Elf1 promotes Rad26's interaction with lesion-arrested Pol II for transcription-coupled repair.

Transcription-coupled nucleotide excision repair (TC-NER) is a highly conserved DNA repair pathway that removes bulky lesions in the transcribed genome. Cockayne syndrome B protein (CSB), or its yeast ortholog Rad26, has been known for decades to play important roles in the lesion-recognition steps of TC-NER. Another conserved protein ELOF1, or its yeast ortholog Elf1, was recently identified as a core transcription-coupled repair factor. How Rad26 distinguishes between RNA polymerase II (Pol II) stalled at a DNA lesion or other obstacles and what role Elf1 plays in this process remains unknown. Here, we present cryo-EM structures of Pol II-Rad26 complexes stalled at different obstacles that show that Rad26 uses a common mechanism to recognize a stalled Pol II, with additional interactions when Pol II is arrested at a lesion. A cryo-EM structure of lesion-arrested Pol II-Rad26 bound to Elf1 revealed that Elf1 induces further interactions between Rad26 and a lesion-arrested Pol II. Biochemical and genetic data support the importance of the interplay between Elf1 and Rad26 in TC-NER initiation. Together, our results provide important mechanistic insights into how two conserved transcription-coupled repair factors, Rad26/CSB and Elf1/ELOF1, work together at the initial lesion recognition steps of transcription-coupled repair.

[Infection stress and a driver mutation interact to promote transformation to hematological malignancies].

Myelodysplastic syndrome (MDS) is a refractory cancer that arises from hematopoietic stem cells and predominantly affects elderly adults. In addition to driver gene mutations, which are also found in clonal hematopoiesis in healthy elderly people, systemic inflammation caused by infection or collagen disease has long been known as an extracellular factor in the pathogenesis of MDS. Wild-type HSCs have an "innate immune memory" that functions in response to infection and inflammatory stress, and my colleagues and I used an infection stress model to demonstrate that the innate immune response by the TLR-TRIF-PLK-ELF1 pathway is similarly critical in impairment of hematopoiesis and dysregulation of chromatin in MDS stem cells. This revealed that not only are MDS stem cells expanded by the TRAF6-NF-kB pathway, the innate immune response is also involved in generating MDS stem cells. In this review, I will present research findings related to "innate immune memory," one of the pathogenic mechanisms of blood cancer, and discuss future directions for basic pathological research and potential therapeutic development.

ELF1 suppresses autophagy to reduce cisplatin resistance via the miR-152-3p/NCAM1/ERK axis in lung cancer cells.

Resistance to chemotherapeutic drugs limits the efficacy of chemotherapy in non-small cell lung cancer (NSCLC). Autophagy is an essential mechanism which involves in drug resistance. Our previous research has revealed that miR-152-3p represses NSCLC progression. However, the mechanism of miR-152-3p in autophagy-mediated chemoresistance in NSCLC remains unclear. Cisplatin-resistant cell lines (A549/DDP and H446/DDP) were transfected with related vectors and subjected to cisplatin, autophagy inhibitor, activator, or extracellular signal-regulated kinase (ERK) activator. Flow cytometry, CCK8 and colony formation assays were performed for testing apoptosis and cell viability. The related RNAs or proteins were detected by qRT-PCR or Western blot. Chromatin immunoprecipitation, luciferase reporter assay or RNA immunoprecipitation were used for validating the interaction between miR-152-3p and ELF1 or NCAM1. Co-IP verified the binding between NCAM1 and ERK. The role of miR-152-3p in cisplatin resistance of NSCLC was also validated in vivo. The results showed that miR-152-3p and ELF1 were decreased in NSCLC tissues. miR-152-3p reversed cisplatin resistance by inhibiting autophagy through NCAM1. NCAM1 promoted autophagy through the ERK pathway and facilitated cisplatin resistance. ELF1 positively regulated miR-152-3p level by directly interacting with miR-152-3p promoter. miR-152-3p targeted NCAM1 to regulate NCAM1 level and then affected the binding of NCAM1 to ERK1/2. ELF1 inhibited autophagy and reversed cisplatin resistance through miR-152-3p/NCAM1. miR-152-3p inhibited autophagy and cisplatin resistance of xenograft tumor in mice. In conclusion, our study revealed that ELF1 inhibited autophagy to attenuate cisplatin resistance through the miR-152-3p/NCAM1/ERK pathway in H446/DDP and A549/DDP cells, suggesting a potential novel treatment strategy for NSCLC.

Expression of ELF1, a lymphoid ETS domain-containing transcription factor, is recurrently lost in classical Hodgkin lymphoma.

Loss of B cell-specific transcription factors (TFs) and the resulting loss of B-cell phenotype of Hodgkin and Reed-Sternberg (HRS) cells is a hallmark of classical Hodgkin lymphoma (cHL). Here we have analysed two members of ETS domain containing TFs, ELF1 and ELF2, regarding (epi)genomic changes as well as gene and protein expression. We observed absence or lower levels of ELF1 protein in HRS cells of 31/35 (89%) cases compared to the bystander cells and significant (P < 0·01) downregulation of the gene on mRNA as well as protein level in cHL compared to non-cHL cell lines. However, no recurrent loss of ELF2 protein was observed. Moreover, ELF1 was targeted by heterozygous deletions combined with hypermethylation of the remaining allele(s) in 4/7 (57%) cell lines. Indeed, DNA hypermethylation (range 95-99%, mean 98%) detected in the vicinity of the ELF1 transcription start site was found in all 7/7 (100%) cHL cell lines. Similarly, 5/18 (28%) analysed primary biopsies carried heterozygous deletions of the gene. We demonstrate that expression of ELF1 is impaired in cHL through genetic and epigenetic alterations, and thus, it may represent an additional member of a TF network whose downregulation contributes to the loss of B-cell phenotype of HRS cells.

The transcription factor MEF/Elf4 is dually modulated by p53-MDM2 axis and MEF-MDM2 autoregulatory mechanism.

Myeloid Elf-1-like factor (MEF) or Elf4 is an ETS transcription factor that activates innate immunity-associated genes such as lysozyme (LYZ), human ß-defensin 2 (HßD2), and interleukin-8 (IL-8) in epithelial cells and is also known to influence cell cycle progression. MEF is transcriptionally activated by E2F1, but the E2F1-mediated transcriptional activation is inhibited by p53 through E2F1-p53 protein interaction. Although the transcriptional activation of MEF has been investigated in depth, its post-translational regulation is not well explored. By overexpressing MEF cDNA in human cell lines, here we show that MEF protein expression is suppressed by p53. By screening a number of E3 ligases regulated by p53, we found that MDM2 is involved in the effect of p53 on MEF. MDM2 is transcriptionally activated by p53 and interacts with MEF protein to enhance MEF degradation. MDM2 reduces MEF protein expression, as well as stability and function of MEF as transcriptional activator. Furthermore, MDM2 was able to down-regulate MEF in the absence of p53, indicating a p53-independent effect on MEF. Notably, MEF transcriptionally activates MDM2, which was previously demonstrated to be the mechanism by which MEF suppresses the p53 protein. These results reveal that in addition to the potential of MEF to down-regulate p53 by transcriptionally activating E3 ligase MDM2, MEF participates with MDM2 in a novel autoregulatory feedback loop to regulate itself. Taken together with the findings on the effect of p53 on MEF, these data provide evidence that the p53-MDM2-MEF axis is a feedback mechanism that exquisitely controls the balance of these transcriptional regulators.

ARL11 knockdown alleviates spinal cord injury by inhibiting neuroinflammation and M1 activation of microglia in mice.

Spinal cord injury (SCI) is a severe central nervous system injury and microglia are major participants in neuroinflammation after injury. ADP-ribosylation factor-like GTPase 11 (ARL11) is a GTP-binding protein. Whether ARL11 is involved in the SCI progression is unknown. In the impactor-induced moderate SCI mouse model, ARL11 protein and mRNA expression were significantly increased in the injury site. LPS (100 ng/mL) and IFN-γ (20 ng/mL) were incubated with BV2 cells (immortalized mouse microglial cell line) to drive them into an M1-like phenotype. ARL11 up-regulation was also observed in activated microglia in SCI mice and LPS and IFN-γ treated BV2 cells. Basso Mouse Scale scores and inclined plate test revealed that ARL11 deletion promoted motor function recovery in SCI mice. Pathological examination showed ARL11 knockdown reduced spinal cord tissue damage, increased neuron numbers, and inhibited neuronal apoptosis in SCI mice. ARL11 knockdown notably inhibited IL-1ß and IL-6 production in vivo and in vitro. Furthermore, ARL11 deletion significantly inhibited iNOS protein and mRNA expression in vivo and in vitro, and COX-2 expression in vivo. Mechanism studies revealed that ARL11 silencing decreased phosphorylated ERK1/2 protein expression. Additionally, ELF1 knockdown significantly inhibited ARL11 protein and mRNA expression in vitro. ELF1 acted as a transcription activator in regulating ARL11 expression by binding to the promoter. In conclusion, ARL11 knockdown protects neurons by inhibiting M1 microglia-induced neuroinflammation, thereby promoting motor functional recovery in SCI mice. This may occur in part under the regulation of ELF1. Our study provides a new molecular target for SCI treatment.

E74-like ETS transcription factor 1 promotes the progression of pancreatic cancer by regulating doublecortin-like kinase 1/Janus kinase/signal transducer and activator of transcription pathway.

This study was targeted at investigating the biological functions of E74-like ETS transcription factor 1 (ELF1) in pancreatic cancer (PC) and its underlying mechanism. ELF1 expression in PC tissues was detected by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemistry. Cell counting kit-8 (CCK-8) method, EdU method and flow cytometry were used to detect the cell proliferation and apoptosis of PC cell lines after transfection. A subcutaneous tumorigenesis model was constructed to validate the oncogenic role of ELF1 in vivo. PROMO database was used to predict the binding site of ELF1 on the promoter region of doublecortin-like kinase 1 (DCLK1). Dual-luciferase reporter gene assay, chromatin immunoprecipitation-quantitative polymerase chain reaction (ChIP-qPCR) assay and quantitative real-time PCR were performed to detect the binding of ELF1 to the promoter region of DCLK1. The effect of ELF1 on DCLK1 expression was detected by Western blot assay. It was found that ELF1 expression in PC tissues and cells was up-regulated. ELF1 overexpression promoted the proliferation and inhibited the apoptosis of PC cells, while knocking down ELF1 had the opposite effects. ELF1 could bind to the promoter region of DCLK1 and ELF1 overexpression promoted the expression of DCLK1. Bioinformatics analysis suggested that Janus kinase (JAK) - signal transducer and activator of transcription (STAT) signaling pathway was associated to DCLK1 expression, and overexpression of ELF1 promoted the expression of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3). In conclusion, ELF1 promoted the malignant progression of PC via regulating DCLK1/ JAK/STAT signaling pathway.

Transcription activation of SPINK4 by ELF-1 augments progression of colon cancer by regulating biological behaviors.

BACKGROUND: SPINK4 was highly expressed in colorectal cancer and resulted in worse prognosis of colorectal cancer patients. However, the expression and function of SPINK4 in colon cancer have not been revealed. METHODS: Analysis from GEPIA website showed the expression and function of SPINK4 in colon cancer samples. Colon cancer cell lines were applied to detect the biological function of SPINK4. Functionally, the transcriptional factor of SPINK4 has been predicted and verified. Finally, the associations between transcriptional factor and SPINK4 have been confirmed. RESULTS: SPINK4 expression was obviously increased in colon cancer samples. HCT-116 and DXH-1 cells in si-SPINK4-1 or si-SPINK4-2 group displayed an obvious reduction in its proliferation, cell cycle, invasion and migration compared to those in the si-control group. Moreover, transcriptional factor ELF-1 bound to the promoter of SPINK4 and affected its expression in colon cancer cells. High ELF-1 expression was presented in colon cancer samples and resulted in worse prognosis of colon cancer patients. Additionally, si-SPINK4 antagonized the function of ELF-1 overexpression in modulating colon cancer cell proliferation, cell cycle and mobility. CONCLUSIONS: Our findings afforded a theoretical basis for further research on the treatment of colon cancer based on the control of ELF-1/SPINK4 expression.

ELF1/PRR11/ARP2/3 promoted trophoblast cells proliferation and motility in early pregnancy.

BACKGROUND/OBJECTIVE: Early pregnancy loss (EPL) is a common adverse pregnancy outcome with an incidence of approximately 10-30%. There are many factors that cause EPL, among which the lack of proliferation and invasive properties of trophoblast cells can lead to embryonic development. Therefore, in this study, the molecular biology of trophoblast cells was investigated. METHODS: Placental villous tissues from EPL patients were collected to explore ELF1 and PRR11 gene expression. The proliferation and migration of trophoblast cells were assessed by MTT, crystalline violet staining, and traswell assays, respectively. Western blotting and RT-qPCR were performed to investigate the relationship between ELF1, PRR11, and ARP2/3. F-actin polymerization and FAK activation were evaluated by immunofluorescence and western blotting. Ultimately, ELF1/PRR11/ARP2/3 expression was verified in the EPL mice model RESULTS: ELF1 and PRR11 were lowly expressed in placental villous tissues from EPL. The overexpression of ELF1 and PRR11 promoted proliferation and migration of trophoblast cells. Moreover, while ELF1 bound to the PRR11 promoter and promoted transcriptional activation. Finally, ELF1/PRR11/ARP2/3 showed low expression in the placental tissue of EPL mice. CONCLUSION: Our study suggested that PRR11 promoted the motility of trophoblast cells by binding to the ARP2/3 complex to promote F-actin polymerization and FAK activation. In addition, ELF1 bound to the initiation site of PRR11 to promote its transcription. ELF1/PRR11/ARP2/3 may play an important role in EPL.

LncRNA HOXD-AS1 affects proliferation and apoptosis of cervical cancer cells by promoting FRRS1 expression via transcription factor ELF1.

To investigate the function of lncRNA HOXD-AS1 in cervical squamous cell carcinoma (CESC) and the underlying mechanism. The expressions of HOXD-AS1 and FRRS1 were analyzed on the online software GEPIA based on CESC-related information in The Cancer Genome Atlas (TCGA). Cervical cancer cells (SiHa and Hela) were accordingly transfected with pCDNA3.1-HOXD-AS1, sh-HOXD-AS1, sh-FRRS1 or pCDNA3.1-ELF1. After cell transfection, CCK-8, EDU and flow cytometry were applied for measurement of cell vitality, quantity and apoptosis, respectively. The relationship between HOXD-AS1 and FRRS1 was predicted on the online software LncMap and further verified by RNA binding protein immunoprecipitation. Nude mice were injected with stabilized SiHa cells transfected with sh-HOXD-AS1 to assess the tumorigenic ability of HOXD-AS1 in vivo. Immunohistochemistry detected the expression of the proliferation marker Ki-67. The levels of HOXD-AS1, ELF1 and FRRS1 were measured in vivo and in vitro. HOXD-AS1 and FRRS1 were overexpressed in CESC. After transfection of sh-HOXD-AS1, sh-ELF1 or sh-FRRS1, the proliferation of SiHa and Hela cells was inhibited and their apoptosis was promoted; while HOXD-AS1 overexpression had opposite effects on CESC development. Co-transfection of sh-FRRS1 and pCDNA3.1-HOXD-AS1 could abolish the tumor suppressive effect of FRRS1 knockdown. HOXD-AS1 elevated the level of FRRS1 by binding ELF1. Furthermore, HOXD-AS1 contributed to the CESC growth in mouse models. HOXD-AS1 promotes CESC by up-regulating FRRS1 via ELF1.

Transcription Factor ELF1 Activates MEIS1 Transcription and Then Regulates the GFI1/FBW7 Axis to Promote the Development of Glioma.

Glioma is the most common malignancy in the central nervous system with no immediate prospect of a cure. Comprehensive understanding on the pathogenesis of the disorder contributes to a better outcome. Herein, we aimed to investigate whether transcription factors erythroblast transformation-specific (ETS) transcription factor (ELF1), myeloid ecotropic viral integration site 1 (MEIS1), and growth factor independence 1 (GFI1)/F-box/WD repeat-containing protein 7 (FBW7) mediate progression of glioma. ELF1, MEIS1, and GFI1 were upregulated in glioma cells and tissues, as ELF1 was correlated with poor prognosis. Bioinformatics analysis identified the binding between ELF1 and MEIS1 as well as between GFI1 and FBW7, confirmed by chromatin immunoprecipitation (ChIP) experiments. Functional experiment indicated that silencing of ELT1 decreased MEIS1 expression and that overexpression of MEIS1 increased GFI1 expression by activating GFI1 enhancer but decreased FBW7 expression. Importantly, silencing of ELF1 decreased the capacities of proliferation, migration, and invasion of glioma cells whereas it increased apoptosis, supported by increased capase-3 and decreased matrix metalloproteinase-9 (MMP-9) and proliferating cell nuclear antigen (PCNA) expression. Moreover, an in vivo experiment confirmed the inhibitory role of silenced ELF1 in tumor growth, with a decreased level of MEIS1 and GFI1. Taken together, our study elucidated a potential mechanism that ELF1 promoted cell progression by increasing GFI1 and METS1 as well as decreasing FBW7 expression in glioma.

ELF1 Transcription Factor Enhances the Progression of Glioma via ATF5 promoter.

A key transcriptional activator, activating transcription factor 5 (ATF5), is aberrantly overexpressed in glioma and supports both poor prognosis and antiapototic potential. Unfortunately, data on ATF5 is largely based on its regulatory mechanism. Further investigation of the upstream regulatory factor for ATF5 transcription in glioma is required. Clinical data for patients with diagnosed glioma were obtained from The Cancer Genome Atlas (TCGA). Additionally, transcription factors potentially regulating the ATF5 promoter in glioma were screened with bioinformatics. A further experimental study was performed to investigate both the role of E74-like factor 1 (ELF1) and the binding of ELF1 and the ATF5 promoter in glioma. We show that ATF5 expression is upregulated in glioma tissues and associated with tumor malignancy and worse prognosis. As a putative upstream regulator, silencing ELF1 inhibits glioma cell growth and migration with ATF5 involvement. Moreover, ELF1 upregulation is also associated with poor prognosis in glioma. Importantly, the luciferase assay and chromatin immunoprecipitation (ChIP) reveal that the ATF5 gene promoter is essential for ELF1-dependent activation of ATF5 gene transcription. These results indicate that a high expression of ELF1 may be related to the malignant behavior of human glioma and ELF1 promotes glioma development mediated by transactivation of the ATF5 gene.

Modulation of STIM1 by a risk insertion/deletion polymorphism underlying genetics susceptibility to sudden cardiac death originated from coronary artery disease.

Stromal interaction molecule 1 (STIM1), as a dynamic calcium signal transducer and key regulator of cardiomyocyte Ca2+ homeostasis, has been implicated in various pathological processes related to sudden cardiac death originated from coronary artery disease (SCD-CAD). In this study, we performed a systematic variant screening on promoter region of STIM1 to filter potential functional genetic variations. Based on the screening results, a 5-bp insertion/deletion (indel) polymorphism (rs3061890) in promoter region of STIM1 was selected as the candidate variant. We investigated the association of rs3061890 with SCD-CAD susceptibility in Chinese Han populations. The homozygote del/del genotype significantly increased risk for SCD-CAD as compared with the ins/ins genotype (odds ratio, 2.86 [95% confidence interval, 1.69-4.29]; P = 2.3 × 10-5). Compared with the common allele, the 5-bp deletion risk allele exhibited lower transcriptional capacity in luciferase assays. Intriguingly, genotype-phenotype correlation studies using human myocardium tissue samples revealed that the expression of STIM1 was associated with the genotype of rs3061890. Computational prediction combined with electrophoretic mobility shift (EMSA) and chromatin immunoprecipitation (ChIP) assays provided convincing evidence for stronger binding affinity of ELF1 (E74 like ETS transcription factor 1) with the deletion allele promoter. Taken together, our findings implied an allele-specific mechanism of regulating the transcription of STIM1 via ELF1, which contribute to SCD-CAD susceptibility. rs3061890 may thus considered as a candidate genetic marker for SCD-CAD prediction and prevention.

ELF1-activated FOXD3-AS1 promotes the migration, invasion and EMT of osteosarcoma cells via sponging miR-296-5p to upregulate ZCCHC3.

Osteosarcoma (OS) is a malignant carcinoma often occurring in adolescents. The critical function of long non-coding RNAs (lncRNAs) in cancer arouses increasing attention. Nevertheless, the specific function of FOXD3 Antisense RNA 1 (FOXD3-AS1) in OS has not been understood yet. In this research, FOXD3-AS1 showed strengthened level in OS specimens and cell lines, and its deficiency restrained cell migration, invasion and epithelial-to-mesenchymal transition (EMT) in OS. Then, we confirmed the interaction of FOXD3-AS1 with microRNA-296-5p (miR-296-5p) and that miR-296-5p overexpression blocked OS cell migration, invasion and EMT. Besides, miR-296-5p targeted zinc finger CCHC-type containing 3 (ZCCHC3), and FOXD3-AS1 released ZCCHC3 via sequestering miR-296-5p. Moreover, rescue assays delineated that ZCCHC3 upregulation neutralized the inhibitory effect of FOXD3-AS1 depletion on in vitro behaviors and in vivo tumorigenesis in OS. In addition, E74 like ETS transcription factor 1 (ELF1) stimulated FOXD3-AS1 transcription, and ELF1 silence-suppressed malignant phenotypes of OS cells were offset by FOXD3-AS1 upregulation. Overall, present work elucidated that ELF1-activated FOXD3-AS1 aggravated cell migration, invasion and EMT in OS via absorbing miR-296-5p to augment ZCCHC3 expression, which might provide potential guidance for researchers to find effective targets for OS treatment.

Knocking down Israa, the Zmiz1 intron-nested gene, unveils interrelated T cell activation functions in mouse.

We previously reported Israa (immune-system-released activating agent), a novel gene nested in intron 6 of the mouse Zmiz1 gene. Zmiz1 is involved in several functions such as fertility and T cell development and its knockout leads to non-viable embryos. We also reported ISRAA's expression in lymphoid organs, particularly in the thymus CD3+ T cells during all developmental stages. In addition, we showed that ISRAA is a binding partner of Fyn and Elf-1 and regulates the expression of T cell activation-related genes in vitro. In this paper, we report the generation and characterization of an Israa -/- constitutive knockout mouse. The histological study shows that Israa -/- mice exhibit thymus and spleen hyperplasia. Israa -/- derived T cells showed increased proliferation compared to the wild-type mice T cells. Moreover, gene expression analysis revealed a set of differentially expressed genes in the knockout and wild-type animals during thymus development (mostly genes of T cell activation pathways). Immunological phenotyping of the thymocytes and splenocytes of Israa -/- showed no difference with those of the wild-type. Moreover, we observed that knocking out the Zmiz1 intron embedded Israa gene does not affect mice fertility, thus does not disturb this Zmiz1 function. The characterization of the Israa -/- mouse confirms the role ISRAA plays in the expression regulation of genes involved in T cell activation established in vitro. Taken together, our findings point toward a potential functional interrelation between the intron nested Israa gene and the Zmiz1 host gene in regulating T cell activation. This constitutively Israa -/- mice can be a good model to study T cell activation and to investigate the relationship between host and intron-nested genes.

ELF1-mediated LUCAT1 promotes choroidal melanoma by modulating RBX1 expression.

Long noncoding RNAs (lncRNAs) are essential regulators of gene expression and biological behaviors. However, the contribution of lncRNA LUCAT1 to choroidal melanoma (CM) remains unexplored. Here, we examined the expression of LUCAT1 in CM cells by qRT-PCR and investigated its biological effects by cell counting kit-8, EdU, TUNEL, transwell assays, and Western blot. Bioinformatics tools were applied to find RNA candidates for further study. Moreover, mechanistic experiments including RNA immunoprecipitation assay, pull-down assay, and luciferase reporter assay confirmed the relation or interaction among the indicated molecules. Here, we reported ELF1 as the transcription activator of LUCAT1. Functionally, elevated expression of LUCAT1 positively regulated CM cell proliferation, metastasis, and epithelial-mesenchymal transition process. In addition, we verified the competing endogenous RNA (ceRNA) hypothesis of LUCAT1 and confirmed LUCAT1 modulates CM progression by modulating miR-514a/b-3p/RBX1 axis. Meanwhile, miR-514a/b-3p was suggested to repress CM progression, whereas RBX1 was unmasked to aggravate CM development. Of note, RBX1 overexpression rescued the inhibitory effect of LUCAT1 silence on the biological processes of CM cells. Altogether, this study unveiled the modulation axis ELF1/LUCAT1/miR-514a/b-3p/RBX1 and evidenced LUCAT1 as a promoter in CM for the first time, providing a novel insight into future treatment of CM.

ELF-1 expression in nasopharyngeal carcinoma facilitates proliferation and metastasis of cancer cells via modulation of CCL2/CCR2 signaling.

Background: Nasopharyngeal carcinoma (NPC) is a prevalent malignant tumor in Southeast Asia. The management of NPC has remained a challenge until now. ELF-1 is a member of the ETS family of transcription factors that regulate genes involved in cellular growth. ELF-1 expression has been reported in various cancers and is required for tumor growth and angiogenesis; however, its function in NPC remains unclear. In the present study, we characterized the role and underlying mechanism of ELF-1 in NPC. Methods: The biological functions of ELF-1 in NPC cells such as proliferation, migration, invasion, and drug resistance were investigated using MTT, BrdU incorporation, and Transwell assays. To gain more insight into the mechanism of ELF-1 in NPC, we analyzed CCL2/CCR2 signaling by Western blotting, ELISA, siRNAs, and CCR2 antagonist. Results: Gain-of-function of ELF-1 in TW01 and TW04 cells promoted NPC cell proliferation, BrdU incorporation, migration, invasion and cisplatin resistance. By contrast, knockdown of ELF-1 produced opposite results. Overexpression of ELF-1 enhanced the expression of CCL2 via binding to its promoter region and increased the level of the extracellular matrix protein CCL2 in cell culture medium. ELF-1 expression also modulated the downstream targets of CCL2/CCR2 signaling. Most importantly, ELF-1-induced NPC malignant phenotypes were abrogated by a CCR2 inhibitor, implying that the CCL2/CCR2 signaling axis was involved in ELF-1-mediated regulation in NPC. Conclusion: Our data suggest that ELF-1 plays an oncogenic role in NPC development associated with the CCL2/CCR2 signaling pathway and may therefore be a potential target for NPC therapy.

The mouse intron-nested gene, Israa, is expressed in the lymphoid organs and involved in T-cell activation and signaling.

We have previously reported Israa, immune-system-released activating agent, as a novel gene nested in intron 8 of the mouse Zmiz1 gene. We have also shown that Israa encodes for a novel FYN-binding protein and might be involved in the regulation of T-cell activation. In this report, we demonstrate that Israa gene product regulates the expression of a pool of genes involved in T-cell activation and signaling. Real time PCR and GFP knock-in expression analysis showed that Israa is transcribed and expressed in the spleen mainly by CD3+CD8+ cells as well as in the thymus by CD3+ (DP and DN), CD4+SP and CD8+SP cells at different developmental stages. We also showed that Israa is downregulated in T-cells following activation of T-cell receptor. Using yeast two-hybrid analysis, we identified ELF1, a transcription factor involved in T-cell regulation, as an ISRAA-binding partner. Transcriptomic analysis of an EL4 cell line overexpressing ISRAA revealed differential expression of several genes involved in T-cell signaling, activation and development. Among these genes, Prkcb, Mib2, Fos, Ndfip2, Cxxc5, B2m, Gata3 and Cd247 were upregulated whereas Itk, Socs3, Tigit, Ifng, Il2ra and FoxJ1 were downregulated. Our findings support the existence in mouse of a novel FYN-related T-cell regulation pathway involving the product of an intron-nested gene.

Common ELF1 deletion in prostate cancer bolsters oncogenic ETS function, inhibits senescence and promotes docetaxel resistance.

ETS family transcription factors play major roles in prostate tumorigenesis with some acting as oncogenes and others as tumor suppressors. ETS factors can compete for binding at some cis-regulatory sequences, but display specific binding at others. Therefore, changes in expression of ETS family members during tumorigenesis can have complex, multimodal effects. Here we show that ELF1 was the most commonly down-regulated ETS factor in primary prostate tumors, and expression decreased further in metastatic disease. Genome-wide mapping in cell lines indicated that ELF1 has two distinct tumor suppressive roles mediated by distinct cis-regulatory sequences. First, ELF1 inhibited cell migration and epithelial-mesenchymal transition by interfering with oncogenic ETS functions at ETS/AP-1 cis-regulatory motifs. Second, ELF1 uniquely targeted and activated genes that promote senescence. Furthermore, knockdown of ELF1 increased docetaxel resistance, indicating that the genomic deletions found in metastatic prostate tumors may promote therapeutic resistance through loss of both RB1 and ELF1.

The cutting edge of archaeal transcription.

The archaeal RNA polymerase (RNAP) is a double-psi ß-barrel enzyme closely related to eukaryotic RNAPII in terms of subunit composition and architecture, promoter elements and basal transcription factors required for the initiation and elongation phase of transcription. Understanding archaeal transcription is, therefore, key to delineate the universally conserved fundamental mechanisms of transcription as well as the evolution of the archaeo-eukaryotic transcription machineries. The dynamic interplay between RNAP subunits, transcription factors and nucleic acids dictates the activity of RNAP and ultimately gene expression. This review focusses on recent progress in our understanding of (i) the structure, function and molecular mechanisms of known and less characterized factors including Elf1 (Elongation factor 1), NusA (N-utilization substance A), TFS4, RIP and Eta, and (ii) their evolution and phylogenetic distribution across the expanding tree of Archaea.