Activation of cellular invasion by trefoil peptides and src is mediated by cyclooxygenase- and thromboxane A2 receptor-dependent signaling pathways

FASEB J. 2001 Jul;15(9):1517-28. doi: 10.1096/fj.00-0802com.

Abstract

We have investigated the possible functional relationships between cellular invasion pathways induced by trefoil factors (TFFs), src, and the cyclooxygenases COX-1 and COX-2. Pharmacological inhibitors of the Rho small GTPase (C3 exoenzyme), phospholipase C (U-73122), cyclooxygenases (SC-560, NS-398), and the thromboxane A2 receptor (TXA2-R) antagonist SQ-295 completely abolished invasion induced by intestinal trefoil factor, pS2, and src in kidney and colonic epithelial cells MDCKts.src and PCmsrc. In contrast, invasion was induced by the TXA2-R mimetic U-46619, constitutively activated forms of the heterotrimeric G-proteins Galphaq (AGalphaq), Galpha12, Galpha13 (AGalpha12/13), which are signaling elements downstream of TXA2-R. Ectopic overexpression of pS2 cDNA and protein in MDCKts.src-pS2 cells and human colorectal cancer cells HCT8/S11-pS2 initiate distinct invasion signals that are Rho independent and COX and TXA2-R dependent. We detected a marked induction of COX-2 protein and accumulation of the stable PGH2/TXA2 metabolite TXB2 in the conditioned medium from cells transformed by src. This led to activation of the TXA2-R-dependent invasion pathway, which is monitored via a Rho- and Galpha12/Galpha13-independent mechanism using the Galphaq/PKC signaling cascade. These findings identify a new intracrine/paracrine loop that can be monitored by TFFs and src in inflammatory diseases and progression of colorectal cancers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Transformed
  • Cells, Cultured
  • Culture Media, Conditioned
  • Cyclooxygenase 1
  • Cyclooxygenase 2
  • DNA, Complementary / genetics
  • DNA-Binding Proteins / metabolism
  • GTP Phosphohydrolases / metabolism
  • GTP-Binding Protein alpha Subunits, G12-G13
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • Growth Substances / pharmacology*
  • Heterotrimeric GTP-Binding Proteins / metabolism
  • Humans
  • Intestinal Mucosa / cytology
  • Intestinal Mucosa / enzymology
  • Isoenzymes / metabolism
  • Kidney / cytology
  • Kidney / enzymology
  • Membrane Proteins
  • Mucins*
  • Muscle Proteins*
  • Neoplasm Invasiveness
  • Neuropeptides*
  • Peptides / pharmacology*
  • Prostaglandin-Endoperoxide Synthases / metabolism*
  • Proteins / genetics
  • Proteins / pharmacology
  • Proto-Oncogene Proteins pp60(c-src) / pharmacology*
  • Receptors, Thromboxane / metabolism*
  • Signal Transduction
  • Transfection
  • Trefoil Factor-1
  • Trefoil Factor-2
  • Trefoil Factor-3
  • Tumor Cells, Cultured
  • Tumor Suppressor Proteins
  • Type C Phospholipases / metabolism

Substances

  • Culture Media, Conditioned
  • DNA, Complementary
  • DNA-Binding Proteins
  • Growth Substances
  • Isoenzymes
  • Membrane Proteins
  • Mucins
  • Muscle Proteins
  • Neuropeptides
  • Peptides
  • Proteins
  • Receptors, Thromboxane
  • TFF1 protein, human
  • TFF3 protein, rat
  • Trefoil Factor-1
  • Trefoil Factor-2
  • Trefoil Factor-3
  • Tumor Suppressor Proteins
  • Cyclooxygenase 1
  • Cyclooxygenase 2
  • PTGS1 protein, human
  • PTGS2 protein, human
  • Prostaglandin-Endoperoxide Synthases
  • Proto-Oncogene Proteins pp60(c-src)
  • Type C Phospholipases
  • GTP Phosphohydrolases
  • GTP-Binding Protein alpha Subunits, G12-G13
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • Heterotrimeric GTP-Binding Proteins