Glucocorticoid-resistant B cell acute lymphoblastic leukemia displays receptor tyrosine kinase activation

Prolonged dexamethasone treatment induces dexamethasone resistance in B cell acute lymphoblastic leukemia (B-ALL) cells: a human B-ALL cell lines 697, NALM-6, RS4;11, and TANOUE were treated with increasing concentrations (from 1？nM to 5？μM) of dexamethasone for 90 days following 14 days of culture in the absence of dexamethasone. Half-maximal effective concentration (EC50) was measured using PrestoBlue cell viability assay. Initial EC50 values were measured before dexamethasone treatment started. b B-ALL cells were lysed and lysates were processed for Western blotting analysis using anti-glucocorticoid receptor (GR) and anti-β-actin antibodies. Blots were derived from the same experiment and were processed in paralle