Adhesion to laminin and expression of laminin in clonally related transformed and control sublines from an alveolar epithelial cell strain.

Abstract

Clonally related sublines of the NAL1A cell strain were used to examine the expression of laminin and the importance for the attachment and morphology of these control and spontaneously transformed alveolar epithelial cells. A laminin component was detected by immunoblot analysis in extracts of control cells cultured on plastic as a Mr 410,000 species consisting of disulfide-linked Mr 200,000 components. The laminin content of the malignant cells was reduced at least 40-fold as compared to that of the control cells. Cell attachment to laminin or to a laminin-like neurite promotion factor was compared with attachment to fibronectin and to extracellular matrix from bovine endothelial cells. Both control and transformed cells attached as well to laminin or neurite promotion factor as to fibronectin, in a serum-free adhesion assay. The control cells showed enhanced cell spreading on the surfaces coated with laminin, neurite promotion factor, or fibronectin. The transformed cells had very similar cell shape, as determined by phase contrast and scanning electron microscopy, when cultured on laminin or neurite promotion factor or fibronectin, as on tissue culture plastic.