Chicken Ovalbumin Upstream Promoter Transcription Research Articles

Transcriptional regulation of genetic variants in the SLC40A1 promoter.

Solute carrier 40A1 (SLC40A1) encodes ferroportin, which is the only known transmembrane protein that exports elemental iron from mammalian cells and is essential for iron homeostasis. Mutations in SLC40A1 are associated with iron-overload disorders. In addition to ferroportin diseases, SLC40A1 expression is downregulated in various cancer types. Despite the clinical significance of the SLC40A1 transporter, only a few studies have investigated genetic variants in SLC40A1. The present study was performed to identify genetic variations in the SLC40A1 promoter and functionally characterize each variant using in vitro assays. We investigated four haplotypes and five variants in the SLC40A1 promoter. We observed that haplotype 3 (H3) had significantly lower promoter activity than H1, whereas the activity of H4 was significantly higher than that of H1. Luciferase activity of H2 was comparable to that of H1. In addition, four variants of SLC40A1, c.-1355G>C, c.-662C>T, c.-98G>C, and c.-8C>G, showed significantly increased luciferase activity compared to the wild type (WT), whereas c.-750G>A showed significantly decreased luciferase activity compared to the WT. Three transcription factors, cAMP response element-binding protein-1 (CREB-1), chicken ovalbumin upstream promoter transcription factor 1, and hepatic leukemia factor (HLF), were predicted to bind to the promoter regions of SLC40A1 near c.-662C>T, c.-98G>C, and c.-8C>G, respectively. Among these, CREB-1 and HLF bound more strongly to the variant sequences than to the WT and functioned as activators of SLC40A1 transcription. Collectively, our findings indicate that the two SLC40A1 promoter haplotypes affect SLC40A1 transcription, which is regulated by CREB-1 and HLF.

Development of multifunctional pyrrole-imidazole polyamides that increase hepatocyte growth factor and suppress transforming growth factor-β1

PurposeThe DNA recognition peptide compounds pyrrole-imidazole (PI) polyamides bind to the minor groove and can block the binding of transcription factors to target sequences. To develop more PI polyamides as potential treatments for fibrotic diseases, including chronic renal failure, we developed multifunctional PI polyamides that increase hepatocyte growth factor (HGF) and decrease transforming growth factor (TGF)-β1. MethodsWe designed seven PI polyamides (HGF-1 to HGF-7) that bind to the chicken ovalbumin upstream promoter transcription factor-1 (COUP-TF1) binding site of the HGF promoter sequence. We selected PI polyamides that increase HGF and suppress TGF-β1 in human dermal fibroblasts (HDFs). FindingsGel shift assays showed that HGF-2 and HGF-4 bound the appropriate dsDNAs. HGF-2 and HGF-4 significantly inhibited the TGF-β1 mRNA expression in HDFs stimulated by phorbol 12-myristate 13-acetate. HGF-2 and HGF-4 significantly inhibited the TGF-β1 protein expression in HDFs with siRNA targeting HGF, indicating that HGF-2 and HGF-4 directly inhibited the expression of TGF-β1. ConclusionThe designed and synthetic HGF PI polyamides targeting the HGF promoter, which increased the expression of HGF and suppressed the expression of TGF-β, will be a potential practical medicine for fibrotic diseases, including progressive renal diseases.

Endothelial TIE1 Restricts Angiogenic Sprouting to Coordinate Vein Assembly in Synergy With Its Homologue TIE2

BACKGROUND: Vascular growth followed by vessel specification is crucial for the establishment of a hierarchical blood vascular network. We have shown that TIE2 is required for vein development while little is known about its homologue TIE1 (tyrosine kinase with immunoglobulin-like and EGF [epithelial growth factor]-like domains 1) in this process. METHODS: We analyzed functions of TIE1 as well as its synergy with TIE2 in the regulation of vein formation by employing genetic mouse models targeting Tie1 , Tek , and Nr2f2 , together with in vitro cultured endothelial cells to decipher the underlying mechanism. RESULTS: Cardinal vein growth appeared normal in TIE1-deficient mice, whereas TIE2 deficiency altered the identity of cardinal vein endothelial cells with the aberrant expression of DLL4 (delta-like canonical Notch ligand 4). Interestingly, the growth of cutaneous veins, which was initiated at approximately embryonic day 13.5, was retarded in mice lack of TIE1. TIE1 deficiency disrupted the venous integrity, displaying increased sprouting angiogenesis and vascular bleeding. Abnormal venous sprouts with defective arteriovenous alignment were also observed in the mesenteries of Tie1 -deleted mice. Mechanistically, TIE1 deficiency resulted in the decreased expression of venous regulators including TIE2 and COUP-TFII (chicken ovalbumin upstream promoter transcription factor, encoded by Nr2f2 , nuclear receptor subfamily 2 group F member 2) while angiogenic regulators were upregulated. The alteration of TIE2 level by TIE1 insufficiency was further confirmed by the siRNA-mediated knockdown of Tie1 in cultured endothelial cells. Interestingly, TIE2 insufficiency also reduced the expression of TIE1. Combining the endothelial deletion of Tie1 with 1 null allele of Tek resulted in a progressive increase of vein-associated angiogenesis leading to the formation of vascular tufts in retinas, whereas the loss of Tie1 alone produced a relatively mild venous defect. Furthermore, the induced deletion of endothelial Nr2f2 decreased both TIE1 and TIE2. CONCLUSIONS: Findings from this study imply that TIE1 and TIE2, together with COUP-TFII, act in a synergistic manner to restrict sprouting angiogenesis during the development of venous system.

Chicken ovalbumin upstream promoter transcription factor type II interacts and functionally cooperates with GATA4 to regulate anti-Müllerian hormone receptor type 2 transcription in mouse MA-10 Leydig cells.

Leydig cells produce testosterone and insulin-like 3, two hormones essential for male sex differentiation and reproductive function. The orphan nuclear receptor, chicken ovalbumin upstream promoter transcription factor type II (COUP-TFII), and the zinc finger factor GATA4 are two transcription factors involved in Leydig cell differentiation, gene expression, and function. Several Leydig cell gene promoters contain binding motifs for both GATA factors and nuclear receptors. The goal of the present study is to determine whether GATA4 and COUP-TFII cooperate to regulate gene expression in Leydig cells. The transcriptomes from GATA4- and COUP-TFII-depleted MA-10 Leydig cells were analyzed using bioinformatic tools. Functional cooperation between GATA4 and COUP-TFII, and other related family members, was assessed by transient transfections in Leydig (MA-10 and MLTC-1) and fibroblast (CV-1) cell lines on several gene promoters. Recruitment of GATA4 and COUP-TFII to gene promoters was investigated by chromatin immunoprecipitation. Co-immunoprecipitation was used to determine whether GATA4 and COUP-TFII interact in MA-10 Leydig cells. Transcriptomic analyses of GATA4- and COUP-TFII-depleted MA-10 Leydig cells revealed 44 commonly regulated genes including the anti-Müllerian hormone receptor type (Amhr2) gene. GATA4 and COUP-TFII independently activated the Amhr2 promoter, and their combination led to a stronger activation. A GC-rich element, located in the proximal Amhr2 promoter was found to be essential for GATA4- and COUP-TFII-dependent activation as well as for the COUP-TFII/GATA4 cooperation. COUP-TFII and GATA4 directly interacted in MA-10 Leydig cell extracts. Chromatin immunoprecipitation revealed that GATA4 and COUP-TFII are recruited to the proximal Amhr2 promoter, which contains binding sites for both factors in addition to the GC-rich element. Cooperation between COUP-TFII and GATA6, but not GATA1 and GATA3, was also observed. Our results establish the importance of physical and functional cooperation between COUP-TFII/GATA4 in the regulation of gene expression in MA-10 Leydig cells, and more specifically the Amhr2 gene.

YAP1 overexpression contributes to the development of enzalutamide resistance by induction of cancer stemness and lipid metabolism in prostate cancer

Metastatic castration-resistant prostate cancer (mCRPC) is a malignant and lethal disease caused by relapse after androgen-deprivation (ADT) therapy. Since enzalutamide is innovated and approved by US FDA as a new treatment option for mCRPC patients, drug resistance for enzalutamide is a critical issue during clinical usage. Although several underlying mechanisms causing enzalutamide resistance were previously identified, most of them revealed that drug resistant cells are still highly addicted to androgen and AR functions. Due to the numerous physical functions of AR in men, innovated AR-independent therapy might alleviate enzalutamide resistance and prevent production of adverse side effects. Here, we have identified that yes-associated protein 1 (YAP1) is overexpressed in enzalutamide-resistant (EnzaR) cells. Furthermore, enzalutamide-induced YAP1 expression is mediated through the function of chicken ovalbumin upstream promoter transcription factor 2 (COUP-TFII) at the transcriptional and the post-transcriptional levels. Functional analyses reveal that YAP1 positively regulates numerous genes related to cancer stemness and lipid metabolism and interacts with COUP-TFII to form a transcriptional complex. More importantly, YAP1 inhibitor attenuates the growth and cancer stemness of EnzaR cells in vitro and in vivo. Finally, YAP1, COUP-TFII, and miR-21 are detected in the extracellular vesicles (EVs) isolated from EnzaR cells and sera of patients. In addition, treatment with EnzaR-EVs induces the abilities of cancer stemness, lipid metabolism and enzalutamide resistance in its parental cells. Taken together, these results suggest that YAP1 might be a crucial factor involved in the development of enzalutamide resistance and can be an alternative therapeutic target in prostate cancer.

Augmented angiogenic transcription factor, SOX18, is associated with asthma exacerbation

Background Asthma characterized by airway hyperresponsiveness, inflammation, fibrosis, and angiogenesis. SRY-related HMG-box 18 (SOX18) is an important transcription factor involved in angiogenesis, tissue injury, wound-healing, and in embryonic cardiovascular and lymphatic vessels development. The role of angiogenic transcription factors, SOX18 and the related, prospero homeobox 1 (PROX1) and chicken ovalbumin upstream promoter transcription factor II (COUP-TFII), in asthma has had limited study. Objective In this study, we aimed to elucidate the role of SOX18 in the pathogenesis of bronchial asthma. Methods Plasma SOX18 protein was measured in control subjects, and subject with stable or exacerbated asthma. SOX18, PROX1, and COUP-TFII protein was measured by western blot, and immunohistochemistry in a murine model of ovalbumin-induced allergic asthma (OVA). SOX18, PROX1, and COUP-TFII protein was measured in lung human microvascular endothelial cells (HMVEC-L) and normal human bronchial epithelial (NHBE) cells treated with house dust mite (Der p1). Results Plasma SOX18 tended to be higher in subject with asthma compared to control subjects and increased more during exacerbation as compared to stable disease. In mice, OVA challenge lead to increased lung SOX18, PROX1, COUP-TFII, mucous gland hyperplasia and submucosal collagen. In NHBE cells, SOX18, PROX1 and COUP-TFII increased following Der p1 treatment. SOX18 protein increased in HMVEC-L following Der p1 treatment. Conclusion These results suggest that SOX18 may be involved in asthma pathogenesis and be associated with asthma exacerbation.

Establishment of a stem Leydig cell line capable of 11-ketotestosterone production.

The deficiency or insufficiency of androgen can trigger a range of reproductive diseases as well as other symptoms. Stem Leydig cells (SLCs) are critical for the formation and maintenance of a functional androgen-producing cell (Leydig cell, LC) population throughout adult male life. However, to date, our knowledge about SLCs is poor. Here we report the derivation and characterisation of a clonal stem LC line (designated as TSL) capable of 11- ketotestosterone (11-KT) production from a 3-month-old Nile tilapia (Oreochromis niloticus) testis. The cells retained stable proliferation after 77 generations with normal karyotype and growth factor dependency. They expressed platelet-derived growth factor receptor-α (pdgfrα), nestin and chicken ovalbumin upstream promoter transcription factor II (coup-tfIIa), which are characteristic of SLCs. Upon induction in defined medium, TSLs could undergo differentiation into steroidogenically active LCs and produce 11-KT. When implanted into recipient Nile tilapia testes from which endogenous LCs had been eliminated by ethane dimethanesulphonate (EDS) treatment, the PKH26-labelled TSLs could colonise the interstitium, subsequently express steroidogenic genes and restore 11-KT production. Taken together, our data suggest that TSLs possess the ability of continuous proliferation and potential of differentiation into functional LCs invitro and invivo. To the best of our knowledge TSL might represent the first stem LC line capable of 11-KT production to date. Our study may offer new opportunities for investigating the self-renewal of SLCs and steroidogenesis invitro, and provide an invaluable invitro model for investigating endocrine disruptors.

COUP-TFII in Health and Disease.

The nuclear receptors (NRs) belong to a vast family of evolutionary conserved proteins acting as ligand-activated transcription factors. Functionally, NRs are essential in embryogenesis and organogenesis and in adulthood they are involved in almost every physiological and pathological process. Our knowledge of NRs action has greatly improved in recent years, demonstrating that both their expression and activity are tightly regulated by a network of signaling pathways, miRNA and reciprocal interactions. The Chicken Ovalbumin Upstream Promoter Transcription Factor II (COUP-TFII, NR2F2) is a NR classified as an orphan due to the lack of a known natural ligand. Although its expression peaks during development, and then decreases considerably, in adult tissues, COUP-TFII is an important regulator of differentiation and it is variably implicated in tissues homeostasis. As such, alterations of its expression or its transcriptional activity have been studied and linked to a spectrum of diseases in organs and tissues of different origins. Indeed, an altered COUP-TFII expression and activity may cause infertility, abnormality in the vascular system and metabolic diseases like diabetes. Moreover, COUP-TFII is actively investigated in cancer research but its role in tumor progression is yet to be fully understood. In this review, we summarize the current understanding of COUP-TFII in healthy and pathological conditions, proposing an updated and critical view of the many functions of this NR.

The Nuclear Receptor COUP-TFII Regulates Amhr2 Gene Transcription via a GC-Rich Promoter Element in Mouse Leydig Cells.

The nuclear receptor chicken ovalbumin upstream promoter–transcription factor type II (COUP-TFII)/NR2F2 is expressed in adult Leydig cells, and conditional deletion of the Coup-tfii/Nr2f2 gene impedes their differentiation. Steroid production is also reduced in COUP-TFII–depleted Leydig cells, supporting an additional role in steroidogenesis for this transcription factor. COUP-TFII action in Leydig cells remains to be fully characterized. In the present work, we report that COUP-TFII is an essential regulator of the gene encoding the anti-Müllerian hormone receptor type 2 (Amhr2), which participates in Leydig cell differentiation and steroidogenesis. We found that Amhr2 mRNA levels are reduced in COUP-TFII–depleted MA-10 Leydig cells. Consistent with this, COUP-TFII directly activates a −1486 bp fragment of the mouse Amhr2 promoter in transient transfection assays. The COUP-TFII responsive region was localized between −67 and −34 bp. Chromatin immunoprecipitation assay confirmed COUP-TFII recruitment to the proximal Amhr2 promoter whereas DNA precipitation assay revealed that COUP-TFII associates with the −67/−34 bp region in vitro. Even though the −67/−34 bp region contains an imperfect nuclear receptor element, COUP-TFII–mediated activation of the Amhr2 promoter requires a GC-rich sequence at −39 bp known to bind the specificity protein (SP)1 transcription factor. COUP-TFII transcriptionally cooperates with SP1 on the Amhr2 promoter. Mutations that altered the GCGGGGCGG sequence at −39 bp abolished COUP-TFII–mediated activation, COUP-TFII/SP1 cooperation, and reduced COUP-TFII binding to the proximal Amhr2 promoter. Our data provide a better understanding of the mechanism of COUP-TFII action in Leydig cells through the identification and regulation of the Amhr2 promoter as a novel target.

COUP-TFII is a modulator of cell-type-specific genetic programs based on genomic localization maps

Chicken ovalbumin upstream promoter transcription factor II (COUP-TFII) is a member of the steroid/thyroid hormone receptor superfamily, but its ligand has not yet been identified. Little is known about the role of the COUP-TFII nuclear receptor in cancer cells. In this study, we mapped the cistrome of COUP-TFII in three different cancer cells, namely breast cancer cells (MCF-7), myelogenous leukaemia cells (K562) and liver cancer cells (HepG2) using publicly available ChIP-seq data. Our results show that COUP-TFII co-localises with master transcription factors (TFs) in a cell-specific manner such as estrogen receptor alpha in MCF-7, hepatocyte nuclear factor alpha in HepG2, and GATA-binding factor in K562, while the shared, non-specific COUP-TFII binding sites are co-occupied by CTCF. We identified chromatin environments for these COUP-TFII and master TF co-bound sites together with COUP-TFII and CTCF co-bound sites. Our results show that COUP-TFII and master TF co-bound sites are marked with active enhancer specific histone modifications (H3K27ac and H3K4me1), while COUP-TFII and CTCF co-bound sites reveal active promoter specific histone marks (H3K27ac and H3K4me3). These results describe the genomic context and role of COUP-TFII in the cell-type specific transcriptional programs. Furthermore, we report that the VEGFA gene regulated by shared COUP-TFII and CTCF co-bound regulatory elements is involved in long-range looping in a cell-type-independent manner. These findings provide a genomic insight into the regulation and angiogenic role of COUP-TFII.

Prognostic Role of Chicken Ovalbumin Upstream Promoter Transcription Factor II in Isocitrate Dehydrogenase-Mutant Glioma with 1p19q Co-Deletion.

Chicken ovalbumin upstream promoter transcription factor II is known to play a crucial role in the tumor microenvironment. However, the role of NR2F2 in gliomas is unknown. The genomic and clinical data of 530 cases of lower grade gliomas (LGGs) patients and 167 cases of glioblastoma (GBM) patients in The Cancer Genome Atlas (TCGA) were extracted for analysis. R2 and UCSC Xena browser were used for Kaplan-Meier survival in the GSE16011 dataset and TCGA dataset, respectively. GraphPad Prism 7 was used to compare the differences in NR2F2 expression between various groups and subtypes. LGG patients with low NR2F2 expression had a significantly favorable outcome compared with those with high NR2F2 expression (p < 0.05). By matching histological subtypes and gene expression profiles of LGG patients, grade II glioma group showed lowest levels of NR2F2 expression compared with grade III gliomas and GBM. Patients diagnosed with astrocytoma have highest expression of NR2F2 but lowest OS (p < 0.05). In LGGs, NR2F2 expression was significantly downregulated in patient group with IDH mutation and 1p19q co-deletion (p < 0.05). Our study suggests that NR2F2 can be used as a prognostic marker in LGG patients with IDH mutation and 1p19 co-deletion.

Grafted Human iPSC-Derived Neural Progenitor Cells Express Integrins and Extend Long-Distance Axons Within the Developing Corticospinal Tract.

After spinal cord injury (SCI), regeneration of adult motor axons such as axons in the corticospinal tract (CST) is severely limited. Alongside the inhibitory lesion environment, most neuronal subtypes in the mature central nervous system (CNS) are intrinsically unrepairable. With age, expression of growth-promoting proteins in neurons, such as integrins, declines. Integrin receptors allow communication between the extracellular matrix (ECM) and cell cytoskeleton and their expression in axons facilitates growth and guidance throughout the ECM. The α9β1 integrin heterodimer binds to tenascin-C (TN-C), an ECM glycoprotein expressed during development and after injury. In the mature CST however, expression of the α9 integrin subunit is downregulated, adding to the intrinsic inability of axons to regenerate. Our previous work has shown the α9 integrin subunit is not trafficked within axons of mature CST or rubrospinal tracts (RSTs). Thus, here we have utilized human induced pluripotent stem cell (iPSC)-derived neural progenitor cells (NPCs) to increase expression of α9 integrinwithin the developing rat CST. We demonstrate that human NPCs (hNPCs) express endogenous levels of both α9 and β1 integrin subunits as well as cortical neuron markers such as chicken ovalbumin upstream promoter transcription factor (COUP-TF) interacting protein 2 (Ctip2) and T-box brain 1 (Tbr1). In addition, lentivirus-mediated α9 integrin overexpression in hNPCs resulted in increased neurite outgrowth in the presence of TN-C in vitro. Following transplantation into the sensorimotor cortex of newborn rats, both wild type (WT) and α9-expressing hNPCs extend along the endogenous CST and retain expression of α9 throughout the length of the axonal compartment for up to 8 weeks following transplantation. These data highlight the growth potential of transplanted human iPSCs which may be a future target for regenerative therapies after nervous system injury.

Hepatic Nuclear Receptor Expression Associates with Features of Histology in Pediatric Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children and adults. This study examined the relationship between hepatic nuclear receptor (NR) expression and histologic features of NAFLD. Drugs targeting a variety of NRs for nonalcoholic steatohepatitis (NASH) are in clinical trials. Liver messenger RNA was isolated from 40 children (10‐19 years) undergoing end‐of‐treatment biopsy in the Treatment of NAFLD in Children (TONIC) trial. High‐throughput quantitative polymerase chain reaction assayed NR messenger RNA. Cluster analysis was used to group 36 NRs, and NR levels were related to histologic measures of specific NAFLD features. Cluster analysis determined five groupings of NRs. Significant (P < 0.05) differential expressions of specific NRs associated with histologic measures include farnesoid X receptor alpha and retinoic acid receptor (RARβ and RARβ) for steatosis; estrogen receptor alpha (ERα) and peroxisome proliferator‐activated receptor gamma 3 (PPARγ3) for hepatocellular ballooning; ER and PPARγ2 for lobular inflammation; PPARα/δ/γ1/γ2, ERα, constitutive androstane receptor, chicken ovalbumin upstream promoter transcription factor 1, RARα, RARβ1, retinoid X receptor, pregnane X receptor, thyroid hormone receptors α and β, and nuclear receptor related‐1 for fibrosis; and ERα and RARβ/β1/α for diagnosis of NASH. Conclusion: Differential expression of specific NRs correlates with histologic severity of specific NAFLD features. These NRs are pleiotropic transactivators regulating basal metabolic functions and inflammatory responses. Derangement of activity of these receptors in NAFLD provides a rationale for exploiting their ability with receptor‐specific ligands to ameliorate NASH and its consequences.

Elimination of the male reproductive tract in the female embryo is promoted by COUP-TFII in mice

The sexual differentiation paradigm contends that the female pattern of the reproductive system is established by default because the male reproductive tracts (Wolffian ducts) in the female degenerate owing to a lack of androgen. Here, we discovered that female mouse embryos lacking Coup-tfII (chicken ovalbumin upstream promoter transcription factor II) in the Wolffian duct mesenchyme became intersex—possessing both female and male reproductive tracts. Retention of Wolffian ducts was not caused by ectopic androgen production or action. Instead, enhanced phosphorylated extracellular signal-regulated kinase signaling in Wolffian duct epithelium was responsible for the retention of male structures in an androgen-independent manner. We thus suggest that elimination of Wolffian ducts in female embryos is actively promoted by COUP-TFII, which suppresses a mesenchyme-epithelium cross-talk responsible for Wolffian duct maintenance.

Tbx20 Is Required in Mid-Gestation Cardiomyocytes and Plays a Central Role in Atrial Development.

Mutations in the transcription factor TBX20 (T-box 20) are associated with congenital heart disease. Germline ablation of Tbx20 results in abnormal heart development and embryonic lethality by embryonic day 9.5. Because Tbx20 is expressed in multiple cell lineages required for myocardial development, including pharyngeal endoderm, cardiogenic mesoderm, endocardium, and myocardium, the cell type-specific requirement for TBX20 in early myocardial development remains to be explored. Here, we investigated roles of TBX20 in midgestation cardiomyocytes for heart development. Ablation of Tbx20 from developing cardiomyocytes using a doxycycline inducible cTnTCre transgene led to embryonic lethality. The circumference of developing ventricular and atrial chambers, and in particular that of prospective left atrium, was significantly reduced in Tbx20 conditional knockout mutants. Cell cycle analysis demonstrated reduced proliferation of Tbx20 mutant cardiomyocytes and their arrest at the G1-S phase transition. Genome-wide transcriptome analysis of mutant cardiomyocytes revealed differential expression of multiple genes critical for cell cycle regulation. Moreover, atrial and ventricular gene programs seemed to be aberrantly regulated. Putative direct TBX20 targets were identified using TBX20 ChIP-Seq (chromatin immunoprecipitation with high throughput sequencing) from embryonic heart and included key cell cycle genes and atrial and ventricular specific genes. Notably, TBX20 bound a conserved enhancer for a gene key to atrial development and identity, COUP-TFII/Nr2f2 (chicken ovalbumin upstream promoter transcription factor 2/nuclear receptor subfamily 2, group F, member 2). This enhancer interacted with the NR2F2 promoter in human cardiomyocytes and conferred atrial specific gene expression in a transgenic mouse in a TBX20-dependent manner. Myocardial TBX20 directly regulates a subset of genes required for fetal cardiomyocyte proliferation, including those required for the G1-S transition. TBX20 also directly downregulates progenitor-specific genes and, in addition to regulating genes that specify chamber versus nonchamber myocardium, directly activates genes required for establishment or maintenance of atrial and ventricular identity. TBX20 plays a previously unappreciated key role in atrial development through direct regulation of an evolutionarily conserved COUPT-FII enhancer.

Downregulation of COUP-TFII inhibits glioblastoma growth via targeting MPC1.

Chicken ovalbumin upstream promoter transcription factor II (COUP-TFII) is a steroid receptor that is broadly expressed in many tissues throughout embryonic development. Previous studies indicated that COUP-TFII is dysregulated in multiple types of cancer and serves crucial roles in cancer development. The mitochondrial pyruvate carrier 1 (MPC1) is involved in transporting pyruvate for entry into the citric acid cycle, an important event in cancer progression. However, the roles of COUP-TFII and MPC1 in glioma remain unknown. In the present study, it was demonstrated that MPC1 is downregulated in glioblastoma. Furthermore, the inhibition of COUP-TFII was able to increase MPC1 expression and inhibit the growth of glioblastoma cells in vitro and in vivo. The findings from the present study demonstrated that downregulation of COUP-TFII inhibits glioblastoma growth via targeting MPC1. Therefore, COUP-TFII is a potential therapeutic target for glioma.

Overexpression of COUP‑TFII suppresses proliferation and metastasis of human gastric cancer cells.

The abnormal expression of the chicken ovalbumin upstream promoter transcription factor 2 (COUP-TFII) is associated with numerous forms of cancer, including gastric, prostate, colon and lung cancer. However, previous studies investigating the association between COUP-TFII expression and the occurrence, recurrence, invasion and metastasis of gastric cancer are limited in number. In the present study, it was revealed that the expression of COUP-TFII is significantly reduced in gastric carcinoma tissues compared with normal gastric mucosa cells (GES-1). In addition, the expression of COUP-TFII was also reduced in gastric cancer cell lines compared with GES-1 cells. Furthermore, it was revealed that ectopic expression of COUP-TFII was able to suppress the proliferation, migration and invasion of gastric cells, as well as inhibit hepatic metastasis, in vivo. In addition, it was demonstrated that COUP-TFII knockdown was able to promote the proliferation, migration and invasion of GES-1 cells in vitro. Furthermore, database analysis suggested that COUP-TFII expression in patients with gastric cancer is correlated with clinical stage classification and increased expression levels of COUP-TFII improved overall survival rates in patients with gastric cancer. The results of the present study suggest that COUP-TFII functions as a significant regulatory suppressor of gastric cancer growth and metastasis, and suggests that COUP-TFII may serve as a novel diagnostic and prognostic biomarker for gastric cancer metastasis.

Endoglin inhibition leads to intussusceptive angiogenesis via activation of factors related to COUP-TFII signaling pathway.

Angiogenesis is a highly coordinated, extremely complex process orchestrated by multiple signaling molecules and blood flow conditions. While sprouting mode of angiogenesis is very well investigated, the molecular mechanisms underlying intussusception, the second mode of angiogenesis, remain largely unclear. In the current study two molecules involved in vascular growth and differentiation, namely endoglin (ENG/CD105) and chicken ovalbumin upstream promoter transcription factor II (COUP-TFII) were examined to unravel their specific roles in angiogenesis. Down- respectively up-regulation of both molecules tightly correlates with intussusceptive microvascular growth. Upon ENG inhibition in chicken embryo model, formation of irregular capillary meshwork accompanied by increased expression of COUP-TFII could be observed. This dynamic expression pattern of ENG and COUP-TFII during vascular development and remodeling correlated with formation of pillars and progression of intussusceptive angiogenesis. Similar findings could be observed in mammalian model of acute rat Thy1.1 glomerulonephritis, which was induced by intravenous injection of anti-Thy1 antibody and has shown upregulation of COUP-TFII in initial phase of intussusception, while ENG expression was not disturbed compared to the controls but decreased over the time of pillar formation. In this study, we have shown that ENG inhibition and at the same time up-regulation of COUP-TFII expression promotes intussusceptive angiogenesis.

Elimination of the male reproductive tract in the female embryo is promoted by COUP-TFII in mice.

The sexual differentiation paradigm contends that the female pattern of the reproductive system is established by default because the male reproductive tracts (Wolffian ducts) in the female degenerate owing to a lack of androgen. Here, we discovered that female mouse embryos lacking Coup-tfII (chicken ovalbumin upstream promoter transcription factor II) in the Wolffian duct mesenchyme became intersex-possessing both female and male reproductive tracts. Retention of Wolffian ducts was not caused by ectopic androgen production or action. Instead, enhanced phosphorylated extracellular signal-regulated kinase signaling in Wolffian duct epithelium was responsible for the retention of male structures in an androgen-independent manner. We thus suggest that elimination of Wolffian ducts in female embryos is actively promoted by COUP-TFII, which suppresses a mesenchyme-epithelium cross-talk responsible for Wolffian duct maintenance.

MicroRNA-382 inhibits prostate cancer cell proliferation and metastasis through targeting COUP-TFII.

MicroRNAs (miRNAs) have emerged as important regulators in cancer that are implicated in regulation of various cellular processes. miR-382 has been proposed as a tumor suppressor by several recent studies. However, the function of miR-382 in prostate cancer remains unknown. In this study, we aimed to investigate the potential function of miR-382 in prostate cancer. We found that miR-382 was significantly decreased in prostate cancer specimens and cancer cell lines. The overexpression of miR-382 in prostate cancer cells markedly inhibited cell proliferation, migration, and invasion. In contrast, miR-382 suppression exhibited an opposite effect. Target analysis predicted that chicken ovalbumin upstream promoter transcription factor II (COUP‑TFII) was a direct target of miR-382. This prediction was experimentally confirmed by dual-luciferase reporter assay, real-time quantitative polymerase chain reaction, and western blot analysis. Our results further demonstrated that miR-382 inhibited the downstream genes of COUP‑TFII, including Snail and matrix metalloproteinase 2 (MMP2). Moreover, the restoration of COUP‑TFII expression significantly blocked the inhibitory effect of miR-382 on cell proliferation, migration, and invasion, and Snail expression. Taken together, this study suggests that miR-382 inhibits prostate cancer cell proliferation and metastasis through inhibiting COUP‑TFII, representing an important new mechanism for understanding prostate cancer pathogenesis and providing a novel therapeutic candidate target for prostate cancer therapy.