ObjectiveTo investigate the role of osteopontin (OPN) on the expressions of matrix metalloproteinase 13 (MMP-13) mRNA and protein in human knee osteoarthritic chondrocytes and to find the optimal time and concentration for OPN treatment. MethodsChondrocytes were isolated from articular cartilage tissues of patients with primary osteoarthritis (OA) and cultured using one step digestive treatment with collagenase typeⅡ. The chondrocytes were then identified using immunohistochemistry of collagen typeⅡ. The first generation of chondrocytes were stimulated with OPN at a concentration of 1μg/mL for 0, 24, 48, and 72 hours, and with OPN at the concentrations of 0, 0.5, 1, 2, and 4μg/mL for 48 hours. The levels of MMP-13 mRNA and protein expressions were measured with real-time fluorescent quantitative PCR and Western blot. ResultsThe immunohistochemical staining showed that first generation of chondrocytes expressed collagen typeⅡ. Both MMP-13 mRNA and protein expression levels in OA chondrocytes increased significantly in the presence of OPN (1μg/ mL) and peaked at 48 hours after incubation, showing significant difference between different time points (P < 0.05). The MMP-13 mRNA expression level in OA chondrocytes at the OPN concentration of 1μg/mL was significantly higher than those at the other concentrations (P < 0.05), and the MMP-13 protein expression level at the OPN concentration of 1μg/mL was significantly higher than that at 0μg/mL (P < 0.05). MMP-13 protein expression level at the OPN concentrations of 0.5, 2, and 4μg/mL were significantly higher than that at 0μg/mL (P < 0.05). ConclusionOPN induces up-regulation of MMP-13 mRNA and protein expressions in human knee osteoarthritic chondrocytes in time-and dose-dependent manners. The optimal time and concentration for OPN treatment are 48 hours and 1μg/mL, respectively.
ObjectiveTo investigate the expression of ErbB3 and Flotillin-2 in osteosarcoma biopsies and possible clinical pathology significance. MethodsThe tissue biopsies were harvested from 38 osteosarcoma patients and 13 osteochondroma patients between September 2009 and March 2014 for immunohistochemical staining. The ErbB3 and Flotillin-2 expressions were observed in osteosarcoma and osteochondroma biopsies, and the correlation and the relationship to the clinical and pathological features were analyzed. ResultsThe expression levels of ErbB3 and Flotillin-2 in osteosarcoma were significantly higher than those in osteochondroma (P<0.05). The high expressions of ErbB3 and Flotillin-2 had good consistency in osteosarcoma (Kappa=0.434, P=0.000). The high expression of ErbB3 was positively correlated to the clinical stages and lung metastasis (P<0.05), but it was not associated with gender, age, tumor location, and size (P>0.05). The high expression of Flotillin-2 had no correlation with clinical and pathological features (P>0.05). The influence factors of patients' overall survival included clinical stages, lung metastasis, high expression of ErbB3, and tumor size (P<0.05). Only lung metastasis and high expression of ErbB3 were independent factor affecting overall survival (P<0.05). ConclusionThe ErbB3 and Flotillin-2 express highly in osteosarcoma and the high expression has good consisitency. Besides, the high expression of ErbB3 is associated with the clinical stages and lung metastasis, indicating a poor prognosis for osteosarcoma.