MOZ is fused to p300 in an acute monocytic leukemia with t(8;22)

We report on the fusion of the monocytic leukemia zinc finger protein (MOZ) gene to the adenoviral EIA-associated protein p300 (p300) gene in acute mo nocytic leukemia M5 associated with a t(8;22)(p11;q13) translocation. We st udied two patients with double-color fluorescence in situ hybridization (FI SH) using the yeast artificial chromosome 176C9 and the bacterial artificia l chromosome clone H59D10 specific to the MOZ and p300 genes, respectively. Both probes were split. in the patients' chromosome metaphase cells, and t he two derivative chromosomes were each labeled with both probes. We showed by Southern blot the rearrangement of the MOZ gene, and cloned the fusion transcripts in one patient carrying the t(8;22) by reverse transcription-po lymerase chain reaction using MOZ- and p300-specific primers. Both fusion t ranscripts were expressed. This result defines a novel reciprocal transloca tion involving Mo acetyltransferases, MOZ and p300, resulting in an: abnorm al transcriptional co-activator that could play a critical role in leukemog enesis. Genes Chromosomes Cancer 28: 138-144, 2000. (C) 2000 Wiley-Liss, In c.