1. Academic Validation
  2. Ectopic viral integration Site-1 oncogene promotes NRAS pathway through epigenetic silencing of microRNA-124 in acute myeloid leukemia

Ectopic viral integration Site-1 oncogene promotes NRAS pathway through epigenetic silencing of microRNA-124 in acute myeloid leukemia

  • Cell Signal. 2022 Nov;99:110402. doi: 10.1016/j.cellsig.2022.110402.
Wenjing Lang 1 Xiaofeng Han 1 Jiayi Cai 1 Fangyuan Chen 2 Lan Xu 1 Hua Zhong 1 Jihua Zhong 1
Affiliations

Affiliations

  • 1 Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai 200127, China.
  • 2 Department of Hematology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai 200127, China. Electronic address: chenfangyuan62@163.com.
Abstract

Background: Acute myeloid leukemia (AML) is an aggressive hematological malignancy characterized by genetic mutations that promote proliferation of myeloid progenitors and prevent their differentiation. Over-expression of Ectopic Viral Integration site-1(EVI-1) is related to the poor prognosis in myeloid leukemia, but the underlying mechanism remains unclear.

Methods: Using qRT-PCR and western blotting, we quantified expressions of EVI-1, NRAS and ERK/p-ERK in leukemia cell lines and PBMCs. Using WTS-8 and cell cycle analysis, we further investigated whether downregulation of EVI-1 by siRNA can inhibit cell proliferation. Microscopic observation of peripheral blood cells from EVI-1 transgenic zebrafish and WT control were analyzed by Wright Giemsa staining. Using miR-seq, qPCR, dual-luciferase reporter and coimmunoprecipitation assays, we revealed the relationship between EVI-1, miR-124 and NRAS.

Results: EVI-1 was highly expressed in both primary AML and leukemia cell lines (THP-1 and K562). In a transgenic zebrafish model, EVI-1 mediated higher mortality and induced immature hematopoietic cells in the blood circulation, suggesting its oncogenic role. Furthermore, our results suggested that EVI-1 upregulated NRAS expression, thereby activating the Ras/ERK pathway through epigenetic silencing of a potent NRAS suppressor, miR-124. In this study, we found that EVI1 physically interacts with Dnmt3a to form a protein complex that targets and binds to regulatory elements of miR-124.

Conclusions: Overall, the current findings demonstrate that EVI-1 overexpression converges on the regulation of miR-124 promoter methylation and activation of the Ras/ERK pathway in AML carcinogenesis, and suggest EVI-1 and/or miR-124 as therapeutic targets for this dismal disease.

Keywords

AML; EVI-1; NRAS/ERK pathway; miR-124.

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