Mitogen-activated protein kinase mediates proliferation and apoptosis induced by dexamethasone in acute lymphoblastic leukemia cells

Objective:To investigate the effect of mitogen-activated protein kinase on proliferation and apoptosis induced by dexamethasone in CEM cells. Methods: Cell viability was determined by trypan blue dye exclusion. Apoptosis was evaluated by morphology and flow cytometry. Results: Proliferation of dexamethasone-induced CEM cells was 62.3%,35.5% and 11.6% at 24h,48h and 72h. Apoptotic percentage was 26.2% at 36h. When treatment with SB203580 and dexamethasone for 24h to 72h, the survival percentage was increased to 82.8%,54.7% and 48.1%, respectively(P0.05). Co-treatment with SB203580 and dexamethasone resulted in the decrease of apoptotic percentage to 7.1% at 36h(P0.01). When treatment with PD98059 and dexamethasone, the survival percentage was decreased to 52.3%,19.8% and 7.1%, respectively(P0.05). Co-treatment with PD98059 and dexamethasone resulted in the increase of apoptotic percentage to 38.6%(P0.05). When treatment with SP600125 and dexamethasone, the survival percentage was decreased to 51.2%,19.5% and 6.9%, respectively(P0.05). Co-treatment with SP600125 and dexamethasone resulted in the increase of apoptotic percentage to 32.3%(P0.05). Conclusion: Mitogen-activated protein kinase mediates proliferation and apoptosis induced by dexamethasone in CEM cells. p38MAPK inhibits CEM cells proliferation and enhances apoptosis, but ERK and JNK enhance proliferation and inhibit apoptosis.