Installation of a cancer promoting WNT/SIX1 signaling axis by the oncofusion protein MLL-AF9Research in the context

Autor: Li-shu Zhang, Xunlei Kang, Jianming Lu, Yuannyu Zhang, Xiaofeng Wu, Guojin Wu, Junke Zheng, Rubina Tuladhar, Heping Shi, Qiaoling Wang, Lorraine Morlock, Huiyu Yao, Lily Jun-shen Huang, Pascal Maire, James Kim, Noelle Williams, Jian Xu, Chuo Chen, Cheng Cheng Zhang, Lawrence Lum
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: EBioMedicine, Vol 39, Iss , Pp 145-158 (2019)
Druh dokumentu: article
ISSN: 2352-3964
DOI: 10.1016/j.ebiom.2018.11.039
Popis: Background: Chromosomal translocation-induced expression of the chromatin modifying oncofusion protein MLL-AF9 promotes acute myelocytic leukemia (AML). Whereas WNT/β-catenin signaling has previously been shown to support MLL-AF9-driven leukemogenesis, the mechanism underlying this relationship remains unclear. Methods: We used two novel small molecules targeting WNT signaling as well as a genetically modified mouse model that allow targeted deletion of the WNT protein chaperone Wntless (WLS) to evaluate the role of WNT signaling in AML progression. ATAC-seq and transcriptome profiling were deployed to understand the cellular consequences of disrupting a WNT signaling in leukemic initiating cells (LICs). Findings: We identified Six1 to be a WNT-controlled target gene in MLL-AF9-transformed leukemic initiating cells (LICs). MLL-AF9 alters the accessibility of Six1 DNA to the transcriptional effector TCF7L2, a transducer of WNT/β-catenin gene expression changes. Disruption of WNT/SIX1 signaling using inhibitors of the Wnt signaling delays the development of AML. Interpretation: By rendering TCF/LEF-binding elements controlling Six1 accessible to TCF7L2, MLL-AF9 promotes WNT/β-catenin-dependent growth of LICs. Small molecules disrupting WNT/β-catenin signaling block Six1 expression thereby disrupting leukemia driven by MLL fusion proteins.
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