Trichostatin A, sodium butyrate, and 5-aza-2′-deoxycytidine alter the expression of glucocorticoid receptor α and β isoforms in Hut-78 T- and Raji B-lymphoma cell lines

The glucocorticoid receptor (GR) is mainly expressed as nine-exon alternatively spliced variants, encoding functional GRα and nonfunctional GRβ. Overexpression of GRβ splice variant was found in glucocorticoid-resistant patients with some autoimmune diseases and hematological malignancies. Employing reverse transcription, real-time quantitative PCR, and western blot analysis, we determined an effect of trichostatin A (TSA), sodium butyrate (NaBu) and 5-aza-2′-deoxycytidine (5-dAzaC) on GRα and GRβ expression in Hut-78 T- and Raji B-lymphoma cell lines. We found that TSA, NaBu, and 5-dAzaC significantly increase the expression of GRα transcript and protein, whereas GRβ transcript and protein expression was profoundly decreased in Hut-78 T- and Raji B- lymphoma cell lines. Our observation suggests that changes of epigenetic milieu inside cells may alter the expression of GRα and GRβ isoforms.