[Show abstract][Hide abstract] ABSTRACT: The formation of EMT and EMT-induced CSC-like phenotype is crucial for the metastasis of tumor cells. The stromal cell-derived factor-1 (SDF-1) is upregulated in various human carcinomas, which is closely associated with proliferation, migration, invasion and prognosis of malignancies. However, limited attention has been directed towards the effect of SDF-1 on epithelial to mesenchymal transition (EMT) or cancer stem cell (CSC)-like phenotype formation in breast cancer cells and the related mechanism. In the present study, we screened MCF-7 cells with low SDF-1 expression level for the purpose of evaluating whether SDF-1 is involved in EMT and CSC-like phenotype formation in MCF-7 cells. The pEGFP-N1-SDF-1 plasmid was transfected into MCF-7 cells, and the stably overexpressed SDF-1 in MCF-7 cells was confirmed by real-time PCR and western blot analysis. Colony formation assay, MTT, wound healing assay and Transwell invasion assay demonstrated that overexpression of SDF-1 significantly boosted the proliferation, migration and invasion of MCF-7 cells compared with parental (P<0.05). Flow cytometry analysis revealed a notable increase of CD44+/CD24- subpopulation in SDF-1 overexpressing MCF-7 cells (P<0.001), accompanied by the apparently elevated ALDH activity and the upregulation of the stem cell markers OCT-4, Nanog, and SOX2 compared with parental (P<0.01). Besides, western blot analysis and immunofluorescence assay observed the significant decreased expression of E-cadherin and enhanced expression of slug, fibronectin and vimentin in SDF-1 overexpressed MCF-7 cells in comparison with parental (P<0.01). Further study found that overexpression of SDF-1 induced the activation of NF-κB pathway in MCF-7 cells. Conversely, suppressing or silencing p65 expression by antagonist or RNA interference could remarkably increase the expression of E-cadherin in SDF-1 overexpressed MCF-7 cells (P<0.001). Overall, the above results indicated that overexpression of SDF-1 enhanced EMT by activating the NF-κB pathway of MCF-7 cells and further induced the formation of CSC-like phenotypes, ultimately promoting the proliferation and metastasis of MCF-7 cells. Therefore, SDF-1 may further be assessed as a potential target for gene therapy of breast cancer.
No preview · Article · Jan 2016 · International Journal of Oncology
[Show abstract][Hide abstract] ABSTRACT: We have examined the effects of bFGF (basic fibroblast growth factor) on p-ERK (phosphorylated extracellular signal-regulated kinase) through PDGFRβ (platelet-derived growth factor receptor β) in the proliferation and migration of EPCs (endothelial progenitor cells). EPC migration was detected using the Transwell system. The expression of PDGFRβ mRNA and protein, total ERK and p-ERK proteins was respectively assessed by real-time PCR and Western blottings. bFGF promote the proliferation and migration of EPCs, the effects of bFGF being implemented by activating ERK signalling through the expression of PDGFRβ, whereas an anti-bFGF antibody and inhibitor of PDGF (platelet-derived growth factor) receptor kinase (AG1296) could respectively decrease the expression of PDGFRβ mRNA and protein and p-ERK protein. Total ERK protein did not change under the same experimental conditions, and an inhibitor of p-ERK (PD98059) inhibited the proliferation and migration of EPCs. The findings strongly suggest that a PDGFRβ/p-ERK signalling pathway triggered by bFGF plays an important role in the proliferation and migration of EPCs.
No preview · Article · Jun 2012 · Cell Biology International