Background: A sub-population of stem cells termed side population (SP) has a unique ability for the efflux of Hoechst 33342 dye. Recently, it was hypothesized that efflux properties might facilitate the efflux of accumulated chemotherapeutic drugs and as such constitute a tumor escape mechanism.
Materials and methods: As SP characterization in leukemia is incomplete, we characterized SP frequencies in 19 children diagnosed with acute B cell precursor leukemia (BCP-ALL), AML and T-ALL and described engraftment properties in immune-compromised NOD.Cg-Prkdc(scid)IL2rg(tmWjl)/Sz (NSG) mice.
Results: SP cells are detectable in children and mice irrespective of the origin of the leukemia and flow-cytometric analysis reveals that the SP population is a distinct sub-population. Functionally, the SP size remains stable over serial transplantations indicating that the "stemness" potential of our SP sample cohort was overall low.
Conclusion: SP cells exist in pediatric leukemia and are maintainable in NSG mice. Thus, our observations may facilitate down-stream characterization of LSCs in future studies.
Keywords: Acute myeloic leukemia; Leukemic stem cells; NSG mice; acute B cell precursor leukemia; hematopoietic stem cells; side population.
Copyright © 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.