1 3347 106 HISTONE DEACETYLASES MEDIATE THE SILENCING OF MIR-15A, MIR-16, AND MIR-29B IN CHRONIC LYMPHOCYTIC LEUKEMIA. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) DEMONSTRATES A GLOBAL DOWN-REGULATION OF MIR-15A AND MIR-16 AND A SELECTIVE SILENCING OF THE RELATED MIR-29B IN AGGRESSIVE DISEASE. DELETIONS IN CHROMOSOME 13 [DEL(13Q14)] PARTIALLY ACCOUNT FOR THE LOSS OF EXPRESSION OF MIR-15A AND MIR-16, BUT THE MECHANISMS BY WHICH MIR-29B BECOMES SILENCED IS UNKNOWN. IN THE PRESENT STUDY, WE SHOW THAT THE HISTONE DEACETYLASES (HDACS) ARE OVEREXPRESSED IN CLL AND MEDIATE THE EPIGENETIC SILENCING OF MIR-15A, MIR-16, AND MIR-29B. HDAC INHIBITION TRIGGERED THE ACCUMULATION OF THE TRANSCRIPTIONALLY ACTIVATING CHROMATIN MODIFICATION H3K4ME2 AND RESTORED THE EXPRESSION OF MIR-15A, MIR-16, AND MIR-29B IN APPROXIMATELY 35% OF SAMPLES. ECTOPIC EXPRESSION OF MIR-15A AND MIR-16 AND HDAC INHIBITION-INDUCED EXPRESSION OF MIR-15A, MIR-16, OR MIR-29B IN PRIMARY CLL CELLS WAS ASSOCIATED WITH DECLINES IN THE LEVELS OF MCL-1, BUT NOT BCL-2, MITOCHONDRIAL DYSFUNCTION, AND INDUCTION OF CELL DEATH. THEREFORE, OUR RESULTS SHOW THAT HDACS ABERRANTLY SILENCE THE EXPRESSION OF THE CRITICAL TUMOR SUPPRESSORS MIR-15A, MIR-16, AND MIR-29B IN CLL. DEACETYLASE INHIBITION MAY BE A THERAPEUTIC STRATEGY THAT RESTORES THE EXPRESSION OF THESE MIRS TO ANTAGONIZE MCL-1, AN IMPORTANT SURVIVAL PROTEIN IN THESE CELLS. CONSEQUENTLY, CLL PATIENTS WHO EXHIBIT SUCH EPIGENETIC SILENCING MAY BENEFIT FROM HDAC INHIBITOR-BASED THERAPY. 2012 2 351 34 ALTERED ENDOTHELIAL DYSFUNCTION-RELATED MIRS IN PLASMA FROM ME/CFS PATIENTS. MYALGIC ENCEPHALOMYELITIS/CHRONIC FATIGUE SYNDROME (ME/CFS) IS A COMPLEX DISEASE CHARACTERIZED BY UNEXPLAINED DEBILITATING FATIGUE. ALTHOUGH THE ETIOLOGY IS UNKNOWN, EVIDENCE SUPPORTS IMMUNOLOGICAL ABNORMALITIES, SUCH AS PERSISTENT INFLAMMATION AND IMMUNE-CELL ACTIVATION, IN A SUBSET OF PATIENTS. SINCE THE INTERPLAY BETWEEN INFLAMMATION AND VASCULAR ALTERATIONS IS WELL-ESTABLISHED IN OTHER DISEASES, ENDOTHELIAL DYSFUNCTION HAS EMERGED AS ANOTHER PLAYER IN ME/CFS PATHOGENESIS. ENDOTHELIAL NITRIC OXIDE SYNTHASE (ENOS) GENERATES NITRIC OXIDE (NO) THAT MAINTAINS ENDOTHELIAL HOMEOSTASIS. ENOS IS ACTIVATED BY SILENT INFORMATION REGULATOR 1 (SIRT1), AN ANTI-INFLAMMATORY PROTEIN. DESPITE ITS RELEVANCE, NO STUDY HAS ADDRESSED THE SIRT1/ENOS AXIS IN ME/CFS. THE INTEREST IN CIRCULATING MICRORNAS (MIRS) AS POTENTIAL BIOMARKERS IN ME/CFS HAS INCREASED IN RECENT YEARS. ACCORDINGLY, WE ANALYZE A SET OF MIRS REPORTED TO MODULATE THE SIRT1/ENOS AXIS USING PLASMA FROM ME/CFS PATIENTS. OUR RESULTS SHOW THAT MIR-21, MIR-34A, MIR-92A, MIR-126, AND MIR-200C ARE JOINTLY INCREASED IN ME/CFS PATIENTS COMPARED TO HEALTHY CONTROLS. A SIMILAR FINDING WAS OBTAINED WHEN ANALYZING PUBLIC MIR DATA ON PERIPHERAL BLOOD MONONUCLEAR CELLS. BIOINFORMATICS ANALYSIS SHOWS THAT ENDOTHELIAL FUNCTION-RELATED SIGNALING PATHWAYS ARE ASSOCIATED WITH THESE MIRS, INCLUDING OXIDATIVE STRESS AND OXYGEN REGULATION. INTERESTINGLY, HISTONE DEACETYLASE 1, A PROTEIN RESPONSIBLE FOR EPIGENETIC REGULATIONS, REPRESENTED THE MOST RELEVANT NODE WITHIN THE NETWORK. IN CONCLUSION, OUR STUDY PROVIDES A BASIS TO FIND ENDOTHELIAL DYSFUNCTION-RELATED BIOMARKERS AND EXPLORE NOVEL TARGETS IN ME/CFS. 2021 3 4364 31 MIRNA DEREGULATION BY EPIGENETIC SILENCING DISRUPTS SUPPRESSION OF THE ONCOGENE PLAG1 IN CHRONIC LYMPHOCYTIC LEUKEMIA. MICRORNAS (MIRNA) PLAY A KEY ROLE IN CELLULAR REGULATION AND, IF DEREGULATED, IN THE DEVELOPMENT OF NEOPLASTIC DISORDERS INCLUDING CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). RNAS FROM PRIMARY CELLS OF 50 TREATMENT-NAIVE CLL PATIENTS AND PERIPHERAL B CELLS OF 14 HEALTHY DONORS WERE APPLIED TO MIRNA EXPRESSION PROFILING USING BEAD CHIP TECHNOLOGY. IN CLL CELLS, A SET OF 7 UP- AND 19 DOWN-REGULATED MIRNAS WAS IDENTIFIED. AMONG THE MIRNAS DOWN-REGULATED IN CLL CELLS, 6 OF 10 MIRNA PROMOTERS EXAMINED SHOWED GAIN OF METHYLATION COMPARED WITH NORMAL B-CELL CONTROLS. SUBSEQUENT TARGET PREDICTION OF DEREGULATED MIRNAS REVEALED A HIGHLY SIGNIFICANT BINDING PREDICTION AT THE 3' UNTRANSLATED REGION OF THE PLEOMORPHIC ADENOMA GENE 1 (PLAG1) ONCOGENE. LUCIFERASE REPORTER ASSAYS INCLUDING SITE-DIRECTED MUTAGENESIS OF BINDING SITES REVEALED A SIGNIFICANT REGULATION OF PLAG1 BY MIR-181A, MIR-181B, MIR-107, AND MIR-424. ALTHOUGH EXPRESSION OF PLAG1 MRNA WAS NOT AFFECTED, PLAG1 PROTEIN EXPRESSION WAS SHOWN TO BE SIGNIFICANTLY ELEVATED IN CLL CELLS COMPARED WITH THE LEVELS IN HEALTHY DONOR B CELLS. IN SUMMARY, WE COULD DEMONSTRATE DISRUPTION OF MIRNA-MEDIATED TRANSLATIONAL CONTROL, PARTLY DUE TO EPIGENETIC TRANSCRIPTIONAL SILENCING OF MIRNAS, WITH SUBSEQUENT OVEREXPRESSION OF THE ONCOGENIC TRANSCRIPTION FACTOR PLAG1 AS A PUTATIVE NOVEL MECHANISM OF CLL PATHOGENESIS. 2009 4 4350 30 MIR-181A-5P IS A POTENTIAL CANDIDATE EPIGENETIC BIOMARKER IN MULTIPLE SCLEROSIS. MULTIPLE SCLEROSIS (MS) IS A CHRONIC INFLAMMATORY DISEASE OF THE CENTRAL NERVOUS SYSTEM (CNS) CHARACTERIZED BY DEMYELINATION AND AXONAL DEGENERATION. ABNORMAL EXPRESSION OF MICRORNAS (MIRNAS) PLAYS AN IMPORTANT ROLE IN MS PATHOLOGY. IN THIS COHORT STUDY, DIFFERENTIAL EXPRESSION OF THE FOUR MIRNAS (HSA-MIR-155-5P, HSA-MIR-9-5P, HSA-MIR-181A-5P, AND HSA-MIR-125B-5P) WAS INVESTIGATED IN 69 INDIVIDUALS, INCLUDING 39 MS PATIENTS (RELAPSING-REMITTING MS (RRMS), N = 27; SECONDARY PROGRESSIVE MS (SPMS), N = 12) AND 30 HEALTHY CONTROLS. IN SILICO ANALYSES REVEALED POSSIBLE GENES AND PATHWAYS SPECIFIC TO MIRNAS. PERIPHERAL BLOOD MIRNA EXPRESSIONS WERE DETECTED BY QUANTITATIVE REAL-TIME PCR (QPCR). HSA-MIR-181A-5P WAS DOWNREGULATED AND ASSOCIATED WITH INCREASED MS RISK (P = 0.012). THE OTHER THREE MIRNAS WERE UPREGULATED AND NOT ASSOCIATED WITH MS (P < 0.05). THE AREA UNDER THE CURVE (AUC) IS 0.779. IN SILICO ANALYSES SHOWED THAT HSA-MIR-181A-5P MAY PARTICIPATE IN MS PATHOLOGY BY TARGETING MAP2K1, CREB1, ATXN1, AND ATXN3 GENES IN INFLAMMATION AND NEURODEGENERATION PATHWAYS. THE CIRCULATORY HSA-MIR-181A-5P CAN REGULATE TARGET GENES, REVERSING THE MECHANISMS INVOLVED IN MS PATHOLOGIES SUCH AS PROTEIN UPTAKE AND PROCESSING, CELL PROLIFERATION AND SURVIVAL, INFLAMMATION, AND NEURODEGENERATION. THUS, THIS MIRNA COULD BE USED AS AN EPIGENOMIC-GUIDED DIAGNOSTIC TOOL AND FOR THERAPEUTIC PURPOSE. 2022 5 1227 33 CRITICAL ROLE OF MICRORNAS IN CHRONIC LYMPHOCYTIC LEUKEMIA: OVEREXPRESSION OF THE ONCOGENE PLAG1 BY DEREGULATED MIRNAS. MICRORNAS (MIRNAS) ARE SMALL, GENE ENCODED RNAS WHICH ARE ABLE TO INFLUENCE GENE EXPRESSION IN BINDING TO THE 3'UTR OF MRNAS. COMPARED TO HEALTHY TISSUES, THE GLOBAL EXPRESSION OF MIRNAS IN CANCEROUS TISSUE IS FREQUENTLY DOWN-REGULATED. LIKEWISE IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), DOWN-REGULATION OF SEVERAL MIRNAS HAS BEEN REPORTED. ANALYSIS OF MIRNA PROMOTERS FOR EPIGENETIC MODIFICATIONS REVEALED A STRONGER METHYLATION OF DOWN-REGULATED MIRNAS IN CLL. TO DATE, SEVERAL TARGET GENES AFFECTED BY DEREGULATED MIRNAS HAVE BEEN IDENTIFIED THAT HAVE IMPACT ON CLL PATHOGENESIS. THE BEST-DESCRIBED CONSEQUENCE OF MIRNA DEREGULATION IS FOR MIRNA-15/16 CLUSTER DELETION, WHICH IS FREQUENTLY DOWN-REGULATED IN A SUBGROUP OF PATIENTS WITH CLL CARRYING 13Q14 DELETION. SO FAR, MODELS FOR MIRNA DEREGULATION HAVE ADDRESSED JUST SINGLE MIRNAS. FOR ASSESSMENT OF COMPLETE MIRNA DEREGULATION, FURTHER EVALUATION OF THE RESULTS FROM MICROARRAY STUDIES IS NEEDED. PREVIOUSLY WE IDENTIFIED THE ONCOGENE PLAG1, WHOSE EXPRESSION IS AFFECTED BY VARIOUS MIRNAS DEREGULATED IN CLL. THE INVOLVEMENT OF MIRNAS IN PLAG1 EXPRESSION WAS SHOWN TO BE RELEVANT IN PLEOMORPHIC ADENOMAS OF THE SALIVARY GLAND, TOO. AS PLAG1 IS HIGHLY OVEREXPRESSED, AND ITS TARGET GENES APPEAR TO BE DEREGULATED IN CLL, E.G. BCL-2, PLAG1 IS A PUTATIVE NEW RELEVANT ONCOGENE INVOLVED IN THE PATHOGENESIS OF CLL. 2010 6 2749 27 EXPRESSION AND POLYMORPHISM OF MICRO-RNA ACCORDING TO BODY MASS INDEX AND BREAST CANCER PRESENTATION IN TUNISIAN PATIENTS. MICRO-RNAS (MIRS) CONSTITUTE A CLASS OF SMALL NONCODING RNAS IMPLICATED IN THE REGULATION OF GENE EXPRESSION BY BINDING TO TARGET MRNAS. A MIR CAN TARGET SEVERAL MRNAS, BEING INVOLVED IN DIFFERENT BIOLOGIC PROCESSES AND PATHOLOGIES. THIS PLEIOTROPIC FUNCTION MIGHT EXPLAIN THE LINK BETWEEN DISEASES CO-OCCURRENCE. EPIGENETIC ORIGIN OF THE LINK BETWEEN OBESITY AND BREAST CANCER (BC) IS INVESTIGATED IN A COHORT OF TUNISIAN PATIENTS, FOCUSING ON POLYMORPHISM AT GERMLINE LEVEL (MIR-146A) AND ON EXPRESSION IN MAMMARY TUMORS (MIR-21, MIR-146A, AND MIR-34A), ACCORDING TO BODY MASS INDEX (BMI) AND CLINICO-PATHOLOGIC FEATURES. THE MEASURE OF MIR EXPRESSION IN 60 MAMMARY TUMORS WAS REALIZED USING QUANTITATIVE RT-PCR. STUDY OF RS 2910164 IN MIR-146A WAS PERFORMED BY PCR AND DIRECT SEQUENCING USING BLOOD DNA OF 83 AFFECTED WOMEN AND 50 UNRELATED SUBJECTS FROM GREAT TUNIS. MIR-21, MIR-146A, AND MIR-34A HAVE BEEN QUANTIFIED IN BREAST TUMOR ACCORDING TO BMI. MIR-21 IS SIGNIFICANTLY MORE EXPRESSED IN TUMORS OF OBESE WOMEN COMPARATIVELY TO NONOBESE PATIENTS. ON THE CONTRARY, MIR-34A IS DECREASED IN TUMORS OF OBESE WOMEN. MOREOVER, IN OBESE BC PATIENTS, A SIGNIFICANT INCREASE IN BOTH MIR-21 AND MIR-146A EXPRESSION IS REVEALED IN CASES WITH LYMPH NODE METASTASIS. THE POLYMORPHISM AT RS 2910164 (MIR-146A) LOCUS WAS NOT SHOWN AS A RISK FACTOR FOR BC. HOWEVER THE MUTANT CC GENOTYPE WAS REVEALED TO BE ASSOCIATED WITH A RISK FOR BAD OUTCOME OF THE DISEASE. CHRONIC INFLAMMATION IN OBESE WOMEN WOULD BE LINKED TO AGGRESSIVE BREAST TUMORS VIA INDUCTION OF ONCOMIRS OVEREXPRESSION AND DECREASE OF TUMOR SUPPRESSOR MIRS. 2019 7 2132 31 EPIGENETIC INACTIVATION OF THE MIR-124-1 IN HAEMATOLOGICAL MALIGNANCIES. MIR-124-1 IS A TUMOUR SUPPRESSOR MICRORNA (MIR). EPIGENETIC DEREGULATION OF MIRS IS IMPLICATED IN CARCINOGENESIS. PROMOTER DNA METHYLATION AND HISTONE MODIFICATION OF MIR-124-1 WAS STUDIED IN 5 NORMAL MARROW CONTROLS, 4 LYMPHOMA, 8 MULTIPLE MYELOMA (MM) CELL LINES, 230 DIAGNOSTIC PRIMARY SAMPLES OF ACUTE MYELOID LEUKAEMIA (AML), ACUTE LYMPHOBLASTIC LEUKAEMIA (ALL), CHRONIC MYELOID LEUKAEMIA (CML), CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL), MM, AND NON-HODGKIN'S LYMPHOMA (NHL), AND 53 MM SAMPLES AT STABLE DISEASE OR RELAPSE. PROMOTER OF MIR-124-1 WAS UNMETHYLATED IN NORMAL CONTROLS BUT HOMOZYGOUSLY METHYLATED IN 4 OF 4 LYMPHOMA AND 4 OF 8 MYELOMA CELL LINES. TREATMENT OF 5-AZA-2'-DEOXYCYTIDINE LED TO MIR-124-1 DEMETHYLATION AND RE-EXPRESSION OF MATURE MIR-124, WHICH ALSO ASSOCIATED WITH EMERGENCE OF EUCHROMATIC TRIMETHYL H3K4 AND CONSEQUENT DOWNREGULATION OF CDK6 IN MYELOMA CELLS HARBORING HOMOZYGOUS MIR-124-1 METHYLATION. IN PRIMARY SAMPLES AT DIAGNOSIS, MIR-124-1 METHYLATION WAS ABSENT IN CML BUT DETECTED IN 2% EACH OF MM AT DIAGNOSIS AND RELAPSE/PROGRESSION, 5% ALL, 15% AML, 14% CLL AND 58.1% OF NHL (P<0.001). AMONGST LYMPHOID MALIGNANCIES, MIR-124-1 WAS PREFERENTIALLY METHYLATED IN NHL THAN MM, CLL OR ALL. IN PRIMARY LYMPHOMA SAMPLES, MIR-124-1 WAS PREFERENTIALLY HYPERMETHYLATED IN B- OR NK/T-CELL LYMPHOMAS AND ASSOCIATED WITH REDUCED MIR-124 EXPRESSION. IN CONCLUSION, MIR-124-1 WAS HYPERMETHYLATED IN A TUMOUR-SPECIFIC MANNER, WITH A HETEROCHROMATIC HISTONE CONFIGURATION. HYPOMETHYLATION LED TO PARTIAL RESTORATION OF EUCHROMATIC HISTONE CODE AND MIR RE-EXPRESSION. INFREQUENT MIR-124-1 METHYLATION DETECTED IN DIAGNOSTIC AND RELAPSE MM SAMPLES SHOWED AN UNIMPORTANT ROLE IN MM PATHOGENESIS, DESPITE FREQUENT METHYLATION FOUND IN CELL LINES. AMONGST HAEMATOLOGICAL CANCERS, MIR-124-1 WAS MORE FREQUENTLY HYPERMETHYLATED IN NHL, AND HENCE WARRANTS FURTHER STUDY. 2011 8 6390 25 THE ROLE OF THE GENETIC ABNORMALITIES, EPIGENETIC AND MICRORNA IN THE PROGNOSIS OF CHRONIC LYMPHOCYTIC LEUKEMIA. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS INCREASED PROLIFERATION OF B-CELLS WITH PERIPHERAL BLOOD AND BONE MARROW INVOLVEMENT, WHICH IS USUALLY OBSERVED IN OLDER PEOPLE. GENETIC MUTATIONS, EPIGENETIC CHANGES AND MIRS PLAY A ROLE IN CLL PATHOGENESIS. DEL 11Q, DEL L17Q, DEL 6Q, TRISOMY 12, P53 AND IGVH MUTATIONS ARE THE MOST IMPORTANT GENETIC CHANGES IN CLL. DELETION OF MIR-15A AND MIR-16A CAN INCREASE BCL2 GENE EXPRESSION, MIR-29 AND MIR-181 DELETIONS DECREASE THE EXPRESSION OF TCL1, AND MIR-146A DELETION PREVENTS TUMOR METASTASIS. EPIGENETIC CHANGES SUCH AS HYPO- AND HYPERMETHYLATION, UBIQUITINATION, HYPO- AND HYPERACETYLATION OF GENE PROMOTERS INVOLVED IN CLL PATHOGENESIS CAN ALSO PLAY A ROLE IN CLL. EXPRESSION OF CD38 AND ZAP70, PRESENCE OR ABSENCE OF MUTATION IN IGVH AND P53 MUTATION ARE AMONG THE FACTORS INVOLVED IN CLL PROGNOSIS. USE OF MONOCLONAL ANTIBODIES AGAINST SURFACE MARKERS OF B-CELLS LIKE ANTI-CD20 AS WELL AS TYROSINE KINASE INHIBITORS ARE THE MOST IMPORTANT THERAPEUTIC APPROACHES FOR CLL. 2018 9 4300 28 MICRORNA-19A CONTRIBUTES TO THE EPIGENETIC REGULATION OF TISSUE FACTOR IN DIABETES. BACKGROUND: DIABETES MELLITUS IS CHARACTERIZED BY CHRONIC VASCULAR DISORDER AND PRESENTS A MAIN RISK FACTOR FOR CARDIOVASCULAR MORTALITY. IN PARTICULAR, HYPERGLYCAEMIA AND INFLAMMATORY CYTOKINES INDUCE VASCULAR CIRCULATING TISSUE FACTOR (TF) THAT PROMOTES PRO-THROMBOTIC CONDITIONS IN DIABETES. IT HAS RECENTLY BECOME EVIDENT THAT ALTERATIONS OF THE POST-TRANSCRIPTIONAL REGULATION OF TF VIA SPECIFIC MICRORNA(MIR)S, SUCH AS MIR-126, CONTRIBUTE TO THE PATHOGENESIS OF DIABETES AND ITS COMPLICATIONS. THE ENDOTHELIAL MIR-19A IS INVOLVED IN VASCULAR HOMEOSTASIS AND ATHEROPROTECTION. HOWEVER, ITS ROLE IN DIABETES-RELATED THROMBOGENICITY IS UNKNOWN. UNDERSTANDING MIR-NETWORKS REGULATING PROCOAGULABILITY IN DIABETES MAY HELP TO DEVELOP NEW TREATMENT OPTIONS PREVENTING VASCULAR COMPLICATIONS. METHODS AND RESULTS: PLASMA OF 44 PATIENTS WITH KNOWN DIABETES WAS ASSESSED FOR THE EXPRESSION OF MIR-19A, TF PROTEIN, TF ACTIVITY, AND MARKERS FOR VASCULAR INFLAMMATION. HIGH MIR-19A EXPRESSION WAS ASSOCIATED WITH REDUCED TF PROTEIN, TF-MEDIATED PROCOAGULABILITY, AND VASCULAR INFLAMMATION BASED ON EXPRESSION OF VASCULAR ADHESION MOLECULE-1 AND LEUKOCYTE COUNT. WE FOUND PLASMA EXPRESSION OF MIR-19A TO STRONGLY CORRELATE WITH MIR-126. MIR-19A REDUCED THE TF EXPRESSION ON MRNA AND PROTEIN LEVEL IN HUMAN MICROVASCULAR ENDOTHELIAL CELLS (HMEC) AS WELL AS TF ACTIVITY IN HUMAN MONOCYTES (THP-1), WHILE ANTI-MIR-19A INCREASED THE TF EXPRESSION. INTERESTINGLY, MIR-19A INDUCED VCAM EXPRESSION IN HMEC. HOWEVER, MIR-19A AND MIR-126 CO-TRANSFECTION REDUCED TOTAL ENDOTHELIAL VCAM EXPRESSION AND EXHIBITED ADDITIVE INHIBITION OF A LUCIFERASE REPORTER CONSTRUCT CONTAINING THE F3 3'UTR. CONCLUSIONS: WHILE BOTH MIRS HAVE DIFFERENTIAL FUNCTIONS ON ENDOTHELIAL VCAM EXPRESSION, MIR-19A AND MIR-126 COOPERATE TO EXHIBIT ANTI-THROMBOTIC PROPERTIES VIA REGULATING VASCULAR TF EXPRESSION. MODULATING THE POST-TRANSCRIPTIONAL CONTROL OF TF IN DIABETES MAY PROVIDE A FUTURE ANTI-THROMBOTIC AND ANTI-INFLAMMATORY THERAPY. 2018 10 3770 26 INTEGRATIVE SMALL AND LONG RNA OMICS ANALYSIS OF HUMAN HEALING AND NONHEALING WOUNDS DISCOVERS COOPERATING MICRORNAS AS THERAPEUTIC TARGETS. MICRORNAS (MIR), AS IMPORTANT EPIGENETIC CONTROL FACTORS, REPORTEDLY REGULATE WOUND REPAIR. HOWEVER, OUR INSUFFICIENT KNOWLEDGE OF CLINICALLY RELEVANT MIRS HINDERS THEIR POTENTIAL THERAPEUTIC USE. FOR THIS, WE PERFORMED PAIRED SMALL AND LONG RNA-SEQUENCING AND INTEGRATIVE OMICS ANALYSIS IN HUMAN TISSUE SAMPLES, INCLUDING MATCHED SKIN AND ACUTE WOUNDS COLLECTED AT EACH HEALING STAGE AND CHRONIC NONHEALING VENOUS ULCERS (VUS). ON THE BASIS OF THE FINDINGS, WE DEVELOPED A COMPENDIUM (HTTPS://WWW.XULANDENLAB.COM/HUMANWOUNDS-MIRNA-MRNA), WHICH WILL BE AN OPEN, COMPREHENSIVE RESOURCE TO BROADLY AID WOUND HEALING RESEARCH. WITH THIS FIRST CLINICAL, WOUND-CENTRIC RESOURCE OF MIRS AND MRNAS, WE IDENTIFIED 17 PATHOLOGICALLY RELEVANT MIRS THAT EXHIBITED ABNORMAL VU EXPRESSION AND DISPLAYED THEIR TARGETS ENRICHED EXPLICITLY IN THE VU GENE SIGNATURE. INTERMESHING REGULATORY NETWORKS CONTROLLED BY THESE MIRS REVEALED THEIR HIGH COOPERATIVITY IN CONTRIBUTING TO CHRONIC WOUND PATHOLOGY CHARACTERIZED BY PERSISTENT INFLAMMATION AND PROLIFERATIVE PHASE INITIATION FAILURE. FURTHERMORE, WE DEMONSTRATED THAT MIR-34A, MIR-424, AND MIR-516, UPREGULATED IN VU, COOPERATIVELY SUPPRESSED KERATINOCYTE MIGRATION AND GROWTH WHILE PROMOTING INFLAMMATORY RESPONSE. BY COMBINING MIR EXPRESSION PATTERNS WITH THEIR SPECIFIC TARGET GENE EXPRESSION CONTEXT, WE IDENTIFIED MIRS HIGHLY RELEVANT TO VU PATHOLOGY. OUR STUDY OPENS THE POSSIBILITY OF DEVELOPING INNOVATIVE WOUND TREATMENT THAT TARGETS PATHOLOGICALLY RELEVANT COOPERATING MIRS TO ATTAIN HIGHER THERAPEUTIC EFFICACY AND SPECIFICITY. 2022 11 2133 25 EPIGENETIC INACTIVATION OF THE MIR-34A IN HEMATOLOGICAL MALIGNANCIES. MIR-34A IS A TRANSCRIPTIONAL TARGET OF P53 AND IMPLICATED IN CARCINOGENESIS. WE STUDIED THE ROLE OF MIR-34A METHYLATION IN A PANEL OF HEMATOLOGICAL MALIGNANCIES INCLUDING ACUTE LEUKEMIA [ACUTE MYELOID LEUKEMIA (AML) AND ACUTE LYMPHOBLASTIC LEUKEMIA (ALL)], CHRONIC LEUKEMIA [CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) AND CHRONIC MYELOID LEUKEMIA (CML)], MULTIPLE MYELOMA (MM) AND NON-HODGKIN'S LYMPHOMA (NHL). THE METHYLATION STATUS OF MIR-34A PROMOTER WAS STUDIED IN 12 CELL LINES AND 188 DIAGNOSTIC SAMPLES BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. MIR-34A PROMOTER WAS UNMETHYLATED IN NORMAL CONTROLS BUT METHYLATED IN 75% LYMPHOMA AND 37% MYELOMA CELL LINES. HYPOMETHYLATING TREATMENT LED TO RE-EXPRESSION OF PRI-MIR-34A TRANSCRIPT IN LYMPHOMA CELLS WITH HOMOZYGOUS MIR-34A METHYLATION. IN PRIMARY SAMPLES AT DIAGNOSIS, MIR-34A METHYLATION WAS DETECTED IN 4% CLL, 5.5% MM SAMPLES AND 18.8% OF NHL AT DIAGNOSIS BUT NONE OF ALL, AML AND CML (P = 0.011). IN MM PATIENTS WITH PAIRED SAMPLES, MIR-34A METHYLATION STATUS REMAINED UNCHANGED AT PROGRESSION. AMONGST LYMPHOID MALIGNANCIES, MIR-34A WAS PREFERENTIALLY METHYLATED IN NHL (P = 0.018), IN PARTICULAR NATURAL KILLER (NK)/T-CELL LYMPHOMA. IN CONCLUSION, AMONGST HEMATOLOGICAL MALIGNANCIES, MIR-34A METHYLATION IS PREFERENTIALLY HYPERMETHYLATED IN NHL, IN PARTICULAR NK/T-CELL LYMPHOMA, IN A TUMOR-SPECIFIC MANNER, THEREFORE THE ROLE OF MIR-34A IN LYMPHOMAGENESIS WARRANTS FURTHER STUDY. 2010 12 5120 23 POSSIBLE EPIGENETIC REGULATORY EFFECT OF DYSREGULATED CIRCULAR RNAS IN EPILEPSY. CIRCULAR RNAS (CIRCRNAS) INVOLVE IN THE EPIGENETIC REGULATION AND ITS MAJOR MECHANISM IS THE SEQUESTRATION OF THE TARGET MICRO RNAS (MIRNAS). WE HYPOTHESIZED THAT CIRCRNAS MIGHT BE RELATED WITH THE PATHOPHYSIOLOGY OF CHRONIC EPILEPSY AND EVALUATED THE ALTERED CIRCRNA EXPRESSIONS AND THEIR POSSIBLE REGULATORY EFFECTS ON THEIR TARGET MIRNAS AND MRNAS IN A MOUSE EPILEPSY MODEL. THE CIRCRNA EXPRESSION PROFILE IN THE HIPPOCAMPUS OF THE PILOCARPINE MICE WAS ANALYZED AND COMPARED WITH CONTROL. THE CORRELATION BETWEEN THE EXPRESSION OF MIRNA BINDING SITES (MIRNA RESPONSE ELEMENTS, MRE) IN THE DYSREGULATED CIRCRNAS AND THE EXPRESSION OF THEIR TARGET MIRNAS WAS EVALUATED. AS MIRNAS ALSO INHIBIT THEIR TARGET MRNAS, CIRCRNA-MIRNA-MRNA REGULATORY NETWORK, COMPRISED OF DYSREGULATED RNAS THAT TARGETS ONE ANOTHER WERE SEARCHED. FOR THE IDENTIFIED NETWORKS, BIOINFORMATICS ANALYSES WERE PERFORMED. AS THE RESULT, FORTY-THREE CIRCRNAS WERE DYSREGULATED IN THE HIPPOCAMPUS (UP-REGULATED, 26; DOWN-REGULATED, 17). THE CHANGE IN THE EXPRESSION OF MRE IN THOSE CIRCRNAS NEGATIVELY CORRELATED WITH THE CHANGE IN THE RELEVANT TARGET MIRNA EXPRESSION (R = -0.461, P<0.001), SUPPORTING THAT CIRCRNAS INHIBIT THEIR TARGET MIRNA. 333 DYSREGULATED CIRCRNA-MIRNA-MRNA NETWORKS WERE IDENTIFIED. GENE ONTOLOGY AND PATHWAY ANALYSES DEMONSTRATED THAT THE UP-REGULATED MRNAS IN THOSE NETWORKS WERE CLOSELY RELATED TO THE MAJOR PROCESSES IN EPILEPSY. AMONG THEM, STRING ANALYSIS IDENTIFIED 37 KEY MRNAS WITH ABUNDANT (>/=4) INTERACTIONS WITH OTHER DYSREGULATED TARGET MRNAS. THE DYSREGULATION OF THE CIRCRNAS WHICH HAD MULTIPLE INTERACTIONS WITH KEY MRNAS WERE VALIDATED BY PCR. WE CONCLUDED THAT DYSREGULATED CIRCRNAS MIGHT HAVE A PATHOPHYSIOLOGIC ROLE IN CHRONIC EPILEPSY BY REGULATING MULTIPLE DISEASE RELEVANT MRNAS VIA CIRCRNA-MIRNA-MRNA INTERACTIONS. 2018 13 4054 21 MAPK IS A MUTUAL PATHWAY TARGETED BY ANXIETY-RELATED MIRNAS, AND E2F5 IS A PUTATIVE TARGET FOR ANXIOLYTIC MIRNAS. ANXIETY-RELATED DISORDERS (ARDS) ARE CHRONIC NEUROPSYCHOLOGICAL DISEASES AND THE SIXTH LEADING CAUSE OF DISABILITY IN THE WORLD. AS DYSREGULATION OF MICRORNAS (MIRS) ARE OBSERVED IN THE PATHOLOGICAL COURSE OF NEUROPSYCHIATRIC DISORDERS, THE PRESENT STUDY AIMED TO INTRODUCE MIRS THAT UNDERLIE ANXIETY PROCESSING IN THE BRAIN. FIRST, WE COLLECTED THE EXPERIMENTALLY CONFIRMED ANXIETY-RELATED MIRNAS (ARMIRS), PREDICTED THEIR TARGET TRANSCRIPTS, AND INTRODUCED CRITICAL CELLULAR PATHWAYS WITH KEY COMMUNE HUB GENES. AS A RESULT, WE HAVE FOUND NINE ANXIOLYTIC AND TEN ANXIOGENIC ARMIRS. THE ANXIOLYTIC MIRS FREQUENTLY TARGET THE MRNA OF ACYL-COA SYNTHETASE LONG-CHAIN FAMILY MEMBER 4 (ACSL4), AFF4-AF4/FMR2 FAMILY MEMBER 4 (AFF4), AND KRUPPEL LIKE TRANSCRIPTION FACTOR 4 (KLF4) GENES, WHERE MIR-34B-5P AND MIR-34C-5P INTERACT WITH ALL OF THEM. MOREOVER, THE ANXIOGENIC MIRS FREQUENTLY TARGET THE MRNA OF NINE GENES; AMONG THEM, ONLY TWO MIR (MIR-142-5P AND MIR-218-5P) HAVE NO INTERACTION WITH THE MRNA OF TRINUCLEOTIDE REPEAT-CONTAINING ADAPTOR 6B (TNRC6B), AND MIR-124-3P INTERACTS WITH ALL OF THEM WHERE MAPK IS THE MAIN SIGNALING PATHWAY AFFECTED BY BOTH ANXIOLYTIC AND ANXIOGENIC MIR. IN ADDITION, THE ANXIOLYTIC MIR COMMONLY TARGET E2F TRANSCRIPTION FACTOR 5 (E2F5) IN THE TGF-BETA SIGNALING PATHWAY, AND THE ANXIOGENIC MIR COMMONLY TARGET ATAXIN 1 (ATXN1), WASP-LIKE ACTIN NUCLEATION PROMOTING FACTOR (WASL), AND SOLUTE CARRIER FAMILY 17 MEMBER 6 (SLC17A6) GENES IN THE NOTCH SIGNALING, ADHERENCE JUNCTION, AND SYNAPTIC VESICLE CYCLE PATHWAYS, RESPECTIVELY. TAKEN TOGETHER, WE CONCLUDE THAT THE MOST IMPORTANT ANXIOLYTIC (MIR-34C, LET-7D, AND MIR-17) AND ANXIOGENIC (MIR-19B, MIR-92A, AND 218) MIR, AS HUB EPIGENETIC MODULATORS, POTENTIALLY INFLUENCE THE PATHOPHYSIOLOGY OF ANXIETY, PRIMARILY VIA INTERACTION WITH THE MAPK SIGNALING PATHWAY. MOREOVER, THE ROLE OF E2F5 AS A NOVEL PUTATIVE TARGET FOR ANXIOLYTIC MIRNAS IN ARDS DISORDERS DESERVES FURTHER EXPLORATION. 2023 14 3654 32 INDOXYL SULFATE ACCELERATES VASCULAR SMOOTH MUSCLE CELL CALCIFICATION VIA MICRORNA-29B DEPENDENT REGULATION OF WNT/BETA-CATENIN SIGNALING. VASCULAR CALCIFICATION (VC) IS A VERY COMMON PHENOMENON IN PATIENTS WITH CHRONIC KIDNEY DISEASE(CKD) AND IT INCREASES THE INCIDENCE OF CARDIOVASCULAR DISEASE AND LEADS TO HIGH MORTALITY IN CKD PATIENTS. IT HAS BEEN REPORTED THAT SOME MICRORNAS (MIRS) PLAY ROLES IN VASCULAR CALCIFICATION AS AN EPIGENETIC REGULATOR. INDOXYL SULFATE (IS) IS A PROTEIN-BOUND UREMIC TOXIN WHICH HAS BEEN PROVEN AS ONE OF THE MAJOR RISK FACTORS OF CARDIOVASCULAR DISEASE IN CKD. HERE WE INVESTIGATED WHETHER MICRORNA-29B (MIR-29B) IS INVOLVED IN IS-INDUCED VASCULAR CALCIFICATION. WE FOUND THAT VASCULAR MIR-29B WAS DOWN-REGULATED IN RADIAL ARTERIES OF PATIENTS WITH END-STAGE RENAL DISEASE. CONSISTENTLY, IS ALSO DECREASED MIR-29B EXPRESSION IN HUMAN AORTIC SMOOTH MUSCLE CELLS (HASMCS) AND POTENTIATED THEIR CALCIFICATION. MIR-29B MIMICS SIGNIFICANTLY SUPPRESSED, WHILE MIR-29B ANTI-MIR MARKEDLY ENHANCED, IS-INDUCED RUNT-RELATED TRANSCRIPTION FACTOR 2 AND OSTEOPONTIN EXPRESSION. THE EXPRESSION OF WNT7B/BETA-CATENIN IN RADIAL ARTERIES WAS HIGHER IN END STAGE RENAL DISEASE THAN IN CONTROL GROUP, AND IS INCREASED WNT7B/BETA-CATENIN EXPRESSION IN HASMCS AS EARLY AS 3DAYS AFTER STIMULATION. FURTHERMORE, MIR-29B MIMICS POTENTLY REPRESSED WNT7B/BETA-CATENIN PROTEIN EXPRESSION IN HASMCS, WHEREAS MIR-29B ANTI-MIR INCREASED THEIR EXPRESSION, INDICATING MIR-29B INDEED NEGATIVELY REGULATES WNT7B/BETA-CATENIN SIGNALING. DICKKOPF-1 PROTEIN, THE WNT/BETA-CATENIN SIGNALING INHIBITOR, SUPPRESSED ANTI-MIR-29B-ENHANCED HASMCS CALCIFICATION. OUR DATA THUS INDICATE THAT MIR-29B DOWNREGULATION AND WNT/BETA-CATENIN SIGNALING ACTIVATION MAY BE THE KEY MECHANISM OF IS INDUCED VASCULAR CALCIFICATION IN CHRONIC KIDNEY DISEASE. 2018 15 4303 34 MICRORNA-223 INHIBITS TISSUE FACTOR EXPRESSION IN VASCULAR ENDOTHELIAL CELLS. OBJECTIVE: ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY PROCESS, IN WHICH VASCULAR ENDOTHELIAL CELLS (ECS) BECOME DYSFUNCTIONAL OWING TO THE EFFECTS OF CHEMICAL SUBSTANCES, SUCH AS INFLAMMATORY FACTOR AND GROWTH FACTORS. TISSUE FACTOR (TF) EXPRESSION IS INDUCED BY THE ABOVE CHEMICAL SUBSTANCES IN ACTIVATED ECS. TF INITIATES THROMBOSIS ON DISRUPTED ATHEROSCLEROTIC PLAQUES WHICH PLAYS AN ESSENTIAL ROLE DURING THE ONSET OF ACUTE CORONARY SYNDROMES (ACS). INCREASING EVIDENCES SUGGEST THE IMPORTANT ROLE OF MICRORNAS AS EPIGENETIC REGULATORS OF ATHEROSCLEROTIC DISEASE. THE AIM OF OUR STUDY IS TO IDENTIFY IF MICRORNA-223 (MIR-223) TARGETS TF IN ECS. METHODS AND RESULTS: BIOINFORMATIC ANALYSIS SHOWED THAT TF IS A TARGET CANDIDATE OF MIR-223. WESTERN BLOTTING ANALYSIS REVEALED THAT TUMOR NECROSIS FACTOR ALPHA (TNF-ALPHA) INCREASED TF EXPRESSION IN AORTA OF C57BL/6J MICE AND CULTURED ECS (EA.HY926 CELLS AND HUVEC) AFTER 4 H TREATMENT. IN TNF-ALPHA TREATED ECS, TF MRNA WAS ALSO INCREASED MEASURED BY REAL-TIME PCR. REAL-TIME PCR RESULTS SHOWED THAT MIR-223 LEVELS WERE DOWNREGULATED IN TNF-ALPHA-TREATED AORTA OF C57BL/6J MICE AND CULTURED ECS. TRANSFECTION OF ECS WITH MIR-223 MIMIC OR MIR-223 INHIBITOR MODIFIED TF EXPRESSION BOTH IN MRNA AND PROTEIN LEVELS. LUCIFERASE ASSAYS CONFIRMED THAT MIR-223 SUPPRESSED TF EXPRESSION BY BINDING TO THE SEQUENCE OF TF 3'-UNTRANSLATED REGIONS (3'UTR). TF PROCOAGULANT ACTIVITY WAS INHIBITED BY OVEREXPRESSING MIR-223 WITH OR WITHOUT TNF-ALPHA STIMULATION. CONCLUSIONS: MIR-223-MEDIATED SUPPRESSION OF TF EXPRESSION PROVIDES A NOVEL MOLECULAR MECHANISM FOR THE REGULATION OF COAGULATION CASCADE, AND SUGGESTS A CLUE AGAINST THROMBOGENESIS DURING THE PROCESS OF ATHEROSCLEROTIC PLAQUE RUPTURE. 2014 16 4287 30 MICRORNA EXPRESSION PROFILING IN BEHCET'S DISEASE. BACKGROUND: BEHCET'S DISEASE (BD) IS A CHRONIC INFLAMMATORY MULTISYSTEM DISEASE CHARACTERIZED BY ORAL AND GENITAL ULCERS, UVEITIS, AND SKIN LESIONS. MICRORNAS (MIRNAS) ARE KEY REGULATORS OF IMMUNE RESPONSES. DIFFERENTIAL EXPRESSION OF MIRNAS HAS BEEN REPORTED IN SEVERAL INFLAMMATORY AUTOIMMUNE DISEASES; HOWEVER, THEIR ROLE IN BD IS NOT FULLY ELUCIDATED. WE AIMED TO IDENTIFY MIRNA EXPRESSION SIGNATURES ASSOCIATED WITH BD AND TO INVESTIGATE THEIR POTENTIAL IMPLICATION IN THE DISEASE PATHOGENESIS. METHODS: MIRNA MICROARRAY ANALYSIS WAS PERFORMED IN BLOOD CELLS OF BD PATIENTS AND HEALTHY CONTROLS. MIRNA EXPRESSION PROFILES WERE ANALYZED USING AFFYMETRIX ARRAYS WITH A COMPREHENSIVE COVERAGE OF MIRNA SEQUENCES. PATHWAY ANALYSES WERE PERFORMED, AND THE GLOBAL MIRNA PROFILING WAS COMBINED WITH TRANSCRIPTOMA DATA IN BD. DEREGULATION OF SELECTED MIRNAS WAS VALIDATED BY REAL-TIME PCR. RESULTS: WE IDENTIFIED SPECIFIC MIRNA SIGNATURES ASSOCIATED WITH BD PATIENTS WITH ACTIVE DISEASE. THESE MIRNAS TARGET PATHWAYS RELEVANT IN BD, SUCH AS TNF, IFN GAMMA, AND VEGF-VEGFR SIGNALING CASCADES. NETWORK ANALYSIS REVEALED SEVERAL MIRNAS REGULATING HIGHLY CONNECTED GENES WITHIN THE BD TRANSCRIPTOMA. CONCLUSIONS: THE COMBINED ANALYSIS OF DEREGULATED MIRNAS AND BD TRANSCRIPTOME SHEDS LIGHT ON SOME EPIGENETIC ASPECTS OF BD IDENTIFYING SPECIFIC MIRNAS, WHICH MAY REPRESENT PROMISING CANDIDATES AS BIOMARKERS AND/OR FOR THE DESIGN OF NOVEL THERAPEUTIC STRATEGIES IN BD. 2018 17 2126 37 EPIGENETIC INACTIVATION OF MIR-34B/C IN ADDITION TO MIR-34A AND DAPK1 IN CHRONIC LYMPHOCYTIC LEUKEMIA. BACKGROUND: TP53 MUTATION/DELETION IS UNCOMMON IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). WE POSTULATED THAT COMPONENTS OF TP53-CENTERED TUMOR SUPPRESSOR NETWORK, MIR-34B/C, IN ADDITION TO DAPK1 AND MIR-34A MIGHT BE INACTIVATED BY DNA HYPERMETHYLATION. MOREOVER, WE TESTED IF MIR-34B/C METHYLATION MIGHT CORRELATE WITH MIR-203 OR MIR-124-1 METHYLATION IN CLL. METHODS: MIR-34B/C, MIR-34A AND DAPK1 METHYLATION WAS STUDIED IN 11 NORMAL CONTROLS, 7 CLL CELL LINES, AND 78 DIAGNOSTIC CLL SAMPLES BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. MEC-1 CELLS WERE TREATED WITH 5-AZA-2'-DEOXYCYTIDINE FOR REVERSAL OF METHYLATION-ASSOCIATED MIRNA SILENCING. TUMOR SUPPRESSOR PROPERTIES OF MIR-34B WERE DEMONSTRATED BY OVER-EXPRESSION OF PRECURSOR MIR-34B IN MEC-1 CELLS. RESULTS: MIR-34B/C PROMOTER WAS UNMETHYLATED IN NORMAL CONTROLS, BUT COMPLETELY METHYLATED IN 4 CLL CELL LINES. MIR-34B/C EXPRESSION WAS INVERSELY CORRELATED WITH MIR-34B/C METHYLATION. DIFFERENT MSP STATUSES OF MIR-34B/C, INCLUDING COMPLETE METHYLATION AND COMPLETE UNMETHYLATION, WERE VERIFIED BY QUANTITATIVE BISULFITE PYROSEQUENCING. 5-AZA-2'-DEOXYCYTIDINE TREATMENT RESULTED IN PROMOTER DEMETHYLATION AND MIR-34B RE-EXPRESSION IN MEC1 CELLS. MOREOVER, OVER-EXPRESSION OF MIR-34B RESULTED IN INHIBITION OF CELLULAR PROLIFERATION AND INCREASED CELL DEATH. IN PRIMARY CLL SAMPLES, MIR-34A, MIR-34B/C AND DAPK1 METHYLATION WAS DETECTED IN 2.6%, 17.9% AND 34.6% OF PATIENTS AT DIAGNOSIS RESPECTIVELY. FURTHERMORE, 39.7%, 3.8% AND 2.6% PATIENTS HAD METHYLATION OF ONE, TWO OR ALL THREE GENES RESPECTIVELY. OVERALL, 46.2% PATIENTS HAD METHYLATION OF AT LEAST ONE OF THESE THREE GENES. BESIDES, MIR-34B/C METHYLATION WAS ASSOCIATED WITH METHYLATION OF MIR-34A (P = 0.03) AND MIR-203 (P = 0.012) IN CLL. CONCLUSIONS: TAKEN TOGETHER, MIR-34B/C IS A TUMOR SUPPRESSOR MIRNA FREQUENTLY METHYLATED, AND HENCE SILENCED IN CLL. TOGETHER WITH DAPK1 METHYLATION, MIR-34B/C METHYLATION IS IMPLICATED IN THE DISRUPTION OF THE TP53-CENTERED TUMOR SUPPRESSOR NETWORK. MOREOVER, THE ASSOCIATION OF MIRNA METHYLATION WARRANTS FURTHER STUDY. 2014 18 2131 32 EPIGENETIC INACTIVATION OF THE HSA-MIR-203 IN HAEMATOLOGICAL MALIGNANCIES. MIR-203 IS A TUMOUR SUPPRESSOR MICRORNA (MIRNA). WE STUDIED THE METHYLATION OF HSA-MIR-203 IN 150 SAMPLES INCLUDING ACUTE MYELOID LEUKAEMIA (AML), ACUTE LYMPHOBLASTIC LEUKAEMIA (ALL), CHRONIC MYELOID LEUKAEMIA (CML), CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) AND NON-HODGKIN'S LYMPHOMA (NHL) BY METHYLATION-SPECIFIC PCR, AND MIRNA EXPRESSION BY STEM-LOOP RT-QPCR. HSA-MIR-203 PROMOTER WAS UNMETHYLATED IN NORMAL CONTROLS BUT HOMOZYGOUSLY METHYLATED IN TWO AML AND FOUR LYMPHOMA CELL LINES, IN WHICH 5-AZA-2'-DEOXYCYTIDINE TREATMENT LED TO PROMOTER DEMETHYLATION AND MIR-203 RE-EXPRESSION. RESTORATION OF MIR-203 EXPRESSION IN LYMPHOMA CELLS INHIBITED CELLULAR PROLIFERATION AND INCREASED CELL DEATH, SUGGESTING AN INHERENT TUMOUR SUPPRESSOR ACTIVITY. IN PRIMARY SAMPLES, HSA-MIR-203 METHYLATION WAS ABSENT IN CML BUT DETECTED IN 5.0% ALL, 10.0% AML, 42.0% CLL AND 38.8% OF NHL (INCLUDING SIX [60.0%] NATURAL KILLER-CELL, NINE [40.9%] B-CELL AND FOUR [23.5%] T CELL NHL). MOREOVER, HSA-MIR-203 METHYLATION WAS ASSOCIATED WITH HYPERMETHYLATION OF HSA-MIR-34A, -124A AND -196B IN NHL BUT NOT CLL. IN CLL, HSA-MIR-203 METHYLATION WAS ASSOCIATED WITH A HIGHER PRESENTING HB LEVEL (P = 0.033). THE PROJECTED 10 YEAR OVERALL SURVIVAL OF THE CLL PATIENTS WAS 58.2%, WHICH WAS IMPACTED BY RAI STAGE AND HIGH-RISK KARYOTYPES BUT NOT HSA-MIR-203 METHYLATION. HSA-MIR-203 WAS MORE FREQUENTLY METHYLATED IN LYMPHOID THAN MYELOID MALIGNANCIES (P = 0.002). IN CONCLUSION, MIR-203, A TUMOUR SUPPRESSOR GENE, WAS HYPERMETHYLATED IN A TUMOUR-SPECIFIC MANNER WITH GENE SILENCING. HSA-MIR-203 WAS MORE FREQUENTLY HYPERMETHYLATED IN LYMPHOID THAN MYELOID MALIGNANCIES. IN NHL, HSA-MIR-203 METHYLATION WAS ASSOCIATED WITH CONCOMITANT METHYLATION OF OTHER TUMOUR SUPPRESSOR MIRNAS. THE FREQUENT HSA-MIR-203 METHYLATION IN LYMPHOID MALIGNANCIES SUGGESTED A PATHOGENETIC ROLE OF HSA-MIR-203 METHYLATION. 2011 19 4288 30 MICRORNA IN LEUKEMIA: TUMOR SUPPRESSORS AND ONCOGENES WITH PROGNOSTIC POTENTIAL. LEUKEMIA IS KNOWN AS A PROGRESSIVE MALIGNANT DISEASE, WHICH DESTROYS THE BLOOD-FORMING ORGANS AND RESULTS IN ADVERSE EFFECTS ON THE PROLIFERATION AND DEVELOPMENT OF LEUKOCYTES AND THEIR PRECURSORS IN THE BLOOD AND BONE MARROW. THERE ARE FOUR MAIN CLASSES OF LEUKEMIA INCLUDING ACUTE LEUKEMIA, CHRONIC LEUKEMIA, MYELOGENOUS LEUKEMIA, AND LYMPHOCYTIC LEUKEMIA. GIVEN THAT A VARIETY OF INTERNAL AND EXTERNAL FACTORS COULD BE ASSOCIATED WITH THE INITIATION AND PROGRESSION OF DIFFERENT TYPES OF LEUKEMIA. ONE OF THE IMPORTANT FACTORS IS EPIGENETIC REGULATORS SUCH AS MICRORNAS (MIRNAS) AND LONG NONCODING RNAS (NCRNA). MIRNAS ARE SHORT NCRNAS WHICH ACT AS TUMOR SUPPRESSOR (I.E., MIR-15, MIR-16, LET-7, AND MIR-127) OR ONCOGENE (I.E., MIR-155, MIR-17-92, MIR-21, MIR-125B, MIR-93, MIR-143-P3, MIR-196B, AND MIR-223) IN LEUKEMIA. IT HAS BEEN SHOWN THAT DEREGULATION OF THESE MOLECULES ARE ASSOCIATED WITH THE INITIATION AND PROGRESSION OF LEUKEMIA. HENCE, MIRNAS COULD BE USED AS POTENTIAL THERAPEUTIC CANDIDATES IN THE TREATMENT OF PATIENTS WITH LEUKEMIA. MOREOVER, INCREASING EVIDENCE REVEALED THAT MIRNAS COULD BE USED AS DIAGNOSTIC AND PROGNOSTIC BIOMARKERS IN MONITORING PATIENTS IN EARLY STAGES OF DISEASE OR AFTER RECEIVED CHEMOTHERAPY REGIMEN. IT SEEMS THAT IDENTIFICATION AND DEVELOPMENT OF NEW MIRNAS COULD PAVE TO THE WAY TO THE DEVELOPMENT NEW THERAPEUTIC PLATFORMS FOR PATIENTS WITH LEUKEMIA. HERE, WE SUMMARIZED VARIOUS MIRNAS AS TUMOR SUPPRESSOR AND ONCOGENE WHICH COULD BE INTRODUCED AS THERAPEUTIC TARGETS IN TREATMENT OF LEUKEMIA. 2019 20 4368 33 MIRNA-DEPENDENT CD4(+) T CELL DIFFERENTIATION IN THE PATHOGENESIS OF MULTIPLE SCLEROSIS. MULTIPLE SCLEROSIS (MS) IS CHARACTERIZED BY MULTIFOCAL LESIONS, CHRONIC INFLAMMATORY CONDITION, AND DEGENERATIVE PROCESSES WITHIN THE CENTRAL NERVOUS SYSTEM (CNS) LEADING TO DEMYELINATION. THE MOST IMPORTANT CELLS INVOLVED IN ITS PATHOGENESIS ARE THOSE WHICH ARE CD4(+), PARTICULARLY PROINFLAMMATORY TH1/TH17 AND REGULATORY TREG. SIGNAL CASCADES ASSOCIATED WITH CD4(+) DIFFERENTIATION ARE REGULATED BY MICRORNAS (MIRNAS): SHORT, SINGLE-STRANDED RNAS, RESPONSIBLE FOR NEGATIVE REGULATION OF GENE EXPRESSION AT THE POSTTRANSCRIPTIONAL LEVEL. SEVERAL MIRNAS HAVE BEEN CONSISTENTLY REPORTED AS SHOWING DYSREGULATED EXPRESSION IN MS, AND THEIR EXPRESSION PATTERNS MAY BE ELEVATED OR DECREASED, DEPENDING ON THE FUNCTION OF SPECIFIC MIRNA IN THE IMMUNE SYSTEM. STUDIES IN MS PATIENTS INDICATE THAT, AMONG OTHERS, MIR-141, MIR-200A, MIR-155, MIR-223, AND MIR-326 ARE UPREGULATED, WHILE MIR-15B, MIR-20B, MIR-26A, AND MIR-30A ARE DOWNREGULATED. DYSREGULATION OF THESE MIRNAS MAY CONTRIBUTE TO THE IMBALANCE BETWEEN PRO- AND ANTI-INFLAMMATORY PROCESSES, SINCE THEIR TARGETS ARE ASSOCIATED WITH THE REGULATION OF TH1/TH17 AND TREG CELL DIFFERENTIATION. HIGHLY EXPRESSED MIRNAS CAN IN TURN SUPPRESS TRANSLATION OF KEY TH1/TH17 DIFFERENTIATION INHIBITORS. MIRNA DYSREGULATION MAY RESULT FROM THE IMPACT OF VARIOUS FACTORS AT EACH STAGE OF THEIR BIOGENESIS. IMMATURE MIRNA UNDERGOES MULTISTAGE TRANSCRIPTIONAL AND POSTTRANSCRIPTIONAL MODIFICATIONS; THEREFORE, ANY PROTEIN INVOLVED IN THE PROCESSING OF MIRNAS CAN POTENTIALLY LEAD TO DISTURBANCES IN THEIR EXPRESSION. EPIGENETIC MODIFICATIONS THAT HAVE A DIRECT IMPACT ON MIRNA GENE TRANSCRIPTION MAY ALSO PLAY AN IMPORTANT ROLE. 2021