Tumor necrosis factor‐α induces a kB sequence‐specific DNA‐binding protein in human hepatoblastoma HepG2 cells

Abstract

Tumor necrosis factor‐α is an inducer of acute‐phase protein synthesis in liver cells. The mechanism by which tumor necrosis factor‐α alters gene expression in these cells is largely unknown. In this study, we demonstrate that tumor necrosis factor‐α stimulates human immunodeficiency virus‐1 long terminal repeat‐promoted gene expression in the human hepatoblastoma HepG2 cell line and increased binding of trans‐activating factors to kappa B (kB) DNA sequences. In contrast to lymphocytic cells where the nuclear factors recognizing the kB sequences are activated by both tumor necrosis factor‐α and phorbol‐12‐myristate‐13‐acetate through a posttranslational mechanism, in HepG2 cells phorbol‐12‐myristate‐13‐acetate does not activate these factor(s), and de novo protein synthesis seems to be required in HepG2 cells for gene activation by tumor necrosis factor‐α. Copyright © 1989 American Association for the Study of Liver Diseases