HuR-mediated control of C/EBPbeta mRNA stability and translation in ALK-positive anaplastic large cell lymphomas

Mol Cancer Res. 2011 Apr;9(4):485-96. doi: 10.1158/1541-7786.MCR-10-0351. Epub 2011 Feb 22.


The CCAAT/enhancer-binding protein β (C/EBPβ) plays a major role in the pathogenesis of anaplastic large cell lymphomas (ALCL) that express the nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) tyrosine kinase (ALK(+)). Although ALK-mediated C/EBPβ transcriptional activation has been reported, C/EBPβ mRNA possesses U- and AU-rich domains in its 3'-untranslated region (3'-UTR) that might be privileged targets for posttranscriptional control in ALK(+) ALCLs. The purpose of this study was to explore this possibility. By using human ALCL-derived cells and a murine model of ALK-transformed cells, we show that the AU-binding protein HuR binds to the 3'-UTR of C/EBPβ mRNA, as previously reported in adipocytes, and that NPM-ALK enhances this interaction. Interaction between HuR and C/EBPβ mRNA impacts on C/EBPβ gene expression at both the mRNA and protein levels. Indeed, C/EBPβ mRNA stability following HuR silencing is reduced and reaches the value observed in ALK-inactivated cells. Remarkably, HuR expression is not modified by NPM-ALK, but its association with actively translating polysomes is dramatically increased in ALK(+) cells. HuR/polysomes association diminishes when NPM-ALK activity is inhibited and is accompanied by a concomitant decrease of C/EBPβ mRNA translation. Finally, we show that HuR and NPM-ALK colocalized in cytoplasmic granules and HuR is phosphroylated on tyrosine residues in ALK(+) ALCL cells. Our study thus demonstrates that C/EBPβ is indeed regulated at the posttranscriptional level by HuR in ALK(+) cells, leading us to propose that part of NPM-ALK oncogenic properties relies on its ability to modify HuR properties in the cytoplasm and hence to alter expression of key actors of transformation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Anaplastic Lymphoma Kinase
  • Animals
  • Antigens, Surface / genetics
  • Antigens, Surface / metabolism*
  • CCAAT-Enhancer-Binding Proteins / genetics*
  • CCAAT-Enhancer-Binding Proteins / metabolism
  • Cell Line, Tumor
  • Cell Transformation, Neoplastic / genetics
  • ELAV Proteins
  • ELAV-Like Protein 1
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Lymphoma, Large-Cell, Anaplastic / genetics*
  • Lymphoma, Large-Cell, Anaplastic / metabolism
  • Mice
  • NIH 3T3 Cells
  • Protein Biosynthesis / genetics
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism
  • RNA Stability*
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Receptor Protein-Tyrosine Kinases / genetics
  • Receptor Protein-Tyrosine Kinases / metabolism*


  • 3' Untranslated Regions
  • Antigens, Surface
  • CCAAT-Enhancer-Binding Proteins
  • ELAV Proteins
  • ELAV-Like Protein 1
  • ELAVL1 protein, human
  • RNA-Binding Proteins
  • p80(NPM-ALK) protein
  • ALK protein, human
  • Alk protein, mouse
  • Anaplastic Lymphoma Kinase
  • Protein-Tyrosine Kinases
  • Receptor Protein-Tyrosine Kinases