Growth hormone inhibits the interleukin-6 induced junB protooncogene and fibrinogen expression in HepG2 human hepatoma cells

Growth hormone (GH) and interleukin-6 (IL-6) play important regulatory roles in multiple endocrinological and immunological functions. In this study we examined whether GH can modulate the actions of IL-6. In HepG2 human hepatoma cells we studied the effects of different GH concentrations on the expression of the junB mRNA as an early and on the biosynthesis of fibrinogen protein as a late model of IL-6-related hepatic response. Both GH and IL-6 alone induced the expression of junB and fibrinogen but GH significantly inhibited the actions of higher (10 and 20 ng/ml) IL-6 concentrations in a dose dependent manner. These findings further underline the importance of interplay between the effectiveness of IL-6 and GH in various physiological processes.