Cross-talk between endothelial and breast cancer cells regulates reciprocal expression of angiogenic factors in vitro.
J Cell Biochem
; 113(4): 1142-51, 2012 Apr.
Article
em En
| MEDLINE
| ID: mdl-22095586
ABSTRACT
Reciprocal growth factor exchange between endothelial and malignant cells within the tumor microenvironment may directly stimulate neovascularization; however, the role of host vasculature in regulating tumor cell activity is not well understood. While previous studies have examined the angiogenic response of endothelial cells to tumor-secreted factors, few have explored tumor response to endothelial cells. Using an in vitro co-culture system, we investigated the influence of endothelial cells on the angiogenic phenotype of breast cancer cells. Specifically, VEGF, ANG1, and ANG2 gene and protein expression were assessed. When co-cultured with microvascular endothelial cells (HMEC-1), breast cancer cells (MDA-MB-231) significantly increased expression of ANG2 mRNA (20-fold relative to MDA-MB-231 monoculture). Moreover, MDA-MB-231/HMEC-1 co-cultures produced significantly increased levels of ANG2 (up to 580 pg/ml) and VEGF protein (up to 38,400 pg/ml) while ANG1 protein expression was decreased relative to MDA-MB-231 monocultures. Thus, the ratio of ANG1ANG2 protein, a critical indicator of neovascularization, shifted in favor of ANG2, a phenomenon known to correlate with vessel destabilization and sprouting in vivo. This angiogenic response was not observed in nonmalignant breast epithelial cells (MCF-10A), where absolute protein levels of MCF-10A/HMEC-1 co-cultures were an order of magnitude less than that of the MDA-MB-231/HMEC-1 co-cultures. Results were further verified with a functional angiogenesis assay demonstrating well-defined microvascular endothelial cell (TIME) tube formation when cultured in media collected from MDA-MB-231/HMEC-1 co-cultures. This study demonstrates that the angiogenic activity of malignant mammary epithelial cells is significantly enhanced by the presence of endothelial cells.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Mama
/
Endotélio Vascular
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Angiopoietina-1
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Angiopoietina-2
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Fator A de Crescimento do Endotélio Vascular
Limite:
Female
/
Humans
Idioma:
En
Revista:
J Cell Biochem
Ano de publicação:
2012
Tipo de documento:
Article