Changes in the expression of differentiated functions during long-term cultivation of rat hepatoma cells.

The stability of the expression of six differentiated functions was examined during long-term cultivation of rat hepatoma cells. Faza 967 cell line--a clonal descendant of the Reuber H35 hepatoma--is characterized by the activity of tyrosine aminotransferase (TAT) and gluconeogenetic enzymes; secretion of serum albumin; and the presence of liver isozymes of alcohol dehydrogenase (ADH-L), aldolase (aldolase-B) and five isozymes of lactate dehydrogenase (LDH). During the 3-year-long cultivation of Faza 967 cells TAT specific activity, inducibility, and albumin production were reduced drastically whereas the expression of the three liver-specific isozymes examined was maintained. The majority of Faza 967 cells were able to perform gluconeogenesis after 3 years of continuous cultivation. Our results show that long-term cultivation of hepatoma cells may change the expression of certain liver-specific functions independently of the expression of other differentiated functions.