MicroRNA Expression Profiles in Chronic Myelomonocytic Leukemia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2699-2699
Author(s):  
Mehdi Nassiri ◽  
Joseph Olczyk ◽  
Samantha Knapp ◽  
Gail Vance ◽  
Anupama Tewari ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mirna Expression ◽  
Expression Profiles ◽  
Chronic Myelomonocytic Leukemia ◽  
Differentially Expressed ◽  
Cytogenetic Abnormalities ◽  
Normal Bone ◽  
Normal Reference ◽  
Mirna Expression Profiles ◽  
Myelomonocytic Leukemia

Abstract Chronic myelomonocytic leukemia (CMML) is a hematopoietic malignancy with hybrid myeloproliferative and myelodysplastic features. The diagnostic criteria for CMML are evolving with the progress of our knowledge on various genetic lesions involved in the pathogenesis of myeloid neoplasms. This shift, including molecular genetic lesions in the diagnosis process, is highlighted in updated 2008 WHO classification system, which excludes myeloproliferative neoplasms with PDGFRB rearrangement, monocytosis and eosinophilia from CMML category. Despite these recent advancements, CMML remains a heterogeneous group of diseases with variable patient outcomes and no well-defined targeted therapy. To further investigate the biological diversity of this disorder, we studied microRNA (miRNA) expression profiles, their relation to the diagnostic and clinical parameters in CMML, and compared these profiles to global miRNA expression in normal reference bone marrow samples. MicroRNAs are a class of non-coding RNA molecules that alter gene expression by targeting and blocking mRNA. The role of miRNAs in carcinogenesis is related to their targeting of messenger RNAs encoding for oncogenes and tumor suppressor genes. Bone marrow samples from 22 patients with CMML were included in the study. Median age of the patients was 71 years with a range from 39 to 92 years. There were 15 males and 7 females. Seventeen patients presented with CMML-1 (blasts less than 5% in peripheral blood and less than 10% of bone marrow differential count). The remaining patients showed CMML-2. Nine patients had WBC below 13×109/L defining a myelodysplastic type of CMML. Cytogenetic results were available in 20 patients. Fourteen patients demonstrated a normal karyotype. Normal pooled bone marrow samples were used as a reference. The total RNA was isolated using RecoverAll RNA extraction kit. Micoroarray studies were performed using Agilent human miRNA microarrays (version 1.0) containing probes for 470 human and 64 human viral miRNAs cataloged in the Sanger database v9.1. The results were analyzed using BRB array tool and Genesis software. Unsupervised hierarchical clustering discovered two different groups of CMML samples with patterns of miRNA expression distinct from normal bone marrows (oneway ANOVA). Twenty seven miRNAs were differentially expressed in normal bone marrow reference samples vs. CMML-1 and -2. There was an overlap in miRNA profiles between groups of CMML based on blast percentage (CMML-1 vs. CMML-2), WBC count (<13×109/L vs. ≥13×109/L) and presence or absence of cytogenetic abnormalities. However, using PAM algorithm the following miRNAs showed predictive power: hsa-miR-519b (in CMML-1 vs. 2); hsa-miR-15b and hsa-miR-432* (in groups of samples separated by a cut-off WBC of 13×109/L) and hsa-miR-223 (comparing CMML with and without cytogenetic abnormalities). In summary, significantly different miRNA profiles were seen in CMML as compared to normal reference bone marrow. Two distinct subgroups of CMML were defined by the miRNA expression profiles. Select miRNAs were differentially expressed in known biological and clinical subgroups of CMML. Further correlation of clinical and outcome data with subgroups of CMML defined by miRNA expression profiles will be presented.

scholarly journals MicroRNA expression patterns associated with hyperfunctioning and non-hyperfunctioning phenotypes in adrenocortical adenomas

2014 ◽  
Vol 170 (4) ◽  
pp. 583-591 ◽  
Author(s):  
David Velázquez-Fernández ◽  
Stefano Caramuta ◽  
Deniz M Özata ◽  
Ming Lu ◽  
Anders Höög ◽  
...  
Keyword(s):  
Mirna Expression ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Gene Mutations ◽  
Mirna Expression Profile ◽  
Differentially Expressed ◽  
Adrenocortical Adenoma ◽  
Tumor Subtypes ◽  
Mirna Expression Profiles ◽  
Differentially Expressed Mirnas

BackgroundThe adrenocortical adenoma (ACA) entity includes aldosterone-producing adenoma (APA), cortisol-producing adenoma (CPA), and non-hyperfunctioning adenoma (NHFA) phenotypes. While gene mutations and mRNA expression profiles have been partly characterized, less is known about the alterations involving microRNA (miRNA) expression.AimTo characterize miRNA expression profile in relation to the subtypes of ACAs.Subjects and methodsmiRNA expression profiles were determined in 26 ACAs (nine APAs, ten CPAs, and seven NHFAs) and four adrenal references using microarray-based screening. Significance analysis of microarrays (SAM) was carried out to identify differentially expressed miRNAs between ACA and adrenal cortices or between tumor subtypes. Selected differentially expressed miRNAs were validated in an extended series of 43 ACAs and ten adrenal references by quantitative RT-PCR.ResultsAn hierarchical clustering revealed separate clusters for APAs and CPAs, while the NHFAs were found spread out within the APA/CPA clusters. When NHFA was excluded, the clustering analysis showed a better separation between APA and CPA. SAM analysis identified 40 over-expressed and three under-expressed miRNAs in the adenomas as compared with adrenal references. Fourteen miRNAs were common among the three ACA subtypes. Furthermore, we found specific miRNAs associated with different tumor phenotypes.ConclusionThe results suggest that miRNA expression profiles can distinguish different subtypes of ACA, which may contribute to a deeper understanding of ACA development and potential therapeutics.

scholarly journals Renal Tissue miRNA Expression Profiles in ANCA-Associated Vasculitis—A Comparative Analysis

2021 ◽  
Vol 23 (1) ◽  
pp. 105
Author(s):  
Matic Bošnjak ◽  
Željka Večerić-Haler ◽  
Emanuela Boštjančič ◽  
Nika Kojc
Keyword(s):  
Mirna Expression ◽  
Expression Profiles ◽  
Target Organ Damage ◽  
Organ Damage ◽  
Renal Tissue ◽  
Differentially Expressed ◽  
Tissue Samples ◽  
Anca Associated Vasculitis ◽  
Mirna Expression Profiles ◽  
Differentially Expressed Mirnas

Anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) comprises autoimmune disease entities that cause target organ damage due to relapsing-remitting small vessel necrotizing vasculitis, and which affects various vascular beds. The pathogenesis of AAV is incompletely understood, which translates to considerable disease- and treatment-related morbidity and mortality. Recent advances have implicated microRNAs (miRNAs) in AAV; however, their accurate characterization in renal tissue is lacking. The goal of this study was to identify the intrarenal miRNA expression profile in AAV relative to healthy, non-inflammatory and inflammatory controls to identify candidate-specific miRNAs. Formalin-fixed, paraffin-embedded renal biopsy tissue samples from 85 patients were obtained. Comprehensive miRNA expression profiles were performed using panels with 752 miRNAs and revealed 17 miRNA that differentiated AAV from both controls. Identified miRNAs were annotated to characterize their involvement in pathways and to define their targets. A considerable subset of differentially expressed miRNAs was related to macrophage and lymphocyte polarization and cytokines previously deemed important in AAV pathogenesis, lending credence to the obtained results. Interestingly, several members of the miR-30 family were detected. However, a validation study of these differentially expressed miRNAs in an independent, larger sample cohort is needed to establish their potential diagnostic utility.

scholarly journals Profiling 25 Bone Marrow microRNAs in Acute Leukemias and Secondary Nonleukemic Hematopoietic Conditions

Biomedicines ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 607
Author(s):  
Igor B. Kovynev ◽  
Sergei E. Titov ◽  
Pavel S. Ruzankin ◽  
Mechti M. Agakishiev ◽  
Yuliya A. Veryaskina ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mirna Expression ◽  
Expression Profiles ◽  
Lymphoblastic Leukemia ◽  
Molecular Genetic ◽  
Mirna Expression Profile ◽  
Classification Systems ◽  
Acute Leukemias ◽  
Mirna Expression Profiles ◽  
Genetic Features

Introduction: The standard treatment of acute leukemias (AL) is becoming more efficacious and more selective toward the mechanisms via which to suppress hematologic cancers. This tendency in hematology imposes additional requirements on the identification of molecular-genetic features of tumor clones. MicroRNA (miRNA, miR) expression levels correlate with cytogenetic and molecular subtypes of acute leukemias recognized by classification systems. The aim of this work is analyzing the miRNA expression profiles in acute myeloblastic leukemia (AML) and acute lymphoblastic leukemia (ALL) and hematopoietic conditions induced by non-tumor pathologies (NTP). Methods: A total of 114 cytological samples obtained by sternal puncture and aspiration biopsy of bone marrow (22 ALLs, 44 AMLs, and 48 NTPs) were analyzed by real-time PCR regarding preselected 25 miRNAs. For the classification of the samples, logistic regression was used with balancing of comparison group weights. Results: Our results indicated potential feasibility of (i) differentiating ALL+AML from a nontumor hematopoietic pathology with 93% sensitivity and 92% specificity using miR-150:miR-21, miR-20a:miR-221, and miR-24:nf3 (where nf3 is a normalization factor calculated from threshold cycle values of miR-103a, miR-191, and miR-378); (ii) diagnosing ALL with 81% sensitivity and 81% specificity using miR-181b:miR-100, miR-223:miR-124, and miR-24:nf3; and (iii) diagnosing AML with 81% sensitivity and 84% specificity using miR-150:miR-221, miR-100:miR-24, and miR-181a:miR-191. Conclusion: The results presented herein allow the miRNA expression profile to de used for differentiation between AL and NTP, no matter what AL subtype.

scholarly journals Detection of Differentially Expressed MicroRNAs in Rheumatic Heart Disease: miR-1183 and miR-1299 as Potential Diagnostic Biomarkers

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Ni Li ◽  
Jiangfang Lian ◽  
Sheng Zhao ◽  
Dawei Zheng ◽  
Xi Yang ◽  
...  
Keyword(s):  
Heart Disease ◽  
Pulmonary Artery ◽  
Rheumatic Heart Disease ◽  
Mirna Expression ◽  
Expression Profiles ◽  
Differentially Expressed ◽  
Mirna Expression Profiles ◽  
Differentially Expressed Mirnas ◽  
Secondary Pulmonary Hypertension ◽  
Rheumatic Heart

This study compared microRNA (miRNA) expression profiles between rheumatic heart disease (RHD) patients and healthy controls to investigate their differential expression and help elucidate their mechanisms of action. Microarray analysis was used to measure miRNA expression, and a total of 133 miRNAs were shown to be significantly upregulated in RHD patients compared with controls, including miR-1183 and miR-1299. A total of 137 miRNAs, including miR-4423-3p and miR-218-1-3p, were significantly downregulated in RHD patients. Quantitative real-time-PCR confirmed microarray findings for miR-1183 and miR-1299 in both tissue and plasma. Bioinformatic predictions were also made of differentially expressed miRNAs as biomarkers in RHD by databases and GO/pathway analysis. Furthermore, we investigated miR-1183 and miR-1299 expression in RHD patients with secondary pulmonary hypertension (PAH). Our findings identified an important role for miR-1299 as a direct regulator of RHD, while the observed difference in expression of miR-1183 between RHD-PAH patients with high or low pulmonary artery pressure suggests that miR-1183 overexpression may reflect pulmonary artery remodeling. miR-1183 and miR-1299 appear to play distinct roles in RHD pathogenesis accompanied by secondary PAH and could be used as potential biological markers for disease development.

miRNA Profiling in Human Granulopoiesis and in Activated Neutrophils From Skin Window.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2136-2136
Author(s):  
Maria Torp Larsen ◽  
Christoffer Hother ◽  
Mattias Hager ◽  
Corinna Cavan Pedersen ◽  
Lars Jacobsen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Bone Marrow ◽  
Inflammatory Response ◽  
Mirna Expression ◽  
Peripheral Blood ◽  
Expression Profiles ◽  
Cycle Arrest ◽  
Mirna Expression Profiles ◽  
Differentially Expressed Mirnas ◽  
Activated Neutrophils

Abstract Abstract 2136 Formation of polymorphonuclear neutrophils (PMN) is a tightly regulated process where the myeloid progenitor cells, myeloblasts (MBs), divide and mature in the bone marrow, along a well defined path. The cells pass through six well defined stages in differentiation ending up with the release of mature PMNs to peripheral blood (granulopoiesis). Expression of essential transcription factors such as RUNX1, C/EBP-a, and C/EBP-e during granulopoiesis has been shown to have great importance for correct neutrophil development. microRNAs (miRNAs) could be important players in the fine-tuning of transcription factor expression due to their ability to regulate protein synthesis. The function of neutrophils is to detect and destroy invading microorganisms. This involves activation of the PMNs in the blood stream causing a release of secretory vesicles and up-regulation of extracellular adhesion molecules followed by migration in the tissue towards the focus of inflammation. Expression of miRNAs might also be regulated during activation and diapedesis of the neutrophils in order to adapt the neutrophil to its new environment and function. A regulatory role for miRNAs has been demonstrated for several biological processes, such as proliferation, differentiation, inflammation and cancer, and dysregulation of miRNA expression has been shown to contribute to disease development. The purpose of this study was to determine the miRNA expression profiles during normal human granulopoiesis starting with the first identifiable granulocytic precursor cell (MB) and ending with activated neutrophils that have migrated into the tissue using an Affymetrix 2,0 miRNA microarray platform. We isolated four populations of cells: Myeloblasts (MB) and promyelocytes (PM), myelocytes (MC) and metamyelocytes (MM), and band cells (BC) and segmented cells (SC) from the bone marrow and PMNs from peripheral blood from three different donors. We found 135 differentially expressed miRNAs in granulopoiesis, which could be divided into six clusters according to their expression pattern. 87% of the 135 miRNAs were differentially regulated between the MB/PM (dividing cells) and the MC/MM stages (cessation of cell proliferation and initiation of terminal differentiation) and could imply a need for miRNA-mediated regulation of the many proteins involved in regulating this process. Interestingly, we also found two distinct clusters of miRNAs that were either up- or down-regulated only in the MC/MM population, indicating the importance of a specific temporary regulation of some proteins during neutrophil development. To determine miRNA expression profiles in activated granulocytes, we examined PMNs and activated neutrophils from skin window (i.e. PMNs migrated to a site of inflammation). We found seven differentially expressed miRNAs, - all of them up regulated in the activated neutrophils. Using microRNA target-prediction software, we found that miRNAs 155, 146a and 130a, all of which are strongly up-regulated in the MB/PM stage, have several targets in the IL1-receptor signalling cascade, indicating the importance of miRNA of dampening an innate immune response in immature neutrophil precursors. miR-146a, 155 and 130a also have predicted targets in either the TGF-βI or the TGF-βII receptor which inhibits proliferation when binding to TGF-β. This finding supports the proliferating profile for the MB/PM cells, and the shift towards cell cycle arrest when the cells differentiate to the next stage, where expression of these three miRNAs is low. miRNA-34c-3p is highly expressed only in the MC/MM stage and has verified targets in many different mRNAs involved in the regulation of cell cycle arrest. All the miRNAs that were up-regulated in the activated neutrophils have several predicted targets in the IL1R pathway, and some of them (miR-212, −132 and −297) have previously been shown to be important in regulating the inflammatory response. The study indicates that several different miRNAs have important roles in the regulation of normal granulopoiesis, and that miRNAs also might be part of a possible negative feed back loop in the inflammatory response in activated neutrophils. Grant acknowledgments: The Danish Cancer Society, Lundbeck foundation, Danish Medical Research Council, Brøchner Mortensen foundation Disclosures: No relevant conflicts of interest to declare.

Integrative Analysis Of mRNA/miRNA Expression Profiles Identified JARID2 As a Shared Target Of Deregulated Mirnas In Primary Myelofibrosis

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1600-1600
Author(s):  
Roberta Zini ◽  
Ruggiero Norfo ◽  
Valentina Pennucci ◽  
Elisa Bianchi ◽  
Simona Salati ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mirna Expression ◽  
Expression Profiles ◽  
Primary Myelofibrosis ◽  
Integrative Analysis ◽  
Differentially Expressed ◽  
Luciferase Reporter ◽  
Potential Contribution ◽  
Cd34 Cells ◽  
Mirna Expression Profiles

Abstract Ph-negative myeloproliferative neoplasms (MPNs) are characterized by many somatic mutations which have already been shown useful in the prognostic assessment of MPN patients [A.M. Vannucchi et al., Leukemia, 2013]. Moreover, aberrant microRNA (miRNA) expression seems to add to the molecular complexity of MPNs, as specific miRNA signatures capable of discriminating MPN cells from those of normal donors were previously reported [P. Guglielmelli et al., Exp Hematol, 2007]. In order to have a comprehensive picture of miRNA deregulation and its relationship with differential gene expression in primary myelofibrosis (PMF) cells, we obtained gene- (GEP) and miRNA expression profiles (miEP) of CD34+ cells from 31 healthy donors and 42 PMF patients using Affymetrix technology (HG-U219 and miRNA 2.0 arrays). Among 726 differentially expressed genes (DEG) we found that several putative cancer markers (WT1, ANGPT1) and several genes related to PMF progression, i.e. involved in megakaryocyte (MK) differentiation (NFE2, CD9), and fibrosis development (DLK1, LEPR1), were significantly more expressed in PMF samples than in the normal counterpart. Similarly, as regards the miEP, among 74 human differentially expressed miRNAs (DEM) in PMF compared to controls we found the upregulation of several miRNAs associated with hematological malignancies or known as oncomiRs (i.e. hsa-miR-155-5p [S. Jiang et al., Cancer Res, 2010], miRNAs belonging to the miR-17-92 cluster [L. Venturini et al., Blood, 2007]), and other aberrantly expressed miRNAs never described in hematopoiesis (i.e. hsa-miR-335-5p). Then, in order to construct regulatory networks of the functional human miRNA-target interactions, we performed an integrative analysis (IA) with Ingenuity Pathway analysis software, which combines the miRNA expression profile with computational predicted targets and with the gene expression data. IA between DEG and DEM disclosed a high number of predicted targets with anti-correlated expression to the trend of their targeting miRNAs. Of note, IA identified an interaction network (see Figure) in which the upregulated oncomirs miR-155-5p [R.M. O'Connel et al., J Exp Med, 2008], miR29a-3p [Y.C. Han et al., J Exp Med, 2010] and miR-19b-3p [K.J. Mavrakis et al., Nat Cell Biol, 2010] could explain the downregulation of targets whose lower expression was already described as involved in myeloproliferative phenotypes, such as NR4A3, CDC42, HMGB3. Additionally, IA disclosed the chromatin remodeler JARID2, which is frequently deleted in leukemic transformation of chronic myeloid malignancies, as a shared target of several upregulated miRNAs in PMF samples (i.e. miR-155-5p, miR-152-3p). Noteworthy, these miRNA-mRNA interactions were functionally confirmed by 3' UTR luciferase reporter assays. Next, in order to characterize the role of JARID2 in PMF pathogenesis, we performed RNAi-mediated gene silencing experiments on CD34+ cells of healthy donor. Interestingly, inhibition of JARID2 expression produces in silenced cells a significant increase of CD41 expression when compared with control (28.6±3.1% vs 15.3±1.8% at day 8, 52.6±7.6% vs 35.4±4.9% at day 12 of serum free liquid culture) and a remarkable increase in CFU-MK colonies (59.6±6.5% vs 39.8±5.9%). The values are reported as mean ± 2S.E.M from five independent experiments. Moreover, morphological analysis after May-Grunwald-Giemsa staining showed that JARID2 silencing induces in normal CD34+ cells a considerable enrichment in MK precursors at different stages of maturation. This study allowed the identification of different networks possibly involved in PMF onset, highlighting the potential contribution of miRNAs to PMF pathogenesis. Furthermore, for the first time, we demonstrated that the JARID2 downregulation in CD34+ cells might contribute to the abnormal megakaryopoiesis typical of PMF. Disclosures: Rambaldi: Novartis: Honoraria; Sanofi: Honoraria; Italfarmaco: Honoraria.

scholarly journals Chinese Herbal Medicine Formula Shenling Baizhu San Ameliorates High-Fat Diet-Induced NAFLD in Rats by Modulating Hepatic MicroRNA Expression Profiles

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Maoxing Pan ◽  
Yuanjun Deng ◽  
Chuiyang Zheng ◽  
Huan Nie ◽  
Kairui Tang ◽  
...  
Keyword(s):  
Mirna Expression ◽  
High Fat Diet ◽  
Target Genes ◽  
Expression Profiles ◽  
Differentially Expressed ◽  
High Fat ◽  
Expression Levels ◽  
Qrt Pcr ◽  
Mirna Expression Profiles ◽  
Differentially Expressed Mirnas

Objective. The purpose of present study was to investigate the potential mechanism underlying the protective effect of Shenling Baizhu San (SLBZS) on nonalcoholic fatty liver disease (NAFLD) by microRNA (miRNA) sequencing. Methods. Thirty male Wistar rats were randomly divided into a normal control (NC) group, a high-fat diet (HFD) group, and an SLBZS group. After 12 weeks, the biochemical parameters and liver histologies of the rats were assessed. The Illumina HiSeq 2500 sequencing platform was used to analyse the hepatic miRNA expression profiles. Representative differentially expressed miRNAs were further validated by qRT-PCR. The functions of the differentially expressed miRNAs were analysed by bioinformatics. Results. Our results identified 102 miRNAs that were differentially expressed in the HFD group compared with the NC group. Among those differentially expressed miRNAs, the expression levels of 28 miRNAs were reversed by SLBZS administration, suggesting the modulation effect of SLBZS on hepatic miRNA expression profiles. The qRT-PCR results confirmed that the expression levels of miR-155-5p, miR-146b-5p, miR-132-3p, and miR-34a-5p were consistent with those detected by sequencing. Bioinformatics analyses indicated that the target genes of the differentially expressed miRNAs reversed by SLBZS were mainly related to metabolic pathways. Conclusion. This study provides novel insights into the mechanism of SLBZS in protecting against NAFLD; this mechanism may be partly related to the modulation of hepatic miRNA expression and their target pathways.

Predictive Progenitor Profiling in Chronic Myelomonocytic Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4739-4739
Author(s):  
Catriona Jamieson ◽  
Jason Gotlib ◽  
Steve Coutre ◽  
Kevin Li ◽  
Irving Weissman
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Chronic Myelomonocytic Leukemia ◽  
Normal Bone Marrow ◽  
Hematopoietic Stem ◽  
Normal Bone ◽  
Basic Biology ◽  
Myelomonocytic Leukemia ◽  
Myeloid Progenitors

Abstract Chronic myelomonocytic leukemia (CMML) is a unique myeloproliferative disease characterized by marrow dysplasia and an increase in monocytes. The median survival of patients with CMML is short, in part, because CMML is frequently resistant to therapy. In order to provide more effective CMML targeted therapies, a better understanding of the basic biology of CMML progenitors is required. We used FACS analysis and recently identified cell surface markers to identify phenotypic and functional differences between normal and CMML (n=14) bone marrow hematopoietic stem cells and myeloid progenitors. CMML marrow was typified by a reduction in CD34+CD38−CD90+(Thy1)Lin− hematopoietic stem cells and an expansion of CD34+CD38−CD90−Flk2+Lin- cells relative to normal bone marrow. In addition, there was a two-fold expansion in common myeloid progenitors (CMPs) and a corresponding decrease in megakaryocyte-erythroid progenitors (MEPs) suggesting that there was a skew in differentiation toward the myeloid lineage. In contrast to normal bone marrow derived CMPs, CMML CMPs gave rise to myeloid but not erythroid colonies. Moreover, real time quantitative RT-PCR analysis of highly purified FACS-sorted CMML CMPs demonstrated increased expression of two key regulators of myelomonocytic differentiation, PU.1 and c-jun, compared with normal bone marrow. A more detailed understanding of the basic biology of CMML myeloid progenitors and the genes that work in concert to expand them may aid in identifying novel molecular targets for CMML therapy.

miRNAs Function As Biomarker in Pediatric AML and Regulate Gene-Silencing in AML-Relevant Pathways

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 570-570
Author(s):  
Svenja Daschkey ◽  
Silja Röttgers ◽  
Jutta Bradtke ◽  
Andrea Teigler-Schlegel ◽  
Arndt Borkhardt ◽  
...  
Keyword(s):  
Cell Growth ◽  
Mirna Expression ◽  
Expression Profiles ◽  
Statistical Testing ◽  
Differentially Expressed ◽  
Mirna Sequence ◽  
Argonaute Proteins ◽  
Mirna Expression Profiles ◽  
Differentially Expressed Mirnas ◽  
Pediatric Aml

Abstract Abstract 570 microRNAs (miRNAs) are small (21-24 nt), non-coding and highly conserved molecules, which are involved in several important regulatory processes like cell growth, proliferation, differentiation, immune response and apoptosis. Thus, their involvement in the pathogenesis of several diseases, including acute myeloid leukemia (AML) is not surprising. Several studies address the miRNA expression changes in adulthood AML, however, comprehensive studies in AML of children and adolescents are missing so far. We investigated the miRNA expression profiles of different AML subtypes from pediatric patients, in order to identify differentially expressed miRNAs. Subsequently, appropriate cell line models were used for global biochemical identification of miRNA targeting structures. miRNA expression profiles of 102 pediatric AML patient samples were identified using microarray technology, and analyzed by unsupervised hierarchical cluster analysis and statistical testing. AML subtypes with translocations t(8;21) and t(15;17) can be separated from each other, solely based on their miRNA expression profile, while other translocations involving mixed-lineage leukemia (MLL) rearrangements are interspersed and lack a characteristic miRNA signature. Only six and seven miRNAs are differentially expressed between AML samples with translocations t(8;21) and t(15;17), respectively, and all other AML subtypes. This is surprising, since patients of different AML subtypes, investigated in this study, differ greatly in their clinical presentation. Differentially expressed miRNAs contain lineage specific miRNAs (miR-223), oncogenic miRNAs (miR-21) and more ubiquitously expressed miRNAs (let-7b/c, miR-100, −125b and −181a/b) with no designated characteristics. Furthermore, these differentially expressed miRNAs were not described as abundant in adult AML patients. To gain further insights into the function of differentially expressed miRNAs, we established a modified PAR-CLIP method termed PAR-CLIP-Array (Photo-activatable-Ribonucleoside-Enhanced Crosslinking-Immunoprecipitation and Microarray Hybridization) for global identification of Ago-associated miRNAs and their mRNA-targets. On average 25% of mRNAs in AML cell lines bearing the AML1/ETO or PML/RARα translocation were identified in Argonaute complexes and carry at least one miRNA binding site and thus are under miRNA control. 60% and 27% of miRNAs and mRNAs, respectively, overlap between the four analyzed Argonaute proteins, while 50% and 52% (46 miRNAs and 241 mRNAs) were associated with one Argonaute protein specifically. However, pathway classification of Ago-associated target-mRNAs indicate more than 90% overlap between the Argonaute proteins and thus are indicative of a concerted action of these four proteins in 150 pathways identified. Moreover, miR-181a/b, up-regulated in t(15;17)-positive AML patients, were detected in association with the four human Argonaute proteins in NB4 cells and show binding sites for the protein kinase PDPK1 potentially leading to inhibition of AKT, whereas eight other Ago-associated miRNA sequence families (seqgrp-miR-98, −130a, −19a, −25, −27a, −301a, −361 and −320) in association with Ago3 are able to repress the upstream tumor suppressor TSC1 leading to activation of the mTOR pathway and increased cell growth. In addition, the repression of the MAP kinase phosphatase DUSP6 by four Ago-associated miRNA sequence families (seqgrp-miR-29a, −17, −125a and −98) leads to activation of proliferative genes in the MAPK pathway of both, t(8;21)- and t(15;17)-positive AML. In summary, miRNAs represent suitable biomarkers for differentiation of AML subtypes of pediatric AML patients. Furthermore, our studies show that the four human Argonaute proteins cooperate in the regulation of AML-relevant signaling pathways providing new insights into AML biology and may present the starting point for novel therapeutic interventions. Disclosures: No relevant conflicts of interest to declare.

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