Dose dependent activation of retinoic acid-inducible gene-I promotes both proliferation and apoptosis signals in human head and neck squamous cell carcinoma

PLoS One. 2013;8(3):e58273. doi: 10.1371/journal.pone.0058273. Epub 2013 Mar 4.

Abstract

The retinoic-acid-inducible gene (RIG)-like receptor (RLR) family proteins are major pathogen reorganization receptors (PRR) responsible for detection of viral RNA, which initiates antiviral response. Here, we evaluated the functional role of one RLR family member, RIG-I, in human head and neck squamous cell carcinoma (HNSCC). RIG-I is abundantly expressed both in poorly-differentiated primary cancer and lymph node metastasis, but not in normal adjacent tissues. Activation of RIG-I by transfection with low dose of 5'-triphosphate RNA (3p-RNA) induces low levels of interferon and proinflammatory cytokines and promotes NF-κB- and Akt-dependent cell proliferation, migration and invasion. In contrast, activation of RIG-I by a high dose of 3p-RNA induces robust mitochondria-derived apoptosis accompanied by decreased activation of Akt, which is independent of the interferon and TNFα receptor, but can be rescued by over-expression of constitutively active Akt. Furthermore, co-immunoprecipitation experiments indicate that the CARD domain of RIG-I is essential for inducing apoptosis by interacting with caspase-9. Together, our results reveal a dual role of RIG-I in HNSCC through regulating activation of Akt, in which RIG-I activation by low-dose viral dsRNA increases host cell survival, whereas higher level of RIG-I activation leads to apoptosis. These findings highlight the therapeutic potential of dsRNA mediated RIG-I activation in the treatment of HNSCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / physiology*
  • Blotting, Western
  • Carcinoma, Squamous Cell / metabolism*
  • Cell Proliferation / drug effects*
  • DEAD Box Protein 58
  • DEAD-box RNA Helicases / metabolism
  • DEAD-box RNA Helicases / pharmacology*
  • Dose-Response Relationship, Drug
  • Head and Neck Neoplasms / metabolism*
  • Humans
  • Immunohistochemistry
  • Immunoprecipitation
  • Interferon-Induced Helicase, IFIH1
  • RNA, Small Interfering / genetics
  • Receptors, Immunologic
  • Transfection

Substances

  • RNA, Small Interfering
  • Receptors, Immunologic
  • RIGI protein, human
  • IFIH1 protein, human
  • DEAD Box Protein 58
  • DEAD-box RNA Helicases
  • Interferon-Induced Helicase, IFIH1

Grants and funding

This study was supported by Project of National Natural Science Foundation of China(Grant No. 31140007) to JH and Shanghai Leading Academic Discipline Project (Project No. S30206) to ZZ. The URL of National Natural Science Foundation of China (http://www.nsfc.gov.cn/Portal0/default152.htm). The URL of Shanghai education committee: http://www.shec.edu.cn/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.