[Effects of nitrosamine on in vitro cultured human esophageal epithelial cells].

Explant-cell culture system of human esophageal mucosa was used for studying the in vitro biological effects of nitrosamines, the major suspected causative agents of esophageal cancer in Linxian County, on esophageal epithelial cells. These carcinogens showed a cytotoxic effect in most of the 10 cases tested. A dose-response relationship of cell number reduction was observed at certain dose range. However, the effect of these carcinogens on cellular DNA synthesis was not always suppressive. At certain concentrations, nitrosamines mainly stimulated DNA synthesis in all of the 4 cases studied. The cells treated by these carcinogens seemed to have an enhanced growth potential during subculturing.