Genetic inactivation of Ikaros is a rare event in human T-ALL.

ABSTRACT

The Ikaros (Ikzf1) gene, encoding a transcription regulator, is a major tumor suppressor in B-cell acute lymphoblastic leukemia (B-ALL). In the mouse, however, loss of Ikaros is primarily associated with T-ALL development. Whether Ikaros is also implicated in human T-ALL remains unclear. We studied Ikaros in 25 human T-ALL samples from diverse molecular subtypes at the mRNA, protein, sequence and genomic copy number level. We found that Ikaros was abnormal in only one sample one allele was lost by genomic deletion, while proteins generated from the remaining allele were delocalized and concentrated at a single cytoplasmic structure. Thus, inactivation of Ikaros by deletion or mutation is rare in human T-ALL.