title: Mechanisms of cadmium carcinogenicity in the gastrointestinal tract.
abstract: Cancer, a serious public health problem in worldwide, results from an excessive and uncontrolled proliferation of the body cells without obvious physiological demands of organs. The gastrointestinal tract, including the esophagus, stomach and intestine, is a unique organ system. It has the highest cancer incidence and cancer- related mortality in the body and is influenceed by both genetic and environmental factors. Among the various chemical elements recognized in the nature, some of them including zinc, iron, cobalt, and copper have essential roles in the various biochemical and physiological processes, but only at low levels and others such as cadmium, lead, mercury, arsenic, and nickel are considered as threats for human health especially with chronic exposure at high levels. Cadmium, an environment contaminant, cannot be destroyed in nature. Through impairment of vitamin D metabolism in the kidney it causes nephrotoxicity and subsequently bone metabolism impairment and fragility. The major mechanisms involved in cadmium carcinogenesis could be related to the suppression of gene expression, inhibition of DNA damage repair, inhibition of apoptosis, and induction of oxidative stress. In addition, cadmium may act through aberrant DNA methylation. Cadmium affects multiple cellular processes, including signal transduction pathways, cell proliferation, differentiation, and apoptosis. Down-regulation of methyltransferases enzymes and reduction of DNA methylation have been stated as epigenetic effects of cadmium. Furthermore, increasing intracellular free calcium ion levels induces neuronal apoptosis in addition to other deleterious influence on the stability of the genome.
authors: Student Research Committee, Nutrition Research Center, Department of Nutrition, Tabriz University of Medical sciences, Tabriz, Iran E-mail : nourazariana@tbzmed.ac.ir.
authors: Yaser Khaje
authors: YK
authors: Bishak
authors: Laleh
authors: L
authors: Payahoo
authors: Alireza
authors: A
authors: Osatdrahimi
authors: Alireza
authors: A
authors: Nourazarian
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002104:Cadmium / Q000633:toxicity*; D002273:Carcinogens / Q000633:toxicity*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced*; D019175:DNA Methylation / Q000187:drug effects; D004260:DNA Repair / Q000187:drug effects; D004785:Environmental Pollutants; D005770:Gastrointestinal Neoplasms / Q000139:chemically induced* / Q000453:epidemiology; D041981:Gastrointestinal Tract / Q000473:pathology*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D008780:Methyltransferases / Q000096:biosynthesis; D018384:Oxidative Stress / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D002273:Carcinogens; D004785:Environmental Pollutants; D002104:Cadmium; D008780:Methyltransferases