1 1502 120 DNA METHYLATION AND EPIGENETIC EVENTS UNDERLYING RENAL CELL CARCINOMAS. RENAL CELL CARCINOMA (RCC) REFERS TO A GROUP OF TUMORS THAT DEVELOP FROM THE EPITHELIUM OF THE KIDNEY TUBES, INCLUDING CLEAR CELL RCC, PAPILLARY RCC, AND CHROMOPHOBE RCC. MOST CLEAR CELL RENAL CARCINOMAS HAVE A LARGE HISTOLOGIC SUBTYPE, GENETIC OR EPIGENETIC VON HIPPEL-LINDAU (VHL). A COMPREHENSIVE ANALYSIS OF THE GENETIC MODIFICATION GENOME SUGGESTED THAT CHROMOSOME 3P LOSS AND CHROMOSOME GAINS 5Q AND 7 MAY BE SIGNIFICANT COPY DEFECTS IN THE DEVELOPMENT OF CLEAR RCC. A MORE POTENT RCC MAY DEVELOP IF CHROMOSOME 1P, 4, 9, 13Q, OR 14Q IS ALSO LOST. RENAL CARCINOGENESIS IS NOT ASSOCIATED WITH CHRONIC INFLAMMATION OR HISTOLOGICAL CHANGES. HOWEVER, IF REGIONAL HYPERMETHYLATION OF DNA IN CPG C-TYPE ISLANDS HAS ALREADY ACCUMULATED IN CANCER-FREE KIDNEY TISSUE, IT IMPLIES THAT THE PRESENCE OF MALIGNANT KIDNEY LESIONS MAY ALSO BE DETECTED BY MODIFIED DNA METHYLATION. MODIFICATION OF DNA METHYLATION IN CANCEROUS KIDNEY TISSUE MAY ADVANCE KIDNEY TISSUE TO EPIGENETIC MUTATIONS AND GENES, LEADING TO MORE SERIOUS CANCERS AND EVEN DETERMINING A PATIENT'S OUTCOME. THE GENETIC AND EPIGENETIC PROFILE PROVIDES ACCURATE PREDICTORS FOR PATIENTS WITH KIDNEY CANCER. NEW GENETIC AND EPIGENETIC ANALYSIS TECHNOLOGIES WILL HELP TO SPEED UP THE IDENTIFICATION OF VITAL CELLS FOR KIDNEY CANCER PREVENTION, DIAGNOSIS, AND TREATMENT. 2022 2 2937 84 GENETIC AND EPIGENETIC ALTERATIONS DURING RENAL CARCINOGENESIS. RENAL CELL CARCINOMA (RCC) IS NOT A SINGLE ENTITY, BUT COMPRISES A GROUP OF TUMORS INCLUDING CLEAR CELL RCC, PAPILLARY RCC AND CHROMOPHOBE RCC, WHICH ARISE FROM THE EPITHELIUM OF RENAL TUBULES. THE MAJORITY OF CLEAR CELL RCCS, THE MAJOR HISTOLOGICAL SUBTYPE, HAVE GENETIC OR EPIGENETIC INACTIVATION OF THE VON HIPPEL-LINDAU (VHL) GENE. GERMLINE MUTATIONS IN THE MET AND FUMARATE HYDRATASE (FH) GENES LEAD TO THE DEVELOPMENT OF TYPE 1 AND TYPE 2 PAPILLARY RCCS, RESPECTIVELY, AND SUCH MUTATIONS OF EITHER THE TSC1 OR TSC2 GENE INCREASE THE RISK OF RCC. GENOME-WIDE COPY NUMBER ALTERATION ANALYSIS HAS SUGGESTED THAT LOSS OF CHROMOSOME 3P AND GAIN OF CHROMOSOMES 5Q AND 7 MAY BE COPY NUMBER ABERRATIONS INDISPENSABLE FOR THE DEVELOPMENT OF CLEAR CELL RCC. WHEN CHROMOSOME 1P, 4, 9, 13Q OR 14Q IS ALSO LOST, MORE CLINICOPATHOLOGICALLY AGGRESSIVE CLEAR CELL RCC MAY DEVELOP. SINCE RENAL CARCINOGENESIS IS ASSOCIATED WITH NEITHER CHRONIC INFLAMMATION NOR PERSISTENT VIRAL INFECTION, AND HARDLY ANY HISTOLOGICAL CHANGE IS EVIDENT IN CORRESPONDING NON-TUMOROUS RENAL TISSUE FROM PATIENTS WITH RENAL TUMORS, PRECANCEROUS CONDITIONS IN THE KIDNEY HAVE BEEN RARELY DESCRIBED. HOWEVER, REGIONAL DNA HYPERMETHYLATION ON C-TYPE CPG ISLANDS HAS ALREADY ACCUMULATED IN SUCH NON-CANCEROUS RENAL TISSUES, SUGGESTING THAT, FROM THE VIEWPOINT OF ALTERED DNA METHYLATION, THE PRESENCE OF PRECANCEROUS CONDITIONS CAN BE RECOGNIZED EVEN IN THE KIDNEY. GENOME-WIDE DNA METHYLATION PROFILES IN PRECANCEROUS CONDITIONS ARE BASICALLY INHERITED BY THE CORRESPONDING CLEAR CELL RCCS DEVELOPING IN INDIVIDUAL PATIENTS: DNA METHYLATION ALTERATIONS AT THE PRECANCEROUS STAGE MAY FURTHER PREDISPOSE RENAL TISSUE TO EPIGENETIC AND GENETIC ALTERATIONS, GENERATE MORE MALIGNANT CANCERS, AND EVEN DETERMINE PATIENT OUTCOME. THE LIST OF TUMOR-RELATED GENES SILENCED BY DNA HYPERMETHYLATION HAS RECENTLY BEEN INCREASING. GENETIC AND EPIGENETIC PROFILING PROVIDES AN OPTIMAL MEANS OF PROGNOSTICATION FOR PATIENTS WITH RCCS. RECENTLY DEVELOPED HIGH-THROUGHPUT TECHNOLOGIES FOR GENETIC AND EPIGENETIC ANALYSES WILL FURTHER ACCELERATE THE IDENTIFICATION OF KEY MOLECULES FOR USE IN THE PREVENTION, DIAGNOSIS AND THERAPY OF RCCS. 2010 3 3694 38 INFLAMMATORY COMPONENTS OF THE THYROID CANCER MICROENVIRONMENT: AN AVENUE FOR IDENTIFICATION OF NOVEL BIOMARKERS. THE INCIDENCE OF THYROID CANCER IN THE UNITED STATES IS ON THE RISE WITH AN APPRECIABLY HIGH DISEASE RECURRENCE RATE OF 20-30%. ANAPLASTIC THYROID CANCER (ATC), ALTHOUGH RARE IN OCCURRENCE, IS AN AGGRESSIVE FORM OF CANCER WITH LIMITED TREATMENT OPTIONS AND BLEAK CURE RATES. THIS CHAPTER USES DISCUSSIONS OF IN VITRO MODELS THAT ARE REPRESENTATIVE OF PAPILLARY, ANAPLASTIC, AND FOLLICULAR THYROID CANCER TO EVALUATE THE CROSSTALK BETWEEN SPECIFIC CELLS OF THE TUMOR MICROENVIRONMENT (TME), WHICH SERVES AS A HIGHLY HETEROGENEOUS REALM OF SIGNALING CASCADES AND METABOLISM THAT ARE ASSOCIATED WITH TUMORIGENESIS. THE CELLULAR CONSTITUENTS OF THE TME CARRY OUT VARYING CHARACTERISTIC IMMUNOMODULATORY FUNCTIONS THAT ARE DISCUSSED THROUGHOUT THIS CHAPTER. THE AFOREMENTIONED CELL TYPES INCLUDE CANCER-ASSOCIATED FIBROBLASTS (CAFS), ENDOTHELIAL CELLS (ECS), AND CANCER STEM CELLS (CSCS), AS WELL AS SPECIFIC IMMUNE CELLS, INCLUDING NATURAL KILLER (NK) CELLS, DENDRITIC CELLS (DCS), MAST CELLS, T REGULATORY (TREG) CELLS, CD8+ T CELLS, AND TUMOR-ASSOCIATED MACROPHAGES (TAMS). TAM-MEDIATED INFLAMMATION IS ASSOCIATED WITH A POOR PROGNOSIS OF THYROID CANCER, AND THE MOLECULAR BASIS OF THE CELLULAR CROSSTALK BETWEEN MACROPHAGES AND THYROID CANCER CELLS WITH RESPECT TO INDUCING A METASTATIC PHENOTYPE IS NOT YET KNOWN. THE DYNAMIC NATURE OF THE PHYSIOLOGICAL TRANSITION TO PATHOLOGICAL METASTATIC PHENOTYPES WHEN ESTABLISHING THE TME ENCOMPASSES A WIDE RANGE OF CHARACTERISTICS THAT ARE FURTHER EXPLORED WITHIN THIS CHAPTER, INCLUDING THE ROLES OF SOMATIC MUTATIONS AND EPIGENETIC ALTERATIONS THAT DRIVE THE GENETIC HETEROGENEITY OF CANCER CELLS, ALLOWING FOR SELECTIVE ADVANTAGES THAT AID IN THEIR PROLIFERATION. INDUCTION OF THESE PROLIFERATING CELLS IS TYPICALLY ACCOMPLISHED THROUGH INFLAMMATORY INDUCTION, WHEREBY CHRONIC INFLAMMATION SETS UP A CONSTANT PHYSIOLOGICAL STATE OF INFLAMMATORY CELL RECRUITMENT. THE SECRETIONS OF THESE INFLAMMATORY CELLS CAN ALTER THE GENETIC MAKEUP OF PROLIFERATING CELLS, WHICH CAN IN TURN, PROMOTE TUMOR GROWTH.THIS CHAPTER ALSO PRESENTS AN IN-DEPTH ANALYSIS OF MOLECULAR INTERACTIONS WITHIN THE TME, INCLUDING SECRETORY CYTOKINES AND EXOSOMES. SINCE THE EXOSOMAL CARGO OF A CELL IS A REFLECTION AND FINGERPRINT OF THE ORIGINATING PARENTAL CELLS, THE PROFILING OF EXOSOMAL MIRNA DERIVED FROM THYROID CANCER CELLS AND MACROPHAGES IN THE TME MAY SERVE AS AN IMPORTANT STEP IN BIOMARKER DISCOVERY. IDENTIFICATION OF A DISTINCT SET OF TUMOR SUPPRESSIVE MIRNAS DOWNREGULATED IN ATC-SECRETED EXOSOMES INDICATES THEIR ROLE IN THE REGULATION OF TUMOR SUPPRESSIVE GENES THAT MAY INCREASE THE METASTATIC PROPENSITY OF ATC. ADDITIONALLY, THE HIGH EXPRESSION OF PRO-INFLAMMATORY CYTOKINES IN STUDIES LOOKING AT THYROID CANCER AND ACTIVATED MACROPHAGE CONDITIONED MEDIA SUGGESTS THE EXISTENCE OF AN INFLAMMATORY TME IN THYROID CANCER. NEW FINDINGS ARE SUGGESTIVE OF THE PRESENCE OF A METASTATIC NICHE IN ATC TISSUES THAT IS INFLUENCED BY THYROID TUMOR MICROENVIRONMENT SECRETOME-INDUCED EPITHELIAL TO MESENCHYMAL TRANSITION (EMT), MEDIATED BY A RECIPROCAL INTERACTION BETWEEN THE PRO-INFLAMMATORY M1 MACROPHAGES AND THE THYROID CANCER CELLS. THUS, TARGETING THE METASTATIC THYROID CARCINOMA MICROENVIRONMENT COULD OFFER POTENTIAL THERAPEUTIC BENEFITS AND SHOULD BE EXPLORED FURTHER IN PRECLINICAL AND TRANSLATIONAL MODELS OF HUMAN METASTATIC THYROID CANCER. 2021 4 852 34 CHOLANGIOCARCINOMA IN PATIENTS WITH PRIMARY SCLEROSING CHOLANGITIS (PSC): A COMPREHENSIVE REVIEW. CHOLANGIOCARCINOMA (CCA) IS THE MOST COMMON MALIGNANCY IN PATIENTS WITH PRIMARY SCLEROSING CHOLANGITIS (PSC) AND CARRIES A HIGH RATE OF MORTALITY. ALTHOUGH THE PATHOGENESIS OF CCA IN PSC IS LARGELY UNKNOWN, INFLAMMATION-DRIVEN CARCINOGENESIS CONCOMITANT WITH VARIOUS GENETIC AND EPIGENETIC ABNORMALITIES ARE UNDERLYING FACTORS. THE MAJORITY OF CCA CASES DEVELOP FROM A DOMINANT STRICTURE (DS), WHICH IS DEFINED AS A STRICTURE WITH A DIAMETER < 1.5 MM IN THE COMMON BILE DUCT OR < 1.0 MM IN THE HEPATIC DUCT. IN PSC PATIENTS PRESENTING WITH AN ABRUPT AGGRAVATION OF JAUNDICE, PAIN, FATIGUE, PRURITUS, WEIGHT LOSS, OR WORSENING LIVER BIOCHEMISTRIES, CCA SHOULD BE SUSPECTED AND EVALUATED UTILIZING A VARIETY OF DIAGNOSTIC MODALITIES. HOWEVER, EARLY RECOGNITION OF CCA IN PSC REMAINS A MAJOR CHALLENGE. IMPORTANTLY, 30-50% OF CCA IN PSC PATIENTS ARE OBSERVED WITHIN THE FIRST YEAR FOLLOWING THE DIAGNOSIS OF PSC FOLLOWED BY AN ANNUAL INCIDENCE RANGING FROM 0.5 TO 1.5 PER 100 PERSONS, WHICH IS NEARLY 10 TO 1000 TIMES HIGHER THAN THAT IN THE GENERAL POPULATION. CUMULATIVE 5-YEAR, 10-YEAR, AND LIFETIME INCIDENCES ARE 7%, 8-11%, AND 9-20%, RESPECTIVELY. WHEN PSC-ASSOCIATED CCA IS DIAGNOSED, MOST TUMORS ARE UNRESECTABLE, AND NO EFFECTIVE MEDICATIONS ARE AVAILABLE. GIVEN THE POOR THERAPEUTIC OUTCOME, THE SURVEILLANCE AND MANAGEMENT OF PSC PATIENTS WHO ARE AT AN INCREASED RISK OF DEVELOPING CCA ARE OF IMPORTANCE. SUCH PATIENTS INCLUDE OLDER MALES WITH LARGE-DUCT PSC AND POSSIBLY CONCURRENT ULCERATIVE COLITIS. THUS, MORE ATTENTION SHOULD BE PAID TO PATIENTS WITH THESE CLINICAL FEATURES, IN PARTICULAR WITHIN THE FIRST YEAR AFTER PSC DIAGNOSIS. IN CONTRAST, CCA IS LESS FREQUENTLY OBSERVED IN PEDIATRIC OR FEMALE PSC PATIENTS OR IN THOSE WITH SMALL-DUCT PSC OR CONCURRENT CROHN'S DISEASE. RECENTLY, NEW BIOMARKERS SUCH AS ANTIBODIES TO GLYCOPROTEIN 2 HAVE BEEN FOUND TO BE ASSOCIATED WITH AN INCREASED RISK OF DEVELOPING CCA IN PSC. HEREIN, WE REVIEW THE LITERATURE ON THE PATHOGENESIS, INCIDENCE, CLINICAL FEATURES, AND RISK FACTORS, WITH A FOCUS ON VARIOUS DIAGNOSTIC MODALITIES OF PSC-ASSOCIATED CCA. 2020 5 5830 34 STRESS, THYROID DYSREGULATION, AND THYROID CANCER IN CHILDREN AND ADOLESCENTS: PROPOSED IMPENDING MECHANISMS. STRESS IS A POTENTIAL CATALYST FOR THYROID DYSREGULATION THROUGH CROSS-COMMUNICATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AND HYPOTHALAMIC-PITUITARY-THYROID (HPT) AXES. STRESS AND STRESSORS EXPOSURE MOTIVATES MOLECULAR MECHANISMS AFFECTING COMPOUND FEEDBACK LOOPS OF THE HPT AXIS. WHILE THERE IS EVIDENCE OF CONNECTION BETWEEN STRESS AND THYROID DYSREGULATION, THE QUESTION WHETHER THIS CONNECTION IS IMPLICATED IN THE DEVELOPMENT OF THYROID CANCER (TC) REMAINS UNANSWERED. IN VIEW OF THE RISING INCIDENCE OF TC IN BOTH ADULTS AND CHILDREN ALONGSIDE THE INCREASING STRESS IN OUR MODERN SOCIETY, THERE IS A NEED TO UNDERSTAND POSSIBLE INTERRELATIONS BETWEEN STRESS, THYROID DYSREGULATION, AND TC. PROLONGED GLUCOCORTICOID SECRETION DUE TO STRESS INTERFERES WITH IMMUNE SYSTEM RESPONSE BY ALTERING THE CYTOKINES, INDUCING LOW-GRADE CHRONIC INFLAMMATION, AND SUPPRESSING FUNCTION OF IMMUNE-PROTECTIVE CELLS. CHRONIC INFLAMMATION IS A RISK FACTOR LINKED TO TC. THE ROLE OF AUTOIMMUNITY HAS BEEN A MATTER OF CONTROVERSY. HOWEVER, THERE IS EPIDEMIOLOGICAL CONNECTION BETWEEN AUTOIMMUNE THYROID DISEASE (AITD) AND TC; PATIENTS WITH AITD SHOW INCREASED INCIDENCE IN PAPILLARY THYROID CARCINOMA (PTC), AND THOSE WITH TC SHOW A HIGH PREVALENCE OF INTRATHYROIDAL LYMPHOCYTE INFILTRATION AND THYROID AUTOANTIBODIES. TIMING AND DURATION-DEPENDENT EXPOSURE TO SPECIFIC ENDOCRINE DISRUPTING CHEMICALS (EDCS) HAS AN IMPACT ON THYROID DEVELOPMENT, FUNCTION, AND PROLIFERATION, LEADING TO THYROID DISEASE AND POTENTIALLY CANCER. THYROID HORMONE IMBALANCE, CHRONIC INFLAMMATION, AND EDCS ARE POTENTIAL RISK FACTORS FOR OXIDATIVE STRESS. OXYGEN FREE RADICALS ARE CAPABLE OF CAUSING DNA DAMAGE VIA STIMULATION OF THE MITOGEN-ACTIVATING PROTEIN KINASE OR PHOSPHATIDYLINOSITOL-3-KINASE AND/OR NUCLEAR FACTOR KB PATHWAYS, RESULTING IN TC-ASSOCIATED GENE MUTATIONS SUCH AS RET/PTC, AKAP9-BRAF, NTRK1, RAASF, PIK3CA, AND PTEN. STRESSFUL EVENTS DURING THE CRITICAL PERIODS OF PRENATAL AND EARLY LIFE CAN INFLUENCE NEUROENDOCRINE REGULATION AND INDUCE EPIGENETIC CHANGES. ABERRANT METHYLATION OF TUMOR SUPPRESSOR GENES SUCH AS P16INK4A, RASSF, AND PTEN IS ASSOCIATED WITH PTC; HISTONE H3 ACETYLATION IS SHOWN TO BE HIGHER IN TC, AND THYROID-SPECIFIC NONCODING RNAS ARE DOWNREGULATED IN PTC. THIS REVIEW FOCUSES ON THE ABOVE PROPOSED MECHANISMS THAT POTENTIALLY LEAD TO THYROID TUMORIGENESIS WITH THE AIM TO HELP IN THE DEVELOPMENT OF NOVEL PROGNOSTIC AND THERAPEUTIC STRATEGIES FOR TC. 2023 6 1435 44 DIFFERENTIAL METHYLATION LANDSCAPE OF PANCREATIC DUCTAL ADENOCARCINOMA AND ITS PRECANCEROUS LESIONS. BACKGROUND: PANCREATIC CANCER IS ONE OF THE MOST LETHAL DISEASES WITH AN INCIDENCE ALMOST EQUAL TO THE MORTALITY. IN ADDITION TO HAVING GENETIC CAUSES, CANCER CAN ALSO BE CONSIDERED AN EPIGENETIC DISEASE. DNA METHYLATION IS THE PREMIER EPIGENETIC MODIFICATION AND PATTERNS OF ABERRANT DNA METHYLATION ARE RECOGNIZED TO BE A COMMON HALLMARK OF HUMAN TUMOR. IN THE MULTISTAGE CARCINOGENESIS OF PANCREAS STARTING FROM PRECANCEROUS LESIONS TO PANCREATIC DUCTAL ADENOCARCINOMA (PDAC), THE EPIGENETIC CHANGES PLAY A SIGNIFICANT ROLE. DATA SOURCES: RELEVANT STUDIES FOR THIS REVIEW WERE DERIVED VIA AN EXTENSIVE LITERATURE SEARCH IN PUBMED VIA USING VARIOUS KEYWORDS SUCH AS PANCREATIC DUCTAL ADENOCARCINOMA, PRECANCEROUS LESIONS, METHYLATION PROFILE, EPIGENETIC BIOMARKERS THAT ARE RELEVANT DIRECTLY OR CLOSELY ASSOCIATED WITH THE CONCERNED AREA OF OUR INTEREST. THE LITERATURE SEARCH WAS INTENSIVELY DONE CONSIDERING A TIME FRAME OF 20 YEARS (1998-2018). RESULT: IN THIS REVIEW WE HAVE HIGHLIGHTED THE HYPERMETHYLATION AND HYPOMETHYLATION OF THE PRECANCEROUS PDAC LESIONS (PANCREATIC INTRA-EPITHELIAL NEOPLASIA, INTRADUCTAL PAPILLARY MUCINOUS NEOPLASM, MUCINOUS CYSTIC NEOPLASM AND CHRONIC PANCREATITIS) AND PDAC ALONG WITH THE POTENTIAL BIOMARKERS. WE HAVE ALSO ACHIEVED THE EARLY EPIGENETIC DRIVER THAT LEADS TO PROGRESSION FROM PRECANCEROUS LESIONS TO PDAC. A BUNCH OF EPIGENETIC DRIVER GENES LEADS TO PROGRESSION OF PRECANCEROUS LESIONS TO PDAC (PPENK, APC, P14/5/16/17, HMLH1 AND MGMT) ARE ALSO DOCUMENTED. WE SUMMARIZED THE IMPORTANCE OF THESE OBSERVATIONS IN THERAPEUTICS AND DIAGNOSIS OF PDAC HENCE IDENTIFYING THE POTENTIAL USE OF EPIGENETIC BIOMARKERS IN EPIGENETIC TARGETED THERAPY. EPIGENETIC INACTIVATION OCCURS BY HYPERMETHYLATION OF CPG ISLANDS IN THE PROMOTER REGIONS OF TUMOR SUPPRESSOR GENES. WE LISTED ALL HYPER- AND HYPOMETHYLATION OF CPG ISLANDS OF SEVERAL GENES IN PDAC INCLUDING ITS PRECANCEROUS LESIONS. CONCLUSIONS: THE CONCEPT OF THE REVIEW WOULD HELP TO UNDERSTAND THEIR BIOLOGICAL EFFECTS, AND TO DETERMINE WHETHER THEY MAY BE SUCCESSFULLY COMBINED WITH OTHER EPIGENETIC DRUGS. HOWEVER, WE NEED TO CONTINUE OUR RESEARCH TO DEVELOP MORE SPECIFIC DNA-DEMETHYLATING AGENTS, WHICH ARE THE TARGETS FOR HYPERMETHYLATED CPG METHYLATION SITES. 2020 7 3934 39 LIVER TUMOR INDUCTION. THE SIGNIFICANCE OF THE DEVELOPMENT OF NODULAR LIVER LESIONS IN RODENTS FOLLOWING THE ADMINISTRATION OF TEST AGENTS RAISES SEVERAL QUESTIONS WHICH COULD BE PLACED IN ONE OF TWO GENERAL CATEGORIES: DIAGNOSTIC AND INTERPRETATIONAL. FROM A DIAGNOSTIC POINT OF VIEW, THE PROPER CLASSIFICATION OF LIVER TUMORS INTO A BENIGN AND MALIGNANT CATEGORY HAS TO BE BASED ON THE DIRECT CORRELATION BETWEEN THE MORPHOLOGY AND THE BIOLOGIC BEHAVIOR OF THE LESIONS. THEREFORE, EXTREME CARE SHOULD BE TAKEN TO SEPARATE THE MALIGNANT TUMORS FROM THE BENIGN AND THE BENIGN NEOPLASIA FROM THE HYPERPLASIA. THE SUBSTITUTION OF THE TERM "NEOPLASTIC NODULE" FOR HYPERPLASTIC NODULE IN RATS IS MISLEADING. MOST OF THESE NODULES, WHEN INDUCED UNDER SPECIAL EXPERIMENTAL CONDITIONS, MAY REGRESS OR REMODEL AND THUS THEY ARE NOT NEOPLASTIC IN NATURE. CHRONIC CARCINOGENICITY BIOASSAYS SHOULD INCLUDE "STOP" TYPE OF TREATMENT LEAVING ENOUGH OF THE OBSERVATIONAL TIME TO ESTABLISH THE FATE OF INDUCED NODULAR LESIONS. THE INDUCTION OF HISTOCHEMICALLY CHANGED FOCI CAN SERVE ONLY AS AN INDICATION OF POTENTIAL HEPATOCARCINOGENICITY AND SHOULD NOT BE EQUATED WITH THE INDUCTION OF BONA FIDE CANCER. THE BIOLOGIC INTERPRETATION OF NODULAR LIVER LESIONS, ESPECIALLY IN MICE, NEEDS FURTHER SCRUTINY BECAUSE THESE LESIONS HAVE A TENDENCY TO DEVELOP SPONTANEOUSLY WITH HIGH INCIDENCE IN SOME STRAINS. THIS CHARACTERISTIC THEN RAISES THE QUESTION AS TO THE MECHANISM BY WHICH VARIOUS AGENTS AUGMENT AND/OR ACCELERATE THE DEVELOPMENT OF SUCH TUMORS. IS THIS ACTION PRIMARILY PROMOTING OR INITIATING IN NATURE OR DOES IT REPRESENT THE INDUCTION OF TUMORS DE NOVO? THE ANSWER TO THIS DILEMMA MAY HAVE A DECISIVE BEARING ON CARCINOGENIC RISK ASSESSMENT AND THE TYPE OF REGULATORY ACTION, SINCE THE PROMOTING AGENTS POSSESS A THRESHOLD EFFECT AND THE PROMOTED CHANGES MAY REGRESS FOLLOWING WITHDRAWAL OF TREATMENT. THE INTERPRETATION OF HEPATOCARCINOGENESIS IS FURTHER COMPLICATED BY THE FACT THAT SEVERAL FACTORS, SUCH AS SEX HORMONAL ENVIRONMENT, INCREASED MITOTIC ACTIVITY FOLLOWING AN EXCESSIVE LOSS OF PARENCHYMAL CELLS, DEGREE OF CALORIC INTAKE, ENZYMATIC COMPLEMENT, AND ANIMALS' AGE AT THE TIME OF THE EXPOSURE TO A TEST AGENT, MAY INFLUENCE THE OUTCOME OF LIVER TUMOR DEVELOPMENT BY MODULATING "INITIATION" AND/OR "PROMOTION" OF CARCINOGENESIS. BROAD FLUCTUATION IN THE HISTORIC INCIDENCE OF LIVER TUMORS FURTHER COMPOUNDS THE COMPLEXITY OF THE PROPER BIOASSAY INTERPRETATION. THE SPECIFICALLY DESIGNED EXPERIMENTS MAY HAVE THE OBJECTIVE TO EXPLORE PREDOMINANTLY THE INITIATING OR PROMOTING EFFECTS OF THE AGENT. SUCH PROTOCOLS SHOULD BE USED WHENEVER NECESSARY TO DIFFERENTIATE BETWEEN THESE TWO MECHANISMS OF ACTION. IN THE CAUCASIANS, THE "SPONTANEOUS" DEVELOPMENT OF THE PRIMARY HEPATOCELLULAR TUMORS IS RARE. THE MAJORITY OF THESE TUMORS ARE MALIGNANT AND RAPIDLY FATAL. ACCORDING TO SOME HUMAN PATHOLOGISTS, THE BENIGN VARIETY OF LIVER TUMORS IS RARE AND IT DOES NOT REPRESENT NECESSARILY A PREMALIGNANT STAGE IN TUMOR DEVELOPMENT. CARCINOMA OF THE LIVER MAY OCCUR IN INFANCY, ESPECIALLY IN MALES BEFORE THE AGE OF 2 YEARS. THIS SUGGESTS A GENETIC CAUSATION OR CARCINOGENIC EXPOSURE IN UTERO. ONE OF THE GEOGRAPHIC FACTORS WHICH SIGNIFICANTLY ENHANCES THE INCIDENCE OF HEPATOCELLULAR CARCINOMA IN HUMANS IS EXPOSURE TO AFLATOXIN B(1) WHICH IS APPARENTLY POTENTIATED BY CONCURRENT LIVER CIRRHOSIS. BECAUSE MANY MORE AGENTS HAVE BEEN FOUND TO BE HEPATOCARCINOGENIC IN MICE AND RATS THAN IN MEN, A QUESTION ARISES AS TO THE DIRECT RELEVANCE OF RODENT STUDIES TO HUMANS. A BALANCED ASSESSMENT OF THE CARCINOGENICITY OF THE AGENT COULD ONLY BE REACHED IN CONSIDERING BOTH THE PHARMACOKINETICS AND THE DEVELOPMENT OF MALIGNANT NEOPLASIA IN OTHER ORGANS. IN THE CASE OF POSITIVE CARCINOGENICITY ASSESSMENT, THE OUTCOME OF THE MUTAGENICITY BIOASSAYS CAN SUGGEST GENIC (GENOTOXIC) OR PARAGENIC (EPIGENETIC) MODE OF ACTION IN MAMMALIAN SYSTEMS. 1982 8 5960 30 TELOMERE LENGTH IN HEPATOCELLULAR CARCINOMA AND PAIRED ADJACENT NON-TUMOR TISSUES BY QUANTITATIVE PCR. TELOMERE SHORTENING LIMITS THE PROLIFERATIVE CAPACITY OF HUMAN CELLS, RESTRAINS THE REGENERATIVE CAPACITY OF ORGAN SYSTEMS DURING CHRONIC DISEASES AND AGING AND ALSO INDUCES CHROMOSOMAL INSTABILITY AS WELL AS INITIATION OF CANCER. PREVIOUS STUDIES DEMONSTRATED THAT TELOMERES ARE OFTEN SIGNIFICANTLY SHORTER IN TUMOR TISSUE, INCLUDING HEPATOCELLULAR CARCINOMA (HCC), COMPARED TO THE SURROUNDING TISSUE, BUT TELOMERE LENGTH IN HCC TISSUES WAS NOT CORRELATED WITH SEVERAL CLINICAL PARAMETERS, SUCH AS AGE, SEX, HBV OR HCV INFECTIONS AND TUMOR SIZE. IN THE PRESENT STUDY, THE TELOMERE LENGTH RATIO OF 36 PAIRED HCC, AND THEIR ADJACENT NON-TUMOR TISSUES WAS MEASURED BY QUANTITATIVE PCR (Q-PCR). THE MEAN TELOMERE LENGTHS (SD) FOR HCC AND ADJACENT NON-TUMOR TISSUES WERE 0.26 (0.10) AND 0.47 (0.20) RESPECTIVELY (T = 6.22, P < 0.0001). THERE WAS A LARGE DIFFERENCE IN THE DISTRIBUTION OF SUBJECTS BASED ON TELOMERE LENGTH IN TUMOR AND ADJACENT NON-TUMOR TISSUES. THE NUMBER OF TUMORS WITH TELOMERE LENGTH SHORTER THAN 0.50 WAS MUCH HIGHER THAN THAT OF ADJACENT NON-TUMOR TISSUES; MORE THAN 90% OF THE TISSUES WITH TELOMERE LENGTH > OR = 0.50 WERE ADJACENT NON-TUMOR TISSUES. THE CORRELATIONS BETWEEN TELOMERE LENGTH AND AFLATOXIN B1- AND POLYCYCLIC AROMATIC HYDROCARBON-DNA ADDUCTS LEVEL, P53 MUTATIONS AND P16 HYPERMETHYLATION STATUS WERE ALSO TESTED, BUT NO SIGNIFICANT ASSOCIATIONS WERE FOUND. THE RELATIONSHIP BETWEEN TELOMERE LENGTH SHORTENING, CHEMICAL CARCINOGEN EXPOSURE, AND GENETIC AND EPIGENETIC CHANGES IN HEPATOCARCINOGENESIS NEEDS FURTHER INVESTIGATION. 2007 9 1582 42 DNA METHYLATION PROFILES IN PRECANCEROUS TISSUE AND CANCERS: CARCINOGENETIC RISK ESTIMATION AND PROGNOSTICATION BASED ON DNA METHYLATION STATUS. ALTERATIONS IN DNA METHYLATION, WHICH ARE ASSOCIATED WITH DNA METHYLTRANSFERASE ABNORMALITIES AND RESULT IN SILENCING OF TUMOR-RELATED GENES AND CHROMOSOMAL INSTABILITY, ARE INVOLVED EVEN IN PRECANCEROUS CHANGES IN VARIOUS ORGANS. DNA METHYLATION ALTERATIONS ALSO ACCOUNT FOR THE HISTOLOGICAL HETEROGENEITY AND CLINICOPATHOLOGICAL DIVERSITY OF HUMAN CANCERS. THEREFORE, WE HAVE ANALYZED DNA METHYLATION ON A GENOME-WIDE SCALE IN CLINICAL TISSUE SAMPLES. OUR APPROACH USING THE BACTERIAL ARTIFICIAL CHROMOSOME ARRAY-BASED METHYLATED CPG ISLAND AMPLIFICATION METHOD HAS REVEALED THAT DNA METHYLATION ALTERATIONS CORRELATED WITH THE FUTURE DEVELOPMENT OF MORE MALIGNANT CANCERS ARE ALREADY ACCUMULATED AT THE PRECANCEROUS STAGE IN THE KIDNEY, LIVER AND URINARY TRACT. DNA METHYLATION PROFILES AT PRECANCEROUS STAGES ARE BASICALLY INHERITED BY THE CORRESPONDING CANCERS DEVELOPING IN INDIVIDUAL PATIENTS. SUCH DNA METHYLATION ALTERATIONS MAY CONFER VULNERABILITY TO FURTHER GENETIC AND EPIGENETIC ALTERATIONS, GENERATE MORE MALIGNANT CANCERS, AND THUS DETERMINE PATIENT OUTCOME. ON THE BASIS OF BACTERIAL ARTIFICIAL CHROMOSOME ARRAY-BASED METHYLATED CPG ISLAND AMPLIFICATION DATA, INDICATORS FOR CARCINOGENETIC RISK ESTIMATION HAVE BEEN ESTABLISHED USING LIVER TISSUE SPECIMENS FROM PATIENTS WITH HEPATITIS VIRUS INFECTION, CHRONIC HEPATITIS AND LIVER CIRRHOSIS OR HISTOLOGICALLY NORMAL UROTHELIA, AND FOR PROGNOSTICATION USING BIOPSY OR SURGICALLY RESECTED SPECIMENS FROM PATIENTS WITH RENAL CELL CARCINOMA, HEPATOCELLULAR CARCINOMA AND UROTHELIAL CARCINOMA. SUCH GENOME-WIDE DNA METHYLATION PROFILING HAS NOW FIRMLY ESTABLISHED THE CLINICAL RELEVANCE OF TRANSLATIONAL EPIGENETICS. 2010 10 1107 30 COMBINING CYTOGENETIC AND EPIGENETIC APPROACHES IN CHRONIC LYMPHOCYTIC LEUKEMIA IMPROVES PROGNOSIS PREDICTION FOR PATIENTS WITH ISOLATED 13Q DELETION. BACKGROUND: BOTH DEFECTIVE DNA METHYLATION AND ACTIVE DNA DEMETHYLATION PROCESSES ARE EMERGING AS IMPORTANT RISK FACTORS IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). HOWEVER, ASSOCIATIONS BETWEEN 5-CYTOSINE EPIGENETIC MARKERS AND THE MOST FREQUENT CHROMOSOMAL ABNORMALITIES DETECTED IN CLL REMAIN TO BE ESTABLISHED. METHODS: CLL PATIENTS WERE RETROSPECTIVELY CLASSIFIED INTO A CYTOGENETIC LOW-RISK GROUP (ISOLATED 13Q DELETION), AN INTERMEDIATE-RISK GROUP (NORMAL KARYOTYPE OR TRISOMY 12), AND A HIGH-RISK GROUP (11Q DELETION, 17P DELETION, OR COMPLEX KARYOTYPE [>/= 3 BREAKPOINTS]). THE TWO 5-CYTOSINE DERIVATIVES, 5-METHYLCYTOSINE (5-MCYT) AND 5-HYDROXYMETHYLCYTOSINE (5-HMCYT), WERE TESTED BY ELISA (N = 60), WHILE REAL-TIME QUANTITATIVE PCR WAS USED FOR DETERMINING TRANSCRIPTIONAL EXPRESSION LEVELS OF DNMT AND TET (N = 24). RESULTS: BY USING GLOBAL DNA METHYLATION/DEMETHYLATION LEVELS, IN THE LOW-RISK DISEASE GROUP, TWO SUBGROUPS WITH SIGNIFICANTLY DIFFERENT CLINICAL OUTCOMES HAVE BEEN IDENTIFIED (MEDIAN TREATMENT-FREE SURVIVAL [TFS] 45 VERSUS > 120 MONTHS FOR 5-MCYT, P = 0.0008, AND 63 VERSUS > 120 MONTHS FOR 5-HMCYT, P = 0.04). A DEFECTIVE 5-MCYT STATUS WAS FURTHER ASSOCIATED WITH A HIGHER PERCENTAGE OF 13Q DELETED NUCLEI (> 80%), THUS SUGGESTING AN ACQUIRED PROCESS. WHEN CONSIDERING THE CYTOGENETIC INTERMEDIATE/HIGH-RISK DISEASE GROUPS, AN ASSOCIATION OF 5-MCYT STATUS WITH LYMPHOCYTOSIS (P = 0.0008) AND THE LYMPHOCYTE DOUBLING TIME (P = 0.04) BUT NOT WITH TFS WAS OBSERVED, AS WELL AS A REDUCTION OF DNMT3A, TET1, AND TET2 TRANSCRIPTS. CONCLUSIONS: COMBINING CYTOGENETIC STUDIES WITH 5-MCYT ASSESSMENT ADDS ACCURACY TO CLL PATIENTS' PROGNOSES AND PARTICULARLY FOR THOSE WITH 13Q DELETION AS A SOLE CYTOGENETIC ABNORMALITY. 2017 11 4423 40 MOLECULAR AND IMMUNOLOGIC MARKERS OF KIDNEY CANCER-POTENTIAL APPLICATIONS IN PREDICTIVE, PREVENTIVE AND PERSONALIZED MEDICINE. KIDNEY CANCER IS ONE OF THE DEADLIEST MALIGNANCIES DUE TO FREQUENT LATE DIAGNOSIS (33 % OR RENAL CELL CARCINOMA ARE METASTATIC AT DIAGNOSIS) AND POOR TREATMENT OPTIONS. THERE ARE TWO MAJOR SUBTYPES OF KIDNEY CANCER: RENAL CELL CARCINOMA (RCC) AND RENAL PELVIS CARCINOMA. THE RISK FACTORS FOR RCC, ACCOUNTING FOR MORE THAN 90 % OF ALL KIDNEY CANCERS, ARE SMOKING, OBESITY, HYPERTENSION, MISUSE OF PAIN MEDICATION, AND SOME GENETIC DISEASES. THE MOST COMMON MOLECULAR MARKERS OF KIDNEY CANCER INCLUDE MUTATIONS AND EPIGENETIC INACTIVATION OF VON HIPPEL-LINDAU (VHL) GENE, GENES OF VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) PATHWAY, AND CARBONIC ANHYDRASE IX (CIAX). THE ROLE OF EPIGENETIC PATHWAYS, INCLUDING DNA METHYLATION AND CHROMATIN STRUCTURE REMODELING, WAS ALSO DEMONSTRATED. IMMUNOLOGIC PROPERTIES OF RCC ENABLE THIS TYPE OF TUMOR TO ESCAPE IMMUNE RESPONSE EFFECTIVELY. AN IMPORTANT ROLE IN THIS PROCESS IS PLAYED BY TUMOR-ASSOCIATED MACROPHAGES THAT DEMONSTRATE MIXED M1/M2 PHENOTYPE. IN THIS REVIEW, WE DISCUSS MOLECULAR AND CELLULAR ASPECTS FOR RCC DEVELOPMENT AND CURRENT STATE OF KNOWLEDGE ALLOWING PERSONALIZED APPROACHES FOR DIAGNOSTICS AND PROGNOSTIC PREDICTION OF THIS DISEASE. A SET OF MACROPHAGE MARKERS IS SUGGESTED FOR THE ANALYSIS OF THE ASSOCIATION OF MACROPHAGE PHENOTYPE AND DISEASE PROGNOSIS. 2015 12 6386 31 THE ROLE OF QUANTITATIVE NPTX2 HYPERMETHYLATION AS A NOVEL SERUM DIAGNOSTIC MARKER IN PANCREATIC CANCER. OBJECTIVES: THE MAJORITY OF PANCREATIC CANCERS ARE FOUND TO BE UNRESECTABLE, AND THE ONLY CHANCE FOR CURE LIES ON EARLY DETECTION AND COMPLETE RESECTION. SEVERAL GENES HAVE BEEN DISCOVERED TO BE ABERRANTLY METHYLATED IN PRIMARY PANCREATIC CANCER TISSUE, AND THIS CANCER DNA CAN BE DETECTED IN THE PLASMA. THE AIMS OF THIS STUDY WERE TO DEVELOP A NOVEL DIAGNOSTIC MARKER BASED ON EPIGENETIC CHARACTERISTICS OF PANCREATIC CANCER. METHODS: WE ENROLLED 104 PATIENTS WITH PANCREATIC CANCER, 60 WITH CHRONIC PANCREATITIS, AND 5 WITH BENIGN BILIARY STONE DISEASES. THE BLOOD SAMPLES WERE COLLECTED BEFORE SURGERY OR ANY KINDS OF TREATMENT MODALITIES. DNA WAS EXTRACTED FROM THE PLASMA OF EACH PATIENT, AND NPTX2 (NEURONAL PENTRAXIN II) CPG ISLAND HYPERMETHYLATION WAS EXAMINED QUANTITATIVELY BY REAL-TIME POLYMERASE CHAIN REACTION. RESULTS: NPTX2 HYPERMETHYLATION LEVELS WERE SIGNIFICANTLY HIGHER COMPARED WITH CHRONIC PANCREATITIS (P = 0.016). THE SENSITIVITY AND SPECIFICITY WERE 80% AND 76%, RESPECTIVELY (CUTOFF = 0.015). NPTX2 GENE HYPERMETHYLATION LEVEL WAS SIGNIFICANTLY ELEVATED IN CORRELATION WITH HIGHER AMERICAN JOINT COMMITTEE ON CANCER STAGES. CONCLUSIONS: THE ABERRANTLY METHYLATED NPTX2 GENE MAY HELP TO DISTINGUISH BETWEEN CHRONIC PANCREATITIS AND PANCREATIC CANCER WITH CONVENTIONAL DIAGNOSTIC TOOLS AND COULD BECOME A VALUABLE DIAGNOSTIC MARKER. 2012 13 6539 27 TRANSCRIPTIONAL VARIATIONS IN THE WIDER PERITUMORAL TISSUE ENVIRONMENT OF PANCREATIC CANCER. TRANSCRIPTIONAL PROFILING WAS PERFORMED ON 452 RNA PREPARATIONS ISOLATED FROM VARIOUS TYPES OF PANCREATIC TISSUE FROM TUMOUR PATIENTS AND HEALTHY DONORS, WITH A PARTICULAR FOCUS ON PERITUMORAL SAMPLES. PANCREATIC DUCTAL ADENOCARCINOMAS (PDAC) AND CYSTIC TUMOURS WERE MOST DIFFERENT IN THESE NON-TUMOROUS TISSUES SURROUNDING THEM, WHEREAS THE ACTUAL TUMOURS EXHIBITED RATHER SIMILAR TRANSCRIPT PATTERNS. THE ENVIRONMENT OF CYSTIC TUMOURS WAS TRANSCRIPTIONALLY NEARLY IDENTICAL TO NORMAL PANCREAS TISSUE. IN CONTRAST, THE TISSUE AROUND PDAC BEHAVED A LOT LIKE THE TUMOUR, INDICATING SOME KIND OF FIELD DEFECT, WHILE SHOWING FAR LESS MOLECULAR RESEMBLANCE TO BOTH CHRONIC PANCREATITIS AND HEALTHY TISSUE. THIS SUGGESTS THAT THE MAJOR PATHOGENIC DIFFERENCE BETWEEN CYSTIC AND DUCTAL TUMOURS MAY BE DUE TO THEIR CELLULAR ENVIRONMENT RATHER THAN THE FEW VARIATIONS BETWEEN THE TUMOURS. LACK OF CORRELATION BETWEEN DNA METHYLATION AND TRANSCRIPT LEVELS MAKES IT UNLIKELY THAT THE OBSERVED FIELD DEFECT IN THE PERITUMORAL TISSUE OF PDAC IS CONTROLLED TO A LARGE EXTENT BY SUCH EPIGENETIC REGULATION. FUNCTIONALLY, A STRIKINGLY LARGE NUMBER OF AUTOPHAGY-RELATED TRANSCRIPTS WAS CHANGED IN BOTH PDAC AND ITS PERITUMORAL TISSUE, BUT NOT IN OTHER PANCREATIC TUMOURS. A TRANSCRIPTION SIGNATURE OF 15 AUTOPHAGY-RELATED GENES WAS ESTABLISHED THAT PERMITS A PROGNOSIS OF SURVIVAL WITH HIGH ACCURACY AND INDICATES THE ROLE OF AUTOPHAGY IN TUMOUR BIOLOGY. 2018 14 1481 32 DIVERSITY OF GENOME PROFILES IN MALIGNANT LYMPHOMA. CHARACTERISTIC CHROMOSOME TRANSLOCATIONS ARE ASSOCIATED WITH SPECIFIC DISEASE ENTITIES, AND ARE KNOWN TO PLAY A PIVOTAL ROLE IN LYMPHOMA DEVELOPMENT. CHROMOSOME TRANSLOCATION ALONE, HOWEVER, IS NOT SUFFICIENT TO PRODUCE TUMORS. FACTORS INCLUDING THE MICROENVIRONMENT AND EPIGENETIC AND GENETIC ALTERATIONS OTHER THAN CHROMOSOME TRANSLOCATIONS HAVE BEEN SHOWN TO PLAY A ROLE IN LYMPHOMA DEVELOPMENT. FOLLICULAR LYMPHOMA CELLS PROLIFERATE IN CLOSE CONTACT WITH FOLLICULAR DENDRITIC CELLS. MUCOSA-ASSOCIATED LYMPHOID TISSUE (MALT) LYMPHOMA CELLS PROLIFERATE AT THE MARGINAL ZONE AREA OF REACTIVE FOLLICLES WHICH ARE FORMED BY PRECEDING CHRONIC INFLAMMATION. THE IMPORTANCE OF GENETIC ALTERATIONS OTHER THAN CHROMOSOME TRANSLOCATION HAS BEEN RECOGNIZED SINCE THE INTRODUCTION OF ARRAY COMPARATIVE GENOMIC HYBRIDIZATION (ARRAY CGH). VARIATIONS IN THE GENOMIC PROFILE AMONG PATIENTS WITH THE SAME DISEASE ENTITY HAVE BEEN FOUND BY ARRAY CGH ANALYSES. THESE VARIATIONS INDICATE THAT MULTIPLE GENETIC PATHWAYS LEADING TO THE DEVELOPMENT OF LYMPHOMAS MAY EXIST AND HENCE RESULT IN THE VARIABLE CLINICOPATHOLOGICAL FEATURES OBSERVED. 2010 15 1064 31 CLINICAL SIGNIFICANCE OF PROMOTER METHYLATION STATUS OF TUMOR SUPPRESSOR GENES IN CIRCULATING DNA OF PANCREATIC CANCER PATIENTS. INTRODUCTION: PANCREATIC DUCTAL ADENOCARCINOMA (PDAC) IS A VERY AGGRESSIVE CANCER. THERE ARE VARIOUS SUB-CELLULAR EVENTS (BOTH GENETIC AND EPIGENETIC) THAT GET DYSREGULATED LEADING TO TUMORIGENESIS. METHYLATION IN PROMOTERS OF TUMOR SUPPRESSOR GENES IS ONE OF THESE EPIGENETIC PHENOMENA CONTRIBUTING TO THE PATHOGENESIS OF CANCER. GENES ANALYZED FOR PROMOTER METHYLATION STATUS IN THIS STUDY NAMELY SPARC (SECRETED PROTEIN ACIDIC AND RICH IN CYSTEINE, UCHL1 (UBIQUITIN CARBOXY-TERMINAL HYDROLASE L1), NPTX2 (NEURONAL PENTRAXIN 2), PENK (PROENKEPHALIN) HAD BEEN STUDIED IN PANCREATIC CANCER, BUT THERE IS A NEED TO CHECK METHYLATION IN THESE GENES AS CIRCULATORY NON-INVASIVE MARKERS. THIS STUDY ANALYZED THE ABSOLUTE QUANTIFICATION OF METHYLATION LEVELS OF SPARC, UCHL1, PENK, AND NPTX2 GENES PROMOTERS IN PDAC PATIENTS AS WELL AS IN CHRONIC PANCREATITIS (CP) PATIENTS AND HEALTHY SUBJECTS (HC) AND EVALUATED ITS CLINICAL SIGNIFICANCE IN PDAC. MATERIALS AND METHODS: THE STUDY INCLUDED 65 PDAC PATIENTS, 25 CP PATIENTS, AND 25 HEALTHY CONTROLS. DNA WAS EXTRACTED FROM THEIR PLASMA SAMPLES AND SUBSEQUENTLY GIVEN BISULFITE TREATMENT. ABSOLUTE QUANTIZATION OF METHYLATED AND UNMETHYLATED COPIES OF GENE PROMOTERS OF ALL THE FOUR GENES WAS PERFORMED USING REAL-TIME PCR (SYBR GREEN) BY THE STANDARD CURVE METHOD. METHYLATION LEVELS WERE EXPRESSED AS METHYLATION INDEX (MI) FOR EACH GENE IN EACH PATIENT. MI WAS CALCULATED FROM ABSOLUTE COPY NUMBERS AS FOLLOWS: MI-METHYLATED COPY NUMBER/METHYLATED COPY NUMBER + UNMETHYLATED COPY NUMBER). THESE INDICES WERE USED TO COMPARE GENE METHYLATION LEVELS WITHIN DIFFERENT GROUPS AND TO CORRELATE WITH CLINICOPATHOLOGICAL FEATURES AND SURVIVAL OF PANCREATIC CANCER PATIENTS. AN APPROPRIATE STATISTICAL ANALYSIS WAS APPLIED. RESULTS: METHYLATION INDICES FOR ALL THE FOUR GENES IN PDAC CASES WERE FOUND TO BE SIGNIFICANTLY HIGHER AS COMPARED TO THAT IN HEALTHY INDIVIDUALS. SPARC MI VALUES WERE FOUND TO DIFFERENTIATE EARLY-STAGE PDAC PATIENTS FROM CP PATIENTS. PDAC PATIENTS WITH THE METASTASIZED DISEASE AND STAGE IV DISEASE WERE FOUND TO HAVE HIGH MI FOR THE SPARC GENE AS WELL AS FOR THE NPTX2 GENE, WHILE A HIGHER UCHL1 METHYLATION INDEX WAS FOUND TO CORRELATE WITH AN ADVANCED STAGE OF THE DISEASE. HIGHER MI VALUES FOR SPARC AND NPTX2 GENES WERE FOUND TO ASSOCIATE WITH POOR SURVIVAL IN PATIENTS WITH PDAC. CONCLUSION: METHYLATION LOAD IN THE FORM OF MI FOR EACH OF THE FOUR GENES ASSESSED IN PLASMA MAY EMERGE AS A NON-INVASIVE BIOMARKER TO DIFFERENTIATE PANCREATIC CANCER FROM HEALTHY INDIVIDUALS. BUT ONLY SPARC AND NPTX2 HYPERMETHYLATION WERE ABLE TO DISTINGUISH PANCREATIC CANCER FROM CHRONIC PANCREATITIS. ASSOCIATION OF ABERRANT METHYLATION IN SPARC AND NPTX2 GENE WITH METASTASIS AND POOR SURVIVAL OF PATIENTS SUGGEST THE ROLE OF METHYLATION IN THESE GENES AS PROGNOSTIC MARKERS. 2020 16 414 30 ANALYSIS OF PROMOTER METHYLATION IN STOOL: A NOVEL METHOD FOR THE DETECTION OF COLORECTAL CANCER. BACKGROUND & AIMS: DETECTION OF TUMOR-DERIVED DNA ALTERATIONS IN STOOL IS AN INTRIGUING NEW APPROACH WITH HIGH POTENTIAL FOR THE NONINVASIVE DETECTION OF COLORECTAL CANCER (CRC). BECAUSE OF HETEROGENEITY OF TUMORS, USUALLY MULTIPLE MARKERS DISTRIBUTED THROUGHOUT THE HUMAN GENOME NEED TO BE ANALYZED. THIS IS LABOR INTENSIVE AND DOES NOT ALLOW FOR HIGH THROUGH-PUT SCREENING. THEREFORE, MARKERS WITH HIGH SENSITIVITY AND GOOD SPECIFICITY ARE NEEDED. WE EXPLORED THE POTENTIAL OF A SINGLE EPIGENETIC MARKER IN COMPARISON WITH FECAL OCCULT BLOOD TESTING (FOBT) FOR THE DISCRIMINATION OF PATIENTS WITH CRCS AND ADENOMAS FROM THOSE WITHOUT. METHODS: METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) WAS PERFORMED TO ANALYZE HYPERMETHYLATED IN CANCER 1 (HIC1) PROMOTER METHYLATION STATUS IN A BLINDED FASHION IN STOOL SAMPLES FROM 26 PATIENTS WITH CRC, 13 WITH ADENOMA > OR =1 CM, 9 WITH HYPERPLASTIC POLYPS, 9 WITH CHRONIC INFLAMMATORY BOWEL DISEASE, AND 32 WITH ENDOSCOPICALLY NORMAL COLON. RESULTS: NINETY-SEVEN PERCENT OF THE STOOL SAMPLES CONTAINED AMPLIFIABLE DNA. FORTY-TWO PERCENT OF THE SAMPLES FROM PATIENTS WITH CRC AND 31% OF THE SAMPLES FROM PATIENTS WITH COLORECTAL ADENOMA > OR =1 CM WERE POSITIVE FOR HIC1 PROMOTER METHYLATION. NO METHYLATED HIC1 PROMOTER DNA WAS DETECTED IN THE FECAL DNA FROM PATIENTS WITH ENDOSCOPICALLY NORMAL COLON OR HYPERPLASTIC POLYPS. CONCLUSIONS: THE EPIGENETIC MARKER HIC1 PROMOTER METHYLATION CARRIES HIGH POTENTIAL FOR THE REMOTE DETECTION OF CRCS. WE POSTULATE THAT A PANEL OF MERELY A FEW GENETIC AND EPIGENETIC MARKERS WILL BE REQUIRED FOR THE HIGHLY SENSITIVE AND SPECIFIC DETECTION OF CRCS AND ADENOMAS IN FECAL SAMPLES FROM AFFECTED PATIENTS. 2005 17 342 45 ALTERATIONS OF DNA METHYLATION ASSOCIATED WITH ABNORMALITIES OF DNA METHYLTRANSFERASES IN HUMAN CANCERS DURING TRANSITION FROM A PRECANCEROUS TO A MALIGNANT STATE. ALTERATIONS OF DNA METHYLATION ARE ONE OF THE MOST CONSISTENT EPIGENETIC CHANGES IN HUMAN CANCERS. HUMAN CANCERS GENERALLY SHOW GLOBAL DNA HYPOMETHYLATION ACCOMPANIED BY REGION-SPECIFIC HYPERMETHYLATION. ALTERATIONS OF DNA METHYLATION MAY RESULT IN CHROMOSOMAL INSTABILITY AS A RESULT OF CHANGES IN CHROMATIN STRUCTURE. DNA HYPERMETHYLATION OF CPG ISLANDS SILENCES VARIOUS TUMOR-RELATED GENES. ALTERATIONS OF DNA METHYLATION ARE FREQUENTLY OBSERVED IN CANCERS ASSOCIATED WITH CHRONIC INFLAMMATION AND/OR PERSISTENT INFECTION WITH VIRUSES OR OTHER PATHOGENIC MICROORGANISMS, SUCH AS HEPATITIS B OR C VIRUSES, EPSTEIN-BARR VIRUS, HUMAN PAPILLOMAVIRUS AND HELICOBACTER PYLORI, OR WITH CIGARETTE SMOKING. ACCUMULATING EVIDENCE SUGGESTS THAT ALTERATIONS OF DNA METHYLATION ARE INVOLVED EVEN IN THE EARLY AND PRECANCEROUS STAGES. ON THE OTHER HAND, IN PATIENTS WITH CANCERS, ABERRANT DNA METHYLATION IS SIGNIFICANTLY ASSOCIATED WITH POORER TUMOR DIFFERENTIATION, TUMOR AGGRESSIVENESS AND POOR PROGNOSIS. PRECANCEROUS CONDITIONS SHOWING ALTERATIONS OF DNA METHYLATION MAY PROGRESS RAPIDLY AND GENERATE MORE MALIGNANT CANCERS. DNA METHYLTRANSFERASE (DNMT) 1 OVER-EXPRESSION IS NOT A SECONDARY RESULT OF INCREASED CELL PROLIFERATIVE ACTIVITY BUT IS SIGNIFICANTLY CORRELATED WITH THE CPG ISLAND METHYLATOR PHENOTYPE, WHICH IS DEFINED AS FREQUENT DNA HYPERMETHYLATION OF C-TYPE CPG ISLANDS THAT ARE USUALLY METHYLATED IN A CANCER-SPECIFIC (NOT AGE-DEPENDENT) MANNER. SPLICING ALTERATION OF DNMT3B MAY RESULT IN CHROMOSOMAL INSTABILITY THROUGH DNA HYPOMETHYLATION OF PERICENTROMERIC SATELLITE REGIONS. ALTERATION OF DNA METHYLATION MAY BECOME AN INDICATOR FOR CARCINOGENETIC RISK ESTIMATION AND EARLY DIAGNOSIS OF CANCERS AND A BIOLOGICAL PREDICTOR OF POOR PROGNOSIS IN PATIENTS WITH CANCERS. CORRECTION OF DNA METHYLATION STATUS MAY OFFER A NEW STRATEGY FOR PREVENTION AND THERAPY OF CANCERS. 2007 18 1031 38 CIRCULATING TUMOR DNA DETECTION AND ITS APPLICATION STATUS IN GASTRIC CANCER: A NARRATIVE REVIEW. CIRCULATING TUMOR DNA (CTDNA) IS THE SMALL GENOMIC FRAGMENT RELEASED BY TUMOR CELLS INTO THE CIRCULATING SYSTEM, WHICH CARRIES THE GENE VARIATION FEATURES, SUCH AS MUTATION, INSERTION, DELETION, REARRANGEMENT, COPY NUMBER VARIATION (CNV) AND METHYLATION, RENDERING IT AN IMPORTANT BIOMARKER. IT CAN BE USED NOT ONLY TO DIAGNOSE CERTAIN TYPES OF SOLID TUMORS, BUT ALSO TO MONITOR THE THERAPEUTIC RESPONSE AND EXPLORE THE MINIMAL RESIDUAL DISEASE (MRD) AND RESISTANT MUTATION OF TARGETED THERAPY. THEREFORE, CTDNA DETECTION MAY BECOME THE PREFERRED NON-INVASIVE TUMOR SCREENING METHOD. FOR PATIENTS WHO CANNOT RECEIVE FURTHER GENE DETECTION DUE TO INSUFFICIENT OR RESTRICTED SAMPLE COLLECTION WITH THE DEFINED PATHOLOGICAL DIAGNOSIS, CTDNA DETECTION CAN BE CARRIED OUT TO DETERMINE THE GENE MUTATION TYPE, WITH NO NEED FOR REPEATED SAMPLING. GASTRIC CANCER (GC) IS A MALIGNANCY WITH EXTREMELY HIGH MORBIDITY AND MORTALITY, AND ITS GENESIS AND DEVELOPMENT ARE THE CONSEQUENCE OF INTERACTIONS OF MULTIPLE FACTORS, INCLUDING ENVIRONMENT, DIET, HEREDITY, HELICOBACTER PYLORI INFECTION, CHRONIC INFLAMMATORY INFILTRATION, AND PRECANCEROUS LESION. AS THE RESEARCH ON GC MOVES FORWARD, THE EXISTING RESEARCH MAINLY FOCUSES ON GENETIC AND EPIGENETIC CHANGES, INCLUDING DNA METHYLATION, HISTONE MODIFICATION, NON-CODING RNA CHANGES, GENE MUTATION, GENE HETEROZYGOSITY LOSS AND MICROSATELLITE INSTABILITY. THIS PAPER AIMED TO SUMMARIZE THE CONTENTS OF CTDNA DETECTION, ITS APPLICATION STATUS IN GC AND CLINICAL SIGNIFICANCE. 2021 19 3067 49 GENOME-WIDE DNA METHYLATION PROFILES IN PRECANCEROUS CONDITIONS AND CANCERS. ALTERATIONS OF DNA METHYLATION, WHICH RESULT IN CHROMOSOMAL INSTABILITY AND SILENCING OF TUMOR-RELATED GENES, ARE AMONG THE MOST CONSISTENT EPIGENETIC CHANGES OBSERVED IN HUMAN CANCERS. ANALYSIS OF TISSUE SPECIMENS HAS REVEALED THAT DNA METHYLATION ALTERATIONS PARTICIPATE IN MULTISTAGE CARCINOGENESIS, EVEN FROM THE EARLY AND PRECANCEROUS STAGES, ESPECIALLY IN ASSOCIATION WITH CHRONIC INFLAMMATION AND/OR PERSISTENT VIRAL INFECTION, SUCH AS CHRONIC HEPATITIS OR LIVER CIRRHOSIS RESULTING FROM INFECTION WITH HEPATITIS B OR C VIRUS. DNA METHYLATION ALTERATIONS CAN ACCOUNT FOR THE HISTOLOGICAL HETEROGENEITY AND CLINICOPATHOLOGICAL DIVERSITY OF HUMAN CANCERS. OVEREXPRESSION OF DNA METHYLTRANSFERASE 1 IS NOT A SECONDARY RESULT OF INCREASED CELL PROLIFERATIVE ACTIVITY, BUT IS SIGNIFICANTLY CORRELATED WITH ACCUMULATION OF DNA HYPERMETHYLATION IN CPG ISLANDS OF TUMOR-RELATED GENES. ALTERATION OF DNA METHYLTRANSFERASE 3B SPLICING MAY RESULT IN CHROMOSOMAL INSTABILITY THROUGH DNA HYPOMETHYLATION IN PERICENTROMERIC SATELLITE REGIONS. GENOME-WIDE ANALYSIS OF DNA METHYLATION STATUS HAS REVEALED THAT THE DNA METHYLATION PROFILE AT THE PRECANCEROUS STAGE IS BASICALLY INHERITED BY THE CORRESPONDING CANCERS DEVELOPING IN INDIVIDUAL PATIENTS. DNA METHYLATION STATUS IS NOT SIMPLY ALTERED AT THE PRECANCEROUS STAGE; RATHER, DNA METHYLATION ALTERATIONS AT THE PRECANCEROUS STAGE MAY CONFER VULNERABILITY TO FURTHER GENETIC AND EPIGENETIC ALTERATIONS, GENERATE MORE MALIGNANT CANCERS, AND THUS DETERMINE PATIENT OUTCOME. THEREFORE, GENOME-WIDE DNA METHYLATION PROFILING MAY PROVIDE OPTIMAL INDICATORS FOR CARCINOGENETIC RISK ESTIMATION AND PROGNOSTICATION, AND THUS PROVIDE AN AVENUE FOR CANCER PREVENTION AND THERAPY ON AN INDIVIDUAL BASIS. 2010 20 4905 28 P16INK4A HYPERMETHYLATION IS ASSOCIATED WITH HEPATITIS VIRUS INFECTION, AGE, AND GENDER IN HEPATOCELLULAR CARCINOMA. PURPOSE: THE TUMOR SUPPRESSOR GENE P16INK4A IS MAINLY INACTIVATED BY AN EPIGENETIC CHANGE INVOLVING PROMOTER HYPERMETHYLATION IN HEPATOCARCINOGENESIS. THE POSSIBLE CLINICAL IMPACT OF P16INK4A METHYLATION AND THE POTENTIAL RISK FACTORS FOR THIS EPIGENETIC ALTERATION HAVE NOT BEEN THOROUGHLY INVESTIGATED. EXPERIMENTAL DESIGN: WE STUDIED THE METHYLATION STATUS AND MRNA AND PROTEIN EXPRESSION OF P16INK4A IN 50 HEPATOCELLULAR CARCINOMAS AND CORRESPONDING NONNEOPLASTIC LIVER LESIONS USING METHYLATION-SPECIFIC PCR, REVERSE TRANSCRIPTION-PCR, AND IMMUNOHISTOCHEMICAL TECHNIQUES. RESULTS: P16INK4A HYPERMETHYLATION WAS OBSERVED IN 58% (29 OF 50) OF THE HEPATOCELLULAR CARCINOMAS AND 16% (6 OF 38) OF THE CORRESPONDING CHRONIC HEPATITIS AND CIRRHOSIS TISSUE SAMPLES. P16INK4A METHYLATION WAS SIGNIFICANTLY ASSOCIATED WITH MRNA AND PROTEIN EXPRESSION (P <0.001 AND P=0.003, RESPECTIVELY). ALL OF THE P16INK4A-METHYLATED TUMORS WERE POSITIVE FOR HEPATITIS B VIRUS OR HEPATITIS C VIRUS MARKERS, BUT NONE OF THE VIRUS-NEGATIVE TUMORS EXHIBITED P16INK4A METHYLATION (P=0.006). THE FREQUENCY OF P16INK4A HYPERMETHYLATION TENDED TO BE HIGHER IN HEPATITIS C VIRUS-RELATED TUMORS (23 OF 32, 72%) THAN IN HEPATITIS B VIRUS-RELATED TUMORS (6 OF 13, 46%; P=0.1). ABERRANT METHYLATION OF P16INK4A WAS ALSO RELATED SIGNIFICANTLY TO INCREASING AGE, FEMALE GENDER, AND NORMAL LEVELS OF SERUM PIVKA-II (P=0.02, 0.04, AND 0.04, RESPECTIVELY). NO STATISTICALLY SIGNIFICANT DIFFERENCE IN SURVIVAL WAS OBSERVED BETWEEN PATIENTS WITH P16INK4A HYPERMETHYLATION AND THOSE WITHOUT. CONCLUSIONS: OUR OBSERVATIONS SUGGEST THAT P16INK4A HYPERMETHYLATION MAY CONTRIBUTE TO HEPATOCARCINOGENESIS FROM AN EARLY STAGE AND THAT MULTIPLE RISK FACTORS, SUCH AS VIRAL INFECTIONS, AGE, AND GENDER, MAY BE ASSOCIATED WITH P16INK4A HYPERMETHYLATION IN HEPATOCARCINOGENESIS. 2004