Clinical & Experimental Metastasis

, Volume 24, Issue 1, pp 13–23

Differential expression of hypoxia and (lymph)angiogenesis-related genes at different metastatic sites in breast cancer

  • Gert G. Van den Eynden
  • Steven J. Van Laere
  • Ilse Van der Auwera
  • Leen Gilles
  • J. Lance Burn
  • Cecile Colpaert
  • Peter van Dam
  • Eric A. Van Marck
  • Luc Y. Dirix
  • Peter B. Vermeulen
Original Paper

DOI: 10.1007/s10585-006-9049-3

Cite this article as:
Van den Eynden, G.G., Van Laere, S.J., Van der Auwera, I. et al. Clin Exp Metastasis (2007) 24: 13. doi:10.1007/s10585-006-9049-3

Abstract

Introduction

Breast cancer can metastasize via lymphatic and hematogenous pathways. Hypoxia and (lymph)angiogenesis are closely related processes that play a pivotal role in the tumor progression and metastasis. The aim of this study was to compare expression of hypoxia and (lymph)angiogenesis-related genes between primary breast tumors and metastases in different tissues.

Materials and methods

A gene list of 269 hypoxia and (lymph)angiogenesis-related genes was composed and validated using Onto-Express, Pathway-express and Ingenuity software. The expression of these genes was compared in microarray data of 62 samples of primary tumors and metastases of 31 patients with breast cancer retrieved from Gene Expression Omnibus. Similarity between samples was investigated using unsupervised hierarchical clustering analysis, principal component analysis and permutation testing. Differential gene expression between primary tumors and metastases and between metastases from different organs was analyzed using Kruskall–Wallis and Mann–Whitney statistics.

Results

Unsupervised hierarchical cluster analysis demonstrated that hypoxia and (lymph)angiogenesis-related gene expression was more similar between samples from the same patient, than between samples from the same organ. Principal component analysis indicated that 22.7% and 7.0% of the total variation in the gene list was respectively patient and organ related. When differences in gene expression were studied between different organs, liver metastases seemed to differ most from the other secondary sites. Some of the best characterized molecules differentially expressed were VEGFA, PDGFRB, FGF4, TIMP1, TGFB-R1 and collagen 18A1 (precursor of endostatin). To confirm the results of these experiments at the protein level, immunohistochemical experiments were performed with antibodies for VEGFA and MMP-2.

Conclusions

Our results suggest that hypoxia and (lymph)angiogenesis-related gene expression is more dependent on the characteristics of the primary tumor than on the characteristics of the organs that bear the metastasis. However, when different organs are compared, the expression in liver metastases differs most from other metastatic sites and primary tumors, possibly due to organ-specific angiogenic and lymphangiogenic responses to metastasis-related hypoxia.

Keywords

AngiogenesisHypoxiaBreast cancer metastases

Supplementary material

Copyright information

© Springer Science + Business Media B.V. 2007

Authors and Affiliations

  • Gert G. Van den Eynden
    • 1
  • Steven J. Van Laere
    • 1
  • Ilse Van der Auwera
    • 1
  • Leen Gilles
    • 1
  • J. Lance Burn
    • 2
  • Cecile Colpaert
    • 1
  • Peter van Dam
    • 1
  • Eric A. Van Marck
    • 1
  • Luc Y. Dirix
    • 1
  • Peter B. Vermeulen
    • 1
    • 3
  1. 1.Translational Cancer Research Group (Lab Pathology, University of Antwerp/University Hospital Antwerp, Oncology Center, General Hospital, St.-Augustinus)Wilrijk, AntwerpBelgium
  2. 2.The Liver Research GroupUniversity of SheffieldSheffieldUK
  3. 3.Department of PathologyAZ St.-AugustinusWilrijkBelgium