The significance of spliceosome mutations in chronic lymphocytic leukemia

Abstract

Cellular proteins produced via alternative splicing provide neoplastic cells with survival advantage and/or promote neoplastic cell proliferation. Pre-mRNA is spliced by the spliceosome consisting of large complexes of small nuclear RNA (snRNA) and protein subunits. Spliceosome gene mutations were detected in 40–80% of patients with myelodysplastic syndrome (MDS), particularly in those with ringed sideroblasts. Recently, two large whole-genome sequencing studies identified mutations in the spliceosome gene SF3B1 in approximately 10% of patients with chronic lymphocytic leukemia (CLL). Intrigued by these findings, we performed a pathway enrichment analysis and found that, unlike in MDS, in CLL spliceosome mutations exist almost exclusively in SF3B1. Patients with CLL with an SF3B1 gene mutation are characterized by a short progression-free survival and a low 10-year survival rate. Furthermore, the frequency of SF3B1 mutations is significantly higher in chemotherapy treated than in untreated patients with CLL, suggesting that chemotherapy induces SF3B1 gene mutations or selects a population of mutated cells. Whether SF3B1 gene mutations have a role in leukemogenesis, either because of altered splicing or other splicing-unrelated functions such as ectopic expression of Homeobox (Hox) genes previously reported in SF3B1+^/− mice, remains to be determined.

Keywords::

• CLL
• spliceosome mutations
• secondary AML
• MDS

Acknowledgements

We thank Kathryn L. Hale for editing our manuscript. Dr. Rozovski is a recipient of The Kimberly Patterson Fellowship in Leukemia Research. This research has been supported by a grant from the CLL Global Research Foundation.

Potential conflict of interest:

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