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 3396 28 HOST SHP1 PHOSPHATASE ANTAGONIZES HELICOBACTER PYLORI CAGA AND CAN BE DOWNREGULATED BY EPSTEIN-BARR VIRUS. MOST IF NOT ALL GASTRIC CANCERS ARE ASSOCIATED WITH CHRONIC INFECTION OF THE STOMACH MUCOSA WITH HELICOBACTER PYLORI CAGA-POSITIVE STRAINS(1-4). APPROXIMATELY 10% OF GASTRIC CANCERS ALSO HARBOUR EPSTEIN-BARR VIRUS (EBV) IN THE CANCER CELLS(5,6). FOLLOWING DELIVERY INTO GASTRIC EPITHELIAL CELLS VIA TYPE IV SECRETION(7,8), THE CAGA-ENCODED CAGA PROTEIN UNDERGOES TYROSINE PHOSPHORYLATION ON THE GLU-PRO-ILE-TYR-ALA (EPIYA) MOTIFS INITIALLY BY SRC FAMILY KINASES (SFKS) AND THEN BY C-ABL(9,10). TYROSINE-PHOSPHORYLATED CAGA BINDS TO THE PRO-ONCOGENIC PROTEIN TYROSINE PHOSPHATASE SHP2 AND THEREBY DEREGULATES THE PHOSPHATASE ACTIVITY(11,12), WHICH HAS BEEN CONSIDERED TO PLAY AN IMPORTANT ROLE IN GASTRIC CARCINOGENESIS(13). HERE WE SHOW THAT THE SHP2 HOMOLOGUE SHP1 INTERACTS WITH CAGA INDEPENDENTLY OF THE EPIYA MOTIF. THE INTERACTION POTENTIATES THE PHOSPHATASE ACTIVITY OF SHP1 THAT DAMPENS THE ONCOGENIC ACTION OF CAGA BY DEPHOSPHORYLATING THE CAGA EPIYA MOTIFS. IN VITRO INFECTION OF GASTRIC EPITHELIAL CELLS WITH EBV INDUCES SHP1 PROMOTER HYPERMETHYLATION, WHICH STRENGTHENS PHOSPHORYLATION-DEPENDENT CAGA ACTION VIA EPIGENETIC DOWNREGULATION OF SHP1 EXPRESSION. CLINICAL SPECIMENS OF EBV-POSITIVE GASTRIC CANCERS ALSO EXHIBIT SHP1 HYPERMETHYLATION WITH REDUCED SHP1 EXPRESSION. THE RESULTS REVEAL THAT SHP1 IS THE LONG-SOUGHT PHOSPHATASE THAT CAN ANTAGONIZE CAGA. AUGMENTED H. PYLORI CAGA ACTIVITY, VIA SHP1 INHIBITION, MIGHT ALSO CONTRIBUTE TO THE DEVELOPMENT OF EBV-POSITIVE GASTRIC CANCER. 2016 4 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 5 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 6 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 7 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 8 1540 30 DNA METHYLATION IN GASTRIC CANCER, RELATED TO HELICOBACTER PYLORI AND EPSTEIN-BARR VIRUS. GASTRIC CANCER IS A LEADING CAUSE OF CANCER DEATH WORLDWIDE, AND SIGNIFICANT EFFORT HAS BEEN FOCUSED ON CLARIFYING THE PATHOLOGY OF GASTRIC CANCER. IN PARTICULAR, THE DEVELOPMENT OF GENOME-WIDE ANALYSIS TOOLS HAS ENABLED THE DETECTION OF GENETIC AND EPIGENETIC ALTERATIONS IN GASTRIC CANCER; FOR EXAMPLE, ABERRANT DNA METHYLATION IN GENE PROMOTER REGIONS IS THOUGHT TO PLAY A CRUCIAL ROLE IN GASTRIC CARCINOGENESIS. THE ETIOLOGICAL VIEWPOINT IS ALSO ESSENTIAL FOR THE STUDY OF GASTRIC CANCERS, AND TWO DISTINCT PATHOGENS, HELICOBACTER PYLORI (H. PYLORI) AND EPSTEIN-BARR VIRUS (EBV), ARE KNOWN TO PARTICIPATE IN GASTRIC CARCINOGENESIS. CHRONIC INFLAMMATION OF THE GASTRIC EPITHELIUM DUE TO H. PYLORI INFECTION INDUCES ABERRANT POLYCLONAL METHYLATION THAT MAY LEAD TO AN INCREASED RISK OF GASTRIC CANCER. IN ADDITION, EBV INFECTION IS KNOWN TO CAUSE EXTENSIVE METHYLATION, AND EBV-POSITIVE GASTRIC CANCERS DISPLAY A HIGH METHYLATION EPIGENOTYPE, IN WHICH ABERRANT METHYLATION EXTENDS TO NOT ONLY POLYCOMB REPRESSIVE COMPLEX (PRC)-TARGET GENES IN EMBRYONIC STEM CELLS BUT ALSO NON-PRC-TARGET GENES. HERE, WE REVIEW ABERRANT DNA METHYLATION IN GASTRIC CANCER AND THE ASSOCIATION BETWEEN METHYLATION AND INFECTION WITH H. PYLORI AND EBV. 2014 9 6381 31 THE ROLE OF ONCOGENIC DNA VIRUSES IN PENILE CANCER DEVELOPMENT. PENILE CANCER IS A RELATIVELY RARE NEOPLASIA IN DEVELOPED COUNTRIES, WITH SIGNIFICANT MORBIDITY AND MORTALITY IN DEVELOPING COUNTRIES. PENILE CANCER CAN BE SUBDIVIDED INTO HUMAN PAPILLOMAVIRUS (HPV)-POSITIVE AND HPV-NEGATIVE CASES. WORLDWIDE, THE HPV PREVALENCE IN PENILE CANCER SAMPLES IS AROUND 50%, AND HPV16 IS THE MOST PREVALENT GENOTYPE. ALTHOUGH HPV IS AN IMPORTANT FACTOR FOR CANCER DEVELOPMENT, OTHER ONCOGENIC FACTORS MAY BE ASSOCIATED WITH CARCINOGENESIS. SOME OF THESE FACTORS CAN BE INFECTIOUS, SUCH AS THE EPSTEIN-BARR VIRUS (EBV), AS WELL AS THE MERKEL CELL POLYOMAVIRUS (MCPYV). THE PREVALENCE RATES OF NEARLY 50% FOR BOTH HPV AND EBV INFECTIONS INDICATE AN IMPORTANT ROLE OF THESE VIRUSES IN PENILE TISSUE MALIGNANCY, REINFORCING THE IDEA OF A MULTIFACTORIAL ETIOLOGY OF THE DISEASE. ALTHOUGH THE HPV ROLE IS BETTER UNDERSTOOD, EBV IS THOUGHT TO FACILITATE PERSISTENCE, INTEGRATION, AND MUTATIONS. RECENT STUDIES ON THE MERKEL CELL POLYOMAVIRUS HAVE NOT SHOWN A RELEVANT PREVALENCE IN PENILE CANCER SAMPLES, BUT ITS PRESENCE INDICATES THE OPPORTUNISTIC INFECTIOUS POTENTIAL OF THIS VIRUS. REGARDING HPV-NEGATIVE CASES, THE LITERATURE SUGGESTS A LINK WITH YOUNGER AGE AND EPIGENETIC ALTERATIONS, MAINLY THROUGH THE P16INK4A PATHWAY. RECENTLY, SEVERAL BIOMARKERS THAT MIGHT ACT AS PROGNOSTIC TOOLS (E.G., KI-67, SQUAMOUS CELL CARCINOMA ANTIGEN, AMONG OTHERS) HAVE BEEN PROPOSED, BUT THE RESULTS REMAIN CONTROVERSIAL. IN ADDITION, OTHER RISK FACTORS HAVE ALSO BEEN ASSOCIATED WITH PENILE CARCINOGENESIS, SUCH AS THE PRESENCE OF PHIMOSIS, NONCIRCUMCISION, CHRONIC INFLAMMATION, AND NUMBER OF SEXUAL PARTNERS. FURTHER STUDIES ARE NEEDED TO DEVELOP TOOLS FOR EARLY DETECTION AND EPIDEMIOLOGICAL SURVEILLANCE OF PENILE CANCER. 2019 10 2662 41 EPSTEIN-BARR VIRUS AND MULTIPLE SCLEROSIS: A CONVOLUTED INTERACTION AND THE OPPORTUNITY TO UNRAVEL PREDICTIVE BIOMARKERS. SINCE THE EARLY 1980S, EPSTEIN-BARR VIRUS (EBV) INFECTION HAS BEEN DESCRIBED AS ONE OF THE MAIN RISK FACTORS FOR DEVELOPING MULTIPLE SCLEROSIS (MS), AND RECENTLY, NEW EPIDEMIOLOGICAL EVIDENCE HAS REINFORCED THIS PREMISE. EBV SEROCONVERSION PRECEDES ALMOST 99% OF THE NEW CASES OF MS AND LIKELY PREDATES THE FIRST CLINICAL SYMPTOMS. THE MOLECULAR MECHANISMS OF THIS ASSOCIATION ARE COMPLEX AND MAY INVOLVE DIFFERENT IMMUNOLOGICAL ROUTES, PERHAPS ALL RUNNING IN PARALLEL (I.E., MOLECULAR MIMICRY, THE BYSTANDER DAMAGE THEORY, ABNORMAL CYTOKINE NETWORKS, AND COINFECTION OF EBV WITH RETROVIRUSES, AMONG OTHERS). HOWEVER, DESPITE THE LARGE AMOUNT OF EVIDENCE AVAILABLE ON THESE TOPICS, THE ULTIMATE ROLE OF EBV IN THE PATHOGENESIS OF MS IS NOT FULLY UNDERSTOOD. FOR INSTANCE, IT IS UNCLEAR WHY AFTER EBV INFECTION SOME INDIVIDUALS DEVELOP MS WHILE OTHERS EVOLVE TO LYMPHOPROLIFERATIVE DISORDERS OR SYSTEMIC AUTOIMMUNE DISEASES. IN THIS REGARD, RECENT STUDIES SUGGEST THAT THE VIRUS MAY EXERT EPIGENETIC CONTROL OVER MS SUSCEPTIBILITY GENES BY MEANS OF SPECIFIC VIRULENCE FACTORS. SUCH GENETIC MANIPULATION HAS BEEN DESCRIBED IN VIRALLY-INFECTED MEMORY B CELLS FROM PATIENTS WITH MS AND ARE THOUGHT TO BE THE MAIN SOURCE OF AUTOREACTIVE IMMUNE RESPONSES. YET, THE ROLE OF EBV INFECTION IN THE NATURAL HISTORY OF MS AND IN THE INITIATION OF NEURODEGENERATION IS EVEN LESS CLEAR. IN THIS NARRATIVE REVIEW, WE WILL DISCUSS THE AVAILABLE EVIDENCE ON THESE TOPICS AND THE POSSIBILITY OF HARNESSING SUCH IMMUNOLOGICAL ALTERATIONS TO UNCOVER PREDICTIVE BIOMARKERS FOR THE ONSET OF MS AND PERHAPS FACILITATE PROGNOSTICATION OF THE CLINICAL COURSE. 2023 11 3597 44 IMPLICATIONS OF VIRAL INFECTIONS AND ONCOGENESIS IN UTERINE CERVICAL CARCINOMA ETIOLOGY AND PATHOGENESIS. BACKGROUND: UTERINE CERVICAL CARCINOMA (UCC) IS THE MOST PREVALENT GYNECOLOGICAL MALIGNANCY GLOBALLY, WITH A RISING INCIDENCE IN RECENT YEARS. ACCUMULATING EVIDENCE INDICATES THAT SPECIFIC VIRAL INFECTIONS, INCLUDING HUMAN PAPILLOMAVIRUS (HPV), EPSTEIN-BARR VIRUS (EBV), HEPATITIS B AND C VIRUSES (HBV AND HCV), AND HUMAN HERPESVIRUS (HHV), MAY CONTRIBUTE TO UCC DEVELOPMENT AND PROGRESSION. UNDERSTANDING THE COMPLEX INTERPLAY BETWEEN VIRAL INFECTIONS AND UCC RISK IS CRUCIAL FOR DEVELOPING NOVEL PREVENTATIVE AND THERAPEUTIC INTERVENTIONS. METHODS: THIS COMPREHENSIVE REVIEW INVESTIGATES THE ASSOCIATION BETWEEN VIRAL INFECTIONS AND UCC RISK BY EXAMINING THE ROLES OF VARIOUS VIRAL PATHOGENS IN UCC ETIOLOGY AND PATHOGENESIS, AND POSSIBLE MOLECULAR MECHANISMS. ADDITIONALLY, WE EVALUATE CURRENT DIAGNOSTIC METHODS AND POTENTIAL THERAPEUTIC STRATEGIES TARGETING VIRAL INFECTIONS FOR UCC PREVENTION OR TREATMENT. RESULTS: THE PREVENTION OF UCC HAS BEEN SIGNIFICANTLY ADVANCED BY THE EMERGENCE OF SELF-SAMPLING FOR HPV TESTING AS A CRUCIAL TOOL, ALLOWING FOR EARLY DETECTION AND INTERVENTION. HOWEVER, AN ESSENTIAL CHALLENGE IN UCC PREVENTION LIES IN UNDERSTANDING HOW HPV AND OTHER VIRAL COINFECTIONS, INCLUDING EBV, HBV, HCV, HHV, HIV, OR THEIR CONCURRENT PRESENCE, MAY POTENTIALLY CONTRIBUTE TO UCC DEVELOPMENT. THE MOLECULAR MECHANISMS IMPLICATED IN THE ASSOCIATION BETWEEN VIRAL INFECTIONS AND CERVICAL CANCER DEVELOPMENT INCLUDE: (1) INTERFERENCE OF VIRAL ONCOGENES WITH CELLULAR REGULATORY PROTEINS, RESULTING IN UNCONTROLLED CELL PROLIFERATION AND MALIGNANT TRANSFORMATION; (2) INACTIVATION OF TUMOR SUPPRESSOR GENES BY VIRAL PROTEINS; (3) EVASION OF HOST IMMUNE RESPONSES BY VIRUSES; (4) INDUCTION OF A PERSISTENT INFLAMMATORY RESPONSE, CONTRIBUTING TO A TUMOR-PROMOTING MICROENVIRONMENT; (5) EPIGENETIC MODIFICATIONS THAT LEAD TO ABERRANT GENE EXPRESSION; (6) STIMULATION OF ANGIOGENESIS BY VIRUSES; AND (7) ACTIVATION OF TELOMERASE BY VIRAL PROTEINS, LEADING TO CELLULAR IMMORTALIZATION. ADDITIONALLY, VIRAL COINFECTIONS CAN ALSO ENHANCE ONCOGENIC POTENTIAL THROUGH SYNERGISTIC INTERACTIONS BETWEEN VIRAL ONCOPROTEINS, EMPLOY IMMUNE EVASION STRATEGIES, CONTRIBUTE TO CHRONIC INFLAMMATION, MODULATE HOST CELLULAR SIGNALING PATHWAYS, AND INDUCE EPIGENETIC ALTERATIONS, ULTIMATELY LEADING TO CERVICAL CARCINOGENESIS. CONCLUSION: RECOGNIZING THE IMPLICATIONS OF VIRAL ONCOGENES IN UCC ETIOLOGY AND PATHOGENESIS IS VITAL FOR ADDRESSING THE ESCALATING BURDEN OF UCC. DEVELOPING INNOVATIVE PREVENTATIVE AND THERAPEUTIC INTERVENTIONS REQUIRES A THOROUGH UNDERSTANDING OF THE INTRICATE RELATIONSHIP BETWEEN VIRAL INFECTIONS AND UCC RISK. 2023 12 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 13 5276 35 PROMOTER METHYLATION OF TUMOR-RELATED GENES IN GASTRIC CARCINOGENESIS. ABERRANT PROMOTER METHYLATION AND SUBSEQUENT SILENCING OF CANCER-RELATED GENES HAS BEEN RECOGNIZED AS AN IMPORTANT PATHWAY INVOLVED IN GASTRIC CARCINOGENESIS. IN FACT, SEVERAL FACTORS ARE BELIEVED TO CONTRIBUTE TO ITS INDUCTION IN GASTRIC EPITHELIA, INCLUDING AGING, DIET, CHRONIC INFLAMMATION AND INFECTION OF HELICOBACTER PYLORI (H. PYLORI) AND EPSTEIN-BARR VIRUS (EBV). HOWEVER, THE UNDERLING MECHANISMS ARE NOT COMPLETELY IDENTIFIED, DESPITE THE BELIEF THAT INCREASED EXPRESSION OR ACTIVITY OF DNA METHYLTRANSFERASES (DNMTS), OR DECREASED DEMETHYLATION ACTIVITY MAY CONTRIBUTE TO THE EXCESSIVE METHYLATION. A GREAT NUMBER OF GENES WITH PROMOTER METHYLATION HAVE BEEN OBSERVED IN GASTRIC CANCER (GC), AMONG WHICH P16INK4A (P16), MUT L HOMOLOGUE 1 (MLH1), EPITHELIAL-CADHERIN (E-CADHERIN), RUNT-RELATED TRANSCRIPTION FACTOR 3 (RUNX3), ADENOMATOUS POLYPOSIS COLI (APC), O(6)-METHYLGUANINE-DNA METHYLTRANSFERASE (MGMT), RAS ASSOCIATION DOMAIN FAMILY 1A (RASSF1A) AND DEATH-ASSOCIATED PROTEIN KINASE (DAPK) HAVE BEEN EXTENSIVELY STUDIED. UNLIKE THE DISTINCT METHYLATION CHARACTERIZATION IN SINGLE GENES, METHYLATION ANALYSIS OF MULTIPLE GENES MAY PROVIDE MORE INFORMATION IN RISK PREDICTION, EARLY DETECTION, PROGNOSIS ASSESSMENT AND CHEMOTHERAPY CHOICE FOR GC. SPECIFICALLY, PARTICULAR MONITORING AND SCREENING SHOULD BE PERFORMED ON THOSE OVER 45 YEARS OLD, WITH PRECANCEROUS GASTRIC DISEASE OR INFECTION OF H. PYLORI OR EBV. AS AN ALTERNATIVE TO TUMOR TISSUES, METHYLATION DETECTION IN PATIENT SERA OR GASTRIC WASHES MAY ALSO BE USED IN RISK PREDICTION AND EARLY DETECTION. HOWEVER, WHAT STILL POSES A GREAT CHALLENGE AS WELL AS A PUZZLE IS THE DETERMINATION OF THE VERY GENES THAT SHOULD BE USED IN METHYLATION ANALYSIS. BECAUSE EPIGENETIC ALTERATIONS ARE NORMALLY REVERSIBLE, DRUGS OR CHEMICAL COMPOUNDS WITH DEMETHYLATING ACTIVITY, SUCH AS 5-AZA-2'-DEOXYCYTIDINE (5-AZA-DC) COULD BE USED IN THE TREATMENT OF PATIENTS WITH MULTIPLE GENE METHYLATION. IN VIEW OF THE ADVERSE EFFECTS OF 5-AZA-DC, DNMT-TARGETED STRATEGY HAS BEEN PROPOSED AND MAY PROVE TO BE MORE EFFECTIVE THAN DEMETHYLATING AGENTS. 2012 14 4409 27 MOLECULAR ANATOMY AND PATHOGENIC ACTIONS OF HELICOBACTER PYLORI CAGA THAT UNDERPIN GASTRIC CARCINOGENESIS. CHRONIC INFECTION WITH HELICOBACTER PYLORI CAGA-POSITIVE STRAINS IS THE STRONGEST RISK FACTOR FOR GASTRIC CANCER. THE CAGA GENE PRODUCT, CAGA, IS DELIVERED INTO GASTRIC EPITHELIAL CELLS VIA THE BACTERIAL TYPE IV SECRETION SYSTEM. DELIVERED CAGA THEN UNDERGOES TYROSINE PHOSPHORYLATION AT THE GLU-PRO-ILE-TYR-ALA (EPIYA) MOTIFS IN ITS C-TERMINAL REGION AND ACTS AS AN ONCOGENIC SCAFFOLD PROTEIN THAT PHYSICALLY INTERACTS WITH MULTIPLE HOST SIGNALING PROTEINS IN BOTH TYROSINE PHOSPHORYLATION-DEPENDENT AND -INDEPENDENT MANNERS. ANALYSIS OF CAGA USING IN VITRO CULTURED GASTRIC EPITHELIAL CELLS HAS INDICATED THAT THE NONPHYSIOLOGICAL SCAFFOLDING ACTIONS OF CAGA CELL-AUTONOMOUSLY PROMOTE THE MALIGNANT TRANSFORMATION OF THE CELLS BY ENDOWING THE CELLS WITH MULTIPLE PHENOTYPIC CANCER HALLMARKS: SUSTAINED PROLIFERATION, EVASION OF GROWTH SUPPRESSORS, INVASIVENESS, RESISTANCE TO CELL DEATH, AND GENOMIC INSTABILITY. TRANSGENIC EXPRESSION OF CAGA IN MICE LEADS TO IN VIVO ONCOGENIC ACTION OF CAGA WITHOUT ANY OVERT INFLAMMATION. THE IN VIVO ONCOGENIC ACTIVITY OF CAGA IS FURTHER POTENTIATED IN THE PRESENCE OF CHRONIC INFLAMMATION. SINCE HELICOBACTER PYLORI INFECTION TRIGGERS A PROINFLAMMATORY RESPONSE IN HOST CELLS, A FEEDFORWARD STIMULATION LOOP THAT AUGMENTS THE ONCOGENIC ACTIONS OF CAGA AND INFLAMMATION IS CREATED IN CAGA-INJECTED GASTRIC MUCOSA. GIVEN THAT HELICOBACTER PYLORI IS NO LONGER COLONIZED IN ESTABLISHED GASTRIC CANCER LESIONS, THE MULTISTEP NATURE OF GASTRIC CANCER DEVELOPMENT SHOULD INCLUDE A "HIT-AND-RUN" PROCESS OF CAGA ACTION. THUS, ACQUISITION OF GENETIC AND EPIGENETIC ALTERATIONS THAT COMPENSATE FOR CAGA-DIRECTED CANCER HALLMARKS MAY BE REQUIRED FOR COMPLETION OF THE "HIT-AND-RUN" PROCESS OF GASTRIC CARCINOGENESIS. 2020 15 4596 33 NATURAL KILLER CELLS IN HUMAN IMMUNODEFICIENCY VIRUS-1 INFECTION: SPOTLIGHT ON THE IMPACT OF HUMAN CYTOMEGALOVIRUS. HUMAN CYTOMEGALOVIRUS (HCMV) HAS BEEN CLOSELY ASSOCIATED WITH THE HUMAN RACE ACROSS EVOLUTIONARY TIME. HCMV CO-INFECTION IS NEARLY UNIVERSAL IN HUMAN IMMUNODEFICIENCY VIRUS-1 (HIV-1)-INFECTED INDIVIDUALS AND REMAINS AN IMPORTANT COFACTOR IN HIV-1 DISEASE PROGRESSION EVEN IN THE ERA OF EFFECTIVE ANTIRETROVIRAL TREATMENT. HCMV INFECTION HAS BEEN SHOWN TO HAVE A BROAD AND POTENT INFLUENCE ON THE HUMAN IMMUNE SYSTEM AND HAS BEEN LINKED WITH THE DISCOVERY AND CHARACTERIZATION OF ADAPTIVE NATURAL KILLER (NK) CELLS. DISTINCT NK-CELL SUBSETS, PREDOMINATELY EXPRESSING THE ACTIVATING RECEPTOR NKG2C AND THE MARKER OF TERMINAL DIFFERENTIATION CD57, EXPAND IN RESPONSE TO HCMV. THESE NK-CELL POPULATIONS ENGAGED IN THE LONG-LASTING INTERACTION WITH HCMV, IN ADDITION TO CHARACTERISTIC BUT VARIABLE EXPRESSION OF SURFACE RECEPTORS, EXHIBIT REDUCED EXPRESSION OF SIGNALING PROTEINS AND TRANSCRIPTION FACTORS EXPRESSED BY CANONICAL NK CELLS. BROAD EPIGENETIC MODIFICATIONS DRIVE THE EMERGENCE AND PERSISTENCE OF HCMV-ADAPTED NK CELLS THAT HAVE DISTINCT FUNCTIONAL CHARACTERISTICS. NKG2C(+) NK-CELL EXPANSIONS HAVE BEEN OBSERVED IN HIV-1 INFECTED PATIENTS AND OTHER ACUTE AND CHRONIC VIRAL INFECTIONS BEING SYSTEMATICALLY ASSOCIATED WITH HCMV SEROPOSITIVITY. THE LATTER IS POTENTIALLY AN IMPORTANT CONFOUNDING VARIABLE IN STUDIES FOCUSED ON THE CELLULAR NK-CELL RECEPTOR REPERTOIRE AND FUNCTIONAL CAPACITY. HERE, FOCUSING ON HIV-1 INFECTION WE REVIEW THE EVIDENCE IN FAVOR OF "ADAPTIVE" CHANGES LIKELY INDUCED BY HCMV CO-INFECTION IN NK-CELL SUBSETS. WE HIGHLIGHT A NUMBER OF KEY QUESTIONS AND HOW INSIGHTS INTO THE ADAPTIVE BEHAVIOR OF NK CELLS WILL INFORM NEW STRATEGIES EXPLOITING THEIR UNIQUE PROPERTIES IN THE FIGHT AGAINST HIV-1. 2017 16 6841 34 [MECHANISMS OF H. PYLORI INFECTION-INDUCED GASTRIC CARCINOGENESIS]. MANY EPIDEMIOLOGICAL STUDIES HAVE DEMONSTRATED A STRONG ASSOCIATION BETWEEN H. PYLORI (HELICOBACTER PYLORI) INFECTION AND HUMAN GASTRIC CANCER DEVELOPMENT. THE PRECISE MECHANISMS ACCOUNTING FOR GASTRIC CANCER DEVELOPMENT INDUCED BY H. PYLORI INFECTION ARE STILL NOT COMPLETELY UNDERSTOOD. HOWEVER, IT SHOULD BE REASONABLE TO ASSUME THAT THERE ARE TWO DISTINCT MOLECULAR PATHWAYS FOR GASTRIC CARCINOGENESIS BY H. PYLORI INFECTION; THE DIRECT ACTION OF THE BACTERIA ITSELF ON GASTRIC EPITHELIAL CELLS, AND THE ACCUMULATION OF GENETIC CHANGES CAUSED BY PROLONGED BACTERIAL INFECTION AND CHRONIC INFLAMMATION. AS A DIRECT ACTION OF H. PYLORI, BACTERIAL PROTEINS SUCH AS CAGA COULD BE DELIVERED INTO GASTRIC EPITHELIAL CELLS VIA THE TYPE IV SECRETION APPARATUS AND MODIFY THE HOST CELL FUNCTIONS RELATED TO CELL PROLIFERATION. IN ADDITION TO THE DIRECT BACTERIAL ACTION, H. PYLORI INFECTION AND THE RESULTANT INFLAMMATORY RESPONSE CAUSE VARIOUS GENETIC AND EPIGENETIC CHANGES IN TUMOR-RELATED GENES OF THE GASTRIC EPITHELIAL CELLS. NOTABLY, EXPRESSION OF AID (ACTIVATION-INDUCED CYTIDINE DEAMINASE), A DNA EDITING ENZYME THAT UNDERGOES SOMATIC HYPERMUTATION ON HUMAN GENES, IS INDUCED IN RESPONSE TO H. PYLORI INFECTION AND PROINFLAMMATORY CYTOKINE STIMULATION IN HUMAN GASTRIC EPITHELIAL CELLS. AS A RESULT, THE ACCUMULATION OF GENETIC ALTERATIONS WOULD PERSIST UNTIL THE CLINICAL STAGE OF ATROPHIC GASTRITIS AND EVENTUALLY TRIGGER THE MALIGNANT TRANSFORMATION OF GASTRIC CELLS. 2010 17 3232 20 HELICOBACTER PYLORI-INDUCED SIGNALING PATHWAYS CONTRIBUTE TO INTESTINAL METAPLASIA AND GASTRIC CARCINOGENESIS. HELICOBACTER PYLORI (H. PYLORI) INDUCES CHRONIC GASTRIC INFLAMMATION, ATROPHIC GASTRITIS, INTESTINAL METAPLASIA, AND CANCER. ALTHOUGH THE RISK OF GASTRIC CANCER INCREASES EXPONENTIALLY WITH THE EXTENT OF ATROPHIC GASTRITIS, THE PRECISE MECHANISMS OF GASTRIC CARCINOGENESIS HAVE NOT BEEN FULLY ELUCIDATED. H. PYLORI INDUCES GENETIC AND EPIGENETIC CHANGES IN GASTRIC EPITHELIAL CELLS THROUGH ACTIVATING INTRACELLULAR SIGNALING PATHWAYS IN A CAGPAI-DEPENDENT MANNER. H. PYLORI EVENTUALLY INDUCES GASTRIC CANCER WITH CHROMOSOMAL INSTABILITY (CIN) OR MICROSATELLITE INSTABILITY (MSI), WHICH ARE CLASSIFIED AS TWO MAJOR SUBTYPES OF GASTRIC CANCER. ELUCIDATION OF THE PRECISE MECHANISMS OF GASTRIC CARCINOGENESIS WILL ALSO BE IMPORTANT FOR CANCER THERAPY. 2015 18 3229 22 HELICOBACTER PYLORI-INDUCED GASTRIC INFLAMMATION AND GASTRIC CANCER. HELICOBACTER PYLORI (H. PYLORI) INFECT OVER HALF OF THE WORLD'S POPULATION. THE PREVALENCE OF H. PYLORI INFECTION AND THE PREDOMINANT GENOTYPE OF H. PYLORI VIRULENCE FACTORS VARY CONSIDERABLY ACROSS DIFFERENT GEOGRAPHICAL REGIONS. H. PYLORI COULD UNIQUELY PERSIST FOR DECADES IN THE HARSH STOMACH ENVIRONMENT, WHERE IT DAMAGES THE GASTRIC MUCOSA AND CHANGES THE PATTERN OF GASTRIC HORMONE RELEASE, THEREBY AFFECTS GASTRIC PHYSIOLOGY. BY UTILIZING VARIOUS VIRULENCE FACTORS, H. PYLORI TARGETS DIFFERENT CELLULAR PROTEINS TO MODULATE THE HOST INFLAMMATORY RESPONSE AND INITIATE MULTIPLE "HITS" ON THE GASTRIC MUCOSA, RESULTING IN CHRONIC GASTRITIS AND PEPTIC ULCERATION. AMONG THE LONG-TERM CONSEQUENCES OF H. PYLORI INFECTION IS GASTRIC MALIGNANCIES, PARTICULARLY GASTRIC CANCER (GC) AND GASTRIC MUCOSA-ASSOCIATED LYMPHOID TISSUE (MALT) LYMPHOMA. AS SUCH, H. PYLORI HAS BEEN RECOGNIZED AS A CLASS I CARCINOGEN BY THE INTERNATIONAL AGENCY FOR RESEARCH ON CANCER. DESPITE A CLOSE CAUSAL LINK BETWEEN H. PYLORI INFECTION AND THE DEVELOPMENT OF GASTRIC MALIGNANCIES, THE PRECISE MECHANISMS INVOLVED IN THIS PROCESS ARE STILL OBSCURE. STUDIES OVER THE PAST TWO DECADES HAVE REVEALED THAT H. PYLORI EXERT ONCOGENIC EFFECTS ON GASTRIC MUCOSA THROUGH A COMPLEX INTERACTION BETWEEN BACTERIAL FACTORS, HOST FACTORS, AND ENVIRONMENTAL FACTORS. NUMEROUS SIGNALING PATHWAYS CAN BE ACTIVATED BY H. PYLORI. IN THIS REVIEW, WE AIM TO ELABORATE ON THE RECENT DEVELOPMENTS IN THE PATHOPHYSIOLOGICAL MECHANISMS OF H. PYLORI-INDUCED GASTRIC INFLAMMATION AND GASTRIC CANCER. 2014 19 3226 29 HELICOBACTER PYLORI INFECTION, ONCOGENIC PATHWAYS AND EPIGENETIC MECHANISMS IN GASTRIC CARCINOGENESIS. CHRONIC COLONIZATION OF THE HUMAN STOMACH BY HELICOBACTER PYLORI, A GRAM-NEGATIVE BACTERIUM, IS THE MAJOR CAUSE OF CHRONIC GASTRITIS, PEPTIC ULCERS AND GASTRIC CANCER. RECENT PROGRESS HAS ELUCIDATED IMPORTANT BACTERIAL AND HOST FACTORS THAT ARE RESPONSIBLE FOR H. PYLORI-INDUCED GASTRIC INFLAMMATION AND GASTRIC MALIGNANCY. H. PYLORI CYTOTOXIN-ASSOCIATED ANTIGEN A IS THE MAJOR ONCOGENIC FACTOR INJECTED INTO HOST CELLS FROM BACTERIA AND IT DISRUPTS EPITHELIAL CELL FUNCTIONS. TOGETHER WITH H. PYLORI CAG PATHOGENICITY ISLAND, IT CAUSES GENERAL INFLAMMATORY STRESS WITHIN GASTRIC MUCOSA AND ACTIVATES MULTIPLE ONCOGENIC PATHWAYS IN EPITHELIAL CELLS. A GROWING LIST OF THESE PATHWAYS INCLUDES NF-KAPPAB, ACTIVATOR PROTEIN-1, PI3K, SIGNAL TRANSDUCERS AND ACTIVATORS OF TRANSCRIPTION 3, WNT/BETA-CATENIN AND CYCLOOXYGENASE 2. H. PYLORI INDUCES EPIGENETIC ALTERATIONS, SUCH AS DNA METHYLATION AND HISTONE MODIFICATION, WHICH PLAY CRITICAL ROLES IN ONCOGENIC TRANSFORMATION. IN ADDITION, INVESTIGATIONS INTO GASTRIC STEM CELL OR PROGENITOR CELL BIOLOGY HAVE SHED LIGHT ON THE MECHANISMS THROUGH WHICH GASTRIC CANCER MAY ORIGINATE. CONTINUED INVESTIGATION IN THESE AREAS WILL YIELD NOVEL INSIGHTS AND HELP TO ELUCIDATE THE MECHANISMS OF BACTERIA-INDUCED CARCINOGENESIS. 2010 20 1478 26 DIVERSE ROLES OF HEPATITIS B VIRUS IN LIVER CANCER. HEPATITIS B VIRUS (HBV) IS A WIDESPREAD HUMAN PATHOGEN RESPONSIBLE FOR ACUTE AND CHRONIC LIVER DISEASES. THE HEPATITIS B BURDEN IS PARTICULARLY HEAVY IN ENDEMIC COUNTRIES, WHERE LIVER CIRRHOSIS AND HEPATOCELLULAR CARCINOMA ARE LEADING CAUSES OF DEATH. HOWEVER, THE ONCOGENIC ROLE OF HBV REMAINS ENIGMATIC. AS THE VIRUS HAS NO CYTOPATHIC EFFECT, LIVER DAMAGE IS ATTRIBUTED TO IMMUNE RESPONSES THAT INDUCE INFLAMMATION, APOPTOSIS AND REGENERATION, FOSTERING THE ACCUMULATION OF GENETIC AND EPIGENETIC ALTERATIONS. IN A MORE DIRECT ACTION, FREQUENT INTEGRATION OF HBV DNA INTO HOST CHROMOSOMES MAY LEAD TO INSERTIONAL MUTAGENESIS OF CANCER-RELATED GENES AND CHROMOSOMAL INSTABILITY. HBV PROTEINS, NOTABLY THE HBX TRANSACTIVATOR, PARTICIPATE AS CO-FACTORS IN ONCOGENESIS. BETTER UNDERSTANDING OF HEPATITIS B PATHOGENESIS IS MANDATORY FOR IMPROVING DISEASE MANAGEMENT. 2012