increases the ionotropic activity, leading to the development of contraction, and T upregulates the expression of both receptors and improves the myocardial performance.

CONCLUSIONS

Androgens play an essential role in the adrenergic system of vascular, airway, and cardiac myocytes, favoring either a state of health or disease. While the use of androgens as a therapeutic tool for treating asthma symptoms or heart disease is proposed, the vascular system is warmly affected.

Essential Intracrine Androgenic Action in Lung Development for Both Sexes

Albeit their recognized negative effects on lung maturation, androgens have been proposed to play an essential positive role in lung development. This work aimed to evaluate the impact of blocking endogenous androgen and estrogen actions and to study the effect of an excess of androgen and estrogen during the end of saccular stage and the beginning of the alveolar stage on lung development. This was performed with normal oxygen atmosphere and with hyperoxia, a model of alveolar simplification, which is observed in new bronchopulmonary dysplasia. Mouse lung samples were collected on postnatal day 9 after exposure to 21% or 80% oxygen (postnatal days 1 to 4), and after administration (postnatal days 3 to 8) of vehicle, pure antiandrogen (flutamide), dihydrotestosterone, pure antiestrogen (fulvestrant), or 17β-estradiol. With 21% oxygen, the major effects on morphometric parameters were induced by flutamide. In contrast, with hyperoxia, both flutamide and dihydrotestosterone had similar effects on several morphometric parameters. For instance, a decrease in the relative frequency of closed areas (mainly composed of saccules/alveoli) < 1000 μm² and an increase for those > 2500 μm² were observed after flutamide administration. In conclusion, during the junction between the saccular and the alveolar stages, endogenous androgens play an essential intracrine role in lung development for both sexes while an excess of androgens are deleterious when combined with a hyperoxia treatment, but not with normal oxygen levels. Endogenous estrogens have no effects on the lungs during the developmental window studied, while exogenous estrogens had only isolated effects on some morphometric parameters.

Steroid sulfatase inhibition success and limitation in breast cancer clinical assays: An underlying mechanism

Steroid sulfatase is detectable in most hormone-dependent breast cancers. STX64, an STS inhibitor, induced tumor reduction in animal assay. Despite success in phase І clinical trial, the results of phase II trial were not that significant. Breast Cancer epithelial cells (MCF-7 and T47D) were treated with two STS inhibitors (STX64 and EM1913). Cell proliferation, cell cycle, and the concentrations of estradiol and 5α-dihydrotestosterone were measured to determine the endocrinological mechanism of sulfatase inhibition. Comparisons were made with inhibitions of reductive 17β-hydroxysteroid dehydrogenases (17β-HSDs). Proliferation studies showed that DNA synthesis in cancer cells was modestly decreased (approximately 20%), accompanied by an up to 6.5% in cells in the G0/G1 phase and cyclin D1 expression reduction. The concentrations of estradiol and 5α-dihydrotestosterone were decreased by 26% and 3% respectively. However, supplementation of 5α-dihydrotestosterone produced a significant increase (approximately 35.6%) in the anti-proliferative effect of sulfatase inhibition. This study has clarified sex-hormone control by sulfatase in BC, suggesting that the different roles of estradiol and 5α-dihydrotestosterone can lead to a reduction in the effect of sulfatase inhibition when compared with 17β-HSD7 inhibition. This suggests that combined treatment of sulfatase inhibitors with 17β-HSD inhibitors such as the type7 inhibitor could hold promise for hormone-dependent breast cancer.

Sex-specific effects of sex steroids on alveolar epithelial Na+ transport

Alveolar fluid clearance mediates perinatal lung transition to air breathing in newborn infants, which is accomplished by epithelial Na⁺ channels (ENaC) and Na-K-ATPase. Male sex represents a major risk factor for developing respiratory distress, especially in preterm infants. We previously showed that male sex is associated with reduced epithelial Na⁺ transport, possibly contributing to the sexual dimorphism in newborn respiratory distress. This study aimed to determine sex-specific effects of sex steroids on epithelial Na⁺ transport. The effects of testosterone, 5α-dihydrotestosterone (DHT), estradiol, and progesterone on Na⁺ transport and Na⁺ channel expression were determined in fetal distal lung epithelial (FDLE) cells of male and female rat fetuses by Ussing chamber and mRNA expression analyses. DHT showed a minor effect only in male FDLE cells by decreasing epithelial Na⁺ transport. However, flutamide, an androgen receptor antagonist, did not abolish the gender imbalance, and testosterone lacked any effect on Na⁺ transport in male and female FDLE cells. In contrast, estradiol and progesterone increased Na⁺ transport and Na⁺ channel expression especially in females, and prevented the inhibiting effect of DHT in males. Estrogen receptor inhibition decreased Na⁺ channel expression and eliminated the sex differences. In conclusion, female sex steroids stimulate Na⁺ transport especially in females and prevent the inhibitory effect of DHT in males. The ineffectiveness of testosterone suggests that Na⁺ transport is largely unaffected by androgens. Thus, the higher responsiveness of female cells to female sex steroids explains the higher Na⁺ transport activity, possibly leading to a functional advantage in females.

Dehydroepiandrosterone-induces miR-21 transcription in HepG2 cells through estrogen receptor β and androgen receptor

Although oncomiR miR-21 is highly expressed in liver and overexpressed in hepatocellular carcinoma (HCC), its regulation is uncharacterized. We examined the effect of physiologically relevant nanomolar concentrations of dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) on miR-21 expression in HepG2 human hepatoma cells. 10nM DHEA and DHEA-S increase pri-miR-21 transcription in HepG2 cells. Dietary DHEA increased miR-21 in vivo in mouse liver. siRNA and inhibitor studies suggest that DHEA-S requires desulfation for activity and that DHEA-induced pri-miR-21 transcription involves metabolism to androgen and estrogen receptor (AR and ER) ligands. Activation of ERβ and AR by DHEA metabolites androst-5-ene-3,17-dione (ADIONE), androst-5-ene-3β,17β-diol (ADIOL), dihydrotestosterone (DHT), and 5α-androstane-3β,17β-diol (3β-Adiol) increased miR-21 transcription. DHEA-induced miR-21 increased cell proliferation and decreased Pdcd4 protein, a bona fide miR-21. Estradiol (E2) inhibited miR-21 expression via ERα. DHEA increased ERβ and AR recruitment to the miR-21 promoter within the VMP1/TMEM49 gene, with possible significance in hepatocellular carcinoma.

Major enzymes controlling the androgenic pressure in the developing lung

A sex difference is observed in the incidence and morbidity of respiratory distress syndrome (RDS) of the neonate and in bronchopulmonary dysplasia (BPD). The involvement of androgens is well evidenced in RDS and it is suspected in BPD. Interestingly, the developing lung is not an inert tissue just exposed to circulating androgens, but is rather an active androgen metabolizing tissue, expressing enzymes involved in both androgen synthesis and inactivation. The present review focuses on the major enzymes involved in androgen metabolism within the developing lung. Testosterone synthesis and inactivation by AKR1C3/Akr1c6 (human/mouse 17β-hydroxysteroid dehydrogenases (HSDs) type 5) and HSD17B2 (17β-HSD type 2), respectively, play an important role in the developing lung. Akr1c14 (3α-HSD) shows a strong increase in expression according to developmental time. The canalicular stage of lung development corresponding to the surge of surfactant lipid synthesis, which is linked to RDS, as well as saccularization/alveolarization, which are linked to BPD, are covered by this review for the mouse and human species. The androgen metabolizing enzymes expressed within the developing lung can become potential pharmaceutical targets in the objective of accelerating lung maturation by specific treatments. The classic deleterious effects of androgens on lung maturation and the surge of surfactant synthesis in males are well known. Conversely, androgens also have positive impacts on the development of both male and female lungs. Steroidogenic enzymes are key regulators of these positive effects. This article is part of a Special Issue entitled 'CSR 2013'.

5-alpha-reductase type I (SRD5A1) is up-regulated in non-small cell lung cancer but does not impact proliferation, cell cycle distribution or apoptosis

BACKGROUND

Non-small cell lung cancer (NSCLC) is one of the most frequent malignancies and has a high mortality rate due to late detection and lack of efficient treatments. Identifying novel drug targets for this indication may open the way for new treatment strategies. Comparison of gene expression profiles of NSCLC and normal adjacent tissue (NAT) allowed to determine that 5-alpha-reductase type I (SRD5A1) was up-regulated in NSCLC compared to NAT. This raised the question whether SRD5A1 was involved in sustained proliferation and survival of NSCLC.

METHODS

siRNA-mediated silencing of SRD5A1 was performed in A549 and NCI-H460 lung cancer cell lines in order to determine the impact on proliferation, on distribution during the different phases of the cell cycle, and on apoptosis/necrosis. In addition, lung cancer cell lines were treated with 4-azasteroids, which specifically inhibit SRD5A1 activity, and the effects on proliferation were measured. Statistical analyses using ANOVA and post-hoc Tamhane-T2-test were performed. In the case of non-parametric data, the Kruskal-Wallis test and the post-hoc Mann-Whitney-U-test were used.

RESULTS

The knock-down of SRDA51 expression was very efficient with the SRD5A1 transcripts being reduced to 10% of control levels. Knock-down efficiency was furthermore confirmed at the protein level. However, no effect of SRD5A1 silencing was observed in the proliferation assay, the cell cycle analysis, and the apoptosis/necrosis assay. Treatment of lung cancer cell lines with 4-azasteroids did not significantly inhibit proliferation.

CONCLUSIONS

In summary, the results suggest that SRD5A1 is not a crucial enzyme for the sustained proliferation of NSCLC cell lines.

Oestrogen treatment enhances the sensitivity of hormone-resistant breast cancer cells to doxorubicin

Recently, it was shown that the resistance of breast cancer cells to growth-stimulating oestrogen action may be accompanied with the paradoxical tumour sensitization to oestrogen apoptotic action. In the present paper, we studied the influence of oestrogens on the sensitivity of resistant breast tumours to cytostatic drugs, and to evaluate the role of NF-κB (nuclear factor κB) signalling in the regulation of the apoptotic response of the resistant cells. The experiments were carried out on the oestrogen-dependent MCF-7 breast cancer cells and resistant MCF-7/LS subline generated through long-term cultivation of the parental cells in the absence of oestrogen. The cell treatment with the combination of oestradiol and Dox (doxorubicin) was found to enhance the apoptotic action of Dox in MCF-7/LS cells but not in the parent cells. MCF-7/LS cells were characterized by the increased level of ROS (reactive oxygen species) and decreased NF-κB activity. Oestradiol in combination with Dox leads to significant NF-κB stimulation and its accumulation in the nucleus of MCF-7/LS cells. The knockdown of NF-κB with siRNA (small interfering RNA) increased the apoptotic response of the MCF-7/LS cells to both Dox and oestradiol demonstrating the important role of NF-κB in the protection of the MCF-7/LS cells against apoptosis. In general, the results obtained show that: (i) oestradiol enhances the apoptotic action of Dox in the resistant breast cancer cells; and (ii) suppression of NF-κB signalling amplifies the apoptotic response of the resistant cells to both oestrogen and Dox, demonstrating that NF-κB may serve as a potential target in the therapy of the resistant breast cancer.

Human mast cells express androgen receptors but treatment with testosterone exerts no influence on IgE-independent mast cell degranulation elicited by neuromuscular blocking agents

Women predominate in the anaphylactic reactions to neuromuscular blocking agents (NMBA). The expression of oestrogen receptors has been demonstrated in mast cells and oestrogen treatment can enhance mast cell degranulation, but the influence of androgens remains largely unclear. Our immunocytochemical study showed the expression of androgen receptor (AR) in mast cells isolated from human foreskin as well as in two human mast cell lines, HMC-1 and LAD2. The amount of AR was most abundant in human skin mast cells as determined by real-time polymerase chain reaction analysis. Treatment of the HMC-1 mast cells with testosterone or 17beta-oestradiol, alone or in combination with different NMBA, did not affect mast cell degranulation as measured by the release of beta-hexosaminidase. Our study shows for the first time the expression of AR in human skin mast cells. Further studies using primary human mast cell cultures are needed to understand whether and how sex hormones can influence mast cell activation.

NF-kappaB suppression provokes the sensitization of hormone-resistant breast cancer cells to estrogen apoptosis

The progression of breast cancer cells to estrogen-independent growth may be accompanied with the paradoxical cell sensitization to estrogen apoptotic action; however, the mechanism of this phenomenon is still unclear. In the present study, we have shown that the sensitization of hormone-resistant breast cancer cells to estrogen apoptotic action is accompanied with the gradual NF-kappaB suppression. Using the chemical inhibitors of NF-kappaB as well as the dominant-negative NF-kappaB constructs, we have proved the sufficiency of NF-kappaB inhibition for the sensitization of the resistant cells to estrogen apoptosis. Estradiol treatment results in the additional suppression of NF-kappaB, demonstrating the possible NF-kappaB involvement in the regulation of cell response to estrogens. Totally, the results presented suggest that the constitutive NF-kappaB suppression in the estrogen-independent cells may be considered as one of the factors resulting in a imbalance between pro- and anti-apoptotic pathways and enhancement in estrogen apoptotic action in the cells.

Intratumoral estrogens and estrogen receptors in human non-small cell lung carcinoma

PURPOSE

The possible involvement of gender-dependent factors has been suggested in human non-small cell lung carcinomas (NSCLC), but their precise roles remain largely unclear. Therefore, we examined intratumoral estradiol concentrations in NSCLC to examine local actions of estrogens in NSCLC.

EXPERIMENTAL DESIGN

Fifty-nine frozen specimens of NSCLC were available for liquid chromatography/electrospray tandem mass spectrometry to study intratumoral estradiol concentrations. In addition, A549 NSCLC cells stably expressing estrogen receptor (ER) alpha (A549 + ERalpha) or ERbeta (A549 + ERbeta) were used in vitro studies.

RESULTS

Forty-three (73%) of 59 NSCLC showed higher concentration of estradiol in carcinoma tissues than the corresponding nonneoplastic lung tissues from the same patient, and intratumoral estradiol concentrations were significantly (P = 0.0002 and 2.2-fold) higher than the corresponding nonneoplastic lungs. The intratumoral concentration of estradiol was positively correlated with aromatase expression, tumor size, and Ki-67 status in ERalpha- or ERbeta-positive cases. In in vitro studies, estradiol significantly increased cell proliferation of A549 + ERalpha or A549 + ERbeta, which was significantly suppressed by selective ER modulators, tamoxifen or raloxifene. Both A549 + ERalpha and A549 + ERbeta cells expressed aromatase. The cell proliferation level in these cells was significantly increased under treatment with testosterone, and it was inhibited by addition of the aromatase inhibitor letrozole.

CONCLUSIONS

These results suggest that estradiol is locally produced in NSCLC mainly by aromatase and plays an important role in the growth of ERalpha- or ERbeta-positive NSCLC. Therefore, use of selective ER modulators and/or aromatase inhibitors may be clinically effective in NSCLC that are positive for both ER and aromatase.

Inhibition of vascular inflammation by dehydroepiandrosterone sulfate in human aortic endothelial cells: roles of PPARalpha and NF-kappaB

Dehydroepiandrosterone sulfate (DHEAS) is a hormone produced by the adrenal gland and is a precursor for both androgens and estrogens. Atherosclerosis is a well characterized inflammatory disease, but little is known about the role of DHEAS in vascular inflammation. We hypothesize that DHEAS can reduce inflammation in vascular endothelial cells and the mechanism involves the peroxisome proliferator-activated receptor alpha (PPARalpha), thereby inhibiting transcription factors involved in endothelial cell inflammation. To test our hypothesis, aortic endothelial cells were pretreated for 48 h with DHEAS, then with TNF-alpha. TNF-alpha-induced upregulation of the expression of inflammatory genes interleukin (IL)-8 and intracellular adhesion molecule (ICAM)-1 was attenuated by incubation with DHEAS. DHEAS inhibited the TNF-alpha-induced surface expression of vascular cell adhesion molecule (VCAM)-1. This effect was abolished by the addition of MK866, a PPARalpha inhibitor, indicating that PPARalpha is involved in the mechanism of this inhibition. The addition of the aromatase inhibitor letrozole had no effect on the inhibition of TNF-alpha-induced VCAM-1 expression by DHEAS. Treatment of endothelial cells with DHEAS dramatically inhibited the TNF-alpha-induced activation of NF-kappaB, an inflammatory transcription factor, and increased protein levels of the NF-kappaB inhibitor, IkappaB-alpha. These results signify the ability of DHEAS to directly inhibit the inflammatory process and show a potential direct effect of DHEAS on vascular inflammation that has implications for the development of atherosclerotic cardiovascular disease.

Parathyroid hormone-related protein varies with sex and androgen status in nonsmall cell lung cancer

BACKGROUND

In nonsmall cell lung cancer, tumor parathyroid hormone-related protein (PTHrP) expression predicts longer survival in women but not in men. To explain the sex-dependent survival effect, the authors proposed that hormonal influences decrease PTHrP in men versus women, that PTHrP inhibits tumor growth, and that the effect is greater in women than in men. The objectives of this study were to compare lung carcinoma PTHrP expression and carcinoma growth in male and female mice and to determine whether gonadal steroids regulate PTHrP in lung cancer cells.

METHODS

Tumor PTHrP content was measured by immunoassay, and tumor burden was assessed with multiple measures in BEN squamous cell orthotopic lung carcinomas in athymic mice. In addition, lung adenocarcinoma PTHrP messenger RNA (mRNA) values determined by microarray analyses were compared between men and women. Cultured lung cancer cells were assayed for PTHrP after treatment with estradiol or R1881, a synthetic androgen.

RESULTS

Lung carcinomas contained approximately 3 times more PTHrP in female mice than in male mice. Similarly, levels of PTHrP mRNA were significantly greater in adenocarcinomas from patients who were women than from patients who were men. Male mice had greater tumor burden than female mice. Androgen treatment reduced PTHrP in 3 lung cancer lines. Estradiol had no effect. Testosterone treatment also reduced lung carcinoma PTHrP in female mice.

CONCLUSIONS

Lung carcinomas in females expressed more PTHrP than in males possibly because of negative regulation by androgens in males. Female mice with higher tumor PTHrP content had significantly less tumor burden than male mice, supporting the hypothesis that PTHrP inhibits tumor growth.

Mechanism of estrogen-induced apoptosis in breast cancer cells: role of the NF-kappaB signaling pathway

The ability of sex steroid hormones to up-regulate the apoptotic signaling proteins is well documented; however, the apoptotic potential of sex hormones is not remarkable and fully compensated by their growth stimulatory action to target cells. In the present study using the long-term cultivation of estrogen-dependent MCF-7 breast cancer cells in steroid-free medium, we have established a cell subline, designed as MCF-7/LS, which was characterized by the resistance to growth stimulatory estradiol action and hypersensitivity to estrogen-induced apoptosis. We have demonstrated that estrogen treatment of the cells does not influence on the level of TNF-R1 or Fas, but dramatically decreases the transcriptional activity of NF-kappaB. Importantly, the MCF-7/LS cells, which are insensitive to growth stimulatory estrogen action, retain the ability to decrease in the NF-kappaB activity in response to estrogen stimulus. Furthermore, the significant increase in the basal (in the absence of ligand) estrogen receptor (ER)-dependent transcriptional activity in the MCF-7/LS cells was revealed and reciprocal transcriptional antagonism between ER and NF-kappaB was demonstrated. Finally, we proved the possible involvement of phosphatidylinositol-3 kinase (PI3K) in the ligand-independent ER activation. In general, the results presented suggest that long-term growth of MCF-7 breast cancer cells in steroid-free medium is accompanied with the increase in the basal ER-dependent transcriptional activity as well as the maintenance of the negative regulatory loop ER-NF-kappaB. The latter may be considered as one of the factors resulting in a disbalance between pro- and anti-apoptotic pathways and enhancement in estrogen apoptotic action in the cells.

The impact of sex and sex hormones on lung physiology and disease: lessons from animal studies

Numerous animal studies have revealed significant effects of sex and sex hormones on normal lung development, lung physiology, and various lung diseases. The primary goal of this review is to summarize knowledge to date on the effects of sex and sex hormones on lung development, physiology, and disease in animals. Specific emphasis will be placed on fibrosis, allergic airway disease, acute lung injury models, respiratory infection, and lung toxicology studies.

Sexually dimorphic gene expression that overlaps maturation of type II pneumonocytes in fetal mouse lungs

BACKGROUND

In human, respiratory distress of the neonates, which occurs in prematurity, is prevalent in male. Late in gestation, maturation of type II pneumonocytes, and consequently the surge of surfactant synthesis are delayed in male fetuses compared with female fetuses. Although the presence of higher levels of androgens in male fetuses is thought to explain this sex difference, the identity of genes involved in lung maturation that are differentially modulated according to fetal sex is unknown. We have studied the sex difference in developing mouse lung by gene profiling during a three-day gestational window preceding and including the emergence of mature PTII cells (the surge of surfactant synthesis in the mouse occurs on GD 17.5).

METHODS

Total RNA was extracted from lungs of male and female fetal mice (gestation days 15.5, 16.5, and 17.5), converted to cRNA, labeled with biotin, and hybridized to oligonucleotide microarrays (Affymetrix MOE430A). Analysis of data was performed using MAS5.0, LFCM and Genesis softwares.

RESULTS

Many genes involved in lung maturation were expressed with no sex difference. Of the approximative 14,000 transcripts covered by the arrays, only 83 genes presented a sex difference at one or more time points between GDs 15.5 and 17.5. They include genes involved in hormone metabolism and regulation (i.e. steroidogenesis pathways), apoptosis, signal transduction, transcriptional regulation, and lipid metabolism with four apolipoprotein genes. Genes involved in immune functions and other metabolisms also displayed a sex difference.

CONCLUSION

Among these sexually dimorphic genes, some may be candidates for a role in lung maturation. Indeed, on GD 17.5, the sex difference in surfactant lipids correlates with the sex difference in pulmonary expression of apolipoprotein genes, which are involved in lipid transport. This suggests a role for these genes in the surge of surfactant synthesis. Our results would help to identify novel genes involved in the physiopathology of the respiratory distress of the neonates.

Sensitization of MCF-7 breast cancer cells to the apoptotic effect of estradiol

A new substrain of hormone-resistant MCF-7/T breast cancer cells was selected after long-term culturing of estrogen-dependent MCF-7 cells in the presence of tamoxifen. These cells were resistant to the growth-stimulating and cytostatic effects of estradiol and tamoxifen, respectively. MCF-7/T cells gained paradoxical sensitivity to the apoptotic effect of estradiol. Estradiol stimulated p53 expression and decreased DNA-binding activity of NF-kappaB. Our findings provide indirect evidence that these proteins are involved in the regulation of estrogen-induced apoptosis. These results indicate that tamoxifen-resistant breast cancer cells can be sensitized to the apoptotic effect of estradiol. The data form a basis for the development of new methods of endocrine therapy for breast cancer patients.

Genes involved in the adrenal pathway of glucocorticoid synthesis are transiently expressed in the developing lung

We have studied the expression of genes involved in glucocorticoid synthesis in the developing lungs of male and female mouse fetuses on gestation days (GD) 15-18 (surge of surfactant, GD 17; term, GD 19). High levels of steroidogenic acute regulatory protein, cytochrome P450 cholesterol side chain cleavage, 3beta-hydroxysteroid dehydrogenase type 1, 21-hydroxylase, and 11 beta-hydroxylase mRNAs were observed in three of the six litters studied on GD 15 and in none of the 14 litters analyzed between GD 16 and 18. Of these three litters, two showed high expression levels for these five genes in lung tissues from female fetuses only, whereas in the remaining litter, only tissues from male fetuses presented high expression of these genes. In contrast, 11 beta-hydroxysteroid dehydrogenase type 1 mRNA level was very low on GD 15 and presented a gradual increase between GD 15 and 18 with no sex difference. Our data indicate that, like the mature adrenal, the fetal lung expresses all genes required in glucocorticoid synthesis from cholesterol. In addition, our results demonstrate that transient expression of these genes on GD 15 in the fetal lung occurs for both male and female fetuses, 2 d before the surge of surfactant synthesis, which is stimulated by glucocorticoids.

Paracoccidioidomycosis in a woman with idiopathic hirsutism

Paracoccidioidomycosis, especially the chronic pulmonary form of the disease, is not commonly described in females. Data from in vitro and vivo studies support the hypothesis that estrogens might influence the pathogenesis of paracoccidioidomycosis in humans by inhibition of transition of conidia or mycelia to yeast form of Paracoccidioides brasiliensis. The authors describe a chronic progressive pulmonary form of paracoccidioidomycosis in a woman with idiopathic hirsutism. In addition to estrogens, the present report suggests that other hormonal factors might play an important role in the pathogenesis of paracoccidioidomycosis, including the increased production of 5alpha-dehydrotestosterone frequently described in individuals with idiopathic hirsutism.

Expression du gène 17β-HSD2 dans le poumon fœtal et le placenta : contrôle de l’action des stéroïdes sexuels

During gestation, sex steroids could potentially have detrimental effects on fetal development. At least two distinct mechanisms should prevent such effects. The 17beta-hydroxysteroid dehydrogenase-2 (HSD17beta2) plays a key role in each mechanism. Being expressed both in lung fibroblasts and placental endothelial cells, the HSD17beta2 should restrict testosterone and estradiol actions, thus enabling normal development.

Androgen inactivation in human lung fibroblasts: variations in levels of 17 beta-hydroxysteroid dehydrogenase type 2 and 5 alpha-reductase activity compatible with androgen inactivation

Androgens delay lung maturation through their action on lung fibroblasts. Knowing that testosterone is secreted by the lung epithelial-like cell line A-549, we have studied the metabolism of androgens by several human lung diploid fibroblasts cell lines. No 17-ketosteroid reductase activity was detected. In contrast, testosterone was transformed mainly into androstenedione and androstanedione with no 5 alpha-dihydrotestosterone formed, indicating the presence of 17 beta- hydroxysteroid dehydrogenase (HSD) type 2 and 5 alpha-reductase activities. The eight cell lines analyzed had either a low or high 17 beta-HSD type 2 activity level. No correlation between these levels and the sex or age stage of cells was established, but Northern blot analysis of human lung RNA samples of five adult subjects revealed very similar variations between subjects in the level of 17 beta-HSD type 2 mRNA. The 5 alpha-reductase activity had a marked substrate preference for androstenedione, the product of 17 beta-HSD type 2. When tritiated testosterone was used as substrate, only barely detectable levels of 5 alpha-dihydrotestosterone were observed by HPLC in the presence of the 17 beta-HSD type 2 inhibitor EM-919. The use of unlabeled testosterone or of the antiandrogen hydroxyflutamide demonstrated that the tritiated testosterone substrate itself had no effect on levels of 5 alpha-reduction. In fact, in these cells, 5 alpha-reductase has no significant activity on testosterone, but it further converts the product of 17 beta-HSD type 2, thus playing a role with 17 beta-HSD type 2 in androgen inactivation. Because androgens delay lung maturation and surfactant synthesis by their action on lung fibroblasts, it is of particular interest to find that the steroid metabolism of these lung fibroblast cells is oriented toward androgen inactivation. Because lung fibroblasts of subjects with low 17 beta-HSD type 2 expression levels are likely to be exposed to higher levels of androgens, an allelic variation of the 17 beta-HSD-2 gene is suspected, which would result in familial incidence of respiratory distress. This is in line with reported cases of familial incidence of respiratory distress.