Correlation of alpha-fetoprotein expression in normal hepatocytes during development with tyrosine phosphorylation and insulin receptor expression.

ABSTRACT: The molecular mechanism of hepatic cell growth and differentiation is ill defined. In the present study, we examined the putative role of tyrosine phosphorylation in normal rat liver development and in an in vitro model, the alpha-fetoprotein-producing (AFP+) and AFP-nonproducing (AFP-) clones of the McA-RH 7777 rat hepatoma. We demonstrated in vivo and in vitro that the AFP+ phenotype is clearly associated with enhanced tyrosine phosphorylation, as assessed by immunoblotting and flow cytometry. Moreover, immunoprecipitation of proteins with anti-phosphotyrosine antibody showed that normal fetal hepatocytes expressed the same phosphorylation pattern as stable AFP+ clones and likewise for adult hepatocytes and AFP- clones. The tyrosine phosphorylation of several proteins, including the beta

SUBMITTER: Khamzina L 

PROVIDER: S-EPMC25332 | biostudies-literature | 1998 May

REPOSITORIES: biostudies-literature