The Diverse Roles of ETV6 Alterations in B-Lymphoblastic Leukemia and Other Hematopoietic Cancers.

Genetic alterations of the repressive ETS family transcription factor gene ETV6 are recurrent in several categories of hematopoietic malignancy, including subsets of B-cell and T-cell acute lymphoblastic leukemias (B-ALL and T-ALL), myeloid neoplasms, and mature B-cell lymphomas. ETV6 is essential for adult hematopoietic stem cells (HSCs), contributes to specific functions of some mature immune cells, and plays a key role in thrombopoiesis as demonstrated by familial ETV6 mutations associated with thrombocytopenia and predisposition to hematopoietic cancers, particularly B-ALL. ETV6 appears to have a tumor suppressor role in several hematopoietic lineages, as demonstrated by recurrent somatic loss-of-function (LoF) and putative dominant-negative alterations in leukemias and lymphomas. ETV6 rearrangements contribute to recurrent fusion oncogenes such as the B-ALL-associated transcription factor (TF) fusions ETV6::RUNX1 and PAX5::ETV6, rare drivers such as ETV6::NCOA6, and a spectrum of tyrosine kinase gene fusions encoding hyperactive signaling proteins that self-associate via the ETV6 N-terminal pointed domain. Another subset of recurrent rearrangements involving the ETV6 gene locus appear to function primarily to drive overexpression of the partner gene. This review surveys what is known about the biochemical and genome regulatory properties of ETV6 as well as our current understanding of how alterations in these functions contribute to hematopoietic and nonhematopoietic cancers.

An oncogenic enhancer promotes melanoma progression via regulating ETV4 expression.

BACKGROUND: Enhancers are important gene regulatory elements that promote the expression of critical genes in development and disease. Aberrant enhancer can modulate cancer risk and activate oncogenes that lead to the occurrence of various cancers. However, the underlying mechanism of most enhancers in cancer remains unclear. Here, we aim to explore the function and mechanism of a crucial enhancer in melanoma. METHODS: Multi-omics data were applied to identify an enhancer (enh17) involved in melanoma progression. To evaluate the function of enh17, CRISPR/Cas9 technology were applied to knockout enh17 in melanoma cell line A375. RNA-seq, ChIP-seq and Hi-C data analysis integrated with luciferase reporter assay were performed to identify the potential target gene of enh17. Functional experiments were conducted to further validate the function of the target gene ETV4. Multi-omics data integrated with CUT&Tag sequencing were performed to validate the binding profile of the inferred transcription factor STAT3. RESULTS: An enhancer, named enh17 here, was found to be aberrantly activated and involved in melanoma progression. CRISPR/Cas9-mediated deletion of enh17 inhibited cell proliferation, migration, and tumor growth of melanoma both in vitro and in vivo. Mechanistically, we identified ETV4 as a target gene regulated by enh17, and functional experiments further support ETV4 as a target gene that is involved in cancer-associated phenotypes. In addition, STAT3 acts as a transcription factor binding with enh17 to regulate the transcription of ETV4. CONCLUSIONS: Our findings revealed that enh17 plays an oncogenic role and promotes tumor progression in melanoma, and its transcriptional regulatory mechanisms were fully elucidated, which may open a promising window for melanoma prevention and treatment.

α-Ketoglutarate alleviates osteoarthritis by inhibiting ferroptosis via the ETV4/SLC7A11/GPX4 signaling pathway.

Osteoarthritis (OA) is the most common degenerative joint disorder that causes disability in aged individuals, caused by functional and structural alterations of the knee joint. To investigate whether metabolic drivers might be harnessed to promote cartilage repair, a liquid chromatography-mass spectrometry (LC-MS) untargeted metabolomics approach was carried out to screen serum biomarkers in osteoarthritic rats. Based on the correlation analyses, α-ketoglutarate (α-KG) has been demonstrated to have antioxidant and anti-inflammatory properties in various diseases. These properties make α-KG a prime candidate for further investigation of OA. Experimental results indicate that α-KG significantly inhibited H2O2-induced cartilage cell matrix degradation and apoptosis, reduced levels of reactive oxygen species (ROS) and malondialdehyde (MDA), increased superoxide dismutase (SOD) and glutathione (GSH)/glutathione disulfide (GSSG) levels, and upregulated the expression of ETV4, SLC7A11 and GPX4. Further mechanistic studies observed that α-KG, like Ferrostatin-1 (Fer-1), effectively alleviated Erastin-induced apoptosis and ECM degradation. α-KG and Fer-1 upregulated ETV4, SLC7A11, and GPX4 at the mRNA and protein levels, decreased ferrous ion (Fe2+) accumulation, and preserved mitochondrial membrane potential (MMP) in ATDC5 cells. In vivo, α-KG treatment inhibited ferroptosis in OA rats by activating the ETV4/SLC7A11/GPX4 pathway. Thus, these findings indicate that α-KG inhibits ferroptosis via the ETV4/SLC7A11/GPX4 signaling pathway, thereby alleviating OA. These observations suggest that α-KG exhibits potential therapeutic properties for the treatment and prevention of OA, thereby having potential clinical applications in the future.

MYCT1 controls environmental sensing in human haematopoietic stem cells.

The processes that govern human haematopoietic stem cell (HSC) self-renewal and engraftment are poorly understood and challenging to recapitulate in culture to reliably expand functional HSCs1-3. Here we identify MYC target 1 (MYCT1; also known as MTLC) as a crucial human HSC regulator that moderates endocytosis and environmental sensing in HSCs. MYCT1 is selectively expressed in undifferentiated human haematopoietic stem and progenitor cells (HSPCs) and endothelial cells but becomes markedly downregulated during HSC culture. Lentivirus-mediated knockdown of MYCT1 prevented human fetal liver and cord blood (CB) HSPC expansion and engraftment. By contrast, restoring MYCT1 expression improved the expansion and engraftment of cultured CB HSPCs. Single-cell RNA sequencing of human CB HSPCs in which MYCT1 was knocked down or overexpressed revealed that MYCT1 governs important regulatory programmes and cellular properties essential for HSC stemness, such as ETS factor expression and low mitochondrial activity. MYCT1 is localized in the endosomal membrane in HSPCs and interacts with vesicle trafficking regulators and signalling machinery. MYCT1 loss in HSPCs led to excessive endocytosis and hyperactive signalling responses, whereas restoring MYCT1 expression balanced culture-induced endocytosis and dysregulated signalling. Moreover, sorting cultured CB HSPCs on the basis of lowest endocytosis rate identified HSPCs with preserved MYCT1 expression and MYCT1-regulated HSC stemness programmes. Our work identifies MYCT1-moderated endocytosis and environmental sensing as essential regulatory mechanisms required to preserve human HSC stemness. Our data also pinpoint silencing of MYCT1 as a cell-culture-induced vulnerability that compromises human HSC expansion.

ETV4 is a mechanical transducer linking cell crowding dynamics to lineage specification.

Dynamic changes in mechanical microenvironments, such as cell crowding, regulate lineage fates as well as cell proliferation. Although regulatory mechanisms for contact inhibition of proliferation have been extensively studied, it remains unclear how cell crowding induces lineage specification. Here we found that a well-known oncogene, ETS variant transcription factor 4 (ETV4), serves as a molecular transducer that links mechanical microenvironments and gene expression. In a growing epithelium of human embryonic stem cells, cell crowding dynamics is translated into ETV4 expression, serving as a pre-pattern for future lineage fates. A switch-like ETV4 inactivation by cell crowding derepresses the potential for neuroectoderm differentiation in human embryonic stem cell epithelia. Mechanistically, cell crowding inactivates the integrin-actomyosin pathway and blocks the endocytosis of fibroblast growth factor receptors (FGFRs). The disrupted FGFR endocytosis induces a marked decrease in ETV4 protein stability through ERK inactivation. Mathematical modelling demonstrates that the dynamics of cell density in a growing human embryonic stem cell epithelium precisely determines the spatiotemporal ETV4 expression pattern and, consequently, the timing and geometry of lineage development. Our findings suggest that cell crowding dynamics in a stem cell epithelium drives spatiotemporal lineage specification using ETV4 as a key mechanical transducer.

The function of the ELF3 gene and its mechanism in cancers.

E74-like factor 3 (ELF3) is an important member of the E-twenty-six (ETS) transcription factor family. ELF3 is expressed in various types of cells and regulates a variety of biological behaviors, such as cell proliferation, differentiation, apoptosis, migration, and invasion, by binding to DNA to regulate the expression of other genes. In recent years, studies have shown that ELF3 plays an important role in the occurrence and development of many tumors and inflammation and immune related diseases. ELF3 has different functions and expression patterns in different tumors; it can function as a tumor suppressor gene or an oncogene, highlighting its dual effects of tumor promotion and inhibition. ELF3 also affects the levels of tumor immunity-related cytokines and is involved in the regulation and expression of multiple signaling pathways. In tumor therapy, ELF3 is a complex and multifunctional gene and has become a key focus of targeted treatment research. An in-depth study of the biological function of ELF3 can help to elucidate its role in biological processes and provide ideas and a basis for the development and clinical application of ELF3-related therapeutic methods. This review introduces the structure and physiological and cellular functions of the ELF3 gene, summarizes the mechanisms of action of ELF3 in different types of malignant tumors and its role in immune regulation, inflammation, etc., and discusses treatment methods for ELF3-related diseases, providing significant reference value for scholars studying the ELF3 gene and related diseases.

Seihaito, a Kampo medicine, attenuates IL-13-induced mucus production and goblet cell metaplasia.

Goblet cell hyperplasia and increased mucus production are features of airway diseases, including asthma, and excess airway mucus often worsens these conditions. Even steroids are not uniformly effective in mucus production in severe asthma, and new therapeutic options are needed. Seihaito is a Japanese traditional medicine that is used clinically as an antitussive and expectorant. In the present study, we examined the effect of Seihaito on goblet cell differentiation and mucus production. In in vitro studies, using air-liquid interface culture of guinea-pig tracheal epithelial cells, Seihaito inhibited IL-13-induced proliferation of goblet cells and MUC5AC, a major component of mucus production. Seihaito suppressed goblet cell-specific gene expression, without changing ciliary cell-specific genes, suggesting that it inhibits goblet cell differentiation. In addition, Seihaito suppressed MUC5AC expression in cells transfected with SPDEF, a transcription factor activated by IL-13. Furthermore, Seihaito attenuated in vivo goblet cell proliferation and MUC5AC mRNA expression in IL-13-treated mouse lungs. Collectively, these findings demonstrated that Seihaito has an inhibitory effect on goblet cell differentiation and mucus production, which is at least partly due to the inhibition of SPDEF.

ELK3 destabilization by speckle-type POZ protein suppresses prostate cancer progression and docetaxel resistance.

Accumulating evidence demonstrates that the activity regulation of ELK3, a member of the E26 transformation-specific oncogene family, is critical to regulating cell proliferation, migration, and survival in human cancers. However, the molecular mechanisms of how ELK3 induces chemoresistance in prostate cancer (PCa) have not been elucidated. In this study, we found that SPOP and ELK3 are an interacting partner. The interaction between SPOP and ELK3 resulted in increased ELK3 ubiquitination and destruction, assisted by checkpoint kinase-mediated ELK3 phosphorylation. Notably, the modulation of SPOP-mediated ELK3 protein stability affected the c-Fos-induced cell proliferation and invasion of PCa cells. The clinical involvement of the SPOP-ELK3 axis in PCa development was confirmed by an immunohistochemical assay on 123 PCa tissues, with an inverse correlation between increased ELK3 and decreased SPOP being present in ~80% of the specimens. This observation was supported by immunohistochemistry analysis using a SPOP-mutant PCa specimen. Finally, docetaxel treatment induced cell death by activating checkpoint kinase- and SPOP-mediated ELK3 degradation, while SPOP-depleted or SPOP-mutated PCa cells showed cell death resistance. Notably, this observation was correlated with the protein levels of ELK3. Taken together, our study reveals the precise mechanism of SPOP-mediated degradation of ELK3 and provides evidence that SPOP mutations contribute to docetaxel resistance in PCa.

Switch of ELF3 and ATF4 transcriptional axis programs the amino acid insufficiency-linked epithelial-to-mesenchymal transition.

Epithelial-to-mesenchymal transition (EMT) that endows cancer cells with increased invasive and migratory capacity enables cancer dissemination and metastasis. This process is tightly associated with metabolic reprogramming acquired for rewiring cell status and signaling pathways for survival in dietary insufficiency conditions. However, it remains largely unclear how transcription factor (TF)-mediated transcriptional programs are modulated during the EMT process. Here, we reveal that depletion of a key epithelial TF, ELF3 (E74-like factor-3), triggers a transforming growth factor ß (TGF-ß) signaling activation-like mesenchymal transcriptomic profile and metastatic features linked to the aminoacyl-tRNA biogenesis pathway. Moreover, the transcriptome alterations elicited by ELF3 depletion perfectly resemble an ATF4-dependent weak response to amino acid starvation. Intriguingly, we observe an exclusive enrichment of ELF3 and ATF4 in epithelial and TGF-ß-induced or ELF3-depletion-elicited mesenchymal enhancers, respectively, with rare co-binding on altered enhancers. We also find that the upregulation of aminoacyl-tRNA synthetases and some mesenchymal genes upon amino acid deprivation is diminished in ATF4-depleted cells. In sum, the loss of ELF3 binding on epithelial enhancers and the gain of ATF4 binding on the enhancers of mesenchymal factors and amino acid deprivation responsive genes facilitate the loss of epithelial cell features and the gain of TGF-ß-signaling-associated mesenchymal signatures, which further promote lung cancer cell metastasis.

ETS transcription factors regulate precise matrix metalloproteinase expression and follicle rupture in Drosophila.

Drosophila matrix metalloproteinase 2 (MMP2) is specifically expressed in posterior follicle cells of stage-14 egg chambers (mature follicles) and is crucial for the breakdown of the follicular wall during ovulation, a process that is highly conserved from flies to mammals. The factors that regulate spatiotemporal expression of MMP2 in follicle cells remain unknown. Here, we demonstrate crucial roles for the ETS-family transcriptional activator Pointed (Pnt) and its endogenous repressor Yan in the regulation of MMP2 expression. We found that Pnt is expressed in posterior follicle cells and overlaps with MMP2 expression in mature follicles. Genetic analysis demonstrated that pnt is both required and sufficient for MMP2 expression in follicle cells. In addition, Yan was temporally upregulated in stage-13 follicle cells to fine-tune Pnt activity and MMP2 expression. Furthermore, we identified a 1.1 kb core enhancer that is responsible for the spatiotemporal expression of MMP2 and contains multiple pnt/yan binding motifs. Mutation of pnt/yan binding sites significantly impaired the Mmp2 enhancer activity. Our data reveal a mechanism of transcriptional regulation of Mmp2 expression in Drosophila ovulation, which could be conserved in other biological systems.

Affinity-optimizing enhancer variants disrupt development.

Enhancers control the location and timing of gene expression and contain the majority of variants associated with disease1-3. The ZRS is arguably the most well-studied vertebrate enhancer and mediates the expression of Shh in the developing limb4. Thirty-one human single-nucleotide variants (SNVs) within the ZRS are associated with polydactyly4-6. However, how this enhancer encodes tissue-specific activity, and the mechanisms by which SNVs alter the number of digits, are poorly understood. Here we show that the ETS sites within the ZRS are low affinity, and identify a functional ETS site, ETS-A, with extremely low affinity. Two human SNVs and a synthetic variant optimize the binding affinity of ETS-A subtly from 15% to around 25% relative to the strongest ETS binding sequence, and cause polydactyly with the same penetrance and severity. A greater increase in affinity results in phenotypes that are more penetrant and more severe. Affinity-optimizing SNVs in other ETS sites in the ZRS, as well as in ETS, interferon regulatory factor (IRF), HOX and activator protein 1 (AP-1) sites within a wide variety of enhancers, cause gain-of-function gene expression. The prevalence of binding sites with suboptimal affinity in enhancers creates a vulnerability in genomes whereby SNVs that optimize affinity, even slightly, can be pathogenic. Searching for affinity-optimizing SNVs in genomes could provide a mechanistic approach to identify causal variants that underlie enhanceropathies.

Huaier suppresses cell viability, migration and invasion in human non-small cell lung cancer via lncRNA DLEU2/miR-212-5p/ELF3 axis.

Accumulating studies suggest that Huaier exerts anti-tumor effects through intricate mechanisms. Despite extensive research on its efficacy in lung cancer, further investigation is required to elucidate the molecular mechanism of Huaier. The involvement of long noncoding RNAs (lncRNAs) in the anti-lung cancer effects of Huaier remains unknown. In this study, we found Huaier suppressed cell viability, migration and invasion in non-small cell lung cancer (NSCLC) cells. LncRNA sequencing analysis revealed Deleted in lymphocytic leukemia 2 (DLEU2) to be significantly downregulated in Huaier-treated NSCLC cells. Furthermore, DLEU2 silencing was observed to suppress NSCLC progression, while DLEU2 overexpression attenuated the anti-tumor effects of Huaier in NSCLC, thereby promoting cell viability, migration and invasion of NSCLC. The ceRNA role of DLEU2 had been demonstrated in NSCLC, which directly interacted with miR-212-5p to rescue the repression of E74 Like ETS Transcription Factor 3 (ELF3) by this microRNA. Additionally, Huaier was found to regulate the expression of miR-212-5p and ELF3. Functionally, miR-212-5p inhibitor or ELF3 overexpression reversed the effects of DLEU2 silencing or Huaier treatment, resulting in increased colony formation, migration and invasion in NSCLC. Taken together, these results illuminate the mechanism underlying Huaier's anti-tumor effects via the DLEU2/miR-212-5p/ELF3 signaling pathway, which offers novel insights into the anti-tumor effects of Huaier and constitutes a promising therapeutic target for the treatment in NSCLC.

A complex with poly(A)-binding protein and EWS facilitates the transcriptional function of oncogenic ETS transcription factors in prostate cells.

The ETS transcription factor ERG is aberrantly expressed in approximately 50% of prostate tumors due to chromosomal rearrangements such as TMPRSS2/ERG. The ability of ERG to drive oncogenesis in prostate epithelial cells requires interaction with distinct coactivators, such as the RNA-binding protein EWS. Here, we find that ERG has both direct and indirect interactions with EWS, and the indirect interaction is mediated by the poly-A RNA-binding protein PABPC1. PABPC1 directly bound both ERG and EWS. ERG expression in prostate cells promoted PABPC1 localization to the nucleus and recruited PABPC1 to ERG/EWS-binding sites in the genome. Knockdown of PABPC1 in prostate cells abrogated ERG-mediated phenotypes and decreased the ability of ERG to activate transcription. These findings define a complex including ERG and the RNA-binding proteins EWS and PABPC1 that represents a potential therapeutic target for ERG-positive prostate cancer and identify a novel nuclear role for PABPC1.

Genome-wide identification and characteristic analysis of ETS gene family in blood clam Tegillarca granosa.

BACKGROUND: ETS transcription factors, known as the E26 transformation-specific factors, assume a critical role in the regulation of various vital biological processes in animals, including cell differentiation, the cell cycle, and cell apoptosis. However, their characterization in mollusks is currently lacking. RESULTS: The current study focused on a comprehensive analysis of the ETS genes in blood clam Tegillarca granosa and other mollusk genomes. Our phylogenetic analysis revealed the absence of the SPI and ETV subfamilies in mollusks compared to humans. Additionally, several ETS genes in mollusks were found to lack the PNT domain, potentially resulting in a diminished ability of ETS proteins to bind target genes. Interestingly, the bivalve ETS1 genes exhibited significantly high expression levels during the multicellular proliferation stage and in gill tissues. Furthermore, qRT-PCR results showed that Tg-ETS-14 (ETS1) is upregulated in the high total hemocyte counts (THC) population of T. granosa, suggesting it plays a significant role in stimulating hemocyte proliferation. CONCLUSION: Our study significantly contributes to the comprehension of the evolutionary aspects concerning the ETS gene family, while also providing valuable insights into its role in fostering hemocyte proliferation across mollusks.

ETV4 facilitates angiogenesis in hepatocellular carcinoma by upregulating MMP14 expression.

Abnormal vascularization plays a crucial role in cell proliferation, tumor invasion and metastasis of hepatocellular carcinoma (HCC). It has been reported that ETV4 functions as an oncogenic gene in driving the carcinogenesis and progression, and promoting invasion and metastasis of HCC. However, the function of ETV4 on angiogenesis in HCC remains unclear. In the current study, immunohistochemistry showed that knockdown of ETV4 reduced angiogenesis in HCC xenograft tumor tissues. In vitro, tube formation assay verified that ETV4 expression promoted angiogenesis through simulating the angiogenic environment in HCC cells. Transcriptome sequencing indicated that MMP14 was one of the differentially expressed genes enriched in angiogenesis process. Subsequently, it was confirmed that MMP14 was regulated by ETV4 at the transcription level in HCC cells, clinical tissue samples and online databases. Further, we demonstrated that MMP14 induced angiogenesis in ETV4-mediated HCC microenvironment. Collectively, this research further reveals the biological mechanism of ETV4 in promoting the migration and invasion of HCC, and provides novel mechanistic insights and strategic guidance for anti-angiogenic therapy in HCC.

Shared metabolic shifts in endothelial cells in stroke and Alzheimer's disease revealed by integrated analysis.

Since metabolic dysregulation is a hallmark of both stroke and Alzheimer's disease (AD), mining shared metabolic patterns in these diseases will help to identify their possible pathogenic mechanisms and potential intervention targets. However, a systematic integration analysis of the metabolic networks of the these diseases is still lacking. In this study, we integrated single-cell RNA sequencing datasets of ischemic stroke (IS), hemorrhagic stroke (HS) and AD models to construct metabolic flux profiles at the single-cell level. We discovered that the three disorders cause shared metabolic shifts in endothelial cells. These altered metabolic modules were mainly enriched in the transporter-related pathways and were predicted to potentially lead to a decrease in metabolites such as pyruvate and fumarate. We further found that Lef1, Elk3 and Fosl1 may be upstream transcriptional regulators causing metabolic shifts and may be possible targets for interventions that halt the course of neurodegeneration.

E74­like ETS transcription factor 5 facilitates cell proliferation through regulating the expression of adenomatous polyposis coli 2 in non­small cell lung cancer.

E74­like ETS transcription factor 5 (ELF5) is known to regulate the specification and differentiation of epithelial cells in the embryonic lung. However, the pathological function of ELF5 in lung cancer has yet to be fully elucidated. In the present study, the expression of ELF5 was found to be significantly higher in lung adenocarcinoma compared with that in corresponding adjacent normal tissues. Subsequently, cell and animal experiments were performed to investigate the role of ELF5 in lung adenocarcinoma cells. The results indicated that the overexpression of ELF5 increased the proliferation of lung adenocarcinoma cells, whereas, by contrast, a reduction in the expression of ELF5 led to a decrease in their proliferation. Mechanistically, the hypothesis is advanced that ELF5 can promote lung cancer cell proliferation through inhibiting adenomatous polyposis coli 2 and increasing the expression of cyclin D1, which is a critical downstream target of the Wnt pathway. Taken together, these findings support the notion that ELF5 exerts an essential role in the proliferation of lung adenocarcinoma cells and may be a therapeutic target for the treatment of lung adenocarcinoma.

Down-regulated MiRNA 29-b as a diagnostic marker in colorectal cancer and its correlation with ETV4 and Cyclin D1 immunohistochemical expression.

BACKGROUND: Colorectal cancer (CRC) is the most common malignant tumor of the gastrointestinal tract with unfavorable prognosis. Therefore, novel biomarkers that may be used for new diagnostic strategies and drug-targeting therapy should be developed. OBJECTIVES: To investigate the expression of miR-29b in CRC and its association with ETV4 and cyclin D1 expression. Moreover, the current work aims to investigate the association between them and the clinicopathological features of CRC. METHODS: The expression of miR-29b and ETV4 (by qRT-PCR) and ETV4 and cyclin D1 (immunohistochemistry) was investigated in 65 cases of colon cancer and surrounding healthy tissues. RESULTS: MiR-29b down-regulated and ETV4 and Cyclin D1 up-regulated significantly in colon cancer tissues compared to normal nearby colonic tissues. In addition, significant associations between ETV4 and cyclin D1 expressions and progressive stage and lymph node (LN) metastasis (P< 0.001 for each) were found. Furthermore, there was a negative correlation between miR-29b gene expression and ETV4 gene expression (r=-0.298, P<0.016). CONCLUSION: Down-regulation of miR-29b and over-expression of ETV4 and cyclin D1 may be utilized as early diagnostic marker for development of colon cancer. ETV4 and cyclin D1 correlate with poor prognostic indicators and considered as a possible target for therapy in colon cancer.

ETV7 reduces inflammatory responses in breast cancer cells by repressing the TNFR1/NF-κB axis.

The transcription factor ETV7 is an oncoprotein that is up-regulated in all breast cancer (BC) types. We have recently demonstrated that ETV7 promoted breast cancer progression by increasing cancer cell proliferation and stemness and was also involved in the development of chemo- and radio-resistance. However, the roles of ETV7 in breast cancer inflammation have yet to be studied. Gene ontology analysis previously performed on BC cells stably over-expressing ETV7 demonstrated that ETV7 was involved in the suppression of innate immune and inflammatory responses. To better decipher the involvement of ETV7 in these signaling pathways, in this study, we identified TNFRSF1A, encoding for the main receptor of TNF-α, TNFR1, as one of the genes down-regulated by ETV7. We demonstrated that ETV7 directly binds to the intron I of this gene, and we showed that the ETV7-mediated down-regulation of TNFRSF1A reduced the activation of NF-κB signaling. Furthermore, in this study, we unveiled a potential crosstalk between ETV7 and STAT3, another master regulator of inflammation. While it is known that STAT3 directly up-regulates the expression of TNFRSF1A, here we demonstrated that ETV7 reduces the ability of STAT3 to bind to the TNFRSF1A gene via a competitive mechanism, recruiting repressive chromatin remodelers, which results in the repression of its transcription. The inverse correlation between ETV7 and TNFRSF1A was confirmed also in different cohorts of BC patients. These results suggest that ETV7 can reduce the inflammatory responses in breast cancer through the down-regulation of TNFRSF1A.

Nervous system-related gene regulatory networks and functional evolution of ETS proteins across species.

The ETS domain transcription factor family is one of the major transcription factor superfamilies that play regulatory roles in development, cell growth, and cancer progression. Although different functions of ETS member proteins in the nervous system have been demonstrated in various studies, their role in neuronal cell differentiation and the evolutionary conservation of its target genes have not yet been extensively studied. In this study, we focused on the regulatory role of ETS transcription factors in neuronal differentiation and their functional evolution by comparative transcriptomics. In order to investigate the regulatory role of ETS transcription factors in neuronal differentiation across species, transcriptional profiles of ETS members and their target genes were investigated by comparing differentially expressed genes and gene regulatory networks, which were analyzed using human, gorilla, mouse, fruit fly and worm transcriptomics datasets. Bioinformatics approaches to examine the evolutionary conservation of ETS transcription factors during neuronal differentiation have shown that ETS member proteins regulate genes associated with neuronal differentiation, nervous system development, axon, and synaptic regulation in different organisms. This study is a comparative transcriptomic study of ETS transcription factors in terms of neuronal differentiation using a gene regulatory network inference algorithm. Overall, a comparison of gene regulation networks revealed that ETS members are indeed evolutionarily conserved in the regulation of neuronal differentiation. Nonetheless, ETS, PEA3, and ELF subfamilies were found to be relatively more active transcription factors in the transcriptional regulation of neuronal differentiation.