Abstract: Objective To explore whether epithelial-mesenchymal transition(EMT) is affected after the human bone marrow mesenchymal stem cells (hBMSCs) co-cultured with MCF-7 breast cancer cells. Study the effect of paracrine factors on proliferation and migration in MCF7 cells. Methods hBMSCs was isolated successfully in vitro.Co-cultured hBMSCs with breast cancer cell line MCF-7 by transwell chamber, then observed the morphological changes of MCF-7 cells. The expression levels of E-cadherin, vimentin,α-SMA and β-catenin were detected by real-time quantitative PCR,Western blot and immunofluorescence. Collected conditional-culture medium from co-culture system and acted on MCF7 cells, Western blot analysis tested EMT markers of MCF7 cells,CCK8 assay deteced cell growth activity, flow cytometry tested cell cycle, transwell investigated invasion and metastasis of MCF7 cells. Results After co-cultured with hBMSCs,MCF7 cells showed incresed EMT ability(P<0.05). Stimulated with conditional-medium from the co-cultured system,the EMT characteristics and proliferation, migration ability of MCF7 cells were enhanced(P<0.01). Conclusion hBMSCs could induce EMT of breast cancer cells and promote the prolifertion,migration and invasion capacity of breast cancer cells by paracrine signal.

Key words: Key words: human bone marrow mesenchymal stem cells, Breast cancer, Epithelial-mesenchymal transition, paracrine mechanism