OBJECTIVETo study the effect and mechanisms of quercetin (Qu) on proliferation and apoptosis of human methotrexate resistant osteosarcoma cell U-2OS/MTX300.

METHODMTT assay was used to observe cell proliferation. The apoptosis was examined by using Annexin V/PI staining. Western blot of mitochondrial membrane potential and cytochrome c were used to detect mitochondria spoptosis pathway. The protein expressions related to Akt pathway was detected by continuous activated Akt transient transfection and western blot.

RESULTQu can obviously inhibit the growth of human MTX resistant osteosarcoma cell U-2OS/MTX300 cells in a dose- and time-dependent manner. Annexin V/PI staining showed obvious cell apoptosis. Reduction of mitochondrial membrane potential, release of mitochondrial cytochrome c to cytosol and dephoshorylation of Akt were observed after Qu treatment.

CONCLUSIONQu can inhibit proliferation and induce apoptosis of human MTX resistant osteosarcoma cell U-2OS/MTX300, which may be related with mitochondrial apoptosis pathway and Akt activity.

Apoptosis ; drug effects ; Bone Neoplasms ; drug therapy ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Osteosarcoma ; drug therapy ; pathology ; Proto-Oncogene Proteins c-akt ; metabolism ; Quercetin ; pharmacology

OBJECTIVETo study the clinicopathologic and radiologic features of dedifferentiated chondrosarcoma, focusing on its diagnosis and differential diagnosis.

METHODClinical, radiological and pathologic findings of 14 cases of dedifferentiated chondrosarcoma (including biopsy and surgical specimens) were analyzed by hematoxylin and eosin stained sections and immunohistochemistry.

RESULTSThe mean age of patients was 52 years. The male-to-female ratio was 9:5. The most common sites of involvement were pelvis, femur and humerus, similar to the conventional chondrosarcoma. Radiologically, they were malignant tumors with dimorphic pattern. Grossly, central chondrosarcomas were more common than those of the peripheral. An essential histological feature of dedifferentiated chondrosarcoma was an abrupt interface between the low-grade cartilaginous tumor and high-grade anaplastic sarcoma. The most common dedifferentiated components were osteosarcoma, malignant fibrous histocytoma and fibrosarcoma. False negative diagnosis and erroneous diagnosis were frequent when only one-time biopsy was available.

CONCLUSIONSDedifferentiated chondrosarcoma is a rare subtype of chondrosarcoma with poor prognosis, which has different features of clinical manifestation, imaging features and pathological characteristics, compared to conventional chondrosarcoma and chondroblastic osteosarcoma.

Adult ; Aged ; Bone Neoplasms ; diagnostic imaging ; drug therapy ; pathology ; surgery ; Cell Differentiation ; Chondrosarcoma ; diagnostic imaging ; drug therapy ; pathology ; surgery ; Chondrosarcoma, Mesenchymal ; pathology ; Diagnosis, Differential ; Female ; Femoral Neoplasms ; diagnostic imaging ; drug therapy ; pathology ; surgery ; Follow-Up Studies ; Humans ; Humerus ; pathology ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Osteosarcoma ; pathology ; Pelvic Bones ; pathology ; Radiography ; Vimentin ; metabolism ; Young Adult

OBJECTIVETo study the histogenesis of giant cell tumor (GCT) and factors related to tumor recurrence, invasiveness and malignant transformation.

METHODSThe clinical features, radiologic classification, surgical approach, pathologic findings, immunophenotypes and follow-up data of 123 cases of GCT were analyzed.

RESULTSThere was a significant correlation between tumor recurrence and radiographic classification (P = 0.032), over-expression of CD147 (P = 0.034) and p53 (P = 0.005), and surgical approach (P = 0.0048) in GCT. The biologic behavior showed no correlation with intramedullary infiltration, cortical bone involvement, parosteal soft tissue extension, tumor thrombi, fusiform changes of mononuclear tumor cells, mitotic count, Ki-67 index, coagulative tumor necrosis, secondary aneurysmal bone cyst formation, and adjoining bony reaction. The positive rate of p63 in stromal cells of GCT (79.7%, 94/118) was significantly higher than that in chondroblastoma (44.7%, 21/47), osteosarcoma (22.2%, 10/45) and other giant cell-rich tumors.

CONCLUSIONSGCT is a bone tumor of low malignant potential. It is sometimes characterized by locally invasive growth, active proliferation, coagulative necrosis, secondary aneurysmal bone cyst and surrounding bony reaction. It is difficult to predict the biologic behavior of GCT. Over-expression of p53 in the tumor cells and CD147 in all components of GCT correlate with tumor invasiveness, recurrence and malignant transformation. Selection of suitable surgical approach with reference to radiologic classification is considered as an important factor in reducing the recurrence rate.

Adolescent ; Adult ; Aged ; Basigin ; metabolism ; Bone Neoplasms ; diagnostic imaging ; drug therapy ; metabolism ; pathology ; surgery ; Chemotherapy, Adjuvant ; Female ; Follow-Up Studies ; Giant Cell Tumor of Bone ; diagnostic imaging ; drug therapy ; metabolism ; pathology ; surgery ; Humans ; Male ; Membrane Proteins ; metabolism ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Recurrence, Local ; Osteosarcoma ; pathology ; Phosphoglucomutase ; metabolism ; Radiography ; Tumor Suppressor Protein p53 ; metabolism ; Young Adult

OBJECTIVETo investigate the prognostic values of HIF-1α, APE1, VEGF, and COX-2 protein expressions and their predictive value of tumor necrosis rate and prognosis in osteosarcoma, as well as their interrelationships.

METHODSFormalin-fixed paraffin-embedded tissue samples were obtained from patients with osteosarcoma. Immunohistochemical assay was performed in pre-chemotherapy samples to determine the HIF-1α, VEGF, APE1, and COX-2 protein expression levels. Hematoxylin-eosin staining was used in post-operative samples to determine the tumor necrosis rate. Univariate and multivariate analyses were used to assess the impact of protein expression on prognosis.

RESULTSTumor tissues were obtained from 49 patients. Their median follow up was 29 months. HIF-1α was significantly correlated to every protein we tested: VEGF (P = 0.032), APE1 (P < 0.001), and COX-2 (P < 0.001). HIF-1α protein expression had a significant impact on disease free survival (P = 0.006). Expression of HIF-1α had a sensitivity of 64.7% and a specificity of 71.9% for poor pathological response (< 90% of tumor necrosis) versus good pathological response to chemotherapy (≥ 90% necrosis).

CONCLUSIONExpression of HIF-1α is a predictor of tumor response to neoadjuvant chemotherapy and outcome in osteosarcoma and is correlated with VEGF, APE1, and COX-2 expression.

Adolescent ; Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Bone Neoplasms ; drug therapy ; metabolism ; pathology ; Chemotherapy, Adjuvant ; Child ; Cyclooxygenase 2 ; metabolism ; DNA-(Apurinic or Apyrimidinic Site) Lyase ; metabolism ; Disease-Free Survival ; Female ; Follow-Up Studies ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Male ; Middle Aged ; Neoadjuvant Therapy ; Neoplasm Staging ; Osteosarcoma ; drug therapy ; metabolism ; pathology ; Vascular Endothelial Growth Factor A ; metabolism ; Young Adult

OBJECTIVETo evaluate the expression of N-cadherin and β-catenin protein and their relationship with clinicopathological characteristics of osteosarcoma.

METHODSThe expressions of N-cadherin and β-catenin at protein level were detected by immunohistochemical staining in 54 cases of osteosarcoma, 11 cases of osteoid osteoma, 7 cases of osteoblastoma and 8 cases of newly formed bone in nonmalignant bone diseases. The relationship between the two indexes and clinicopathological characteristics of osteosarcoma was analyzed.

RESULTSIn newly formed bone, osteoblastoma, osteoid osteoma and osteosarcoma, the positive expression rate of N-cadherin protein was 75.0%, 71.4%, 63.6% and 35.2%, respectively. The positive expression rate of N-cadherin protein in osteosarcoma was significantly lower than that in osteoid osteoma, osteoblastoma and newly formed bone in nonmalignant bone diseases (P = 0.035). The positive expression rate of N-cadherin protein in osteosarcoma cases with pulmonary metastasis was lower than that in cases without (21.7% vs. 56.3%, P = 0.027). The positive expression rate of N-cadherin protein in osteosarcoma cases died in two years was lower than that in cases lived for more than two years (18.2% vs. 50.0%, P = 0.024). In newly formed bone, osteoblastoma, osteoid osteoma and osteosarcoma, the aberrant expression rate of β-catenin protein was 12.5%, 28.6%, 27.3% and 66.7%, respectively. The aberrant expression rate of β-catenin protein in osteosarcoma was significantly higher than that in osteoid osteoma, osteoblastoma and newly formed bone (P = 0.002). Aberrant expression rate of β-catenin in osteosarcoma cases with pulmonary metastasis was higher than that without (82.6% vs. 43.8%, P = 0.011). An inverse correlation was found between the aberrant expression of β-catenin and N-cadherin expression in osteosarcoma(r = -0.302, P = 0.027).

CONCLUSIONThe positive expression rate of N-cadherin is decreased in osteosarcoma while aberrant expression rate of β-catenin increased. The expression of N-cadherin protein is closely correlated with the metastasis and prognosis of osteosarcoma, but the expression of β-catenin protein is merely correlated with the metastasis of osteosarcoma.

Adolescent ; Adult ; Bone Neoplasms ; drug therapy ; metabolism ; pathology ; surgery ; Cadherins ; metabolism ; Child ; Female ; Follow-Up Studies ; Humans ; Lung Neoplasms ; metabolism ; secondary ; Male ; Middle Aged ; Osteoblastoma ; metabolism ; Osteoma, Osteoid ; metabolism ; Osteosarcoma ; drug therapy ; metabolism ; secondary ; surgery ; Survival Rate ; Young Adult ; beta Catenin ; metabolism

Multidrug resistance (MDR) is one of the major obstacles in cancer chemotherapy. Our previous study has shown that icariin could reverse MDR in MG-63 doxorubicin-resistant (MG-63/DOX) cells. It is reported that icariin is usually metabolized to icariside II and icaritin. Herein, we investigated the effects of icariin, icariside II, and icaritin (ICT) on reversing MDR in MG-63/DOX cells. Among these compounds, ICT exhibited strongest effect and showed no obvious cytotoxicity effect on both MG-63 and MG-63/DOX cells ranging from 1 to 10 μmol·L. Furthermore, ICT increased accumulation of rhodamine 123 and 6-carboxyfluorescein diacetate and enhanced DOX-induced apoptosis in MG-63/DOX cells in a dose-dependent manner. Further studies demonstrated that ICT decreased the mRNA and protein levels of multidrug resistance protein 1 (MDR1) and multidrug resistance-associated protein 1 (MRP1). We also verified that blockade of STAT3 phosphorylation was involved in the reversal effect of multidrug resistance in MG-63/DOX cells. Taken together, these results indicated that ICT may be a potential candidate in chemotherapy for osteosarcoma.
ATP Binding Cassette Transporter, Subfamily B ; drug effects ; genetics ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Doxorubicin ; metabolism ; pharmacology ; toxicity ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Flavonoids ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Multidrug Resistance-Associated Proteins ; drug effects ; genetics ; metabolism ; Osteosarcoma ; drug therapy ; metabolism ; pathology ; Phosphorylation ; drug effects ; Rhodamine 123 ; metabolism ; STAT3 Transcription Factor ; antagonists & inhibitors ; metabolism ; Triterpenes ; pharmacology

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), a member of the TNF superfamily of cytokines, is one of the most promising candidates for cancer therapeutics. However, many osteosarcomas are resistant to TRAIL. Bisphosphonates are very effective in the treatment of bone problems associated with malignancies; the antitumor effects are due to the inhibition of protein prenylation that is essential for cell function and survival. The purpose of this study was to determine the effects of bisphosphonates on TRAIL-resistant MG 63 human osteosarcoma cells. The cells showed no response to TRAIL alone; however, pre-treatment with bisphosphonates significantly increased TRAIL-mediated apoptosis and cellular activation of caspase-3. Bisphosphonates significantly induced mRNA and protein expression of the TRAIL receptor, DR5. Bisphosphonates induced protein unprenylation in MG 63 cells; in addition, co-treatment with TRAIL also significantly increased protein unprenylation. Blocking of protein unprenylation using geranylgeraniol attenuated the cellular responses, including cell apoptosis and protein unprenylation induced by bisphosphonates and TRAIL. This is the first study to demonstrate that bisphosphonates markedly enhanced TRAIL-induced apoptosis in human osteosarcoma cells. These findings suggest that bisphosphonates may be a new and effective anticancer treatment with TRAIL proteins for TRAIL-resistant cancer cells.
*Apoptosis ; Blotting, Western ; Bone Density Conservation Agents/*pharmacology ; Bone Neoplasms/*drug therapy/metabolism/pathology ; Cell Proliferation ; Diphosphonates/*pharmacology ; Fluorescent Antibody Technique ; Humans ; Osteosarcoma/*drug therapy/metabolism/pathology ; Receptors, TNF-Related Apoptosis-Inducing Ligand/*metabolism ; TNF-Related Apoptosis-Inducing Ligand/*metabolism ; Tumor Cells, Cultured ; Up-Regulation