1 3694 236 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 2 2813 50 FIBROBLAST REPROGRAMMING IN GASTROINTESTINAL CANCER. GASTROINTESTINAL CANCERS ARE A SIGNIFICANT CAUSE OF CANCER MORTALITY WORLDWIDE AND HAVE BEEN STRONGLY LINKED WITH CHRONIC INFLAMMATION. CURRENT THERAPIES FOCUS ON EPITHELIAL/CANCER CELLS; HOWEVER, THE IMPORTANCE OF THE TUMOR MICROENVIRONMENT IN THE DEVELOPMENT AND TREATMENT OF THE DISEASE IS ALSO NOW WELL ESTABLISHED. CANCER-ASSOCIATED FIBROBLASTS (CAFS) ARE A MAJOR COMPONENT OF THE TUMOR MICROENVIRONMENT, AND ARE ACTIVELY PARTICIPATING IN TUMOR INITIATION, PROMOTION AND METASTASIS. THEY STRUCTURALLY AND FUNCTIONALLY AFFECT CANCER CELL PROLIFERATION, TUMOR IMMUNITY, ANGIOGENESIS, EXTRACELLULAR MATRIX REMODELING AND METASTASIS THROUGH A VARIETY OF SIGNALING PATHWAYS. CAFS ORIGINATE PREDOMINANTLY FROM RESIDENT MESENCHYMAL CELLS, WHICH ARE ACTIVATED AND REPROGRAMMED IN RESPONSE TO CUES FROM CANCER CELLS. IN RECENT YEARS, CHRONIC INFLAMMATION OF THE GASTROINTESTINAL TRACT HAS ALSO PROVEN AN IMPORTANT DRIVER OF MESENCHYMAL CELL ACTIVATION AND SUBSEQUENT CAF DEVELOPMENT, WHICH IN TURN ARE CAPABLE OF REGULATING THE TRANSITION FROM ACUTE TO CHRONIC INFLAMMATION AND CANCER. IN THIS REVIEW, WE WILL PROVIDE A CONCISE OVERVIEW OF THE MECHANISMS THAT DRIVE FIBROBLAST REPROGRAMMING IN CANCER AND THE RECENT ADVANCES ON THE DOWNSTREAM SIGNALING PATHWAYS THAT REGULATE THE FUNCTIONAL PROPERTIES OF THE ACTIVATED MESENCHYME. THIS NEW MECHANISTIC INSIGHT COULD PAVE THE WAY FOR NEW THERAPEUTIC STRATEGIES AND BETTER PROGNOSIS FOR CANCER PATIENTS. 2020 3 5412 48 REGULATION OF ANTITUMOR IMMUNITY BY INFLAMMATION-INDUCED EPIGENETIC ALTERATIONS. CHRONIC INFLAMMATION PROMOTES TUMOR DEVELOPMENT, PROGRESSION, AND METASTATIC DISSEMINATION AND CAUSES TREATMENT RESISTANCE. THE ACCUMULATION OF GENETIC ALTERATIONS AND LOSS OF NORMAL CELLULAR REGULATORY PROCESSES ARE NOT ONLY ASSOCIATED WITH CANCER GROWTH AND PROGRESSION BUT ALSO RESULT IN THE EXPRESSION OF TUMOR-SPECIFIC AND TUMOR-ASSOCIATED ANTIGENS THAT MAY ACTIVATE ANTITUMOR IMMUNITY. THIS ANTAGONISM BETWEEN INFLAMMATION AND IMMUNITY AND THE ABILITY OF CANCER CELLS TO AVOID IMMUNE DETECTION AFFECT THE COURSE OF CANCER DEVELOPMENT AND TREATMENT OUTCOMES. WHILE INFLAMMATION, PARTICULARLY ACUTE INFLAMMATION, SUPPORTS T-CELL PRIMING, ACTIVATION, AND INFILTRATION INTO INFECTED TISSUES, CHRONIC INFLAMMATION IS MOSTLY IMMUNOSUPPRESSIVE. HOWEVER, THE MAIN MECHANISMS THAT DICTATE THE OUTCOME OF THE INFLAMMATION-IMMUNITY INTERPLAY ARE NOT WELL UNDERSTOOD. RECENT DATA SUGGEST THAT INFLAMMATION TRIGGERS EPIGENETIC ALTERATIONS IN CANCER CELLS AND COMPONENTS OF THE TUMOR MICROENVIRONMENT. THESE ALTERATIONS CAN AFFECT AND MODULATE NUMEROUS ASPECTS OF CANCER DEVELOPMENT, INCLUDING TUMOR GROWTH, THE METABOLIC STATE, METASTATIC SPREAD, IMMUNE ESCAPE, AND IMMUNOSUPPRESSIVE OR IMMUNOSUPPORTIVE LEUKOCYTE GENERATION. IN THIS REVIEW, WE DISCUSS THE ROLE OF INFLAMMATION IN INITIATING EPIGENETIC ALTERATIONS IN IMMUNE CELLS, CANCER-ASSOCIATED FIBROBLASTS, AND CANCER CELLS AND SUGGEST HOW AND WHEN EPIGENETIC INTERVENTIONS CAN BE COMBINED WITH IMMUNOTHERAPIES TO IMPROVE THERAPEUTIC OUTCOMES. 2022 4 6428 42 THE TUMOR MICROENVIRONMENT AND METASTATIC DISEASE. THE MICROENVIRONMENT OF SOLID TUMORS IS A HETEROGENEOUS, COMPLEX MILIEU FOR TUMOR GROWTH AND SURVIVAL THAT INCLUDES FEATURES SUCH AS ACIDIC PH, LOW NUTRIENT LEVELS, ELEVATED INTERSTITIAL FLUID PRESSURE (IFP) AND CHRONIC AND FLUCTUATING LEVELS OF OXYGENATION THAT RELATE TO THE ABNORMAL VASCULAR NETWORK THAT EXISTS IN TUMORS. THE METASTATIC POTENTIAL OF TUMOR CELLS IS BELIEVED TO BE REGULATED BY INTERACTIONS BETWEEN THE TUMOR CELLS AND THEIR EXTRACELLULAR ENVIRONMENT (EXTRACELLULAR MATRIX (ECM)). THESE INTERACTIONS CAN BE MODIFIED BY THE ACCUMULATION OF GENETIC CHANGES AND BY THE TRANSIENT ALTERATIONS IN GENE EXPRESSION INDUCED BY THE LOCAL TUMOR MICROENVIRONMENT. CLINICAL AND EXPERIMENTAL EVIDENCE SUGGESTS THAT ALTERED GENE EXPRESSION IN RESPONSE TO THE HYPOXIC MICROENVIRONMENT IS A CONTRIBUTING FACTOR TO INCREASED METASTATIC EFFICIENCY. A NUMBER OF GENES THAT HAVE BEEN IMPLICATED IN THE METASTATIC PROCESS, INVOLVING ANGIOGENESIS, INTRA/EXTRAVASATION, SURVIVAL AND GROWTH, HAVE BEEN FOUND TO BE HYPOXIA-RESPONSIVE. THE VARIOUS METASTATIC DETERMINANTS, GENETIC AND EPIGENETIC, SOMATIC AND INHERITED MAY SERVE AS PRECEDENTS FOR THE FUTURE IDENTIFICATION OF MORE GENES THAT ARE INVOLVED IN METASTASIS. MUCH RESEARCH HAS FOCUSED ON GENETIC AND MOLECULAR PROPERTIES OF THE TUMOR CELLS THEMSELVES. IN THE PRESENT REVIEW WE DISCUSS THE EPIGENETIC AND PHYSIOLOGICAL REGULATION OF METASTASIS AND EMPHASIZE THE NEED FOR FURTHER STUDIES ON THE INTERACTIONS BETWEEN THE PATHOPHYSIOLOGIC TUMOR MICROENVIRONMENT AND THE TUMOR EXTRACELLULAR MATRIX. 2009 5 6592 54 TUMOR-ASSOCIATED MACROPHAGES IN HEPATOCELLULAR CARCINOMA PATHOGENESIS, PROGNOSIS AND THERAPY. HEPATOCELLULAR CARCINOMA (HCC) CONSTITUTES A MAJOR HEALTH BURDEN GLOBALLY, AND IT IS CAUSED BY INTRINSIC GENETIC MUTATIONS ACTING IN CONCERT WITH A MULTITUDE OF EPIGENETIC AND EXTRINSIC RISK FACTORS. CANCER INDUCES MYELOPOIESIS IN THE BONE MARROW, AS WELL AS THE MOBILIZATION OF HEMATOPOIETIC STEM AND PROGENITOR CELLS, WHICH RESIDE IN THE SPLEEN. MONOCYTES PRODUCED IN THE BONE MARROW AND THE SPLEEN FURTHER INFILTRATE TUMORS, WHERE THEY DIFFERENTIATE INTO TUMOR-ASSOCIATED MACROPHAGES (TAMS). THE RELATIONSHIP BETWEEN CHRONIC INFLAMMATION AND HEPATOCARCINOGENESIS HAS BEEN THOROUGHLY INVESTIGATED OVER THE PAST DECADE; HOWEVER, SEVERAL ASPECTS OF THE ROLE OF TAMS IN HCC DEVELOPMENT ARE YET TO BE DETERMINED. IN RESPONSE TO CERTAIN STIMULI AND SIGNALING, MONOCYTES DIFFERENTIATE INTO MACROPHAGES WITH ANTITUMOR PROPERTIES, WHICH ARE CLASSIFIED AS M1-LIKE. ON THE OTHER HAND, UNDER DIFFERENT STIMULI AND SIGNALING, THE POLARIZATION OF MACROPHAGES SHIFTS TOWARDS AN M2-LIKE PHENOTYPE WITH A TUMOR PROMOTING CAPACITY. M2-LIKE MACROPHAGES DRIVE TUMOR GROWTH BOTH DIRECTLY AND INDIRECTLY, VIA THE SUPPRESSION OF CYTOTOXIC CELL POPULATIONS, INCLUDING CD8+ T CELLS AND NK CELLS. THE TUMOR MICROENVIRONMENT AFFECTS THE RESPONSE TO IMMUNOTHERAPIES. THEREFORE, AN ENHANCED UNDERSTANDING OF ITS IMMUNOBIOLOGY IS ESSENTIAL FOR THE DEVELOPMENT OF NEXT-GENERATION IMMUNOTHERAPIES. THE UTILIZATION OF VARIOUS MONOCYTE-CENTERED ANTICANCER TREATMENT MODALITIES HAS BEEN UNDER CLINICAL INVESTIGATION, SELECTIVELY TARGETING AND MODULATING THE PROCESSES OF MONOCYTE RECRUITMENT, ACTIVATION AND MIGRATION. THIS REVIEW SUMMARIZES THE CURRENT EVIDENCE ON THE ROLE OF TAMS IN HCC PATHOGENESIS AND PROGRESSION, AS WELL AS IN THEIR POTENTIAL INVOLVEMENT IN TUMOR THERAPY, SHEDDING LIGHT ON EMERGING ANTICANCER TREATMENT METHODS TARGETING MONOCYTES. 2022 6 1232 47 CROSSTALK BETWEEN INFLAMMATORY SIGNALING AND METHYLATION IN CANCER. INFLAMMATION IS AN INTRICATE IMMUNE RESPONSE AGAINST INFECTION AND TISSUE DAMAGE. WHILE THE INITIAL IMMUNE RESPONSE IS IMPORTANT FOR PREVENTING TUMORIGENESIS, CHRONIC INFLAMMATION IS IMPLICATED IN CANCER PATHOGENESIS. IT HAS BEEN LINKED TO VARIOUS STAGES OF TUMOR DEVELOPMENT INCLUDING TRANSFORMATION, PROLIFERATION, ANGIOGENESIS, AND METASTASIS. IMMUNE CELLS, THROUGH THE PRODUCTION OF INFLAMMATORY MEDIATORS SUCH AS CYTOKINES, CHEMOKINES, TRANSFORMING GROWTH FACTORS, AND ADHESION MOLECULES CONTRIBUTE TO THE SURVIVAL, GROWTH, AND PROGRESSION OF THE TUMOR IN ITS MICROENVIRONMENT. THE ABERRANT EXPRESSION AND SECRETION OF PRO-INFLAMMATORY AND GROWTH FACTORS BY THE TUMOR CELLS RESULT IN THE RECRUITMENT OF IMMUNE CELLS, THUS CREATING A MUTUAL CROSSTALK. THE RECIPROCAL SIGNALING BETWEEN THE TUMOR CELLS AND THE IMMUNE CELLS CREATES AND MAINTAINS A SUCCESSFUL TUMOR NICHE. MANY INFLAMMATORY FACTORS ARE REGULATED BY EPIGENETIC MECHANISMS INCLUDING DNA METHYLATION AND HISTONE MODIFICATIONS. IN PARTICULAR, DNA AND HISTONE METHYLATION ARE CRUCIAL FORMS OF TRANSCRIPTIONAL REGULATION AND ABERRANT METHYLATION HAS BEEN ASSOCIATED WITH DEREGULATED GENE EXPRESSION IN ONCOGENESIS. SUCH DEREGULATIONS HAVE BEEN REPORTED IN BOTH SOLID TUMORS AND HEMATOLOGICAL MALIGNANCIES. WITH TECHNOLOGICAL ADVANCEMENTS TO STUDY GENOME-WIDE EPIGENETIC LANDSCAPES, IT IS NOW POSSIBLE TO IDENTIFY MOLECULAR MECHANISMS UNDERLYING ALTERED INFLAMMATORY PROFILES IN CANCER. IN THIS REVIEW, WE DISCUSS THE ROLE OF DNA AND HISTONE METHYLATION IN REGULATION OF INFLAMMATORY PATHWAYS IN HUMAN CANCERS AND REVIEW THE MERITS AND CHALLENGES OF TARGETING INFLAMMATORY MEDIATORS AS WELL AS EPIGENETIC REGULATORS IN CANCER. 2021 7 928 37 CHRONIC INFLAMMATION, THE TUMOR MICROENVIRONMENT AND CARCINOGENESIS. CHRONIC INFLAMMATION OFTEN PRECEDES OR ACCOMPANIES A SUBSTANTIAL NUMBER OF CANCERS. INDEED, ANTI-INFLAMMATORY THERAPIES HAVE SHOWN EFFICACY IN CANCER PREVENTION AND TREATMENT. THE EXACT MECHANISMS THAT TURN A WOUND HEALING PROCESS INTO A CANCER PRECURSOR ARE TOPICS OF INTENSE RESEARCH. A PATHOGENIC LINK HAS BEEN IDENTIFIED BETWEEN INFLAMMATORY MEDIATORS, INFLAMMATION RELATED GENE POLYMORPHISMS AND CARCINOGENESIS. ANIMAL MODELS OF CANCER HAVE BEEN INSTRUMENTAL IN DEMONSTRATING THE DIVERSITY OF MECHANISMS THROUGH WHICH EVERY TUMOR COMPARTMENT AND TUMOR STAGE MAY BE AFFECTED BY THE UNDERLYING INFLAMMATORY PROCESS. IN THIS REVIEW, WE FOCUS ON THE INTERACTION BETWEEN CHRONIC INFLAMMATION, TUMOR STEM CELLS AND THE TUMOR MICROENVIRONMENT. WE SUMMARIZE THE PROPOSED MECHANISMS THAT LEAD TO THE RECRUITMENT OF BONE MARROW DERIVED CELLS AND EXPLORE THE GENETIC AND EPIGENETIC ALTERATIONS THAT MAY OCCUR IN INFLAMMATION ASSOCIATED CANCERS. 2009 8 2036 32 EPIGENETIC CHANGES OF THE IMMUNE SYSTEM WITH ROLE IN TUMOR DEVELOPMENT. TUMOR DEVELOPMENT IS CLOSELY RELATED TO CHRONIC INFLAMMATION AND TO EVASION OF IMMUNE DEFENSE MECHANISMS BY NEOPLASTIC CELLS. THE MEDIATORS OF THE INFLAMMATORY PROCESS AS WELL AS PROTEINS INVOLVED IN IMMUNE RESPONSE OR IMMUNE RESPONSE EVASION CAN BE SUBJECT TO VARIOUS EPIGENETIC CHANGES SUCH AS METHYLATION, ACETYLATION, OR PHOSPHORYLATION. SOME OF THESE, SUCH AS CYTOKINE SUPPRESSORS, ARE UNDERGOING REPRESSION THROUGH EPIGENETIC CHANGES, AND OTHERS SUCH AS CYTOKINES OR CHEMOKINES ARE UNDERGOING ACTIVATION THROUGH EPIGENETIC CHANGES, BOTH MODIFICATIONS HAVING AS A RESULT TUMOR PROGRESSION. THE ACTIVATING CHANGES CAN AFFECT THE RECEPTOR MOLECULES INVOLVED IN IMMUNE RESPONSE AND THESE PROMOTE INFLAMMATION AND SUBSEQUENTLY TUMOR DEVELOPMENT WHILE THE INACTIVATING CHANGES SEEM TO BE RELATED TO THE TUMOR REGRESSION PROCESS. THE PROTEINS INVOLVED IN ANTIGEN PRESENTATION, AND, THEREFORE IN IMMUNE RESPONSE ESCAPE, SUCH AS CLASSICAL HLA PROTEINS AND RELATED APM (ANTIGEN PRESENTATION MACHINERY) WITH THEIR EPIGENETIC CHANGES CONTRIBUTE TO THE TUMOR DEVELOPMENT PROCESS, EITHER TO TUMOR PROGRESSION OR REGRESSION, DEPENDING ON THE IMMUNE EFFECTOR CELLS THAT ARE IN PLAY. 2018 9 2897 33 GASTRIC TUMOR MICROENVIRONMENT. A COMPELLING BODY OF EVIDENCE HAS DEMONSTRATED THAT GASTRIC CANCER HAS A VERY PARTICULAR TUMOR MICROENVIRONMENT, A SIGNATURE VERY SUITABLE TO PROMOTE TUMOR PROGRESSION AND METASTASIS. RECENT INVESTIGATIONS HAVE PROVIDED NEW INSIGHTS INTO THE MULTIPLE MOLECULAR MECHANISMS, DEFINED BY GENETIC AND EPIGENETIC MECHANISMS, SUPPORTING A VERY ACTIVE CROSS TALK BETWEEN THE COMPONENTS OF THE TUMOR MICROENVIRONMENT AND THUS DEFINING THE FATE OF TUMOR PROGRESSION. IN THIS REVIEW, WE INTEND TO HIGHLIGHT THE ROLE OF VERY ACTIVE CONTRIBUTORS AT GASTRIC CANCER TME, PARTICULARLY CANCER-ASSOCIATED FIBROBLASTS, BONE MARROW-DERIVED CELLS, TUMOR-ASSOCIATED MACROPHAGES, AND TUMOR-INFILTRATING NEUTROPHILS, ALL OF THEM SURROUNDED BY AN OVERTIME CHANGING EXTRACELLULAR MATRIX. IN ADDITION, THE VERY ACTIVE CROSS TALK BETWEEN THE COMPONENTS OF THE TUMOR MICROENVIRONMENT, DEFINED BY GENETIC AND EPIGENETIC MECHANISMS, THUS DEFINING THE FATE OF TUMOR PROGRESSION, IS ALSO REVIEWED. 2020 10 6395 52 THE ROLE OF THE MEDIATORS OF INFLAMMATION IN CANCER DEVELOPMENT. EPIGENETIC DISORDERS SUCH AS POINT MUTATIONS IN CELLULAR TUMOR SUPPRESSOR GENES, DNA METHYLATION AND POST-TRANSLATIONAL MODIFICATIONS ARE NEEDED TO TRANSFORMATION OF NORMAL CELLS INTO CANCER CELLS. THESE EVENTS RESULT IN ALTERATIONS IN CRITICAL PATHWAYS RESPONSIBLE FOR MAINTAINING THE NORMAL CELLULAR HOMEOSTASIS, TRIGGERING TO AN INFLAMMATORY RESPONSE WHICH CAN LEAD THE DEVELOPMENT OF CANCER. THE INFLAMMATORY RESPONSE IS A UNIVERSAL DEFENSE MECHANISM ACTIVATED IN RESPONSE TO AN INJURY TISSUE, OF ANY NATURE, THAT INVOLVES BOTH INNATE AND ADAPTIVE IMMUNE RESPONSES, THROUGH THE COLLECTIVE ACTION OF A VARIETY OF SOLUBLE MEDIATORS. MANY INFLAMMATORY SIGNALING PATHWAYS ARE ACTIVATED IN SEVERAL TYPES OF CANCER, LINKING CHRONIC INFLAMMATION TO TUMORIGENESIS PROCESS. THUS, INFLAMMATORY RESPONSES PLAY DECISIVE ROLES AT DIFFERENT STAGES OF TUMOR DEVELOPMENT, INCLUDING INITIATION, PROMOTION, GROWTH, INVASION, AND METASTASIS, AFFECTING ALSO THE IMMUNE SURVEILLANCE. IMMUNE CELLS THAT INFILTRATE TUMORS ENGAGE IN AN EXTENSIVE AND DYNAMIC CROSSTALK WITH CANCER CELLS, AND SOME OF THE MOLECULAR EVENTS THAT MEDIATE THIS DIALOG HAVE BEEN REVEALED. A RANGE OF INFLAMMATION MEDIATORS, INCLUDING CYTOKINES, CHEMOKINES, FREE RADICALS, PROSTAGLANDINS, GROWTH AND TRANSCRIPTION FACTORS, MICRORNAS, AND ENZYMES AS, CYCLOOXYGENASE AND MATRIX METALLOPROTEINASE, COLLECTIVELY ACTS TO CREATE A FAVORABLE MICROENVIRONMENT FOR THE DEVELOPMENT OF TUMORS. IN THIS REVIEW ARE PRESENTED THE MAIN MEDIATORS OF THE INFLAMMATORY RESPONSE AND DISCUSSED THE LIKELY MECHANISMS THROUGH WHICH, THEY INTERACT WITH EACH OTHER TO CREATE A CONDITION FAVORABLE TO DEVELOPMENT OF CANCER. 2015 11 1150 56 CONNECTION BETWEEN INFLAMMATION AND CARCINOGENESIS IN GASTROINTESTINAL TRACT: FOCUS ON TGF-BETA SIGNALING. INFLAMMATION IS A PRIMARY DEFENSE PROCESS AGAINST VARIOUS EXTRACELLULAR STIMULI, SUCH AS VIRUSES, PATHOGENS, FOODS, AND ENVIRONMENTAL POLLUTANTS. WHEN CELLS RESPOND TO STIMULI FOR SHORT PERIODS OF TIME, IT RESULTS IN ACUTE OR PHYSIOLOGICAL INFLAMMATION. HOWEVER, IF THE STIMULATION IS SUSTAINED FOR LONGER TIME OR A PATHOLOGICAL STATE OCCURS, IT IS KNOWN AS CHRONIC OR PATHOLOGICAL INFLAMMATION. SEVERAL STUDIES HAVE SHOWN THAT TUMORIGENESIS IN THE GASTROINTESTINAL (GI) TRACT IS CLOSELY ASSOCIATED WITH CHRONIC INFLAMMATION, FOR WHICH ABNORMAL CELLULAR ALTERATIONS THAT ACCOMPANY CHRONIC INFLAMMATION SUCH AS OXIDATIVE STRESSES, GENE MUTATIONS, EPIGENETIC CHANGES, AND INFLAMMATORY CYTOKINES, ARE SHARED WITH CARCINOGENIC PROCESSES, WHICH FORMS A CRITICAL CROSS-LINK BETWEEN CHRONIC INFLAMMATION AND CARCINOGENESIS. TRANSFORMING GROWTH FACTOR (TGF)-BETA IS A MULTI-POTENT CYTOKINE THAT PLAYS AN IMPORTANT ROLE IN REGULATION OF CELL GROWTH, APOPTOSIS AND DIFFERENTIATION. MOST IMPORTANTLY, TGF-BETA IS A STRONG ANTI-INFLAMMATORY CYTOKINE THAT REGULATES THE DEVELOPMENT OF EFFECTOR CELLS. TGF-BETA HAS A SUPPRESSIVE EFFECT ON CARCINOGENESIS UNDER NORMAL CONDITIONS BY INHIBITING ABNORMAL CELL GROWTH, BUT ON THE OTHER HAND, MANY GI CANCERS ORIGINATE FROM UNCONTROLLED CELL GROWTH AND DIFFERENTIATION BY GENETIC LOSS OF TGF-BETA SIGNALING MOLECULES OR PERTURBATION OF TGF-BETA ADAPTORS. ONCE A TUMOR HAS DEVELOPED, TGF-BETA EXERTS A PROMOTING EFFECT ON THE TUMOR ITSELF AND STROMAL CELLS TO ENHANCE CELL GROWTH, ALTER THE RESPONSIVENESS OF TUMOR CELLS TO STIMULATE INVASION AND METASTASIS, AND INHIBITED IMMUNE SURVEILLANCE. THEREFORE, NOVEL DEVELOPMENT OF THERAPEUTIC AGENTS TO INHIBIT TGF-BETA-INDUCED PROGRESSION OF TUMOR AND TO RETAIN ITS GROWTH INHIBITORY ACTIVITIES, IN ADDITION TO ANTI-INFLAMMATORY ACTIONS, COULD BE USEFUL IN ONCOLOGY. IN THIS REVIEW, WE DISCUSS THE ROLE OF TGF-BETA IN INFLAMMATION AND CARCINOGENESIS OF THE GI TRACT RELATED TO ABNORMAL TGF-BETA SIGNALING. 2010 12 6151 38 THE FIRE WITHIN: CELL-AUTONOMOUS MECHANISMS IN INFLAMMATION-DRIVEN CANCER. INFLAMMATORY CELLS ARE IMPORTANT FOR TUMOR INITIATION AND PROMOTION, PROVIDING CANCER CELLS WITH CYTOKINES THAT ENHANCE CELL PROLIFERATION AND SURVIVAL. ALTHOUGH MALIGNANT EPITHELIAL CELLS WERE TRADITIONALLY CONSIDERED TO BE ON THE RECEIVING END OF THESE MICROENVIRONMENTAL INTERACTIONS, RECENT STUDIES SHOW THAT EPITHELIAL CELLS CAN UNDERGO INFLAMMATORY REPROGRAMMING ON THEIR OWN. SUCH EPIGENETIC SWITCHES ARE OFTEN TRIGGERED BY CHRONIC TISSUE INJURY AND PLAY IMPORTANT ROLES IN TISSUE REPAIR. BY CONVERTING TERMINALLY DIFFERENTIATED CELLS THAT HARBOR EVEN A SINGLE ONCOGENIC MUTATION TO A LESS DIFFERENTIATED STATE WITH A HIGHER PROLIFERATIVE POTENTIAL, CELL-AUTONOMOUS INFLAMMATION IS AN IMPORTANT CONTRIBUTOR TO TUMOR INITIATION. 2019 13 3799 43 INTERPLAY BETWEEN INFLAMMATION AND EPIGENETIC CHANGES IN CANCER. IMMUNE RESPONSES CAN SUPPRESS TUMORIGENESIS, BUT ALSO CONTRIBUTE TO CANCER INITIATION AND PROGRESSION SUGGESTING A COMPLEX INTERACTION BETWEEN THE IMMUNE SYSTEM AND CANCER. EPIGENETIC ALTERATIONS, WHICH ARE HERITABLE CHANGES IN GENE EXPRESSION WITHOUT CHANGES TO THE DNA SEQUENCE, ALSO PLAY A ROLE IN CARCINOGENESIS THROUGH SILENCING EXPRESSION OF TUMOR SUPPRESSOR GENES AND ACTIVATING ONCOGENIC SIGNALING. INTERESTINGLY, EPITHELIAL CELLS AT SITES OF CHRONIC INFLAMMATION UNDERGO DNA METHYLATION ALTERATIONS THAT ARE SIMILAR TO THOSE PRESENT IN CANCER CELLS, SUGGESTING THAT INFLAMMATION MAY INITIATE CANCER-SPECIFIC EPIGENETIC CHANGES IN EPITHELIAL CELLS. FURTHERMORE, EPIGENETIC CHANGES OCCUR DURING IMMUNE CELL DIFFERENTIATION AND PARTICIPATE IN REGULATING THE IMMUNE RESPONSE, INCLUDING THE REGULATION OF INFLAMMATORY CYTOKINES. CANCER CELLS UTILIZE EPIGENETIC SILENCING OF IMMUNE-RELATED GENES TO EVADE THE IMMUNE RESPONSE. THIS CHAPTER WILL DETAIL THE INTERACTIONS BETWEEN INFLAMMATION AND EPIGENETICS IN TUMOR INITIATION, PROMOTION, AND IMMUNE EVASION AND HOW THESE CONNECTIONS ARE BEING LEVERAGED IN CANCER PREVENTION AND TREATMENT. 2016 14 2335 34 EPIGENETIC REGULATION OF INFLAMMATORY CYTOKINES AND ASSOCIATED GENES IN HUMAN MALIGNANCIES. INFLAMMATION IS A MULTIFACETED DEFENSE RESPONSE OF IMMUNE SYSTEM AGAINST INFECTION. CHRONIC INFLAMMATION HAS BEEN IMPLICATED AS AN IMMINENT THREAT FOR MAJOR HUMAN MALIGNANCIES AND IS DIRECTLY LINKED TO VARIOUS STEPS INVOLVED IN TUMORIGENESIS. INFLAMMATORY CYTOKINES, INTERLEUKINS, INTERFERONS, TRANSFORMING GROWTH FACTORS, CHEMOKINES, AND ADHESION MOLECULES HAVE BEEN ASSOCIATED WITH CHRONIC INFLAMMATION. NUMEROUS CYTOKINES ARE REPORTED TO BE ABERRANTLY REGULATED BY DIFFERENT EPIGENETIC MECHANISMS LIKE DNA METHYLATION AND HISTONE MODIFICATIONS IN TUMOR TISSUES, CONTRIBUTING TO PATHOGENESIS OF TUMOR IN MULTIPLE WAYS. SOME OF THESE CYTOKINES ALSO WORK AS EPIGENETIC REGULATORS OF OTHER CRUCIAL GENES IN TUMOR BIOLOGY, EITHER DIRECTLY OR INDIRECTLY. SUCH REGULATIONS ARE REPORTED IN LUNG, BREAST, CERVICAL, GASTRIC, COLORECTAL, PANCREATIC, PROSTATE, AND HEAD AND NECK CANCERS. EPIGENETICS OF INFLAMMATORY MEDIATORS IN CANCER IS CURRENTLY SUBJECT OF EXTENSIVE RESEARCH. THESE INVESTIGATIONS MAY HELP IN UNDERSTANDING CANCER BIOLOGY AND TO DEVELOP EFFECTIVE THERAPEUTIC STRATEGIES. THE PURPOSE OF THIS PAPER IS TO HAVE A BRIEF VIEW OF THE ABERRANT REGULATION OF INFLAMMATORY CYTOKINES IN HUMAN MALIGNANCIES. 2015 15 2416 33 EPIGENETIC SIGNALING OF CANCER STEM CELLS DURING INFLAMMATION. MALIGNANT TUMORS POSE A GREAT CHALLENGE TO HUMAN HEALTH, WHICH HAS LED TO MANY STUDIES INCREASINGLY ELUCIDATING THE TUMORIGENIC PROCESS. CANCER STEM CELLS (CSCS) HAVE PROFOUND IMPACTS ON TUMORIGENESIS AND DEVELOPMENT OF DRUG RESISTANCE. RECENTLY, THERE HAS BEEN INCREASED INTEREST IN THE RELATIONSHIP BETWEEN INFLAMMATION AND CSCS BUT THE MECHANISM UNDERLYING THIS RELATIONSHIP HAS NOT BEEN FULLY ELUCIDATED. INFLAMMATORY CYTOKINES PRODUCED DURING CHRONIC INFLAMMATION ACTIVATE SIGNALING PATHWAYS THAT REGULATE THE GENERATION OF CSCS THROUGH EPIGENETIC MECHANISMS. IN THIS REVIEW, WE FOCUS ON THE EFFECTS OF INFLAMMATION ON CANCER STEM CELLS, PARTICULARLY THE ROLE OF SIGNALING PATHWAYS SUCH AS NF-KAPPAB PATHWAY, STAT3 PATHWAY AND SMAD PATHWAY INVOLVED IN REGULATING EPIGENETIC CHANGES. WE HOPE TO PROVIDE A NOVEL PERSPECTIVE FOR IMPROVING STRATEGIES FOR TUMOR TREATMENT. 2021 16 737 50 CANCER STEM CELLS. THERE IS AN INCREASING EVIDENCE SUPPORTING THE CANCER STEM CELL HYPOTHESIS. NORMAL STEM CELLS IN THE ADULT ORGANISM ARE RESPONSIBLE FOR TISSUE RENEWAL AND REPAIR OF AGED OR DAMAGED TISSUE. A SUBSTANTIAL CHARACTERISTIC OF STEM CELLS IS THEIR ABILITY FOR SELF-RENEWAL WITHOUT LOSS OF PROLIFERATION CAPACITY WITH EACH CELL DIVISION. THE STEM CELLS ARE IMMORTAL, AND RATHER RESISTANT TO ACTION OF DRUGS. THEY ARE ABLE TO DIFFERENTIATE AND FORM SPECIFIC TYPES OF TISSUE DUE TO THE INFLUENCE OF MICROENVIRONMENTAL AND SOME OTHER FACTORS. STEM CELLS DIVIDE ASYMMETRICALLY PRODUCING TWO DAUGHTER CELLS -- ONE IS A NEW STEM CELL AND THE SECOND IS PROGENITOR CELL, WHICH HAS THE ABILITY FOR DIFFERENTIATION AND PROLIFERATION, BUT NOT THE CAPABILITY FOR SELF-RENEWAL. CANCER STEM CELLS ARE IN MANY ASPECTS SIMILAR TO THE STEM CELLS. IT HAS BEEN PROVEN THAT TUMOR CELLS ARE HETEROGENEOUS COMPRISING RARE TUMOR INITIATING CELLS AND ABUNDANT NON-TUMOR INITIATING CELLS. TUMOR INITIATING CELLS -- CANCER STEM CELLS HAVE THE ABILITY OF SELF-RENEWAL AND PROLIFERATION, ARE RESISTANT TO DRUGS, AND EXPRESS TYPICAL MARKERS OF STEM CELLS. IT IS NOT CLEAR WHETHER CANCER STEM CELLS ORIGINATE FROM NORMAL STEM CELLS IN CONSEQUENCE OF GENETIC AND EPIGENETIC CHANGES AND/OR BY REDIFFERENTIATION FROM SOMATIC TUMOR CELLS TO THE STEM-LIKE CELLS. PROBABLY BOTH MECHANISMS ARE INVOLVED IN THE ORIGIN OF CANCER STEM CELLS. DYSREGULATION OF STEM CELL SELF-RENEWAL IS A LIKELY REQUIREMENT FOR THE DEVELOPMENT OF CANCER. ISOLATION AND IDENTIFICATION OF CANCER STEM CELLS IN HUMAN TUMORS AND IN TUMOR CELL LINES HAS BEEN SUCCESSFUL. TO DATE, THE EXISTENCE OF CANCER STEM CELLS HAS BEEN PROVEN IN ACUTE AND CHRONIC MYELOID LEUKEMIA, IN BREAST CANCER, IN BRAIN TUMORS, IN LUNG CANCER AND GASTROINTESTINAL TUMORS. CANCER STEM CELL MODEL IS ALSO CONSISTENT WITH SOME CLINICAL OBSERVATIONS. ALTHOUGH STANDARD CHEMOTHERAPY KILLS MOST CELLS IN A TUMOR, CANCER STEM CELLS REMAIN VIABLE. DESPITE THE SMALL NUMBER OF SUCH CELLS, THEY MIGHT BE THE CAUSE OF TUMOR RECURRENCE, SOMETIMES MANY YEARS AFTER THE "SUCCESSFUL" TREATMENT OF PRIMARY TUMOR. GROWTH OF METASTASES IN DISTINCT AREAS OF BODY AND THEIR CELLULAR HETEROGENEITY MIGHT BE CONSEQUENCE OF CANCER STEM CELL DIFFERENTIATION AND/OR DEDIFFERENTIATION AND ASYMMETRIC DIVISION OF CANCER STEM CELLS. FURTHER CHARACTERIZATION OF CANCER STEM CELLS IS NEEDED IN ORDER TO FIND WAYS TO DESTROY THEM, WHICH MIGHT CONTRIBUTE SIGNIFICANTLY TO THE THERAPEUTIC MANAGEMENT OF MALIGNANT TUMORS. 2005 17 3672 29 INFLAMMATION AND CANCER: AN ANCIENT LINK WITH NOVEL POTENTIALS. INFECTION AND CHRONIC INFLAMMATION CONTRIBUTE TO ABOUT 1 IN 4 OF ALL CANCER CASES. MEDIATORS OF THE INFLAMMATORY RESPONSE, E.G., CYTOKINES, FREE RADICALS, PROSTAGLANDINS AND GROWTH FACTORS, CAN INDUCE GENETIC AND EPIGENETIC CHANGES INCLUDING POINT MUTATIONS IN TUMOR SUPPRESSOR GENES, DNA METHYLATION AND POST-TRANSLATIONAL MODIFICATIONS, CAUSING ALTERATIONS IN CRITICAL PATHWAYS RESPONSIBLE FOR MAINTAINING THE NORMAL CELLULAR HOMEOSTASIS AND LEADING TO THE DEVELOPMENT AND PROGRESSION OF CANCER. RECENT DISCOVERY OF AN INTERACTION BETWEEN MICRORNAS AND INNATE IMMUNITY DURING INFLAMMATION HAS FURTHER STRENGTHENED THE ASSOCIATION BETWEEN INFLAMMATION AND CANCER. 2007 18 736 49 CANCER STEM CELLS--NEW APPROACH TO CANCEROGENENSIS AND TREATMENT. RECENTLY, THERE IS AN INCREASING EVIDENCE SUPPORTING THE THEORY OF CANCER STEM CELLS NOT ONLY IN LEUKEMIA BUT ALSO IN SOLID CANCER. TO DATE, THE EXISTENCE OF CANCER STEM CELLS HAS BEEN PROVEN IN ACUTE AND CHRONIC MYELOID LEUKEMIA, IN BREAST CANCER, IN BRAIN TUMORS, IN LUNG CANCER AND GASTROINTESTINAL TUMORS. THIS REVIEW IS FOCUSING ON THE RECENT DISCOVERY OF STEM CELLS IN LEUKEMIA, HUMAN BRAIN TUMORS AND BREAST CANCER. A SMALL POPULATION OF CELLS IN THE TUMOR (LESS THAN 1%) SHOWS THE POTENTIAL TO GIVE RISE TO THE TUMOR AND ITS GROWTH. THESE CELLS HAVE A SUBSTANTIAL CHARACTERISTIC OF STEM CELLS--ABILITY FOR SELF-RENEWAL WITHOUT LOSS OF PROLIFERATION CAPACITY WITH EACH CELL DIVISION. FURTHERMORE THEY ARE IMMORTAL, RATHER RESISTANT TO TREATMENT AND EXPRESS TYPICAL MARKERS OF STEM CELLS. THE ORIGIN OF THESE RESIDENT CANCER STEM CELLS IS NOT CLEAR. WHETHER THE CANCER STEM CELLS ORIGINATE FROM NORMAL STEM CELLS IN CONSEQUENCE OF GENETIC AND EPIGENETIC CHANGES AND/OR REDIFFERENTIATION FROM SOMATIC TUMOR CELLS TO THE STEM-LIKE CELLS REMAINS TO BE INVESTIGATED. WE PROPOSE THE IDEA OF THE RELATION BETWEEN NORMAL TISSUE STEM CELLS AND CANCER STEM CELLS AND THEIR POPULATIONS--PROGENITOR CELLS. BASED ON THIS WE HIGHLIGHT ONE OF THE MAJOR CHARACTERISTIC OF STEM CELL--PLASTICITY, WHICH IS EQUALLY IMPORTANT IN THE PHYSIOLOGICAL REGENERATION PROCESS AS WELL AS CARCINOGENESIS. FURTHERMORE, WE CONSIDER THE MICROENVIRONMENT AS A LIMITING FACTOR FOR TUMOR GENESIS IN AML, BREAST CANCER AND BRAIN TUMORS. THUS THE BIOLOGICAL PROPERTIES OF CANCER STEM CELLS ARE JUST BEGINNING TO BE REVEALED, THE CONTINUATION OF THESE STUDIES SHOULD LEAD TO THE DEVELOPMENT OF CANCER STEM CELLS TARGET THERAPIES FOR CANCER TREATMENT. 2008 19 6591 47 TUMOR-ASSOCIATED MACROPHAGES AS A PARADIGM OF MACROPHAGE PLASTICITY, DIVERSITY, AND POLARIZATION: LESSONS AND OPEN QUESTIONS. MACROPHAGES ARE PRESENT IN ALL BODY COMPARTMENTS, INCLUDING CANCEROUS TISSUES, AND THEIR FUNCTIONS ARE PROFOUNDLY AFFECTED BY SIGNALS FROM THE MICROENVIRONMENT UNDER HOMEOSTATIC AND PATHOLOGICAL CONDITIONS. TUMOR-ASSOCIATED MACROPHAGES ARE A MAJOR CELLULAR COMPONENT OF CANCER-RELATED INFLAMMATION AND HAVE SERVED AS A PARADIGM FOR THE PLASTICITY AND FUNCTIONAL POLARIZATION OF MONONUCLEAR PHAGOCYTES. TUMOR-ASSOCIATED MACROPHAGES CAN EXERT DUAL INFLUENCE OF CANCER DEPENDING ON THE ACTIVATION STATE, WITH CLASSICALLY ACTIVATED (M1) AND ALTERNATIVELY ACTIVATED (M2) CELLS GENERALLY EXERTING ANTITUMORAL AND PROTUMORAL FUNCTIONS, RESPECTIVELY. THESE ARE EXTREMES IN A CONTINUUM OF POLARIZATION STATES IN A UNIVERSE OF DIVERSITY. TUMOR-ASSOCIATED MACROPHAGES AFFECT VIRTUALLY ALL ASPECTS OF TUMOR TISSUES, INCLUDING STEM CELLS, METABOLISM, ANGIOGENESIS, INVASION, AND METASTASIS. PROGRESS HAS BEEN MADE IN DEFINING SIGNALING MOLECULES, TRANSCRIPTION FACTORS, EPIGENETIC CHANGES, AND REPERTOIRE OF MICRORNAS UNDERLYING MACROPHAGE POLARIZATION. PRECLINICAL AND EARLY CLINICAL DATA SUGGEST THAT MACROPHAGES MAY SERVE AS TOOLS FOR THE DEVELOPMENT OF INNOVATIVE DIAGNOSTIC AND THERAPEUTIC STRATEGIES IN CANCER AND CHRONIC NONRESOLVING INFLAMMATORY DISEASES. 2013 20 6359 44 THE ROLE OF INFLAMMATION IN THE PATHOGENESIS OF LUNG CANCER. INTRODUCTION: IT IS REPORTED THAT CANCER MAY ARISE IN CHRONICALLY INFLAMED TISSUE. THERE IS MOUNTING EVIDENCE SUGGESTING THAT THE CONNECTION BETWEEN INFLAMMATION AND LUNG CANCER IS NOT COINCIDENTAL BUT MAY INDEED BE CAUSAL. THE INFLAMMATORY MOLECULES MAY BE RESPONSIBLE FOR AUGMENTED MACROPHAGE RECRUITMENT, DELAYED NEUTROPHIL CLEARANCE AND AN INCREASE IN REACTIVE OXYGEN SPECIES. THE CYTOKINES AND GROWTH FACTORS UNUSUALLY PRODUCED IN CHRONIC PULMONARY DISORDERS HAVE BEEN FOUND TO HAVE HARMFUL PROPERTIES THAT PAVE THE WAY FOR EPITHELIAL-TO-MESENCHYMAL TRANSITION AND TUMOR MICROENVIRONMENT. HOWEVER, THE ROLE OF INFLAMMATION IN LUNG CANCER IS NOT YET FULLY UNDERSTOOD. AREAS COVERED: THE ROLE OF CHRONIC INFLAMMATION IN THE PATHOGENESIS OF LUNG CANCER AND SOME OF THE POSSIBLE MECHANISMS INVOLVED, WITH PARTICULAR FOCUS ON INFLAMMATORY MEDIATORS, GENETIC AND EPIGENETIC ALTERATIONS, INFLAMMATORY MARKERS, TUMOR MICROENVIRONMENT AND ANTI-INFLAMMATORY DRUGS ARE DISCUSSED. A FRAMEWORK FOR UNDERSTANDING THE CONNECTION BETWEEN INFLAMMATION AND LUNG CANCER IS PROVIDED, WHICH MAY AFFORD THE OPPORTUNITY TO INTERCEDE IN SPECIFIC INFLAMMATORY DAMAGE MEDIATING LUNG CARCINOGENESIS AND THERAPEUTIC RESISTANCE. EXPERT OPINION: ADVANCES IN TUMOR IMMUNOLOGY SUPPORT THE CLINICAL IMPLEMENTATION OF IMMUNOTHERAPIES FOR LUNG CANCER. ALONG WITH THERAPEUTIC BENEFITS, IMMUNOTHERAPY PRESENTS THE CHALLENGES OF DRUG-RELATED TOXICITIES. GENE MODIFICATION OF IMMUNOCYTOKINE MAY LOWER THE ASSOCIATED TOXIC EFFECTS. 2011