Inhibition of Signal Transducer and Activator of Transcription 6 Activity in the Hodgkin Lymphoma Cell Line L1236 Induces Growth Inhibition and Apoptosis.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4593-4593
Author(s):  
Cheng Liu ◽  
Margareta Andersson ◽  
Dawei Xu ◽  
Hans-Erik Claesson ◽  
Magnus Bjorkholm ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Cell Line ◽  
Hodgkin Lymphoma ◽  
Target Genes ◽  
Signal Transducer ◽  
Autocrine Growth ◽  
Regulated Expression ◽  
Hodgkin Lymphoma Cell ◽  
Interfering Rna

Abstract Signal transducer and activator of transcription 6 (STAT6) plays a central role in interleukin (IL)-4 and -13 signaling. Upon binding of the cognate receptors by these cytokines, STAT6 becomes phosphorylated by Jak family kinases and subsequently translocates to the nucleus where transcription of its target genes is regulated. Expression of IL-13 and its receptor are common features of Hodgkin lymphoma (HL) tumor cells, the so-called Hodgkin Reed-Sternberg (H-RS) cells, in which this cytokine has been shown to act as an autocrine growth factor. Consequently, constitutively phosphorylated STAT6 with a nuclear localization is a common and distinctive feature of H-RS cells in classical HL. We knocked down STAT6 expression in the HL cell line L1236 with small interfering RNA (siRNA) and found that inhibition of STAT6 activity results in cell growth inhibition, decreased viability and increased apoptosis. The results depict a central role of STAT6 in the growth of H-RS cells and indicate that STAT6 could be a potential target for therapeutic intervention in HL. Moreover, in order to identify the target genes of this transcription factor in H-RS cells, a combined approach of RNA interference and microarray is performed and the results will be presented.

scholarly journals CsWRKY25 Improves Resistance of Citrus Fruit to Penicillium digitatum via Modulating Reactive Oxygen Species Production

2022 ◽  
Vol 12 ◽  
Author(s):  
Wenjun Wang ◽  
Ting Li ◽  
Qi Chen ◽  
Shixiang Yao ◽  
Lili Deng ◽  
...  
Keyword(s):  
Target Genes ◽  
Citrus Fruit ◽  
Cinnamyl Alcohol Dehydrogenase ◽  
Transcription Level ◽  
Pr Genes ◽  
Citrus Peel ◽  
Regulated Expression ◽  
Transient Overexpression ◽  
Species Production

WRKY transcription factors (TFs) play crucial roles in the regulation of biotic stress. Citrus is the most productive fruit in the world. It is of great value to investigate the regulatory molecular mechanism of WRKYs in improving disease resistance. In this research, the transcription level of CsWRKY25 was upregulated in P. digitatum infected citrus peel, and CsWRKY25 activated the expression of three target genes (RbohB, RbohD, and PR10). Besides, the Agrobacterium-mediated transient overexpression of CsWRKY25 has also been shown to enhance resistance to P. digitatum in citrus, and caused the accumulation of hydrogen peroxide and lignin. The accumulation of ROS also activated the antioxidant system, the catalase (CAT), peroxidase (POD), and cinnamyl alcohol dehydrogenase (CAD) genes were significant upregulated, leading to activation of antioxidant enzymes. In addition, the up-regulated expression of MPK5 and MPK6 genes suggested that the regulatory role of CsWRKY25 might be related to the phosphorylation process. In conclusion, CsWRKY25 could enhance the resistance to P. digitatum via modulating ROS production and PR genes in citrus peel.

scholarly journals Epigenetic Regulation of miR-92a and TET2 and Their Association in Non-Hodgkin Lymphoma

2021 ◽  
Vol 12 ◽  
Author(s):  
Esther K. Elliott ◽  
Lloyd N. Hopkins ◽  
Robert Hensen ◽  
Heidi G. Sutherland ◽  
Larisa M. Haupt ◽  
...  
Keyword(s):  
Hodgkin Lymphoma ◽  
Cell Lines ◽  
Target Genes ◽  
Cpg Islands ◽  
Mature Mirnas ◽  
Tumour Suppressor Genes ◽  
Promoter Regions ◽  
Aberrant Expression ◽  
Non Hodgkin Lymphoma

MicroRNAs (miRNAs) are well known for their ability to regulate the expression of specific target genes through degradation or inhibition of translation of the target mRNA. In various cancers, miRNAs regulate gene expression by altering the epigenetic status of candidate genes that are implicated in various difficult to treat haematological malignancies such as non-Hodgkin lymphoma by acting as either oncogenes or tumour suppressor genes. Cellular and circulating miRNA biomarkers could also be directly utilised as disease markers for diagnosis and monitoring of non-Hodgkin lymphoma (NHL); however, the role of DNA methylation in miRNA expression regulation in NHL requires further scientific inquiry. In this study, we investigated the methylation levels of CpGs in CpG islands spanning the promoter regions of the miR-17–92 cluster host gene and the TET2 gene and correlated them with the expression levels of TET2 mRNA and miR-92a-3p and miR-92a-5p mature miRNAs in NHL cell lines, tumour samples, and the whole blood gDNA of an NHL case control cohort. Increased expression of both miR-92a-3p and miR-92a-5p and aberrant expression of TET2 was observed in NHL cell lines and tumour tissues, as well as disparate levels of dysfunctional promoter CGI methylation. Both miR-92a and TET2 may play a concerted role in NHL malignancy and disease pathogenesis.

Phospholipase D1 mediates bFGF-induced Bcl-2 expression leading to neurite outgrowth in H19-7 cells

2011 ◽  
Vol 441 (1) ◽  
pp. 407-416 ◽  
Author(s):  
Sung Nyo Yoon ◽  
Kang Sik Kim ◽  
Ju Hwan Cho ◽  
Weina Ma ◽  
Hye-Jin Choi ◽  
...  
Keyword(s):  
Neurite Outgrowth ◽  
Dominant Negative ◽  
Signal Transducer ◽  
Downstream Effector ◽  
Phospholipase D1 ◽  
Protein Kinase Cα ◽  
Phosphoinositide 3 Kinase ◽  
Interfering Rna ◽  
Transcription 3

The purpose of the present study was to investigate the role of PLD (phospholipase D) in bFGF (basic fibroblast growth factor)-induced Bcl-2 expression and to examine whether overexpressed Bcl-2 influences neurite outgrowth in immortalized hippocampal progenitor cells (H19-7 cells). We found that Bcl-2 expression was maximally induced by bFGF within 24 h, and that this effect was reduced by inhibiting PLD1 expression with PLD1 small interfering RNA or by overexpressing DN (dominant-negative)-PLD1, whereas PLD1 overexpression markedly induced Bcl-2 expression. bFGF treatment activated Ras, Src, PI3K (phosphoinositide 3-kinase), PLCγ (phospholipase Cγ) and PKCα (protein kinase Cα). Among these molecules, Src and PKCα were not required for Bcl-2 expression. PLD activity was decreased by Ras, PI3K or PLCγ inhibitor, suggesting that PLD1 activation occurred through Ras, PI3K or PLCγ. We found that Ras was the most upstream molecule among these proteins, followed by the PI3K/PLCγ pathway, indicating that bFGF-induced PLD activation took place through the Ras/PI3K/PLCγ pathway. Furthermore, PLD1 was required for activation of JNK (c-Jun N-terminal kinase), which led to activation of STAT3 (signal transducer and activator of transcription 3) and finally Bcl-2 expression. When Bcl-2 was overexpressed, neurite outgrowth was stimulated along with induction of neurotrophic factors such as brain-derived neurotrophic factor and neurotrophin 4/5. In conclusion, PLD1 acts as a downstream effector of bFGF/Ras/PI3K/PLCγ signalling and regulates Bcl-2 expression through JNK/STAT3, which leads to neurite outgrowth in H19-7 cells.

ASXL2 Is a Novel Mediator of RUNX1-ETO Transcriptional Function and Collaborates with RUNX1-ETO to Promote Leukemogenesis

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 302-302
Author(s):  
Jean-Baptiste Micol ◽  
Nicolas Duployez ◽  
Alessandro Pastore ◽  
Robert Williams ◽  
Eunhee Kim ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Line ◽  
Hematopoietic Stem Cell ◽  
Binding Sites ◽  
Target Genes ◽  
Cell Function ◽  
Rna Seq ◽  
Hematopoietic Stem

Abstract Mutations in Addition of Sex Combs Like 1 (ASXL1) are common in patients with myeloid leukemias. More recently, mutations in ASXL2, a paralog of ASXL1 with ~40% shared amino acid homology, have been discovered to occur specifically in patients with acute myeloid leukemia (AML) patients bearing the RUNX1-ETO (AML1-ETO; RUNX1-RUNX1T1) translocation and are amongst the most common mutations in RUNX1-ETO AML (mutated in 20-25% of patients). Although ASXL1 is critical for Polycomb Repressive Complex 2 function in myeloid hematopoietic cells and loss of Asxl1 recapitulates key aspects of myelodysplastic syndrome (MDS), the function of ASXL2 in normal or malignant hematopoiesis is unknown. We therefore set out to perform a functional comparison of ASXL1and ASXL2on hematopoiesis and transcription and determine the functional basis for frequent mutations in RUNX1-ETO AML. In vitro analyses of ASXL2 insertion/deletion mutations revealed that these mutations resulted in substantial reduction of ASXL2 protein expression, stability, and half-life. We therefore generated Asxl2 conditional knockout (cKO) mice to delineate the effect of ASXL2 loss on hematopoiesis. Competitive (Fig. 1A) and noncompetitive transplantation revealed that Asxl2 or compound Asxl1/2 loss resulted in cell-autonomous, rapid defects of hematopoietic stem cell function, self-renewal, and number with peripheral blood leukopenia and thrombocytopenia but without any obvious MDS features- phenotypes distinct from Asxl1 cKO mice. Mice with heterozygous deletion of Asxl2 demonstrated an intermediate phenotype between control and homozygous cKO mice indicating a gene dosage effect of Asxl2 loss. RNA sequencing (RNA-seq) of hematopoietic stem/progenitor cells from Asxl2- and Asxl1-deficient mice revealed twenty-fold greater differentially expressed genes in Asxl2 cKO mice relative to Asxl1 cKO mice. Interestingly, genes differentially expressed with Asxl2 loss significantly overlapped with direct transcriptional targets of RUNX1-ETO, findings not seen in Asxl1 cKO mice (Fig. 1B). Asxl2 target genes appeared to also be targets of RUNX1, a key gene repressed by RUNX1-ETO to promote leukemogenesis. Consistent with this, genome-wide analysis of Asxl2 binding sites through anti-Asxl2 ChIP-seq revealed that Asxl2 binding sites substantially overlap with those of Runx1. Overall, the above data suggest that Asxl2 may be a critical mediator of RUNX1-ETO mediated leukemogenesis by affecting the expression of RUNX1 and/or RUNX1-ETO target genes. RNA-seq of primary RUNX1-ETO AML patient samples revealed that ASXL2-mutant RUNX1-ETO patients form a distinct transcriptional subset of RUNX1-ETO AML (Fig. 1C) suggesting a specific role of ASXL2 in leukemogenesis. To functionally interrogate the role of ASXL2 loss in RUNX1-ETO mediated leukemogenesis we first utilized an in vitro model with RNAi-mediated depletion of ASXL1 or ASXL2 in the SKNO1 cell line (the only ASXL-wildtype human RUNX1-ETO cell line). RNA-seq revealed distinct target genes dysregulated by ASXL1 versus ASXL2 loss in these cells without any significant overlap. Anti-ASXL2, RUNX1, and RUNX1-ETO ChIPSeq in SKNO1 cells revealed significant co-occupancy of ASXL2 with RUNX1 and RUNX1-ETO binding sites. Moreover, analysis of histone modification ChIPSeq revealed an enrichment in intergenic and enhancer H3K4me1 abundance following ASXL2 loss in SKNO1 cells. Next, to understand the in vivo effects of Asxl2 loss in the context of RUNX1-ETO, we performed retroviral bone marrow (BM) transplantation assays using RUNX1-ETO9a in Asxl2 cKO mice. In contrast to the failure of hematopoietic stem cell function with Asxl2 deletion alone, mice reconstituted with BM cells expressing RUNX1-ETO9a in Asxl2-deficient background had a shortened leukemia-free survival compared to Asxl2 -wildtype control. Overall, these data reveal that ASXL2 is required for hematopoiesis and has differing biological and transcriptional functions from ASXL1. Moreover, this work identifies ASXL2 as a novel mediator of RUNX1-ETOtranscriptional function and provides a new model of penetrant RUNX1-ETO AML based on genetic events found in a substantial proportion of t(8;21) AML patients. Further interrogation of the enhancer alterations generated by ASXL2 loss in RUNX1-ETO AML may highlight new therapeutic approaches for this subset of AML. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare.

Establishment and characterization of a novel Hodgkin lymphoma cell line, AM-HLH, carrying the Epstein-Barr virus genome integrated into the host chromosome

2016 ◽  
Vol 35 (4) ◽  
pp. 567-575 ◽  
Author(s):  
Masahiko Hayashida ◽  
Masanori Daibata ◽  
Erika Tagami ◽  
Takahiro Taguchi ◽  
Fumiyo Maekawa ◽  
...  
Keyword(s):  
Cell Line ◽  
Hodgkin Lymphoma ◽  
Epstein Barr Virus ◽  
Virus Genome ◽  
Lymphoma Cell Line ◽  
Host Chromosome ◽  
Barr Virus ◽  
Hodgkin Lymphoma Cell ◽  
Epstein Barr

scholarly journals Micro-RNA Profiling Reveals the Key Role of miR-206 in the Hematopoietic Potential of Human Embryonic and Induced Pluripotent Stem Cells

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1275-1275
Author(s):  
Stephane Flamant ◽  
Jean-Claude Chomel ◽  
Christophe Desterke ◽  
Olivier Feraud ◽  
Emilie Gobbo ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Line ◽  
Cell Lines ◽  
Pluripotent Stem Cells ◽  
Target Genes ◽  
Hematopoietic Differentiation ◽  
Induced Pluripotent

Abstract Although human pluripotent stem cells (hPSCs) can theoretically be differentiated into any cell type, their ability to generate hematopoietic cells shows a major variability from one cell line to another. The reasons of this variable differentiation potential, which is constant and reproducible in a given hPSC line, are not clearly established. In order to study this phenomenon, we comparatively studied 4 human embryonic stem cell lines (hESC) and 11 human induced pluripotent stem cell (hiPSC) lines using transcriptome assays. These cell lines exhibited a significant variability to generate in vitro hematopoiesis as evaluated by day-16 embryoid body (EB) formation followed by clonogenic (CFC) assays. Four out of 11 iPSC lines (PB6, PB9, PB12.1, and PB14.3) were found to lack any hematopoietic differentiation ability whereas 7 cell lines showed variable hematopoietic potential. Among hESC lines, H9 and CL0 had low H1 and SA01 exhibited high hematopoietic potential using the above assays. Among hESC and hIPSC displaying hematopoietic potential, two sub-groups were further defined based on their hematopoietic CFC efficiency: a group of poor (generation of less than 100 CFC/105 cells, PB4 / PB10 /H9 /CL01), and high hematopoietic competency (more than 120 CFC/105 cells, PB3/ PB6.1 /PB7 /PB13 /PB17 /SA01/H1). Using global miRNome analysis performed at the pluripotency stage, the expression of 754 individual miRNAs was analyzed from 15 hPSC lines in order to explore a potential predictive marker between both sub-groups of pluripotent cells according to their hematopoietic potency. Using this approach, 27 miRNAs out of 754 appeared differentially expressed allowing the identification of a miRNA signature associated with hematopoietic-competency. The hematopoietic competency was associated with down-regulation of miR-206, miR-135b, miR-105, miR-492, miR-622 and upregulation of miR-520a, miR-296, miR-122, miR-515, miR-335. Amongst these, miR-206 harbored the most significant variation (0.04-Fold change). To explore the role of miRNA-206 in this phenomenon, we have generated a miR-206-eFGP-Puro lentiviral vector which was transfected in hESC line H1 followed by puromycin selection. As a control, H1 cell line was transfected with a Arabidopsis thaliana microRNA sequence (ath-miR-159a), which has no specific targets in mammalian cells. The correct expression of the transgenes were evaluated by flow cytometry (using GFP) and q-RT-PCR for miR-206 expression. The hematopoietic potential of H1 cell line and its miR-206-overexpressing counterpart was then tested using standard in vitro assays via d16-EB generation. We found that both CFC numbers and percentage of CD34+ were significantly lower in H1-mir-206-derived day-16 EB cells than in H1-ath- derived day-16 EB cells (p < 0.05). Thus, over-expression of miR-206 in this blood-competent hESC appeared to repress its hematopoietic potential at very early stage, since a similar lower CFC efficiency was observed in day-3 EB cells derived from miR-206 overexpressing H1 cell line. We then conducted an integrative bioinformatics analysis on miR-206 predicted target genes. To this end, 773 mRNA target transcripts of the broadly conserved (across vertebrates) miR-1-3p/206 family were identified in the TargetScan database and were integrated into the global transcriptomic analysis performed by microarray on day-16 EB cells. Using supervised ranking product analysis, 62 predicted gene targets of the miR-1-3p/206 family were found to be significantly up-regulated in hematopoietic-competent EB samples including the transcription factors RUNX1 and TAL1. Hierarchical unsupervised clustering, based on this subset of 62 predicted mir-206 target genes, fully discriminated hematopoietic-deficient from hematopoietic-competent cells. In conclusion, miRNA profiling performed at pluripotency stage could be useful to predict the ability to human iPSC to give rise to blood cell progenitors. This work emphasizes for the first time the critical role of the muscle-specific miR-206 in hematopoietic differentiation. Finally, these results suggest that genetic manipulation of hESC/iPSC could be used to enhance their hematopoietic potential and to design protocols for generation of hPSC-derived hematopoietic stem cells with long-term reconstitution ability. Disclosures No relevant conflicts of interest to declare.

scholarly journals Foxa1 and Foxa2 Regulate α-Cell Differentiation, Glucagon Biosynthesis, and Secretion

Endocrinology ◽  
2014 ◽  
Vol 155 (10) ◽  
pp. 3781-3792 ◽  
Author(s):  
Mounia Heddad Masson ◽  
Caroline Poisson ◽  
Audrey Guérardel ◽  
Aline Mamin ◽  
Jacques Philippe ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Differentiation ◽  
Target Genes ◽  
Adult Mouse ◽  
Glucagon Secretion ◽  
Mrna Levels ◽  
Forkhead Box ◽  
Interfering Rna

Abstract The Forkhead box A transcription factors are major regulators of glucose homeostasis. They show both distinct and redundant roles during pancreas development and in adult mouse β-cells. In vivo ablation studies have revealed critical implications of Foxa1 on glucagon biosynthesis and requirement of Foxa2 in α-cell terminal differentiation. In order to examine the respective role of these factors in mature α-cells, we used small interfering RNA (siRNA) directed against Foxa1 and Foxa2 in rat primary pancreatic α-cells and rodent α-cell lines leading to marked decreases in Foxa1 and Foxa2 mRNA levels and proteins. Both Foxa1 and Foxa2 control glucagon gene expression specifically through the G2 element. Although we found that Foxa2 controls the expression of the glucagon, MafB, Pou3f4, Pcsk2, Nkx2.2, Kir6.2, and Sur1 genes, Foxa1 only regulates glucagon gene expression. Interestingly, the Isl1 and Gipr genes were not controlled by either Foxa1 or Foxa2 alone but by their combination. Foxa1 and Foxa2 directly activate and bind the promoter region the Nkx2.2, Kir6.2 and Sur1, Gipr, Isl1, and Pou3f4 genes. We also demonstrated that glucagon secretion is affected by the combined effects of Foxa1 and Foxa2 but not by either one alone. Our results indicate that Foxa1 and Foxa2 control glucagon biosynthesis and secretion as well as α-cell differentiation with both common and unique target genes.

scholarly journals STAT6 and STAT1 are essential antagonistic regulators of cell survival in classical Hodgkin lymphoma cell line

Leukemia ◽  
2009 ◽  
Vol 23 (10) ◽  
pp. 1885-1893 ◽  
Author(s):  
D Baus ◽  
F Nonnenmacher ◽  
S Jankowski ◽  
C Döring ◽  
C Bräutigam ◽  
...  
Keyword(s):  
Cell Survival ◽  
Cell Line ◽  
Hodgkin Lymphoma ◽  
Lymphoma Cell ◽  
Lymphoma Cell Line ◽  
Classical Hodgkin Lymphoma ◽  
Hodgkin Lymphoma Cell

scholarly journals Pax6 Regulates the Proglucagon Processing Enzyme PC2 and Its Chaperone 7B2

2009 ◽  
Vol 29 (8) ◽  
pp. 2322-2334 ◽  
Author(s):  
Liora S. Katz ◽  
Yvan Gosmain ◽  
Eric Marthinet ◽  
Jacques Philippe
Keyword(s):  
Target Genes ◽  
Dominant Negative ◽  
Prohormone Convertase ◽  
Endocrine Differentiation ◽  
Processing Enzyme ◽  
Dominant Negative Form ◽  
Prohormone Convertase 2 ◽  
Interfering Rna ◽  
Negative Form

ABSTRACT Pax6 is important in the development of the pancreas and was previously shown to regulate pancreatic endocrine differentiation, as well as the insulin, glucagon, and somatostatin genes. Prohormone convertase 2 (PC2) is the main processing enzyme in pancreatic α cells, where it processes proglucagon to produce glucagon under the spatial and temporal control of 7B2, which functions as a molecular chaperone. To investigate the role of Pax6 in glucagon biosynthesis, we studied potential target genes in InR1G9 α cells transfected with Pax6 small interfering RNA and in InR1G9 clones expressing a dominant-negative form of Pax6. We now report that Pax6 controls the expression of the PC2 and 7B2 genes. By binding and transactivation studies, we found that Pax6 indirectly regulates PC2 gene transcription through cMaf and Beta2/NeuroD1 while it activates the 7B2 gene both directly and indirectly through the same transcription factors, cMaf and Beta2/NeuroD1. We conclude that Pax6 is critical for glucagon biosynthesis and processing by directly and indirectly activating the glucagon gene through cMaf and Beta2/NeuroD1, as well as the PC2 and 7B2 genes.

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