1 6466 125 TISSUE STEM CELLS AND CANCER STEM CELLS: POTENTIAL IMPLICATIONS FOR GASTRIC CANCER. GASTRIC CANCER REMAINS THE SECOND LEADING CAUSE OF DEATH IN THE WORLD TODAY, MAKING THE SEARCH FOR ITS MOLECULAR AND CELLULAR BASIS AN IMPORTANT PRIORITY. THOUGH RECOGNITION OF THE TIGHT LINK BETWEEN INFLAMMATION AND TUMORIGENESIS IS CENTURIES OLD, ONLY RECENTLY ARE THE PIECES OF THE ETIOLOGICAL PUZZLE BEGINNING TO FALL TOGETHER. RECENT ADVANCES IN GASTRIC STEM CELL BIOLOGY APPEAR TO BE CENTRAL TO THIS SLOWLY RESOLVING PUZZLE. AT LEAST TWO TYPES OF STEM CELLS MAY BE IMPORTANT. RESIDENT ADULT OR TISSUE STEM CELLS MAY, IN A CHRONICALLY INFLAMED ENVIRONMENT, SLOWLY ACQUIRE A SERIES OF GENETIC AND EPIGENETIC CHANGES THAT LEAD TO THEIR EMERGENCE AS ''CANCER STEM CELLS''. THIS SCENARIO HAS NOT YET BEEN PROVEN EXPERIMENTALLY, ALTHOUGH THE FIRST STEP, PROSPECTIVE RECOGNITION OF A GASTRIC STEM CELL HAS RECENTLY BEEN CONQUERED. ALTERNATIVELY, THE SETTING OF CHRONIC INFLAMMATORY STRESS AND INJURY MAY LEAD TO LOSS OF THE INDIGENOUS GASTRIC STEM CELLS FROM THEIR NICHES; BONE MARROW DERIVED STEM CELLS MAY THEN BE RECRUITED TO AND ENGRAFT INTO THE GASTRIC EPITHELIUM. SUCH RECRUITED CELLS HAVE THE POTENTIAL TO CONTRIBUTE TO THE TUMOR MASS. INDEED, EVIDENCE SUPPORTING THIS SCENARIO HAS BEEN PUBLISHED. HERE, WE REVIEW THESE RECENT FINDINGS AND DISCUSS IMPLICATIONS FOR THE FUTURE. 2008 2 928 33 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 3 6273 34 THE ORIGINS OF GASTRIC CANCER FROM GASTRIC STEM CELLS: LESSONS FROM MOUSE MODELS. THE CELLULAR ORIGIN OF DIGESTIVE CANCERS HAS BEEN A LONG-STANDING QUESTION IN THE CANCER FIELD. MOUSE MODELS HAVE IDENTIFIED LONG-LIVED STEM CELLS IN MOST ORGAN SYSTEMS, INCLUDING THE LUMINAL GASTROINTESTINAL TRACT, AND NUMEROUS STUDIES HAVE POINTED TO TISSUE RESIDENT STEM CELLS AS THE MAIN CELLULAR ORIGIN OF CANCER. DURING GASTRIC CARCINOGENESIS, CHRONIC INFLAMMATION INDUCES GENETIC AND EPIGENETIC ALTERATIONS IN LONG-LIVED STEM CELLS, ALONG WITH EXPANSION OF STEM CELL NICHES, EVENTUALLY LEADING TO INVASIVE CANCER. THE GASTRIC CORPUS AND ANTRUM HAVE DISTINCT STEM CELLS AND STEM CELL NICHES, SUGGESTING DIFFERENTIAL REGULATION OF CANCER INITIATION AT THE 2 SITES. IN THIS SHORT REVIEW, WE DISCUSS RECENT EXPERIMENTAL MODELS AND HUMAN STUDIES, WHICH PROVIDE IMPORTANT INSIGHTS INTO THE PATHOGENESIS OF GASTRIC CANCER. 2017 4 736 47 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 5 733 38 CANCER EPIGENETICS: LINKING BASIC BIOLOGY TO CLINICAL MEDICINE. CANCER EVOLUTION AT ALL STAGES IS DRIVEN BY BOTH EPIGENETIC ABNORMALITIES AS WELL AS GENETIC ALTERATIONS. DYSREGULATION OF EPIGENETIC CONTROL EVENTS MAY LEAD TO ABNORMAL PATTERNS OF DNA METHYLATION AND CHROMATIN CONFIGURATIONS, BOTH OF WHICH ARE CRITICAL CONTRIBUTORS TO THE PATHOGENESIS OF CANCER. THESE EPIGENETIC ABNORMALITIES ARE SET AND MAINTAINED BY MULTIPLE PROTEIN COMPLEXES AND THE INTERPLAY BETWEEN THEIR INDIVIDUAL COMPONENTS INCLUDING DNA METHYLATION MACHINERY, HISTONE MODIFIERS, PARTICULARLY, POLYCOMB (PCG) PROTEINS, AND CHROMATIN REMODELING PROTEINS. RECENT ADVANCES IN GENOME-WIDE TECHNOLOGY HAVE REVEALED THAT THE INVOLVEMENT OF THESE DYSREGULATED EPIGENETIC COMPONENTS APPEARS TO BE EXTENSIVE. MOREOVER, THERE IS A GROWING CONNECTION BETWEEN EPIGENETIC ABNORMALITIES IN CANCER AND CONCEPTS CONCERNING STEM-LIKE CELL SUBPOPULATIONS AS A DRIVING FORCE FOR CANCER. EMERGING DATA SUGGEST THAT ASPECTS OF THE EPIGENETIC LANDSCAPE INHERENT TO NORMAL EMBRYONIC AND ADULT STEM/PROGENITOR CELLS MAY HELP FOSTER, UNDER THE STRESS OF CHRONIC INFLAMMATION OR ACCUMULATING REACTIVE OXYGEN SPECIES, EVOLUTION OF MALIGNANT SUBPOPULATIONS. FINALLY, UNDERSTANDING MOLECULAR MECHANISMS INVOLVED IN INITIATION AND MAINTENANCE OF EPIGENETIC ABNORMALITIES IN ALL TYPES OF CANCER HAS GREAT POTENTIAL FOR TRANSLATIONAL PURPOSES. THIS IS ALREADY EVIDENT FOR EPIGENETIC BIOMARKER DEVELOPMENT, AND FOR PHARMACOLOGICAL TARGETING AIMED AT REVERSING CANCER-SPECIFIC EPIGENETIC ALTERATIONS. 2011 6 2416 28 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 7 6213 29 THE INTESTINAL EPITHELIAL CELL CYCLE: UNCOVERING ITS 'CRYPTIC' NATURE. PURPOSE OF REVIEW: TO DISCUSS THE RECENT LANDMARK FINDINGS THAT HAVE INCREASED OUR UNDERSTANDING NOT ONLY OF THE ROLE OF THE EPITHELIAL CELL CYCLE IN THE HOMEOSTASIS OF THE SMALL INTESTINE, BUT ALSO ITS RELEVANCE TO INFLAMMATION AND CANCER. RECENT FINDINGS: RECENT DATA HAVE UNVEILED NOVEL INFORMATION ON PROTEIN INTERACTIONS DIRECTLY INVOLVED IN THE CELL CYCLE AS WELL AS IN THE PATHWAYS THAT TRANSDUCE EXTERNAL ENVIRONMENTAL SIGNALS TO THE CELL CYCLE. A GROWING BODY OF THE RECENT EVIDENCE CONFIRMS THE IMPORTANCE OF FOOD AS WELL AS HORMONAL REGULATION IN THE GUT ON CELL CYCLE. INFORMATION ON THE CONTRIBUTION OF THE EPITHELIAL MICROENVIRONMENT, INCLUDING THE MICROBIOTA, HAS GROWN SUBSTANTIALLY IN THE RECENT YEARS AS WELL AS ON THE GENE-ENVIRONMENT INTERACTIONS AND THE MULTIPLE EPIGENETIC MECHANISMS INVOLVED IN REGULATING CELL-CYCLE PROTEINS AND SIGNALLING. FINALLY, FURTHER STUDIES INVESTIGATING THE DYSREGULATION OF THE CELL CYCLE DURING INFLAMMATION AND PROLIFERATION HAVE INCREASED OUR UNDERSTANDING OF THE PATHOPHYSIOLOGY OF CHRONIC INFLAMMATORY DISEASES AND CANCER. SUMMARY: THIS REVIEW HIGHLIGHTS SOME OF THE MOST RECENT ADVANCES THAT FURTHER EMPHASIZE THE IMPORTANCE OF THE CELL CYCLE IN THE SMALL INTESTINE DURING HOMEOSTASIS AS WELL AS IN INFLAMMATION AND CANCER. 2015 8 6143 37 THE EVOLVING LANDSCAPE OF CANCER STEM CELLS AND WAYS TO OVERCOME CANCER HETEROGENEITY. CANCER STEM CELLS (CSCS) WITH THERAPEUTIC RESISTANCE AND PLASTICITY CAN BE FOUND IN VARIOUS TYPES OF TUMORS AND ARE RECOGNIZED AS ATTRACTIVE TARGETS FOR TREATMENTS. AS CSCS ARE DERIVED FROM TISSUE STEM OR PROGENITOR CELLS, AND/OR DEDIFFERENTIATED MATURE CELLS, THEIR SIGNAL TRANSDUCTION PATHWAYS ARE CRITICAL IN THE REGULATION OF CSCS; CHRONIC INFLAMMATION CAUSES THE ACCUMULATION OF GENETIC MUTATIONS AND ABERRANT EPIGENETIC CHANGES IN THESE CELLS, POTENTIALLY LEADING TO THE PRODUCTION OF CSCS. HOWEVER, THE NATURE OF CSCS APPEARS TO BE STRONGER THAN THE TREATMENTS OF THE PAST. TO IMPROVE THE TREATMENTS TARGETING CSCS, IT IS IMPORTANT TO INHIBIT SEVERAL MOLECULES ON THE SIGNALING CASCADES IN CSCS SIMULTANEOUSLY, AND TO OVERCOME CANCER HETEROGENEITY CAUSED BY THE PLASTICITY. TO SELECT SUITABLE TARGET MOLECULES FOR CSCS, WE HAVE TO EXPLORE THE LANDSCAPE OF CSCS FROM THE PERSPECTIVE OF CANCER STEMNESS AND SIGNALING SYSTEMS, BASED ON THE CURATED DATABASES OF CANCER-RELATED GENES. WE HAVE BEEN STUDYING THE INTEGRATION OF A BROAD RANGE OF KNOWLEDGE AND EXPERIENCES FROM CANCER BIOLOGY, AND ALSO FROM OTHER INTERDISCIPLINARY BASIC SCIENCES. IN THIS REVIEW, WE HAVE INTRODUCED THE CONCEPT OF DEVELOPING NOVEL STRATEGIES TARGETING CSCS. 2019 9 5798 34 STEM CELLS AND LUNG REGENERATION. THE ABILITY TO REPLACE DEFECTIVE CELLS IN AN AIRWAY WITH CELLS THAT CAN ENGRAFT, INTEGRATE, AND RESTORE A FUNCTIONAL EPITHELIUM COULD POTENTIALLY CURE A NUMBER OF LUNG DISEASES. PROGRESS TOWARD THE DEVELOPMENT OF STRATEGIES TO REGENERATE THE ADULT LUNG BY EITHER IN VIVO OR EX VIVO TARGETING OF ENDOGENOUS STEM CELLS OR PLURIPOTENT STEM CELL DERIVATIVES IS LIMITED BY OUR FUNDAMENTAL LACK OF UNDERSTANDING OF THE MECHANISMS CONTROLLING HUMAN LUNG DEVELOPMENT, THE PRECISE IDENTITY AND FUNCTION OF HUMAN LUNG STEM AND PROGENITOR CELL TYPES, AND THE GENETIC AND EPIGENETIC CONTROL OF HUMAN LUNG FATE. IN THIS REVIEW, WE INTEND TO DISCUSS THE KNOWN STEM/PROGENITOR CELL POPULATIONS, THEIR RELATIVE DIFFERENCES BETWEEN RODENTS AND HUMANS, THEIR ROLES IN CHRONIC LUNG DISEASE, AND THEIR THERAPEUTIC PROSPECTS. ADDITIONALLY, WE HIGHLIGHT THE RECENT BREAKTHROUGHS THAT HAVE INCREASED OUR UNDERSTANDING OF THESE CELL TYPES. THESE ADVANCEMENTS INCLUDE NOVEL LINEAGE-TRACED ANIMAL MODELS AND SINGLE-CELL RNA SEQUENCING OF HUMAN AIRWAY CELLS, WHICH HAVE PROVIDED CRITICAL INFORMATION ON THE STEM CELL SUBTYPES, TRANSITION STATES, IDENTIFYING CELL MARKERS, AND INTRICATE PATHWAYS THAT COMMIT A STEM CELL TO DIFFERENTIATE OR TO MAINTAIN PLASTICITY. AS OUR CAPACITY TO MODEL THE HUMAN LUNG EVOLVES, SO WILL OUR UNDERSTANDING OF LUNG REGENERATION AND OUR ABILITY TO TARGET ENDOGENOUS STEM CELLS AS A THERAPEUTIC APPROACH FOR LUNG DISEASE. 2020 10 4550 29 MUTATION-PROMOTING MOLECULAR NETWORKS OF UNCONTROLLED INFLAMMATION. MORE AND MORE STUDIES SHOW THAT CHRONIC INFLAMMATION CAN LEAD TO TUMOR FORMATION. THE COMPLEX INTERACTIONS OF INFLAMMATORY CELLS, STROMA AND TUMOR PARENCHYMAL CELL ARE CLOSELY RELATED TO TUMOR FORMATION. UNDER THE STATE OF CHRONIC INFLAMMATORY MICROENVIRONMENT, LONG-TERM INTERACTION OF INFLAMMATORY CELLS AND STROMAL CELLS AS WELL AS THE PARENCHYMAL CELLS MAKES SIGNALING PATHWAY IN PARENCHYMA CELLS DISORDERED. A SERIES OF GENE LEVEL EDITOR MODIFICATION, EPIGENETIC CHANGES, AND THE REGULATION OF TRANSCRIPTION AND TRANSLATION CHANGES WILL HAPPEN BASED ON SIGNALING PATHWAY DISORDER. THE CHANGES ULTIMATELY LEAD TO CELL MUTATIONS AND PHENOTYPIC TRANSFORMATION OCCURRED. RECENT FINDINGS PROVIDE AN OBJECTIVE BASIS FOR CANCER TREATMENT AND PREVENTION. HOWEVER, FURTHER DISCUSSES AT THE CORE OF THE POSSIBLE MOLECULAR IN TUMOR FORMATION PROVIDE A THEORETICAL FOUNDATION FOR FUTURE STUDY OF THE PATHOGENESIS AND MOLECULAR TARGETED THERAPY OF CANCER. THIS REVIEW SUMMARIZES THE RESEARCH IN THE FIELD OF CHRONIC INFLAMMATION AND CANCER IN RECENT YEARS, AND ANALYZE THE MOLECULES NETWORK IN THE PROCESS OF THE CARCINOGENIC INFLAMMATION COMPREHENSIVELY. BEYOND THAT, THIS REVIEW INTENDS TO DESCRIBE POSSIBLE CARCINOGENIC INFLAMMATION CORE MOLECULAR AND PROVIDES A THEORETICAL BASIS FOR FUTURE STUDY OF THE PATHOGENESIS, CHEMOPREVENTION AND MOLECULAR TARGETED THERAPY OF CANCER. 2017 11 6395 33 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 12 2894 61 GASTRIC CANCER AS A STEM-CELL DISEASE: DATA AND HYPOTHESES. THE MAIN FUNCTION OF GASTRIC STEM CELLS IS TO MAINTAIN THE INTEGRITY OF THE GASTROINTESTINAL EPITHELIUM AND REPLENISH ALL THE MATURE CELL LINEAGES. IN ORDER TO ACCOMPLISH THIS, GASTRIC STEM CELLS PROLIFERATE AND SELF-RENEW, GIVING RISE TO TRANSIENT AMPLIFYING CELLS WHICH REPLACE THE CONSTANTLY RENEWING EPITHELIUM, ESPECIALLY AFTER INJURY INDUCED BY LONG-TERM INFLAMMATION. GASTRIC CANCER (GC) REMAINS THE FOURTH MOST COMMON CANCER AND THE SECOND LEADING CAUSE OF DEATH FOR CANCER IN THE WORLD. THE MOST ACCEPTED MODEL OF GASTRIC CARCINOGENESIS PROVIDES A MULTIFACTORIAL AND MULTISTEP PATHOGENESIS, INVOLVING A NUMBER OF INITIATORS AND OTHER CONTINUATOR AGENTS. HELICOBACTER PYLORI INFECTION IS RECOGNIZED AS A NECESSARY BUT INSUFFICIENT CAUSE OF GC. RECENT ADVANCES IN GASTRIC STEM CELL BIOLOGY POINT OUT TO TWO HYPOTHESES. IN THE FIRST, IT IS POSTULATED THAT RESIDENT STEM CELLS MAY, IN A CHRONICALLY INFLAMED ENVIRONMENT, AS IN THE CASE OF HELICOBACTER PYLORI-INDUCED GASTRITIS, ACCUMULATE OVER TIME A SERIES OF GENETIC AND EPIGENETIC CHANGES THAT LEAD TO THE EMERGENCE OF GC STEM CELLS. ALTERNATIVELY, THE SETTING OF CHRONIC INFLAMMATORY STRESS MAY LEAD TO LOSS OF THE INDIGENOUS GASTRIC STEM CELLS FROM THEIR NICHES, FOLLOWED BY RECRUITMENT AND ENGRAFTMENT OF BONE MARROW DERIVED STEM CELLS (BMDCS) INTO THE GASTRIC EPITHELIUM. IN THE MOUSE MODEL, INCREASING EVIDENCE SUPPORTS THE HYPOTHESIS THAT BMDCS ARE IMPORTANT CELLULAR SOURCE OF HELICOBACTER-INDUCED GC. THIS REVIEW HIGHLIGHTS DATA AND HYPOTHESES ABOUT GC AS A MODEL OF STEM-CELL DISEASE. 2014 13 5412 31 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 14 2335 31 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 15 737 42 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 16 3697 35 INFLAMMATORY MARKERS IN CANCER: POTENTIAL RESOURCES. CANCER IS A LEADING CAUSE OF DEATH WORLDWIDE AND A MAJOR BURDEN ON DEVELOPING AND LESS DEVELOPED COUNTRIES OF THE WORLD WITH LIMITED RESOURCES FOR PREVENTION AND EFFECTIVE TREATMENT OF CANCER. ALTHOUGH CANCER IS MULTIFACTORIAL IN ORIGIN, VARIOUS EPIDEMIOLOGICAL AND EXPERIMENTAL STUDIES SUGGEST THAT CHRONIC INFLAMMATION HAS AN IMPORTANT ROLE IN ALL STAGES OF CANCER, FROM INITIATION TO PROGRESSION AND EVEN SURVIVAL OF THE PATIENT. INFLAMMATORY PRODUCTS LIKE CYTOKINES, CHEMOKINES, LEUCOCYTES, PROSTAGLANDINS, CYCLOOXYGENASE, REACTIVE OXYGEN AND NITROGEN SPECIES, METALLOPROTEINASE INDUCE GENETIC AND EPIGENETIC CHANGES IN NORMAL CELLS DAMAGING ITS DNA, INHIBITING ITS REPAIR, ALTERING TRANSCRIPTION FACTORS, PREVENTING APOPTOSIS, AND STIMULATING ANGIOGENESIS, AND THUS RESULTING IN CARCINOGENESIS. THUS, THESE INFLAMMATORY MEDIATORS HAVE A POTENTIAL ROLE TO BECOME CANCER BIOMARKERS FOR ALL STAGES OF CANCER AS MANY OF THEM CAN BE MEASURED IN A COST-EFFECTIVE MANNER. HOWEVER, LARGE SCALE PROSPECTIVE TRIALS ARE REQUIRED TO VALIDATE THESE POTENTIAL CANCER BIOMARKERS. NONETHELESS, A TRANSITION FROM POTENTIAL TO PRACTICAL UTILIZATION OF THESE MARKERS WILL BE AN EFFECTIVE TOOL FOR THE AMELIORATION OF CANCER BURDEN AND MORTALITY IN A RESOURCE LIMITED SETTING. 2020 17 551 43 AUTOIMMUNITY AS AN ETIOLOGICAL FACTOR OF CANCER: THE TRANSFORMATIVE POTENTIAL OF CHRONIC TYPE 2 INFLAMMATION. RECENT EPIDEMIOLOGICAL STUDIES HAVE FOUND AN ALARMING TREND OF INCREASED CANCER INCIDENCE IN ADULTS YOUNGER THAN 50 YEARS OF AGE AND PROJECTED A SUBSTANTIAL RISE IN CANCER INCIDENCE OVER THE NEXT 10 YEARS IN THIS AGE GROUP. THIS TREND WAS EXEMPLIFIED IN THE INCIDENCE OF NON-CARDIA GASTRIC CANCER AND ITS DISPROPORTIONATE IMPACT ON NON-HISPANIC WHITE FEMALES UNDER THE AGE OF 50. THE TREND IS CONCURRENT WITH THE INCREASING INCIDENCE OF AUTOIMMUNE DISEASES IN INDUSTRIALIZED COUNTRIES, SUGGESTING A CAUSAL LINK BETWEEN THE TWO. WHILE AUTOIMMUNITY HAS BEEN SUSPECTED TO BE A RISK FACTOR FOR SOME CANCERS, THE EXACT MECHANISMS UNDERLYING THE CONNECTION BETWEEN AUTOIMMUNITY AND CANCER REMAIN UNCLEAR AND ARE OFTEN CONTROVERSIAL. THE LINK HAS BEEN ATTRIBUTED TO SEVERAL MEDIATORS SUCH AS IMMUNE SUPPRESSION, INFECTION, DIET, ENVIRONMENT, OR, PERHAPS MOST PLAUSIBLY, CHRONIC INFLAMMATION BECAUSE OF ITS WELL-RECOGNIZED ROLE IN TUMORIGENESIS. IN THAT REGARD, AUTOIMMUNE CONDITIONS ARE COMMON CAUSES OF CHRONIC INFLAMMATION AND MAY TRIGGER REPETITIVE CYCLES OF ANTIGEN-SPECIFIC CELL DAMAGE, TISSUE REGENERATION, AND WOUND HEALING. ILLUSTRATING THE CONNECTION BETWEEN AUTOIMMUNE DISEASES AND CANCER ARE PATIENTS WHO HAVE AN INCREASED RISK OF CANCER DEVELOPMENT ASSOCIATED WITH GENETICALLY PREDISPOSED INSUFFICIENCY OF CYTOTOXIC T LYMPHOCYTE-ASSOCIATED PROTEIN 4 (CTLA4), A PROTOTYPICAL IMMUNE CHECKPOINT AGAINST AUTOIMMUNITY AND ONE OF THE MAIN TARGETS OF CANCER IMMUNE THERAPY. THE TUMORIGENIC PROCESS TRIGGERED BY CTLA4 INSUFFICIENCY HAS BEEN SHOWN IN A MOUSE MODEL TO BE DEPENDENT ON THE TYPE 2 CYTOKINES INTERLEUKIN-4 (IL4) AND INTERLEUKIN-13 (IL13). IN THIS TYPE 2 INFLAMMATORY MILIEU, CROSSTALK WITH TYPE 2 IMMUNE CELLS MAY INITIATE EPIGENETIC REPROGRAMMING OF EPITHELIAL CELLS, LEADING TO A METAPLASTIC DIFFERENTIATION AND EVENTUALLY MALIGNANT TRANSFORMATION EVEN IN THE ABSENCE OF CLASSICAL ONCOGENIC MUTATIONS. THOSE FINDINGS COMPLEMENT A LARGE BODY OF EVIDENCE FOR TYPE 1, TYPE 3, OR OTHER INFLAMMATORY MEDIATORS IN INFLAMMATORY TUMORIGENESIS. THIS REVIEW ADDRESSES THE POTENTIAL OF AUTOIMMUNITY AS A CAUSAL FACTOR FOR TUMORIGENESIS, THE UNDERLYING INFLAMMATORY MECHANISMS THAT MAY VARY DEPENDING ON HOST-ENVIRONMENT VARIATIONS, AND IMPLICATIONS TO CANCER PREVENTION AND IMMUNOTHERAPY. 2021 18 4429 31 MOLECULAR BIOLOGY AS A TOOL FOR THE TREATMENT OF CANCER. CANCER IS A GENETIC DISEASE CHARACTERIZED BY UNCONTROLLED CELL GROWTH AND METASTASIS. CANCER CAN HAVE A NUMBER OF CAUSES, SUCH THE ACTIVATION OF ONCOGENES, THE INACTIVATION OF TUMOR-SUPPRESSING GENES, MUTAGENESIS PROVOKED BY EXTERNAL FACTORS, AND EPIGENETIC MODIFICATIONS. THE DEVELOPMENT OF DIAGNOSTIC TOOLS AND TREATMENTS USING A MOLECULAR BIOLOGICAL APPROACH PERMITS THE USE OF SENSITIVE, LOW-COST, NONINVASIVE TESTS FOR CANCER PATIENTS. BIOMARKERS CAN BE USED TO PROVIDE RAPID, PERSONALIZED ONCOLOGY, IN PARTICULAR THE MOLECULAR DIAGNOSIS OF CHRONIC MYELOID LEUKEMIA, AND GASTRIC, COLON, AND BREAST CANCERS. MOLECULAR TESTS BASED ON DNA METHYLATION CAN ALSO BE USED TO DIRECT TREATMENTS OR EVALUATE THE TOXIC EFFECTS OF CHEMOTHERAPY. THE ADEQUATE DIAGNOSIS, PROGNOSIS, AND PREDICTION OF THE RESPONSE OF CANCER PATIENTS TO TREATMENT ARE ESSENTIAL TO ENSURE THE MOST EFFECTIVE THERAPY, REDUCE THE DAMAGING EFFECTS OF TREATMENT, AND DIRECT THE THERAPY TO SPECIFIC TARGETS, AND IN THIS CONTEXT, MOLECULAR BIOLOGY HAS BECOME INCREASINGLY IMPORTANT IN ONCOLOGY. IN THIS BRIEF REVIEW, WE WILL DEMONSTRATE THE FUNDAMENTAL IMPORTANCE OF MOLECULAR BIOLOGY FOR THE TREATMENT OF THREE TYPES OF CANCER-CHRONIC MYELOID LEUKEMIA, HEREDITARY DIFFUSE GASTRIC CANCER, AND ASTROCYTOMAS (SPORADIC TUMORS OF THE CENTRAL NERVOUS SYSTEM). IN EACH OF THESE THREE MODELS, DISTINCT BIOLOGICAL MECHANISMS ARE INVOLVED IN THE TRANSFORMATION OF THE CELLS, BUT IN ALL CASES, MOLECULAR BIOLOGY IS FUNDAMENTAL TO THE DEVELOPMENT OF PERSONALIZED ANALYSES FOR EACH PATIENT AND EACH TYPE OF NEOPLASIA, AND TO GUARANTEE THE SUCCESS OF THE TREATMENT. 2018 19 45 32 A COMPREHENSIVE REVIEW ON RNA INTERFERENCE-MEDIATED TARGETING OF INTERLEUKINS AND ITS POTENTIAL THERAPEUTIC IMPLICATIONS IN COLON CANCER. COLON CANCER IS THE WORLD'S FOURTH LEADING CAUSE OF DEATH. IT IS CANCER OF THE LATTER PART OF THE LARGE INTESTINE, I.E. THE COLON. CHRONIC INFLAMMATION OVER A LONG PERIOD ALSO LEADS TO THE DEVELOPMENT OF CANCER. CANCER IN THE COLON REGION IS ARDUOUS TO DIAGNOSE AND IS DETECTED AT A LATER STAGE WHEN IT METASTASIZES TO OTHER PARTS OF THE BODY LIKE THE LIVER, LUNGS, PERITONEUM, ETC. COLON CANCER IS A GREAT EXAMPLE OF SOLID TUMOURS ASSOCIATED WITH CHRONIC INFLAMMATION. ALTHOUGH CONVENTIONAL THERAPIES ARE EFFECTIVE, THEY LOSE THEIR EFFECTIVENESS BEYOND A CERTAIN POINT. RELAPSE OF THE DISEASE OCCURS FREQUENTLY. RNA INTERFERENCE (RNAI) IS EMERGING AS A GREAT TOOL TO SPECIFICALLY ATTACK THE CANCER CELLS OF A TARGET SITE LIKE THE COLON. RNAI DEALS WITH EPIGENETIC CHANGES MADE IN THE DEFECTIVE CELLS WHICH ULTIMATELY LEADS TO THEIR DEATH WITHOUT HARMING THE HEALTHY CELLS. IN THIS REVIEW, TWO TYPES OF EPIGENETIC MODULATORS HAVE BEEN CONSIDERED, NAMELY SIRNA AND MIRNA, AND THEIR EFFECT ON INTERLEUKINS. INTERLEUKINS, A CLASS OF CYTOKINES, ARE MAJOR INFLAMMATORY RESPONSES OF THE BODY THAT ARE RELEASED BY IMMUNE CELLS LIKE LEUKOCYTES AND MACROPHAGES. SOME OF THESE INTERLEUKINS ARE PRO-INFLAMMATORY, THEREBY PROMOTING INFLAMMATION WHICH EVENTUALLY CAUSES CANCER. RNAI CAN PREVENT COLON CANCER BY INHIBITING PRO-INFLAMMATORY INTERLEUKINS. 2023 20 2658 33 EPITHELIAL METAPLASIA: ADULT STEM CELL REPROGRAMMING AND (PRE)NEOPLASTIC TRANSFORMATION MEDIATED BY INFLAMMATION? THROUGHOUT ADULT LIFE, NEW DEVELOPMENTAL COMMITMENT OF ADULT STEM CELLS CAUSES METAPLASTIC CONVERSIONS TO OCCUR FREQUENTLY IN SOME ORGANS. THESE REVERSIBLE EPITHELIAL REPLACEMENTS ARE ALMOST ALWAYS OBSERVED IN ASSOCIATION WITH CHRONIC INFLAMMATION AND PERSISTENT IRRITATION. ALTHOUGH METAPLASIA IS NOT SYNONYMOUS WITH DYSPLASIA, CLINICAL SURVEILLANCE HAS DEMONSTRATED THAT THESE ADAPTIVE PROCESSES HAVE AN INCREASED SUSCEPTIBILITY TO EVOLVE INTO CANCER. WE PROPOSE THAT CYTOKINES AND OTHER SOLUBLE FACTORS RELEASED BY BOTH EPITHELIAL AND INFLAMMATORY CELLS MIGHT ALTER THE TRANSCRIPTION-FACTOR EXPRESSION PROFILE OF STEM CELLS AND LEAD TO THE DEVELOPMENT OF METAPLASIA. FURTHERMORE, INFLAMMATORY MEDIATORS MIGHT ALSO PROMOTE THE MALIGNANT TRANSFORMATION OF EPITHELIAL METAPLASIA BY INDUCING GENETIC AND EPIGENETIC CHANGES AND BY PREVENTING THE IMMUNE SYSTEM FROM MOUNTING AN EFFICIENT ANTI-TUMOUR IMMUNE RESPONSE. A BETTER UNDERSTANDING OF THE MOLECULAR MECHANISMS LEADING TO METAPLASIA MIGHT HELP IN THE DESIGN OF NEW THERAPIES FOR NEOPLASTIC AND DEGENERATIVE DISEASES. 2009