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 lin e PC-1.0, was tested for its efficiency in promoting the in vitro adhe sion of normal and tumor cells (pancreas, lung, kidney, colon, breast, skin, prostate, neuroblast, melanocyte) derived from human, monkey, b ovine, hamster, and rat sources. Using a modification of the dimethylt hyazol diphenyl tetrazolium (MTT) assay, the factor was found to induc e 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 presen ce or absence of the factor. Conditioned medium of each cell line test ed showed significantly less adhesion effect than that produced by PC- 1.0 cells. Because our previous study indicated that the adhesion fact or produced by PC-1.0 cells differed from known growth factors and adh esion molecules including fibronectin, vibronectin, laminin, and colla gen, it appears that PC-1.0 cells produce a novel adhesion factor that enhances adherence of normal and malignant cells of different species .