Objective To investigate the effects of miR-129-5p on the proliferation and migration of osteosarcoma cells and the regulation of HMGB1 gene.

Methods The expression of miR-129-5p and HMGB1 in osteosarcoma cell line MG-63, Saos-2 and osteoblast hFOB1.19 were detected by RT-PCR and Western blot. Bioinformatics methods were used to predict whether there were binding sites between mir-129-5p and HMGB1 gene. Double luciferase reporter gene system was used to verify the interaction between miR-129-5p and the target gene HMGB1. miR-129-5p mimic and inhibitor were transfected into osteosarcoma cell lines with low and high miR-129-5p expression, respectively, and the transfection efficiency was detected by RT-PCR. After successful transfection, the proliferation and migration of osteosarcoma cell lines were detected by CCK-8 assay, scratch assay and Transwell migration assay, respectively, and Western blot was used to detect the expression of HMGB1 in the transfected osteosarcoma cell lines.

Results Expression of miR-129-5p in osteosarcoma cells was lower than that in normal osteoblasts (P < 0.05), and the expression of HMGB1 in osteosarcoma cell lines was higher than that in normal osteoblasts (P < 0.05). There were binding sites between miR-129-5p and HMGB1 genes, and the luciferase activity of HMGB1-WT plasmid group was down-regulated after transfection with miR-129-5p mimic (P < 0.05). Transfection of miR-129-5p mimic significantly increased the expression of miR-129-5p in MG-63 cells (P < 0.05), inhibited the proliferation and migration of MG-63 cells (P < 0.05), and decreased the expression level of HMGB1. After transfection with miR-129-5p inhibitor, the expression of miR-129-5p in Saos-2 cells was significantly decreased (P < 0.05), the proliferation and migration abilities of Saos-2 cells were enhanced (P < 0.05), and the expression level of HMGB1 was also increased.

Conclusion miR-129-5p may inhibit the proliferation and migration of osteosarcoma cells through HMGB1 gene.