Trib1 promotes acute myeloid leukemia progression by modulating transcriptional programs of Hoxa9 [ChIP-seq]
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ABSTRACT: The pseudokinase Trib1 functions as a myeloid oncogene that recruits E3 ubiquitin ligase COP1 to C/EBP, and interacts with MEK1 to enhance ERK phosphorylation. Close genetic interaction between Trib1 and Hoxa9 has been observed in myeloid leukemogenesis as Trib1 overexpression significantly accelerates Hoxa9-induced leukemia onset. Yet the mechanism how Trib1 functionally modulates Hoxa9 transcription activity is unclear. Here we provide evidence that Trib1 modulates Hoxa9-associated super-enhancers. ChIP-seq analyses identified increased Histone H3K27Ac signals at the super-enhancers such as Erg, Aff3, Spns2 and Coro2 loci, as well as increased mRNA expression of these genes. The modification of super-enhancer activities is mostly achieved by degradation of C/EBP by Trib1 and the MEK/ERK pathway only slightly contributes to the activities. Silencing of Erg abrogates the growth advantage acquired by Trib1 overexpression, indicating that Erg is a critical downstream target of the Trib1/Hoxa9 axis. Moreover, treatment of AML cells with the BRD4 inhibitor JQ1 showed growth inhibition in the Trib1/Erg-dependent manner. Upregulation of ERG by TRIB1 was also observed in human AML cell lines, suggesting that Trib1 is a potential target of Hoxa9-associated AML.
ORGANISM(S): Mus musculus
PROVIDER: GSE140313 | GEO | 2020/10/21
REPOSITORIES: GEO
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