Cytokine-dependent imatinib resistance in mouse BCR-ABL⁺, Arf-null lymphoblastic leukemia

Abstract

Retroviral transduction of the BCR-ABL kinase into primary mouse bone marrow cells lacking the Arf tumor suppressor rapidly generates polyclonal populations of continuously self-renewing pre-B cells, virtually all of which have leukemic potential. Intravenous infusion of 20 such cells into healthy syngeneic mice induces rapidly fatal, transplantable lymphoblastic leukemias that resist imatinib therapy. Introduction of BCR-ABL into Arf-null severe combined immunodeficient (SCID) bone marrow progenitors lacking the cytokine receptor common γ-chain yields leukemogenic pre-B cells that exhibit greater sensitivity to imatinib in vivo. Hence, salutary cytokines in the hematopoietic microenvironment can facilitate leukemic proliferation and confer resistance to targeted therapy.

Keywords

• BCR-ABL kinase
• Arf tumor suppressor
• imatinib (Gleevec)
• leukemia-initiating cells
• cytokines
• drug resistance