Loss of microRNA-30a and sex-specific effects on the neonatal hyperoxic lung injury.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is characterized by an arrest in lung development and is a leading cause of morbidity in premature neonates. It has been well documented that BPD disproportionally affects males compared to females, but the molecular mechanisms behind this sex-dependent bias remain unclear. Female mice show greater preservation of alveolarization and angiogenesis when exposed to hyperoxia, accompanied by increased miR-30a expression. In this investigation, we tested the hypothesis that loss of miR-30a would result in male and female mice experiencing similar impairments in alveolarization and angiogenesis under hyperoxic conditions. METHODS: Wild-type and miR-30a-/- neonatal mice were exposed to hyperoxia [95% FiO2, postnatal day [PND1-5] or room air before being euthanized on PND21. Alveolarization, pulmonary microvascular development, differences in lung transcriptome, and miR-30a expression were assessed in lungs from WT and miR-30a-/- mice of either sex. Blood transcriptomic signatures from preterm newborns (with and without BPD) were correlated with WT and miR-30a-/- male and female lung transcriptome data. RESULTS: Significantly, the sex-specific differences observed in WT mice were abrogated in the miR-30a-/- mice upon exposure to hyperoxia. The loss of miR-30a expression eliminated the protective effect in females, suggesting that miR-30a plays an essential role in regulating alveolarization and angiogenesis. Transcriptome analysis by whole lung RNA-Seq revealed a significant response in the miR-30a-/- female hyperoxia-exposed lung, with enrichment of pathways related to cell cycle and neuroactive ligand-receptor interaction. Gene expression signature in the miR-30a-/- female lung associated with human BPD blood transcriptomes. Finally, we showed the spatial localization of miR-30a transcripts in the bronchiolar epithelium. CONCLUSIONS: miR-30a could be one of the biological factors mediating the resilience of the female preterm lung to neonatal hyperoxic lung injury. A better understanding of the effects of miR-30a on pulmonary angiogenesis and alveolarization may lead to novel therapeutics for treating BPD.

Bronchopulmonary dysplasia (BPD) is a lung condition that affects babies born prematurely, causing problems with their lung development. Interestingly, BPD tends to affect boys more than girls, but we do not fully understand why. To investigate this, we conducted a study using mice. Female mice had better lung development and blood vessel formation when exposed to high oxygen levels. We found higher expression of a molecule called miR-30a in the female mice and seemed to be protective. So, we wanted to see if removing miR-30a would have the same effect on both male and female mice. To test this, we exposed newborn mice without miR-30a and normal mice to high oxygen levels or regular room air. Interestingly, the differences between normal males and females were no longer present in the mice without miR-30a. This suggested that miR-30a plays an important role in lung development. We also identified that the female mice without miR-30a, when exposed to high oxygen, had the greatest number of genes affected, and these gene changes were like those seen in blood samples from premature babies with BPD. Finally, we report that miR-30a was in a specific part of the lung called the bronchiolar epithelium. Overall, this study suggests that miR-30a is crucial in protecting premature lungs from damage caused by high oxygen levels. By understanding how miR-30a affects lung development, we may be able to develop new treatments for BPD in the future.

Aryl hydrocarbon receptor maintains hepatic mitochondrial homeostasis in mice.

OBJECTIVE: Mitophagy removes damaged mitochondria to maintain cellular homeostasis. Aryl hydrocarbon receptor (AhR) expression in the liver plays a crucial role in supporting normal liver functions, but its impact on mitochondrial function is unclear. Here, we identified a new role of AhR in the regulation of mitophagy to control hepatic energy homeostasis. METHODS: In this study, we utilized primary hepatocytes from AhR knockout (KO) mice and AhR knockdown AML12 hepatocytes. An endogenous AhR ligand, kynurenine (Kyn), was used to activate AhR in AML12 hepatocytes. Mitochondrial function and mitophagy process were comprehensively assessed by MitoSOX and mt-Keima fluorescence imaging, Seahorse XF-based oxygen consumption rate measurement, and Mitoplate S-1 mitochondrial substrate utilization analysis. RESULTS: Transcriptomic analysis indicated that mitochondria-related gene sets were dysregulated in AhR KO liver. In both primary mouse hepatocytes and AML12 hepatocyte cell lines, AhR inhibition strongly suppressed mitochondrial respiration rate and substrate utilization. AhR inhibition also blunted the fasting response of several essential autophagy genes and the mitophagy process. We further identified BCL2 interacting protein 3 (BNIP3), a mitophagy receptor that senses nutrient stress, as an AhR target gene. AhR is directly recruited to the Bnip3 genomic locus, and Bnip3 transcription was enhanced by AhR endogenous ligand treatment in wild-type liver and abolished entirely in AhR KO liver. Mechanistically, overexpression of Bnip3 in AhR knockdown cells mitigated the production of mitochondrial reactive oxygen species (ROS) and restored functional mitophagy. CONCLUSIONS: AhR regulation of the mitophagy receptor BNIP3 coordinates hepatic mitochondrial function. Loss of AhR induces mitochondrial ROS production and impairs mitochondrial respiration. These findings provide new insight into how endogenous AhR governs hepatic mitochondrial homeostasis.

Constitutive loss of DNMT3A causes morbid obesity through misregulation of adipogenesis.

DNA Methyltransferase 3 A (DNMT3A) is an important facilitator of differentiation of both embryonic and hematopoietic stem cells. Heterozygous germline mutations in DNMT3A lead to Tatton-Brown-Rahman Syndrome (TBRS), characterized by obesity and excessive height. While DNMT3A is known to impact feeding behavior via the hypothalamus, here we investigated a role in adipocyte progenitors utilizing heterozygous knockout mice that recapitulate cardinal TBRS phenotypes. These mice become morbidly obese due to adipocyte enlargement and tissue expansion. Adipose tissue in these mice exhibited defects in preadipocyte maturation and precocious activation of inflammatory gene networks, including interleukin-6 signaling. Adipocyte progenitor cell lines lacking DNMT3A exhibited aberrant differentiation. Furthermore, mice in which Dnmt3a was specifically ablated in adipocyte progenitors showed enlarged fat depots and increased progenitor numbers, partly recapitulating the TBRS obesity phenotypes. Loss of DNMT3A led to constitutive DNA hypomethylation, such that the DNA methylation landscape of young adipocyte progenitors resemble that of older wild-type mice. Together, our results demonstrate that DNMT3A coordinates both the central and local control of energy storage required to maintain normal weight and prevent inflammatory obesity.

HIV-1 Viral Protein R Couples Metabolic Inflexibility With White Adipose Tissue Thermogenesis.

Persons living with HIV (PLWH) manifest chronic disorders of brown and white adipose tissues that lead to diabetes and metabolic syndrome. The mechanisms that link viral factors to defective adipose tissue function and abnormal energy balance in PLWH remain incompletely understood. Here, we explored how the HIV accessory protein viral protein R (Vpr) contributes to adaptive thermogenesis in two mouse models and human adipose tissues. Uncoupling protein 1 (UCP1) gene expression was strongly increased in subcutaneous white adipose tissue (WAT) biopsy specimens from PLWH and in subcutaneous WAT of the Vpr mice, with nearly equivalent mRNA copy number. Histology and functional studies confirmed beige transformation in subcutaneous but not visceral WAT in the Vpr mice. Measurements of energy balance indicated Vpr mice displayed metabolic inflexibility and could not shift efficiently from carbohydrate to fat metabolism during day-night cycles. Furthermore, Vpr mice showed a marked inability to defend body temperature when exposed to 4°C. Importantly, Vpr couples higher tissue catecholamine levels with UCP1 expression independent of ß-adrenergic receptors. Our data reveal surprising deficits of adaptive thermogenesis that drive metabolic inefficiency in HIV-1 Vpr mouse models, providing an expanded role for viral factors in the pathogenesis of metabolic disorders in PLWH.

Paracrine signaling in islet function and survival.

The pancreatic islet is a dense cellular network comprised of several cell types with endocrine function vital in the control of glucose homeostasis, metabolism, and feeding behavior. Within the islet, endocrine hormones also form an intricate paracrine network with supportive cells (endothelial, neuronal, immune) and secondary signaling molecules regulating cellular function and survival. Modulation of these signals has potential consequences for diabetes development, progression, and therapeutic intervention. Beta cell loss, reduced endogenous insulin secretion, and dysregulated glucagon secretion are hallmark features of both type 1 and 2 diabetes that not only impact systemic regulation of glucose, but also contribute to the function and survival of cells within the islet. Advancing research and technology have revealed new islet biology (cellular identity and transcriptomes) and identified previously unrecognized paracrine signals and mechanisms (somatostatin and ghrelin paracrine actions), while shifting prior views of intraislet communication. This review will summarize the paracrine signals regulating islet endocrine function and survival, the disruption and dysfunction that occur in diabetes, and potential therapeutic targets to preserve beta cell mass and function.

S100a4-Cre-mediated deletion of Patched1 causes hypogonadotropic hypogonadism: role of pituitary hematopoietic cells in endocrine regulation.

Hormones produced by the anterior pituitary gland regulate an array of important physiological functions, but pituitary hormone disorders are not fully understood. Herein we report that genetically-engineered mice with deletion of the hedgehog signaling receptor Patched1 by S100a4 promoter-driven Cre recombinase (S100a4-Cre;Ptch1fl/fl mutants) exhibit adult-onset hypogonadotropic hypogonadism and multiple pituitary hormone disorders. During the transition from puberty to adult, S100a4-Cre;Ptch1fl/fl mice of both sexes develop hypogonadism coupled with reduced gonadotropin levels. Their pituitary glands also display severe structural and functional abnormalities, as revealed by transmission electron microscopy and expression of key genes regulating pituitary endocrine functions. S100a4-Cre activity in the anterior pituitary gland is restricted to CD45+ cells of hematopoietic origin, including folliculo-stellate cells and other immune cell types, causing sex-specific changes in the expression of genes regulating the local microenvironment of the anterior pituitary. These findings provide in vivo evidence for the importance of pituitary hematopoietic cells in regulating fertility and endocrine function, in particular during sexual maturation and likely through sexually dimorphic mechanisms. These findings support a previously unrecognized role of hematopoietic cells in causing hypogonadotropic hypogonadism and provide inroads into the molecular and cellular basis for pituitary hormone disorders in humans.

Mitochondrial pyruvate import is a metabolic vulnerability in androgen receptor-driven prostate cancer.

Specific metabolic underpinnings of androgen receptor (AR)-driven growth in prostate adenocarcinoma (PCa) are largely undefined, hindering the development of strategies to leverage the metabolic dependencies of this disease when hormonal manipulations fail. Here we show that the mitochondrial pyruvate carrier (MPC), a critical metabolic conduit linking cytosolic and mitochondrial metabolism, is transcriptionally regulated by AR. Experimental MPC inhibition restricts proliferation and metabolic outputs of the citric acid cycle (TCA) including lipogenesis and oxidative phosphorylation in AR-driven PCa models. Mechanistically, metabolic disruption resulting from MPC inhibition activates the eIF2α/ATF4 integrated stress response (ISR). ISR signaling prevents cell cycle progression while coordinating salvage efforts, chiefly enhanced glutamine assimilation into the TCA, to regain metabolic homeostasis. We confirm that MPC function is operant in PCa tumors in-vivo using isotopomeric metabolic flux analysis. In turn, we apply a clinically viable small molecule targeting the MPC, MSDC0160, to pre-clinical PCa models and find that MPC inhibition suppresses tumor growth in hormone-responsive and castrate-resistant conditions. Collectively, our findings characterize the MPC as a tractable therapeutic target in AR-driven prostate tumors.

Constitutive Androstane Receptor Differentially Regulates Bile Acid Homeostasis in Mouse Models of Intrahepatic Cholestasis.

Bile acid (BA) homeostasis is tightly regulated by multiple transcription factors, including farnesoid X receptor (FXR) and small heterodimer partner (SHP). We previously reported that loss of the FXR/SHP axis causes severe intrahepatic cholestasis, similar to human progressive familial intrahepatic cholestasis type 5 (PFIC5). In this study, we found that constitutive androstane receptor (CAR) is endogenously activated in Fxr:Shp double knockout (DKO) mice. To test the hypothesis that CAR activation protects DKO mice from further liver damage, we generated Fxr;Shp;Car triple knockout (TKO) mice. In TKO mice, residual adenosine triphosphate (ATP) binding cassette, subfamily B member 11 (ABCB11; alias bile salt export pump [BSEP]) function and fecal BA excretion are completely impaired, resulting in severe hepatic and biliary damage due to excess BA overload. In addition, we discovered that pharmacologic CAR activation has different effects on intrahepatic cholestasis of different etiologies. In DKO mice, CAR agonist 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP; here on TC) treatment attenuated cholestatic liver injury, as expected. However, in the PFIC2 model Bsep knockout (BKO) mice, TC treatment exhibited opposite effects that reflect increased BA accumulation and liver injury. These contrasting results may be linked to differential regulation of systemic cholesterol homeostasis in DKO and BKO livers. TC treatment selectively up-regulated hepatic cholesterol levels in BKO mice, supporting de novo BA synthesis. Conclusion: CAR activation in DKO mice is generally protective against cholestatic liver injury in these mice, which model PFIC5, but not in the PFIC2 model BKO mice. Our results emphasize the importance of the genetic and physiologic background when implementing targeted therapies to treat intrahepatic cholestasis.

Chimeric antigen receptor (CAR) T cells targeting a pathogenic MHC class II:peptide complex modulate the progression of autoimmune diabetes.

A primary initiating epitope in the NOD mouse model of Type 1 Diabetes (T1D) lies between residues 9 and 23 of the insulin B chain. The B:9-23 peptide can bind to the NOD MHC class II molecule (I-Ag7) in multiple registers, but only one, (register 3, R3), creates complexes able to stimulate the majority of pathogenic B:9-23-specific CD4+ T cells. Previously we generated a monoclonal antibody (mAb287) that targets this critical I-Ag7-B:9-23(R3) complex. When given weekly to pre-diabetic mice at either early or late stages of disease, mAb287 was able to delay or prevent T1D in the treated animals. Although the precise mechanism of action of mAb287 remains unclear, we hypothesized that it may involve deletion of antigen presenting cells (APCs) bearing the pathogenic IAg7-B:9-23(R3) complexes, and that this process might be rendered more efficient by re-directing cytotoxic T cells using a mAb287 chimeric antigen receptor (287-CAR). As anticipated, 287-CAR T cells secreted IFN-γ in response to stimulation by I-Ag7-B:9-23(R3) complexes expressed on artificial APCs, but not I-Ag7 loaded with other peptides, and killed the presenting cells in vitro. A single infusion of 287-CAR CD8+ T cells to young (5 week old) NOD mice significantly delayed the onset of overt hyperglycemia compared to untreated animals (p = 0.022). None of the 287-CAR CD8+ T cell treated mice developed diabetes before 18 weeks of age, while 29% of control-CAR T cell treated mice (p = 0.044) and 52% of the un-treated mice (p = 0.0001) had developed T1D by this time. However, the protection provided by 287-CAR CD8+ T cells declined with time, and no significant difference in overall incidence by 30 weeks between the 3 groups was observed. Mechanistic studies indicated that the adoptively transferred 287-CAR T cells selectively homed to pancreatic lymph nodes, and in some animals could persist for at least 1-2 weeks post-transfer, but were essentially undetectable 10-15 weeks later. Our study demonstrates that CAR T cells specific for a pathogenic MHC class II:peptide complex can be effective in vivo, but that a single infusion of the current iteration can only delay, but not prevent, the development of T1D. Future studies should therefore be directed towards optimizing strategies designed to improve the longevity of the transferred cells.

Correction to: The Emerging Roles of Steroid Hormone Receptors in Ductal Carcinoma in Situ (DCIS) of the Breast.

The original version of this article unfortunately contained mistakes.

The Emerging Roles of Steroid Hormone Receptors in Ductal Carcinoma in Situ (DCIS) of the Breast.

Ductal carcinoma in situ (DCIS) is a non-obligate precursor to most types of invasive breast cancer (IBC). Although it is estimated only one third of untreated patients with DCIS will progress to IBC, standard of care for treatment is surgery and radiation. This therapeutic approach combined with a lack of reliable biomarker panels to predict DCIS progression is a major clinical problem. DCIS shares the same molecular subtypes as IBC including estrogen receptor (ER) and progesterone receptor (PR) positive luminal subtypes, which encompass the majority (60-70%) of DCIS. Compared to the established roles of ER and PR in luminal IBC, much less is known about the roles and mechanism of action of estrogen (E2) and progesterone (P4) and their cognate receptors in the development and progression of DCIS. This is an underexplored area of research due in part to a paucity of suitable experimental models of ER+/PR + DCIS. This review summarizes information from clinical and observational studies on steroid hormones as breast cancer risk factors and ER and PR as biomarkers in DCIS. Lastly, we discuss emerging experimental models of ER+/PR+ DCIS.

miR-30a Remodels Subcutaneous Adipose Tissue Inflammation to Improve Insulin Sensitivity in Obesity.

Chronic inflammation accompanies obesity and limits subcutaneous white adipose tissue (WAT) expandability, accelerating the development of insulin resistance and type 2 diabetes mellitus. MicroRNAs (miRNAs) influence expression of many metabolic genes in fat cells, but physiological roles in WAT remain poorly characterized. Here, we report that expression of the miRNA miR-30a in subcutaneous WAT corresponds with insulin sensitivity in obese mice and humans. To examine the hypothesis that restoration of miR-30a expression in WAT improves insulin sensitivity, we injected adenovirus (Adv) expressing miR-30a into the subcutaneous fat pad of diabetic mice. Exogenous miR-30a expression in the subcutaneous WAT depot of obese mice coupled improved insulin sensitivity and increased energy expenditure with decreased ectopic fat deposition in the liver and reduced WAT inflammation. High-throughput proteomic profiling and RNA-Seq suggested that miR-30a targets the transcription factor STAT1 to limit the actions of the proinflammatory cytokine interferon-γ (IFN-γ) that would otherwise restrict WAT expansion and decrease insulin sensitivity. We further demonstrated that miR-30a opposes the actions of IFN-γ, suggesting an important role for miR-30a in defending adipocytes against proinflammatory cytokines that reduce peripheral insulin sensitivity. Together, our data identify a critical molecular signaling axis, elements of which are involved in uncoupling obesity from metabolic dysfunction.

Pharmacological targeting of MYC-regulated IRE1/XBP1 pathway suppresses MYC-driven breast cancer.

The unfolded protein response (UPR) is a cellular homeostatic mechanism that is activated in many human cancers and plays pivotal roles in tumor progression and therapy resistance. However, the molecular mechanisms for UPR activation and regulation in cancer cells remain elusive. Here, we show that oncogenic MYC regulates the inositol-requiring enzyme 1 (IRE1)/X-box binding protein 1 (XBP1) branch of the UPR in breast cancer via multiple mechanisms. We found that MYC directly controls IRE1 transcription by binding to its promoter and enhancer. Furthermore, MYC forms a transcriptional complex with XBP1, a target of IRE1, and enhances its transcriptional activity. Importantly, we demonstrate that XBP1 is a synthetic lethal partner of MYC. Silencing of XBP1 selectively blocked the growth of MYC-hyperactivated cells. Pharmacological inhibition of IRE1 RNase activity with small molecule inhibitor 8866 selectively restrained the MYC-overexpressing tumor growth in vivo in a cohort of preclinical patient-derived xenograft models and genetically engineered mouse models. Strikingly, 8866 substantially enhanced the efficacy of docetaxel chemotherapy, resulting in rapid regression of MYC-overexpressing tumors. Collectively, these data establish the synthetic lethal interaction of the IRE1/XBP1 pathway with MYC hyperactivation and provide a potential therapy for MYC-driven human breast cancers.

Progesterone Receptor Signaling Mechanisms.

Progesterone receptor (PR) is a master regulator in female reproductive tissues that controls developmental processes and proliferation and differentiation during the reproductive cycle and pregnancy. PR also plays a role in progression of endocrine-dependent breast cancer. As a member of the nuclear receptor family of ligand-dependent transcription factors, the main action of PR is to regulate networks of target gene expression in response to binding its cognate steroid hormone, progesterone. This paper summarizes recent advances in understanding the structure-function properties of the receptor protein and the tissue/cell-type-specific PR signaling pathways that contribute to the biological actions of progesterone in the normal breast and in breast cancer.

The Landscape of microRNA Targeting in Prostate Cancer Defined by AGO-PAR-CLIP.

MicroRNA (miRNA) deregulation in prostate cancer (PCa) contributes to PCa initiation and metastatic progression. To comprehensively define the cancer-associated changes in miRNA targeting and function in commonly studied models of PCa, we performed photoactivatable ribonucleoside-enhanced cross-linking immunoprecipitation of the Argonaute protein in a panel of PCa cell lines modeling different stages of PCa progression. Using this comprehensive catalogue of miRNA targets, we analyzed miRNA targeting on known drivers of PCa and examined tissue-specific and stage-specific pathway targeting by miRNAs. We found that androgen receptor is the most frequently targeted PCa oncogene and that miR-148a targets the largest number of known PCa drivers. Globally, tissue-specific and stage-specific changes in miRNA targeting are driven by homeostatic response to active oncogenic pathways. Our findings indicate that, even in advanced PCa, the miRNA pool adapts to regulate continuing alterations in the cancer genome to balance oncogenic molecular changes. These findings are important because they are the first to globally characterize miRNA changes in PCa and demonstrate how the miRNA target spectrum responds to staged tumorigenesis.

The tumor suppressive miR-200b subfamily is an ERG target gene in human prostate tumors.

The TMPRSS2-ERG fusion occurs in approximately 50% of prostate cancer (PCa), resulting in expression of the oncogenic ERG in the prostate. Because ERG is a transcriptional activator, we hypothesized that ERG-regulated genes contribute to PCa development. Since microRNA (miRNA) has crucial functions in cancer, we searched for miRNAs regulated by ERG in PCas. We mined published datasets based on the MSKCC Prostate Oncogene Project, in which a comprehensive analysis defined the miRNA transcriptomes in 113 PCas. We retrieved the miRNA expression datasets, and identified miRNAs differentially expressed between ERG-positive and ERG-negative samples. Out of 369 miRNAs, miR-200a, -200b, -429 and -205 are the only miRNAs significantly increased in ERG-positive tumors. Strikingly, miR-200a, -200b and -429 are transcribed as a single polycistronic transcript, suggesting they are regulated at the transcriptional level. With ChIP-qPCR and in vitro binding assay, we identified two functional ETS motifs in the miR-200b/a/429 gene promoter. Knockdown of ERG in PCa cells reduced expression of these three miRNAs. In agreement with the well-established tumor suppressor function, overexpression of the miR-200b/a/429 gene inhibited PCa cell growth and invasion. In summary, our study reveals that miR-200b/a/429 is an ERG target gene, which implicates an important role in TMPRSS2/ERG-dependent PCa development. Although induction of the tumor suppressive miR-200b subfamily by oncogenic ERG appears to be counterintuitive, it is consistent with the observation that the vast majority of primary prostate cancers are slow-growing and indolent.

GATA2 facilitates steroid receptor coactivator recruitment to the androgen receptor complex.

The androgen receptor (AR) is a key driver of prostate cancer (PC), even in the state of castration-resistant PC (CRPC) and frequently even after treatment with second-line hormonal therapies such as abiraterone and enzalutamide. The persistence of AR activity via both ligand-dependent and ligand-independent mechanisms (including constitutively active AR splice variants) highlights the unmet need for alternative approaches to block AR signaling in CRPC. We investigated the transcription factor GATA-binding protein 2 (GATA2) as a regulator of AR signaling and an actionable therapeutic target in PC. We demonstrate that GATA2 directly promotes expression of both full-length and splice-variant AR, resulting in a strong positive correlation between GATA2 and AR expression in both PC cell lines and patient specimens. Conversely, GATA2 expression is repressed by androgen and AR, suggesting a negative feedback regulatory loop that, upon androgen deprivation, derepresses GATA2 to contribute to AR overexpression in CRPC. Simultaneously, GATA2 is necessary for optimal transcriptional activity of both full-length and splice-variant AR. GATA2 colocalizes with AR and Forkhead box protein A1 on chromatin to enhance recruitment of steroid receptor coactivators and formation of the transcriptional holocomplex. In agreement with these important functions, high GATA2 expression and transcriptional activity predicted worse clinical outcome in PC patients. A GATA2 small molecule inhibitor suppressed the expression and transcriptional function of both full-length and splice-variant AR and exerted potent anticancer activity against PC cell lines. We propose pharmacological inhibition of GATA2 as a first-in-field approach to target AR expression and function and improve outcomes in CRPC.

The epidermal growth factor receptor critically regulates endometrial function during early pregnancy.

Infertility and adverse gynecological outcomes such as preeclampsia and miscarriage represent significant female reproductive health concerns. The spatiotemporal expression of growth factors indicates that they play an important role in pregnancy. The goal of this study is to define the role of the ERBB family of growth factor receptors in endometrial function. Using conditional ablation in mice and siRNA in primary human endometrial stromal cells, we identified the epidermal growth factor receptor (Egfr) to be critical for endometrial function during early pregnancy. While ablation of Her2 or Erbb3 led to only a modest reduction in litter size, mice lacking Egfr expression are severely subfertile. Pregnancy demise occurred shortly after blastocyst implantation due to defects in decidualization including decreased proliferation, cell survival, differentiation and target gene expression. To place Egfr in a genetic regulatory hierarchy, transcriptome analyses was used to compare the gene signatures from mice with conditional ablation of Egfr, wingless-related MMTV integration site 4 (Wnt4) or boneless morphogenic protein 2 (Bmp2); revealing that not only are Bmp2 and Wnt4 key downstream effectors of Egfr, but they also regulate distinct physiological functions. In primary human endometrial stromal cells, marker gene expression, a novel high content image-based approach and phosphokinase array analysis were used to demonstrate that EGFR is a critical regulator of human decidualization. Furthermore, inhibition of EGFR signaling intermediaries WNK1 and AKT1S1, members identified in the kinase array and previously unreported to play a role in the endometrium, also attenuate decidualization. These results demonstrate that EGFR plays an integral role in establishing the cellular context necessary for successful pregnancy via the activation of intricate signaling and transcriptional networks, thereby providing valuable insight into potential therapeutic targets.

Steroid receptor coactivator 1 is an integrator of glucose and NAD+/NADH homeostasis.

Steroid receptor coactivator 1 (SRC-1) drives diverse gene expression programs necessary for the dynamic regulation of cancer metastasis, inflammation and gluconeogenesis, pointing to its overlapping roles as an oncoprotein and integrator of cell metabolic programs. Nutrient utilization has been intensely studied with regard to cellular adaptation in both cancer and noncancerous cells. Nonproliferating cells consume glucose through the citric acid cycle to generate NADH to fuel ATP generation via mitochondrial oxidative phosphorylation. In contrast, cancer cells undergo metabolic reprogramming to support rapid proliferation. To generate lipids, nucleotides, and proteins necessary for cell division, most tumors switch from oxidative phosphorylation to glycolysis, a phenomenon known as the Warburg Effect. Because SRC-1 is a key coactivator responsible for driving a hepatic gluconeogenic program under fasting conditions, we asked whether SRC-1 responds to alterations in nutrient availability to allow for adaptive metabolism. Here we show SRC-1 is stabilized by the 26S proteasome in the absence of glucose. RNA profiling was used to examine the effects of SRC-1 perturbation on gene expression in the absence or presence of glucose, revealing that SRC-1 affects the expression of complex I of the mitochondrial electron transport chain, a set of enzymes responsible for the conversion of NADH to NAD(+). NAD(+) and NADH were subsequently identified as metabolites that underlie SRC-1's response to glucose deprivation. Knockdown of SRC-1 in glycolytic cancer cells abrogated their ability to grow in the absence of glucose consistent with SRC-1's role in promoting cellular adaptation to reduced glucose availability.

Identification of a pan-cancer oncogenic microRNA superfamily anchored by a central core seed motif.

MicroRNAs modulate tumorigenesis through suppression of specific genes. As many tumour types rely on overlapping oncogenic pathways, a core set of microRNAs may exist, which consistently drives or suppresses tumorigenesis in many cancer types. Here we integrate The Cancer Genome Atlas (TCGA) pan-cancer data set with a microRNA target atlas composed of publicly available Argonaute Crosslinking Immunoprecipitation (AGO-CLIP) data to identify pan-tumour microRNA drivers of cancer. Through this analysis, we show a pan-cancer, coregulated oncogenic microRNA 'superfamily' consisting of the miR-17, miR-19, miR-130, miR-93, miR-18, miR-455 and miR-210 seed families, which cotargets critical tumour suppressors via a central GUGC core motif. We subsequently define mutations in microRNA target sites using the AGO-CLIP microRNA target atlas and TCGA exome-sequencing data. These combined analyses identify pan-cancer oncogenic cotargeting of the phosphoinositide 3-kinase, TGFß and p53 pathways by the miR-17-19-130 superfamily members.