PPT-Chemical carcinogenesis DR. AYSER HAMEED

LEC5 Chemical carcinogenesis General principles of chemical carcinogens I Could be natural or synthetic chemical   II Chemicals either direct acting chemical active without transformation in the body. scielobraabc Chemical carcinogenesis PAULA A OLIVEIRA AURA COLA57543O RAQUEL CHAVES HENRIQUE GUEDESPINTO LUIS F DELACRUZ P and CARLOS LOPES Department of Veterinary Sciences CECAV University of Tr57569sosMontes and Alto Douro 5000801 Vila Real Por ProportionPercentageChemicals tested in both rats and mice 350/59059%Naturally occurring chemicals 79/13957%Synthetic chemicals 271/45160%Chem. in Carcinogen. Potency Database 702/134852%Natural pesti Topics for Principles of Toxicology: Part B. Endocrine Toxicity. Carcinogenicity. Neurotoxicity. Persistence and Bioaccumulation. The topics for “Part C” (what we could not cover). Summary. The systemic problem. Carcinogenesis. Are there differences in the mechanisms of carcinogenesis associated with chemical, radiation, or dietary carcinogens?. What is Carcinogenesis?. Carcinogenesis is the production of cancer cells or the process of normal cells transforming into cancerous cells. . A. Abdel . Baky. Associate Professor. Pharmacology and Toxicology. Carcinogenesis. Carcinogenesis is a multistep process at both the phenotypic and the genetic levels . that . end with the disease . DroughtandfoodsecurityinthemiddleeastAnanalyticalframeworkMaysounHameedAliAhmadalipourHamidMoradkhaniCenterforComplexHydrosystemsResearchDepartmentofCivilConstructionandEnvironmentalEngineeringUnivers LEC.2. Most benign tumors grow slowly . & most of cancers grow faster . & eventually spread locally & to distant sites (metastasis) & causing death.. In some exception, some benign tumors grow more rapidly than some cancers e.g. leiomyoma (uterine fibroid), which is benign smooth muscle tumor influence by estrogen & so increase in size during pregnancy.. LEC.1. General Features . Inflammation is defined as "the response of living . vascularized. tissues to harmful agents.”. . It consists principally of vascular changes associated with leukocytes infiltration and systemic reactions. LEC.2. Binding of a particle to . phagocytic. leukocyte receptors initiates the process of active . phagocytosis. .. During engulfment, extensions of the cytoplasm (. pseudopods. ) flow around the particle to be engulfed, eventually resulting in complete enclosure of the particle within a . LEC.4. Examples of tumor suppressor genes:. 1. RB gene:. This is the . first discovered suppressor gene. , . loss of normal RB gene was discovered initially in Retinoblastoma, but recently proved it lost in many tumors (breast cancer, bladder & lung cancer, osteosarcoma).. LEC.3. Incidence of cancer. In male. . 30% Carcinoma of prostate. .. 14% Carcinoma of Lung.. 11% Carcinoma of colon & rectum.. In female. . . 31% breast carcinoma. .. 12% carcinoma of lung. . LEC.1. Abnormal mass of tissue. , characterized by followings:- . Its . growth is uncoordinated & exceeded. with that of the normal tissues.. Neoplasm . persist its growth after the cessation of stimuli which cause the change.. LEC.4. Carcinogenesis:. is a multistep process at both . phenotypic & genetic levels.. Phenotypic level . includes:. I. Excessive growth.. II. Local invasion.. III. Metastasis.. These three criteria are called collectively . LEC.5. 3. Evasion of apoptosis:. Normally, . the mechanism of . apoptosis is mediated by many genes, & achieve by two phases. . Initiation phase. , which is mediated by . TNF- Fas receptor . & inhibited by FLIP protein..