Anterior gradient protein-2 is a regulator of cellular adhesion in prostate cancer

PLoS One. 2014 Feb 27;9(2):e89940. doi: 10.1371/journal.pone.0089940. eCollection 2014.

Abstract

Anterior Gradient Protein (AGR-2) is reported to be over-expressed in many epithelial cancers and promotes metastasis. A clear-cut mechanism for its observed function(s) has not been previously identified. We found significant upregulation of AGR-2 expression in a bone metastatic prostate cancer cell line, PC3, following culturing in bone marrow-conditioned medium. Substantial AGR-2 expression was also confirmed in prostate cancer tissue specimens in patients with bone lesions. By developing stable clones of PC3 cells with varying levels of AGR-2 expression, we identified that abrogation of AGR-2 significantly reduced cellular attachment to fibronectin, collagen I, collagen IV, laminin I and fibrinogen. Loss of cellular adhesion was associated with sharp decrease in the expression of α4, α5, αV, β3 and β4 integrins. Failure to undergo apoptosis following detachment is a hallmark of epithelial cancer metastasis. The AGR-2-silenced PC3 cells showed higher resistance to Tumor necrosis factor-related apoptosis- inducing ligand (TRAIL) induced apoptosis in vitro. This observation was also supported by significantly reduced Caspase-3 expression in AGR-2-silenced PC3 cells, which is a key effector of both extrinsic and intrinsic death signaling pathways. These data suggest that AGR-2 influence prostate cancer metastasis by regulation of cellular adhesion and apoptosis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Bone Marrow / metabolism
  • Bone Marrow / pathology
  • Cell Adhesion / drug effects
  • Cell Adhesion / genetics
  • Cell Death / drug effects
  • Cell Death / genetics
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Proliferation
  • Cluster Analysis
  • Gene Expression
  • Gene Expression Profiling
  • Gene Silencing
  • Humans
  • Integrins / genetics
  • Integrins / metabolism
  • Male
  • Mice
  • Mucoproteins
  • Neoplasm Metastasis
  • Oncogene Proteins
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology
  • Proteins / genetics
  • Proteins / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • TNF-Related Apoptosis-Inducing Ligand / pharmacology

Substances

  • AGR2 protein, human
  • Integrins
  • Mucoproteins
  • Oncogene Proteins
  • Proteins
  • RNA, Messenger
  • TNF-Related Apoptosis-Inducing Ligand