A novel adhesion factor produced by hamster pancreatic cancer cell line is effective on normal and carcinoma cell lines of different species.

An adhesion factor, produced by the hamster pancreatic cancer cell line PC-1.0, was tested for its efficiency in promoting the in vitro adhesion of normal and tumor cells (pancreas, lung, kidney, colon, breast, skin, prostate, neuroblast, melanocyte) derived from human, monkey, bovine, hamster, and rat sources. Using a modification of the dimethylthyazol diphenyl tetrazolium (MTT) assay, the factor was found to induce adhesion in all cell lines in a dose-dependent manner. Although the effect was variously expressed, there was a statistically significant difference between the MTT absorbance of cells incubated in the presence or absence of the factor. Conditioned medium of each cell line tested showed significantly less adhesion effect than that produced by PC-1.0 cells. Because our previous study indicated that the adhesion factor produced by PC-1.0 cells differed from known growth factors and adhesion molecules including fibronectin, vibronectin, laminin, and collagen, it appears that PC-1.0 cells produce a novel adhesion factor that enhances adherence of normal and malignant cells of different species.