1 937 58 CHRONIC LYMPHOCYTIC LEUKAEMIA GENOMICS AND THE PRECISION MEDICINE ERA. MASSIVE GENOMIC ANALYSES HAVE UNDERSCORED THE DIVERSITY OF CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) BETWEEN PATIENTS. GENETIC HETEROGENEITY OF TUMOUR CLONES WITHIN A PATIENT MAY FUEL TUMOUR EVOLUTION. SEVERAL RECURRENTLY DEREGULATED INTRA-CELLULAR PATHWAYS ARE CANDIDATES FOR TARGETED THERAPIES THAT ARE VERY PROMISING AND ARE DRAMATICALLY CHANGING CLINICAL PATIENTS' PERSPECTIVES. IN THIS REVIEW WE PRESENT AN OVERVIEW OF THE GENETIC AND EPIGENETIC FEATURES OF CLL AND THEIR CLINICAL AND BIOLOGICAL IMPLICATIONS. 2017 2 4481 24 MOLECULAR PROFILING OF CHRONIC LYMPHOCYTIC LEUKAEMIA: GENETICS MEETS EPIGENETICS TO IDENTIFY PREDISPOSING GENES. MOLECULAR PROFILING MAY LEAD TO A BETTER UNDERSTANDING OF A DISEASE. THIS KNOWLEDGE IS ESPECIALLY IMPORTANT IN MALIGNANCIES, WHERE MULTIPLE ALTERATIONS ARE REQUIRED DURING THE PROGRESSION FROM PREMALIGNANT TO MALIGNANT STAGES. SUCH INFORMATION CAN BE USEFUL FOR THE DEVELOPMENT OF NOVEL BIOMARKERS THAT ALLOW THE PREDICTION OF A CLINICAL COURSE, RESPONSE TO TREATMENT OR EARLY DETECTION. MOLECULAR DATA IS ALSO UTILIZED TO DEVELOP TARGETED THERAPIES. MOREOVER, GENE DEFECTS IDENTIFIED IN PROFILING STUDIES WILL HELP TO UNDERSTAND THE MOLECULAR PATHWAYS DISRUPTED IN THE DISEASE. THIS REVIEW PROVIDES AN OVERVIEW OF MOLECULAR PROFILING APPROACHES IN CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL). WE WILL DESCRIBE OUR CURRENT UNDERSTANDING OF GENETIC ALTERATIONS IN CLL, THE USE OF FAMILIAL CLL FOR THE IDENTIFICATION OF PREDISPOSING MUTATIONS, AND THE SEARCH FOR EPIGENETIC ALTERATIONS IN CLL. 2007 3 945 24 CHRONIC LYMPHOCYTIC LEUKEMIA: MOLECULAR HETEROGENEITY REVEALED BY HIGH-THROUGHPUT GENOMICS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) HAS BEEN CONSISTENTLY AT THE FOREFRONT OF GENETIC RESEARCH OWING TO ITS PREVALENCE AND THE ACCESSIBILITY OF SAMPLE MATERIAL. RECENTLY, GENOME-WIDE TECHNOLOGIES HAVE BEEN INTENSIVELY APPLIED TO CLL GENETICS, WITH REMARKABLE PROGRESS. SINGLE NUCLEOTIDE POLYMORPHISM ARRAYS HAVE IDENTIFIED RECURRING CHROMOSOMAL ABERRATIONS, THEREBY FOCUSING FUNCTIONAL STUDIES ON DISCRETE GENOMIC LESIONS AND LEADING TO THE FIRST IMPLICATION OF SOMATIC MICRORNA DISRUPTION IN CANCER. NEXT-GENERATION SEQUENCING (NGS) HAS FURTHER TRANSFORMED OUR UNDERSTANDING OF CLL BY IDENTIFYING NOVEL RECURRENTLY MUTATED PUTATIVE DRIVERS, INCLUDING THE UNEXPECTED DISCOVERY OF SOMATIC MUTATIONS AFFECTING SPLICEOSOME FUNCTION. NGS HAS FURTHER ENABLED IN-DEPTH EXAMINATION OF THE TRANSCRIPTIONAL AND EPIGENETIC CHANGES IN CLL THAT ACCOMPANY GENETIC LESIONS, AND HAS SHED LIGHT ON HOW DIFFERENT DRIVER EVENTS APPEAR AT DIFFERENT STAGES OF DISEASE PROGRESSION AND CLONALLY EVOLVE WITH RELAPSED DISEASE. IN ADDITION TO PROVIDING IMPORTANT INSIGHTS INTO DISEASE BIOLOGY, THESE DISCOVERIES HAVE SIGNIFICANT TRANSLATIONAL POTENTIAL. THEY ENHANCE PROGNOSIS BY HIGHLIGHTING SPECIFIC LESIONS ASSOCIATED WITH POOR CLINICAL OUTCOMES (FOR EXAMPLE, DRIVER EVENTS SUCH AS MUTATIONS IN THE SPLICING FACTOR SUBUNIT GENE SF3B1) OR WITH INCREASED CLONAL HETEROGENEITY (FOR EXAMPLE, THE PRESENCE OF SUBCLONAL DRIVER MUTATIONS). HERE, WE REVIEW NEW GENOMIC DISCOVERIES IN CLL AND DISCUSS THEIR POSSIBLE IMPLICATIONS IN THE ERA OF PRECISION MEDICINE. 2013 4 944 25 CHRONIC LYMPHOCYTIC LEUKEMIA: FROM MOLECULAR PATHOGENESIS TO NOVEL THERAPEUTIC STRATEGIES. CHRONIC LYMPHOCYTIC LEUKEMIA IS A WELL-DEFINED LYMPHOID NEOPLASM WITH VERY HETEROGENEOUS BIOLOGICAL AND CLINICAL BEHAVIOR. THE LAST DECADE HAS BEEN REMARKABLY FRUITFUL IN NOVEL FINDINGS ELUCIDATING MULTIPLE ASPECTS OF THE PATHOGENESIS OF THE DISEASE INCLUDING MECHANISMS OF GENETIC SUSCEPTIBILITY, INSIGHTS INTO THE RELEVANCE OF IMMUNOGENETIC FACTORS DRIVING THE DISEASE, PROFILING OF GENOMIC ALTERATIONS, EPIGENETIC SUBTYPES, GLOBAL EPIGENOMIC TUMOR CELL REPROGRAMMING, MODULATION OF TUMOR CELL AND MICROENVIRONMENT INTERACTIONS, AND DYNAMICS OF CLONAL EVOLUTION FROM EARLY STEPS IN MONOCLONAL B CELL LYMPHOCYTOSIS TO PROGRESSION AND TRANSFORMATION INTO DIFFUSE LARGE B-CELL LYMPHOMA. ALL THIS KNOWLEDGE HAS OFFERED NEW PERSPECTIVES THAT ARE BEING EXPLOITED THERAPEUTICALLY WITH NOVEL TARGET AGENTS AND MANAGEMENT STRATEGIES. IN THIS REVIEW WE PROVIDE AN OVERVIEW OF THESE NOVEL ADVANCES AND HIGHLIGHT QUESTIONS AND PERSPECTIVES THAT NEED FURTHER PROGRESS TO TRANSLATE INTO THE CLINICS THE BIOLOGICAL KNOWLEDGE AND IMPROVE THE OUTCOME OF THE PATIENTS. 2020 5 2992 28 GENETIC LANDSCAPE AND DEREGULATED PATHWAYS IN B-CELL LYMPHOID MALIGNANCIES. WITH THE INTRODUCTION OF NEXT-GENERATION SEQUENCING, THE GENETIC LANDSCAPE OF THE COMPLEX GROUP OF B-CELL LYMPHOID MALIGNANCIES HAS RAPIDLY BEEN UNRAVELLED IN RECENT YEARS. THIS HAS PROVIDED IMPORTANT INFORMATION ABOUT RECURRENT GENETIC EVENTS AND IDENTIFIED KEY PATHWAYS DEREGULATED IN EACH LYMPHOMA SUBTYPE. IN PARALLEL, THERE HAS BEEN INTENSE SEARCH AND DEVELOPMENT OF NOVEL TYPES OF TARGETED THERAPY THAT 'HIT' CENTRAL MECHANISMS IN LYMPHOMA PATHOBIOLOGY, SUCH AS BTK, PI3K OR BCL2 INHIBITORS. IN THIS REVIEW, WE WILL OUTLINE THE CURRENT VIEW OF THE GENETIC LANDSCAPE OF SELECTED ENTITIES: FOLLICULAR LYMPHOMA, DIFFUSE LARGE B-CELL LYMPHOMA, MANTLE CELL LYMPHOMA, CHRONIC LYMPHOCYTIC LEUKAEMIA AND MARGINAL ZONE LYMPHOMA. WE WILL DETAIL RECURRENT ALTERATIONS AFFECTING IMPORTANT SIGNALLING PATHWAYS, THAT IS THE B-CELL RECEPTOR/NF-KAPPAB PATHWAY, NOTCH SIGNALLING, JAK-STAT SIGNALLING, P53/DNA DAMAGE RESPONSE, APOPTOSIS AND CELL CYCLE REGULATION, AS WELL AS OTHER PERHAPS UNEXPECTED CELLULAR PROCESSES, SUCH AS IMMUNE REGULATION, CELL MIGRATION, EPIGENETIC REGULATION AND RNA PROCESSING. WHILST MANY OF THESE PATHWAYS/PROCESSES ARE COMMONLY ALTERED IN DIFFERENT LYMPHOID TUMORS, ALBEIT AT VARYING FREQUENCIES, OTHERS ARE PREFERENTIALLY TARGETED IN SELECTED B-CELL MALIGNANCIES. SOME OF THESE GENETIC LESIONS ARE EITHER INVOLVED IN DISEASE ONTOGENY OR LINKED TO THE EVOLUTION OF EACH DISEASE AND/OR SPECIFIC CLINICOBIOLOGICAL FEATURES, AND SOME OF THEM HAVE BEEN DEMONSTRATED TO HAVE PROGNOSTIC AND EVEN PREDICTIVE IMPACT. FUTURE WORK IS ESPECIALLY NEEDED TO UNDERSTAND THE THERAPY-RESISTANT DISEASE, PARTICULARLY IN PATIENTS TREATED WITH TARGETED THERAPY, AND TO IDENTIFY NOVEL TARGETS AND THERAPEUTIC STRATEGIES IN ORDER TO REALIZE TRUE PRECISION MEDICINE IN THIS CLINICALLY HETEROGENEOUS PATIENT GROUP. 2017 6 3015 20 GENETICS AND EPIGENETICS OF CLL. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) HAS A HETEROGENEOUS BIOLOGICAL BEHAVIOR, WHICH IS HIGHLY INFLUENCED BY ITS IMMUNOGENETIC, EPIGENETIC, AND GENOMIC PROPERTIES. THE REMARKABLY VARIABLE CLINICAL COURSE OF THE DISEASE HAS BEEN ASSOCIATED WITH GENETIC FEATURES SUCH AS CHROMOSOMAL ABNORMALITIES, THE PRESENCE OF EITHER HIGH OR LOW NUMBERS OF SOMATIC HYPERMUTATIONS (SHM) IN THE VARIABLE REGION OF THE IMMUNOGLOBULIN HEAVY CHAIN LOCUS (IGHV), AND SOMATIC MUTATIONS OF SEVERAL SPECIFIC DRIVER GENES. NEXT-GENERATION SEQUENCING (NGS) TECHNOLOGIES HAVE PROVIDED A COMPREHENSIVE CHARACTERIZATION OF THE GENOMIC AND EPIGENOMIC LANDSCAPE IN CLL, ELUCIDATING IMPORTANT UNDERLYING MECHANISMS OF THE DISEASE'S BIOLOGY. THE SCOPE OF THIS REVIEW IS TO SUMMARIZE THE MOST RECENT DISCOVERIES ABOUT NOVEL GENETIC AND EPIGENETIC ALTERATIONS, DISCUSSING THEIR IMPACT ON CLINICAL OUTCOMES AND RESPONSE TO CURRENTLY AVAILABLE THERAPY. 2023 7 2695 20 EVOLVING UNDERSTANDING OF THE CLL GENOME. OVER THE PAST FEW YEARS, MASSIVELY PARALLEL SEQUENCING TECHNOLOGIES HAVE REVEALED WITH HIGH RESOLUTION THE TREMENDOUS GENETIC AND EPIGENETIC HETEROGENEITY IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). WE HAVE LEARNED HOW THE MOLECULAR ARCHITECTURE DIFFERS NOT ONLY BETWEEN AFFECTED INDIVIDUALS BUT ALSO WITHIN SAMPLES AND OVER TIME. THESE INSIGHTS HAVE CATALYZED OUR UNDERSTANDING OF THE PATHOBIOLOGY OF CLL AND POINT TO CRITICAL SIGNALING PATHWAYS IN THE DEVELOPMENT AND PROGRESSION OF THE DISEASE. SEVERAL KEY DRIVER ALTERATIONS HAVE BEEN IDENTIFIED, WHICH SERVE TO REFINE PROGNOSTIC SCHEMATA BUT ALSO TO INSPIRE THE DEVELOPMENT OF NEW THERAPEUTIC STRATEGIES. ONGOING ADVANCES IN TECHNOLOGY PROMISE TO FURTHER ELUCIDATE THE MOLECULAR BASIS OF CLL, AND THIS KNOWLEDGE IS ANTICIPATED TO AID US IN UNDERSTANDING AND ADDRESSING THE CLINICAL CHALLENGE PRESENTED BY THE VAST VARIABILITY IN THE CLINICAL COURSE OF PATIENTS WITH CLL. 2014 8 4473 18 MOLECULAR PATHOGENESIS OF CLL AND ITS EVOLUTION. IN SPITE OF BEING THE MOST PREVALENT ADULT LEUKEMIA IN WESTERN COUNTRIES, THE MOLECULAR MECHANISMS DRIVING THE ESTABLISHMENT AND PROGRESSION OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) REMAIN LARGELY UNKNOWN. IN RECENT YEARS, THE USE OF NEXT-GENERATION SEQUENCING TECHNIQUES HAS UNCOVERED NEW AND, IN SOME CASES, UNEXPECTED DRIVER GENES WITH PROGNOSTIC AND THERAPEUTIC VALUE. THE MUTATIONAL LANDSCAPE OF CLL IS CHARACTERIZED BY HIGH-GENETIC AND EPIGENETIC HETEROGENEITY, LOW MUTATION RECURRENCE AND A LONG TAIL OF CASES WITH UNDEFINED DRIVER GENES. ON THE OTHER HAND, THE USE OF DEEP SEQUENCING HAS ALSO REVEALED HIGH INTRA-TUMOR HETEROGENEITY AND PROVIDED A DETAILED PICTURE OF CLONAL EVOLUTION PROCESSES. THIS PHENOMENON, IN WHICH ABERRANT DNA METHYLATION CAN ALSO PARTICIPATE, APPEARS TO BE TIGHTLY ASSOCIATED TO POOR OUTCOMES AND CHEMO-REFRACTORINESS, THUS PROVIDING A NEW SUBJECT FOR THERAPEUTIC INTERVENTION. HENCE, AND HAVING IN MIND THE LIMITATIONS DERIVED FROM THE CLL COMPLEXITY THUS DESCRIBED, THE APPLICATION OF MASSIVELY PARALLEL SEQUENCING STUDIES HAS UNVEILED A WEALTH OF INFORMATION THAT IS EXPECTED TO SUBSTANTIALLY IMPROVE PATIENT STAGING SCHEMES AND CLL CLINICAL MANAGEMENT. 2015 9 3091 22 GENOMIC AND EPIGENOMIC HETEROGENEITY IN CHRONIC LYMPHOCYTIC LEUKEMIA. DEFINING FEATURES OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) ARE NOT ONLY ITS IMMUNOPHENOTYPE OF CD19(+)CD5(+)CD23(+)SIGDIM EXPRESSING CLONAL MATURE B CELLS BUT ALSO ITS HIGHLY VARIABLE CLINICAL COURSE. IN RECENT YEARS, ADVANCES IN MASSIVELY PARALLEL SEQUENCING TECHNOLOGIES HAVE LED TO RAPID PROGRESS IN OUR UNDERSTANDING OF THE CLL GENOME AND EPIGENOME. OVERALL, THESE STUDIES HAVE CLEARLY DEMARCATED NOT ONLY THE VAST DEGREE OF GENETIC AND EPIGENETIC HETEROGENEITY AMONG INDIVIDUALS WITH CLL BUT ALSO EVEN WITHIN INDIVIDUAL PATIENT LEUKEMIAS. WE HEREIN REVIEW THE RAPIDLY GROWING SERIES OF STUDIES ASSESSING THE GENETIC AND EPIGENETIC FEATURES OF CLL WITHIN CLINICALLY DEFINED PERIODS OF ITS GROWTH. THESE STUDIES STRONGLY SUGGEST AN EVOLVING SPECTRUM OF LESIONS OVER TIME AND THAT THESE FEATURES MAY HAVE CLINICAL IMPACT. 2015 10 3089 20 GENOMIC AND EPIGENOMIC ALTERATIONS IN CHRONIC LYMPHOCYTIC LEUKEMIA. CHRONIC LYMPHOCYTIC LEUKEMIA IS A COMMON DISEASE IN WESTERN COUNTRIES AND HAS HETEROGENEOUS CLINICAL BEHAVIOR. THE RELEVANCE OF THE GENETIC BASIS OF THE DISEASE HAS COME TO THE FOREFRONT RECENTLY, WITH GENOME-WIDE STUDIES THAT HAVE PROVIDED A COMPREHENSIVE VIEW OF STRUCTURAL VARIANTS, SOMATIC MUTATIONS, AND DIFFERENT LAYERS OF EPIGENETIC CHANGES. THE MUTATIONAL LANDSCAPE IS CHARACTERIZED BY RELATIVELY COMMON COPY NUMBER ALTERATIONS, A FEW MUTATED GENES OCCURRING IN 10-15% OF CASES, AND A LARGE NUMBER OF GENES MUTATED IN A SMALL NUMBER OF CASES. THE EPIGENOMIC PROFILE HAS REVEALED A MARKED REPROGRAMMING OF REGULATORY REGIONS IN TUMOR CELLS COMPARED WITH NORMAL B CELLS. ALL OF THESE ALTERATIONS ARE DIFFERENTIALLY DISTRIBUTED IN CLINICAL AND BIOLOGICAL SUBSETS OF THE DISEASE, INDICATING THAT THEY MAY UNDERLIE THE HETEROGENEOUS EVOLUTION OF THE DISEASE. THESE GLOBAL STUDIES ARE REVEALING THE MOLECULAR COMPLEXITY OF CHRONIC LYMPHOCYTIC LEUKEMIA AND PROVIDE NEW PERSPECTIVES THAT HAVE HELPED TO UNDERSTAND ITS PATHOGENIC MECHANISMS AND IMPROVE THE CLINICAL MANAGEMENT OF PATIENTS. 2020 11 2944 26 GENETIC AND EPIGENETIC BASIS OF CHRONIC LYMPHOCYTIC LEUKEMIA. PURPOSE OF REVIEW: NEXT-GENERATION SEQUENCING OF WHOLE GENOMES, EXOMES AND DNA METHYLOMES IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) HAS PROVIDED THE FIRST COMPREHENSIVE VIEW OF SOMATIC MUTATIONS AND METHYLATION CHANGES IN THIS DISEASE. THIS REVIEW SUMMARIZES THE RECENT FINDINGS IN THIS FIELD AND THEIR IMPACT ON OUR CURRENT UNDERSTANDING OF THIS NEOPLASM. RECENT FINDINGS: GENOMIC STUDIES HAVE REVEALED A REMARKABLE MOLECULAR HETEROGENEITY OF THE DISEASE, WITH ONLY FEW GENES MUTATED IN UP TO 10-15% OF THE PATIENTS AND A RELATIVELY LARGE NUMBER OF GENES RECURRENTLY MUTATED AT LOW FREQUENCY. THE MUTATED GENES TEND TO CLUSTER IN DIFFERENT PATHWAYS THAT INCLUDE NOTCH1 SIGNALING, RNA SPLICING, PROCESSING AND TRANSPORT MACHINERY, INNATE INFLAMMATORY RESPONSE, AND DNA DAMAGE AND CELL CYCLE CONTROL, AMONG OTHERS. NOTCH1 AND SF3B1 MUTATIONS ARE EMERGING AS NEW DRIVERS OF AGGRESSIVE FORMS OF THE DISEASE. GENOME-WIDE METHYLATION STUDIES HAVE SHOWN THAT CLL TRANSFORMATION IS ASSOCIATED WITH A MASSIVE HYPOMETHYLATION PHENOMENON FREQUENTLY AFFECTING THE ENHANCER REGIONS. THIS EPIGENETIC REPROGRAMMING MAINTAINS AN IMPRINT OF THE PUTATIVE CELL OF ORIGIN FROM NAIVE AND MEMORY B-CELLS. SUMMARY: GENOMIC AND EPIGENOMIC STUDIES OF CLL ARE RESHAPING OUR UNDERSTANDING OF THE DISEASE AND PROVIDE NEW PERSPECTIVE FOR A MORE INDIVIDUALIZED DIAGNOSIS AND NEW POTENTIAL THERAPEUTIC TARGETS. 2013 12 2652 19 EPIGENOMICS OF LEUKEMIA: FROM MECHANISMS TO THERAPEUTIC APPLICATIONS. LEUKEMOGENESIS IS A MULTISTEP PROCESS IN WHICH SUCCESSIVE TRANSFORMATIONAL EVENTS ENHANCE THE ABILITY OF A CLONAL POPULATION ARISING FROM HEMATOPOIETIC PROGENITOR CELLS TO PROLIFERATE, DIFFERENTIATE AND SURVIVE. CLINICALLY AND PATHOLOGICALLY, LEUKEMIA IS SUBDIVIDED INTO FOUR MAIN CATEGORIES: CHRONIC LYMPHOCYTIC LEUKEMIA, CHRONIC MYELOID LEUKEMIA, ACUTE LYMPHOCYTIC LEUKEMIA AND ACUTE MYELOID LEUKEMIA. LEUKEMIA HAS BEEN PREVIOUSLY CONSIDERED ONLY AS A GENETIC DISEASE. HOWEVER, IN RECENT YEARS, SIGNIFICANT ADVANCES HAVE BEEN MADE IN THE ELUCIDATION OF THE LEUKEMOGENESIS-ASSOCIATED PROCESSES. THUS, WE HAVE COME TO UNDERSTAND THAT EPIGENETIC ALTERATIONS INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND MIRNA ARE INVOLVED IN THE PERMANENT CHANGES OF GENE EXPRESSION CONTROLLING THE LEUKEMIA PHENOTYPE. IN THIS ARTICLE, WE WILL FOCUS ON THE EPIGENETIC DEFECTS ASSOCIATED WITH LEUKEMIA AND THEIR IMPLICATIONS AS BIOMARKERS FOR DIAGNOSTIC, PROGNOSTIC AND THERAPEUTIC APPLICATIONS. 2011 13 4320 22 MICRORNAS IN CHRONIC LYMPHOCYTIC LEUKEMIA: AN OLD DISEASE WITH NEW GENETIC INSIGHTS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS THE MOST COMMON LEUKEMIA AMONG ADULT POPULATION IN WESTERN COUNTRY. IN THE LAST DECADE, SEVERAL FINDINGS HAVE SUBSTANTIALLY REVOLUTIONIZED THE OLD CONCEPT THAT CLL IS A DISEASE ORIGINATING FROM MATURE, NOT-DIVIDING CELL WITH INDOLENT CLINICAL COURSE. NOTABLY, NEXT GENERATION SEQUENCING (NGS) HAS CONTRIBUTED TO DEEPEN THE KNOWLEDGE OF THE CELLULAR NETWORKS THAT IMPLY THE ONSET AND THE PROGRESSION OF CLL. AMONG GENETIC ABERRATIONS THAT ARE RECURRENTLY OBSERVED IN B-CELLS FROM PATIENTS WITH CLL, MICRORNA DEREGULATION REPRESENTED THE FIRST EPIGENETIC MECHANISM THAT HAS BEEN IDENTIFIED. THROUGH EPIGENETIC MECHANISM THEY CAN MODULATE GENE EXPRESSION AND INTERFERE WITH CELLULAR PATHWAYS THAT ARE INVOLVED IN CELL CYCLE, APOPTOSIS AND B-CELL RECEPTOR (BCR) ACTIVATION. ALTHOUGH FEW STUDIES HAVE SHOWN THE PROGNOSTIC AND PREDICTIVE VALUE OF MICRORNA EXPRESSION LEVELS, THEIR VALIDATION WITHIN PROSPECTIVE CLINICAL TRIALS IS WARRANTED. 2016 14 2857 21 FROM PATHOGENESIS TO TREATMENT OF CHRONIC LYMPHOCYTIC LEUKAEMIA. CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) HAS SEVERAL UNIQUE FEATURES THAT DISTINGUISH IT FROM OTHER CANCERS. MOST CLL TUMOUR CELLS ARE INERT AND ARRESTED IN G0/G1 OF THE CELL CYCLE AND THERE IS ONLY A SMALL PROLIFERATIVE COMPARTMENT; HOWEVER, THE PROGRESSIVE ACCUMULATION OF MALIGNANT CELLS WILL ULTIMATELY LEAD TO SYMPTOMATIC DISEASE. PATHOGENIC MECHANISMS HAVE BEEN ELUCIDATED THAT INVOLVE MULTIPLE EXTERNAL (FOR EXAMPLE, MICROENVIRONMENTAL STIMULI AND ANTIGENIC DRIVE) AND INTERNAL (GENETIC AND EPIGENETIC) EVENTS THAT ARE CRUCIAL IN THE TRANSFORMATION, PROGRESSION AND EVOLUTION OF CLL. OUR GROWING UNDERSTANDING OF CLL BIOLOGY IS ALLOWING THE TRANSLATION OF TARGETS AND BIOLOGICAL CLASSIFIERS INTO CLINICAL PRACTICE. 2010 15 3768 22 INTEGRATIVE EPIGENOMICS IN CHRONIC LYMPHOCYTIC LEUKAEMIA: BIOLOGICAL INSIGHTS AND CLINICAL APPLICATIONS. CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) IS NOT ONLY CHARACTERISED BY DRIVER GENETIC ALTERATIONS BUT BY EXTENSIVE EPIGENETIC CHANGES. OVER THE LAST DECADE, EPIGENOMIC STUDIES HAVE DESCRIBED THE DNA METHYLOME, CHROMATIN ACCESSIBILITY, HISTONE MODIFICATIONS AND THE THREE-DIMENSIONAL (3D) GENOME ARCHITECTURE OF CLL. BEYOND ITS REGULATORY ROLE, THE DNA METHYLOME CONTAINS IMPRINTS OF THE CELLULAR ORIGIN AND PROLIFERATIVE HISTORY OF CLL CELLS. THESE TWO ASPECTS ARE STRONG INDEPENDENT PROGNOSTIC FACTORS. INTEGRATIVE ANALYSES OF CHROMATIN MARKS HAVE UNCOVERED NOVEL REGULATORY ELEMENTS AND ALTERED TRANSCRIPTION FACTOR NETWORKS AS NON-GENETIC MEANS MEDIATING GENE DEREGULATION IN CLL. ADDITIONALLY, CLL CELLS DISPLAY A DISEASE-SPECIFIC PATTERN OF 3D GENOME INTERACTIONS. FROM THE TECHNOLOGICAL PERSPECTIVE, WE ARE CURRENTLY WITNESSING A TRANSITION FROM BULK OMICS TO SINGLE-CELL ANALYSES. THIS REVIEW AIMS AT SUMMARISING THE MAJOR FINDINGS FROM THE EPIGENOMICS FIELD AS WELL AS PROVIDING A PROSPECT OF THE PRESENT AND FUTURE OF SINGLE-CELL ANALYSES IN CLL. 2023 16 5913 16 TARGETED THERAPY IN LEUKEMIA. RESEARCH CONDUCTED OVER THE LAST TWO DECADES HAS YIELDED A DETAILED UNDERSTANDING OF THE MOLECULAR LESIONS THAT CONTRIBUTE TO THE MALIGNANT TRANSFORMATION OF HEMATOPOIETIC STEM CELLS AND COMMITTED PROGENITORS INTO THE VARIOUS FORMS OF ACUTE AND CHRONIC LEUKEMIA. ALTHOUGH OUR UNDERSTANDING OF THE MOLECULAR PATHOLOGY OF LEUKEMIA REMAINS INCOMPLETE, THE INFORMATION GAINED TO DATE HAS HAD A PROFOUND IMPACT ON THE WAY THESE MALIGNANCIES ARE BOTH DIAGNOSED AND MONITORED DURING THERAPY. MORE RECENTLY, TARGETED THERAPIES HAVE BEEN DEVELOPED AGAINST SOME OF THE IDENTIFIED GENETIC LESIONS. THESE THERAPIES HAVE LED TO SIGNIFICANT IMPROVEMENTS IN PATIENT OUTCOMES WHILE SIMULTANEOUSLY DECREASING THERAPY-RELATED TOXICITY. WITH THE ADVENT OF GENOME-WIDE METHODS TO DEFINE THE TOTAL COMPLEMENT OF GENETIC AND EPIGENETIC LESIONS INVOLVED IN LEUKEMOGENESIS, NEW TARGETED THERAPIES CAN BE ANTICIPATED. THIS REVIEW HIGHLIGHTS SOME OF THE TARGETED THERAPIES THAT ARE PRESENTLY BEING USED TO TREAT HEMATOPOIETIC MALIGNANCIES AND DESCRIBES SOME OF THE RECENT ADVANCES THAT SHOULD HAVE A SIGNIFICANT IMPACT ON THE DEVELOPMENT OF FUTURE TARGET THERAPIES. 2008 17 467 25 ARE WE FINALLY GETTING PERSONAL? MOVING TOWARDS A PERSONALIZED APPROACH IN CHRONIC LYMPHOCYTIC LEUKEMIA. WITH ITS HETEROGENEOUS BIOLOGICAL FEATURES AND CLINICAL COURSE, CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), THE MOST FREQUENT ADULT LEUKEMIA IN THE WESTERN WORLD, IS A PARADIGMATIC CONDITION REQUIRING A TAILORED APPROACH AND A PRECISE KNOWLEDGE OF THE BIOLOGY BEHIND EACH INDIVIDUAL PATIENT. THIS PERSONALIZED MANAGEMENT IS BECOMING EVEN MORE CRUCIAL, SINCE, AFTER DECADES OF PRECLINICAL WORK UNRAVELLING THE KEY ROLE OF THE B-CELL RECEPTOR (BCR) SIGNALLING PATHWAYS AND THE ANTI-APOPTOTIC MECHANISMS IN CLL CELL SURVIVAL AND PROLIFERATION, WE HAVE NOW BCR AND BCL2 INHIBITORS AVAILABLE IN CLINICAL PRACTICE. THANKS TO THIS, WE ARE NOW ABLE TO EXPLOIT SPECIFIC BIOMARKERS TO TAILOR OUR TREATMENT STRATEGIES AND IMPROVE LONG-TERM DISEASE CONTROL, PATIENT OUTCOME AND QUALITY OF LIFE. THAT NOTWITHSTANDING, AS THE DISEASE ITSELF REMAINS INCURABLE, NOVEL CHALLENGES AND UNMET CLINICAL NEEDS HAVE RISEN FROM THE INTRODUCTION OF NOVEL TARGETED AGENTS, INCLUDING MECHANISMS OF RESISTANCE AT BOTH GENETIC AND EPIGENETIC LEVELS. IN THIS REVIEW, WE SUMMARIZE THE CURRENTLY ESTABLISHED PREDICTIVE BIOMARKERS (I.E. IGHV MUTATION STATUS AND TP53 GENE DISRUPTION) THAT SHOULD BE APPLIED IN CLINICAL PRACTICE TO INFORM TREATMENT DECISION IN 2021 BUT ALSO DISCUSS THE MOST PROMISING PROGNOSTIC BIOMARKERS (B-CELL RECEPTOR STEREOTYPY, COMPLEX KARYOTYPE, SOMATIC GENE MUTATIONS, MEASURABLE RESIDUAL DISEASE - MRD) THAT MIGHT BECOME KEY TO DEFINE THE MANAGEMENT OF OUR PATIENTS IN A NEAR FUTURE. 2022 18 3565 22 IMPACT OF GENETIC POLYMORPHISMS AND BIOMARKERS ON THE EFFECTIVENESS AND TOXICITY OF TREATMENT OF CHRONIC MYELOID LEUKEMIA AND ACUTE MYELOID LEUKEMIA. MOST MALIGNANT HEMATOLOGICAL DISEASES ARE GENERALLY A CONSEQUENCE OF ACQUIRED MUTATIONS OR REARRANGEMENTS IN CELL REPLICATION PROCESSES. ACUTE MYELOID LEUKEMIA (AML) IS A CLINICALLY AND MOLECULARLY HETEROGENEOUS DISEASE THAT RESULTS FROM ACQUIRED GENETIC AND EPIGENETIC ALTERATIONS IN HEMATOPOIETIC PROGENITOR CELLS. DESPITE THE ADVANCES MADE IN UNDERSTANDING THE PATHOGENESIS OF THIS DISEASE, THE OVERALL SURVIVAL OF PATIENTS REMAINS VERY LOW DUE TO THE HIGH RELAPSE RATE. PHARMACOGENETICS AND MASSIVE SEQUENCING STUDIES HAVE ALLOWED THE IDENTIFICATION OF NEW RECURRENT MUTATIONS WITH SIGNIFICANT PROGNOSTIC IMPACT IN AML; FURTHERMORE, IT SEEMS LIKELY THAT WHOLE GENOME SEQUENCING WILL SOON BECOME A STANDARD DIAGNOSTIC TEST, WHICH WILL ALLOW THE MOLECULAR DIAGNOSIS OF PATIENTS. THEREFORE, IT IS NECESSARY TO DEVELOP MOLECULAR TARGETS THAT OPEN NEW THERAPEUTIC PERSPECTIVES AND ALLOW INDIVIDUALIZED TREATMENT OF PATIENTS WITH THIS AGGRESSIVE DISEASE. CHRONIC MYELOID LEUKEMIA (CML) IS THE FIRST NEOPLASTIC DISEASE FOR WHICH A CHARACTERISTIC GENETIC ALTERATION WAS DESCRIBED. IT HAS, BY DEFINITION, A GENETIC MARKER, THE BCR::ABL1 REARRANGEMENT, AS A CONSEQUENCE OF THE T9;22(Q34;Q11) TRANSLOCATION. ITS STUDY IS ESSENTIAL FOR THE DIAGNOSIS OF THIS ENTITY AND ALSO FOR MONITORING THE RESPONSE TO TREATMENT. DRUGS KNOWN AS TYROSINE KINASE INHIBITORS (TKIS) THAT TARGET THE BCR::ABL1 PROTEIN (ORAL TARGETED THERAPY) ARE THE CONVENTIONAL TREATMENT OF CML, REPRESENTING A CHANGE OF PARADIGM IN THE MANAGEMENT OF ONCOHEMATOLOGICAL PATIENTS. 2022 19 2535 17 EPIGENETICS IN CHRONIC LYMPHOCYTIC LEUKEMIA. ENORMOUS EVIDENCE HAS ACCUMULATED IN THE PAST DECADES THAT ESTABLISHES THE IMPORTANCE OF EPIGENETIC MODIFICATIONS IN CANCER AND HAS RESULTED IN SHIFTING THE FOCUS FROM ENTIRELY GENETIC-BASED STUDIES TO INTEGRATED STUDIES INVOLVING BOTH GENETIC AND EPIGENETIC ALTERATIONS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS ONE SUCH EXAMPLE WHERE STUDIES INVOLVING EPIGENETIC ABERRATIONS HAVE ACCELERATED THE SEARCH FOR AFFECTED GENES, WHICH WAS INITIALLY RESTRICTED TO COMMONLY DELETED CHROMOSOMAL REGIONS. MANY NOVEL GENES THAT ARE EPIGENETICALLY SILENCED IN CLL HAVE BEEN IDENTIFIED. ADVANCES IN THE UNDERSTANDING OF POST-TRANSLATIONAL HISTONE MODIFICATIONS AND DNA METHYLATION IN NORMAL AND IN CLL CELLS HAVE PROVEN TO BE EXTREMELY BENEFICIAL IN FINDING POWERFUL DIAGNOSTIC MARKERS, AS WELL AS IN EXPLORING NOVEL THERAPIES. AT PRESENT, THE FIELD OF EPIGENETICS IS AT AN EVOLVING STAGE, BUT THERE IS NO DOUBT THAT FURTHER UNRAVELING OF ITS CAUSE AND EFFECTS IN TRANSFORMED CELLS WILL BRING A NEW REVOLUTION IN CANCER THERAPEUTICS. 2006 20 6588 25 TUMOR HETEROGENEITY IN LYMPHOMAS: A DIFFERENT BREED. THE FACTS THAT CANCER REPRESENTS TISSUES CONSISTING OF HETEROGENEOUS NEOPLASTIC, AS WELL AS REACTIVE, CELL POPULATIONS AND THAT CANCERS OF THE SAME HISTOTYPE MAY SHOW PROFOUND DIFFERENCES IN CLINICAL BEHAVIOR HAVE LONG BEEN RECOGNIZED. WITH THE ADVENT OF NEW TECHNOLOGIES AND THE DEMANDS OF PRECISION MEDICINE, THE INVESTIGATION OF TUMOR HETEROGENEITY HAS GAINED MUCH INTEREST. AN UNDERSTANDING OF INTERTUMORAL HETEROGENEITY IN PATIENTS WITH THE SAME DISEASE ENTITY IS NECESSARY TO OPTIMALLY GUIDE PERSONALIZED TREATMENT. IN ADDITION, INCREASING EVIDENCE INDICATES THAT DIFFERENT TUMOR AREAS OR PRIMARY TUMORS AND METASTASES IN AN INDIVIDUAL PATIENT CAN SHOW SIGNIFICANT INTRATUMORAL HETEROGENEITY ON DIFFERENT LEVELS. THIS PHENOMENON CAN BE DRIVEN BY GENOMIC INSTABILITY, EPIGENETIC EVENTS, THE TUMOR MICROENVIRONMENT, AND STOCHASTIC VARIATIONS IN CELLULAR FUNCTION AND ANTITUMORAL THERAPIES. THESE MECHANISMS MAY LEAD TO BRANCHED SUBCLONAL EVOLUTION FROM A COMMON PROGENITOR CLONE, RESULTING IN SPATIAL VARIATION BETWEEN DIFFERENT TUMOR SITES, DISEASE PROGRESSION, AND TREATMENT RESISTANCE. THIS REVIEW ADDRESSES TUMOR HETEROGENEITY IN LYMPHOMAS FROM A PATHOLOGIST'S VIEWPOINT. THE RELATIONSHIP BETWEEN MORPHOLOGIC, IMMUNOPHENOTYPIC, AND GENETIC HETEROGENEITY IS EXEMPLIFIED IN DIFFERENT LYMPHOMA ENTITIES AND REVIEWED IN THE CONTEXT OF HIGH-GRADE TRANSFORMATION AND TRANSDIFFERENTIATION. IN ADDITION, FACTORS DRIVING HETEROGENEITY, AS WELL AS CLINICAL AND THERAPEUTIC IMPLICATIONS OF LYMPHOMA HETEROGENEITY, WILL BE DISCUSSED. 2018