The regulation of NDRG2 expression during ATLL development after HTLV-1 infection

Biochim Biophys Acta Mol Basis Dis. 2019 Oct 1;1865(10):2633-2646. doi: 10.1016/j.bbadis.2019.07.001. Epub 2019 Jul 8.

Abstract

N-myc downstream-regulated gene 2 (NDRG2) is a candidate tumor suppressor that is frequently downregulated in adult T-cell leukemia/lymphoma (ATLL) and functions to negatively regulate several cellular signaling pathways as PP2A recruiter. To clarify the molecular mechanisms of suppression of NDRG2 expression, we initially determined the expression pattern of NDRG2 in various types of T-cells and ATLL cells. NDRG2 expression was significantly upregulated in HTLV-1/Tax-immortalized T-cells, which was mediated by NF-κB activation through Tax expression. On the other hand, NDRG2 expression was suppressed in HTLV-1-infected cell lines and various types of ATLL cells, which was dependent on the DNA methylation of the NDRG2 promoter. We found that the expression of enhancer of zeste homolog 2 (EZH2), a member of the polycomb family, is increased in ATLL, and that EZH2 directly binds to the NDRG2 promoter and induces DNA methylation of the NDRG2 promoter. Since the expression of EZH2 were anti-parallelly regulated with the NDRG2 expression, EZH2 might be one of the most important regulators of the downregulation of NDRG2, contributing to enhanced activation of signaling pathways during ATLL development.

Keywords: ATLL; DNA promoter methylation; EZH2; NDRG2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cell Line, Tumor
  • Cell Proliferation
  • DNA Methylation
  • Down-Regulation
  • Enhancer of Zeste Homolog 2 Protein / metabolism
  • Gene Expression Regulation, Neoplastic
  • HTLV-I Infections / complications*
  • Human T-lymphotropic virus 1
  • Humans
  • Leukemia-Lymphoma, Adult T-Cell / genetics*
  • Leukemia-Lymphoma, Adult T-Cell / metabolism*
  • NF-kappa B / metabolism
  • Signal Transduction
  • T-Lymphocytes
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / metabolism*
  • Up-Regulation

Substances

  • NDRG2 protein, human
  • NF-kappa B
  • Tumor Suppressor Proteins
  • EZH2 protein, human
  • Enhancer of Zeste Homolog 2 Protein