[Case control study on micro external fixator in treating supracondylar fracture of humerus in children].

OBJECTIVE: To explore clinical effects of micro external fixator for the treatment of supracondylar fracture of humerus in children. METHODS: From October 2017 to December 2018, 20 children with supracondylar fracture of humerus (treatment group) were admitted and treated with micro-external fixation after closed reduction, including 14 males and 6 females, aged from 6 to 14 years old with an average of (7.9±2.4) years old, classified to Gartland Ⅲ. Thirty nine children with supracondylar fracture of humerus were admitted as control group from January 2015 to September 2017, and treated with closed reduction Kirschner wire fixation. Among them, including 24 males and 15 females, aged from 6 to 14 years old with an average of (8.1±1.9) years old, classified to GartlandⅢ. Operation time, times of intraoperative fluoroscopy, and complications between two groups were observed and compared, Mayo scoring system at the latest follow up was used to evaluate clinical effect. RESULTS: Twenty children in treatment group were followed up from 6 to 12 months with an average of (8.0±2.5) months, operation time was(30.10±12.50) min, times of intraoperative fluoroscopy was(10.00±2.50). Fifteen patients got excellent results, 3 good, 2 fair according to Mayo elbow joint scoring. No ulnar nerve injury moderate or severe elbow varus occurred in treatment group. Thirty-nine children in control group were followed up from 5 to 13 months with an average of (9.0±3.1) months, operation time was(45.60±18.90) min, times of intraoperative fluoroscopy was(19.00±5.60). Twenty-three patients got excellent results, 12 good, 3 fair and 1 poor according to Mayo elbow joint scoring. One child occurred ulnar nerve injury and recovered at the final follow-up, 1 child occurred severe cubitus varus and 2 children occurred moderate cubitus varus. There was no statistical difference in clinical effect between two groups (P>0.05). Occurrence rate of moderate and server cubitus varus, operation time and times of intraoperative fluoroscopy in treatment group were better than that of control group(P<0.05). CONCLUSION: Treated with closedreduction and mini external fixator fixed on children humerus condyle fracture could receive the same clinical result as closed as reduction gram needle fixation, which has advantages of shorter operation time, less times of intraoperative fluoroscopy, not esay to damage ulnar nerve during operation, less incidence of moderate and severe cubitus varus deformity after operation, and the permeation was simple.

MicroRNA-503 represses epithelial-mesenchymal transition and inhibits metastasis of osteosarcoma by targeting c-myb.

Deregulated expression of miRNAs contributes to the development of osteosarcoma. Our previous study has showed that miR-503 was downregulated in osteosarcoma tissues. However, the mechanism of the miR-503 in osteosarcoma development still remains largely undefined. In our study, we found that miR-503 overexpression suppressed cell invasion and migration and inhibited epithelial-to-mesenchymal transition (EMT) of MG-63. Furthermore, we identified that c-myb, an oncogene, was a direct target of miR-503. Moreover, overexpression of c-myb could rescue miR-503-suppressed invasion and EMT. The expression of c-myb was upregulated in osteosarcoma cell lines. Therefore, we conclude that high miR-503 expression suppressed osteosarcoma cell mobility and EMT through targeting c-myb, and this may serve as a therapeutic target.

MicroRNA-503 acts as a tumor suppressor in osteosarcoma by targeting L1CAM.

Deregulated microRNAs and their roles in tumorigenesis have attracted much attention in recent years. Although miR-503 was shown to be important in tumorigenesis, its role in osteosarcoma remains unknown. In this study, we focused on the expression and mechanisms of miR-503 in osteosarcoma development. We found that miR-503 was down-regulated in osteosarcoma cell lines and primary tumor samples, and the restoration of miR-503 reduced cell proliferation, migration and invasion. Low level of miR-503 in patients with osteosarcoma was associated with considerably shortened disease-free survival. Furthermore, bioinformatic prediction and experimental validation revealed that the anti-tumor effect of miR-503 was probably exerted through targeting and repressing of L1CAM expression. L1CAM was up-regulated in osteosarcoma cell lines and primary tumor samples and the expression level of L1CAM were negatively correlated with miR-503 levels in osteosarcoma tissues. Collectively, our data identify the important roles of miR-503 in osteosarcoma pathogenesis, indicating its potential application in cancer therapy.