1 5257 148 PROGRESSION OF MYELOPROLIFERATIVE NEOPLASMS (MPN): DIAGNOSTIC AND THERAPEUTIC PERSPECTIVES. CLASSICAL BCR-ABL-NEGATIVE MYELOPROLIFERATIVE NEOPLASMS (MPN) ARE A HETEROGENEOUS GROUP OF HEMATOLOGIC MALIGNANCIES, INCLUDING ESSENTIAL THROMBOCYTHEMIA (ET), POLYCYTHEMIA VERA (PV), AND PRIMARY MYELOFIBROSIS (PMF), AS WELL AS POST-PV-MF AND POST-ET-MF. PROGRESSION TO MORE SYMPTOMATIC DISEASE, SUCH AS OVERT MF OR ACUTE LEUKEMIA, REPRESENTS ONE OF THE MAJOR CAUSES OF MORBIDITY AND MORTALITY. THERE ARE CLINICALLY EVIDENT BUT ALSO SUBCLINICAL TYPES OF MPN PROGRESSION. CLINICALLY EVIDENT PROGRESSION INCLUDES EVOLUTION FROM ET TO PV, ET TO POST-ET-MF, PV TO POST-PV-MF, OR PRE-PMF TO OVERT PMF, AND TRANSFORMATION OF ANY OF THESE SUBTYPES TO MYELODYSPLASTIC NEOPLASMS OR ACUTE LEUKEMIA. THROMBOSIS, MAJOR HEMORRHAGE, SEVERE INFECTIONS, OR INCREASING SYMPTOM BURDEN (E.G., PRURITUS, NIGHT SWEATS) MAY HERALD PROGRESSION. SUBCLINICAL TYPES OF PROGRESSION MAY INCLUDE INCREASES IN THE EXTENT OF BONE MARROW FIBROSIS, INCREASES OF DRIVER GENE MUTATIONAL ALLELE BURDEN, AND CLONAL EVOLUTION. THE UNDERLYING CAUSES OF MPN PROGRESSION ARE DIVERSE AND CAN BE ATTRIBUTED TO GENETIC ALTERATIONS AND CHRONIC INFLAMMATION. PARTICULARLY, BYSTANDER MUTATIONS IN GENES ENCODING EPIGENETIC REGULATORS OR SPLICING FACTORS WERE ASSOCIATED WITH PROGRESSION. FINALLY, COMORBIDITIES SUCH AS SYSTEMIC INFLAMMATION, CARDIOVASCULAR DISEASES, AND ORGAN FIBROSIS MAY AUGMENT THE RISK OF PROGRESSION. THE AIM OF THIS REVIEW WAS TO DISCUSS TYPES AND MECHANISMS OF MPN PROGRESSION AND HOW THEIR KNOWLEDGE MIGHT IMPROVE RISK STRATIFICATION AND THERAPEUTIC INTERVENTION. IN VIEW OF THESE ASPECTS, WE DISCUSS THE POTENTIAL BENEFITS OF EARLY DIAGNOSIS USING MOLECULAR AND FUNCTIONAL IMAGING AND EXPLOITABLE THERAPEUTIC STRATEGIES THAT MAY PREVENT PROGRESSION, BUT ALSO HIGHLIGHT CURRENT CHALLENGES AND METHODOLOGICAL PITFALLS. 2021 2 3747 44 INSIGHTS INTO THE MOLECULAR GENETICS OF MYELOPROLIFERATIVE NEOPLASMS. THE MOLECULAR BIOLOGY OF THE BCR-ABL1-NEGATIVE CHRONIC MYELOPROLIFERATIVE NEOPLASMS (MPNS) HAS WITNESSED UNPRECEDENTED ADVANCES SINCE THE DISCOVERY OF THE ACQUIRED JAK2 V617F MUTATION IN 2005. DESPITE THE HIGH PREVALENCE OF JAK2 V617F IN POLYCYTHEMIA VERA (PV), ESSENTIAL THROMBOCYTHEMIA (ET), AND PRIMARY MYELOFIBROSIS (PMF), AND THE COMMON FINDING OF DYSREGULATED JAK-STAT SIGNALING IN THESE DISORDERS, IT IS NOW APPRECIATED THAT MPN PATHOGENESIS CAN REFLECT THE ACQUISITION OF MULTIPLE GENETIC MUTATIONS THAT ALTER SEVERAL BIOLOGIC PATHWAYS, INCLUDING EPIGENETIC CONTROL OF GENE EXPRESSION. ALTHOUGH CERTAIN GENE MUTATIONS ARE IDENTIFIED AT HIGHER FREQUENCIES WITH DISEASE EVOLUTION TO THE BLAST PHASE, MPN INITIATION AND PROGRESSION ARE NOT EXPLAINED BY A SINGLE, TEMPORAL PATTERN OF CLONAL CHANGES. A COMPLEX INTERPLAY BETWEEN ACQUIRED MOLECULAR ABNORMALITIES AND HOST GENETIC BACKGROUND, IN ADDITION TO THE TYPE AND ALLELIC BURDEN OF MUTATIONS, CONTRIBUTES TO THE PHENOTYPIC HETEROGENEITY OF MPNS. AT THE POPULATION LEVEL, AN INHERITED PREDISPOSITION TO DEVELOPING MPNS IS LINKED TO A RELATIVELY COMMON JAK2-ASSOCIATED HAPLOTYPE (REFERRED TO AS '46/1'), BUT IT EXHIBITS A RELATIVELY LOW PENETRANCE. THIS REVIEW DETAILS THE CURRENT STATE OF KNOWLEDGE OF THE MOLECULAR GENETICS OF THE CLASSIC MPNS PV, ET, AND PMF AND DISCUSSES THE CLINICAL IMPLICATIONS OF THESE FINDINGS. 2012 3 1076 43 CLONAL HEMATOPOIESIS IN MYELOPROLIFERATIVE NEOPLASMS CONFERS A PREDISPOSITION TO BOTH THROMBOSIS AND CANCER. PURPOSE OF REVIEW: THIS REVIEW FOCUSES ON VASCULAR COMPLICATIONS ASSOCIATED WITH CHRONIC MYELOPROLIFERATIVE NEOPLASMS (MPN) AND MORE SPECIFICALLY AIMS TO DISCUSS THE CLINICAL AND BIOLOGICAL EVIDENCE SUPPORTING THE EXISTENCE OF A LINK BETWEEN CLONAL HEMATOPOIESIS, CARDIOVASCULAR EVENTS (CVE), AND SOLID CANCER (SC). RECENT FINDINGS: THE MPN NATURAL HISTORY IS DRIVEN BY UNCONTROLLED CLONAL MYELOPROLIFERATION SUSTAINED BY ACQUIRED SOMATIC MUTATIONS IN DRIVER (JAK2, CALR, AND MPL) AND NON-DRIVER GENES, INVOLVING EPIGENETIC (E.G., TET2, DNMT3A) REGULATORS, CHROMATIN REGULATOR GENES (E.G., ASXL1, EZH2), AND SPLICING MACHINERY GENES (E.G., SF3B1). THE GENOMIC ALTERATIONS AND ADDITIONAL THROMBOSIS ACQUIRED RISK FACTORS ARE DETERMINANTS FOR CVE. THERE IS EVIDENCE THAT CLONAL HEMATOPOIESIS CAN ELICIT A CHRONIC AND SYSTEMIC INFLAMMATION STATUS THAT ACTS AS DRIVING FORCE FOR THE DEVELOPMENT OF THROMBOSIS, MPN EVOLUTION, AND SECOND CANCER (SC). THIS NOTION MAY EXPLAIN THE MECHANISM THAT LINKS ARTERIAL THROMBOSIS IN MPN PATIENTS AND SUBSEQUENT SOLID TUMORS. IN THE LAST DECADE, CLONAL HEMATOPOIESIS OF INDETERMINATE POTENTIAL (CHIP) HAS BEEN DETECTED IN THE GENERAL POPULATION PARTICULARLY IN THE ELDERLY AND INITIALLY FOUND IN MYOCARDIAL INFARCTION AND STROKE, RISING THE HYPOTHESIS THAT THE INFLAMMATORY STATUS CHIP-ASSOCIATED COULD CONFER PREDISPOSITION TO BOTH CARDIOVASCULAR DISEASES AND CANCER. IN SUMMARY, CLONAL HEMATOPOIESIS IN MPN AND CHIP CONFER A PREDISPOSITION TO CARDIOVASCULAR EVENTS AND CANCER THROUGH CHRONIC AND SYSTEMIC INFLAMMATION. THIS ACQUISITION COULD OPEN NEW AVENUES FOR ANTITHROMBOTIC THERAPY BOTH IN MPNS AND IN GENERAL POPULATION BY TARGETING BOTH CLONAL HEMATOPOIESIS AND INFLAMMATION. 2023 4 6852 41 [MYELOPROLIFERATIVE NEOPLASMS: UPDATES ON MOLECULAR PATHOPHYSIOLOGY, DIAGNOSIS AND TREATMENT STRATEGIES]. MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE CHRONIC HEMATOPOIETIC STEM CELL DISORDERS, INCLUDING POLYCYTHEMIA VERA, ESSENTIAL THROMBOCYTOSIS, AND PRIMARY MYELOFIBROSIS. THE JAK2V617F MUTATION WAS IDENTIFIED IN 2005, FOLLOWED BY THE DISCOVERY OF THE JAK2 EXON12, MPNW515 MUTATION, AND CALR MUTATION. ABOUT 90% OF PATIENTS WITH BCR/ABL NEGATIVE MPNS HAVE BEEN SHOWN TO HAVE ONE OF THESE DRIVER MUTATIONS. IN ADDITION, MUTATIONS IN EPIGENETIC REGULATORS AND RNA SPLICING GENES WERE FOUND TO CO-EXIST WITH DRIVER MUTATIONS AND TO PLAY CRITICAL ROLES IN THE DISEASE PROGRESSION OF MPNS. CURRENTLY, EVALUATIONS OF THESE GENE MUTATIONS ARE ESSENTIAL FOR THE DIAGNOSIS OF MPNS, AND ARE ALSO NECESSARY FOR ESTIMATING THE CLINICAL COURSE AND THE RISK OF DISEASE PROGRESSION. GUIDELINES FOR THE MANAGEMENT OF MPNS WERE BASED ON THE RESULTS OF LARGE CLINICAL TRIALS. FURTHERMORE, RECENT ADVANCEMENTS IN UNDERSTANDING THE PATHOGENESIS OF MPNS ARE ANTICIPATED TO PROMOTE THE DEVELOPMENT OF MPN-TARGETED THERAPIES SUCH AS JAK2 INHIBITORS. CLINICAL TRIALS FOR PATIENTS WITH PMF AND PV HAVE CONFIRMED THE EFFICACIES OF JAK2 INHIBITORS. 2016 5 5799 42 STEPPING OUT OF ANTIQUITY: AN UPDATE ON EMERGING DRUGS FOR THE TREATMENT OF POLYCYTHEMIA VERA. INTRODUCTION: POLYCYTHEMIA VERA IS A CHRONIC HEMATOLOGIC MALIGNANCY FREQUENTLY PRESENTED WITH CONSTITUTIONAL SYMPTOMS AND ASSOCIATED WITH AN INCREASED RISK OF THROMBOSIS, HEMORRHAGE, AND PROGRESSION TO MYELOFIBROSIS OR ACUTE MYELOID LEUKEMIA. CURRENT TREATMENT STRATEGIES REDUCE THROMBOHEMORRHAGIC RISK BY CONTROLLING BLOOD COUNTS AND INHIBITING PLATELETS, BUT OFTEN FAIL TO ADDRESS DISEASE-RELATED SYMPTOMS OR BIOLOGICALLY MODIFY THE DISEASE.AREAS COVERED: WE REVIEW THE CURRENT PARADIGM FOR TREATING POLYCYTHEMIA VERA, HIGHLIGHT AREAS OF UNMET NEED, REVIEW THERAPEUTIC AGENTS IN LATE STAGE CLINICAL DEVELOPMENT, AND PROVIDE AN OVERARCHING VIEW OF HOW THESE EMERGING AGENT MAY FIT INTO THE FUTURE ARMAMENTARIUM OF POLYCYTHEMIA VERA TREATMENTS.EXPERT OPINION: THE SHIFT FROM FOCUSING SOLELY ON SECONDARY PREVENTION OF THROMBOHEMORRHAGIC EVENTS TO A COMPREHENSIVE TREATMENT STRATEGY THAT ADDITIONALLY AIMS TO IMPROVE QUALITY OF LIFE AND PREVENT DISEASE PROGRESSION HAS RESULTED IN A RAPIDLY EVOLVING THERAPEUTIC LANDSCAPE THAT PROMISES TO MOVE THE TREATMENT OF POLYCYTHEMIA VERA OUT OF ANTIQUITY INTO THE MODERN AGE. 2021 6 3575 46 IMPACT OF MOLECULAR PROFILING ON THE MANAGEMENT OF PATIENTS WITH MYELOFIBROSIS. MYELOFIBROSIS (MF) IS A CHRONIC MYELOPROLIFERATIVE NEOPLASM (MPN) CHARACTERIZED BY A HIGHLY HETEROGENEOUS CLINICAL COURSE, WHICH CAN BE COMPLICATED BY SEVERE CONSTITUTIONAL SYMPTOMS, MASSIVE SPLENOMEGALY, PROGRESSIVE BONE MARROW FAILURE, CARDIOVASCULAR EVENTS, AND DEVELOPMENT OF ACUTE LEUKEMIA. CONSTITUTIVE SIGNALING THROUGH THE JAK-STAT PATHWAY PLAYS A FUNDAMENTAL ROLE IN ITS PATHOGENESIS, GENERALLY DUE TO ACTIVATING MUTATIONS OF JAK2, CALR AND MPL GENES (I.E., THE MPN DRIVER MUTATIONS), PRESENT IN MOST MF PATIENTS. NEXT GENERATION SEQUENCING (NGS) PANEL TESTING HAS SHOWN THAT ADDITIONAL SOMATIC MUTATIONS CAN ALREADY BE DETECTED AT THE TIME OF DIAGNOSIS IN MORE THAN HALF OF PATIENTS, AND THAT THEY ACCUMULATE ALONG THE DISEASE COURSE. THESE MUTATIONS, MOSTLY AFFECTING EPIGENETIC MODIFIERS OR SPLICEOSOME COMPONENTS, MAY COOPERATE WITH MPN DRIVERS TO FAVOR CLONAL DOMINANCE OR INFLUENCE THE CLINICAL PHENOTYPE, AND SOME, SUCH AS HIGH MOLECULAR RISK MUTATIONS, CORRELATE WITH A MORE AGGRESSIVE CLINICAL COURSE WITH POOR TREATMENT RESPONSE. THE CURRENT MAIN ROLE OF MOLECULAR PROFILING IN CLINICAL PRACTICE IS PROGNOSTICATION, PRINCIPALLY FOR SELECTING HIGH-RISK PATIENTS WHO MAY BE CANDIDATES FOR TRANSPLANTATION, THE ONLY CURATIVE TREATMENT FOR MF TO DATE. TO THIS END, CONTEMPORARY PROGNOSTIC MODELS INCORPORATING MOLECULAR DATA ARE USEFUL TOOLS TO DISCRIMINATE DIFFERENT RISK CATEGORIES. ASIDE FROM CERTAIN CLINICAL SITUATIONS, DECISIONS REGARDING MEDICAL TREATMENT ARE NOT BASED ON PATIENT MOLECULAR PROFILING, YET THIS APPROACH MAY BECOME MORE RELEVANT IN NOVEL TREATMENT STRATEGIES, SUCH AS THE USE OF VACCINES AGAINST THE MUTANT FORMS OF JAK2 OR CALR, OR DRUGS DIRECTED AGAINST ACTIONABLE MOLECULAR TARGETS. 2022 7 4322 47 MICRORNAS IN MYELOPROLIFERATIVE NEOPLASMS. THE CHRONIC MYELOPROLIFERATIVE NEOPLASMS (MPN), INCLUDING POLYCYTHAEMIA VERA (PV), ESSENTIAL THROMBOCYTHAEMIA (ET) AND PRIMARY MYELOFIBROSIS (PMF), ARE CLONAL STEM CELL DISORDERS CHARACTERIZED BY DYSREGULATED HAEMATOPOIETIC STEM CELL EXPANSION AND PRODUCTION OF RED CELLS, WHITE CELLS AND PLATELETS ALONE OR IN COMBINATION. AN ACQUIRED MUTATION JAK2(V617F) CAN BE FOUND IN ALL THREE DISORDERS AND SHOWS MANY OF THE PHENOTYPIC ABNORMALITIES OF THE DISEASES IN MURINE MODELS. THE DISEASE PHENOTYPE IS ALSO INFLUENCED BY OTHER UNKNOWN GENETIC OR EPIGENETIC FACTORS. MICRORNAS (MIRNA) ARE 18-24 NUCLEOTIDE SINGLE-STRANDED NON-PROTEIN-CODING RNAS THAT FUNCTION PRIMARILY AS GENE REPRESSORS BY BINDING TO THEIR TARGET MESSENGER RNAS. THERE IS GROWING EVIDENCE THAT MIRNAS REGULATE HAEMATOPOIESIS IN BOTH HAEMATOPOIETIC STEM CELLS AND COMMITTED PROGENITOR CELLS. HERE, WE REVIEW THE FIELD OF MIRNA BIOLOGY AND ITS REGULATORY ROLES IN NORMAL HAEMATOPOIESIS WITH AN EMPHASIS ON MIRNA DEREGULATIONS IN MPNS. CONTINUED RESEARCH INTO HOW MIRNAS IMPACT JAK2(V617F) CLONAL EXPANSION, DIFFERENTIAL HAEMATOPOIESIS AMONG DIFFERENT MPNS, DISEASE PROGRESSION AND LEUKAEMIA TRANSFORMATION WILL LEAD TO A BETTER UNDERSTANDING OF THE DEVELOPMENT OF THESE DISORDERS, THEIR CLINICAL MANIFESTATIONS, AND THEIR TREATMENT. 2013 8 255 40 ADVANCES IN MYELOFIBROSIS: A CLINICAL CASE APPROACH. PRIMARY MYELOFIBROSIS IS A MEMBER OF THE MYELOPROLIFERATIVE NEOPLASMS, A DIVERSE GROUP OF BONE MARROW MALIGNANCIES. SYMPTOMS OF MYELOFIBROSIS, PARTICULARLY THOSE ASSOCIATED WITH SPLENOMEGALY (ABDOMINAL DISTENTION AND PAIN, EARLY SATIETY, DYSPNEA, AND DIARRHEA) AND CONSTITUTIONAL SYMPTOMS, REPRESENT A SUBSTANTIAL BURDEN TO PATIENTS. MOST PATIENTS EVENTUALLY DIE FROM THE DISEASE, WITH A MEDIAN SURVIVAL RANGING FROM APPROXIMATELY 5-7 YEARS. MUTATIONS IN JANUS KINASE 2 (JAK2), A KINASE THAT IS ESSENTIAL FOR THE NORMAL DEVELOPMENT OF ERYTHROCYTES, GRANULOCYTES, AND PLATELETS, NOTABLY THE V617F MUTATION, HAVE BEEN IDENTIFIED IN APPROXIMATELY 50% OF PATIENTS WITH MYELOFIBROSIS. THE APPROVAL OF A JAK2 INHIBITOR IN 2011 HAS IMPROVED THE OUTLOOK OF MANY PATIENTS WITH MYELOFIBROSIS AND HAS CHANGED THE TREATMENT LANDSCAPE. THIS ARTICLE FOCUSES ON SOME OF THE IMPORTANT ISSUES IN CURRENT MYELOFIBROSIS TREATMENT MANAGEMENT, INCLUDING DIFFERENTIATION OF MYELOFIBROSIS FROM ESSENTIAL THROMBOCYTHEMIA AND POLYCYTHEMIA VERA, UP-DATED DATA ON THE RESULTS OF JAK2 INHIBITOR THERAPY, THE ROLE OF EPIGENETIC MECHANISMS IN MYELOFIBROSIS PATHOGENESIS, INVESTIGATIONAL THERAPIES FOR MYELOFIBROSIS, AND ADVANCES IN HEMATOPOIETIC STEM CELL TRANSPLANT. THREE MYELOFIBROSIS CASES ARE INCLUDED TO UNDERSCORE THE ISSUES IN DIAGNOSING AND TREATING THIS COMPLEX DISEASE. 2013 9 2548 34 EPIGENETICS IN MYELOPROLIFERATIVE NEOPLASMS. THE MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE A GROUP OF ACQUIRED CLONAL DISORDERS WHERE MUTATIONS DRIVE PROLIFERATIVE DISEASE RESULTING IN INCREASED BLOOD COUNTS AND IN SOME CASES END-STAGE MYELOFIBROSIS. EPIGENETIC CHANGES ARE THE REVERSIBLE MODIFICATIONS TO DNA- AND RNA-ASSOCIATED PROTEINS THAT IMPACT GENE ACTIVITY WITHOUT CHANGING THE DNA SEQUENCE. THIS REVIEW SUMMARIZES MECHANISMS OF EPIGENETIC CHANGES AND THE NUCLEOSOME. THE DRIVERS AND EPIGENETIC REGULATORS IN MPNS ARE OUTLINED. IN MPNS, DISTINCT PATTERNS OF EPIGENETIC DYSREGULATION HAVE BEEN SEEN IN CHRONIC AND IN ADVANCED PHASES. METHYLATION AGE AND HISTONE MODIFICATION ARE ALTERED IN MPNS AND BY FURTHER TREATMENT. THE ALTERATIONS FOUND IN METHYLATION AGE IN MPNS AND WITH TREATMENT ARE DISCUSSED, AND THE CHANGES IN HISTONE MODIFICATION WITH JANUS KINASE (JAK) INHIBITION ARE EVALUATED. CURRENTLY AVAILABLE THERAPEUTIC AREAS WHERE THE EPIGENOME CAN BE ALTERED ARE OUTLINED. THUS, WE REVIEW THE CURRENT KNOWLEDGE AND UNDERSTANDING OF EPIGENETICS IN MPN AND CONSIDER FURTHER MANAGEMENT OPTIONS. UNDERSTANDING THE EPIGENOME AND ITS ALTERATION IN MPNS AND EPIGENETIC CHANGES ASSOCIATED WITH THE PROGRESSION OF DISEASE WILL LEAD TO ADVANCES IN THERAPEUTIC OPTIONS. 2023 10 5953 48 TARGETS IN MPNS AND POTENTIAL THERAPEUTICS. PHILADELPHIA-NEGATIVE CLASSICAL MYELOPROLIFERATIVE NEOPLASMS (MPNS), INCLUDING POLYCYTHEMIA VERA (PV), ESSENTIAL THROMBOCYTHEMIA (ET) AND PRIMARY MYELOFIBROSIS (PMF), ARE CLONAL HEMOPATHIES THAT EMERGE IN THE HEMATOPOIETIC STEM CELL (HSC) COMPARTMENT. MPN DRIVER MUTATIONS ARE RESTRICTED TO SPECIFIC EXONS (14 AND 12) OF JANUS KINASE 2 (JAK2), THROMBOPOIETIN RECEPTOR (MPL/TPOR) AND CALRETICULIN (CALR) GENES, ARE INVOLVED DIRECTLY IN CLONAL MYELOPROLIFERATION AND GENERATE THE MPN PHENOTYPE. AS A RESULT, AN INCREASED NUMBER OF FULLY FUNCTIONAL ERYTHROCYTES, PLATELETS AND LEUKOCYTES IS OBSERVED IN THE PERIPHERAL BLOOD. NEVERTHELESS, THE COMPLEXITY AND HETEROGENEITY OF MPN CLINICAL PHENOTYPES CANNOT BE SOLELY EXPLAINED BY THE TYPE OF DRIVER MUTATION. OTHER FACTORS, SUCH AS ADDITIONAL SOMATIC MUTATIONS AFFECTING EPIGENETIC REGULATORS OR SPLICEOSOMES COMPONENTS, MUTANT ALLELE BURDENS AND MODIFIERS OF SIGNALING BY DRIVER MUTANTS, CLONAL ARCHITECTURE AND THE ORDER OF MUTATION ACQUISITION, SIGNALING EVENTS THAT OCCUR DOWNSTREAM OF A DRIVER MUTATION, THE PRESENCE OF SPECIFIC GERM-LINE VARIANTS, THE INTERACTION OF THE NEOPLASTIC CLONE WITH BONE MARROW MICROENVIRONMENT AND CHRONIC INFLAMMATION, ALL CAN MODULATE THE DISEASE PHENOTYPE, INFLUENCE THE MPN CLINICAL COURSE AND THEREFORE, MIGHT BE USEFUL THERAPEUTIC TARGETS. 2022 11 4566 35 MYELOID SOMATIC MUTATION PANEL TESTING IN MYELOPROLIFERATIVE NEOPLASMS. MYELOPROLIFERATIVE NEOPLASMS ARE CHARACTERISED BY SOMATIC MUTATIONS IN PATHWAYS THAT REGULATE CELL PROLIFERATION, EPIGENETIC MODIFICATIONS, RNA SPLICING OR DNA REPAIR. ASSESSMENT OF THE MUTATIONAL PROFILE ASSISTS DIAGNOSIS AND CLASSIFICATION, BUT ALSO AIDS ASSESSMENT OF PROGNOSIS, AND MAY GUIDE THE USE OF EMERGING TARGETED THERAPIES. THE MOST PRACTICAL WAY TO PROVIDE INFORMATION ON NUMEROUS GENETIC VARIANTS IS BY USING MASSIVELY PARALLEL SEQUENCING, COMMONLY IN THE FORM OF DISEASE SPECIFIC NEXT GENERATION SEQUENCING (NGS) PANELS. THIS REVIEW SUMMARISES THE DIAGNOSTIC AND PROGNOSTIC VALUE OF SOMATIC MUTATION TESTING IN PHILADELPHIA-NEGATIVE MYELOPROLIFERATIVE NEOPLASMS: POLYCYTHAEMIA VERA, ESSENTIAL THROMBOCYTHAEMIA, PRIMARY MYELOFIBROSIS, CHRONIC NEUTROPHILIC LEUKAEMIA, SYSTEMIC MASTOCYTOSIS, AND CHRONIC EOSINOPHILIC LEUKAEMIA. NGS PANEL TESTING IS INCREASING IN ROUTINE PRACTICE AND PROMISES TO IMPROVE THE ACCURACY AND EFFICIENCY OF PATHOLOGICAL DIAGNOSIS AND PROGNOSIS. 2021 12 3111 38 GENOTYPE-PHENOTYPE INTERACTIONS IN THE MYELOPROLIFERATIVE NEOPLASMS. THE CHRONIC MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE CLONAL DISORDERS CHARACTERIZED BY OVERPRODUCTION OF MATURE MYELOID CELLS. THEY SHARE ASSOCIATIONS WITH MOLECULAR ABNORMALITIES SUCH AS THE JAK2V617F MUTATION BUT ARE DISTINGUISHED BY IMPORTANT PHENOTYPIC DIFFERENCES. THIS REVIEW FIRST CONSIDERS THE FACTORS THAT MAY INFLUENCE PHENOTYPE IN JAK2-MUTATED MPNS, ESPECIALLY POLYCYTHEMIA VERA (PV) AND ESSENTIAL THROMBOCYTHEMIA (ET), AND THEN DISCUSSES THE MUTATIONS IMPLICATED IN JAK2-NEGATIVE MPNS SUCH AS IN MPL AND EPIGENETIC REGULATORS. CURRENT EVIDENCE SUPPORTS A MODEL WHERE ET AND PV ARE DISORDERS OF RELATIVELY LOW GENETIC COMPLEXITY, WHEREAS EVOLUTION TO MYELOFIBROSIS OR BLAST-PHASE DISEASE REFLECTS ACCUMULATION OF A HIGHER MUTATION BURDEN. 2012 13 924 38 CHRONIC INFLAMMATION AS A PROMOTOR OF MUTAGENESIS IN ESSENTIAL THROMBOCYTHEMIA, POLYCYTHEMIA VERA AND MYELOFIBROSIS. A HUMAN INFLAMMATION MODEL FOR CANCER DEVELOPMENT? THE PHILADELPHIA-NEGATIVE CHRONIC MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE ACQUIRED STEM CELL NEOPLASMS, IN WHICH A STEM CELL LESION INDUCES AN AUTONOMOUS PROLIFERATIVE ADVANTAGE. IN ADDITION TO THE JAK2V617 MUTATION SEVERAL OTHER MUTATIONS HAVE BEEN DESCRIBED. RECENTLY CHRONIC INFLAMMATION HAS BEEN PROPOSED AS A TRIGGER AND DRIVER OF CLONAL EVOLUTION IN MPNS. HEREIN, IT IS HYPOTHESIZED THAT SUSTAINED INFLAMMATION MAY ELICIT THE STEM CELL INSULT BY INDUCING A STATE OF CHRONIC OXIDATIVE STRESS WITH ELEVATED LEVELS OF REACTIVE OXYGEN SPECIES (ROS) IN THE BONE MARROW, THEREBY CREATING A HIGH-RISK MICROENVIRONMENT FOR INDUCTION OF MUTATIONS DUE TO THE PERSISTENT INFLAMMATION-INDUCED OXIDATIVE DAMAGE TO DNA IN HEMATOPOIETIC CELLS. ALTERATIONS IN THE EPIGENOME INDUCED BY THE CHRONIC INFLAMMATORY DRIVE MAY LIKELY ELICIT A "EPIGENETIC SWITCH" PROMOTING PERSISTENT INFLAMMATION. THE PERSPECTIVES OF CHRONIC INFLAMMATION AS THE DRIVER OF MUTAGENESIS IN MPNS ARE DISCUSSED, INCLUDING EARLY INTERVENTION WITH INTERFERON-ALPHA2 AND POTENT ANTI-INFLAMMATORY AGENTS (E.G. JAK1-2 INHIBITORS, HISTONE DEACETYLASE INHIBITORS, DNA-HYPOMETHYLATORS AND STATINS) TO DISRUPT THE SELF-PERPETUATING CHRONIC INFLAMMATION STATE AND ACCORDINGLY ELIMINATING A POTENTIAL TRIGGER OF CLONAL EVOLUTION AND DISEASE PROGRESSION WITH MYELOFIBROTIC AND LEUKEMIC TRANSFORMATION. 2013 14 4959 28 PATHOGENESIS OF MYELOPROLIFERATIVE DISORDERS. MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE A SET OF CHRONIC HEMATOPOIETIC NEOPLASMS WITH OVERLAPPING CLINICAL AND MOLECULAR FEATURES. RECENT YEARS HAVE WITNESSED CONSIDERABLE ADVANCES IN OUR UNDERSTANDING OF THEIR PATHOGENETIC BASIS. DUE TO THEIR PROTRACTED CLINICAL COURSE, THE EVOLUTION TO ADVANCED HEMATOLOGICAL MALIGNANCIES, AND THE ACCESSIBILITY OF NEOPLASTIC TISSUE, THE STUDY OF MPNS HAS PROVIDED A WINDOW INTO THE EARLIEST STAGES OF TUMORIGENESIS. WITH THE DISCOVERY OF MUTATIONS IN CALR, THE MAJORITY OF MPN PATIENTS NOW BEAR AN IDENTIFIABLE MARKER OF CLONAL DISEASE; HOWEVER, THE MECHANISM BY WHICH MUTATED CALR PERTURBS MEGAKARYOPOIESIS IS CURRENTLY UNRESOLVED. WE ARE BEGINNING TO UNDERSTAND BETTER THE ROLE OF JAK2(V617F) HOMOZYGOSITY, THE FUNCTION OF COMUTATIONS IN EPIGENETIC REGULATORS AND SPLICEOSOME COMPONENTS, AND HOW THESE MUTATIONS COOPERATE WITH JAK2(V617F) TO MODULATE MPN PHENOTYPE. 2016 15 1947 51 EPIGENETIC ABNORMALITIES IN MYELOPROLIFERATIVE NEOPLASMS: A TARGET FOR NOVEL THERAPEUTIC STRATEGIES. THE MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE A GROUP OF CLONAL HEMATOLOGICAL MALIGNANCIES CHARACTERIZED BY A HYPERCELLULAR BONE MARROW AND A TENDENCY TO DEVELOP THROMBOTIC COMPLICATIONS AND TO EVOLVE TO MYELOFIBROSIS AND ACUTE LEUKEMIA. UNLIKE CHRONIC MYELOGENOUS LEUKEMIA, WHERE A SINGLE DISEASE-INITIATING GENETIC EVENT HAS BEEN IDENTIFIED, A MORE COMPLICATED SERIES OF GENETIC MUTATIONS APPEAR TO BE RESPONSIBLE FOR THE BCR-ABL1-NEGATIVE MPNS WHICH INCLUDE POLYCYTHEMIA VERA, ESSENTIAL THROMBOCYTHEMIA, AND PRIMARY MYELOFIBROSIS. RECENT STUDIES HAVE REVEALED A NUMBER OF EPIGENETIC ALTERATIONS THAT ALSO LIKELY CONTRIBUTE TO DISEASE PATHOGENESIS AND DETERMINE CLINICAL OUTCOME. INCREASING EVIDENCE INDICATES THAT ALTERATIONS IN DNA METHYLATION, HISTONE MODIFICATION, AND MICRORNA EXPRESSION PATTERNS CAN COLLECTIVELY INFLUENCE GENE EXPRESSION AND POTENTIALLY CONTRIBUTE TO MPN PATHOGENESIS. EXAMPLES INCLUDE MUTATIONS IN GENES ENCODING PROTEINS THAT MODIFY CHROMATIN STRUCTURE (EZH2, ASXL1, IDH1/2, JAK2V617F, AND IKZF1) AS WELL AS EPIGENETIC MODIFICATION OF GENES CRITICAL FOR CELL PROLIFERATION AND SURVIVAL (SUPPRESSORS OF CYTOKINE SIGNALING, POLYCYTHEMIA RUBRA VERA-1, CXC CHEMOKINE RECEPTOR 4, AND HISTONE DEACETYLASE (HDAC)). THESE EPIGENETIC LESIONS SERVE AS NOVEL TARGETS FOR EXPERIMENTAL THERAPEUTIC INTERVENTIONS. CLINICAL TRIALS ARE CURRENTLY UNDERWAY EVALUATING HDAC INHIBITORS AND DNA METHYLTRANSFERASE INHIBITORS FOR THE TREATMENT OF PATIENTS WITH MPNS. 2011 16 4680 45 NEW MUTATIONS AND PATHOGENESIS OF MYELOPROLIFERATIVE NEOPLASMS. MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE CLONAL DISORDERS CHARACTERIZED BY EXCESSIVE PRODUCTION OF MATURE BLOOD CELLS. IN THE MAJORITY OF CLASSIC MPN--POLYCYTHEMIA VERA, ESSENTIAL THROMBOCYTHEMIA, AND PRIMITIVE MYELOFIBROSIS--DRIVER ONCOGENIC MUTATIONS AFFECTING JANUS KINASE 2 (JAK2) OR MPL LEAD TO CONSTITUTIVE ACTIVATION OF CYTOKINE-REGULATED INTRACELLULAR SIGNALING PATHWAYS. LNK, C-CBL, OR SOCSS (ALL NEGATIVE REGULATORS OF SIGNALING PATHWAYS), ALTHOUGH INFREQUENTLY TARGETED, MAY EITHER DRIVE THE DISEASE OR SYNERGIZE WITH JAK2 AND MPL MUTATIONS. IZF1 DELETIONS OR TP53 MUTATIONS ARE MAINLY FOUND AT TRANSFORMATION PHASES AND ARE PRESENT AT GREATER FREQUENCY THAN IN DE NOVO ACUTE MYELOID LEUKEMIAS. LOSS-OF-FUNCTION MUTATIONS IN 3 GENES INVOLVED IN EPIGENETIC REGULATION, TET2, ASXL1, AND EZH2, MAY BE EARLY EVENTS PRECEDING JAK2V617F BUT MAY ALSO OCCUR LATE DURING DISEASE PROGRESSION. THEY ARE MORE FREQUENTLY OBSERVED IN PMF THAN PV AND ET AND ARE ALSO PRESENT IN OTHER TYPES OF MALIGNANT MYELOID DISEASES. A LIKELY HYPOTHESIS IS THAT THEY FACILITATE CLONAL SELECTION, ALLOWING THE DOMINANCE OF THE JAK2V617F SUBCLONE DURING THE CHRONIC PHASE AND, TOGETHER WITH COOPERATING MUTATIONS, PROMOTE BLAST CRISIS. THEIR PRECISE ROLES IN HEMATOPOIESIS AND IN THE PATHOGENESIS OF MPN, AS WELL AS THEIR PROGNOSTIC IMPACT AND POTENTIAL AS A THERAPEUTIC TARGET, ARE CURRENTLY UNDER INVESTIGATION. 2011 17 963 28 CHRONIC MYELOMONOCYTIC LEUKEMIA: INSIGHTS INTO BIOLOGY, PROGNOSTIC FACTORS, AND TREATMENT. PURPOSE OF REVIEW: CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) IS A CLONAL HEMATOLOGICAL MALIGNANCY CHARACTERIZED BY BOTH DYSPLASTIC AND PROLIFERATIVE FEATURES, WITH AN INHERENT RISK FOR LEUKEMIC TRANSFORMATION. WITH THE HELP OF THIS REVIEW, WE AIM TO SUMMARIZE KEY CONCEPTS WITH REGARDS TO CMML BIOLOGY, DIAGNOSIS, RISK STRATIFICATION, AND THERAPEUTICS. RECENT FINDINGS: BASED ON RECENT STUDIES, CMML IS HALLMARKED BY A RELATIVELY LOW GENETIC COMPLEXITY, WHICH CONTRASTS WITH A COMPELLING PHENOTYPICAL HETEROGENEITY, LARGELY DRIVEN BY EPIGENETIC MECHANISMS. RECENT ADVANCES IN THE CHARACTERIZATION OF CMML BIOLOGY HAS LED TO AN IMPROVEMENT IN RISK-STRATIFICATION, BY MEANS OF INCORPORATING PROGNOSTICALLY RELEVANT GENE MUTATIONS. THIS, HOWEVER, HAS NOT SIGNIFICANTLY IMPACTED AVAILABLE THERAPIES AND OUTCOMES CONTINUE TO REMAIN POOR. ADVANCES IN CMML BIOLOGY HAVE BETTER EXPLAINED THE PHENOTYPIC HETEROGENEITY, WHILE CONTINUING TO DEFINE THE GENETIC AND EPIGENETIC LANDSCAPE. IN SPITE OF RECENT ADVANCES, LIMITED EFFECTIVE THERAPIES EXIST AND DEVELOPING RATIONALLY DERIVED THERAPEUTIC APPROACHES IS MUCH NEEDED. 2019 18 5782 37 SPLICING ANOMALIES IN MYELOPROLIFERATIVE NEOPLASMS: PAVING THE WAY FOR NEW THERAPEUTIC VENUES. SINCE THE DISCOVERY OF SPLICEOSOME MUTATIONS IN MYELOID MALIGNANCIES, ABNORMAL PRE-MRNA SPLICING, WHICH HAS BEEN WELL STUDIED IN VARIOUS CANCERS, HAS ATTRACTED NOVEL INTEREST IN HEMATOLOGY. HOWEVER, DESPITE THE COMMON OCCURRENCE OF SPLICEOSOME MUTATIONS IN MYELO-PROLIFERATIVE NEOPLASMS (MPN), NOT MUCH IS KNOWN REGARDING THE CHARACTERIZATION AND MECHANISMS OF SPLICING ANOMALIES IN MPN. IN THIS ARTICLE, WE REVIEW THE CURRENT SCIENTIFIC LITERATURE REGARDING "SPLICING AND MYELOPROLIFERATIVE NEOPLASMS". WE FIRST ANALYSE THE CLINICAL SERIES REPORTING SPLICEOSOME MUTATIONS IN MPN AND THEIR CLINICAL CORRELATES. WE THEN PRESENT THE CURRENT KNOWLEDGE ABOUT MOLECULAR MECHANISMS BY WHICH THESE MUTATIONS PARTICIPATE IN THE PATHOGENESIS OF MPN OR OTHER MYELOID MALIGNANCIES. BESIDE SPLICEOSOME MUTATIONS, SPLICING ANOMALIES HAVE BEEN DESCRIBED IN MYELOPROLIFERATIVE NEOPLASMS, AS WELL AS IN ACUTE MYELOID LEUKEMIAS, A DREADFUL COMPLICATION OF THESE CHRONIC DISEASES. BASED ON SPLICING ANOMALIES REPORTED IN CHRONIC MYELOGENOUS LEUKEMIA AS WELL AS IN ACUTE LEUKEMIA, AND THE MECHANISMS PRESIDING SPLICING DEREGULATION, WE PROPOSE THAT ABNORMAL SPLICING PLAYS A MAJOR ROLE IN THE EVOLUTION OF MYELOPROLIFERATIVE NEOPLASMS AND MAY BE THE TARGET OF SPECIFIC THERAPEUTIC STRATEGIES. 2020 19 6442 37 THERAPEUTIC APPROACHES IN MYELOFIBROSIS AND MYELODYSPLASTIC/MYELOPROLIFERATIVE OVERLAP SYNDROMES. THE DISCOVERY OF JAK2 (V617F) A DECADE AGO LED TO OPTIMISM FOR A RAPIDLY DEVELOPING TREATMENT REVOLUTION IN PH(-) MYELOPROLIFERATIVE NEOPLASMS. UNLIKE BCR-ABL, HOWEVER, JAK2 WAS FOUND TO HAVE A MORE HETEROGENEOUS ROLE IN CARCINOGENESIS. THEREFORE, FOR YEARS, DEVELOPMENT OF NEW THERAPIES WAS SLOW, DESPITE STANDARD TREATMENT OPTIONS THAT DID NOT ADDRESS THE OVERWHELMING SYMPTOM BURDEN IN PATIENTS WITH PRIMARY MYELOFIBROSIS (MF), POST-ESSENTIAL THROMBOCYTHEMIA MF, POST-POLYCYTHEMIA VERA MF, AND MYELODYSPLASTIC SYNDROME (MDS)/MYELOPROLIFERATIVE NEOPLASM (MPN) SYNDROMES. JAK-STAT INHIBITORS HAVE CHANGED THIS, DRASTICALLY AMELIORATING SYMPTOMS AND ULTIMATELY BEGINNING TO SHOW EVIDENCE OF IMPACT ON SURVIVAL. NOW, THE GENETIC FOUNDATIONS OF MYELOFIBROSIS AND MDS/MPN ARE RAPIDLY BEING ELUCIDATED AND CONTRIBUTING TO TARGETED THERAPY DEVELOPMENT. THIS HAS BEEN EMPOWERED THROUGH UPDATED RESPONSE CRITERIA FOR MDS/MPN AND REFINED PROGNOSTIC SCORING SYSTEMS IN THESE DISEASES. THE AIM OF THIS ARTICLE IS TO SUMMARIZE CONCISELY THE CURRENT AND RATIONALLY DESIGNED INVESTIGATIONAL THERAPEUTICS DIRECTED AT JAK-STAT, HEDGEHOG, PI3K-AKT, BONE MARROW FIBROSIS, TELOMERASE, AND ROGUE EPIGENETIC SIGNALING. THE REVOLUTION IN IMMUNOTHERAPY AND NOVEL TREATMENTS AIMED AT PREVIOUSLY UNTARGETED SIGNALING PATHWAYS PROVIDES HOPE FOR CONSIDERABLE ADVANCEMENT IN THERAPY OPTIONS FOR THOSE WITH CHRONIC MYELOID DISEASE. 2016 20 1043 43 CLINICAL CHARACTERISTICS AND WHOLE EXOME/TRANSCRIPTOME SEQUENCING OF COEXISTING CHRONIC MYELOID LEUKEMIA AND MYELOFIBROSIS. MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE CLONAL HEMATOPOIETIC STEM CELL (HSC) DISORDERS THAT CAN BE CLASSIFIED ON THE BASIS OF GENETIC, CLINICAL, PHENOTYPIC FEATURES. GENETIC LESIONS SUCH AS JAK2 MUTATIONS AND BCR-ABL TRANSLOCATION ARE OFTEN MUTUALLY EXCLUSIVE IN MPN PATIENTS AND LEAD TO ESSENTIAL THROMBOCYTHEMIA, POLYCYTHEMIA VERA, OR MYELOFIBROSIS OR CHRONIC MYELOID LEUKEMIA, RESPECTIVELY. NEVERTHELESS, COEXISTENCE OF THESE GENETIC ABERRATIONS IN THE SAME PATIENT HAS BEEN REPORTED. WHETHER THESE ABERRATIONS OCCUR IN THE SAME STEM CELL OR A DIFFERENT CELL IS UNCLEAR, BUT AN UNSTABLE GENOME IN THE HSCS SEEMS TO BE THE COMMON ANTECEDENT. IN AN EFFORT TO CHARACTERIZE THE UNDERLYING GENETIC EVENTS THAT MIGHT CONTRIBUTE TO THE APPEARANCE OF MORE THAN ONE MPN IN A PATIENT, WE STUDIED NEOPLASTIC CELLS FROM PATIENTS WITH DUAL MPNS BY NEXT-GENERATION SEQUENCING. WE OBSERVED THAT MOST PATIENTS WITH TWO MPNS HARBORED MUTATIONS IN GENES KNOWN TO CONTRIBUTE TO CLONAL HEMATOPOIESIS THROUGH ALTERED EPIGENETIC REGULATION SUCH AS TET2, ASXL1/2, SRSF2, AND IDH2 AT VARYING FREQUENCIES (1%-47%). IN ADDITION, WE FOUND THAT SOME PATIENTS ALSO HARBORED ONCOGENIC MUTATIONS IN N/KRAS, TP53, BRAF, EZH2, AND GNAS AT LOW FREQUENCIES, WHICH PROBABLY REPRESENT CLONAL EVOLUTION. THESE FINDINGS SUPPORT THE HYPOTHESIS THAT HEMATOPOIETIC CELLS FROM MPN PATIENTS HARBOR MULTIPLE GENETIC ABERRATIONS, SOME OF WHICH CAN CONTRIBUTE TO CLONAL DOMINANCE. ACQUIRING MUTATIONS IN JAK2/CALR/MPL OR THE BCR-ABL TRANSLOCATION PROBABLY DRIVE THE ONCOGENIC PHENOTYPE TOWARDS A SPECIFIC MPN. FURTHER, WE PROPOSE THAT THE ACQUISITION OF BCR-ABL IN THESE PATIENTS IS FREQUENTLY A SECONDARY EVENT RESULTING FROM AN UNSTABLE GENOME. 2017