Research ArticleVascular endothelial growth factor-A stimulates Snail expression in breast tumor cells: Implications for tumor progression
Introduction
The transition of a “normal” epithelial cell to a metastatic tumor cell requires that this cell evolve the ability to survive in foreign environments, to migrate and to invade tissue. The E-cadherin transcriptional repressor Snail is unique in its ability to impart on a cell a number of these activities associated with metastatic tumor progression. Strikingly, Snail is a prognostic marker for metastatic breast carcinoma, being expressed in node-positive, but not in low grade, node-negative specimens [1]. Early studies of Snail focused on its ability to induce an epithelial–mesenchymal transition (EMT) by acting as an E-cadherin transcriptional repressor [2], [3]. However, recent studies indicate that Snail also maintains cell survival and promotes cell migration [4]. Furthermore, in mouse models of cancer, Snail is critical for tumor growth and recurrence [5], [6]. Based on its established importance for breast tumor progression, studies identifying the factors that regulate Snail expression in metastatic breast carcinoma are of utmost importance.
We and others established previously that breast tumor cells express the VEGF receptor Neuropilin-1 (NP-1) [7], [8], [9], and that an autocrine VEGF/NP-1 pathway stimulates constitutive PI3-kinase activity in breast tumor cells [7]. Similar to the expression pattern of Snail in breast tumors [1], VEGF-A expression is significantly increased in metastatic compared to non-metastatic breast tumors [10]. Furthermore, recombinant VEGF can stimulate the expression of Snail family members in pancreatic tumor cells [11]. Based on these findings, in the current work, we address the hypothesis that autocrine VEGF-A signaling in breast tumor cells stimulates Snail expression and activity. We also investigate a novel activity for a VEGF-A-directed therapeutic in suppressing tumor cell expression of Snail.
Section snippets
Cell lines
T47D and MDA-MB-435 cells were obtained from Duke University Comprehensive Cancer Center's cell culture facility, and were cultured in RPMI/5% FBS and DMEM/5% FBS, respectively. SUM159 cells were kindly provided by Dr. Stephen Ethier, and cultured in DMEM/F12(1:1)/5% FBS. MCF-7 cells were obtained from Dr. Joseph Geradts (Duke University Medical Center), and were cultured in DMEM/5% FBS.
Antibodies
The following antibodies were used in these studies: Neuropilin-1-neutralizing antibody (R&D Systems-MAB566),
Results/discussion
We investigated the impact of introducing VEGF-A to two well-differentiated breast tumor cell lines in vitro. MCF-7 and T47D cells were transfected transiently with a VEGF-A-expressing or control vector. After 24h, a 5-fold increase in VEGF-A expression levels was observed in VEGF-A transfectants compared to control transfectants (Figs. 1A and B). Control transfectants grew as islands of clustered cells maintaining strong cell–cell adhesion, reflecting the fact that these cells express
Acknowledgments
We thank Dr. Valentina Folgiero for her assistance with this study. In addition, we thank Dr. Arthur Mercurio for his valuable advice on this work. This work was supported by NIH grant CA093855 (R.E.B.) and a pilot award (R.E.B.) from the Duke Comprehensive Cancer Center's Breast and Ovarian Oncology Research Program.
References (22)
- et al.
The transcriptional repressor Snail promotes mammary tumor recurrence
Cancer Cell
(2005) - et al.
Neuropilin-1 is expressed by endothelial and tumor cells as an isoform-specific receptor for vascular endothelial growth factor
Cell
(1998) - et al.
Correlation of Snail expression with histological grade and lymph node status in breast carcinomas
Oncogene
(2002) - et al.
The transcription factor snail is a repressor of E-cadherin gene expression in epithelial tumour cells
Nat. Cell Biol.
(2000) - et al.
The transcription factor snail controls epithelial–mesenchymal transitions by repressing E-cadherin expression
Nat. Cell Biol.
(2000) - et al.
The Snail genes as inducers of cell movement and survival: implications in development and cancer
Development (Cambridge, England)
(2005) - et al.
Snail silencing effectively suppresses tumour growth and invasiveness
Oncogene
(2007) - et al.
Vascular endothelial growth factor is an autocrine survival factor for neuropilin-expressing breast carcinoma cells
Cancer Res.
(2001) - et al.
Competing autocrine pathways involving alternative neuropilin-1 ligands regulate chemotaxis of carcinoma cells
Cancer Res.
(2003) - et al.
Vascular stroma formation in carcinoma in situ, invasive carcinoma, and metastatic carcinoma of the breast
Clin. Cancer Res.
(1999)
Vascular endothelial growth factor receptor-1 activation mediates epithelial to mesenchymal transition in human pancreatic carcinoma cells
Cancer Res.
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