Publication Date:
2019-11-13
Description:
The myelodysplastic syndromes (MDS) are common myeloid malignancies. Mutations in genes involved in pre-mRNA splicing (SF3B1, SRSF2, U2AF1 and ZRSR2) are the most common mutations found in MDS. There is evidence that some spliceosomal components play a role in the maintenance of genomic stability. Splicing is a transcription coupled process; splicing factor mutations affect transcription and may lead to the accumulation of R-loops (RNA-DNA hybrids with a displaced single stranded DNA). Mutations in the splicing factors SRSF2 and U2AF1 have been recently shown to increase R-loops formation in leukemia cell lines, resulting in increased DNA damage, replication stress and activation of the ATR-Chk1 pathway. SF3B1 is the most frequently mutated splicing factor gene in MDS, but a role for mutated SF3B1 in R-loop accumulation and DNA damage has not yet been reported in hematopoietic cells. We have investigated the effects of the common SF3B1 K700E mutation on R-loop formation and DNA damage response in MDS and leukemia cells. R-loop signals and the DNA damage response were measured by immunofluorescence staining using S9.6 and anti-γ-H2AX antibodies respectively. Firstly, we studied K562 (myeloid leukemia) cells with the SF3B1 K700E mutation and isogenic SF3B1 K700K wildtype (WT) K562 cells. K562 cells with SF3B1 mutation showed a significant increase in the number of S9.6 foci [Fold change (FC) 2.01, p
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine
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