[Establishment of a new culture system for fetal human tracheobronchus]

Human tracheobronchial tissues were cultured in CMRL 1066 medium containing insulin, hydrocortisone, bovine pituitary extract, and trace elements, with or without fetal bovine serum, in a rocked atmosphere chamber. The morphology of the epithelium remained normal for two months after in organ culture, and then, squamous metaplasia appeared in the epithelium and maintained for more than one year. There were continuous epithelial outgrowths from the human tracheobronchial tissues during the whole duration of organ culture, and the epithelial outgrowth can be subcultured in MCDB 151 medium supplemented with growth factors and grew as a tightly packed monolayer of polygonal cells with the presence of keratin and microvilli. The advantages of organ culture and epithelial cell culture were combined in this new culture system. The new culture model has already been used for the investigation of in vitro transformation of human tracheobronchial epithelial cells by chemical carcinogens in our laboratory.