Unscheduled DNA synthesis in human bronchial epithelium treated with various chemical carcinogens in vitro.
A system was developed in which organ culture of human bronchial epithelium was used in combination with autoradiography for quantitative measurement of unscheduled DNA synthesis (UDS) in bronchial epithelial cells. Human bronchi obtained at surgery were cut into small sections and treated with various carcinogens plus [methyl-3H]thymidine in short-term organ culture. Significant numbers of silver grains, indicating UDS, were detected on the nuclei of epithelial cells of human bronchi treated with carcinogens, and the numbers were proportional to the concentrations of carcinogens. In this system seven representative carcinogens induced UDS. Four active metabolites of benzo[a]pyrene, and benz[a]anthracene also were found to induce very active UDS in human bronchial epithelium. These findings suggest that human bronchial epithelial cells can repair different types of DNA modification induced by chemical carcinogens.
D001345:Autoradiography; D001980:Bronchi / Q000187:drug effects / Q000378:metabolism*; D002273:Carcinogens / Q000633:toxicity*; D004261:DNA Replication / Q000187:drug effects*; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D009924:Organ Culture Techniques; D013936:Thymidine / Q000378:metabolism; D014316:Tritium
D002273:Carcinogens; D014316:Tritium; D013936:Thymidine