To assess the impact of spliceosome mutations on splicing and to identify common pathways/genes affected by distinct mutations, we performed RNA-sequencing of MDS bone marrow samples harboring spliceosome mutations (including hotspot alterations of SF3B1, SRSF2 and U2AF1; small deletions of SRSF2 and truncating mutations of ZRSR2), and devoid of other common co-occurring mutations.
Our meta-analysis suggested that SF3B1 has no impact on OS of patients with MDS, however, an adequately designed prospective study with a large number of patients with different type of SF3B1 mutations is needed to confirm these results.
Patient was initially diagnosed with low-risk myelodysplastic syndrome-refractory cytopenias and multilineage dysplasia (MDS-RCMD), progressed to AML after failing hypomethylating agent therapy.
Ring sideroblasts (RS) emerge as result of aberrant erythroid differentiation leading to excessive mitochondrial iron accumulation, a characteristic feature for myelodysplastic syndromes (MDS) with mutations in the spliceosome gene SF3B1.
Given that mRNA splicing and nuclear export are coordinated processes, we hypothesised that SF3B1 mutation might also affect export of certain mRNAs and that this may represent a targetable pathway for the treatment of SF3B1-mutant MDS.
Metformin, a widely used antidiabetic drug, has previously been demonstrated to exert anti-cancer effects in certain hematological malignancies, but its effects on the transformation of myelodysplastic syndromes to acute myeloid leukemia (AML-MDS) remain unclear.
Mutations of <i>SF3B1</i> are commonly seen in myelodysplastic syndromes with ring sideroblasts (MDS-RS)and MDS/myeloproliferative neoplasm (MPN-RS-T).
In the phase III MDS-005 study of patients with lower-risk, non-del(5q) myelodysplastic syndromes, lenalidomide was associated with a higher rate of ≥ 8 weeks red blood cell transfusion independence (RBC-TI) compared with placebo, but also with a higher risk of hematologic adverse events (AEs).
The spliceosomal component Splicing Factor 3B, subunit 1 (SF3B1) is one of the most prevalently mutated factors in the bone marrow failure disorder myelodysplastic syndrome.
Thus, the current meta-analysis suggests that SF3B1 mutations have no significant impact on the OS of MDS patients, and the hematologic parameters of SF3B1 mutations identify a distinct subset of MDS patients with homogeneous features.
We found that there was a significant difference between SF3B1-mutant and SF3B1-wild-type MDS patients in intracellular iron III, intracellular iron IV and ring sideroblasts.
Splicing factor 3b subunit 1 (<i>SF3B1</i>), a splicing factor modulating RNA alternative splicing, is frequently mutated in multiple hematological malignancies including myelodysplastic syndromes and chronic lymphocytic leukemia (CLL).
Two myeloid neoplasms defined by the presence of RS, include refractory anemia with ring sideroblasts (RARS), now classified under myelodysplastic syndromes with RS (MDS-RS) and RARS with thrombocytosis (RARS-T); now called myelodysplastic/myeloproliferative neoplasm with RS and thrombocytosis (MDS/MPN-RS-T).
To better understand how spliceosomal mutations contribute to MDS pathogenesis in vivo, numerous groups have sought to establish conditional murine models of SF3B1, SRSF2, and U2AF1 mutations.
NGS can be used for various applications: (i) in the diagnostic process to discriminate between MDS and other diseases such as aplastic anaemia, myeloproliferative disorders and idiopathic cytopenias; (ii) for classification, for example, where the presence of SF3B1 mutation is one criterion for the ring sideroblast anaemia subgroups in the World Health Organization 2016 classification; (iii) for identification of patients suitable for targeted therapy (e.g.
Mutations in SF3B1 are frequently found in myelodysplastic syndromes (MDS), particularly in patients with refractory anemia with ringed sideroblasts (RARS), characterized by isolated anemia.
Contrary to previous reports, we found no association between TET2 mutations and HMA treatment response (40% vs 41%; P = 0.9), even in the absence of ASXL1 mutations (P = 0.4).We conclude that ASXL1 mutations in MDS predict inferior response to treatment with both HMAs and LEN; response to LEN was also compromised by U2AF1 mutations and high risk karyotype; SF3B1 mutations identified patients likely to respond to LEN.
Heterozygous somatic mutations in spliceosome genes (<i>U2AF1, SF3B1, ZRSR2</i>, or <i>SRSF2</i>) occur in >50% of patients with myelodysplastic syndrome (MDS).