[Disruption of intercellular contacts and cell-extracellular matrix interaction in rapidly growing murine...

A rapidly growing anaplastic variant spontaneously separating from differentiated transplanted hepatocarcinoma of mice differed from the parental tumour by a severe reduction of intercellular contacts, by alteration of interaction with extracellular matrix (ECM), speed of growth, loss of cell polarity and expression of some specific liver proteins. Almost all the cells in the parental tumor directly contact with ECM and, besides this, the tumor cells are surrounded by collagens of type I and IV. The majority of the cells in the rapidly growing tumor do not contact with matrix fibrillae. Cell culture of this variant retained its characteristics. Culture cells synthetize all the matrix components studied but collagens of type I and IV are lacking between matrix deposits. The critical stage responsible for the phenotypic changes in the anaplastic variant seem to be the disturbances in the system of integrins, reacting with collagens, in particular.