EGFR modulates microRNA maturation in response to hypoxia through phosphorylation of AGO2 Journal Article


Authors: Shen, J.; Xia, W.; Khotskaya, Y. B.; Huo, L.; Nakanishi, K.; Lim, S. O.; Du, Y.; Wang, Y.; Chang, W. C.; Chen, C. H.; Hsu, J. L.; Wu, Y.; Lam, Y. C.; James, B. P.; Liu, X.; Liu, C. G.; Patel, D. J.; Hung, M. C.
Article Title: EGFR modulates microRNA maturation in response to hypoxia through phosphorylation of AGO2
Abstract: MicroRNAs (miRNAs) are generated by two-step processing to yield small RNAs that negatively regulate target gene expression at the post-transcriptional level. Deregulation of miRNAs has been linked to diverse pathological processes, including cancer. Recent studies have also implicated miRNAs in the regulation of cellular response to a spectrum of stresses, such as hypoxia, which is frequently encountered in the poorly angiogenic core of a solid tumour. However, the upstream regulators of miRNA biogenesis machineries remain obscure, raising the question of how tumour cells efficiently coordinate and impose specificity on miRNA expression and function in response to stresses. Here we show that epidermal growth factor receptor (EGFR), which is the product of a well-characterized oncogene in human cancers, suppresses the maturation of specific tumour-suppressor-like miRNAs in response to hypoxic stress through phosphorylation of argonaute 2 (AGO2) at Tyr 393. The association between EGFR and AGO2 is enhanced by hypoxia, leading to elevated AGO2-Y393 phosphorylation, which in turn reduces the binding of Dicer to AGO2 and inhibits miRNA processing from precursor miRNAs to mature miRNAs. We also identify a long-loop structure in precursor miRNAs as a critical regulatory element in phospho-Y393-AGO2- mediated miRNA maturation. Furthermore, AGO2-Y393 phosphorylation mediates EGFR-enhanced cell survival and invasiveness under hypoxia, and correlates with poorer overall survival in breast cancer patients. Our study reveals a previously unrecognized function of EGFR in miRNA maturation and demonstrates how EGFR is likely to function as a regulator of AGO2 through novel post-translational modification. These findings suggest that modulation of miRNA biogenesis is important for stress response in tumour cells and has potential clinical implications. © 2013 Macmillan Publishers Limited. All rights reserved.
Keywords: survival; epidermal growth factor; protein phosphorylation; survival analysis; overall survival; cell survival; breast cancer; microrna; gene expression; protein binding; receptor, epidermal growth factor; cell line, tumor; breast neoplasms; phosphorylation; hypoxia; rna; oncogene; gene expression regulation, neoplastic; protein processing; cancer cell; cell hypoxia; neoplasm invasiveness; oxidative stress; nucleic acid conformation; micrornas; enzyme binding; rna precursors; dicer; ribonuclease iii; argonaute 2 protein; phosphotyrosine; maturation; correlation; environmental stress; rna precursor; pathogen; argonaute proteins
Journal Title: Nature
Volume: 497
Issue: 7449
ISSN: 0028-0836
Publisher: Nature Publishing Group  
Date Published: 2013-05-16
Start Page: 383
End Page: 387
Language: English
DOI: 10.1038/nature12080
PUBMED: 23636329
PROVIDER: scopus
PMCID: PMC3717558
DOI/URL:
Notes: --- - "Export Date: 1 July 2013" - "CODEN: NATUA" - "Source: Scopus"
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  1. Dinshaw J Patel
    477 Patel