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BACKGROUND/AIM: Osteosarcoma (OS) is the most common malignant bone tumor. As the same agents have been in use since the mid-1970s, new therapeutic approaches are needed to improve prognosis. Pazopanib (PZP) has already demonstrated marked antitumor activity clinically and can be effective in patients with metastatic OS. We investigated the combination treatment of candidate agents with PZP and examined effects on tumor growth using an in vivo model. MATERIALS AND METHODS: A library of 324 compounds was used. MG63 OS cells were treated with PZP and each compound. Cell viability was measured. The antiproliferative effects of compound combination on four OS cell lines was tested. Cell signaling was evaluated by western blot analysis. In vivo antitumor testing was performed using 143B-bearing mice. RESULTS: The screening process identified crizotinib (CRZ) as the most effective drug for combination with PZP. The combination of PZP and CRZ demonstrated effects compared to control or single therapy. Cell signal investigation showed that dual therapy down-regulated c-MYC, p-AKT, p-STAT3, p-cyclin D1 and survivin and up-regulated cleaved caspase-3 and cleaved PARP compared to control or single therapy. In vivo analysis showed dual therapy achieved synergic effects for tumor growth compared to control or single-treatment groups. No significant difference in the change in body weight was observed among groups. CONCLUSION: Combined use of PZP and CRZ offers synergic anti-tumor effects against OS, inducing apoptosis in vitro and in vivo by down-regulating AKT and STAT3. Our data suggest that these agents can be used for patients clinically.

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PURPOSE: We investigated the effect of carbonic anhydrase IX (CA IX) inhibitor under hypoxia and normoxia in SaOS2 human osteosarcoma cell line. We also evaluated the expression of CA IX in 27 patients diagnosed with osteosarcoma. MATERIALS AND METHODS: CA IX expression in SaOS2 cells cultured under different oxygen tensions was analyzed by Western blotting. To evaluate the effect of CA IX inhibitor, MTS cell viability assay was performed after cells were treated with various concentrations of doxorubicin with or without a CA IX inhibitor. Finally, CA IX expression in patient-derived osteosarcoma samples was evaluated by immunohistochemistry. RESULTS: Treatment with CA IX inhibitor significantly suppressed cell proliferation and migration under hypoxic conditions. CA IX expression was observed in 81% of 27 patients. The 5-year survival rates in patients with high and low stain scores were 43.8% and 81.8%, respectively. CONCLUSION: CA IX inhibitors have the potential to suppress cell proliferation, migration, and chemoresistance.

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The development of clinical agents remains a costly and time-consuming process. Although identification of new uses of existing drugs has been recognized as a more efficient approach for drug discovery than development of novel drugs, little screening of drugs that might be used for a rare malignant tumor such as osteosarcoma (OS) has been performed. In this study, we attempted to identify new molecular targeted agents for OS by employing Screening Committee of Anticancer Drugs (SCADS) kits. To screen compounds for OS treatment, their effect on cell viability of the OS cell lines 143B, MG63, HOS, SAOS-2, and HUO9 were evaluated. Candidate drugs were narrowed down based on a global anti-proliferative effect against these five OS cell lines. After excluding cytotoxic compounds and compounds unsuitable for in vivo administration, cucurbitacin I was extracted. Cucurbitacin I has been found to have cytotoxic and anti-proliferative properties against several tumors through inhibition of signal transducer and activator of transcription 3 (STAT3) activation. Cucurbitacin I dose- and time-dependently inhibited the proliferation of all five OS cell lines. Following cucurbitacin I treatment, STAT3 was inactivated and analysis of Mcl-1, cleaved PARP and caspase-3 indicated apoptosis induction. Expression of cell cycle regulator proteins, such as phospho-cyclin D1, c-Myc and survivin, were suppressed. Finally, cucurbitacin I potently inhibited the tumor growth of human OS 143B cells in nude mice. Our in vitro and in vivo results suggest that STAT3 inhibition by cucurbitacin I will be an effective and new approach for the treatment of OS.

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BACKGROUND: Fibrinogen, a 340 kDa glycoprotein synthesized in the liver, is known to be involved in tumor angiogenesis, enlargement, and metastasis. Elevated plasma fibrinogen levels are associated with tumor progression in many cancer patients. However, there are no reports about differences in fibrinogen levels between benign and malignant soft tissue tumors. OBJECTIVES: The purpose of this study was to clarify whether preoperative plasma fibrinogen levels can be used for differential diagnosis of benign or malignant soft tissue tumors. METHODS: The plasma fibrinogen levels from 102 primary soft tissue tumor patients were measured before biopsy or treatment. Fibrinogen levels were analyzed and compared to various clinical parameters. RESULTS: According to receiver operating characteristic (ROC) curve analysis, a threshold of serum fibrinogen of 315 mg/dL identified malignant patients with 60.9% sensitivity and 87.5% specificity. The diagnostic accuracy was evaluated by area under the curve (AUC: 0.805). Over 315 mg/dL of fibrinogen was associated with a significantly increased risk of malignancy by multiple logistic regression analysis (OR: 6.452, p= 0.0004). CONCLUSIONS: We demonstrated that plasma fibrinogen levels have a relationship with tumor malignancy of soft tissue tumors. High fibrinogen levels can be a helpful subsidiary tool for the prediction of malignant soft tissue tumors with other diagnostic tools.

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Very few reports have described giant pseudomeningoceles ≥ 8 cm in diameter. We report this case of the biggest giant pseudomeningocele at the unusual cervicothoracic level. A 59 year old man who underwent cervicothoracic laminectomy had a giant pseudomeningocele detected and the lesion gradually grew to about 15 cm in diameter by 2 years postoperatively. Cerebrospinal fluid leak closure was performed and the postoperative course was favorable. We present this case, review the literature and discuss the size and portion, mechanism of formation, symptoms and treatments of giant pseudomeningocele.