Alcohol consumption and decreased risk of non-Hodgkin lymphoma: role of mTOR dysfunction

Blood. 2009 May 28;113(22):5526-35. doi: 10.1182/blood-2008-11-191783. Epub 2009 Mar 17.

Abstract

Several epidemiologic studies support the emerging paradigm that current alcohol consumers have decreased risk of most types of non-Hodgkin lymphoma. The observed lower risk among people who drank alcohol does not seem to vary with beverage type. The mechanisms accounting for alcohol-induced decrease in the incidence of lymphomas remain largely unknown. We demonstrate that low-dose chronic exposure to ethanol inhibits mammalian target of rapamycin (mTOR) C1 complex formation, resulting in decreased phosphorylation events involved in mTOR pathway signaling in a lymphoid-tissue specific manner. These changes in mTOR signaling lead to a decrease in eIF4E associated with the translation initiation complex and a repression of global cap-dependent synthesis in both lymphoma cell lines and normal donor lymphocytes. We show that chronic exposure of ethanol at physiologically relevant concentrations in a xenograft model results in a striking inhibition of lymphoma growth. Our data support a paradigm in which chronic ethanol exposure inhibits mTOR signaling in lymphocytes with a significant repression of cap-dependent translation, reducing the tumorigenic capacity of non-Hodgkin lymphoma in a human xenograft model. The ethanol-mediated repression of mTOR signaling coupled with decreased in vivo lymphoma growth underscore the critical role of mTOR signaling and translation in lymphoma.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Alcohol Drinking / metabolism
  • Alcohol Drinking / physiopathology*
  • Animals
  • Carrier Proteins / metabolism
  • Cell Cycle Proteins
  • Ethanol / pharmacology
  • Eukaryotic Initiation Factor-4E / metabolism
  • Eukaryotic Initiation Factors
  • Humans
  • Lymphoma, Non-Hodgkin / etiology*
  • Mechanistic Target of Rapamycin Complex 1
  • Mice
  • Mice, SCID
  • Multiprotein Complexes
  • Phosphoproteins / metabolism
  • Phosphorylation / drug effects
  • Protein Binding / drug effects
  • Protein Kinases / metabolism
  • Protein Kinases / physiology*
  • Proteins
  • Ribosomal Protein S6 / metabolism
  • Ribosomal Protein S6 Kinases, 70-kDa / metabolism
  • Risk Factors
  • TOR Serine-Threonine Kinases
  • Transcription Factors / metabolism
  • Transplantation, Heterologous
  • Tumor Cells, Cultured

Substances

  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Cell Cycle Proteins
  • Eif4ebp1 protein, mouse
  • Eukaryotic Initiation Factor-4E
  • Eukaryotic Initiation Factors
  • Multiprotein Complexes
  • Phosphoproteins
  • Proteins
  • Ribosomal Protein S6
  • Transcription Factors
  • ribosomal protein S6, mouse
  • Ethanol
  • Protein Kinases
  • MTOR protein, human
  • mTOR protein, mouse
  • Mechanistic Target of Rapamycin Complex 1
  • Ribosomal Protein S6 Kinases, 70-kDa
  • TOR Serine-Threonine Kinases