Elevated PLGF contributes to small-cell lung cancer brain metastasis

Oncogene. 2013 Jun 13;32(24):2952-62. doi: 10.1038/onc.2012.313. Epub 2012 Jul 16.

Abstract

Brain metastasis (BM) is a major cause of mortality in small-cell lung cancer (SCLC) patients; however, the molecular pathway of SCLC BM remains largely unknown because of a lack of investigation. Here we screen the levels of some candidate-soluble factors in the serum of SCLC patients and find that SCLC patients with high levels of placental growth factor (PLGF) are prone to BM. Using in vitro blood-brain barrier model, we show that PLGF derived from SCLC cells triggers vascular endothelial growth factor receptor-1-Rho-extracellular regulated protein kinase 1/2 signaling axis activation, results in disassembly of tight junction in brain endothelial cells and promotes SCLC cell transendothelial migration. Furthermore, the downregulation of PLGF suppresses SCLC cell metastasis to the brain in an experimental BM model. These data suggest that PLGF is a potential signature of SCLC BM and a prospective therapeutic target for SCLC BM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / pathology
  • Brain Neoplasms / secondary*
  • Cell Line, Tumor
  • Endothelial Cells / pathology
  • Enzyme Activation
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Female
  • Humans
  • Lung Neoplasms / blood*
  • Lung Neoplasms / pathology*
  • Male
  • Mice
  • Placenta Growth Factor
  • Pregnancy Proteins / blood*
  • Signal Transduction
  • Small Cell Lung Carcinoma / blood*
  • Small Cell Lung Carcinoma / pathology*
  • Tight Junctions / metabolism
  • Tight Junctions / pathology
  • Transendothelial and Transepithelial Migration
  • Vascular Endothelial Growth Factor Receptor-1 / metabolism
  • rho-Associated Kinases / metabolism

Substances

  • PGF protein, human
  • Pgf protein, mouse
  • Pregnancy Proteins
  • Placenta Growth Factor
  • Vascular Endothelial Growth Factor Receptor-1
  • rho-Associated Kinases
  • Extracellular Signal-Regulated MAP Kinases