The TGF-ß/Smad pathway induces breast cancer cell invasion through the up-regulation of matrix metalloproteinase 2 and 9 in a spheroid invasion model system.
Breast Cancer Res Treat
; 128(3): 657-66, 2011 Aug.
Article
em En
| MEDLINE
| ID: mdl-20821046
ABSTRACT
Transforming growth factor-ß (TGF-ß) has opposing roles in breast cancer progression by acting as a tumor suppressor in the initial phase, but stimulating invasion and metastasis at later stages. In contrast to the mechanisms by which TGF-ß induces growth arrest, the pathways that mediate tumor invasion are not well understood. Here, we describe a TGF-ß-dependent invasion assay system consisting of spheroids of MCF10A1 normal breast epithelial cells (M1) and RAS-transformed (pre-)malignant derivatives (M2 and M4) embedded in collagen gels. Both basal and TGF-ß-induced invasion of these cell lines was found to correlate with their tumorigenic potential; M4 showing the most aggressive behavior and M1 showing the least. Basal invasion was strongly inhibited by the TGF-ß receptor kinase inhibitor SB-431542, indicating the involvement of autocrine TGF-ß or TGF-ß-like activity. TGF-ß-induced invasion in premalignant M2 and highly malignant M4 cells was also inhibited upon specific knockdown of Smad3 or Smad4. Interestingly, both a broad spectrum matrix metalloproteinase (MMP) inhibitor and a selective MMP2 and MMP9 inhibitor mitigated TGF-ß-induced invasion of M4 cells, while leaving basal invasion intact. In line with this, TGF-ß was found to strongly induce MMP2 and MMP9 expression in a Smad3- and Smad4-dependent manner. This collagen-embedded spheroid system therefore offers a valuable screening model for TGF-ß/Smad- and MMP2- and MMP9-dependent breast cancer invasion.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Mama
/
Regulação Neoplásica da Expressão Gênica
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Fator de Crescimento Transformador beta
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Metaloproteinase 2 da Matriz
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Metaloproteinase 9 da Matriz
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Proteínas Smad
/
Invasividade Neoplásica
Tipo de estudo:
Prognostic_studies
Limite:
Female
/
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article