Vascular gene expression patterns are conserved in primary and metastatic brain tumors

J Neurooncol. 2010 Aug;99(1):13-24. doi: 10.1007/s11060-009-0105-0. Epub 2010 Jan 9.

Abstract

Malignant primary glial and secondary metastatic brain tumors represent distinct pathological entities. Nevertheless, both tumor types induce profound angiogenic responses in the host brain microvasculature that promote tumor growth. We hypothesized that primary and metastatic tumors induce similar microvascular changes that could function as conserved angiogenesis based therapeutic targets. We previously isolated glioma endothelial marker genes (GEMs) that were selectively upregulated in the microvasculature of proliferating glioblastomas. We sought to determine whether these genes were similarly induced in the microvasculature of metastatic brain tumors. RT-PCR and quantitative RT-PCR were used to screen expression levels of 20 candidate GEMs in primary and metastatic clinical brain tumor specimens. Differentially regulated GEMs were further evaluated by immunohistochemistry or in situ hybridization to localize gene expression using clinical tissue microarrays. Thirteen GEMs were upregulated to a similar degree in both primary and metastatic brain tumors. Most of these genes localize to the cell surface (CXCR7, PV1) or extracellular matrix (COL1A1, COL3A1, COL4A1, COL6A2, MMP14, PXDN) and were selectively expressed by the microvasculature. The shared expression profile between primary and metastatic brain tumors suggests that the molecular pathways driving the angiogenic response are conserved, despite differences in the tumor cells themselves. Anti-angiogenic therapies currently in development for primary brain tumors may prove beneficial for brain metastases and vice versa.

Publication types

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

MeSH terms

  • Brain Neoplasms / genetics
  • Brain Neoplasms / metabolism*
  • Brain Neoplasms / pathology
  • Brain Neoplasms / secondary
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Chi-Square Distribution
  • Collagen / classification
  • Collagen / genetics
  • Collagen / metabolism*
  • Extracellular Matrix Proteins / genetics
  • Extracellular Matrix Proteins / metabolism
  • Gene Expression Regulation, Neoplastic / physiology*
  • Glioma / genetics
  • Glioma / metabolism*
  • Glioma / pathology
  • Glioma / secondary
  • Humans
  • Matrix Metalloproteinase 14 / genetics
  • Matrix Metalloproteinase 14 / metabolism*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Peroxidase / genetics
  • Peroxidase / metabolism
  • Peroxidasin
  • RNA, Messenger / metabolism
  • Receptors, CXCR / genetics
  • Receptors, CXCR / metabolism

Substances

  • ACKR3 protein, human
  • Carrier Proteins
  • Extracellular Matrix Proteins
  • Membrane Proteins
  • PLVAP protein, human
  • RNA, Messenger
  • Receptors, CXCR
  • Collagen
  • Peroxidase
  • Matrix Metalloproteinase 14