Impact of U2AF1 mutations on circular RNA expression in myelodysplastic neoplasms

Area of Science:

• Molecular Biology
• Genetics
• Oncology

Background:

• Mutations in U2AF1 are common in myelodysplastic neoplasms (MDS) and linked to poor prognosis.
• The molecular mechanisms driving MDS progression due to U2AF1 mutations are not fully understood.
• The role of circular RNAs (circRNAs) in cancer and their regulation by splicing factors is an emerging area of research.

Purpose of the Study:

• To investigate the impact of U2AF1 mutations on circRNA biogenesis.
• To determine if U2AF1 mutations alter circRNA expression profiles in MDS.
• To explore the potential of circRNAs as biomarkers in U2AF1-mutated MDS.

Main Methods:

• RNA sequencing was performed on K562 cells with inducible U2AF1 mutations, a mouse model with inducible U2AF1 mutations, and FACS-sorted CD34+ bone marrow cells from MDS patients.
• Global circRNA expression levels were quantified and compared between U2AF1-mutated and wild-type samples.
• Specific circRNAs, including cancer-associated ones, were analyzed for differential expression.

Main Results:

• U2AF1 mutations consistently led to increased global circRNA levels across all tested systems (cells, mice, patients).
• This increase in circRNA expression was independent of changes in the host linear genes.
• U2AF1 mutations, specifically S34 and Q157, were associated with elevated circRNA expression in MDS patients, with non-Alu-mediated circRNAs showing the most significant increase.
• Upregulation of cancer-associated circRNAs like circZNF609 and circCSNK1G3 was observed in U2AF1-mutated MDS.

Conclusions:

• High circRNA expression is a hallmark associated with U2AF1 mutations in MDS.
• These findings highlight circRNAs as potential biomarkers for MDS prognosis and therapeutic targets.
• Further investigation into circRNA dysregulation in U2AF1-mutated MDS is warranted.