OBJECTIVE: Glucocorticoid can induce apoptosis by regulating some genes' expression,but its effect on the pro-apoptotic protein Puma in leukemia remains unclear. This study was designed to investigate the effect of glucocorticoid on the expression of Puma in glucocorticoid-induced apoptosis of acute lymphoblastic leukemia cells in vitro. METHODS: Leukemia cells from acute lymphoblastic leukemia patients were transplanted into the immunodeficient mice. The transplanted leukemia cells were collected and then were treated with dexamethasone at the final concentration of 1 μM. The expression of Puma protein and mRNA in leukemia cells after dexamethasone treatment was detected by Western Blot and real-time quantitative PCR.A drug sensitive test was performed by MTT assay. RESULTS: The leukemia cells which came from the patients who had good clinical outcomes were sensitive to dexamethasone, while the ones from the patients who had poor clinical outcomes were resistant to dexamethasone in vitro. The sensitivity to dexamethasone in vitro between the resistant and sensitive leukemia cells was significantly different (P<0.05). No upregulation of Puma protein and mRNA was detected in resistant and sensitive leukemia cells after dexamethasone treatment. CONCLUSIONS: Glucocorticoid can not upregulate the expression of Puma in glucocorticoid-induced apoptosis of acute lymphoblastic leukemia cells in vitro.