[Independence of alpha-fetoprotein expression from production of adult rat serum proteins in hepatoma McA-RH7777].

Clonal cell lines were isolated from rat hepatoma McA-RH7777 to study expression of alpha-fetoprotein (AFP) in these clones. AFP contained by the cells was determined by immunofluorescent and immunoperoxidase staining, while AFP secreted into the medium by aggregate-hemagglutination and immunoisotachophoresis. The existence of the clones that drastically differ in the intensity of AFP synthesis was demonstrated, with these clones being implicated in the monitoring of AFP synthesis. The differences between the clones gradually diminished in the course of long-term cultivation. It was also shown that the clones under consideration secreted, apart from AFP, at least 8 proteins of adult rat serum. One of the proteins was identified as transferrin. No albumin was detected in the cultural media tested. The level of AFP production did not correlate with the synthesis of other serum proteins and thus seems likely to be controlled by an independent mechanism.