Exploring downstream targets of EVI1-highly expressing leukemia using genetically engineered mice

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K16297
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 54010:Hematology and medical oncology-related
• Research Institution: The University of Tokyo
• Principal Investigator: Chiba Akira 東京大学, 医学部附属病院, 助教 (70875947)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: 急性骨髄性白血病

Outline of Final Research Achievements

We used the CRISPR-Cas9 to generate mice in which a 3×FLAG tag was knocked in at the 3' end of the Evi1 locus. The mice were used to perform CUT&RUN-seq to comprehensively search for downstream targets of Evi1. First, CUT&RUN-seq was performed on Lineage-c-kit+Sca-1+ fraction expressing Evi1 to comprehensively explore downstream targets of EVI1 in a normal hematopoiesis.
In addition, we retrovirally transfected the bone marrow cells with genes that cause AML with high expression of EVI1. Secondary transplantation of these cells produced a mouse model of AML with high expression of EVI1, and genome-wide binding of EVI1 was analyzed with anti-FLAG antibody. The results were compared using GSEA and other methods. As a result, we obtained several target genes of Evi1, specifically up-regulated in Evi1+AML. These genes include EGFL7 and PHACTR1, assumed to be involved in proliferation signaling. When these genes were silenced in Evi1-expressing AML cells, the proliferation was suppressed.

Free Research Field

血液内科学

Academic Significance and Societal Importance of the Research Achievements

EVI1を高発現するAMLは極めて予後不良だが、正常造血幹細胞の維持にもEVI1は必須なため治療標的とするのは難しい。本研究ではCRISPR-Cas9 systemを用いた遺伝子改変マウスを用いてEVI1の正常造血およびEVI1高発現白血病における下流標的の網羅的な探索を行い、白血病特異的に作用するいくつかの候補遺伝子を明らかにした。これはEVI1高発現AMLのみならず、造血幹細胞に発現する遺伝子の高発現で特徴づけられるタイプの他の難治性AMLに共通する治療開発のモデルとなりうる可能性があり、学術的な意義が高いと考えられる。