1 1419 131 DIFFERENT CLINICAL FORMS OF HEREDITARY TYROSINEMIA (TYPE I) IN PATIENTS WITH IDENTICAL GENOTYPES. HEREDITARY TYROSINEMIA TYPE I (HTI, MCKUSICK 276700) IS AN AUTOSOMAL RECESSIVE DISEASE CAUSED BY DEFICIENT FUMARYLACETOACETATE HYDROLASE (FAH, EC 3.7.1.2) ACTIVITY. HTI IS CHARACTERIZED BY PROGRESSIVE LIVER DYSFUNCTION WITH NODULAR CIRRHOSIS OFTEN LEADING TO HEPATOCELLULAR CARCINOMA. TWO EXTREMES OF THE CLINICAL PHENOTYPE HAVE BEEN DESCRIBED: THE "ACUTE" (SEVERE, EARLY ONSET AND DEATH) AND "CHRONIC" (DELAYED ONSET AND SLOW COURSE) PHENOTYPE. ALLELIC HETEROGENEITY AND/OR MUTATION REVERSION IN HEPATIC CELLS HAVE BEEN PROPOSED EARLIER TO EXPLAIN THE CLINICAL HETEROGENEITY. TWO PROBANDS (ONE "ACUTE," ONE "CHRONIC") FROM THE FRENCH-CANADIAN ISOLATE WHERE HTI IS PREVALENT WERE STUDIED. BOTH WERE HOMOZYGOUS (GERM LINE) FOR THE SEVERE SPLICE MUTATION IVS12 + 5G --> A; BOTH SHOWED LIVER MOSAICISM FOR FAH IMMUNOREACTIVITY WITH EVIDENCE FOR MUTATION REVERSION TO HETEROZYGOSITY (IVS12 + 5G --> A/+) IN FAH-STAINED NODULES AS SHOWN BY AMPLIFICATION OF DNA EXTRACTED FROM MICRODISSECTED NODULES. WESTERN BLOT ANALYSIS OF PROTEINS FROM A REVERTED FAH-EXPRESSING NODULE SHOWED 29 +/- 3% FAH IMMUNOREACTIVE MATERIAL AS COMPARED TO AN AVERAGE NORMAL LIVER. THIS WAS CONSISTENT WITH THE MEASURED FAA HYDROLYTIC ACTIVITY (25%) IN THIS LARGE REGENERATING NODULE. THESE FINDINGS SHOW THAT GENOTYPIC HETEROGENEITY IS NOT A SUFFICIENT EXPLANATION FOR CLINICAL HETEROGENEITY AND IMPLICATE EPIGENETIC AND OTHER FACTORS MODIFYING THE PHENOTYPE IN HTI. 1998 2 1067 30 CLINICAL UTILITY OF PDSS2 EXPRESSION TO STRATIFY PATIENTS AT RISK FOR RECURRENCE OF HEPATOCELLULAR CARCINOMA. IDENTIFICATION OF NOVEL GENETIC AND EPIGENETIC ALTERATIONS IS REQUIRED FOR OPTIMAL STRATIFICATION OF PATIENTS WITH HEPATOCELLULAR CARCINOMA (HCC) AT RISK FOR RECURRENCE AND ADVERSE PROGNOSIS. COENZYME Q10 (COQ10), WHICH MEDIATES APOPTOSIS, IS SYNTHESIZED BY PRENYL DIPHOSPHATE SYNTHASE SUBUNIT 2 (PDSS2). IN THE PRESENT STUDY WE EVALUATED THE CLINICAL SIGNIFICANCE AND REGULATORY MECHANISMS OF PDSS2 EXPRESSION IN HCC. PDSS2 EXPRESSION LEVELS AND THOSE OF GENES ENCODING POTENTIALLY INTERACTING PROTEINS AS WELL AS THE METHYLATION STATUS OF THE PDSS2 PROMOTER REGION WERE ANALYZED IN HCC CELL LINES. PDSS2 MRNA LEVELS IN 151 PAIRS OF RESECTED SPECIMENS WERE DETERMINED TO EVALUATE THE ASSOCIATION OF PDSS2 EXPRESSION AND CLINICOPATHOLOGICAL FACTORS. THE EXPRESSION AND DISTRIBUTION OF PDSS2 WERE DETERMINED USING IMMUNOHISTOCHEMISTRY. PDSS2 MRNA EXPRESSION WAS DECREASED IN SIX OF NINE HCC CELL LINES AND SIGNIFICANTLY CORRELATED WITH THOSE OF HEPATOCYTE NUCLEAR FACTOR 4ALPHA. PDSS2 TRANSCRIPTION IN HCC CELLS WITH DECREASED PDSS2 EXPRESSION ACCOMPANYING HYPERMETHYLATION WAS REACTIVATED AFTER TREATING THESE CELLS WITH A METHYLATION INHIBITOR. MEAN EXPRESSION LEVELS OF PDSS2 MRNA RELATIVE TO THAT OF UNINVOLVED LIVER DIMINISHED GRADUALLY IN THE ORDER OF CHRONIC HEPATITIS TO CIRRHOSIS, AND EACH WAS SIGNIFICANTLY HIGHER THAN THOSE OF HCCS. PDSS2 AND PDSS2 MRNA LEVELS WERE CONSISTENT. DECREASED PDSS2 MRNA LEVELS WERE DETECTED IN HCC TISSUES OF 56 PATIENTS, CORRELATED WITH SHORTER DISEASE-SPECIFIC SURVIVAL, AND WAS IDENTIFIED AS AN INDEPENDENT PROGNOSTIC FACTOR. PDSS2 IS A PUTATIVE TUMOR SUPPRESSOR, AND PROMOTER HYPERMETHYLATION IS A KEY REGULATORY MECHANISM IN HCC. DECREASED LEVELS OF PDSS2 MRNA EXPRESSION MAY REPRESENT A NOVEL BIOMARKER OF HCC. 2014 3 2974 28 GENETIC AND METHYLATION STATUS OF CDKN2A (P14(ARF)/P16(INK4A)) AND TP53 GENES IN RECURRENT RESPIRATORY PAPILLOMATOSIS. RECURRENT RESPIRATORY PAPILLOMATOSIS (RRP) IS A RARE AND CHRONIC DISEASE AFFECTING THE UPPER AIRWAY WITH PAPILLOMATOUS LESIONS CAUSED BY THE HUMAN PAPILLOMAVIRUS (HPV) INFECTION, ESPECIALLY HPV-6 AND/OR HPV-11 TYPES. LITTLE IS KNOWN ABOUT THE GENETIC AND EPIGENETIC DRIVERS IN RRP PATHOPHYSIOLOGY. FOR THIS PURPOSE, WE ANALYZED 27 PAPILLOMATOUS LESIONS FROM PATIENTS WITH RRP TO EVALUATE SOMATIC MUTATIONS AND METHYLATION STATUS IN CDKN2A (P14(ARF)/P16(INK4A)) AND TP53, WHICH ARE KEY TUMOR SUPPRESSOR GENES FOR THE CELL CYCLE CONTROL. SANGER SEQUENCING ANALYSIS REVEALED ONE SOMATIC MUTATION IN TP53 (C.733_734INSA) AND FOUR MUTATIONS IN CDKN2A (C.-30G > T, C.29_30INSA, C.69DELT, AND C.300C > A). THESE MUTATIONS WERE OBSERVED IN 10 PATIENTS, 6 OF WHICH CARRIED DOUBLE MUTATION. FURTHERMORE, 50% (5/10) OF THESE PATIENTS CARRYING SOMATIC MUTATIONS HAD RRP SEVERITY, REPRESENTING 62.5% (5/8) OF THE SEVERITY CASES IN THIS STUDY, ALBEIT NO SIGNIFICANT ASSOCIATION WAS FOUND BETWEEN SOMATIC MUTATIONS AND DISEASE SEVERITY. METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION ASSAYS REVEALED P14(ARF) PROMOTER HYPERMETHYLATION IN 100% OF CASES, FOLLOWED BY TP53 (96.3%) AND P16(INK4A) (55.6%), SUGGESTING THE INFLUENCE OF HPV IN THE DNA METHYLATION MACHINERY. IN CONCLUSION, SOMATIC MUTATIONS WERE NOT COMMON EVENTS IDENTIFIED IN PATIENTS WITH RRP. HOWEVER, EPIGENETIC MODULATION BY HIGH METHYLATION RATES, PARTICULARLY FOR THE P14(ARF)/TP53 PATHWAY, SEEMS TO BE IN THE COURSE OF RRP DEVELOPMENT. 2022 4 6636 35 UNRAVELING A NEW PLAYER IN MULTIPLE SCLEROSIS PATHOGENESIS: THE RNA-BINDING PROTEIN HUR. BACKGROUND: ELAV-LIKE PROTEINS ARE A SMALL FAMILY OF RNA-BINDING PROTEINS THAT ARE FUNDAMENTAL PLAYERS IN POST-TRANSCRIPTIONAL MECHANISMS AND ARE INVOLVED IN THE PATHOGENESIS OF NEUROLOGIC AND PSYCHIATRIC DISORDERS. HUR, THE UBIQUITOUSLY EXPRESSED MEMBER OF THE FAMILY, IS ALSO IMPLICATED IN SUSTAINING INFLAMMATION AND INFLAMMATORY DISEASES, SUPPORTING THE PRODUCTION OF PRO-INFLAMMATORY CYTOKINES. INFLAMMATION PLAYS A CENTRAL ROLE IN MULTIPLE SCLEROSIS (MS), WHICH REPRESENTS THE MOST COMMON CAUSE OF PERMANENT PHYSICAL DISABILITY IN YOUNG ADULTS. MS IS A CHRONIC AUTOIMMUNE DISEASE AFFECTING THE CENTRAL NERVOUS SYSTEM, WITH A COMPLEX AETIOLOGY INVOLVING GENETIC, ENVIRONMENTAL AND EPIGENETIC FACTORS. NO DATA ARE AVAILABLE ON THE POTENTIAL ENTANGLEMENT OF HUR IN MS PATHOGENESIS IN PATIENTS. IN THE PRESENT WORK, WE AIMED AT EXPLORING HUR PROTEIN LEVELS IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) FROM MS PATIENTS, COMPARED TO HEALTHY CONTROLS. TO FURTHER ELUCIDATE THE POSSIBLE INVOLVEMENT OF HUR IN MS, WE ALSO INVESTIGATED THE RELATIONSHIP BETWEEN THIS SPECIFIC RNA-BINDING PROTEIN AND HSP70-2 PROTEIN, ALSO CONSIDERING THE HSP70-2 RS1061581 POLYMORPHISM, GIVEN THAT HSP70-2 MRNA HAS BEEN REPORTED AS A HUR TARGET AND THIS SPECIFIC POLYMORPHISM TO BE ASSOCIATED WITH MS RISK. METHODS: ALLELES AND GENOTYPES FOR HSP70-2 RS1061581 POLYMORPHISM WERE ASSESSED, BY USING A POLYMERASE CHAIN REACTION-RESTRICTION FRAGMENT LENGTH POLYMORPHISM, FOLLOWED BY DIGESTION WITH RESTRICTION ENZYME, IN MS PATIENTS AND HEALTHY CONTROLS. PBMCS FROM A SUBGROUP OF PATIENTS AND CONTROLS WERE USED TO EVALUATE HUR AND HSP70-2 PROTEIN CONTENT BY WESTERN BLOT. RESULTS: PBMCS FROM 52 MS PATIENTS HAD A LOWER HUR AND HIGHER HSP70-2 PROTEIN CONTENT COMPARED TO 43 HEALTHY CONTROLS. AN INCREASE OF 100 UNITS OF HUR SIGNIFICANTLY DECREASED THE RISK OF DEVELOPING MS BY 9.8% (OR: 0.902, 95% CI: 0.83-0.98), CONTROLLING FOR HSP70-2 PROTEIN EXPRESSION, HSP70-2 RS1061581 GENOTYPE, AGE AND SEX. MOREOVER, HOLDING HUR LEVELS, AN INCREASE OF 100 UNITS OF HSP70-2 PROTEIN SIGNIFICANTLY INCREASED THE MS RISK BY 18.1% (OR: 1.181, 95% CI: 1.03-1.36) AND THE GENETIC SUSCEPTIBILITY OF DEVELOPING MS FOR HSP70-2 RS1061581 GG CARRIERS IS CONFIRMED. OF INTEREST, MS PATIENTS WITH A MODERATE TO SEVERE FORM OF MS (MSSS >/= 3) SHOWED A TREND TOWARDS A REDUCTION OF HUR PROTEIN LEVELS COMPARED TO PATIENTS WITH MILD DISEASE SEVERITY (MSSS < 3). CONCLUSIONS: HUR PROTEIN LEVELS ARE REDUCED IN MS PATIENTS COMPARED TO HEALTHY SUBJECTS, AND THE PROTEIN AMOUNT MAY CONTINUE TO DECLINE WITH DISEASE PROGRESSION, SUGGESTING A PUTATIVE ROLE OF THIS RNA-BINDING PROTEIN. MOREOVER, OUR RESULTS SUGGEST THAT MS PATHOLOGY MAY HAVE DISRUPTED THE LINK BETWEEN HUR AND ITS TARGET TRANSCRIPT HSP70-2. IT WILL BE IMPORTANT TO FURTHER EXPLORE THE EXACT ROLE OF HUR IN MS, CONSIDERING THE COMPLEX INTERPLAY WITH OTHER RNA-BINDING FACTORS AND TARGET MRNAS. 2020 5 5640 30 SERUM TUMOR MARKERS AND MOLECULAR BIOLOGICAL DIAGNOSIS IN PANCREATIC CANCER. RECENT STUDIES ON GENETIC ABNORMALITIES IN PANCREATIC DUCTAL CANCER HAVE LED TO THE INVESTIGATION OF TUMOR MARKERS AND GENETIC MARKERS IN BOTH SERUM AND PANCREATIC JUICE (PJ). SERUM TYPE 1 CHAIN CARBOHYDRATE ANTIGENS SUCH AS CA19-9 ARE POSITIVE IN NEARLY 80% OF PATIENTS WITH PANCREATIC CANCER (PCA), OF WHICH MOST ARE IN ADVANCED STAGE, WHEREAS FALSE-POSITIVE RATES ARE RELATIVELY HIGH AT 20%-30% IN BENIGN HEPATOBILIARY AND PANCREATIC DISEASES. ALTHOUGH THE PREVALENCE OF TYPE 2 CHAIN CARBOHYDRATE ANTIGENS, SUCH AS SLX, IS RELATIVELY LOW, CANCER SPECIFICITY OF THESE ANTIGENS IS HIGH. HOWEVER, SERUM TUMOR MARKERS HAVE LIMITED DIAGNOSTIC VALUE FOR EARLY DETECTION OF PCA. IN PJ COLLECTED ENDOSCOPICALLY FROM PATIENTS WITH PCA, K-RAS MUTATIONS (KRM) ARE DETECTABLE IN > 80%, WHEREAS KRM ARE OBSERVED IN 20%-30% OF PJ FROM PATIENTS WITH CHRONIC PANCREATITIS (CP), REFLECTING BENIGN MUCOUS CELL HYPERPLASIA HARBORING KRM. THUS, A QUALITATIVE ANALYSIS OF KRM IN PJ IS UNSUITABLE FOR DIAGNOSIS OF PCA. ON THE OTHER HAND, USING AN HYBRIDIZATION PROTECTION ASSAY THAT CAN QUANTITATIVELY DETERMINE KRM, KRM WERE POSITIVE IN 66% OF PCA BUT ONLY IN 40% OF CP CASES, INDICATING THAT QUALITATIVE ANALYSIS OF KRM IN PJ MAY BE USEFUL FOR DIFFERENTIATING PCA FROM CP. P53 MUTATIONS ARE FOUND IN 4%-50% IN PJ FROM PATIENTS WITH PCA BUT ARE NOT DETECTABLE IN PJ FROM CP, SUGGESTING THAT THE SPECIFICITY OF P53 MUTATIONS IS VERY HIGH FOR PCA. FURTHERMORE, P53 MUTATIONS WERE DETECTED IN 7 OF 15 (47%) PATIENTS WITH PCA IN WHICH THE PJ CYTOLOGIC DIAGNOSIS WAS NEGATIVE. TELOMERASE (TE) ACTIVITY OR ITS CATALYTIC SUBUNIT, H-TERT, WAS REPORTEDLY POSITIVE >80% IN PJ FROM PCA BUT WAS DETECTED IN <20% OF PJ FROM CP. TE ACTIVITY IN PJ FROM CP ORIGINATES FROM LYMPHOCYTES. THE DEVELOPMENT AND APPLICATION OF THESE NEW GENETIC AND EPIGENETIC MARKERS WITH HIGH SPECIFICITY AND SENSITIVITY FOR PCA IN SERUM AND PJ WILL SIGNIFICANTLY IMPROVE OUR DIAGNOSTIC ACCURACY. 2004 6 5511 22 RIBONUCLEASES IN TUMOR GROWTH. THIS REVIEW SUMMARIZES DATA ON AMBIGUOUS BIOLOGICAL FUNCTIONS OF RIBONUCLEASES (RNASES) AT TUMOR GROWTH. IN SOME CASES THE RAISED LEVEL OF ENZYME ACTIVITY IN BIOLOGICAL FLUIDS CAN BE REGARDED AS AN ADDITIONAL MARKER OF MALIGNANT GROWTH (PANCREAS CANCER, CHRONIC MYELOID LEUKEMIA, ETC.). AT THE SAME TIME THE ACTIVITY OF RNASES IS OFTEN LOWERED IN TUMOR TISSUE. HIGH SUBSTRATE SPECIFICITY OF PARTICULAR RNASES PROVIDES METABOLIC BALANCE BETWEEN VARIOUS KINDS OF RNAS WITH VARIOUS HALF-TIME EXCHANGE TURN. RNASES ARE THE IMPORTANT FACTORS OF EPIGENETIC REGULATION OF GENE ACTIVITY IN CELLS. THE ACTIVITY OF RNASES IS ADJUSTABLE BY INHIBITORS AND OTHER FACTORS, AND DEFINES TIME OF EXISTENCE OF DIFFERENT KINDS OF RNAS. RNASES (THE MODIFIED VARIANTS OF RNASE A, RNASES OF SEMEN FLUID OF THE CATTLE, RNASE OF AMPHIBIA OOCYTES) CAN BE USED AS ANTI-TUMOR THERAPEUTIC AGENTS. ON THE OTHER HAND, SOME INHIBITORS OF RNASES OF NATURAL OR SYNTHETIC ORIGIN WERE DEMONSTRATED TO BE PERSPECTIVE DRUGS THAT INHIBIT TUMOR GROWTH. 2009 7 6835 23 [INFLUENCE OF AGE OF PATIENTS WITH BRONCHOPULMONARY PATHOLOGY ON LOW-MOLECULAR DNA CONCENTRATION IN BLOOD PLASMA.]. THE AIM OF THE WORK WAS TO DETERMINE THE CONCENTRATION OF LOW-MOLECULAR-WEIGHT PLASMA DNA (LMDNA) IN PATIENTS WITH COPD AND CHRONIC NON-OBSTRUCTIVE BRONCHITIS (CNONB) OF TWO AGE GROUPS - 34-59 AND 60-80 YEARS. THE LEVELS OF LMDNA IN HEALTHY DONORS, PATIENTS WITH CNONB, HEALTHY RELATIVES OF PATIENTS WITH COPD DID NOT DIFFER, WHILE THE CONCENTRATION OF LMDNA IN PATIENTS WITH COPD WAS SIGNIFICANTLY LOWER. IN COPD PATIENTS AGED 34-59 YEARS, THE LEVEL OF LMDNA WAS REDUCED BY MORE THAN 7 TIMES, AND IN COPD PATIENTS WHO SURVIVED TO 60-80 YEARS, IT WAS 3 TIMES LOWER COMPARED TO THE VALUE OF THIS BIOCHEMICAL INDICATOR IN HEALTHY DONORS OF THE SAME AGE. THE REDUCTION OF LMDNA REFLECTED A REDUCED SYSTEMIC APOPTOTIC ACTIVITY IN THE BODY OF PATIENTS WITH COPD. A SIGNIFICANT DIFFERENCE IN THE CONCENTRATION OF LMDNA IN PATIENTS WITH COPD AND CNONB IN REMISSION CAN BE USED FOR DIFFERENTIAL DIAGNOSIS OF THE DEVELOPMENT OF THESE PATHOLOGICAL PROCESSES. AN INCREASE IN THE LOW LEVEL OF LMDNA IN COPD PATIENTS DURING AGING MAY INDICATE THE INVOLVEMENT OF EPIGENETIC MECHANISMS IN LIFE EXTENSION. 2022 8 2761 25 EXPRESSION OF TESTIS-SPECIFIC GENES, TEX101 AND ODF4, IN CHRONIC MYELOID LEUKEMIA AND EVALUATION OF TEX101 IMMUNOGENICITY. BACKGROUND AND OBJECTIVES: CANCER-TESTIS (CT) ANTIGENS ARE A GROUP OF ANTIGENS WITH A RESTRICTED EXPRESSION IN NORMAL TISSUES, EXCEPT TESTIS, AND THEY HAVE ABERRANT EXPRESSION IN DIFFERENT TUMORS. THIS PATTERN OF EXPRESSION HAS MADE THEM PROMISING TARGETS FOR IMMUNOTHERAPY AND CANCER DETECTION. OUR AIM WAS TO FIND NEW MEMBERS OF THIS GROUP THAT MIGHT BE USEFUL AS MARKERS IN THE DETECTION OF CANCER AND IMMUNOTHERAPY. DESIGN AND SETTING: A DESCRIPTIVE STUDY CONDUCTED IN REFERRAL CENTERS OF TEHRAN UNIVERSITY OF MEDICAL SCIENCE FROM JANUARY 2008 TO JANUARY 2009. PATIENTS AND METHODS: WE ANALYZED THE EXPRESSION OF TWO TESTIS-SPECIFIC GENES NAMED ODF4 (OUTER DENSE FIBER OF SPERM TAILS 4) AND TEX101 (TESTIS EXPRESSED 101) IN 20 CHRONIC MYELOID LEUKEMIA (CML) AND 20 NORMAL SAMPLES BY REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION AND SEQUENCING. IMMUNOGENICITY OF TEX101 WAS EVALUATED BY MEANS OF ENZYME-LINKED IMMUNOSORBENT ASSAY. RESULTS: THESE TWO GENES WERE EXPRESSED IN 30% OF CML PATIENTS BUT NOT IN ANY OF THE HEALTHY DONORS. HUMORAL RESPONSE AGAINST TEX101 WAS NOT DETECTED IN ANY SAMPLES. CONCLUSIONS: TEX101 AND ODF4 ARE CT GENES USEFUL FOR DETECTION OF CML. UNLIKE MANY CT GENES, OVEREXPRESSION OF TEX101 WAS NOT SHOWN TO INDUCE IMMUNOLOGIC RESPONSES IN THESE SAMPLES. ACCORDING TO THE PREVIOUS STUDIES, OVEREXPRESSION OF TEX101 LEADS TO SUPPRESSION OF CANCER INVASION AND METASTASIS; THUS, THE INDUCTION OF THE EXPRESSION OF TEX101 IN CANCER BY EPIGENETIC MECHANISMS MAY BE A TREATMENT STRATEGY. 2012 9 2818 16 FIBROSIS UNDER ARREST. APPROXIMATELY 5% OF PEOPLE THAT ARE HOSPITALIZED FOR ANY REASON DEVELOP ACUTE KIDNEY FAILURE, WHICH, IN SOME CASES, PROGRESSES TO A CHRONIC CONDITION RESULTING IN FIBROSIS OF THE KIDNEY AND PERMANENT CHANGES IN THE ORGAN'S FUNCTION. TWO NEW STUDIES SUGGEST THAT CELL CYCLE ARREST OF EPITHELIAL CELLS AND EPIGENETIC MODIFICATIONS HAVE KEY ROLES IN THE SWITCH TO CHRONIC DISEASE (PAGES 535-543 AND 544-550). 2010 10 5340 32 QUORUM SENSING AND VIRULENCE OF PSEUDOMONAS AERUGINOSA DURING LUNG INFECTION OF CYSTIC FIBROSIS PATIENTS. PSEUDOMONAS AERUGINOSA IS THE PREDOMINANT MICROORGANISM IN CHRONIC LUNG INFECTION OF CYSTIC FIBROSIS PATIENTS. THE CHRONIC LUNG INFECTION IS PRECEDED BY INTERMITTENT COLONIZATION. WHEN THE CHRONIC INFECTION BECOMES ESTABLISHED, IT IS WELL ACCEPTED THAT THE ISOLATED STRAINS DIFFER PHENOTYPICALLY FROM THE INTERMITTENT STRAINS. DOMINATING CHANGES ARE THE SWITCH TO MUCOIDITY (ALGINATE OVERPRODUCTION) AND LOSS OF EPIGENETIC REGULATION OF VIRULENCE SUCH AS THE QUORUM SENSING (QS). TO ELUCIDATE THE DYNAMICS OF P. AERUGINOSA QS SYSTEMS DURING LONG TERM INFECTION OF THE CF LUNG, WE HAVE INVESTIGATED 238 ISOLATES OBTAINED FROM 152 CF PATIENTS AT DIFFERENT STAGES OF INFECTION RANGING FROM INTERMITTENT TO LATE CHRONIC. ISOLATES WERE CHARACTERIZED WITH REGARD TO QS SIGNAL MOLECULES, ALGINATE, RHAMNOLIPID AND ELASTASE PRODUCTION AND MUTANT FREQUENCY. THE GENETIC BASIS FOR CHANGE IN QS REGULATION WERE INVESTIGATED AND IDENTIFIED BY SEQUENCE ANALYSIS OF LASR, RHLR, LASI AND RHLI. THE FIRST QS SYSTEM TO BE LOST WAS THE ONE ENCODED BY LAS SYSTEM 12 YEARS (MEDIAN VALUE) AFTER THE ONSET OF THE LUNG INFECTION WITH SUBSEQUENT LOSS OF THE RHL ENCODED SYSTEM AFTER 17 YEARS (MEDIAN VALUE) SHOWN AS DEFICIENCIES IN PRODUCTION OF THE 3-OXO-C12-HSL AND C4-HSL QS SIGNAL MOLECULES RESPECTIVELY. THE CONCOMITANT DEVELOPMENT OF QS MALFUNCTION SIGNIFICANTLY CORRELATED WITH THE REDUCED PRODUCTION OF RHAMNOLIPIDS AND ELASTASE AND WITH THE OCCURRENCE OF MUTATIONS IN THE REGULATORY GENES LASR AND RHLR. ACCUMULATION OF MUTATIONS IN BOTH LASR AND RHLR CORRELATED WITH DEVELOPMENT OF HYPERMUTABILITY. INTERESTINGLY, A HIGHER NUMBER OF MUCOID ISOLATES WERE FOUND TO PRODUCE C4-HSL SIGNAL MOLECULES AND RHAMNOLIPIDS COMPARED TO THE NON-MUCOID ISOLATES. AS SEEN FROM THE PRESENT DATA, WE CAN CONCLUDE THAT P. AERUGINOSA AND PARTICULARLY THE MUCOID STRAINS DO NOT LOSE THE QS REGULATION OR THE ABILITY TO PRODUCE RHAMNOLIPIDS UNTIL THE LATE STAGE OF THE CHRONIC INFECTION. 2010 11 1843 25 EFFECTS OF TELOMERASE INHIBITOR ON EPIGENETIC CHROMATIN MODIFICATION ENZYMES IN MALIGNANCIES. TELOMERASE HAS A CRITICAL ROLE IN CELL PROLIFERATION, TUMOR MAINTAINING, AND THERAPY RESISTANCE, WHICH ACT BY MODIFYING MANY SIGNALING PATHWAYS. 2-[(E)-3-NAPHTALEN-2-YL-BUT-2-ENOYLAMINO]-BENZOIC ACID (BIBR1532) IS ONE OF THE MOST STUDIED TELOMERASE INHIBITORS, AND IT TARGETS TELOMERASE COMPONENTS TERC AND TERT. IN THIS NOVEL STUDY, WE AIMED TO INVESTIGATE THE EPIGENETIC EFFECTS OF BIBR1532 ON BOTH HEMATOLOGIC MALIGNANCIES AND SOLID TUMORS. K-562 HUMAN CHRONIC MYELOID LEUKEMIA CELL LINE AND U87MG GLIOBLASTOMA CELL LINE WERE COMPARED WITH CONTROL GROUPS WITHOUT BIBR1532 TREATMENT. CYTOTOXIC EFFECTS OF BIBR1532 WERE DETERMINED BY USING WST-1 ASSAY. APOPTOTIC EFFECTS OF BIBR1532 WERE DETECTED BY USING ANNEXIN V METHOD. TO ASSESS EXPRESSION CHANGES IN THE HUMAN EPIGENETIC CHROMATIN MODIFICATION ENZYME GENES, TOTAL RNA WAS ISOLATED FROM K-562 AND U87MG CELLS TREATED WITH BIBR1532 AND UNTREATED CONTROL CELLS. BIBR1532 INDUCED 2.41-FOLD APOPTOTIC CELL DEATH IN U87MG CELL LINES COMPARED WITH CONTROL GROUPS. APOPTOSIS WAS SLIGHTLY INDUCED IN K-562 CELLS WITH BIBR1532 TREATMENT COMPARED WITH CONTROL CELLS. WE OBSERVED THAT BIBR1532 ALSO REGULATES SIMILAR GENES IN BOTH CELL LINES, AND IT IS USEFUL ON EPIGENETIC MECHANISMS. AS A RESULT, TELOMERASE INHIBITOR BIBR1532 HAS A SIGNIFICANT EFFECT ON BOTH HEMATOLOGICAL MALIGNANCIES AND SOLID TUMORS. 2018 12 5353 25 RE-EVALUATION OF POLIHEXANIDE USE IN WOUND ANTISEPSIS IN ORDER TO CLARIFY AMBIGUITIES OF TWO ANIMAL STUDIES. OBJECTIVE: DUE TO CLASSIFICATION OF THE AGENT POLIHEXANIDE (PHMB) IN CATEGORY 2 'MAY CAUSE CANCER' BY THE COMMITTEE FOR RISK ASSESSMENT OF THE EUROPEAN CHEMICALS AGENCY IN 2011, THE USERS OF WOUND ANTISEPTICS MAY BE HIGHLY CONFUSED. IN 2017, THIS STATEMENT WAS UPDATED, DEFINING PHMB UP TO 0.1% AS A PRESERVATIVE SAFE IN ALL COSMETIC PRODUCTS. IN THE INTEREST OF PATIENT SAFETY, A SCIENTIFIC CLARIFICATION OF THE POTENTIAL CARCINOGENICITY OF PHMB IS NECESSARY. METHODS: A MULTIDISCIPLINARY TEAM (MDT) OF MICROBIOLOGISTS, SURGEONS, DERMATOLOGISTS AND BIOCHEMISTS CONDUCTED A BENEFIT-RISK ASSESSMENT TO CLARIFY THE HAZARD OF ANTISEPTIC USE OF PHMB. RESULTS: IN TWO ANIMAL STUDIES, FROM WHICH THE ASSESSMENT OF A CARCINOGENIC RISK WAS DERIVED, PHMB WAS ADMINISTERED ORALLY OVER TWO YEARS IN EXTREMELY HIGH CONCENTRATIONS FAR ABOVE THE NO(A)EL (NO-OBSERVED-(ADVERSE-) EFFECT LEVEL) IN RATS AND MICE. FEEDING IN THE NO(A)EL RANGE RESULTED IN NO ABNORMAL EFFECTS. IN ONE MALE IN THE HIGHEST DOSE GROUP OF 4000PPM PHMB, AN ADENOCARCINOMA WAS FOUND, WHICH THE AUTHOR ATTRIBUTED TO CHRONIC INFLAMMATION OF THE COLON WITH SYSTEMIC ATYPICAL EXPOSURE. THE INCREASING INCIDENCE OF HEMANGIOSARCOMAS HIGHLY PROBABLY RESULTED FROM INCREASED ENDOTHELIAL PROLIFERATION, TRIGGERED BY THE EXCEEDINGLY HIGH DOSAGE FED, BECAUSE PHMB IS NOT GENOTOXIC AND THERE IS NO EVIDENCE FOR EPIGENETIC EFFECTS. DISCUSSION: IT IS WELL KNOWN THAT PHMB IS NOT ABSORBED WHEN APPLIED TOPICALLY. CONSIDERING THE ABSENCE OF GENOTOXICITY AND EPIGENETIC EFFECTS TOGETHER WITH THE INTERPRETATION OF THE ANIMAL STUDIES, IT IS THE CONSENSUS OF THE MULTIDISCIPLINARY EXPERTS THAT A CARCINOGENIC RISK FROM PHMB-USE FOR WOUND ANTISEPSIS CAN BE RULED OUT. CONCLUSION: ON THIS BASIS AND CONSIDERING THEIR EFFECTIVENESS, TOLERABILITY AND CLINICAL EVIDENCE, THE INDICATIONS FOR PHMB BASED WOUND ANTISEPTICS ARE JUSTIFIED. 2019 13 6603 30 TWO SISTERS WITH FAMILIAL MEDITERRANEAN FEVER: LACK OF CORRELATION BETWEEN GENOTYPE AND PHENOTYPE? FAMILIAL MEDITERRANEAN FEVER (FMF) IS AN AUTOSOMAL RECESSIVE DISORDER CHARACTERIZED BY ATTACKS OF FEVER AND SEROSITIS. THE MOST IMPORTANT COMPLICATION OF FMF IS RENAL AMYLOIDOSIS, WHICH DETERMINES THE PROGNOSIS. THE GENE CODING THE DISEASE (MEFV) IS IDENTIFIED ON THE 16TH CHROMOSOME. THE MOST COMMON MEFV MUTATIONS ARE M694V, M680I, V726A AND M694I LOCATED ON EXON 10 AND E148Q LOCATED ON EXON 2. UNFORTUNATELY, GENOTYPE-PHENOTYPE CORRELATION IS NOT WELL ESTABLISHED AND THERE ARE UNEXPLAINED ETHNIC DIFFERENCES IN AMYLOIDOSIS RATES. WE REPORT TWO SISTERS WITH A COMMON GENOTYPE (M694V/M694V) PRESENTING WITH DIFFERENT PHENOTYPIC CHARACTERISTICS: ONE COMPLAINING OF INTERMITTENT ABDOMINAL PAIN, ARTHRITIS AND FEVER, WHILE THE OTHER WAS SUFFERING FROM INTERMITTENT PLEURITIS AND FEVER DURING ATTACKS. THE OBSERVATION OF DIFFERENT PHENOTYPIC PRESENTATIONS WITH A COMMON GENOTYPE IN TWO FAMILY MEMBERS SHOWS THAT DIFFERENT PHENOTYPES CANNOT BE EXPLAINED BY PARTICULAR MUTATIONS. TO UNDERSTAND THE CORRELATION BETWEEN GENOTYPIC AND PHENOTYPIC FMF VARIANTS THE EXISTENCE OF COMPLEX ALLELES, MODIFIER LOCI, GENETIC HETEROGENEITY AND POSSIBLE EPIGENETIC FACTORS SHOULD BE STUDIED EXTENSIVELY. 2006 14 6036 28 THE CHARACTERISTICS OF EXTRACHROMOSOMAL CIRCULAR DNA IN PATIENTS WITH END-STAGE RENAL DISEASE. BACKGROUND: END-STAGE RENAL DISEASE (ESRD) IS THE FINAL STAGE OF CHRONIC KIDNEY DISEASE (CKD). IN ADDITION TO THE STRUCTURALLY INTACT CHROMOSOME GENOMIC DNA, THERE IS A DOUBLE-STRANDED CIRCULAR DNA CALLED EXTRACHROMOSOMAL CIRCULAR DNA (ECCDNA), WHICH IS THOUGHT TO BE INVOLVED IN THE EPIGENETIC REGULATION OF HUMAN DISEASE. HOWEVER, THE FEATURES OF ECCDNA IN ESRD PATIENTS ARE BARELY KNOWN. IN THIS STUDY, WE IDENTIFIED ECCDNA FROM ESRD PATIENTS AND HEALTHY PEOPLE, AS WELL AS REVEALED THE CHARACTERISTICS OF ECCDNA IN PATIENTS WITH ESRD. METHODS: USING THE HIGH-THROUGHPUT CIRCLE-SEQUENCING TECHNIQUE, WE EXAMINED THE ECCDNA IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) FROM HEALTHY PEOPLE (NC) (N = 12) AND ESRD PATIENTS (N = 16). WE ANALYZED THE LENGTH DISTRIBUTION, GENOME ELEMENTS, AND MOTIFS FEATURE OF ECCDNA IN ESRD PATIENTS. THEN, AFTER IDENTIFYING THE SPECIFIC ECCDNA IN ESRD PATIENTS, WE EXPLORED THE POTENTIAL FUNCTIONS OF THE TARGET GENES OF THE SPECIFIC ECCDNA. FINALLY, WE INVESTIGATED THE PROBABLE HUB ECCDNA USING ALGORITHMS. RESULTS: IN TOTAL, 14,431 AND 11,324 ECCDNAS WERE FOUND IN THE ESRD AND NC GROUPS, RESPECTIVELY, WITH SIZES RANGING FROM 0.01 KB TO 60 KB AT MOST. ADDITIONALLY, THE ESRD GROUP HAD A GREATER DISTRIBUTION OF ECCDNA ON CHROMOSOMES 4, 11, 13, AND 20. IN TWO GROUPS, WE ALSO DISCOVERED SEVERAL MOTIFS OF SPECIFIC ECCDNAS. FURTHERMORE, WE IDENTIFIED 13,715 SPECIFIC ECCDNAS IN THE ESRD GROUP AND 10,585 SPECIFIC ECCDNAS IN THE NC GROUP, BOTH OF WHICH WERE LARGELY ANNOTATED AS MRNA CATALOG. PATHWAY STUDIES USING GENE ONTOLOGY (GO) AND THE KYOTO ENCYCLOPEDIA OF GENES AND GENOMES (KEGG) SHOWED THAT THE SPECIFIC ECCDNA IN ESRD WAS MARKEDLY ENRICHED IN CELL JUNCTION AND COMMUNICATION PATHWAYS. FURTHERMORE, WE IDENTIFIED POTENTIALLY 20 HUB ECCDNA-TARGETING GENES FROM ALL ESRD-SPECIFIC ECCDNA-TARGETING GENES. ALSO, WE FOUND THAT 39 ECCDNA-TARGETING GENES WERE ASSOCIATED WITH ESRD, AND SOME OF THESE ECCDNAS MAY BE RELATED TO THE PATHOGENESIS OF ESRD. CONCLUSIONS: OUR FINDINGS REVEALED THE CHARACTERISTICS OF ECCDNA IN ESRD PATIENTS AND DISCOVERED POTENTIALLY HUB AND ESRD-RELEVANT ECCDNA-TARGETING GENES, SUGGESTING A NOVEL PROBABLE MECHANISM OF ESRD. 2023 15 1950 25 EPIGENETIC ACTIVATION OF TENSIN 4 PROMOTES GASTRIC CANCER PROGRESSION. GASTRIC CANCER (GC) IS A COMPLEX DISEASE INFLUENCED BY MULTIPLE GENETIC AND EPIGENETIC FACTORS. CHRONIC INFLAMMATION CAUSED BY HELICOBACTER PYLORI INFECTION AND DIETARY RISK FACTORS CAN RESULT IN THE ACCUMULATION OF ABERRANT DNA METHYLATION IN GASTRIC MUCOSA, WHICH PROMOTES GC DEVELOPMENT. TENSIN 4 (TNS4), A MEMBER OF THE TENSIN FAMILY OF PROTEINS, IS LOCALIZED TO FOCAL ADHESION SITES, WHICH CONNECT THE EXTRACELLULAR MATRIX AND CYTOSKELETAL NETWORK. WE IDENTIFIED UPREGULATION OF TNS4 IN GC USING QUANTITATIVE REVERSE TRANSCRIPTION PCR WITH 174 PAIRED SAMPLES OF GC TUMORS AND ADJACENT NORMAL TISSUES. TRANSCRIPTIONAL ACTIVATION OF TNS4 OCCURRED EVEN DURING THE EARLY STAGE OF TUMOR DEVELOPMENT. TNS4 DEPLETION IN GC CELL LINES THAT EXPRESSED HIGH TO MODERATE LEVELS OF TNS4, I.E., SNU-601, KATO III, AND MKN74, REDUCED CELL PROLIFERATION AND MIGRATION, WHEREAS ECTOPIC EXPRESSION OF TNS4 IN THOSE LINES THAT EXPRESSED LOWER LEVELS OF TNS4, I.E., SNU-638, MKN1, AND MKN45 INCREASED COLONY FORMATION AND CELL MIGRATION. THE PROMOTER REGION OF TNS4 WAS HYPOMETHYLATED IN GC CELL LINES THAT SHOWED UPREGULATION OF TNS4. WE ALSO FOUND A SIGNIFICANT NEGATIVE CORRELATION BETWEEN TNS4 EXPRESSION AND CPG METHYLATION IN 250 GC TUMORS BASED ON THE CANCER GENOME ATLAS (TCGA) DATA. THIS STUDY ELUCIDATES THE EPIGENETIC MECHANISM OF TNS4 ACTIVATION AND FUNCTIONAL ROLES OF TNS4 IN GC DEVELOPMENT AND PROGRESSION AND SUGGESTS A POSSIBLE APPROACH FOR FUTURE GC TREATMENTS. 2023 16 6484 19 TOXICOLOGIC PROFILE OF ACRYLONITRILE. ACRYLONITRILE IS A MONOMER USED EXTENSIVELY AS A RAW MATERIAL IN THE MANUFACTURING OF ACRYLIC FIBERS, PLASTICS, SYNTHETIC RUBBERS, AND ACRYLAMIDE. IT HAS BEEN CLASSIFIED AS A PROBABLE HUMAN CARCINOGEN ACCORDING TO THE RESULTS OF NUMEROUS CHRONIC RAT BIOASSAYS. THE PRESENT REPORT SUMMARIZES THE TOXICITY DATA ON ACRYLONITRILE AND REVIEWS AVAILABLE DATA CONCERNING THE MECHANISM (GENETIC VERSUS EPIGENETIC) BY WHICH ACRYLONITRILE IS CARCINOGENIC IN RATS. FROM THE EVALUATION OF THE RELEVANT TOXICITY DATA, IT CAN BE CONCLUDED THAT ACRYLONITRILE IS INDEED CARCINOGENIC TO RATS AFTER EITHER ORAL OR INHALATIONAL EXPOSURE. HOWEVER, INFORMATION ON OTHER MAMMALIAN SPECIES IS LACKING, AND, MOREOVER, THE EXACT MECHANISM OF THE CARCINOGENIC PROCESS IS UNCLEAR. THEREFORE, IT IS RECOMMENDED TO CONDUCT AN ADDITIONAL LONG-TERM INHALATION CARCINOGENICITY STUDY WITH ACRYLONITRILE IN MICE, AS WELL AS STUDIES INTO THE MECHANISM BY WHICH ACRYLONITRILE INDUCES (BRAIN) TUMORS IN RATS (GENETIC VERSUS EPIGENETIC). 1998 17 3381 27 HLA AND AUTOIMMUNE DISEASES: TYPE 1 DIABETES (T1D) AS AN EXAMPLE. AUTOIMMUNE DISEASES NEED TO BE CONSIDERED AT A GENETIC AND MECHANISTIC LEVEL. T1D IS AN AUTOIMMUNE, CHRONIC, MULTIFACTORIAL AND POLYGENIC DISEASE CHARACTERIZED BY THE DESTRUCTION OF THE PANCREATIC BETA-CELLS ASSOCIATED WITH LONG TERM DYSFUNCTION OF SEVERAL ORGANS AND TISSUES. MECHANISMS OF SUSCEPTIBILITY INCLUDE EPI-GENETIC AND POST-TRANSCRIPTIONAL EFFECTS THAT REGULATE TRANSMISSION AND EXPRESSION OF THE INHERITED GENES. THE HLA COMPLEX, CONSTITUTES THE MOST RELEVANT REGION CONTRIBUTING 50% OF THE INHERITED RISK FOR T1D. AN ADDITIONAL 17 GENES WITH VARIABLE BUT SMALL EFFECTS HAVE BEEN DESCRIBED. IN NON-CAUCASIANS, THE PRESENCE OF E-DRBETA1-74 AND/OR D-DRBETA1-57 ARE RELEVANT IN PREDISPOSITION. THE "DIABETOGENIC HAPLOTYPES" IN MEXICANS WERE DRB1*0301-DQA1*0501-DQB1*0201 (OR = 21.4); DRB1*0405-DQA1-*0301-DQB1*0302 (OR = 44.5) AND THE SAME DQA1/DQB1 WITH DRB1*0404/*0401 CONFERRING LOWER RISK, INCREASING (OR = 61.3) WITH AN EARLY AGE AT ONSET AND A HETEROZYGOTE DR3/DR4 GENOTYPE. IN MOST POPULATIONS, THE ABSENCE OF D-57 AND THE PRESENCE OF R-52 ARE IMPORTANT TO THE SUSCEPTIBILITY, BUT IN HISPANICS, ALL DR4S (INCLUDING THE PROTECTIVE DRB1*0403/*0407/*0411) ARE IN LINKAGE DISEQUILIBRIUM WITH DQA1/DQB1 SUSCEPTIBILITY ALLELES. THUS, SUSCEPTIBILITY ALLELES IN LATIN AMERICAN MESTIZOS ARE OF MEDITERRANEAN ANCESTRY WHEREAS PROTECTIVE ALLELES ARE OF AMERINDIAN ORIGIN. IN THIS REVIEW, WE DISCUSS THE COMPLEXITY OF T1D AND SOME ASPECTS OF PREVENTION/INTERVENTION BASED ON IMMUNOGENETICS. 2006 18 3074 21 GENOME-WIDE DNA METHYLOME AND TRANSCRIPTOME CHANGES INDUCED BY INORGANIC NANOPARTICLES IN HUMAN KIDNEY CELLS AFTER CHRONIC EXPOSURE. THE UNIQUE PHYSICOCHEMICAL PROPERTIES MAKE INORGANIC NANOPARTICLES (INPS) AN EXCITING TOOL IN DIAGNOSIS AND DISEASE MANAGEMENT. HOWEVER, AS INPS ARE RELATIVELY DIFFICULT TO FULLY DEGRADE AND EXCRETE, THEIR UNINTENDED ACCUMULATION IN THE TISSUE MIGHT RESULT IN ADVERSE HEALTH EFFECTS. HEREIN, WE PROVIDE A METHYLOME-TRANSCRIPTOME FRAMEWORK FOR CHRONIC EFFECTS OF INPS, COMMONLY USED IN BIOMEDICAL APPLICATIONS, IN HUMAN KIDNEY TH-1 CELLS. RENAL CLEARANCE IS ONE OF THE MOST IMPORTANT ROUTES OF NANOPARTICLE EXCRETION; THEREFORE, A DETAILED EVALUATION OF NANOPARTICLE-MEDIATED NEPHROTOXICITY IS AN IMPORTANT TASK. INTEGRATED ANALYSIS OF METHYLOME AND TRANSCRIPTOME CHANGES INDUCED BY INPS (PEG-AUNPS, FE(3)O(4)NPS, SIO(2)NPS, AND TIO(2)NPS) REVEALED SIGNIFICANTLY DEREGULATED GENES WITH FUNCTIONAL CLASSIFICATION IN IMMUNE RESPONSE, DNA DAMAGE, AND CANCER-RELATED PATHWAYS. ALTHOUGH MOST DEREGULATED GENES WERE UNIQUE TO INDIVIDUAL INPS, A RELATIVELY HIGH PROPORTION OF THEM ENCODED THE TRANSCRIPTION FACTORS. INTERESTINGLY, FOS HYPERMETHYLATION INVERSELY CORRELATING WITH GENE EXPRESSION WAS ASSOCIATED WITH ALL INPS EXPOSURES. OUR STUDY EMPHASIZES THE NEED FOR A MORE COMPREHENSIVE INVESTIGATION OF INPS' BIOLOGICAL SAFETY, ESPECIALLY AFTER CHRONIC EXPOSURE. 2022 19 1668 31 DOWNREGULATION OF SOCS1 INCREASES INTERFERON-INDUCED ISGYLATION DURING DIFFERENTIATION OF INDUCED-PLURIPOTENT STEM CELLS TO HEPATOCYTES. BACKGROUND & AIMS: INCREASED EXPRESSION OF IFN-STIMULATED GENE 15 (ISG15) AND SUBSEQUENTLY INCREASED ISGYLATION ARE KEY FACTORS IN THE HOST RESPONSE TO VIRAL INFECTION. IN THIS STUDY, WE SOUGHT TO CHARACTERIZE THE EXPRESSION OF ISG15, ISGYLATION, AND ASSOCIATED ENZYMES AT EACH STAGE OF DIFFERENTIATION FROM INDUCED PLURIPOTENT STEM CELLS (IPSCS) TO HEPATOCYTES. METHODS: TO STUDY THE REGULATION OF ISGYLATION, WE UTILIZED PATIENT SAMPLES AND IN VITRO CELL CULTURE MODELS INCLUDING IPSCS, HEPATOCYTES-LIKE CELLS, IMMORTALIZED CELL LINES, AND PRIMARY HUMAN HEPATOCYTES. PROTEIN/MRNA EXPRESSION WERE MEASURED FOLLOWING TREATMENT WITH POLY(I:C), IFNALPHA AND HCV INFECTION. RESULTS: WHEN COMPARED TO HLCS, WE OBSERVED SEVERAL NOVEL ASPECTS OF THE ISGYLATION PATHWAY IN IPSCS. THESE INCLUDE A LOWER BASELINE EXPRESSION OF THE ISGYLATION-ACTIVATING ENZYME, UBE1L, A LACK OF IFN-INDUCED EXPRESSION OF THE ISGYLATION-CONJUGATION ENZYME UBE2L6, AN ATTENUATED ACTIVATION OF THE TRANSCRIPTION FACTOR STAT1 AND CONSTITUTIVE EXPRESSION OF SOCS1. ISGYLATION WAS OBSERVED IN IPSCS FOLLOWING DOWNREGULATION OF SOCS1, WHICH FACILITATED STAT1 ACTIVATION AND SUBSEQUENTLY INCREASED EXPRESSION OF UBE2L6. INTRIGUINGLY, HCV PERMISSIVE TRANSFORMED HEPATOMA CELL LINES DEMONSTRATED HIGHER INTRINSIC EXPRESSION OF SOCS1 AND WEAKER ISGYLATION FOLLOWING IFN TREATMENT. SOCS1 DOWNREGULATION IN HCV-INFECTED HUH 7.5.1 CELLS LED TO INCREASED ISGYLATION. CONCLUSIONS: HEREIN, WE SHOW THAT HIGH BASAL LEVELS OF SOCS1 INHIBIT STAT1 ACTIVATION AND SUBSEQUENTLY IFN-INDUCED UBE2L6 AND ISGYLATION IN IPSCS. FURTHERMORE, AS IPSCS DIFFERENTIATE INTO HEPATOCYTES, EPIGENETIC MECHANISMS REGULATE ISGYLATION BY MODIFYING UBE1L AND SOCS1 EXPRESSION LEVELS. OVERALL, THIS STUDY DEMONSTRATES THAT THE DEVELOPMENT OF CELL-INTRINSIC INNATE IMMUNITY DURING THE DIFFERENTIATION OF IPSCS TO HEPATOCYTES PROVIDES INSIGHT INTO CELL TYPE-SPECIFIC REGULATION OF HOST DEFENSE RESPONSES AND RELATED ONCOGENIC PROCESSES. IMPACT AND IMPLICATIONS: TO ELUCIDATE THE MECHANISM UNDERLYING REGULATION OF ISGYLATION, A KEY PROCESS IN THE INNATE IMMUNE RESPONSE, WE STUDIED CHANGES IN ISGYLATION-ASSOCIATED GENES AT THE DIFFERENT STAGES OF DIFFERENTIATION FROM IPSCS TO HEPATOCYTES. WE FOUND THAT HIGH BASAL LEVELS OF SOCS1 INHIBIT STAT1 ACTIVATION AND SUBSEQUENTLY IFN-INDUCED UBE2L6 AND ISGYLATION IN IPSCS. IMPORTANTLY, EPIGENETIC REGULATION OF SOCS1 AND SUBSEQUENTLY ISGYLATION MAY BE IMPORTANT FACTORS IN THE DEVELOPMENT OF CELL TYPE-SPECIFIC HOST DEFENSE RESPONSES IN HEPATOCYTES THAT SHOULD BE CONSIDERED WHEN STUDYING CHRONIC INFECTIONS AND ONCOGENIC PROCESSES IN THE LIVER. 2022 20 1457 32 DISEASE PROGRESSION FROM CHRONIC HEPATITIS C TO CIRRHOSIS AND HEPATOCELLULAR CARCINOMA IS ASSOCIATED WITH INCREASING DNA PROMOTER METHYLATION. BACKGROUND: CHANGES IN DNA METHYLATION PATTERNS ARE BELIEVED TO BE EARLY EVENTS IN HEPATOCARCINOGENESIS. A BETTER UNDERSTANDING OF METHYLATION STATES AND HOW THEY CORRELATE WITH DISEASE PROGRESSION WILL AID IN FINDING POTENTIAL STRATEGIES FOR EARLY DETECTION OF HCC. THE AIM OF OUR STUDY WAS TO ANALYZE THE METHYLATION FREQUENCY OF TUMOR SUPPRESSOR GENES, P14, P15, AND P73, AND A MISMATCH REPAIR GENE (O6MGMT) IN HCV RELATED CHRONIC LIVER DISEASE AND HCC TO IDENTIFY CANDIDATE EPIGENETIC BIOMARKERS FOR HCC PREDICTION. MATERIALS AND METHODS: 516 EGYPTIAN PATIENTS WITH HCV-RELATED LIVER DISEASE WERE RECRUITED FROM KASR ALAINI MULTIDISCIPLINARY HCC CLINIC FROM APRIL 2010 TO JANUARY 2012. SUBJECTS WERE DIVIDED INTO 4 DIFFERENT CLINICALLY DEFINED GROUPS - HCC GROUP (N=208), LIVER CIRRHOSIS GROUP (N=108), CHRONIC HEPATITIS C GROUP (N=100), AND CONTROL GROUP (N=100) - TO ANALYZE THE METHYLATION STATUS OF THE TARGET GENES IN PATIENT PLASMA USING EPITECT METHYL QPCR ARRAY TECHNOLOGY. METHYLATION WAS CONSIDERED TO BE HYPERMETHYLATED IF >10% AND/OR INTERMEDIATELY METHYLATED IF >60%. RESULTS: IN OUR SERIES, A SIGNIFICANT DIFFERENCE IN THE HYPERMETHYLATION STATUS OF ALL STUDIED GENES WAS NOTED WITHIN THE DIFFERENT STAGES OF CHRONIC LIVER DISEASE AND ULTIMATELY HCC. HYPERMETHYLATION OF THE P14 GENE WAS DETECTED IN 100/208 (48.1%), 52/108 (48.1%), 16/100 (16%) AND 8/100 (8%) AMONG HCC, LIVER CIRRHOSIS, CHRONIC HEPATITIS AND CONTROL GROUPS, RESPECTIVELY, WITH A STATISTICALLY SIGNIFICANT DIFFERENCE BETWEEN THE STUDIED GROUPS (P-VALUE 0.008). WE ALSO DETECTED P15 HYPERMETHYLATION IN 92/208 (44.2%), 36/108 (33.3%), 20/100 (20%) AND 4/100 (4%) , RESPECTIVELY (P-VALUE 0.006). IN ADDITION, HYPERMETHYLATION OF P73 WAS DETECTED IN 136/208 (65.4%), 72/108 (66.7%), 32/100 (32%) AND 4/100 (4%) (P-VALUE <0.001). ALSO, WE DETECTED O6MGMT HYPERMETHYLATION IN 84/208 (40.4%), 60/108 (55.3%), 20/100 (20%) AND 4/100 (4%), RESPECTIVELY (P VALUE <0.001. CONCLUSIONS: THE EPIGENETIC CHANGES OBSERVED IN THIS STUDY INDICATE THAT HCC TUMORS EXHIBIT SPECIFIC DNA METHYLATION SIGNATURES WITH POTENTIAL CLINICAL APPLICATIONS IN DIAGNOSIS AND PROGNOSIS. IN ADDITION, METHYLATION FREQUENCY COULD BE USED TO MONITOR WHETHER A PATIENT WITH CHRONIC HEPATITIS C IS LIKELY TO PROGRESS TO LIVER CIRRHOSIS OR EVEN HCC. WE CAN CONCLUDE THAT METHYLATION PROCESSES ARE NOT JUST EARLY EVENTS IN HEPATOCARCINOGENESIS BUT ACCUMULATE WITH PROGRESSION TO CANCER. 2014