Translation from unconventional 5' start sites drives tumour initiation.

Publication Type Academic Article
Authors Sendoel A, Dunn J, Rodriguez E, Naik S, Gomez N, Hurwitz B, Levorse J, Dill B, Schramek D, Molina H, Weissman J, Fuchs E
Journal Nature
Volume 541
Issue 7638
Pagination 494-499
Date Published 01/11/2017
ISSN 1476-4687
Keywords 5' Untranslated Regions, Carcinogenesis, Carcinoma, Squamous Cell, Open Reading Frames, Peptide Chain Initiation, Translational, Skin Neoplasms
Abstract We are just beginning to understand how translational control affects tumour initiation and malignancy. Here we use an epidermis-specific, in vivo ribosome profiling strategy to investigate the translational landscape during the transition from normal homeostasis to malignancy. Using a mouse model of inducible SOX2, which is broadly expressed in oncogenic RAS-associated cancers, we show that despite widespread reductions in translation and protein synthesis, certain oncogenic mRNAs are spared. During tumour initiation, the translational apparatus is redirected towards unconventional upstream initiation sites, enhancing the translational efficiency of oncogenic mRNAs. An in vivo RNA interference screen of translational regulators revealed that depletion of conventional eIF2 complexes has adverse effects on normal but not oncogenic growth. Conversely, the alternative initiation factor eIF2A is essential for cancer progression, during which it mediates initiation at these upstream sites, differentially skewing translation and protein expression. Our findings unveil a role for the translation of 5' untranslated regions in cancer, and expose new targets for therapeutic intervention.
DOI 10.1038/nature21036
PubMed ID 28077873
PubMed Central ID PMC5287289
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