Functional interrogation of HOXA9 regulome in MLLr leukemia via reporter-based CRISPR/Cas9 screen.

Abstract

Aberrant HOXA9 expression is a hallmark of most aggressive acute leukemias, notably those with KMT2A (MLL) gene rearrangements. HOXA9 overexpression not only predicts poor diagnosis and outcome but also plays a critical role in leukemia transformation and maintenance. However, our current understanding of HOXA9 regulation in leukemia is limited, hindering development of therapeutic strategies. Here, we generated the HOXA9-mCherry knock-in reporter cell lines to dissect HOXA9 regulation. By utilizing the reporter and CRISPR/Cas9 screens, we identified transcription factors controlling HOXA9 expression, including a novel regulator, USF2, whose depletion significantly down-regulated HOXA9 expression and impaired MLLr leukemia cell proliferation. Ectopic expression of Hoxa9 rescued impaired leukemia cell proliferation upon USF2 loss. Cut and Run analysis revealed the direct occupancy of USF2 at HOXA9 promoter in MLLr leukemia cells. Collectively, the HOXA9 reporter facilitated the functional interrogation of the HOXA9 regulome and has advanced our understanding of the molecular regulation network in HOXA9-driven leukemia.

• Authors: Hao Zhang, Yang Zhang, Xinyue Zhou, Shaela Wright, Judith Hyle, Lianzhong Zhao, Jie An, Xujie Zhao, Ying Shao, Beisi Xu, Hyeong-Min Lee, Taosheng Chen, Yang Zhou, Xiang Chen, Rui Lu, Chunliang Li
• Journal: eLife (Elife) Vol. 9 (10 01 2020) ISSN: 2050-084X [Electronic] England
• PMID: 33001025 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © 2020, Zhang et al.

Chemical References

• Homeodomain Proteins
• KMT2A protein, human
• USF1 protein, human
• USF2 protein, human
• Upstream Stimulatory Factors
• homeobox protein HOXA9
• Myeloid-Lymphoid Leukemia Protein
• Histone-Lysine N-Methyltransferase

Topics

• Alleles
• CRISPR-Cas Systems
• Cell Line, Tumor
• Cell Proliferation
• Down-Regulation
• Epigenesis, Genetic
• Gene Expression Regulation, Leukemic
• Genes, Reporter
• Histone-Lysine N-Methyltransferase (genetics)
• Homeodomain Proteins (metabolism)
• Humans
• Leukemia (metabolism)
• Myeloid-Lymphoid Leukemia Protein (genetics)
• Upstream Stimulatory Factors (metabolism)