SET-NUP214-positive patients were predominantly (10 [91%] of 11) T-cell receptor (TCR)-negative and strikingly associated with TCRγδ lineage T-ALLs, as defined by expression of TCRγδ, TCRδ and/or TCRγ rearrangements but no complete TCRβ variable diversity joining rearrangement in surface CD3/TCR-negative cases.
We showed that SET expression was significantly upregulated in 96.5% of B-acute lymphoblastic leukemia (28 of 29; 16.6 fold) and 93% of T-acute lymphoblastic leukemia (28 of 30; 47.6 fold) patients.
Overall, these results indicate that, in T-cell acute lymphoblastic leukemia, PHF6 mutations are a recurrent genetic abnormality associated with mutations of NOTCH1, JAK1 and rearrangement of SET-NUP214.
Multiplex-polymerase chain reaction analysis and gene expression profiling of 129 further cases found five additional cases of TAF_I-NUP214-positive T-cell acute lymphoblastic leukemia.
Of 141 human leukemia/lymphoma cell lines tested, only the T-ALL cell line LOUCY and the AML cell line MEGAL expressed the SET(TAF-Ibeta)-NUP214 fusion gene transcript.