1 4666 114 NEW INSIGHTS AND OPTIONS INTO THE MECHANISMS AND EFFECTS OF COMBINED TARGETED THERAPY AND IMMUNOTHERAPY IN PROSTATE CANCER. CHRONIC INFLAMMATION IS BELIEVED TO DRIVE PROSTATE CARCINOGENESIS BY PRODUCING REACTIVE OXYGEN SPECIES OR REACTIVE NITROGEN SPECIES TO INDUCE DNA DAMAGE. THIS EFFECT MIGHT SUBSEQUENTLY CAUSE EPIGENETIC AND GENOMIC ALTERATIONS, LEADING TO MALIGNANT TRANSFORMATION. ALTHOUGH ESTABLISHED THERAPEUTIC ADVANCES HAVE EXTENDED OVERALL SURVIVAL, TUMORS IN PATIENTS WITH ADVANCED PROSTATE CANCER ARE PRONE TO METASTASIS, TRANSFORMATION INTO METASTATIC CASTRATION-RESISTANT PROSTATE CANCER, AND THERAPEUTIC RESISTANCE. THE TUMOR MICROENVIRONMENT (TME) OF PROSTATE CANCER IS INVOLVED IN CARCINOGENESIS, INVASION AND DRUG RESISTANCE. A PLETHORA OF PRECLINICAL STUDIES HAVE FOCUSED ON IMMUNE-BASED THERAPIES. UNDERSTANDING THE INTRICATE TME SYSTEM IN PROSTATE CANCER MAY HOLD MUCH PROMISE FOR DEVELOPING NOVEL THERAPIES, DESIGNING COMBINATIONAL THERAPEUTIC STRATEGIES, AND FURTHER OVERCOMING RESISTANCE TO ESTABLISHED TREATMENTS TO IMPROVE THE LIVES OF PROSTATE CANCER PATIENTS. IN THIS REVIEW, WE DISCUSS NONIMMUNE COMPONENTS AND VARIOUS IMMUNE CELLS WITHIN THE TME AND THEIR PUTATIVE ROLES DURING PROSTATE CANCER INITIATION, PROGRESSION, AND METASTASIS. WE ALSO OUTLINE THE UPDATED FUNDAMENTAL RESEARCH FOCUSING ON THERAPEUTIC ADVANCES OF TARGETED THERAPY AS WELL AS COMBINATIONAL OPTIONS FOR PROSTATE CANCER. 2023 2 944 31 CHRONIC LYMPHOCYTIC LEUKEMIA: FROM MOLECULAR PATHOGENESIS TO NOVEL THERAPEUTIC STRATEGIES. CHRONIC LYMPHOCYTIC LEUKEMIA IS A WELL-DEFINED LYMPHOID NEOPLASM WITH VERY HETEROGENEOUS BIOLOGICAL AND CLINICAL BEHAVIOR. THE LAST DECADE HAS BEEN REMARKABLY FRUITFUL IN NOVEL FINDINGS ELUCIDATING MULTIPLE ASPECTS OF THE PATHOGENESIS OF THE DISEASE INCLUDING MECHANISMS OF GENETIC SUSCEPTIBILITY, INSIGHTS INTO THE RELEVANCE OF IMMUNOGENETIC FACTORS DRIVING THE DISEASE, PROFILING OF GENOMIC ALTERATIONS, EPIGENETIC SUBTYPES, GLOBAL EPIGENOMIC TUMOR CELL REPROGRAMMING, MODULATION OF TUMOR CELL AND MICROENVIRONMENT INTERACTIONS, AND DYNAMICS OF CLONAL EVOLUTION FROM EARLY STEPS IN MONOCLONAL B CELL LYMPHOCYTOSIS TO PROGRESSION AND TRANSFORMATION INTO DIFFUSE LARGE B-CELL LYMPHOMA. ALL THIS KNOWLEDGE HAS OFFERED NEW PERSPECTIVES THAT ARE BEING EXPLOITED THERAPEUTICALLY WITH NOVEL TARGET AGENTS AND MANAGEMENT STRATEGIES. IN THIS REVIEW WE PROVIDE AN OVERVIEW OF THESE NOVEL ADVANCES AND HIGHLIGHT QUESTIONS AND PERSPECTIVES THAT NEED FURTHER PROGRESS TO TRANSLATE INTO THE CLINICS THE BIOLOGICAL KNOWLEDGE AND IMPROVE THE OUTCOME OF THE PATIENTS. 2020 3 737 37 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 4 6143 36 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 5 5798 33 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 6 6675 30 USING EPIGENETIC THERAPY TO OVERCOME CHEMOTHERAPY RESISTANCE. IT HAS BEEN KNOWN FOR DECADES THAT AS CANCER PROGRESSES, TUMORS DEVELOP GENETIC ALTERATIONS, MAKING THEM HIGHLY PRONE TO DEVELOPING RESISTANCE TO THERAPIES. CLASSICALLY, IT HAS BEEN THOUGHT THAT THESE ACQUIRED GENETIC CHANGES ARE FIXED. THIS HAS LED TO THE PARADIGM OF MOVING FROM ONE CANCER THERAPY TO THE NEXT WHILE AVOIDING PAST THERAPIES. HOWEVER, EMERGING DATA ON EPIGENETIC CHANGES DURING TUMOR PROGRESSION AND USE OF EPIGENETIC THERAPIES HAVE SHOWN THAT EPIGENETIC MODIFICATIONS LEADING TO CHEMOTHERAPY RESISTANCE HAVE THE POTENTIAL TO BE REVERSIBLE WITH EPIGENETIC THERAPY. IN FACT, PROMISING CLINICAL DATA EXIST THAT TREATMENT WITH EPIGENETIC AGENTS CAN DIMINISH CHEMOTHERAPY RESISTANCE IN A NUMBER OF TUMOR TYPES INCLUDING CHRONIC MYELOGENOUS LEUKEMIA, COLORECTAL, OVARIAN, LUNG AND BREAST CANCER. THE POTENTIAL FOR EPIGENETIC-MODIFYING DRUGS TO ALLOW FOR TREATMENT OF RESISTANT DISEASE IS EXCITING AND CLINICAL TRIALS HAVE JUST BEGUN TO EVALUATE THIS AREA. 2016 7 4429 35 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 8 2992 33 GENETIC LANDSCAPE AND DEREGULATED PATHWAYS IN B-CELL LYMPHOID MALIGNANCIES. WITH THE INTRODUCTION OF NEXT-GENERATION SEQUENCING, THE GENETIC LANDSCAPE OF THE COMPLEX GROUP OF B-CELL LYMPHOID MALIGNANCIES HAS RAPIDLY BEEN UNRAVELLED IN RECENT YEARS. THIS HAS PROVIDED IMPORTANT INFORMATION ABOUT RECURRENT GENETIC EVENTS AND IDENTIFIED KEY PATHWAYS DEREGULATED IN EACH LYMPHOMA SUBTYPE. IN PARALLEL, THERE HAS BEEN INTENSE SEARCH AND DEVELOPMENT OF NOVEL TYPES OF TARGETED THERAPY THAT 'HIT' CENTRAL MECHANISMS IN LYMPHOMA PATHOBIOLOGY, SUCH AS BTK, PI3K OR BCL2 INHIBITORS. IN THIS REVIEW, WE WILL OUTLINE THE CURRENT VIEW OF THE GENETIC LANDSCAPE OF SELECTED ENTITIES: FOLLICULAR LYMPHOMA, DIFFUSE LARGE B-CELL LYMPHOMA, MANTLE CELL LYMPHOMA, CHRONIC LYMPHOCYTIC LEUKAEMIA AND MARGINAL ZONE LYMPHOMA. WE WILL DETAIL RECURRENT ALTERATIONS AFFECTING IMPORTANT SIGNALLING PATHWAYS, THAT IS THE B-CELL RECEPTOR/NF-KAPPAB PATHWAY, NOTCH SIGNALLING, JAK-STAT SIGNALLING, P53/DNA DAMAGE RESPONSE, APOPTOSIS AND CELL CYCLE REGULATION, AS WELL AS OTHER PERHAPS UNEXPECTED CELLULAR PROCESSES, SUCH AS IMMUNE REGULATION, CELL MIGRATION, EPIGENETIC REGULATION AND RNA PROCESSING. WHILST MANY OF THESE PATHWAYS/PROCESSES ARE COMMONLY ALTERED IN DIFFERENT LYMPHOID TUMORS, ALBEIT AT VARYING FREQUENCIES, OTHERS ARE PREFERENTIALLY TARGETED IN SELECTED B-CELL MALIGNANCIES. SOME OF THESE GENETIC LESIONS ARE EITHER INVOLVED IN DISEASE ONTOGENY OR LINKED TO THE EVOLUTION OF EACH DISEASE AND/OR SPECIFIC CLINICOBIOLOGICAL FEATURES, AND SOME OF THEM HAVE BEEN DEMONSTRATED TO HAVE PROGNOSTIC AND EVEN PREDICTIVE IMPACT. FUTURE WORK IS ESPECIALLY NEEDED TO UNDERSTAND THE THERAPY-RESISTANT DISEASE, PARTICULARLY IN PATIENTS TREATED WITH TARGETED THERAPY, AND TO IDENTIFY NOVEL TARGETS AND THERAPEUTIC STRATEGIES IN ORDER TO REALIZE TRUE PRECISION MEDICINE IN THIS CLINICALLY HETEROGENEOUS PATIENT GROUP. 2017 9 6588 35 TUMOR HETEROGENEITY IN LYMPHOMAS: A DIFFERENT BREED. THE FACTS THAT CANCER REPRESENTS TISSUES CONSISTING OF HETEROGENEOUS NEOPLASTIC, AS WELL AS REACTIVE, CELL POPULATIONS AND THAT CANCERS OF THE SAME HISTOTYPE MAY SHOW PROFOUND DIFFERENCES IN CLINICAL BEHAVIOR HAVE LONG BEEN RECOGNIZED. WITH THE ADVENT OF NEW TECHNOLOGIES AND THE DEMANDS OF PRECISION MEDICINE, THE INVESTIGATION OF TUMOR HETEROGENEITY HAS GAINED MUCH INTEREST. AN UNDERSTANDING OF INTERTUMORAL HETEROGENEITY IN PATIENTS WITH THE SAME DISEASE ENTITY IS NECESSARY TO OPTIMALLY GUIDE PERSONALIZED TREATMENT. IN ADDITION, INCREASING EVIDENCE INDICATES THAT DIFFERENT TUMOR AREAS OR PRIMARY TUMORS AND METASTASES IN AN INDIVIDUAL PATIENT CAN SHOW SIGNIFICANT INTRATUMORAL HETEROGENEITY ON DIFFERENT LEVELS. THIS PHENOMENON CAN BE DRIVEN BY GENOMIC INSTABILITY, EPIGENETIC EVENTS, THE TUMOR MICROENVIRONMENT, AND STOCHASTIC VARIATIONS IN CELLULAR FUNCTION AND ANTITUMORAL THERAPIES. THESE MECHANISMS MAY LEAD TO BRANCHED SUBCLONAL EVOLUTION FROM A COMMON PROGENITOR CLONE, RESULTING IN SPATIAL VARIATION BETWEEN DIFFERENT TUMOR SITES, DISEASE PROGRESSION, AND TREATMENT RESISTANCE. THIS REVIEW ADDRESSES TUMOR HETEROGENEITY IN LYMPHOMAS FROM A PATHOLOGIST'S VIEWPOINT. THE RELATIONSHIP BETWEEN MORPHOLOGIC, IMMUNOPHENOTYPIC, AND GENETIC HETEROGENEITY IS EXEMPLIFIED IN DIFFERENT LYMPHOMA ENTITIES AND REVIEWED IN THE CONTEXT OF HIGH-GRADE TRANSFORMATION AND TRANSDIFFERENTIATION. IN ADDITION, FACTORS DRIVING HETEROGENEITY, AS WELL AS CLINICAL AND THERAPEUTIC IMPLICATIONS OF LYMPHOMA HETEROGENEITY, WILL BE DISCUSSED. 2018 10 2897 26 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 11 736 33 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 12 3110 34 GENOTYPE- OR PHENOTYPE-TARGETING ANTICANCER THERAPIES? LESSONS FROM TUMOR EVOLUTIONARY BIOLOGY. DESPITE THE EFFICACY OF MOST CANCER THERAPIES, DRUG RESISTANCE REMAINS A MAJOR PROBLEM IN THE CLINIC. THE ERADICATION OF THE ENTIRE TUMOR AND THE CURE OF THE PATIENT BY CHEMOTHERAPY ALONE ARE RARE, IN PARTICULAR FOR ADVANCED DISEASE. FROM AN EVOLUTIONARY PERSPECTIVE, THE SELECTIVE PRESSURE EXERTED BY CHEMOTHERAPY LEADS TO THE EMERGENCE OF RESISTANT CLONES WHERE RESISTANCE CAN BE ASSOCIATED WITH MANY DIFFERENT FUNCTIONAL MECHANISMS AT THE SINGLE CELL LEVEL OR CAN INVOLVE CHANGES IN THE TUMOR MICRO-ENVIRONMENT. IN THE LAST DECADE, TUMOR GENOMICS HAS CONTRIBUTED TO THE IMPROVEMENT OF OUR UNDERSTANDING OF TUMORIGENESIS AND HAS LED TO THE IDENTIFICATION OF NUMEROUS CELLULAR TARGETS FOR THE DEVELOPMENT OF NOVEL THERAPIES. HOWEVER, SINCE TUMORS ARE BY NATURE EXTREMELY HETEROGENEOUS, THE DRUG EFFICACY AND ECONOMICAL SUSTAINABILITY OF THIS APPROACH IS NOW DEBATABLE. IMPORTANTLY, TUMOR CELL HETEROGENEITY DEPENDS NOT ONLY ON GENETIC MODIFICATIONS BUT ALSO ON NON-GENETIC PROCESSES INVOLVING EITHER STOCHASTIC EVENTS OR EPIGENETIC MODIFICATIONS MAKING GENETIC BIOMARKERS OF UNCERTAIN UTILITY. IN THIS REVIEW, WE WISH TO HIGHLIGHT HOW EVOLUTIONARY BIOLOGY CAN IMPACT OUR UNDERSTANDING OF CARCINOGENESIS AND RESISTANCE TO THERAPIES. WE WILL DISCUSS NEW APPROACHES BASED ON APPLIED ECOLOGY AND EVOLUTION DYNAMICS THAT CAN BE USED TO CONVERT THE CANCER INTO A CHRONIC DISEASE WHERE THE DRUGS WOULD CONTROL TUMOR GROWTH. FINALLY, WE WILL DISCUSS THE WAY METABOLIC DYSFUNCTION OR PHENOTYPIC CHANGES CAN HELP DEVELOPING NEW DELIVERY SYSTEMS OR PHENOTYPETARGETED DRUGS AND HOW EXPLORING NEW SOURCES OF ACTIVE COMPOUNDS CAN CONDUCT TO THE DEVELOPMENT OF DRUGS WITH ORIGINAL MECHANISMS OF ACTION. 2016 13 4733 31 NOVEL BIOMARKERS FOR THE IDENTIFICATION AND TARGETED THERAPY OF GASTRIC CANCER. GASTRIC CANCER DEVELOPMENT FOLLOWS THE PATHOLOGIC PATTERN SUCH THAT CHRONIC INFLAMMATION IN THE GASTRIC MUCOSA PROGRESSIVELY TRANSFORMS NORMAL MUCOSA INTO ATROPHY, INTESTINAL METAPLASIA, ADENOMA/DYSPLASIA AND EVENTUALLY INVASIVE AND METASTATIC TUMORS. THE ACCUMULATION OF MULTIPLE GENETIC AND EPIGENETIC ALTERATIONS LEADS TO THE DYSREGULATION OF ONCOGENES AND TUMOR SUPPRESSORS, WHICH WAS CONSIDERED AS THE DRIVER BEHIND EVENTS DURING THE TUMORIGENESIS. ALMOST ALL GASTRIC CANCERS ARE ADENOCARCINOMAS, WHICH SHARE CONSIDERABLE HETEROGENEITY WITH DISTINCT MORPHOLOGY, PATHOGENESIS AND CLINICAL BEHAVIOR. THEREFORE, IDENTIFYING SUBTYPES OF GASTRIC CANCERS WITH MOLECULAR AND GENETIC FEATURES WILL BE BENEFICIAL FOR THE EARLY IDENTIFICATION AND SELECTION OF NEW EFFECTIVE AGENTS FOR TARGETED TREATMENT. HIGH-THROUGHPUT SEQUENCING TECHNIQUES SUCH AS WHOLE GENOMIC, EPIGENOME AND TRANSCRIPTOME SEQUENCING AND PROTEOMICS PLATFORMS HAVE IDENTIFIED MAJOR GENOMIC CHARACTERISTICS THAT EXHIBIT IDENTIFICATION AND PROGNOSTIC IMPACTS AND DISTINCT RESPONSE PATTERNS. IN THIS ARTICLE, THE AUTHORS AIM TO SUMMARIZE THE INFORMATION REGARDING THE MOST PROMISING MOLECULES THAT MAY HAVE CLINICAL APPLICATION AS NON-INVASIVE BIOMARKERS AND THERAPY TARGETS. 2015 14 3811 35 INTRATUMORAL HETEROGENEITY: CLONAL COOPERATION IN EPITHELIAL-TO-MESENCHYMAL TRANSITION AND METASTASIS. ALTHOUGH PHENOTYPIC INTRATUMORAL HETEROGENEITY WAS FIRST DESCRIBED MANY DECADES AGO, THE ADVENT OF NEXT-GENERATION SEQUENCING HAS PROVIDED CONCLUSIVE EVIDENCE THAT IN ADDITION TO PHENOTYPIC DIVERSITY, SIGNIFICANT GENOTYPIC DIVERSITY EXISTS WITHIN TUMORS. TUMOR HETEROGENEITY LIKELY ARISES BOTH FROM CLONAL EXPANSIONS, AS WELL AS FROM DIFFERENTIATION HIERARCHIES EXISTENT IN THE TUMOR, SUCH AS THAT ESTABLISHED BY CANCER STEM CELLS (CSCS) AND NON-CSCS. THESE DIFFERENTIATION HIERARCHIES MAY ARISE DUE TO GENETIC MUTATIONS, EPIGENETIC ALTERATIONS, OR MICROENVIRONMENTAL INFLUENCES. AN ADDITIONAL DIFFERENTIATION HIERARCHY WITHIN EPITHELIAL TUMORS MAY ARISE WHEN ONLY A FEW TUMOR CELLS TRANS-DIFFERENTIATE INTO MESENCHYMAL-LIKE CELLS, A PROCESS KNOWN AS EPITHELIAL-TO-MESENCHYMAL TRANSITION (EMT). AGAIN, THIS PROCESS CAN BE INFLUENCED BY BOTH GENETIC AND NON-GENETIC FACTORS. IN THIS REVIEW WE DISCUSS THE EVIDENCE FOR CLONAL INTERACTION AND COOPERATION FOR TUMOR MAINTENANCE AND PROGRESSION, PARTICULARLY WITH RESPECT TO EMT, AND FURTHER ADDRESS THE FAR-REACHING EFFECTS THAT TUMOR HETEROGENEITY MAY HAVE ON CANCER THERAPY. 2015 15 733 35 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 16 1678 39 DRUG REPURPOSING AT THE INTERFACE OF MELANOMA IMMUNOTHERAPY AND AUTOIMMUNE DISEASE. CANCER CELLS HAVE A REMARKABLE ABILITY TO EVADE RECOGNITION AND DESTRUCTION BY THE IMMUNE SYSTEM. AT THE SAME TIME, CANCER HAS BEEN ASSOCIATED WITH CHRONIC INFLAMMATION, WHILE CERTAIN AUTOIMMUNE DISEASES PREDISPOSE TO THE DEVELOPMENT OF NEOPLASIA. ALTHOUGH CANCER IMMUNOTHERAPY HAS REVOLUTIONIZED ANTITUMOR TREATMENT, IMMUNE-RELATED TOXICITIES AND ADVERSE EVENTS DETRACT FROM THE CLINICAL UTILITY OF EVEN THE MOST ADVANCED DRUGS, ESPECIALLY IN PATIENTS WITH BOTH, METASTATIC CANCER AND PRE-EXISTING AUTOIMMUNE DISEASES. HERE, THE COMBINATION OF MULTI-OMICS, DATA-DRIVEN COMPUTATIONAL APPROACHES WITH THE APPLICATION OF NETWORK CONCEPTS ENABLES IN-DEPTH ANALYSES OF THE DYNAMIC LINKS BETWEEN CANCER, AUTOIMMUNE DISEASES, AND DRUGS. IN THIS REVIEW, WE FOCUS ON MOLECULAR AND EPIGENETIC METASTASIS-RELATED PROCESSES WITHIN CANCER CELLS AND THE IMMUNE MICROENVIRONMENT. WITH MELANOMA AS A MODEL, WE UNCOVER VULNERABILITIES FOR DRUG DEVELOPMENT TO CONTROL CANCER PROGRESSION AND IMMUNE RESPONSES. THEREBY, DRUG REPURPOSING ALLOWS TAKING ADVANTAGE OF EXISTING SAFETY PROFILES AND ESTABLISHED PHARMACOKINETIC PROPERTIES OF APPROVED AGENTS. THESE PROCEDURES PROMISE FASTER ACCESS AND OPTIMAL MANAGEMENT FOR CANCER TREATMENT. TOGETHER, THESE APPROACHES PROVIDE NEW DISEASE-BASED AND DATA-DRIVEN OPPORTUNITIES FOR THE PREDICTION AND APPLICATION OF TARGETED AND CLINICALLY USED DRUGS AT THE INTERFACE OF IMMUNE-MEDIATED DISEASES AND CANCER TOWARDS NEXT-GENERATION IMMUNOTHERAPIES. 2022 17 3964 33 LONG NONCODING RNAS IN LUNG CANCER. DESPITE GREAT PROGRESS IN RESEARCH AND TREATMENT OPTIONS, LUNG CANCER REMAINS THE LEADING CAUSE OF CANCER-RELATED DEATHS WORLDWIDE. ONCOGENIC DRIVER MUTATIONS IN PROTEIN-ENCODING GENES WERE DEFINED AND ALLOW FOR PERSONALIZED THERAPIES BASED ON GENETIC DIAGNOSES. NONETHELESS, DIAGNOSIS OF LUNG CANCER MOSTLY OCCURS AT LATE STAGES, AND CHRONIC TREATMENT IS FOLLOWED BY A FAST ONSET OF CHEMORESISTANCE. HENCE, THERE IS AN URGENT NEED FOR RELIABLE BIOMARKERS AND ALTERNATIVE TREATMENT OPTIONS. WITH THE ERA OF WHOLE GENOME AND TRANSCRIPTOME SEQUENCING TECHNOLOGIES, LONG NONCODING RNAS EMERGED AS A NOVEL CLASS OF VERSATILE, FUNCTIONAL RNA MOLECULES. ALTHOUGH FOR MOST OF THEM THE MECHANISM OF ACTION REMAINS TO BE DEFINED, ACCUMULATING EVIDENCE CONFIRMS THEIR INVOLVEMENT IN VARIOUS ASPECTS OF LUNG TUMORIGENESIS. THEY ARE FUNCTIONAL ON THE EPIGENETIC, TRANSCRIPTIONAL, AND POSTTRANSCRIPTIONAL LEVEL AND ARE REGULATORS OF PATHOPHYSIOLOGICAL KEY PATHWAYS INCLUDING CELL GROWTH, APOPTOSIS, AND METASTASIS. LONG NONCODING RNAS ARE GAINING INCREASING ATTENTION AS POTENTIAL BIOMARKERS AND A NOVEL CLASS OF DRUGGABLE MOLECULES. IT HAS BECOME CLEAR THAT WE ARE ONLY BEGINNING TO UNDERSTAND THE COMPLEXITY OF TUMORIGENIC PROCESSES. THE CLINICAL INTEGRATION OF LONG NONCODING RNAS IN TERMS OF PROGNOSTIC AND PREDICTIVE BIOMARKER SIGNATURES AND ADDITIONAL CANCER TARGETS COULD PROVIDE A CHANCE TO INCREASE THE THERAPEUTIC BENEFIT. HERE, WE REVIEW THE CURRENT KNOWLEDGE ABOUT THE EXPRESSION, REGULATION, BIOLOGICAL FUNCTION, AND CLINICAL RELEVANCE OF LONG NONCODING RNAS IN LUNG CANCER. 2016 18 5702 25 SINGLE-CELL GENOMICS FOR INVESTIGATING PATHOGENESIS OF INFLAMMATORY DISEASES. RECENT TECHNICAL ADVANCES HAVE ENABLED UNBIASED TRANSCRIPTOMIC AND EPIGENETIC ANALYSIS OF EACH CELL, KNOWN AS "SINGLE-CELL ANALYSIS". SINGLE-CELL ANALYSIS HAS A VARIETY OF TECHNICAL APPROACHES TO INVESTIGATE THE STATE OF EACH CELL, INCLUDING MRNA LEVELS (TRANSCRIPTOME), THE IMMUNE REPERTOIRE (IMMUNE REPERTOIRE ANALYSIS), CELL SURFACE PROTEINS (SURFACE PROTEOME ANALYSIS), CHROMATIN ACCESSIBILITY (EPIGENOME), AND ACCORDANCE WITH GENOME VARIANTS (EQTLS; EXPRESSION QUANTITATIVE TRAIT LOCI). AS AN EFFECTIVE TOOL FOR INVESTIGATING ROBUST IMMUNE RESPONSES IN CORONAVIRUS DISEASE 2019 (COVID-19), MANY RESEARCHERS PERFORMED SINGLE-CELL ANALYSIS TO CAPTURE THE DIVERSE, UNBIASED IMMUNE CELL ACTIVATION AND DIFFERENTIATION. DESPITE CHALLENGES ELUCIDATING THE COMPLICATED IMMUNE MICROENVIRONMENTS OF CHRONIC INFLAMMATORY DISEASES USING EXISTING EXPERIMENTAL METHODS, IT IS NOW POSSIBLE TO CAPTURE THE SIMULTANEOUS IMMUNE FEATURES OF DIFFERENT CELL TYPES ACROSS INFLAMED TISSUES USING VARIOUS SINGLE-CELL TOOLS. IN THIS REVIEW, WE INTRODUCE PATIENT-BASED AND EXPERIMENTAL MOUSE MODEL RESEARCH UTILIZING SINGLE-CELL ANALYSES IN THE FIELD OF CHRONIC INFLAMMATORY DISEASES, AS WELL AS MULTI-ORGAN ATLAS TARGETING IMMUNE CELLS. 2023 19 3694 44 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 20 6466 29 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