NAB2 Research Articles

Research on the Therapeutic Effect of Qizhu Anti Cancer Recipe on Colorectal Cancer Based on RNA Sequencing Analysis.

Colorectal cancer is one of the common malignant tumors in clinical practice, and traditional Chinese medicine, as an important adjuvant treatment method, plays important roles in the treatment of malignant tumors. This study aims to explore the mechanism of action of the Qizhu anti-cancer recipe on colorectal cancer through transcriptome sequencing. The control group and Qizhu anti-cancer recipe group were established separately, and sequencing of the cells of the two groups was performed using the Illumina sequencing platform. Two sets of Differentially Expressed Genes (DEGs) were screened using the DESeq2 algorithm, and Principal Component Analysis (PCA), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Reactome, Disease Ontology (DO), and Protein-Protein Interaction (PPI) were used to comprehensively analyze the molecular functions and signaling pathways enriched by DEGs. A total of 122 DEGs were identified through differential analysis, including 24 upregulated genes and 98 downregulated genes. GO analysis showed that DEGs were mainly enriched in functions such as alkaline phase activity, ion transport, cell differentiation, etc.; KEGG analysis showed that DEGs were mainly enriched in pathways such as Thiamine metabolism, apoptosis, signaling pathways regulating pluripotency of stem cells, cellular senescence and so on. Reactom analysis showed that DEGs were mainly enriched in response pathways such as EGR1,2,3 bind to the NAB2 promoter, EGR binds ARC gene, EGR-dependent NAB2 gene expression, etc.; DO analysis showed that differentially expressed genes were mainly enriched in diseases such as disease of cellular proliferation, disease of anatomical entity, organ system cancer, etc.; PPI analysis identified key differentially expressed genes, including DDIT3, CHAC1, TRIB3, and ASNS. Based on transcriptome sequencing and bioinformatics analysis, it was found that the Qizhu anti-cancer recipe may involve DEGs and signaling pathways in the treatment of colorectal cancer. Our study may provide potential drug targets for developing new treatment strategies for colorectal cancer.

High-Throughput Hybridization Assay as First-Line Diagnostic Test for Sarcomas: Clinical Assessment in a Tertiary Referral Center.

Sarcomas are rare and highly heterogeneous mesenchymal tumors with deceptive morphologic features that pose a challenge for precise diagnostics. Chromosomal rearrangements generating pathognomonic gene fusions are useful diagnostic markers, traditionally tested using single-plex standard of care assays with limited diagnostic yield. NanoString nCounter technology has emerged as a robust solution with multiplexing capabilities. To optimize NanoString effective coverage of specific entities and conduct a validation study to support its clinical implementation. We reconfigured a NanoString's codeset by including a set of probes for detecting gene fusion variants of solitary fibrous tumors, low-grade fibromyxoid sarcomas/sclerosing epithelioid fibrosarcomas, and undifferentiated small round cell sarcomas, totaling 188 probes. A technical validation study was conducted with 96 retrospective samples. Additionally, 76 prospective samples were evaluated to assess the assay's clinical performance. Both technical and clinical validation studies showed that NanoString's codeset reached >88% sensitivity and 100% specificity, compared with standard of care methods, and superior diagnostic yield as a first-line test. Our design enabled the detection of almost all fusion variants of NGFI-A binding protein 2 (NAB2) with signal transducer and activator of transcription 6 (STAT6) in solitary fibrous tumors, as well as cAMP responsive element binding protein 3 like 1/2 (CREB3L1/2) rearrangements in all low-grade fibromyxoid sarcoma/sclerosing epithelioid fibrosarcoma cases. Identification of specific gene fusions of undifferentiated small round cell sarcoma was also improved, but additional strategies are necessary to attain full coverage. The NanoString platform demonstrated good sensitivity, specificity, and superior diagnostic yield. It is a cost-effective assay with rapid turnaround time, low sample consumption, streamlined analysis, and easy customization. Therefore, it is a promising alternative first-line diagnostic tool for routine sarcoma testing.

A DEAD-box helicase drives the partitioning of a pro-differentiation NAB protein into nuclear foci

How cells regulate gene expression in a precise spatiotemporal manner during organismal development is a fundamental question in biology. Although the role of transcriptional condensates in gene regulation has been established, little is known about the function and regulation of these molecular assemblies in the context of animal development and physiology. Here we show that the evolutionarily conserved DEAD-box helicase DDX-23 controls cell fate in Caenorhabditis elegans by binding to and facilitating the condensation of MAB-10, the C. elegans homolog of mammalian NGFI-A-binding (NAB) protein. MAB-10 is a transcriptional cofactor that functions with the early growth response (EGR) protein LIN-29 to regulate the transcription of genes required for exiting the cell cycle, terminal differentiation, and the larval-to-adult transition. We suggest that DEAD-box helicase proteins function more generally during animal development to control the condensation of NAB proteins important in cell identity and that this mechanism is evolutionarily conserved. In mammals, such a mechanism might underlie terminal cell differentiation and when dysregulated might promote cancerous growth.

Zinc finger transcription factor Egf1 promotes non-alcoholic fatty liver disease

Background & AimsNon-alcoholic fatty liver disease (NAFLD) contributes to the global epidemic of metabolic syndrome and is considered a prelude to end-stage liver diseases such as cirrhosis and hepatocellular carcinoma. During NAFLD pathogenesis, hepatic parenchymal cells (hepatocytes) undergo both morphological and functional changes owing to a rewired transcriptome. The underlying mechanism is not entirely clear. In the present study, we investigated the involvement of early growth response 1 (Egr1) in NAFLD. MethodsQuantitative PCR, Western blotting, and histochemical staining were used to assess gene expression levels. Chromatin immunoprecipitation was used to evaluate protein binding to DNA. NAFLD was evaluated in leptin receptor-deficient (db/db) mice. ResultsWe report here that Egr1 was upregulated by pro-NAFLD stimuli in vitro and in vivo. Further analysis revealed that serum response factor (SRF) was recruited to the Egr1 promoter and mediated Egr1 transactivation. Importantly, Egr1 depletion markedly mitigated NAFLD in db/db mice. RNA sequencing revealed that Egr1 knockdown in hepatocytes, on the one hand, boosted fatty acid oxidation (FAO) and, on the other hand, suppressed the synthesis of chemoattractants. Mechanistically, Egr1 interacted with peroxisome proliferator-activated receptor α (PPARα) to repress PPARα-dependent transcription of FAO genes by recruiting its co-repressor NGFI-A binding protein 1 (Nab1), which potentially led to promoter deacetylation of FAO genes. ConclusionsOur data identify Egr1 as a novel modulator of NAFLD and a potential target for NAFLD intervention. Impact and ImplicationsNon-alcoholic fatty liver disease (NAFLD) precedes cirrhosis and hepatocellular carcinoma. In this paper, we describe a novel mechanism whereby early growth response 1 (Egr1), a transcription factor, contributes to NAFLD pathogenesis by regulating fatty acid oxidation. Our data provide novel insights and translational potential for NAFLD intervention.

Cis-regulatory elements (CREs) in spinal solitary fibrous tumours (SFT)

Spinal Solitary Fibrous Tumour is a rare soft tissue neoplasm. Although a lot of genes are involved in Spinal Solitary Fibrous Tumour progression, survival and metastasis, NGFI-A binding protein 2 (NAB2) - signal transducer and activator of transcription 6 (STAT6) gene fusion is one of the most commonly occurring genetic abnormalities in all types of Solitary Fibrous Tumours (SFT). The interaction of STAT6 (Early Growth Response (EGR) transcriptional activator) and NAB2 (EGR transcriptional repressor) activates the conversion of the transcription repressor to the transcriptional activator and promotes EGR-induced promoter activity. EGR has shown to plays a role in the regulation of cell survival, proliferation and cell death. Cis-regulatory elements (CREs) are genomic sequences in non-coding regions of the genomic DNA which binds with the transcription factors, and they play an essential role in precise control of gene expression. CREs composed of enhancers, suppressors and insulators play pivotal roles in gene expression throughout life and development. They have important role in maintaining the normal homeostasis, preventing organogenesis, tumourigenesis and teratoma formation. In this study, we investigate the non-coding regions in the human genome to detect enhancers and suppressors present in different tissue samples of Spinal SFT using Encyclopedia of DNA Elements (ENCODE). The study of these enhancers and suppressors may be used to develop newer diagnostic and treatment strategies. A total of 75 genes and immunohistochemistry (IHC) markers expressed in Spinal SFT were obtained from PubMed and Google Scholar. CREs were identified using the ENCODE consortium. Protein interaction network was obtained using String v11.0 using the proteins corresponding to these 75 genes. Results obtained from ENCODE were enumerated and web-hosted for public access to design a treatment strategy. This may enable the wet lab scientist design CREs specific for Spinal SFT using the in silico results obtained.

Correlation between small-scale methylation changes and gene expression during the development of myopia.

Visually induced changes in the expression of early growth response-1 (EGR1), FBJ osteosarcoma oncogene (FOS), and NGFI-A binding protein-2 (NAB2) appear to form a part of a retinal network fundamental to ocular growth regulation, and thus, the development of myopia (short-sightedness). However, it is unclear how environmental (visual) cues are translated into these molecular changes. One possibility is through epigenetic modifications such as DNA methylation, a known regulator of such processes. By sequencing bisulfite-converted DNA amplicons, this study examined whether changes in DNA methylation occur within specific regulatory and promoter regions of EGR1, FOS, and NAB2 during the periods of increased and decreased ocular growth in chicks. Visually induced changes in ocular growth rates were associated with single-point, but not large-scale, shifts in methylation levels within the investigated regions. Analysis of methylation pattern variability (entropy) demonstrated that the observed methylation changes are occurring within small subpopulations of retinal cells. This concurs with previous observations that EGR1 and FOS are differentially regulated at the peptide level within specific retinal cell types. Together, the findings of this study support a potential role for DNA methylation in the translation of external visual cues into molecular changes critical for ocular growth regulation and myopia development.

A Rare Cause of Recurrent Hypoglycemia - The “Big-IGF-II” Factor

Abstract Introduction: Hormone secreting tumors are a rare cause of hypoglycemia. Here we present an interesting case of paraneoplastic phenomenon resulting in a non-islet cell tumor causing hypoglycemia (NICTH) from a solitary fibrous tumor (SFT). Clinical Case: An 83-year-old female with a history of hypertension presented with recurrent episodes of lightheadedness and falls for one month. Review of systems was negative except for insignificant weight loss. Her vital signs and physical examination were unremarkable. Only significant finding on initial blood work was a blood glucose level of 30 mg/dL (n: >70mg/dL). Additional work-up of hypoglycemia revealed a low serum free insulin level 0.6 IU/mL (n:1.5 - 14.9 IU/mL), low proinsulin <4 pmol/L (n: <18.8 pmol/L), low C-peptide level 0.14 ng/mL (n: 0.80-3.85 ng/mL), low serum insulin-like growth factor-I (IGF-I) 33 ng/ml (n:34-246 ng/ml) and elevated IGF-II levels 370 ng/mL (n:47-350 ng/mL). Blood sulfonylurea and insulin antibodies screen were negative, ACTH and morning cortisol levels were within normal limits. A CT scan of chest, abdomen and pelvis for neoplastic workup demonstrated a large heterogeneous mass within the lower lobe of the right lung. A CT-guided biopsy disclosed spindle cell neoplasm, positive for signal transducer and activator of transcription-6 (STAT6) and CD34. Reverse transcription-polymerase chain reaction (RT-PCR) confirmed the NGFI-A binding protein 2 (NAB2) and STAT6 fusion which is specific for solitary fibrous tumor (SFT). She underwent surgical resection of the thoracic mass which resulted in complete resolution of her symptoms. Clinical Lessons: NICTH is a paraneoplastic syndrome associated with various benign and malignant tumors including SFT, hemangiopericytoma and metastatic hepatocellular carcinoma to name a few. Our case is an example of NICTH associated with SFT called Doege-Potter syndrome. The prevalence of hypoglycemia is seen in less than 5% of patients with SFT. It is often secondary to ectopic overexpression of unprocessed precursor ‘big’ IGF-II molecule, which binds to IGF-I receptor, resulting in tumorigenesis. An IGF-II/IGF-1 ratio is a sensitive marker and a value of more than 10 suggests excess production of IGF-II and is likely the cause of NICTH. Physicians should be cognizant of NICTH, especially in non-diabetic, otherwise healthy individuals in whom preliminary workup for hypoglycemia is negative and should look to identify any potential tumor as the likely cause. Surgical treatment is often the only curative option. Frequent meals, dextrose infusion, glucagon and growth hormone are bridging modalities until definitive surgical treatment.

Gene Expression in Solitary Fibrous Tumors (SFTs) Correlates with Anatomic Localization and NAB2-STAT6 Gene Fusion Variants

Solitary fibrous tumors (SFTs) harbor recurrent NAB2-STAT6 gene fusions, promoting constitutional up-regulation of oncogenic early growth response 1 (EGR1)-dependent gene expression. SFTs with the most common canonical NAB2 exon 4-STAT6 exon 2 fusion variant are often located in the thorax (pleuropulmonary) and are less cellular with abundant collagen. In contrast, SFTs with NAB2 exon 6-STAT6 exon 16/17 fusion variants typically display a cellular round to ovoid cell morphology and are often located in the deep soft tissue of the retroperitoneum and intra-abdominal pelvic region or in the meninges. Here, we employed next-generation sequencing-based gene expression profiling to identify significant differences in gene expression associated with anatomic localization and NAB2-STAT6 gene fusion variants. SFTs with the NAB2 exon 4-STAT6 exon 2 fusion variant showed a transcriptional signature enriched for genes involved in DNA binding, gene transcription, and nuclear localization, whereas SFTs with the NAB2 exon 6-STAT6 exon 16/17 fusion variants were enriched for genes involved in tyrosine kinase signaling, cell proliferation, and cytoplasmic localization. Specific transcription factor binding motifs were enriched among differentially expressed genes in SFTs with different fusion variants, implicating co-transcription factors in the modification of chimeric NGFI-A binding protein 2 (NAB2)-STAT6-dependent deregulation of EGR1-dependent gene expression. In summary, this study establishes a potential molecular biologic basis for clinicopathologic differences in SFTs with distinct NAB2-STAT6 gene fusion variants.

Using CRISPR/Cas9 to Investigate the Role of Egr1 and NAB2 in Neuronal Differentiation of PC12 Cells

PC12 cells are a common model system used to study the molecular events underlying neuronal differentiation due to their ability to differentiate into neuronal cells following treatment with nerve growth factor (NGF). NGF induces neuronal differentiation through activation of the Ras/Raf/MEK/ERK signaling pathway, which in turn activates a transcriptional program leading to up‐regulation of neuronal genes, neurite outgrowth, and establish electrical excitability. Interestingly, treatment with epidermal growth factor (EGF) also activates Ras/Raf/MEK/ERK signaling, but induces proliferation rather than differentiation. The differential effects of NGF versus EGF are due to differences in ERK signal duration; EGF induces more transient ERK signaling that lasts 30–60 min, whereas NGF induces more sustained ERK signaling that lasts 4–6 h. Work in our lab and others indicate that sustained ERK signaling in response to NGF drives differentiation in part through sustained activity of the transcription factor Egr1 and, in turn, sustained expression of Egr1 target genes. Egr1 activity in response to EGF and NGF is regulated at two levels. First, Egr1 levels rapidly rise to peak levels by 1 h after treatment and then decline to baseline levels; similar to ERK signaling, Egr1 levels are sustained longer in response to NGF versus EGF. Second, one Egr1 target gene is its corepressor NAB2, which binds and represses Egr1 transactivation once expressed. This project was designed to further test our hypothesis that sustained Egr1 activity is a major driver of PC12 neuronal differentiation by evaluating whether knockout of NAB2 will lead to sustained Egr1 activity in response to EGF and, in turn, neuronal differentiation. To acquire PC12 cells that lack NAB2 protein, we used CRISPR/Cas9 technology to knockout the NAB2 gene. More specifically, a CRISPR NAB2‐KO plasmid was purchased from Santa Cruz Biotechnology, which encodes a green fluorescent protein (GFP) selectable marker, the Cas9 protein, and the guide RNA (gRNA). The plasmid had three variations for the gRNA which target different locations in the NAB2 gene. One day after transfection, GFP‐positive cells were sorted into 96‐well plates to isolate clones. Following clonal expansion, clones were first screened for NAB2 expression by Western blot, which identified eight putative knockout clones. Genomic DNA was then extracted from the eight clones, the NAB2 gene amplified by PCR, and the PCR project then subjected to Sanger sequencing to identify the INDELs responsible for NAB2 knockout. Ongoing work is examining the effects of NAB2 knockout on Egr1 levels and activity in response to EGF and NGF, as well as neuronal differentiation based on neurite outgrowth with the prediction that NAB2 knockout will result in sustained Egr1 activity and neuronal differentiation in response to both growth factors.Support or Funding InformationBridgewater State University Undergraduate Research Program

NAB2-STAT6 fusion protein mediates cell proliferation and oncogenic progression via EGR-1 regulation

Solitary fibrous tumors are rare mesenchymal tumors derived from soft tissues and vascular walls. NAB2-STAT6 fusion gene serves as a marker gene for this disease and consists of the truncated repressor domain of NGFI-A-Binding protein 2 (NAB2) and the intact activation domain of STAT6. In this study, we found that EGR-1 and the proliferation-related EGR-1 target gene IGF2 were upregulated in NIH-3T3 cells transfected with NAB2-STAT6. Additionally, p-Rb (Ser795) and cyclin D1 levels were upregulated, and cell proliferation was also enhanced. We identified that treatment with the IGF2 inhibitor reduced cell proliferation in NIH-3T3 cells transfected with NAB2-STAT6. The oncogenic progression was enhanced in NIH-3T3 cells transfected with NAB2-STAT6 compared with those transfected with the empty vector. Taken together, our study suggests that the NAB2-STAT6 fusion gene is associated with cell proliferation through EGR-1 transcriptional expression and IGF2 can be a drug target for the treatment of solitary fibrous tumors.

Potential Salivary mRNA Biomarkers for Early Detection of Oral Cancer.

We evaluated potential biomarkers in human whole saliva for the early diagnosis of oral squamous cell carcinoma (OSCC). We selected 30 candidate genes with relevance to cancer from recent reports in PubMed. Saliva samples were obtained from 34 non-tumor control and 33 OSCC patients. Real-time PCR was performed, and mRNA levels were compared. Normalized mRNA levels of six genes (NGFI-A binding protein 2 (NAB2), cytochrome P450, family 27, subfamily A, polypeptide 1 (CYP27A1), nuclear pore complex interacting protein family, member B4 (NPIPB4), monoamine oxidase B (MAOB), sialic acid acetyltransferase (SIAE), and collagen, type III, alpha 1 (COL3A1)) were significantly lower in saliva of OSCC patients. Receiver operating characteristics (ROC) analysis was used to individually evaluate the predictive power of the potential biomarkers for OSCC diagnosis. The area under the curve (AUC) values were evaluated for the OSCC vs. non-tumor groups via univariate ROC analyses, as well as multivariate ROC analyses of combinations of multiple potential biomarkers. The combination of CYP27A1 + SIAE showed a favorable AUC value of 0.84. When we divided saliva samples into two groups according to age using a 60-year cut-off, with OSCC patients and controls evaluated together, the AUC of MAOB–NAB2 was more predictive of OSCC in the under-60 group (AUC, 0.91; sensitivity, 0.92; and specificity, 0.86) than any other gene combination. These results are expected to aid the early diagnosis of OSCC, especially in patients under 60 years of age. While more studies with larger numbers of patients are necessary, our result suggest that salivary mRNA would be a potent biomarker for early OSCC diagnosis.

Human Cytomegalovirus miRNAs Regulate TGF-β to Mediate Myelosuppression while Maintaining Viral Latency in CD34+ Hematopoietic Progenitor Cells

Infection with human cytomegalovirus (HCMV) remains a significant cause of morbidity and mortalityfollowing hematopoietic stem cell transplant (HSCT)because of various hematologic problems, includingmyelosuppression. Here, we demonstrate that latently expressed HCMV miR-US5-2 downregulates the transcriptional repressor NGFI-A binding protein(NAB1) to induce myelosuppression of uninfected CD34+ hematopoietic progenitor cells (HPCs) through an increase in TGF-β production. Infection of HPCs with an HCMVΔmiR-US5-2 mutant resulted in decreased TGF-β expression and restoration of myelopoiesis. In contrast, we show that infected HPCs are refractory to TGF-β signaling as another HCMV miRNA, miR-UL22A, downregulates SMAD3, which is required for maintenance of latency. Our data suggest that latently expressed viral miRNAs manipulate stem cell homeostasis by inducing secretion of TGF-β while protecting infected HPCs from TGF-β-mediated effects on viral latency and reactivation. These observations provide a mechanism through which HCMV induces global myelosuppression following HSCT while maintaining lifelong infection in myeloid lineage cells.

NGFI-A Binding Protein 2 Promotes EGF-Dependent HNSCC Cell Invasion.

NGFI-A binding protein 2 (NAB2) represses the transcriptional activation of early growth response protein-1 (EGR1), a tumor-suppressor. However, Epidermal Growth Factor (EGF) promotes tumor progression even with significant EGR1 upregulation. The molecular mechanism through which NAB2 is involved in cancer is largely unknown. Therefore, we evaluated how the NAB2-mediated suppression of EGR1 facilitates head and neck squamous cell carcinoma (HNSCC) cancer progression, in association with Sp1, which competes with EGR1 as a transcriptional regulator. The effect of NAB2 on EGR1/SP1 binding to the consensus promoter sequences of MMP2 and MMP9 was evaluated by chromatin immunoprecipitation (ChIP) and promoter luciferase assay. The correlation between EGR1-NAB2 expression and metastatic status was investigated using The Cancer Genome Atlas (TCGA) for HNSCC patients. Our data showed that NAB2 knockdown in FaDu and YD-10B HNSCC cells alleviated EGF-dependent increase of Matrigel invasion. In addition, NAB2 upregulation in EGF-treated FaDu cell diminishes EGR1 transcriptional activity, resulting in the upregulation of Sp1-dependent tumor-promoting genes. TCGA data analysis of 483 HNSCC tumors showed that higher levels of both EGR1 and NAB2 mRNA were significantly associated with metastasis, corresponding to in vitro results. Our data suggest that NAB2 upregulation facilitates EGF-mediated cancer cell invasion through the transactivation of Sp1-dependent tumor-promoting genes. These results provide insight into the paradoxical roles of EGF-EGR1 in cancer progression.

Immediate Early Genes Anchor a Biological Pathway of Proteins Required for Memory Formation, Long-Term Depression and Risk for Schizophrenia.

While the causes of myriad medical and infectious illnesses have been identified, the etiologies of neuropsychiatric illnesses remain elusive. This is due to two major obstacles. First, the risk for neuropsychiatric disorders, such as schizophrenia, is determined by both genetic and environmental factors. Second, numerous genes influence susceptibility for these illnesses. Genome-wide association studies have identified at least 108 genomic loci for schizophrenia, and more are expected to be published shortly. In addition, numerous biological processes contribute to the neuropathology underlying schizophrenia. These include immune dysfunction, synaptic and myelination deficits, vascular abnormalities, growth factor disruption, and N-methyl-D-aspartate receptor (NMDAR) hypofunction. However, the field of psychiatric genetics lacks a unifying model to explain how environment may interact with numerous genes to influence these various biological processes and cause schizophrenia. Here we describe a biological cascade of proteins that are activated in response to environmental stimuli such as stress, a schizophrenia risk factor. The central proteins in this pathway are critical mediators of memory formation and a particular form of hippocampal synaptic plasticity, long-term depression (LTD). Each of these proteins is also implicated in schizophrenia risk. In fact, the pathway includes four genes that map to the 108 loci associated with schizophrenia: GRIN2A, nuclear factor of activated T-cells (NFATc3), early growth response 1 (EGR1) and NGFI-A Binding Protein 2 (NAB2); each of which contains the “Index single nucleotide polymorphism (SNP)” (most SNP) at its respective locus. Environmental stimuli activate this biological pathway in neurons, resulting in induction of EGR immediate early genes: EGR1, EGR3 and NAB2. We hypothesize that dysfunction in any of the genes in this pathway disrupts the normal activation of Egrs in response to stress. This may result in insufficient electrophysiologic, immunologic, and neuroprotective, processes that these genes normally mediate. Continued adverse environmental experiences, over time, may thereby result in neuropathology that gives rise to the symptoms of schizophrenia. By combining multiple genes associated with schizophrenia susceptibility, in a functional cascade triggered by neuronal activity, the proposed biological pathway provides an explanation for both the polygenic and environmental influences that determine the complex etiology of this mental illness.

Hyperglycemia induced early growth response-1 regulates vascular dysfunction in human retinal endothelial cells

Early growth response-1 (Egr-1) protein upregulation is reported in diabetes and vascular disorders. This study aims at deciphering its role in hyperglycemia induced changes of retinal endothelium. Human retinal endothelial cells (hRECs) were exposed to hyperglycemia (25mM) and normoglycemia (5.5mM). Gene silencing was done using siRNA against Egr-1. Transcript and protein level analysis of Egr-1 and gene targets were done using qPCR and immunoblotting respectively in hRECs, diabetic and nondiabetic human retina and immunofluorescence for localization in retinal sections. Hyperglycemia induced Egr-1 and vascular endothelial growth factor-A (VEGF-A) but not pigment epithelium derived factor (PEDF) in hRECs. Expression of Egr-1 repressor NGFI-A binding protein-2 (NAB-2) was unaltered. Egr-1 downstream gene targets, tissue factor (TF) and intercellular adhesion molecule-1 (ICAM-1) expression were increased in hRECs which was reduced by Egr-1 silencing in hyperglycemia. Diabetic retina, showed an increase in Egr-1, VEGF-A and gene target TF, ICAM-1 but not NAB-2 and PEDF similar to the changes seen in hyperglycemic hRECs. Hyperglycemic induction of Egr-1 and absence of NAB-2 repression in retinal endothelium, up-regulates downstream genes involved in pro-thrombotic and pro-inflammatory pathways linking Egr-1 in diabetes mediated vascular aberration of retina.

Meningeal solitary fibrous tumor/hemangiopericytoma: Emphasizing on STAT 6 immunohistochemistry with a review of literature.

The 2016 central nervous system (CNS) World Health Organisation (WHO) Update has merged the entities of meningeal solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) into a single entity based on the presence of the nerve growth factor 1A (NGFI-A) binding protein 2 (NAB2)- signal transducer and activator of transcription 6 (STAT6) gene fusion in these tumors. Immunohistochemical (IHC) staining with STAT6 results in a strong nuclear positivity confirming the diagnosis. Meningeal SFT/HPCs are currently histologically graded according to a three-tiered system. Grade I (SFT phenotype) is benign, whereas grades II and III (HPC phenotype) are malignant and require radiotherapy in addition to gross total resection. The objectives were to review the cases diagnosed as meningeal SFT or HPC between 2010 and 2017 and classify them into SFT (grade I) or HPC (grades II and III) phenotypes; to confirm the diagnosis by performing STAT6 immunohistochemistry; and to observe and record the histological features in detail and correlate the tumor grades with their behavior. The published literature on the subject was also reviewed. A total of 21 cases diagnosed between 2010 and 2017 as meningeal SFT or HPC were included in the study. All cases were reviewed by the authors and were categorized and graded according to histologic phenotype and mitotic count. STAT6 immunohistochemistry was performed in all the cases. The epidemiological data and histologic findings in each case were recorded in detail. The follow-up of patients was obtained. Fifteen patients were males and six were females. The mean age was 43.5 years. The mean tumor size was 6.8 cm. The tumor specimens in 20 out of 21 cases corresponded to the HPC phenotype, of which 6 were in grade II while 14 were in grade III. Thus, over 95% cases had malignant lesions. The tumor in all the 21 cases recruited for the study showed immunohistochemical positivity for SAT6, while CD34 was positive in all the 18 tumor in which it was performed. The follow-up was available in 14 of the patients. Recurrence occurred in six patients who had either a grade II or a grade III tumor and three patients died (including one patient with a grade III tumor. This patient died a month after initial resection although there was no evidence of recurrence). Radiotherapy was given to only 4 out of 14 patients in whom follow-up was available. These rare tumors need to be accurately diagnosed and optimally treated (gross total resection and radiotherapy) to improve the prognosis.

FNA cytology of solitary fibrous tumors and the diagnostic value of STAT6 immunocytochemistry.

Solitary fibrous tumors (SFTs) are rare mesenchymal tumors commonly located in the pleura, soft tissues, or meninges and are characterized by the NGFI-A-binding protein 2 (NAB2)-signal transducer and activator of transcription 6 (STAT6) fusion gene. Recent studies have indicated that nuclear STAT6 immunohistochemistry is a specific marker for SFTs. The authors reviewed fine-needle aspiration (FNA) specimens from extracranial SFTs diagnosed at their institution between 1993 and 2017. Histologic blocks and available formalin-fixed smears of FNA specimens from SFTs were investigated for STAT6 immunoreactivity using a monoclonal antibody. STAT6 immunocytochemistry was also investigated in schwannomas and spindle cell lipomas. Cytopathologic and clinical characteristics were described. Nineteen benign and 9 malignant SFTs were identified. Both benign and malignant SFTs had a female predominance (female-to-male ratio, 2.8:1 and 1.25, respectively). Localization varied, and approximately one-half of the extrapleural tumors were located in the extremities and frequently were intramuscular. Benign and malignant primary tumors had limited differences in cytologic presentation, the most notable feature being nuclear pleomorphism. Cytomorphologic features included low-to-moderate cellularity of mixed oval, elongated, round, and stellate cells with pink collagenous stroma and hypercellular clusters with infrequent atypia. In metastatic SFTs, the cytopathology was suggestive of sarcoma. Immunohistochemistry revealed nuclear STAT6 immunoreactivity in SFTs (n = 5) with cytoplasmic reactivity in cytologic mimickers. Benign and malignant SFTs have common cytopathologic features, and the ability to distinguish between them is limited. Nuclear STAT6 immunoreactivity is a valuable cytologic marker for SFTs. Cancer Cytopathol 2018;126:36-43. © 2017 American Cancer Society.

Expression of Egr-1, Nab2 and Cav-1 and its relationship with scar hyperplasia

Objective To investigate the expression of early growth response protein 1 (Egr-1),NGFI-A binding protein 2 (Nab2) and caveolin 1 (Cav-1) in normal skin,flat-cicatrix and hypertrophic scar,and explore its role in the formation of hypertrophic scar.Methods The expression of Egr-1,Nab2 and Cav-1 protein in 9 normal skin tissues,8 flat-cicatrix tissues and 9 hypertrophic scar tissues were examined with immunohistochemistry SP method and were analyzed statistically.Results The expression of Egr-1 in epidermal cells of hypertrophic scar was significantly higher than that in normal skin and flat scar tissue.The expression of Egr-1 increased in the course of scar proliferation.The distribution patterns of Nab2 were different from Egr-1.The expression of Egr-1 was increased,while expression of Nab2 was decreased.The expression of Cav-1 in normal skin and flat-cicatrix was significantly higher than that in hypertrophic scar.Conclusions The expression of Egr-1,Nab2 and Cav-1 is closely related to the formation of hypertrophic scar,and the up-regulated expression of Egr-1 and the deficient expression of Nab2 and Cav-1 may be the indicators of the progress of formation of hypertrophic scar.

Yersinia ruckeri lipopolysaccharide is necessary and sufficient for eliciting a protective immune response in rainbow trout (Oncorhynchus mykiss, Walbaum)

Enteric redmouth disease (ERM), caused by Yersinia ruckeri, has been controlled successfully using immersion-applied bacterin vaccines for several decades. While the host response to vaccination and the mechanism of protection of this vaccine have been elucidated, the bacterial components eliciting protection have remained unclear. Here we show that highly purified serotype O1 Y.ruckeri lipopolysaccharide (LPS) is sufficient to induce a protective response to experimental challenge in rainbow trout (Oncorhynchus mykiss). Dose response experiments demonstrated that Y.ruckeri LPS at doses of 1ng/fish and above resulted in essentially complete protection and doses as low as 0.01ng/fish (1.38ng/kg) resulted in significant protection, thus demonstrating the extremely high potency of this immunogen. Analysis of the Y.ruckeri genome identified a cluster of putative O-antigen biosynthetic genes specific to serotype O1 strains. This cluster primarily consisted of genes encoding proteins predicted to function in the biosynthesis of legionamic acid, a nonulosonic acid known to be part of the O-polysaccharide repeat of O1 Y.ruckeri. Mutation of the nab2 gene, a nonulosonic acid biosynthesis gene (nab gene), resulted in production of severely truncated forms of LPS. Vaccination with bacterin vaccines derived from the nab2 mutant and its wild type parent strain demonstrated that LPS is a required component of the whole-cell bacterin vaccine and suggests that LPS is the only cellular component contributing to the protective response elicited by this vaccine. We speculate that the exceptionally high potency of Y.ruckeri LPS accounts for the unusual success of this vaccine when delivered by immersion.

Distinct clinicopathological features of NAB2-STAT6 fusion gene variants in solitary fibrous tumor with emphasis on the acquisition of highly malignant potential.

The impact of NGFI-A binding protein 2 (NAB2)-signal transducer and activator of transcription 6 (STAT6) fusion on the biological behavior and the mechanism of acquisition of malignant phenotype in solitary fibrous tumor (SFT) is not well understood. We examined variations of the NAB2-STAT6 fusion gene in 40 cases of SFT using formalin-fixed, paraffin-embedded tissues and secondary genetic alterations of tumor protein p53 (TP53),, platelet-derived growth factor receptor, β polypeptide (PDGFRB), and telomerase reverse transcriptase (TERT) promoters. These gene variations were compared with the clinicopathological features. The 2-year and 5-year disease-free survival rates (DFSRs) were 91% and 83%, respectively. All 40 samples demonstrated nuclear staining for STAT6, including CD34-negative cases. Moreover, p53-positive staining was associated with a lower DFSR and was significantly associated with higher Ki-67 label index, higher mitotic rate (mitosis, >4/high-power field), and the presence of nuclear atypia/pleomorphism. NAB2-STAT6 fusions were detected in all of the cases; the NAB2 exon 4-STAT6 exon 2, the most common genotype, appeared in 18 cases, which was associated with thoracic tumor location and the less aggressive phenotype. In contrast, tumors with NAB2 exon 6-STAT6 exon 16/18 demonstrated an aggressive phenotype. Mutations in TP53 and PDGFRB were detected in 2 and 3 cases respectively, and these occurred in a mutually exclusive fashion. TERT promoter hot spot mutations were observed in 5 cases, which were associated with shorter DFSR. Two dedifferentiated SFT cases harbored both TP53 and TERT promoter mutations. TP53 mutations, which result in its overexpression, in combination with TERT promoter mutations seem to play an important role in the dedifferentiation process.