Genetic variation reveals a homeotic long noncoding RNA that modulates human hematopoietic stem cells

Area of Science:

• Genetics
• Molecular Biology
• Hematology

Background:

• The HOXA gene locus is crucial for development, hematopoiesis, and differentiation.
• Genetic variations within the HOXA locus can influence blood cell phenotypes and disease susceptibility.

Purpose of the Study:

• To investigate the functional impact of a specific genetic variant (rs17437411) associated with blood count variations and cancer protection.
• To identify and characterize a novel long non-coding RNA (lncRNA) involved in regulating HOXA gene expression.

Main Methods:

• Analysis of human genetic variation data linked to blood phenotypes.
• Identification and functional characterization of a novel antisense lncRNA (HOTSCRAMBL).
• Assays to assess the impact of the variant on hematopoietic stem cell (HSC) self-renewal and HOXA gene expression, including SRSF2-dependent splicing.

Main Results:

• The genetic variant rs17437411 disrupts the function of the HOTSCRAMBL lncRNA.
• Disruption of HOTSCRAMBL reduces human HSC self-renewal and impairs HOXA gene expression, particularly HOXA9.
• HOTSCRAMBL dysfunction compromises HOXA-dependent acute myeloid leukemias.

Conclusions:

• Human genetic variation can uncover critical regulatory pathways in gene expression.
• HOTSCRAMBL is a key regulator of HOXA gene expression in HSCs, influencing hematopoiesis and leukemogenesis.
• Understanding HOTSCRAMBL's role provides insights into blood disorders and potential therapeutic targets.