Dolatshad H, Pellagatti A, Fernandez-Mercado M, Yip B H, Malcovati L, Attwood M, Przychodzen B, Sahgal N, Kanapin A A, Lockstone H, Scifo L, Vandenberghe P, Papaemmanuil E, Smith C W J, Campbell P J, Ogawa S, Maciejewski J P, Cazzola M, Savage K I, Boultwood J
LLR Molecular Haematology Unit, NDCLS, RDM, University of Oxford, Oxford, UK.
1] Department of Hematology Oncology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy [2] Department of Molecular Medicine and Medical Therapy, University of Pavia, Pavia, Italy.
Leukemia. 2015 May;29(5):1092-103. doi: 10.1038/leu.2014.331. Epub 2014 Nov 27.
The splicing factor SF3B1 is the most commonly mutated gene in the myelodysplastic syndrome (MDS), particularly in patients with refractory anemia with ring sideroblasts (RARS). We investigated the functional effects of SF3B1 disruption in myeloid cell lines: SF3B1 knockdown resulted in growth inhibition, cell cycle arrest and impaired erythroid differentiation and deregulation of many genes and pathways, including cell cycle regulation and RNA processing. MDS is a disorder of the hematopoietic stem cell and we thus studied the transcriptome of CD34(+) cells from MDS patients with SF3B1 mutations using RNA sequencing. Genes significantly differentially expressed at the transcript and/or exon level in SF3B1 mutant compared with wild-type cases include genes that are involved in MDS pathogenesis (ASXL1 and CBL), iron homeostasis and mitochondrial metabolism (ALAS2, ABCB7 and SLC25A37) and RNA splicing/processing (PRPF8 and HNRNPD). Many genes regulated by a DNA damage-induced BRCA1-BCLAF1-SF3B1 protein complex showed differential expression/splicing in SF3B1 mutant cases. This is the first study to determine the target genes of SF3B1 mutation in MDS CD34(+) cells. Our data indicate that SF3B1 has a critical role in MDS by affecting the expression and splicing of genes involved in specific cellular processes/pathways, many of which are relevant to the known RARS pathophysiology, suggesting a causal link.
剪接因子SF3B1是骨髓增生异常综合征（MDS）中最常发生突变的基因，尤其是在伴有环形铁粒幼细胞的难治性贫血（RARS）患者中。我们研究了SF3B1破坏在髓系细胞系中的功能影响：敲低SF3B1导致生长抑制、细胞周期停滞、红系分化受损以及许多基因和信号通路失调，包括细胞周期调控和RNA加工。MDS是一种造血干细胞疾病，因此我们使用RNA测序研究了携带SF3B1突变的MDS患者CD34(+)细胞的转录组。与野生型病例相比，在转录本和/或外显子水平上SF3B1突变体中显著差异表达的基因包括参与MDS发病机制的基因（ASXL1和CBL）、铁稳态和线粒体代谢相关基因（ALAS2、ABCB7和SLC25A37）以及RNA剪接/加工相关基因（PRPF8和HNRNPD）。许多受DNA损伤诱导的BRCA1 - BCLAF1 - SF3B1蛋白复合物调控的基因在SF3B1突变体病例中表现出差异表达/剪接。这是第一项确定MDS患者CD34(+)细胞中SF3B1突变靶基因的研究。我们的数据表明，SF3B1通过影响参与特定细胞过程/信号通路的基因的表达和剪接在MDS中起关键作用，其中许多与已知的RARS病理生理学相关，提示存在因果联系。
