DIFFERENTIAL EXPRESSION OF A LAMININLIKE SUBSTANCE BY HIGH-METASTATIC AND LOW-METASTATIC TUMOR-CELLS

Abstract

High-metastatic murine fibrosarcoma cells readily attached to Type IV (basement membrane) collagen, whereas low-metastatic cells isolated from the same tumor did not. The addition of laminin-a glycoprotein that facilitates the adherence of epithelial cells to their baasement membranes-enhanced the attachment of the low-metastatic cells, but not the high-metastatic cells. Using anti-laminin antibodies and a laminin-binding lectin as probes, a moiety associated with the high-metastatic cells, but not the low-metastatic cells, which cross-reacted with murine laminin purified from the EHS sarcoma was identified by immunofluorescence. When extracts from the high-metastatic cells were separated by affinity chromatography with the laminin-binding lectin as the affinity substrate, a substance was isolated that had an apparent MW of 56,000 daltons. The affinity-purified material reacted strongly with anti-laminin antibodies by enzyme-linked immunosorbent assay.