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Purpose To investigate the expression of signal transduction and activator 3 (Stat3) ,and phosphorylated Stat3 (p-Stat3) in human gastric cancer cell lines MGC-803 and BGC-823,and to explore the role of p-Stat3 in the invasion and migration of gastric cancer. Methods The expressed Stat3 and p-Stat3 in gastric cancer MGC-803 and BGC-823 cells were investigated by flow cytometry,and the migration and invasion abilities of cancer cells were observed using scratch test and in vitro Transwell test. Results Flow cytometry showed that the expression of Stat3 in MGC-803 and BGC-823 cells was basically unchanged before and after IL-6 stimulation (10 ng/mL) ,and the activated p-Stat3,however,was significantly higher after IL-6 stimulation. The activated p-Stat3 in BGC-823 cells was higher than that of MGC-803 cells (P < 0. 001) . The results of scratch tests showed that the scar healing area of BGC-823 cells was significantly larger than that of MGC-803 cells after 48 h (P = 0. 031) . Transwell cell experiments showed that the number of penetrating cells from BGC-823 cell line were significantly greater than those from MGC-803 cell line (P < 0. 001) . Conclusion Over activated p-Stat3 enhances the invasion and migration of MGC-803 and BGC-823 gastric cancer cells.
RESUMO
BACKGROUND: Closed reduction and percutaneous fixation are considered as the optional treatments for displaced supracondylar humerus fractures. However, there was no published report about the biomechanical analysis in Orthofix® external fixator. In this study, we developed a model of supracondylar humerus fractures and compared the biomechanical analysis of external fixator and different K-wires configurations in order to evaluate the stability of external fixator in supracondylar humerus fractures. METHODS: We developed an anatomic humerus model by third-generation synthetic composite, and 60 synthetic humeris were osteotomized to simulate the humeral transverse supracondylar fracture. Those fractures were reduced and fixed by external fixator or K-wires, and then biomechanical analysis was performed in extension, varus, valgus, and internal and external rotation loading. A paired-sample t test was used to evaluate the distance at the fracture site between the external fixator and K-wire configurations. RESULTS: During all direction loading, there was a significant statistical difference between external fixator and K-wires (P < 0.001 for all pairwise comparisons). In extension and internal rotation loading, the external fixator and three crossed K-wires had no comparable stiffness values (P = 0.572; P = 0.795), and both were significantly greater than two crossed and lateral K-wires (P < 0.05). In external rotation loading, there was no significance between the external fixator and K-wire configurations except two lateral K-wires (P > 0.05). In valgus loading, the stability of the external fixator was less than that of three crossed K-wires (P = 0.001) but was not significantly different with those of two crossed or three lateral K-wires (P = 0.126; P = 0.564). In varus loading, the stability of the external fixator was larger than those of two and three lateral K-wires (P = 0.000; P = 007). CONCLUSIONS: External fixator could provide enough stability for pediatric supracondylar humerus fractures without the injury of the ulnar nerve. Besides, it could enhance the rotational stiffness of the construct in rotation loading to avoid the complication of cubitus varus.
