Glucocorticoids are broadly used for chemotherapy in childhood acute lymphoblastic leukaemia (ALL). The intracellular effects of glucocorticoids are mediated through the glucocorticoid receptor. The human glucocorticoid receptor gamma isoform (hGR-gamma) differs from the main isoform (hGR-alpha) by an additional amino acid within the DNA binding domain of the receptor protein. This may decrease hGR-alpha-mediated transcriptional activation. The importance of hGR-gamma expression in childhood ALL is unknown. To evaluate hGR-gamma mRNA expression levels, a real-time polymerase chain reaction (PCR)-based approach, allowing the selective amplification of hGR-gamma, was developed and optimized. We were able to demonstrate target selectivity of hGR-gamma amplification using sequence-specific primers. Studying the structure of the 3′ end of hGR-gamma, a combination of this isoform with other hGR isoforms could be demonstrated. Using analysis of hGR-gamma-specific amplification in comparison with the expression of hGR-total (all isoforms) in leukaemic blasts from patients with either a good response to prednisone (PGR) or poor-prednisone response (PPR) in vivo, relative hGR-gamma expression was observed to be lower in cells from patients with PGR compared with PPR, in particular after 10 h of dexamethasone stimulation. These data were correlated with cell survival, demonstrating a more pronounced induction of apoptosis in cells from patients with PGR as compared with PPR.

Expression, Glucocorticoid receptor, Human leukaemia, Isoform gamma, Real-time PCR,
British Journal of Haematology
Department of Pediatrics

Berger, M.Y, Gerdes, K, Lauten, M, Tissing, W.J.E, Fernandez-Munoz, I, Schrappe, M, & Welte, K. (2003). Expression and structural analysis of glucocorticoid receptor isoform gamma in human leukaemia cells using an isoform-specific real-time polymerase chain reaction approach. British Journal of Haematology, 122(2), 245–252. doi:10.1046/j.1365-2141.2003.04426.x