ZEB1 Upregulates VEGF Expression and Stimulates Angiogenesis in Breast Cancer

PLoS One. 2016 Feb 16;11(2):e0148774. doi: 10.1371/journal.pone.0148774. eCollection 2016.

Abstract

Although zinc finger E-box binding homeobox 1 (ZEB1) has been identified as a key factor in the regulation of breast cancer differentiation and metastasis, its potential role in modulating tumor angiogenesis has not been fully examined. Here, we present the novel finding that conditioned medium derived from ZEB1-expressing MDA-MB-231 cells significantly increased the capillary tube formation of human umbilical vein endothelial cells (HUVECs), whereas ZEB1 knockdown by RNA interference had the opposite effect. ZEB1 caused marked upregulation of the expression of vascular endothelial growth factor A (VEGFA) at both mRNA and protein levels. Pre-incubation of HUVECs with anti-VEGFA neutralized antibody attenuated ZEB1-mediated tube formation of HUVECs. In breast cancer tissues, expression of ZEB1 was positively correlated with those of VEGFA and CD31. At the molecular level, ZEB1 activated VEGFA transcription by increasing SP1 recruitment to its promoter, which was mediated via the activation of PI3K and p38 pathways. Using a nude mouse xenograft model, we demonstrated that elevated expression of ZEB1 promotes in vivo tumorigenesis and angiogenesis in breast cancer. Collectively, we found that ZEB1-expressing breast cancer cells increase VEGFA production and thus stimulate tumor growth and angiogenesis via a paracrine mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / pathology
  • Carcinogenesis / drug effects
  • Cell Line, Tumor
  • Culture Media / pharmacology
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Homeodomain Proteins / biosynthesis*
  • Homeodomain Proteins / genetics
  • Humans
  • Mice
  • Neovascularization, Pathologic / genetics*
  • Neovascularization, Pathologic / pathology
  • Transcription Factors / biosynthesis*
  • Transcription Factors / genetics
  • Vascular Endothelial Growth Factor A / biosynthesis*
  • Vascular Endothelial Growth Factor A / genetics
  • Xenograft Model Antitumor Assays
  • Zinc Finger E-box-Binding Homeobox 1

Substances

  • Culture Media
  • Homeodomain Proteins
  • Transcription Factors
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • ZEB1 protein, human
  • Zinc Finger E-box-Binding Homeobox 1

Grants and funding

This work is supported by grants from the International S&T Cooperation Program of China (No. 2015DFA30420), the National Natural Science Foundation of China (No. 81272184; No. 81472545; No. 81170443), the Natural Science Foundation of Tianjin (No. 13JCZDJC30200). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.