1 3571 119 IMPACT OF LOCAL ANESTHETICS ON EPIGENETICS IN CANCER. DEFECTIVE SILENCING OF TUMOR SUPPRESSOR GENES THROUGH EPIGENETIC ALTERATIONS CONTRIBUTES TO ONCOGENESIS BY PERTURBING CELL CYCLE REGULATION, DNA REPAIR OR CELL DEATH MECHANISMS. REVERSAL OF SUCH EPIGENETIC CHANGES INCLUDING DNA HYPERMETHYLATION PROVIDES A PROMISING ANTICANCER STRATEGY. UNTIL NOW, THE NUCLEOSIDE DERIVATIVES 5-AZACYTIDINE AND DECITABINE ARE THE SOLE DNA METHYLTRANSFERASE (DNMT) INHIBITORS APPROVED BY THE FDA FOR THE TREATMENT OF SPECIFIC HEMATOLOGICAL CANCERS. NEVERTHELESS, DUE TO THEIR NUCLEOSIDE STRUCTURE, THESE INHIBITORS DIRECTLY INCORPORATE INTO DNA, WHICH LEADS TO SEVERE SIDE EFFECTS AND COMPROMISES GENOMIC STABILITY. MUCH EMPHASIS HAS BEEN PLACED ON THE DEVELOPMENT OF LESS TOXIC EPIGENETIC MODIFIERS. RECENTLY, SEVERAL PRECLINICAL STUDIES DEMONSTRATED THE POTENT EPIGENETIC EFFECTS OF LOCAL ANESTHETICS, WHICH ARE ROUTINELY USED DURING PRIMARY TUMOR RESECTION TO RELIEF SURGICAL PAIN. THESE NON-NUCLEOSIDE MOLECULES INHIBIT DNMT ACTIVITY, AFFECT THE EXPRESSION OF MICRO-RNAS AND REPRESS HISTONE ACETYLATION, THUS EXERTING CYTOTOXIC EFFECTS ON MALIGNANT CELLS. THE IN-DEPTH MECHANISTIC COMPREHENSION OF THESE EPIGENETIC EFFECTS MIGHT PROMOTE THE USE OF LOCAL ANESTHETICS AS ANTICANCER DRUGS. 2022 2 5499 36 REVIEW: RECENT CLINICAL TRIALS IN EPIGENETIC THERAPY. EPIGENETIC FACTORS SUCH AS DNA METHYLATION AND HISTONE DEACETYLATION ARE KNOWN TO CONTRIBUTE TO THE MALIGNANT TRANSFORMATION OF CELLS BY SILENCING CRITICAL GENES. DRUGS THAT INHIBIT DNA METHYLTRANSFERASES OR HISTONE DEACETYLASES WERE SHOWN TO HAVE THE POTENTIAL TO REACTIVATE SILENCED GENES AND INDUCE DIFFERENTIATION OR APOPTOSIS OF MALIGNANT CELLS. THE MOST INTENSIVELY STUDIED CLASS OF SUCH AGENTS IS DNA METHYLTRANSFERASE INHIBITORS, INCLUDING 5-AZACYTIDINE (AZACITIDINE) AND 5-AZA-2'-DEOXYCYTIDINE (DECITABINE). IN 2004, AZACITIDINE WAS APPROVED FOR THE TREATMENT OF MYELODYSPLASTIC SYNDROME ON THE BASIS OF PHASE II AND III STUDIES THAT SHOWED A RESPONSE RATE (COMPLETE AND PARTIAL RESPONSES) OF 15%. AZACITIDINE IS ALSO BEING EVALUATED IN CLINICAL TRIALS FOR OTHER MALIGNANT DISEASES. DECITABINE HAS RESPONSE RATES OF 17-49% IN MYELODYSPLASTIC SYNDROME IN MULTIPLE PHASE II AND III STUDIES AND ALSO ACTIVITY IN ACUTE AND CHRONIC MYELOGENOUS LEUKEMIA. HISTONE DEACETYLASE INHIBITORS BELONG TO ANOTHER CLASS OF EPIGENETIC MODIFYING AGENTS THAT INCLUDE DEPSIPEPTIDE, BUTYRATE DERIVATIVES, SUBEROYLANILIDE HYDROXAMIC ACID AND VALPROIC ACID. NO AGENT IN THIS CLASS HAS BEEN STUDIED IN A PHASE III TRIAL, BUT SEVERAL AGENTS HAVE BEEN OR ARE BEING STUDIED IN PHASE II TRIALS. FURTHER RESEARCH IS NEEDED TO DETERMINE THE APPROPRIATE PATIENT SELECTION AND DOSING SCHEDULES. 2006 3 745 38 CANNABIS ALTERS EPIGENETIC INTEGRITY AND ENDOCANNABINOID SIGNALLING IN THE HUMAN FOLLICULAR NICHE. STUDY QUESTION: DO PHYTOCANNABINOIDS (PCS) AFFECT FOLLICULAR ENDOCANNABINOID SIGNALLING AND THE EPIGENOME IN THE SURROUNDING GRANULOSA CELLS (GCS)? SUMMARY ANSWER: EXPOSURE TO PCS INCREASES THE EXPRESSION OF ENDOCANNABINOID RECEPTORS AND REDUCES DNA METHYLATION ENZYME EXPRESSION AND GLOBAL DNA METHYLATION IN NAIVE GCS. WHAT IS KNOWN ALREADY: CANNABIS PLANT DERIVATIVES, KNOWN AS PCS, ARE USED FOR MEDICINAL AND RECREATIONAL PURPOSES. THE MAIN PC, TETRAHYDROCANNABINOL (THC), IS THE THIRD MOST COMMONLY USED SUBSTANCE BY WOMEN OF CHILDBEARING AGE, HENCE KNOWLEDGE OF THE EFFECT IT HAS ON REPRODUCTION IS OF UTMOST IMPORTANCE. THC EXERTS ITS EFFECTS VIA RECEPTORS OF THE ENDOCANNABINOID SYSTEM (ECS) AND CAN INTERFERE WITH FOLLICULOGENESIS, OOCYTE DEVELOPMENT AND OVULATION. ENDOCANNABINOIDS HAVE BEEN MEASURED IN FOLLICULAR FLUID (FF) OBTAINED DURING OOCYTE RETRIEVAL AND ARE IMPLICATED IN CONTROLLING FOLLICULOGENESIS. IT HAS BEEN ESTABLISHED THAT IN THE PLACENTA, PCS DISRUPT ENDOCANNABINOID HOMEOSTASIS VIA IMPAIRMENT OF THE SYNTHETIC AND DEGRADING ENZYMES, LEADING TO A NET INCREASE OF ENDOCANNABINOID LEVELS. FINALLY, PREVIOUS STUDIES HAVE SHOWN THAT THC ALTERS METHYLATION AND HISTONE MODIFICATIONS IN SPERM, BRAIN AND BLOOD CELLS. STUDY DESIGN, SIZE, DURATION: THIS STUDY INCLUDED AN IN VIVO COHORT ASSESSMENT OF CANNABIS EXPOSURE AND ITS EFFECTS ON THE FOLLICLE AND IN VITRO ASSAYS CONDUCTED TO VALIDATE THE IN VIVO FINDINGS AND TO EXPLORE POSSIBLE MECHANISMS OF ACTION. PARTICIPANTS/MATERIALS, SETTING, METHODS: A TOTAL OF 318 FF SAMPLES, FROM 261 PATIENTS UNDERGOING IVF TREATMENT AT A PRIVATE FERTILITY CLINIC WHO CONSENTED FOR BIOBANKING BIOLOGICAL WASTE MATERIAL BETWEEN JANUARY 2018 AND JULY 2019, WERE INCLUDED IN THIS STUDY. CONCENTRATIONS OF PCS AND ENDOCANNABINOIDS WERE ASSESSED IN FF BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY (LC-MS/MS). EXPOSURE TO PCS WAS DETERMINED BASED ON THESE MEASURED LEVELS. LEVELS OF BOTH ENDOCANNABINOID RECEPTORS (CB1R, CB2R) AND THE DE NOVO DNA METHYLATING ENZYME, DNMT3B, IN GCS WERE ASSESSED BY FLOW CYTOMETRY BOTH IN VITRO AND IN VIVO AND GLOBAL DNA METHYLATION WAS ASSESSED IN VITRO BY ELISA. IN VIVO EFFECTS WERE ASSESSED BY COMPARING SAMPLES POSITIVE FOR AT LEAST ONE PC, WITH SAMPLES NEGATIVE FOR ALL MEASURED PCS. IN VITRO EFFECTS WERE DETERMINED IN NAIVE GCS, OBTAINED CONCURRENTLY WITH FF SAMPLES THAT HAD TESTED NEGATIVE FOR ALL PCS. THESE GCS WERE TREATED WITH DIFFERENT COMBINATIONS OF THE MAIN THREE PCS. MAIN RESULTS AND THE ROLE OF CHANCE: OVERALL, 17 PATIENTS (6.4%) WERE POSITIVE FOR CANNABIS CONSUMPTION. FURTHERMORE, THE PREVALENCE OF CANNABIS POSITIVITY IN THE FF INCREASED FROM 4% OF THE TESTED SAMPLES THAT WERE COLLECTED PRIOR TO NATIONAL LEGALISATION IN OCTOBER 2018 TO 12% OF THOSE COLLECTED FOLLOWING LEGALISATION. OF NOTE, 59% OF PATIENTS WHO TESTED POSITIVE FOR PCS (10 OF 17) REPORTED PREVIOUS OR ONGOING EXPOSURE TO CANNABIS UPON THEIR INITIAL INTAKE. ENDOCANNABINOID LEVELS WERE NOT AFFECTED BY THE PRESENCE OF PCS. CB2R WAS MORE PREVALENT THAN CB1R IN GCS AND ITS EXPRESSION INCREASED FOLLOWING ACUTE AND CHRONIC IN VITRO EXPOSURE TO PCS. THE EXPRESSION OF DNMT3B AND GLOBAL METHYLATION DECREASED FOLLOWING EXPOSURE, SUGGESTING THAT CANNABIS MAY AFFECT THE EPIGENOME IN THE FOLLICULAR NICHE. THE ACUTE CHANGES WERE SUSTAINED THROUGHOUT CHRONIC TREATMENT. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: OUR STUDY IS LIMITED BY LACK OF DETAILS REGARDING MODE, FREQUENCY AND TIMING OF PC CONSUMPTION. MOREOVER, WE WERE NOT ABLE TO ADEQUATELY ASSESS THE EFFECT OF PCS ON IMMEDIATE OR LONG-TERM CLINICAL OUTCOMES, DUE TO THE SMALL SAMPLE SIZE AND THE LACK OF FOLLOW UP. FUTURE, LARGE-SCALE STUDIES SHOULD FOCUS ON ASSESS THE CLINICAL IMPLICATIONS OF CANNABIS EXPOSURE, VALIDATE OUR FINDINGS, AND DETERMINE TO WHAT EXTENT CANNABIS AFFECTS THE EPIGENOME OVARIAN FOLLICLE AND THE DEVELOPING OOCYTE. WIDER IMPLICATIONS OF THE FINDINGS: TO OUR KNOWLEDGE, THIS IS THE FIRST STUDY MEASURING PCS IN FF BY LC-MS/MS. WE SHOW THAT CONSUMING CANNABIS ALTERS THE ECS IN THE DEVELOPING FOLLICLE, AND DIRECTLY AFFECTS DNMT EXPRESSION AND GLOBAL DNA METHYLATION LEVELS. CANNABIS LEGALISATION AND USE IS INCREASING WORLDWIDE, THEREFORE FURTHER UNDERSTANDING ITS ROLE IN FEMALE FERTILITY AND FOLLICULOGENESIS IS CRITICAL. STUDY FUNDING/COMPETING INTEREST(S): ALL FUNDING WAS PROVIDED BY CREATE FERTILITY CENTRE THROUGH THE REINVESTMENT OF CLINICAL EARNINGS. THE AUTHORS DECLARE NO COMPETING INTERESTS. 2021 4 439 31 ANTILEUKEMIC ACTIVITY OF VALPROIC ACID IN CHRONIC LYMPHOCYTIC LEUKEMIA B CELLS DEFINED BY MICROARRAY ANALYSIS. EPIGENETIC CODE MODIFICATIONS BY HISTONE DEACETYLASE INHIBITORS HAVE RECENTLY BEEN PROPOSED AS POTENTIAL NEW THERAPIES FOR HEMATOLOGICAL MALIGNANCIES. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) REMAINS INCURABLE DESPITE THE INTRODUCTION OF NEW TREATMENTS. CLL B CELLS ARE CHARACTERIZED BY AN APOPTOSIS DEFECT RATHER THAN EXCESSIVE PROLIFERATION, BUT PROLIFERATION CENTERS HAVE BEEN FOUND IN ORGANS SUCH AS THE BONE MARROW AND LYMPH NODES. IN THIS STUDY, WE ANALYZED GENE EXPRESSION MODIFICATIONS IN CLL B CELLS AFTER TREATMENT WITH VALPROIC ACID (VPA), A WELL-TOLERATED ANTI-EPILEPTIC DRUG WITH HDAC INHIBITORY ACTIVITY. CLL B CELLS OBTAINED FROM 14 PATIENTS WERE TREATED IN VITRO WITH A CONCENTRATION OF 1 MM VPA FOR 4 H. VPA EFFECTS ON GENE EXPRESSION WERE THEREAFTER STUDIED USING AFFYMETRIX TECHNOLOGY, AND SOME IDENTIFIED GENES WERE VALIDATED BY REAL-TIME PCR AND WESTERN BLOT. WE OBSERVED THAT VPA INDUCED APOPTOSIS BY DOWNREGULATING SEVERAL ANTI-APOPTOTIC GENES AND BY UPREGULATING PRO-APOPTOTIC GENES. FURTHERMORE, VPA SIGNIFICANTLY INCREASED CHEMOSENSITIVITY TO FLUDARABINE, FLAVOPIRIDOL, BORTEZOMIB, THALIDOMIDE AND LENALIDOMIDE. VPA INHIBITED THE PROLIFERATION OF CPG/IL2-STIMULATED CLL B CELLS AND MODULATED MANY CELL CYCLE MESSENGER RNAS. IN CONCLUSION, EXPOSURE OF CLL B CELLS TO VPA INDUCED APOPTOSIS, POTENTIATED CHEMOTHERAPEUTIC AGENT EFFECTS AND INHIBITED PROLIFERATION. THESE DATA STRONGLY SUGGEST THE USE OF VPA IN CLL TREATMENT, PARTICULARLY IN COMBINATION WITH ANTILEUKEMIA AGENTS. 2009 5 826 25 CHARACTERIZATION OF K562 CELLS: UNCOVERING NOVEL CHROMOSOMES, ASSESSING TRANSFERRIN RECEPTOR EXPRESSION, AND PROBING PHARMACOLOGICAL THERAPIES. HUMAN ERYTHROLEUKEMIC K562 CELLS REPRESENT THE PROTOTYPICAL CELL CULTURE MODEL OF CHRONIC MYELOID LEUKEMIA (CML). THE CELLS ARE PSEUDO-TRIPLOID AND POSITIVE FOR THE PHILADELPHIA CHROMOSOME. THEREFORE, K562 CELLS HAVE BEEN WIDELY USED FOR INVESTIGATING THE BCR/ABL1 ONCOGENE AND THE TYROSINE KINASE INHIBITOR, IMATINIB-MESYLATE. FURTHER, K562 CELLS OVEREXPRESS TRANSFERRIN RECEPTORS (TFR) AND HAVE BEEN USED AS A MODEL FOR TARGETING CYTOTOXIC THERAPIES, VIA RECEPTOR-MEDIATED ENDOCYTOSIS. HERE, WE HAVE CHARACTERIZED K562 CELLS FOCUSING ON THE KARYOTYPE OF CELLS IN PROLONGED CULTURE, REGULATION OF EXPRESSION OF TFR IN WILDTYPE (WT) AND DOXORUBICIN-RESISTANT CELLS, AND RESPONSES TO HISTONE DEACETYLASE INHIBITION (HDACI). KARYOTYPE ANALYSIS INDICATES NOVEL CHROMOSOMES AND GENE EXPRESSION ANALYSIS SUGGESTS A SHIFT OF CULTURED K562 CELLS AWAY FROM PATIENT-DERIVED LEUKEMIC CELLS. WE CONFIRM THE HIGH EXPRESSION OF TFR ON K562 CELLS USING IMMUNOFLUORESCENCE AND CELL-SURFACE RECEPTOR BINDING RADIOASSAYS. IMPORTANTLY, HIGH TFR EXPRESSION IS OBSERVED IN PATIENT-DERIVED CELLS, AND WE HIGHLIGHT THE PERSISTENT EXPRESSION OF TFR FOLLOWING DOXORUBICIN ACQUIRED RESISTANCE. EPIGENETIC ANALYSIS INDICATES THAT PERMISSIVE HISTONE ACETYLATION AND METHYLATION AT THE PROMOTER REGION REGULATES THE TRANSCRIPTION OF TFR IN K562 CELLS. FINALLY, WE SHOW RELATIVELY HIGH EXPRESSION OF HDAC ENZYMES IN K562 CELLS AND DEMONSTRATE THE CHEMOTOXIC EFFECTS OF HDACI, USING THE FDA-APPROVED HYDROXAMIC ACID, VORINOSTAT. TOGETHER WITH A DESCRIPTION OF MORPHOLOGY, INFRARED SPECTRAL ANALYSIS, AND EXAMINATION OF METABOLIC PROPERTIES, WE PROVIDE A COMPREHENSIVE CHARACTERIZATION OF K562 CELLS. OVERALL, K562 CELL CULTURE SYSTEMS REMAIN WIDELY USED FOR THE INVESTIGATION OF NOVEL THERAPEUTICS FOR CML, WHICH IS PARTICULARLY IMPORTANT IN CASES OF IMATINIB-MESYLATE RESISTANCE. 2023 6 1103 26 COMBINED DUAL EFFECT OF MODULATION OF HUMAN NEUTROPHILS' OXIDATIVE BURST AND INHIBITION OF COLON CANCER CELLS PROLIFERATION BY HYDROXYCINNAMIC ACID DERIVATIVES. COLON CANCER IS ONE OF THE MOST INCIDENT CANCERS IN THE WESTERN WORLD. WHILE BOTH GENETIC AND EPIGENETIC FACTORS MAY CONTRIBUTE TO THE DEVELOPMENT OF COLON CANCER, IT IS KNOWN THAT CHRONIC INFLAMMATION ASSOCIATED TO EXCESSIVE PRODUCTION OF REACTIVE OXYGEN AND NITROGEN SPECIES BY PHAGOCYTES MAY ULTIMATELY INITIATE THE MULTISTEP PROCESS OF COLON CANCER DEVELOPMENT. PHENOLIC COMPOUNDS, WHICH REVEAL ANTIOXIDANT AND ANTIPROLIFERATIVE ACTIVITIES IN COLON CANCER CELLS, CAN BE A GOOD APPROACH TO SURPASS THIS PROBLEM. IN THIS WORK, HYDROXYCINNAMIC AMIDES AND THE RESPECTIVE ACID PRECURSORS WERE TESTED IN VITRO FOR THEIR CAPACITY TO MODULATE HUMAN NEUTROPHILS' OXIDATIVE BURST AND SIMULTANEOUSLY TO INHIBIT GROWTH OF COLON CANCER CELLS. A PHENOLIC AMIDE DERIVATIVE, CAFFEIC ACID HEXYLAMIDE (CAHA) (4) WAS FOUND TO BE THE MOST ACTIVE COMPOUND IN BOTH ASSAYS, INHIBITING HUMAN NEUTROPHILS' OXIDATIVE BURST, RESTRAINING THE INFLAMMATORY PROCESS, INHIBITING GROWTH OF COLON CANCER CELLS AND TRIGGERING MITOCHONDRIAL DYSFUNCTION THAT LEADS CANCER CELLS TO APOPTOSIS. ALTOGETHER, THESE ACHIEVEMENTS CAN CONTRIBUTE TO THE UNDERSTANDING OF THE RELATIONSHIP BETWEEN ANTIOXIDANT AND ANTICANCER ACTIVITIES AND BASED ON THE STRUCTURE-ACTIVITY RELATIONSHIPS (SAR) ESTABLISHED CAN BE THE STARTING POINT TO FIND MORE EFFECTIVE PHENOLIC COMPOUNDS AS ANTICANCER AGENTS. 2016 7 1406 32 DIETARY HISTONE DEACETYLASE INHIBITORS: FROM CELLS TO MICE TO MAN. SULFORAPHANE (SFN) IS AN ISOTHIOCYANATE FOUND IN CRUCIFEROUS VEGETABLES, SUCH AS BROCCOLI AND BROCCOLI SPROUTS. THIS ANTICARCINOGEN WAS FIRST IDENTIFIED AS A POTENT INDUCER OF PHASE 2 DETOXIFICATION ENZYMES, BUT EVIDENCE IS MOUNTING THAT SFN ALSO ACTS THROUGH EPIGENETIC MECHANISMS. SFN HAS BEEN SHOWN TO INHIBIT HISTONE DEACETYLASE (HDAC) ACTIVITY IN HUMAN COLON AND PROSTATE CANCER LINES, WITH AN INCREASE IN GLOBAL AND LOCAL HISTONE ACETYLATION STATUS, SUCH AS ON THE PROMOTER REGIONS OF P21 AND BAX GENES. SFN ALSO INHIBITED THE GROWTH OF PROSTATE CANCER XENOGRAFTS AND SPONTANEOUS INTESTINAL POLYPS IN MOUSE MODELS, WITH EVIDENCE FOR ALTERED HISTONE ACETYLATION AND HDAC ACTIVITIES IN VIVO. IN HUMAN SUBJECTS, A SINGLE INGESTION OF 68 G BROCCOLI SPROUTS INHIBITED HDAC ACTIVITY IN CIRCULATING PERIPHERAL BLOOD MONONUCLEAR CELLS 3-6 H AFTER CONSUMPTION, WITH CONCOMITANT INDUCTION OF HISTONE H3 AND H4 ACETYLATION. THESE FINDINGS PROVIDE EVIDENCE THAT ONE MECHANISM OF CANCER CHEMOPREVENTION BY SFN IS VIA EPIGENETIC CHANGES ASSOCIATED WITH INHIBITION OF HDAC ACTIVITY. OTHER DIETARY AGENTS SUCH AS BUTYRATE, BIOTIN, LIPOIC ACID, GARLIC ORGANOSULFUR COMPOUNDS, AND METABOLITES OF VITAMIN E HAVE STRUCTURAL FEATURES COMPATIBLE WITH HDAC INHIBITION. THE ABILITY OF DIETARY COMPOUNDS TO DE-REPRESS EPIGENETICALLY SILENCED GENES IN CANCER CELLS, AND TO ACTIVATE THESE GENES IN NORMAL CELLS, HAS IMPORTANT IMPLICATIONS FOR CANCER PREVENTION AND THERAPY. IN A BROADER CONTEXT, THERE IS GROWING INTEREST IN DIETARY HDAC INHIBITORS AND THEIR IMPACT ON EPIGENETIC MECHANISMS AFFECTING OTHER CHRONIC CONDITIONS, SUCH AS CARDIOVASCULAR DISEASE, NEURODEGENERATION AND AGING. 2007 8 2326 26 EPIGENETIC REGULATION OF HOTAIR IN ADVANCED CHRONIC MYELOID LEUKEMIA. PURPOSE: CHRONIC MYELOID LEUKEMIA (CML) ACCOUNTS FOR ~10% OF LEUKEMIA CASES, AND ITS PROGRESSION INVOLVES EPIGENETIC GENE REGULATION. THIS STUDY INVESTIGATED EPIGENETIC REGULATION OF HOTAIR AND ITS TARGET MICRORNA, MIR-143, IN ADVANCED CML. PATIENTS AND METHODS: WE FIRST ISOLATED BONE MARROW MONONUCLEAR CELLS FROM 70 PATIENTS WITH DIFFERENT PHASES OF CML AND FROM HEALTHY DONORS AS NORMAL CONTROL; WE ALSO CULTURED K562 AND KCL22 CELLS, TREATED WITH DEMETHYLATION DRUG; MTT ASSAY, FLOW CYTOMETRY, QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (QPCR), METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP), WESTERN BLOT, LUCIFERASE ASSAY, RNA PULL-DOWN ASSAY AND RNA-BINDING PROTEIN IMMUNOPRECIPITATION (RIP) ASSAY WERE PERFORMED. RESULT: AS MEASURED BY QPCR, HOTAIR EXPRESSION IN K562 CELLS, KCL22 CELLS, AND SAMPLES FROM CASES OF ADVANCED-STAGE CML INCREASED WITH LEVELS OF SEVERAL DNA METHYLTRANSFERASES AND HISTONE DEACETYLATES, INCLUDING DNMT1, DNMT3A, HDAC1, EZH2, AND LSD1, AND MIR-143 LEVELS WERE DECREASED AND HOTAIR LEVELS WERE INCREASED. TREATMENT WITH 5-AZACYTIDINE, A DNA METHYLATION INHIBITOR, DECREASED DNMT1, DNMT3A, HDAC1, EZH2, LSD1 MRNA, PROTEIN LEVELS, AND HOTAIR MRNA LEVELS BUT INCREASED MIR-143 LEVELS. HOTAIR KNOCKDOWN AND MIR-143 OVEREXPRESSION BOTH INHIBITED PROLIFERATION AND PROMOTED APOPTOSIS IN KCL22 AND K562 CELLS THROUGH THE PI3K/AKT PATHWAY. RNA PULL-DOWN, MASS SPECTROMETRY, AND RIP ASSAYS SHOWED THAT HOTAIR INTERACTED WITH EZH2 AND LSD1. A DUAL-LUCIFERASE ASSAY DEMONSTRATED THAT HOTAIR INTERACTED WITH MIR-143. CONCLUSION: OUR FINDINGS DEMONSTRATE THE KEY EPIGENETIC INTERACTIONS OF HOTAIR RELATED TO CML PROGRESSION AND SUGGEST HOTAIR AS A POTENTIAL THERAPEUTIC TARGET FOR ADVANCED CML. FURTHERMORE, OUR RESULTS SUPPORT THE USE OF DEMETHYLATION DRUGS AS A CML TREATMENT STRATEGY. 2018 9 3729 28 INHIBITION OF TET1 PREVENTS THE DEVELOPMENT OF OSTEOARTHRITIS AND REVEALS THE 5HMC LANDSCAPE THAT ORCHESTRATES PATHOGENESIS. OSTEOARTHRITIS (OA) IS A DEGENERATIVE DISEASE OF THE JOINT, WHICH RESULTS IN PAIN, LOSS OF MOBILITY, AND, EVENTUALLY, JOINT REPLACEMENT. CURRENTLY, NO DISEASE-MODIFYING DRUGS EXIST, PARTLY BECAUSE OF THE MULTIPLE LEVELS AT WHICH CARTILAGE HOMEOSTASIS IS DISRUPTED. RECENT STUDIES HAVE HIGHLIGHTED THE IMPORTANCE OF EPIGENETIC DYSREGULATION IN OA, SPARKING INTEREST IN THE EPIGENETIC MODULATION FOR THIS DISEASE. IN OUR PREVIOUS WORK, WE CHARACTERIZED A FIVEFOLD INCREASE IN CYTOSINE HYDROXYMETHYLATION (5HMC), AN OXIDIZED DERIVATIVE OF CYTOSINE METHYLATION (5MC) ASSOCIATED WITH GENE ACTIVATION, ACCUMULATING AT OA-ASSOCIATED GENES. TO TEST THE ROLE OF 5HMC IN OA, HERE, WE USED A MOUSE MODEL OF SURGICALLY INDUCED OA AND FOUND THAT OA ONSET WAS ACCOMPANIED BY A GAIN OF ~40,000 DIFFERENTIALLY HYDROXYMETHYLATED SITES BEFORE THE NOTABLE HISTOLOGICAL APPEARANCE OF DISEASE. WE DEMONSTRATED THAT TEN-ELEVEN-TRANSLOCATION ENZYME 1 (TET1) MEDIATES THE 5HMC DEPOSITION BECAUSE 98% OF SITES ENRICHED FOR 5HMC IN OA WERE LOST IN TET1(-/-) MICE. LOSS OF TET1-MEDIATED 5HMC PROTECTED THE TET1(-/-) MICE FROM OA DEVELOPMENT, INCLUDING DEGENERATION OF THE CARTILAGE SURFACE AND OSTEOPHYTE FORMATION, BY DIRECTLY PREVENTING THE ACTIVATION OF MULTIPLE OA PATHWAYS. LOSS OF TET1 IN HUMAN OA CHONDROCYTES REDUCED THE EXPRESSION OF THE MATRIX METALLOPROTEINASES MMP3 AND MMP13 AND MULTIPLE INFLAMMATORY CYTOKINES. INTRA-ARTICULAR INJECTIONS OF A DIOXYGENASES INHIBITOR, 2-HYDROXYGLUTARATE, ON MICE AFTER SURGICAL INDUCTION OF OA STALLED DISEASE PROGRESSION. TREATMENT OF HUMAN OA CHONDROCYTES WITH THE SAME INHIBITOR ALSO PHENOCOPIED TET1 LOSS. COLLECTIVELY, THESE DATA DEMONSTRATE THAT TET1-MEDIATED 5HMC DEPOSITION REGULATES MULTIPLE OA PATHWAYS AND CAN BE MODULATED FOR THERAPEUTIC INTERVENTION. 2020 10 1107 24 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 1046 28 CLINICAL DEVELOPMENT OF DECITABINE AS A PROTOTYPE FOR AN EPIGENETIC DRUG PROGRAM. THIS REVIEW HIGHLIGHTS DECITABINE AS A PROTOTYPE EPIGENETIC MODIFYING DRUG TO SHOW HOW THE CLINICAL DEVELOPMENT OF EPIGENETIC AGENTS DIFFERS FROM THAT OF TRADITIONAL CYTOTOXIC CHEMOTHERAPIES. DECITABINE, A CYTOSINE ANALOGUE, IS CYTOTOXIC AT HIGH DOSES BUT HAS SELECTIVE DNA DEMETHYLATING ACTIVITY AT LOW DOSES. THE FOCUS OF CURRENT DECITABINE INVESTIGATIONS IS TWOFOLD: TO ELUCIDATE ALL OF THE MECHANISMS OF ACTION AND TO DETERMINE THE OPTIMAL DOSE, SCHEDULE, AND CONCOMITANT THERAPIES. NEW PHASE I TRIALS HAVE IDENTIFIED A "BIOLOGICALLY EFFECTIVE DOSE," WHICH IS 1 TO 2 LOGS LOWER THAN THE CYTOTOXIC DOSE. A CLINICAL DEVELOPMENT PROGRAM WITH LOW-DOSE DECITABINE IN MALIGNANT DISEASES IS FOCUSED ON MYELODYSPLASTIC SYNDROME (MDS), ACUTE MYELOGENOUS LEUKEMIA (AML), AND CHRONIC MYELOGENOUS LEUKEMIA (CML). A PHASE III TRIAL IN MDS SHOWED OBJECTIVE RESPONSES (COMPLETE [CR] PLUS PARTIAL [PR] REMISSION) AND LONGER MEDIAN TIME TO PROGRESSION TO AML OR DEATH WITH DECITABINE THAN WITH SUPPORTIVE CARE ALONE. THE OPTIMAL USE OF DECITABINE MAY BE IN COMBINATION WITH OTHER AGENTS THAT PROMOTE GENE EXPRESSION, NAMELY, HISTONE DEACETYLASE (HDAC) INHIBITORS. OPTIMIZED DECITABINE DOSES AND COMBINATIONS WITH OTHER EPIGENETIC THERAPIES THAT CAN BE USED AT MINIMALLY TOXIC DOSES PROVIDE POTENTIALLY SAFER THERAPEUTIC OPTIONS AND INTRODUCE NOVEL COMBINATION THERAPIES. 2005 12 3348 34 HISTONE DEACETYLASES MEET MICRORNA-ASSOCIATED MMP-9 EXPRESSION REGULATION IN GLUCOCORTICOID-SENSITIVE AND -RESISTANT CELL LINES. GLUCOCORTICOIDS ARE LARGELY USED IN THE TREATMENT OF INFLAMMATORY PATHOLOGIES AND/OR HEMATOLOGICAL MALIGNANCIES AND REGULATE THE EXPRESSION OF A VARIETY OF GENES INVOLVED IN INFLAMMATION OR METASTASIS SUCH AS MATRIX METALLOPROTEINASES (MMP). LONG-TERM EXPOSURE TO GLUCOCORTICOIDS CAN RESULT IN FAILURE OF RESPONSIVENESS, WHICH IS OFTEN ASSOCIATED WITH AN UNWANTED GENE EXPRESSION. EPIGENETIC MECHANISMS ARE INVOLVED IN GENE EXPRESSION MODULATED AFTER DEVELOPMENT OF GLUCOCORTICOID RESISTANCE BUT HOW THESE MECHANISMS TAKE PLACE MUST BE FURTHER STUDIED. THE EFFECTS OF HDAC INHIBITORS (HDACI) IN A CONTEXT OF GLUCOCORTICOID RESISTANCE ARE STILL NOT WELL UNDERSTOOD AND NEED TO BE FURTHER INVESTIGATED. WE HYPOTHESIZED THAT ACQUIRED GLUCOCORTICOID RESISTANCE ASSOCIATED TO HDACI COULD DISTURBS EPIGENETIC LANDSCAPE, ESPECIALLY MIR EXPRESSION, LEADING TO A MODULATION OF MMP-9 GENE EXPRESSION AND/OR PROTEIN SECRETION, DESCRIBED AS LARGELY INVOLVED IN BONE REMODELING AND TUMOR INVASION IN MULTIPLE MYELOMA. TO THIS AIM, WE USED SENSITIVE RPMI-8226 CELL LINE AND ITS DEXAMETHASONE- AND METHYLPREDNISOLONE-RESISTANT DERIVATIVES. THE RESISTANT CELL LINES DISPLAYED AN 'OPEN CHROMATIN' AND AN MMP-9 OVEREXPRESSION COMPARATIVELY TO THE SENSITIVE CELL LINE. HDACI TREATMENT WITH MS-275 INCREASED EVEN MORE MMP-9 OVEREXPRESSION NOT ONLY AT AN MRNA LEVEL BUT ALSO AT THE PROTEIN LEVEL. WE SHOWED THAT MMP-9 EXPRESSION REGULATION WAS NOT DIRECTLY LINKED WITH HAT/HDAC BALANCE ALTERATIONS BUT RATHER WITH THE DEREGULATION OF MMP-9-TARGETING MIRS. THEN, WE FIRST DEMONSTRATED THAT MIR?149 DOWNREGULATION WAS DIRECTLY INVOLVED IN THE MMP-9 OVEREXPRESSION FOLLOWING A CHRONIC GLUCOCORTICOID EXPOSURE AND THAT MS-275 COULD AMPLIFY THIS OVEREXPRESSION BY INHIBITION OF MIR?149 EXPRESSION AND MIR?520C OVEREXPRESSION. TAKEN TOGETHER, THESE RESULTS INDICATE THAT THE USE OF HDACI IN A CONTEXT OF ACQUIRED GLUCOCORTICOID RESISTANCE COULD MODIFY THE EPIGENETIC LANDSCAPE, HIGHLIGHTING THE IMPORTANCE OF TAKING THE GLUCOCORTICOID RESPONSE STATUS INTO CONSIDERATION IN TREATMENT WITH HDACI. 2017 13 4147 31 MECHANISMS UNDERLYING BIOLOGICAL EFFECTS OF CRUCIFEROUS GLUCOSINOLATE-DERIVED ISOTHIOCYANATES/INDOLES: A FOCUS ON METABOLIC SYNDROME. AN INVERSE CORRELATION BETWEEN VEGETABLE CONSUMPTION AND THE INCIDENCE OF CANCER HAS LONG BEEN DESCRIBED. THIS PROTECTIVE EFFECT IS STRONGER WHEN CRUCIFEROUS VEGETABLES ARE SPECIFICALLY CONSUMED. THE BENEFICIAL PROPERTIES OF VEGETABLES ARE ATTRIBUTED TO THEIR BIOACTIVE COMPONENTS LIKE FIBER, ANTIOXIDANTS VITAMINS, ANTIOXIDANTS, MINERALS, AND PHENOLIC COMPOUNDS. CRUCIFEROUS VEGETABLES CONTAIN ALL THESE MOLECULES; HOWEVER, WHAT MAKES THEM DIFFERENT ARE THEIR SULFUROUS COMPONENTS, CALLED GLUCOSINOLATES, RESPONSIBLE FOR THEIR SPECIAL SMELL AND TASTE. GLUCOSINOLATES ARE INACTIVE BIOLOGICALLY IN THE ORGANISM BUT ARE HYDROLYZED BY THE ENZYME MYROSINASE RELEASED AS A RESULT OF CHEWING, LEADING TO THE FORMATION OF ACTIVE DERIVATIVES SUCH AS ISOTHIOCYANATES AND INDOLES. A CONSIDERABLE NUMBER OF IN VITRO AND IN VIVO STUDIES HAVE REPORTED THAT ISOTHIOCYANATES AND INDOLES ELICIT CHEMOPREVENTIVE POTENCY THROUGH MULTIPLE MECHANISMS THAT INCLUDE MODULATION OF PHASES I AND II DETOXIFICATION PATHWAY ENZYMES, REGULATION OF CELL CYCLE ARREST, AND CONTROL OF CELL GROWTH, INDUCTION OF APOPTOSIS, ANTIOXIDANT ACTIVITY, ANTI-ANGIOGENIC EFFECTS, AND EPIGENETIC REGULATION. NUCLEAR ERYTHROID 2-RELATED FACTOR 2 (NRF2) AND NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) ARE KEY AND CENTRAL REGULATORS IN ALL THESE PROCESSES WITH A MAIN ROLE IN OXIDATIVE STRESS AND INFLAMMATION CONTROL. IT HAS BEEN DESCRIBED THAT ISOTHIOCYANATES AND INDOLES REGULATE THEIR ACTIVITY DIRECTLY AND INDIRECTLY. TODAY, THE METABOLIC SYNDROME (CENTRAL OBESITY, INSULIN RESISTANCE, HYPERLIPIDEMIA, AND HYPERTENSION) IS RESPONSIBLE FOR A MAJORITY OF DEATHS WORLDWIDE. ALL COMPONENTS OF METABOLIC SYNDROME ARE CHARACTERIZED BY CHRONIC INFLAMMATION WITH DEREGULATION OF THE PI3K/AKT/MTOR, MAPK/EKR/JNK, NRF2, AND NF-KAPPAB SIGNALING PATHWAYS. THE EFFECTS OF GLSS DERIVATIVES CONTROLLING THESE PATHWAYS HAVE BEEN WIDELY DESCRIBED IN RELATION TO CANCER. CHANGES IN FOOD CONSUMPTION PATTERNS OBSERVED IN THE LAST DECADES TO HIGHER CONSUMPTION OF ULTRA-PROCESSED FOODS, WITH ELEVATION IN SIMPLE SUGAR AND SATURATED FAT CONTENTS AND LOWER CONSUMPTION OF VEGETABLES AND FRUITS HAVE BEEN DIRECTLY CORRELATED WITH METABOLIC SYNDROME PREVALENCE. IN THIS REVIEW, IT IS SUMMARIZED THE KNOWLEDGE REGARDING THE MECHANISMS BY WHICH CRUCIFEROUS GLUCOSINOLATE DERIVATIVES (ISOTHIOCYANATES AND INDOLES) DIRECTLY AND INDIRECTLY REGULATE THESE PATHWAYS. HOWEVER, THE REVIEW PLACES A SPECIAL FOCUS ON THE KNOWLEDGE OF THE EFFECTS OF GLUCOSINOLATES DERIVATIVES IN METABOLIC SYNDROME, SINCE THIS HAS NOT BEEN REVIEWED BEFORE. 2020 14 337 22 ALTERATIONS IN DNA METHYLATION/DEMETHYLATION INTERMEDIATES PREDICT CLINICAL OUTCOME IN CHRONIC LYMPHOCYTIC LEUKEMIA. CYTOSINE DERIVATIVE DYSREGULATIONS REPRESENT IMPORTANT EPIGENETIC MODIFICATIONS WHOSE IMPACT ON THE CLINICAL OUTCOME IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS INCOMPLETELY UNDERSTOOD. HENCE, GLOBAL LEVELS OF 5-METHYLCYTOSINE (5-MCYT), 5-HYDROXYMETHYLCYTOSINE (5-HMCYT), 5-CARBOXYLCYTOSINE (5-CACYT) AND 5-HYDROXYMETHYLURACIL WERE TESTED IN PURIFIED B CELLS FROM CLL PATIENTS (N = 55) AND CONTROLS (N = 17). THE DNA METHYLATION 'WRITERS' (DNA METHYLTRANSFERASES [DNMT1/3A/3B]), 'READERS' (METHYL-CPG-BINDING DOMAIN [MBD2/4]), 'EDITORS' (TEN-ELEVEN TRANSLOCATION [TET1/2/3]) AND 'MODULATORS' (SAT1) WERE ALSO EVALUATED. ACCORDINGLY, PATIENTS WERE STRATIFIED INTO THREE SUBGROUPS. FIRST, A SUBGROUP WITH A GLOBAL DEFICIT IN CYTOSINE DERIVATIVES CHARACTERIZED BY HYPERLYMPHOCYTOSIS, REDUCED MEDIAN PROGRESSION FREE SURVIVAL (PFS = 52 MONTHS) AND SHORTER TREATMENT FREE SURVIVAL (TFS = 112 MONTHS) WAS IDENTIFIED. IN THIS SUBGROUP, MAJOR EPIGENETIC MODIFICATIONS WERE HIGHLIGHTED INCLUDING A REDUCTION OF 5-MCYT, 5-HMCYT, 5-CACYT ASSOCIATED WITH DNMT3A, MBD2/4 AND TET1/2 DOWNREGULATION. SECOND, THE CYTOSINE DERIVATIVE ANALYSIS REVEALED A SUBGROUP WITH A PARTIAL DEFICIT (PFS = 84, TFS = 120 MONTHS), MAINLY AFFECTING DNA DEMETHYLATION (5-HMCYT REDUCTION, SAT1 INDUCTION). THIRD, A SUBGROUP EPIGENETICALLY SIMILAR TO CONTROLS WAS IDENTIFIED (PFS AND TFS > 120 MONTHS). THE PROGNOSTIC IMPACT OF STRATIFYING CLL PATIENTS WITHIN THREE EPIGENETIC SUBGROUPS WAS CONFIRMED IN A VALIDATION COHORT. IN CONCLUSION, OUR RESULTS SUGGEST THAT DYSREGULATIONS OF CYTOSINE DERIVATIVE REGULATORS REPRESENT MAJOR EVENTS ACQUIRED DURING CLL PROGRESSION AND ARE INDEPENDENT FROM IGHV MUTATIONAL STATUS. 2017 15 5221 21 PRIMARY BILIARY CHOLANGITIS: PATHOGENESIS AND THERAPEUTIC OPPORTUNITIES. PRIMARY BILIARY CHOLANGITIS IS A CHRONIC, SEROPOSITIVE AND FEMALE-PREDOMINANT INFLAMMATORY AND CHOLESTATIC LIVER DISEASE, WHICH HAS A VARIABLE RATE OF PROGRESSION TOWARDS BILIARY CIRRHOSIS. SUBSTANTIAL PROGRESS HAS BEEN MADE IN PATIENT RISK STRATIFICATION WITH THE GOAL OF PERSONALIZED CARE, INCLUDING EARLY ADOPTION OF NEXT-GENERATION THERAPY WITH LICENSED USE OF OBETICHOLIC ACID OR OFF-LABEL FIBRATE DERIVATIVES FOR THOSE WITH INSUFFICIENT BENEFIT FROM URSODEOXYCHOLIC ACID, THE CURRENT FIRST-LINE DRUG. THE DISEASE BIOLOGY SPANS GENETIC RISK, EPIGENETIC CHANGES, DYSREGULATED MUCOSAL IMMUNITY AND ALTERED BILIARY EPITHELIAL CELL FUNCTION, ALL OF WHICH INTERACT AND ARISE IN THE CONTEXT OF ILL-DEFINED ENVIRONMENTAL TRIGGERS. A CURRENT FOCUS OF RESEARCH ON NUCLEAR RECEPTOR PATHWAY MODULATION THAT SPECIFICALLY AND POTENTLY IMPROVES BILIARY EXCRETION, REDUCES INFLAMMATION AND ATTENUATES FIBROSIS IS REDEFINING THERAPY. PATIENTS ARE BENEFITING FROM PHARMACOLOGICAL AGONISTS OF FARNESOID X RECEPTOR AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTORS. IMMUNOTHERAPY REMAINS A CHALLENGE, WITH A LACK OF TARGET DEFINITION, PLEIOTROPIC IMMUNE PATHWAYS AND AN INTERPLAY BETWEEN HEPATIC IMMUNE RESPONSES AND CHOLESTASIS, WHEREIN BILE ACID-INDUCED INFLAMMATION AND FIBROSIS ARE DOMINANT CLINICALLY. THE MANAGEMENT OF PATIENT SYMPTOMS, PARTICULARLY PRURITUS, IS A NOTABLE GOAL REFLECTED IN THE DEVELOPMENT OF RATIONAL THERAPY WITH APICAL SODIUM-DEPENDENT BILE ACID TRANSPORTER INHIBITORS. 2020 16 709 27 C-MYC ONCOPROTEIN DICTATES TRANSCRIPTIONAL PROFILES OF ATP-BINDING CASSETTE TRANSPORTER GENES IN CHRONIC MYELOGENOUS LEUKEMIA CD34+ HEMATOPOIETIC PROGENITOR CELLS. RESISTANCE TO CHEMOTHERAPEUTIC AGENTS REMAINS ONE OF THE MAJOR IMPEDIMENTS TO A SUCCESSFUL TREATMENT OF CHRONIC MYELOID LEUKEMIA (CML). MISREGULATION OF THE ACTIVITY OF A SPECIFIC GROUP OF ATP-BINDING CASSETTE TRANSPORTERS (ABC) IS RESPONSIBLE FOR REDUCING THE INTRACELLULAR CONCENTRATION OF DRUGS IN LEUKEMIC CELLS. MOREOVER, A CONSISTENT BODY OF EVIDENCE ALSO SUGGESTS THAT ABC TRANSPORTERS PLAY A ROLE IN CANCER PROGRESSION BEYOND THE EFFLUX OF CYTOTOXIC DRUGS. DESPITE A LARGE NUMBER OF STUDIES THAT INVESTIGATED THE FUNCTION OF THE ABC TRANSPORTERS, LITTLE IS KNOWN ABOUT THE TRANSCRIPTIONAL REGULATION OF THE ABC GENES. HERE, WE PRESENT DATA SHOWING THAT THE ONCOPROTEIN C-MYC IS A DIRECT TRANSCRIPTIONAL REGULATOR OF A LARGE SET OF ABC TRANSPORTERS IN CML. FURTHERMORE, MOLECULAR ANALYSIS CARRIED OUT IN CD34+ HEMATOPOIETIC CELL PRECURSORS OF 21 CML PATIENTS REVEALS THAT THE OVEREXPRESSION OF ABC TRANSPORTERS DRIVEN BY C-MYC IS A PECULIAR CHARACTERISTIC OF THE CD34+ POPULATION IN CML AND WAS NOT FOUND EITHER IN THE POPULATION OF MONONUCLEAR CELLS FROM WHICH THEY HAD BEEN PURIFIED NOR IN CD34+ CELLS ISOLATED FROM HEALTHY DONORS. FINALLY, WE DESCRIBE HOW THE METHYLATION STATE OF CPG ISLANDS MAY REGULATE THE ACCESS OF C-MYC TO ABCG2 GENE PROMOTER, A WELL-STUDIED GENE ASSOCIATED WITH MULTIDRUG RESISTANCE IN CML, HENCE, AFFECTING ITS EXPRESSION. TAKEN TOGETHER, OUR FINDINGS SUPPORT A MODEL IN WHICH C-MYC-DRIVEN TRANSCRIPTIONAL EVENTS, COMBINED WITH EPIGENETIC MECHANISMS, DIRECT AND REGULATE THE EXPRESSION OF ABC GENES WITH POSSIBLE IMPLICATIONS IN TUMOR MALIGNANCY AND DRUG EFFLUX IN CML. 2011 17 1616 32 DNA METHYLTRANSFERASE AND HISTONE DEACETYLASE INHIBITORS IN THE TREATMENT OF MYELODYSPLASTIC SYNDROMES. THE RECENTLY APPROVED DRUGS 5-AZACITIDINE (5AC) AND 5-AZA-2'-DEOXYAZACYTIDINE (DAC) ARE IN WIDE CLINICAL USE FOR THE TREATMENT OF MYELODYSPLASTIC SYNDROME (MDS) OF ALL TYPES AND CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML). THESE AGENTS WERE DEVELOPED BASED UPON AN UNDERSTANDING OF THE IMPORTANCE OF EPIGENETIC CHANGES IN MALIGNANCY, AND THEY HAVE BEEN EVALUATED IN RANDOMIZED CLINICAL TRIALS, WHICH DEMONSTRATE RESPONSE RATES BETWEEN 20% AND 40% IN PATIENTS FOR WHOM NO PREVIOUS STANDARD OF CARE WAS AVAILABLE. AS UNDERSTANDING OF THE EPIGENETIC CHANGES CHARACTERISTIC OF THE MALIGNANT PHENOTYPE IMPROVES, WE ARE ABLE TO TARGET OTHER REGULATORS OF CHROMATIN CONFORMATION THAT CONTRIBUTE TO ABERRANT GENE TRANSCRIPTION AND DYSREGULATED CELL GROWTH. THE HISTONE DEACETYLASE (HDAC) INHIBITORS BELONG TO ONE CLASS OF THERAPEUTICS DEVELOPED USING THIS PARADIGM. ALTHOUGH RESPONSES USING HDAC INHIBITORS ALONE IN MDS HAVE BEEN MODEST, ROBUST PRECLINICAL DATA DRIVE CLINICAL TRIALS IN WHICH THEY ARE UTILIZED IN COMBINATION WITH DNA METHYLTRANSFERASE (DNMT) INHIBITORS. COMBINATION THERAPY OFFERS THE POSSIBILITY OF HEMATOLOGIC IMPROVEMENT AND REMISSION TO MYELODYSPLASTIC PATIENTS WITH PREVIOUSLY UNTREATABLE DISEASE. 2008 18 5947 23 TARGETING THE EPIGENOME: SCREENING BIOACTIVE COMPOUNDS THAT REGULATE HISTONE DEACETYLASE ACTIVITY. SCOPE: NUTRIGENOMICS IS A RAPIDLY EXPANDING FIELD THAT ELUCIDATES THE LINK BETWEEN DIET-GENOME INTERACTIONS. RECENT EVIDENCE DEMONSTRATES THAT REGULATION OF THE EPIGENOME, AND IN PARTICULAR INHIBITION OF HISTONE DEACETYLASES (HDACS), IMPACT PATHOGENETIC MECHANISMS INVOLVED IN CHRONIC DISEASE. FEW STUDIES, TO DATE, HAVE SCREENED LIBRARIES OF BIOACTIVE COMPOUNDS THAT ACT AS EPIGENETIC MODIFIERS. THIS STUDY SCREENED A LIBRARY OF 131 NATURAL COMPOUNDS TO DETERMINE BIOACTIVE COMPOUNDS THAT INHIBIT ZN-DEPENDENT HDAC ACTIVITY. METHODS AND RESULTS: USING CLASS-SPECIFIC HDAC SUBSTRATES, WE SCREENED 131 NATURAL COMPOUNDS FOR HDAC ACTIVITY IN BOVINE CARDIAC TISSUE. FROM THIS SCREEN, WE IDENTIFIED 18 BIOACTIVE COMPOUND HDAC INHIBITORS. USING OUR CLASS-SPECIFIC HDAC SUBSTRATES, WE NEXT SCREENED THESE 18 BIOACTIVE COMPOUNDS AGAINST RECOMBINANT HDAC PROTEINS. CONSISTENT WITH INHIBITION OF HDAC ACTIVITY, THESE COMPOUNDS WERE CAPABLE OF INHIBITING ACTIVITY OF INDIVIDUAL HDAC ISOFORMS. LASTLY, WE REPORT THAT TREATMENT OF H9C2 CARDIAC MYOBLASTS WITH BIOACTIVE HDAC INHIBITORS WAS SUFFICIENT TO INCREASE LYSINE ACETYLATION AS ASSESSED VIA IMMUNOBLOT. CONCLUSION: THIS STUDY PROVIDED THE FIRST STEP IN IDENTIFYING MULTIPLE BIOACTIVE COMPOUND HDAC INHIBITORS. TAKEN TOGETHER, THIS REPORT SETS THE STAGE FOR FUTURE EXPLORATION OF THESE BIOACTIVE COMPOUNDS AS EPIGENETIC REGULATORS TO POTENTIALLY AMELIORATE CHRONIC DISEASE. 2017 19 5965 21 TEN-ELEVEN-TRANSLOCATION 2 (TET2) NEGATIVELY REGULATES HOMEOSTASIS AND DIFFERENTIATION OF HEMATOPOIETIC STEM CELLS IN MICE. THE TEN-ELEVEN-TRANSLOCATION 2 (TET2) GENE ENCODES A MEMBER OF TET FAMILY ENZYMES THAT ALTERS THE EPIGENETIC STATUS OF DNA BY OXIDIZING 5-METHYLCYTOSINE TO 5-HYDROXYMETHYLCYTOSINE (5HMC). SOMATIC LOSS-OF-FUNCTION MUTATIONS OF TET2 ARE FREQUENTLY OBSERVED IN PATIENTS WITH DIVERSE MYELOID MALIGNANCIES, INCLUDING MYELODYSPLASTIC SYNDROMES, MYELOPROLIFERATIVE NEOPLASMS, AND CHRONIC MYELOMONOCYTIC LEUKEMIA. BY ANALYZING MICE WITH TARGETED DISRUPTION OF THE TET2 CATALYTIC DOMAIN, WE SHOW HERE THAT TET2 IS A CRITICAL REGULATOR OF SELF-RENEWAL AND DIFFERENTIATION OF HEMATOPOIETIC STEM CELLS (HSCS). TET2 DEFICIENCY LED TO DECREASED GENOMIC LEVELS OF 5HMC AND AUGMENTED THE SIZE OF THE HEMATOPOIETIC STEM/PROGENITOR CELL POOL IN A CELL-AUTONOMOUS MANNER. IN COMPETITIVE TRANSPLANTATION ASSAYS, TET2-DEFICIENT HSCS WERE CAPABLE OF MULTILINEAGE RECONSTITUTION AND POSSESSED A COMPETITIVE ADVANTAGE OVER WILD-TYPE HSCS, RESULTING IN ENHANCED HEMATOPOIESIS INTO BOTH LYMPHOID AND MYELOID LINEAGES. IN VITRO, TET2 DEFICIENCY DELAYED HSC DIFFERENTIATION AND SKEWED DEVELOPMENT TOWARD THE MONOCYTE/MACROPHAGE LINEAGE. OUR DATA INDICATE THAT TET2 HAS A CRITICAL ROLE IN REGULATING THE EXPANSION AND FUNCTION OF HSCS, PRESUMABLY BY CONTROLLING 5HMC LEVELS AT GENES IMPORTANT FOR THE SELF-RENEWAL, PROLIFERATION, AND DIFFERENTIATION OF HSCS. 2011 20 2189 26 EPIGENETIC MECHANISMS UNDERLYING THE THERAPEUTIC EFFECTS OF HDAC INHIBITORS IN CHRONIC MYELOID LEUKEMIA. CHRONIC MYELOID LEUKEMIA (CML) IS A HEMATOLOGICAL DISORDER CAUSED BY THE ONCOGENIC BCR-ABL FUSION PROTEIN IN MORE THAN 90% OF PATIENTS. DESPITE THE STRIKING IMPROVEMENTS IN THE MANAGEMENT OF CML PATIENTS SINCE THE INTRODUCTION OF TYROSINE KINASE INHIBITORS (TKIS), THE APPEARANCE OF TKI RESISTANCE AND SIDE EFFECTS LEAD TO TREATMENT FAILURE, JUSTIFYING THE NEED OF NOVEL THERAPEUTIC APPROACHES. HISTONE DEACETYLASE INHIBITORS (HDACIS), ABLE TO MODULATE GENE EXPRESSION PATTERNS AND IMPORTANT CELLULAR SIGNALING PATHWAYS THROUGH THE REGULATION OF THE ACETYLATION STATUS OF BOTH HISTONE AND NON-HISTONE PROTEIN TARGETS, HAVE BEEN REPORTED TO DISPLAY PROMISING ANTI-LEUKEMIC PROPERTIES ALONE OR IN COMBINATION WITH TKIS. THIS REVIEW SUMMARIZES PRE-CLINICAL AND CLINICAL STUDIES THAT INVESTIGATED THE MECHANISMS UNDERLYING THE ANTICANCER POTENTIAL OF HDACIS AND DISCUSSES THE RATIONALE FOR A COMBINATION OF HDACIS WITH TKIS AS A THERAPEUTIC OPTION IN CML. 2020