Anti-angiogenesis and anti-immunosuppression gene therapy through targeting COUP-TFII in an in situ glioblastoma mouse model.

Glioblastoma (GBM) is the most common and aggressive primary brain cancer; angiogenesis and immunosuppression exacerbate GBM progression. COUP-TFII demonstrates pro-angiogenesis activity; however, its role in glioma progression remains unclear. This study revealed that COUP-TFII promotes angiogenesis in gliomas by inducing transdifferentiation of glioma cells into endothelial-like cells. Mechanistic investigation suggested that COUP-TFII as a transcription factor exerts its function via binding to the promoter of TXNIP. Interestingly, COUP-TFII knockdown attenuated tumorigenesis and tumor progression in an immunocompetent mouse model but promoted tumor progression in an immuno-deficient mouse model. As an explanation, repression of COUP-TFII induces cellular senescence and activates immune surveillance in glioma cells in vitro and in vivo. In addition, we used heparin-polyethyleneimine (HPEI) nanoparticles to deliver COUP-TFII shRNA, which regulated tumor angiogenesis and immunosuppression in an in situ GBM mouse model. This study provides a novel strategy and potential therapeutic targets to treat GBM.

Targeted deletion of NR2F2 and VCAM1 in theca cells impacts ovarian follicular development: insights into polycystic ovary syndrome?†.

Defining features of polycystic ovary syndrome (PCOS) include elevated expression of steroidogenic genes, theca cell androgen biosynthesis, and peripheral levels of androgens. In previous studies, we identified vascular cell adhesion molecule 1 (VCAM1) as a selective androgen target gene in specific NR2F2/SF1 (+/+) theca cells. By deleting NR2F2 and VCAM1 selectively in CYP17A1 theca cells in mice, we documented that NR2F2 and VCAM1 impact distinct and sometimes opposing theca cell functions that alter ovarian follicular development in vivo: including major changes in ovarian morphology, steroidogenesis, gene expression profiles, immunolocalization images (NR5A1, CYP11A1, NOTCH1, CYP17A1, INSL3, VCAM1, NR2F2) as well as granulosa cell functions. We propose that theca cells impact follicle integrity by regulating androgen production and action, as well as granulosa cell differentiation/luteinization in response to androgens and gonadotropins that may underlie PCOS.

The NR2F2-HAND2 signaling axis regulates progesterone actions in the uterus at early pregnancy.

Endometrial function is dependent on a tight crosstalk between the epithelial and stromal cells of the endometrium. This communication is critical to ensure a fertile uterus and relies on progesterone and estrogen signaling to prepare a receptive uterus for embryo implantation in early pregnancy. One of the key mediators of this crosstalk is the orphan nuclear receptor NR2F2, which regulates uterine epithelial receptivity and stromal cell differentiation. In order to determine the molecular mechanism regulated by NR2F2, RNAseq analysis was conducted on the uterus of PgrCre;Nr2f2f/f mice at Day 3.5 of pregnancy. This transcriptomic analysis demonstrated Nr2f2 ablation in Pgr-expressing cells leads to a reduction of Hand2 expression, increased levels of Hand2 downstream effectors Fgf1 and Fgf18, and a transcriptome manifesting suppressed progesterone signaling with an altered immune baseline. ChIPseq analysis conducted on the Day 3.5 pregnant mouse uterus for NR2F2 demonstrated the majority of NR2F2 occupies genomic regions that have H3K27ac and H3K4me1 histone modifications, including the loci of major uterine transcription regulators Hand2, Egr1, and Zbtb16. Furthermore, functional analysis of an NR2F2 occupying site that is conserved between human and mouse was capable to enhance endogenous HAND2 mRNA expression with the CRISPR activator in human endometrial stroma cells. These data establish the NR2F2 dependent regulation of Hand2 in the stroma and identify a cis-acting element for this action. In summary, our findings reveal a role of the NR2F2-HAND2 regulatory axis that determines the uterine transcriptomic pattern in preparation for the endometrial receptivity.

An epigenetic switch controls an alternative NR2F2 isoform that unleashes a metastatic program in melanoma.

Metastatic melanoma develops once transformed melanocytic cells begin to de-differentiate into migratory and invasive melanoma cells with neural crest cell (NCC)-like and epithelial-to-mesenchymal transition (EMT)-like features. However, it is still unclear how transformed melanocytes assume a metastatic melanoma cell state. Here, we define DNA methylation changes that accompany metastatic progression in melanoma patients and discover Nuclear Receptor Subfamily 2 Group F, Member 2 - isoform 2 (NR2F2-Iso2) as an epigenetically regulated metastasis driver. NR2F2-Iso2 is transcribed from an alternative transcriptional start site (TSS) and it is truncated at the N-terminal end which encodes the NR2F2 DNA-binding domain. We find that NR2F2-Iso2 expression is turned off by DNA methylation when NCCs differentiate into melanocytes. Conversely, this process is reversed during metastatic melanoma progression, when NR2F2-Iso2 becomes increasingly hypomethylated and re-expressed. Our functional and molecular studies suggest that NR2F2-Iso2 drives metastatic melanoma progression by modulating the activity of full-length NR2F2 (Isoform 1) over EMT- and NCC-associated target genes. Our findings indicate that DNA methylation changes play a crucial role during metastatic melanoma progression, and their control of NR2F2 activity allows transformed melanocytes to acquire NCC-like and EMT-like features. This epigenetically regulated transcriptional plasticity facilitates cell state transitions and metastatic spread.

Inflammation and DKK1-induced AKT activation contribute to endothelial dysfunction following NR2F2 loss.

NR2F2 is expressed in endothelial cells (ECs) and Nr2f2 knockout produces lethal cardiovascular defects. In humans, reduced NR2F2 expression is associated with cardiovascular diseases including congenital heart disease and atherosclerosis. Here, NR2F2 silencing in human primary ECs led to inflammation, endothelial-to-mesenchymal transition (EndMT), proliferation, hypermigration, apoptosis-resistance, and increased production of reactive oxygen species. These changes were associated with STAT and AKT activation along with increased production of DKK1. Co-silencing DKK1 and NR2F2 prevented NR2F2-loss-induced STAT and AKT activation and reversed EndMT. Serum DKK1 concentrations were elevated in patients with pulmonary arterial hypertension (PAH) and DKK1 was secreted by ECs in response to in vitro loss of either BMPR2 or CAV1, which are genetic defects associated with the development of PAH. In human primary ECs, NR2F2 suppressed DKK1, whereas its loss conversely induced DKK1 and disrupted endothelial homeostasis, promoting phenotypic abnormalities associated with pathologic vascular remodeling. Activating NR2F2 or blocking DKK1 may be useful therapeutic targets for treating chronic vascular diseases associated with EC dysfunction.NEW & NOTEWORTHY NR2F2 loss in the endothelial lining of blood vessels is associated with cardiovascular disease. Here, NR2F2-silenced human endothelial cells were inflammatory, proliferative, hypermigratory, and apoptosis-resistant with increased oxidant stress and endothelial-to-mesenchymal transition. DKK1 was induced in NR2F2-silenced endothelial cells, while co-silencing NR2F2 and DKK1 prevented NR2F2-loss-associated abnormalities in endothelial signaling and phenotype. Activating NR2F2 or blocking DKK1 may be useful therapeutic targets for treating vascular diseases associated with endothelial dysfunction.

COUP-TFII plays a role in cAMP-induced Schwann cell differentiation and in vitro myelination by up-regulating Krox20.

Schwann cells (SCs) are known to produce myelin for saltatory nerve conduction in the peripheral nervous system (PNS). Schwann cell differentiation and myelination processes are controlled by several transcription factors including Sox10, Oct6/Pou3f1, and Krox20/Egr2. Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII/NR2F2) is an orphan receptor that plays a role in the development and differentiation. However, the role of COUP-TFII in the transcriptional regulatory network of SC differentiation has not been fully identified yet. Thus, the objective of this study was to investigate the role and molecular hierarchy of COUP-TFII during cAMP-induced SC differentiation. Our results showed that dibutyryl-cAMP (db-cAMP) increased expression levels of COUP-TFII along with the expressions of Oct6, Krox20, and myelin-related genes known to be related to SC differentiation. Our mechanistic studies showed that COUP-TFII acted downstream of Hsp90/ErbB2/Gab1/ERK-AKT pathway during db-cAMP-induced SC differentiation. In addition, we found that COUP-TFII induced Krox20 expression by directly binding to Krox20-MSE8 as revealed by chromatin immunoprecipitation assay and promoter activity assay. In line with this, the expression of COUP-TFII was increased before up-regulation of Oct6, Krox20, and myelin-related genes in the sciatic nerves during early postnatal myelination period. Finally, COUP-TFII knockdown by COUP-TFII siRNA or via AAV-COUP-TFII shRNA in SCs inhibited db-cAMP-induced SC differentiation and in vitro myelination of sensory axons, respectively. Taken together, these findings indicate that COUP-TFII might be involved in postnatal myelination through induction of Krox20 in SCs. Our results present a new insight into the transcriptional regulatory mechanism in SC differentiation and myelination.

Long non-coding RNA NR2F2-AS1 regulates human osteosarcoma growth and metastasis through miR-425-5p-mediated HMGB2.

BACKGROUND: Multiple studies have revealed that long non-coding RNA (lncRNA) NR2F2-AS1 plays a role in affecting cancer cell proliferation and metastasis. Here, both in vitro and in vivo experiments were performed for investigating the function and mechanism of NR2F2-AS1 in human osteosarcoma (OS). METHODS: The NR2F2-AS1 level in human OS tissues and adjacent non-tumor tissues was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The NR2F2-AS1 overexpression model was constructed in OS cells, then cell proliferation, invasion, and apoptosis were monitored. The OS xenograft model was established in nude mice using NR2F2-AS1-overexpressed OS cells. The downstream target genes of NR2F2-AS1 were predicted. qRT-PCR and Western blot were implemented to validate the profiles of miR-425-5p and HMGB2. The targeting link between NR2F2-AS1 and miR-425-5p, miR-425-5p and HMGB2 was further probed by dual-luciferase reporter experiment. RESULTS: In comparison to adjacent non-tumor tissues, OS tissues showed upregulated NR2F2-AS1 expression. Higher NR2F2-AS1 level was predominantly correlated with worse clinical stages. In vivo and in vitro tests corroborated that NR2F2-AS1 overexpression spurred OS cell proliferation, growth, invasion, and choked apoptosis. Mechanistically, NR2F2-AS1 hampered miR-425-5p expression as its competitive endogenous RNA (ceRNA). Thus, NR2F2-AS1 facilitated the HMGB2 expression. However, miR-425-5p inhibited HMGB2 expression by targeting the latter. CONCLUSION: NR2F2-AS1 expedited the evolution of OS by elevating HMGB2 levels through sponging miR-425-5p. The NR2F2-AS1/miR-425-5p/HMGB2 regulatory axis is a promising target in treating human OS.

NR2F2 Regulates Cell Proliferation and Immunomodulation in Whartons' Jelly Stem Cells.

(1) Background: Wharton's Jelly stem cells (WJ-MSCs) are multipotent mesenchymal stem cells that can proliferate rapidly and have low immunogenicity. Therefore, WJ-MSCs have gained considerable attention in the fields of immunomodulation and disease treatment and have entered clinical trials for the treatment of various diseases. Therefore, it is crucial to study the underlying mechanisms of WJ-MSCs proliferation, immune regulation, and disease treatment. Nuclear Receptor Subfamily 2 Group F Member 2 (NR2F2) is a transcription factor that is involved in the regulation of many different genes. However, it remains unknown how NR2F2 regulates stem cell identity in WJ-MSCs. (2) Methods: We used RNAi technology to knock down NR2F2 in WJ-MSCs, and studied the regulatory role of NR2F2 in WJ-MSCs by MTT, flow cytometry, RNA-seq, and other methods. We also utilized a co-culture system in which NR2F2-depleted WJ-MSCs with MH7A and HCT116/HepG2 were used to investigate the role of NR2F2 in immunomodulation and the inhibition of cancer cell growth. (3) Results: NR2F2 knockdown resulted in decreased expressions of Cyclin D1 and CDK4, slower cell proliferation, and increased expressions of IL6 and IL8. Furthermore, Cyclin D1, CDK4, and inflammatory factors were increased in human rheumatoid fibroblast-like synoviocyte line MH7A if co-cultured with NR2F2 depleted WJ-MSCs. In addition, we observed increased p53, decreased BCL-2, and increased cell apoptosis in liver cancer cell line HepG2 if co-cultured with NR2F2-depleted WJ-MSCs. (4) Conclusions: NR2F2 not only plays an important role in the cell cycle and immune regulation of WJ-MSCs but also has potential effects on the WJ-MSCs treatment of related diseases.

Long non-coding RNA NR2F2-AS1: its expanding oncogenic roles in tumor progression.

Long non-coding RNA (LncRNA) is a new type of non-coding RNA whose transcription is more than 200 nucleotides in length and can be up to 100 kb. The crucial regulatory function of lncRNAs in different cellular processes is now notable in many human diseases, especially in different steps of tumorigenesis, making them clinically significant. This research tried to collect all evidence obtained so far regarding Nuclear Receptor subfamily 2 group F member 2 Antisense RNA 1 (NR2F2-AS1) to explore its role in carcinogenesis and molecular mechanism in several cancers. Collecting evidence value an oncogenic role for NR2F2-AS1, whose dysregulation changes the status for cancerous cells to gain the supremacy toward cellular proliferation, dissemination, and ultimately migration. The NR2F2-AS1 acts as competitive endogenous RNA (ceRNA) and contains several microRNA response elements (MREs) for different microRNAs involved in various pathways such as PI3K/AKT, Wnt/ß-catenin, and TGF-ß. This clinically makes NR2F2-AS1 a remarkable lncRNA which contributes to cancer progression and invasion and perhaps could be a candidate as a prognostic marker or even a therapeutic target.

Isoforms of the orphan nuclear receptor COUP­TFII differentially modulate pancreatic cancer progression.

The expression of the nuclear receptor transcription factor (TF) COUP­TFII is broadly associated with cell differentiation and cancer development, including of pancreatic ductal adenocarcinoma (PDAC), a devastating disease with one of the poorest prognoses among cancers worldwide. Recent studies have started to investigate the pathological and physiological roles of a novel COUP­TFII isoform (COUP­TFII_V2) that lacks the DNA­binding domain. As the role of the canonical COUP­TFII in PDAC was previously demonstrated, the present study evaluated whether COUP­TFII_V2 may have a functional role in PDAC. It was demonstrated that COUP­TFII_V2 naturally occurs in PDAC cells and in primary samples, where its expression is consistent with shorter overall survival and peripheral invasion. Of note, COUP­TFII_V2, exhibiting nuclear and cytosolic expression, is linked to epithelial to mesenchymal transition (EMT) and cancer progression, as confirmed by nude mouse experiments. The present results demonstrated that COUP­TFII_V2 distinctively regulates the EMT of PDAC and, similarly to its sibling, it is associated with tumor aggressiveness. The two isoforms have both overlapping and exclusive functions that cooperate with cancer growth and dissemination. By studying how PDAC cells switch from one isoform to the other, novel insight into cancer biology was gained, indicating that this receptor may serve as a novel possible target for PDAC management.

LncRNA NR2F2-AS1 functions as a tumor suppressor in gastric cancer through targeting miR-320b/PDCD4 pathway.

Gastric cancer is among the most frequently occurring gastrointestinal malignancies with a high mortality rate worldwide. Long non-coding RNAs (lncRNAs) are defined as core regulators in the occurrence and progression of multiple cancers, including gastric carcinoma. Mounting evidence has indicated that NR2F2-AS1 can inhibit several malignant tumors. However, the function and potential mechanism of NR2F2-AS1 remain unclear. In the current study, we found that NR2F2-AS1 was weakly expressed in gastric cancer cells in comparison with normal cells. The study has further disclosed that ectopic of NR2F2-AS1 repressed cell proliferation, migration, invasion and EMT whereas it promoted cell apoptosis in gastric carcinoma. Subsequently, our results confirmed that miR-320b was negatively regulated and that suppression of miR-320b alleviated the malignant behaviors of GC cells. More importantly, PDCD4 was a target of miR-320b. Mechanistically, NR2F2-AS1 modulated the expression level of PDCD4 by sponging miR-320b. Finally, rescue assays demonstrated that NR2F2-AS1 down-regulated PDCD4 expression to restrain the development of gastric cancer by competitively binding to miR-320b. On the whole, our study revealed the role of NR2F2-AS1/miR-320b/PDCD4 regulatory network in gastric cancer, suggesting NR2F2-AS1 may represent a novel therapeutic target for patients with gastric carcinoma.

lncRNA NR2F2-AS1 inhibits the methylation of miR-494 to regulate oral squamous cell carcinoma cell proliferation.

OBJECTIVE: This study aimed to investigate the role of lncRNA NR2F2-AS1 in oral squamous cell carcinoma cells (OSCC). MATERIALS AND METHODS: The TCGA datasets were used to explore the differential expression of NR2F2-AS1 in OSCC. To further explore the potential interaction between NR2F2-AS1 and miR-494, SCC090 cells were transfected with the NR2F2-AS1 expression vector, NR2F2-AS1 siRNA, and a miR-494 mimic. The effect of NR2F2-AS1 on miR-494 methylation was evaluated by performing methylation-specific PCR (MSP). Cell Counting Kit-8 (CCK-8) assay was used to assess the effects of NR2F2-AS1 silencing and miR-494 and NR2F2-AS1 overexpression on OSCC cell proliferation. RESULTS: NR2F2-AS1 expression was downregulated in OSCC and positively correlated with miR-494 expression. In OSCC cells, NR2F2-AS1 overexpression upregulated miR-494 level, while NR2F2-AS1 silencing decreased miR-494 expression. MSP results showed that NR2F2-AS1 overexpression decreased miR-494 methylation while NR2F2-AS1 silencing increased miR-494 methylation. In addition, NR2F2-AS1 silencing increased OSCC cell proliferation rate while overexpression of miR-494 and NR2F2-AS1 decreased OSCC cell proliferation. Furthermore, miR-494 overexpression attenuated the effects of NR2F2-AS1 silencing on cell proliferation. CONCLUSION: NR2F2-AS1 may inhibit miR-494 methylation to regulate cell proliferation in OSCC. AVAILABILITY OF DATA AND MATERIALS: The analyzed data sets generated during the study are available from the corresponding author upon reasonable request.

Abnormal hsa_circ_0003948 expression affects chronic periodontitis development by regulating miR-144-3p/NR2F2/PTEN signaling.

BACKGROUND AND OBJECTIVE: This study aimed to investigate the correlation between chronic periodontitis (CP) and abnormal circular RNA (circRNA) expression and to identify the role of hsa_circ_0003948 in the progression of CP. METHODS: Next-generation sequencing was utilized to investigate abnormal expression of circRNA in gingival tissues from CP patients and healthy control subjects. Bioinformatics and luciferase reporting analyses were used to clarify the interactive relationship among circRNA, miRNA, and mRNA. Periodontal ligament cells (PDLCs) were employed to analyze proliferation and apoptosis after lipopolysaccharide (LPS) treatment using the cell counting kit 8 (CCK8) assay and flow cytometry detection. RESULTS: High-throughput sequencing and RT-qPCR analyses confirmed that hsa_circ_0003948 expression decreased dramatically in gingival samples of CP patients. Overexpression of hsa_circ_0003948 alleviated LPS-induced PDLC injury by regulating NR2F2/PTEN signaling. The miR-144-3p and NR2F2 were determined to be hsa_circ_0003948 downstream targets. NR2F2 downregulation or miR-144-3p overexpression reversed the protective effect of hsa_circ_0003948 in PDLCs after treatment with LPS. Upregulation of NR2F2 reversed the inhibitory effect of miR-144-3p on surviving PDLCs after LPS treatment. CONCLUSION: Overexpression of hsa_circ_0003948 exerts a protective effect in CP via miR-144-3p/NR2F2/PTEN signaling regulation.

Exome sequencing of fetuses with congenital diaphragmatic hernia supports a causal role for NR2F2, PTPN11, and WT1 variants.

BACKGROUND: To identify genes associated with congenital diaphragmatic hernia (CDH) to help understand the etiology and inform prognosis. METHODS: We performed exome sequencing on fetuses with CDH and their parents to identify rare genetic variants likely to mediate risk. We reviewed prenatal characteristics and neonatal outcomes. RESULTS: Data were generated for 22 parent-offspring trios. Six Likely Damaging (LD) variants were identified in five families (23 %). Three LD variants were in genes that contain variants in other CDH cohorts (NR2F2, PTPN11, WT1), while three were in genes that do not (CTR9, HDAC6, TP53). Integrating these data bolsters the evidence of association of NR2F2, PTPN11, and WT1 with CDH in humans. Of the five fetuses with a genetic diagnosis, one was terminated, two underwent perinatal demise, while two survived until repair. CONCLUSIONS: Exome sequencing expands the diagnostic yield of genetic testing in CDH. Correlating CDH patients' exomes with clinical outcomes may enable personalized counseling and therapies.

Identification of novel genes and pathways regulated by the orphan nuclear receptor COUP-TFII in mouse MA-10 Leydig cells†.

In males, Leydig cells are the main producers of testosterone and insulin-like 3 (INSL3), two hormones essential for sex differentiation and reproductive functions. Chicken ovalbumin upstream promoter-transcription factors I (COUP-TFI/NR2F1) and COUP-TFII (NR2F2) belong to the steroid/thyroid hormone nuclear receptor superfamily of transcription factors. In the testis, COUP-TFII is expressed and plays a role in the differentiation of cells committed to give rise to fully functional steroidogenic adult Leydig cells. Steroid production has also been shown to be diminished in COUP-TFII-depleted Leydig cells, indicating an important functional role in steroidogenesis. Until now, only a handful of target genes have been identified for COUP-TFII in Leydig cells. To provide new information into the mechanism of action of COUP-TFII in Leydig cells, we performed microarray analyses of COUP-TFII-depleted MA-10 Leydig cells. We identified 262 differentially expressed genes in COUP-TFII-depleted MA-10 cells. Many of the differentially expressed genes are known to be involved in lipid biosynthesis, lipid metabolism, male gonad development, and steroidogenesis. We validated the microarray data for a subset of the modulated genes by RT-qPCR. Downregulated genes included hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1 (Hsd3b1), cytochrome P450, family 11, subfamily a, polypeptide 1 (Cyp11a1), prolactin receptor (Prlr), nuclear receptor subfamily 0, group B, member 2 (Shp/Nr0b2), ferredoxin 1 (Fdx1), scavenger receptor class B, member 1 (Scarb1), inhibin alpha (Inha), and glutathione S-transferase, alpha 3 (Gsta3). Finally, analysis of the Gsta3 and Inha gene promoters showed that at least two of the downregulated genes are potentially new direct targets for COUP-TFII. These data provide new evidence that further strengthens the important nature of COUP-TFII in steroidogenesis, androgen homeostasis, cellular defense, and differentiation in mouse Leydig cells.

Decidual NR2F2-Expressing CD4+ T Cells Promote TH2 Transcriptional Program During Early Pregnancy.

A unique immunotolerant microenvironment with Th2 bias in the decidua provides an essential security for successful pregnancy. The disorganized maternal-fetal immune tolerance contributes to more than 50% of unexplained recurrent spontaneous abortion (RSA). How the Th2 bias is developed at the maternal-fetal interface remains undefined. NR2F2, a member of steroid/thyroid nuclear receptor superfamily, is endowed with diverse importance in cell-fate specification, organogenesis, angiogenesis, and metabolism. Here, we showed that NR2F2 was absolutely highly expressed in decidual CD4+T(dCD4+T) cells, but not in peripheral circulating CD4+T cells during early pregnancy. Decidual NR2F2-expressing CD4+T cells dominantly produced Th2 cytokines. In unexplained RSA patients, NR2F2 expression in dCD4+T cells was significantly decreased, accompanied with disordered phenotype of dCD4+T cells. Furthermore, overexpression of NR2F2 promoted the Th2 differentiation of naive CD4+T cells. Immunoprecipitation experiment confirmed the binding relationship between GATA-3 and NR2F2, which implied GATA-3 may be an important interactive element involved in the immunoregulatory process of NR2F2. This study is the first to reveal a previously unappreciated role for NR2F2-mediated dCD4+T cells in maternal-fetal immune tolerance and maintenance of normal pregnancy, in the hope of providing a potential biomarker for prediction and prevention of clinical unexplained RSA.

The miR-106b/NR2F2-AS1/PLEKHO2 Axis Regulates Migration and Invasion of Colorectal Cancer through the MAPK Pathway.

Increasing numbers of miRNAs have been observed as oncogenes or tumor suppressors in colorectal cancer (CRC). It was recently reported that hsa-miR-106b-5p (miR-106b) promoted CRC cell migration and invasion. However, there were also studies showing contradictory results. Therefore, in the present study, we further explore the role of miR-106b and its downstream networks in the carcinogenesis of CRC. We observed that the expression of miR-106b is significantly increased in Pan-Cancer and CRC tissues compared with normal tissues from The Cancer Genome Atlas (TCGA) database. Furthermore, we used Transwell, Cell Counting Kit-8, and colony formation assays to clarify that miR-106b promotes the migratory, invasive, and proliferative abilities of CRC cells. For the first time, we systematically screened the target mRNAs and lncRNAs of miR-106b using TCGA database and the bioinformatics algorithms. Dual-luciferase reporter assay confirmed that NR2F2-AS1 and PLEKHO2 are the direct targets of miR-106b. Furthermore, NR2F2-AS1 acts as a competing endogenous RNA (ceRNA) to regulate PLEKHO2 expression by sponging miR-106b. The results of Gene set enrichment analysis (GSEA) and Western blot indicated that they play important roles in CRC progression by regulating MAPK pathway. Thus, miR-106b/NR2F2-AS1/PLEKHO2/MAPK signaling axis may suggest the potential usage in CRC treatment.

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.

Persistent COUP-TFII expression underlies the myopathy and impaired muscle regeneration observed in resistance to thyroid hormone-alpha.

Thyroid hormone signaling plays an essential role in muscle development and function, in the maintenance of muscle mass, and in regeneration after injury, via activation of thyroid nuclear receptor alpha (THRA). A mouse model of resistance to thyroid hormone carrying a frame-shift mutation in the THRA gene (THRA-PV) is associated with accelerated skeletal muscle loss with aging and impaired regeneration after injury. The expression of nuclear orphan receptor chicken ovalbumin upstream promoter-factor II (COUP-TFII, or Nr2f2) persists during myogenic differentiation in THRA-PV myoblasts and skeletal muscle of aged THRA-PV mice and it is known to negatively regulate myogenesis. Here, we report that in murine myoblasts COUP-TFII interacts with THRA and modulates THRA binding to thyroid response elements (TREs). Silencing of COUP-TFII expression restores in vitro myogenic potential of THRA-PV myoblasts and shifts the mRNA expression profile closer to WT myoblasts. Moreover, COUP-TFII silencing reverses the transcriptomic profile of THRA-PV myoblasts and results in reactivation of pathways involved in muscle function and extracellular matrix remodeling/deposition. These findings indicate that the persistent COUP-TFII expression in THRA-PV mice is responsible for the abnormal muscle phenotype. In conclusion, COUP-TFII and THRA cooperate during post-natal myogenesis, and COUP-TFII is critical for the accelerated skeletal muscle loss with aging and impaired muscle regeneration after injury in THRA-PV mice.

Nonlinear relationship between chromatin accessibility and estradiol-regulated gene expression.

Chromatin accessibility is central to basal and inducible gene expression. Through ATAC-seq experiments in estrogen receptor-positive (ER+) breast cancer cell line MCF-7 and integration with multi-omics data, we found estradiol (E2) induced chromatin accessibility changes in a small number of breast cancer-relevant E2-regulated genes. As expected, open chromatin regions associated with E2-inducible gene expression showed enrichment of estrogen response element (ERE) and those associated with E2-repressible gene expression were enriched for ERE, PBX1, and PBX3. While a significant number of open chromatin regions showed pioneer factor FOXA1 occupancy in the absence of E2, E2-treatment further enhanced FOXA1 occupancy suggesting that ER-E2 enhances chromatin occupancy of FOXA1 to a subset of E2-regulated genes. Surprisingly, promoters of 80% and enhancers of 60% of E2-inducible genes displayed closed chromatin configuration both in the absence and presence of E2. Integration of ATAC-seq data with ERα ChIP-seq data revealed that ~40% ERα binding sites in the genome are found in chromatin regions that are not accessible as per ATAC-seq. Such ERα binding regions were enriched for binding sites of multiple nuclear receptors including ER, ESRRB, ERRγ, COUP-TFII (NR2F2), RARα, EAR2 as well as traditional pioneer factors FOXA1 and GATA3. Similar data were also obtained when ERα ChIP-seq data were integrated with MNase-seq and DNase-seq data sets. In summation, our results reveal complex mechanisms of ER-E2 interaction with nucleosomes. Notably, "closed chromatin" configuration as defined by ATAC-seq or by other techniques is not necessarily associated with lack of gene expression and technical limitations may preclude ATAC-seq to demonstrate accessibility of chromatin regions that are bound by ERα.