Hypoxia-induced vasculogenic mimicry formation via VE-cadherin regulation by Bcl-2

Med Oncol. 2012 Dec;29(5):3599-607. doi: 10.1007/s12032-012-0245-5. Epub 2012 May 5.

Abstract

Vasculogenic mimicry (VM) refers to the unique ability of highly aggressive tumor cells to mimic the pattern of embryonic vasculogenic networks. Hypoxia plays a pivotal role in the formation of VM. Hypoxia-induced Bcl-2 overexpression is observed in many types of tumors including melanoma, in which it is associated with tumorigenicity and angiogenesis. VE-cadherin, the major endothelial adhesion molecule controlling cellular junctions and blood vessel formation, is also overexpressed in melanoma. Despite these connections, whether hypoxia induces VM formation via VE-cadherin regulation by Bcl-2 is not confirmed. We used human melanoma cells to upregulate or knockdown the expression of Bcl-2 to investigate the possible molecular mechanism of VM formation under hypoxia. Bcl-2 overexpression increased VE-cadherin expression and VM formation under normoxia, whereas Bcl-2 siRNA significantly decreased VE-cadherin expression and VM formation under hypoxia. We then demonstrated that Bcl-2 regulated VE-cadherin transcription activity by Western blot, three-dimensional cultures, reporter gene assay, and clinical analysis. Therefore, Bcl-2-dependent VE-cadherin overexpression may be an important mechanism by which hypoxia induces VM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD / metabolism*
  • Blood Vessels
  • Blotting, Western
  • Cadherins / metabolism*
  • Cell Hypoxia / physiology*
  • Cell Line, Tumor
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Immunohistochemistry
  • Melanoma / metabolism*
  • Melanoma / pathology
  • Molecular Mimicry / physiology*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism*

Substances

  • Antigens, CD
  • Cadherins
  • Proto-Oncogene Proteins c-bcl-2
  • cadherin 5