MiR-1271-5p Regulates The Expression Of TMBIM-6 Gene And Promotes The Mechanism Of Breast Cancer Cell Apoptosis

Objective: To analyze and compare the expression level of miRNA-1271-5p in breast cancer tissues and cell lines,and then to explore the biological function and related molecular mechanism of miRNA-1271-5p in the development of breast cancer.Materials and methods: In order to screen miRNA with differential expression in normal tissues and breast cancer tissues,it was firstly analyzed and screened in the Cancer Genome Atlas(TCGA)database,and then the 54 pairs of adenocarcinoma tissues and para-tumor tissues were tested by real-time quantitative polymerase chain reaction(RT-qPCR).In the results of miRNA-1271-5p relative expression,miRNA-1271-5p decreased by nearly 50% in breast cancer tissues compared with normal tissues.The effects of miRNA-1271-5p on proliferative ability were evaluated by Cell EdU-test and monoclonal formation experiment,and the rate of apoptosis was evaluated by flow cytometry(FCM).The effect of miRNA-1271-5p in vivo on tumor formation was observed by subcutaneous tumor experiment in nude mouse xenotransplantation model.Biological information analysis was used to screen the potential targets of miRNA-1271-5p in breast cancer,and the RT-qPCR and immune imprinting(Western Blot)experiments were validated by luciferase reporter assay.The process of mediated apoptosis was studied by Western Blot experiment in Calpain and Bcl-2 pathways.Results: 1.miRNA-1271-5p decreased expression in breast cancer tissue,breast cancer cells and TCGA databases.2.miRNA-1271-5p inhibits the proliferation of breast cancer cells and tumor growth and promotes apoptosis in vivo and vitro experiments.3.Luciferase reporter assay confirmed that TMBIM6 is a direct target of miRNA-1271-5p,and its expression is subject to negative regulation.4.miRNA-1271-5p can play a biological role in breast cancer by inhibiting the expression of TMBIM6.5.Inhibition of TMBIM6 expression promotes the Calpain pathway to mediate the miRNA-1271-5p downstream effect.Conclusion: This study shows that miRNA-1271-5p promotes apoptosis by combining carcinogenic gene TMBIM6,and this may be a new diagnostic and therapeutic target in breast cancer.