miR-9-5p-induced autophagy and apoptosis in multiple myeloma cells by targeting TIMP2
Objective To investigate the mechanism of the interaction between miR-9-5p and tissue metalloproteinase inhibitor 2(TIMP2)on autophagy and apoptosis in multiple myeloma(MM)cells.Methods Real-time fluorescence quantitative PCR(qRT-PCR)was used to detect expression levels of miR-9-5p and TIMP2 in bone marrow samples of 9 patients with newly diagnosed MM and 9 patients with recurrent MM.The correlation of expression levels between the two were analyzed.U266 cells were divided into the miR-control group,the miR-9-5p group,the pcDNA3.1 group,the pcDNA3.1-TIMP2 group,the miR-9-5p+pcDNA3.1 group,and the miR-9-5p+pcDNA3.1-TIMP2 group.The effects of overexpressed miR-9-5p and TIMP2 on autophagy and apoptosis in U266 cells were detected by flow cytometry,immunofluorescence staining and Western blot experiments.The dual luciferase report experiment verified the interaction between miR-9-5p and TIMP2.Results Compared with newly diagnosed MM patients,the expression level of miR-9-5p was increased and the expression level of TIMP2 was decreased in patients with recurrent MM.The expression levels of miR-9-5p and TIMP2 were negatively correlated(P<0.05).Compared with the miR-control group,the miR-9-5p group showed a decrease in the expression level of MAP1LC3B-Ⅱ,an increase in expression levels of MAP1LC3B-Ⅰ and SQSTM1,and a decrease in cell apoptosis rate(P<0.05).Compared with the pcDNA3.1 group,the expression level of MAP1LC3B-Ⅱ was increased in the pcDNA3.1-TIMP2 group,while the expression levels of MAP1LC3B-Ⅰ and SQSTM1 were decreased,and the apoptosis rate of cells increased(P<0.05).Bioinformatics and dual luciferase reporter experiments confirmed that TIMP2 was the target gene of miR-9-5p.Conclusion miR-9-5p inhibits autophagy and apoptosis in MM cells by targeting TIMP2,thereby promoting the occurrence and development of MM.
multiple myelomaautophagyapoptosistissue inhibitor of metalloproteinase-2miR-9-5p
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维普
