ABSTRACT
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.
ABSTRACT
Objective To study the degradation behavior and mechanical properties of magnesium alloy plate on treatment of tibial fracture in New Zealand rabbits. Methods Thirty-six adult New Zealand rabbits were randomly divided into experimental group (magnesium alloy bone plate group, n=18) and control group (titanium alloy bone plate group, n=18). Tibial fractures in experimental group and control group were fixed with magnesium alloy bone plate and titanium alloy bone plate, respectively. After operation, X-ray, scanning electron microscopy, energy spectrum analysis, weight loss test and four-point bending test were performed in each group to analyze the degradation behavior and mechanical properties of magnesium alloy plate after tibial fracture treatment. Results Magnesium alloy bone plate could be degraded gradually in vivo. The degradation of magnesium alloy bone plate was deepened gradually with the implantation time, and the surface was corroded uniformly. The mechanical properties of magnesium alloy bone plate decreased gradually with the degradation in vivo. Conclusions Magnesium alloy bone plate can degrade gradually with fracture healing in vivo, and its mechanical properties gradually decline, but it can still meet the requirements of fracture internal fixation, and is a kind of good new degradable orthopedic implant material.