Accelerated DNA replication fork speed due to Loss of R-Loops in Myelodysplastic Syndromes with SF3B1 Mutation [RNAseq_CMNhuman]
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ABSTRACT: Myelodysplastic syndromes (MDS) with mutated SF3B1 gene have many features including a favorable outcome that are distinct from MDS with mutations in other splicing factor genes SRSF2 or U2AF1. Molecular bases of these divergences are poorly understood. Here we show that SF3B1-mutated MDS are characterized by a dramatically reduced R-loop formation predominating in gene bodies, which associates with intron retention reduction specifically found in SF3B1-mutated, but not in U2AF1- or SRSF2-mutated MDS. Compared to erythroblasts from SRSF2- or U2AF1-mutated patients, SF3B1-mutated erythroblasts exhibited augmented DNA synthesis, accelerated replication forks, and single-stranded DNA exposure upon differentiation. Importantly, histone deacetylase inhibition using vorinostat restored Rloop formation,slowed down DNA replication forks and improved SF3B1-mutated erythroblast differentiation. In conclusion, loss of R-loops with associated DNA replication stress is a hallmark of SF3B1-mutated MDS ineffective erythropoiesis, which could be used as a new therapeutic target.
ORGANISM(S): Homo sapiens
PROVIDER: GSE220525 | GEO | 2024/02/22
REPOSITORIES: GEO
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