TEL-AML1 regulation of survivin and apoptosis via miRNA-494 and miRNA-320a

Blood. 2010 Dec 2;116(23):4885-93. doi: 10.1182/blood-2009-02-206706. Epub 2010 Aug 31.

Abstract

There is increasing evidence that miRNA and transcription factors interact in an instructive fashion in normal and malignant hematopoiesis. We explored the impact of TEL-AML1 (ETV6-RUNX1), the most common fusion protein in childhood leukemia, on miRNA expression and the leukemic phenotype. Using RNA interference, miRNA expression arrays, and quantitative polymerase chain reaction, we identified miRNA-494 and miRNA-320a to be up-regulated upon TEL-AML1 silencing independently of TEL expression. Chromatin immunoprecipitation analysis identified miRNA-494 as a direct miRNA target of the fusion protein TEL-AML1. Using bioinformatic analysis as well as functional luciferase experiments, we demonstrate that survivin is a target of the 2 miRNAs. miRNA-494 and miRNA-320a were introduced to the cells by transfection and survivin expression determined by Western blot analysis. These miRNAs blocked survivin expression and resulted in apoptosis in a similar manner as TEL-AML1 silencing by itself; this silencing was also shown to be Dicer-dependent. miRNAs-494 and -320a are expressed at lower levels in TEL-AML1+ leukemias compared with immunophenotype-matched nonTEL-AML1 acute lymphoblastic leukemia subtypes, and within TEL-AML1+ leukemias their expression is correlated to survivin levels. In summary our data suggest that TEL-AML1 might exert its antiapoptotic action at least in part by suppressing miRNA-494 and miRNA-320a, lowering their expression causing enhanced survivin expression.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Apoptosis / genetics*
  • Blotting, Western
  • Cell Line, Tumor
  • Child
  • Child, Preschool
  • Chromatin Immunoprecipitation
  • Core Binding Factor Alpha 2 Subunit / genetics*
  • Gene Expression
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Inhibitor of Apoptosis Proteins
  • MicroRNAs / genetics*
  • Microtubule-Associated Proteins / biosynthesis
  • Microtubule-Associated Proteins / genetics*
  • Oligonucleotide Array Sequence Analysis
  • Oncogene Proteins, Fusion / genetics*
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / genetics
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / metabolism
  • RNA, Messenger / analysis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Survivin
  • Transfection

Substances

  • BIRC5 protein, human
  • Core Binding Factor Alpha 2 Subunit
  • Inhibitor of Apoptosis Proteins
  • MicroRNAs
  • Microtubule-Associated Proteins
  • Oncogene Proteins, Fusion
  • RNA, Messenger
  • Survivin
  • TEL-AML1 fusion protein