Cordycepin augments the chemosensitivity of osteosarcoma to cisplatin by activating AMPK and suppressing the AKT signaling pathway.

BACKGROUND: Osteosarcoma is the most common primary bone tumor in children and adolescents. However, some patients with osteosarcoma develop resistance to chemotherapy, leading to a poor clinical prognosis. Hence, effective therapeutic agents that can improve the response to chemotherapy drugs to improve the prognosis of patients with osteosarcoma are urgently needed. Cordycepin has recently emerged as a promising antitumor drug candidate. This study aims to explore the effect of cordycepin in suppressing osteosarcoma in vivo and in vitro and the synergistic effect of cordycepin combined with cisplatin and to demonstrate the underlying molecular mechanism. METHODS: CCK-8 assay was performed to investigate the inhibition effect of cordycepin combined with cisplatin in osteosarcoma cell lines. The colony formation and invasion abilities were measured by colony formation assay and Transwell assay. Osteosarcoma cells apoptosis was detected by flow cytometry. Western blot analysis were used to detect the expression of cell apoptosis-related proteins and AMPK and AKT/mTOR signaling pathway-related proteins. Finally, we performed the in vivo animal model to further explore whether cordycepin and cisplatin exert synergistic antitumor effects. RESULTS: Notably, we found that treatment with cordycepin inhibited cell proliferation, invasion, and induced apoptosis in osteosarcoma cells in vitro and in vivo. Moreover, the combination of cordycepin and cisplatin led to marked inhibition of osteosarcoma cell proliferation and invasion and promoted osteosarcoma cell apoptosis in vitro and in vivo. Mechanistically, we demonstrated that cordycepin enhanced the sensitivity of osteosarcoma cells to cisplatin by activating AMPK and inhibiting the AKT/mTOR signaling pathway. CONCLUSIONS: In brief, this study provides comprehensive evidence that cordycepin inhibits osteosarcoma cell growth and invasion and induces osteosarcoma cell apoptosis by activating AMPK and inhibiting the AKT/mTOR signaling pathway and enhances the sensitivity of osteosarcoma cells to cisplatin, suggesting that cordycepin is a promising treatment for osteosarcoma.

LDOC1 regulates Wnt5a expression and osteosarcoma cell metastasis and is correlated with the survival of osteosarcoma patients.

Osteosarcomas are common bone malignancies in children and adolescents. LDOC1 (leucine zipper, down-regulated in cancer 1), a tumor suppressor, is down-regulated in many cancers. In this study, we investigated the role of LDOC1 in tumor metastasis and its prognostic significance in osteosarcomas. We established osteosarcoma cells stably expressing LDOC1, driven by an HIV-based lentiviral system. We investigated the impact of LDOC1 on migration and invasion abilities in these cells using a transwell assay. LDOC1-associated changes in expression of metastasis-promoting genes were analyzed with a quantitative real-time polymerase chain reaction primer array. A xenograft tumor model (n = 7 mice/group) was used to assess the effect of LDOC1 on osteosarcoma metastasis in vivo. The overall survival and disease-free survival of osteosarcoma patients (n = 74) were analyzed retrospectively based on immunohistochemical analysis of LDOC1 levels in tumors and Kaplan-Meier analysis. LDOC1-expressing osteosarcoma cells displayed decreased migration and invasion in vitro. The quantitative real-time polymerase chain reaction primer array data showed that increased LDOC1 expression up-regulated many metastasis-suppressor genes. In the xenograft model, micro-computed tomography imaging data indicated that increased LDOC1 expression is associated with weaker lung metastasis ability. The Wnt5a signaling pathway promotes osteosarcoma metastasis; LDOC1 expression decreased Wnt5a levels in osteosarcoma cells. Kaplan-Meier analysis showed that higher LDOC1 expression was associated with improved osteosarcoma patient overall survival and disease free survival (p = 0.022). Our data show that LDOC1 is a tumor suppressor in osteosarcoma, and that it regulates metastasis of osteosarcoma cells. Furthermore, LDOC1 might be a valuable prognostic marker in osteosarcomas.

Analysis of Selenium Levels in Osteosarcoma Patients and the Effects of Se-Methylselenocysteine on Osteosarcoma Cells In Vitro.

The form of selenium appears to be important for preventing cancer in humans. Here, we evaluated selenium levels in the serum and bone tissue samples from osteosarcoma patients using atomic absorption spectrometry. The in vitro effects of Se-methylselenocysteine (Se-MSC) on growth, cell cycle status, and apoptosis of osteosarcoma cells were assessed using the WST-1 assay, Hoechst 33342/propidium iodide staining, and flow cytometry, respectively. In osteosarcoma cases, the mean serum selenium levels in osteosarcoma tissue and normal bone were 0.08 mg/kg and 0.03 mg/kg, respectively (P < 0.05). Serum selenium levels in osteosarcoma and non-osteosarcoma cases were 0.09 mg/L and 0.08 mg/L, respectively (P > 0.05). Se-MSC-treated MG63 cells showed altered cellular morphology, decreased viability in a time- and dose-dependent manner, and an increase in the sub-G1 cell population. Se-MSC also downregulated Bcl-2 expression and upregulated Bax. Se-MSC inhibited the proliferation of the drug-resistant osteosarcoma cell line Saos-2/MTX300 and enhanced the inhibitory effect of pirarubicin on MG63 cells. Our data demonstrate that selenium levels are significantly higher in osteosarcoma tissue than normal bone tissue in osteosarcoma patients. The results also support the anticancer effects of Se-MSC in osteosarcoma. Further development of Se-MSC as an ancillary chemotherapy agent in osteosarcoma is warranted.

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.

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.

METTL14-mediated epitranscriptome modification of MN1 mRNA promote tumorigenicity and all-trans-retinoic acid resistance in osteosarcoma.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor in adolescents. The molecular mechanism behind OS progression and metastasis remains poorly understood, which limits the effectiveness of current therapies. RNA N6-methyladenosine (m6A) modification plays a critical role in influencing RNA fate. However, the biological significance of m6A modification and its potential regulatory mechanisms in the development of OS remain unclear. METHODS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS), dot blotting, and colorimetric ELISA were used to detect m6A levels. Western blotting, quantitative real-time PCR (RT-qPCR) and immunohistochemistry (IHC) were used to investigate METTL14 expression levels. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and transcriptomic RNA sequencing (RNA-seq) were used to screen the target genes of METTL14. RNA pull-down and RNA immunoprecipitation (RIP) assays were conducted to explore the specific binding of target genes and relevant m6A "readers". RNA stability and polysome analysis assays were used to detect the half-lives and translation efficiencies of the downstream genes of METTL14. IHC and clinical data were applied to explore the clinical correlations of METTL14 and its downstream target genes with the prognosis of OS. FINDINGS: We observed the abundance of m6A modifications in OS and revealed that METTL14 plays an oncogenic role in facilitating OS progression. MeRIP-seq and RNA-seq revealed that MN1 is a downstream gene of METTL14. MN1 contributes to tumor progression and all-trans-retinoic acid (ATRA) chemotherapy resistance in OS. Mechanistically, MN1 is methylated by METTL14, specifically in the coding sequence (CDS) regions, and this modification is recognized by the specific m6A reader insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) to prevent MN1 mRNA degradation and promote it translation efficiency. IHC showed that MN1 expression was positively correlated with METTL14 and IGF2BP2 expression in OS tissues. The METTL14-IGF2BP2-MN1 panel demonstrated more promising prognostic value for OS patients than any of these molecules individually. INTERPRETATION: Our study revealed that METTL14 contributes to OS progression and ATRA resistance as an m6A RNA methylase by regulating the stability and translation efficiency of MN1 and thus provides both an underlying biomarker panel for prognosis prediction in OS patients. FUNDING: This work was supported by the National Natural Science Foundation of China (Grants 81972510 and 81772864).

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.

Eosinophilic granuloma of bilateral humerus with unusual diagnostic process.

A 15-year-old boy presented with a right shoulder pain and the inability to use his right upper limb after carrying a heavy object. Physical examination and local imaging revealed a benign tumor or tumor-like lesion in the upper ends of both humeri and a pathologic fracture in the right humerus. An initial biopsy was reported as fibroblastic osteosarcoma. But the CT-guided biopsy was diagnosed as eosinophilic granuloma (EG). Bone curretage and grafting confirmed diagnosis of EG. This case illustrates the importance of combining a clinical impression with imaging and pathology in bone and soft tissue tumors.

[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.

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.

[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.

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.

Chromosomal translocation-derived aberrant Rab22a drives metastasis of osteosarcoma.

Osteosarcoma is a type of aggressive malignant bone tumour that frequently metastasizes to lungs, resulting in poor prognosis. However, the molecular mechanisms of lung metastasis of osteosarcoma remain poorly understood. Here we identify exon-intron fusion genes in osteosarcoma cell lines and tissues. These fusion genes are derived from chromosomal translocations that juxtapose the coding region for amino acids 1-38 of Rab22a (Rab22a1-38) with multiple inverted introns and untranslated regions of chromosome 20. The resulting translation products, designated Rab22a-NeoFs, acquire the ability to drive lung metastasis of osteosarcoma. The Rab22a1-38 moiety governs the function of Rab22a-NeoFs by binding to SmgGDS-607, a GTP-GDP exchange factor of RhoA. This association facilitates the release of GTP-bound RhoA from SmgGDS-607, which induces increased activity of RhoA and promotes metastasis. Disrupting the interaction between Rab22a-NeoF1 and SmgGDS-607 with a synthetic peptide prevents lung metastasis in an orthotopic model of osteosarcoma. Our findings may provide a promising strategy for a subset of osteosarcoma patients with lung metastases.

Author Correction: Chromosomal translocation-derived aberrant Rab22a drives metastasis of osteosarcoma.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Establishment and characteristics of two syngeneic human osteosarcoma cell lines from primary tumor and skip metastases.

AIM: To characterize and compare the different biological behaviors of 2 novel human osteosarcoma cell lines, Zos and Zos-M, established respectively from the primary tumor and the skip metastasis of an osteosarcoma patient. METHODS: In vitro studies included morphological observations, karyotype analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell proliferation assay, and cell sensitivity to chemotherapeutic drugs. Subcutaneous and intravenous inoculations into nude mice were carried out to study the tumorigenicity and the metastatic potential. RT-PCR was performed to assess the expression of the osteoblastic markers and some metastasis-related genes. RESULTS: Both cell lines remained stable for more than 100 passages in vitro without interruption. The RT-PCR examination indicated that they retained the molecular characteristics of an osteoblastic lineage. The karyotype analysis displayed aneuploidy and various structural abnormalities. Both cell lines are tumorigenic; Zos-M differs from Zos by the former's ability to develop lung metastasis after intravenous injection. The comparison of the expression patterns of some metastasis-related genes revealed that the decreased expression of cadherin-11 in Zos-M may correlate with a high potential of metastases. Moreover, both cell lines are less sensitive to the current chemotherapy protocols. CONCLUSION: The establishment of osteosarcoma cell lines, Zos and Zos-M, and related animal models provide a useful resource for studying the aggressive behavior of osteosarcoma and will be helpful for screening effective treatment strategies.

[Detection of serum biomakers of osteosarcoma by proteomic profiling].

OBJECTIVE: To detect differentially expressed proteins in serum of patient with osteosarcoma. METHODS: 8 serum protein samples were recruited (4 cases of osteosarcoma and 4 cases of normal adults), cross-labeled with variant CyDye, followed by two-dimensional differential in-gel electrophoresis (2-D DIGE), image analysis, and identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). RESULTS: 24 protein spot-features were significantly increased, and 34 were significantly decreased in the serum from patients with osteosarcoma relative to the controls. The mass spectrometry analysis revealed 18 unique proteins that were increased, and 25 unique proteins decreased in the serum of patients with osteosarcoma. Gelsolin was down-regulated in osteosarcoma, and Western blotting also confirmed a decreased level of gelsolin in the serum of patients with osteosarcoma. CONCLUSION: Our results indicate that gelsolin may have great potential as a biomarker of osteosarcoma and as a potential target for therapy. These preliminary data suggest that incorporation of more samples and new datasets will permit the identification of serum biomarkers for osteosarcoma.

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.

Oridonin induced apoptosis through Akt and MAPKs signaling pathways in human osteosarcoma cells.

Previous studies have shown that oridonin, a diterpenoid isolated from Rabdosia rubescens, was able to inhibit proliferation and induce apoptosis in several cell types. But the mechanisms remain poorly understood. In this study, we investigated the apoptosis-inducing effect and mechanisms of action of oridonin in human osteosarcoma cells. Our results demonstrated that oridonin induced concentration- and time-dependent suppression of proliferation and activation of apoptosis in U2OS, MG63 and SaOS-2 osteosarcoma cell lines. Oridonin induced the release of cytochrome c accompanied by activation of caspase-9, caspase-3 and cleavage of poly(ADP-ribose) polymerase (PARP). These events were all inhibited by z-VAD-fmk, a universal inhibitor of caspases. Oridonin treatment dephosphorylated constitutively active AKT, FOXO transcription factor, and glycogen synthase kinase 3 (GSK3). In addition, oridonin decreased the phosphorylation of ERK and increased the phosphorylation of p38 MAPK and JNK. Furthermore, oridonin treatment down-regulated the expression of the inhibitor of apoptosis protein(IAP) in osteosarcoma cells. All together, our results suggested that oridonin is able to inactivate Akt and ERK and activate p38 MAPK and JNK signalling pathways in osteosarcoma cells causing the suppression of proliferation and induction of mitochondria- and caspase-dependent apoptosis.