SNX3-dependent regulation of epidermal growth factor receptor (EGFR) trafficking and degradation by aspirin in epidermoid carcinoma (A-431) cells

Cell Mol Life Sci. 2012 May;69(9):1505-21. doi: 10.1007/s00018-011-0887-z. Epub 2011 Dec 11.

Abstract

Since being introduced globally as aspirin in 1899, acetylsalicylic acid has been widely used as an analgesic, anti-inflammation, anti-pyretic, and anti-thrombotic drug for years. Aspirin had been reported to down-regulate surface expression of CD40, CD80, CD86, and MHCII in myeloid dendritic cells (DC), which played essential roles in regulating the immune system. We hypothesized that the down-regulation of these surface membrane proteins is partly due to the ability of aspirin in regulating trafficking/sorting of endocytosed surface membrane proteins. By using an established epidermoid carcinoma cell line (A-431), which overexpresses the epidermal growth factor receptor (EGFR) and transferrin receptor (TfnR), we show that aspirin (1) reduces cell surface expression of EGFR and (2) accumulates endocytosed-EGFR and -TfnR in the early/sorting endosome (ESE). Further elucidation of the mechanism suggests that aspirin enhances recruitment of SNX3 and SNX5 to membranes and consistently, both SNX3 and SNX5 play essential roles in the aspirin-mediated accumulation of endocytosed-TfnR at the ESE. This study sheds light on how aspirin may down-regulate surface expression of EGFR by inhibiting/delaying the exit of endocytosed-EGFR from the ESE and recycling of endocytosed-EGFR back to the cell surface.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspirin / pharmacology*
  • Base Sequence
  • Biological Transport, Active / drug effects
  • Carcinoma, Squamous Cell / genetics
  • Carcinoma, Squamous Cell / metabolism*
  • Carcinoma, Squamous Cell / ultrastructure
  • Cell Line, Tumor
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • DNA Primers / genetics
  • Endocytosis / drug effects
  • ErbB Receptors / metabolism*
  • Gene Knockdown Techniques
  • Humans
  • Microscopy, Immunoelectron
  • Models, Biological
  • Receptors, Transferrin / metabolism
  • Signal Transduction / drug effects
  • Sorting Nexins / antagonists & inhibitors
  • Sorting Nexins / genetics
  • Sorting Nexins / metabolism*

Substances

  • DNA Primers
  • Receptors, Transferrin
  • SNX3 protein, human
  • Sorting Nexins
  • ErbB Receptors
  • Aspirin