Abstract: Objective  To investigate the effect of miR-597 on the proliferation,migration and invasion of breast cancer cells,and its relationship with FOS related antigen 2(FOSL2).
Methods  Breast cancer cell lines T-47D,SK-BR-3,MDA-MB-231,MCF7,BT-474 and normal breast cell line MCF10A were selected as the study objects.According to the transfection,it was divided into:NC group(null plasmid) and miR-597 group(simulated sequence).Meanwhile,30 patients with breast cancer tissue and normal breast tissue adjacent to cancer were selected，rapid cryopreservation of liquid nitrogen to extract RNA for qRT-PCR.The expression level of miR-597 in cells and tissues was detected by real-time fluorescence quantitative PCR.The cell proliferation was detected by MTT and flow cytometry.The cell migration and invasion were detected by Transwell chamber.The expression of FOSL2 was detected by Western blot.The target effect of miR-597 and FOSL2 was confirmed by bioinformatics methodsand the luciferase reporter assay.
Results  The expression of miR-597 in breast cancer tissue was lower than that in normal breast tissue(P<0.01).The  cell proliferation ability of miR-597 in breast cancer cell line was lower than that in normal breast cell line(P<0.01).The percentage of G0G1 phase cells in miR-597 group was higher than that in NC group,and the percentage of S-phase cells was lower than that in NC group(t=10.215,10.336,P=0.000,0.000).The cell invasion ability of miR-597 group was lower than that of NC group(t=8.404,P=0.000).The cell migration ability of miR-597 group was lower than that of NC group(t=5.801,P=0.016).The expression level of FOSL2 in miR-597 group was lower than that of NC group(t=13.658,P=0.000).MiR-597 had a good targeting relationship with FOSL2.
Conclusion  miR-597 was low expressed in breast cancer tissue and cell lines.The high expression of miR-597 can inhibit the proliferation,migration and invasion of breast cancer cells,and which was related to the regulation of FOSL2.

Key words: miR-597, Fos like antigen 2, breast cancer, metastasis, invasion