SRSF2 P95H

To survive carcinogen treatment, Srsf2 P95H+/- cells undergo substantial transcriptional rewiring and restore bi-directional gene expression. Thus, our study underscores SRSF2's importance in regulating transcription to orchestrate the cell cycle and the DNA damage response.

Inhibition of splicing with a glycogen synthase kinase 3 inhibitor promoted retention of the poison intron, impairing mitophagy and activating apoptosis in SRSF2P95H/+ cells. These data reveal a homeostatic mechanism for sensing mitochondrial stress through PINK1 splicing and identify increased mitophagy as a disease marker and a therapeutic vulnerability in SRSF2P95H mutant MDS and AML.

Accordingly, Srsf2 delays myelofibrosis induced by the thrombopoietin receptor agonist Romiplostim in Jak2 wild-type animals. These results unveil JAK2 exon 14 skipping promotion as a strategy to reduce JAK/STAT signaling in pathological conditions.

Second, murine Srsf2P95H leukemias showed improved prolonged survival when treated with olaparib (PARPi) compared to vehicle treatment in vivo...In summary, our data establish a previously unknown link between R-loop-induced PARP1 response and RNA splicing perturbation and provide a mechanistic rationale to evaluate the clinical efficacy of PARP inhibitors in spliceosome-mutant malignancies. Furthermore, our study highlights a new therapeutic potential of targeting the R-loop tolerance pathways caused by different spliceosome gene mutations.

Three patients were treated with thrombopoietin receptor agonists (2 eltrombopag, 1 romiplostim) and had minimal transient platelet count increases not meeting the IWG MDS criteria for response. Three patients have received allogeneic hematopoietic stem cell transplant.Conclusion :This series describes a subset of CCUS patients with isolated thrombocytopenia associated with SRSF2 mutations. We also describe atypical megakaryocytic findings which do not meet current WHO diagnostic criteria for dysmegakaryopoiesis; however, the uniform presence of these findings in this cohort suggests an association with thrombocytopenia and CCUS.