Description
To examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in T-ALL driven by its knockdown. This causes rapid transcriptional repression of Notch1 and associated targets including Myc, even in leukemias harboring spontaneous activating Notch1 mutations (producing aberrant ICN1) similar to those found in 60% of human T-ALL. Ikaros restoration results in sustained regression of Notch1-wild type leukemias while endogenous or engineered ICN1 expression promotes rapid disease relapse, indicating that ICN1 functionally antagonizes Ikaros in T-ALL. Overall design: RNA-seq was performed on T-ALL (Vav-tTA;TRE-GFP-shIkaros primary leukemia ALL211) cells isolated from two untreated and two 3-day Dox-treated mice.