The effect of conditioned medium on fetal human liver cells in primary culture.

A medium conditioned by rat embryo cultures (RCM) promoted the adhesion of liver cells from human fetuses to plastic dish. Colonies were also formed in primary cultures of the same cells in the presence of RCM. The majority of the colonies formed were composed of large polygonal cells with a few colonies composed of both clear epithelial-like cells and fibroblast-like cells. RCM was superior to the rat embryo feeder layer for promotion of colony formation of cells. A number of colonies were formed from fetal human livers when a conditioned medium from human hepatoma cells (HCM) was used, but most of the colonies formed were composed of fibroblast-like cells. The cells derived from the polygonal cell colonies, which were formed in the presence of RCM, have been passaged four times and they are still growing with albumin-producing capacity. The effect of RCM was reduced by various physico-chemical treatments.