[Protein-free culture of esophageal cancer cell lines]

We have established 13 esophageal cancer cell lines capable of growing in a protein-free environment. The growth of these cells was not affected by conditioned medium, but the growth of NIH3T3 cells and human fibroblasts was stimulated by conditioned medium. On the other hand, conditioned medium inhibited the growth of human endothelial cells. Amplified int-2 oncogene correlated well with the growth of cells in a protein-free environment but the number of EGF receptors and growth effect of EGF did not relate to such growth. Esophageal cancer cells grow automatically, possibly involving mesenchymal cells via the paracrine system. This results in a poor prognosis in patients.