The Blk pathway functions as a tumor suppressor in chronic myeloid leukemia stem cells

UMMS Affiliation

Program in Gene Function and Expression; Department of Medicine, Division of Hematology and Oncology; Program in Molecular Medicine; Department of Pathology; Department of Pediatrics

Publication Date


Document Type



Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Neoplastic Stem Cells; Genes, Tumor Suppressor


Cancer Biology | Genetics and Genomics


A therapeutic strategy for treating cancer is to target and eradicate cancer stem cells (CSCs) without harming their normal stem cell counterparts. The success of this approach relies on the identification of molecular pathways that selectively regulate CSC function. Using BCR-ABL-induced chronic myeloid leukemia (CML) as a disease model for CSCs, we show that BCR-ABL downregulates the Blk gene (encoding B-lymphoid kinase) through c-Myc in leukemic stem cells (LSCs) in CML mice and that Blk functions as a tumor suppressor in LSCs but does not affect normal hematopoietic stem cells (HSCs) or hematopoiesis. Blk suppresses LSC function through a pathway involving an upstream regulator, Pax5, and a downstream effector, p27. Inhibition of this Blk pathway accelerates CML development, whereas increased activity of the Blk pathway delays CML development. Blk also suppresses the proliferation of human CML stem cells. Our results show the feasibility of selectively targeting LSCs, an approach that should be applicable to other cancers.

DOI of Published Version



Nat Genet. 2012 Jul 15;44(8):861-71. doi: 10.1038/ng.2350. Link to article on publisher's site

Journal/Book/Conference Title

Nature genetics


Co-author Haojian Zhang is a student in the Cancer Biology program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.

Related Resources

Link to Article in PubMed

PubMed ID