53BP1 suppresses epithelial-mesenchymal transition by downregulating ZEB1 through microRNA-200b/429 in breast cancer.
Bottom Line: Consistently, in MCF-7 breast cancer cells, low 53BP1 expression reduced E-cadherin expression, resulting in increased migration and invasion.These effects were reversed by miR-200b and miR-429 inhibition or overexpression.It was also found that 53BP1 was associated with lymph node metastasis.
Affiliation: Department of Breast Surgery, Qilu Hospital, Shandong University, Jinan, China.Show MeSH
Related in: MedlinePlus
Mentions: In order to investigate the functions of 53BP1, we previously established 53BP1 overexpressed MDA-MB-231 cell lines (MDA-MB-231-53BP1 cells) and 53BP1 knockdown MCF-7 cell lines (MCF-7-sh53BP1 cells).17 During the culture of these cells, we observed morphology changes. MDA-MB-231-53BP1 cells had an epithelial-like morphology. Consistent with this observation, MCF-7-sh53BP1 cells showed a mesenchymal-like morphology, including a greater number of spindles (Fig.1a). We next examined the expressions of EMT markers by using Western blot and qRT-PCR methods. The results showed that, in MDA-MB-231-53BP1 cells, the expression of epithelial marker E-cadherin was increased, whereas the expression of mesenchymal markers ZEB1, vimentin, and fibronectin was obviously reduced. MCF-7-sh53BP1 cells showed downregulation of the expression of epithelial marker and upregulation of the expression of mesenchymal markers (Fig.1b). The expressions of other EMT transcription factors (TFs) were slightly regulated but less obvious than ZEB1 (Fig.1b, right). The expressions of epithelial marker E-cadherin and mesenchymal markers including ZEB1 and fibronectin were also confirmed by immunofluorescence staining, as shown in Figure1(c).
Affiliation: Department of Breast Surgery, Qilu Hospital, Shandong University, Jinan, China.