Appearance of fibronectin in putative preneoplastic lesions and in hepatocellular carcinoma during chemical hepatocarcinogenesis in rats and in human hepatomas.

The distribution of a high-molecular-weight glycoprotein, fibronectin (FN), was studied by immunohistochemical methods in putative preneoplastic lesions, as well as in fully developed hepatocellular carcinomas, formed in rats during chemical hepatocarcinogenesis, and in 10 human hepatomas. All but two preneoplastic lesions contained FN in their intercellular matrix. FN was present around groups of transformed liver cells, as well as on the surfaces and in the cytoplasms of certain cells. A similar, typically altered, distribution pattern was seen in the majority of the carcinomas studied. Six out of seven human hepatocellular carcinomas were found to contain FN. In three cases of cholangiocarcinoma, FN was, however, confined to the reactive stroma only. The presence of FN in hepatomas, which is in contrast to carcinomas of other organs, may serve as a marker for the demonstration of preneoplastic lesions of experimental carcinogenesis and for diagnostic differentiation of human hepatomas.