1 4225 112 METHYLATION DEGREE OF METALLOPROTEINASE INHIBITOR RECK GENE: LINKS TO RECK PROTEIN LEVEL AND HEPATOCELLULAR CARCINOMA IN CHRONIC HCV INFECTION PATIENTS. THE RECK GENE, A TUMOR SUPPRESSOR GENE, INHIBITS ANGIOGENESIS, INVASION, AND TUMOR METASTASIS. EPIGENETIC REGULATION OF THE RECK GENE CONSTITUTES A POTENT APPROACH TO THE MOLECULAR BASIS OF LIVER MALIGNANCY. THIS STUDY AIMS TO EVALUATE THE PROMOTER METHYLATION STATUS OF THE RECK GENE AND ITS SERUM LEVEL IN PATIENTS WITH HEPATITIS C VIRUS (HCV)-RELATED HEPATOCELLULAR CARCINOMA (HCC) AND THE POTENTIAL ASSOCIATION OF RECK GENE METHYLATION WITH CLINICAL CRITERIA OF HCC. ONE HUNDRED AND FIFTY-FIVE SUBJECTS WERE INCLUDED (HEALTHY CONTROL [55], CHRONIC HCV PATIENTS [55], HCV-RELATED HCC PATIENTS [45]). THE METHYLATION STATUS OF THE RECK GENE PROMOTER AND SERUM RECK LEVEL WERE INVESTIGATED BY METHYLATION-SPECIFIC PCR AND ENZYME-LINKED IMMUNOSORBENT ASSAY TECHNIQUES, RESPECTIVELY. RECK GENE PROMOTER HYPERMETHYLATION WAS RECORDED IN 46.7% OF HCC PATIENTS, AND 10.9% OF HCV PATIENTS, BUT NOT IN CONTROL SUBJECTS (0%). IT WAS RELATED TO RECK PROTEIN LEVEL, VARICES, EDEMA, ASCITES, LYMPH NODE METASTASIS, VASCULAR INVASION, AND THE LARGEST DIAMETER OF FOCAL LESIONS. MEANWHILE, IT WAS NOT ASSOCIATED WITH FOCAL LESION NUMBER NOR DISTANT METASTASIS OF HCC. IN CONCLUSION, RECK GENE PROMOTER HYPERMETHYLATION IS LINKED TO HCV GENOTYPE-4-RELATED HCC. MOREOVER, DIFFERENT DEGREES OF RECK GENE PROMOTER METHYLATION ARE ASSOCIATED WITH SERUM RECK LEVEL, LYMPH NODE METASTASIS, AND VASCULAR INVASION, WHICH COULD PROVE ITS PATHOGENIC ROLE IN HEPATOCARCINOGENESIS IN CHRONIC HCV-INFECTED PATIENTS. 2021 2 1067 33 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 1457 43 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 4 145 40 ABERRANT DNA METHYLATION STATUS AND MRNA EXPRESSION LEVEL OF SMG1 GENE IN CHRONIC MYELOID LEUKEMIA: A CASE-CONTROL STUDY. OOBJECTIVE: CHRONIC MYELOID LEUKEMIA (CML) IS A MYELOPROLIFERATIVE MALIGNANCY WITH DIFFERENT STAGES. ABERRANT EPIGENETIC MODIFICATIONS, SUCH AS DNA METHYLATION, HAVE BEEN INTRODUCED AS A SIGNATURE FOR DIVERSE CANCERS WHICH ALSO PLAYS A CRUCIAL ROLE IN CML PATHOGENESIS AND DEVELOPMENT. SUPPRESSOR WITH MORPHOGENETIC EFFECT ON GENITALIA (SMG1) GENE RECENTLY HAS BEEN BROUGHT TO THE SPOTLIGHT AS A POTENT TUMOR SUPPRESSOR GENE THAT CAN BE SUPPRESSED BY TUMORS FOR FURTHER PROGRESS. THE PRESENT STUDY AIMS TO INVESTIGATE SMG1 STATUS IN CML PATIENTS. MATERIALS AND METHODS: IN THIS CASE-CONTROL STUDY, PERIPHERAL BLOOD FROM 30 PATIENTS WITH DIFFERENT PHASES OF CML [NEW CASE (N)=10, COMPLETE MOLECULAR REMISSION (CMR)=10, BLASTIC PHASE (BP)=10] AND 10 HEALTHY SUBJECTS WERE COLLECTED. METHYLATION STATUS AND EXPRESSION LEVEL OF SMG1 GENE PROMOTER WAS ASSESSED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) AND QUANTITATIVE REVERSE-TRANSCRIPTION PCR, RESPECTIVELY. RESULTS: MSP RESULTS OF SMG1 GENE PROMOTOR IN THE NEW CASE GROUP WERE METHYLATED (60% METHYLATED, 30% HEMIMETHYLATED AND 10% UNMETHYLATED). ALL CMR AND CONTROL GROUP PATIENTS WERE UNMETHYLATED IN THE SMG1 GENE PROMOTER. IN THE BP GROUP, METHYLATED SMG1 PROMOTER WAS SEEN (50% OF PATIENTS HAD A METHYLATED STATUS AND 50% HAD HEMIMETHYLATED STATUS). IN COMPARISON WITH THE HEALTHY SUBJECTS, EXPRESSION LEVEL OF SMG1 IN THE NEW CASE GROUP WAS DECREASED (P<0.01); IN THE CMR GROUP AND BP-CML GROUPS, IT WAS INCREASED (P<0.05). NO SIGNIFICANT CORRELATION BETWEEN PATIENTS' HEMATOLOGICAL FEATURES AND SMG1 METHYLATION WAS SEEN. CONCLUSION: OUR RESULTS DEMONSTRATED THAT ABERRANT METHYLATION OF SMG1 OCCURRED IN CML PATIENTS AND IT HAD A SIGNIFICANT ASSOCIATION WITH SMG1 EXPRESSION. SMG1 GENE PROMOTER SHOWED DIVERSE METHYLATED STATUS AND SUBSEQUENT EXPRESSION LEVELS IN DIFFERENT PHASES OF CML. THESE FINDINGS SUGGESTED POSSIBLE PARTICIPATION OF SMG1 SUPPRESSION IN THE CML PATHOGENESIS. 2022 5 1428 37 DIFFERENTIAL EXPRESSION OF LONG NONCODING RNA IN HEPATOCELLULAR CARCINOMA ON TOP OF CHRONIC HCV AND HBV INFECTIONS. AIM OF THE STUDY: THE TASK OF LONG NONCODING RNAS (LNCRNAS) AS A PROSPECTIVE GOAL FOR HEPATOCELLULAR CARCINOMA (HCC) IS A CANDIDATE FOR RESEARCH. SEVERAL LNCRNAS ARE INVOLVED IN SIGNAL TRANSDUCTION, DIRECTING GENE EXPRESSION AND EPIGENETIC ALTERATION IN NORMAL AND CANCER CELLS. DYSREGULATION OF DIVERSE LNCRNAS HAS BEEN INVOLVED IN THE PATHOGENESIS AND PROGRESSION OF DIFFERENT CANCERS INCLUDING HCC. WE AIMED TO INVESTIGATE THE DIFFERENTIAL EXPRESSION OF LNCRNAS (AHIF, HPVT1, ANRIL) IN HCC ON TOP OF CHRONIC HEPATITIS C VIRUS (HCV) AND HEPATITIS B VIRUS (HBV) INFECTIONS. MATERIAL AND METHODS: 182 PARTICIPANTS WERE INCLUDED: 85 PATIENTS WITH HCC IN ADDITION TO 50 PATIENTS WITH CIRRHOSIS ON TOP OF CHRONIC HCV OR HBV, AND 47 HEALTHY SUBJECTS AS CONTROLS. HCC WAS DIAGNOSED BY TRIPHASIC COMPUTED TOMOGRAPHY (CT). DETECTION OF ALPHA-FETOPROTEIN (AFP) AND SEROLOGICAL MARKERS OF HCVAB AND HBSAG BY ENZYME-LINKED FLUORESCENT IMMUNOASSAY (ELFA) AND QUANTITATION OF LNCRNAS BY REAL TIME PCR WERE APPLIED. RESULTS: UPREGULATION OF ANRIL AND HPVT1 AND DOWNREGULATION OF AHIF WERE OBSERVED IN PATIENTS WITH HCC ON TOP OF HCV AND HBV VS. CONTROLS. CIRCULATING AHIF COULD BE OF MAJOR DIAGNOSTIC IMPORTANCE TO DISCRIMINATE HCC ON TOP OF HCV FROM CIRRHOTIC PATIENTS WITH SENSITIVITY 86.67% AND SPECIFICITY 91.89% WHEREAS CIRCULATING HPVT1 HAD SENSITIVITY 85.0% AND SPECIFICITY 84.62%; MOREOVER ANRIL HAD AUC 0.902 AND COULD DISCRIMINATE HCC ON TOP OF HBV FROM CIRRHOTIC PATIENTS. CONCLUSIONS: THE DIFFERENTIAL EXPRESSION OF LNCRNAS (ANRIL, HPVT1 AND AHIF) MIGHT BE OF MAJOR WORTH IN PREDICTING THE OCCURRENCE OF HCC IN CIRRHOTIC PATIENTS RELATED TO CHRONIC VIRAL HEPATITIS AND COULD BE BENEFICIAL IN THE EARLY MANAGEMENT. 2021 6 6243 41 THE MECHANISM OF APOLIPROTEIN A1 DOWN-REGULATED BY HEPATITIS B VIRUS. BACKGROUND: HEPATITIS B VIRUS (HBV) INFECTION CORRELATED WITH THE DEVELOPMENT OF CIRRHOSIS, LIVER FAILURE AND HEPATOCELLULAR CARCINOMA (HCC), POSES A HUGE HEALTH BURDEN ON THE GLOBAL COMMUNITY. HOWEVER, THE PATHOGENESIS OF CHRONIC HEPATITIS B (CHB) REMAINS UNCLEAR. APOLIPOPROTEIN A1 (APOA1) MAINLY SECRETED BY HEPATOCYTES, REPRESENTS THE MAJOR PROTEIN COMPONENT OF HIGH-DENSITY LIPOPROTEIN. APOA1 SECRETION MAY BE DISRUPTED BY HBV INFECTION. IN THIS STUDY, WE MAINLY INVESTIGATED THE MOLECULAR MECHANISM OF APOA1 DOWN REGULATED BY HBV FOR REVEALING THE PATHOGENESIS OF CHB. METHODS: APOA1 EXPRESSION IN LIVERS OF CHB PATIENTS AS WELL AS HEALTHY CONTROLS WERE PERFORMED BY REAL-TIME PCR (RT-PCR) AND WESTERN BLOT. THE SERUM APOA1 LEVELS WERE MEASURED BY ENZYMED-LINKED IMMUNOSORBENT ASSAY (ELISA). EXPRESSION OF APOA1 MRNA AND PROTEIN LEVELS WERE PERFORMED BY RT-PCR AND WESTERN BLOT IN HUMAN HEPATOMA HEPG2 CELLS AND SUBLINE HEPG2.2.15 CELLS. HBV EXPRESSION CONSTRUCT, PHBV1.3 WERE TRANSFECTED INTO HEPG2, THE CHANGES OF APOA1 MRNA AND PROTEIN EXPRESSION WERE DETECTED BY RT-PCR AND WESTERN BLOT. TO FURTHER STUDY THE MECHANISM OF APOA1 DOWN REGULATION BY HBV, 11 CPG ISLANDS IN APOA1 PROMOTOR WERE TESTED FOR DNA METHYLATION STATUS BY MSP. HEPG2.2.15 CELL LINES WERE TREATED WITH DNA METHYLTRANSFERASE INHIBITOR 5-AZA-DEOXYCYTIDINE (5-AZA-DC), THEN, EXPRESSION OF APOA1 MRNA AND HBV PARTICLES IN THE SUPERNATANT, AS WELL AS APOA1 PROTEIN LEVELS WERE DETECTED BY RT-PCR AND WESTERN BLOT. SECRETION OF HBSAG AND HBEAG IN HEPG2 CELLS COTRANSFECTED WITH PAPOA1 AND PHBV1.3 CONSTRUCTS WAS TESTED BY ELISA. MEANWHILE, SECRETION OF HBSAG AND HBEAG IN THE SUPERNATANT WERE QUANTIFIED BY ELISA IN THE HEPG2.2.15 CELLS TREATED WITH 5-AZA-DC PLUS APOA1 SIRNA. RESULTS: EXPRESSION OF APOA1 MRNA AND PROTEIN LEVELS, AS WELL AS SERUM APOA1 LEVELS IN CHB PATIENTS WERE DECREASED CORRESPONDING HEALTHY CONTROLS IN VIVO. IN ADDITION, THE EXPRESSION OF APOA1 MRNA AND PROTEIN LEVELS WERE DOWN REGULATED IN HEPG2.2.15 CELLS CORREPONDING HEPG2 CELLS, 11 CPG ISLANDS IN APOA1 PROMOTER WERE TESTED FOR METHYLATION STATUS BY MSP IN HEPG2.2.15 CELLS COMPARED TO HEPG2 CELLS, WHILE TWO CPG ISLANDS WERE FOUND HYPERMETHYLATED. EXPRESSION OF APOA1 MRNA AND PROTEIN LEVELS WERE INCREASED IN HEPG2.2.15 CELLS TREATED WITH DNA METHYLTRANSFERASE INHIBITOR 5-AZA-DC. FURTHERMORE, OVEREXPRESSION OF APOA1 CAN ENHANCE HBV EXPRESSION IN HEPG2 CELLS WHILE THE INHIBITORY EFFECT OF 5-AZA-DC ON HBV EXPRESSION WAS COMPLETELY ABOLISHED BY BLOCKING 5-AZA-DC-INDUCED UP-REGULATION OF APOA1 USING RNAI. CONCLUSIONS: EPIGENETIC SILENCING OF APOA1 GENE EXPRESSION BY CPG ISLAND DNA HYPERMETHYLATION INDUCED BY HBV MAY CONTRIBUTE TO THE PATHOGENESIS OF CHB. 2016 7 2761 27 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 8 4220 35 METHYLATED CYSTEINE DIOXYGENASE-1 GENE PROMOTER IN THE SERUM IS A POTENTIAL BIOMARKER FOR HEPATITIS B VIRUS-RELATED HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE THIRD LEADING CAUSE OF CANCER-RELATED MORTALITY WORLDWIDE. EPIGENETIC ANALYSIS HAS ATTRACTED INCREASING ATTENTION IN THE MOLECULAR DIAGNOSIS OF HCC. CYSTEINE DIOXYGENASE 1 (CDO1) IS A KEY ENZYME IN THE TAURINE BIOSYNTHETIC PATHWAY AND CONVERTS CYSTEINE TO CYSTEINE SULFINATE. THE CDO1 GENE IS A TUMOR SUPPRESSOR GENE AND IS USUALLY SILENCED BY THE METHYLATION OF ITS PROMOTER IN CARCINOGENESIS. IN THIS STUDY, WE EVALUATED WHETHER THE METHYLATION STATUS OF CDO1 GENE PROMOTER IS OF DIAGNOSTIC VALUE FOR HEPATITIS B VIRUS (HBV)-RELATED HCC. THE CDO1 PROMOTER METHYLATION STATUS WAS DETERMINED IN SERUM SAMPLES USING METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) IN A COHORT OF 123 PATIENTS WITH HBV-RELATED HCC, 28 WITH LIVER CIRRHOSIS (LC), 29 WITH CHRONIC HEPATITIS B (CHB) AND 20 HEALTHY CONTROLS. THE FREQUENCY OF THE CDO1 PROMOTER METHYLATION IN HBV-RELATED HCC (42.3%) WAS SIGNIFICANTLY HIGHER THAN THAT IN LC (14.3%), CHB (6.9%) AND HEALTHY CONTROLS (0%) (P = 0.006; P < 0.0001; P < 0.0001; RESPECTIVELY). FURTHERMORE, IN HCC PATIENTS, THE FREQUENCY OF CDO1 PROMOTER METHYLATION WAS HIGHER IN ADVANCED STAGES (III-IV) (53%) THAN THE EARLY STAGES (I-II) (20%) (P = 0.001). EVALUATION OF THE CDO1 PROMOTER METHYLATION STATUS IN SERUM, IN COMBINATION WITH AFP (> 20 NG/ML), SIGNIFICANTLY IMPROVED THE DIAGNOSTIC VALUE, WITH SENSITIVITY AND SPECIFICITY OF 82.9% AND 75.4%, RESPECTIVELY IN DISTINGUISHING HCC FROM LC AND CHB. IN CONCLUSION, METHYLATION STATUS OF SERUM CDO1 GENE PROMOTER MAY BE HELPFUL IN THE DIAGNOSIS OF HCC AND THE ESTIMATION OF THE HCC STAGES. 2014 9 388 35 AN INTEGRATED ANALYSIS OF SOCS1 DOWN-REGULATION IN HBV INFECTION-RELATED HEPATOCELLULAR CARCINOMA. PERSISTENT INFLAMMATION TOGETHER WITH GENETIC/EPIGENETIC ABERRATIONS IS STRONGLY ASSOCIATED WITH CHRONIC HEPATITIS B VIRUS (HBV) INFECTION-RELATED HEPATOCARCINOGENESIS. HERE, WE INVESTIGATED THE ALTERATIONS OF THE SUPPRESSOR OF CYTOKINE SIGNALLING (SOCS) FAMILY GENES IN HBV-RELATED HEPATOCELLULAR CARCINOMA (HCC). A TOTAL OF 116 PATIENTS WITH HCC WERE ENROLLED IN THIS STUDY. THE METHYLATION STATUSES OF SOCS1-7 AND CISH GENES WERE QUANTITATIVELY MEASURED AND CLINICOPATHOLOGICAL SIGNIFICANCE OF SOCS1 METHYLATION WAS STATISTICALLY ANALYSED. THE GENE COPY NUMBER VARIATION WAS ASSAYED BY ACGH. LUCIFERASE REPORTER ASSAY AND WESTERN BLOT WERE USED TO DETECT THE INVOLVEMENT OF SOCS1 IN P53 SIGNALLING. WE FOUND HIGH FREQUENCIES OF SOCS1 GENE HYPERMETHYLATION IN BOTH TUMOUR (56.03%) AND ADJACENT NONTUMOUR TISSUES (54.31%), BUT TUMOUR TISSUES EXHIBITED INCREASED METHYLATION INTENSITY (24.01% VS 13.11%, P < 0.0001), PARTICULARLY IN PATIENTS WITH LARGER TUMOUR SIZE OR CIRRHOSIS BACKGROUND (P < 0.0001). IN ADDITION, THE FREQUENCY AND INTENSITY OF SOCS1 HYPERMETHYLATION IN TUMOUR TISSUES WERE BOTH SIGNIFICANTLY HIGHER THAN THOSE IN NONTUMOUR TISSUES IN MALE GENDER PATIENTS AND IN PATIENTS >/=45 YEARS OLD (P = 0.0214 AND P < 0.0001, P = 0.0232 AND P < 0.0001, RESPECTIVELY). SOCS1 GENE DELETION WAS FOUND IN 8 OF 25 ACGH ASSAYED TUMOUR SPECIMENS, WHICH WAS ASSOCIATED WITH LOWER SOCS1 MRNA EXPRESSION (P = 0.0448). FURTHERMORE, ECTOPIC SOCS1 OVEREXPRESSION COULD ACTIVATE THE P53 SIGNALLING PATHWAY IN HCC CELL LINES. HYPERMETHYLATION OF SOCS2-7 AND CISH GENES WAS SELDOM FOUND IN HCC. OUR RESULTS SUGGESTED THAT THE GENE LOSS AND EPIGENETIC SILENCING OF SOCS1 WERE STRONGLY ASSOCIATED WITH HBV-RELATED HCC. 2014 10 5914 28 TARGETED-BISULFITE SEQUENCE ANALYSIS OF THE METHYLATION OF CPG ISLANDS IN GENES ENCODING PNPLA3, SAMM50, AND PARVB OF PATIENTS WITH NON-ALCOHOLIC FATTY LIVER DISEASE. BACKGROUND & AIMS: THE PATHOGENESIS OF NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS AFFECTED BY EPIGENETIC FACTORS AS WELL AS BY GENETIC VARIATION. METHODS: WE PERFORMED TARGETED-BISULFITE SEQUENCING TO DETERMINE THE LEVELS OF DNA METHYLATION OF 4 CPG ISLANDS (CPG99, CPG71, CPG26, AND CPG101) IN THE REGULATORY REGIONS OF PNPLA3, SAMM50, PARVB VARIANT 1, AND PARVB VARIANT 2, RESPECTIVELY. WE COMPARED THE LEVELS OF METHYLATION OF DNA IN THE LIVERS OF THE FIRST AND SECOND SETS OF PATIENTS WITH MILD (FIBROSIS STAGES 0 AND 1) OR ADVANCED (FIBROSIS STAGES 2 TO 4) NAFLD AND IN THOSE OF PATIENTS WITH MILD (F0 TO F2) OR ADVANCED (F3 AND F4) CHRONIC HEPATITIS C INFECTION. THE HEPATIC MRNA LEVELS OF PNPLA3, SAMM50, AND PARVB WERE MEASURED USING QPCR. RESULTS: CPG26, WHICH RESIDES IN THE REGULATORY REGION OF PARVB VARIANT 1, WAS MARKEDLY HYPOMETHYLATED IN THE LIVERS OF PATIENTS WITH ADVANCED NAFLD. CONVERSELY, CPG99 IN THE REGULATORY REGION OF PNPLA3 WAS SUBSTANTIALLY HYPERMETHYLATED IN THESE PATIENTS. THESE DIFFERENCES IN DNA METHYLATION WERE REPLICATED IN A SECOND SET OF PATIENTS WITH NAFLD OR CHRONIC HEPATITIS C. PNPLA3 MRNA LEVELS IN THE LIVER OF THE SAME SECTION OF A BIOPSY SPECIMEN USED FOR GENOMIC DNA PREPARATION WERE LOWER IN PATIENTS WITH ADVANCED NAFLD COMPARED WITH THOSE WITH MILD NAFLD AND CORRELATED INVERSELY WITH CPG99 METHYLATION IN LIVER DNA. MOREOVER, THE LEVELS OF CPG99 METHYLATION AND PNPLA3 MRNA WERE AFFECTED BY THE RS738409 GENOTYPE. CONCLUSIONS: HYPOMETHYLATION OF CPG26 AND HYPERMETHYLATION OF CPG99 MAY CONTRIBUTE TO THE SEVERITY OF FIBROSIS IN PATIENTS WITH NAFLD OR CHRONIC HEPATITIS C INFECTION. 2015 11 2974 32 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 12 1950 22 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 13 155 25 ABERRANT METHYLATION OF POLO-LIKE KINASE CPG ISLANDS IN PLK4 HETEROZYGOUS MICE. BACKGROUND: HEPATOCELLULAR CARCINOMA (HCC), ONE OF THE MOST COMMON CANCERS WORLD-WIDE OCCURS TWICE AS OFTEN IN MEN COMPARED TO WOMEN. PREDISPOSING CONDITIONS SUCH AS ALCOHOLISM, CHRONIC VIRAL HEPATITIS, AFLATOXIN B1 INGESTION, AND CIRRHOSIS ALL CONTRIBUTE TO THE DEVELOPMENT OF HCC. METHODS: WE USED A COMBINATION OF METHYLATION SPECIFIC PCR AND BISULFITE SEQUENCING, QREAL-TIME PCR (QPCR), AND WESTERN BLOT ANALYSIS TO EXAMINE EPIGENETIC CHANGES FOR THE POLO-LIKE KINASES (PLKS) DURING THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC) IN PLK4 HETEROZYGOUS MICE AND MURINE EMBRYONIC FIBROBLASTS (MEFS). RESULTS: HERE WE REPORT THAT THE PROMOTER METHYLATION OF PLK4 CPG ISLANDS INCREASES WITH AGE, WAS MORE PREVALENT IN MALES AND THAT PLK4 EPIGENETIC MODIFICATION AND SUBSEQUENT DOWNREGULATION OF EXPRESSION WAS ASSOCIATED WITH THE DEVELOPMENT OF HCC IN PLK4 MUTANT MICE. INTERESTINGLY, THE OPPOSITE OCCURS WITH ANOTHER PLK FAMILY MEMBER, PLK1 WHICH WAS TYPICALLY HYPERMETHYLATED IN NORMAL LIVER TISSUE BUT BECAME HYPOMETHYLATED AND UPREGULATED IN LIVER TUMOURS. FURTHERMORE, UPON ALCOHOL EXPOSURE MURINE EMBRYONIC FIBROBLASTS EXHIBITED INCREASED PLK4 HYPERMETHYLATION AND DOWNREGULATION ALONG WITH INCREASED CENTROSOME NUMBERS AND MULTINUCLEATION. CONCLUSIONS: THESE RESULTS SUGGEST THAT ABERRANT PLK METHYLATION IS CORRELATED WITH THE DEVELOPMENT OF HCC IN MICE. 2011 14 2763 25 EXPRESSION OF THE LEUKEMIC PROGNOSTIC MARKER CD7 IS LINKED TO EPIGENETIC MODIFICATIONS IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: EXPRESSION LEVELS OF THE CELL SURFACE GLYCOPROTEIN, CD7, AND THE SERINE PROTEASE, ELASTASE 2 (ELA2), IN THE LEUKEMIC CELLS OF PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) HAVE BEEN ASSOCIATED WITH CLINICAL OUTCOME. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS THAT UNDERLIE THE VARIABLE EXPRESSION OF THESE GENES IN THE LEUKEMIC CELLS. RESULTS: TO ADDRESS THIS QUESTION, WE COMPARED THE LEVEL OF THEIR EXPRESSION WITH THE DNA METHYLATION AND HISTONE ACETYLATION STATUS OF 5' SEQUENCES OF BOTH GENES IN LEUKEMIC CELL LINES AND PRIMITIVE (LIN-CD34+) LEUKEMIC CELLS FROM CHRONIC PHASE CML PATIENTS. DNA METHYLATION OF THE ELA2 GENE PROMOTER DID NOT CORRELATE WITH ITS EXPRESSION PATTERN IN LIN-CD34+ CELLS FROM CHRONIC PHASE CML PATIENT SAMPLES EVEN THOUGH THERE WAS CLEAR DIFFERENTIAL DNA METHYLATION OF THIS LOCUS IN ELA2-EXPRESSING AND NON-EXPRESSING CELL LINES. IN CONTRAST, WE FOUND A STRONG RELATION BETWEEN CD7 EXPRESSION AND TRANSCRIPTION-PERMISSIVE CHROMATIN MODIFICATIONS, BOTH AT THE LEVEL OF DNA METHYLATION AND HISTONE ACETYLATION WITH EVIDENCE OF HYPOMETHYLATION OF THE CD7 PROMOTER REGION IN THE LIN-CD34+ CELLS FROM CML PATIENTS WITH HIGH CD7 EXPRESSION. CONCLUSION: THESE FINDINGS INDICATE A LINK BETWEEN EPIGENETIC MODIFICATIONS AND CD7 EXPRESSION IN PRIMITIVE CML CELLS. 2010 15 3476 31 IDENTIFICATION OF A TRANSMEMBRANE PROTEIN INVOLVED IN SHEAR STRESS SIGNALING AND HEPATOCARCINOGENESIS AFTER A SUSTAINED VIROLOGICAL RESPONSE TO HEPATITIS C VIRUS. BACKGROUND & AIMS: THE RISK OF HEPATOCELLULAR CARCINOMA (HCC) REMAINS AFTER ACHIEVING A SUSTAINED VIROLOGICAL RESPONSE (SVR) IN PATIENTS WITH CHRONIC HEPATITIS C (CHC). EPIGENETIC ABNORMALITIES MIGHT BE KEY REGULATORS IN THE DEVELOPMENT OF HCC. THIS STUDY AIMED TO IDENTIFY THE GENES INVOLVED IN HEPATOCARCINOGENESIS AFTER AN SVR. METHODS: DNA METHYLATION IN LIVER TISSUE WAS COMPARED BETWEEN 21 CHC PATIENTS WITHOUT HCC AND 28 CHC PATIENTS WITH HCC, ALL OF WHOM HAD ACHIEVED AN SVR. ADDITIONAL COMPARISONS WITH 23 CHC PATIENTS BEFORE TREATMENT AND 10 NORMAL LIVERS WERE PERFORMED. THE CHARACTERISTICS OF A NEWLY IDENTIFIED GENE WERE EXPLORED IN VITRO AND IN VIVO. RESULTS: WE FOUND THAT THE TRANSMEMBRANE PROTEIN NO. 164 (TMEM164) GENE WAS DEMETHYLATED BY HEPATITIS C VIRUS INFECTION AND HCC DEVELOPMENT AFTER ACHIEVING AN SVR. TMEM164 WAS EXPRESSED MAINLY IN ENDOTHELIAL CELLS, ALPHA SMOOTH MUSCLE ACTIN-POSITIVE CELLS, AND SOME CAPILLARIZED LIVER SINUSOIDAL ENDOTHELIAL CELLS. TMEM164 EXPRESSION WAS SIGNIFICANTLY CORRELATED WITH LIVER FIBROSIS AND RELAPSE-FREE SURVIVAL IN HCC PATIENTS. TMEM164 WAS INDUCED BY SHEAR STRESS, INTERACTED WITH GRP78/BIP, ACCELERATED ATF6 (ACTIVATING TRANSCRIPTION FACTOR 6)-MEDIATED ENDOPLASMIC RETICULUM (ER) STRESS SIGNALING, AND ACTIVATED INTERLEUKIN-6/STAT3 (SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3) SIGNALING IN THE TMNK1 LIVER ENDOTHELIAL CELL LINE. THEREFORE, WE TERMED TMEM164 "SHEAR STRESS-INDUCED TRANSMEMBRANE PROTEIN ASSOCIATED WITH ER STRESS SIGNALING" (SHERMER). SHERMER KNOCKOUT MICE WERE PROTECTED AGAINST CCL4-INDUCED LIVER FIBROSIS. SHERMER OVEREXPRESSION IN TMNK1 CELLS ACCELERATED HCC GROWTH IN A XENOGRAFT MODEL. CONCLUSIONS: WE IDENTIFIED A NEW TRANSMEMBRANE PROTEIN, SHERMER, IN CHC PATIENTS WITH HCC AFTER ACHIEVING AN SVR. SHERMER WAS INDUCED BY SHEAR STRESS AND ACCELERATED ATF6-MEDIATED ER STRESS SIGNALING IN ENDOTHELIAL CELLS. THUS, SHERMER IS A NOVEL ENDOTHELIAL MARKER ASSOCIATED WITH LIVER FIBROSIS, HEPATOCARCINOGENESIS, AND PROGRESSION OF HCC. 2023 16 2453 28 EPIGENETIC SUPPRESSION OF THE IMMUNOREGULATOR MZB1 IS ASSOCIATED WITH THE MALIGNANT PHENOTYPE OF GASTRIC CANCER. PREDICTION OF TUMOR RECURRENCE AFTER CURATIVE RESECTION IS CRITICAL FOR DETERMINING THE PROGNOSIS OF PATIENTS WITH GASTRIC CANCER (GC). THE INITIATION AND PROGRESSION OF GC ARE ASSOCIATED WITH INAPPROPRIATE IMMUNE RESPONSES CAUSED BY CHRONIC INFLAMMATION OF THE GASTRIC MUCOSA. TO IDENTIFY IMMUNOREGULATORY MOLECULES INVOLVED IN GC PROGRESSION, GC CELL LINES AND 200 PAIRS OF TUMOR AND NORMAL TISSUES FROM PATIENTS WITH GC WERE ANALYZED FOR GENE EXPRESSION, AMPLIFICATION AND METHYLATION AS WELL AS FUNCTION OF A DIFFERENTIALLY EXPRESSED GENE. THE TRANSCRIPTOME ANALYSIS REVEALED THAT MARGINAL ZONE B AND B1 CELL SPECIFIC PROTEIN (MZB1) WAS EXPRESSED AT SIGNIFICANTLY DECREASED LEVELS IN PRIMARY GC TISSUES WHEN COMPARED WITH THE CORRESPONDING NORMAL GASTRIC MUCOSA. PCR ARRAY ANALYSIS EXPLORING GENES EXPRESSED COOPERATIVELY WITH MZB1 REVEALED THAT DIFFERENTIAL EXPRESSION OF MZB1 MRNA IN GC CELL LINES CORRELATED POSITIVELY WITH THE LEVELS OF THE MRNAS ENCODING ESTROGEN RECEPTOR 1 AND DESUMOYLATING ISOPEPTIDASE 1. HYPERMETHYLATION OF THE MZB1 PROMOTER WAS FREQUENT IN CELL LINES WITH DECREASED LEVELS OF MZB1 MRNA. SIRNA-MEDIATED KNOCKDOWN OF MZB1 SIGNIFICANTLY INCREASED PROLIFERATION, INVASION AND MIGRATION OF GC CELL LINES. LOW MZB1 EXPRESSION WAS AN INDEPENDENT PROGNOSTIC FACTOR FOR RECURRENCE AFTER CURATIVE GASTRECTOMY AND WAS ASSOCIATED SIGNIFICANTLY WITH INCREASED HEMATOGENOUS RECURRENCE. MZB1 ACTS AS A SUPPRESSOR OF GC. LOW MZB1 EXPRESSION IN THE PRIMARY GC TISSUE IS PREDICTIVE OF RECURRENCE AFTER CURATIVE RESECTION. 2016 17 1622 28 DNA METHYLTRANSFERASES IN MALAR MELASMA AND THEIR MODIFICATION BY SUNSCREEN IN COMBINATION WITH 4% NIACINAMIDE, 0.05% RETINOIC ACID, OR PLACEBO. BACKGROUND: MALAR MELASMA HAS A CHRONIC AND RECURRENT CHARACTER THAT MAY BE RELATED TO EPIGENETIC CHANGES. OBJECTIVE: TO RECOGNIZE THE EXPRESSION AND DNA METHYLATION OF DNA METHYLTRANSFERASES (DNMTS) IN MALAR MELASMA AND PERILESIONAL SKIN, AS WELL AS THE CHANGES IN DNMTS AFTER THEIR TREATMENT WITH SUNSCREEN IN COMBINATION WITH 4% NIACINAMIDE, 0.05% RETINOIC ACID, OR PLACEBO. METHODS: THIRTY FEMALE PATIENTS WERE CLINICALLY EVALUATED FOR THE EXPRESSION OF DNMT1 AND DNMT3B USING REAL-TIME PCR AND IMMUNOFLUORESCENCE. THESE INITIAL RESULTS WERE COMPARED TO RESULTS AFTER EIGHT WEEKS OF TREATMENT WITH SUNSCREEN IN COMBINATION WITH NIACINAMIDE, RETINOIC ACID, OR PLACEBO. RESULTS: THE RELATIVE EXPRESSION OF DNMT1 WAS SIGNIFICANTLY ELEVATED IN MELASMA COMPARED WITH UNAFFECTED SKIN IN ALL SUBJECTS, INDICATING DNA HYPERMETHYLATION. AFTER TREATMENT, IT WAS DECREASED IN ALL GROUPS: NIACINAMIDE (7 VERSUS 1; P<0.01), RETINOIC ACID (7 VERSUS 2; P<0.05), AND PLACEBO (7 VERSUS 3; P<0.05), WHICH CORRELATES WITH CLINICAL IMPROVEMENT. DNMT3B WAS NOT OVEREXPRESSED IN LESIONAL SKIN BUT REDUCED IN ALL GROUPS. CONCLUSIONS: WE FOUND DNA HYPERMETHYLATION IN MELASMA LESIONS. ENVIRONMENTAL FACTORS SUCH AS SOLAR RADIATION MAY INDUCE CELLULAR CHANGES THAT TRIGGER HYPERPIGMENTATION THROUGH THE ACTIVATION OF PATHWAYS REGULATED BY EPIGENETIC MODIFICATIONS. HOWEVER, LIMITING OR DECREASING DNA METHYLATION THROUGH SUNSCREEN, NIACINAMIDE, AND RETINOIC ACID TREATMENTS THAT PROVIDE PHOTOPROTECTION AND GENETIC TRANSCRIPTION CAN COUNTERACT THIS. 2019 18 2304 28 EPIGENETIC REGULATION OF CATHEPSIN L EXPRESSION IN CHRONIC MYELOID LEUKAEMIA. THE EXPRESSION AND SIGNIFICANCE OF CATHEPSIN L (CTSL) HAS BEEN EXTENSIVELY STUDIED IN SOLID TUMOURS. HOWEVER NO SUCH INFORMATION IN CHRONIC MYELOID LEUKAEMIA (CML) WAS AVAILABLE. WE INVESTIGATED THE ACTIVITY AND EXPRESSION OF THIS PROTEASE IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) OF 47 ADULT CML PATIENTS. THIRTY ADULTS SUFFERING FROM SYSTEMIC DISEASES AND 50 HEALTHY VOLUNTEERS SERVED AS CONTROLS. THE MRNA LEVELS OF CTSL, ITS SPECIFIC ENDOGENOUS INHIBITOR CYSTATIN C AND TRANSCRIPTIONAL UP-REGULATOR VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) WERE QUANTITATED BY REAL-TIME QPCR. CTSL PROTEASE ACTIVITY AND ITS MRNA EXPRESSION WERE SIGNIFICANTLY HIGHER IN CML CHRONIC PHASE (CP) PATIENTS COMPARED TO CML ACCELERATED PHASE/BLAST CRISIS (AP/BC) PATIENTS AND CONTROLS (P