Malignant behaviour of three adenovirus-2-transformed brain cell lines and their methyl cellulose-selected sub-clones

Three adenovirus-2-transformed rat embryo brain cell lines and their methylcellulose-selected sub-clones were examined for fibronectin expression, anchorage-independent growth, saturation density, T antigen expression and morphology. Tumorigenicity studies were carried out on newborn and ATS immunosuppressed syngeneic rats and congenitally athymic nude mice. With one exception the methylcellulose sub-clones contained significantly fewer fibronectin-positive cells than the parent lines; a number of sub-clones contained no fibronectin-positive cells. Methylcellulose selection did not always alter cell morphology, saturation density or anchorage-independent growth as compared with parent lines. However, the methylcellulose sub-clones were considerably more malignant than the parent cell lines as measured by invasion and metastasis in nude mice. No in vitro characteristic correlated with malignant behaviour.