1 1273 137 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 2 1044 35 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 3 1775 43 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 4 4549 28 MUTATION ANALYSIS OF THERAPY-RELATED MYELOID NEOPLASMS. WE ANALYZED THE GENETIC MUTATION STATUS OF 13 PATIENTS WITH THERAPY-RELATED MYELOID NEOPLASMS (T-MN). CONSISTENT WITH PREVIOUS REPORTS, T-MN CELLS PREFERENTIALLY ACQUIRED MUTATIONS IN TP53 AND EPIGENETIC MODIFYING GENES, INSTEAD OF MUTATIONS IN TYROSINE KINASE AND SPLICEOSOME GENES. FURTHERMORE, WE COMPARED THE MUTATION STATUS OF THREE T-MN CELLS WITH EACH OF THE INITIAL LYMPHOID MALIGNANT CELLS, AND IDENTIFIED COMMON MUTATIONS AMONG T-MN AND THE INITIAL MALIGNANT CELLS IN TWO PATIENTS. IN A PATIENT WHO DEVELOPED CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) AFTER FOLLICULAR LYMPHOMA (FL), TET2 MUTATION WAS IDENTIFIED IN BOTH CMML AND FL CELLS. NOTABLY, THE TET2 MUTATION WAS ALSO IDENTIFIED IN PERIPHERAL BLOOD CELLS IN THE DISEASE-FREE PERIOD WITH THE SAME ALLELIC FREQUENCY AS CMML AND FL CELLS, BUT NOT IN A GERM-LINE CONTROL, INDICATING THAT THE TET2 MUTATION OCCURRED SOMATICALLY IN THE INITIATING CLONE FOR BOTH MALIGNANT CELLS. ON THE OTHER HAND, A GERM-LINE MYB MUTATION WAS IDENTIFIED IN A PATIENT WHO DEVELOPED MYELODYSPLASTIC SYNDROMES (MDS) AFTER FL. THESE RESULTS SUGGEST THAT GERM-LINE DEPOSITION AND CLONAL HEMATOPOIESIS ARE CLOSELY ASSOCIATED WITH T-MN SUSCEPTIBILITY; HOWEVER, FURTHER ANALYSIS IS NECESSARY TO CLARIFY THE MECHANISM REQUIRED TO PROVIDE THE INITIATING CLONE WITH LINEAGE COMMITMENT AND CLONAL EXPANSION. 2018 5 2935 37 GENETIC ALTERATION ASSOCIATED WITH CHRONIC LYMPHOCYTIC LEUKEMIA. THE GENETICS OF B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (B-CLL) DIFFER CONSIDERABLY FROM MOST OTHER FORMS OF HEMATOLOGIC MALIGNANCY WHICH ARE USUALLY CHARACTERIZED BY CHROMOSOME TRANSLOCATIONS. B-CLL TYPICALLY CONTAINS CHROMOSOMAL DELETIONS AND CHROMOSOMES 13Q14 AND 11Q22-->Q23 ARE THE MOST COMMON. THESE TWO REGIONS APPEAR TO SHARE A COMMON ANCESTRAL ORIGIN (AUER ET AL., 2007B). OVERALL, CHROMOSOMAL ABNORMALITIES CAN BE FOUND IN THE MAJORITY OF PATIENTS WITH B-CLL WHEN USING SENSITIVE TECHNIQUES (DOHNERET AL., 2000) AND POSSIBLY REFLECTS AN UNDERLYING PREDISPOSITION, WITH A SMALL BUT SIGNIFICANT NUMBER OF FAMILIAL CASES. ALTHOUGH SINGLE AND CONSISTENT ABNORMALITIES ARE MOST COMMON, MULTIPLE REARRANGEMENTS CAN OCCUR, OFTEN WITH DISEASE PROGRESSION (FEGANETAL., 1995; DOHNER ET AL., 2000). REGIONS OF RECURRENT DELETION SUGGEST THE PRESENCE OF TUMOR SUPPRESSOR GENES IF FOLLOWING KNUDSON'S THEORETICAL 2-HIT MODEL. HOWEVER, DESPITE EXTENSIVE SEQUENCING ANALYSIS OVER THE LAST DECADE AND LACK OF PATHOGENIC MUTATIONS IDENTIFIED, THERE HAS BEEN A MOVE AWAY FROM THIS SUGGESTED HYPOTHESIS AND ALTERNATIVE MECHANISMS OF GENE INACTIVATION INVOLVING EPIGENETIC SILENCING OR HAPLOINSUFFICIENCY MAY BE CONSIDERED AS MORE LIKELY IN THIS DISEASE. THIS REVIEW FOCUSES ON THE COMMON GENETIC ABNORMALITIES IN B-CLL AND RELATES THEM TO SOME OF THE MORE RECENT HYPOTHESES ON INACTIVATION OF GENES WITHIN THESE REGIONS OF DELETION. 2007 6 867 45 CHRONIC ACTIVE EPSTEIN-BARR VIRUS INFECTION OF T/NK-CELL TYPE MIMICKING CLASSIC HODGKIN LYMPHOMA: CLINICOPATHOLOGIC AND GENETIC FEATURES OF 8 CASES SUPPORTING A VARIANT WITH "HODGKIN/REED-STERNBERG-LIKE" CELLS OF NK PHENOTYPE. CHRONIC ACTIVE EPSTEIN-BARR VIRUS (EBV) INFECTION OF T-CELL AND NK-CELL TYPE, SYSTEMIC FORM (CAEBV-T/NK-S) IS CHARACTERIZED BY EBV T-CELL AND/OR NK-CELL PROLIFERATION WITH NO CHANGES SUGGESTING MALIGNANCY. THEREFORE, WHEN HODGKIN/REED-STERNBERG (HRS)-LIKE CELLS ARE SCATTERED IN CAEBV-T/NK-S, IT IS MORE LIKELY TO BE MISDIAGNOSED AS CLASSIC HODGKIN LYMPHOMA. WE ENCOUNTERED A CASE WHEREIN THE PATIENT SHOWED HRS-LIKE CELLS WITH TYPICAL NK PHENOTYPE. THEREFORE, WE FURTHER INVESTIGATED 8 SIMILAR CASES TO PROVIDE CLINICOPATHOLOGIC AND GENETIC FEATURES AND DISCUSS THEIR DISTINCTION FROM OTHER RELATED DISEASES. CLINICALLY, ALL CASES MET THE DIAGNOSTIC CRITERIA OF CAEBV. MOREOVER, 4/8 PATIENTS HAD HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS. THE MEDIAN SURVIVAL WAS 16 MONTHS (RANGE, 5 TO 35 MO). PATHOLOGICALLY, ALL LYMPH NODE SAMPLES HAD A REMARKABLY SIMILAR MORPHOLOGY WITH SCATTERED HRS-LIKE CELLS SURROUNDED BY A MIXTURE OF SMALL-SIZED LYMPHOCYTES, PLASMA CELLS, AND MACROPHAGES THAT MASQUERADED CLASSIC HODGKIN LYMPHOMA. BESIDES, ERYTHROPHAGOCYTOSIS WAS DETECTED IN 4/11 SAMPLES. THE HRS-LIKE CELLS WERE POSITIVE FOR CD2, CD3P, CD30, CD56, GRB, AND EBER-ISH, BUT NEGATIVE FOR CD20, CD5, PAX-5, AND LMP-1. THE SURROUNDING LYMPHOCYTES WERE MAINLY CD8 CYTOTOXIC T CELLS, WITHOUT OBVIOUS ABERRANT EXPRESSION. IN ADDITION, ALL PATIENTS WERE POLYCLONAL IN THE T-CELL RECEPTOR GAMMA REARRANGEMENT TEST. THE HARBORED MUTATIONS WERE MAINLY IN EPIGENETIC MODIFIERS, JAK-STAT SIGNALING PATHWAY, AND APOPTOSIS/CELL CYCLE PATHWAY, INCLUDING SOCS1, DDX3X, AND KMT2D, SIMILAR TO OTHER EBV-ASSOCIATED T/NK-CELL LYMPHOPROLIFERATIVE DISORDERS. THEREFORE, THE EVIDENCE INDICATES THAT "HRS-LIKE CELLS OF NK PHENOTYPE" IS A VARIANT OF CAEBV-T/NK-S. THIS STUDY MAY RAISE AWARENESS OF SUCH CONFOUNDING CAEBV-T/N-S CASES IN CLINICAL PRACTICE TO AVOID MISDIAGNOSIS AND TREATMENT DELAY. 2019 7 3317 29 HISTOLOGICAL TRANSFORMATION TO SIGNET-RING CELL CARCINOMA IN A PATIENT WITH CLINICALLY AGGRESSIVE POORLY DIFFERENTIATED ADENOCARCINOMA OF THE ASCENDING COLON AFTER RESPONSE TO CHEMOTHERAPY PLUS CETUXIMAB: A CASE REPORT. BACKGROUND: ALTERATION OF CHEMOSENSITIVITY OR TUMOR AGGRESSIVENESS IN RESPONSE TO CHEMOTHERAPY HAS BEEN REPORTED, AND LIQUID BIOPSY ASSESSMENT DURING CHEMOTHERAPY FOR COLORECTAL CANCERS HAS CONFIRMED THE ACQUISITION OF MUTATIONS IN VARIOUS ONCOGENES. HOWEVER, THE OCCURRENCE OF HISTOLOGICAL TRANSFORMATION SEEMS TO BE EXTREMELY RARE IN COLORECTAL CANCERS, AND THE FEW EXISTING CASE REPORTS OF THIS TRANSFORMATION ARE FROM LUNG CANCER AND BREAST CANCER. IN THIS REPORT, WE DESCRIBE THE HISTOLOGICAL TRANSFORMATION OF CLINICALLY AGGRESSIVE SCIRRHOUS-TYPE POORLY DIFFERENTIATED ADENOCARCINOMA OF THE ASCENDING COLON TO SIGNET-RING CELL CARCINOMA IN ALMOST ALL RECURRENT TUMORS THAT WERE CONFIRMED BY AUTOPSY AFTER RESPONSE TO CHEMOTHERAPY PLUS CETUXIMAB. CASE PRESENTATION: A 59-YEAR-OLD WOMAN VISITED OUR HOSPITAL WITH WHOLE ABDOMINAL PAIN AND BODY WEIGHT LOSS AND WAS DIAGNOSED WITH SCIRRHOUS-TYPE POORLY DIFFERENTIATED ADENOCARCINOMA OF THE ASCENDING COLON WITH AGGRESSIVE LYMPH NODE METASTASES. THE INTRINSIC CHEMOSENSITIVITY OF THE TUMORS WAS EVIDENT UPON INITIATION OF MFOLFOX6 PLUS CETUXIMAB THERAPY, AND RIGHT HEMICOLECTOMY WAS PERFORMED, AND THE TUMOR OBVIOUSLY REMAINED IN THE PERIPANCREATIC AREA, PARAAORTIC REGION, OR OTHER RETROPERITONEAL AREAS. THE ASCENDING COLON TUMORS MAINLY CONSISTED OF POORLY DIFFERENTIATED ADENOCARCINOMA AND WERE NOT ASSOCIATED WITH SIGNET-RING CELL COMPONENTS EXCEPT FOR MINUTE CLUSTERS IN A FEW LYMPHATIC EMBOLI IN THE MAIN TUMOR. CHEMOTHERAPY WAS CONTINUED, AND METASTASES WERE ELIMINATED AT 8 MONTHS AFTER THE OPERATION; THIS RESPONSE WAS MAINTAINED FOR AN ADDITIONAL 4 MONTHS. DISCONTINUATION OF CHEMOTHERAPY PLUS CETUXIMAB RESULTED IN IMMEDIATE TUMOR RECURRENCE AND RAPID EXPANSION, AND THE PATIENT DIED OF THE RECURRENT TUMOR 1 YEAR AND 2 MONTHS AFTER THE OPERATION. AUTOPSY SPECIMENS REVEALED THAT ALMOST ALL OF THE RECURRENT TUMORS EXHIBITED TRANSFORMATION AND CONSISTED OF SIGNET-RING CELL HISTOLOGY. CONCLUSION: THIS CASE MIGHT SUGGEST THAT VARIOUS ONCOGENE MUTATIONS OR EPIGENETIC CHANGES RESULTING FROM CHEMOTHERAPY, ESPECIALLY REGIMENS THAT INCLUDE CETUXIMAB, CONTRIBUTE TO THE TRANSFORMATION OF NON-SIGNET-RING CELL COLORECTAL CARCINOMA TO SIGNET-RING CELL CARCINOMA HISTOLOGY AND CAN PROMOTE THE AGGRESSIVE CLINICAL PROGRESSION CHARACTERISTIC OF SIGNET-RING CELL CARCINOMA. 2023 8 1420 31 DIFFERENT PATTERNS OF ACETYLATION AND DIMETHYLATION OF HISTONE H3 BETWEEN YOUNG AND AGED CASES WITH CHRONIC TONSILLITIS: INFLUENCES OF INFLAMMATION AND AGING. INTRODUCTION: EPIGENETICS IS NOW CONSIDERED TO BE CRUCIALLY INVOLVED IN NORMAL GENETICS AND DIFFERENTIATION AND IN PATHOLOGICAL CONDITIONS, SUCH AS CANCER, AGING, AND INFLAMMATION. EPIGENETIC MECHANISMS INVOLVE DNA METHYLATION AND HISTONE MODIFICATIONS. THE PURPOSE OF THIS STUDY WAS TO INVESTIGATE THE EFFECTS OF INFLAMMATION ON EPIGENETICS IN YOUNG SUBJECTS AND THE EFFECT OF AGING. MATERIALS AND METHODS: THE PALATINE TONSILS WERE EXTRACTED FROM CHILD AND ADULT PATIENTS WITH CHRONIC TONSILLITIS. HEMATOXYLIN-EOSIN STAINING WAS PERFORMED TO EXAMINE THE MORPHOLOGY OF THE PALATINE TONSILS. A FLUORESCENCE IMMUNOLOGICAL EXAMINATION WAS ALSO PERFORMED TO DETECT ACETYL-HISTONE H3 OR DIMETHYL-HISTONE H3. CONFOCAL SCANNING MICROSCOPY WAS USED FOR OBSERVATIONS. RESULTS: ACETYLATED HISTONE H3 WAS DETECTED IN TONSILS FROM CHILD PATIENTS BUT NOT FROM ADULT PATIENTS. DIMETHYLATED HISTONE H3 WAS NOT DETECTED IN TONSILS FROM EITHER GROUP OF PATIENTS. DEGENERATION OF THE TONSILLAR STRUCTURES WAS APPARENT IN TONSILS FROM ADULT PATIENTS. DISCUSSION: THE DIFFERENTIAL EXPRESSION OF ACETYLATED HISTONE H3 LYS9 MAY REFLECT IMMUNOLOGICAL DIFFERENCES BETWEEN YOUNG AND AGED TONSILS. THE DECREASE OBSERVED IN THE ACTIVITY OF HISTONE METHYLTRANSFERASE INDUCED THE DOWN-REGULATED EXPRESSION OF METHYLATED HISTONE H3. CONCLUSION: OUR RESULTS SUGGEST THAT EPIGENETIC CHANGES PARTICIPATE IN CHRONIC INFLAMMATION AND AGING IN THE PALATINE TONSILS. ALTHOUGH THE RESULTS DO NOT LEAD TO A DIRECT TREATMENT, THE EPIGENETIC PATHOGENESIS OF CHRONIC INFLAMMATION, SUCH AS IMMUNOGLOBULIN A NEPHROPATHY, BY FOCAL INFECTIONS WILL BE DESCRIBED IN GREATER DETAIL IN FUTURE STUDIES, WHICH WILL LEAD TO NEW TREATMENTS BEING DEVELOPED. 2016 9 2469 14 EPIGENETIC TRAJECTORIES OF THE PREMALIGNANT-TO-MALIGNANT TRANSITION OF CHRONIC LYMPHOCYTIC LEUKEMIA. KRETZMER AND COLLEAGUES SHOW THAT THE TRANSITION TO ALTERED METHYLOME OCCURS VERY EARLY IN CHRONIC LYMPHOCYTIC LEUKEMIA, AND ONCE ACQUIRED, IT IS A CLONAL AND EXTREMELY STABLE CHANGE. HOWEVER, THE PRECISE TIME POINT WHEN THE LEUKEMIC CLONE STARTS DEVIATING SIGNIFICANTLY FROM THE NORMAL B-CELL DIFFERENTIATION TRAJECTORY IS STILL ELUSIVE. SEE RELATED ARTICLE BY KRETZMER ET AL., P. 54. 2021 10 6222 17 THE LANDSCAPE OF SOMATIC MUTATIONS IN LYMPHOBLASTOID CELL LINES. SOMATIC MUTATIONS HAVE IMPORTANT BIOLOGICAL RAMIFICATIONS WHILE EXERTING SUBSTANTIAL RATE, TYPE, AND GENOMIC LOCATION HETEROGENEITY. YET, THEIR SPORADIC OCCURRENCE MAKES THEM DIFFICULT TO STUDY AT SCALE AND ACROSS INDIVIDUALS. LYMPHOBLASTOID CELL LINES (LCLS), A MODEL SYSTEM FOR HUMAN POPULATION AND FUNCTIONAL GENOMICS, HARBOR LARGE NUMBERS OF SOMATIC MUTATIONS AND HAVE BEEN EXTENSIVELY GENOTYPED. BY COMPARING 1,662 LCLS, WE REPORT THAT THE MUTATIONAL LANDSCAPE OF THE GENOME VARIES ACROSS INDIVIDUALS IN TERMS OF THE NUMBER OF MUTATIONS, THEIR GENOMIC LOCATIONS, AND THEIR SPECTRA; THIS VARIATION MAY ITSELF BE MODULATED BY SOMATIC TRANS-ACTING MUTATIONS. MUTATIONS ATTRIBUTED TO THE TRANSLESION DNA POLYMERASE ETA FOLLOW TWO DIFFERENT MODES OF FORMATION, WITH ONE MODE ACCOUNTING FOR THE HYPERMUTABILITY OF THE INACTIVE X CHROMOSOME. NONETHELESS, THE DISTRIBUTION OF MUTATIONS ALONG THE INACTIVE X CHROMOSOME APPEARS TO FOLLOW AN EPIGENETIC MEMORY OF THE ACTIVE FORM. 2023 11 230 29 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 12 6584 21 TRIGGERING RECEPTORS EXPRESSED ON MYELOID CELLS 1 : OUR NEW PARTNER IN HUMAN ONCOLOGY? INFLAMMATION IS RECOGNIZED AS ONE OF THE HALLMARKS OF CANCER. INDEED, STRONG EVIDENCE INDICATES THAT CHRONIC INFLAMMATION PLAYS A MAJOR ROLE IN ONCOGENESIS, PROMOTING GENOME INSTABILITY, EPIGENETIC ALTERATIONS, PROLIFERATION AND DISSEMINATION OF CANCER CELLS. MONONUCLEAR PHAGOCYTES (MPS) HAVE BEEN IDENTIFIED AS KEY CONTRIBUTORS OF THE INFLAMMATORY INFILTRATE IN SEVERAL SOLID HUMAN NEOPLASIA, PROMOTING ANGIOGENESIS AND CANCER PROGRESSION. ONE OF THE MOST DESCRIBED AMPLIFIERS OF MPS PRO-INFLAMMATORY INNATE IMMUNE RESPONSE IS THE TRIGGERING RECEPTORS EXPRESSED ON MYELOID CELLS 1 (TREM-1). GROWING EVIDENCE SUGGESTS TREM-1 INVOLVEMENT IN ONCOGENESIS THROUGH CANCER RELATED INFLAMMATION AND THE SURROUNDING TUMOR MICROENVIRONMENT. IN HUMAN ONCOLOGY, HIGH LEVELS OF TREM-1 AND/OR ITS SOLUBLE FORM HAVE BEEN ASSOCIATED WITH POORER SURVIVAL DATA IN SEVERAL SOLID MALIGNANCIES, ESPECIALLY IN HEPATOCELLULAR CARCINOMA AND LUNG CANCER. TREM-1 SHOULD BE CONSIDERED AS A POTENTIAL BIOMARKER IN HUMAN ONCOLOGY AND COULD BE USED AS A NEW THERAPEUTIC TARGET OF INTEREST IN HUMAN ONCOLOGY (TREM-1 INHIBITORS, TREM-1 AGONISTS). MORE CLINICAL STUDIES ARE URGENTLY NEEDED TO CONFIRM TREM-1 (AND TREM FAMILY) ROLES IN THE PROGNOSIS AND THE TREATMENT OF HUMAN SOLID CANCERS. 2022 13 1260 22 CURRENT VIEWS ON THE INTERPLAY BETWEEN TYROSINE KINASES AND PHOSPHATASES IN CHRONIC MYELOID LEUKEMIA. CHRONIC MYELOID LEUKEMIA (CML) IS A MYELOPROLIFERATIVE DISORDER CHARACTERIZED BY BCR-ABL1 ONCOGENE EXPRESSION. THIS DYSREGULATED PROTEIN-TYROSINE KINASE (PTK) IS KNOWN AS THE PRINCIPAL DRIVER OF THE DISEASE AND IS TARGETED BY TYROSINE KINASE INHIBITORS (TKIS). EXTENSIVE DOCUMENTATION HAS ELUCIDATED HOW THE TRANSFORMATION OF MALIGNANT CELLS IS CHARACTERIZED BY MULTIPLE GENETIC/EPIGENETIC CHANGES LEADING TO THE LOSS OF TUMOR-SUPPRESSOR GENES FUNCTION OR PROTO-ONCOGENES EXPRESSION. THE IMPAIRMENT OF ADEQUATE LEVELS OF SUBSTRATES PHOSPHORYLATION, THUS AFFECTING THE BALANCE PTKS AND PROTEIN PHOSPHATASES (PPS), REPRESENTS A WELL-ESTABLISHED CELLULAR MECHANISM TO ESCAPE FROM SELF-LIMITING SIGNALS. IN THIS REVIEW, WE FOCUS OUR ATTENTION ON THE CHARACTERIZATION OF AND INTERACTIONS BETWEEN PTKS AND PPS, EMPHASIZING THEIR BIOLOGICAL ROLES IN DISEASE EXPANSION, THE REGULATION OF LSCS AND TKI RESISTANCE. WE DECIDED TO SEPARATE THOSE PPS THAT HAVE BEEN VALIDATED IN PRIMARY CELL MODELS OR LEUKEMIA MOUSE MODELS FROM THOSE WHOSE STUDIES HAVE BEEN PERFORMED ONLY IN CELL LINES (AND, THUS, REQUIRE VALIDATION), AS THERE MAY BE DIFFERENCES IN THE MANNER THAT THE ASSOCIATED PATHWAYS ARE MODIFIED UNDER THESE TWO CONDITIONS. THIS REVIEW SUMMARIZES THE ROLES OF DIVERSE PPS, WITH HOPE THAT BETTER KNOWLEDGE OF THE INTERPLAY AMONG PHOSPHATASES AND KINASES WILL EVENTUALLY RESULT IN A BETTER UNDERSTANDING OF THIS DISEASE AND CONTRIBUTE TO ITS ERADICATION. 2021 14 5275 34 PROMOTER METHYLATION OF THE BONE MORPHOGENETIC PROTEIN-6 GENE IN ASSOCIATION WITH ADULT T-CELL LEUKEMIA. BONE MORPHOGENETIC PROTEINS (BMP), BELONGING TO THE TRANSFORMING GROWTH FACTOR-BETA SUPERFAMILY, ARE MULTIFUNCTIONAL REGULATORS OF CELL PROLIFERATION, DIFFERENTIATION AND APOPTOSIS IN VARIOUS TYPES OF MALIGNANT CELLS. IN THIS STUDY, WE INVESTIGATED BMP-6 PROMOTER METHYLATION IN PATIENTS WITH VARIOUS TYPES OF LEUKEMIAS. THE BMP-6 METHYLATION WAS FOUND PREFERENTIALLY IN ADULT T-CELL LEUKEMIA (ATL) (49 OF 60, 82%) COMPARED WITH OTHER TYPES OF LEUKEMIAS STUDIED INCLUDING ACUTE MYELOID LEUKEMIA (3 OF 67, 5%), ACUTE LYMPHOBLASTIC LEUKEMIA (6 OF 38, 16%) AND CHRONIC LYMPHOCYTIC LEUKEMIA (1 OF 21, 5%). AMONG SUBTYPES OF ATL, THE BMP-6 GENE WAS MORE FREQUENTLY METHYLATED IN AGGRESSIVE ATL FORMS OF ACUTE (96%) AND LYMPHOMA (94%) TYPES THAN LESS MALIGNANT CHRONIC ATL (44%) AND SMOLDERING ATL (20%). WE ALSO ANALYZED THE METHYLATION STATUS OF PERIPHERAL BLOOD MONONUCLEAR CELLS FROM HEALTHY DONORS AND NONMALIGNANT LYMPH NODES WITH REACTIVE LYMPHADENOPATHY, NONE OF WHICH SHOWED DETECTABLE BMP-6 METHYLATION IN THIS STUDY. THE BMP-6 METHYALTION WAS CORRELATED WITH DECREASED MRNA TRANSCRIPT AND PROTEIN EXPRESSION. EXPRESSION OF BMP-6 WAS RESTORED BY THE DEMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE, SUGGESTING THAT METHYLATION WAS ASSOCIATED WITH THE TRANSCRIPTIONAL SILENCING. SERIAL ANALYSIS DEMONSTRATED AN INCREASING METHYLATION OF CPG SITES IN THE BMP-6 PROMOTER AND THE RESULTANT SUPPRESSION OF BMP-6 EXPRESSION AS ATL PROGRESSED. THESE FINDINGS SUGGESTED THAT BMP-6 PROMOTER METHYLATION IS LIKELY TO BE A COMMON EPIGENETIC EVENT AT LATER STAGES OF ATL AND THAT THE METHYLATION PROFILES MAY BE USEFUL FOR THE STAGING OF ATL AS WELL AS FOR EVALUATION OF THE INDIVIDUAL RISK OF DEVELOPING THE DISEASE. 2008 15 4545 28 MUTANT P53 GAIN OF FUNCTION AND CHEMORESISTANCE: THE ROLE OF MUTANT P53 IN RESPONSE TO CLINICAL CHEMOTHERAPY. PURPOSE: TO REVIEW MECHANISMS UNDERLYING MUTANT P53 (MUTP53) GAIN OF FUNCTION (GOF) AND MUTP53-INDUCED CHEMORESISTANCE, AND TO INVESTIGATE THE ROLE OF MUTP53 IN RESPONSE TO CLINICAL CHEMOTHERAPY. METHODS: WE SEARCHED THE PUBMED DATABASE FOR CLINICAL STUDIES FROM THE PAST DECADE, INCLUDING DATA EVALUATING THE IMPACT OF MUTP53 IN CLINICAL CHEMOTHERAPY RESPONSE. RESULTS: INTERACTIONS BETWEEN MUTP53 AND TRANSCRIPTIONAL FACTORS, PROTEINS OR DNA STRUCTURES, AS WELL AS EPIGENETIC REGULATION, CONTRIBUTE TO MUTP53 GOF. MAJOR MECHANISMS OF MUTP53-INDUCED CHEMORESISTANCE INCLUDE ENHANCED DRUG EFFLUX AND METABOLISM, PROMOTING SURVIVAL, INHIBITING APOPTOSIS, UPREGULATING DNA REPAIR, SUPPRESSING AUTOPHAGY, ELEVATING MICROENVIRONMENTAL RESISTANCE AND INDUCING A STEM-LIKE PHENOTYPE. CLINICALLY, MUTP53 PREDICTED RESISTANCE TO CHEMOTHERAPY IN DIFFUSE LARGE B-CELL LYMPHOMA, AND ESOPHAGEAL AND OROPHARYNGEAL CANCERS, BUT ITS IMPACT ON CHRONIC LYMPHOCYTIC LEUKEMIA WAS UNCLEAR. IN BLADDER CANCER, MUTP53 DID NOT PREDICT RESISTANCE, WHEREAS IN SOME BREAST AND OVARIAN CANCERS, IT WAS ASSOCIATED WITH SENSITIVITY TO CERTAIN CHEMOTHERAPEUTIC AGENTS. CONCLUSION: MUTP53 HAS AN INTRICATE ROLE IN THE RESPONSE TO CLINICAL CHEMOTHERAPY AND SHOULD NOT BE INTERPRETED IN ISOLATION. FURTHERMORE, WHEN PREDICTING TUMOR RESPONSE TO CHEMOTHERAPY BASED ON THE P53 STATUS, THE DRUGS USED SHOULD ALSO BE TAKEN INTO CONSIDERATION. THESE CONCEPTS REQUIRE FURTHER INVESTIGATION. 2017 16 4837 23 ONCOGENIC GENE EXPRESSION AND EPIGENETIC REMODELING OF CIS-REGULATORY ELEMENTS IN ASXL1-MUTANT CHRONIC MYELOMONOCYTIC LEUKEMIA. MYELOID NEOPLASMS ARE CLONAL HEMATOPOIETIC STEM CELL DISORDERS DRIVEN BY THE SEQUENTIAL ACQUISITION OF RECURRENT GENETIC LESIONS. TRUNCATING MUTATIONS IN THE CHROMATIN REMODELER ASXL1 (ASXL1(MT)) ARE ASSOCIATED WITH A HIGH-RISK DISEASE PHENOTYPE WITH INCREASED PROLIFERATION, EPIGENETIC THERAPEUTIC RESISTANCE, AND POOR SURVIVAL OUTCOMES. WE PERFORMED A MULTI-OMICS INTERROGATION TO DEFINE GENE EXPRESSION AND CHROMATIN REMODELING ASSOCIATED WITH ASXL1(MT) IN CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML). ASXL1(MT) ARE ASSOCIATED WITH A LOSS OF REPRESSIVE HISTONE METHYLATION AND INCREASE IN PERMISSIVE HISTONE METHYLATION AND ACETYLATION IN PROMOTER REGIONS. ASXL1(MT) ARE FURTHER ASSOCIATED WITH DE NOVO ACCESSIBILITY OF DISTAL ENHANCERS BINDING ETS TRANSCRIPTION FACTORS, TARGETING IMPORTANT LEUKEMOGENIC DRIVER GENES. CHROMATIN REMODELING OF PROMOTERS AND ENHANCERS IS STRONGLY ASSOCIATED WITH GENE EXPRESSION AND HETEROGENOUS AMONG OVEREXPRESSED GENES. THESE RESULTS PROVIDE A COMPREHENSIVE MAP OF THE TRANSCRIPTOME AND CHROMATIN LANDSCAPE OF ASXL1(MT) CMML, FORMING AN IMPORTANT FRAMEWORK FOR THE DEVELOPMENT OF NOVEL THERAPEUTIC STRATEGIES TARGETING ONCOGENIC CIS INTERACTIONS. 2022 17 3537 42 IMMUNE DYSREGULATION IN KABUKI SYNDROME: A CASE REPORT OF EVANS SYNDROME AND HYPOGAMMAGLOBULINEMIA. KABUKI SYNDROME (KS) IS A RARE MULTISYSTEMIC DISEASE DUE TO MUTATIONS IN THE KMT2D OR KDM6A GENES, WHICH ACT AS EPIGENETIC MODULATORS OF DIFFERENT PROCESSES, INCLUDING IMMUNE RESPONSE. THE SYNDROME IS CHARACTERIZED BY ANOMALIES IN MULTIPLE ORGAN SYSTEMS, AND IT IS ASSOCIATED WITH AUTOIMMUNE AND INFLAMMATORY DISORDERS, AND AN UNDERLYING IMMUNOLOGICAL PHENOTYPE CHARACTERIZED BY IMMUNODEFICIENCY AND IMMUNE DYSREGULATION. UP TO 17% OF KS PATIENTS PRESENT WITH IMMUNE THROMBOCYTOPENIA CHARACTERIZED BY A SEVERE, CHRONIC OR RELAPSING COURSE, AND OFTEN ASSOCIATED TO OTHER HEMATOLOGICAL AUTOIMMUNE DISEASES INCLUDING AUTOIMMUNE HEMOLYTIC ANEMIA, EVENTUALLY RESULTING IN EVANS SYNDROME (ES). A 23-YEAR-OLD WOMAN, CLINICALLY DIAGNOSED WITH KS AND PRESENTING FROM THE AGE OF 3 YEARS WITH ES WAS REFERRED TO THE RARE DISEASES CENTRE OF OUR PEDIATRIC DEPARTMENT FOR CORTICOSTEROID-INDUCED HYPERGLYCEMIA. SEVERAL ES RELAPSES AND RECURRENT RESPIRATORY INFECTIONS IN THE PREVIOUS YEARS WERE REPORTED. SEVERE HYPOGAMMAGLOBULINEMIA, SPLENOMEGALY AND SIGNS OF CHRONIC LUNG INFLAMMATION WERE DIAGNOSED ONLY AT THE TIME OF OUR OBSERVATION. SUPPORTIVE TREATMENT WITH AMOXICILLIN-CLAVULANATE PROPHYLAXIS AND RECOMBINANT HUMAN HYALURONIDASE-FACILITATED SUBCUTANEOUS IMMUNOGLOBULIN REPLACEMENT WERE IMMEDIATELY STARTED. IN KS PATIENTS, THE FAILURE OF B-CELL DEVELOPMENT AND THE LACK OF AUTOREACTIVE IMMUNE CELLS SUPPRESSION CAN LEAD TO IMMUNODEFICIENCY AND AUTOIMMUNITY THAT MAY BE UNDIAGNOSED FOR A LONG TIME. OUR PATIENT'S CASE IS PARADIGMATIC SINCE SHE PRESENTED WITH PREVENTABLE MORBIDITY AND SEVERE LUNG DISEASE YEARS AFTER DISEASE ONSET. THIS CASE EMPHASIZES THE IMPORTANCE OF SUSPECTING IMMUNE DYSREGULATION IN KS. PATHOGENESIS AND IMMUNOLOGICAL COMPLICATIONS OF KS ARE DISCUSSED. MOREOVER, THE NEED TO PERFORM IMMUNOLOGIC EVALUATIONS IS HIGHLIGHTED BOTH AT THE TIME OF KS DIAGNOSIS AND DURING DISEASE FOLLOW-UP, IN ORDER TO ALLOW PROPER TREATMENT WHILE INTERCEPTING AVOIDABLE MORBIDITY IN THESE PATIENTS. 2023 18 493 30 ASSESSMENT OF P53 AND ATM FUNCTIONALITY IN CHRONIC LYMPHOCYTIC LEUKEMIA BY MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION. THE ATM-P53 DNA-DAMAGE RESPONSE (DDR) PATHWAY HAS A CRUCIAL ROLE IN CHEMORESISTANCE IN CLL, AS INDICATED BY THE ADVERSE PROGNOSTIC IMPACT OF GENETIC ABERRATIONS OF TP53 AND ATM. IDENTIFYING AND DISTINGUISHING TP53 AND ATM FUNCTIONAL DEFECTS HAS BECOME RELEVANT AS EPIGENETIC AND POSTTRANSCRIPTIONAL DYSREGULATION OF THE ATM/P53 AXIS IS INCREASINGLY BEING RECOGNIZED AS THE UNDERLYING CAUSE OF CHEMORESISTANCE. ALSO, SPECIFIC TREATMENTS SENSITIZING TP53- OR ATM-DEFICIENT CLL CELLS ARE EMERGING. WE THEREFORE DEVELOPED A NEW ATM-P53 FUNCTIONAL ASSAY WITH THE AIM TO (I) IDENTIFY AND (II) DISTINGUISH ABNORMALITIES OF TP53 VERSUS ATM AND (III) ENABLE THE IDENTIFICATION OF ADDITIONAL DEFECTS IN THE ATM-P53 PATHWAY. REVERSED TRANSCRIPTASE MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION (RT-MLPA) WAS USED TO MEASURE ATM AND/OR P53-DEPENDENT GENES AT THE RNA LEVEL FOLLOWING DNA DAMAGE USING IRRADIATION. HERE, WE SHOWED THAT THIS ASSAY IS ABLE TO IDENTIFY AND DISTINGUISH THREE SUBGROUPS OF CLL TUMORS (I.E., TP53-DEFECTIVE, ATM-DEFECTIVE AND WT) AND IS ALSO ABLE TO DETECT ADDITIONAL SAMPLES WITH A DEFECTIVE DDR, WITHOUT MOLECULAR ABERRATIONS IN TP53 AND/OR ATM. THESE FINDINGS MAKE THE ATM-P53 RT-MLPA FUNCTIONAL ASSAY A PROMISING PROGNOSTIC TOOL FOR PREDICTING TREATMENT RESPONSES IN CLL. 2015 19 2637 27 EPIGENOME-WIDE STUDY IDENTIFIES EPIGENETIC OUTLIERS IN NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER. NONGENETIC PREDISPOSITION TO COLORECTAL CANCER CONTINUES TO BE DIFFICULT TO MEASURE PRECISELY, HAMPERING EFFORTS IN TARGETED PREVENTION AND SCREENING. EPIGENETIC CHANGES IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER CAN SERVE AS A TOOL IN PREDICTING COLORECTAL CANCER OUTCOMES. WE IDENTIFIED EPIGENETIC CHANGES AFFECTING THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER. DNA METHYLATION PROFILING ON NORMAL COLON MUCOSA FROM 77 PATIENTS WITH COLORECTAL CANCER AND 68 CONTROLS IDENTIFIED A DISTINCT SUBGROUP OF NORMALLY-APPEARING MUCOSA WITH MARKEDLY DISRUPTED DNA METHYLATION AT A LARGE NUMBER OF CPGS, TERMED AS "OUTLIER METHYLATION PHENOTYPE" (OMP) AND ARE PRESENT IN 15 OF 77 PATIENTS WITH CANCER VERSUS 0 OF 68 CONTROLS (P < 0.001). SIMILAR FINDINGS WERE ALSO SEEN IN PUBLICLY AVAILABLE DATASETS. COMPARISON OF NORMAL COLON MUCOSA TRANSCRIPTION PROFILES OF PATIENTS WITH OMP CANCER WITH THOSE OF PATIENTS WITH NON-OMP CANCER INDICATES GENES WHOSE PROMOTERS ARE HYPERMETHYLATED IN THE OMP PATIENTS ARE ALSO TRANSCRIPTIONALLY DOWNREGULATED, AND THAT MANY OF THE GENES MOST AFFECTED ARE INVOLVED IN INTERACTIONS BETWEEN EPITHELIAL CELLS, THE MUCUS LAYER, AND THE MICROBIOME. ANALYSIS OF 16S RRNA PROFILES SUGGESTS THAT NORMAL COLON MUCOSA OF OMPS ARE ENRICHED IN BACTERIAL GENERA ASSOCIATED WITH COLORECTAL CANCER RISK, ADVANCED TUMOR STAGE, CHRONIC INTESTINAL INFLAMMATION, MALIGNANT TRANSFORMATION, NOSOCOMIAL INFECTIONS, AND KRAS MUTATIONS. IN CONCLUSION, OUR STUDY IDENTIFIES AN EPIGENETICALLY DISTINCT OMP GROUP IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER THAT IS CHARACTERIZED BY A DISRUPTED METHYLOME, ALTERED GENE EXPRESSION, AND MICROBIAL DYSBIOSIS. PROSPECTIVE STUDIES ARE NEEDED TO DETERMINE WHETHER OMP COULD SERVE AS A BIOMARKER FOR AN ELEVATED EPIGENETIC RISK FOR COLORECTAL CANCER DEVELOPMENT. PREVENTION RELEVANCE: OUR STUDY IDENTIFIES AN EPIGENETICALLY DISTINCT OMP GROUP IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER THAT IS CHARACTERIZED BY A DISRUPTED METHYLOME, ALTERED GENE EXPRESSION, AND MICROBIAL DYSBIOSIS. IDENTIFICATION OF OMPS IN HEALTHY CONTROLS AND PATIENTS WITH COLORECTAL CANCER WILL LEAD TO PREVENTION AND BETTER PROGNOSIS, RESPECTIVELY. 2022 20 5663 30 SEZARY SYNDROME COEXISTING WITH B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA: CASE REPORT AND REVIEW OF THE LITERATURE. INTRODUCTION: THE SIMULTANEOUS PRESENTATION OF CHRONIC B-CELL LYMPHOCYTIC LEUKEMIA (B-CLL) AND CUTANEOUS T-CELL LYMPHOMA (CTCL) IS EXTREMELY RARE. CASE REPORT: WE DESCRIBE A PATIENT WITH B-CLL AND SEZARY SYNDROME (SS), AN ERYTHRODERMIC AND LEUKEMIC VARIANT OF CTCL. DESPITE TREATMENT, THE SS PROGRESSED TO INVOLVE INTERNAL ORGANS AND EVENTUAL DEATH OF THE PATIENT FROM SEPSIS. THIS IS THE FIRST REPORTED CASE OF SS COEXISTING WITH CHRONIC LYMPHOCYTIC LEUKEMIA IN WHICH AN ANTI-V BETA 13.6 ANTIBODY WAS USED TO SERIALLY TRACK CHANGES IN CIRCULATING NEOPLASTIC T CELLS VIS-A-VIS NEOPLASTIC B CELLS AND TO DETECT NEOPLASTIC T CELLS IN ASCITIC FLUID NEAR THE END OF THE PATIENT'S LIFE. DISCUSSION: WE SPECULATE THAT THE COEXISTENCE OF B-CLL AND CTCL IS THE RESULT OF AN INITIATING GENETIC OR EPIGENETIC DEFECT AT THE LEVEL OF THE COMMON LYMPHOID STEM CELL THAT PREDISPOSES BOTH B-CELL AND T-CELL LINEAGES TO ADDITIONAL ONCOGENIC CHANGES AT A MORE ADVANCED STAGE OF DIFFERENTIATION. 2008