[Zajdela hepatoma cells cultured in vitro]

Two continuous cell lines, monolayer (ZH-ad) and suspension (ZH-fl), which doffer in the level of cell differentiation and tumorigenicity, were obtained from explants of ascitic Zajdela hepatoma. Using tumor-specific rabbit immune serum tumor-associated antigens were detected in the fraction of plasma membrane of ZH-fl cells, synthesis of that was reduced or suppressed in ZH-ad cells. Intraperitoneal injection of ZH-fl cells as few as 0.5 - 10(6) cells/rat was enough for development of ascites tumor, while minimal dose for ZH-ad cells increase to 20 - 10(6) cells. Three types of generated clones were revealed by means of clonogenic analysis of ZH-fl cells: nonadhesive sphere colonies and two types of monolayer clones ranging in proliferative potential, shape of colonies and cell composition. When the spherical colonies had reached a critical size they disintegrated with dissociation of single cells or islets of various sizes, part of which attached to the plate to form a monolayer. Three clonal cell lines were obtained: IC - as a result of expansion of sphere clone cells, 4G and 10E - from monolayer clones. Our results demonstrate a clonogenic origin of multicellular islets of ascetic hepatoma Zajdela.