Episomal amplification of NUP214-ABL1 fusion gene in B-cell acute lymphoblastic leukemia

摘要

The NUP214-ABL1 fusion gene is found amplified as multiple (5-50) episomal copies in 6% of T-cell acute lymphoblastic leukemia (T-ALL). Alterations of the TLK1, TLK3, CDKN2A/B, and N0TCH1 genes are commonly associated with NUP214-ABL1 T-ALL. Recently, the NUP214-ABL1 fusion gene has been reported in 2 of 15 cases of B-cell acute lymphoblastic leukemia (B-ALL) identified by RNA-sequencing with no evidence of episomal amplification, suggesting an intrachromosomal rearrangement. In 1 of 2 cases, phosphoflow analysis demonstrated increased CRK-like protein phosphorylation, suggesting active ABL1 signaling, that was sensitive to tyrosine kinase inhibitors (TKIs). We now report the first case of B-ALL associated with extrachromosomal, episomal amplification of NUP214-ABL1. All methods can be found in supplemental Methods (available on the Blood Web site; see the Supplemental Materials link at the top of the online article).