The effects of interleukin-6, leukemia inhibitory factor and interferon-gamma on STAT DNA binding and c-fos mRNA levels in cortical astrocytes and C6 glioma cells.

OBJECTIVES: The purpose of this study was to compare the effects of neurotrophic cytokines on the JAK/STAT transcription factors and the immediate early gene, c-fos, in C6 glioma cells and in primary astrocyte cultures.

METHODS: In this study we compared the effects of interleukin 6, leukemia inhibitory factor and interferon gamma on C6 glioma cells and on primary astrocyte cultures using electrophoretic mobility shift assay and quantitative solution hybridization/Northern Blot analysis.

RESULTS: We show that interleukin 6, leukemia inhibitory factor and interferon gamma treatment induce the nuclear STAT3 and STAT1 proteins to bind to the sis inducible element of c-fos in both C6 glioma cells and primary cortical astrocytes. Furthermore, quantitative solution hybridization and Northern blot analysis show the differential regulation of c-fos mRNA levels by interleukin-6 (8.1 and 4.0 folds) and leukemia inhibitory factor (5.4 and 3.2 folds) in C6 and astrocyte cultures (respectively). However, interferon gamma increases in c-fos mRNA levels (2.9 fold in both C6 and astrocyte cultures) were not significant in a one way ANOVA.

CONCLUSION: This study suggests that two initial cytokine signaling pathways are present and functional in C6 glioma cells and in primary astrocyte cultures.