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 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 4 4666 44 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 5 2225 53 EPIGENETIC MODIFICATIONS IN TUMOR-ASSOCIATED MACROPHAGES: A NEW PERSPECTIVE FOR AN OLD FOE. TUMORIGENESIS IS FREQUENTLY ACCOMPANIED BY CHRONIC INFLAMMATION, AND THE TUMOR MICROENVIRONMENT (TME) CAN BE CONSIDERED AN ECOSYSTEM THAT CONSISTS OF TUMOR CELLS, ENDOTHELIOCYTES, FIBROBLASTS, IMMUNE CELLS AND ACELLULAR COMPONENTS SUCH AS EXTRACELLULAR MATRIX. FOR TUMOR CELLS, THEIR SURVIVAL ADVANTAGES ARE DEPENDENT ON BOTH GENETIC AND EPIGENETIC ALTERATIONS, WHILE OTHER CELLS MAINLY PRESENT EPIGENETIC MODIFICATIONS. MACROPHAGES ARE THE MOST PLASTIC TYPE OF IMMUNE CELLS AND UNDERGO DIVERSE EPIGENETIC ALTERATIONS IN THE TME. SOME OF THESE EPIGENETIC MODIFICATIONS MITIGATE AGAINST CANCER PROGRESSION, AND OTHERS ACCELERATE THIS PROCESS. DUE TO THE COMPLEX ROLES OF MACROPHAGES IN THE TME, IT IS URGENT TO UNDERSTAND THEIR EPIGENETIC MODIFICATIONS ASSOCIATED WITH THE TME. HERE, WE MAINLY SUMMARIZE RECENT FINDINGS ON TME-ASSOCIATED EPIGENETIC ALTERATIONS OF TUMOR-ASSOCIATED MACROPHAGES (TAMS), INCLUDING DNA METHYLATION, POSTTRANSLATIONAL MODIFICATIONS OF HISTONE PROTEINS, CHROMATIN REMODELING, AND NONCODING RNA-MEDIATED EPIGENETIC REGULATION. AT THE END OF THIS REVIEW, WE ALSO DISCUSS THE TRANSLATIONAL POTENTIAL OF THESE EPIGENETIC MODIFICATIONS FOR DEVELOPING NOVEL CANCER THERAPIES TARGETING TAMS. 2022 6 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 7 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 8 3674 38 INFLAMMATION AND DYSREGULATED FIBROBLAST PROLIFERATION--NEW MECHANISMS? IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A DEVASTATING, AGE-RELATED LUNG DISEASE OF UNKNOWN CAUSE THAT HAS FEW TREATMENT OPTIONS. ONCE THOUGHT TO BE A CHRONIC INFLAMMATORY PROCESS, CURRENT EVIDENCE INDICATES THAT THE FIBROTIC RESPONSE MAY PRIMARILY BE DRIVEN BY ABNORMALLY ACTIVATED ALVEOLAR EPITHELIAL CELLS AND THE UNDERLYING MESENCHYME. THE MEDIATORS PRODUCED AND PRESENT IN THIS MICROENVIRONMENT INDUCE THE FORMATION OF FIBROBLAST FOCI THROUGH THE PROLIFERATION OF RESIDENT MESENCHYMAL CELLS, ATTRACTION OF CIRCULATING FIBROCYTES, AND STIMULATION OF EPITHELIAL TO MESENCHYMAL TRANSITION. THE FIBROBLAST AND MYOFIBROBLAST FOCI SECRETE EXCESSIVE AMOUNTS OF EXTRACELLULAR MATRIX, MAINLY COLLAGENS, RESULTING IN SCARRING AND DESTRUCTION OF THE LUNG ARCHITECTURE. THE DETAILED MECHANISMS THAT LINK IPF WITH AGEING AND ABERRANT EPITHELIAL ACTIVATION ARE UNKNOWN, BUT SOME EVIDENCE SUGGESTS THAT THE ABNORMAL RECAPITULATION OF DEVELOPMENTAL PATHWAYS AND EPIGENETIC CHANGES MAY PLAY A ROLE. THIS REVIEW PROVIDES A BRIEF SYNOPSIS OF HIGHLIGHTS IN THE CURRENT UNDERSTANDING OF THE PATHOPHYSIOLOGY OF IPF, AS WELL AS NOVEL THERAPEUTICS BEING EXPLORED IN CLINICAL TRIALS FOR THE TREATMENT OF THIS DEVASTATING DISEASE. 2013 9 111 59 A ROLE FOR G-PROTEIN COUPLED ESTROGEN RECEPTOR (GPER) IN ESTROGEN-INDUCED CARCINOGENESIS: DYSREGULATED GLANDULAR HOMEOSTASIS, SURVIVAL AND METASTASIS. MECHANISMS OF CARCINOGENESIS BY ESTROGEN CENTER ON ITS MITOGENIC AND GENOTOXIC POTENTIAL ON TUMOR TARGET CELLS. THESE MODELS SUGGEST THAT ESTROGEN RECEPTOR (ER) SIGNALING PROMOTES EXPANSION OF THE TRANSFORMED POPULATION AND THAT SUBSEQUENT ACCUMULATION OF SOMATIC MUTATIONS THAT DRIVE CANCER PROGRESSION OCCUR VIA METABOLIC ACTIVATION OF CATHECOL ESTROGENS OR BY EPIGENETIC MECHANISMS. RECENT FINDINGS THAT GPER IS LINKED TO OBESITY, VASCULAR PATHOLOGY AND IMMUNOSUPPRESSION, KEY EVENTS IN THE DEVELOPMENT OF METABOLIC SYNDROME AND INTRA-TISSULAR ESTROGEN SYNTHESIS, PROVIDES AN ALTERNATE VIEW OF ESTROGEN-INDUCED CARCINOGENESIS. CONSISTENT WITH THIS CONCEPT, GPER IS DIRECTLY ASSOCIATED WITH CLINICOPATHOLOGICAL INDICES THAT PREDICT CANCER PROGRESSION AND POOR SURVIVAL IN BREAST AND GYNECOLOGICAL CANCERS. MOREOVER, GPER MANIFESTS CELL BIOLOGICAL RESPONSES AND A MICROENVIRONMENT CONDUCIVE FOR TUMOR DEVELOPMENT AND CANCER PROGRESSION, REGULATING CELLULAR RESPONSES ASSOCIATED WITH GLANDULAR HOMEOSTASIS AND SURVIVAL, INVADING SURROUNDING TISSUE AND ATTRACTING A VASCULAR SUPPLY. THUS, THE CELLULAR ACTIONS ATTRIBUTED TO GPER FIT WELL WITH THE KNOWN MOLECULAR MECHANISMS OF G-PROTEIN COUPLED RECEPTORS, GPCRS, NAMELY, THEIR ABILITY TO TRANSACTIVATE INTEGRINS AND EGF RECEPTORS AND ALTER THE INTERACTION BETWEEN GLANDULAR EPITHELIA AND THEIR EXTRACELLULAR ENVIRONMENT, AFFECTING EPITHELIAL-TO-MESENCHYMAL TRANSITION (EMT) AND ALLOWING FOR TUMOR CELL SURVIVAL AND DISSEMINATION. THIS PERSPECTIVE REVIEWS THE MOLECULAR AND CELLULAR RESPONSES MANIFESTED BY GPER AND EVALUATES ITS CONTRIBUTION TO FEMALE REPRODUCTIVE CANCERS AS DISEASES THAT PROGRESS AS A RESULT OF DYSREGULATED GLANDULAR HOMEOSTASIS RESULTING IN CHRONIC INFLAMMATION AND METASTASIS. THIS REVIEW IS ORGANIZED IN SECTIONS AS FOLLOWS: I) A BRIEF SYNOPSIS OF THE CURRENT STATE OF KNOWLEDGE REGARDING ESTROGEN-INDUCED CARCINOGENESIS, II) A REVIEW OF EVIDENCE FROM CLINICAL AND ANIMAL-BASED STUDIES THAT SUPPORT A ROLE FOR GPER IN CANCER PROGRESSION, AND III) A MECHANISTIC FRAMEWORK DESCRIBING HOW GPER-MEDIATED ESTROGEN ACTION MAY INFLUENCE THE TUMOR AND ITS MICROENVIRONMENT. 2018 10 3811 48 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 11 3245 26 HEPATIC STELLATE CELLS AS KEY TARGET IN LIVER FIBROSIS. PROGRESSIVE LIVER FIBROSIS, INDUCED BY CHRONIC VIRAL AND METABOLIC DISORDERS, LEADS TO MORE THAN ONE MILLION DEATHS ANNUALLY VIA DEVELOPMENT OF CIRRHOSIS, ALTHOUGH NO ANTIFIBROTIC THERAPY HAS BEEN APPROVED TO DATE. TRANSDIFFERENTIATION (OR "ACTIVATION") OF HEPATIC STELLATE CELLS IS THE MAJOR CELLULAR SOURCE OF MATRIX PROTEIN-SECRETING MYOFIBROBLASTS, THE MAJOR DRIVER OF LIVER FIBROGENESIS. PARACRINE SIGNALS FROM INJURED EPITHELIAL CELLS, FIBROTIC TISSUE MICROENVIRONMENT, IMMUNE AND SYSTEMIC METABOLIC DYSREGULATION, ENTERIC DYSBIOSIS, AND HEPATITIS VIRAL PRODUCTS CAN DIRECTLY OR INDIRECTLY INDUCE STELLATE CELL ACTIVATION. DYSREGULATED INTRACELLULAR SIGNALING, EPIGENETIC CHANGES, AND CELLULAR STRESS RESPONSE REPRESENT CANDIDATE TARGETS TO DEACTIVATE STELLATE CELLS BY INDUCING REVERSION TO INACTIVATED STATE, CELLULAR SENESCENCE, APOPTOSIS, AND/OR CLEARANCE BY IMMUNE CELLS. CELL TYPE- AND TARGET-SPECIFIC PHARMACOLOGICAL INTERVENTION TO THERAPEUTICALLY INDUCE THE DEACTIVATION WILL ENABLE MORE EFFECTIVE AND LESS TOXIC PRECISION ANTIFIBROTIC THERAPIES. 2017 12 3512 33 IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS IS A DEVASTATING, AGE-RELATED LUNG DISEASE OF UNKNOWN CAUSE THAT HAS FEW TREATMENT OPTIONS. THIS DISEASE WAS ONCE THOUGHT TO BE A CHRONIC INFLAMMATORY PROCESS, BUT CURRENT EVIDENCE INDICATES THAT THE FIBROTIC RESPONSE IS DRIVEN BY ABNORMALLY ACTIVATED ALVEOLAR EPITHELIAL CELLS (AECS). THESE CELLS PRODUCE MEDIATORS THAT INDUCE THE FORMATION OF FIBROBLAST AND MYOFIBROBLAST FOCI THROUGH THE PROLIFERATION OF RESIDENT MESENCHYMAL CELLS, ATTRACTION OF CIRCULATING FIBROCYTES, AND STIMULATION OF THE EPITHELIAL TO MESENCHYMAL TRANSITION. THE FIBROBLAST AND MYOFIBROBLAST FOCI SECRETE EXCESSIVE AMOUNTS OF EXTRACELLULAR MATRIX, MAINLY COLLAGENS, RESULTING IN SCARRING AND DESTRUCTION OF THE LUNG ARCHITECTURE. THE MECHANISMS THAT LINK IDIOPATHIC PULMONARY FIBROSIS WITH AGEING AND ABERRANT EPITHELIAL ACTIVATION ARE UNKNOWN; EVIDENCE SUGGESTS THAT THE ABNORMAL RECAPITULATION OF DEVELOPMENTAL PATHWAYS AND EPIGENETIC CHANGES HAVE A ROLE. IN THIS SEMINAR, WE REVIEW RECENT DATA ON THE CLINICAL COURSE, THERAPEUTIC OPTIONS, AND UNDERLYING MECHANISMS THOUGHT TO BE INVOLVED IN THE PATHOGENESIS OF IDIOPATHIC PULMONARY FIBROSIS. 2011 13 6621 45 UNDERSTANDING FIBROSIS IN SYSTEMIC SCLEROSIS: SHIFTING PARADIGMS, EMERGING OPPORTUNITIES. FIBROSIS IN MULTIPLE ORGANS IS A PROMINENT PATHOLOGICAL FINDING AND DISTINGUISHING HALLMARK OF SYSTEMIC SCLEROSIS (SSC). FINDINGS DURING THE PAST 5 YEARS HAVE CONTRIBUTED TO A MORE COMPLETE UNDERSTANDING OF THE COMPLEX CELLULAR AND MOLECULAR UNDERPINNING OF FIBROSIS IN SSC. FIBROBLASTS, THE PRINCIPAL EFFECTOR CELLS, ARE ACTIVATED IN THE PROFIBROTIC CELLULAR MILIEU BY CYTOKINES AND GROWTH FACTORS, DEVELOPMENTAL PATHWAYS, ENDOTHELIN 1 AND THROMBIN. INNATE IMMUNE SIGNALING VIA TOLL-LIKE RECEPTORS, MATRIX-GENERATED BIOMECHANICAL STRESS SIGNALING VIA INTEGRINS, HYPOXIA AND OXIDATIVE STRESS SEEM TO BE IMPLICATED IN PERPETUATING THE PROCESS. BEYOND CHRONIC FIBROBLAST ACTIVATION, FIBROSIS REPRESENTS A FAILURE TO TERMINATE TISSUE REPAIR, COUPLED WITH AN EXPANDED POPULATION OF MESENCHYMAL CELLS ORIGINATING FROM BONE MARROW AND TRANSDIFFERENTIATION OF EPITHELIAL CELLS, ENDOTHELIAL CELLS AND PERICYTES. IN ADDITION, STUDIES HAVE IDENTIFIED INTRINSIC ALTERATIONS IN SSC FIBROBLASTS RESULTING FROM EPIGENETIC CHANGES, AS WELL AS ALTERED MICRORNA EXPRESSION THAT MIGHT UNDERLIE THE CELL-AUTONOMOUS, PERSISTENT ACTIVATION PHENOTYPE OF THESE CELLS. PRECISE CHARACTERIZATION OF THE DEREGULATED EXTRACELLULAR AND INTRACELLULAR SIGNALING PATHWAYS, MEDIATORS AND CELLULAR DIFFERENTIATION PROGRAMS THAT CONTRIBUTE TO FIBROSIS IN SSC WILL FACILITATE THE DEVELOPMENT OF SELECTIVE, TARGETED THERAPEUTIC STRATEGIES. EFFECTIVE ANTIFIBROTIC THERAPY WILL ULTIMATELY INVOLVE NOVEL COMPOUNDS AND REPURPOSING OF DRUGS THAT ARE ALREADY APPROVED FOR OTHER INDICATIONS. 2011 14 3289 46 HIF-1ALPHA MEDIATES TUMOR HYPOXIA TO CONFER A PERPETUAL MESENCHYMAL PHENOTYPE FOR MALIGNANT PROGRESSION. ALTHOUGH TUMOR PROGRESSION INVOLVES GENETIC AND EPIGENETIC ALTERATIONS TO NORMAL CELLULAR BIOLOGY, THE UNDERLYING MECHANISMS OF THESE CHANGES REMAIN OBSCURE. NUMEROUS STUDIES HAVE SHOWN THAT HYPOXIA-INDUCIBLE FACTOR 1ALPHA (HIF-1ALPHA) IS OVEREXPRESSED IN MANY HUMAN CANCERS AND UP-REGULATES A HOST OF HYPOXIA-RESPONSIVE GENES FOR CANCER GROWTH AND SURVIVAL. WE RECENTLY IDENTIFIED AN ALTERNATIVE MECHANISM OF HIF-1ALPHA FUNCTION THAT INDUCES GENETIC ALTERATIONS BY SUPPRESSING DNA REPAIR. HERE, WE SHOW THAT LONG-TERM HYPOXIA, WHICH MIMICS THE TUMOR MICROENVIRONMENT, DRIVES A PERPETUAL EPITHELIAL-MESENCHYMAL TRANSITION (EMT) THROUGH UP-REGULATION OF THE ZINC FINGER E-BOX BINDING HOMEOBOX PROTEIN ZEB2, WHEREAS SHORT-TERM HYPOXIA INDUCES A REVERSIBLE EMT THAT REQUIRES THE TRANSCRIPTION FACTOR TWIST1. MOREOVER, WE SHOW THAT THE PERPETUAL EMT DRIVEN BY CHRONIC HYPOXIA DEPENDS ON HIF-1ALPHA INDUCTION OF GENETIC ALTERATIONS RATHER THAN ITS CANONICAL TRANSCRIPTIONAL ACTIVATOR FUNCTION. THESE MESENCHYMAL TUMOR CELLS NOT ONLY ACQUIRE TUMORIGENICITY BUT ALSO DISPLAY CHARACTERISTICS OF ADVANCED CANCERS, INCLUDING NECROSIS, AGGRESSIVE INVASION, AND METASTASIS. HENCE, THESE RESULTS REVEAL A MECHANISM BY WHICH HIF-1ALPHA PROMOTES A PERPETUAL MESENCHYMAL PHENOTYPE, THEREBY ADVANCING TUMOR PROGRESSION. 2011 15 5939 45 TARGETING MECHANOTRANSDUCTION AT THE TRANSCRIPTIONAL LEVEL: YAP AND BRD4 ARE NOVEL THERAPEUTIC TARGETS FOR THE REVERSAL OF LIVER FIBROSIS. LIVER FIBROSIS IS THE RESULT OF A DEREGULATED WOUND HEALING PROCESS CHARACTERIZED BY THE EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX. HEPATIC STELLATE CELLS (HSCS), WHICH ARE ACTIVATED IN RESPONSE TO LIVER INJURY, ARE THE MAJOR SOURCE OF EXTRACELLULAR MATRIX AND DRIVE THE WOUND HEALING PROCESS. HOWEVER, CHRONIC LIVER DAMAGE LEADS TO PERPETUAL HSC ACTIVATION, PROGRESSIVE FORMATION OF PATHOLOGICAL SCAR TISSUE AND ULTIMATELY, CIRRHOSIS AND ORGAN FAILURE. HSC ACTIVATION IS TRIGGERED LARGELY IN RESPONSE TO MECHANOSIGNALING FROM THE MICROENVIRONMENT, WHICH INDUCES A PROFIBROTIC NUCLEAR TRANSCRIPTION PROGRAM THAT PROMOTES HSC PROLIFERATION AND EXTRACELLULAR MATRIX SECRETION THEREBY SETTING UP A POSITIVE FEEDBACK LOOP LEADING TO MATRIX STIFFENING AND SELF-SUSTAINED, PATHOLOGICAL, HSC ACTIVATION. DESPITE THE SIGNIFICANT PROGRESS IN OUR UNDERSTANDING OF LIVER FIBROSIS, THE MOLECULAR MECHANISMS THROUGH WHICH THE EXTRACELLULAR MATRIX PROMOTES HSC ACTIVATION ARE NOT WELL UNDERSTOOD AND NO EFFECTIVE THERAPIES HAVE BEEN APPROVED TO DATE THAT CAN TARGET THIS EARLY, REVERSIBLE, STAGE IN LIVER FIBROSIS. SEVERAL NEW LINES OF INVESTIGATION NOW PROVIDE IMPORTANT INSIGHT INTO THIS AREA OF STUDY AND IDENTIFY TWO NUCLEAR TARGETS WHOSE INHIBITION HAS THE POTENTIAL OF REVERSING LIVER FIBROSIS BY INTERFERING WITH HSC ACTIVATION: YES-ASSOCIATED PROTEIN (YAP), A TRANSCRIPTIONAL CO-ACTIVATOR AND EFFECTOR OF THE MECHANOSENSITIVE HIPPO PATHWAY, AND BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4), AN EPIGENETIC REGULATOR OF GENE EXPRESSION. YAP AND BRD4 ACTIVITY IS INDUCED IN RESPONSE TO MECHANICAL STIMULATION OF HSCS AND EACH PROTEIN INDEPENDENTLY CONTROLS WAVES OF EARLY GENE EXPRESSION NECESSARY FOR HSC ACTIVATION. SIGNIFICANTLY, INHIBITION OF EITHER PROTEIN CAN REVERT THE CHRONIC ACTIVATION OF HSCS AND IMPEDE PATHOLOGICAL PROGRESSION OF LIVER FIBROSIS IN CLINICALLY RELEVANT MODEL SYSTEMS. IN THIS REVIEW WE WILL DISCUSS THE ROLES OF THESE NUCLEAR CO-ACTIVATORS IN HSC ACTIVATION, THEIR MECHANISM OF ACTION IN THE FIBROTIC PROCESS IN THE LIVER AND OTHER ORGANS, AND THE POTENTIAL OF TARGETING THEIR ACTIVITY WITH SMALL MOLECULE DRUGS FOR FIBROSIS REVERSAL. 2016 16 4154 47 MECHANISTIC ROLES OF EPITHELIAL AND IMMUNE CELL SIGNALING DURING THE DEVELOPMENT OF COLITIS-ASSOCIATED CANCER. TO DATE, SUBSTANTIAL EVIDENCE HAS SHOWN A SIGNIFICANT ASSOCIATION BETWEEN INFLAMMATORY BOWEL DISEASES (IBD) AND DEVELOPMENT OF COLITIS-ASSOCIATED CANCER (CAC). THE INCIDENCE/PREVALENCE OF IBD IS HIGHER IN WESTERN COUNTRIES INCLUDING THE US, AUSTRALIA, AND THE UK. ALTHOUGH CAC DEVELOPMENT IS GENERALLY CHARACTERIZED BY STEPWISE ACCUMULATION OF GENETIC AS WELL AS EPIGENETIC CHANGES, PRECISE MECHANISMS OF HOW CHRONIC INFLAMMATION LEADS TO THE DEVELOPMENT OF CAC ARE LARGELY UNKNOWN. PRECEDING INTESTINAL INFLAMMATION IS ONE OF THE MAJOR INFLUENTIAL FACTORS FOR CAC TUMORIGENESIS. MUCOSAL IMMUNE RESPONSES INCLUDING ACTIVATION OF ABERRANT SIGNALING PATHWAYS BOTH IN INNATE AND ADAPTIVE IMMUNE CELLS PLAY A PIVOTAL ROLE IN CAC. TUMOR PROGRESSION AND METASTASIS ARE SHAPED BY A TIGHTLY CONTROLLED TUMOR MICROENVIRONMENT WHICH IS ORCHESTRATED BY SEVERAL IMMUNE CELLS AND STROMAL CELLS INCLUDING MACROPHAGES, NEUTROPHILS, DENDRITIC CELLS, MYELOID DERIVED SUPPRESSOR CELLS, T CELLS, AND MYOFIBROBLASTS. IN THIS ARTICLE, WE WILL DISCUSS THE CONTRIBUTING FACTORS OF EPITHELIAL AS WELL AS IMMUNE CELL SIGNALING IN INITIATION OF CAC TUMORIGENESIS AND MUCOSAL IMMUNE REGULATORY FACTORS IN THE COLONIC TUMOR MICROENVIRONMENT. IN DEPTH UNDERSTANDING OF THESE FACTORS IS NECESSARY TO DEVELOP NOVEL ANTI-INFLAMMATORY AND ANTI-CANCER THERAPIES FOR CAC IN THE NEAR FUTURE. 2016 17 3688 59 INFLAMMATION: GEARING THE JOURNEY TO CANCER. CHRONIC INFLAMMATION PLAYS A MULTIFACETED ROLE IN CARCINOGENESIS. MOUNTING EVIDENCE FROM PRECLINICAL AND CLINICAL STUDIES SUGGESTS THAT PERSISTENT INFLAMMATION FUNCTIONS AS A DRIVING FORCE IN THE JOURNEY TO CANCER. THE POSSIBLE MECHANISMS BY WHICH INFLAMMATION CAN CONTRIBUTE TO CARCINOGENESIS INCLUDE INDUCTION OF GENOMIC INSTABILITY, ALTERATIONS IN EPIGENETIC EVENTS AND SUBSEQUENT INAPPROPRIATE GENE EXPRESSION, ENHANCED PROLIFERATION OF INITIATED CELLS, RESISTANCE TO APOPTOSIS, AGGRESSIVE TUMOR NEOVASCULARIZATION, INVASION THROUGH TUMOR-ASSOCIATED BASEMENT MEMBRANE AND METASTASIS, ETC. INFLAMMATION-INDUCED REACTIVE OXYGEN AND NITROGEN SPECIES CAUSE DAMAGE TO IMPORTANT CELLULAR COMPONENTS (E.G., DNA, PROTEINS AND LIPIDS), WHICH CAN DIRECTLY OR INDIRECTLY CONTRIBUTE TO MALIGNANT CELL TRANSFORMATION. OVEREXPRESSION, ELEVATED SECRETION, OR ABNORMAL ACTIVATION OF PROINFLAMMATORY MEDIATORS, SUCH AS CYTOKINES, CHEMOKINES, CYCLOOXYGENASE-2, PROSTAGLANDINS, INDUCIBLE NITRIC OXIDE SYNTHASE, AND NITRIC OXIDE, AND A DISTINCT NETWORK OF INTRACELLULAR SIGNALING MOLECULES INCLUDING UPSTREAM KINASES AND TRANSCRIPTION FACTORS FACILITATE TUMOR PROMOTION AND PROGRESSION. WHILE INFLAMMATION PROMOTES DEVELOPMENT OF CANCER, COMPONENTS OF THE TUMOR MICROENVIRONMENT, SUCH AS TUMOR CELLS, STROMAL CELLS IN SURROUNDING TISSUE AND INFILTRATED INFLAMMATORY/IMMUNE CELLS GENERATE AN INTRATUMORAL INFLAMMATORY STATE BY ABERRANT EXPRESSION OR ACTIVATION OF SOME PROINFLAMMATORY MOLECULES. MANY OF PROINFLAMMATORY MEDIATORS, ESPECIALLY CYTOKINES, CHEMOKINES AND PROSTAGLANDINS, TURN ON THE ANGIOGENIC SWITCHES MAINLY CONTROLLED BY VASCULAR ENDOTHELIAL GROWTH FACTOR, THEREBY INDUCING INFLAMMATORY ANGIOGENESIS AND TUMOR CELL-STROMA COMMUNICATION. THIS WILL END UP WITH TUMOR ANGIOGENESIS, METASTASIS AND INVASION. MOREOVER, CELLULAR MICRORNAS ARE EMERGING AS A POTENTIAL LINK BETWEEN INFLAMMATION AND CANCER. THE PRESENT ARTICLE HIGHLIGHTS THE ROLE OF VARIOUS PROINFLAMMATORY MEDIATORS IN CARCINOGENESIS AND THEIR PROMISE AS POTENTIAL TARGETS FOR CHEMOPREVENTION OF INFLAMMATION-ASSOCIATED CARCINOGENESIS. 2008 18 6143 46 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 19 5140 39 POTENTIAL REGULATORS OF THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE DURING SENESCENCE AND AGING. SENESCENT CELLS EXPRESS AND SECRETE A VARIETY OF EXTRACELLULAR MODULATORS THAT INCLUDE CYTOKINES, CHEMOKINES, PROTEASES, GROWTH FACTORS, AND SOME ENZYMES ASSOCIATED WITH EXTRACELLULAR MATRIX REMODELING, DEFINED AS THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). SASP REINFORCES SENESCENT CELL CYCLE ARREST, STIMULATES AND RECRUITS IMMUNE CELLS FOR IMMUNE-MEDIATED CLEARANCE OF POTENTIALLY TUMORIGENIC CELLS, LIMITS OR INDUCES FIBROSIS, AND PROMOTES WOUND HEALING AND TISSUE REGENERATION. ON THE OTHER HAND, SASP MEDIATES CHRONIC INFLAMMATION LEADING TO THE DESTRUCTION OF TISSUE STRUCTURE AND FUNCTION AND STIMULATING THE GROWTH AND SURVIVAL OF TUMOR CELLS. SASP IS HIGHLY HETEROGENEOUS AND THE ROLE OF SASP DEPENDS ON THE CONTEXT. THE REGULATION OF SASP OCCURS AT MULTIPLE LEVELS INCLUDING CHROMATIN REMODELING, TRANSCRIPTION, MRNA TRANSLATION, INTRACELLULAR TRAFFICKING, AND SECRETION. SEVERAL SASP MODULATORS HAVE ALREADY BEEN IDENTIFIED SETTING THE STAGE FOR FUTURE RESEARCH ON THEIR CLINICAL APPLICATIONS. IN THIS REVIEW, WE SUMMARIZE IN DETAIL THE POTENTIAL SIGNALING PATHWAYS THAT TRIGGER AND REGULATE SASP PRODUCTION DURING AGING AND SENESCENCE. 2022 20 6910 33 [TRANSFORMING GROWTH FACTOR-BETA AND RENAL FIBROSIS]. TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA) IS A DRIVING FORCE OF RENAL FIBROSIS, WHICH MAY LEAD TO CHRONIC KIDNEY DISEASES AND EVEN END STAGE RENAL DISEASES. BY ACTIVATING CANONICAL AND NON-CANONICAL SIGNALING PATHWAYS, TGF-BETA PROMOTES THE SYNTHESIS OF EXTRACELLULAR MATRIX WHILE PREVENTING THEIR DEGRADATION. IN THE INJURED KIDNEY, TGF-BETA INDUCES APOPTOSIS, PROLIFERATION AND FIBROTIC RESPONSE OF RENAL CELLS INCLUDING EPITHELIAL CELLS, ENDOTHELIAL CELLS, PODOCYTES, FIBROBLASTS, PERICYTES AND MACROPHAGES, AND IT ALSO PROMOTES TRANSDIFFERENTIATION, ACTIVATION AND PROLIFERATION OF MYOFIBROBLASTS. ADDITIONALLY, TGF-BETA EXERTS PROFIBROTIC EFFECTS BY INTERPLAYING WITH OTHER SIGNALING PATHWAYS LIKE BMP-7, WNT/BETA-CATENIN AND MAP KINASE. SMAD3 IS THE CENTRAL PATHOLOGICAL GENE IN RENAL FIBROSIS, AND EPIGENETIC REGULATION OF TGF-BETA/SMAD3 IS A HOT TOPIC IN KIDNEY FIELD. ALTHOUGH DIRECT TARGETING TGF-BETA MAY CAUSE SIDE EFFECTS INCLUDING TUMORIGENESIS AND IMMUNE DISEASES, THE THERAPEUTIC STRATEGIES TARGETING THE BALANCE OF DOWNSTREAM SMAD3 AND SMAD7 MAY PREVENT OR DELAY THE PROGRESSION OF FIBROTIC KIDNEY DISEASE. 2018