Endothelial NLRP3 inflammasome regulation in atherosclerosis

AIM

The activation of Nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in endothelial cells (ECs) contributes to vascular inflammation in atherosclerosis. Considering the high glycolytic rate of ECs, we delineated whether and how glycolysis determines endothelial NLRP3 inflammasome activation in atherosclerosis.

METHODS AND RESULTS

Our results demonstrated a significant upregulation of 6-Phosphofructo-2-Kinase/Fructose-2,6-Biphosphatase 3 (PFKFB3), a key regulator of glycolysis, in human and mouse atherosclerotic endothelium, which positively correlated with NLRP3 levels. Atherosclerotic stimuli upregulated endothelial PFKFB3 expression via sterol regulatory element binding protein 2 (SREBP2) transactivation. EC-selective haplodeficiency of Pfkfb3 in Apoe-/- mice resulted in reduced endothelial NLRP3 inflammasome activation and attenuation of atherogenesis. Mechanistic investigations revealed that PFKFB3-driven glycolysis increased the NADH content and induced oligomerization of C-terminal binding protein 1 (CtBP1), an NADH-sensitive transcriptional co-repressor. The monomer form, but not the oligomer form, of CtBP1 was found to associate with the transcriptional repressor Forkhead box P1 (FOXP1) and acted as a transrepressor of inflammasome components, including NLRP3, caspase-1, and interleukin-1β (IL-1β). Interfering with NADH-induced CtBP1 oligomerization restored its binding to FOXP1 and inhibited the glycolysis-dependent upregulation of NLRP3, Caspase-1, and IL-1β. Additionally, EC-specific overexpression of NADH-insensitive CtBP1 alleviates atherosclerosis.

CONCLUSIONS

Our findings highlight the existence of a glycolysis-dependent NADH/CtBP/FOXP1-transrepression pathway that regulates endothelial NLRP3 inflammasome activation in atherogenesis. This pathway represents a potential target for selective PFKFB3 inhibitors or strategies aimed at disrupting CtBP1 oligomerization to modulate atherosclerosis.

An integrated analysis of the anticarcinogenic role of forkhead box protein 1 in oesophageal squamous cell carcinoma

Forkhead box protein 1 (FOXP1) serves as a tumour promoter or suppressor depending on different cancers, but its effect in oesophageal squamous cell carcinoma has not been fully elucidated. This study investigated the role of FOXP1 in oesophageal squamous cell carcinoma through bioinformatics analysis and experimental verification. We determined through public databases that FOXP1 expresses low in oesophageal squamous cell carcinoma compared with normal tissues, while high expression of FOXP1 indicates a better prognosis. We identified potential target genes regulated by FOXP1, and explored the potential biological processes and signalling pathways involved in FOXP1 in oesophageal squamous cell carcinoma through GO and KEGG enrichment, gene co-expression analysis, and protein interaction network construction. We also analysed the correlation between FOXP1 and tumour immune infiltration levels. We further validated the inhibitory effect of FOXP1 on the proliferation of oesophageal squamous cell carcinoma cells through CCK-8, colony formation and subcutaneous tumour formation assays. This study revealed the anticarcinogenic effect of FOXP1 in oesophageal squamous cell carcinoma, which may serve as a novel biological target for the treatment of tumour.

FoxP1 Represses MEF2A in Striated Muscle

Myocyte enhancer factor 2 (MEF2) proteins are involved in multiple developmental, physiological, and pathological processes in vertebrates. Protein-protein interactions underlie the plethora of biological processes impacted by MEF2A, necessitating a detailed characterization of the MEF2A interactome. A nanobody based affinity-purification/mass spectrometry strategy was employed to achieve this goal. Specifically, the MEF2A protein complexes were captured from myogenic lysates using a GFP-tagged MEF2A protein immobilized with a GBP-nanobody followed by LC-MS/MS proteomic analysis to identify MEF2A interactors. After bioinformatic analysis, we further characterized the interaction of MEF2A with a transcriptional repressor, FOXP1. FOXP1 coprecipitated with MEF2A in proliferating myogenic cells which diminished upon differentiation (myotube formation). Ectopic expression of FOXP1 inhibited MEF2A driven myogenic reporter genes (derived from the creatine kinase muscle and myogenin genes) and delayed induction of endogenous myogenin during differentiation. Conversely, FOXP1 depletion enhanced MEF2A transactivation properties and myogenin expression. The FoxP1:MEF2A interaction is also preserved in cardiomyocytes and FoxP1 depletion enhanced cardiomyocyte hypertrophy. FOXP1 prevented MEF2A phosphorylation and activation by the p38MAPK pathway. Overall, these data implicate FOXP1 in restricting MEF2A function in order to avoid premature differentiation in myogenic progenitors and also to possibly prevent re-activation of embryonic gene expression in cardiomyocyte hypertrophy.

FOXP1 Haploinsufficiency Contributes to the Development of Congenital Diaphragmatic Hernia

FOXP1 encodes a transcription factor involved in tissue regulation and cell-type-specific functions. Haploinsufficiency of FOXP1 is associated with a neurodevelopmental disorder: autosomal dominant mental retardation with language impairment with or without autistic features. More recently, heterozygous FOXP1 variants have also been shown to cause a variety of structural birth defects including central nervous system (CNS) anomalies, congenital heart defects, congenital anomalies of the kidney and urinary tract, cryptorchidism, and hypospadias. In this report, we present a previously unpublished case of an individual with congenital diaphragmatic hernia (CDH) who carries an approximately 3.8 Mb deletion. Based on this deletion, and deletions previously reported in two other individuals with CDH, we define a CDH critical region on chromosome 3p13 that includes FOXP1 and four other protein-coding genes. We also provide detailed clinical descriptions of two previously reported individuals with CDH who carry de novo, pathogenic variants in FOXP1 that are predicted to trigger nonsense-mediated mRNA decay. A subset of individuals with putatively deleterious FOXP4 variants has also been shown to develop CDH. Since FOXP proteins function as homo- or heterodimers and the homologs of FOXP1 and FOXP4 are expressed at the same time points in the embryonic mouse diaphragm, they may function together as a dimer, or in parallel as homodimers, to regulate gene expression during diaphragm development. Not all individuals with heterozygous, loss-of-function changes in FOXP1 develop CDH. Hence, we conclude that FOXP1 acts as a susceptibility factor that contributes to the development of CDH in conjunction with other genetic, epigenetic, environmental, and/or stochastic factors.

Identification of a Novel FOXP1 Variant in a Patient with Hypotonia, Intellectual Disability, and Severe Speech Impairment

The FOXP subfamily includes four different transcription factors: FOXP1, FOXP2, FOXP3, and FOXP4, all with important roles in regulating gene expression from early development through adulthood. Haploinsufficiency of FOXP1, due to deleterious variants (point mutations, copy number variants) disrupting the gene, leads to an emerging disorder known as "FOXP1 syndrome", mainly characterized by intellectual disability, language impairment, dysmorphic features, and multiple congenital abnormalities with or without autistic features in some affected individuals (MIM 613670). Here we describe a 10-year-old female patient, born to unrelated parents, showing hypotonia, intellectual disability, and severe language delay. Targeted resequencing analysis allowed us to identify a heterozygous de novo FOXP1 variant c.1030C>T, p.(Gln344Ter) classified as likely pathogenetic according to the American College of Medical Genetics and Genomics guidelines. To the best of our knowledge, our patient is the first to date to report carrying this stop mutation, which is, for this reason, useful for broadening the molecular spectrum of FOXP1 clinically relevant variants. In addition, our results highlight the utility of next-generation sequencing in establishing an etiological basis for heterogeneous conditions such as neurodevelopmental disorders and providing additional insight into the phenotypic features of FOXP1-related syndrome.

HTRA3 transcriptionally inhibited by FOXP1 suppresses tumorigenesis of osteosarcoma via the PTEN/PI3K/AKT pathway

Despite recent advances in understanding the biological behavior of osteosarcoma (OS), OS is still the most common primary bone sarcoma that endangers the health of children and adolescents. High-temperature requirement A (HTRA) protease family plays an important regulatory role in numerous malignancies and acts as a prognostic biomarker. However, the function and underlying mechanisms of the HTRA family in OS development remain unknown. Through analyzing the GSE126209 dataset obtained from different Gene Expression Omnibus (GEO) databases, we found that HTRA3 as a member of the HTRA family was downregulated in OS tissues compared with that in normal tissues. Functional experiments indicated that HTRA3 overexpression suppressed malignant behaviors of OS cells in vitro and tumor growth in vivo. Mechanistically, we found that HTRA3 co-localized with the X-linked inhibitor of apoptosis protein (XIAP) and decreased XIAP stability. Further investigation showed that XIAP knockdown inhibited the degradation of phosphatase and tensin homolog (PTEN) and that HTRA3 caused the blockage of PTEN/phosphoinositide 3-kinase (PI3K)/AKT pathway, characterized as the reverse of cell function caused by HTRA3 overexpression after PTEN inhibitor BpV (HOpic) treatment. Detailed investigations showed that forkhead box protein 1 (FOXP1), an oncogene in OS progression, downregulated HTRA3 expression and inhibited the transcriptional activity of HTRA3, suggesting that HTRA3 was regulated negatively by FOXP1. In conclusion, our study demonstrates that HTRA3 is a repressor involved in OS development via the PTEN/PI3K/AKT pathway under the modulation of transcription factor FOXP1, and it may provide a therapeutic direction for OS patients.

Reanalysis of Chromosomal Microarray Data Using a Smaller Copy Number Variant Call Threshold Identifies Four Cases with Heterozygous Multiexon Deletions of ARID1B, EHMT1, and FOXP1 Genes

Introduction

Chromosomal microarray (CMA) is a highly accurate and established method for detecting copy number variations (CNVs) in clinical genetic testing. CNVs are important etiological factors for disorders such as intellectual disability, developmental delay, and multiple congenital anomalies. Recently developed analytical methods have facilitated the identification of smaller CNVs. Therefore, reanalyzing CMA data using a smaller CNV calling threshold may yield useful information. However, this method was left to the discretion of each institution.

Methods

We reanalyzed the CMA data of 131 patients using a smaller CNV call threshold: 50 kb 50 probes for gain and 25 kb 25 probes for loss. We interpreted the reanalyzed CNVs based on the most recently available information. In the reanalysis, we filtered the data using the Clinical Genome Resource dosage sensitivity gene list as an index to quickly and efficiently check morbid genes.

Results

The number of copy number loss was approximately 20 times greater, and copy number gain was approximately three times greater compared to those in the previous analysis. We detected new likely pathogenic CNVs in four participants: a 236.5 kb loss within ARID1B, a 50.6 kb loss including EHMT1, a 46.5 kb loss including EHMT1, and an 89.1 kb loss within the FOXP1 gene.

Conclusion

The method employed in this study is simple and effective for CMA data reanalysis using a smaller CNV call threshold. Thus, this method is efficient for both ongoing and repeated analyses. This study may stimulate further discussion of reanalysis methodology in clinical laboratories.

Deacetylation of FOXP1 by HDAC7 potentiates self-renewal of mesenchymal stem cells

BACKGROUND

Mesenchymal stem cells (MSCs) are widely used in a variety of tissue regeneration and clinical trials due to their multiple differentiation potency. However, it remains challenging to maintain their replicative capability during in vitro passaging while preventing their premature cellular senescence. Forkhead Box P1 (FOXP1), a FOX family transcription factor, has been revealed to regulate MSC cell fate commitment and self-renewal capacity in our previous study.

METHODS

Mass spectra analysis was performed to identify acetylation sites in FOXP1 protein. Single and double knockout mice of FOXP1 and HDAC7 were generated and analyzed with bone marrow MSCs properties. Gene engineering in human embryonic stem cell (hESC)-derived MSCs was obtained to evaluate the impact of FOXP1 key modification on MSC self-renewal potency.

RESULTS

FOXP1 is deacetylated and potentiated by histone deacetylase 7 (HDAC7) in MSCs. FOXP1 and HDAC7 cooperatively sustain bone marrow MSC self-renewal potency while attenuating their cellular senescence. A mutation within human FOXP1 at acetylation site (T176G) homologous to murine FOXP1 T172G profoundly augmented MSC expansion capacity during early passages.

CONCLUSION

These findings reveal a heretofore unanticipated mechanism by which deacetylation of FOXP1 potentiates self-renewal of MSC and protects them from cellular senescence. Acetylation of FOXP1 residue T172 as a critical modification underlying MSC proliferative capacity. We suggest that in vivo gene editing of FOXP1 may provide a novel avenue for manipulating MSC capability during large-scale expansion in clinical trials.

FOXP1-GINS1 axis promotes DLBCL proliferation and directs doxorubicin resistance

GINS1 is overexpressed in several types of cancers including leukemia and linked to poor outcomes. However, GINS1 remains poorly investigated in DLBCL (diffuse large B-cell lymphoma). This project aimed to explore the expression, functions and regulation of GINS1 in DLBCL. In this study, through analysis of clinical specimens from DLBCL patients, we uncovered that GINS1 was upregulated in DLBCL. By EMSA, ChIP and luciferase reporter assays, it was found that FOXP1 transcriptionally activated GINS1 expression by directly binding to the promoter region of the GINS1 gene. Western blotting and RT-PCR also revealed that GINS1 expression positively correlated with FOXP1 in human DLBCL specimens and cell lines. In an in vivo xenograft lymphoma mouse model, the FOXP1/GINS1 regulatory axis was also validated. Moreover, with CCK8 cell proliferation assays and colony formation assay, elevated GINS1 expression was found to be associated with doxorubicin resistance in lymphoma cells. Our findings showed that the FOXP1-GINS1 axis played a critical role in DLBCL development and doxorubicin resistance, and targeting the FOXP1-GINS1 axis could be a potential therapeutic approach for DLBCL treatment.

Case report: Expanding the phenotype of FOXP1-related intellectual disability syndrome and hyperkinetic movement disorder in differential diagnosis with epileptic seizures

Objective

We aimed to report on previously unappreciated clinical features associated with FOXP1-related intellectual disability (ID) syndrome, a rare neurodevelopmental disorder characterized by global developmental delay, intellectual disability, and language delay, with or without autistic features.

Methods

We performed whole-exome sequencing (WES) to molecularly characterize an individual presenting with ID, epilepsy, autism spectrum disorder, behavioral problems, and facial dysmorphisms as major features.

Results

WES allowed us to identify a previously unreported de novo splice site variant, c.1429-1G>T (NM_032682.6), in the FOXP1 gene (OMIM^*605515) as the causative event underlying the phenotype. Clinical reassessment of the patient and revision of the literature allowed us to refine the phenotype associated with FOXP1 haploinsufficiency, including hyperkinetic movement disorder and flat angiomas as associated features. Interestingly, the patient also has an asymmetric face and choanal atresia and a novel de novo variant of the CHD7 gene.

Conclusion

We suggest that FOXP1-related ID syndrome may also predispose to the development of hyperkinetic movement disorders and flat angiomas. These features could therefore require specific management of this condition.

Cataracts in Havanese: genome wide association study reveals two loci associated with posterior polar cataract

BACKGROUND

Cataract is considered an important health issue in Havanese, and studies indicate a breed predisposition. Possible consequences of cataracts include lens induced uveitis, reduced eyesight, and blindness in severe cases. Reducing the prevalence of cataracts could therefore improve health and welfare significantly. The most frequently diagnosed forms of cataract in Havanese are cortical- and anterior suture line cataract, but cases of posterior polar cataract are also regularly reported. Out of the three, posterior polar- and cortical cataracts are considered the most clinically relevant.

RESULTS

We performed a genome wide association study that included 57 controls and 27 + 23 + 7 cases of cortical-, anterior suture line- and posterior polar cataract, respectively. An association analysis using a mixed linear model, revealed two SNPs on CFA20 (BICF2S23632983, p = 7.2e-09) and CFA21 (BICF2G630640490, p = 3.3e-09), that were significantly associated with posterior polar cataract, both of which are linked to relevant candidate genes. The results suggest that the two variants are linked to alleles with large effects on posterior polar cataract formation, possibly in a dominant fashion, and identifies regions that should be subject to further sequencing. Promising regions on CFA4 and CF30 were also identified in the association analysis of cortical cataract. The top SNPs on each chromosome, chr4_12164500 (p = 4.3e-06) and chr30_28836339 (p = 5.6e-06), are located within, or in immediate proximity to, potential cataract candidate genes. The study shows that age at examination is strongly associated with sensitivity of cataract screening. Havanese in Norway are on average 3.4 years old when eye examinations are performed: an age where most dogs that are genetically at risk have not yet developed clinically observable changes. Increasing the average age of breeding animals could increase accuracy of selection, leading to improved health.

CONCLUSIONS

The study identified two loci, on CFA20 and CFA21, that were significantly associated with posterior polar cataract in Havanese. SNPs that showed putative association with cortical cataracts, were observed on CFA4 and CFA30. All the top SNPs are located in close proximity to cataract candidate genes. The study also show that sensitivity of cataract screening is highly dependent on age at examination.

A Patient with Corticobasal Syndrome and Progressive Non-Fluent Aphasia (CBS-PNFA), with Variants in ATP7B, SETX, SORL1, and FOXP1 Genes

Our aim was to analyze the phenotypic-genetic correlations in a patient diagnosed with early onset corticobasal syndrome with progressive non-fluent aphasia (CBS-PNFA), characterized by predominant apraxia of speech, accompanied by prominent right-sided upper-limb limb-kinetic apraxia, alien limb phenomenon, synkinesis, myoclonus, mild cortical sensory loss, and right-sided hemispatial neglect. Whole-exome sequencing (WES) identified rare single heterozygous variants in ATP7B (c.3207C>A), SORL1 (c.352G>A), SETX (c.2385_2387delAAA), and FOXP1 (c.1762G>A) genes. The functional analysis revealed that the deletion in the SETX gene changed the splicing pattern, which was accompanied by lower SETX mRNA levels in the patient's fibroblasts, suggesting loss-of-function as the underlying mechanism. In addition, the patient's fibroblasts demonstrated altered mitochondrial architecture with decreased connectivity, compared to the control individuals. This is the first association of the CBS-PNFA phenotype with the most common ATP7B pathogenic variant p.H1069Q, previously linked to Wilson's disease, and early onset Parkinson's disease. This study expands the complex clinical spectrum related to variants in well-known disease genes, such as ATP7B, SORL1, SETX, and FOXP1, corroborating the hypothesis of oligogenic inheritance. To date, the FOXP1 gene has been linked exclusively to neurodevelopmental speech disorders, while our study highlights its possible relevance for adult-onset progressive apraxia of speech, which guarantees further study.

LncRNA ROR promotes NLRP3-mediated cardiomyocyte pyroptosis by upregulating FOXP1 via interactions with PTBP1

OBJECTIVE

The purpose of this design was to explore the specific role and related mechanism of long noncoding RNA (lncRNA) regulators of reprogramming (ROR) in viral myocarditis (VMC).

METHODS

AC16 cells were infected with coxsackievirus B3 (CVB3) to establish a VMC cell model in vitro. The release of interleukin (IL)-1β and IL-18 was evaluated by enzyme-linked immunosorbent assay (ELISA). Gene expression was calculated using quantitative real-time (qRT)-PCR. Cell pyroptosis was determined by flow cytometry and Western blot assays. Cell counting Kit-8 (CCK-8) detected cell viability. The molecular associations were verified by employing RNA immunoprecipitation (RIP), RNA pulldown and chromatin immunoprecipitation (ChIP) assays.

RESULTS

The lncRNA ROR was more highly expressed in CVB3 virus-infected AC16 cells than in controls. Knockdown of ROR markedly rescued cell viability and reduced the release of IL-1β and IL-18, cell pyroptosis and pyroptotic proteins such as NLRP3, ASC and cleaved caspase 1. Mechanistically, ROR destroyed the mRNA stability of Forkhead Box P Factor 1 (FOXP1) by binding polypyrimidine tract binding protein 1 (PTBP1). FOXP1 repressed the transcription of NLRP3 by directly interacting with its promoter. Importantly, coinhibition of FOXP1 impeded the protective role of ROR silencing in CVB3-infected AC16 cells.

CONCLUSION

In conclusion, these findings elucidated that ROR knockdown inhibited CVB3-induced cardiomyocyte inflammation and NLRP3-mediated pyroptosis by regulating the PTBP1/FOXP1 axis, implying that ROR might be a new inducer in CVB3-infected VMC.

Forkhead box protein 1 transcriptionally activates sestrin1 to alleviate oxidized low-density lipoprotein-induced inflammation and lipid accumulation in macrophages

Transcription factor forkhead box protein 1 (FOXP1) has been shown cardiovascular protection. We aimed to analyze the role of FOXP1 in oxidized low-density lipoprotein (ox-LDL)-induced macrophages and its possible regulatory effect on sestrin1 (SESN1) expression. After stimulation with ox-LDL, FOXP1 expression in RAW264.7 cells was evaluated with RT-qPCR and Western blotting. Then, FOXP1 was overexpressed, followed by detection of inflammatory mediator levels using ELISA kits and RT-qPCR. Lipid accumulation was detected with oil red O staining. Additionally, the JASPAR database was used to predict the potential genes that could be transcriptionally regulated by FOXP1. ChIP and luciferase reporter assays were used to verify this combination. To further clarify the regulatory effects of FOXP1 on SESN1 in damage of macrophages triggered by ox-LDL, SESN1 was silenced to determine the inflammation and lipid accumulation under the condition of FOXP1 overexpression. Results indicated that ox-LDL stimulation led to a significant decrease in FOXP1 expression. FOXP1 overexpression notably reduced the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6, accompanied by a decreased in phosphorylated NF-κB p65 expression. Besides, FOXP1-upregulation inhibited lipid accumulation and reduced CD36 expression level in RAW264.7 cells upon ox-LDL stimulation. Moreover, results of ChIP and luciferase reporter assays suggested that FOXP1 could transcriptionally regulate SESN1 expression. Further experiments supported that SESN1 silencing restored the inhibitory effects of FOXP1 overexpression on the inflammation and lipid accumulation in RAW264.7 cells exposed to ox-LDL. Collectively, FOXP1 transcriptionally activates SESN1 for the alleviation of ox-LDL-induced inflammation and lipid accumulation in macrophages.

circRNA hsa_circ_104566 Sponged miR-338-3p to Promote Hepatocellular Carcinoma Progression

Circular RNAs (circRNAs) could sponge micro-RNAs (miRNAs) to regulate tumor progression of hepatocellular carcinoma (HCC). Hsa_circ_104566 contributes to papillary thyroid carcinoma progression. However, the tumorigenic mechanism of hsa_circ_104566 on HCC remains enigmatic. The role of hsa_circ_104566 on HCC was therefore evaluated in this study. First, the high expression of hsa_circ_104566 was found in HCC tissues, which was significantly associated with poor prognosis in HCC patients. Second, Hsa_circ_104566 promoted HCC progression by decreasing apoptosis and E-cadherin, while increasing cell viability, proliferation, migration, invasion, and N-cadherin. On the other hand, HCC progression was suppressed by knockdown of hsa_circ_104566. Hsa_circ_104566 could target miR-338-3p, and its expression was negatively correlated with miR-338-3p in HCC patients. Moreover, miR-338-3p suppressed protein expression of Forkhead box protein 1 (FOXP1) and had a negative correlation with FOXP1 in HCC patients. Functional assay further indicated that the promotion of HCC progression by hsa_circ_104566 was reversed by miR-338-3p, and miR-338-3p inhibitor could counteract the effect of hsa_circ_104566 knockdown on the suppression of HCC progression. In vivo assay indicated that hsa_circ_104566 knockdown suppressed HCC tumor growth and metastasis. In conclusion, hsa_circ_104566 sponged miR-338-3p to promote HCC progression, providing a potential therapeutic target for cancer intervention.

FOXP1 and NDRG1 act differentially as downstream effectors of RAD9-mediated prostate cancer cell functions

Metastatic progression is the key feature of prostate cancer primarily responsible for mortality caused by this disease. RAD9 is an oncogene for prostate cancer, and the encoded protein enhances metastasis-related phenotypes. RAD9 is a transcription factor with a limited set of regulated target genes, but the complete list of downstream genes critical for prostate carcinogenesis is unknown. We used microarray gene expression profiling and chromatin immunoprecipitation in parallel to identify genes transcriptionally controlled by RAD9 that contribute to this cancer. We found expression of 44 genes altered in human prostate cancer DU145 cells when RAD9 is knocked down by siRNA, and all of them bind RAD9 at their genomic location. FOXP1 and NDRG1 were down regulated when RAD9 expression was reduced, and we evaluated them further. We demonstrate that reduced RAD9, FOXP1 or NDGR1 expression decreases cell proliferation, rapid migration, anchorage-independent growth, anoikis resistance, and aerobic glycolysis. Ectopic expression of FOXP1 or NDRG1 partially restored aerobic glycolysis to prostate cancer cells with reduced RAD9 abundance, but only FOXP1 significantly complemented the other deficiencies. We thus show, for the first time, that RAD9 regulates FOXP1 and NDRG1 expression, and they function differently as downstream effectors for RAD9-mediated prostate cancer cell activities.

NEAT1 Negatively Regulates Cell Proliferation and Migration of Neuroblastoma Cells by miR-183-5p/FOXP1 Via the ERK/AKT Pathway

Neuroblastoma, a malignant tumor of the sympathetic nervous system, is an aggressive extracranial tumor in childhood. Long noncoding RNAs (lncRNAs) have been discovered to play a key role in the eukaryotic regulatory gene network and be involved in a wide variety of biological processes. We observed that the expression of lncRNA nuclear-enriched abundant transcript-1 (NEAT1) was significantly decreased in human neuroblastoma tissues and cell lines, compared with the normal. We observed cell proliferation, migration, and invasion with Cell Counting Kit-8 assay, colony formation assay, and Transwell assay to investigate the effects of NEAT1, miR-183-5p, or FOXP1 on neuroblastoma cells. And we also used StarBase and luciferase reporter gene assay to predict and confirm the interaction of NEAT1, miR-183-5p, and FOXP1 in neuroblastoma cells. First, overexpression of NEAT1 suppressed cell proliferation and played a key role in cell migration and invasion. In addition, NEAT1 was demonstrated to directly interact with miR-183-5p and exerted its antioncogenic role in neuroblastoma by negatively regulating miR-183-5p expression. miR-183-5p suppressed the expression of FOXP1 and regulated cell proliferation and migration by directly targeting FOXP1 mRNA 3′-untranslated region. Moreover, FOXP1 antagonized the effect of miR-183-5p on the phosphorylation of extracellular-regulated kinase/protein kinase B (ERK/AKT), while FOXP1 siRNA increased the reduced phosphorylation of ERK/AKT caused by miR-183-5p inhibitor in neuroblastoma cells. Taken together, these data showed that NEAT1 negatively regulated cell proliferation and migration of neuroblastoma by the miR-183-5p/FOXP1 axis via suppression of the ERK/AKT pathway. Our findings may provide a new target for the study of pathogenesis and treatment of neuroblastoma.

FOXP1 syndrome: a review of the literature and practice parameters for medical assessment and monitoring

FOXP1 syndrome is a neurodevelopmental disorder caused by mutations or deletions that disrupt the forkhead box protein 1 (FOXP1) gene, which encodes a transcription factor important for the early development of many organ systems, including the brain. Numerous clinical studies have elucidated the role of FOXP1 in neurodevelopment and have characterized a phenotype. FOXP1 syndrome is associated with intellectual disability, language deficits, autism spectrum disorder, hypotonia, and congenital anomalies, including mild dysmorphic features, and brain, cardiac, and urogenital abnormalities. Here, we present a review of human studies summarizing the clinical features of individuals with FOXP1 syndrome and enlist a multidisciplinary group of clinicians (pediatrics, genetics, psychiatry, neurology, cardiology, endocrinology, nephrology, and psychology) to provide recommendations for the assessment of FOXP1 syndrome.

The circACC1/miR-29c-3p/FOXP1 network plays a key role in gastric cancer by regulating cell proliferation

Although substantial progress has been made in early detection and treatment of GC, this disease remains a major burden worldwide. CircRNAs have potential as prognostic and diagnostic biomarkers in tumorigenesis. Therefore, we aimed to clarify the role and mechanism of circACC1 in GC cell proliferation. The expression levels of circACC1, miR-29c-3p and FOXP1 were validated in GC tissue samples and adjacent tissue samples. The impact of circACC1 and miR-29c-3p on overall survival was evaluated in GC specimens. A functional study was performed on MKN-45 and BGC823 cells transfected with different vectors. Cell proliferation was assayed by CCK-8 and colony formation assays. The interactions among circACC1, miR-29c-3p and FOXP1 were tested by RNA immunoprecipitation and luciferase reporter assays. This study demonstrated that circACC1 is upregulated in GC tissues, and its upregulation predicts poorer OS in GC patients. Upregulation of circACC1 promoted GC cell proliferation, as indicated by CCK-8 and colony formation assays. A mechanistic study revealed that the pro-oncogenic effect of circACC1 was mainly caused by binding to miR-29c-3p, thus regulating expression of its downstream target FOXP1. The circACC1/miR-29c-3p/FOXP1 network plays a key role in gastric cancer by regulating cell proliferation.

CircRNA_OTUD7A upregulates FOXP1 expression to facilitate the progression of diffuse large B-cell lymphoma via acting as a sponge of miR-431-5p

BACKGROUND

A growing number of studies have shown that circular RNA (circRNA) is an important regulator molecule in cancer progression, but it has been poorly studied in diffuse large b-cell lymphoma (DLBCL).

OBJECTIVE

This study aimed to explore the role of circ_OTUD7A in DLBCL.

METHODS

Relative expression levels of circ_OTUD7A, microRNA (miR)-431-5p and forkhead box P1 (FOXP1) were determined by quantitative real-time PCR (qRT-PCR). The proliferation of cells was elevated by colony formation assay and MTT assay. Western blot (WB) analysis was employed to measure the protein levels of proliferation marker, epithelial-mesenchymal transition (EMT) markers, cyclin marker, apoptosis markers and FOXP1. Moreover, the apoptosis, cell cycle process, migration and invasion of cells were detected using flow cytometry and transwell assay, respectively. In addition, the interaction between miR-431-5p and circ_OTUD7A or FOXP1 was confirmed by dual-luciferase reporter assay.

RESULTS

Circ_OTUD7A was highly expressed in DLBCL, and its knockdown could inhibit DLBCL cell proliferation and metastasis, while promote cell cycle arrest and apoptosis. Similarly, FOXP1 also was upregulated in DLBCL, and its silencing could restrain the progression of DLBCL cells. Further experiments revealed that circ_OTUD7A could sponge miR-431-5p and miR-431-5p could target FOXP1. MiR-431-5p inhibitor could reverse the suppressive effect of circ_OTUD7A silencing on DLBCL progression, and FOXP1 overexpression also could reverse the inhibitory effect of miR-431-5p mimic on DLBCL progression.

CONCLUSION

Circ_OTUD7A promoted the progression of DLBCL by regulating the miR-431-5p/FOXP1 axis, which suggested that circ_OTUD7A might function as an oncogene in DLBCL.

Single-Cell Analysis of Foxp1-Driven Mechanisms Essential for Striatal Development

The striatum is a critical forebrain structure integrating cognitive, sensory, and motor information from diverse brain regions into meaningful behavioral output. However, the transcriptional mechanisms underlying striatal development at single-cell resolution remain unknown. Using single-cell RNA sequencing (RNA-seq), we examine the cellular diversity of the early postnatal striatum and show that Foxp1, a transcription factor strongly linked to autism and intellectual disability, regulates the cellular composition, neurochemical architecture, and connectivity of the striatum in a cell-type-dependent fashion. We also identify Foxp1-regulated target genes within distinct cell types and connect these molecular changes to functional and behavioral deficits relevant to phenotypes described in patients with FOXP1 loss-of-function mutations. Using this approach, we could also examine the non-cell-autonomous effects produced by disrupting one cell type and the molecular compensation that occurs in other populations. These data reveal the cell-type-specific transcriptional mechanisms regulated by Foxp1 that underlie distinct features of striatal circuitry.

LINC01116 promotes proliferation and migration of endometrial stromal cells by targeting FOXP1 via sponging miR-9-5p in endometriosis

Endometriosis is a common multi-factorial gynaecological disease. Recent studies have revealed that long non-coding RNAs (lncRNAs) are involved in the pathogenesis of endometriosis. In the present study, the expression profiles of lncRNAs in 6 pairs of endometriosis ectopic endometrium (ecEM) and eutopic endometrium (euEM) tissues were analysed by RNA sequencing. From the profiles, LINC01116 was found to be up-regulated in ecEM tissues compared to euEM tissues and was verified by quantitative real-time PCR (qRT-PCR). Then, functional experiments demonstrated that LINC01116 promoted the proliferation and migration of ectopic primary endometrial stromal cells (ESCs), while miR-9-5p exerted the opposite effects. Dual-luciferase reporter assays verified that LINC01116 directly sponged miR-9-5p and relieved the suppression of its target, Forkhead box protein P1 (FOXP1). Rescue experiments further demonstrated that LINC01116 could promote proliferation and migration of ESCs by targeting FOXP1 via sponging miR-9-5p. Overall, our study illuminates that LINC01116 promotes the progression of endometriosis through the miR-9-5p/FOXP1 axis. This finding provides a novel therapeutic target for patients with endometriosis.

miR-375-3p contributes to hypoxia-induced apoptosis by targeting forkhead box P1 (FOXP1) and Bcl2 like protein 2 (Bcl2l2) in rat cardiomyocyte h9c2 cells

miRNAs have been pointed to play critical role in the development of congenital heart disease (CHD). miRNA-375-3p (miR-375-3p) was involved in cardiac dysfunction and cardiogenesis. However, no prior study had established a therapeutic role of miR-375-3p in CHD. We intended to investigate the effect and mechanism of miR-375-3p on apoptosis in hypoxic cardiomyocytes in vitro. Expression of miR-375-3p, forkhead box P1 (FOXP1) and Bcl2 like protein 2 (Bcl2l2) was detected using real-time quantitative PCR and western blot. Apoptosis was measured with MTT assay, flow cytometry and caspase-3 activity assay. The potential target binding between miR-375-3p and FOXP1/Bcl2l2 was predicted on DianaTools, and was validated by luciferase reporter assay and RNA pull-down assay. As a result, miR-375-3p was upregulated and FOXP1/Bcl2l2 was downregulated in maternal serum of women with fetal CHD and hypoxia-induced rat cardiomyocyte h9c2 cells. Hypoxia induced apoptosis rate elevation, caspase-3 activity promotion and viability inhibition in h9c2 cells; overexpression of miR-375-3p promoted, whereas knockdown of miR-375-3p antagonized hypoxia-induced effects in h9c2 cells. In addition, miR-375-3p was validated to negatively regulate FOXP1 and Bcl2l2 expression through target binding, and silencing of FOXP1 and Bcl2l2 could independently abate the anti-apoptosis role of miR-375-3p knockdown in hypoxic h9c2 cells. Collectively, blocking miR-375-3p suppressed hypoxia-evoked apoptosis of cardiomyocytes by targeting and upregulating FOXP1 and Bcl2l2. Our results might suggest maternal serum miR-375-3p as a potential biomarker for prenatal detection of fetal CHD.

Circular RNA Circ_ANKMY2 Regulates Temporal Lobe Epilepsy Progression via the miR-106b-5p/FOXP1 Axis

Temporal lobe epilepsy (TLE) is common intractable epilepsy that affects the patient's lives. The circular RNA circ_ANKMY2 (circ_ANKMY2) has been reported to be abnormally expressed in TLE. Nevertheless, the role and mechanism of circ_ANKMY2 in TLE are unclear. A human neuroblastoma cell line (SK-N-AS) was used for a series of studies. Expression levels of circ_ANKMY2, miR-106b-5p, and Forkhead Box Protein 1 (FOXP1) mRNA in TLE tissues were assessed through quantitative real-time polymerase chain reaction (qRT-PCR). Cell colony formation, proliferation, and apoptosis were determined by cell colony formation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), or flow cytometry assays. The levels of FOXP1 protein, Ki67, B cell lymphoma (Bcl-2), Bcl-2 Associated X (Bax), and Cleaved caspase-3 were evaluated by western blot analysis. The relationship between circ_ANKMY2 or FOXP1 and miR-106b-5p was verified with dual-luciferase reporter assay. We observed that circ_ANKMY2 and FOXP1 expression were reduced while miR-106b-5p expression was increased in TLE tissues. Overexpression of circ_ANKMY2 decreased spontaneous recurrent seizures (SRSs) in rat TLE model and blocked cell colony formation, proliferation, and induced cell apoptosis in SK-N-AS cells. Importantly, circ_ANKMY2 was verified as a sponge for miR-106b-5p. In addition, miR-106b-5p mimics abolished circ_ANKMY2 elevation-mediated effects on colony formation, proliferation, and apoptosis of SK-N-AS cells. Also, FOXP1 served as a target for miR-106b-5p. And FOXP1 silencing overturned the effects of miR-106b-5p inhibitors on the colony formation, proliferation, and apoptosis of SK-N-AS cells. In sum, circ_ANKMY2 modulated TLE advancement via regulation of FOXP1 expression through sponging miR-106b-5p, and circ_ANKMY2 might be an underlying target for the improvement of TLE.

An Autism-Related, Nonsense Foxp1 Mutant Induces Autophagy and Delays Radial Migration of the Cortical Neurons

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that has a strong genetic component. Disruptions of FOXP1, a transcription factor expressed in the developing cerebral cortex, were associated with ASD. FOXP1(R525X) is a de novo heterozygous mutation found in patients with autism and severe mental retardation. To explore the neuronal basis of FOXP1(R525X) in ASD, we created Foxp1(R521X), a mouse homolog of the human variant. Ectopic expression of Foxp1(R521X) led to cytoplasmic aggregates and activated macroautophagy in neuroblastoma N2a cells and the developing neuronal cells. Cortical neurons expressing Foxp1(R521X) exhibited delayed migration and altered dendritic morphology. As a control, mutant Y435X that was expressed diffusively in the cytoplasm did not induce autophagy and migration delay in the cortex. The embryonic cortical cells had a minimal activity of nonsense-mediated mRNA decay (NMD) as assayed by a splicing-dependent NMD reporter. We hypothesize that the developing neuronal cells use autophagy but not NMD as a safeguard mechanism against nonsense mutant aggregates, resulting in impairment of the cortical development. This study suggests a novel mechanism other than heterozygous loss of FOXP1 for the development of ASD and may advance our understanding of the complex relationships between gene mutation and the related psychiatric disorders.

Long noncoding RNA MIR99AHG promotes gastric cancer progression by inducing EMT and inhibiting apoptosis via miR577/FOXP1 axis

Background

Long non-coding RNAs (lncRNAs) play a vital role in the genesis and development of human cancer. LncRNA MIR99AHG has been reported to be upregulated in acute myeloid leukemia (AML); however, its function in gastric cancer (GC) is still not clear. Here we were aiming to screen the prognostic lncRNA candidates and to explore the function of MIR99AHG in GC.

Methods

We have preliminarily screened some candidate lncRNA biomarkers in GC tissues through analyzing microarray datasets. The expression level of MIR99AHG in GC cell lines and tissues was monitored via qPCR. Survival analysis was performed with the patients of our hospital and TCGA database cases. CCK-8 assay, trans-well assay and flow cytometry were performed to determine cell proliferation, invasion, migration and apoptosis. Meanwhile, a target of MIR99AHG was predicted and identified by luciferase reporter gene detection experiments.

Results

MIR99AHG was strongly up-regulated in human GC and contributed to cancer progression. Kaplan–Meier analysis revealed that up-regulating MIR99AHG expression was positively correlated with unfavorable overall survival (P < 0.01) of patients from our hospital and TCGA database. Knockdown of MIR99AHG expression inhibited cell proliferation, invasion, migration and promoted cell apoptosis. Moreover, MIR99AHG worked as an oncogenic gene though competing for endogenous RNA (ceRNA) of miR-577.

Conclusions

Our findings suggested that MIR99AHG contributes to malignant phenotypes of GC and may become a promising therapeutic target.

Epstein-Barr virus-encoded miR-BART11 promotes tumor-associated macrophage-induced epithelial-mesenchymal transition via targeting FOXP1 in gastric cancer

Gastric carcinoma (GC) is an Epstein-Barr virus (EBV)-associated malignancy characterized by early metastasis. Unlike that of cellular micro(mi)RNAs, the role of viral miRNAs in epithelial-mesenchymal transition (EMT) and metastasis in cancers has not been fully investigated. In this study, we elucidated the involvement of miR-BART11, an EBV-encoded viral miRNA, in the EMT and metastasis of GC cells. EBV-miR-BART11 upregulation can lead to downregulation of forkhead box protein P1 (FOXP1) in both tissues and cell lines of gastric carcinoma. Downregulation of FOXP1 might trigger the secretion of interleukin 1β (IL-1β), IL-6, and 1L-10 in cancer cells, resulting in poor survival of GC patients. We found that the observed EMT phenotypes resulted from the EBV-miR-BART11 overexpression-induced FOXP1 downregulation, which impacted the expression of the EMT-transcription factors E-cadherin and snail. We further demonstrated that conditioned medium-derived tumor-associated macrophages (TAMs) promoted phenotypic changes and expression of EMT-related molecules in GC cells. Additionally, EMT changes were significantly promoted in GC cells cultured in conditioned medium from TAMs infected with EBV-miR-BART11-containing lentivirus. On the contrary, GC cells cultured in conditioned medium from TAMs infected with FOXP1-carrying lentivirus showed little or no EMT change. Taken together, our results suggest that EBV-encoded viral miRNA BART11 downregulates the FOXP1 transcription factor, and promotes EMT by directly influencing gastric tumor cells or indirectly affecting the tumor microenvironment, which might, in turn, accelerate cancer invasion and metastasis, thereby affecting the survival and prognosis of patients.

t(3;14)(p14.1;q32)/FOXP1-IGH translocation in thyroid extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)

OBJECTIVES

MALT lymphoma occurs in various organs and has several characteristic genetic aberrations. Thyroid MALT lymphoma has been reported to include t(3;14)(p14.1;q32)/FOXP1-IGH as a specific genetic aberration, but the number of studies is limited.

METHOD AND RESULTS

We examined 86 thyroid lymphoma cases using fluorescence in situ hybridization (FISH) for the detection of t(3;14)/FOXP1-IGH in formalin fixed paraffin-embedded tissue (FFPE). Histopathological diagnoses of the analyzed specimen were as follows: thyroid MALT lymphoma (n = 59), DLBCL (n = 23), follicular lymphoma (n = 4), and benign lesions (n = 14) included Hashimoto's thyroiditis (n = 13) and other (n = 1). Of the 100 analyzed cases, thirty-six (36 %) thyroid lymphoma cases were positive for t(3;14)/FOXP1-IGH. Thirty-three (55.9 %) of the 59 MALT lymphoma cases were positive for t(3;14)/FOXP1-IGH. Three (13.0 %) of the 23 DLBCL cases were positive for t(3;14)/FOXP1-IGH. All 4 follicular lymphomas examined were negative for t(3;14)/FOXP1-IGH. None of the benign cases was positive for t(3;14)/FOXP1-IGH, including Hashimoto's thyroiditis (0/13) and benign tissue (0/1).

CONCLUSIONS

Our study found that t(3;14)/FOXP1-IGH was frequently found in thyroid MALT lymphoma. A detection of t(3;14)/FOXP1-IGH is extremely useful for the differential diagnosis between primary MALT lymphoma of the thyroid and other thyroid disorders.

PRMT5 and FOXP1 expression profile in invasive breast cancer patients undergoing neoadjuvant chemotherapy

Neoadjuvant chemotherapy is the standard treatment for patients with advanced localized breast cancer, but today it has found a good place in the early stages to achieve a negative surgical margin and increase the possibility of breast preservation. Numerous studies have shown that patient survival increases with a complete pathological response in the relationship of some immunological molecules known as immunohistochemistry markers. The aim of this study was to investigate the complete pathological response in the relationship between PRMT5 and FOXP1 expression. In a cross-sectional study of breast cancer patients in stages I to III, who were treated with Neoadjuvant chemotherapy at the Breast Cancer Research Institute during the years 2018 to 2019, were examined. A complete pathological response was obtained in cases where no tumors remained in the breast and axillary tissue after surgery. Immunohistochemical analyzes for FOXP1, PRMT5, and PR and ER biomarkers of the tumor were conducted. Data were analyzed using descriptive and analytical statistics by SPSS v. 21 software. 157 patients with a mean age of 47.5 ±16.2 years were included in the study. Our results revealed that there was no significant difference between the foxp1 Positive and Negative patients, in terms of cancer stage, metastasis, being PR or ER-positive (P&gt;0.05).  While being PRMT5+/- had a significant relationship with FOXP1 expression (p=0.001). In the case of the response to treatment, there was a significant association between a complete response and being foxp1 + (p=0.01). While in other immunohistochemistry markers, no significant association was found (P&gt;0.05). Our study revealed no association of foxp1 and PRMT5 with other biomarkers of breast cancer and clinical progress of the disease. Our study revealed no association of foxp1 and PRMT5 with other biomarkers of breast cancer and clinical progress of the disease.

CRISPR/Cas9-Mediated Foxp1 Silencing Restores Immune Surveillance in an Immunocompetent A20 Lymphoma Model

The interaction of lymphoma cells with their microenvironment has an important role in disease pathogenesis and is being actively pursued therapeutically using immunomodulatory drugs, including immune checkpoint inhibitors. Diffuse large B-cell lymphoma (DLBCL) is an aggressive high-grade disease that remains incurable in ~40% of patients treated with R-CHOP immunochemotherapy. The FOXP1 transcription factor is abundantly expressed in such high-risk DLBCL and we recently identified its regulation of immune response signatures, in particular, its suppression of the cell surface expression of major histocompatibility class II (MHC-II), which has a critical role in antigen presentation to T cells. Using CRISPR/Cas9 genome editing we have depleted Foxp1 expression in the aggressive murine A20 lymphoma cell line. When grown in BALB/c mice, this cell line provides a high-fidelity immunocompetent disseminated lymphoma model that displays many characteristics of human DLBCL. Transient Foxp1-depletion using siRNA, and stable depletion using CRISPR (generated by independently targeting Foxp1 exon six or seven) upregulated cell surface I-Ab (MHC-II) expression without impairing cell viability in vitro. RNA sequencing of Foxp1-depleted A20 clones identified commonly deregulated genes, such as the B-cell marker Cd19, and hallmark DLBCL signatures such as MYC-targets and oxidative phosphorylation. Immunocompetent animals bearing Foxp1-depleted A20 lymphomas showed significantly-improved survival, and 20% did not develop tumors; consistent with modulating immune surveillance, this was not observed in immunodeficient NOD SCIDγ mice. The A20 Foxp1 CRISPR model will help to further characterize the contribution of Foxp1 to lymphoma immune evasion and the potential for Foxp1 targeting to synergize with other immunotherapies.

Down-regulated lncRNA AGAP2-AS1 contributes to pre-eclampsia as a competing endogenous RNA for JDP2 by impairing trophoblastic phenotype

Recently, growing evidence has shown that aberrant long non‐coding RNA (lncRNA) expression in conjunction with an impaired trophoblastic phenotype could implicate the pathological process of pre‐eclampsia (PE). However, only a small portion of lncRNAs has been characterized with regard to the function and molecular mechanisms involved in PE. There are still gaps in the available knowledge; as a result, there are currently only a few applicable treatments for PE in the context of lncRNA. Here, we found that lncRNA AGAP2‐AS1 is abnormally down‐regulated in severe PE placenta tissues. Using human trophoblasts, we established that AGAP2‐AS1 knockdown could inhibit trophoblasts proliferation and invasion and promote cell apoptosis. Further, we showed that overexpression of AGAP2‐AS1 substantially stimulated the development of the trophoblastic phenotype. Through high‐throughput sequencing analysis, we demonstrated that silencing of AGAP2‐AS1 favourably regulated various genes which are relevant to trophoblastic growth and invasion. Mechanistically, AGAP2‐AS1 promoted the suppressor protein, Jun dimerization protein 2 (JDP2), by sponging miR‐574‐5p. Resultantly, further impairment of the trophoblastic phenotype was achieved by way of inhibiting cell growth, apoptosis and invasion. We also determined that the expression of AGAP2‐AS1 could be mediated by FOXP1. Our results showed that the down‐regulated expression of lncRNA AGAP2‐AS1 might serve as a key suppressor in PE via inhibition of JDP2 at the post‐transcriptional level by competing for miR‐574; thus, this presents a novel therapeutic strategy for PE.

Knockdown of LINC00473 Enhances Radiosensitivity in Hepatocellular Carcinoma via Regulating the miR-345-5p/FOXP1 Axis

Background

Hepatocellular carcinoma (HCC) is the most common form of liver cancer. Radioresistance is a significant obstacle in HCC therapy. Long non-coding RNA 473 (LINC00473) has been found to impair the effect of radiotherapy. This study aimed to explore the function and molecular basis of LINC00473 in the radiosensitivity of HCC cells.

Methods

The levels of LINC00473, miR-345-5p and Forkhead Box P1 (FOXP1) were determined by quantitative real-time polymerase chain reaction. Cell viability was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Survival fraction was calculated by colony survival assay after exposure to different doses of radiation. Cell apoptosis was evaluated by flow cytometry. The interaction among LINC00473, miR-345-5p and FOXP1 was confirmed by dual-luciferase reporter assay. The protein level of FOXP1 was detected by Western blot assay.

Results

LINC00473 and FOXP1 were up-regulated, while miR-345-5p was down-regulated in HCC tissues and cells. Radiation elevated LINC00473 expression in a dose- and time-dependent manner. Depletion of LINC00473 inhibited proliferation and heightened radiosensitivity and apoptosis in HCC cells. In addition, LINC00473 was a sponge of miR-345-5p. Also, miR-345-5p overexpression sensitized HCC cells to radiation. Moreover, miR-345-5p directly targeted FOXP1. MiR-345-5p inhibition or FOXP1 up-regulation reversed the enhanced radiosensitivity caused by LINC00473 knockdown.

Conclusion

LINC00473 contributed to radioresistance in HCC via modulating the miR-345-5p/FOXP1 axis, which might provide a promising diagnostic marker for HCC radiotherapy.

miR-29c-3p inhibits autophagy and cisplatin resistance in ovarian cancer by regulating FOXP1/ATG14 pathway

Autophagy, characterized by the elevator of autophagy-related gene 14 (ATG14) and the dysregulation of autophagy-related proteins, contributes to the cisplatin (DDP) resistance in ovarian cancer. Forkhead box protein P1 (FOXP1), which is a well-defined transcription factor, is reported to have the oncogenic effect on ovarian cancer. This study aims to identify the effect of miR-29c-3p/FOXP1/ATG14 pathway in regulating autophagy and DDP resistance in ovarian cancer. The expressions of miR-29c-3p, FOXP1, ATG14 and autophagy-related proteins were detected in DDP-sensitive ovarian cancer cell lines (SKOV3 and A2780) and DDP-resistant cell lines (SKOV3/DDP and A2780/DDP). Cell viability was detected using the MTT assay. The therapeutic effect of miR-29c-3p overexpression was observed in the xenograft model of nude mice.Compared with DDP-sensitive cells, miR-29c-3p was decreased in DDP-resistant cells, and an enhancement of FOXP1, ATG14, autophagy, and drug resistance was shown in DDP-resistant cells. The anti-resistant effect of miR-29c-3p was observed as overexpressing miR-29c-3p inhibited cell viability of DDP-resistant cells. Moreover, FOXP1 was a target of miR-29c-3p, which was confirmed by the luciferase reporter assay, and ATG14 was transactivated by FOXP1, which was confirmed by the ChIP assay. Overexpression of miR-29c-3p increased DDP sensitivity by downregulating FOXP1/ATG14 in vitro. The tumor volume was reduced after the injection of miR-29c-3p-overexpressing SKOV3/DDP cells in vivo. Overexpression of miR-29c-3p inhibited autophagy and DDP resistance partly via downregulating FOXP1/ATG14 pathway, suggesting miR-29c-3p as a novel target in overcoming DDP resistance in ovarian cancer.

Evaluation of S1PR1, pSTAT3, S1PR2, FOXP1 Expression in Aggressive, Mature B Cell Lymphomas

Background

Aggressive, mature B-cell lymphomas include Burkitt Lymphoma (BL), High Grade B Cell Lymphomas (HGBL) (eg, Double-Hit B cell lymphomas (HGBL-DH: HGBL with MYC and BCL2 and/or BCL6 translocations)), HGBL, Not Otherwise Specified (HGBL, NOS) and Diffuse Large B Cell Lymphoma (DLBCL). Overlapping morphologic and immunohistochemical features of these lymphomas pose diagnostic challenges in some cases, and better understanding of potential diagnostic biomarkers and possible therapeutic targets is needed. Sphingosine 1 Phosphate Receptors (S1PR1-5) are G-protein coupled receptors that bind S1P and influence migration and survival in multiple cell types, including lymphocytes. S1PRs are emerging as biomarkers in B cell biology and interaction between S1PR pathways and STAT3 or FOXP1 has been reported in DLBCL.

Aim and Methods

Our aim was to extend the understanding of S1PR1, STAT3 and S1PR2, FOXP1 expression beyond DLBCL, into additional aggressive, mature B cell lymphomas using immunohistochemical expression analysis of human tissue samples.

Results

S1PR1 and S1PR2 showed different expression patterns in mantle zones and follicle centers in reactive lymphoid tissue. BL showed a unique expression pattern compared to HGBL and DLBCL. Additionally, S1PR1 and S1PR2 expression were typically mutually exclusive and were expressed in a low proportion of cases (frequently HGBL involving extranodal sites). FOXP1 was expressed in a high proportion of various case types and pSTAT3 was detected in a significant proportion of HGBL and DLBCL.

Conclusions

These findings provide further evidence that S1PR1, pSTAT3, S1PR2 and FOXP1 play a role in a subset of aggressive, mature B cell lymphomas.

Pathogenic missense mutation pattern of forkhead box genes in neurodevelopmental disorders

Background

Forkhead box (FOX) proteins are a family of transcription factors. Mutations of three FOX genes, including FOXP1, FOXP2, and FOXG1, have been reported in neurodevelopmental disorders (NDDs). However, due to the lack of site‐specific statistical significance, the pathogenicity of missense mutations of these genes is difficult to determine.

Methods

DNA and RNA were extracted from peripheral blood lymphocytes. The mutation was detected by single‐molecule molecular inversion probe‐based targeted sequencing, and the variant was validated by Sanger sequencing. Real‐time quantitative PCR and western blot were performed to assay the expression of the mRNA and protein. To assess the pattern of disorder‐related missense mutations of NDD‐related FOX genes, we manually curated de novo and inherited missense or inframeshift variants within FOXP1, FOXP2, and FOXG1 that co‐segregated with phenotypes in NDDs. All variants were annotated by ANNOVAR.

Results

We detected a novel de novo missense mutation (NM_001244815: c.G1444A, p.E482K) of FOXP1 in a patient with intellectual disability and severe speech delay. Real‐time PCR and western blot revealed a dramatic reduction of mRNA and protein expression in patient‐derived lymphocytes, indicating a loss‐of‐function mechanism. We observed that the majority of the de novo or transmitted missense variants were located in the FOX domains, and 95% were classified as pathogenic mutations. However, 10 variants were located outside of the FOX domain and were classified as likely pathogenic or variants of uncertain significance.

Conclusion

Our study shows the pathogenicity of missense and inframeshift variants of NDD‐related FOX genes, which is important for clinical diagnosis and genetic counseling. Functional analysis is needed to determine the pathogenicity of the variants with uncertain clinical significance.

Identification of a de novo FOXP1 mutation and incidental discovery of inherited genetic variants contributing to a case of autism spectrum disorder and epilepsy

Background

Autism spectrum disorder is commonly co‐diagnosed intellectual disability, language disorder, anxiety, and epilepsy, however, symptom management is difficult due to the complex genetic nature of ASD.

Methods

We present a next‐generation sequencing‐based case study with both de novo and inherited genetic variants and highlight the impact of structural variants on post‐translational regulation of protein expression. Since management of symptoms has classically been through pharmaceutical therapies, a pharmacogenomics screen was also utilized to determine possible drug/gene interactions.

Results

A de novo variant was identified within the FOXP1 3′ untranslated regulatory region using exome sequencing. Additionally, inherited variants that likely contribute to the current and potential future traits were identified within the COMT, SLC6A4, CYP2C19, and CYP2D6 genes.

Conclusion

This study aims to elucidate how a collection of variant genotypes could potentially impact neural development resulting in a unique phenotype including ASD and epilepsy. Each gene's contribution to neural development is assessed, and the interplay of these genotypes is discussed. The results highlight the utility of exome sequencing in conjunction with pharmacogenomics screening when evaluating possible causes of and therapeutic treatments for ASD‐related symptoms.

MiR-449b-5p regulates cell proliferation, migration and radioresistance in cervical cancer by interacting with the transcription suppressor FOXP1

MicroRNAs (miRNAs) have been acknowledged as crucial regulators for the malignant progression of human cancers. However, the molecular mechanism associated with the malignant progression of cervical cancer (CC) is still largely unmarked. The focus of this study is to explore the potential functional mechanism of miR-449b-5p in CC. Using qRT-PCR analysis, we detected a relative lower expression level of miR-449b-5p in CC tissues and cell lines by comparing with the normal tissues and cells. Low level of miR-449b-5p in CC cell lines was further demonstrated by northern blot. Subsequently, downregulation of miR-449b-5p was closely correlated with the low overall survival rate of patients with cervical cancer. Gain-of-function assays demonstrated that upregulation of miR-449b-5p had an inhibitory effect on cell proliferation, migration and invasion. Moreover, FOXP1 was found to be a transcription suppressor and downstream target of miR-449b-5p. Rescue assays and in vivo experiment were applied to demonstrate the biological function of miR-449b-5p-FOXP1 feedback loop. In summary, miR-449b-5p interacted with FOXP1 to regulate cell proliferation, migration, invasion and radiosensitivity in CC.

Expression of FOXP1 and FOXO3a in extrahepatic cholangiocarcinoma and the implications in clinicopathological significance and prognosis

Aims: Extrahepatic cholangiocarcinoma (EHCC) is a highly malignant tumor with poor prognosis and intrinsic resistance to cytotoxic agents. The molecular mechanisms associated with high malignancy and resistance to chemotherapy and radiotherapy have not been fully elucidated. This study investigated the clinicopathological significances of FOXP1 and FOXO3a expression in EHCC.

Methods: We assayed FOXP1 and FOXO3a expressions in 100 EHCC, 30 peritumoral tissues, 10 adenoma and 15 normal biliary tract tissues using EnVision immunohistochemistry.

Results: The positive rates of FOXP1 and FOXO3a proteins were significantly lower in EHCC tumors than in peritumoral tissues, adenoma, and normal bile tract tissues (P<0.05 or P<0.01). Adenoma and pericancerous tissues with negative FOXP1 and/or FOXO3a protein expressions exhibited atypical hyperplasia. The positive correlation was established between the expression of FOXP1 and FOXO3a in EHCC (P<0.01). The positive rates of FOXP1 and FOXO3a expression were significantly higher in cases with well differentiation, no metastasis in lymph node, no invasion to surrounding tissues and organs, TNM I + II stage and radical resection (p<0.05 or p<0.01). Kaplan-Meier survival analysis showed that EHCC patients with positive FOXP1 and FOXO3a expression survived significantly higher than patients with negative FOXP1 and FOXO3a expression, respectively (P<0.001). Cox multivariate analysis revealed that negative FOXP1 or FOXO3a expressions were independent poor prognostic factors in EHCC patients. The AUCs for FOXP1 and FOXO3a were 0.676 (95% CI: 0.589–0.763, P＜0.001) and 0.652 (95% CI: 0.563–741, P=0.002), respectively.

Conclusion: The present study indicates that negative FOXP1 and FOXO3a expressions are closely associated with the pathogenesis, clinical, pathological and biological behaviors, and poor prognosis in EHCC.

miR-3687 Overexpression Promotes Bladder Cancer Cell Growth by Inhibiting the Negative Effect of FOXP1 on Cyclin E2 Transcription

Cyclin E2, a member of the cyclin family, is a key cell cycle-related protein. This protein plays essential roles in cancer progression, and, as such, an inhibitor of cyclin E2 has been approved to treat several types of cancers. Even so, mechanisms underlying how to regulate cyclin E2 expression in cancer remain largely unknown. In the current study, miR-3687 was upregulated in clinical bladder cancer (BC) tumor tissues, The Cancer Genome Atlas (TCGA) database, and human BC cell lines. Inhibition of miR-3687 expression significantly reduced human BC cell proliferation in vitro and tumor growth in vivo, which coincided with the induction of G₀/G₁ cell cycle arrest and downregulation of cyclin E2 protein expression. Interestingly, overexpression of cyclin E2 reversed the inhibition of BC proliferation induced by miR-3687. Mechanistic studies suggested that miR-3687 binds to the 3' UTR of foxp1 mRNA, downregulates FOXP1 protein expression, and in turn promotes the transcription of cyclin E2, thereby promoting the growth of BC cells. Collectively, the current study not only establishes a novel regulatory axis of miR-3687/FOXP1 regarding regulation of cyclin E2 expression in BC cells, but also provides strong suggestive evidence that miR-3687 and FOXP1 may be promising targets in therapeutic strategies for human BC.

Regulatory genes and pathways disrupted in autism spectrum disorders

Autism spectrum disorder (ASD) is a highly prevalent and complex genetic disorder. The complex genetic make-up of ASD has been extensively studied and both common and rare genetic variants in up to 1000 genes have been linked to increased ASD risk. While these studies highlight the genetic complexity and begin to provide a window for delineating pathways at risk in ASD, the pathogenicity and specific contribution of many mutations to the disorder are poorly understood. Defining the convergent pathways disrupted by this large number of ASD-associated genetic variants will help to understand disease pathogenesis and direct future therapeutic efforts for the groups of patients with distinct etiologies. Here, we review some of the common regulatory pathways including chromatin remodeling, transcription, and alternative splicing that have emerged as common features from genetic and transcriptomic profiling of ASD. For each category, we focus on one gene (CHD8, FOXP1, and RBFOX1) that is significantly linked to ASD and functionally characterized in recent years. Finally, we discuss genetic and transcriptomic overlap between ASD and other neurodevelopmental disorders.

Leukocyte integrin signaling regulates FOXP1 gene expression via FOXP1-IT1 long non-coding RNA-mediated IRAK1 pathway

Leukocyte integrin-dependent downregulation of the transcription factor FOXP1 is required for monocyte differentiation and macrophage functions, but the precise gene regulatory mechanism is unknown. Here, we identify multi-promoter structure (P1, P2, and P3) of the human FOXP1 gene. Clustering of the β₂-leukocyte integrin Mac-1 downregulated transcription from these promoters. We extend our prior observation that IL-1 receptor-associated kinase 1 (IRAK1) is physically associated with Mac-1 and provide evidence that IRAK1 is a potent suppressor of human FOXP1 promoter. IRAK1 reduced phosphorylation of histone deacetylase 4 (HDAC4) via inhibiting phosphorylation of calcium/calmodulin dependent protein kinase II delta (CaMKIIδ), thereby promoting recruitment of HDAC4 to P1 chromatin. A novel human FOXP1 intronic transcript 1 (FOXP1-IT1) long non-coding RNA (lncRNA), whose gene is embedded within that of FOXP1, has been cloned and found to bind directly to HDAC4 and regulate FOXP1 in cis manner. Overexpression of FOXP1-IT1 counteracted Mac-1 clustering-dependent downregulation of FOXP1, reduced IRAK1 downregulation of HDAC4 phosphorylation, and attenuated differentiation of THP-1 monocytic cells. In contrast, Mac-1 clustering inhibited FOXP1-IT1 expression with reduced binding to HDAC4 as well as phosphorylation of CaMKIIδ to activate the IRAK1 signaling pathway. Importantly, both IRAK1 and HDAC4 inhibitors significantly reduced integrin clustering-triggered downregulation of FOXP1 expression in purified human blood monocytes. Identification of this Mac-1/IRAK-1/FOXP1-IT1/HDAC4 signaling network featuring crosstalk between lncRNA and epigenetic factor for the regulation of FOXP1 expression provides new targets for anti-inflammatory therapeutics.

Vocal cord immobility as a cause of aphonia in a child with 3p13p12 deletion syndrome encompassing FOXP1 gene

Congenital bilateral laryngeal paralysis/immobilization is an uncommon condition and has been described as isolated or accompanying to some recognizable syndromes. Heterozygous mutations in the FOXP1 gene (605515) are related with intellectual disability and, language impairment with or without autistic features. Expressive language is more affected than receptive language and more than half of the patients experience oromotor dysfunction and/or feeding difficulties. Here we report a child with severe developmental, speech delay and aphonia which was considered due to bilaterally abductor vocal cord immobility. Interstitial 8700 kbp deletion encompassing FOXP1 gene was detected on 3p13p12 chromosomal region. Although it is known that FOXP1 defects are related to abnormalities in vocal communication, FOXP1-associated laryngomalacia or vocal cord paralysis/immobilization cases have not been reported yet. The FOXP1 defects are considered to be a cause of delay in speech, and it is suggested that vocal cord evaluation should be conducted in suspicious cases.

FOXP1 negatively regulates tumor infiltrating lymphocyte migration in human breast cancer

Background

FOXP1, a transcriptional regulator of lymphocyte development, is abnormally expressed in some human tumors. This study investigated FOXP1-mediated regulation of tumor infiltrating lymphocytes (TIL) in untreated primary breast cancer (BC).

Methods

FOXP1 expression was analyzed in tissues from primary untreated breast tumors, BC cell lines and the METABRIC gene expression BC dataset. Cytokine and chemokine expression and lymphocyte migration in response to primary tumor supernatants (SN) was compared between FOXP1^hi and FOXP1^lo primary BC.

Finding

FOXP1 expression was higher in estrogen receptor positive compared to negative BC. FOXP1^hi tumors were significantly associated with lower TIL and fewer tertiary lymphoid structures (TLS) compared to FOXP1^lo BC. Silencing FOXP1 in BC cell lines positively impacted cytokine and chemokine expression with the inverse effect associated with overexpression. CXCL9, CXCL10, CXCL11, CXCL13, CX3CL, CCL20, IL2, IL21, GZMB and IFNG expression decreased while IL10 and TGFβ increased in FOXP1^hi compared to FOXP1^lo primary BC. Lymphocyte migration using primary BC supernatants detected decreased mobility toward FOXP1^hi supernatants. FOXP1^lo BC expresses higher levels of chemokines driving TIL migration. The METABRIC gene expression dataset analysis show FOXP1 expression is associated with unfavorable BC outcomes.

Interpretation

These data identify FOXP1 as an important negative regulator of immune responses in BC via its regulation of cytokine and chemokine expression.

Fund

Belgian Fund for Scientific Research (FNRS 3.4513.12F) and Opération Télévie (7.4636.13F and 7.4609.15F), Fonds J.C. Heuson and Fonds Lambeau-Marteaux.

FOXP1 enhances fibrosis via activating Wnt/β-catenin signaling pathway in endometriosis

Endometriosis is a common gynecological disorder affecting 6-10% women. Endometriosis is associated with excess fibrosis, leading to chronic pain, scarring and aberrant tissue function. However, molecular and cellular mechanisms underlying fibrosis during endometriosis still remain elusive. In this study we used endometrial and endometriotic stromal cells isolated from patients, and employed siRNA to knockdown Forkhead box protein P1 (FOXP1) to investigate the effect of FOXP1 on collagen contraction, cell proliferation and mitigation. Western blot and quantitative PCR were applied for analysis of protein and mRNA levels, respectively. Compared to control stromal cells, endometriotic stromal cells from patients exhibited higher levels of FOXP1 expression and Wnt-related β-catenin acetylation. FOXP1 knockdown decreased not only Wnt signaling, but also the expression of fibrotic marker genes, including connective tissue growth factor, type I collagen, α-smooth muscle actin and fibronectin. Furthermore, FOXP1 knockdown reversed the endometriotic cellular phenotypes, including reducing collagen gel contraction, inhibiting cell proliferation and migration. Finally, Wnt signaling inhibitor AVX939 blocked β-catenin acetylation and endometrial stromal cell proliferation induced by ectopic FOXP1 expression. FOXP1 enhances fibrosis during endometriosis through upregulating Wnt signaling activity.

Knockdown of FOXP1 promotes the development of lung adenocarcinoma

Lung cancer is one of the most common cancers in the world, which accounts for about 27% of all cancer deaths. However, the mechanisms underlying the pathogenesis of lung cancer cells remain largely elusive. In this study, we examined the role of the Forkhead box protein P1 (FOXP1) in lung cancer development. Our Oncomine analysis shows that FOXP1 is downregulated in lung adenocarcinoma compared with normal lung tissue. Knockdown of FOXP1 promotes the growth and invasion of PC9 and A549 cells by regulating genes of chemokine signaling molecules, including CCR1, ADCY5, GNG7, VAV3, and PLCB1. Simultaneous knockdown of CCR1 and FOXP1 attenuated FOXP1 knockdown-induced increase of lung cancer cell growth. Finally, knockdown of FOXP1 in PC9 cells promotes the tumorigenesis via CCR1 signaling in xenograft mouse model. Taken together, our data suggest that FOXP1 plays important roles in preventing lung adenocarcinoma development via suppressing chemokine signaling pathways.

Downregulation of FOXP1 correlates with tendon stem/progenitor cells aging

Aging is known as a major risk factor for tendon disorders whereas the molecular mechanisms of age-related tendon disorders still remains unclear. Since tendon-derived stem/progenitor cells (TSPCs) play a vital role in tendon maintenance and healing, in this study we aimed to investigate the role of Forkhead box P1 (FOXP1) in aged TSPCs, we found that FOXP1 mRNA and protein levels were markedly decreased in the aged TSPCs. Moreover, overexpression of FOXP1 attenuates TSPCs aging, as confirmed by decreased of senescence-associated β-gal staining, as well as the senescence marker, p16^INK4A. Conversely, FOXP1 depletion by siRNA promoted senescence in young TSPCs. Meanwhile, FOXP1 overexpression also restores the age-associated reduction of self-renewal, migration and differentiation of TSPCs. In addition, FOXP1 overexpression rescued decreased levels of E2F1, pRb and cyclin D1 in aged TSPCs, which suggested that FOXP1 regulates TSPCs aging through cellular senescence. These results indicate that FOXP1 plays a crucial role in TSPCs aging.

STAT3 promotes tumour progression in glioma by inducing FOXP1 transcription

Objective

This paper investigated the effects of STAT3 through promoting FOXP1 transcription on proliferation, apoptosis and invasion in glioma cells.

Methods

Quantitative real‐time PCR (qRT‐PCR) and Western blot assay were administered to assess the mRNA and protein expression levels of STAT3 and FOXP1 in glioma tissues and cells, respectively. Luciferase reporter and Chromatin Immunoprecipitation (ChIP) assays were implemented to determine the correlation between STAT3 and FOXP1. MTT and colony formation assays were conducted to identify cell growth. Flow cytometry was run to detect the cell apoptosis rate of glioma cells. Transwell assays were conducted to reveal cell invasion ability.

Results

The mRNA and protein expression levels of STAT3 were highly expressed in glioma tissues and cells. After cells transfected with siRNA of STAT3, both STAT3 and FOXP1 were simultaneously downregulated. STAT3 directly regulated FOXP1 transcription. STAT3 promoted cell proliferation, inhibited cell apoptosis and enhanced cell invasion through promoting FOXP1 transcription in glioma cells.

Conclusion

In summary, STAT3 gene was a transcriptional regulator of FOXP1. Depleted STAT3 restrained cell proliferation and invasion, promoted cell apoptosis in glioma cells. This molecular mechanism between STAT3 and FOXP1 can serve as a therapeutic target for glioma treatment.

Long noncoding RNA SNHG12 facilitates the tumorigenesis of glioma through miR-101-3p/FOXP1 axis

The increasing vital roles of long coding RNA (lncRNAs) in the glioma tumorigenesis have renewedly and roundly recognized. Nevertheless, the in-depth that lncRNAs modulate the gliomagenesis is still elusive. In this research, we focus on the functional study of lncRNA SNHG12 in the glioma pathogenesis. SNHG12 expression was enhanced and high-expressed in the glioma clinical tissue samples and cell lines, especially in the advanced clinical grade. In functional study, knockdown of SNHG12 impaired the proliferation, induced the apoptosis in vitro and, meanwhile, inhibited the tumor growth in vivo. In mechanistic study, it was found that SNHG12 harbored the complementary binding sites with miR-101-3p at 3'-UTR, acting as a miRNA 'sponge'. Furthermore, miR-101-3p also targeted the 3'-UTR of FOXP1 mRNA. The three elements construct the SNHG12/miR-101-3p/FOXP1 axis. Overall, we confirmed a functional regulatory pathway that SNHG12 and miR-101-3p regulated the expression of FOXP1 in glioma cells, forming the SNHG12/miR-101-3p/FOXP1 pathway. This finding might act as a valuable target for glioma.

FOXP1 Promotes Embryonic Neural Stem Cell Differentiation by Repressing Jagged1 Expression

Mutations in FOXP1 have been linked to neurodevelopmental disorders including intellectual disability and autism; however, the underlying molecular mechanisms remain ill-defined. Here, we demonstrate with RNA and chromatin immunoprecipitation sequencing that FOXP1 directly regulates genes controlling neurogenesis. We show that FOXP1 is expressed in embryonic neural stem cells (NSCs), and modulation of FOXP1 expression affects both neuron and astrocyte differentiation. Using a murine model of cortical development, FOXP1-knockdown in utero was found to reduce NSC differentiation and migration during corticogenesis. Furthermore, transplantation of FOXP1-knockdown NSCs in neonatal mice after hypoxia-ischemia challenge demonstrated that FOXP1 is also required for neuronal differentiation and functionality in vivo. FOXP1 was found to repress the expression of Notch pathway genes including the Notch-ligand Jagged1, resulting in inhibition of Notch signaling. Finally, blockade of Jagged1 in FOXP1-knockdown NSCs rescued neuronal differentiation in vitro. Together, these data support a role for FOXP1 in regulating embryonic NSC differentiation by modulating Notch signaling.

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FOXP1 promotes astrocyte and neuronal differentiation of NSCs in vitro

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FOXP1 promotes neuronal differentiation of NSCs in vivo

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FOXP1 transcriptionally regulates pro-neural genes and represses Notch pathway genes

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FOXP1 promotes neuronal differentiation by limiting Jagged1 expression

MiR-206 is down-regulated and suppresses cell proliferation by targeting FOXP1 in brain gliomas

Aberrant expression of miR-206 has been repeatedly found and demonstrated to play crucial roles in cancers. However, the role of miR-206 in brain glioma remains unclear. To address this issue, we detected miR-206 expression of 60 gliomas and 18 normal peritumor tissues, and found that miR-206 is significantly down-regulated in gliomas. Further in silico analysis of 198 glioma samples from the Chinese Glioma Genome Atlas (CGGA) indicated that miR-206 is significantly down-regulated in high grade gliomas and that miR-206 predicts favorable patients' prognosis. Notably, we found that miR-206 expression is negatively correlated with Ki-67 staining, indicating a proliferative inhibition of miR-206 in gliomas. To explore the crucial role of miR-206 in gliomas, we constructed miR-206 stably overexpressed LN229 glioma cell lines and found that the proliferation is significantly inhibited. Through flow cytometry (FCM) analyses, we found that the apoptotic rate is increased and the cell cycle is arrested in LN229 cells after overexpression of miR-206. Bioinformatic analysis, qPCR, western blot and luciferase assay indicated that the Forkhead Box Protein 1 (FOXP1) is a direct target of miR-206 in gliomas. Overexpression of FOXP1 could partially rescue the proliferative inhibition in the miR-206 stably overexpressed LN229 cells. In summary, our results suggest that miR-206 might function as a tumor suppressor of gliomas by inhibition of proliferation and could serve as a promising candidate for therapeutic applications in glioma by targeting FOXP1.