Cell lines derived from human tumors of 4 different histo-described (Carey et al., 1976;Kimmel and Carey, 1986; logical types (SWamous carcinoma, melanomas, gliomas and McKeever et al., 1986; Varani et al., 1986). All of the lines a fibrosarcoma) were examined for cell-substrate adhesion on were grown in monolayer culture using minimal essential plastic culture dishes and dishes coated with 50 pg of type-IV medium of ~~~l~ (MEM) with ~~~l ~' salts, non-essential collagen. In the absence of exogenous adhesion factors the squamous carcinoma cells attached and spread amino acids, L-glutamine and 15% fetal bovine serum as the than the other cells on both substrates. Once attached, the "lture medium* The were grown at 370c and 5% c02 squamous carcinoma cells were also more difficult than the and subcultured by tVPsiniZatiOn as required. other cells to remove with proteolytic enzymes/EDTA. While R~~~~~~~ the cell lines derived from melanomas, gliomas and the fibrosarcoma were less adhesive than the squamous carcinoma Laminin prepared in our laboratory or purchased from lines in the absence of exogenous adhesion factors, these cells GIBCO (Grand Island, NY) was isolated from the murine were highly responsive to laminin. In contrast, laminin only Englebreth-Holm-Swam (EHS) tumor by the method of Timpl Slightly enhanced the attachment and spreading of squamous et al. (1979). The purity of each lot of laminin was confirmed carcinoma cells on the plastic dishes and actually inhibited by sodium dodecyl sulfate-polyacrylamide gel electrophoresis characteristic of laminin A (M, = 400,000) and B (M, = results indicate that there are tumor-type-specific differences in adhesiveness among human tumor cell lines and that cells from different tumor types may have distinct mechanisms for 2 ~, ~)
subunits, Were Seen on the gels after staining with carrying out one of the functions critical to invasion.
MATERIAL AND METHODS
Cells
lines were used. 4T0 whom reprint requests should be sent, at the Department of Pathol-Among these were 10 squamous cell carcinoma lines derived ogy,