Abstract
MicroRNAs are involved in the pathogenesis of various human malignant tumors. This study aims to explore the role of miR-513b-5p in the malignant proliferation of retinoblastoma (RB) cells and its potential molecular mechanisms. The function-gain and function-loss experiments were performed in Weri-RB1 cells using miR-513b-5 mimics and inhibitors. miR-513b-5p mimics inhibited the proliferation and clone formation and promoted apoptosis of Weri-RB1 cells. In contrast, the miR-513b-5p inhibitor promoted the proliferation and clone formation of Weri-RB1 cells and inhibited cell apoptosis. miR-513b-5p can directly bind to the 3'UTR region of TRIB1 mRNA, and inhibit its protein expression. Overexpression of TRIB1 promoted the proliferation and cloning of Weri-RB1 cells but inhibited their apoptosis. The knockdown of TRIB1 inhibited the proliferation and clone formation of Weri-RB1 cells and promoted cell apoptosis. In addition, miR-513b-5p mimics neutralized the effects of TRIB1 overexpression on the proliferation and apoptosis of Weri-RB1 cells. Finally, miR-513b-5p can inhibit the phosphorylation level of AKT, mTOR, and p70, while TRIB1 played the opposite role. miR-513b-5p inhibits the malignant proliferation of Weri-RB1 cells by repressing the expression of TRIB1. miR-513b-5p and TRIB1 may be the biomarkers and/or key targets for clinical diagnosis and treatment of RB.