BCR-ABL-transformed GMP as myeloid leukemic stem cells

Area of Science:

• Hematology
• Cancer Biology
• Stem Cell Research

Background:

• Chronic myelogenous leukemia (CML) blast crisis involves abnormal granulocyte macrophage progenitors (GMP) with self-renewal potential, potentially acting as leukemic stem cells.
• Nuclear beta-catenin accumulation is implicated in the self-renewal capacity of these CML-initiating GMP.

Purpose of the Study:

• To develop a mouse model for CML-initiating GMP.
• To investigate the role of BCR-ABL and beta-catenin activity in GMP transformation.

Main Methods:

• BCR-ABL was expressed in E2A-knockout mouse bone marrow (BM) cells with retained ex vivo pluripotency.
• Leukemia-initiating cells were generated and characterized within the GMP compartment.
• Beta-catenin activity was assessed in transformed and non-transformed GMP.

Main Results:

• BCR-ABL expression stimulated myeloid expansion and generated leukemia-initiating cells within the GMP compartment.
• Leukemogenic GMP exhibited elevated beta-catenin activity compared to normal or non-leukemic GMP.
• Restoring E2A function did not reverse BCR-ABL-induced transformation.

Conclusions:

• BCR-ABL-transformed GMP with aberrant beta-catenin signaling can function as leukemic stem cells in CML.
• This study provides a model for investigating CML-initiating GMP and their associated molecular pathways.