Post-transcriptional gene regulation by HuR promotes a more tumorigenic phenotype.

Published

Journal Article

In a breast tumor xenograft model, the MCT-1 oncogene increases the in vivo tumorgenicity of MCF7 cells by promoting angiogenesis and inhibiting apoptosis. Increases in the tumor microvascular density are accompanied by a strong reduction in the levels of the angiogenesis inhibitor thrombospondin-1 (TSP1), but the mechanisms underlying this process are unknown. We show that TSP1 expression is controlled, at least in part, by post-transcriptional events. Using RNA interference to knock down the expression of the RNA-binding protein HuR in MCF7 cells as well as HuR overexpression, we demonstrate that HuR plays an important role in translation of the TSP1 mRNA. Furthermore, employing the RIP-Chip assay yielded 595 transcripts with significantly altered binding to HuR in the more tumorigenic breast cancer clones compared with the weakly tumorigenic clones. These mRNAs clustered in several pathways implicated in the transformed phenotype, such as the RAS pathway (involved in mitogenesis), the PI3K pathway (evasion of apoptosis) and pathways mediating angiogenesis and the cellular response to hypoxia. These findings demonstrate for the first time that global changes in HuR-bound mRNAs are implicated in the evolution to a more tumorigenic phenotype in an in vivo tumor model and underscore the role of global mRNA-protein interactions toward tumor progression.

Full Text

Duke Authors

Cited Authors

  • Mazan-Mamczarz, K; Hagner, PR; Corl, S; Srikantan, S; Wood, WH; Becker, KG; Gorospe, M; Keene, JD; Levenson, AS; Gartenhaus, RB

Published Date

  • October 16, 2008

Published In

Volume / Issue

  • 27 / 47

Start / End Page

  • 6151 - 6163

PubMed ID

  • 18641687

Pubmed Central ID

  • 18641687

Electronic International Standard Serial Number (EISSN)

  • 1476-5594

Digital Object Identifier (DOI)

  • 10.1038/onc.2008.215

Language

  • eng

Conference Location

  • England