Musashi2 sustains the mixed-lineage leukemia-driven stem cell regulatory program.

Area of Science:

• Hematology
• Molecular Biology
• Oncology

Background:

• Leukemia stem cells (LSCs) drive aggressive myeloid diseases and therapeutic resistance.
• Overexpression of RNA-binding protein Musashi2 (MSI2) correlates with poor leukemia survival.
• Genetic and epigenetic alterations dysregulate leukemia cell development.

Purpose of the Study:

• To investigate the role of Musashi2 (MSI2) in leukemogenesis and LSC function.
• To explore MSI2 as a potential therapeutic target in myeloid leukemia.

Main Methods:

• Conditional deletion of Msi2 in hematopoietic cells of a murine leukemia model.
• Gene expression profiling of Msi2-deficient and control animals.
• Analysis of MSI2 interactions with Hoxa9, Myc, and Ikzf2 mRNA targets.
• Assessment of Ikzf2 depletion effects on LSC function.

Main Results:

• Msi2 deletion delayed leukemogenesis, reduced disease burden, and impaired LSC function in mice.
• Msi2 deficiency led to decreased self-renewal and increased differentiation gene signatures.
• A gene signature similar to Msi2-deficient LSCs correlated with improved survival in acute myeloid leukemia patients.
• MSI2 was found to directly maintain the self-renewal program by ensuring efficient translation of Hoxa9, Myc, and Ikzf2.
• Depletion of MSI2 target Ikzf2 in LSCs reduced colony formation, proliferation, and increased apoptosis.

Conclusions:

• MSI2 controls the oncogenic LSC self-renewal program through efficient mRNA translation.
• MSI2 is a critical driver of leukemogenesis and LSC function.
• MSI2 represents a promising therapeutic target for myeloid leukemia.