scholarly journals High Mobility Group A1 Chromatin Remodeling Proteins Amplify Inflammatory Networks to Drive Leukemic Transformation in Chronic Myeloproliferative Neoplasia in Humans and JAK2V617F Transgenic Mouse Models

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 102-102
Author(s):  
Linda Resar ◽  
Donna Marie Williams ◽  
Lingling Xian ◽  
Wenyan Lu ◽  
Briyana Chisholm ◽  
...  
Keyword(s):  
Disease Progression ◽  
Mouse Models ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Immune Cell ◽  
Cell Trafficking ◽  
Murine Models ◽  
Rna Seq ◽  
Leukemic Transformation ◽  
Cd34 Cells

Abstract Introduction: Myeloproliferative neoplasms (MPN) are clonal hematopoietic stem cell (HSC) disorders characterized by overproduction of mature blood cells and increased risk of transformation to myelofibrosis (MF) and acute myeloid leukemia (AML), although molecular mechanisms driving disease progression remain elusive. While most patients who acquire a JAK2V617F mutation in CD34+ cells present with chronic, indolent Polycythemia Vera (PV), ~25% will progress to MF or AML. High Mobility Group A1/2 (HMGA1/2) genes encode oncogenic chromatin remodeling proteins which are overexpressed in aggressive leukemia where they portend adverse outcomes. In murine models, Hmga1/2 overexpression drives clonal expansion and uncontrolled proliferation. HMGA1/2 genes are also overexpressed in MPN with disease progression. We therefore sought to: 1) test the hypothesis that HMGA proteins are required for leukemic transformation and rational therapeutic targets in MPN progression, and, 2) identify mechanisms mediated by HMGA1/2 during disease progression. Methods: We measured HMGA1/2 in JAK2V617F mutant human AML cell lines from MPN patients (DAMI, SET-2), CD34+ cells from PV patients during chronic and transformation phases, and JAK2V617F transgenic murine models of PV (transgenic JAK2V617F) and PV-AML (transgenic JAK2V617F/MPLSV; Blood 2015;126:484). To elucidate HMGA1/2 function, we silenced HMGA1 or HMGA2 via short hairpin RNA in human MPN-AML cell lines (DAMI, SET-2) and assessed proliferation, colony formation, and leukemic engraftment in immunodeficient mice. To further assess Hmga1 function in vivo, we crossed mice with heterozygous Hmga1 deficiency onto murine models of PV and PV-AML. Finally, to dissect molecular mechanisms underlying HMGA1, we compared RNA-Seq from MPN-AML cell lines (DAMI, SET-2) after silencing HMGA1/2 to that of controls and applied Ingenuity Pathway Analysis. Results: HMGA1/2 mRNA are up-regulated in all JAK2V617F-positive contexts, including primary human PV CD34+ cells and total bone marrow from JAK2V617F mouse models for PV compared to controls. Further, there is a marked up-regulation in both HMGA1/2 in CD34+ cells from PV patients after transformation to MF or AML and in leukemic blasts from our PV-AML mouse model compared to PV mice. Overexpression of HMGA1/2 also correlates with clonal dominance of human JAK2V617F-homozygous stem cells and additional mutations of epigenetic regulators (EZH2, SETBP1). Silencing HMGA1 or HMGA2 in human MPN-AML cell lines (DAMI, SET-2) dramatically halts proliferation, disrupts clonogenicity, and prevents leukemic engraftment in mice. Further, heterozygous Hmga1 deficiency decreases splenic enlargement in PV mouse models with advancing age. Moreover, heterozygous Hmga1 deficiency prolongs survival in the transgenic PV-AML murine model with fulminant leukemia and early mortality. PV-AML mice survived a median of 5 weeks whereas PV-AML mice with heterozygous Hmga1 deficiency survive a median of 12 weeks (P< 0.002). The leukemic burden was also decreased in mice with Hmga1 deficiency. Preliminary RNA-Seq analyses from DAMI and SET-2 cells show that HMGA1 drives pathways involved in Th1/Th2 activation, chemotaxis, cell-cell signaling, myeloid cell accumulation and other immune cell trafficking, inflammation, and injury, suggesting that HMGA1 co-opts immune and inflammatory networks to drive tumor progression. Surprisingly, atherosclerosis pathways are also induced by HMGA1. Conclusions: HMGA1/2 genes are overexpressed in MPN with highest levels in more advanced disease (MF, AML) both in primary human tumors and murine models. Strikingly, silencing HMGA1 or HMGA2 halts proliferation and clonogenicity in vitro and prevents leukemic engraftment in vivo. Further, heterozygous Hmga1 deficiency prolongs survival in a murine model of fulminant MPN AML and decreases tumor burdens. Finally, preliminary RNA-Seq analyses suggest that HMGA1 amplifies transcriptional networks involved in immune cell trafficking and inflammation to drive tumor progression. Unexpectedly, HMGA1 also regulates pathways involved in atherosclerosis, implicating HMGA1 as a novel link between clonal hematopoiesis and cardiovascular disease. Our findings further highlight HMGA1/2 as a key molecular switch for leukemic transformation in MPN and opens the door to novel therapeutic approaches to prevent disease progression. Disclosures No relevant conflicts of interest to declare.

scholarly journals High Mobility Group A1 Chromatin Regulators: Key Epigenetic Switches and Therapeutic Targets Required for Leukemic Transformation in JAK2 Mutant MPN

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1680-1680
Author(s):  
Liping Li ◽  
Wenyan Lu ◽  
Alison R. Moliterno ◽  
Lingling Xian ◽  
Joseph Kim ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Lines ◽  
Cell Cycle Progression ◽  
High Mobility ◽  
Transcriptional Networks ◽  
Murine Models ◽  
Rna Seq ◽  
Leukemic Transformation ◽  
Cycle Progression ◽  
Cd34 Cells

Introduction: Myeloproliferative neoplasms (MPN) are clonal hematopoietic stem cell (HSC) disorders characterized by hyperactive JAK/STAT signaling and increased risk of transformation to myelofibrosis (MF) and acute myeloid leukemia (AML). However, mechanisms driving progression remain elusive and therapies are ineffective after leukemia develops. The High Mobility Group A1/2 (HMGA1/2) genes encode oncogenic chromatin remodeling proteins which are overexpressed in aggressive solid tumors where they portend adverse outcomes. HMGA1/2 genes are also up-regulated in hematologic malignancies and MPN with disease progression. In murine models, Hmga1/2 overexpression drives clonal expansion and deregulated proliferation while Hmga1 overexpression is sufficient for lymphoid leukemic transformation. We therefore sought to: 1) test the hypothesis that HMGA1/2 proteins are rational therapeutic targets required for leukemic transformation in MPN, 2) elucidate mechanisms mediated by HMGA1/2 during disease progression, and, 3) identify therapeutic approaches to disrupt HMGA function and intercept the transition from chronic disease to aggressive leukemia. Methods: We compared HMGA1/2 in JAK2V617F mutant AML cell lines from MPN patients (DAMI, SET-2), CD34+ cells from PV patients during chronic and transformation phases, and JAK2V617F murine models of PV (transgenic JAK2V617F) and PV-AML (transgenic JAK2V617F/MPLSV). To elucidate HMGA1/2 function, we silenced HMGA1 or HMGA2 via short hairpin RNA in human MPN-AML cells and generated murine models of PV-AML with heterozygous Hmga1 or Hmga2 deficiency. To dissect molecular mechanisms underlying HMGA, we compared RNA-Seq from MPN-AML cell lines after gene silencing. Finally, to identify therapies to target HMGA pathways, we integrated the RNA-Seq data with the Broad Connectivity Map (cMAP). Results: There is a marked up-regulation in HMGA1/2 in CD34+ cells from PV patients after transformation to AML and in leukemic blasts from our PV-AML mouse model. Conversely, silencing HMGA1 or HMGA2 in human MPN-AML cell lines (DAMI, SET-2) dramatically halts proliferation, disrupts clonogenicity, and prevents leukemia development in mice. Further, heterozygous Hmga1 deficiency prolongs survival in the transgenic PV-AML murine model with fulminant leukemia and early mortality, although Hmga2 deficiency has no effect. RNA-Seq analyses from human MPN-AML cell lines revealed that HMGA1 up-regulates transcriptional networks involved in cell cycle progressions (E2F targets, mitotic spindle, G2M checkpoint, MYC targets) while repressing immune pathways (inflammation, interferon gamma) and oxidative phosphorylation. HMGA2 up-regulates similar pathways, but represses TNFalpha signaling. cMAP identified inhibitors of histone deacetylation and cell cycle progression as potential agents to target HMGA1 pathways; DNA synthesis inhibitors were predicted to target HMGA2 pathways. Cytotoxicity assays demonstrate that epigenetic therapy with HDAC inhibitors synergizes with Ruxolitinib in JAK2 mutant MPN cells after transformation to leukemia. Conclusions: HMGA1/2 genes are overexpressed in MPN with highest levels after leukemic transformation. Further, silencing HMGA1/2 disrupts leukemogenic phenotypes in vitro and prevents the development of leukemia in mice. In addition, heterozygous deficiency of Hmga1 prolongs survival in a fulminant MPN-AML model. Mechanistically, RNA-Seq analyses revealed that HMGA amplifies transcriptional networks involved cell cycle progression, which can be targeted with epigenetic therapies. Our findings further underscore the key role for HMGA as an epigenetic switch required for leukemic transformation in MPN and opens the door to novel therapeutic approaches to intercept the transition from chronic indolent disease to aggressive leukemia. Disclosures No relevant conflicts of interest to declare.

scholarly journals Cooperative Epigenetic Regulation By ASXL1 and NF1 Loss on Leukemogenesis

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 652-652
Author(s):  
Peng Zhang ◽  
Fuhong He ◽  
Jie Bai ◽  
Shi Chen ◽  
Stephen D. Nimer ◽  
...  
Keyword(s):  
Disease Progression ◽  
Signaling Pathway ◽  
Mouse Models ◽  
Myeloid Leukemia ◽  
Molecular Mechanisms ◽  
Mapk Pathway ◽  
Gene Mutations ◽  
Rna Seq ◽  
Ras Pathway ◽  
Myeloid Malignancies

Abstract Introduction: Additional sex combs-like 1 (ASXL1) is frequently mutated in a wide range of myeloid malignancies, including myelodysplastic syndrome (MDS), myeloproliferative neoplasm, chronic myelomonocytic leukemia, and acute myeloid leukemia (AML). Notably, ASXL1 mutations are generally associated with the poor clinical outcomes. We and others have established Asxl1 mouse models and demonstrated that loss of Asxl1 leads to MDS-like disease, which can transform to myeloid leukemia in aged mice. These studies suggest that additional mutations may cooperate with Asxl1 loss to induce the leukemia transformation. However, the molecular mechanisms underlying the leukemogenesis associated with ASXL1 and cooperating mutations remain to be elucidated. Methods: To identify cooperating events with ASXL1 mutations in myeloid malignancies, we recruited a cohort of 138 ASXL1 mutated patients and performed targeted exome sequencing. We then characterized the hematopoietic features using mouse models. A serial hematopoietic phenotypic analyses were used, including peripheral blood counts, flow cytometry, colony assay, morphology and transplantation assays. To decipher the molecular mechanisms by which loss of Asxl1 and Nf1 cooperate in promoting myeloid leukemia transformation, we performed RNA-seq and ChIP-seq to identify the differentially expressed genes and their associated histone modifications in four genotypes of mice, WT, Asxl1+/-, Nf1+/-, and Asxl1+/-;Nf1+/- mice. Finally, the leukemic mice were treated with pharmacologic inhibitors targeting both MAPK pathway and BET bromodomain in vivo as a proof-of-concept approach. Results: We analyzed the gene mutation profiles of 138 ASXL1 mutated patients based on targeted sequencing and found that 35 of these patients have gene mutations involving in RAS/MAPK signaling pathway, including NF1, NRAS, KRAS, PTPN11 or CBL. The incidence of AML was significantly higher in patients with RAS pathway mutations (48.6%) than in the cases without RAS pathway mutations (29.1%, p = 0.036, chi-square test). These data suggest that concomitant mutations of ASXL1 and RAS pathway genes associate with poor prognosis in myeloid malignancies. To validate the functional significance of cooperative mutations of ASXL1 and NF1, a negative regulator of the RAS signaling pathway, in the disease progression of myeloid leukemia, we generated Asxl1+/-;Nf1+/- and Mx1Cre;Asxl1fl/fl;Nf1fl/fl (Asxl1Δ/Δ;Nf1Δ/Δ) mice and performed hematopoietic phenotypic analyses. Asxl1 loss cooperates with haploinsufficiency of Nf1 to accelerate the development of myeloid leukemia in mice. Asxl1Δ/Δ;Nf1Δ/Δ mice displayed a rapid, progressive leukocytosis with severe anemia and thrombocytopenia 3-6 months after pIpC injection, indicative of aggressive myeloid leukemia with a 100% penetrance. Loss of Asxl1 and Nf1 in hematopoietic stem and progenitor cells lead to transcriptional activation of multiple pathways critical for leukemogenesis, such as MYC, NRAS, and BRD4. Convergent analysis of RNA-seq and ChIP-seq data reveal that the hyperactive MYC and BRD4 transcription program is correlated with elevated H3K4 tri-methylation at the promoter regions of genes involving these pathways. Importantly, pharmacological inhibition of both MAPK pathway and BET bromodomain prevents leukemia initiation and inhibits disease progression in Asxl1Δ/Δ;Nf1Δ/Δ mice, and significantly prolonged the survival of leukemic Asxl1+/-;Nf1+/- mice. Conclusion: This study sheds lights on the understanding of the cooperative effect between epigenetic alterations and signaling pathways in accelerating the progression of myeloid malignancies and provides a rationale therapeutic strategy for the treatment of myeloid malignancies with ASXL1 and RAS pathway gene mutations. Disclosures No relevant conflicts of interest to declare.

scholarly journals Genetically Altered Mouse Models: the Good, the Bad, and the Ugly

2003 ◽  
Vol 14 (3) ◽  
pp. 154-174 ◽  
Author(s):  
Tamizchelvi Thyagarajan ◽  
Satish Totey ◽  
Mary Jo S. Danton ◽  
Ashok B. Kulkarni
Keyword(s):  
Gene Targeting ◽  
Mouse Models ◽  
Molecular Mechanisms ◽  
Gene Knockout ◽  
Genetically Engineered ◽  
Murine Models ◽  
Functional Roles ◽  
Targeted Gene Disruption ◽  
Gene Knockout Mouse

Targeted gene disruption in mice is a powerful tool for generating murine models for human development and disease. While the human genome program has helped to generate numerous candidate genes, few genes have been characterized for their precise in vivo functions. Gene targeting has had an enormous impact on our ability to delineate the functional roles of these genes. Many gene knockout mouse models faithfully mimic the phenotypes of the human diseases. Because some models display an unexpected or no phenotype, controversy has arisen about the value of gene-targeting strategies. We argue in favor of gene-targeting strategies, provided they are used with caution, particularly in interpreting phenotypes in craniofacial and oral biology, where many genes have pleiotropic roles. The potential pitfalls are outweighed by the unique opportunities for developing and testing different therapeutic strategies before they are introduced into the clinic. In the future, we believe that genetically engineered animal models will be indispensable for gaining important insights into the molecular mechanisms underlying development, as well as disease pathogenesis, diagnosis, prevention, and treatment.

scholarly journals Specific and Recurrent Cytogenomic Abnormalities Originate in the Spleens of Myelofibrosis Patients and Contribute to Clonal Diversity and Disease Progression

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1871-1871
Author(s):  
Vesna Najfeld ◽  
Joseph Tripodi ◽  
Xiaoli Wang ◽  
Myron Schwartz ◽  
Marina Kremyanskaya ◽  
...  
Keyword(s):  
Disease Progression ◽  
Copy Number ◽  
Chromosomal Abnormalities ◽  
Donor Cell ◽  
Normal Karyotype ◽  
Chromosome 9 ◽  
Leukemic Transformation ◽  
Genomic Changes ◽  
Cd34 Cells ◽  
Entire Chromosome

Abstract Hematopoietic stem cells located in spleens (SP) of patients with myelofibrosis (MF) have functional properties that differ from those present in peripheral blood (PB) (Wang et al, JCI,122: 3888, 2012 ). We hypothesized that the spleen might be a source of malignant stem cells in MF which ultimately lead to disease progression and leukemic transformation. To investigate the genetic diversity of MF SP cells, cytogenetic analyses of SP and peripheral blood (PB )/bone marrow (BM) cells from 13 MF patients were performed. Nine of 13 patients (69%) had concordant normal (n=5) and abnormal (n=4) cytogenetic and FISH analyses when comparing SP and PB/BM cells. Four (30%) patients had discordant results with specific chromosomal abnormalities present in either SP or PB cells. One patient had 3 cytogenetic abnormalities associated with an unfavorable prognosis: (1;7), del(12p), and i(17q) in SP cells that were not observed in PB cells. A second patient who had progressed to acute leukemia had pentasomy 21 in 45% of SP cells but not in PB cells and had del (20q) in PB cells but not SP cells, suggesting that del (20q) had arisen in the BM while pentasomy 21 had originated in the SP . In a third patent 20% of PB cells had +8 while only 1.6% of SP cells had +8, indicating that the +8 clone originated in the BM. Studies of BM and PB of the 4 th patient showed a normal karyotype in 2008 and 2011 while 2% of SP cells in 2011, at the time of progression to MF, possessed del 20q while the BM remained normal. In 2014, when the patient developed an accelerated phase of MF, 85% of BM cells possessed del (20q), indicating that del(20q) originated in the SP and migrated to the BM. We next hybridized SP DNA from 12 of the 13 patients to the Agilent 400k platform [355515 (CGH) + 59646 (SNP)] and performed CGH and SNP analysis. These studies revealed that all 12 patients had additional gains and losses of chromosomal regions as well as uniparental disomy (UPD) in SP cells. Two groups of acquired genomic changes were observed in SP cells: 1) four acquired regions were present in over 60% of pts and 2) three regions of acquired changes were observed in 25- 33% of patients. Irrespective of the patient’s karyotype, gains of 4 chromosomal regions: 1p13.2 (RHOC), 12q24.31 (NCOR2), 13q34 (RASA3) and 17q12 (TAF15) were detected in 83%, 83%, 75% and 67%, of patient’s SP cells, respectively. All four genes are known to be involved in leukemogenesis. Gains of these 4 chromosomal regions have not been observed in normal controls or PB CD34+ cells from 437 patients with MPNs including MF (Klampfl et al, Blood 167, 2011, Rumi et al Am J Hematol 974, 2011). Gains of an additional three regions, 18q21.31 (NEDD4L), 16q23.2 (WWOX) and 17q21.31 (WNT3) were detected in the SP cells of 25-33% of patients. These genes have also been implicated in leukemogenesis. The greater the complexity of the karyotype of the SP cells the greater the number of copy number genomic changes (up to 92) were observed. Although SNP analyses demonstrated 28 acquired UPD regions in 12 patients 9p13-p24 was the most common occurring in 25% of patients. SNP analyses also demonstrated triplication of 9q and quadruplication of 9p, suggesting that UPD of the entire chromosome 9 in SP cells can be associated with disease progression. Transplantation of SP CD34+ cells with a normal karyotype or with one chromosomal abnormality into NOD/SCID/IL2Rγ(null) mice resulted in a modest degree of donor cell chimerism (0.2%-4%), while transplantation of SP CD34+ cells with UPD of 9p, the entire chromosome 9 UPD, del20q originating in SP cells, complex karyotypes and gains of 4 chromosomal regions (1p,13, 12q24, 13q34 and 17q12 ) resulted in a higher degree of donor cell chimerism (18%-25%) indicating the association of these genetic events with altered stem cell function. Our findings indicate that some chromosomal abnormalities are acquired in MPNs initially in the SP sometimes occurring years prior to their appearance in the BM/PB. Other abnormalities, such as del(20q) may originate in either the BM or SP. All MF SP cells were characterized by additional diverse cytogenomic changes involving at least four regions, containing genes associated with leukemogenesis, leading to recurrent copy number gains in 67% to 83% of MF patients. We hypothesize that the SP provides a microenvironment in a subpopulation of MF patients which is associated with increased genomic diversity resulting in disease progression and leukemic transformation. Disclosures Mascarenhas: Incyte Corporation: Consultancy.

scholarly journals Dietary Intervention Impacts Immune Cell Functions and Dynamics by Inducing Metabolic Rewiring

2021 ◽  
Vol 11 ◽  
Author(s):  
Takuma Okawa ◽  
Motoyoshi Nagai ◽  
Koji Hase
Keyword(s):  
T Cell ◽  
Cell Fate ◽  
Molecular Mechanisms ◽  
Dietary Intervention ◽  
Immune Cell ◽  
Aerobic Glycolysis ◽  
Acid Oxidation ◽  
Intermittent Fasting ◽  
Cell Trafficking ◽  
Cell Functions

Accumulating evidence has shown that nutrient metabolism is closely associated with the differentiation and functions of various immune cells. Cellular metabolism, including aerobic glycolysis, fatty acid oxidation, and oxidative phosphorylation, plays a key role in germinal center (GC) reaction, B-cell trafficking, and T-cell-fate decision. Furthermore, a quiescent metabolic status consolidates T-cell-dependent immunological memory. Therefore, dietary interventions such as calorie restriction, time-restricted feeding, and fasting potentially manipulate immune cell functions. For instance, intermittent fasting prevents the development of experimental autoimmune encephalomyelitis. Meanwhile, the fasting response diminishes the lymphocyte pool in gut-associated lymphoid tissue to minimize energy expenditure, leading to the attenuation of Immunoglobulin A (IgA) response. The nutritional status also influences the dynamics of several immune cell subsets. Here, we describe the current understanding of the significance of immunometabolism in the differentiation and functionality of lymphocytes and macrophages. The underlying molecular mechanisms also are discussed. These experimental observations could offer new therapeutic strategies for immunological disorders like autoimmunity.

scholarly journals Circular RNAs of the Nucleophosmin 1 (NPM1) Gene in Acute Myeloid Leukemia Patients

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2695-2695
Author(s):  
Susanne Hirsch ◽  
Tamara J. Blätte ◽  
Sarah Grasedieck ◽  
Arefeh Rouhi ◽  
Mojca Jongen-Lavrencic ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Principal Component ◽  
Circular Rnas ◽  
Rna Seq ◽  
Leukemic Transformation ◽  
Healthy Control ◽  
Tlr Signaling Pathway ◽  
Control Samples

Abstract Background: The nucleophosmin 1 (NPM1) gene is not only commonly mutated in acute myeloid leukemia (AML), but also encodes several linear splice isoforms, one of which was recently shown to be of prognostic importance. Furthermore, circular RNAs (circRNAs) are transcribed from the NPM1 gene which demands further investigation with regard to function in normal hematopoiesis and impact on leukemogenesis. Aims: We aimed to investigate circRNAs derived from NPM1 and gain insights into their regulation and function. Additionally, we wanted to determine changes in the circular RNAome in the course of hematopoietic differentiation and leukemic transformation. Methods: Circular NPM1 transcripts were detected by PCR and sequenced in leukemic cell lines (n=7) and healthy control samples (n=3, peripheral blood-derived mononuclear cells). Expression of hsa_circ_0075001 and total NPM1 was measured in a cohort of 23 NPM1 wildtype (NPM1wt) and 23 NPM1 mutated (NPM1mut) AML patients via quantitative real-time PCR (qPCR), and Affymetrix U133plus2 microarray data was set in relation to the expression levels. Principal component analysis (PCA) was conducted to identify groups with similarities in gene expression patterns and differentially expressed genes were subjected to pathway analysis. Next, ribosomal RNA-depleted RNA-seq was performed for 5 NPM1mut and 5 NPM1wt AML cases, as well as 10 healthy control samples derived from 4 FACS-sorted myeloid differentiation stages (myeloblasts, promyelocytes, metamyelocytes and neutrophils). PCA and unsupervised hierarchical clustering were performed based on circRNA expression. Results: We detected and sequenced multiple circular NPM1 transcripts (n=23) in leukemic as well as in healthy control cells. As hsa_circ_0075001 showed differential expression between different AML cell lines in a semi-quantitative PCR analysis, quantification in 46 AML patients via qPCR was performed. This analysis revealed that total NPM1 and hsa_circ_0075001 expression were independent of the NPM1 mutational status. Furthermore, the hsa_circ_0075001 expression status defined distinct leukemia subgroups characterized by similarities in gene expression as determined by PCA. For example, differentially expressed genes between high versus low hsa_circ_0075001 expression groups (dichotomized at the median) were significantly enriched in components of the Toll-like receptor (TLR) signaling pathway, which was downregulated in patients with high hsa_circ_0075001 expression. Expression of hsa_circ_0075001 correlated positively with total NPM1 expression, and RNA-seq analysis further revealed a global correlation of circRNA and parental gene expression. In total, in our cohort circRNAs were found for 19 % of all expressed genes. PCA based on circRNA expression illustrated that immature and mature hematopoietic cells, as well as NPM1wt and NPM1mut AML samples, exhibit distinct circRNA signatures (Figure 1). Thus, circRNA expression seems to play a role during differentiation of normal hematopoietic cells, but also seems to be severely deregulated in AML. Figure 1: Altered circular RNA expression in AML patients compared to healthy control samples. Principal component analysis (PCA) of circRNA expression data of 5 NPM1mut patients (red), 5 NPM1wt patients (green), and 10 healthy control samples, of which 4 were derived from immature (blue) and 6 from more mature myeloid differentiation stages (purple). Data was generated via RNA-Seq and reads derived from circRNAs were aligned and quantified using STAR, and normalized and transformed using DESeq2. PCA was performed based on 500 genes with the highest variance of circRNA expression across all samples. Conclusions: circRNAs transcribed from the NPM1 gene showed differential expression in AML cell lines and healthy cells, and higher hsa_circ_0075001 expression defined an AML subgroup characterized by downregulation of the TLR signaling pathway. These findings provide evidence for the relevance of circular NPM1 transcripts and add another level of complexity to the multifaceted gene NPM1. In general, circRNA expression seems to be involved in the regulation of hematopoietic differentiation, which is in line with previous observations, but, based on distinct circRNA expression profiles in AML, they might also play a significant pathogenic role in leukemic transformation. Figure 1 Figure 1. Disclosures Paschka: Celgene: Honoraria; Pfizer Pharma GmbH: Honoraria; Bristol-Myers Squibb: Honoraria; Medupdate GmbH: Honoraria; Novartis: Consultancy; ASTEX Pharmaceuticals: Consultancy.

scholarly journals Breed, Diet, and Interaction Effects on Adipose Tissue Transcriptome in Iberian and Duroc Pigs Fed Different Energy Sources

Genes ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 589 ◽  
Author(s):  
Rita Benítez ◽  
Nares Trakooljul ◽  
Yolanda Núñez ◽  
Beatriz Isabel ◽  
Eduard Murani ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Immune Cell ◽  
Live Weight ◽  
Joint Analysis ◽  
Energy Sources ◽  
Cell Trafficking ◽  
Rna Seq ◽  
High Oleic Sunflower Oil ◽  
High Oleic ◽  
Subcutaneous Adipose

In this study, we analyzed the effects of breed, diet energy source, and their interaction on adipose tissue transcriptome in growing Iberian and Duroc pigs. The study comprised 29 Iberian and 19 Duroc males, which were kept under identical management conditions except the nutritional treatment. Two isoenergetic diets were used with 6% high oleic sunflower oil (HO) or carbohydrates (CH) as energy sources. All animals were slaughtered after 47 days of treatment at an average live weight of 51.2 kg. Twelve animals from each breed (six fed each diet) were employed for ham subcutaneous adipose tissue RNA-Seq analysis. The data analysis was performed using two different bioinformatic pipelines. We detected 837 and 1456 differentially expressed genes (DEGs) according to breed, depending on the pipeline. Due to the strong effect of breed on transcriptome, the effect of the diet was separately evaluated in the two breeds. We identified 207 and 57 DEGs depending on diet in Iberian and Duroc pigs, respectively. A joint analysis of both effects allowed the detection of some breed–diet interactions on transcriptome, which were inferred from RNA-Seq and quantitative PCR data. The functional analysis showed the enrichment of functions related to growth and tissue development, inflammatory response, immune cell trafficking, and carbohydrate and lipid metabolism, and allowed the identification of potential regulators. The results indicate different effects of diet on adipose tissue gene expression between breeds, affecting relevant biological pathways.

AML1/RUNX1 point mutation possibly promotes leukemic transformation in myeloproliferative neoplasms

Blood ◽  
2009 ◽  
Vol 114 (25) ◽  
pp. 5201-5205 ◽  
Author(s):  
Ye Ding ◽  
Yuka Harada ◽  
Jun Imagawa ◽  
Akiro Kimura ◽  
Hironori Harada
Keyword(s):  
Molecular Mechanisms ◽  
Myeloproliferative Neoplasms ◽  
Point Mutations ◽  
Chronic Phase ◽  
Myeloid Cell ◽  
Leukemic Transformation ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Immature Myeloid Cells ◽  
Gene Alterations

Abstract Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell disorders characterized by proliferation of one or more myeloid cell lineages. Some patients exhibit leukemic transformation (LT) by unknown mechanisms, and chemotherapy may increase the risk of LT. To clarify the molecular mechanisms of LT, gene alterations involved in LT from patients in the chronic phase (CP) of MPNs were identified. Among 18 patients who progressed to leukemia, AML1/RUNX1 mutations were detected in 5 patients at the LT but in none at the CP. To investigate the leukemogenic effect of AML1/RUNX1 mutants, the AML1D171N mutant was transduced into CD34+ cells from patients in the CP of MPNs. The D171N transduction resulted in proliferation of immature myeloid cells, enhanced self-renewal capacity, and proliferation of primitive progenitors. Taken together, these results indicate that AML1/RUNX1 point mutations may have a leukemogenic potential in MPN stem cells, and they may promote leukemic transformation in MPN.

scholarly journals Imetelstat Inhibits Telomerase and Prevents Propagation of ADAR1-Activated Myeloproliferative Neoplasm and Leukemia Stem Cells

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 18-18
Author(s):  
Wenxue Ma ◽  
Larissa Balaian ◽  
Phoebe Mondala ◽  
Yudou He ◽  
Cayla Mason ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Telomere Length ◽  
Mouse Models ◽  
Telomerase Activity ◽  
Rna Seq ◽  
Publicly Traded ◽  
Cd34 Cells

BACKGROUND Clonal stem cell derived myeloproliferative neoplasms (MPNs) have a propensity to evolve to acute myeloid leukemia (AML). Deregulation of the innate immune deaminase associated with RNA1 (ADAR1) has been linked to malignant progression and therapeutic resistance. Increased expression of the stem cell gene, human telomerase reverse transcriptase (hTERT), has also been linked with malignant transformation. However, the combinatorial role of ADAR1 and hTERT in the evolution of MPN stem cells to therapy resistant acute myeloid leukemia stem cells (LSCs) and the capacity of a telomerase inhibitor, imetelstat, to prevent survival and self-renewal of pre-LSC and LSC had not been established. Recent clinical trials show early signs of efficacy of imetelstat in treatment of myelofibrosis (MF). However, its role in selectively inhibiting pre-LSC transformation to self-renewing LSC has not been elucidated. Here we show that targeting telomerase activity prevents pre-LSC and LSC maintenance both in vitro and in vivo, suggesting telomerase inhibition as an effective strategy for preventing MPN progression. METHODS To quantify hTERT level and ADAR1 activity in the setting of normal HSPC and MPN stem cell evolution, whole genome sequencing (WGS) analysis was performed on 76 normal and MPN blood CD34+ cells and matching saliva samples. Results were compared with RNA-seq of 100 FACS purified young, aged, MPN and AML CD34+CD38- stem cells and CD34+CD38+ progenitor cells. Confocal fluorescence microscopic evaluation of stem cell ADAR1 and hTERT localization, telomere length by Flow-FISH and telomerase activity by TRAP assays, lentiviral ADAR1 overexpression and shRNA knockdown were performed. In vitro stromal co-cultures, and humanized immunocompromised mouse models were established to determine the impact of imetelstat (a oligonucleotide inhibitor of telomerase) on normal, MPN stem cell and LSC maintenance. RESULTS Combined hTERT overexpression, ADAR1 activation and a significant reduction in telomere length correlated with accelerated stem cell aging during MPN progression to AML. Increased ADAR1 mediated adenosine to inosine (A-to-I) transcript editing coincided with accelerated telomere shortening in high risk MPN stem cells. Moreover, lentiviral ADAR1 overexpression enhanced pre-LSC engraftment. Treatment with imetelstat reduced MPN stem cell and LSC propagation in stromal co-cultures as well as in humanized mouse models commensurate with reduced hTERT expression levels and telomerase activity and decreased ADAR1 editing activity. Specifically, stromal co-culture assays revealed that combined treatment with dasatinib at 1 nM, and imetelstat at 1 µM or 5 µM significantly inhibited survival and replating of blast crisis (BC) CML progenitors compared with aged bone marrow progenitors (p &lt; 0.001, ANOVA). As a single agent, imetelstat (5 µM) inhibited survival and replating of pre-LSC derived from myelofibrosis compared with normal bone marrow progenitor samples (p &lt; 0.001, ANOVA). In pre-LSC MPN NSG-SGM mouse models established from 4 different MF samples, a significant reduction in proliferation of human CD45+ cells (p &lt; 0.01, t test) was observed in bone marrow and spleen, when compared with vehicle control. Treatment of humanized LSC mouse models, established with 5 different BC CML, with 30 mg/kg of imetelstat, 3 times a week for 4 weeks resulted in a significant reduction in proliferation of malignant progenitors and human CD45+ cells (p &lt; 0.001, ANOVA). As measured by a Flow-FISH assay, abnormal telomere length was reversed by imetelstat treatment compared with mismatch control (p &lt; 0.05, ANOVA). In addition, FACS analysis revealed a significant reduction in activated beta-catenin expression after imetelstat treatment of LSC engrafted mice compared with vehicle control (p &lt; 0.01, ANOVA). Finally, RNA-seq analysis performed on human CD34+ cells from imetelstat treated LSC mouse models revealed a significant reduction in LSC harboring malignant ADAR1-mediated A-to-I editing at doses that spared normal hematopoietic stem cells. CONCLUSIONS Combined WGS and RNA-Seq analyses, lentiviral ADAR1 overexpression, stromal co-culture assays and humanized pre-LSC and LSC mouse model studies reveal that pre-LSC evolution into LSC coincides with both ADAR1 and hTERT activation, which can be prevented with imetelstat. Disclosures Rizo: Geron Corp: Current Employment, Current equity holder in publicly-traded company. Huang:Geron Corp: Current Employment, Current equity holder in publicly-traded company. Jamieson:Forty Seven Inc: Patents & Royalties; Bristol-Myers Squibb: Other.

scholarly journals RELA is Sufficient to Mediate Interleukin-1 (IL-1) Repression of Androgen Receptor Expression and Activity in LNCaP Disease Progression Model

2019 ◽  
Author(s):  
Shayna E. Thomas-Jardin ◽  
Haley Dahl ◽  
Mohammed S. Kanchwala ◽  
Freedom Ha ◽  
Joan Jacob ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Androgen Receptor ◽  
Disease Progression ◽  
Cell Lines ◽  
Pathway Analysis ◽  
Molecular Mechanisms ◽  
Interleukin 1 ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Lncap Cells

ABSTRACTBackgroundThe Androgen Receptor (AR) nuclear transcription factor is a therapeutic target for prostate cancer (PCa). Unfortunately, patients can develop resistance to AR-targeted therapies and progress to lethal disease, underscoring the importance of understanding the molecular mechanisms that underlie treatment resistance. Inflammation is implicated in PCa initiation and progression and we have previously reported that the inflammatory cytokine, interleukin-1 (IL-1), represses AR mRNA levels and activity in AR-positive (AR+) PCa cell lines concomitant with the upregulation of pro-survival biomolecules. Thus, we contend that IL-1 can select for AR-independent, treatment-resistant PCa cells.MethodsTo begin to explore how IL-1 signaling leads to the repression of AR mRNA levels, we performed comprehensive pathway analysis on our RNA sequencing data from IL-1-treated LNCaP PCa cells. Our pathway analysis predicted Nuclear Factor Kappa B (NF-κB) p65 subunit (RELA), a canonical IL-1 signal transducer, to be significantly active and potentially regulate many genes, including AR. We used siRNA to silence the NF-κB family of transcription factor subunits, RELA, RELB, c-REL, NFKB1, or NFKB2, in IL-1-treated LNCaP, C4-2, and C4-2B PCa cell lines. C4-2 and C4-2B cell lines are castration-resistant LNCaP sublines and represent progression towards metastatic PCa disease; and we have previously shown that IL-1 represses AR mRNA levels in C4-2 and C4-2B cells.ResultssiRNA revealed that RELA alone is sufficient to mediate IL-1 repression of AR mRNA and AR activity. Intriguingly, while LNCaP cells are more sensitive to IL-1-mediated repression of AR than C4-2 and C4-2B cells, RELA siRNA led to a more striking de-repression of AR mRNA levels and AR activity in C4-2 and C4-2B cells than in LNCaP cells.ConclusionsThese data indicate that there are RELA-independent mechanisms that regulate IL-1-mediated AR repression in LNCaP cells and suggest that the switch to RELA-dependent IL-1 repression of AR in C4-2 and C4-2B cells reflects changes in epigenetic and transcriptional programs that evolve during PCa disease progression.

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