| 1. |
- Naber, Hildegonda P H, et al.
(författare)
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BMP-7 inhibits TGF-β-induced invasion of breast cancer cells through inhibition of integrin β(3) expression
- 2012
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Ingår i: Cellular Oncology. - : Springer. - 2211-3428 .- 2211-3436. ; 35:1, s. 19-28
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The transforming growth factor (TGF)-β superfamily comprises cytokines such as TGF-β and Bone Morphogenetic Proteins (BMPs), which have a critical role in a multitude of biological processes. In breast cancer, high levels of TGF-β are associated with poor outcome, whereas inhibition of TGF-β-signaling reduces metastasis. In contrast, BMP-7 inhibits bone metastasis of breast cancer cells. METHODS: In this study, we investigated the effect of BMP-7 on TGF-β-induced invasion in a 3 dimensional invasion assay. RESULTS: BMP-7 inhibited TGF-β-induced invasion of the metastatic breast cancer cell line MCF10CA1a, but not of its premalignant precursor MCF10AT in a spheroid invasion model. The inhibitory effect appears to be specific for BMP-7, as its closest homolog, BMP-6, did not alter the invasion of MCF10CA1a spheroids. To elucidate the mechanism by which BMP-7 inhibits TGF-β-induced invasion, we analyzed invasion-related genes. BMP-7 inhibited TGF-β-induced expression of integrin α(v)β(3) in the spheroids. Moreover, targeting of integrins by a chemical inhibitor or knockdown of integrin β(3) negatively affected TGF-β-induced invasion. On the other hand, overexpression of integrin β(3) counteracted the inhibitory effect of BMP7 on TGF-β-induced invasion. CONCLUSION: Thus, BMP-7 may exert anti-invasive actions by inhibiting TGF-β-induced expression of integrin β(3).
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| 2. |
- Naber, Hildegonda P. H., et al.
(författare)
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Snail and Slug, key regulators of TGF-beta-induced EMT, are sufficient for the induction of single-cell invasion
- 2013
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 435:1, s. 58-63
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Tidskriftsartikel (refereegranskat)abstract
- TGF-beta plays a dual role in cancer; in early stages it inhibits tumor growth, whereas later it promotes invasion and metastasis. TGF-beta is thought to be pro-invasive by inducing epithelial-to-mesenchymal transition (EMT) via induction of transcriptional repressors, including Slug and Snail. In this study, we investigated the role of Snail and Slug in TGF-beta-induced invasion in an in vitro invasion assay and in an embryonic zebrafish xenograft model. Ectopic expression of Slug or Snail promoted invasion of single, rounded amoeboid cells in vitro. In an embryonic zebrafish xenograft model, forced expression of Slug and Snail promoted single cell invasion and metastasis. Slug and Snail are sufficient for the induction of single-cell invasion in an in vitro invasion assay and in an embryonic zebrafish xenograft model.
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| 3. |
- Wiercinska, Eliza, et al.
(författare)
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The TGF-β/Smad pathway induces breast cancer cell invasion through the up-regulation of matrix metalloproteinase 2 and 9 in a spheroid invasion model system
- 2011
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Ingår i: Breast Cancer Research and Treatment. - : Springer. - 0167-6806 .- 1573-7217. ; 128:3, s. 657-666
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Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor-β (TGF-β) 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-β induces growth arrest, the pathways that mediate tumor invasion are not well understood. Here, we describe a TGF-β-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-β-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-β receptor kinase inhibitor SB-431542, indicating the involvement of autocrine TGF-β or TGF-β-like activity. TGF-β-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-β-induced invasion of M4 cells, while leaving basal invasion intact. In line with this, TGF-β 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-β/Smad- and MMP2- and MMP9-dependent breast cancer invasion.
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