[Distribution of surface fibronectin in low- and high-density cultures of normal and transformed mouse fibroblasts].

Indirect immunofluorescence was used to study the distribution of surface fibronectin in normal embryonic and in four lines of transformed mouse fibroblasts. Accumulation of the fibronectin matrix with increasing culture density was discovered not only in normal but also in transformed cells. In three out of the four transformed lines studied, fibronectin was found in a considerable amount, which is in agreement with the data obtained with lactoperoxidase iodination. In these neoplastic lines, fibronectin was organized in the form of a fibrillar network like in normal cells. The data provided indicate that the changes in fibronectin content upon neoplastic transformation should be evaluated in dense cultures with maximum expression of this glycoprotein.