Nuclear exosome targeting complex safeguards hematopoietic stem cell self-renewal and genomic integrity through...

Area of Science:

• Molecular Biology
• Genetics
• Hematology

Background:

• Pervasive transcription generates non-functional transcripts, leading to R-loop formation and DNA breaks.
• Maintaining genome integrity is critical for hematopoietic stem cells (HSCs).

Purpose of the Study:

• To investigate the role of the nuclear exosome targeting (NEXT) complex in HSC genome maintenance.
• To explore the function of ZCCHC8, a core subunit of NEXT, in HSCs.
• To assess the clinical relevance of ZCCHC8 in diffuse large B cell lymphoma (DLBCL).

Main Methods:

• Hematopoietic-specific deletion of ZCCHC8 in mice.
• Analysis of DNA lesions and DNA repair pathways in HSCs.
• Investigation of ZCCHC8 dysregulation in DLBCL patient samples.

Main Results:

• Deletion of ZCCHC8 impaired HSC self-renewal and increased DNA lesions due to accumulated R loops.
• DNA repair pathways were upregulated in ZCCHC8-deficient HSCs.
• ZCCHC8 dysregulation in DLBCL correlated with poor clinical outcomes.

Conclusions:

• The NEXT complex is a novel protector of HSC genome integrity.
• ZCCHC8 plays a pivotal role in preventing R-loop-induced DNA damage in HSCs.
• ZCCHC8 is a potential therapeutic target for DLBCL.