1 5849 114 SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) AND CLADRIBINE SYNERGISTICALLY INDUCE APOPTOSIS IN NK-LGL LEUKAEMIA. NATURAL KILLER (NK) LARGE GRANULAR LYMPHOCYTE (LGL) LEUKAEMIA FEATURES A CLONAL PROLIFERATION OF CD3(-) NK CELLS THAT CAN BE CLASSIFIED INTO EITHER AGGRESSIVE OR CHRONIC CATEGORIES. THE NKL CELL LINE, DERIVED FROM AN AGGRESSIVE ASIAN NK CELL LEUKAEMIA, AND PATIENT SAMPLES FROM CHRONIC NK-LGL LEUKAEMIA WERE USED IN OUR STUDY TO PROBE FOR SYNERGISTIC EFFICACY OF THE EPIGENETIC DRUGS VORINOSTAT (SAHA) AND CLADRIBINE IN THIS DISEASE. WE DEMONSTRATE THAT HISTONE DEACETYLASES (HDACS) ARE OVER-EXPRESSED IN BOTH AGGRESSIVE AND CHRONIC NK LEUKAEMIA. ADMINISTRATION OF THE HDAC INHIBITOR SAHA REDUCES CLASS I AND II HDAC EXPRESSION AND ENHANCES HISTONE ACETYLATION IN LEUKAEMIC NK CELLS. IN VITRO COMBINATION TREATMENT WITH SAHA AND CLADRIBINE DOSE-DEPENDENTLY EXERTS SYNERGISTIC CYTOTOXIC AND APOPTOTIC EFFECTS ON LEUKAEMIC NK CELLS. EXPRESSION PROFILING OF APOPTOTIC REGULATORY GENES SUGGESTS THAT BOTH COMPOUNDS LED TO CASPASE-DEPENDENT APOPTOSIS THROUGH ACTIVATION OF INTRINSIC MITOCHONDRIAL AND EXTRINSIC DEATH RECEPTOR PATHWAYS. COLLECTIVELY, THESE DATA SHOW THAT COMBINED EPIGENETIC THERAPY, USING HDAC AND DNA METHYLTRANSFERASE INHIBITORS, MAY BE A PROMISING THERAPEUTIC APPROACH FOR NK-LGL LEUKAEMIA. 2015 2 171 42 ABROGATION OF HISTONE DEACETYLASES (HDACS) DECREASES SURVIVAL OF CHRONIC MYELOID LEUKEMIA CELLS: NEW INSIGHT INTO ATTENUATING EFFECTS OF THE PI3K/C-MYC AXIS ON PANOBINOSTAT CYTOTOXICITY. ALTHOUGH THE IDENTIFICATION OF TYROSINE KINASE INHIBITORS (TKIS) HAS CHANGED THE TREATMENT PARADIGM OF MANY CANCER TYPES INCLUDING CHRONIC MYELOID LEUKEMIA (CML), STILL ADJUSTMENT OF NEOPLASTIC CELLS TO CYTOTOXIC EFFECTS OF ANTICANCER DRUGS IS A SERIOUS CHALLENGE. IN THE AREA OF DRUG RESISTANCE, EPIGENETIC ALTERATIONS ARE AT THE CENTER OF ATTENTION AND THE PRESENT STUDY AIMED TO EVALUATE WHETHER BLOCKAGE OF EPIGENETICS MECHANISMS USING A PAN-HISTONE DEACETYLASE (HDAC) INHIBITOR INDUCES CELL DEATH IN CML-DERIVED K562 CELLS. WE FOUND THAT THE ABROGATION OF HDACS USING PANOBINOSTAT RESULTED IN A REDUCTION IN SURVIVAL OF THE K562 CELL LINE THROUGH P27-MEDIATED CELL CYCLE ARREST. NOTEWORTHY, THE RESULTS OF THE SYNERGISTIC EXPERIMENTS REVEALED THAT HDAC SUPPRESSION COULD BE RECRUITED AS A WAY TO POTENTIATE CYTOTOXICITY OF IMATINIB AND TO ENHANCE THE THERAPEUTIC EFFICACY OF CML. HERE, WE PROPOSED FOR THE FIRST TIME THAT THE INHIBITORY EFFECT OF PANOBINOSTAT WAS OVERSHADOWED, AT LEAST PARTIALLY, THROUGH THE ABERRANT ACTIVATION OF THE PHOSPHOINOSITIDE 3-KINASE (PI3K)/C-MYC AXIS. MEANWHILE, WE FOUND THAT UPON BLOCKAGE OF AUTOPHAGY AND THE PROTEASOME PATHWAY, AS THE MAIN AXIS INVOLVED IN THE ACTIVATION OF AUTOPHAGY, THE ANTI-LEUKEMIC PROPERTY OF THE HDAC INHIBITOR WAS POTENTIATED. TAKEN TOGETHER, OUR STUDY SUGGESTS THE BENEFICIAL APPLICATION OF HDAC INHIBITION IN THE TREATMENT STRATEGIES OF CML; HOWEVER, FURTHER IN VIVO STUDIES ARE NEEDED TO DETERMINE THE EFFICACY OF THIS INHIBITOR, EITHER AS A SINGLE AGENT OR IN COMBINATION WITH SMALL MOLECULE INHIBITORS OF PI3K AND/OR C-MYC IN THIS MALIGNANCY. 2021 3 5691 38 SILENCING OF HDAC6 AS A THERAPEUTIC TARGET IN CHRONIC LYMPHOCYTIC LEUKEMIA. ALTHOUGH THE TREATMENT PARADIGM FOR CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS RAPIDLY CHANGING, THE DISEASE REMAINS INCURABLE, EXCEPT WITH ALLOGENEIC BONE MARROW TRANSPLANTATION, AND RESISTANCE, RELAPSED DISEASE, AND PARTIAL RESPONSES PERSIST AS SIGNIFICANT CHALLENGES. RECENT STUDIES HAVE UNCOVERED ROLES FOR EPIGENETIC MODIFICATION IN THE REGULATION OF MECHANISMS CONTRIBUTING TO MALIGNANT PROGRESSION OF CLL B CELLS. HOWEVER, THE EXTENT TO WHICH EPIGENETIC MODIFIERS CAN BE TARGETED FOR THERAPEUTIC BENEFIT IN CLL PATIENTS REMAINS POORLY EXPLORED. WE REPORT FOR THE FIRST TIME THAT EXPRESSION OF EPIGENETIC MODIFIER HISTONE DEACETYLASE 6 (HDAC6) IS UPREGULATED IN CLL PATIENT SAMPLES, CELL LINES, AND EUTCL1 TRANSGENIC MOUSE MODELS COMPARED WITH HDAC6 IN NORMAL CONTROLS. GENETIC SILENCING OF HDAC6 CONFERRED SURVIVAL BENEFIT IN EUTCL1 MICE. ADMINISTRATION OF ISOFORM-SPECIFIC HDAC6 INHIBITOR ACY738 IN THE EUTCL1 AGING AND ADOPTIVE TRANSFER MODELS DETERRED PROLIFERATION OF CLL B CELLS, DELAYED DISEASE ONSET VIA DISRUPTION OF B-CELL RECEPTOR SIGNALING, AND SENSITIZED CLL B CELLS TO APOPTOSIS. FURTHERMORE, COADMINISTRATION OF ACY738 AND IBRUTINIB DISPLAYED SYNERGISTIC CELL KILL AGAINST CLL CELL LINES AND IMPROVED OVERALL SURVIVAL COMPARED WITH EITHER SINGLE AGENT IN VIVO. THESE RESULTS DEMONSTRATE FOR THE FIRST TIME THE THERAPEUTIC EFFICACY OF SELECTIVE HDAC6 INHIBITION IN PRECLINICAL CLL MODELS AND SUGGEST A RATIONALE FOR THE CLINICAL DEVELOPMENT OF HDAC6 INHIBITORS FOR CLL TREATMENT, EITHER ALONE OR IN COMBINATION WITH BRUTON TYROSINE KINASE INHIBITION. 2018 4 1287 41 DECITABINE-INDUCED APOPTOSIS IS DERIVED BY PUMA AND NOXA INDUCTION IN CHRONIC MYELOID LEUKEMIA CELL LINE AS WELL AS IN PBL AND IS POTENTIATED BY SAHA. RESTORATION OF CELLULAR APOPTOTIC PATHWAYS PLAYS A CRUCIAL ROLE IN CANCER THERAPY STRATEGIES. IN A BROAD SPECTRUM OF ANTICANCER DRUGS, EPIGENETIC EFFECTORS ARE IN THE CENTER OF INTEREST MOSTLY BECAUSE OF POTENTIAL REVERSIBILITY OF THEIR ACTION. METHYLATION STATUS OF THE CELLS IS INFLUENCED BY METHYLTRANSFERASE INHIBITOR 2-DEOXY-5'-AZACYTIDINE (DECITABINE, DAC), BUT HIGHER CONCENTRATIONS OF THIS AGENT CAUSE A DNA-DAMAGE. IN OUR STUDY, TUMOR SUPRESSOR P53-APOPTOTIC PATHWAY WAS ACTIVATED IN DECITABINE-INDUCED CELL DEATH. EXPRESSION OF P53-INDUCIBLE BH3-ONLY APOPTOTIC PROTEINS PUMA AND NOXA WAS ELEVATED AND LARGE ACTIVATION OF EXECUTIVE CASPASES WAS OBSERVED. THE EXTENT OF ACETYLATION IN THE CELL IS AFFECTED BY HISTONEDEACETYLASE INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA). COMBINATION OF SAHA WITH DECITABINE BROUGHT SYNERGISTIC EFFECT ON APOPTOSIS TRIGGERING IN CML-T1 CELL LINE, BUT APOPTOSIS AS WELL AS NECROSIS OCCURRED ALSO IN NORMAL PERIPHERAL BLOOD LYMPHOCYTES. THEREFORE, PROMISING POTENTIAL OF SUCH COMBINED THERAPY CALLS FOR MORE DETAILED INVESTIGATION OF UNWANTED EFFECTS IN NORMAL CELLS. 2011 5 4877 40 OVEREXPRESSION OF MIR-4433 BY SUBEROYLANILIDE HYDROXAMIC ACID SUPPRESSES GROWTH OF CML CELLS AND INDUCES APOPTOSIS THROUGH TARGETING BCR-ABL. BACKGROUND: TARGETING BCR-ABL IS THE KEY FOR THE TREATMENT OF CML. ALTHOUGH GREAT PROGRESS HAS BEEN ACHIEVED FOR THE TREATMENT OF CML PATIENTS IN CHRONIC STAGE, EFFECTIVE DRUGS WITH GOOD SAFETY ARE NOT AVAILABLE FOR THOSE IN ADVANCED STAGES OF CML PATIENTS. IN PRESENT STUDY, A HISTONE DEACETYLASE INHIBITOR, SUBEROYLANILIDE HYDROXAMIC ACID (SAHA), WAS USED TO SCREEN FOR MICRORNA THAT CAN TARGET BCR-ABL. METHODS: RT-QPCR WAS USED TO DETERMINE BCR-ABL AND MIR-4433 TRANSCRIPTION LEVEL IN CML CELLS. IN CML CELLS, PROTEINS INCLUDING PARP, CASPASE-3, ACETYL-HISTONE 3, HISTONE 3 AND BCR-ABL, AS WELL AS BCR-ABL DOWNSTREAM PROTEINS WERE DETECTED USING WESTERN BLOT. CELL VIABILITY AND APOPTOSIS WERE MONITORED RESPECTIVELY BY MTS ASSAY AND FLOW CYTOMETRY. THE CORRELATION BETWEEN MIR-4433 AND BCR-ABL WAS DETERMINED BY LUCIFERASE REPORTER ASSAY. THE ANTI-TUMOR EFFECT OF MIR-4433 TO K562 CELLS WAS EVALUATED BY NUDE MOUSE XENOGRAFT MODEL IN VIVO. RESULTS: SAHA UP-REGULATED THE ACETYLATION LEVEL OF HISTONE 3, AND EFFECTIVELY INHIBITED BCR-ABL MRNA LEVEL AND ITS DOWNSTREAM SIGNAL TRANSDUCTION PATHWAY, WHILE INHIBITING THE GROWTH OF CML CELLS AND INDUCING APOPTOSIS. FURTHERMORE, BIOINFORMATICS TOOLS PREDICTED THAT MIR-4433 IS A PUTATIVE MICRORNA TARGETING BCR-ABL AND THAT THE EXPRESSION LEVEL OF MIR-4433 WAS SIGNIFICANTLY INCREASED AFTER SAHA TREATMENT IN K562 CELLS. LUCIFERASE ACTIVITY ANALYSIS REVEALED THAT MIR-4433 DIRECTLY TARGETS BCR-ABL. ADDITIONALLY, TRANSIENT EXPRESSION OF MIR-4433 ABROGATED BCR-ABL ACTIVITY AND ITS DOWNSTREAM SIGNALING PATHWAYS WHILE INDUCING APOPTOSIS IN K562 CELLS. MOREOVER, STABLE EXPRESSION OF MIR-4433 SUPPRESSED BCR-ABL AND ITS DOWNSTREAM SIGNALING PATHWAY, AND INHIBITED THE GROWTH OF K562 CELLS IN VITRO AND THE GROWTH OF K562-XENOGRAFTS IN NUDE MICE. CONCLUSION: MIR-4433 WAS IDENTIFIED AS A MICRORNA TARGETING BCR-ABL, WHICH MAY BE SUBJECT TO EPIGENETIC REGULATION OF SAHA, A HISTONE DEACETYLASE INHIBITOR THAT HAS BEEN APPROVED BY THE US FDA FOR THE TREATMENT OF CUTANEOUS T-CELL LYMPHOMA. THE FINDINGS OF THIS STUDY PROVIDE A MOLECULAR BASIS FROM ANOTHER ANGLE FOR THE USE OF SAHA IN THE TREATMENT OF CML. 2019 6 3195 37 HDAC INHIBITORS AUGMENTED CELL MIGRATION AND METASTASIS THROUGH INDUCTION OF PKCS LEADING TO IDENTIFICATION OF LOW TOXICITY MODALITIES FOR COMBINATION CANCER THERAPY. PURPOSE: HISTONE DEACETYLASE INHIBITORS (HDACI) ARE ACTIVELY EXPLORED AS NEW-GENERATION EPIGENETIC DRUGS BUT HAVE LOW EFFICACY IN CANCER MONOTHERAPY. TO REVEAL NEW MECHANISM FOR COMBINATION THERAPY, WE SHOW THAT HDACI INDUCE CELL DEATH BUT SIMULTANEOUSLY ACTIVATE TUMOR-PROGRESSIVE GENES TO RUIN THERAPEUTIC EFFICACY. COMBINED TREATMENTS TO TARGET TUMORIGENESIS AND HDACI-ACTIVATED METASTASIS WITH LOW TOXIC MODALITIES COULD DEVELOP NEW STRATEGIES FOR LONG-TERM CANCER THERAPY. EXPERIMENTAL DESIGN: BECAUSE METASTASIS IS THE MAJOR CAUSE OF CANCER MORTALITY, WE MEASURED CELL MIGRATION ACTIVITY AND PROFILED METASTASIS-RELATED GENE EXPRESSIONS IN HDACI-TREATED CANCER CELLS. WE DEVELOPED LOW TOXIC COMBINATION MODALITIES TARGETING TUMORIGENESIS AND HDACI-ACTIVATED METASTASIS FOR PRECLINICAL THERAPIES IN MICE. RESULTS: WE SHOWED THAT CELL MIGRATION ACTIVITY WAS DRAMATICALLY AND DOSE DEPENDENTLY ENHANCED BY VARIOUS CLASSES OF HDACI TREATMENTS IN 13 OF 30 EXAMINED HUMAN BREAST, GASTRIC, LIVER, AND LUNG CANCER CELL LINES. TUMOR METASTASIS WAS ALSO ENHANCED IN HDACI-TREATED MICE. HDACI TREATMENTS ACTIVATED MULTIPLE PKCS AND DOWNSTREAM SUBSTRATES ALONG WITH UPREGULATED PROAPOPTOTIC P21. FOR TARGETING TUMORIGENESIS AND METASTASIS WITH IMMEDIATE CLINICAL IMPACT, WE SHOWED THAT NEW MODALITIES OF HDACI COMBINED DRUGS WITH PKC INHIBITORY AGENT, CURCUMIN OR TAMOXIFEN, NOT ONLY SUPPRESSED HDACI-ACTIVATED TUMOR PROGRESSIVE PROTEINS AND CELL MIGRATION IN VITRO BUT ALSO INHIBITED TUMOR GROWTH AND METASTASIS IN VIVO. CONCLUSION: TREATMENTS OF DIFFERENT STRUCTURAL CLASSES OF HDACI SIMULTANEOUSLY INDUCED CELL DEATH AND PROMOTED CELL MIGRATION AND METASTASIS IN MULTIPLE CANCER CELL TYPES. SUPPRESSION OF HDACI-INDUCED PKCS LEADS TO DEVELOPMENT OF LOW TOXIC AND LONG-TERM THERAPEUTIC STRATEGIES TO POTENTIALLY TREAT CANCER AS A CHRONIC DISEASE. 2012 7 5475 33 RESTORING MLL REACTIVATES LATENT TUMOR SUPPRESSION-MEDIATED VULNERABILITY TO PROTEASOME INHIBITORS. MLL UNDERGOES MULTIPLE DISTINCT CHROMOSOMAL TRANSLOCATIONS TO YIELD AGGRESSIVE LEUKEMIA WITH DISMAL OUTCOMES. BESIDES THEIR WELL-ESTABLISHED ROLE IN LEUKEMOGENESIS, MLL FUSIONS ALSO POSSESS LATENT TUMOR-SUPPRESSIVE ACTIVITY, WHICH CAN BE EXPLOITED AS EFFECTIVE CANCER TREATMENT STRATEGIES USING PHARMACOLOGICAL MEANS SUCH AS PROTEASOME INHIBITORS (PIS). HERE, USING MLL-REARRANGED XENOGRAFTS AND MLL LEUKEMIC CELLS AS MODELS, WE SHOW THAT WILD-TYPE MLL IS INDISPENSABLE FOR THE LATENT TUMOR-SUPPRESSIVE ACTIVITY OF MLL FUSIONS. MLL DYSFUNCTION, SHOWN AS LOSS OF THE CHROMATIN ACCUMULATION AND SUBSEQUENT DEGRADATION OF MLL, COMPROMISES THE LATENT TUMOR SUPPRESSION OF MLL-AF4 AND IS INSTRUMENTAL FOR THE ACQUIRED PI RESISTANCE. MECHANISTICALLY, MLL DYSFUNCTION IS CAUSED BY CHRONIC PI TREATMENT-INDUCED EPIGENETIC REPROGRAMMING THROUGH THE H2BUB-ASH2L-MLL AXIS AND CAN BE SPECIFICALLY RESTORED BY HISTONE DEACETYLASE (HDAC) INHIBITORS, WHICH INDUCE HISTONE ACETYLATION AND RECRUITS MLL ON CHROMATIN TO PROMOTE CELL CYCLE GENE EXPRESSION. OUR FINDINGS NOT ONLY DEMONSTRATE THE MECHANISM UNDERLYING THE INEVITABLE ACQUISITION OF PI RESISTANCE IN MLL LEUKEMIC CELLS, BUT ALSO ILLUSTRATE THAT PREVENTING THE EMERGENCE OF PI-RESISTANT CELLS CONSTITUTES A NOVEL RATIONALE FOR COMBINATION THERAPY WITH PIS AND HDAC INHIBITORS IN MLL LEUKEMIAS. 2020 8 6688 36 VALPROATE SYNERGIZES WITH PURINE NUCLEOSIDE ANALOGUES TO INDUCE APOPTOSIS OF B-CHRONIC LYMPHOCYTIC LEUKAEMIA CELLS. RESISTANCE TO CHEMOTHERAPY AND DRUG TOXICITY ARE TWO MAJOR CONCERNS OF CHRONIC LYMPHOCYTIC LEUKAEMIA (B-CLL) TREATMENT BY PURINE NUCLEOSIDE ANALOGUES (PNA, I.E. FLUDARABINE AND CLADRIBINE). WE HYPOTHESIZED THAT TARGETING EPIGENETIC CHANGES MIGHT ADDRESS THESE ISSUES AND EVALUATED THE EFFECT OF THE HISTONE DEACETYLASE INHIBITOR VALPROATE (VPA) AT A CLINICALLY RELEVANT CONCENTRATION. VPA ACTED IN A HIGHLY SYNERGISTIC/ADDITIVE MANNER WITH FLUDARABINE AND CLADRIBINE TO INDUCE APOPTOSIS OF B-CLL CELLS. IMPORTANTLY, VPA ALSO RESTORED SENSITIVITY TO FLUDARABINE IN B CELLS FROM POOR PROGNOSIS CLL PATIENTS WHO BECAME RESISTANT TO CHEMOTHERAPY. MECHANISM OF APOPTOSIS INDUCED BY VPA ALONE OR COMBINED WITH FLUDARABINE OR TO CLADRIBINE WAS CASPASE-DEPENDENT AND INVOLVED THE EXTRINSIC PATHWAY. VPA, BUT NEITHER FLUDARABINE NOR CLADRIBINE, ENHANCED THE PRODUCTION OF REACTIVE OXYGEN SPECIES (ROS) AND INHIBITION OF ROS WITH N-ACETYLCYSTEINE DECREASES APOPTOSIS OF CLL CELLS. VPA STIMULATES HYPERPHOSPHORYLATION OF P42/P44 ERK, CYTOCHROME C RELEASE AND OVEREXPRESSION OF BAX AND FAS. TOGETHER, OUR DATA INDICATE THAT VPA MAY AMELIORATE THE OUTCOME OF PNA-BASED THERAPEUTIC PROTOCOLS AND PROVIDE A POTENTIAL ALTERNATIVE TREATMENT IN BOTH THE RELAPSED AND FRONT-LINE RESISTANT PATIENTS AND IN PATIENTS WITH HIGH RISK FEATURES. 2009 9 4728 28 NOTCH SIGNALING PROMOTES DISEASE INITIATION AND PROGRESSION IN MURINE CHRONIC LYMPHOCYTIC LEUKEMIA. NOTCH1 GAIN-OF-FUNCTION MUTATIONS ARE RECURRENT IN B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (B-CLL), WHERE THEY ARE ASSOCIATED WITH ACCELERATED DISEASE PROGRESSION AND REFRACTORINESS TO CHEMOTHERAPY. THE SPECIFIC ROLE OF NOTCH1 IN THE DEVELOPMENT AND PROGRESSION OF THIS MALIGNANCY IS UNCLEAR. HERE, WE ASSESS THE IMPACT OF LOSS OF NOTCH SIGNALING AND PATHWAY HYPERACTIVATION IN AN IN VIVO MOUSE MODEL OF CLL (IGH.TEMU) THAT FAITHFULLY REPLICATES MANY FEATURES OF THE HUMAN PATHOLOGY. ABLATION OF CANONICAL NOTCH SIGNALING USING CONDITIONAL GENE INACTIVATION OF RBP-J IN IMMATURE HEMATOPOIETIC OR B-CELL PROGENITORS DELAYED CLL INDUCTION AND REDUCED INCIDENCE OF MICE DEVELOPING DISEASE. IN CONTRAST, FORCED EXPRESSION OF A DOMINANT ACTIVE FORM OF NOTCH RESULTED IN MORE ANIMALS DEVELOPING CLL WITH EARLY DISEASE ONSET. COMPARATIVE ANALYSIS OF GENE EXPRESSION AND EPIGENETIC FEATURES OF NOTCH GAIN-OF-FUNCTION AND CONTROL CLL CELLS REVEALED DIRECT AND INDIRECT REGULATION OF CELL CYCLE-ASSOCIATED GENES, WHICH LED TO INCREASED PROLIFERATION OF NOTCH GAIN-OF-FUNCTION CLL CELLS IN VIVO. THESE RESULTS DEMONSTRATE THAT NOTCH SIGNALING FACILITATES DISEASE INITIATION AND PROMOTES CLL CELL PROLIFERATION AND DISEASE PROGRESSION. 2021 10 3415 33 HSP90 INHIBITION INCREASES SOCS3 TRANSCRIPT AND REGULATES MIGRATION AND CELL DEATH IN CHRONIC LYMPHOCYTIC LEUKEMIA. EPIGENETIC OR TRANSCRIPTIONAL SILENCING OF IMPORTANT TUMOR SUPPRESSORS HAS BEEN DESCRIBED TO CONTRIBUTE TO CELL SURVIVAL AND TUMORIGENESIS IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). USING GENE EXPRESSION MICROARRAY ANALYSIS, WE FOUND THAT THOUSANDS OF GENES ARE REPRESSED MORE THAN 2-FOLD IN CLL COMPARED TO NORMAL B CELLS; HOWEVER THERAPEUTIC APPROACHES TO REVERSE THIS HAVE BEEN LIMITED IN CLL. FOLLOWING TREATMENT WITH THE HSP90 INHIBITOR 17-DMAG, A SIGNIFICANT NUMBER OF THESE REPRESSED GENES WERE SIGNIFICANTLY RE-EXPRESSED. ONE OF THE GENES SIGNIFICANTLY REPRESSED IN CLL AND UP-REGULATED BY 17-DMAG WAS SUPPRESSOR OF CYTOKINE SIGNALING 3, (SOCS3). SOCS3 HAS BEEN SHOWN TO BE SILENCED IN SOLID TUMORS AS WELL AS MYELOID LEUKEMIA; HOWEVER LITTLE IS KNOWN ABOUT THE REGULATION IN CLL. WE FOUND THAT 17-DMAG INDUCES EXPRESSION OF SOCS3 BY VIA THE ACTIVATION OF P38 SIGNALING, AND SUBSEQUENTLY INHIBITS AKT AND STAT3 PHOSPHORYLATION RESULTING IN DOWNSTREAM EFFECTS ON CELL MIGRATION AND SURVIVAL. WE THEREFORE SUGGEST THAT SOCS3 IS AN IMPORTANT SIGNALING PROTEIN IN CLL, AND HSP90 INHIBITORS REPRESENT A NOVEL APPROACH TO TARGET TRANSCRIPTIONAL REPRESSION IN B CELL LYMPHOPROLIFERATIVE DISORDERS WHICH EXHIBIT A SUBSTANTIAL DEGREE OF GENE REPRESSION. 2016 11 1272 40 CYTOTOXIC ACTIVITY OF VALPROIC ACID ON PRIMARY CHRONIC LYMPHOCYTIC LEUKEMIA CELLS. BACKGROUND: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS THE MOST COMMON ADULT LEUKEMIA IN WESTERN CIVILIZATION. THE ACCUMULATION OF CD5+CD19+ B LYMPHOCYTES IN PERIPHERAL BLOOD IS DUE TO A DEFECT IN THE APOPTOTIC PATHWAY RATHER THAN EXCESSIVE PROLIFERATION IN THE BONE MARROW AND LYMPH NODES. DESPITE A NUMBER OF TREATMENTS, CLL REMAINS AN INCURABLE DISEASE. VALPROIC ACID (VPA) ACTIVITY, AS A HISTONE DEACETYLASE INHIBITOR, COULD RESTORE THE EPIGENETIC CHANGES UNDERLYING THE PATHOGENESIS OF CLL AND THUS INDUCE CELL DEATH. OBJECTIVES: IN THE PRESENT STUDY WE HYPOTHESIZED THAT VPA COULD INDUCE CLL PRIMARY CELLS DEATH THROUGH ACTIVATION OF APOPTOSIS. MATERIAL AND METHODS: PERIPHERAL BLOOD SAMPLES WERE OBTAINED FROM 53 CLL PATIENTS. PERIPHERAL BLOOD MONONUCLEAR CELLS WERE ISOLATED THROUGH DENSITY GRADIENT CENTRIFUGATION AND WERE THE SUBJECT OF A 24-HOUR CELL CULTURE WITH 10 MM OF VPA. THE CYTOTOXIC EFFECT OF VPA WAS EVALUATED WITH AN XTT TEST AND THEREAFTER CONFIRMED USING ANNEXIN V-FITC/PI STAINING AND FLOW CYTOMETRY TECHNIQUES. RESULTS: IN THIS STUDY, A MEDIAN VPA CYTOTOXICITY OF 13.88% WITH A RANGE OF 0-54.65% WAS OBSERVED. ANNEXIN V/PI STAINING CONFIRMED THAT THE DEMONSTRATED CYTOTOXICITY WAS CAUSED BY INCREASED APOPTOSIS IN THE VPA TREATED CELLS AS COMPARED TO CONTROL CELLS. STATISTICAL ANALYSIS SHOWED THAT VPA'S EFFECT ON CLL CELLS DEPENDS ON LACTATE DEHYDROGENASE SERUM LEVELS, BUT IS INDEPENDENT OF ALL OTHER PROGNOSTIC MARKERS. CONCLUSIONS: THE RESULTS OF THE PRESENT EXPERIMENTS FOUND THAT VPA AT A CLINICALLY APPLICABLE CONCENTRATION SIGNIFICANTLY INDUCES APOPTOSIS INDEPENDENTLY OF THE DISEASE STAGE AND MIGHT BE A VALUABLE THERAPEUTIC AGENT FOR ALL CLL PATIENTS. 2015 12 2389 37 EPIGENETIC REPOLARIZATION OF T LYMPHOCYTES FROM CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS USING 5-AZA-2'-DEOXYCYTIDINE. T CELL IMMUNE DYSFUNCTION HAS AN IMPORTANT ROLE IN THE PROFOUND IMMUNE SUPPRESSION THAT CHARACTERIZES CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). IMPROPER POLARIZATION OF T CELLS HAS BEEN PROPOSED AS ONE OF THE MECHANISM INVOLVED. MOUNTING DATA IMPLICATES CHROMATIN REGULATION, NAMELY PROMOTER METHYLATION, IN THE PLASTICITY OF NAIVE HUMAN T CELLS. RECENT IN VITRO EVIDENCE INDICATES THAT THIS PLASTICITY MAY BE PHENOTYPICALLY ALTERED BY USING METHYLATION INHIBITORS WHICH ARE APPROVED FOR CLINICAL USE IN CERTAIN TYPES OF CANCER. THESE RESULTS BEG THE QUESTION: CAN THE INEFFECTIVE POLARIZATION OF T LYMPHOCYTES IN THE CONTEXT OF CLL BE EFFECTIVELY MODULATED USING METHYLATION INHIBITORS IN A SUSTAINABLE THERAPEUTIC FASHION? TO ANSWER THIS QUESTION OUR LABORATORY HAS STUDIED THE EFFECTS OF 5-AZA-2'-DEOXYCYTIDINE (5A2) IN HELPER AND CYTOTOXIC T LYMPHOCYTES FROM HEALTHY DONORS AND CLL PATIENTS IN WELL CHARACTERIZED MOLECULAR AND EPIGENETIC SIGNALING PATHWAYS INVOLVED IN EFFECTIVE POLARIZATION. MOREOVER, WE SOUGHT TO INVESTIGATE THE CONSEQUENCES OF METHYLATION INHIBITOR TREATMENT ON LYMPHOCYTE SURVIVAL, ACTIVATION INTENSITY, AND NAIVE CELL POLARIZATION. OUR DATA INDICATES THAT 5A2 TREATMENT CAN DEPOLARIZE TH2 CELLS TO EFFECTIVELY SECRETE INTERFERON GAMMA, SIGNAL VIA T-BET, AND ACHIEVE DEMETHYLATION OF CRITICAL TH1 SPECIFIC PROMOTERS. MOREOVER, WE DEMONSTRATE THAT 5A2 CAN FORCE TH1 POLARIZATION OF NAIVE T CELLS DESPITE A STRONG IL-4 STIMULI AND A LACK OF IL-12. IN CONCLUSION OUR DATA SEEKS TO DEFINE A MODALITY IN WHICH IMPROPER OR INEFFECTIVE T CELL POLARIZATION CAN BE ALTERED BY 5AZA AND COULD BE INCORPORATED IN FUTURE THERAPEUTIC INTERVENTIONS. 2011 13 5499 32 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 14 230 34 ADAPTIVE AND INNATE CYTOTOXIC EFFECTORS IN CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) SUBJECTS WITH STABLE DISEASE. CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) IS CHARACTERISED BY THE EXPANSION OF A NEOPLASTIC MATURE B CELL CLONE. CLL CLINICAL OUTCOME IS VERY HETEROGENEOUS, WITH SOME SUBJECTS NEVER REQUIRING THERAPY AND SOME SHOWING AN AGGRESSIVE DISEASE. GENETIC AND EPIGENETIC ALTERATIONS AND PRO-INFLAMMATORY MICROENVIRONMENT INFLUENCE CLL PROGRESSION AND PROGNOSIS. THE INVOLVEMENT OF IMMUNE-MEDIATED MECHANISMS IN CLL CONTROL NEEDS TO BE INVESTIGATED. WE ANALYSE THE ACTIVATION PROFILE OF INNATE AND ADAPTIVE CYTOTOXIC IMMUNE EFFECTORS IN A COHORT OF 26 CLL PATIENTS WITH STABLE DISEASE, AS KEY ELEMENTS FOR IMMUNE-MEDIATED CONTROL OF CANCER PROGRESSION. WE OBSERVED AN INCREASE IN CD54 EXPRESSION AND INTERFERON (IFN)-GAMMA PRODUCTION BY CYTOTOXIC T CELLS (CTL). CTL ABILITY TO RECOGNISE TUMOUR-TARGETS DEPENDS ON HUMAN LEUKOCYTE ANTIGENS (HLA)-CLASS I EXPRESSION. WE OBSERVED A DECREASED EXPRESSION OF HLA-A AND HLA-BC ON B CELLS OF CLL SUBJECTS, ASSOCIATED WITH A SIGNIFICANT REDUCTION IN INTRACELLULAR CALNEXIN THAT IS RELEVANT FOR HLA SURFACE EXPRESSION. NATURAL KILLER (NK) CELLS AND CTL FROM CLL SUBJECTS SHOW AN INCREASED EXPRESSION OF THE ACTIVATING RECEPTOR KIR2DS2 AND A REDUCTION OF 3DL1 AND NKG2A INHIBITING MOLECULES. THEREFORE, AN ACTIVATION PROFILE CHARACTERISES CTL AND NK CELLS OF CLL SUBJECTS WITH STABLE DISEASE. THIS PROFILE IS CONCEIVABLE WITH THE FUNCTIONAL INVOLVEMENT OF CYTOTOXIC EFFECTORS IN CLL CONTROL. 2023 15 1036 34 CLASS I HISTONE DEACETYLASES REGULATE P53/NF-KAPPAB CROSSTALK IN CANCER CELLS. THE TRANSCRIPTION FACTORS NF-KAPPAB AND P53 AS WELL AS THEIR CROSSTALK DETERMINE THE FATE OF TUMOR CELLS UPON THERAPEUTIC INTERVENTIONS. REPLICATIVE STRESS AND CYTOKINES PROMOTE SIGNALING CASCADES THAT LEAD TO THE CO-REGULATION OF P53 AND NF-KAPPAB. CONSEQUENTLY, NUCLEAR P53/NF-KAPPAB SIGNALING COMPLEXES ACTIVATE NF-KAPPAB-DEPENDENT SURVIVAL GENES. THE 18 HISTONE DEACETYLASES (HDACS) ARE EPIGENETIC MODULATORS THAT FALL INTO FOUR CLASSES (I-IV). INHIBITORS OF HISTONE DEACETYLASES (HDACI) BECOME INCREASINGLY APPRECIATED AS ANTI-CANCER AGENTS. BASED ON THEIR EFFECTS ON P53 AND NF-KAPPAB, WE ADDRESSED WHETHER CLINICALLY RELEVANT HDACI AFFECT THE NF-KAPPAB/P53 CROSSTALK. THE CHEMOTHERAPEUTICS HYDROXYUREA, ETOPOSIDE, AND FLUDARABINE HALT CELL CYCLE PROGRESSION, INDUCE DNA DAMAGE, AND LEAD TO DNA FRAGMENTATION. THESE AGENTS CO-INDUCE P53 AND NF-KAPPAB-DEPENDENT GENE EXPRESSION IN CELL LINES FROM BREAST AND COLON CANCER AND IN PRIMARY CHRONIC LYMPHATIC LEUKEMIA (CLL) CELLS. USING SPECIFIC HDACI, WE FIND THAT THE CLASS I SUBGROUP OF HDACS, BUT NOT THE CLASS IIB DEACETYLASE HDAC6, ARE REQUIRED FOR THE HYDROXYUREA-INDUCED CROSSTALK BETWEEN P53 AND NF-KAPPAB. HDACI DECREASE THE BASAL AND STRESS-INDUCED EXPRESSION OF P53 AND BLOCK NF-KAPPAB-REGULATED GENE EXPRESSION. WE FURTHER SHOW THAT CLASS I HDACI INDUCE SENESCENCE IN PANCREATIC CANCER CELLS WITH MUTANT P53. 2017 16 6762 22 ZAP70 IN CHRONIC LYMPHOCYTIC LEUKAEMIA. THE PROTEIN TYROSINE KINASE ZETA-CHAIN ASSOCIATED PROTEIN KINASE (ZAP70), NORMALLY EXPRESSED IN T CELLS AND A SUBSET OF B CELLS, IS SOLELY EXPRESSED IN POOR PROGNOSIS CHRONIC LYMPHOCYTIC LEUKAEMIA AND IMPLICATED IN ENHANCED B CELL RECEPTOR SIGNALLING. AS A RESULT, THE EXPRESSION OF THIS PROTEIN PROVIDES AN IDEAL PROGNOSTIC MARKER FOR THE DISEASE. A PREVIOUS STUDY HAS SHOWN DIFFERENTIAL CPG METHYLATION OF A 5' REGION OF ZAP70 IN LEUKAEMIC LYMPHOID CELLS, ALTHOUGH NO FURTHER EPIGENETIC STUDIES HAVE BEEN REPORTED. FURTHER INVESTIGATION INTO THE EXPRESSION OF ZAP70 MAY THEREFORE PROVIDE TARGETS FOR THERAPIES. 2008 17 3660 39 INDUCTION OF HEPATIC DIFFERENTIATION OF MOUSE BONE MARROW STROMAL STEM CELLS BY THE HISTONE DEACETYLASE INHIBITOR VPA. BONE MARROW STROMAL STEM CELLS (BMSSCS) MAY HAVE POTENTIAL TO DIFFERENTIATE IN VITRO AND IN VIVO INTO HEPATOCYTES. HERE, WE INVESTIGATED THE EFFECTS OF VALPROIC ACID (VPA) INVOLVED IN EPIGENETIC MODIFICATION, A DIRECT INHIBITOR OF HISTONE DEACETYLASE, ON HEPATIC DIFFERENTIATION OF MOUSE BMSSCS. FOLLOWING THE TREATMENT OF 2.5 MM VPA FOR 72 HRS, THE IN VITRO EXPANDED, HIGHLY PURIFIED AND FUNCTIONALLY ACTIVE MOUSE BMSSCS FROM BONE MARROW WERE EITHER EXPOSED TO SOME WELL-DEFINED CYTOKINES AND GROWTH FACTORS IN A SEQUENTIAL WAY (FIBROBLAST GROWTH FACTOR-4 [FGF-4], FOLLOWED BY HGF, AND HGF + OSM + ITS + DEXAMETHASONE, RESEMBLING THE ORDER OF SECRETION DURING LIVER EMBRYOGENESIS) OR TRANSPLANTED (CAUDAL VEIN) IN MICE SUBMITTED TO A PROTOCOL OF CHRONIC INJURY (CHRONIC I.P. INJECTION OF CCL4). ADDITIONAL EXPOSURE OF THE CELLS TO VPA CONSIDERABLY IMPROVED THE IN VITRO DIFFERENTIATION, AS DEMONSTRATED BY A MORE HOMOGENEOUS CELL POPULATION EXHIBITED EPITHELIAL MORPHOLOGY, INCREASING EXPRESSION OF HEPATIC SPECIAL GENES AND ENHANCED HEPATIC FUNCTIONS. FURTHER MORE, IN VIVO RESULTS INDICATE THAT THE PRE-TREATMENT OF VPA SIGNIFICANTLY INCREASED THE HOMING EFFICIENCY OF BMSSCS TO THE SITE OF LIVER INJURY AND, ADDITIONALLY, FOR SUPPORTING HEPATIC DIFFERENTIATION AS WELL AS IN VITRO. WE HAVE DEMONSTRATED THE USEFULNESS OF VPA IN THE TRANSDIFFERENTIATION OF BMSSCS INTO HEPATOCYTES BOTH IN VITRO AND IN VIVO, AND REGULATION OF FIBROBLAST GROWTH FACTOR RECEPTORS (FGFRS) AND C-MET GENE EXPRESSION THROUGH POST-TRANSLATIONAL MODIFICATION OF CORE HISTONES MIGHT BE THE PRIMARY INITIATING EVENT FOR THESE EFFECTS. THIS MODE COULD BE HELPFUL FOR LIVER ENGINEERING AND CLINICAL THERAPY. 2009 18 1542 32 DNA METHYLATION IN HAEMATOLOGICAL MALIGNANCIES: THE ROLE OF DECITABINE. NORMAL CELL DEVELOPMENT AND FUNCTION IS DEPENDENT UPON CONTROLLED GENE EXPRESSION. DNA METHYLATION IS AN EPIGENETIC MODIFICATION THAT CAN PLAY AN IMPORTANT ROLE IN THE CONTROL OF GENE EXPRESSION. DNA METHYLATION AT CYTOSINE RESIDUES IN GENE PROMOTER CPG SEQUENCES IS KNOWN TO INHIBIT GENE TRANSCRIPTION. INAPPROPRIATE INHIBITION OF THE TRANSCRIPTION OF TUMOUR SUPPRESSOR GENES, GENES THAT INHIBIT ANGIOGENESIS AND METASTASIS AND GENES INVOLVED IN DNA REPAIR BY UNCONTROLLED METHYLATION, CAN LEAD TO UNREGULATED GROWTH AND PROLIFERATION OF A CELL AND CARCINOGENESIS. PROMOTER HYPERMETHYLATION AFFECTING THE P16 GENE, RESULTING IN GENE SILENCING, HAS BEEN SHOWN TO OCCUR IN MANY HUMAN SOLID TUMOURS AND A 'HYPERMETHYLATION PROFILE' IN SOME LEUKAEMIAS HAS BEEN DEFINED. THE MOLECULAR MECHANISMS BY WHICH ABERRANT DNA METHYLATION TAKES PLACE DURING CARCINOGENESIS ARE STILL NOT CLEAR. HOWEVER, THE LARGE NUMBER OF TARGET GENES (INVOLVED IN TUMORIGENESIS) THAT ARE SILENCED BY ABERRANT METHYLATION SUGGESTS THAT INHIBITION OF THIS PROCESS MAY HAVE POTENTIAL AS CANCER THERAPY. DECITABINE (NSC-127716, DACOGEN; SUPERGEN) IS A POTENT AND SPECIFIC HYPOMETHYLATING AGENT AND AN INHIBITOR OF THE DNA METHYLTRANSFERASE ACTIVITY THAT MEDIATES DNA METHYLATION. DECITABINE HAS BEEN SHOWN TO HAVE A BROAD RANGE OF ANTINEOPLASTIC ACTIVITY IN PRECLINICAL STUDIES. THIS AGENT HAS EXHIBITED SIGNIFICANT ACTIVITY IN THE TREATMENT OF PATIENTS WITH MYELODYSPLASTIC SYNDROME, CHRONIC MYELOID LEUKAEMIA AND ACUTE MYELOID LEUKAEMIA, ALTHOUGH CLINICAL PHASE I AND II STUDIES WITH SOLID TUMOURS HAVE NOT BEEN VERY PROMISING. PHASE II AND III STUDIES ARE CURRENTLY ONGOING TO EVALUATE DECITABINE, BOTH ALONE AND IN COMBINATION, IN VARIOUS STAGES OF THESE HAEMATOLOGICAL MALIGNANCIES. 2003 19 5055 31 PHASE 2 TRIAL OF THE HISTONE DEACETYLASE INHIBITOR ROMIDEPSIN FOR THE TREATMENT OF REFRACTORY MULTIPLE MYELOMA. BACKGROUND: EPIGENETIC DYSREGULATION IS A HALLMARK OF CANCER, INCLUDING MULTIPLE MYELOMA. INHIBITORS OF HISTONE DEACETYLASES (HDACS) INDUCE DNA HYPERACETYLATION BY INHIBITING REMOVAL OF ACETYL GROUPS FROM AMINO TAILS ON HISTONE PROTEINS, THEREBY UNCOILING CONDENSED CHROMATIN FAVORING TRANSCRIPTION OF SILENCED GENES, INCLUDING TUMOR SUPPRESSOR GENES. ROMIDEPSIN IS AN HDAC INHIBITOR THAT EXHIBITS ANTIPROLIFERATIVE AND APOPTOTIC EFFECTS AGAINST MULTIPLE MYELOMA CELL LINES. METHODS: A PHASE 2 TRIAL WAS PERFORMED OF ROMIDEPSIN IN PATIENTS WITH MULTIPLE MYELOMA WHO WERE REFRACTORY TO STANDARD THERAPY. TREATMENT WAS COMPRISED OF ROMIDEPSIN (13 MG/M(2)) GIVEN AS A 4-HOUR INTRAVENOUS INFUSION ON DAYS 1, 8, AND 15 EVERY 28 DAYS). THIRTEEN PATIENTS RECEIVED A MEDIAN OF 2 CYCLES OF THERAPY (RANGE, 1-7 CYCLES). RESULTS: ALTHOUGH NO PATIENTS HAD AN OBJECTIVE RESPONSE, 4 OF 12 PATIENTS WITH SECRETORY MYELOMA EXHIBITED EVIDENCE OF M-PROTEIN STABILIZATION, AND SEVERAL OTHER PATIENTS EXPERIENCED IMPROVEMENT IN BONE PAIN AND RESOLUTION OF HYPERCALCEMIA. CONCLUSIONS: THE RESULTS OF THE CURRENT STUDY DEMONSTRATE THAT ROMIDEPSIN, AS A SINGLE AGENT, IS UNLIKELY TO BE ASSOCIATED WITH A RESPONSE RATE OF >/=30% IN PATIENTS WITH REFRACTORY MYELOMA, ALTHOUGH THERE WAS SOME CLINICAL EVIDENCE SUGGESTING A BIOLOGICAL EFFECT ASSOCIATED WITH THERAPY. 2011 20 306 30 AKT TARGETING AS A STRATEGY TO BOOST CHEMOTHERAPY EFFICACY IN NON-SMALL CELL LUNG CANCER THROUGH METABOLISM SUPPRESSION. METABOLIC REPROGRAMMING IS A HALLMARK OF CANCER DEVELOPMENT, MEDIATED BY GENETIC AND EPIGENETIC ALTERATIONS THAT MAY BE PHARMACOLOGICALLY TARGETED. AMONG ONCOGENES, THE KINASE AKT IS COMMONLY OVEREXPRESSED IN TUMORS AND FAVORS GLYCOLYSIS, PROVIDING A RATIONALE FOR USING AKT INHIBITORS. HERE, WE ADDRESSED THE QUESTION OF WHETHER AND HOW INHIBITING AKT ACTIVITY COULD IMPROVE THERAPY OF NON-SMALL CELL LUNG CANCER (NSCLC) THAT REPRESENTS MORE THAN 80% OF ALL LUNG CANCER CASES. FIRST, WE DEMONSTRATED THAT AKT INHIBITORS INTERACTED SYNERGISTICALLY WITH MICROTUBULE-TARGETING AGENTS (MTAS) AND SPECIFICALLY IN CANCER CELL LINES, INCLUDING THOSE RESISTANT TO CHEMOTHERAPY AGENTS AND ANTI-EGFR TARGETED THERAPIES. IN VIVO, WE FURTHER REVEALED THAT THE CHRONIC ADMINISTRATION OF LOW-DOSES OF PACLITAXEL - I.E. METRONOMIC SCHEDULING - AND THE ANTI-AKT PERIFOSINE WAS THE MOST EFFICIENT AND THE BEST TOLERATED TREATMENT AGAINST NSCLC. REGARDING DRUG MECHANISM OF ACTION, PERIFOSINE POTENTIATED THE PRO-APOPTOTIC EFFECTS OF PACLITAXEL, INDEPENDENTLY OF CELL CYCLE ARREST, AND COMBINING PACLITAXEL/PERIFOSINE RESULTED IN A SUSTAINED SUPPRESSION OF GLYCOLYTIC AND MITOCHONDRIAL METABOLISM. THIS STUDY POINTS OUT THAT TARGETING CANCER CELL BIOENERGETICS MAY REPRESENT A NOVEL THERAPEUTIC AVENUE IN NSCLC, AND PROVIDES A STRONG FOUNDATION FOR FUTURE CLINICAL TRIALS OF METRONOMIC MTAS COMBINED WITH AKT INHIBITORS. 2017