Ion channel TRPV1-dependent activation of PTP1B suppresses EGFR-associated intestinal tumorigenesis

J Clin Invest. 2014 Sep;124(9):3793-806. doi: 10.1172/JCI72340. Epub 2014 Aug 1.

Abstract

The intestinal epithelium has a high rate of turnover, and dysregulation of pathways that regulate regeneration can lead to tumor development; however, the negative regulators of oncogenic events in the intestinal epithelium are not fully understood. Here we identified a feedback loop between the epidermal growth factor receptor (EGFR), a known mediator of proliferation, and the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), in intestinal epithelial cells (IECs). We found that TRPV1 was expressed by IECs and was intrinsically activated upon EGFR stimulation. Subsequently, TRPV1 activation inhibited EGFR-induced epithelial cell proliferation via activation of Ca2+/calpain and resulting activation of protein tyrosine phosphatase 1B (PTP1B). In a murine model of multiple intestinal neoplasia (Apc(Min/+) mice), TRPV1 deficiency increased adenoma formation, and treatment of these animals with an EGFR kinase inhibitor reversed protumorigenic phenotypes, supporting a functional association between TRPV1 and EGFR signaling in IECs. Administration of a TRPV1 agonist suppressed intestinal tumorigenesis in Apc(Min/+) mice, similar to--as well as in conjunction with--a cyclooxygenase-2 (COX-2) inhibitor, which suggests that targeting both TRPV1 and COX-2 has potential as a therapeutic approach for tumor prevention. Our findings implicate TRPV1 as a regulator of growth factor signaling in the intestinal epithelium through activation of PTP1B and subsequent suppression of intestinal tumorigenesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism
  • Calcium Channels / physiology
  • Calpain / physiology
  • Cell Proliferation
  • Cyclooxygenase 2 Inhibitors / pharmacology
  • Enzyme Activation
  • ErbB Receptors / physiology*
  • Humans
  • Intestinal Neoplasms / prevention & control*
  • Mice
  • Protein Tyrosine Phosphatase, Non-Receptor Type 1 / metabolism*
  • Signal Transduction
  • TRPV Cation Channels / antagonists & inhibitors
  • TRPV Cation Channels / physiology*

Substances

  • Calcium Channels
  • Cyclooxygenase 2 Inhibitors
  • TRPV Cation Channels
  • TRPV1 protein, human
  • ErbB Receptors
  • PTPN1 protein, human
  • Protein Tyrosine Phosphatase, Non-Receptor Type 1
  • Calpain
  • Calcium