The Role Of SDF-1 In Epithelial-mesenchymal Transition, Tumor Stem Cell Phenotype And Its Mechanism In Breast Cancer

The occurrence of breast cancer is a serious threat to women’s health,in recent years,the incidence of breast cancer showed a clear upward trend.The mortality rate in the city female malignant tumor four or fifth [1-2].at present,is still the main method for the treatment of breast cancer treated surgically.Like other malignant tumors,and tumor recurrence after surgical treatment of distant metastasis is the death of breast cancer patients the most important aspects of [3-4].for this,to research the mechanism of invasion and metastasis of breast cancer.For the development of new and effective means of breast cancer treatment to reduce the mortality of patients with breast cancer,has important clinical significance.Objective: To investigate the transfection high expression of stromal derived factor 1(Stromal cell-derived,factor-1,SDF-1)of the breast cancer cells as a carrier of SDF-1 in breast cancer epithelial mesenchymal transformation,tumor stem cell phenotype and its mechanism,provide new targets for clinical treatment of breast.Methods: MDA-MB-231,MDA-MB-435,MCF-7 three groups of cell lines were cultured,Western-blot screening of low expression of SDF-1 in breast cancer cell lines,plasmid p EGFP-N1-SDF-1 was constructed,and transfected to construct stable transfected cell line,and to construct p EGFP-N1 plasmid.Clone formation assay,MTT detection of breast cancer cells,p EGFP-N1-vector,proliferation of p EGFP-N1-SDF-1 three cell scratch test group.(0h,12 h,24 H)the migration ability of.Transwel cells in three groups were detected(Matrigel Matrigel invasion assay).Three groups of cells detected by flow cytometry in three groups of CD44+/CD24-cells proportion,and the application of Real-time PCR and Western blot detection of cell markers of OCT4 stem cells,three groups of Nanog,the expression of SOX2,epithelial and mesenchymal markers E-cadherin,vimentin,fibronectin,Slug expression of I kappa B alpha and P The expression and application of inhibitor BAY 65 11-7028 I kappa B alpha and p65.Results: Clone formation assay,MTT,scratch test and Transwel results showed that p EGFP-N1-SDF-1 cells in the experimental group than in the p EGFP-N1-vector group,MCF-7 cells had stronger ability of proliferation,migration and invasion,the difference was statistically significant(P < 0.05).Flow cytometry showed that compared with the MCF-7 experimental group,p EGFP-N1-SDF-1 cells showed a significant increase of CD44+/CD24-the sub group,the difference was statistically significant(P<0.001),Westernblot observation The results show that compared with the experimental group MCF-7,experimental group p EGFP-N1-SDF-1 cells stem cell markers OCT4,Nanog,SOX2 expression(P<0.01)the difference was statistically significant.In addition,the Westernblot observation results show that compared with MCF-7 cells,epithelial cell marker E-cadherin expression significantly decreased in p EGFP-N1-SDF-1 cells,mesenchymal marker vimentin,fibronectin,the expression of slug increased(P < 0.01),with statistical difference Significance.Further research found that p EGFP-N1-SDF-1 cells can induce NF-B signaling pathway in MCF-7 cells.Then the use of Si RNA inhibitors and NF-kappa B antagonist compared with MCF-7 group,the upregulation of E-cadherin expression in p EGFP-N1-SDF-1 cells,the difference was statistically significant,indicating that NF-B signaling pathway plays a role in the EMT process.Conclusion: overexpression of SDF-1 can induce EMT through activation of NF-B pathway in MCF-7 cells,and induce the expression of stem cell phenotype.Therefore,SDF-1 as a potential target for gene therapy of breast cancer.