Loss of Par3 promotes lung adenocarcinoma metastasis through 14-3-3ζ protein

Oncotarget. 2016 Sep 27;7(39):64260-64273. doi: 10.18632/oncotarget.11728.

Abstract

Partitioning defective protein 3 (Par3) can activate the Tiam1/Rac pathway to inhibit invasion and metastasis in many cancers; however, the role of Par3 in lung adenocarcinoma remains unknown. Here we show that Par3 is downregulated in lung adenocarcinoma tissues and is associated with higher rates of lymph node metastasis and recurrence. Our functional study demonstrated that knock-down of Par3 promoted lung adenocarcinoma cell growth, cell migration, tumor formation, and metastasis, all of which were effectively inhibited when 14-3-3ζ was silenced. We found that Par3 binded with 14-3-3ζ protein and also showed that Par3 abrogated the binding of 14-3-3ζ to Tiam1, which was responsible for Rac1 activation. Knock-down of 14-3-3ζ inhibited Tiam1/Rac-GTP activation and blocked the invasive behavior of cells lacking Par3. These data suggest that loss of Par3 promotes metastatic behavior in lung adenocarcinoma cells through 14-3-3ζ protein.

Keywords: 14-3-3ζ; NSCLC; Par3; metastasis.

MeSH terms

  • 14-3-3 Proteins / genetics
  • 14-3-3 Proteins / metabolism*
  • A549 Cells
  • Adaptor Proteins, Signal Transducing
  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism*
  • Adenocarcinoma / secondary
  • Adenocarcinoma of Lung
  • Animals
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Movement*
  • Cell Proliferation
  • Down-Regulation
  • Female
  • Gene Expression Regulation, Neoplastic
  • Human Umbilical Vein Endothelial Cells / metabolism
  • Human Umbilical Vein Endothelial Cells / pathology
  • Humans
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / pathology
  • Lymphatic Metastasis
  • Male
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice, Nude
  • Middle Aged
  • Neoplasm Invasiveness
  • Neovascularization, Pathologic
  • Protein Binding
  • RNA Interference
  • Signal Transduction
  • T-Lymphoma Invasion and Metastasis-inducing Protein 1 / metabolism
  • Transfection
  • Tumor Burden
  • rac1 GTP-Binding Protein / metabolism

Substances

  • 14-3-3 Proteins
  • Adaptor Proteins, Signal Transducing
  • Cell Cycle Proteins
  • Membrane Proteins
  • PARD3 protein, human
  • RAC1 protein, human
  • T-Lymphoma Invasion and Metastasis-inducing Protein 1
  • TIAM1 protein, human
  • YWHAZ protein, human
  • rac1 GTP-Binding Protein