Extracellular matrix proteins characterize human tumor cell lines

Abstract

Extracellular matrix proteins synthesized and secreted by adherent human tumor cell lines were analyzed using metabolic labelling with glycine and proline in the presence of ascorbate, polypeptide analysis by polyacrylmide gel electrophoresis, affinity chromatography, collagenase digestion, and immunofluorescence staining. The results showed a characteristic pattern of matrix proteins for each tumor cell type. Tumor cell lines of mesenchymal origin produced mostly interstitial types (I and III) of collagen and fibronectin. Carcinoma cell lines secreted only basement membrane proteins, type IV collagen, laminin and fibronectin, but not interstitial collagens. A melanoma and a rhabdomyosarcoma cell line produced type V of procollagen that has not previously been described in cell culture. Neuroblastoma cells were shown to be phenotypically heterogeneous also with respect to matrix protein production. We propose that the analysis of extracellular matrix proteins may serve as an adjunct in the classification of human tumors.