Proteasome inhibitor bortezomib induces apoptosis in prednisone-resistant childhood acute lymphoblastic leukemia cells

The response to initial glucocorticoid (gc) therapy in childhood acute lymphoblastic leukemia (ALL) reliably predicts the response to multi-agent chemotherapy. We detected members of the ubiquitin proteasome system (UPS) to be altered in gc resistant leukemic cell lines, suggesting that the associated pathways might be involved in multi-agent chemotherapy resistance in childhood ALL. To investigate whether the proteasome inhibitor bortezomib (VELCADE®) acts synergistically with gc treatment, human B-cell precursor leukemic cell lines, prednisone poor responding MHH cALL 2 (PPR) and prednisone good responding MHH…