Tyrosine 23 phosphorylation-dependent cell-surface localization of annexin A2 is required for invasion and metastases of pancreatic cancer

PLoS One. 2011 Apr 29;6(4):e19390. doi: 10.1371/journal.pone.0019390.

Abstract

The aggressiveness of pancreatic ductal adenocarcinoma (PDA) is characterized by its high metastatic potential and lack of effective therapies, which is the result of a lack of understanding of the mechanisms involved in promoting PDA metastases. We identified Annexin A2 (ANXA2), a member of the Annexin family of calcium-dependent phospholipid binding proteins, as a new molecule that promotes PDA invasion and metastases. We found ANXA2 to be a PDA-associated antigen recognized by post-treatment sera of patients who demonstrated prolonged survival following treatment with a PDA-specific vaccine. Cell surface ANXA2 increases with PDA development and progression. Knockdown of ANXA2 expression by RNA interference or blocking with anti-ANXA2 antibodies inhibits in vitro invasion of PDA cells. In addition, post-vaccination patient sera inhibits in vitro invasion of PDA cells, suggesting that therapeutic anti-ANXA2 antibodies are induced by the vaccine. Furthermore, cell-surface localization of ANXA2 is tyrosine 23 phosphorylation-dependent; and tyrosine 23 phosphorylation is required for PDA invasion. We demonstrated that tyrosine 23 phosphorylation resulting in surface expression of ANXA2 is required for TGFβ-induced, Rho-mediated epithelial-mesenchymal transition (EMT), linking the cellular function of ANXA2 which was previously shown to be associated with small GTPase-regulated cytoskeletal rearrangements, to the EMT process in PDA. Finally, using mouse PDA models, we showed that shRNA knock-down of ANXA2, a mutation at tyrosine 23, or anti-ANXA2 antibodies, inhibit PDA metastases and prolong mouse survival. Thus, ANXA2 is part of a novel molecular pathway underlying PDA metastases and a new target for development of PDA therapeutics.

Publication types

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

MeSH terms

  • Animals
  • Annexin A2 / genetics
  • Annexin A2 / immunology
  • Annexin A2 / metabolism*
  • Antibodies, Monoclonal / immunology
  • Antibodies, Monoclonal / pharmacology
  • Antigens, Neoplasm / genetics
  • Antigens, Neoplasm / immunology
  • Antigens, Neoplasm / metabolism
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / immunology
  • Biomarkers, Tumor / metabolism
  • Blotting, Western
  • Cancer Vaccines / immunology
  • Cell Line, Tumor
  • Cell Membrane / metabolism*
  • Cell Movement / drug effects
  • Disease-Free Survival
  • Epithelial-Mesenchymal Transition / drug effects
  • Female
  • Humans
  • Liver / drug effects
  • Liver / metabolism
  • Liver / pathology
  • Mice
  • Mice, Inbred C57BL
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Neoplasms, Experimental / metabolism
  • Neoplasms, Experimental / pathology
  • Neoplasms, Experimental / prevention & control
  • Pancreatic Neoplasms / metabolism*
  • Pancreatic Neoplasms / pathology
  • Pancreatic Neoplasms / prevention & control
  • Phosphorylation
  • RNA Interference
  • Tumor Cells, Cultured
  • Tyrosine / genetics
  • Tyrosine / metabolism*

Substances

  • Annexin A2
  • Antibodies, Monoclonal
  • Antigens, Neoplasm
  • Biomarkers, Tumor
  • Cancer Vaccines
  • Tyrosine