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).
In a case-control study, 100 patients with CLL and 105 healthy individuals were investigated for Notch homolog 1, translocation-associated (<i>Drosophila</i>) (NOTCH1) c.7544-7545delCT, recombinant splicing factor 3B subunit 1 (SF3B1) c.2098A>G, mouse double minute 2 homolog (MDM2) 40-bp insertion/deletion and myeloid differentiation primary response 88 (MYD88) L265P mutations by using allele specific-polymerase chain reaction (AS-PCR), a designed AS-PCR, PCR and PCR-restriction fragment length polymorphism methods, respectively.
We report a customized gene panel assay based on multiplex long-PCR followed by third generation sequencing on nanopore technology (MinION), designed to analyze five frequently mutated genes in chronic lymphocytic leukemia (CLL): TP53, NOTCH1, BIRC3, SF3B1 and MYD88.
In both entities, based on mutation load evaluation, MYD88 mutations were found to be present in the stem clone in each case, whereas CXCR4 (LPL) and SF3B1 (CLL) mutations also occurred in subclones only.
This model of secondary structure-dependent selection of cryptic 3'SS was found across multiple clonal processes associated with SF3B1 mutations (myelodysplastic syndrome and chronic lymphocytic leukemia).
TP53 mutations predominate in IG-unmutated CLL, whereas the opposite is seen for MYD88 mutations, enriched in IG-mutated CLL) and in subsets of cases with stereotyped IG (enrichment for SF3B1 mutations in CLL subset #2).
Mutations in NOTCH1 and SF3B1 are recurrent, often associated with progressive CLL that is also IgVH unmutated and ZAP70-positive and are under investigation as targets for novel therapies and as factors influencing CLL outcome.
Chronic lymphocytic leukemia (CLL) is extremely rare in Asian countries and there has been one report on genetic changes for 5 genes (TP53, SF3B1, NOTCH1, MYD88, and BIRC3) by Sanger sequencing in Chinese CLL.
Additionally, MYC rearranged CLL presented as outstanding group by often showing a non-complex karyotype (85%), absence of ID3 mutations, a high frequency of SF3B1 mutations, and a frequent involvement of non-immunoglobulin loci as MYC-partner genes (61%).
Using transcriptome sequencing data from chronic lymphocytic leukemia, breast cancer and uveal melanoma tumor samples, we show that hundreds of cryptic 3' splice sites (3'SSs) are used in cancers with SF3B1 mutations.
Biological and clinical associations were detected including SF3B1 and NOTCH1 mutations with un-mutated IGHV, MYD88 mutations with mutated IGHV, SF3B1 mutations with fludarabine-resistant CLL and NOTCH1 mutation with advanced Binet disease stage and with +12.
Through the European Research Initiative on chronic lymphocytic leukemia (CLL) (ERIC), we screened 3490 patients with CLL for mutations within the NOTCH1 (n=3334), SF3B1 (n=2322), TP53 (n=2309), MYD88 (n=1080) and BIRC3 (n=919) genes, mainly at diagnosis (75%) and before treatment (>90%).
We examined the significance of IgM peaks in chronic lymphocytic leukemia (CLL), including its association with newly reported MYD88, BIRC3, NOTCH1 and SF3B1 mutations.
Although TP53, NOTCH1, and SF3B1 mutations may impair prognosis of patients with chronic lymphocytic leukemia (CLL) receiving frontline therapy, the impact of these mutations or any other, alone or in combination, remains unclear at relapse.
Screening of recurrently mutated genes in 48 additional FR-CLLs revealed that ~70% of FR-CLLs carry ≥1 mutation in genes previously associated with CLL clinical course, including TP53 (27.5%), NOTCH1 (24.1%), SF3B1 (18.9%), and BIRC3 (15.5%).
In contrast, SF3B1 mutations have a lower incidence in early stages of chronic lymphocytic leukemia, are more common in advanced disease, and tend to be associated with poor prognosis, suggesting that they occur during clonal evolution of the disease.
Although the causative link between SF3B1 mutation and CLL pathogenesis remains unclear, several lines of evidence suggest SF3B1 mutation might be linked to genomic stability and epigenetic modification.
We studied the incidences, associations, and prognostic roles of NOTCH1 and SF3B1 mutations (NOTCH1(mut), SF3B1(mut)) as compared with TP53(mut) in fludarabine-refractory chronic lymphocytic leukemia (CLL) patients treated with alemtuzumab in the CLL2H trial.