ANTISENSE OLIGOMERS OF CFOS AND CJUN BLOCK GLUCOCORTICOID STIMULATIONOF THYROTROPIN-RELEASING-HORMONE (TRH) GENE-EXPRESSION IN CULTURED ANTERIOR-PITUITARY-CELLS

The proto-oncogenes, cfos/cjun, are co-localized with thyrotropin-rele asing hormone (TRH) in cultured anterior pituitary cells and increase following exposure to dexamethasone (Dex). To assess the role of cfos and cjun in the Dex stimulation of TRH gene expression, we used antise nse oligonucleotides to block cfos and cjun expression in order to red uce formation of activating protein-1 (AP-1). The results showed that the antisense oligonucleotides together effectively reduced cfos/cjun gene expression and consequently the glucocorticoid stimulation of TRH peptide and mRNA. The findings indicate that cfos/cjun are involved i n the glucocorticoid activation of TRH gene expression. (C) 1998 Elsev ier Science Inc.