1 1481 97 DIVERSITY OF GENOME PROFILES IN MALIGNANT LYMPHOMA. CHARACTERISTIC CHROMOSOME TRANSLOCATIONS ARE ASSOCIATED WITH SPECIFIC DISEASE ENTITIES, AND ARE KNOWN TO PLAY A PIVOTAL ROLE IN LYMPHOMA DEVELOPMENT. CHROMOSOME TRANSLOCATION ALONE, HOWEVER, IS NOT SUFFICIENT TO PRODUCE TUMORS. FACTORS INCLUDING THE MICROENVIRONMENT AND EPIGENETIC AND GENETIC ALTERATIONS OTHER THAN CHROMOSOME TRANSLOCATIONS HAVE BEEN SHOWN TO PLAY A ROLE IN LYMPHOMA DEVELOPMENT. FOLLICULAR LYMPHOMA CELLS PROLIFERATE IN CLOSE CONTACT WITH FOLLICULAR DENDRITIC CELLS. MUCOSA-ASSOCIATED LYMPHOID TISSUE (MALT) LYMPHOMA CELLS PROLIFERATE AT THE MARGINAL ZONE AREA OF REACTIVE FOLLICLES WHICH ARE FORMED BY PRECEDING CHRONIC INFLAMMATION. THE IMPORTANCE OF GENETIC ALTERATIONS OTHER THAN CHROMOSOME TRANSLOCATION HAS BEEN RECOGNIZED SINCE THE INTRODUCTION OF ARRAY COMPARATIVE GENOMIC HYBRIDIZATION (ARRAY CGH). VARIATIONS IN THE GENOMIC PROFILE AMONG PATIENTS WITH THE SAME DISEASE ENTITY HAVE BEEN FOUND BY ARRAY CGH ANALYSES. THESE VARIATIONS INDICATE THAT MULTIPLE GENETIC PATHWAYS LEADING TO THE DEVELOPMENT OF LYMPHOMAS MAY EXIST AND HENCE RESULT IN THE VARIABLE CLINICOPATHOLOGICAL FEATURES OBSERVED. 2010 2 3089 28 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 3 606 25 BEYOND GENETICS--THE EMERGING ROLE OF EPIGENETIC CHANGES IN HEMATOPOIETIC MALIGNANCIES. THE TERM EPIGENETIC REFERS TO A HERITABLE CHANGE IN GENE EXPRESSION THAT IS MEDIATED BY MECHANISMS OTHER THAN ALTERATIONS IN THE PRIMARY NUCLEOTIDE SEQUENCE. DNA METHYLATION AT CYTOSINE BASES THAT ARE LOCATED 5' TO GUANOSINE WITHIN A CPG DINUCLEOTIDE IS THE MAIN EPIGENETIC MODIFICATION IN HUMANS. PATTERNS OF DNA METHYLATION ARE PROFOUNDLY DERANGED IN HUMAN CANCER AND COMPRISE GENOME-WIDE LOSSES AS WELL AS REGIONAL GAINS IN DNA METHYLATION. HYPERMETHYLATION OF CPG ISLANDS WITHIN GENE PROMOTER REGIONS IS ASSOCIATED WITH TRANSCRIPTIONAL INACTIVATION AND REPRESENTS, IN ADDITION TO GENETIC ABERRATIONS, AN IMPORTANT MECHANISM OF GENE SILENCING IN THE PATHOGENESIS OF HEMATOPOIETIC MALIGNANCIES. THIS EPIGENETIC PHENOMENON ACTS AS AN ALTERNATIVE TO MUTATIONS AND DELETIONS TO DISRUPT TUMOR SUPPRESSOR GENE FUNCTION. A LARGE NUMBER OF GENES INVOLVING FUNDAMENTAL CELLULAR PATHWAYS MAY BE AFFECTED IN VIRTUALLY ALL TYPES OF HUMAN CANCER BY ABERRANT CPG ISLAND METHYLATION IN ASSOCIATION WITH TRANSCRIPTIONAL SILENCING. ALTERED METHYLATION PATTERNS CAN BE USED AS BIOMARKERS FOR CANCER DETECTION, ASSESSMENT OF PROGNOSIS, AND PREDICTION OF RESPONSE TO ANTITUMOR TREATMENT. FURTHERMORE, CLINICAL TRIALS USING EPIGENETICALLY TARGETED THERAPIES HAVE YIELDED PROMISING RESULTS FOR ACUTE AND CHRONIC LEUKEMIAS AS WELL AS FOR MYELODYSPLASTIC SYNDROMES. THE EXPLORATION OF OUR GROWING KNOWLEDGE ABOUT EPIGENETIC ABERRATIONS MAY HELP DEVELOP NOVEL STRATEGIES FOR THE DIAGNOSIS AND TREATMENT OF HEMATOPOIETIC MALIGNANCIES IN THE FUTURE. 2004 4 2992 36 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 5 2074 26 EPIGENETIC DEREGULATION IN CHRONIC LYMPHOCYTIC LEUKEMIA: CLINICAL AND BIOLOGICAL IMPACT. DEREGULATED TRANSCRIPTIONAL CONTROL CAUSED BY ABERRANT DNA METHYLATION AND/OR HISTONE MODIFICATIONS IS A HALLMARK OF CANCER CELLS. IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), THE MOST COMMON ADULT LEUKEMIA, THE EPIGENETIC 'LANDSCAPE' HAS ADDED A NEW LAYER OF COMPLEXITY TO OUR UNDERSTANDING OF THIS CLINICALLY AND BIOLOGICALLY HETEROGENEOUS DISEASE. EARLY STUDIES IDENTIFIED ABERRANT DNA METHYLATION, OFTEN BASED ON SINGLE GENE PROMOTER ANALYSIS WITH BOTH BIOLOGICAL AND CLINICAL IMPACT. SUBSEQUENT GENOME-WIDE PROFILING STUDIES REVEALED DIFFERENTIAL DNA METHYLATION BETWEEN CLLS AND CONTROLS AND IN PROGNOSTICS SUBGROUPS OF THE DISEASE. FROM THESE STUDIES, IT BECAME APPARENT THAT DNA METHYLATION IN REGIONS OUTSIDE OF PROMOTERS, SUCH AS ENHANCERS, IS IMPORTANT FOR THE REGULATION OF CODING GENES AS WELL AS FOR THE REGULATION OF NON-CODING RNAS. ALTHOUGH DNA METHYLATION PROFILES ARE REPORTEDLY STABLE OVER TIME AND IN RELATION TO THERAPY, A HIGHER EPIGENETIC HETEROGENEITY OR 'BURDEN' IS SEEN IN MORE AGGRESSIVE CLL SUBGROUPS, ALBEIT AS NON-RECURRENT 'PASSENGER' EVENTS. MORE RECENTLY, DNA METHYLATION PROFILES IN CLL ANALYZED IN RELATION TO DIFFERENTIATING NORMAL B-CELL POPULATIONS REVEALED THAT THE MAJORITY OF THE CLL EPIGENOME REFLECTS THE EPIGENOMES PRESENT IN THE CELL OF ORIGIN AND THAT ONLY A SMALL FRACTION OF THE EPIGENETIC ALTERATIONS REPRESENTS TRULY CLL-SPECIFIC CHANGES. FURTHERMORE, CLL PATIENTS CAN BE GROUPED INTO AT LEAST THREE CLINICALLY RELEVANT EPIGENETIC SUBGROUPS, POTENTIALLY ORIGINATING FROM DIFFERENT CELLS AT VARIOUS STAGES OF DIFFERENTIATION AND ASSOCIATED WITH DISTINCT OUTCOMES. IN THIS REVIEW, WE SUMMARIZE THE CURRENT UNDERSTANDING OF THE DNA METHYLOME IN CLL, THE ROLE OF HISTONE MODIFYING ENZYMES, HIGHLIGHT INSIGHTS DERIVED FROM ANIMAL MODELS AND ATTEMPTS MADE TO TARGET EPIGENETIC REGULATORS IN CLL ALONG WITH THE FUTURE DIRECTIONS OF THIS RAPIDLY ADVANCING FIELD. 2018 6 6854 25 [NEW ADVANCES OF EPIGENETIC STUDY IN TUMORS OF LYMPHATIC SYSTEM---REVIEW]. EPIGENETICS IS AIMED TO STUDY THE HERITABLE CHANGES IN GENE EXPRESSION PATTERNS INDEPENDENT OF ALTERATIONS IN GENOMIC DNA SEQUENCE STRUCTURE, AND THE MECHANISMS OF TRANSLATION FROM GENOTYPE TO PHENOTYPE. IN RECENT YEARS, COMPELLING EVIDENCE GATHERED SUPPORTS A ROLE OF EPIGENETIC ALTERATIONS IN THE PATHOGENESIS OF LYMPHATIC SYSTEM TUMORS. FOR EXAMPLE, RECENT DATA FROM MULTIPLE LABORATORIES INDICATE THAT SEVERAL HUNDRED GENES, INVOLVING DOZENS OF CRITICAL MOLECULAR PATHWAYS, ARE EPIGENETICALLY SUPPRESSED IN ACUTE LYMPHOCYTIC LEUKEMIA; A PANEL OF METHYLATION MARKERS CAN BE USED FOR ADDITIONAL RISK STRATIFICATION OF CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS; BASED ON THE EPIGENETIC PROFILES, THE CLASS PREDICTION MODELS IN GRAY ZONE LYMPHOMA CAN BE ESTABLISHED; THE EPIGENETIC SILENCING OF MICRORNAS IN MULTIPLE MYELOMA GENERALLY APPEARS TO HAVE INTACT P53 FUNCTION; EPIGENETIC THERAPIES HAVE BROADER IMPLICATION AND HIGH POTENTIAL FOR THE DEVELOPMENT OF IMMUNOTHERAPEUTIC STRATEGIES AND SO ON. IN THIS REVIEW, THE LATEST ADVANCES OF EPIGENETIC STUDY AND THE PROSPECT OF EPIGENETIC THERAPY FOR TUMORS IN LYMPHATIC SYSTEM ARE SUMMARIZED. 2012 7 6616 31 UNCOVERING THE DNA METHYLOME IN CHRONIC LYMPHOCYTIC LEUKEMIA. OVER THE PAST TWO DECADES, ABERRANT DNA METHYLATION HAS EMERGED AS A KEY PLAYER IN THE PATHOGENESIS OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), AND KNOWLEDGE REGARDING ITS BIOLOGICAL AND CLINICAL CONSEQUENCES IN THIS DISEASE HAS EVOLVED RAPIDLY. SINCE THE INITIAL STUDIES RELATING DNA HYPOMETHYLATION TO GENOMIC INSTABILITY IN CLL, A PLETHORA OF REPORTS HAVE FOLLOWED SHOWING THE IMPACT OF DNA HYPERMETHYLATION IN SILENCING VITAL SINGLE GENE PROMOTERS AND THE REVERSIBLE NATURE OF DNA METHYLATION THROUGH INHIBITOR DRUGS. WITH THE RECOGNITION THAT DNA HYPERMETHYLATION EVENTS COULD POTENTIALLY ACT AS NOVEL PROGNOSTIC AND TREATMENT TARGETS IN CLL, THE SEARCH FOR ABERRANTLY METHYLATED GENES, GENE FAMILIES AND PATHWAYS HAS ENSUED. SUBSEQUENTLY, THE ADVENT OF MICROARRAY AND NEXT-GENERATION SEQUENCING TECHNOLOGIES HAS SUPPORTED THE HUNT FOR SUCH TARGETS, ALLOWING EXPLORATION OF THE METHYLATION LANDSCAPE IN CLL AT AN UNPRECEDENTED SCALE. IN LIGHT OF THESE ANALYSES, WE NOW UNDERSTAND THAT DIFFERENT CLL PROGNOSTIC SUBGROUPS ARE CHARACTERIZED BY DIFFERENTIAL METHYLATION PROFILES; WE RECOGNIZE DNA METHYLATION OF A NUMBER OF SIGNALING PATHWAYS GENES TO BE ALTERED IN CLL, AND ACKNOWLEDGE THE ROLE OF DNA METHYLATION OUTSIDE OF TRADITIONAL CPG ISLAND PROMOTERS AS FUNDAMENTAL PLAYERS IN THE REGULATION OF GENE EXPRESSION. TODAY, THE SIGNIFICANCE AND TIMING OF ALTERED DNA METHYLATION WITHIN THE COMPLEX EPIGENETIC NETWORK OF CONCOMITANT EPIGENETIC MESSENGERS SUCH AS HISTONES AND MIRNAS IS AN INTENSIVE AREA OF RESEARCH. IN CLL, IT APPEARS THAT DNA METHYLATION IS A RATHER STABLE EPIGENETIC MARK OCCURRING RATHER EARLY IN THE DISEASE PATHOGENESIS. HOWEVER, OTHER CONSEQUENCES, SUCH AS HOW AND WHY ABERRANT METHYLATION MARKS OCCUR, ARE LESS EXPLORED. IN THIS REVIEW, WE WILL NOT ONLY PROVIDE A COMPREHENSIVE SUMMARY OF THE CURRENT LITERATURE WITHIN THE EPIGENETICS FIELD OF CLL, BUT ALSO HIGHLIGHT SOME OF THE NOVEL FINDINGS RELATING TO WHEN, WHERE, WHY AND HOW ALTERED DNA METHYLATION MATERIALIZES IN CLL. 2013 8 2494 23 EPIGENETICS AND CHRONIC LYMPHOCYTIC LEUKEMIA. THE DNA METHYLATION LEVEL IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA IS GENERALLY LOWER THAN HEALTHY INDIVIDUALS. ALTHOUGH DNA METHYLATION IS GLOBALLY DECREASED, REGIONAL HYPERMETHYLATION OF GENE PROMOTERS LEADS TO GENE SILENCING. MANY OF THESE GENES HAVE TUMOR SUPPRESSOR PHENOTYPES. UNLIKE MUTATIONS OR DELETIONS, HYPERMETHYLATION IS POTENTIALLY REVERSIBLE AFTER INHIBITION WITH DNA METHYLATION MODULATORS. MYELODYSPLASTIC SYNDROME HAS BEEN A MODEL DISEASE IN WHICH TREATMENT OF PATIENTS RESULTS IN DEMETHYLATION OF SPECIFIC GENES. THE STORY IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA IS SLOWLY UNRAVELING AS EPIGENETIC MODIFICATIONS LIKELY ALSO PLAY AN IMPORTANT ROLE. ONGOING CLINICAL TRIALS CORRELATING CLINICAL RESPONSE TO GENE EXPRESSION AFTER TREATMENT WITH DNA METHYLATION INHIBITORS WILL ULTIMATELY ALLOW US TO BETTER RISK STRATIFY AND PREDICT THE SUBGROUP OF PATIENTS WHO WILL BENEFIT FROM TREATMENT WITH THIS CLASS OF DRUGS. 2006 9 4426 35 MOLECULAR BASIS OF CHRONIC LYMPHOCYTIC LEUKEMIA DIAGNOSIS AND PROGNOSIS. BACKGROUNDS: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS THE MOST COMMON TYPE OF LEUKEMIA IN ADULTS AND IS CHARACTERIZED BY A CLONAL ACCUMULATION OF MATURE APOPTOSIS-RESISTANT NEOPLASTIC CELLS. IT IS ALSO A HETEROGENEOUS DISEASE WITH A VARIABLE CLINICAL OUTCOME. HERE, WE PRESENT A REVIEW OF CURRENTLY KNOWN (EPI)GENETIC ALTERATIONS THAT ARE RELATED TO THE ETIOLOGY, PROGRESSION AND CHEMO-REFRACTORINESS OF CLL. RELEVANT LITERATURE WAS IDENTIFIED THROUGH A PUBMED SEARCH (1994-2014) OF ENGLISH-LANGUAGE PAPERS USING THE TERMS CLL, SIGNALING PATHWAY, CYTOGENETIC ABNORMALITY, SOMATIC MUTATION, EPIGENETIC ALTERATION AND MICRO-RNA. RESULTS: CLL IS CHARACTERIZED BY THE PRESENCE OF GROSS CHROMOSOMAL ABNORMALITIES, EPIGENETIC ALTERATIONS, MICRO-RNA EXPRESSION ALTERATIONS, IMMUNOGLOBULIN HEAVY CHAIN GENE MUTATIONS AND OTHER GENETIC LESIONS. THE EXPRESSION OF UNMUTATED IMMUNOGLOBULIN HEAVY CHAIN VARIABLE REGION (IGHV) GENES, ZAP-70 AND CD38 PROTEINS, THE OCCURRENCE OF CHROMOSOMAL ABNORMALITIES SUCH AS 17P AND 11Q DELETIONS AND MUTATIONS OF THE NOTCH1, SF3B1 AND BIRC3 GENES HAVE BEEN ASSOCIATED WITH A POOR PROGNOSIS. IN ADDITION, MUTATIONS IN TUMOR SUPPRESSOR GENES, SUCH AS TP53 AND ATM, HAVE BEEN ASSOCIATED WITH REFRACTORINESS TO CONVENTIONAL CHEMOTHERAPEUTIC AGENTS. MICRO-RNA EXPRESSION ALTERATIONS AND ABERRANT METHYLATION PATTERNS IN GENES THAT ARE SPECIFICALLY DEREGULATED IN CLL, INCLUDING THE BCL-2, TCL1 AND ZAP-70 GENES, HAVE ALSO BEEN ENCOUNTERED AND LINKED TO DISTINCT CLINICAL PARAMETERS. CONCLUSIONS: SPECIFIC CHROMOSOMAL ABNORMALITIES AND GENE MUTATIONS MAY SERVE AS DIAGNOSTIC AND PROGNOSTIC INDICATORS FOR DISEASE PROGRESSION AND SURVIVAL. THE IDENTIFICATION OF THESE ANOMALIES BY STATE-OF-THE-ART MOLECULAR (CYTO)GENETIC TECHNIQUES SUCH AS FLUORESCENCE IN SITU HYBRIDIZATION (FISH), COMPARATIVE GENOMIC HYBRIDIZATION (CGH), SINGLE NUCLEOTIDE POLYMORPHISM (SNP) MICROARRAY-BASED GENOMIC PROFILING AND NEXT-GENERATION SEQUENCING (NGS) CAN BE OF PARAMOUNT HELP FOR THE CLINICAL MANAGEMENT OF THESE PATIENTS, INCLUDING OPTIMAL TREATMENT DESIGN. THE EFFICACY OF NOVEL THERAPEUTICS SHOULD TO BE TESTED ACCORDING TO THE PRESENCE OF THESE MOLECULAR LESIONS IN CLL PATIENTS. 2015 10 3015 27 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 11 147 29 ABERRANT EPIGENETIC GENE REGULATION IN LYMPHOID MALIGNANCIES. IN LYMPHOID MALIGNANCIES, ABERRANT EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION AND HISTONE MODIFICATIONS INFLUENCE CHROMATIN ARCHITECTURE AND CAN RESULT IN ALTERED GENE EXPRESSION. THESE ALTERATIONS COMMONLY AFFECT GENES THAT PLAY IMPORTANT ROLES IN THE CELL CYCLE, APOPTOSIS, AND DNA REPAIR IN NON-HODGKIN LYMPHOMA (NHL). THE ABILITY TO IDENTIFY EPIGENETIC MODIFICATIONS TO THESE IMPORTANT GENES HAS INCREASED EXPONENTIALLY DUE TO ADVANCES IN TECHNOLOGY. AS A RESULT, THERE ARE WELL-DEFINED, GENE-SPECIFIC EPIGENETIC ABERRATIONS ASSOCIATED WITH NHL COMPRISING FOLLICULAR LYMPHOMA (FL), MANTLE CELL LYMPHOMA (MCL), CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), AND DIFFUSE LARGE B-CELL LYMPHOMA (DLBCL). THE IDENTIFICATION OF THESE GENES IS IMPORTANT BECAUSE THEY MAY BE USED AS BIOMARKERS FOR PROGNOSIS, DIAGNOSIS AND IN DEVELOPING IMPROVED TREATMENT STRATEGIES. ALSO IMPORTANT, IN THE CONTROL OF GENE EXPRESSION, IS THE PACKAGING OF DNA WITHIN THE NUCLEUS OF A CELL. THIS PACKAGING CAN BE DISTORTED BY EPIGENETIC ALTERATIONS AND MAY ALTER THE ACCESSIBILITY OF CERTAIN REGIONS OF THE GENOME IN CANCER CELLS. THIS REVIEW DISCUSSES THE IMPACT OF KNOWN EPIGENETIC ABERRATION ON THE REGULATION OF GENE EXPRESSION IN NHL AND PROVIDES INSIGHT INTO THE SPATIAL CONFORMATION OF THE GENOME (DNA PACKAGING) IN ACUTE LYMPHOBLASTIC LEUKEMIA. 2013 12 4678 34 NEW MOLECULAR MARKERS IN RESISTANT B-CLL. B-CHRONIC LYMPHOCYTIC LEUKEMIA (B-CLL) IS CHARACTERIZED BY A HIGHLY VARIABLE CLINICAL COURSE WHICH HAS LONG REMAINED A STUMBLING BLOCK FOR CLINICIANS. THIS VARIABILITY APPEARS TO ARISE FROM COMPLEX MOLECULAR ALTERATIONS IDENTIFIED IN MALIGNANT CELLS FROM PATIENT SUBSETS. RECENT STUDIES HAVE FOCUSED IN PARTICULAR ON IDENTIFYING NEW MOLECULAR MARKERS TO HELP PREDICT THE MOST EFFECTIVE AND ADAPTED TREATMENTS. IN ADDITION TO THE MUTATION STATUS OF IMMUNOGLOBULIN VARIABLE HEAVY-CHAIN REGION (IGVH) GENES, WHICH IS A WELL-ESTABLISHED PREDICTIVE FACTOR IN B-CLL, THESE NEW MARKERS INCLUDE DEFECTS OF CELL FACTORS INVOLVED IN THE MAINTENANCE OF GENOME STABILITY, SUCH AS TELOMERE FUNCTION, DNA REPAIR, ATM AND P53. OTHER PREDICTIVE FACTORS, SUCH AS TYROSINE KINASE ZAP-70 AND SOLUBLE FACTORS FOUND IN PATIENT SERA, MAY BE ASSOCIATED WITH B-CELL RECEPTOR SIGNAL TRANSDUCTION. INTERESTINGLY, AN ALTERATION OF THESE FACTORS FITS CLOSELY, THOUGH NOT STRIKINGLY, WITH THE ABSENCE OF SOMATIC MUTATIONS IN IGVH GENES, SUGGESTING THAT THE LATTER MAY BE DUE EITHER TO EPIGENETIC EVENTS LEADING TO AN UNSTABLE GENOME OR TO AN INHERITED DEFECT IN THE IMMUNE RESPONSE OF MALIGNANT B-CELLS. RECENT LESSONS FROM ZAP-70 EXPRESSION/PHOSPHORYLATION SUGGEST THAT SOME OF THESE MARKERS MAY REFLECT THE DEFECTIVE PATHWAYS IN B-CLL CELLS RATHER THAN BEING MARKERS OF CELL MALIGNANCY PER SE. FURTHERMORE, SPECIFIC SUBSETS OF MARKERS ARE FOUND IN PATIENT CELLS RESISTANT TO TREATMENT. CURRENT STUDIES ON GENE EXPRESSION PROFILING AND PROTEOMIC ANALYSES SHOULD SOON LEAD TO A BETTER UNDERSTANDING OF HOW THESE PATHWAYS ARE AFFECTED, ESPECIALLY IN MULTI-DRUG RESISTANT B-CLL. 2006 13 2535 22 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 14 2033 26 EPIGENETIC CHANGES IN SOLID AND HEMATOPOIETIC TUMORS. THERE ARE THREE CONNECTED MOLECULAR MECHANISMS OF EPIGENETIC CELLULAR MEMORY IN MAMMALIAN CELLS: DNA METHYLATION, HISTONE MODIFICATIONS, AND RNA INTERFERENCE. THE FIRST TWO HAVE NOW BEEN FIRMLY LINKED TO NEOPLASTIC TRANSFORMATION. HYPERMETHYLATION OF CPG-RICH PROMOTERS TRIGGERS LOCAL HISTONE CODE MODIFICATIONS RESULTING IN A CELLULAR CAMOUFLAGE MECHANISM THAT SEQUESTERS GENE PROMOTERS AWAY FROM TRANSCRIPTION FACTORS AND RESULTS IN STABLE SILENCING. THIS NORMALLY RESTRICTED MECHANISM IS UBIQUITOUSLY USED IN CANCER TO SILENCE HUNDREDS OF GENES, AMONG WHICH SOME CRITICALLY CONTRIBUTE TO THE NEOPLASTIC PHENOTYPE. VIRTUALLY EVERY PATHWAY IMPORTANT TO CANCER FORMATION IS AFFECTED BY THIS PROCESS. METHYLATION PROFILING OF HUMAN CANCERS REVEALS TISSUE-SPECIFIC EPIGENETIC SIGNATURES, AS WELL AS TUMOR-SPECIFIC SIGNATURES, REFLECTING IN PARTICULAR THE PRESENCE OF EPIGENETIC INSTABILITY IN A SUBSET OF CANCERS AFFECTED BY THE CPG ISLAND METHYLATOR PHENOTYPE. GENERALLY, METHYLATION PATTERNS CAN BE TRACED TO A TISSUE-SPECIFIC, PROLIFERATION-DEPENDENT ACCUMULATION OF ABERRANT PROMOTER METHYLATION IN AGING TISSUES, A PROCESS THAT CAN BE ACCELERATED BY CHRONIC INFLAMMATION AND LESS WELL-DEFINED MECHANISMS INCLUDING, POSSIBLY, DIET AND GENETIC PREDISPOSITION. THE EPIGENETIC MACHINERY CAN ALSO BE ALTERED IN CANCER BY SPECIFIC LESIONS IN EPIGENETIC EFFECTOR GENES, OR BY ABERRANT RECRUITMENT OF THESE GENES BY MUTANT TRANSCRIPTION FACTORS AND COACTIVATORS. EPIGENETIC PATTERNS ARE PROVING CLINICALLY USEFUL IN HUMAN ONCOLOGY VIA RISK ASSESSMENT, EARLY DETECTION, AND PROGNOSTIC CLASSIFICATION. PHARMACOLOGIC MANIPULATION OF THESE PATTERNS-EPIGENETIC THERAPY-IS ALSO POISED TO CHANGE THE WAY WE TREAT CANCER IN THE CLINIC. 2005 15 2944 25 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 16 6588 31 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 17 5742 19 SMOKING MOLECULAR DAMAGE IN BRONCHIAL EPITHELIUM. OUR UNDERSTANDING OF THE MOLECULAR PATHOLOGY OF LUNG CANCER IS ADVANCING RAPIDLY WITH SEVERAL SPECIFIC GENES AND CHROMOSOMAL REGIONS BEING IDENTIFIED. LUNG CANCER APPEARS TO REQUIRE MANY MUTATIONS IN BOTH DOMINANT AND RECESSIVE ONCOGENES TO POSSESS MALIGNANT PHENOTYPES. SEVERAL GENETIC AND EPIGENETIC CHANGES ARE COMMON TO ALL LUNG CANCER HISTOLOGIC TYPES, WHILE OTHERS APPEAR TO BE CELL TYPE SPECIFIC. HOWEVER, SPECIFIC ROLES OF THE GENES UNDERGOING MUTATIONS AND THE ORDER OF CUMULATIVE MOLECULAR CHANGES THAT LEAD TO THE DEVELOPMENT OF EACH LUNG TUMOR HISTOLOGIC TYPE REMAIN TO BE FULLY ELUCIDATED. RECENT FINDINGS OF MOLECULAR ABNORMALITIES IN NORMAL APPEARING AND PRENEOPLASTIC BRONCHIAL EPITHELIUM FROM PATIENTS WITH LUNG CANCER AND CHRONIC SMOKERS SUGGEST THAT GENETIC CHANGES MAY SERVE AS BIOMARKERS FOR EARLY DIAGNOSIS, RISK ASSESSMENT AND MONITORING RESPONSE TO CHEMOPREVENTION. 2002 18 945 25 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 19 4429 25 MOLECULAR BIOLOGY AS A TOOL FOR THE TREATMENT OF CANCER. CANCER IS A GENETIC DISEASE CHARACTERIZED BY UNCONTROLLED CELL GROWTH AND METASTASIS. CANCER CAN HAVE A NUMBER OF CAUSES, SUCH THE ACTIVATION OF ONCOGENES, THE INACTIVATION OF TUMOR-SUPPRESSING GENES, MUTAGENESIS PROVOKED BY EXTERNAL FACTORS, AND EPIGENETIC MODIFICATIONS. THE DEVELOPMENT OF DIAGNOSTIC TOOLS AND TREATMENTS USING A MOLECULAR BIOLOGICAL APPROACH PERMITS THE USE OF SENSITIVE, LOW-COST, NONINVASIVE TESTS FOR CANCER PATIENTS. BIOMARKERS CAN BE USED TO PROVIDE RAPID, PERSONALIZED ONCOLOGY, IN PARTICULAR THE MOLECULAR DIAGNOSIS OF CHRONIC MYELOID LEUKEMIA, AND GASTRIC, COLON, AND BREAST CANCERS. MOLECULAR TESTS BASED ON DNA METHYLATION CAN ALSO BE USED TO DIRECT TREATMENTS OR EVALUATE THE TOXIC EFFECTS OF CHEMOTHERAPY. THE ADEQUATE DIAGNOSIS, PROGNOSIS, AND PREDICTION OF THE RESPONSE OF CANCER PATIENTS TO TREATMENT ARE ESSENTIAL TO ENSURE THE MOST EFFECTIVE THERAPY, REDUCE THE DAMAGING EFFECTS OF TREATMENT, AND DIRECT THE THERAPY TO SPECIFIC TARGETS, AND IN THIS CONTEXT, MOLECULAR BIOLOGY HAS BECOME INCREASINGLY IMPORTANT IN ONCOLOGY. IN THIS BRIEF REVIEW, WE WILL DEMONSTRATE THE FUNDAMENTAL IMPORTANCE OF MOLECULAR BIOLOGY FOR THE TREATMENT OF THREE TYPES OF CANCER-CHRONIC MYELOID LEUKEMIA, HEREDITARY DIFFUSE GASTRIC CANCER, AND ASTROCYTOMAS (SPORADIC TUMORS OF THE CENTRAL NERVOUS SYSTEM). IN EACH OF THESE THREE MODELS, DISTINCT BIOLOGICAL MECHANISMS ARE INVOLVED IN THE TRANSFORMATION OF THE CELLS, BUT IN ALL CASES, MOLECULAR BIOLOGY IS FUNDAMENTAL TO THE DEVELOPMENT OF PERSONALIZED ANALYSES FOR EACH PATIENT AND EACH TYPE OF NEOPLASIA, AND TO GUARANTEE THE SUCCESS OF THE TREATMENT. 2018 20 3686 24 INFLAMMATION-RELATED ABERRANT PATTERNS OF DNA METHYLATION: DETECTION AND ROLE IN EPIGENETIC DEREGULATION OF CANCER CELL TRANSCRIPTOME. IT IS NOW APPARENT THAT EPIGENETIC ABNORMALITIES, IN PARTICULAR ALTERED DNA METHYLATION, PLAY A CRUCIAL ROLE IN THE DEVELOPMENT AND PROGRESSION OF HUMAN CANCERS. DNA HYPERMETHYLATION AT PROMOTER CPG ISLANDS IS NOW RECOGNIZED AS A THIRD MECHANISM BY WHICH INACTIVATION OF TUMOR SUPPRESSOR GENES OCCURS. ABERRANT CPG ISLAND HYPERMETHYLATION IS ALSO FREQUENTLY OBSERVED IN CHRONIC INFLAMMATION AND PRECANCEROUS LESIONS, WHICH SUGGESTS THAT IT IS AN EARLY EVENT IN TUMORIGENESIS THAT COULD SERVE AS A USEFUL TUMOR MARKER. A VARIETY OF SCREENING TECHNIQUES HAVE BEEN DEVELOPED FOR GENOME-WIDE SCREENING OF METHYLATION STATUS. OF THOSE, TRANSCRIPTOME ANALYSIS COUPLED WITH PHARMACOLOGICAL UNMASKING HAS EMERGED AS A POWERFUL TOOL FOR REVEALING DNA METHYLATION PATTERNS IN CANCER CELLS AND IDENTIFYING NEW TUMOR MARKER CANDIDATES. 2009