1 1775 130 EBV IN T-/NK-CELL TUMORIGENESIS. EPSTEIN-BARR VIRUS (EBV), WHICH IS ASSOCIATED WITH B-CELL PROLIFERATIVE DISORDERS, ALSO TRANSFORMS T- OR NATURAL KILLER (NK)-LINEAGE CELLS AND HAS BEEN CONNECTED WITH VARIOUS T- OR NK (T/NK)-CELL MALIGNANCIES, SUCH AS EXTRANODAL NK/T-CELL LYMPHOMA-NASAL TYPE AND AGGRESSIVE NK-CELL LEUKEMIA. CHRONIC ACTIVE EBV (CAEBV) DISEASE , WHICH OCCURS MOST OFTEN IN CHILDREN AND YOUNG ADULTS IN EAST ASIA, IS AN EBV-ASSOCIATED T-/NK-CELL LYMPHOPROLIFERATIVE DISEASE. PATIENTS WITH CAEBV OFTEN PROGRESS TO OVERT LYMPHOMA OR LEUKEMIA OVER A LONG-TERM CLINICAL COURSE. EBV'S TRANSFORMING CAPACITY IN B CELLS IS WELL CHARACTERIZED, BUT THE MOLECULAR PATHOGENESIS OF CLONAL EXPANSION CAUSED BY EBV IN T/NK CELLS HAS NOT YET BEEN CLARIFIED. IN THE PRIMARY INFECTION, EBV INFECTS B CELLS AND EPITHELIAL CELLS AND MAY ALSO INFECT SOME T/NK CELLS. IN SOME INDIVIDUALS, BECAUSE OF POOR PRESENTATION BY SPECIFIC HUMAN LEUKOCYTE ANTIGENS OR THE GENETIC BACKGROUND, EBV-INFECTED T/NK CELLS EVADE HOST IMMUNITY AND SURVIVE. OCCASIONALLY, WITH THE HELP OF VIRAL ONCOGENES, EBV-ASSOCIATED T/NK LYMPHOPROLIFERATIVE DISEASES, SUCH AS CAEBV, MAY DEVELOP. THE SUBSEQUENT ACCUMULATION OF GENETIC MUTATIONS AND/OR EPIGENETIC MODIFICATIONS IN DRIVER GENES, SUCH AS DDX3X AND TP53, MAY LEAD TO OVERT LYMPHOMA AND LEUKEMIA. ACTIVATION-INDUCED CYTIDINE DEAMINASE AND THE APOBEC3 FAMILY, DRIVEN BY EBV INFECTION, MAY INDUCE CHROMOSOMAL RECOMBINATION AND SOMATIC MUTATIONS. 2018 2 1040 49 CLINICAL AND GENETIC CHARACTERIZATION OF EPSTEIN-BARR VIRUS-ASSOCIATED T/NK-CELL LYMPHOPROLIFERATIVE DISEASES. BACKGROUND: EPSTEIN-BARR VIRUS (EBV)-ASSOCIATED T-/NATURAL KILLER (T/NK)-CELL LYMPHOPROLIFERATIVE DISEASES CLINICALLY TAKE ON VARIOUS FORMS, RANGING FROM AN INDOLENT COURSE TO AN AGGRESSIVE CONDITION. OBJECTIVE: CLINICALLY, FAILURE TO ESTABLISH PRECISE DIAGNOSIS AND PROVIDE PROPER TREATMENT MAKES IT DIFFICULT TO HELP PATIENTS. WE SOUGHT TO BETTER UNDERSTAND THE UNDERLYING PATHOGENESIS AND TO IDENTIFY GENETIC PROGNOSTIC FACTORS TO ACHIEVE BETTER TREATMENT EFFICACY. METHODS: IN THIS STUDY, 119 CASES OF EBV-ASSOCIATED LYMPHOPROLIFERATIVE DISEASES, INCLUDING EBV-ASSOCIATED HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (N = 46) AND CHRONIC ACTIVE EBV DISEASE OF T/NK CELL TYPE (N = 73), WERE RETROSPECTIVELY EXAMINED. RESULTS: ADULTS AGED >20 YEARS AT ONSET ACCOUNTED FOR 71.4% OF OUR COHORT. ABOUT 54.6% PATIENTS WITH UNFAVORABLE OVERALL SURVIVAL DEVELOPED HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS AND HAD HIGHER PLASMA EBV LOAD. ALLOGENIC HEMATOPOIETIC STEM-CELL TRANSPLANTATION WAS THE SOLE INDEPENDENT FAVORABLE FACTOR. WE SYSTEMATICALLY SCREENED GERMLINE AND SOMATIC ABERRATIONS BY WHOLE-EXOME AND TARGETED SEQUENCING. AMONG 372 ANTIVIRAL IMMUNITY GENES, GERMLINE VARIANTS OF 8 GENES WERE SIGNIFICANTLY ENRICHED. FROM A PANEL OF 24 DRIVER GENES, SOMATIC MUTATIONS WERE FREQUENTLY IDENTIFIED IN DOMINANT EBV-INFECTED T/NK CELLS. PATIENTS CARRYING ANY GERMLINE/SOMATIC ABERRATIONS IN EPIGENETIC MODIFIERS AND RIG-I-LIKE RECEPTOR (RLR) PATHWAY HAD WORSE OVERALL SURVIVAL THAN THOSE WITHOUT 2 TYPE ABERRATIONS. IMPORTANTLY, PATIENTS WITH IFIH1 AND/OR DDX3X ABERRATIONS IN THE RLR PATHWAY HAD HIGHER PLASMA AND NK-CELL EBV LOAD. KNOCKDOWN OF DDX3X IN NKYS CELLS DOWNREGULATED RLR SIGNALING ACTIVITIES AND ELEVATED THE EXPRESSION OF EBV-ENCODED ONCOGENES SUCH AS LMP1 AND EBNA1. CONCLUSION: GENETIC DEFECTS WERE PREVALENT IN ADULT EBV-ASSOCIATED HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS PATIENTS AND PATIENTS WITH CHRONIC ACTIVE EBV DISEASE OF T/NK CELL TYPE; THESE DEFECTS WERE ASSOCIATED WITH UNFAVORABLE PROGNOSIS. THESE FINDINGS CAN HELP CLINICIANS WORK OUT MORE PRECISE STAGING OF THE CONDITION AND PROVIDE NEW INSIGHTS INTO THESE EBV-ASSOCIATED DISEASES. 2023 3 2661 34 EPSTEIN-BARR VIRUS AND GASTRIC CARCINOMA--VIRAL CARCINOGENESIS THROUGH EPIGENETIC MECHANISMS. EPSTEIN-BARR VIRUS (EBV)-ASSOCIATED GASTRIC CARCINOMA (GC) IS THE MONOCLONAL GROWTH OF EBV-INFECTED EPITHELIAL CELLS, AND THE ENTITY WAS RECOGNIZED ONLY RECENTLY. EBV-ASSOCIATED GC IS DISTRIBUTED WORLDWIDE AND MORE THAN 90,000 PATIENTS ARE ESTIMATED TO DEVELOP GC ANNUALLY IN ASSOCIATION WITH EBV (10% OF TOTAL GC). EBV-ASSOCIATED GC OCCURS IN TWO FORMS IN TERMS OF THE HISTOLOGICAL FEATURES, I.E., LYMPHOEPITHELIOMA-LIKE GC AND ORDINARY TYPE OF GC. BOTH SHARE CHARACTERISTIC CLINICOPATHOLOGICAL FEATURES, SUCH AS THE PREFERENTIAL OCCURRENCE AS MULTIPLE CANCER AND REMNANT STOMACH CANCER. WHILE THE EXPRESSION OF EBV-LATENT GENES IS RESTRICTED TO SEVERAL IN THE INFECTED CELLS (LATENCY I), EBV-ASSOCIATED GC SHOWS GASTRIC CELL PHENOTYPE, RESISTANCE TO APOPTOSIS, AND THE PRODUCTION OF IMMUNOMODULATOR MOLECULES. RECENTLY, GLOBAL AND NON-RANDOM CPG ISLAND METHYLATION OF THE PROMOTER REGION OF MANY CANCER-RELATED GENES HAS BEEN DEMONSTRATED WITH THEIR DECREASED EXPRESSION, SUCH AS P16 INK4A, P73 AND E-CADHERIN. THIS ABNORMALITY IS ACCOMPANIED BY METHYLATION OF THE EBV GENOME ITSELF, SUGGESTING A PROCESS OF VIRUS-DRIVEN HYPERMETHYLATION IN THE DEVELOPMENT OF NEOPLASTIC CELLS. FURTHER STUDIES ARE NECESSARY TO DETERMINE THE PRECISE SEQUENCE OF EBV INFECTION, METHYLATION, TRANSFORMATION AND SELECTION OF THE PREDOMINANT CLONE WITHIN THE STOMACH MUCOSA. FUTURE STUDIES ARE ALSO DESIRABLE FOR THE TARGET AND STRATEGY OF THERAPY, SUCH AS INITIATING VIRAL REPLICATION OR REVERSING THE DNA METHYLATION OF CELLULAR GENES. 2008 4 1273 43 CYTOTOXIC PERIPHERAL T-CELL LYMPHOMAS AND EBV-POSITIVE T/NK-CELL LYMPHOPROLIFERATIVE DISEASES: EMERGING CONCEPTS, RECENT ADVANCES, AND THE PUTATIVE ROLE OF CLONAL HEMATOPOIESIS. A REPORT OF THE 2022 EA4HP/SH LYMPHOMA WORKSHOP. CYTOTOXIC PERIPHERAL T-CELL LYMPHOMAS AND EBV-POSITIVE T/NK-CELL LYMPHOPROLIFERATIVE DISEASES WERE DISCUSSED AT THE 2022 EUROPEAN ASSOCIATION FOR HAEMATOPATHOLOGY/SOCIETY FOR HEMATOPATHOLOGY LYMPHOMA WORKSHOP HELD IN FLORENCE, ITALY. THIS SESSION FOCUSED ON (I) PRIMARY NODAL EBV-POSITIVE T AND NK-CELL LYMPHOMAS (PRIMARY NODAL-EBV-TNKL), (II) EXTRANODAL EBV-POSITIVE T/NK LYMPHOPROLIFERATIVE DISEASES (LPD) IN CHILDREN AND ADULTS, (III) CYTOTOXIC PERIPHERAL T-CELL LYMPHOMAS, NOS (CPTCL-NOS), EBV-NEGATIVE, AND (IV) MISCELLANEOUS CASES. PRIMARY NODAL-EBV-TNKL IS A NEWLY RECOGNIZED ENTITY WHICH IS RARE, AGGRESSIVE, AND ASSOCIATED WITH UNDERLYING IMMUNE DEFICIENCY/IMMUNE DYSREGULATION. ALL CASES PRESENTED WITH LYMPHADENOPATHY BUT SOME DEMONSTRATED INVOLVEMENT OF TONSIL/WALDEYER'S RING AND EXTRANODAL SITES. THE MAJORITY OF TUMORS ARE OF T-CELL LINEAGE, AND THE MOST FREQUENT MUTATIONS INVOLVE THE EPIGENETIC MODIFIER GENES, SUCH AS TET2 AND DNMT3A, AND JAK-STAT GENES. A SPECTRUM OF EBV-POSITIVE T/NK LPD INVOLVING EXTRANODAL SITES WERE DISCUSSED AND HIGHLIGHT THE DIAGNOSTIC CHALLENGE WITH PRIMARY NODAL-EBV-TNKL WHEN THESE EXTRANODAL EBV-POSITIVE T/NK LPD CASES DEMONSTRATE PREDOMINANT NODAL DISEASE EITHER AT PRESENTATION OR DURING DISEASE PROGRESSION FROM CHRONIC ACTIVE EBV DISEASE. THE MAJORITY OF CPTCL-NOS DEMONSTRATED THE TBX21 PHENOTYPE. SOME CASES HAD A BACKGROUND OF IMMUNOSUPPRESSION OR IMMUNE DYSREGULATION. INTERESTINGLY, AN UNEXPECTED ASSOCIATION OF CPTCL-NOS, EBV-POSITIVE AND NEGATIVE, WITH TFH LYMPHOMAS/LPDS WAS OBSERVED IN THE WORKSHOP CASES. SIMILAR TO A PUBLISHED LITERATURE, THE GENETIC LANDSCAPE OF CPTCL-NOS FROM THE WORKSHOP SHOWED FREQUENT MUTATIONS IN EPIGENETIC MODIFIERS, INCLUDING TET2 AND DNMT3A, SUGGESTING A ROLE OF CLONAL HEMATOPOIESIS IN THE DISEASE PATHOGENESIS. 2023 5 2663 36 EPSTEIN-BARR VIRUS PROMOTES B CELL LYMPHOMAS BY MANIPULATING THE HOST EPIGENETIC MACHINERY. DURING THE PAST DECADE, THE RAPID DEVELOPMENT OF HIGH-THROUGHPUT NEXT-GENERATION SEQUENCING TECHNOLOGIES HAS SIGNIFICANTLY REINFORCED OUR UNDERSTANDING OF THE ROLE OF EPIGENETICS IN HEALTH AND DISEASE. ALTERED FUNCTIONS OF EPIGENETIC MODIFIERS LEAD TO THE DISRUPTION OF THE HOST EPIGENOME, ULTIMATELY INDUCING CARCINOGENESIS AND DISEASE PROGRESSION. EPSTEIN-BARR VIRUS (EBV) IS AN ENDEMIC HERPESVIRUS THAT IS ASSOCIATED WITH SEVERAL MALIGNANT TUMOURS, INCLUDING B-CELL RELATED LYMPHOMAS. IN EBV-INFECTED CELLS, THE EPIGENOMIC LANDSCAPE IS EXTENSIVELY RESHAPED BY VIRAL ONCOPROTEINS, WHICH DIRECTLY INTERACT WITH EPIGENETIC MODIFIERS AND MODULATE THEIR FUNCTION. THIS PROCESS IS FUNDAMENTAL FOR THE EBV LIFE CYCLE, PARTICULARLY FOR THE ESTABLISHMENT AND MAINTENANCE OF LATENCY IN B CELLS; HOWEVER, THE ALTERATION OF THE HOST EPIGENETIC MACHINERY ALSO CONTRIBUTES TO THE DYSREGULATED EXPRESSION OF SEVERAL CELLULAR GENES, INCLUDING TUMOUR SUPPRESSOR GENES, WHICH CAN DRIVE LYMPHOMA DEVELOPMENT. THIS REVIEW OUTLINES THE MOLECULAR MECHANISMS UNDERLYING THE EPIGENETIC MANIPULATION INDUCED BY EBV THAT LEAD TO TRANSFORMED B CELLS, AS WELL AS NOVEL THERAPEUTIC INTERVENTIONS TO TARGET EBV-ASSOCIATED B-CELL LYMPHOMAS. 2020 6 1044 43 CLINICAL CHARACTERISTICS OF HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS ASSOCIATED WITH NON-HODGKIN B-CELL LYMPHOMA: A MULTICENTER RETROSPECTIVE STUDY. BACKGROUND: HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (HLH) ASSOCIATED WITH B-CELL LYMPHOMA IS A HIGHLY AGGRESSIVE DISEASE WITH UNCLEAR CLINICAL FEATURES AND HAS NO STANDARD TREATMENT. PATIENTS AND METHODS: WE ANALYZED THE CLINICAL CHARACTERISTICS OF 31 PATIENTS FROM TWO INDIVIDUAL CENTERS. RESULTS: THE MEDIAN OVERALL SURVIVAL WAS ONLY 1.5 MONTHS. BOTH UNIVARIATE AND MULTIVARIATE ANALYSES, BASED ON LYMPHOMA OR HLH-RELATED CHARACTERISTICS, REVEALED THAT PATIENTS WITH HIGH EPSTEIN-BARR VIRUS (EBV) DNA LOAD AND >/= 2 EXTRANODAL LESIONS, OR HYPOFIBRINOGENEMIA, RESPECTIVELY, SHOWED SIGNIFICANTLY POORER OVERALL SURVIVAL. INTERESTINGLY, SOME PATIENTS WITH HIGH EBV DNA LOAD HAD EBV-POSITIVE NATURAL KILLER (NK) AND/OR T CELLS, WHICH MAY BE RELATED TO THE COEXISTENCE OF IMMUNODEFICIENCY AND/OR CHRONIC ACTIVE EBV INFECTION. MOLECULAR GENETICS EXAMINATION CONFIRMED THAT 47.4% (9/19) OF PATIENTS HAD COMPLEX KARYOTYPES, 37.5% (3/8) OF PATIENTS HAD TP53 DELETIONS, AND 21.34% (3/14) OF PATIENTS HAD TP53 MUTATION OR ALTERATION OF MALIGNANCY-RELATED PATHWAYS, INCLUDING BCR/NF-KAPPAB, JAK-STAT, AND EPIGENETIC REGULATORY PATHWAYS, WHICH MAY PROVIDE CLUES TO CHOOSE TARGETS FOR THERAPY. TREATMENT REGIMENS CONTAINING ETOPOSIDE, ANTI-CD20 MONOCLONAL ANTIBODIES, OR ANTHRACYCLINES IMPROVED PATIENT PROGNOSIS (P = .0183, .025, AND .0436, RESPECTIVELY). PATIENTS WITH INFECTIONS HAD SIGNIFICANTLY SHORTER SURVIVAL THAN THOSE WITHOUT INFECTIONS (P = .00019). CONCLUSION: THE PATIENTS' PERFORMANCE STATUS, NUMBER OF EXTRANODAL LESIONS, HIGH EBV DNA LOAD, AND HYPOFIBRINOGENEMIA ARE POOR PROGNOSTIC FACTORS FOR HLH ASSOCIATED WITH B-CELL LYMPHOMA. MOLECULAR GENETIC HIGH-RISK FACTORS ARE OF PARTICULAR IMPORTANCE BECAUSE THESE FACTORS CAN PROVIDE INFORMATION FOR PROGNOSIS PREDICTION, TREATMENT DECISIONS, AND DISEASE SURVEILLANCE. 2021 7 4060 31 MAST CELLS, ANGIOGENESIS AND LYMPHANGIOGENESIS IN HUMAN GASTRIC CANCER. GASTRIC CANCER IS DIAGNOSED IN NEARLY ONE MILLION NEW PATIENTS EACH YEAR AND IT REMAINS THE SECOND LEADING CAUSE OF CANCER-RELATED DEATHS WORLDWIDE. ALTHOUGH GASTRIC CANCER REPRESENTS A HETEROGENEOUS GROUP OF DISEASES, CHRONIC INFLAMMATION HAS BEEN SHOWN TO PLAY A ROLE IN TUMORIGENESIS. CANCER DEVELOPMENT IS A MULTISTEP PROCESS CHARACTERIZED BY GENETIC AND EPIGENETIC ALTERATIONS DURING TUMOUR INITIATION AND PROGRESSION. THE STROMAL MICROENVIRONMENT IS IMPORTANT IN MAINTAINING NORMAL TISSUE HOMEOSTASIS OR PROMOTING TUMOUR DEVELOPMENT. A PLETHORA OF IMMUNE CELLS (I.E., LYMPHOCYTES, MACROPHAGES, MAST CELLS, MONOCYTES, MYELOID-DERIVED SUPPRESSOR CELLS, TREG CELLS, DENDRITIC CELLS, NEUTROPHILS, EOSINOPHILS, NATURAL KILLER (NK) AND NATURAL KILLER T (NKT) CELLS) ARE COMPONENTS OF GASTRIC CANCER MICROENVIRONMENT. MAST CELL DENSITY IS INCREASED IN GASTRIC CANCER AND THERE IS A CORRELATION WITH ANGIOGENESIS, THE NUMBER OF METASTATIC LYMPH NODES AND THE SURVIVAL OF THESE PATIENTS. MAST CELLS EXERT A PROTUMORIGENIC ROLE IN GASTRIC CANCER THROUGH THE RELEASE OF ANGIOGENIC (VEGF-A, CXCL8, MMP-9) AND LYMPHANGIOGENIC FACTORS (VEGF-C AND VEGF-F). GASTRIC MAST CELLS EXPRESS THE PROGRAMMED DEATH LIGANDS (PD-L1 AND PD-L2) WHICH ARE RELEVANT AS IMMUNE CHECKPOINTS IN CANCER. SEVERAL CLINICAL UNDERGOING TRIALS TARGETING IMMUNE CHECKPOINTS COULD BE AN INNOVATIVE THERAPEUTIC STRATEGY IN GASTRIC CANCER. ELUCIDATION OF THE ROLE OF SUBSETS OF MAST CELLS IN DIFFERENT HUMAN GASTRIC CANCERS WILL DEMAND STUDIES OF INCREASING COMPLEXITY BEYOND THOSE ASSESSING MERELY MAST CELL DENSITY AND MICROLOCALIZATION. 2019 8 208 38 ACTIVATION-INDUCED CYTIDINE DEAMINASE (AID) LINKING IMMUNITY, CHRONIC INFLAMMATION, AND CANCER. ACTIVATION-INDUCED CYTIDINE DEAMINASE (AID) IS CRITICALLY INVOLVED IN CLASS SWITCH RECOMBINATION AND SOMATIC HYPERMUTATION OF IG LOCI RESULTING IN DIVERSIFICATION OF ANTIBODIES REPERTOIRE AND PRODUCTION OF HIGH-AFFINITY ANTIBODIES AND AS SUCH REPRESENTS A PHYSIOLOGICAL TOOL TO INTRODUCE DNA ALTERATIONS. THESE PROCESSES TAKE PLACE WITHIN GERMINAL CENTERS OF SECONDARY LYMPHOID ORGANS. UNDER PHYSIOLOGICAL CONDITIONS, AID IS EXPRESSED PREDOMINANTLY IN ACTIVATED B LYMPHOCYTES. BECAUSE OF THE MUTAGENIC AND RECOMBINOGENIC POTENTIAL OF AID, ITS EXPRESSION AND ACTIVITY IS TIGHTLY REGULATED ON DIFFERENT LEVELS TO MINIMIZE THE RISK OF UNWANTED DNA DAMAGE. HOWEVER, CHRONIC INFLAMMATION AND, PROBABLY, COMBINATION OF OTHER NOT-YET-IDENTIFIED FACTORS ARE ABLE TO CREATE A MICROENVIRONMENT SUFFICIENT FOR TRIGGERING AN ABERRANT AID EXPRESSION IN B CELLS AND, IMPORTANTLY, IN NON-B-CELL BACKGROUND. UNDER THESE CIRCUMSTANCES, AID MAY TARGET ALSO NON-IG GENES, INCLUDING CANCER-RELATED GENES AS ONCOGENES, TUMOR SUPPRESSOR GENES, AND GENOMIC STABILITY GENES, AND MODULATE BOTH GENETIC AND EPIGENETIC INFORMATION. DESPITE ONGOING PROGRESS, THE COMPLETE UNDERSTANDING OF FUNDAMENTAL ASPECTS IS STILL LACKING AS (1) WHAT ARE THE CRUCIAL FACTORS TRIGGERING AN ABERRANT AID EXPRESSION/ACTIVITY INCLUDING THE IMPACT OF TH2-DRIVEN INFLAMMATION AND (2) TO WHAT EXTENT MAY ABERRANT AID IN HUMAN NON-B CELLS LEAD TO ABNORMAL CELL STATE ASSOCIATED WITH AN INCREASED RATE OF GENOMIC ALTERATIONS AS POINT MUTATIONS, SMALL INSERTIONS OR DELETIONS, AND/OR RECURRENT CHROMOSOMAL TRANSLOCATIONS DURING SOLID TUMOR DEVELOPMENT AND PROGRESSION. 2012 9 230 35 ADAPTIVE AND INNATE CYTOTOXIC EFFECTORS IN CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) SUBJECTS WITH STABLE DISEASE. CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) IS CHARACTERISED BY THE EXPANSION OF A NEOPLASTIC MATURE B CELL CLONE. CLL CLINICAL OUTCOME IS VERY HETEROGENEOUS, WITH SOME SUBJECTS NEVER REQUIRING THERAPY AND SOME SHOWING AN AGGRESSIVE DISEASE. GENETIC AND EPIGENETIC ALTERATIONS AND PRO-INFLAMMATORY MICROENVIRONMENT INFLUENCE CLL PROGRESSION AND PROGNOSIS. THE INVOLVEMENT OF IMMUNE-MEDIATED MECHANISMS IN CLL CONTROL NEEDS TO BE INVESTIGATED. WE ANALYSE THE ACTIVATION PROFILE OF INNATE AND ADAPTIVE CYTOTOXIC IMMUNE EFFECTORS IN A COHORT OF 26 CLL PATIENTS WITH STABLE DISEASE, AS KEY ELEMENTS FOR IMMUNE-MEDIATED CONTROL OF CANCER PROGRESSION. WE OBSERVED AN INCREASE IN CD54 EXPRESSION AND INTERFERON (IFN)-GAMMA PRODUCTION BY CYTOTOXIC T CELLS (CTL). CTL ABILITY TO RECOGNISE TUMOUR-TARGETS DEPENDS ON HUMAN LEUKOCYTE ANTIGENS (HLA)-CLASS I EXPRESSION. WE OBSERVED A DECREASED EXPRESSION OF HLA-A AND HLA-BC ON B CELLS OF CLL SUBJECTS, ASSOCIATED WITH A SIGNIFICANT REDUCTION IN INTRACELLULAR CALNEXIN THAT IS RELEVANT FOR HLA SURFACE EXPRESSION. NATURAL KILLER (NK) CELLS AND CTL FROM CLL SUBJECTS SHOW AN INCREASED EXPRESSION OF THE ACTIVATING RECEPTOR KIR2DS2 AND A REDUCTION OF 3DL1 AND NKG2A INHIBITING MOLECULES. THEREFORE, AN ACTIVATION PROFILE CHARACTERISES CTL AND NK CELLS OF CLL SUBJECTS WITH STABLE DISEASE. THIS PROFILE IS CONCEIVABLE WITH THE FUNCTIONAL INVOLVEMENT OF CYTOTOXIC EFFECTORS IN CLL CONTROL. 2023 10 6590 36 TUMOR SUPPRESSOR INACTIVATION IN THE PATHOGENESIS OF ADULT T-CELL LEUKEMIA. TUMOR SUPPRESSOR FUNCTIONS ARE ESSENTIAL TO CONTROL CELLULAR PROLIFERATION, TO ACTIVATE THE APOPTOSIS OR SENESCENCE PATHWAY TO ELIMINATE UNWANTED CELLS, TO LINK DNA DAMAGE SIGNALS TO CELL CYCLE ARREST CHECKPOINTS, TO ACTIVATE APPROPRIATE DNA REPAIR PATHWAYS, AND TO PREVENT THE LOSS OF ADHESION TO INHIBIT INITIATION OF METASTASES. THEREFORE, TUMOR SUPPRESSOR GENES ARE INDISPENSABLE TO MAINTAINING GENETIC AND GENOMIC INTEGRITY. CONSEQUENTLY, INACTIVATION OF TUMOR SUPPRESSORS BY SOMATIC MUTATIONS OR EPIGENETIC MECHANISMS IS FREQUENTLY ASSOCIATED WITH TUMOR INITIATION AND DEVELOPMENT. IN CONTRAST, REACTIVATION OF TUMOR SUPPRESSOR FUNCTIONS CAN EFFECTIVELY REVERSE THE TRANSFORMED PHENOTYPE AND LEAD TO CELL CYCLE ARREST OR DEATH OF CANCEROUS CELLS AND BE USED AS A THERAPEUTIC STRATEGY. ADULT T-CELL LEUKEMIA/LYMPHOMA (ATLL) IS AN AGGRESSIVE LYMPHOPROLIFERATIVE DISEASE ASSOCIATED WITH INFECTION OF CD4 T CELLS BY THE HUMAN T-CELL LEUKEMIA VIRUS TYPE 1 (HTLV-I). HTLV-I-ASSOCIATED T-CELL TRANSFORMATION IS THE RESULT OF A MULTISTEP ONCOGENIC PROCESS IN WHICH THE VIRUS INITIALLY INDUCES CHRONIC T-CELL PROLIFERATION AND ALTERS CELLULAR PATHWAYS RESULTING IN THE ACCUMULATION OF GENETIC DEFECTS AND THE DEREGULATED GROWTH OF VIRALLY INFECTED CELLS. THIS REVIEW WILL FOCUS ON THE CURRENT KNOWLEDGE OF THE GENETIC AND EPIGENETIC MECHANISMS REGULATING THE INACTIVATION OF TUMOR SUPPRESSORS IN THE PATHOGENESIS OF HTLV-I. 2015 11 2377 29 EPIGENETIC REGULATION OF TUMOR SUPPRESSORS BY HELICOBACTER PYLORI ENHANCES EBV-INDUCED PROLIFERATION OF GASTRIC EPITHELIAL CELLS. HELICOBACTER PYLORI AND EPSTEIN-BARR VIRUS (EBV) ARE TWO WELL-KNOWN CONTRIBUTORS TO CANCER AND CAN ESTABLISH LIFELONG PERSISTENT INFECTION IN THE HOST. THIS LEADS TO CHRONIC INFLAMMATION, WHICH ALSO CONTRIBUTES TO DEVELOPMENT OF CANCER. ASSOCIATION WITH H. PYLORI INCREASES THE RISK OF GASTRIC CARCINOMA, AND COEXISTENCE WITH EBV ENHANCES PROLIFERATION OF INFECTED CELLS. FURTHER, H. PYLORI-EBV COINFECTION CAUSES CHRONIC INFLAMMATION IN PEDIATRIC PATIENTS. WE HAVE ESTABLISHED AN H. PYLORI-EBV COINFECTION MODEL SYSTEM USING HUMAN GASTRIC EPITHELIAL CELLS. WE SHOWED THAT H. PYLORI INFECTION CAN INCREASE THE ONCOGENIC PHENOTYPE OF EBV-INFECTED CELLS AND THAT THE CYTOTOXIN-ASSOCIATED GENE (CAGA) PROTEIN ENCODED BY H. PYLORI STIMULATED EBV-MEDIATED CELL PROLIFERATION IN THIS COINFECTION MODEL SYSTEM. THIS LED TO INCREASED EXPRESSION OF DNA METHYL TRANSFERASES (DNMTS), WHICH REPROGRAMMED CELLULAR TRANSCRIPTIONAL PROFILES, INCLUDING THOSE OF TUMOR SUPPRESSOR GENES (TSGS), THROUGH HYPERMETHYLATION. THESE FINDINGS PROVIDE NEW INSIGHTS INTO A MOLECULAR MECHANISM WHEREBY COOPERATIVITY BETWEEN TWO ONCOGENIC AGENTS LEADS TO ENHANCED ONCOGENIC ACTIVITY OF GASTRIC CANCER CELLS.IMPORTANCE WE HAVE STUDIED THE COOPERATIVITY BETWEEN H. PYLORI AND EBV, TWO KNOWN ONCOGENIC AGENTS. THIS LED TO AN ENHANCED ONCOGENIC PHENOTYPE IN GASTRIC EPITHELIAL CELLS. WE NOW DEMONSTRATE THAT EBV-DRIVEN EPIGENETIC MODIFICATIONS ARE ENHANCED IN THE PRESENCE OF H. PYLORI, MORE SPECIFICALLY, IN THE PRESENCE OF ITS CAGA SECRETORY ANTIGEN. THIS RESULTS IN INCREASED PROLIFERATION OF THE INFECTED GASTRIC CELLS. OUR FINDINGS NOW ELUCIDATE A MOLECULAR MECHANISM WHEREBY EXPRESSION OF CELLULAR DNA METHYL TRANSFERASES IS INDUCED INFLUENCING INFECTION BY EBV. HYPERMETHYLATION OF THE REGULATORY GENOMIC REGIONS OF TUMOR SUPPRESSOR GENES RESULTS IN THEIR SILENCING. THIS DRASTICALLY AFFECTS THE EXPRESSION OF CELL CYCLE, APOPTOSIS, AND DNA REPAIR GENES, WHICH DYSREGULATES THEIR ASSOCIATED PROCESSES, AND PROMOTION OF THE ONCOGENIC PHENOTYPE. 2018 12 4438 25 MOLECULAR FINDINGS IN BARRETT'S EPITHELIUM. BARRETT'S METAPLASIA IS A PREMALIGNANT CONDITION AND REMAINS THE NUMBER ONE RISK FACTOR FOR DEVELOPING ADENOCARCINOMA. THE HISTOLOGIC CHANGES LEADING TO ADENOCARCINOMA ARE ACCOMPANIED BY GENETIC DISTURBANCES OF THE EPITHELIAL CELLS ITSELF AS WELL AS THE SURROUNDING STROMA. GENETIC AND EPIGENETIC EVENTS AFFECT THE CELL CYCLE, LEADING TO GROWTH SELF-SUFFICIENCY AND IGNORATION OF ANTIGROWTH SIGNALS. THE BALANCE OF CELL TURNOVER IS INSTABLE BY AVOIDANCE OF APOPTOSIS AND A GENERAL LIMITLESS OF THE REPLICATIVE POTENTIAL OF THE (MUTATED) STEM CELLS. SUSTAINED ANGIOGENESIS, NOT ONLY A CONSEQUENCE OF CHRONIC INFLAMMATION, MAY PRECEDE INVASION OF GENETICALLY INSTABLE (ANEUPLOID) CELLS. THE PRINCIPAL GENETIC CHANGES IN BARRETT'S CARCINOGENESIS ARE COMPARABLE TO THOSE KNOWN FROM OTHER EPITHELIAL MALIGNANCIES. LOSS OF P16 GENE EXPRESSION (BY DELETION OR HYPERMETHYLATION), THE LOSS OF P53 EXPRESSION (BY MUTATION AND DELETION), THE INCREASE IN CYCLIN EXPRESSION, AND THE LOSSES OF RB, APC AS WELL AS VARIOUS CHROMOSOMAL LOCI HAVE BEEN REPORTED. SINCE THESE GENETIC OR EPIGENETIC ALTERATIONS ARE NEITHER TUMOR NOR STAGE SPECIFIC, THEY COULD NOT GAIN DIAGNOSTIC SIGNIFICANCE AS BIOMARKERS UNTIL NOW. 2004 13 2992 26 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 14 5491 32 REVIEW ARTICLE: INFLAMMATION-RELATED PROMOTION OF GASTROINTESTINAL CARCINOGENESIS--A PERIGENETIC PATHWAY. CHRONIC INFLAMMATION HAS BEEN REPORTED TO ACCELERATE NEOPLASMAS IN GASTROINTESTINAL TRACT. CERTAIN BACTERIA INCLUDING HELICOBACTER PYLORI DIRECTLY INTERACT WITH HOST CELLS, INDUCE PROINFLAMMATORY CYTOKINES AND STIMULATE PRODUCTION OF FREE RADICALS. FREE RADICALS CAUSE MUTATIONS IN TARGET CELLS SO THAT NEOPLASTIC CLONES ARE ESTABLISHED. ACCUMULATION OF SUCH GENETIC ALTERATIONS MAY CAUSE MALIGNANT TRANSFORMATION OF SOME ESTABLISHED CLONES. IN ADDITION, INFLAMMATORY ALTERATIONS MAY PROMOTE GROWTH, EXPANSION AND INVASION OF GASTROINTESTINAL EPITHELIAL CELLS. THE LATTER CHANGES CAUSED BY INFLAMMATION MAY OCCUR EVEN WITHOUT FURTHER GENETIC MUTATIONS OR EPIGENETIC ALTERATIONS, AND THEREFORE MAY BE CATEGORIZED AS 'PERIGENETIC ALTERATIONS' OF NEOPLASTIC CELLS. FOR AN EXAMPLE, TUMOUR NECROSIS FACTOR ALPHA (TNF-ALPHA) PLAYS PIVOTAL ROLES NOT ONLY IN THE REDUCTION BUT ALSO IN THE GROWTH, INVASION AND METASTASES OF CERTAIN NEOPLASMAS. OUR STUDIES SHOW THAT TNF-ALPHA INCREASES INTRACELLULAR RADICAL PRODUCTION, DEGRADATES E-CADHERIN / BETA-CATENIN COMPLEX AND PROMOTES DISPERSION AND MIGRATION IN EPITHELIAL CELLS TRANSFORMED WITH AN ACTIVATED SRC ONCOGENE (V-SRC). THESE DATA INDICATE THAT AN INFLAMMATORY CYTOKINE INDUCES THE MALIGNANT POTENTIAL OF SRC-ACTIVATED NEOPLASTIC CELLS. INTERESTINGLY, TNF-ALPHA ALSO INDUCED THESE PHENOTYPIC CHANGES IN NONMUTATED CELLS WHOSE C-SRC WAS ACTIVATED BY TGF-ALPHA, SUGGESTING THAT THE INVASIVE PROPERTIES OF THE CELL WERE NOT NECESSARILY RELATED TO GENE MUTATION. FURTHERMORE, CERTAIN RADICAL SCAVENGERS SUPPRESSED THE INVASIVE PHENOTYPE OF THE CELLS. THESE RESULTS INDICATE THAT PERIGENETIC ALTERATIONS ARE AN IMPORTANT TARGET OF PHARMACOLOGICAL INTERVENTION OF CARCINOGENESIS. 2003 15 4728 27 NOTCH SIGNALING PROMOTES DISEASE INITIATION AND PROGRESSION IN MURINE CHRONIC LYMPHOCYTIC LEUKEMIA. NOTCH1 GAIN-OF-FUNCTION MUTATIONS ARE RECURRENT IN B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (B-CLL), WHERE THEY ARE ASSOCIATED WITH ACCELERATED DISEASE PROGRESSION AND REFRACTORINESS TO CHEMOTHERAPY. THE SPECIFIC ROLE OF NOTCH1 IN THE DEVELOPMENT AND PROGRESSION OF THIS MALIGNANCY IS UNCLEAR. HERE, WE ASSESS THE IMPACT OF LOSS OF NOTCH SIGNALING AND PATHWAY HYPERACTIVATION IN AN IN VIVO MOUSE MODEL OF CLL (IGH.TEMU) THAT FAITHFULLY REPLICATES MANY FEATURES OF THE HUMAN PATHOLOGY. ABLATION OF CANONICAL NOTCH SIGNALING USING CONDITIONAL GENE INACTIVATION OF RBP-J IN IMMATURE HEMATOPOIETIC OR B-CELL PROGENITORS DELAYED CLL INDUCTION AND REDUCED INCIDENCE OF MICE DEVELOPING DISEASE. IN CONTRAST, FORCED EXPRESSION OF A DOMINANT ACTIVE FORM OF NOTCH RESULTED IN MORE ANIMALS DEVELOPING CLL WITH EARLY DISEASE ONSET. COMPARATIVE ANALYSIS OF GENE EXPRESSION AND EPIGENETIC FEATURES OF NOTCH GAIN-OF-FUNCTION AND CONTROL CLL CELLS REVEALED DIRECT AND INDIRECT REGULATION OF CELL CYCLE-ASSOCIATED GENES, WHICH LED TO INCREASED PROLIFERATION OF NOTCH GAIN-OF-FUNCTION CLL CELLS IN VIVO. THESE RESULTS DEMONSTRATE THAT NOTCH SIGNALING FACILITATES DISEASE INITIATION AND PROMOTES CLL CELL PROLIFERATION AND DISEASE PROGRESSION. 2021 16 3902 28 LEARNING FROM THE FAILURES OF DRUG DISCOVERY IN B-CELL NON-HODGKIN LYMPHOMAS AND PERSPECTIVES FOR THE FUTURE: CHRONIC LYMPHOCYTIC LEUKEMIA AND DIFFUSE LARGE B-CELL LYMPHOMA AS TWO ENDS OF A SPECTRUM IN DRUG DEVELOPMENT. DESPITE SUBSTANTIAL RECENT ADVANCES, THERE IS STILL AN UNMET NEED FOR BETTER THERAPIES IN B-CELL NON HODGKIN LYMPHOMAS (B-NHL), ESPECIALLY IN RELAPSED OR REFRACTORY DISEASE. MANY NOVEL TARGETED DRUGS HAVE BEEN DEVELOPED BASED ON A BETTER MOLECULAR UNDERSTANDING OF B-NHL. AREAS COVERED: THIS ARTICLE FOCUSES ON CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) AS A REPRESENTATIVE FOR INDOLENT LYMPHOMAS AND PARADIGMATIC FOR THE TREMENDOUS PROGRESS IN TREATING B-NHL ON THE ONE HAND AND DIFFUSE LARGE B-CELL LYMPHOMA (DLBCL) AS A REPRESENTATIVE FOR AGGRESSIVE LYMPHOMAS AND PARADIGMATIC FOR MANY UNSOLVED PROBLEMS IN LYMPHOMA TREATMENT OR THE OTHER HAND. WE HIGHLIGHT SALIENT POINTS IN CURRENT THERAPIES TARGETING GENETIC, EPIGENETIC, IMMUNOLOGICAL AND MICROENVIRONMENTAL ALTERATIONS. POSSIBLE REASONS FOR DRUG FAILURE IN CLINICAL TRIALS LIKE TUMOR HETEROGENEITY, CLONAL EVOLUTION AND DRUG RESISTANCE MECHANISMS ARE DISCUSSED. BASED THEREON, SOME PERSPECTIVES FOR FURTHER DRUG DISCOVERY ARE GIVEN. EXPERT OPINION: IN VIEW OF THE PATHOGENETIC COMPLEXITY OF LYMPHOMAS, THERAPIES TARGETING EXCLUSIVELY A SINGLE ALTERATION MAY FAIL BECAUSE RESISTANCE MECHANISMS ARE PRESENT EITHER INITIALLY OR EVOLVE DURING TREATMENT. THEREFORE, FUTURE THERAPIES IN B-NHL MAY HAVE TO TARGET THE GREATEST POSSIBLE NUMBER OF GENETIC, IMMUNOLOGICAL OR EPIGENETIC ALTERATIONS STILL ALLOWING TOLERABILITY AND TO MONITOR THESE ALTERATIONS DURING THERAPY. 2017 17 5899 28 T-CELL DYSFUNCTION IN CHRONIC LYMPHOCYTIC LEUKEMIA FROM AN EPIGENETIC PERSPECTIVE. CELLULAR IMMUNOTHERAPEUTIC APPROACHES SUCH AS CHIMERIC ANTIGEN RECEPTOR (CAR) T-CELL THERAPY IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) THUS FAR HAVE NOT MET THE HIGH EXPECTATIONS. THEREFORE IT IS ESSENTIAL TO BETTER UNDERSTAND THE MOLECULAR MECHANISMS OF CLLINDUCED T-CELL DYSFUNCTION. EVEN THOUGH A SIGNIFICANT NUMBER OF STUDIES ARE AVAILABLE ON T-CELL FUNCTION AND DYSFUNCTION IN CLL PATIENTS, NONE EXAMINE DYSFUNCTION AT THE EPIGENOMIC LEVEL. IN NON-MALIGNANT T-CELL RESEARCH, EPIGENOMICS IS WIDELY EMPLOYED TO DEFINE THE DIFFERENTIATION PATHWAY INTO T-CELL EXHAUSTION. ADDITIONALLY, METABOLIC RESTRICTIONS IN THE TUMOR MICROENVIRONMENT THAT CAUSE T-CELL DYSFUNCTION ARE OFTEN MEDIATED BY EPIGENETIC CHANGES. WITH THIS REVIEW PAPER WE ARGUE THAT UNDERSTANDING THE EPIGENETIC (DYS)REGULATION IN T CELLS OF CLL PATIENTS SHOULD BE LEVELED TO THE KNOWLEDGE WE CURRENTLY HAVE OF THE NEOPLASTIC B CELLS THEMSELVES. THIS WILL PERMIT A COMPLETE UNDERSTANDING OF HOW THESE IMMUNE CELL INTERACTIONS REGULATE T- AND B-CELL FUNCTION. HERE WE RELATE THE CELLULAR AND PHENOTYPIC CHARACTERISTICS OF CLL-INDUCED T-CELL DYSFUNCTION TO EPIGENETIC STUDIES OF T-CELL REGULATION EMERGING FROM CHRONIC VIRAL INFECTION AND TUMOR MODELS. THIS PAPER PROPOSES A FRAMEWORK FOR FUTURE STUDIES INTO THE EPIGENETIC REGULATION OF CLL-INDUCED TCELL DYSFUNCTION, KNOWLEDGE THAT WILL HELP TO GUIDE IMPROVEMENTS IN THE UTILITY OF AUTOLOGOUS T-CELL BASED THERAPIES IN CLL. 2021 18 1467 36 DISTINCT CLINICAL AND GENETIC FEATURES OF HEPATITIS B VIRUS-ASSOCIATED FOLLICULAR LYMPHOMA IN CHINESE PATIENTS. HEPATITIS B VIRUS (HBV) INFECTION HAS BEEN ASSOCIATED WITH AN INCREASED RISK FOR B-CELL LYMPHOMAS. WE PREVIOUSLY SHOWED THAT 20% OF DIFFUSE LARGE B-CELL LYMPHOMA (DLBCL) PATIENTS FROM CHINA, AN ENDEMIC AREA OF HBV INFECTION, HAVE CHRONIC HBV INFECTION (SURFACE ANTIGEN-POSITIVE, HBSAG+) AND ARE CHARACTERIZED BY DISTINCT CLINICAL AND GENETIC FEATURES. HERE, WE SHOWED THAT 24% OF FOLLICULAR LYMPHOMA (FL) CHINESE PATIENTS ARE HBSAG+. COMPARED WITH THE HBSAG- FL PATIENTS, HBSAG+ PATIENTS ARE YOUNGER, HAVE A HIGHER HISTOLOGICAL GRADE AT DIAGNOSIS, AND HAVE A HIGHER INCIDENCE OF DISEASE PROGRESSION WITHIN 24 MONTHS. MOREOVER, BY SEQUENCING THE GENOMES OF 109 FL TUMORS, WE OBSERVED ENHANCED MUTAGENESIS AND DISTINCT GENETIC PROFILE IN HBSAG+ FLS, WITH A UNIQUE SET OF PREFERENTIALLY MUTATED GENES (TNFAIP3, FAS, HIST1H1C, KLF2, TP53, PIM1, TMSB4X, DUSP2, TAGAP, LYN, AND SETD2) BUT LACK OF THE HALLMARK OF HBSAG- FLS (IE, IGH/BCL2 TRANSLOCATIONS AND CREBBP MUTATIONS). TRANSCRIPTOMIC ANALYSES FURTHER SHOWED THAT HBSAG+ FLS DISPLAYED GENE-EXPRESSION SIGNATURES RESEMBLING THE ACTIVATED B-CELL-LIKE SUBTYPE OF DIFFUSE LARGE B-CELL LYMPHOMA, INVOLVING IRF4-TARGETED GENES AND NF-KAPPAB/MYD88 SIGNALING PATHWAYS. FINALLY, WE IDENTIFIED AN INCREASED INFILTRATION OF CD8+ MEMORY T CELLS, CD4+ TH1 CELLS, AND M1 MACROPHAGES AND HIGHER T-CELL EXHAUSTION GENE SIGNATURE IN HBSAG+ FL SAMPLES. TAKEN TOGETHER, WE PRESENT NEW GENETIC/EPIGENETIC EVIDENCE THAT LINKS CHRONIC HBV INFECTION TO B-CELL LYMPHOMAGENESIS, AND HBV-ASSOCIATED FL IS LIKELY TO HAVE A DISTINCT CELL-OF-ORIGIN AND REPRESENT AS A SEPARATE SUBTYPE OF FL. TARGETABLE GENETIC/EPIGENETIC ALTERATIONS IDENTIFIED IN TUMORS AND THEIR ASSOCIATED TUMOR MICROENVIRONMENT MAY PROVIDE POTENTIAL NOVEL THERAPEUTIC APPROACHES FOR THIS SUBGROUP OF PATIENTS. 2022 19 1078 41 CLONAL NON-MALIGNANT HEMATOLOGICAL DISORDERS: UNRAVELING MOLECULAR PATHOGENIC MECHANISMS TO DEVELOP NOVEL TARGETED THERAPEUTICS. CLONAL NON-MALIGNANT HEMATOLOGICAL DISORDERS ARE A HETEROGENEOUS GROUP OF DISEASES THAT ARE PARTICULARLY CHALLENGING FOR HEMATOLOGISTS. INDEED, MOST OBVIOUS AND FREQUENT HEMATOLOGICAL DISEASES INCLUDE A BROAD SPECTRUM OF MALIGNANCIES, SUCH AS LEUKEMIAS, LYMPHOMAS, MYELOMA, AND OTHER MYELOPROLIFERATIVE OR LYMPHOPROLIFERATIVE DISORDERS. IN RECENT YEARS, ALL THESE DISEASES HAVE BEEN CATEGORIZED BY THE WHO ACCORDING TO A NOVEL CLASSIFICATION OF MYELOID AND LYMPHOID MALIGNANCIES, WHICH TAKES IN ACCOUNT THE OUTSTANDING PROGRESS IN OUR UNDERSTANDING OF MOLECULAR DEFECTS UNDERLYING HEMATOLOGICAL MALIGNANCIES. REGARDLESS OF A NUMBER OF NOVEL TECHNOLOGIES, HEMATOLOGISTS CONTINUE TO DEAL DAILY WITH CONDITIONS WHERE A CLEAR DIAGNOSIS OF A MALIGNANCY IS MISSING: THIS IS THE CASE OF SEVERAL CLONAL HEMATOLOGICAL DISORDERS, WHICH ARE CONSIDERED BONA FIDE NON-MALIGNANT. SOME MYELODYSPLASTIC SYNDROMES, CHRONIC T AND NK DISORDERS OF GRANULAR LYMPHOCYTES, MYELOFIBROSIS, MONOCLONAL GAMMOPATHIES, MONOCLONAL B-CEL LYMPHOCYTOSIS, MASTOCYTOSIS AND PAROXYSMAL NOCTURNAL HEMOGLOBINURIA ARE PARADIGMATIC EXAMPLES OF HOW CLONAL DISORDERS ARE CLEARLY DIFFERENT FROM CANCERS, EVEN IF THEY MAY SHARE WITH HEMATOLOGICAL MALIGNANCIES SIMILAR MOLECULAR, GENETIC, EPIGENETIC AND IMMUNOLOGICAL PROCESSES. INDEED, IT IS NOT ENTIRELY CLEAR WHETHER IN INDIVIDUAL CONDITIONS SUCH PATHOGENIC MECHANISMS MAY REPRESENT INITIAL STEP(S) OF MALIGNANT TRANSFORMATION, MAKING A BRIDGE BETWEEN THESE CLONAL NON-MALIGNANT DISORDERS AND TYPICAL HEMATOLOGICAL CANCERS. SOME OF THESE NON-MALIGNANT DISORDERS IMPLY SPECIFIC PATHOGENIC MECHANISMS AND/OR CLINICAL COURSE, AND SO THEY HAVE BEEN DEFINITELY ESTABLISHED WITH THEIR OWN BIOLOGICAL AND CLINICAL IDENTITY. HOWEVER, THE OBVIOUS QUESTION WHETHER SOME OF THESE CLONAL NON-MALIGNANT HEMATOLOGICAL DISEASES FORM SOME A KIND OF DISEASE-CONTINUUM WITH THEIR CORRESPONDING MALIGNANT COUNTERPART IS STILL TO BE ANSWERED. 2014 20 5462 29 RESEARCH PROGRESS ON EPIGENETICS OF SMALL B-CELL LYMPHOMA. SMALL B-CELL LYMPHOMA IS THE CLASSIFICATION OF B-CELL CHRONIC LYMPHOPROLIFERATIVE DISORDERS THAT INCLUDE CHRONIC LYMPHOCYTIC LEUKAEMIA/SMALL LYMPHOCYTIC LYMPHOMA, FOLLICULAR LYMPHOMA, MANTLE CELL LYMPHOMA, MARGINAL ZONE LYMPHOMA, LYMPHOPLASMACYTIC LYMPHOMA/WALDENSTROM MACROGLOBULINEMIA. THE CLINICAL PRESENTATION IS SOMEWHAT HETEROGENEOUS, AND ITS OCCURRENCE AND DEVELOPMENT MECHANISMS ARE NOT YET PRECISE AND MAY INVOLVE EPIGENETIC CHANGES. EPIGENETIC ALTERATIONS MAINLY INCLUDE DNA METHYLATION, HISTONE MODIFICATION, AND NON-CODING RNA, WHICH ARE ESSENTIAL FOR GENETIC DETECTION, EARLY DIAGNOSIS, AND ASSESSMENT OF TREATMENT RESISTANCE IN SMALL B-CELL LYMPHOMA. AS CHRONIC LYMPHOCYTIC LEUKEMIA/SMALL LYMPHOCYTIC LYMPHOMA HAS ALREADY BEEN REPORTED IN THE LITERATURE, THIS ARTICLE FOCUSES ON SMALL B-CELL LYMPHOMAS SUCH AS FOLLICULAR LYMPHOMA, MANTLE CELL LYMPHOMA, MARGINAL ZONE LYMPHOMA, AND WALDENSTROM MACROGLOBULINEMIA. IT DISCUSSES RECENT DEVELOPMENTS IN EPIGENETIC RESEARCH TO DIAGNOSE AND TREAT THIS GROUP OF LYMPHOMAS. THIS REVIEW PROVIDES NEW IDEAS FOR THE TREATMENT AND PROGNOSIS ASSESSMENT OF SMALL B-CELL LYMPHOMA BY EXPLORING THE CONNECTION BETWEEN SMALL B-CELL LYMPHOMA AND EPIGENETICS. 2022