Abstract: Objective: To investigate the effects of miR-367 on the proliferation, invasion and migration of the human breast cancer MCF-7 cells, and to elucidate their mechanisms. Methods: The relative expression levels of miR-367 in the breast cancer tissues, adjacent tissues, MCF-7 cells and MCF-10A cells were detected. The MCF-7 cells were transfected with miR-NC or miR-367-inhibitor as negative control group and miR-367-inhibitor group, and the cell viabilities, the number of colonies, the positive expression rates of Ki67, the rate of cell wound healing, the number of invasive cells and the relaitive expression levels of KLF4 in the MCF-7 cells in two groups were detected. The MCF-7 cells were transfected with miR-NC or miR-367-mimic as negative control group and miR-367-mimic group, and the number of colonies, the rates of cell wound healing, the number of invasive cells and the relaitive expression levels of KLF4 in the MCF-7 cells in two groups were detected. Results: Compared with adjacent tissue or MCF-10A cells, the relative expression levels of miR-367 in breast cancer tissues and MCF-7 cells were significantly increased (P<0.01).Compared with negative control group,the relative expression level of miR-367 in the MCF-7 cells, the cell viability,the number of colonies,the positive expression rate of Ki67, the rate of cell wound healing and the number of invasive cells in miR-367-inhibitor group were significantly decreased (P<0.01), and the relative expression level of KLF4 was significantly increased (P<0.01);compared with positive control group,the relative expression level of miR-367 in the MCF-7 cells, the number of colonies, rates of cell wound healing and number of invasive cells in miR-367-mimic group were significantly increased (P<0.01), and the relative expression level of KLF4 was significantly decreased (P<0.01). Conclusion: miR-367 promotes the proliferation, migration and invasion of MCF-7 cells, and the mechanism may be related to the inhibition of KLF4 expression.

Key words: microRNA-367, Kruppel factor 4, breast neoplasms, cell proliferation, migration, invasion