1 3934 260 LIVER TUMOR INDUCTION. THE SIGNIFICANCE OF THE DEVELOPMENT OF NODULAR LIVER LESIONS IN RODENTS FOLLOWING THE ADMINISTRATION OF TEST AGENTS RAISES SEVERAL QUESTIONS WHICH COULD BE PLACED IN ONE OF TWO GENERAL CATEGORIES: DIAGNOSTIC AND INTERPRETATIONAL. FROM A DIAGNOSTIC POINT OF VIEW, THE PROPER CLASSIFICATION OF LIVER TUMORS INTO A BENIGN AND MALIGNANT CATEGORY HAS TO BE BASED ON THE DIRECT CORRELATION BETWEEN THE MORPHOLOGY AND THE BIOLOGIC BEHAVIOR OF THE LESIONS. THEREFORE, EXTREME CARE SHOULD BE TAKEN TO SEPARATE THE MALIGNANT TUMORS FROM THE BENIGN AND THE BENIGN NEOPLASIA FROM THE HYPERPLASIA. THE SUBSTITUTION OF THE TERM "NEOPLASTIC NODULE" FOR HYPERPLASTIC NODULE IN RATS IS MISLEADING. MOST OF THESE NODULES, WHEN INDUCED UNDER SPECIAL EXPERIMENTAL CONDITIONS, MAY REGRESS OR REMODEL AND THUS THEY ARE NOT NEOPLASTIC IN NATURE. CHRONIC CARCINOGENICITY BIOASSAYS SHOULD INCLUDE "STOP" TYPE OF TREATMENT LEAVING ENOUGH OF THE OBSERVATIONAL TIME TO ESTABLISH THE FATE OF INDUCED NODULAR LESIONS. THE INDUCTION OF HISTOCHEMICALLY CHANGED FOCI CAN SERVE ONLY AS AN INDICATION OF POTENTIAL HEPATOCARCINOGENICITY AND SHOULD NOT BE EQUATED WITH THE INDUCTION OF BONA FIDE CANCER. THE BIOLOGIC INTERPRETATION OF NODULAR LIVER LESIONS, ESPECIALLY IN MICE, NEEDS FURTHER SCRUTINY BECAUSE THESE LESIONS HAVE A TENDENCY TO DEVELOP SPONTANEOUSLY WITH HIGH INCIDENCE IN SOME STRAINS. THIS CHARACTERISTIC THEN RAISES THE QUESTION AS TO THE MECHANISM BY WHICH VARIOUS AGENTS AUGMENT AND/OR ACCELERATE THE DEVELOPMENT OF SUCH TUMORS. IS THIS ACTION PRIMARILY PROMOTING OR INITIATING IN NATURE OR DOES IT REPRESENT THE INDUCTION OF TUMORS DE NOVO? THE ANSWER TO THIS DILEMMA MAY HAVE A DECISIVE BEARING ON CARCINOGENIC RISK ASSESSMENT AND THE TYPE OF REGULATORY ACTION, SINCE THE PROMOTING AGENTS POSSESS A THRESHOLD EFFECT AND THE PROMOTED CHANGES MAY REGRESS FOLLOWING WITHDRAWAL OF TREATMENT. THE INTERPRETATION OF HEPATOCARCINOGENESIS IS FURTHER COMPLICATED BY THE FACT THAT SEVERAL FACTORS, SUCH AS SEX HORMONAL ENVIRONMENT, INCREASED MITOTIC ACTIVITY FOLLOWING AN EXCESSIVE LOSS OF PARENCHYMAL CELLS, DEGREE OF CALORIC INTAKE, ENZYMATIC COMPLEMENT, AND ANIMALS' AGE AT THE TIME OF THE EXPOSURE TO A TEST AGENT, MAY INFLUENCE THE OUTCOME OF LIVER TUMOR DEVELOPMENT BY MODULATING "INITIATION" AND/OR "PROMOTION" OF CARCINOGENESIS. BROAD FLUCTUATION IN THE HISTORIC INCIDENCE OF LIVER TUMORS FURTHER COMPOUNDS THE COMPLEXITY OF THE PROPER BIOASSAY INTERPRETATION. THE SPECIFICALLY DESIGNED EXPERIMENTS MAY HAVE THE OBJECTIVE TO EXPLORE PREDOMINANTLY THE INITIATING OR PROMOTING EFFECTS OF THE AGENT. SUCH PROTOCOLS SHOULD BE USED WHENEVER NECESSARY TO DIFFERENTIATE BETWEEN THESE TWO MECHANISMS OF ACTION. IN THE CAUCASIANS, THE "SPONTANEOUS" DEVELOPMENT OF THE PRIMARY HEPATOCELLULAR TUMORS IS RARE. THE MAJORITY OF THESE TUMORS ARE MALIGNANT AND RAPIDLY FATAL. ACCORDING TO SOME HUMAN PATHOLOGISTS, THE BENIGN VARIETY OF LIVER TUMORS IS RARE AND IT DOES NOT REPRESENT NECESSARILY A PREMALIGNANT STAGE IN TUMOR DEVELOPMENT. CARCINOMA OF THE LIVER MAY OCCUR IN INFANCY, ESPECIALLY IN MALES BEFORE THE AGE OF 2 YEARS. THIS SUGGESTS A GENETIC CAUSATION OR CARCINOGENIC EXPOSURE IN UTERO. ONE OF THE GEOGRAPHIC FACTORS WHICH SIGNIFICANTLY ENHANCES THE INCIDENCE OF HEPATOCELLULAR CARCINOMA IN HUMANS IS EXPOSURE TO AFLATOXIN B(1) WHICH IS APPARENTLY POTENTIATED BY CONCURRENT LIVER CIRRHOSIS. BECAUSE MANY MORE AGENTS HAVE BEEN FOUND TO BE HEPATOCARCINOGENIC IN MICE AND RATS THAN IN MEN, A QUESTION ARISES AS TO THE DIRECT RELEVANCE OF RODENT STUDIES TO HUMANS. A BALANCED ASSESSMENT OF THE CARCINOGENICITY OF THE AGENT COULD ONLY BE REACHED IN CONSIDERING BOTH THE PHARMACOKINETICS AND THE DEVELOPMENT OF MALIGNANT NEOPLASIA IN OTHER ORGANS. IN THE CASE OF POSITIVE CARCINOGENICITY ASSESSMENT, THE OUTCOME OF THE MUTAGENICITY BIOASSAYS CAN SUGGEST GENIC (GENOTOXIC) OR PARAGENIC (EPIGENETIC) MODE OF ACTION IN MAMMALIAN SYSTEMS. 1982 2 5282 49 PROMOTION OF HEPATOCARCINOGENESIS IN HUMANS AND ANIMAL MODELS. RISK ASSESSMENT BASED ON RODENT CARCINOGENICITY DATA DEPENDS ON THE ASSUMPTION OF SIMILARITY BETWEEN RODENTS AND HUMANS. WHILE THIS ASSUMPTION IS CONCEIVABLE IN THE CASE OF GENOTOXIC INITIATING CARCINOGENS, CONSIDERABLE SPECIES DIFFERENCES HAVE BEEN OBSERVED WITH NONGENOTOXIC TUMOR PROMOTERS. THIS HETEROGENEOUS GROUP OF AGENTS INCREASES THE PROBABILITY OF CANCER BY STIMULATING SELECTION AND CLONAL EXPANSION OF CELLS TRANSFORMED DURING TUMOR INITIATION. SINCE TUMOR PROMOTERS DIFFERENTIALLY AFFECT NORMAL TISSUE AND PRENEOPLASTIC CELL CLONES, THEIR ACTION CANNOT BE DISCUSSED WITHOUT KNOWLEDGE OF PERSISTENT GENOMIC AND EPIGENETIC ALTERATIONS OCCURRING DURING INITIATION AND FORMATION OF PRENEOPLASTIC CELLS. CHEMICAL CARCINOGENESIS, AND IN PARTICULAR, TUMOR PROMOTION, IS KNOWN TO BE TISSUE SPECIFIC. WE FOCUS ON HEPATOCARCINOGENESIS IN HUMANS AND IN ANIMAL MODELS AND EMPHASIZE TWO DIFFERENT MODES OF ACTION: (1) CHRONIC CYTOTOXICITY LEADING TO PROMOTION OF LIVER CARCINOGENESIS IN BOTH HUMANS AND ANIMAL MODELS; (2) SUSTAINED ACTIVATION OF ORPHAN RECEPTORS SUCH AS CAR, PPARALPHA AND AH RECEPTOR LEADING TO PROMOTION OF RODENT BUT PROBABLY NOT HUMAN HEPATOCARCINOGENESIS. FURTHER STUDIES ON THE DIFFERENT MODES OF ACTION MAY HELP TO AVOID OVERESTIMATION OF THE RISK OF LIVER TUMOR PROMOTION. 2008 3 835 56 CHEMICAL CARCINOGEN MECHANISMS OF ACTION AND IMPLICATIONS FOR TESTING METHODOLOGY. CHEMICAL CARCINOGENS ARE OF TWO DISTINCT TYPES, DNA-REACTIVE AND EPIGENETIC. TESTING METHODOLOGY CAN BE DIRECTED TOWARD DETECTING EFFECTS OF BOTH TYPES OF CARCINOGEN. CARCINOGENS OF THE DNA-REACTIVE TYPE ARE DEFINED BY THE FORMATION OF COVALENTLY BOUND DNA ADDUCTS. THESE CHEMICALS HAVE STRUCTURES THAT YIELD ELECTROPHILIC REACTANTS EITHER DIRECTLY OR AFTER BIOACTIVATION. THESE AGENTS CAUSE GENOMIC ALTERATION IN THE STRUCTURE OR FUNCTION OF DNA IN THE TARGET CELL. IN ADDITION, THESE COMPOUNDS CAN EXERT OTHER CELLULAR AND TISSUE EPIGENETIC EFFECTS, SUCH AS CELL PROLIFERATION AND GROWTH PROMOTION. CARCINOGENS OF THE EPIGENETIC (PARAGENETIC) TYPE, IN CONTRAST, DO NOT REACT WITH DNA, BUT RATHER DISPLAY CELLULAR EFFECTS SUCH AS NEOPLASM GROWTH PROMOTION, CYTOTOXICITY, INHIBITION OF TISSUE GROWTH REGULATION, PEROXISOME PROLIFERATION, ENDOCRINE MODIFICATION, IMMUNOSUPPRESSION AND/OR SUSTAINED TISSUE ISCHEMIA THAT CAN BE THE BASIS FOR INCREASES IN NEOPLASIA. THEIR CHEMICAL STRUCTURE IS SUCH THAT THEY DO NOT GIVE RISE TO A REACTIVE ELECTROPHILE. THE TESTING METHODOLOGIES TO IDENTIFY EITHER TYPE FOLLOW A DECISION POINT APPROACH DESIGNED TO IDENTIFY POTENTIAL CARCINOGENICITY AND YIELD MECHANISTIC INFORMATION ON THE PRODUCTION OF EFFECTS THAT UNDERLIE CARCINOGENICITY. IT HAS 5 STAGES FOCUSING ON THE CHEMICAL STRUCTURE, DNA-REACTIVITY, EPIGENETIC EFFECTS, LIMITED BIOASSAYS AND FINALLY THE APPLICATION OF THE ACCELERATED BIOASSAY (ABA). ABA REQUIRES 40 WEEKS AND APPLIES THE USE OF SENSITIVE MARKERS FOR INDUCTION OF NEOPLASIA IN COMPARISON TO POSITIVE CONTROL COMPOUNDS FOR IMPORTANT ORGANS IN HUMAN CARCINOGENESIS. IT ENABLES DATA ACQUISITION OF THE ENTIRE CARCINOGENIC PROCESS DIRECTED TOWARD DEVELOPING MECHANISTIC INFORMATION. THE ABA HAS THE POTENTIAL TO REPLACE THE CHRONIC BIOASSAY IN RODENTS IN SOME CIRCUMSTANCES AND CAN SERVE AS AN ALTERNATIVE TO A CHRONIC BIOASSAY IN A SECOND SPECIES. 1996 4 731 48 CANCER CHEMOPREVENTION: CLASSIC AND EPIGENETIC MECHANISMS INHIBITING TUMORIGENESIS. WHAT HAVE WE LEARNED SO FAR? CANCERS DERIVE FROM STEP BY STEP PROCESSES WHICH ARE DIFFERENTIATED BY THE PROGRESSIVELY ACCUMULATED MUTATIONS. FOR SOME TUMORS THERE IS A CLEAR PROGRESSIVE ADVANCEMENT FROM BENIGN LESIONS TO MALIGNANCY AND FOR THESE, PREVENTIVE SCREENING PROGRAMS EXIST. IN SUCH CASES HAVING THOSE BENIGN LESIONS ARE A CLEAR INDICATOR OF PREDISPOSITION WHILE FOR SOME OTHER CASES, FAMILIAL PATTERNS OF CANCER INCIDENCE AND THE IDENTIFICATION OF MUTATIONS ARE THE MAIN INDICATORS OF HIGHER RISK FOR HAVING THE DISEASE. FOR PATIENTS IDENTIFIED AS HAVING PREDISPOSITION, CHEMOPREVENTION IS A GOAL AND IN SOME CASES A POSSIBILITY. CHEMOPREVENTION IS THE USE OF ANY COMPOUND, EITHER NATURAL OR SYNTHETIC THAT ABROGATES CARCINOGENESIS OR TUMOR PROGRESSION, THROUGH DIFFERENT MECHANISMS, SOME OF WHICH HAVE ALREADY BEEN DESCRIBED. FOR EXAMPLE, THE CLASSIC MECHANISMS MAY INVOLVE ACTIVATION OF FREE RADICAL SCAVENGING ENZYMES, CONTROL OF CHRONIC INFLAMMATION, AND DOWNREGULATION OF SPECIFIC SIGNALING PATHWAYS. MORE RECENTLY, EPIGENETICS ALLOWED FURTHER UNDERSTANDING OF THE CHEMOPREVENTIVE POTENTIAL OF SEVERAL AGENTS, SUCH AS SULFORAPHANE, GREEN TEA DERIVED COMPOUNDS, RESVERATROL, ISOFLAVONES, AND OTHERS WHICH WE EXPLOIT IN THIS REVIEW ARTICLE. THROUGHOUT THE TEXT WE DISCUSS THE PROPERTIES COMPOUNDS SHOULD HAVE IN ORDER TO BE CLASSIFIED AS CHEMOPREVENTIVE ONES AND THE CHALLENGES IN TRANSLATIONAL RESEARCH IN THIS AREA, AS LOTS OF THE SUCCESS ACHIEVED IN VITRO CANNOT BE TRANSLATED INTO THE CLINICAL SETTINGS, DUE TO SEVERAL DIFFERENT DRAWBACKS, WHICH INCLUDE TOXICITY, COST, DOSE DEFINITION, PATIENT ADHERENCE, AND REGIMEN OF USE. 2018 5 6842 35 [MECHANISTIC ISSUES AND PREVENTION STRATEGIES TARGETING OCCUPATIONAL CARCINOGENESIS]. CARCINOGENESIS CAN BE VISUALIZED EITHER AS A MULTISTEP PROCESS (INITIATION, PROMOTION, PROGRESSION, INVASION, AND METASTASIS) OR AS A CONTINUUM OF MUTAGENIC AND MITOGENIC EVENTS, WITH THE CONTRIBUTION OF EPIGENETIC MECHANISMS. THE EXPONENTIAL GROWTH OF THE NEOPLASTIC MASS EXPLAINS THE IMPORTANCE OF SECONDARY PREVENTION (EARLY DIAGNOSIS) AND OF TERTIARY PREVENTION. PRIMARY PREVENTION, WHICH WAS SUCCESSFUL IN CONTROLLING OCCUPATIONAL CANCERS, AIMS AT MINIMIZING EXPOSURES TO CARCINOGENS IN HEALTHY SUBJECTS AND AT FAVORING THE INTAKE OF CHEMOPREVENTIVE AGENTS WITH DIETARY AND PHARMACOLOGICAL AGENTS. BESIDES CHEMICAL CARCINOGENS, OFTEN IN THE FORM OF COMPLEX MIXTURES, THE WORKPLACE MAY INVOLVE EXPOSURES TO PHYSICAL AGENTS, SUCH AS SUNLIGHT AND ARTIFICIAL ILLUMINATION SYSTEMS DELIVERING UV RADIATION, OR TO BIOLOGICAL AGENTS, SUCH AS CHRONIC VIRAL INFECTIONS (HBV, HCV, AND HIV) ASSOCIATED WITH CANCERS. A CONTROVERSIAL ISSUE IS THE OCCURRENCE OF THRESHOLD DOSES FOR CARCINOGENS IN THE WORKPLACE AND THE ENVIRONMENT. 2011 6 5493 26 REVIEW OF IN VITRO TEST SYSTEMS USING DNA DAMAGE AND REPAIR FOR SCREENING OF CHEMICAL CARCINOGENS. CHEMICAL CARCINOGENS ARE MECHANISTICALLY CLASSIFIED AS GENOTOXIC WHICH INTERACT DIRECTLY WITH DNA, AND EPIGENETIC WHICH CAUSE CHRONIC TISSUE INJURY, HORMONAL IMBALANCE, AND PROMOTIONAL EFFECTS. THIS REVIEW EVALUATES IN VITRO TESTS FOR THEIR CONTRIBUTION TO A BATTERY FOR IDENTIFYING GENOTOXIC CHEMICAL CARCINOGENS. IN ADDITION TO BACTERIAL MUTAGENIC ASSAYS, NONSPECIFIC DNA DAMAGE/REPAIR TESTS ARE RECOMMENDED FOR SCREENING CHEMICALS, IN PARTICULAR THE HEPATOCYTE PRIMARY CULTURE/DNA REPAIR TEST. 1979 7 1010 38 CHRONICALLY ELEVATED PROLIFERATION AS A RISK FACTOR FOR NEOPLASIA. CHRONIC DISEASE CONDITIONS THAT ARE ASSOCIATED WITH ELEVATED PROLIFERATION ARE WELL ESTABLISHED AS RISK FACTORS FOR CANCER DEVELOPMENT. THESE MAY BE DUE TO VIRUSES (FOR EXAMPLE, IN THE CASE OF HEPATITIS AND LIVER CANCER), BACTERIAL INFECTIONS, PARASITE INFESTATION OR PHYSICAL TRAUMA. IN ADDITION TO THESE EXOGENOUS AGENTS THERE ARE ALSO METABOLIC ABNORMALITIES THAT CAN CONTRIBUTE, CAUSED BY GENETIC OR EPIGENETIC INFLUENCE. IN THE LATTER CASE, AN INCREASE IN SERUM LEVELS OF THE HORMONES OESTROGEN, TESTOSTERONE AND INSULIN MAY BE OF SPECIAL IMPORTANCE. THE PRESENT REVIEW CONCENTRATES ATTENTION ON FACTORS THAT INDUCE ELEVATED CELL TURNOVER AND FOR WHICH THERE IS EPIDEMIOLOGICAL AND/OR EXPERIMENTAL EVIDENCE OF A LINK WITH NEOPLASIA, WITH PARTICULAR STRESS ON THE INDIVIDUAL ORGAN OR TISSUE LEVEL. 1998 8 837 81 CHEMICALLY INDUCED RENAL TUBULE TUMORS IN THE LABORATORY RAT AND MOUSE: REVIEW OF THE NCI/NTP DATABASE AND CATEGORIZATION OF RENAL CARCINOGENS BASED ON MECHANISTIC INFORMATION. THE INCIDENCE OF RENAL TUBULE CARCINOGENESIS IN MALE AND FEMALE RATS OR MICE WITH 69 CHEMICALS FROM THE 513 BIOASSAYS CONDUCTED TO DATE BY THE NCI/NTP HAS BEEN COLLATED, THE CHEMICALS CATEGORIZED, AND THE RELATIONSHIP BETWEEN CARCINOGENESIS AND RENAL TUBULE HYPERPLASIA AND EXACERBATION OF THE SPONTANEOUS, AGE-RELATED RODENT DISEASE CHRONIC PROGRESSIVE NEPHROPATHY (CPN) EXAMINED. WHERE INFORMATION ON MECHANISM OR MODE OF ACTION EXISTS, THE CHEMICALS HAVE BEEN CATEGORIZED BASED ON THEIR ABILITY TO DIRECTLY OR INDIRECTLY INTERACT WITH RENAL DNA, OR ON THEIR ACTIVITY VIA EPIGENETIC PATHWAYS INVOLVING EITHER DIRECT OR INDIRECT CYTOTOXICITY WITH REGENERATIVE HYPERPLASIA, OR EXACERBATION OF CPN. NINE CHEMICALS WERE IDENTIFIED AS DIRECTLY INTERACTING WITH DNA, WITH SIX OF THESE PRODUCING RENAL TUBULE TUMORS AT HIGH INCIDENCE IN RATS OF BOTH SEXES, AND IN SOME CASES ALSO IN MICE. OCHRATOXIN A WAS THE MOST POTENT COMPOUND IN THIS GROUP, PRODUCING A HIGH TUMOR INCIDENCE AT VERY LOW DOSES, OFTEN WITH METASTASIS. THREE CHEMICALS WERE DISCUSSED IN THE CONTEXT OF INDIRECT DNA DAMAGE MEDIATED BY AN OXIDATIVE FREE RADICAL MECHANISM, ONE OF THESE BEING FROM THE NTP DATABASE. A THIRD CATEGORY INCLUDED FOUR CHEMICALS THAT HAD THE POTENTIAL TO CAUSE DNA DAMAGE FOLLOWING CONJUGATION WITH GLUTATHIONE AND SUBSEQUENT ENZYMATIC ACTIVATION TO A REACTIVE SPECIES, USUALLY A THIOL-CONTAINING ENTITY. TWO CHEMICALS WERE ALLOCATED INTO THE CATEGORY INVOLVING A DIRECT CYTOTOXIC ACTION ON THE RENAL TUBULE FOLLOWED BY SUSTAINED COMPENSATORY CELL PROLIFERATION, WHILE NINE WERE INCLUDED IN A GROUP WHERE THE CELL LOSS AND SUSTAINED INCREASE IN RENAL TUBULE CELL TURNOVER WERE DEPENDENT ON LYSOSOMAL ACCUMULATION OF THE MALE RAT-SPECIFIC PROTEIN, ALPHA2MU-GLOBULIN. IN A SIXTH CATEGORY, MORPHOLOGIC EVIDENCE ON TWO CHEMICALS INDICATED THAT THE RENAL TUMORS WERE A CONSEQUENCE OF EXACERBATED CPN. FOR THE REMAINING CHEMICALS, THERE WERE NO PERTINENT DATA ENABLING ASSIGNMENT TO A MECHANISTIC CATEGORY. ACCORDINGLY, THESE CHEMICALS, ACTING THROUGH AN AS YET UNKNOWN MECHANISM, WERE GROUPED AS EITHER BEING ASSOCIATED WITH AN ENHANCEMENT OF CPN (CATEGORY 7, 16 CHEMICALS), OR NOT ASSOCIATED WITH ENHANCED CPN (CATEGORY 8, 4 CHEMICALS). A NINTH CATEGORY DEALT WITH 11 CHEMICALS THAT WERE REGARDED AS PRODUCING INCREASES IN RENAL TUBULE TUMORS THAT DID NOT REACH STATISTICAL SIGNIFICANCE. A 10TH CATEGORY DISCUSSED 6 CHEMICALS THAT INDUCED RENAL TUMORS IN MICE BUT NOT IN RATS, PLUS 8 CHEMICALS THAT PRODUCED A LOW INCIDENCE OF RENAL TUBULE TUMORS IN MICE THAT DID NOT REACH STATISTICAL SIGNIFICANCE. AS MORE MECHANISTIC DATA ARE GENERATED, SOME CHEMICALS WILL INEVITABLY BE PLACED IN DIFFERENT GROUPS, PARTICULARLY THOSE FROM CATEGORIES 7 AND 8. A LARGE NUMBER OF CHEMICALS IN THE SERIES EXACERBATED CPN, BUT THOSE IN CATEGORY 7 ESPECIALLY MAY BE CANDIDATES FOR INCLUSION IN CATEGORY 6 WHEN FURTHER INFORMATION IS GLEANED FROM THE RELEVANT NTP STUDIES. ALSO, NEW DATA ON SPECIFIC CHEMICALS WILL PROBABLY EXPAND CATEGORY 5 AS CYTOTOXICITY AND CELL REGENERATION ARE IDENTIFIED AS OBLIGATORY STEPS IN RENAL CARCINOGENESIS IN MORE CASES. ADDITIONAL CONFIRMATORY OUTCOMES ARISING FROM THIS REVIEW ARE THAT METASTASES FROM RENAL TUBULE TUMORS, WHILE ENCOUNTERED WITH CHEMICALS CAUSING DNA DAMAGE, ARE RARE WITH THOSE ACTING THROUGH AN EPIGENETIC PATHWAY, WITH THE EXCEPTION BEING FUMONISIN B1; THAT MALE RATS AND MICE ARE GENERALLY MORE SUSCEPTIBLE THAN FEMALE RATS AND MICE TO CHEMICAL INDUCTION OF RENAL TUBULE TUMORS; AND THAT A BACKGROUND OF ATYPICAL TUBULE HYPERPLASIA IS A USEFUL INDICATOR REFLECTING A CHEMICALLY ASSOCIATED RENAL TUBULE TUMOR RESPONSE. WITH RESPECT TO RENAL TUBULE TUMORS AND HUMAN RISK ASSESSMENT, CHEMICALS IN CATEGORIES 1 AND 2, AND POSSIBLY 3, WOULD CURRENTLY BE JUDGED BY LINEAR DEFAULT METHODS; CHEMICALS IN CATEGORY 4 (AND PROBABLY SOME IN CATEGORY 3) AS EXHIBITING A THRESHOLD OF ACTIVITY WARRANTING THE BENCHMARK APPROACH; AND THOSE IN CATEGORIES 5 AND 6 AS REPRESENTING MECHANISMS THAT HAVE NO RELEVANCE FOR EXTRAPOLATION TO HUMANS. 2004 9 5742 34 SMOKING MOLECULAR DAMAGE IN BRONCHIAL EPITHELIUM. OUR UNDERSTANDING OF THE MOLECULAR PATHOLOGY OF LUNG CANCER IS ADVANCING RAPIDLY WITH SEVERAL SPECIFIC GENES AND CHROMOSOMAL REGIONS BEING IDENTIFIED. LUNG CANCER APPEARS TO REQUIRE MANY MUTATIONS IN BOTH DOMINANT AND RECESSIVE ONCOGENES TO POSSESS MALIGNANT PHENOTYPES. SEVERAL GENETIC AND EPIGENETIC CHANGES ARE COMMON TO ALL LUNG CANCER HISTOLOGIC TYPES, WHILE OTHERS APPEAR TO BE CELL TYPE SPECIFIC. HOWEVER, SPECIFIC ROLES OF THE GENES UNDERGOING MUTATIONS AND THE ORDER OF CUMULATIVE MOLECULAR CHANGES THAT LEAD TO THE DEVELOPMENT OF EACH LUNG TUMOR HISTOLOGIC TYPE REMAIN TO BE FULLY ELUCIDATED. RECENT FINDINGS OF MOLECULAR ABNORMALITIES IN NORMAL APPEARING AND PRENEOPLASTIC BRONCHIAL EPITHELIUM FROM PATIENTS WITH LUNG CANCER AND CHRONIC SMOKERS SUGGEST THAT GENETIC CHANGES MAY SERVE AS BIOMARKERS FOR EARLY DIAGNOSIS, RISK ASSESSMENT AND MONITORING RESPONSE TO CHEMOPREVENTION. 2002 10 1918 65 ENVIRONMENTAL CARCINOGENESIS AND TRANSGENERATIONAL TRANSMISSION OF CARCINOGENIC RISK: FROM GENETICS TO EPIGENETICS. THE DOMINANT PATHOGENIC MODEL, SOMATIC MUTATION THEORY (SMT), CONSIDERS CARCINOGENESIS AS A 'GENETIC ACCIDENT' DUE TO THE ACCUMULATION OF 'STOCHASTIC' DNA MUTATIONS. THIS MODEL WAS PROPOSED AND ACCEPTED BY THE SCIENTIFIC COMMUNITY WHEN CANCER MAINLY AFFECTED THE ELDERLY, BUT IT DOES NOT EXPLAIN THE EPIDEMIOLOGICAL OBSERVATION OF THE CONTINUOUS INCREASE IN CANCER INCIDENCE AMONG CHILDREN AND YOUNG ADULTS. SOMATIC MUTATION THEORY HAS BEEN PROPOSED FOR A REVISION BASED ON THE EMERGING EXPERIMENTAL EVIDENCE, AS IT DOES NOT FULLY ADDRESS SOME ISSUES THAT HAVE PROVEN TO BE CRUCIAL FOR CARCINOGENESIS, NAMELY: THE INFLAMMATORY CONTEXT OF CANCER; THE KEY ROLE PLAYED BY THE STROMA, MICROENVIRONMENT, ENDOTHELIAL CELLS, ACTIVATED MACROPHAGES, AND SURROUNDING TISSUES; AND THE DISTORTED DEVELOPMENTAL COURSE FOLLOWED BY THE NEOPLASTIC TISSUE. FURTHERMORE, SMT IS OFTEN NOT ABLE TO CONSIDER EITHER THE EXISTENCE OF SPECIFIC MUTATIONS RESULTING IN A WELL-DEFINED CANCER TYPE, OR A CLEAR RELATIONSHIP BETWEEN MUTATIONS AND TUMOR PROGRESSION. MOREOVER, IT DOES NOT EXPLAIN THE MECHANISM OF ACTION OF THE NON-MUTAGENIC AND ENVIRONMENTAL CARCINOGENS. IN THE LAST DECADE, CANCER RESEARCH HAS HIGHLIGHTED THE PROMINENT ROLE OF AN ALTERED REGULATION OF GENE EXPRESSION, SUGGESTING THAT CANCER SHOULD BE CONSIDERED AS A RESULT OF A POLYCLONAL EPIGENETIC DISRUPTION OF STEM/PROGENITOR CELLS, MEDIATED BY TUMOUR-INDUCING GENES. THE MATERNAL AND FETAL EXPOSURE TO A WIDE RANGE OF CHEMICALS AND ENVIRONMENTAL CONTAMINANTS IS RAISING THE ATTENTION OF THE SCIENTIFIC COMMUNITY. INDEED, THE MOST POWERFUL PROCARCINOGENIC MECHANISMS OF ENDOCRINE DISRUPTORS AND OTHER POLLUTANTS IS LINKED TO THEIR POTENTIAL TO INTERFERE EPIGENETICALLY WITH THE EMBRYO-FETAL PROGRAMMING OF TISSUES AND ORGANS, ALTERING THE REGULATION OF THE GENES INVOLVED IN THE CELL CYCLE, CELL PROLIFERATION, APOPTOSIS, AND OTHER KEY SIGNALING PATHWAYS. THE EMBRYO-FETAL EXPOSURE TO ENVIRONMENTAL, STRESSFUL, AND PROINFLAMMATORY TRIGGERS (FIRST HIT), SEEMS TO ACT AS A 'DISEASE PRIMER', MAKING FETAL CELLS AND TISSUES MORE SUSCEPTIBLE TO THE SUBSEQUENT ENVIRONMENTAL EXPOSURES (SECOND HIT), TRIGGERING THE CARCINOGENIC PATHWAYS. FURTHERMORE, EVEN AT THE MOLECULAR LEVEL, IN CARCINOGENESIS, 'EPIGENETICS PRECEDES GENETICS' AS GLOBAL DNA HYPOMETHYLATION, AND THE HYPERMETHYLATION OF TUMOR SUPPRESSOR GENES ARE COMMON BOTH IN CANCEROUS AND IN PRECANCEROUS CELLS, AND GENERALLY PRECEDE MUTATIONS. THESE EPIGENETIC MODELS MAY BETTER EXPLAIN THE INCREASE OF CANCER AND CHRONIC/DEGENERATIVE DISEASES IN THE LAST DECADES AND COULD BE USEFUL TO ADOPT APPROPRIATE PRIMARY PREVENTION MEASURES, ESSENTIALLY BASED ON THE REDUCTION OF MATERNAL-FETAL AND CHILD EXPOSURE TO SEVERAL PROCARCINOGENIC AGENTS AND FACTORS DISPERSED IN THE ENVIRONMENT AND IN THE FOOD-CHAINS, AS RECENTLY SUGGESTED BY THE WORLD HEALTH ORGANIZATION. 2018 11 3683 49 INFLAMMATION, MICROBIOTA, AND PROSTATE CANCER. CONTEXT: CHRONIC INFLAMMATION OF THE PROSTATE HAS BEEN ASSOCIATED WITH PRENEOPLASTIC LESIONS AND CANCER DEVELOPMENT. MULTIPLE CAUSES HAVE BEEN CONSIDERED FOR CHRONIC INFLAMMATION OF THE PROSTATE. INFLAMMATORY CYTOKINES SUCH AS INTERLEUKINS ARE IMPLICATED IN PROSTATE CARCINOGENESIS AND DEVELOPMENT. OBJECTIVE: TO EVALUATE LITERATURE PUBLISHED ON ETIOLOGICAL FACTORS, URINARY MICROBIOTA, MORPHOLOGICAL FEATURES OF PROLIFERATIVE INFLAMMATORY ATROPHY AND HIGH-GRADE PROSTATE INTRAEPITHELIAL NEOPLASIA, GENETIC POLYMORPHISMS, INFLAMMATORY STRESS, AND CYTOKINE SIGNALING. EVIDENCE ACQUISITION: WE SEARCHED LITERATURE FROM PUBMED FROM 2010 AND ALSO INCLUDED THE MOST IMPORTANT PUBLICATIONS FROM THE PREVIOUS PERIOD. EVIDENCE SYNTHESIS: PROSTATE CANCER INFLAMMATION AND PREMALIGNANT LESIONS HAVE BEEN FREQUENTLY DISCUSSED IN SCIENTIFIC LITERATURE. A LIMITED NUMBER OF MODELS ARE AVAILABLE FOR STUDYING INFLAMMATION AND PREMALIGNANT LESIONS. HOWEVER, MORPHOLOGICAL PATHOLOGY COULD BE COMPLEMENTED BY ANALYSIS OF GENE POLYMORPHISMS IN THESE PATIENTS AND APPROPRIATE FUNCTIONAL STUDIES. CONCLUSIONS: PROSTATITIS COULD BE CAUSED BY BACTERIAL OR VIRAL INFECTIONS, DIETARY COMPOUNDS, AND CHANGES IN TESTOSTERONE:ESTRADIOL RATIO. IN SOME CASES, THE MICROBIOTA CAN EXERT DIRECT EFFECTS ON CANCER DEVELOPMENT. PROSTATE INFLAMMATORY ATROPHY OR HIGH GRADE PROSTATE INTRAEPITHELIAL NEOPLASIA HAVE BEEN ASSOCIATED WITH RESPONSE TO CELLULAR STRESS AND HAVE BEEN DISCUSSED IN CONNECTION TO EARLY CANCER DEVELOPMENT. A LARGE NUMBER OF GENETIC POLYMORPHISMS HAVE BEEN IDENTIFIED IN INFLAMMATORY PROSTATE. GENETIC AND EPIGENETIC ALTERATIONS MAY BE A CONSEQUENCE OF THE PROINFLAMMATORY STRESS IN THE PROSTATE. PROINFLAMMATORY CYTOKINES INTERLEUKIN-6 AND -8 CONTRIBUTE TO PROSTATE MALIGNANCY; HOWEVER, THEIR FUNCTION WAS MORE FREQUENTLY INVESTIGATED IN CANCER TISSUE RATHER THAN IN INFLAMMATION. PATIENT SUMMARY: WE PERFORMED A REVIEW OF RECENT LITERATURE RELATED TO PROSTATE INFLAMMATION, MICROBIOTA, AND PROSTATE CANCER. NEW FUNCTIONAL APPROACHES ARE REQUIRED FOR A BETTER UNDERSTANDING OF THE ROLE OF INFLAMMATION AND CANCER DEVELOPMENT. 2016 12 3697 38 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 13 1844 55 EFFECTS OF THE LIFESTYLE HABITS IN BREAST CANCER TRANSCRIPTIONAL REGULATION. THROUGH RESEARCH CARRIED OUT IN THE LAST 25 YEARS ABOUT THE BREAST CANCER ETIOLOGY, IT HAS BEEN POSSIBLE TO ESTIMATE THAT LESS THAN 10 % OF PATIENTS WHO ARE DIAGNOSED WITH THE CONDITION ARE CARRIERS OF SOME GERMLINE OR SOMATIC MUTATION. THE CLINICAL REPORTS OF BREAST CANCER PATIENTS WITH HEALTHY TWINS AND THE DEVELOPMENT OF DISEASE IN WOMEN WITHOUT HIGH PENETRANCE MUTATIONS DETECTED, WARN THE PARTICIPATION MORE FACTORS IN THE TRANSFORMATION PROCESS. THE HIGH INCIDENCE OF MAMMARY ADENOCARCINOMA IN THE MODERN WOMAN AND THE URGENT NEED FOR NEW METHODS OF PREVENTION AND EARLY DETECTION HAVE DEMANDED MORE INFORMATION ABOUT THE ROLE THAT ENVIRONMENT AND LIFESTYLE HAVE ON THE TRANSFORMATION OF MAMMARY GLAND EPITHELIAL CELLS. OBESITY, ALCOHOLISM AND SMOKING ARE FACTORS THAT HAVE SHOWN A CLOSE CORRELATION WITH THE RISK OF DEVELOPING BREAST CANCER. AND ALTHOUGH THESE CONDITIONS AFFECT DIFFERENT CELL REGULATION LEVELS, THE STUDY OF ITS EFFECTS IN THE MECHANISMS OF TRANSCRIPTIONAL AND EPIGENETIC REGULATION IS CONSIDERED CRITICAL FOR A BETTER UNDERSTANDING OF THE LOSS OF IDENTITY OF EPITHELIAL CELLS DURING CARCINOGENESIS OF THIS TISSUE. THE MAIN OBJECTIVE OF THIS REVIEW WAS TO ESTABLISH THE IMPORTANCE OF CHANGES OCCURRING TO TRANSCRIPTIONAL LEVEL IN THE MAMMARY GLAND AS A CONSEQUENCE OF ACUTE OR CHRONIC EXPOSURE TO HARMFUL PRODUCTS SUCH AS OBESITY-CAUSING FOODS, ETHANOL AND CIGARETTE SMOKE COMPONENTS. AT ANALYZE THE MAIN STUDIES RELATED TO TOPIC, IT HAS CONCLUDED THAT THE UNDERSTANDING OF EFFECTS CAUSED BY THE LIFESTYLE FACTORS IN PERFORMANCE OF THE TRANSCRIPTIONAL MECHANISMS THAT DETERMINE GENE EXPRESSION OF THE MAMMARY GLAND EPITHELIAL CELLS, MAY HELP EXPLAIN THE DEVELOPMENT OF THIS DISEASE IN WOMEN WITHOUT GENETIC PROPENSITY AND DIFFERENT PHENOTYPIC MANIFESTATIONS OF THIS CANCER TYPE. 2016 14 186 43 ACCUMULATION OF GENETIC AND EPIGENETIC ALTERATIONS IN NORMAL CELLS AND CANCER RISK. CANCERS DEVELOP DUE TO THE ACCUMULATION OF GENETIC AND EPIGENETIC ALTERATIONS. GENETIC ALTERATIONS ARE INDUCED BY AGING, MUTAGENIC CHEMICALS, ULTRAVIOLET LIGHT, AND OTHER FACTORS; WHEREAS, EPIGENETIC ALTERATIONS ARE MAINLY BY AGING AND CHRONIC INFLAMMATION. THE ACCUMULATION AND PATTERNS OF ALTERATIONS IN NORMAL CELLS REFLECT OUR PAST EXPOSURE LEVELS AND LIFE HISTORY. MOST ACCUMULATED ALTERATIONS ARE CONSIDERED AS PASSENGERS, BUT THEIR ACCUMULATION IS CORRELATED WITH CANCER DRIVERS. THIS HAS BEEN SHOWN FOR ABERRANT DNA METHYLATION BUT HAS ONLY BEEN SPECULATED FOR GENETIC ALTERATIONS. HOWEVER, RECENT TECHNOLOGICAL ADVANCEMENTS HAVE ENABLED MEASUREMENT OF RARE POINT MUTATIONS, AND STUDIES HAVE SHOWN THAT THEIR ACCUMULATION LEVELS ARE INDEED CORRELATED WITH CANCER RISK. WHEN THE ACCUMULATION LEVELS OF ABERRANT DNA METHYLATION AND POINT MUTATIONS ARE COMBINED, RISK PREDICTION BECOMES EVEN MORE ACCURATE. WHEN HIGH LEVELS OF ALTERATIONS ACCUMULATE, THE TISSUE HAS A HIGH RISK OF DEVELOPING CANCER OR EVEN MULTIPLE CANCERS AND IS CONSIDERED AS A "CANCERIZATION FIELD", WITH OR WITHOUT EXPANSION OF PHYSIOLOGICAL PATCHES OF CLONAL CELLS. IN THIS REVIEW, WE DESCRIBE THE FORMATION OF A CANCERIZATION FIELD AND HOW WE CAN APPLY ITS DETECTION IN PRECISION CANCER RISK DIAGNOSIS. 2019 15 4429 41 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 16 4431 54 MOLECULAR CARCINOGENESIS OF HEPATOCELLULAR CARCINOMA AND INTRAHEPATIC CHOLANGIOCARCINOMA: ONE STEP CLOSER TO PERSONALIZED MEDICINE? HEPATOCELLULAR CARCINOMA (HCC) AND INTRAHEPATIC CHOLANGIOCARCINOMA (ICC) ARE THE TWO MAJOR FORMS OF PRIMARY LIVER CANCERS (PLC), ACCOUNTING FOR APPROXIMATELY 90% AND 5% RESPECTIVELY. THE INCIDENCE OF EACH IS INCREASING RAPIDLY IN THE WESTERN WORLD, HOWEVER OUR KNOWLEDGE OF THE UNDERLYING MECHANISMS REMAINS LIMITED AND THE OUTCOME, DISMAL. THE ETIOLOGIES OF EACH VARY GEOGRAPHICALLY; NEVERTHELESS, CHRONIC INFLAMMATION HAS BEEN IDENTIFIED IN MORE THAN 80% OF THE CASES AND APPEARS TO BE A KEY MEDIATOR IN ALTERING THE LIVER MICROENVIRONMENT, INCREASING THE RISK OF CARCINOGENESIS. HOWEVER, SINCE NOT ALL HCC AND ESPECIALLY ICC CASES HAVE A RECOGNIZED RISK FACTOR, THERE ARE CURRENTLY TWO PROPOSED MODELS FOR LIVER CARCINOGENESIS. THE CLONAL EVOLUTION MODEL DEMONSTRATES A MULTI-STEP PROCESS OF TUMOR DEVELOPMENT FROM PRECANCEROUS LESIONS TO METASTATIC CARCINOMA, ARISING FROM THE ACCUMULATION OF GENETIC AND EPIGENETIC CHANGES IN A CELL IN THE SETTING OF CHRONIC INFLAMMATION. WHILE THE MAJORITY OF CASES DO OCCUR AS A CONSEQUENCE OF CHRONIC INFLAMMATION, MOST INDIVIDUALS WITH CHRONIC INFECTION DO NOT DEVELOP PLC, SUGGESTING THE INVOLVEMENT OF INDIVIDUAL GENETIC AND ENVIRONMENTAL FACTORS. FURTHER, SINCE HEPATOCYTES AND CHOLANGIOCYTES BOTH HAVE REGENERATIVE POTENTIAL AND ARISE FROM THE SAME BI-POTENTIAL PROGENITOR CELL, THE MORE RECENTLY PROPOSED CANCER STEM CELL MODEL IS GAINING ITS DUE ATTENTION. THE INTEGRATION OF THESE MODELS AND THE CONSTANT IMPROVEMENT IN MOLECULAR PROFILING PLATFORMS IS ENABLING A BROADER UNDERSTANDING OF THE MECHANISMS UNDERLYING THESE TWO DEVASTATING MALIGNANCIES, PERHAPS MOVING US CLOSER TO A NEW WORLD OF MOLECULARLY-INFORMED PERSONALIZED MEDICINE. 2011 17 6428 43 THE TUMOR MICROENVIRONMENT AND METASTATIC DISEASE. THE MICROENVIRONMENT OF SOLID TUMORS IS A HETEROGENEOUS, COMPLEX MILIEU FOR TUMOR GROWTH AND SURVIVAL THAT INCLUDES FEATURES SUCH AS ACIDIC PH, LOW NUTRIENT LEVELS, ELEVATED INTERSTITIAL FLUID PRESSURE (IFP) AND CHRONIC AND FLUCTUATING LEVELS OF OXYGENATION THAT RELATE TO THE ABNORMAL VASCULAR NETWORK THAT EXISTS IN TUMORS. THE METASTATIC POTENTIAL OF TUMOR CELLS IS BELIEVED TO BE REGULATED BY INTERACTIONS BETWEEN THE TUMOR CELLS AND THEIR EXTRACELLULAR ENVIRONMENT (EXTRACELLULAR MATRIX (ECM)). THESE INTERACTIONS CAN BE MODIFIED BY THE ACCUMULATION OF GENETIC CHANGES AND BY THE TRANSIENT ALTERATIONS IN GENE EXPRESSION INDUCED BY THE LOCAL TUMOR MICROENVIRONMENT. CLINICAL AND EXPERIMENTAL EVIDENCE SUGGESTS THAT ALTERED GENE EXPRESSION IN RESPONSE TO THE HYPOXIC MICROENVIRONMENT IS A CONTRIBUTING FACTOR TO INCREASED METASTATIC EFFICIENCY. A NUMBER OF GENES THAT HAVE BEEN IMPLICATED IN THE METASTATIC PROCESS, INVOLVING ANGIOGENESIS, INTRA/EXTRAVASATION, SURVIVAL AND GROWTH, HAVE BEEN FOUND TO BE HYPOXIA-RESPONSIVE. THE VARIOUS METASTATIC DETERMINANTS, GENETIC AND EPIGENETIC, SOMATIC AND INHERITED MAY SERVE AS PRECEDENTS FOR THE FUTURE IDENTIFICATION OF MORE GENES THAT ARE INVOLVED IN METASTASIS. MUCH RESEARCH HAS FOCUSED ON GENETIC AND MOLECULAR PROPERTIES OF THE TUMOR CELLS THEMSELVES. IN THE PRESENT REVIEW WE DISCUSS THE EPIGENETIC AND PHYSIOLOGICAL REGULATION OF METASTASIS AND EMPHASIZE THE NEED FOR FURTHER STUDIES ON THE INTERACTIONS BETWEEN THE PATHOPHYSIOLOGIC TUMOR MICROENVIRONMENT AND THE TUMOR EXTRACELLULAR MATRIX. 2009 18 1407 47 DIETARY INFLUENCES ON MUTAGENESIS--WHERE IS THIS FIELD GOING? EARLY STUDIES ON DIETARY MUTAGENESIS WERE MOSTLY OBSERVATIONAL, WITH LARGE NUMBERS OF POTENTIAL DIETARY MUTAGENS BEING IDENTIFIED FROM EVERY CONCEIVABLE DIETARY SOURCE. THESE INCLUDED KNOWN DIETARY CARCINOGENS SUCH AS AFLATOXIN B1 AND BENZO[A]PYRENE, AND HITHERTO UNRECOGNIZED DIETARY MUTAGENS, SUCH AS THE PYROLYSIS PRODUCTS FORMED DURING THE HEATING OF PROTEINACEOUS MATERIALS (HETEROCYCLIC AMINES). THE 1993 EVALUATION OF 2-AMINO-3-METHYL-3H-IMIDAZO(4,5-J)QUINOLINE AS A PROBABLE HUMAN CARCINOGEN BY THE INTERNATIONAL AGENCY FOR RESEARCH ON CANCER WAS A LANDMARK, AS THIS WAS DONE IN THE ABSENCE OF SPECIFIC HUMAN CARCINOGENICITY DATA, AND STRONGLY INFLUENCED BY MUTAGENICITY TEST DATA. IN THE 21ST CENTURY, THE FIELD HAS MOVED FROM THE IDENTIFICATION OF MORE AND MORE MUTAGENS, TO MOLECULAR EPIDEMIOLOGIC APPROACHES THAT NOT ONLY SHOW A MUTAGENIC EFFECT BUT ALSO SEEK TO LINK IT TO A DIETARY (OR ENVIRONMENTAL) CAUSE. EFFECTS OF DIET IN STIMULATING CHRONIC INFLAMMATION MAY LEAD TO REACTIVE SPECIES AND THEREBY MUTATION AS A SECONDARY CONSEQUENCE, WHILE DIETARY DEFICIENCIES AND NUTRIENT IMBALANCES MAY BE STRONG SOURCES OF MUTAGENESIS. RECOGNITION OF THE ROLES OF NUTRIENTS IN CELL SIGNALING PROCESSES AND CONTROL OF MICRORNAS SUGGEST MAJOR INFLUENCES ON GENE EXPRESSION, IN THE ABSENCE OF PERMANENT DNA CHANGES. GENOME-WIDE ASSOCIATION STUDIES HAVE HIGHLIGHTED NEW PATHWAYS SUCH AS JAK/STAT SIGNALING THAT PROFOUNDLY INFLUENCE GENOMIC INSTABILITY AND RESPONSES TO DIETARY MUTAGENS. WITH IMPROVED METHODOLOGIES FOR DNA SEQUENCING AND EPIGENETIC CHANGES, IT IS TIME TO APPLY MORE SOPHISTICATED APPROACHES TO RECOGNIZING AND PROVING THE ROLE OF DIET AS A PRIMARY MODULATOR OF MUTAGENESIS IN HUMANS. 2010 19 6653 40 UPDATE ON PANCREATIC CANCER AND ALCOHOL-ASSOCIATED RISK. DUCTAL ADENOCARCINOMA OF THE PANCREAS IS CHARACTERIZED BY EXTREMELY AGGRESSIVE BEHAVIOR, WITH AN OVERALL 5-YEAR SURVIVAL OF <4%. BECAUSE CONVENTIONAL AND SPECIFICALLY TAILORED THERAPEUTIC REGIMENS HAVE LITTLE IMPACT ON PATIENT SURVIVAL, EPIDEMIOLOGICAL AND MOLECULAR RESEARCH AIMS AT IDENTIFYING AND REDUCING RISK FACTORS. CIGARETTE SMOKING, OBESITY, DIABETES MELLITUS, AND CHRONIC PANCREATITIS ARE AMENABLE TO MEDICAL PREVENTION OR THERAPY. HEAVY ALCOHOL CONSUMPTION IS AN INCONSISTENT SINGLE RISK FACTOR FOR PANCREATIC CANCER BUT MAY PROMOTE CARCINOGENESIS BY INCREASING THE RISK OF DIABETES MELLITUS OR CHRONIC PANCREATITIS. FOR VARIOUS AGENTS, THE KEY CARCINOGENIC EFFECT IS PROBABLY AN INFLAMMATORY RESPONSE IN THE PANCREATIC TISSUE. ON THE MOLECULAR LEVEL, MUTATIONS OF ONCOGENES AND TUMOR SUPPRESSOR GENES, AS WELL AS VARIOUS EPIGENETIC ALTERATIONS, SUCH AS OVEREXPRESSION OF GROWTH FACTORS AND THEIR RECEPTORS, ARE IMPORTANT IN TUMORIGENESIS. COMPLETE AND SAFE SURGICAL RESECTION, TOGETHER WITH ADJUVANT THERAPY, OFFERS PROLONGED SURVIVAL, WITH 5-YEAR SURVIVAL RATES OF APPROXIMATELY 25%. HOWEVER, FOR UNRESECTABLE OR DISSEMINATED DISEASE, WHICH CONSTITUTES THE VAST MAJORITY OF CASES, TREATMENT IS PALLIATIVE. DESPITE INCREASING KNOWLEDGE ABOUT THE MOLECULAR PATHOLOGY OF PANCREATIC CANCER AND DESPITE ADVANCES IN TREATMENT, THE OVERALL COURSE OF THE DISEASE IS DISMAL, AND REINFORCED EFFORTS TO REDUCE INCIDENCE AND IMPROVE OUTCOME ARE NEEDED DESPERATELY. 2006 20 5373 55 RECENT ADVANCES IN UNDERSTANDING THE ROLE OF DIET AND OBESITY IN THE DEVELOPMENT OF COLORECTAL CANCER. COLORECTAL CANCER (CRC) IS A MAJOR CAUSE OF PREMATURE DEATH IN THE UK AND MANY DEVELOPED COUNTRIES. HOWEVER, THE RISK OF DEVELOPING CRC IS WELL RECOGNISED TO BE ASSOCIATED NOT ONLY WITH DIET BUT ALSO WITH OBESITY AND LACK OF EXERCISE. WHILE EPIDEMIOLOGICAL EVIDENCE SHOWS AN ASSOCIATION WITH FACTORS SUCH AS HIGH RED MEAT INTAKE AND LOW INTAKE OF VEGETABLES, FIBRE AND FISH, THE MECHANISMS UNDERLYING THESE EFFECTS ARE ONLY NOW BEING ELUCIDATED. CRC DEVELOPS OVER MANY YEARS AND IS TYPICALLY CHARACTERISED BY AN ACCUMULATION OF MUTATIONS, WHICH MAY ARISE AS A CONSEQUENCE OF INHERITED POLYMORPHISMS IN KEY GENES, BUT MORE COMMONLY AS A RESULT OF SPONTANEOUSLY ARISING MUTATIONS AFFECTING GENES CONTROLLING CELL PROLIFERATION, DIFFERENTIATION, APOPTOSIS AND DNA REPAIR. EPIGENETIC CHANGES ARE OBSERVED THROUGHOUT THE PROGRESS FROM NORMAL MORPHOLOGY THROUGH FORMATION OF ADENOMA, AND THE SUBSEQUENT DEVELOPMENT OF CARCINOMA. THE REASONS WHY THIS ACCUMULATION OF LOSS OF HOMOEOSTATIC CONTROLS ARISES ARE UNCLEAR BUT CHRONIC INFLAMMATION HAS BEEN PROPOSED TO PLAY A CENTRAL ROLE. OBESITY IS ASSOCIATED WITH INCREASED PLASMA LEVELS OF CHEMOKINES AND ADIPOKINES CHARACTERISTIC OF CHRONIC SYSTEMIC INFLAMMATION, AND DIETARY FACTORS SUCH AS FISH OILS AND PHYTOCHEMICALS HAVE BEEN SHOWN TO HAVE ANTI-INFLAMMATORY PROPERTIES AS WELL AS MODULATING ESTABLISHED RISK FACTORS SUCH AS APOPTOSIS AND CELL PROLIFERATION. THERE IS ALSO SOME EVIDENCE THAT DIET CAN MODIFY EPIGENETIC CHANGES. THIS PAPER BRIEFLY REVIEWS THE CURRENT STATE OF KNOWLEDGE IN RELATION TO CRC DEVELOPMENT AND CONSIDERS EVIDENCE FOR POTENTIAL MECHANISMS BY WHICH DIET MAY MODIFY RISK. 2011