Tianjin Medical Journal ›› 2024, Vol. 52 ›› Issue (8): 785-790.doi: 10.11958/20240086

• Cell and Molecular Biology •     Next Articles

miR-9-5p-induced autophagy and apoptosis in multiple myeloma cells by targeting TIMP2

FANG Jie1(), HUANG Rui1, ZHENG Honghui1,2, JIA Qianqian1, BAO Jing2,()   

  1. 1 Department of Hematology, Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei 230031, China
    2 Department of Hematology, the First Affiliated Hospital of Anhui Medical University
  • Received:2024-01-12 Revised:2024-04-11 Published:2024-08-15 Online:2024-08-16
  • Contact: E-mail:baojing@ahmu.edu.cn

Abstract:

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-Ⅱwas increased in the pcDNA3.1-TIMP2 group, while the expression levels of MAP1LC3B-Ⅰand 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.

Key words: multiple myeloma, autophagy, apoptosis, tissue inhibitor of metalloproteinase-2, miR-9-5p

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