1. Accelerated DNA replication fork speed due to loss of R-loops in myelodysplastic syndromes with SF3B1 mutation
- Author
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David Rombaut, Carine Lefèvre, Tony Rached, Sabrina Bondu, Anne Letessier, Raphael M. Mangione, Batoul Farhat, Auriane Lesieur-Pasquier, Daisy Castillo-Guzman, Ismael Boussaid, Chloé Friedrich, Aurore Tourville, Magali De Carvalho, Françoise Levavasseur, Marjorie Leduc, Morgane Le Gall, Sarah Battault, Marie Temple, Alexandre Houy, Didier Bouscary, Lise Willems, Sophie Park, Sophie Raynaud, Thomas Cluzeau, Emmanuelle Clappier, Pierre Fenaux, Lionel Adès, Raphael Margueron, Michel Wassef, Samar Alsafadi, Nicolas Chapuis, Olivier Kosmider, Eric Solary, Angelos Constantinou, Marc-Henri Stern, Nathalie Droin, Benoit Palancade, Benoit Miotto, Frédéric Chédin, and Michaela Fontenay
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Science - Abstract
Abstract Myelodysplastic syndromes (MDS) with mutated SF3B1 gene present features including a favourable outcome distinct from MDS with mutations in other splicing factor genes SRSF2 or U2AF1. Molecular bases of these divergences are poorly understood. Here we find that SF3B1-mutated MDS show reduced R-loop formation predominating in gene bodies associated with intron retention reduction, not found in U2AF1- or SRSF2-mutated MDS. Compared to erythroblasts from SRSF2- or U2AF1-mutated patients, SF3B1-mutated erythroblasts exhibit augmented DNA synthesis, accelerated replication forks, and single-stranded DNA exposure upon differentiation. Importantly, histone deacetylase inhibition using vorinostat restores R-loop formation, slows down DNA replication forks and improves SF3B1-mutated erythroblast differentiation. In conclusion, loss of R-loops with associated DNA replication stress represents a hallmark of SF3B1-mutated MDS ineffective erythropoiesis, which could be used as a therapeutic target.
- Published
- 2024
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