TOX3 is a neuronal survival factor that induces transcription depending on the presence of CITED1 or phosphorylated CREB in the transcriptionally active complex

TOX3 deficiency mitigates hyperglycemia by suppressing hepatic gluconeogenesis through FoxO1

BACKGROUND

Excessive hepatic glucose production is a hallmark that contributes to hyperglycemia in type 2 diabetes (T2D). The regulatory network governing this process remains incompletely understood. Here, we demonstrate that TOX3, a high-mobility group family member, acts as a major transcriptional driver for hepatic glucose production.

METHODS

Tox3-overexpressed and knockout mice were constructed to explore its metabolic functions. Transcriptomic and chromatin-immunoprecipitation sequencing (ChIP-seq) were used to identify downstream targets of TOX3. Both FoxO1 silencing and inhibitor approaches were used to assess the contribution of FoxO1. TOX3 expression levels were examined in the livers of mice and human subjects. Finally, Tox3 was genetically manipulated in diet-induced obese mice to evaluate its therapeutic potential.

RESULTS

Hepatic Tox3 overexpression activates the gluconeogenic program, resulting in hyperglycemia and insulin resistance in mice. Hepatocyte-specific Tox3 knockout suppresses gluconeogenesis and improves insulin sensitivity. Mechanistically, integrated hepatic transcriptomic and ChIP-seq analyses identify FoxO1 as a direct target of TOX3. TOX3 stimulates FoxO1 transcription by directly binding to and activating its promoter, whereas FoxO1 silencing abrogates TOX3-induced dysglycemia in mice. In human subjects, hepatic TOX3 expression shows a significant positive correlation with blood glucose levels under normoglycemic conditions, yet is repressed by high glucose during T2D. Importantly, hepatic Tox3 deficiency markedly protects against and ameliorates the hyperglycemia and glucose intolerance in diet-induced diabetic mice.

CONCLUSIONS

Our findings establish TOX3 as a driver for excessive gluconeogenesis through activating hepatic FoxO1 transcription. TOX3 could serve as a promising target for preventing and treating hyperglycemia in T2D.

Impaired T3 uptake and action in MCT8-deficient cerebral organoids underlie Allan-Herndon-Dudley syndrome

Patients with mutations in the thyroid hormone (TH) cell transporter monocarboxylate transporter 8 (MCT8) gene develop severe neuropsychomotor retardation known as Allan-Herndon-Dudley syndrome (AHDS). It is assumed that this is caused by a reduction in TH signaling in the developing brain during both intrauterine and postnatal developmental stages, and treatment remains understandably challenging. Given species differences in brain TH transporters and the limitations of studies in mice, we generated cerebral organoids (COs) using human induced pluripotent stem cells (iPSCs) from MCT8-deficient patients. MCT8-deficient COs exhibited (i) altered early neurodevelopment, resulting in smaller neural rosettes with thinner cortical units, (ii) impaired triiodothyronine (T3) transport in developing neural cells, as assessed through deiodinase-3-mediated T3 catabolism, (iii) reduced expression of genes involved in cerebral cortex development, and (iv) reduced T3 inducibility of TH-regulated genes. In contrast, the TH analogs 3,5-diiodothyropropionic acid and 3,3',5-triiodothyroacetic acid triggered normal responses (induction/repression of T3-responsive genes) in MCT8-deficient COs, constituting proof of concept that lack of T3 transport underlies the pathophysiology of AHDS and demonstrating the clinical potential for TH analogs to be used in treating patients with AHDS. MCT8-deficient COs represent a species-specific relevant preclinical model that can be utilized to screen drugs with potential benefits as personalized therapeutics for patients with AHDS.

Roles and signaling pathways of CITED1 in tumors: overview and novel insights

CBP/p300 interacting transactivator with Glu/Asp-rich carboxy-terminal domain 1 (CITED1) is a transcriptional activator belonging to the non-DNA-binding transcription co-regulator family. It regulates diverse pathways, including the transforming growth factor/bone morphogenetic protein/SMAD, estrogen, Wnt-β-catenin, and androgen-AR signaling pathways, by binding to CBP/p300 co-activators through its conserved transactivation domain CR2. CITED1 plays an important role in embryonic development and a certain regulatory role in the occurrence and development of various tumors. In this article, the biological characteristics, expression regulation, participating signaling pathways, and potential roles of CITED1 in the clinical diagnosis and treatment of tumors are reviewed.

Revealing the impact of TOX3 on osteoarthritis: insights from bioinformatics

Osteoarthritis, a prevalent long-term condition of the joints, primarily impacts older individuals, resulting in discomfort, restrictions in mobility, and a decrease in overall well-being. Although Osteoarthritis is widely spread, there is a lack of successful interventions to stop the advancement of the condition. Numerous signaling pathways have been emphasized in recent research on Osteoarthritis, yet the diagnostic significance of numerous genes has not been investigated. To identify genes that were expressed differently in osteoarthritis, we utilized the Gene Expression Omnibus database. To identify marker genes, we built machine learning models including Least Absolute Shrinkage and Selection Operator and Random Forest. We categorized Osteoarthritis samples and performed immune cell infiltration analysis based on the expression patterns of these characteristic genes. Both the Least Absolute Shrinkage and Selection Operator and Random Forest models selected six marker genes (TOX3, ARG1, CST7, RERGL, COL11A1, NCRNA00185) out of a total of 17 differentially expressed genes. The osteoarthritis samples were categorized into two groups, namely a high expression group and a low expression group, based on the median levels of TOX3 expression. Comparative analysis of these groups identified 85 differentially expressed genes, showing notable enrichment in pathways related to lipid metabolism in the group with high expression. Analysis of immune cell infiltration revealed noticeable differences in immune profiles among the two groups. The group with high expression of TOX3 showed a notable increase in Mast cells and Type II IFN Response, whereas B cells, Cytolytic activity, Inflammation-promoting cells, NK cells, pDCs, T cell co-inhibition, Th1 cells, and Th2 cells were significantly decreased. We constructed a ceRNA network for TOX3, revealing 57 lncRNAs and 18 miRNAs involved in 57 lncRNA-miRNA interactions, and 18 miRNA-mRNA interactions with TOX3. Validation of TOX3 expression was confirmed using an external dataset (GSE29746), revealing a notable increase in Osteoarthritis samples. In conclusion, our study presents a comprehensive analysis identifying TOX3 as a potential feature gene in Osteoarthritis. The distinct immune profiles and involvement in fat metabolism pathways associated with TOX3 expression suggest its significance in Osteoarthritis pathogenesis. The study establishes a basis for comprehending the intricate correlation between characteristic genes and Osteoarthritis, as well as for the formulation of individualized therapeutic approaches.

Leptin deficiency impairs adipogenesis and browning response in mouse mesenchymal progenitors

Although phenotypically different, brown adipose tissue (BAT) and inguinal white adipose tissue (iWAT) are able to produce heat through non-shivering thermogenesis due to the presence of mitochondrial uncoupling protein 1 (UCP1). The appearance of thermogenically active beige adipocytes in iWAT is known as browning. Both brown and beige cells originate from mesenchymal stem cells (MSCs), and in culture conditions a browning response can be induced with hypothermia (i.e. 32 °C) during which nuclear leptin immunodetection was observed. The central role of leptin in regulating food intake and energy consumption is well recognised, but its importance in the browning process at the cellular level is unclear. Here, immunocytochemical analysis of MSC-derived adipocytes established nuclear localization of both leptin and leptin receptor suggesting an involvement of the leptin pathway in the browning response. In order to elucidate whether leptin modulates the expression of brown and beige adipocyte markers, BAT and iWAT samples from leptin-deficient (ob/ob) mice were analysed and exhibited reduced brown/beige marker expression compared to wild-type controls. When MSCs were isolated and differentiated into adipocytes, leptin deficiency was observed to induce a white phenotype, especially when incubated at 32 °C. These adaptations were accompanied with morphological signs of impaired adipogenic differentiation. Overall, our results indicate that leptin supports adipocyte browning and suggest a potential role for leptin in adipogenesis and browning.

A novel TOX3-WDR5-ABCG2 signaling axis regulates the progression of colorectal cancer by accelerating stem-like traits and chemoresistance

The eradication of cancer stem cells (CSCs) with drug resistance confers the probability of local tumor control after chemotherapy or targeted therapy. As the main drug resistance marker, ABCG2 is also critical for colorectal cancer (CRC) evolution, in particular cancer stem-like traits expansion. Hitherto, the knowledge about the expression regulation of ABCG2, in particular its upstream transcriptional regulatory mechanisms, remains limited in cancer, including CRC. Here, ABCG2 was found to be markedly up-regulated in CRC CSCs (cCSCs) expansion and chemo-resistant CRC tissues and closely associated with CRC recurrence. Mechanistically, TOX3 was identified as a specific transcriptional factor to drive ABCG2 expression and subsequent cCSCs expansion and chemoresistance by binding to -261 to -141 segments of the ABCG2 promoter region. Moreover, we found that TOX3 recruited WDR5 to promote tri-methylation of H3K4 at the ABCG2 promoter in cCSCs, which further confers stem-like traits and chemoresistance to CRC by co-regulating the transcription of ABCG2. In line with this observation, TOX3, WDR5, and ABCG2 showed abnormal activation in chemo-resistant tumor tissues of in situ CRC mouse model and clinical investigation further demonstrated the comprehensive assessment of TOX3, WDR5, and ABCG2 could be a more efficient strategy for survival prediction of CRC patients with recurrence or metastasis. Thus, our study found that TOX3-WDR5/ABCG2 signaling axis plays a critical role in regulating CRC stem-like traits and chemoresistance, and a combination of chemotherapy with WDR5 inhibitors may induce synthetic lethality in ABCG2-deregulated tumors.

Tox4 regulates transcriptional elongation and reinitiation during murine T cell development

HMG protein Tox4 is a regulator of PP1 phosphatases with unknown function in development. Here we show that Tox4 conditional knockout in mice reduces thymic cellularity, partially blocks T cell development, and decreases ratio of CD8 to CD4 through decreasing proliferation and increasing apoptosis of CD8 cells. In addition, single-cell RNA-seq discovered that Tox4 loss also impairs proliferation of the fast-proliferating double positive (DP) blast population within DP cells in part due to downregulation of genes critical for proliferation, notably Cdk1. Moreover, genes with high and low expression level are more dependent on Tox4 than genes with medium expression level. Mechanistically, Tox4 may facilitate transcriptional reinitiation and restrict elongation in a dephosphorylation-dependent manner, a mechanism that is conserved between mouse and human. These results provide insights into the role of TOX4 in development and establish it as an evolutionarily conserved regulator of transcriptional elongation and reinitiation.

DMRT1-mediated regulation of TOX3 modulates expansion of the gonadal steroidogenic cell lineage in the chicken embryo

During gonadal sex determination, the supporting cell lineage differentiates into Sertoli cells in males and pre-granulosa cells in females. Recently, single cell RNA-seq data have indicated that chicken steroidogenic cells are derived from differentiated supporting cells. This differentiation process is achieved by a sequential upregulation of steroidogenic genes and downregulation of supporting cell markers. The exact mechanism regulating this differentiation process remains unknown. We have identified TOX3 as a previously unreported transcription factor expressed in embryonic Sertoli cells of the chicken testis. TOX3 knockdown in males resulted in increased CYP17A1-positive Leydig cells. TOX3 overexpression in male and female gonads resulted in a significant decline in CYP17A1-positive steroidogenic cells. In ovo knockdown of the testis determinant DMRT1 in male gonads resulted in a downregulation of TOX3 expression. Conversely, DMRT1 overexpression caused an increase in TOX3 expression. Taken together, these data indicate that DMRT1-mediated regulation of TOX3 modulates expansion of the steroidogenic lineage, either directly, via cell lineage allocation, or indirectly, via signaling from the supporting to steroidogenic cell populations.

Meta-Analysis Identifies BDNF and Novel Common Genes Differently Altered in Cross-Species Models of Rett Syndrome

Rett syndrome (RTT) is a rare disorder and one of the most abundant causes of intellectual disabilities in females. Single mutations in the gene coding for methyl-CpG-binding protein 2 (MeCP2) are responsible for the disorder. MeCP2 regulates gene expression as a transcriptional regulator as well as through epigenetic imprinting and chromatin condensation. Consequently, numerous biological pathways on multiple levels are influenced. However, the exact molecular pathways from genotype to phenotype are currently not fully elucidated. Treatment of RTT is purely symptomatic as no curative options for RTT have yet to reach the clinic. The paucity of this is mainly due to an incomplete understanding of the underlying pathophysiology of the disorder with no clinically useful common disease drivers, biomarkers, or therapeutic targets being identified. With the premise of identifying universal and robust disease drivers and therapeutic targets, here, we interrogated a range of RTT transcriptomic studies spanning different species, models, and MECP2 mutations. A meta-analysis using RNA sequencing data from brains of RTT mouse models, human post-mortem brain tissue, and patient-derived induced pluripotent stem cell (iPSC) neurons was performed using weighted gene correlation network analysis (WGCNA). This study identified a module of genes common to all datasets with the following ten hub genes driving the expression: ATRX, ADCY7, ADCY9, SOD1, CACNA1A, PLCG1, CCT5, RPS9, BDNF, and MECP2. Here, we discuss the potential benefits of these genes as therapeutic targets.

The TOX subfamily: all-round players in the immune system

The thymocyte selection-related HMG box protein (TOX) subfamily comprises evolutionarily conserved DNA-binding proteins, and is expressed in certain immune cell subsets and plays key roles in the development of CD4+ T cells, innate lymphoid cells (ILCs), T follicular helper (Tfh) cells, and in CD8+ T-cell exhaustion. Although its roles in CD4+ T and natural killer (NK) cells have been extensively studied, recent findings have demonstrated previously unknown roles for TOX in the development of ILCs, Tfh cells, as well as CD8+ T-cell exhaustion; however, the molecular mechanism underlying TOX regulation of these immune cells remains to be elucidated. In this review, we discuss recent studies on the influence of TOX on the development of various immune cells and CD8+ T-cell exhaustion and the roles of specific TOX family members in the immune system. Moreover, this review suggests candidate regulatory targets for cell therapy and immunotherapies.

Transcription Regulation of Tceal7 by the Triple Complex of Mef2c, Creb1 and Myod

Simple Summary

We have previously reported a striated muscle-specific gene during embryogenesis, Tceal7. Our studies have characterized the 0.7 kb promoter of the Tceal7 gene, which harbors important E-box motifs driving the LacZ reporter in the myogenic lineage. However, the underlying mechanism regulating the dynamic expression of Tceal7 during skeletal muscle regeneration is still elusive. In the present work, we have defined a cluster of Mef2#3–CRE#3–E#4 motifs through bioinformatic analysis and transcription assays. Our studies suggested that the triple complex of Mef2c, Creb1 and Myod binds to the Mef2#3–CRE#3–E#4 cluster region, therefore driving the dynamic expression of Tceal7 during skeletal muscle regeneration. The novel mechanism may throw new light on understanding transcription regulation in skeletal muscle myogenesis.

Abstract

Tceal7 has been identified as a direct, downstream target gene of MRF in the skeletal muscle. The overexpression of Tceal7 represses myogenic proliferation and promotes cell differentiation. Previous studies have defined the 0.7 kb upstream fragment of the Tceal7 gene. In the present study, we have further determined two clusters of transcription factor-binding motifs in the 0.7 kb promoter: CRE#2–E#1–CRE#1 in the proximal region and Mef2#3–CRE#3–E#4 in the distal region. Utilizing transcription assays, we have also shown that the reporter containing the Mef2#3–CRE#3–E#4 motifs is synergistically transactivated by Mef2c and Creb1. Further studies have mapped out the protein–protein interaction between Mef2c and Creb1. In summary, our present studies support the notion that the triple complex of Mef2c, Creb1 and Myod interacts with the Mef2#3–CRE#3–E#4 motifs in the distal region of the Tceal7 promoter, thereby driving Tceal7 expression during skeletal muscle development and regeneration.

Molecular studies into cell biological role of Copine-4 in Retinal Ganglion Cells

The molecular mechanisms underlying morphological diversity in retinal cell types are poorly understood. We have previously reported that several members of the Copine family of Ca-dependent membrane adaptors are expressed in Retinal Ganglion Cells and transcriptionally regulated by Brn3 transcription factors. Several Copines are enriched in the retina and their over-expression leads to morphological changes -formation of elongated processes-, reminiscent of neurites, in HEK293 cells. However, the role of Copines in the retina is largely unknown. We now investigate Cpne4, a Copine whose expression is restricted to Retinal Ganglion Cells. Over-expression of Cpne4 in RGCs in vivo led to formation of large varicosities on the dendrites but did not otherwise visibly affect dendrite or axon formation. Protein interactions studies using yeast two hybrid analysis from whole retina cDNA revealed two Cpne4 interacting proteins-Host Cell Factor 1 and Morn2. Mass Spectrometry analysis of retina lysate pulled down using Cpne4 or its vonWillebrand A domain showed 207 interacting proteins. A Gene Ontology analysis of the discovered proteins suggests that Cpne4 is involved in several metabolic and signaling pathways in the retina.

HIV-1 Latency and Viral Reservoirs: Existing Reversal Approaches and Potential Technologies, Targets, and Pathways Involved in HIV Latency Studies

Eradication of latent human immunodeficiency virus (HIV) infection is a global health challenge. Reactivation of HIV latency and killing of virus-infected cells, the so-called "kick and kill" or "shock and kill" approaches, are a popular strategy for HIV cure. While antiretroviral therapy (ART) halts HIV replication by targeting multiple steps in the HIV life cycle, including viral entry, integration, replication, and production, it cannot get rid of the occult provirus incorporated into the host-cell genome. These latent proviruses are replication-competent and can rebound in cases of ART interruption or cessation. In general, a very small population of cells harbor provirus, serve as reservoirs in ART-controlled HIV subjects, and are capable of expressing little to no HIV RNA or proteins. Beyond the canonical resting memory CD4⁺ T cells, HIV reservoirs also exist within tissue macrophages, myeloid cells, brain microglial cells, gut epithelial cells, and hematopoietic stem cells (HSCs). Despite a lack of active viral production, latently HIV-infected subjects continue to exhibit aberrant cellular signaling and metabolic dysfunction, leading to minor to major cellular and systemic complications or comorbidities. These include genomic DNA damage; telomere attrition; mitochondrial dysfunction; premature aging; and lymphocytic, cardiac, renal, hepatic, or pulmonary dysfunctions. Therefore, the arcane machineries involved in HIV latency and its reversal warrant further studies to identify the cryptic mechanisms of HIV reservoir formation and clearance. In this review, we discuss several molecules and signaling pathways, some of which have dual roles in maintaining or reversing HIV latency and reservoirs, and describe some evolving strategies and possible approaches to eliminate viral reservoirs and, ultimately, cure/eradicate HIV infection.

Clinical characterization, genetic profiling, and immune infiltration of TOX in diffuse gliomas

Background

Immunotherapies targeting glioblastoma (GBM) have led to significant improvements in patient outcomes. TOX is closely associated with the immune environment surrounding tumors, but its role in gliomas is not fully understood.

Methods

Using data from The Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA), we analyzed the transcriptomes of 1691 WHO grade I-IV human glioma samples. The R language was used to perform most of the statistical analyses. Somatic mutations and somatic copy number variation (CNV) were analyzed using GISTIC 2.0.

Results

TOX was down-regulated in malignant gliomas compared to low grade gliomas, and upregulated in the proneural and IDH mutant subtypes of GBM. TOX^low tumours are associated with the loss of PTEN and amplification of EGFR, while TOX^high tumours harbor frequent mutations in IDH1 (91%). TOX was highly expressed in leading edge regions of tumours. Gene ontology and pathway analyses demonstrated that TOX was enriched in multiple immune related processes including lymphocyte migration in GBM. Finally, TOX had a negative association with the infiltration of several immune cell types in the tumour microenvironment.

Conclusion

TOX has the potential to be a new prognostic marker for GBM.

TOX3 Promotes Ovarian Estrogen Synthesis: An RNA-Sequencing and Network Study

BACKGROUND

Women who undergo chronic exposure to excessive estrogen are at a high risk of developing breast cancer. TOX3 has been reported to be highly expressed in breast tumors and is closely related to estrogen receptors. However, the effect of TOX3 on estrogen synthesis remains poorly understood.

METHODS

Using lentiviruses as a vector, we stably overexpressed TOX3 in the ovarian granulosa cell line KGN, the cells where estradiol is primarily produced, to investigate its role in estrogen production as well as cell viability and apoptosis. RNA-Sequencing was applied to uncover the global gene expression upon TOX3 overexpression.

RESULTS

We observed an increased level of cell viability and a reduced cell apoptosis rate after TOX3 overexpression, and the level of estradiol in the cell culture supernatant also increased significantly. Gene set enrichment analysis of the transcriptome showed that the ovarian steroidogenesis pathway was significantly enriched. Similarly, pathway mapping using the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses also showed that TOX3 overexpression affects the ovarian steroidogenesis pathway. Further experiments showed that upregulated FSHR, CYP19A1, and BMP6 accounted for the enhanced estrogen synthesis.

CONCLUSION

Our study demonstrated that TOX3 quantitatively and qualitatively stimulates estrogen synthesis by enhancing estrogen signaling pathway-related gene expression in ovarian granulosa cells. These findings suggest that TOX3 may play a vital role in the pathogenesis of breast cancer.

Genotype based Risk Predictors for Polycystic Ovary Syndrome in Western Saudi Arabia

Polycystic ovary syndrome (PCOS) is the most common endocrine disease among premenopausal women. The genetic risk of PCOS in the Saudi population is still unclear. Therefore, it is of interest to study the genotype and allele frequency for six gene variants (THADA rs13429458, TOX3 rs4784165, FSHR rs2268361, YAP1 rs1894116, RAB5B rs705702, and HMGA2 rs2272046) in patients with PCOS in western Saudi population. The study included 95 PCOS patients and 94 normal ovulatory females as controls. Genotyping was performed using TaqMan^™ real-time polymerase chain reaction assays. There was significant link between the THADA rs13429458 variant and PCOS. Homozygosity in allele A of the rs13429458 variant was correlated with hyperandrogenism (HA) risk. Homozygosity in the T allele of the FSHR rs2268361 variant was associated with normal levels of AMH among non-PCOS women. The THADA rs13429458 and TOX3 rs4784165 variants were significantly associated with the combined oligo/amenorrhea (OA) and polycystic ovarian morphology subgroups while the HMGA2 rs2272046 variant was significantly associated with the combined HA and OA subgroup. Thus, results show the genetic risk of the THADA rs13429458, TOX3 rs4784165, and HMGA2 rs2272046 variants on PCOS patients in the western Saudi population.

Relationships between SNPs and prognosis of breast cancer and pathogenic mechanism

Background

Association between several single‐nucleotide polymorphisms (SNPs) and breast cancer risk has been identified through genome‐wide association studies (GWAS), but little is known about their significance in patients’ prognosis. We screened SNPs which were related to the prognosis of breast cancer in Henan Han population, analyzed relevant genes by bioinformatics in database, and further constructed the genetic regulatory network involved in the pathogenesis of breast cancer.

Methods

We evaluated five SNPs in 232 cases of breast cancer at the Affiliated Tumor Hospital of Zhengzhou University. Relationships between five SNPs, clinical prognostic indicators, and disease‐free survival (DFS) were evaluated by Kaplan–Meier analysis and Cox proportional hazards model. Gene ontology (GO) functional annotation and Kyoto Encyclopedia of genes and Genome (KEGG) analysis were carried out to preliminarily establish genetic regulation network model of breast cancer. Bayesian algorithm was used to optimize the model.

Results

The multivariate Cox proportional hazards model confirmed that SNP rs3803662 (TOX3/TNRC9) had correlation with DFS independently. In the multivariate Cox proportional hazards model, compared with GA/AA, GG increased the recurrent risk of breast cancer (p = .021, hazard ratio [HR] = 2.914). GO analysis showed that the function of TOX3/TNRC9 included biological_process, molecular_function, and cellular_component. According to KEGG signaling pathway database, the map of breast cancer‐related gene regulatory network was obtained. IGF‐IGF1R‐PI3K‐Akt‐mTOR‐S6K was the best possible pathway for the differentiation of breast cancer cells in this network and ER‐TOX3/TNRC9 was the best possible pathway for the survival of tumor cells in this network by Bayesian theorem optimization.

Conclusions

SNP rs3803662 (TOX3/TNRC9) is an independent prognostic factor for breast cancer in Henan Han Population. ER‐TOX3/TNRC9 is the best possible pathway involved in the pathogenesis of breast cancer.

Gene expression profiles of CMS2-epithelial/canonical colorectal cancers are largely driven by DNA copy number gains

About 80% of colorectal cancers (CRCs) have chromosomal instability, which is an integral part of aggressive malignancy development, but the importance of specific copy number aberrations (CNAs) in modulating gene expression, particularly within the framework of clinically relevant molecular subtypes, remains mostly elusive. We performed DNA copy number profiling of 257 stage I-IV primary CRCs and integrative gene expression analysis in 151 microsatellite stable (MSS) tumors, focusing on high-level amplifications and the effect of CNAs on the characteristics of the gene expression-based consensus molecular subtypes (CMS). The results were validated in 323 MSS tumors from TCGA. Novel recurrent high-level amplifications (≥15 additional copies) with a major impact on gene expression were found for TOX3 (16q) at 1.5% frequency, as well as for CCND2 (12p) and ANXA11 (10q) at 1% frequency, in addition to the well-known targets ERBB2 (17q) and MYC (8q). Focal amplifications with ≥15 or ≥5 additional copies of at least one of these regions were associated with a poor overall survival among patients with stage I-III MSS CRCs (multivariable hazard ratio ≥3.2, p ≤ 0.01). All high-level amplifications were focal and had a more consistent relationship with gene expression than lower amplitude and/or broad-range amplifications, suggesting specific targeting during carcinogenesis. Genome-wide, copy number driven gene expression was enriched for pathways characteristic of the CMS2-epithelial/canonical subtype, including DNA repair and cell cycle progression. Furthermore, 50% of upregulated genes in CMS2-epithelial/canonical MSS CRCs were driven by CNAs, an enrichment compared with the other CMS groups, and associated with the stronger correspondence between CNAs and gene expression in malignant epithelial cells than in the cells of the tumor microenvironment (fibroblasts, endothelial cells, leukocytes). In conclusion, we identify novel recurrent amplifications with impact on gene expression in CRC and provide the first evidence that CMS2 may have a stronger copy-number related genetic basis than subtypes more heavily influenced by gene expression signals from the tumor microenvironment.

Endoplasmic reticulum and the microRNA environment in the cardiovascular system 1

Stress responses are important to human physiology and pathology, and the inability to adapt to cellular stress leads to cell death. To mitigate cellular stress and re-establish homeostasis, cells, including those in the cardiovascular system, activate stress coping response mechanisms. The endoplasmic reticulum, a component of the cellular reticular network in cardiac cells, mobilizes so-called endoplasmic reticulum stress coping responses, such as the unfolded protein response. MicroRNAs play an important part in the maintenance of cellular and tissue homeostasis, perform a central role in the biology of the cardiac myocyte, and are involved in pathological cardiac function and remodeling. In this paper, we review a link between endoplasmic reticulum homeostasis and microRNA with an emphasis on the impact on stress responses in the cardiovascular system.

Emerging targets for reprograming the immune response to promote repair and recovery of function after spinal cord injury

PURPOSE OF REVIEW

In adult mammals, a traumatic spinal cord injury (SCI) elicits a chronic unregulated neuroinflammatory response accompanied by seemingly paradoxical suppression of systemic immunity. These SCI-induced changes in immune function contribute to poor neurological outcomes and enhanced morbidity or mortality. Nonspecific anti-inflammatory or proinflammatory therapies are ineffective and can even worsen outcomes. Therefore, recent experimental SCI research has advanced the understanding of how neuroimmune cross-talk contributes to spinal cord and systemic pathology.

RECENT FINDINGS

It is now appreciated that the immune response caused by injury to the brain or spinal cord encompasses heterogeneous elements that can drive events on the spectrum between exacerbating pathology and promoting tissue repair, within the spinal cord and throughout the body. Recent novel discoveries regarding the role and regulation of soluble factors, monocytes/macrophages, microRNAs, lymphocytes and systemic immune function are highlighted in this review.

SUMMARY

A more nuanced understanding of how the immune system responds and reacts to nervous system injury will present an array of novel therapeutic opportunities for clinical SCI and other forms of neurotrauma.

TOX3 inhibits cancer cell migration and invasion via transcriptional regulation of SNAI1 and SNAI2 in clear cell renal cell carcinoma

Studies on the mechanism of clear cell renal cell carcinoma (ccRCC) progression are lacking. In this study, TOX3 was identified as a novel cancer suppressor gene in ccRCC. Hypermethylation of CpG probes in the promoter region was associated with the functional loss of TOX3 in ccRCC cancer tissues. Downregulation of TOX3 mRNA was strongly associated with poor clinical outcomes in ccRCC. Immunohistochemistry confirmed TOX3 was downregulated in primary tumors without metastasis (n = 126) and further downregulated in primary metastatic tumors (n = 23) compared with adjacent noncancerous tissues (n = 92). In vitro, overexpression of TOX3 inhibited RCC cell growth, migration and invasion. Mechanistic investigations showed that TOX3 deficiency facilitates the epithelial-mesenchymal transition due to impairment of transcriptional repression of SNAIL members SNAI1 and SNAI2 and promotes cancer cell migration and invasion. In vivo, restoring TOX3 expression reduced lung metastatic lesions and prolonged survival of mice. TOX3 combined with SNAI1 or SNAI2 predicted overall survival in ccRCC patients. Blockage of this pathway could be a promising therapeutic target for advanced ccRCC.

Significant association of TOX3/LOC643714 locus-rs3803662 and breast cancer risk in a cohort of Iranian population

Genome-wide association studies normally focus on low penetrance and moderate to high-frequency single nucleotide polymorphisms (SNPs), which lead to genetic susceptibility to breast cancer. In this regard, the T allele of rs3803662 has been associated with breast cancer risk and with lower expression level of TOX3. We aimed to assess the risk of breast cancer associated with this polymorphism in an Iranian population. Using Tetra Primer ARMS PCR, rs3803662 was analyzed in a total of 943 individuals (430 cases and 513 healthy controls form North East of Iran). Allele frequencies and genotype distribution were analyzed in case and control samples to find out any association using the Chi-squared test and Logistic regression. All cases were pathologically confirmed; all controls were mainly healthy individuals. Genotype frequencies were found to be in agreement with HWE in controls and cases. TOX3-rs3803662 SNP was associated with breast cancer risk in our study (T vs. C allele contrast model: OR 1.36, 95% CI 1.12-1.64, P_value = 0.002; TT vs. CT + TT dominant model: OR 0.67, 95% CI 0.51-0.87, P_value = 0.003; TT vs. CT + CC recessive model: OR 1.54, 95% CI 1.02-2.30, P_vlue = 0.036). Moreover, after adjusting for age, BMI, history of previous cancer and also family history of cancer, all results, except for the recessive model, were remained significant. TOX3-rs3803662, may confer some degrees of risk of breast cancer in Iranian population. This finding is in line with similar results in other populations. It highlights the importance of TOX3 pathway in tumorigenesis.

Data mining of pediatric medulloblastoma microarray expression reveals a novel potential subdivision of the Group 4 molecular subgroup

Medulloblastoma is the most common type of solid brain tumor in children. This type of embryonic tumor is highly heterogeneous and has been classified into 4 molecular subgroups based on their gene expression profiles: WNT, SHH, Group 3 (G3) and Group 4 (G4). WNT and SHH tumors exhibit the specific dysregulation of genes and pathways, whereas G3 and G4 tumors, two of the more frequent subtypes, are the least characterized. Thus, novel markers to aid in the diagnosis, prognosis and management of medulloblastoma are required. In the present study, microarray gene expression data was downloaded from the Gene Expression Omnibus database, including data from the 4 subgroups of medulloblastoma and healthy cerebellum tissue (CT). The data was utilized in an in silico analysis to characterize each subgroup at a transcriptomic level. Using Partek Genomics Suite software, the data were visualized via hierarchical clustering and principal component analysis. The differentially expressed genes were uploaded to the MetaCore portal to perform enrichment analysis using CT gene expression as baseline, with fold change thresholds of <-5 and >5 for differential expression. The data mining analysis of microarray gene expression data enabled the identification of a range of dysregulated molecules associated with each subgroup of medulloblastoma. G4 is the most heterogeneous subgroup, as no definitive pathway defines its pathogenesis; analysis of the gene expression profiles were associated with the G4α and G4β subcategories. TOX high mobility group box family member 3, synuclein α interacting protein and, potassium voltage-gated channel interacting protein 4 were identified as three novel potential markers for distinguishing the α and β subcategories of G4. These genes may be associated with medulloblastoma pathogenesis, and thus may provide a basis for researching novel targeted treatment strategies for G4 medulloblastoma.

The breast cancer susceptibility-related polymorphisms at the TOX3/LOC643714 locus associated with lung cancer risk in a Han Chinese population

It has been well established that besides environmental factors, genetic factors are also associated with lung cancer risk. However, to date, the prior identified genetic variants and loci only explain a small fraction of the familial risk of lung cancer. Hence it is vital to investigate the remaining missing heritability to understand the development and process of lung cancer. In the study, to test our hypothesis that the previously identified breast cancer risk-associated genetic polymorphisms at the TOX3/LOC643714 locus might contribute to lung cancer risk, 16 SNPs at the TOX3/LOC643714 locus were evaluated in a Han Chinese population based on a case-control study. Pearson's chi-square test or Fisher's exact test revealed that rs9933638, rs12443621, and rs3104746 were significantly associated with lung cancer risk (P < 0.001, P < 0.001, and P = 0.005, respectively). Logistic regression analyses displayed that lung cancer risk of individuals with rs9933638(GG+GA) were 1.89 times higher than that of rs9933638AA carriers (OR = 1.893, 95% CI = 1.308-2.741, P = 0.001). Similar findings were manifested for rs12443621 (OR = 1.824, 95% CI = 1.272-2.616, P = 0.001, rs12443621(GG+GA) carriers vs. rs12443621AA carriers) and rs3104746 (OR = 1.665, 95% CI = 1.243-2.230, P = 0.001, rs3104746TT carriers vs. rs3104746(TA+AA) carriers). The study discovered for the first time that three SNPs (rs9933638, rs12443621, and rs3104746) at the TOX3/LOC643714 locus contributed to lung cancer risk, providing new evidences that lung cancer and breast cancer are linked at the molecular and genetic level to a certain extent.

Global Transcriptome Analysis of Primary Cerebrocortical Cells: Identification of Genes Regulated by Triiodothyronine in Specific Cell Types

Thyroid hormones, thyroxine, and triiodothyronine (T3) are crucial for cerebral cortex development acting through regulation of gene expression. To define the transcriptional program under T3 regulation, we have performed RNA-Seq of T3-treated and untreated primary mouse cerebrocortical cells. The expression of 1145 genes or 7.7% of expressed genes was changed upon T3 addition, of which 371 responded to T3 in the presence of cycloheximide indicating direct transcriptional regulation. The results were compared with available transcriptomic datasets of defined cellular types. In this way, we could identify targets of T3 within genes enriched in astrocytes and neurons, in specific layers including the subplate, and in specific neurons such as prepronociceptin, cholecystokinin, or cortistatin neurons. The subplate and the prepronociceptin neurons appear as potentially major targets of T3 action. T3 upregulates mostly genes related to cell membrane events, such as G-protein signaling, neurotransmission, and ion transport and downregulates genes involved in nuclear events associated with the M phase of cell cycle, such as chromosome organization and segregation. Remarkably, the transcriptomic changes induced by T3 sustain the transition from fetal to adult patterns of gene expression. The results allow defining in molecular terms the elusive role of thyroid hormones on neocortical development.

Distinct and common expression of receptors for inflammatory mediators in vagal nodose versus jugular capsaicin-sensitive/TRPV1-positive neurons detected by low input RNA sequencing

Capsaicin-sensitive sensory C-fibers derived from vagal ganglia innervate the visceral organs, and respond to inflammatory mediators and noxious stimuli. These neurons play an important role in maintenance of visceral homeostasis, and contribute to the symptoms of visceral inflammatory diseases. Vagal sensory neurons are located in two ganglia, the jugular ganglia (derived from the neural crest), and the nodose ganglia (from the epibranchial placodes). The functional difference, especially in response to immune mediators, between jugular and nodose neurons is not fully understood. In this study, we microscopically isolated murine nodose and jugular capsaicin-sensitive / Trpv1-expressing C-fiber neurons and performed transcriptome profiling using ultra-low input RNA sequencing. RNAseq detected genes with significantly differential expression in jugular and nodose neurons, which were mostly involved in neural functions. Transcriptional regulators, including Cited1, Hoxb5 and Prdm12 showed distinct expression patterns in the two C-fiber neuronal populations. Common and specific expression of immune receptor proteins was characterized in each neuronal type. The expression of immune receptors that have received little or no attention from vagal sensory biologists is highlighted including receptors for certain chemokines (CXCLs), interleukins (IL-4) and interferons (IFNα, IFNγ). Stimulation of immune receptors with their cognate ligands led to activation of the C-fibers in isolated functional assays.

A meta-analysis of genome-wide association studies identifies 17 new Parkinson's disease risk loci

Common variant genome-wide association studies (GWASs) have, to date, identified >24 risk loci for Parkinson's disease (PD). To discover additional loci, we carried out a GWAS comparing 6,476 PD cases with 302,042 controls, followed by a meta-analysis with a recent study of over 13,000 PD cases and 95,000 controls at 9,830 overlapping variants. We then tested 35 loci (P < 1 × 10^-6) in a replication cohort of 5,851 cases and 5,866 controls. We identified 17 novel risk loci (P < 5 × 10^-8) in a joint analysis of 26,035 cases and 403,190 controls. We used a neurocentric strategy to assign candidate risk genes to the loci. We identified protein-altering or cis-expression quantitative trait locus (cis-eQTL) variants in linkage disequilibrium with the index variant in 29 of the 41 PD loci. These results indicate a key role for autophagy and lysosomal biology in PD risk, and suggest potential new drug targets for PD.

Bioinformatics analyses of pathways and gene predictions in IL-1α and IL-1β knockout mice with spinal cord injury

PURPOSE

This study aimed to explore the potential genes and pathways regulated in spinal cord injury (SCI) model mice with IL-1α and IL-1β knockout (KO).

METHODS

Gene expression profile GSE70302, which includes data from injured spinal cord of 4 IL-1α-KO mice, 4 IL-1β-KO mice and 4 C57BL with 6 mice as controls was downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) of the IL-1α-KO or IL-1β-KO vs. control, and IL-1α-KO vs. IL-1β-KO groups were screened, followed by function enrichment and protein-protein interaction (PPI) analyses. Finally, miRNAs associated with SCI that may target the DEGs were predicted.

RESULTS

A total of 579 and 992 DEGs were selected from the IL-1α-KO vs. control group and the IL-1β-KO vs. control group, respectively, and 208 genes common between the 2 comparison groups were identified. Additionally, 526 DEGs were identified from the IL-1α-KO vs. IL-1β-KO groups. These DEGs were significantly enriched in functions and pathways associated with ion transport, neuron apoptotic processes and inflammatory responses. The common genes were enriched in the pathways for cytokine-cytokine receptor interaction. DEGs of IL-1α-KO vs. IL-1β-KO were significantly enriched in the immune system, hematopoietic cell lineage and PI3K-Akt signalling pathway-associated biological processes and pathways. The PPI network consisted of 76 nodes, such as Saa2, Kcna1, Scn8a, Ccl5, Ccl28 and Pink1. A total of 94 miRNAs, including mir-17-5P and mir-30a-5p were predicted that could target the DEGs.

CONCLUSION

IL-1α and IL-1β may play important roles in SCI by regulating ion transport, inflammation and neuron apoptotic processes and their associated genes or miRNAs. Compared with IL-1β-KO, IL-1α-KO may improve the outcome of SCI via the alteration of hematopoietic cell lineage and PI3K-Akt signalling pathways.

Candidate Gene Analysis of Breast Cancer in the Jordanian Population of Arab Descent: A Case-Control Study

This study aimed to investigate whether there are specific polymorphisms within six genes (BRCA1, BRCA2, TP53, DAPK1, MMP9 promoter, and TOX3) that are associated with breast cancer among the Jordanian population. Sequenom MassARRAY system was used to genotype 17 single nucleotide polymorphisms (SNPs) within these genes in 230 Jordanian breast cancer patients and 225 healthy individuals. Three SNPs (MMP9 (rs6065912), TOX3 (rs1420546), and DAPK1 (rs11141901) were found to be significantly associated with an increased risk of breast cancer (p < .05). This study is the first to provide evidence that genetic variation in MMP9, TOX3, and DAPK1 genes contribute to the development of breast cancer in the Jordanian population.

Previous GWAS hits in relation to young-onset breast cancer

PURPOSE

Genome-wide association studies (GWAS) have identified dozens of single-nucleotide polymorphisms (SNPs) associated with breast cancer. Few studies focused on young-onset breast cancer, which exhibits etiologic and tumor-type differences from older-onset disease. Possible confounding by prenatal effects of the maternal genome has also not been considered.

METHODS

Using a family-based design for breast cancer before age 50, we assessed the relationship between breast cancer and 77 GWAS-identified breast cancer risk SNPs. We estimated relative risks (RR) for inherited and maternally mediated genetic effects. We also used published RR estimates to calculate genetic risk scores and model joint effects.

RESULTS

Seventeen of the candidate SNPs were nominally associated with young-onset breast cancer in our 1296 non-Hispanic white affected families (uncorrected p value <0.05). Top-ranked SNPs included rs3803662-A (TOX3, RR = 1.39; p = 7.0 × 10-6), rs12662670-G (ESR1, RR = 1.56; p = 5.7 × 10-4), rs2981579-A (FGFR2, RR = 1.24; p = 0.002), and rs999737-G (RAD51B, RR = 1.37; p = 0.003). No maternally mediated effects were found. A risk score based on all 77 SNPs indicated that their overall relationship to young-onset breast cancer risk was more than additive (additive-fit p = 2.2 × 10-7) and consistent with a multiplicative joint effect (multiplicative-fit p = 0.27). With the multiplicative formulation, the case sister's genetic risk score exceeded that of her unaffected sister in 59% of families.

CONCLUSIONS

The results of this family-based study indicate that no effects of previously identified risk SNPs were explained by prenatal effects of maternal variants. Many of the known breast cancer risk variants were associated with young-onset breast cancer, with evidence that TOX3, ESR1, FGFR2, and RAD51B are important for young-onset disease.

Genetic and Epigenetic Regulation of TOX3 Expression in Breast Cancer

Genome wide association studies (GWAS) have identified low penetrance and high frequency single nucleotide polymorphisms (SNPs) that contribute to genetic susceptibility of breast cancer. The SNPs at 16q12, close to the TOX3 and CASC16 genes, represent one of the susceptibility loci identified by GWAS, showing strong evidence for breast cancer association across various populations. To examine molecular mechanisms of TOX3 regulation in breast cancer, we investigated both genetic and epigenetic factors using cell lines and datasets derived from primary breast tumors available through The Cancer Genome Atlas (TCGA). TOX3 expression is highly up-regulated in luminal subtype tumors compared to normal breast tissues or basal-like tumors. Expression quantitative trait loci (eQTL) analyses revealed significant associations of rs3803662 and rs4784227 genotypes with TOX3 expression in breast tumors. Bisulfite sequencing of four CpG islands in the TOX3 promoter showed a clear difference between luminal and basal-like cancer cell lines. 5-Aza-2’-deoxycytidine treatment of a basal-like cancer cell line increased expression of TOX3. TCGA dataset verified significantly lower levels of methylation of the promoter in luminal breast tumors with an inverse correlation between methylation and expression of TOX3. Methylation QTL (mQTL) analyses showed a weak or no correlation of rs3803662 or rs4784227 with TOX3 promoter methylation in breast tumors, indicating an independent relationship between the genetic and epigenetic events. These data suggest a complex system of TOX3 regulation in breast tumors, driven by germline variants and somatic epigenetic modifications in a subtype specific manner.

Association of single nucleotide polymorphism rs3803662 with the risk of breast cancer

Large scale association studies have identified the single nucleotide polymorphism rs3803662 associated with breast cancer risk. However, the sample size of most studies is too small. Here, we performed this meta-analysis to make the result more convincing. Relevant articles published up to 2016 were identified by searching the PubMed database. 13 studies, involving a total of 29405 participants, were included in the meta-analysis. Odds Ratios (ORs) with 95% confidence intervals (CIs) was calculated with random or fixed effects model. All data analyses were analyzed by Review Manger 5.3 software. In Caucasian subgroup: Dominant model (TT + CT vs CC): OR = 1.17 (1.06, 1.29), Recessive model (TT vs CT + CC): OR = 1.25 (1.13, 1.39) and Allele frequency (T vs C): OR = 1.15 (1.08, 1.22). The present meta-analysis suggests that rs3803662 polymorphism is significantly associated with breast cancer risk in Caucasian women, and we did not find the association in Asian women.

TOX3 protein expression is correlated with pathological characteristics in breast cancer

TOX3 is a newly identified gene that has been observed to correlate with breast cancer by genome-wide association studies (GWAS) in recent years. In addition, it has been noted that single-nucleotide polymorphisms (SNPs) in the TOX3 gene have a strong correlation with estrogen receptor (ER)-positive tumors. However, the role of TOX3 in breast carcinoma development is still unclear. There are limited studies on the subject of TOX3 mRNA expression in breast tumors and little information on the variation of TOX3 protein expression in relation to the clinical pathological features in breast cancer and healthy tissues. In this study, we characterize the protein expression of TOX3 in breast tumors with respect to various clinical and pathological characteristics and explore the correlation between TOX3 protein expression and ER-positive tumors. A breast cancer tissue microarray containing 267 human breast tumors and 25 healthy controls, breast cancer cell lines (ZR-75-1, MDA-MB-231, MCF-7 and Bcap-37) with positive or negative ER expression, tumor tissues and matched controls were used to analyze the protein expression levels of TOX3 by immunohistochemistry, western blot analysis and quantitative polymerase chain reaction. Among the 267 breast tumor specimens, ER expression was detected in 66 tumor tissues. The expression levels of TOX3 increased in breast carcinoma tissue compared with controls, and were higher in advanced carcinoma (T3 and T4), lymph node metastases tissues (N2) and stage III tissues. Furthermore, TOX3 protein expression was more intense in ER-positive tumors, but did not demonstrate a statistical significance. However, it was significantly increased in ER-positive breast cancer cell lines (ZR-75-1, MCF-7 and Bcap-37) compared with the MDA-MB-231 cell line, which had ER-negative expression. Our findings provide support to the hypothesis that TOX3 has a strong correlation with the development of breast cancer. The current study is likely to assist in investigating the mechanisms involved in breast cancer development.

The Role of TOX in the Development of Innate Lymphoid Cells

TOX, an evolutionarily conserved member of the HMG-box family of proteins, is essential for the development of various cells of both the innate and adaptive immune system. TOX is required for the development of CD4(+) T lineage cells in the thymus, including natural killer T and T regulatory cells, as well as development of natural killer cells and fetal lymphoid tissue inducer cells, the latter required for lymph node organogenesis. Recently, we have identified a broader role for TOX in the innate immune system, demonstrating that this nuclear protein is required for generation of bone marrow progenitors that have potential to give rise to all innate lymphoid cells. Innate lymphoid cells, classified according to transcription factor expression and cytokine secretion profiles, derive from common lymphoid progenitors in the bone marrow and require Notch signals for their development. We discuss here the role of TOX in specifying CLP toward an innate lymphoid cell fate and hypothesize a possible role for TOX in regulating Notch gene targets during innate lymphoid cell development.

IL-1α Gene Deletion Protects Oligodendrocytes after Spinal Cord Injury through Upregulation of the Survival Factor Tox3

Spinal cord injury (SCI) causes the release of danger signals by stressed and dying cells, a process that leads to neuroinflammation. Evidence suggests that inflammation plays a role in both the damage and repair of injured neural tissue. We show that microglia at sites of SCI rapidly express the alarmin interleukin (IL)-1α, and that infiltrating neutrophils and macrophages subsequently produce IL-1β. Infiltration of these cells is dramatically reduced in both IL-1α(-/-) and IL-1β(-/-) mice, but only IL-1α(-/-) mice showed rapid (at day 1) and persistent improvements in locomotion associated with reduced lesion volume. Similarly, intrathecal administration of the IL-1 receptor antagonist anakinra restored locomotor function post-SCI. Transcriptome analysis of SCI tissue at day 1 identified the survival factor Tox3 as being differentially regulated exclusively in IL-1α(-/-) mice compared with IL-1β(-/-) and wild-type mice. Accordingly, IL-1α(-/-) mice have markedly increased Tox3 levels in their oligodendrocytes, beginning at postnatal day 10 (P10) and persisting through adulthood. At P10, the spinal cord of IL-1α(-/-) mice showed a transient increase in mature oligodendrocyte numbers, coinciding with increased IL-1α expression in wild-type animals. In adult mice, IL-1α deletion is accompanied by increased oligodendrocyte survival after SCI. TOX3 overexpression in human oligodendrocytes reduced cellular death under conditions mimicking SCI. These results suggest that IL-1α-mediated Tox3 suppression during the early phase of CNS insult plays a crucial role in secondary degeneration.

SIGNIFICANCE STATEMENT

The mechanisms underlying bystander degeneration of neurons and oligodendrocytes after CNS injury are ill defined. We show that microglia at sites of spinal cord injury (SCI) rapidly produce the danger signal interleukin (IL)-1α, which triggers neuroinflammation and locomotor defects. We uncovered that IL-1α(-/-) mice have markedly increased levels of the survival factor Tox3 in their oligodendrocytes, which correlates with the protection of this cell population, and reduced lesion volume, resulting in unprecedented speed, level, and persistence of functional recovery after SCI. Our data suggest that central inhibition of IL-1α or Tox3 overexpression during the acute phase of a CNS insult may be an effective means for preventing the loss of neurological function in SCI, or other acute injuries such as ischemia and traumatic brain injuries.

The Molecular Genetics of Restless Legs Syndrome

Restless legs syndrome (RLS) is a common sensorimotor trait defined by symptoms that interfere with sleep onset and maintenance in a clinically meaningful way. Nonvolitional myoclonus while awake and asleep is a sign of the disorder and an informative endophenotype. The genetic contributions to RLS/periodic leg movements are substantial, are among the most robust defined to date for a common disease, and account for much of the variance in disease expressivity. The disorder is polygenic, as revealed by recent genome-wide association studies. Experimental studies are revealing mechanistic details of how these common variants might influence RLS expressivity.

Human Enhancers Are Fragile and Prone to Deactivating Mutations

To explore the underlying mechanisms whereby noncoding variants affect transcriptional regulation, we identified nucleotides capable of disrupting binding of transcription factors and deactivating enhancers if mutated (dubbed candidate killer mutations or KMs) in HepG2 enhancers. On average, approximately 11% of enhancer positions are prone to KMs. A comparable number of enhancer positions are capable of creating de novo binding sites via a single-nucleotide mutation (dubbed candidate restoration mutations or RSs). Both KM and RS positions are evolutionarily conserved and tend to form clusters within an enhancer. We observed that KMs have the most deleterious effect on enhancer activity. In contrast, RSs have a smaller effect in increasing enhancer activity. Additionally, the KMs are strongly associated with liver-related Genome Wide Association Study traits compared with other HepG2 enhancer regions. By applying our framework to lymphoblastoid cell lines, we found that KMs underlie differential binding of transcription factors and differential local chromatin accessibility. The gene expression quantitative trait loci associated with the tissue-specific genes are strongly enriched in KM positions. In summary, we conclude that the KMs have the greatest impact on the level of gene expression and are likely to be the causal variants of tissue-specific gene expression and disease predisposition.

TOX3 is expressed in mammary ER(+) epithelial cells and regulates ER target genes in luminal breast cancer

Background

A breast cancer susceptibility locus has been mapped to the gene encoding TOX3. Little is known regarding the expression pattern or biological role of TOX3 in breast cancer or in the mammary gland. Here we analyzed TOX3 expression in murine and human mammary glands and in molecular subtypes of breast cancer, and assessed its ability to alter the biology of breast cancer cells.

Methods

We used a cell sorting strategy, followed by quantitative real-time PCR, to study TOX3 gene expression in the mouse mammary gland. To study the expression of this nuclear protein in human mammary glands and breast tumors, we generated a rabbit monoclonal antibody specific for human TOX3. In vitro studies were performed on MCF7, BT474 and MDA-MB-231 cell lines to study the effects of TOX3 modulation on gene expression in the context of breast cancer cells.

Results

We found TOX3 expression in estrogen receptor-positive mammary epithelial cells, including progenitor cells. A subset of breast tumors also highly expresses TOX3, with poor outcome associated with high expression of TOX3 in luminal B breast cancers. We also demonstrate the ability of TOX3 to alter gene expression in MCF7 luminal breast cancer cells, including cancer relevant genes TFF1 and CXCR4. Knockdown of TOX3 in a luminal B breast cancer cell line that highly expresses TOX3 is associated with slower growth. Surprisingly, TOX3 is also shown to regulate TFF1 in an estrogen-independent and tamoxifen-insensitive manner.

Conclusions

These results demonstrate that high expression of this protein likely plays a crucial role in breast cancer progression. This is in sharp contrast to previous studies that indicated breast cancer susceptibility is associated with lower expression of TOX3. Together, these results suggest two different roles for TOX3, one in the initiation of breast cancer, potentially related to expression of TOX3 in mammary epithelial cell progenitors, and another role for this nuclear protein in the progression of cancer. In addition, these results can begin to shed light on the reported association of TOX3 expression and breast cancer metastasis to the bone, and point to TOX3 as a novel regulator of estrogen receptor-mediated gene expression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1018-2) contains supplementary material, which is available to authorized users.

Associations of two common genetic variants with breast cancer risk in a chinese population: a stratified interaction analysis

Recent genome-wide association studies (GWAS) have identified a series of new genetic susceptibility loci for breast cancer (BC). However, the correlations between these variants and breast cancer are still not clear. In order to explore the role of breast cancer susceptibility variants in a Southeast Chinese population, we genotyped two common SNPs at chromosome 6q25 (rs2046210) and in TOX3 (rs4784227) in a case-control study with a total of 702 breast cancer cases and 794 healthy-controls. In addition, we also evaluated the multiple interactions among genetic variants, risk factors, and tumor subtypes. Associations of genotypes with breast cancer risk was evaluated using multivariate logistic regression to estimate odds ratios (OR) and their 95% confidence intervals (95% CI). The results indicated that both polymorphisms were significantly associated with the risk of breast cancer, with per allele OR = 1.35, (95%CI = 1.17-1.57) for rs2046210 and per allele OR = 1.24 (95%CI = 1.06-1.45) for rs4784227. Furthermore, in subgroup stratified analyses, we observed that the T allele of rs4784227 was significantly associated with elevated OR among postmenopausal populations (OR = 1.44, 95%CI 1.11-1.87) but not in premenopausal populations, with the heterogeneity P value of P = 0.064. These findings suggest that the genetic variants at chromosome 6q25 and in the TOX3 gene may play important roles in breast cancer development in a Chinese population and the underlying biological mechanisms need to be further elucidated.

Epigenetic modulation of type-1 diabetes via a dual effect on pancreatic macrophages and β cells

Epigenetic modifiers are an emerging class of anti-tumor drugs, potent in multiple cancer contexts. Their effect on spontaneously developing autoimmune diseases has been little explored. We report that a short treatment with I-BET151, a small-molecule inhibitor of a family of bromodomain-containing transcriptional regulators, irreversibly suppressed development of type-1 diabetes in NOD mice. The inhibitor could prevent or clear insulitis, but had minimal influence on the transcriptomes of infiltrating and circulating T cells. Rather, it induced pancreatic macrophages to adopt an anti-inflammatory phenotype, impacting the NF-κB pathway in particular. I-BET151 also elicited regeneration of islet β-cells, inducing proliferation and expression of genes encoding transcription factors key to β-cell differentiation/function. The effect on β cells did not require T cell infiltration of the islets. Thus, treatment with I-BET151 achieves a 'combination therapy' currently advocated by many diabetes investigators, operating by a novel mechanism that coincidentally dampens islet inflammation and enhances β-cell regeneration.

Effect of sex and age interactions on functional outcome after stroke

Stroke is one of the leading causes of death and disability worldwide. Experimental and clinical studies showed that sex and age play an important role in deciding the outcome after stroke. At younger ages, males were shown to have a higher risk for stroke than females. However, this trend reverses in older ages particularly when females reach menopause. Many preclinical studies indicate that steroid hormones modulate the age-dependent differential stroke outcome. In addition, patterns of cell death pathways activated following cerebral ischemia are distinct between males and females, but independent of steroid hormones. Recent studies also indicate that microRNAs play important roles in mediating sex-specific stroke outcome by regulating stroke-related genes. This review discusses the contribution of sex and age to outcome after stroke with particular emphasis on the experimental studies that examined the effects of steroid hormones, differential cell death pathways, and involvement of sex-specific microRNAs following cerebral ischemia. Current understanding of the role of thrombolytic agents in stroke therapy is also discussed.

Mutational analysis of TOX3 in Chinese Han women with polycystic ovary syndrome

A previous genome-wide association study of polycystic ovary syndrome (PCOS) identified several susceptibility loci. TOX3 is the nearest gene to signal rs4784165. In the present study, all exons and exon-intron boundaries of TOX3 were amplified and sequenced in 200 Chinese women with PCOS. A 3-bp nucleotide deletion of CAG repeat and two known single nucleotide polymorphisms were identified. No plausible pathogenic mutations were detected. The results suggest that mutations in TOX3 are not common in Chinese Han women with PCOS.

Risk-association of five SNPs in TOX3/LOC643714 with breast cancer in southern China

The specific mechanism by which low-risk genetic variants confer breast cancer risk is currently unclear, with contradictory evidence on the role of single nucleotide polymorphisms (SNPs) in TOX3/LOC643714 as a breast cancer susceptibility locus. Investigations of this locus using a Chinese population may indicate whether the findings initially identified in a European population are generalizable to other populations, and may provide new insight into the role of genetic variants in the etiology of breast cancer. In this case-control study, 623 Chinese female breast cancer patients and 620 cancer-free controls were recruited to investigate the role of five SNPs in TOX3/LOC643714 (rs8051542, rs12443621, rs3803662, rs4784227, and rs3112612); Linkage disequilibrium (LD) pattern analysis was performed. Additionally, we evaluated how these common SNPs influence the risk of specific types of breast cancer, as defined by estrogen receptor (ER) status, progesterone receptor (PR) status and human epidermal growth factor receptor 2 (HER2) status. Significant associations with breast cancer risk were observed for rs4784227 and rs8051542 with odds ratios (OR) of 1.31 ((95% confidence intervals (CI), 1.10-1.57)) and 1.26 (95% CI, 1.02-1.56), respectively, per T allele. The T-rs8051542 allele was significantly associated with ER-positive and HER2-negative carriers. No significant association existed between rs12443621, rs3803662, and rs3112612 polymorphisms and risk of breast cancer. Our results support the hypothesis that the applicability of a common susceptibility locus must be confirmed among genetically different populations, which may together explain an appreciable fraction of the genetic etiology of breast cancer.

TOX3 mutations in breast cancer

TOX3 maps to 16q12, a region commonly lost in breast cancers and recently implicated in the risk of developing breast cancer. However, not much is known of the role of TOX3 itself in breast cancer biology. This is the first study to determine the importance of TOX3 mutations in breast cancers. We screened TOX3 for mutations in 133 breast tumours and identified four mutations (three missense, one in-frame deletion of 30 base pairs) in six primary tumours, corresponding to an overall mutation frequency of 4.5%. One potentially deleterious missense mutation in exon 3 (Leu129Phe) was identified in one tumour (genomic DNA and cDNA). Whilst copy number changes of 16q12 are common in breast cancer, our data show that mutations of TOX3 are present at low frequency in tumours. Our results support that TOX3 should be further investigated to elucidate its role in breast cancer biology.