Modulation of fibronectin, laminin, and cellular adhesion in the transformation and differentiation of murine AKR fibroblasts

The functional relationship between membrane/cell surface expression of fibronectin and laminin and transformation/differentiation was examined in an AKR mouse fibroblastic cell model. This model consisted of the untransformed AKR‐2B cells, their chemically transformed counterpart (AKR‐MCA cells) and the chemically differentiated from of the AKR‐MCA cells. The transformed AKR‐MCA cells were found to express more surface laminin and less fibronectin than the untransformed AKR‐2B cells. The transformed AKR‐MCA cells were slower to attach and spread on both plastic and type IV collagen‐coated dishes in comparison of the AKR‐2B cells. However, a higher percentage of the AKR‐MCA cells ultimately attached and spread on the type IV collagen‐coated dishes. The induction of differentiation in the AKR‐MCA cells by N, N‐dimethylformamide (DMF) restored fibronection to the surface of the AKR‐MCA cells but reduced laminin expression only slightly. The DMF‐treated AKR‐MCA cells resembled the AKR‐2B cells in that they rapidly attached and spread on plastic dishes and dishes coated with type IV collagen. They also resembled the AKR‐ MCA cells in that a high proportion ultimately attached and spread on the collagen‐coated dishes.