Surgical Strategy and Application of Robotic-Assisted Benign Sacral Neurogenic Tumor Resection.

BACKGROUND: Robotic surgery may be advantageous in neurogenic sacral tumor resection but only a few studies reported robotic-assisted neurogenic sacral tumor resection. OBJECTIVE: To propose a new surgical strategy for robotic-assisted benign sacral neurogenic tumor resection and introduce the ultrasonic osteotomy surgical system in robotic surgery. METHODS: Twelve patients who had robotic-assisted primary benign sacral neurogenic tumor resection between May 2015 and March 2021 were included. Our surgical strategy divides tumors into 4 types. Type I: Presacral tumors with diameter <10 cm. Type II: Narrow-base tumors involving the sacrum with diameter <10 cm. Type III: Broad-base tumors involving the sacrum with diameter <10 cm. Type IV: Tumors involving sacral nerve roots ≥2 levels and/or with diameter ≥10 cm. RESULTS: Five type I, 5 type II, and 1 type III patients underwent tumor resection via an anterior approach, and 1 type IV patient via a combined approach. The median operation time, blood loss, and postoperative hospital stay of type I and II were much less than those of type IV. The ultrasonic osteotomy surgical system facilitated osteotomy in 2 type II and 1 type III patients. Eleven patients had total resections, and 1 type III patient had a partial resection. During the follow-up period of 7.9 to 70.9 months (median: 28.5 months), no local recurrences or deaths were noted. CONCLUSION: With the largest single-center series to our knowledge, this surgical strategy helped to guide robotic-assisted benign sacral neurogenic tumor resection. The ultrasonic osteotomy surgical system was effective for type II and III.

A Novel Method to Treat Progressive Desmoid Tumors Involving Neurovascular Bundles: A Retrospective Cohort Study.

BACKGROUND: More effective therapies are needed to treat progressive desmoid tumors when active surveillance and systemic therapy fail. OBJECTIVE: To assess the efficacy and safety of sandwich isolation surgery on the local control of progressive desmoid tumors involving neurovascular bundles. METHODS: A total of 27 patients with progressive desmoid tumors at extremities involving neurovascular bundles who received surgery at our hospital between August 2014 and August 2018 were identified. A total of 13 patients received sandwich isolation surgery, in which R2 resection was performed in neurovasculature-involving regions, and a biomaterial patch was used to envelop involved neurovascular structures and isolate residual tumors. In non-neurovasculature-involving regions, wide resection was performed without isolation. A total of 14 patients received traditional surgery, which included tumor resection without isolation procedure. RESULTS: In sandwich isolation group, tumor progressions and local recurrences occurred in 3 patients outside the isolated neurovasculature-involving regions. However, no progressions or recurrences occurred in any patients in the isolated neurovasculature-involving regions where R2 resection was performed. Sandwich isolation surgery group and traditional surgery group shared similar baseline clinical characteristics. The estimated 3-yr event-free survival rate was 76.9% after sandwich isolation surgery, and 32.7% after traditional surgery (P = .025). Patients who received sandwich isolation surgery were less likely to have local recurrence (hazard ratio: 0.257, P = .040). No complications were noted except intermittent mild pain in operative regions (2 cases). CONCLUSION: Sandwich isolation surgery is effective and safe for local control of desmoid tumors involving neurovascular bundles.

Discontinuous polyostotic fibrous dysplasia with multiple systemic disorders and unique genetic mutations: A case report.

BACKGROUND: Polyostotic fibrous dysplasia (PFD) is an uncommon developmental bone disease in which normal bone and marrow are replaced by pseudotumoral tissue. The etiology of PFD is unclear, but it is generally thought to be caused by sporadic, post-zygotic mutations in the GNAS gene. Herein, we report the case of a young female with bone pain and lesions consistent with PFD, unique physical findings, and gene mutations. CASE SUMMARY: A 27-year-old female presented with unbearable bone pain in her left foot for 4 years. Multiple bone lesions were detected by radiographic examinations, and a diagnosis of PFD was made after a biopsy of her left calcaneus with symptoms including pre-axial polydactyly on her left hand and severe ophthalmological problems such as high myopia, vitreous opacity, and choroidal atrophy. Her serum cortisol level was high, consistent with Cushing syndrome. Due to consanguineous marriage of her grandparents, boosted whole exome screening was performed to identify gene mutations. The results revealed mutations in HSPG2 and RIMS1, which may be contributing factors to her unique findings. CONCLUSION: The unique findings in this patient with PFD may be related to mutations in the HSPG2 and RIMS1 genes.

Telangiectatic osteosarcoma: Outcome analyses and a diagnostic model for differentiation from aneurysmal bone cyst.

BACKGROUND AND PURPOSE: Telangiectatic osteosarcoma (TOS), a rare variant of osteosarcoma, may be easily misdiagnosed as aneurysmal bone cyst (ABC). The aims of this study were to investigate the diagnostic and prognostic factors of TOS by reviewing our experience with TOS and to develop a diagnostic model that may distinguish TOS from ABC. MATERIALS AND METHODS: We identified 51 cases of TOS treated at the First Affiliated Hospital of Sun Yat-Sen University from March 2001 to January 2016 and reviewed their records, imaging information and pathological studies. A diagnostic model was developed to differentiate TOS and ABC by Bayes discriminant analysis and was evaluated. The log-rank test was used to analyze the prognostic factors of TOS and to compare the outcome differences between TOS and other high-grade osteosarcoma subtypes. RESULTS: The multi-disciplinary diagnostic method employed that combined clinical, imaging, and pathological studies enhanced the diagnostic accuracy. Age 18 years or younger and pathologic fracture were more common among the TOS patients than among the ABC patients (P = .004 and .005, respectively). The average white blood cell (WBC), platelet, lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) values of the TOS patients were higher than those of the ABC patients (P = .002, .003, .007, and .007, respectively). Our diagnostic model, including the aforementioned factors, accurately predicted 62% and 78% of the TOS patients in the training and validation sets, respectively. The 5-year estimates of event-free survival and overall survival of the TOS patients were 52.5 ± 9.4% and 54.9 ± 8.8%, respectively, which were similar to those of patients with other osteosarcoma subtypes (P = .950 and .615, respectively). Tumor volume and the LDH level were predictive prognostic factors (P = .040 and .044) but not the presence of pathologic fracture or misdiagnosis (P = .424 and .632, all respectively). CONCLUSIONS: The multi-disciplinary diagnostic method and diagnostic model based on predictive factors, i.e., age, the presence of pathologic fracture, and platelet, LDH, ALP and WBC levels, aided the differentiation of TOS and ABC. Smaller tumors and normal LDH levels were associated with better outcomes.

Degalactotigonin, a Natural Compound from Solanum nigrum L., Inhibits Growth and Metastasis of Osteosarcoma through GSK3ß Inactivation-Mediated Repression of the Hedgehog/Gli1 Pathway.

Purpose: Agents extracted from natural sources with antitumor property have attracted considerable attention from researchers and clinicians because of their safety, efficacy, and immediate availability. Degalactotigonin (DGT), extracted from Solanum nigrum L, has anticancer properties without serious side effects. Here, we explored whether DGT can inhibit the growth and metastasis of osteosarcoma.Experimental Design: MTT, colony formation, and apoptosis assays were performed to analyze the effects of DGT on osteosarcoma cell viability in vitro The migration and invasion abilities were measured using a Transwell assay. Animal models were used to assess the roles of DGT in both tumor growth and metastasis of osteosarcoma. Gli1 expression and function were measured in osteosarcoma cells and clinical samples. After DGT treatment, Gli1 activation and the phosphorylation status of multiple cellular kinases were measured with a luciferase reporter and phospho-kinase antibody array.Results: DGT inhibited proliferation, induced apoptosis, and suppressed migration and invasion in osteosarcoma cells. DGT, injected intraperitoneally after tumor inoculation, significantly decreased the volume of osteosarcoma xenografts and dramatically diminished the occurrence of osteosarcoma xenograft metastasis to the lungs. Mechanistically, DGT inhibited osteosarcoma growth and metastasis through repression of the Hedgehog/Gli1 pathway, which maintains malignant phenotypes and is involved in the prognosis of osteosarcoma patients. DGT decreased the activity of multiple intracellular kinases that affect the survival of osteosarcoma patients, including GSK3ß. In addition, DGT represses the Hedgehog/Gli1 pathway mainly through GSK3ß inactivation.Conclusions: Our studies provide evidence that DGT can suppress the growth and metastasis of human osteosarcoma through modulation of GSK3ß inactivation-mediated repression of the Hedgehog/Gli1 pathway. Clin Cancer Res; 24(1); 130-44. ©2017 AACR.

A proposed classification system for guiding surgical strategy in cases of severe spinal deformity based on spinal cord function.

PURPOSE: Spinal cord function classification systems are not useful for guiding surgery in patients with severe spinal deformities. The aim of this study is to propose a classification system for determining a surgical strategy that minimizes the risk of neurological dysfunction in patients with severe spinal deformities. METHODS: The records of 89 patients with severe spinal deformities treated with vertebral column reconstruction from 2008 to 2013 were retrospectively analyzed. Based on neurophysiological monitoring, magnetic resonance imaging, and neurological symptoms patients were categorized into three groups: group A, normal spinal cord, normal evoked potentials and no neurological symptoms; group B, spinal cord abnormalities and/or abnormal evoked potentials but no neurological symptoms; group C, neurological symptoms with or without spinal cord abnormalities/abnormal evoked potentials. Outcomes and complications were compared between the groups. RESULTS: A total of 89 patients (51 male, 38 female) were included with 47 (52.8 %), 16 (18.0 %), and 26 (29.2 %) patients in groups A, B and C, respectively, and a mean follow-up 34.5 months. There were no differences in age, gender, average preoperative scoliosis, and kyphosis among three groups, but there were differences with respect to the causes of severe spinal deformity and the corrective rate of scoliosis and kyphosis. Changes in intraoperative evoked potentials were different in these three types according to this new classification, and the recovery rates of changes in the three groups were 71.1, 50.0, and 14.1 %, respectively. Postoperative spinal cord injury was positively related to intraoperative changes of evoked potentials. CONCLUSION: The classification system may be useful for guiding surgical decisions in patients with severe spinal deformities to minimize the risk of neurological complications.

Ampelopsin induces apoptosis by regulating multiple c-Myc/S-phase kinase-associated protein 2/F-box and WD repeat-containing protein 7/histone deacetylase 2 pathways in human lung adenocarcinoma cells.

Ampelopsin (AMP), a plant flavonoid, has been reported to inhibit cell growth and/or induce apoptosis in various types of tumor. The aim of the present study was to assess the apoptosis-inducing activity of AMP in A549 human lung adenocarcinoma epithelial cells and the associated underlying mechanism. A549 cells were incubated with different concentrations of AMP in culture medium. Cell growth and apoptosis were evaluated by MTT assay and Annexin V/propidium iodide double staining and flow cytometry, respectively. In addition, western blotting and reverse transcription quantitative polymerase chain reaction analysis were used to examine the time-dependent changes in protein expression. Certain changes in apoptotic protein expression were detected following exposure to AMP, including X-linked inhibitor of apoptosis protein release, reduced B-cell lymphoma 2, myeloid cell leukemia 1 and survivin expression levels, increased Bcl-2-associated X protein expression levels and cleaved-poly ADP ribose polymerase expression. The results revealed that AMP was a potent inhibitor of A549 cell proliferation. The c-Myc/S-phase kinase-associated protein 2 (Skp2) and histone deacetylase (HDAC)1/2 pathways were found to exert an important role in AMP-induced A549 cell apoptosis, as increased levels of c-Myc mRNA and reduced levels of c-Myc/Skp2 and HDAC1 and 2 proteins following AMP treatment were observed. The levels of F-box and WD repeat-containing protein 7α (Fbw7α), Fbw7ß, Fbw7γ, phosphorylated-(p-)c-Myc (Thr58) and glycogen synthase kinase 3ß (GSK3ß) proteins involved in c-Myc ubiquitin-dependent degradation were also analyzed. Following exposure to AMP, the expression levels of Fbw7α, Fbw7γ and GSK3ß were reduced and p-c-Myc (Thr58) expression levels were increased. The results suggest that AMP exerts an anticancer effect, which is associated with the degradation of c-Myc, Skp2 and HDAC1 and 2. The ability of AMP to induce apoptosis independently of Fbwα and Fbw7γ suggests a possible use in drug-resistant cancer associated with Fbw7 deficiency. Understanding the exact underlying mechanism requires further investigation of the association between c-Myc and Fbw7α/γ reversal, and analysis of whether Thr58 phosphorylation of c-Myc is dependent on GSK3ß.

Local control of giant cell tumors of the long bone after aggressive curettage with and without bone cement.

BACKGROUND: Aggressive curettage has been well established for the treatment of giant cell tumors (GCTs) of the bone. The purpose of this study was to review our experience and evaluate the role of different implant materials in patients with GCTs of the extremities after aggressive curettage. METHODS: A total of 119 patients with GCTs of the long bone were treated at the First Affiliated Hospital of Sun Yat-Sen University between 2004 and 2009. We excluded patients presenting metastases, recurrent tumors, and soft tissue involvement and those with Jaffe pathological grade III. The remaining 65 patients were treated with aggressive curettage using a bone graft or bone cement to fill the cavity. The recurrence rates and functional scores associated with the different fillings were analyzed. RESULTS: Aggressive curettage and bone grafting was performed in 34 cases (52.3%), and aggressive curettage with bone cement was performed in 31 cases (47.7%). The overall recurrence rate after the aggressive intralesional procedures was 35.3% with bone grafting and 12.9% when bone cement was used as an adjuvant filling. The recurrence rate following aggressive curettage and bone grafting was higher than that following aggressive curettage with cement (p = 0.038). The Musculoskeletal Tumor Society (MSTS) score for bone graft patients was 91.1%, which was significantly lower than that for patients treated with bone cement (94.7%). CONCLUSIONS: The use of bone cement was associated with a significantly lower recurrence rate than bone grafting following aggressive intralesional curettage to treat benign giant cell tumors of the long bone. Better MSTS functional results were also observed in the bone cement group compared to the bone graft group.

[Proteomics research of bufalin-induced apoptosis in osteosarcoma cell lines].

OBJECTIVE: To study the apoptosis inducing effects of bufalin on various human osteosarcoma cells and the concerning molecular mechanisms. METHOD: MTT assay was used to detect the growth inhibition rates of osteosarcoma cells U-20S, U-20S/MTX300, SaOS-2, IOR/OS9 treated with bufalin in different concentrations and times. The apoptosis of cells was observed flow cytometry 48 h following bufalin treatment. The proteomic techniques were used to separate and compare the treated and control groups 48 h after bufalin-incubation. Then, the proteomic results were validated by western blot. RESULT: Bufalin inhibited the growth of human osteosarcoma cells U20S, U20S/MTX300 (methotrexate resistant cells), SAOS2, IOR/OS9 in a dose- and time-dependent manner. The 72 h IC50 were (37.43 +/- 4.1), (32.24 +/- 5.3) nmol x L(-1) in U20S,U20S/MTX300 cells,respectivly. Flow cytometry showed that the apoptosis cells were increased following bufalin treatment. The protein expression profile showed 24 differentiated expression proteins. Among these proteins, the level of an anti-apoptotic protein, heat shock protein 27 (Hsp27) decreased significantly and the result was then validated by western blot. Ectopic expression of Hsp27 could reduce the bufalin-induced apoptosis remarkably in U20S and U20S/MTX300 cells. CONCLUSION: Bufalin could inhibit the cell growth and induce apoptosis on human osteosarcoma cells. The effect of bufalin may be related to the joint intervention with multiple protein targets. Among them, downregulation of Hsp27 plays a critical role in the bufalin-induced apoptosis in human osteosarcoma cells.

Methyl protodioscin induces G2/M cell cycle arrest and apoptosis in A549 human lung cancer cells.

BACKGROUND: Methyl protodioscin (MPD) is a furostanol bisglycoside with antitumor properties. It has been shown to reduce proliferation, cause cell cycle arrest. OBJECTIVE: The present study elucidates the mechanism underlying MPD's apoptotic effects, using the A549 human lung cancer cell line. MATERIALS AND METHODS: The human pulmonary adenocarcinoma cell line A549 was obtained from the Cell Bank of the Animal Experiment Center, North School Region, Sun Yat-Sen University. All of the cells were grown in RPMI 1640 supplemented with 10% fetal calf serum (Hyclone, Logan, UT, USA), penicillin (10,000 U/l), and streptomycin (100 mg/l) at 37°C in a 5% CO2 humidified atmosphere. The induction of apoptosis was observed in flow cytometry and fluorescent staining experiments. RESULTS: MPD showed growth inhibitory effects in A549 cells in a dose- and time-dependent manner. The significant G2/M cell cycle arrest and apoptotic effect were also seen in A549 cells treated with MPD. MPD-induced apoptosis was accompanied by a significant reduction of mitochondrial membrane potential, release of mitochondrial cytochrome c to cytosol, activation of caspase-3, downregulation of Bcl-2, p-Bad, and upregulation of Bax. CONCLUSION: Our results show that the induction of apoptosis by MPD involves multiple molecular pathways and strongly suggest that Bcl-2 family proteins signaling pathways. In addition, mitochondrial membrane potential, mitochondrial cytochrome c and caspase-3 were also closely associated with MPD-induced apoptotic process in human A549 cells.

Dihydromyricetin activates AMP-activated protein kinase and P38(MAPK) exerting antitumor potential in osteosarcoma.

Numerous patients with osteosarcoma either are not sensitive to chemotherapy or develop drug resistance to current chemotherapy regimens. Therefore, it is necessary to develop several potentially useful therapeutic agents. Dihydromyricetin is the major flavonoid component derived from Ampelopsis grossedentata, which has a long history of use in food and medicine. The present study examined the antitumor activity both in vitro and in vivo without noticeable side effects and the underlying mechanism of action of dihydromyricetin in osteosarcoma cells. We found that dihydromyricetin induced increased p21 expression and G2-M cell-cycle arrest, caused DNA damage, activated ATM-CHK2-H2AX signaling pathways, and induced apoptosis in osteosarcoma cells as well as decreasing the sphere formation capability by downregulating Sox2 expression. Mechanistic analysis showed that the antitumor potential of dihydromyricetin may be due to the activation of AMPKα and p38(MAPK), as the activating AMPKα led to the inactivation of GSK3ß in osteosarcoma cells. Moreover, GSK3ß deletion or GSK3ß inhibition by LiCl treatment resulted in increased p21 expression and reduced Sox2 expression in osteosarcoma cells. Taken together, our results strongly indicate that the antitumor potential of dihydromyricetin is correlated with P38(MAPK) and the AMPKα-GSK3ß-Sox2 signaling pathway. Finally, immunohistochemical analysis indicated that some patients had a lower p-AMPK expression after chemotherapy, which supports that the combination of dihydromyricetin and chemotherapy drug will be beneficial for patients with osteosarcoma. In conclusion, our results are the first to suggest that dihydromyricetin may be a therapeutic candidate for the treatment of osteosarcoma.

Preoperative easily misdiagnosed telangiectatic osteosarcoma: clinical-radiologic-pathologic correlations.

PURPOSE: To describe the clinical, imaging, and pathologic characteristics and diagnostic methods of telangiectatic osteosarcoma (TOS) for improving the diagnostic level. MATERIALS AND METHODS: The authors retrospectively reviewed patient demographics, serum alkaline phosphatase (AKP) levels, preoperative biopsy pathologic reports, pathologic materials, imaging findings, and treatment outcomes from 26 patients with TOS. Patient images from radiography (26 cases) and magnetic resonance (MR) imaging (22 cases) were evaluated by 3 authors in consensus for intrinsic characteristics. There were 15 male and 11 female patients in the study, with an age of 9-32 years (mean age 15.9 years). RESULTS: Eighteen of 26 patients died of lung metastases within 5 years of follow-up. The distal femur was affected more commonly (14 cases, 53.8%). Regarding serum AKP, normal (8 cases) or mildly elevated (18 cases) levels were found before preoperative chemotherapy. Radiographs showed geographic bone lysis without sclerotic margin (26 cases), cortical destruction (26 cases), periosteal new bone formation (24 cases), soft-tissue mass (23 cases), and matrix mineralization (4 cases). The aggressive radiographic features of TOS simulated the appearance of conventional high-grade intramedullary osteosarcoma, though different from aneurysmal bone cyst. MR images demonstrated multiple big (16 cases) or small (6 cases) cystic spaces, fluid-fluid levels (14 cases), soft-tissue mass (22 cases), and thick peripheral and septal enhancement (22 cases). Nine of 26 cases were misdiagnosed as aneurysmal bone cysts by preoperative core-needle biopsy, owing to the absence of viable high-grade sarcomatous cells in the small tissue samples. CONCLUSION: The aggressive growth pattern with occasional matrix mineralization, and multiple big or small fluid-filled cavities with thick peripheral, septal, and nodular tissue surrounding the fluid-filled cavities are characteristic imaging features of TOS, and these features are helpful in making the correct preoperative diagnosis of TOS.

The glycogen synthase kinase-3ß/nuclear factor-kappa B pathway is involved in cinobufagin-induced apoptosis in cultured osteosarcoma cells.

Cinobufagin, a major component of cinobufacini (huachansu), is an important cardenolidal steroid. Several studies have suggested that cinobufagin has potent anti-cancer effects. The present study examines the apoptosis-inducing activity and the underlying mechanism of action of cinobufagin in osteosarcoma (OS) cells. Our results showed that cinobufagin potently inhibited the proliferation of U2OS, MG63 and SaOS-2 cells. Significant increases in G2/M cell-cycle arrest and apoptosis in OS cells were also observed. The expression levels of several apoptotic proteins were assessed after cinobufagin treatment in U2OS cells. Among them, xIAP, cIAP-1, survivin and Bcl-2 levels decreased remarkably, while the levels of Bax and cleaved-PARP increased. Furthermore, we validated the inhibition of GSK-3ß/NF-κB signaling following cinobufagin treatment. Western blots showed a decrease in nuclear p65 protein expression after exposure to different concentrations of cinobufagin, while the phosphorylation of GSK-3ß was simultaneously increased. Transduction with constitutively active forms of GSK-3ß could protect against the downregulation of p65 and upregulation of cleaved-PARP that are induced by cinobufagin treatment. However, combined treatment with cinobufagin and SB216367 resulted in a significant reduction in p65 and an increase in cleaved-PARP in U2OS cells. Altogether, these results show that cinobufagin is a promising agent for the treatment of OS. These studies are the first to reveal the involvement of the GSK-3ß/NF-κB pathway in cinobufagin-induced apoptosis.

Critical role of heat shock protein 27 in bufalin-induced apoptosis in human osteosarcomas: a proteomic-based research.

Bufalin is the primary component of the traditional Chinese herb "Chan Su". Evidence suggests that this compound possesses potent anti-tumor activities, although the exact molecular mechanism(s) is unknown. Our previous study showed that bufalin inhibited growth of human osteosarcoma cell lines U2OS and U2OS/MTX300 in culture. Therefore, this study aims to further clarify the in vitro and in vivo anti-osteosarcoma effects of bufalin and its molecular mechanism of action. We found bufalin inhibited both methotrexate (MTX) sensitive and resistant human osteosarcoma cell growth and induced G2/M arrest and apoptosis. Using a comparative proteomics approach, 24 differentially expressed proteins following bufalin treatment were identified. In particular, the level of an anti-apoptotic protein, heat shock protein 27 (Hsp27), decreased remarkably. The down-regulation of Hsp27 and alterations of its partner signaling molecules (the decrease in p-Akt, nuclear NF-κB p65, and co-immunoprecipitated cytochrome c/Hsp27) were validated. Hsp27 over-expression protected against bufalin-induced apoptosis, reversed the dephosphorylation of Akt and preserved the level of nuclear NF-κB p65 and co-immunoprecipitated Hsp27/cytochrome c. Moreover, bufalin inhibited MTX-resistant osteosarcoma xenograft growth, and a down-regulation of Hsp27 in vivo was observed. Taken together, bufalin exerted potent anti-osteosarcoma effects in vitro and in vivo, even in MTX resistant osteosarcoma cells. The down-regulation of Hsp27 played a critical role in bufalin-induced apoptosis in osteosarcoma cells. Bufalin may have merit to be a potential chemotherapeutic agent for osteosarcoma, particularly in MTX-resistant groups.

Glycogen synthase kinase-3ß, NF-κB signaling, and tumorigenesis of human osteosarcoma.

BACKGROUND: Glycogen synthase kinase-3ß (GSK-3ß), a serine/threonine protein kinase, may function as a tumor suppressor or an oncogene, depending on the tumor type. We sought to determine the biological function of GSK-3ß in osteosarcoma, a rare pediatric cancer for which the identification of new therapeutic targets is urgent. METHODS: We used cell viability assays, colony formation assays, and apoptosis assays to analyze the effects of altered GSK-3ß expression in U2OS, MG63, SAOS2, U2OS/MTX300, and ZOS osteosarcoma cell lines. Nude mice (n = 5-8 mice per group) were injected with U2OS/MTX300, and ZOS cells to assess the role of GSK-3ß in osteosarcoma growth in vivo and to evaluate the effects of inhibitors and/or anticancer drugs on tumor growth. We used an antibody array, polymerase chain reaction, western blotting, and a luciferase reporter assay to establish the effect of GSK-3ß inhibition on the nuclear factor-κB (NF-κB) pathway. Immunochemistry was performed on primary tumor specimens from osteosarcoma patients (n = 74) to determine the relationship of GSK-3ß activity with overall survival. RESULTS: Osteosarcoma cells with low levels of inactive p-Ser9-GSK-3ß formed colonies in vitro and tumors in vivo more readily than cells with higher levels and cells in which GSK-3ß had been silenced formed fewer colonies and smaller tumors than parental cells. Silencing or pharmacological inhibition of GSK-3ß resulted in apoptosis of osteosarcoma cells. Inhibition of GSK-3ß resulted in inhibition of the NF-κB pathway and reduction of NF-κB-mediated transcription. Combination treatments with GSK-3ß inhibitors, NF-κB inhibitors, and chemotherapy drugs increased the effectiveness of chemotherapy drugs in vitro and in vivo. Patients whose osteosarcoma specimens had hyperactive GSK-3ß, and nuclear NF-κB had a shorter median overall survival time (49.2 months) compared with patients whose tumors had inactive GSK-3ß and NF-κB (109.2 months). CONCLUSION: GSK-3ß activity may promote osteosarcoma tumor growth, and therapeutic targeting of the GSK-3ß and/or NF-κB pathways may be an effective way to enhance the therapeutic activity of anticancer drugs against osteosarcoma.

Salinomycin inhibits osteosarcoma by targeting its tumor stem cells.

Osteosarcoma is the most common primary bone tumor in children and adolescents and is typically associated with a poor prognosis. Tumor stem cells (TSCs) are presumed to drive tumor initiation and tumor relapse or metastasis. Hence, the poor prognosis of osteosarcoma likely results from a failure to target the osteosarcoma stem cells. Here, we have utilized three different methods to enrich TSCs in osteosarcoma and further evaluated whether salinomycin could selectively target TSCs in osteosarcoma. Our results indicated that sarcosphere selection, chemotherapy selection and stem cell marker OCT4 or SOX2 over-expression are all effective in the enrichment of TSCs from osteosarcoma cell lines. Further investigation found that salinomycin inhibited osteosarcoma by selectively targeting its stem cells both in vitro and in vivo without severe side effects, and the Wnt/ß-catenin signaling pathway may be involved in this inhibition of salinomycin. Taken together, we have identified that salinomycin is an effective inhibitor of osteosarcoma stem cells, supporting the use of salinomycin for elimination of osteosarcoma stem cells and implying a need for further clinical evaluation.

Enrichment of osteosarcoma stem cells by chemotherapy.

Osteosarcoma is the most common primary malignant bone cancer in children and adolescents. Emerging evidence has suggested that the capability of a tumor to grow is driven by a small subset of cells within a tumor, termed cancer stem cells (CSCs). Although several methods have been explored to identify or enrich CSCs in osteosarcoma, these methods sometimes seem impractical, and chemotherapy enrichment for CSCs in osteosarcoma is rarely investigated. In the present study, we found that short exposure to chemotherapy could change the morphology of osteosarcoma cells and increase sarcosphere formation in vitro, as well as increase tumor formation in vivo. Furthermore, methotrexate (MTX)-resistant U2OS/MTX300 osteosarcoma cells were larger in size and grew much more tightly than parental U2OS cells. More importantly, U2OS/MTX300 cells possessed a higher potential to generate sarcospheres in serum-free conditions compared to parental U2OS cells. Also, U2OS/MTX300 cells exhibited the side population (SP) phenotype and expressed CSC surface markers CD117 and Stro-1. Notably, U2OS/MTX300 cells showed a substantially higher tumorigenicity in nude mice relative to U2OS cells. Therefore, we conclude that chemotherapy enrichment is a feasible and practical way to enrich osteosarcoma stem cells.

[Wide resection and brachytherapy management of extremity soft tissue sarcoma close to neurovascular bundle].

OBJECTIVE: With the extremity soft tissue sarcoma close to neurovascular bundle, combined en bloc resection and brachytherapy or simple en bloc resection were performed to evaluate the treatment outcome of the combined en bloc resection and brachytherapy. METHODS: Retrospectively investigation was performed for the extremity soft tissue sarcoma close to neurovascular bundle between 2000 and 2009. Inclusion criteria were primary extremity soft tissue sarcoma, MRI showed that the reaction zone involved the main neurovascular bundle, and the reaction zone closed less than 1 cm to the main neurovascular bundle. 86 cases were included in the study. There were 41 men and 45 women. The average age was 38.5 years old (Range from 15 to 73). There were malignant fibrous histiocytoma, synovial sarcoma, fibrosarcoma, liposarcoma, clear cell sarcoma, epithelioid sarcoma, leiomyosarcoma, rhabdomyosarcoma and vascular sarcoma etc. The stage were IA (8), IIA (12), IIB (10), IIC (7), III (43) and IV (6). RESULTS: During an average follow-up of 53 months (range 24 - 102 months), the distant metastasis rate 32.56% (28/86) and the lymph node metastasis rate was 6.98% (6/86). The local recurrence rates was 13.95% (12/86). In the group of combined en bloc resection and brachytherapy with 38 cases, the local recurrence rates was 5.26% (2/38). Four cases had wound infection and six cases had wound delay healing. The MSTS functional score was 21.11 ± 1.79. In the group of simple en bloc resection with 48 cases, the local recurrence rates was 20.83% (10/48). One case had wound infection and four cases had wound delay healing. The MSTS functional score was 84.23% (26.11 ± 1.79). The local recurrence rates was significant different between. CONCLUSION: With the extremity soft tissue sarcoma close to neurovascular bundle, combined en bloc resection and brachytherapy could decrease the local recurrence rate.

[Bufalin induces apoptosis in osteosarcoma U-2OS and U-2OS methotrexate 300-resistant cell lines in vitro].

OBJECTIVE: To study the growth inhibition and apoptosis induction effects of bufalin on human osteosarcoma cell lines in vitro. METHODS: U-2OS and U-2OS/methotrexate (MTX) 300-resistant cell lines were treated with bufalin. Cell viability was assessed by MTT assay. Cell-cycle status, apoptosis-inducing effects, and the expression of apoptosis-related proteins were evaluated by flow cytometry, fluorescent staining, DNA fragmentation assay, and Western blotting. RESULTS: Bufalin inhibited cell growth in both U-2OS and U-2OS/MTX300 cells. The IC(50) values of bufalin for U-2OS and U-2OS/MTX300 cells were (8.49 ± 2.1) ng/ml and (10.19 ± 1.7) ng/ml, respectively. The induction of G(2)/M cell-cycle arrest was also seen in the bufalin-treated cells. The bufalin-induced apoptosis was confirmed by increased expression of tumor suppressor protein p53, bax and decreased expression of bcl-2. CONCLUSION: Bufalin inhibits the growth of and induces apoptosis in both MTX-sensitive and MTX-resistant human osteosarcoma U-2OS cell lines. The apoptosis-inducing effect of bufalin is not influenced by the presence of high levels of DHFR.

Clinical imaging characteristics of herniation pits of the femoral neck.

OBJECTIVE: To discuss imaging features of radiographs, computed tomography (CT), magnetic resonance imaging (MRI) and radionuclide imaging of the herniation pit of the femoral neck and their implications for pathogenesis. METHODS: Twenty-seven patients with 31 herniation pits of the femoral neck were analyzed. All patients were examined by plain radiographs, 18 by CT, 16 by MRI, and 8 by radionuclide imaging. RESULTS: Thirty-one herniation pits located in the anterior part of the femoral neck or the base of the femoral head were round, oval or '8'-shaped subcortical defects. The pits were usually seen as mild radiolucent areas on radiographs, soft-tissue attenuation with a thin sclerotic rim and a focal cortical perforation on CT and three different signal intensities on MRI. Only one of eight pits revealed mild focal increased uptake on bone radionuclide scans. CONCLUSION: The occurrence of a herniation pit of the femoral neck correlates closely with the particulars of the structure of the hip joint and corresponding mechanical forces. Round or oval subcortical defects surrounded by a thin sclerotic rim in the superior lateral part of the femoral neck or the anterior lateral base of the femoral head, which are usually normal on radionuclide imaging and have focal cortical perforations on CT, are specific signs for diagnosing herniation pits of the femoral neck.