Identification of transformed rat liver epithelial cells in culture

The growth potential of normal and transformed rat liver epithelial cells in culture was investigated under various experimental conditions. The control cells failed to form colonies over a base layer of living parent cells, whereas transformed cells formed distinct colonies. Contact with living normal liver cells is required for the growth inhibition of the untransformed cells. Malignant cells capable of producing hepatocellular carcinomas in vivo exhibited signs of invasion in vitro. Altered properties of hepatic cells during the early stages of transformation can be assessed by plating such cell population over a living base layer of normal liver cells.