LMO2 intron 1 mutations in pediatric and adult human T-ALL. (A) LMO2 expression as determined by qRT-PCR in LMO2 translocated T-ALL cell lines (KOPT-K1 and P12-Ichikawa) and nontranslocated T-ALL cell lines (DU.528, PF-382, Loucy, DND41, Jurkat, and ALL-SIL). (B) ChIP-Seq tracks at the LMO2 locus for MYB and H3K27ac in PF-382, DU.528, Loucy, and Jurkat T-ALL cell lines. Y-axis values are reads per bin per million mapped reads. Mutations are shown below as identified by Sanger sequencing of PF-382 and DU.528 DNA, with inserted sequences shown in red and MYB motifs underlined. The position weight matrices for the primary and secondary MYB binding sites are from UniPROBE.27 (C) Pie chart summarizing the percentage of LMO2 transcripts identified by rapid amplification of 5′ complementary DNA ends that start from the distal, intermediate, and proximal promoters for the PF-382, DU.528, and Loucy T-ALL cell lines. A total of 20, 21, and 22 LMO2 transcripts was examined for PF-382, DU.528, and Loucy T-ALL cell lines, respectively. (D) Pie chart summarizing mutation recurrence within pediatric and adult human T-ALL cohorts. (E) Indels mapped to the LMO2 intron 1 mutation hotspot labeled with the associated de novo consensus site as aligned to the UniPROBE or HOCOMOCO position weight matrices, in which MYB, ETS1, and RUNX1 sites are marked as a triangle, square, and diamond, respectively. Below, motif analysis of the region shows the native binding sites for members of the TAL1 complex, including RUNX1, E-box (for TAL1 binding), ETS1, MYB, and GATA. TSS, transcription start site.
