Stem cell programs are retained in human leukemic lymphoblasts

Leukemic lymphoblasts within different immunophenotypic populations possess stem cell properties. However, whether or not the self-renewal program is retained from stem cells or conferred on progenitors by leukemogenic molecules remains unknown. We have addressed the issue in the context of TEL-AML1-associated acute lymphoblastic leukemia (ALL) by profiling a refined program edited from genes essential for self-renewal of hematopoietic stem cells and B-cell development. Bioinformatic analysis shows that ALL populations are loosely clustered and close to the normal population that contains stem and primitive progenitor cells. This finding indicates that immunophenotypes do not reflect maturation stages in ALL and that the self-renewal program may be retained from stem cells. Results of assessing 'first hit' function of TEL-AML1 in different populations of normal cells demonstrate the molecular model. Therefore, the current study shows a leukemogenic scenario of human ALL in which programs of stem cells are sustained in distinct fractions by leukemogenic mutations.