Inherited resilience to clonal hematopoiesis by modifying stem cell RNA regulation

Area of Science:

• Hematology
• Genetics
• Molecular Biology

Background:

• Somatic mutations in hematopoietic stem cells (HSCs) drive clonal hematopoiesis (CH), increasing blood cancer risk.
• Genetic factors protecting against CH progression to malignancy are largely unknown.
• Understanding these protective mechanisms is crucial for blood cancer prevention.

Purpose of the Study:

• Identify genetic factors that confer protection against clonal hematopoiesis (CH) and myeloid malignancies.
• Investigate the role of the RNA-binding protein MSI2 in HSC function and CH risk.
• Elucidate the RNA network maintaining human HSCs and influencing CH susceptibility.

Main Methods:

• Analysis of a non-coding regulatory variant (rs17834140-T) associated with CH protection.
• Modeling variant effects on HSC-selective MSI2 expression and function.
• Mapping MSI2 RNA binding targets to define the regulatory network.
• Assessing the impact of MSI2 levels on ASXL1-mutant HSC clonal dominance in experimental models.

Main Results:

• The rs17834140-T variant protects against CH and myeloid malignancies by downregulating HSC-specific MSI2 expression and function.
• An RNA network regulated by MSI2 was identified, crucial for human HSC maintenance and CH risk.
• The rs17834140-T variant correlates with slower CH expansion rates in humans.
• MSI2 levels in HSCs modulate the clonal dominance of ASXL1-mutant HSCs.

Conclusions:

• A specific genetic variant confers resilience to CH and blood cancers by modulating MSI2 activity.
• Post-transcriptional regulation by MSI2 plays a critical role in human HSC function and CH pathogenesis.
• Targeting MSI2 or its downstream RNA network presents a promising strategy for blood cancer prevention.