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Abstract Background Osteosarcoma (OS) is the most common primary malignant tumor of bone in children and adolescents. However, the knowledge in diagnostic modalities has progressed less. To identify new biomarkers for the early diagnosis of OS as well as for potential novel therapeutic candidates, we performed a sub-cellular comparative proteomic research. Methods An osteosarcoma cell line (MG-63) and human osteoblastic cells (hFOB1.19) were used as our comparative model. Plasma membrane (PM) was obtained by aqueous two-phase partition. Proteins were analyzed through iTRAQ-based quantitative differential LC/MS/MS. The location and function of differential proteins were analyzed through GO database. Protein-protein interaction was examined through String software. One of differentially expressed proteins was verified by immunohistochemistry. Results 342 non-redundant proteins were identified, 68 of which were differentially expressed with 1.5-fold difference, with 25 up-regulated and 43 down-regulated. Among those differential proteins, 69% ware plasma membrane, which are related to the biological processes of binding, cell structure, signal transduction, cell adhesion, etc., and interaction with each other. One protein--CD151 located in net nodes was verified to be over-expressed in osteosarcoma tissue by immunohistochemistry. Conclusion It is the first time to use plasma membrane proteomics for studying the OS membrane proteins according to our knowledge. We generated preliminary but comprehensive data about membrane protein of osteosarcoma. Among these, CD151 was further validated in patient samples, and this small molecule membrane might be a new target for OS research. The plasma membrane proteins identified in this study may provide new insight into osteosarcoma biology and potential diagnostic and therapeutic biomarkers.

Osteosarcoma ( OS) is the most frequent primary malignant bone tumour. Alternol, a novel compound purified from microbial fermentation products exerts anti-tumour effects across several cancer types. The effect of alternol on human OS remains to be elucidated. We first evaluated the anti-tumour effect of alternol in several human OS cell lines in vitro and investigated its underlying mechanism. Alternol inhibited OS cell proliferation, migration and induced caspase-dependent apoptosis, G2/M cell cycle arrest in a dose and time-dependent manner. Moreover, alternol treatment inhibited signal transducer and activator of transcription-3 ( STAT3) phosphorylation in 143B and MG63 human OS cells, as evaluated using a STAT3-dependent dual luciferase reporter system. Exposure to alternol resulted in excessive reactive oxygen species ( ROS) generation and Jun amino-terminal kinases (JNK), extracellular signal-regulated kinases (ERK1/2) and p38 activation. Furthermore, alternol-induced cell death was significantly restored in the presence of the ROS scavenger, N-acetyl- l-cysteine ( NAC) or a caspase inhibitor Z- VAD- FMK. NAC also prevented G2/M phase arrest and phosphorylation of mitogen-activated protein kinases (MAPK), but did not reverse STAT3 inactivation. Finally, alternol suppressed tumour growth in vivo in the nude mouse OS tibia orthotopic model. Immunohistochemistry revealed that alternol treatment resulted in down-regulation of phosph- STAT3 Tyr705 and up-regulation of cleaved caspase-3 and phosph-SAPK (Stress-activated protein kinases)/ JNK expression. Taken together, our results reveal that alternol suppresses cell proliferation, migration and induces apoptosis, cell cycle arrest by modulating of ROS-dependent MAPK and STAT3 signalling pathways in human OS cells. Therefore, alternol is a promising candidate for developing anti-tumour drugs target OS. [ABSTRACT FROM AUTHOR]

The gelsolin (GSN) has been involved in the regulation of tumor formation and development, but the biological role of GSN in the pathogenesis of osteosarcoma (OS) has not been well characterized. In this study, we show that high expression of GSN was observed in OS tissues and correlated with tumor size, advanced Enneking stage, and poor patient prognosis. Knockdown of GSN significantly inhibited cell proliferation and invasiveness in the OS cell lines. Furthermore, stable overexpression of GSN in OS cells resulted in a significant increase in cell growth and motility with the downregulation of p-AKT and p-P38 pathway. Finally, overexpression of GSN promoted growth of OS tumors in SCID mice. Taken together, these results provided the first evidence that GSN might contribute to OS cancer development and could be an attractive therapeutic target for patients with OS. [ABSTRACT FROM AUTHOR]

CD151, a tetraspanin family protein involved in cell-cell and cell-extracellular matrix interaction, is differentially expressed in osteosarcoma cell membranes. Thus, this study aimed to investigate the role of CD151 in osteosarcoma metastasis. We analyzed CD151 expression in patient tissue samples using immunohistochemistry. CD151 expression was also silenced with shRNA in osteosarcoma cells of high metastatic potential, and cell adhesion, migration and invasion were evaluated in vitro and pulmonary metastasis was investigated in vivo. Mediators of cell signaling pathways were also examined following suppression of CD151 expression. Overall survival for patients with low versus high CD151 expression level was 94 vs. 41 months (p=0.0451). CD151 expression in osteosarcoma cells with high metastatic potential was significantly higher than in those with low metastatic potential (p<0.001). shRNA-mediated silencing of CD151 did not influence cell viability or proliferation; however, cell adhesion, migration and invasion were all inhibited (all p<0.001). In mice inoculated with shRNA-transduced osteosarcoma cells, the number and size of lung metastatic lesions were reduced compared to the mice inoculated with control-shRNA transduced cells (p<0.001). In addition, CD151 knockdown significantly reduced Akt, p38, and p65 phosphorylation as well as focal adhesion kinase, integrin β1, p70s6, and p-mTOR levels. Taken together, CD151 induced osteosarcoma metastasis likely by regulating cell function through adhesion signaling. Further studies are necessary to fully explore the diagnostic and prognostic value of determining CD151 expression in osteosarcoma patients.

The gelsolin (GSN) has been involved in the regulation of tumor formation and development, but the biological role of GSN in the pathogenesis of osteosarcoma (OS) has not been well characterized. In this study, we show that high expression of GSN was observed in OS tissues and correlated with tumor size, advanced Enneking stage, and poor patient prognosis. Knockdown of GSN significantly inhibited cell proliferation and invasiveness in the OS cell lines. Furthermore, stable overexpression of GSN in OS cells resulted in a significant increase in cell growth and motility with the downregulation of p-AKT and p-P38 pathway. Finally, overexpression of GSN promoted growth of OS tumors in SCID mice. Taken together, these results provided the first evidence that GSN might contribute to OS cancer development and could be an attractive therapeutic target for patients with OS.

Background: Thoracolumbar vertebral metastasis (TVM) affects a large number of cancer patients. However, safe and effective palliative care remains controversial. The aim of the present study was to investigate the safety and efficacy of minimally invasive image-guided radiofrequency ablation (RFA) with percutaneous kyphoplasty (PKP) for TVM treatment., Material and Methods: A retrospective study of 26 patients (mean age: 59.31 ± 11.62 years) was conducted, including 38 vertebral metastases at T11, T12, L1, L2, L3, L4, L5, and S1 with abundant blood vessels. Patients underwent RFA with PKP (4-6 min, 95 ± 5°C, 150 W, effective electrode area of 1.5-2.0 cm) under general anesthesia from February 2005 to January 2009. Electrodes were inserted into the lesions and pre- and post-operative visual analog scale (VAS) scores and X-rays were collected on day 3, week 1, and months 1, 3, and 6. Tumor recurrence and pain level were also evaluated. Safety assessment was conducted based on complications and adverse events. The mean follow-up time was 8.4 ± 2.1 months., Results: A mean of 2.69 ± 0.93 ablation was performed per patient. The ablation procedure required a mean of 15.08 ± 4.64 min, while the injection of bone cement required a mean of 6.73 ± 0.83 min, for a mean total operating time of 47.77 ± 7.13 min. Postoperative VAS scores were significantly lower on day 3, week 1, and months 1, 3, and 6 (P<0.01), without any complications or tumor recurrence., Conclusions: Image-guided RFA with PKP was safe and effective for TVM treatment when used with careful consideration of bone cement volume/viscosity, injection location, and temperature.