MicroRNA-206 Reduces Osteosarcoma Cell Malignancy In Vitro by Targeting the PAX3-MET Axis

PURPOSE: This study was undertaken to explore how miR-206 represses osteosarcoma (OS) development. MATERIALS AND METHODS: Expression levels of miR-206, PAX3, and MET mRNA were explored in paired OS and adjacent tissue specimens. A patient-derived OS cell line was established. miR-206 overexpression and knockdown were achieved by lentiviral transduction. PAX3 and MET overexpression were achieved by plasmid transfection. Treatment with hepatocyte growth factor (HGF) was utilized to activate c-Met receptor. Associations between miR-206 and PAX3 or MET mRNA in OS cells were verified by AGO2-RNA immunoprecipitation assay and miRNA pulldown assay. OS cell malignancy was evaluated in vitro by cell proliferation, metastasis, and apoptosis assays. PAX3 and MET gene expression in OS cells was assayed by RT-qPCR and Western blot. Activation of PI3K-AKT and MAPK-ERK in OS cells were assayed by evaluating Akt1 Ser473 phosphorylation and total threonine phosphorylation of Erk1/2, respectively. RESULTS: Expression levels of miR-206 were significantly decreased in OS tissue specimens, compared to adjacent counterparts, and were inversely correlated with expression of PAX3 and MET mRNA. miR-206 directly interacted with PAX3 and MET mRNA in OS cells. miR-206 overexpression significantly reduced PAX3 and MET gene expression in OS cells in vitro, resulting in significant decreases in Akt1 and Erk1/2 activation, cell proliferation, and metastasis, as well as increases in cell apoptosis, while miR-206 knockdown showed the opposite effects. The effects of miR-206 overexpression on OS cells were reversed by PAX3 or MET overexpression, but only partially attenuated by HGF treatment. CONCLUSION: miR-206 reduces OS cell malignancy in vitro by targeting PAX3 and MET gene expression.

Posterior debridement, interbody fusion, internal fixation for treatment of lumbar discitis / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the clinical effects of posterior debridement, interbody fusion with internal fixation in the treatment of lumbar discitis.</p><p><b>METHODS</b>The clinical data of 13 patients with lumbar discitis treated from January 2005 to June 2012 was retrospectively analyzed. There were 9 males and 4 females, aged from 31 to 68 years old with an average of 56 years old. There were 2 cases on L3, 4, 4 cases on L4, 5, and 7 cases on L5S1. Two cases complicated with diabetes, 4 cases with hypertension, and 1 case with obsolete pulmonary tuberculosis. ESR level of 13 cases was 12-89 mm/h with an average of 42 mm/h; and C reactive protein fluctuations level was level 8-114 ng/L with an average of 47 ng/L. All the patients denied history of operation or injection, and the main symptom was severe pain and limitation of motion in lumbar, with no efficacy for conservative methods. Preoperative VAS was from 5 to 10 points with an average of 7.8 points. All patients were treated with posterior debridement, interbody fusion, and internal fixation.</p><p><b>RESULTS</b>All the patients left hospital after wound healing, and the effective antibiotics were continuously used for 4 weeks intravenously and 2 weeks for orally. All patients were followed up from 7 to 24 months with an average of 18 months. VAS decreased for 0-1 point. No internal fixation breakage, and recurrence were found. Bone graft got fusion, and postoperative pathology showed phlogistic changes.</p><p><b>CONCLUSIONS</b>One-stage posterior debridement, interbody fusion with internal fixation was an effective method in treating lumbar discitis, and it lead to quicker relived pain relief and earlier mobilization.</p>