Trichostatin A, sodium butyrate, and 5-aza-2'-deoxycytidine alter the expression of glucocorticoid receptor alpha and beta 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 GRalpha and nonfunctional GRbeta. Overexpression of GRbeta 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 GRalpha and GRbeta expression in Hut-78 T- and Raji B-lymphoma cell lines. We found that TSA, NaBu, and 5-dAzaC significantly increase the expression of GRalpha transcript and protein, whereas GRbeta 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 GRalpha and GRbeta isoforms.