Fig. 1.

The t(6;9) translocation in ACC results in a MYB-NFIB fusion. (A) Partial SKY-karyotype showing the reciprocal t(6;9) translocation in ACC6. DAPI-banded chromosomes 6 and 9 are shown on the left. (B) Dual-color FISH analysis of a t(6;9)-positive tumor (ACC6) using the NFIB-specific YAC-912E9 (green signals) and BAC clones RP11–104D9 and RP11–349J5 containing the 5′ part of MYB and its flanking sequences (red signals). Chromosome 6 is identified by a red alpha-satellite probe and chromosome 9 by a red telomere probe on the q-arm. Note the presence of the MYB-NFIB fusion gene on the der (6) marker (fused red/green signals marked by arrow). (C) Schematic illustration depicting the MYB and NFIB genes as well as the MYB-NFIB fusion gene (coding exons are shown in darker red and blue) and the resulting fusion protein. Translocation breakpoints are shown by vertical arrows, and miRNA binding sites for miR-15a/16 and miR-150 in the 3′ UTR of MYB are indicated. DBD, DNA binding domain; NRD, negative regulatory domain; TAD, transactivation domain. (D) RT-PCR analyses of MYB-NFIB fusion transcripts using primers located in MYB exons 5/6 and NFIB exon 9 (ACC4, -7, -6) and in MYB exon 14 and NFIB exon 9 (ACC1, -2, -3, -5, - 8–11). Also shown are size markers (M), non-ACC tumors (MEC and PLGA), and negative control. (E) Partial chromatogram showing the MYB-NFIB junction (vertical lines) and the nucleic acid sequence of the chimeric transcript with an in-frame fusion of MYB exon 14 to NFIB exon 9.