Unique SDF-1-induced activation of human precursor-B ALL cells as a result of altered CXCR4 expression and signaling.

The mechanisms governing migration and extramedullary dissemination of leukemic cells remain obscure. In this study the migration and in vivo homing to the bone marrow of nonobese diabetic severe combined immunodeficient (NOD/SCID) mice injected with human precursor-B acute lymphoblastic leukemia (ALL) cells in comparison to normal CD34+ progenitors (both cord blood and mobilized peripheral blood) was investigated. Although migration and homing of both cell populations was dependent on stromal cell-derived factor 1 (SDF-1)/CXCR4 interactions, major differences in receptor expression as well as the migratory capacity toward various concentrations of SDF-1 were found.