Laminin receptors on SCLC cells.

Several studies have suggested a correlation between the metastatic potential and the expression of adhesion molecules and/or their receptors on tumour cell surface membranes. In this study we investigated the expression of functional laminin receptors on small cell lung cancer (SCLC) cells. To this aim we set up an adherence assay to determine the in vitro binding capability of tumour cell lines to laminin. All of the three SCLC lines tested and cells from a short-term SCLC line adhered to laminin in cell culture plates, and the affinity of cell-matrix adhesion proved to be higher than the cell-cell adhesion. This effect was always laminin dose-dependent. On a laminin affinity chromatography column three major proteins could be eluted with EDTA from soluble extracts of SCLC lines. Their molecular weights of 120, 90 and 30 kDa suggested a possible relationship with the integrin family. This putative integrin laminin receptor expressed on SCLC does not react with fibronectin, vitronectin or collagen.