High grade osteosarcoma of the extremities with lung metastases at presentation: treatment with neoadjuvant chemotherapy and simultaneous resection of primary and metastatic lesions

Catechins-Modified Selenium-Doped Hydroxyapatite Nanomaterials for Improved Osteosarcoma Therapy Through Generation of Reactive Oxygen Species

Osteosarcoma is the most common bone cancer with limited therapeutic options. It can be treated by selenium-doped hydroxyapatite owing to its known antitumor potential. However, a high concentration of Se is toxic toward normal and stem cells whereas its low concentration cannot effectively remove cancer cells. Therefore, the current study was aimed to improve the anticancer activity of Se-HAp nanoparticles through catechins (CC) modification owing to their high cancer therapeutic value. The sequentially developed catechins modified Se-HAp nanocomposites (CC/Se-HAp) were characterized for various physico-chemical properties and antitumor activity. Structural analysis showed the synthesis of small rod-like single phase HAp nanoparticles (60 ± 15 nm), which effectively interacted with Se and catechins and formed agglomerated structures. TEM analysis showed the internalization and degradation of CC/Se-HAp nanomaterials within MNNG/HOS cells through a non-specific endocytosis process. Cell toxicity analysis showed that catechins modification improved the antitumor activity of Se-HAp nanocomposites by inducing apoptosis of human osteosarcoma MNNG/HOS cell lines, through generation of reactive oxygen species (ROS) which in turn activated the caspase-3 pathway, without significantly affecting the growth of human normal bone marrow stem cells (hBMSCs). qPCR and western blot analyses revealed that casp3, p53, and bax genes were significantly upregulated while cox-2 and PTK-2 were slightly downregulated as compared to control in CC/Se-HAp-treated MNNG/HOS cell lines. The current study of combining natural biomaterial (i.e., catechins) with Se and HAp, can prove to be an effective therapeutic approach for bone cancer therapy.

Nomograms predicting overall survival and cancer-specific survival in osteosarcoma patients (STROBE)

The aim of this study was to develop nomograms to predict long-term overall survival and cancer-specific survival of patients with osteosarcoma.We carried out univariate and multivariate analyses and set up nomograms predicting survival outcome using osteosarcoma patient data collected from the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute (2004-2011, n = 1426). The patients were divided into a training cohort (2004-2008, n = 863) and a validation cohort (2009-2011, n = 563), and the mean follow-up was 55 months.In the training cohort, 304 patients (35.2%) died from osteosarcoma and 91 (10.5%) died from other causes. In the validation cohort, 155 patients (27.5%) died from osteosarcoma and (12.3%) died from other causes. Nomograms predicting overall survival (OS) and cancer-specific survival (CSS) were developed according to 6 clinicopathologic factors (age, tumor site, historic grade, surgery, AJCC T/N, and M), with concordance indexes (C-index) of 0.725 (OS) and 0.718 (CSS), respectively. The validation C-indexes were 0.775 and 0.742 for OS and CSS, respectively.Our results suggest that we have successfully developed highly accurate nomograms for predicting 5-year OS and CSS for osteosarcoma patients. These nomograms will help surgeons customize treatment and monitoring strategies for osteosarcoma patients.

Survival analysis of patients with metastatic osteosarcoma: a Surveillance, Epidemiology, and End Results population-based study

PURPOSE

The present study is aimed at investigating whether (1) primary tumour surgery confers an improved survival on patients with metastatic osteosarcoma and (2) primary tumour surgery influences survival of patients with metastatic osteosarcoma differently according to primary tumour site.

METHODS

We retrospectively identified 517 patients with high-grade, metastatic osteosarcoma in the Surveillance, Epidemiology, and End Results (SEER) database between 1994 and 2013. The effect of primary tumour surgery on survival was assessed using Kaplan-Meier analyses, log-rank tests, and multivariate Cox proportional hazard regression modeling.

RESULTS

Of those 517 patients with metastatic osteosarcoma in the cohort, 351 patients (68%) underwent primary surgery, and 166 patients (32%) did not undergo surgery. Primary tumour surgery was associated with increased overall survival (hazard ratio (HR) = 0.457, 95% CI 0.354-0.590, p < 0.001) and cancer-specific survival (HR = 0.422, 95% CI 0.325-0.550, p < 0.001). When we focused on different primary tumour sites, receipt of primary tumour surgery significantly prolonged the survival of patients with extremity osteosarcoma (p < 0.05 for overall and cancer-specific survival). However, for patients with pelvis/spine osteosarcoma, both univariate and multivariate analyses indicated that primary tumour surgery might not be associated with improved survival (p > 0.05 for overall and cancer-specific survival).

CONCLUSIONS

Our study is the first population-based analysis to provide evidence of a favourable prognostic impact of primary tumour surgery on metastatic extremity osteosarcoma patients but not metastatic axial (pelvis/spine) osteosarcoma patients. Moreover, we found that surgery type (resection of the primary tumor without amputation vs. amputation) did not influence survival in patients with metastatic osteosarcoma.

A comparison of risk factors for metastasis at diagnosis in humans and dogs with osteosarcoma

Background

Canine osteosarcoma (OS) is a relevant spontaneous model for human OS. Identifying similarities in clinical characteristics associated with metastasis at diagnosis in both species may substantiate research aimed at using canine OS as a model for identifying mechanisms driving distant spread in the human disease.

Methods

This retrospective study included dog OS cases from three academic veterinary hospitals and human OS cases from the Surveillance, Epidemiology, and End Results program. Associations between clinical factors and metastasis at diagnosis were estimated using logistic regression models.

Results

In humans, those with trunk tumors had higher odds of metastasis at diagnosis compared to those with lower limb tumors (OR = 2.38, 95% CI: 1.51, 3.69). A similar observation was seen in dogs with trunk tumors compared to dogs with forelimb tumors (OR = 3.28, 95% CI 1.36, 7.50). Other associations were observed in humans but not in dogs. Humans aged 20‐29 years had lower odds of metastasis at diagnosis compared to those aged 10‐14 years (OR = 0.67, 95% CI: 0.47, 0.96); every 1‐cm increase in tumor size was associated with a 6% increase in the odds of metastasis at diagnosis (95% CI: 1.04, 1.08); compared to those with a white, non‐Hispanic race, higher odds were observed among those with a black, non‐Hispanic race (OR: 1.51, 95% CI: 1.04, 2.16), and those with a Hispanic origin (OR 1.35, 95% CI: 1.00, 1.81).

Conclusion

A common mechanism may be driving trunk tumors to progress to detectable metastasis prior to diagnosis in both species.

Survival and prognosis with osteosarcoma: outcomes in more than 2000 patients in the EURAMOS-1 (European and American Osteosarcoma Study) cohort

Background

High-grade osteosarcoma is a primary malignant bone tumour mainly affecting children and young adults. The European and American Osteosarcoma Study (EURAMOS)-1 is a collaboration of four study groups aiming to improve outcomes of this rare disease by facilitating randomised controlled trials.

Methods

Patients eligible for EURAMOS-1 were aged ≤40 years with M0 or M1 skeletal high-grade osteosarcoma in which case complete surgical resection at all sites was deemed to be possible. A three-drug combination with methotrexate, doxorubicin and cisplatin was defined as standard chemotherapy, and between April 2005 and June 2011, 2260 patients were registered. We report survival outcomes and prognostic factors in the full cohort of registered patients.

Results

For all registered patients at a median follow-up of 54 months (interquartile range: 38–73) from biopsy, 3-year and 5-year event-free survival were 59% (95% confidence interval [CI]: 57–61%) and 54% (95% CI: 52–56%), respectively. Multivariate analyses showed that the most adverse factors at diagnosis were pulmonary metastases (hazard ratio [HR] = 2.34, 95% CI: 1.95–2.81), non-pulmonary metastases (HR = 1.94, 95% CI: 1.38–2.73) or an axial skeleton tumour site (HR = 1.53, 95% CI: 1.10–2.13). The histological subtypes telangiectatic (HR = 0.52, 95% CI: 0.33–0.80) and unspecified conventional (HR = 0.67, 95% CI: 0.52–0.88) were associated with a favourable prognosis compared with chondroblastic subtype. The 3-year and 5-year overall survival from biopsy were 79% (95% CI: 77–81%) and 71% (95% CI: 68–73%), respectively. For patients with localised disease at presentation and in complete remission after surgery, having a poor histological response was associated with worse outcome after surgery (HR = 2.13, 95% CI: 1.76–2.58). In radically operated patients, there was no good evidence that axial tumour site was associated with worse outcome.

Conclusions

In conclusion, data from >2000 patients registered to EURAMOS-1 demonstrated survival rates in concordance with institution- or group-level osteosarcoma trials. Further efforts are required to drive improvements for patients who can be identified to be at higher risk of adverse outcome. This trial reaffirms known prognostic factors, and owing to the large numbers of patients registered, it sheds light on some additional factors to consider.

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Osteosarcoma is a rare disease, and treatment can only improve with international collaboration.

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We have assembled prospectively collected data from treatments of all the patients in the intercontinental European and American Osteosarcoma Study-1 protocol.

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These consistently treated patients provided a strong data set for reporting survival outcomes and reporting on prognostic factors.

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The trial reaffirms known prognostic factors, and the most adverse factors were metastases and tumours in the axial skeleton.

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Owing to the large numbers of patients registered, light is shed on some additional factors to be considered. Around seven in ten patients were still alive five years after diagnosis.

Role of miR-142 in the pathogenesis of osteosarcoma and its potential as therapeutic approach

Osteosarcoma (OS) is the most common primary malignant tumor of the bone with a strong tendency to early metastasis, and occurs in growing bones more commonly in children and adolescents. Considering the limited therapeutic methods and lack of 100% success of these methods, developing innovative therapies with high efficacy and lower side effects is needed. Meanwhile, miRNAs and the studies indicating the involvement of miRNAs in OS development have attracted attentions as a result of the frequent abnormalities in expression of miRNAs in cancer. miRNAs are noncoding short sequences with lengths ranging from 18 to 25 nucleotides that play a very important role in cellular processes, such as proliferation, differentiation, migration, and apoptosis. MiRNAs can have either oncogenic or tumor suppressive role based on cellular function and targets. This review aimed to have overview on miR-142 as a tumor suppressor in OS. Moreover, the genes involved in the disease, such as RAC1, HMAG1, MMP9, MMP2, and E-cadherin, which have irregularities as a result of change in miR-142 expression, and, thereby, result in increasing the proliferation, invasion, and metastasis of the cells in the tissues and OS cells will be discussed.

Combinatorial screening using orthotopic patient derived xenograft-expanded early phase cultures of osteosarcoma identify novel therapeutic drug combinations

Lead discovery in osteosarcoma has been hampered by the lack of new agents, limited representative clinical samples and paucity of accurate preclinical models. We developed orthotopic patient-derived xenografts (PDXs) that recapitulated the molecular, cellular and histologic features of primary tumors, and screened PDX-expanded short-term cultures and commercial cell lines of osteosarcoma against focused drug libraries. Osteosarcoma cells were most sensitive to HDAC, proteasome, and combination PI3K/MEK and PI3K/mTOR inhibitors, and least sensitive to PARP, RAF, ERK and MEK inhibitors. Correspondingly, PI3K signaling pathway genes were up-regulated in metastatic tumors compared to primary tumors. In combinatorial screens, as a class, HDAC inhibitors showed additive effects when combined with standard-of-care agents gemcitabine and doxorubicin. This lead discovery strategy afforded a means to perform high-throughput drug screens of tumor cells that accurately recapitulated those from original human tumors, and identified classes of novel and repurposed drugs with activity against osteosarcoma.

Synergistic inhibitory effects of capsaicin combined with cisplatin on human osteosarcoma in culture and in xenografts

BACKGROUND

The combination of phytochemicals with chemotherapy drugs is an emerging new strategy for cancer therapy to increase antitumor responses.

METHODS

The present study investigates the effect of the combination of capsaicin (CAP) with cisplatin (DDP) and the potential underlying anticancer mechanisms in osteosarcoma (OS) cells in vitro and in vivo.

RESULTS

Cell viability assays and isobolographic analyses demonstrated that the combination of CAP and DDP showed synergistic cytotoxic effects on OS cells. We chose relatively low concentrations of CAP (100 μM) and DDP (16.7 μM) for subsequent experiments. Generally, the combination of CAP and DDP had significant effects on apoptosis induction, cell cycle arrest and cell invasion inhibition in OS cells compared with the individual-treatment groups and the control group. Moreover, cotreatment with CAP and DDP triggered prosurvival autophagy through reactive oxygen species (ROS)/JNK and p-AKT/mTOR signaling in OS cells. The combination regimen of CAP and DDP also inhibited tumor growth in an OS xenograft model.

CONCLUSION

These results suggest that the combination of CAP and DDP has strong inhibitory effects on OS cells and identify CAP as a promising agent for supplementing standard chemotherapy and possible future targeted therapy in OS.

Targeted codelivery of doxorubicin and IL-36γ expression plasmid for an optimal chemo-gene combination therapy against cancer lung metastasis

Cancer metastasis is the main cause for the high mortality in breast cancer patients. In this work we developed a polymer POEG-st-Pmor for targeted co-delivery of IL-36γ expression plasmid and doxorubicin (Dox) to lung metastasis of breast cancer. The polymer readily formed micelles that were effective in loading Dox and simultaneously forming complexes with IL-36γ plasmid. Interestingly, particles co-loaded with Dox and plasmid was significantly smaller and more stable than the particles loaded with Dox only. Gene transfection in both lungs and s.c. tumors was significantly higher with our polymer compared to PEI. In addition, the Dox + IL-36γ/POEG-st-Pmor not only could bring improved anti-metastatic effect but synergistically enhance the type I immune response by increasing the IFN-γ positive CD4⁺ and CD8⁺ T cells and simultaneously decreasing the immunosuppressive myeloid-derived suppressor cells in the lung. POEG-st-Pmor may represent a simple and effective delivery system for an optimal chemo-gene combination therapy.

TRIM2 regulates the development and metastasis of tumorous cells of osteosarcoma

The present study aimed to investigate candidate genes involved in the development and metastasis of osteosarcoma. Candidate genes were screened preliminarily from the Gene Expression Omnibus database and then validated using actual tumor tissues collected from patients with osteosarcoma. The cells were prepared and transfected with specific gene-targeted small interfering RNA followed by an MTS assay for cell viability detection and Transwell assays for cell migration and invasion capacity detection. The cell apoptosis was determined by flow cytometry and the protein level of the genes was detected by western blot analysis. An in vivo nude model was used and injected with cells to detect the functions of the genes. Transcriptome sequencing was performed to verify the regulation network, followed by reverse transcription-quantitative polymerase chain reaction and western blot analyses for validation. Increased tripartite motif-containing protein 2 (TRIM2) was detected in the osteosarcoma tumor tissues compared with normal tissues. The inhibition of TRIM2 induced lower cell viability and cell invasion capacity, and increased the rate of cell apoptosis. Decreased TRIM2 also inhibited the development and metastasis of osteosarcoma in the nude mouse models. The transcriptome sequencing revealed that the regulation of TRIM2 may be correlated with genes, Sirtuin 4, DNA damage inducible transcript 3, cAMP responsive element binding protein 5, G protein-coupled receptor 65 (GPR65) and ADP-ribosyltransferase 5. Western blot analysis indicated that TRIM2 regulated the development and metastasis of osteosarcoma via the phosphoinositide 3-kinase/protein kinase B signaling pathway. Therefore, TRIM2 performs important functions in regulating the development and metastasis of osteosarcoma.

Elevated Expression of Transforming Acidic Coiled-Coil Containing Protein 3 (TACC3) Is Associated With a Poor Prognosis in Osteosarcoma

BACKGROUND

Transforming acidic coiled-coil containing protein 3 (TACC3) is expressed during the mitotic phase of nuclear division and regulates microtubules. Recently, high TACC3 expression in tumor cells of various cancers including soft tissue sarcoma has been reported. However, its role in osteosarcoma remains unknown. Because we have few prognostic markers for survival in osteosarcoma, we wanted to investigate the potential role of TACC3 in human osteosarcoma and determine if it is associated with survival.

QUESTIONS/PURPOSES

(1) Is there a relationship between TACC3 expression and clinicopathologic characteristics such as sex, age (< 20 or ≥ 20 years), histologic type (osteoblastic or others), tumor location (femur or others), American Joint Committee on Cancer staging system (AJCC stage IIA or IIB), tumor necrosis percentage after chemotherapy (< 90% or ≥ 90%), p53 expression (low or high), and Ki-67 expression (low or high)? (2) Is TACC3 expression associated with event-free and overall survival in patients with osteosarcoma?

METHODS

Forty-six conventional patients with osteosarcoma were treated at our institution from 1989 to 2013. Patients were excluded because of unresectable primary site (two patients) and no chemotherapy (two patients). Patients with metastasis at the initial visit (five patients), without pretreatment biopsy samples (two patients), or clinical charts (two patients) were also excluded. The left 33 patients who received neoadjuvant and adjuvant chemotherapy, which consisted of cisplatin/doxorubicin/methotrexate or cisplatin/doxorubicin/methotrexate/ifosfamide, and completed surgical resection with histologic wide tumor margins. Primary tumor samples before chemotherapy were used in this study. We investigated TACC3 expression using immunohistochemical staining and statistically analyzed the TACC3 expression, clinicopathologic characteristics, and event-free and overall survival in patients with osteosarcoma.

RESULTS

High TACC3 expression was observed in 19 of 33 osteosarcoma specimens (58%), and this was associated with larger tumor size (ie, AJCC stage IIB in this study; p = 0.002), higher p53 expression (p = 0.007), and higher Ki-67 expression (p = 0.002). The estimated metastasis-free survival at 5 years was 21% (95% confidence interval [CI], 7%-41%) in patients with high TACC3 expression and 79% (95% CI, 47%-93%) in patients with low TACC3 expression (p < 0.001), and the estimated overall survival at 5 years was 34% (95% CI, 13%-56%) in patients with high TACC3 expression and 86% (95% CI, 54%-96%) in patients with low TACC3 expression (p < 0.001). Furthermore, high TACC3 expression was an independent poor prognostic factor for metastasis-free survival with a hazard ratio of 3.89 (95% CI, 1.07-19.78; p = 0.039) as well as overall survival with 4.41 (95% CI, 1.01-32.97; p = 0.049).

CONCLUSIONS

High TACC3 expression was associated with aggressive clinicopathologic features and unfavorable prognosis in these patients with osteosarcoma. Our preliminary results suggest that further analysis about mutation or an inactive form of TACC3 would be useful to understand the mechanism of abnormal TACC3 expression in patients with osteosarcoma. If these findings are substantiated in larger studies, TACC3 might be useful for predicting survival and a potential therapeutic target for osteosarcoma.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Denosumab does not decrease the risk of lung metastases from bone giant cell tumour

PURPOSE

There are conflicting reports on the effect of denosumab on lung metastases in patients with giant cell tumor (GCT) of bone. To address these reports, we performed this study to determine if denosumab prevents lung metastasis and to evaluate univariate and multivariate predictors for lung metastases in these patients.

MATERIALS AND METHODS

We retrospectively studied 381 GCT patients with surgery alone and 30 GCT patients with surgery and denosumab administration. The median follow-up was 85.2 months (IQR, 54.2-124.4 months). We evaluated lung metastases and local recurrences, univariate and multivariate predictors for lung metastases, response, and adverse events of denosumab administration.

RESULTS

The occurrence of lung metastases was similar (surgery alone 4.7%, 18 patients; denosumab administration 3.3%, 1 patient); however, the occurrence of local recurrences was significantly higher in the patients with denosumab administration. Denosumab administration was not an important predictor for lung metastases; Campanacci stage and type of surgery were the only univariate predictors for lung metastases, and type of surgery and local recurrence were the only multivariate predictors for lung metastases. Histology showed viable tumour in all tumor specimens of the patients with denosumab administration.

CONCLUSION

Denosumab does not decrease the risk of lung metastases in patients with bone GCT; the only important predictors for lung metastases in these patients are type of surgery and local recurrence. However, because the number of patients with lung metastases was small for a multivariate analysis, the possibility of denosumab's effect could not be completely eliminated.

Novel oncogene COPS3 interacts with Beclin1 and Raf-1 to regulate metastasis of osteosarcoma through autophagy

Background

Expression of COP9 signalosome subunit 3 (COPS3), an oncogene overexpressed in osteosarcoma, has been demonstrated to be significantly correlated with tumor metastasis. However, the underlying mechanism by which COPS3 promotes metastasis of osteosarcoma and its role in autophagy remain unknown.

Methods

The expression of COPS3 was detected in primary osteosarcoma tissues and matching lung metastasis tissues by immunohistochemistry (IHC). The effect of COPS3 on the metastasis of osteosarcoma cells was investigated by transwell, wound healing assays and animal studies. Indicated proteins was analyzed by western blotting when COPS3 was knockdown or overexpressed. The COPS3 Interacting protein was determined by immunoprecipitation assay. The relationship between COPS3 and autophagy was detected by western blotting and immunofluorescence.

Results

We found that knockdown of COPS3 significantly reduced the lung metastasis of osteosarcoma cells in a mouse model, coinciding with downregulation of mitogen-activated protein kinase (MEK) and extracellular signal-regulated kinase (ERK) signaling. The silencing of COPS3 also inhibited the epithelial–mesenchymal transition (EMT) through the 90 kDa ribosomal S6 kinases (RSK), a family of signal transduction proteins downstream of MEK/ERK. Reciprocal immunoprecipitation assays revealed that COPS3 directly interacts with Raf-1, an upstream regulator of MEK/ERK. Surprisingly, Beclin1, an important autophagic protein, appeared in the COPS3-immunoprecipitates, along with the autophagic markers LC3-I and LC3-II. Loss of COPS3 completely inhibited H₂O₂-induced autophagic flux and reduced Beclin1 expression. Additionally, autophagy inhibitor or silencing of Beclin1 both decreased cell metastasis.

Conclusions

Taken together, these data reveal a novel function of COPS3 in the regulation of autophagy and highlight the relationship between autophagy and metastasis in osteosarcoma cells.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0791-6) contains supplementary material, which is available to authorized users.

Variants of FasL and ABCC5 are predictive of outcome after chemotherapy-based treatment in osteosarcoma

Objectives

Previous pharmacogenetics studies showed that genetic variants could be indicative of the response to chemotherapy. We aimed to investigate whether variants of FasL, MSH2, ABCC5, CASP3 and CYP3A4 are associated with the outcome after chemotherapy-based treatment in osteosarcoma.

Methods

132 osteosarcoma patients who had completed the neoadjuvant chemotherapy in our center were included. 5-year progression-free survival (PFS) was assessed from the initial treatment to the earliest sign of disease progression or death from any cause. 5 SNPs were genotyped using TaqMan SNP Genotyping Assay, including rs763110 of FasL, rs4638843 of MSH2, rs939338 of ABCC5, rs2720376 of CASP3 and rs4646437 of CYP3A4. Patients were classified into two groups according to the 5-year PFS (event/no event). The chi-square test was used to analyze difference of genotype frequency. Logistic regression analysis was used to determine the independent predictors of the PFS rate.

Results

The overall 5-year PFS was 61.4% (81/132). Genotype TT/CT of rs763110 and genotype GG/AG of rs939338 were significantly associated with the event of 5-year PFS (p = 0.028 for rs763110; p = 0.039 for rs939338). Patients with no risk allele showed a 5-year PFS of 73.7% (42/57), which was significantly higher than a PFS of 54.2% (26/48) for patients with one risk allele and 48.1% (13/27) for patients with two different risk alleles (p = 0.03). Logistic regression analysis showed that allele T of FasL rs763110 and allele G of ABCC5 rs939338 were independent risk factors of the 5-year PFS. The ORs were 2.14 (95%CI = 1.13–3.35, p = 0.01) for rs763110 and 1.73 (95%CI = 1.05–2.52, p = 0.03) for rs939338, respectively.

Conclusions

The association of variants of FASL and ABCC5 with survival outcome after chemotherapy was validated in patients with osteosarcoma. Our findings may provide a new insight into a more personalized treatment for patients with osteosarcoma.

High-Grade Osteosarcoma of the Foot: Presentation, Treatment, Prognostic Factors, and Outcome of 23 Cooperative Osteosarcoma Study Group COSS Patients

Osteosarcoma of the foot is a very rare presentation of a rare tumor entity. In a retrospective analysis, we investigated tumor- and treatment-related variables and outcome of patients registered in the Cooperative Osteosarcoma Study Group (COSS) database between January 1980 and April 2016 who suffered from primary high-grade osteosarcoma of the foot. Among the 23 eligible patients, median age was 32 years (range: 6–58 years), 10 were female, and 13 were male. The tarsus was the most commonly affected site (n=16). Three patients had primary metastases. All patients were operated: 5 underwent primary surgery and 18 received surgery following preoperative chemotherapy. In 21 of the 23 patients, complete surgical remission was achieved. In 4 of 17 patients, a poor response to neoadjuvant chemotherapy was observed in the resected primary tumors. Median follow-up was 4.2 years (range: 0.4–18.5). At the last follow-up, 15 of the 23 patients were alive and 8 had died. Five-year overall and event-free survival estimates were 64% (standard error (SE) 12%) and 54% (SE 13%), which is similar to that observed for osteosarcoma in general. Event-free and overall survival correlated with primary metastatic status and completeness of surgery. Our findings show that high-grade osteosarcoma in the foot has a similar outcome as osteosarcoma of other sites.

Treatment of Sarcoma Lung Metastases with Stereotactic Body Radiotherapy

Background

The most common site of sarcoma metastasis is the lung. Surgical resection of pulmonary metastases and chemotherapy are treatment options that have been employed, but many patients are poor candidates for these treatments for multiple host or tumor-related reasons. In this group of patients, radiation might provide a less morbid treatment alternative. We sought to evaluate the efficacy of radiotherapy in the treatment of metastatic sarcoma to the lung.

Methods

Stereotactic body radiotherapy (SBRT) was used to treat 117 pulmonary metastases in 44 patients. Patients were followed with serial computed tomography imaging of the chest. The primary endpoint was failure of control of a pulmonary lesion as measured by continued growth. Radiation-associated complications were recorded.

Results

The majority of patients (84%) received a total dose of 50 Gy per metastatic nodule utilizing an image-guided SBRT technique. The median interval follow-up was 14.2 months (range 1.6–98.6 months). Overall survival was 82% at two years and 50% at five years. Of 117 metastatic nodules treated, six nodules showed failure of treatment (95% control rate). Twenty patients (27%) developed new metastatic lesions and underwent further SBRT. The side effects of SBRT included transient radiation pneumonitis (n=6), cough (n=2), rib fracture (n=1), chronic pain (n=1), dermatitis (n=1), and dyspnea (n=1).

Conclusion

Stereotactic body radiotherapy is an effective and safe treatment for the ablation of pulmonary metastasis from sarcoma. Further work is needed to evaluate the optimal role of SBRT relative to surgery or chemotherapy for treatment of metastatic sarcoma.

Metformin inhibits the proliferation and metastasis of osteosarcoma cells by suppressing the phosphorylation of Akt

Metformin (Met) is a therapeutic agent for the treatment of type 2 diabetes mellitus. There is evidence that Met may reduce the risk of cancer in patients with type 2 diabetes mellitus by inhibiting tumor cell growth, prolonging the overall survival time in patients with various types of malignancy. However, the function and mechanism of Met have not been fully elucidated in osteosarcoma (OS). The present study evaluated the anti-proliferative effect of Met on MG63 and U2OS OS cells, identifying that it acted in a dose- and time-dependent manner. Met also inhibited OS cell migration and invasion, potentially by regulating the epithelial-mesenchymal transition in OS cells. Mechanistically, Met was demonstrated to partly exert these functions through the suppression of Akt phosphorylation, which was associated with increased phosphatase and tensin (PTEN) expression. Silencing PTEN prevented the Met-induced inhibition of the growth and metastasis of OS cells. As Met has anti-proliferative and anti-metastatic effects on OS cells it is a potential candidate, in combination with other chemotherapeutic agents, for use in the treatment of OS.

Clinical significance of circulating miR-25-3p as a novel diagnostic and prognostic biomarker in osteosarcoma

Background

Emerging evidence has suggested that circulating microRNAs (miRNAs) in body fluids have novel diagnostic and prognostic significance for patients with malignant diseases. The lack of useful biomarkers is a crucial problem of bone and soft tissue sarcomas; therefore, we investigated the circulating miRNA signature and its clinical relevance in osteosarcoma.

Methods

Global miRNA profiling was performed using patient serum collected from a discovery cohort of osteosarcoma patients and controls and cell culture media. The secretion of the detected miRNAs from osteosarcoma cells and clinical relevance of serum miRNA levels were evaluated using in vitro and in vivo models and a validation patient cohort.

Results

Discovery screening identified 236 serum miRNAs that were highly expressed in osteosarcoma patients compared with controls, and eight among these were also identified in the cell culture media. Upregulated expression levels of miR-17-5p and miR-25-3p were identified in osteosarcoma cells, and these were abundantly secreted into the culture media in tumor-derived exosomes. Serum miR-25-3p levels were significantly higher in osteosarcoma patients than in control individuals in the validation cohort, with favorable sensitivity and specificity compared with serum alkaline phosphatase. Furthermore, serum miR-25-3p levels at diagnosis were correlated with patient prognosis and reflected tumor burden in both in vivo models and patients; these associations were more sensitive than those of serum alkaline phosphatase.

Conclusions

Serum-based circulating miR-25-3p may serve as a non-invasive blood-based biomarker for tumor monitoring and prognostic prediction in osteosarcoma patients.

Osteosarcoma of the Pelvis: A Monoinstitutional Experience in Patients Younger than 41 Years

Aims and background

Information is scarce on systemic treatment of pelvic osteosarcoma because most chemotherapy protocols for osteosarcoma include patients with extremity tumors and aged up to 30–40 years.

Methods

Data on patients <41 years of age with high-grade pelvic osteosarcoma were prospectively collected. Patients received two chemotherapy protocols consisting of methotrexate, cisplatin, doxorubicin (MAP) and standard-dose or high-dose ifosfamide.

Results

Forty patients between 11 and 36 years were included. The most frequent histological subtype was osteoblastic followed by chondroblastic (37.5%). Complete surgical remission was achieved in 65% of patients. Eighteen patients had MAP/standard-dose ifosfamide, 22 MAP/high-dose ifosfamide. Primary chemotherapy was given to 25 patients and 6 (24%) of them had a good histological response. Median follow-up was 32 months (range, 4–134). Five-year overall survival was 27.5%: 33% in localized and 0 in metastatic patients (P = 0.02); 45% in patients with complete surgical remission and 0 for patients without complete surgical remission (P = 0.001). Local recurrence rate was 46%. In patients with complete surgical remission, 5-year overall survival was 32% with MAP/standard-dose ifosfamide and 59% with MAP/high-dose ifosfamide regimen (P = 0.3).

Conclusions

Local control is the major issue in the treatment of pelvic osteosarcoma. Poor pathological response and high incidence of chondroblastic variant indicate different characteristics between pelvic and extremity osteosarcoma. Chemotherapy with MAP and high-dose ifosfamide might be beneficial in patients with pelvic osteosarcoma and warrants further investigation.

FKBP14 overexpression contributes to osteosarcoma carcinogenesis and indicates poor survival outcome

The FK506-binding protein 14 (FKBP14) is a subfamily of immunophilins, has been implicated in various biochemical processes. However, its effects on the primary malignant bone tumor, osteosarcoma, are unclear. Here, we reported that FKBP14 may be an oncogene as it overexpressed in osteosarcoma tissues and cell lines, and FKBP14 expression was correlated with metastases, recurrence, tumor maximum diameter and poor survival time. FKBP14 was associated with the biological pathways including cell cycle, apoptosis and metastasis. Furthermore, we detected FKBP14 knockdown induced cell cycle arrest, apoptosis, invasion and adhesion in vitro. FKBP14 knockdown decreased the protein levels of PCNA, CDK1 and CCNB1 that promotes cell cycle, increased Bax, caspase-3 and caspase-7 protein involved in promoting cell apoptosis, and increased KIF4A expression as well as decreased SMC4 and TMEM33 proteins that contribute to cell invasion and adhesion. In addition, FKBP14 knockdown also caused a significant inhibition in tumor growth in vivo. Then, we found that the protein RhoA was identified as a binding partner of FKBP14. Taken together, FKBP14 may act as an oncogene in osteosarcoma via suppressing apoptosis and promoting invasion and adhesion in osteosarcoma carcinogenesis. FKBP14 may be a prognostic factor and potential target for osteosarcoma treatment.

Malignant bone tumors (other than Ewing's): clinical practice guidelines for diagnosis, treatment and follow-up by Spanish Group for Research on Sarcomas (GEIS)

Primary malignant bone tumors are uncommon and heterogeneous malignancies. This document is a guideline developed by the Spanish Group for Research on Sarcoma with the participation of different specialists involved in the diagnosis and treatment of bone sarcomas. The aim is to provide practical recommendations with the intention of helping in the clinical decision-making process. The diagnosis and treatment of bone tumors requires a multidisciplinary approach, involving as a minimum pathologists, radiologists, surgeons, and radiation and medical oncologists. Early referral to a specialist center could improve patients' survival. The multidisciplinary management of osteosarcoma, chondrosarcoma, chordoma, giant cell tumor of bone and other rare bone tumors is reviewed in this guideline. Ewing's sarcoma will be the focus of a separate guideline because of its specific biological, clinical and therapeutic features. Each statement has been accompanied by the level of evidence and grade of recommendation on the basis of the available data. Surgical excision is the mainstay of treatment of a localized bone tumor, with various techniques available depending on the histologic type, grade and location of the tumor. Chemotherapy plays an important role in some chemosensitive subtypes (such as high-grade osteosarcoma). In other subtypes, historically considered chemoresistant (such as chordoma or giant cell tumor of bone), new targeted therapies have emerged recently, with a very significant efficacy in the case of denosumab. Radiation therapy is usually necessary in the treatment of chordoma and sometimes of other bone tumors.

MicroRNAs as a novel class of diagnostic biomarkers for the detection of osteosarcoma: a meta-analysis

MicroRNAs (miRNAs) have been considered as promising diagnostic biomarkers for many diseases, especially for cancers. Numerous studies have reported the value of miRNAs in the diagnosis of osteosarcoma (OS), but the results vary greatly across different studies. Therefore, we conducted this meta-analysis to assess the prospective diagnostic value of miRNAs in diagnosing OS. All relevant articles from prior to July 28, 2017 were selected from PubMed, EMBASE, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, and Wan-fang databases. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was performed to assess the quality of each article. A random-effects model was used to pool the sensitivity and specificity of the positive likelihood ratio (PLR), negative likelihood ratio (NLR) and, diagnostic odds ratio (DOR) together with the area under the curve (AUC) to evaluate diagnostic values. Seventeen studies comprising 2,214 OS patients and 1,534 healthy humans were included in our meta-analysis. The pooled estimations indicated that the miRNAs had a high accuracy for diagnosing OS, with a sensitivity of 0.82, specificity of 0.88, PLR of 10.96, NLR of 0.20, DOR of 54.55, and AUC of 0.93. Twenty-five miRNAs were differentially expressed in OS, including 17 upregulated and 8 downregulated. These miRNAs were correlated with survival time, tumor size, cell differentiation, tumor node metastasis staging, metastasis, tumor/cell invasion, pathological type, and response to radiotherapy and chemotherapy. Several different miRNAs are expressed in OS, and some of them might be potential biomarkers for the early diagnosis of OS.

Comparative review of human and canine osteosarcoma: morphology, epidemiology, prognosis, treatment and genetics

Osteosarcoma (OSA) is a rare cancer in people. However OSA incidence rates in dogs are 27 times higher than in people. Prognosis in both species is relatively poor, with 5 year OSA survival rates in people not having improved in decades. For dogs, 1 year survival rates are only around ~ 45%. Improved and novel treatment regimens are urgently required to improve survival in both humans and dogs with OSA. Utilising information from genetic studies could assist in this in both species, with the higher incidence rates in dogs contributing to the dog population being a good model of human disease. This review compares the clinical characteristics, gross morphology and histopathology, aetiology, epidemiology, and genetics of canine and human OSA. Finally, the current position of canine OSA genetic research is discussed and areas for additional work within the canine population are identified.

Survival and prognostic factors following pulmonary metastasectomy for sarcoma

Sarcomas are a heterogeneous group of malignancies with a marked propensity to metastasize to the lungs. Chemotherapy offers only a limited benefit in metastatic disease, whereas lung metastasectomy, in selected cases, can lead to long-term survival. Other local ablative techniques and hybrid therapies have been proposed. A multidisciplinary setting is of paramount importance for choosing the most appropriate treatment for each case. There is no randomized controlled trial providing formal evidence of the effectiveness of lung metastasectomy. Main areas of controversy concern the selection of surgical candidates, the operative approach and the role of chemotherapy. Five-year survival rates range from 15% to 50.9%, as reported mainly in retrospective case-series in which several prognostic factors were identified. In this article, the authors review the surgical management of sarcoma metastases to the lung, with a particular focus on the outcomes and prognostic factors associated with long-term survival after resection. The role of chemotherapy and other adjunctive therapies is also discussed.

The dynamic role of autophagy and MAPK signaling in determining cell fate under cisplatin stress in osteosarcoma cells

Osteosarcoma (OS) is an aggressive bone malignancy commonly observed in children and adolescents. Sub-optimal therapy for years has irretrievably compromised the chances of OS patient survival; also, lack of extensive research on this rare disease has hindered therapeutic development. Cisplatin, a common anti-tumor drug, is currently an integral part of treatment regime for OS along with methotrexate and doxorubicin. However, toxicity issues associated with combination module impede OS therapy. Also, despite the proven benefits of cisplatin, acquisition of resistance remains a concern with cisplatin-based therapy. This prompted us to investigate the molecular effects of cisplatin exposure and changes associated with acquired resistance in OS cells. Cisplatin shock was found to activate MAPK signaling and autophagy in OS cells. An activation of JNK and autophagy acted as pro-survival strategy, while ERK1/2 triggered apoptotic signals upon cisplatin stress. A crosstalk between JNK and autophagy was observed. Maximal sensitivity to cisplatin was obtained with simultaneous inhibition of both autophagy and JNK pathway. Cisplatin resistant cells were further developed by repetitive drug exposure followed by clonal selection. The resistant cells showed an altered signaling circuitry upon cisplatin exposure. Our results provide valuable cues to possible molecular alterations that can be considered for development of improved therapeutic strategy against osteosarcoma.

The role of 18F-FDG PET/CT in the detection of osteosarcoma recurrence

AIM

The aim of this study was to investigate the diagnostic accuracy of ¹⁸F-FDG-PET/CT in osteosarcoma patients suspicious for disease recurrence after adequate surgical therapy.

METHODS

Inclusion criteria were: a) adequate surgical treatment for proven osteosarcoma and documented complete remission after therapy; b) ¹⁸F-FDG-PET/CT performed during follow-up for clinical/diagnostic suspicion of relapse; c) new surgical treatment with excision of the suspected lesions; d) histological validation of ¹⁸F-FDG-PET/CT findings. Thirty-seven patients matching all inclusion criteria were retrospectively enrolled (20 men and 17 female). Primary surgical treatment consists of resection (31 cases) or amputation (six cases). ¹⁸F-FDG-PET/CT performance was assessed with a per-patient and per-site evaluation of sensitivity, specificity, accuracy, positive predicting value (PPV), and negative predicting value (NPV). The sites of relapse were classified as local, lung, lymphnodes (LNs), and distant (other skeletal segments and/or distant soft tissue). The disease-free survival (DFS) and the overall survival (OS) after 18F-FDG PET/CT were evaluated.

RESULTS

¹⁸F-FDG-PET/CT was positive in 89.2% (33/37) of patients. Local uptake only was observed in 35.1% patients (13/37); lung uptake only in 18.9% (7/37); distant uptake only in 2.7% (1/37) case; multiple sites of uptake in 32.4% (12/37). Histology resulted positive in 92% (34/37) of patients. A total of 51 pathologic lesions were evaluated (22 local relapse, 11 lung metastasis, 10 metastatic LNs, eight distant metastatic lesions). On a per-patient analysis ¹⁸F-FDG-PET/CT showed a sensitivity, specificity, accuracy, PPV, and NPV of 91%, 75%, 89%, 97%, 50%. On a per-site analysis the performance for local relapse was 96%, 100%, 97%, 100%, 93%, while for lung relapse detection was 80%, 100%, 92%, 100%, 88%. The mean follow-up after ¹⁸F-FDG-PET/CT was 21.5 months. At the last follow-up, 19% (7/37) of patients were death with disease, 38% (14/37) were alive with disease, and 43% (16/37) had no evidence of disease. Overall survival was 90% and 75% at 24 and 60 months, respectively.

CONCLUSION

¹⁸F-FDG-PET/CT showed valuable results for detecting recurrence(s) in osteosarcoma patients with suspicious of relapse after treatment, particularly in the detection of local relapse and lung metastasis.

Biomarkers of Osteosarcoma, Chondrosarcoma, and Ewing Sarcoma

Osteosarcoma is the most frequent malignant bone neoplasm, followed by chondrosarcoma and Ewing sarcoma. The diagnosis of bone neoplasms is generally made through histological evaluation of a biopsy. Clinical and radiological features are also important in aiding diagnosis and to complete the staging of bone cancer. In addition to these, there are several non-specific serological or specific molecular markers for bone neoplasms. In bone tumors, molecular markers increase the accuracy of the diagnosis and assist in subtyping bone tumors. Here, we review these markers and discuss their role in the diagnosis and prognosis of the three most frequent malignant bone neoplasms, namely osteosarcoma, chondrosarcoma, and Ewing sarcoma.

Expression of G Protein-coupled Receptor 56 Is an Unfavorable Prognostic Factor in Osteosarcoma Patients

G protein-coupled receptor 56 (GPR56) is an atypical G protein-coupled receptor, with the long extracellular N-terminus. GPR56 can trigger various downstream signaling responsible for cell survival, proliferation, adhesion, and migration. Expression of GPR56 is associated with cell malignant transformation and tumor cell metastasis in several carcinomas such as melanoma and glioma. Osteosarcoma is the most common malignant bone tumor in adolescents and young adults with high metastasis tendency. The overall survival of osteosarcoma is unsatisfied, partially due to the lacking of predictive markers for metastasis and overall prognosis. This study aimed at figuring out whether expression of the GPR56 was associated with clinicopathological features of osteosarcoma. Eighty-nine patients who received osteosarcoma operation between March 2004 and February 2011 in Linyi People's Hospital were recruited. Immunohistochemical staining (IHC) was carried out to identify the expression of GPR56 in those osteosarcoma tissues, and our cohort was divided into higher-expression group and lower-expression group according to the cut-off of IHC score. Expression of GPR56 in osteosarcoma tissues was correlated with the TNM stage and overall survival. Univariate and multivariate analysis showed that GPR56 could act as an independent prognosis factor for osteosarcoma. Western blot results demonstrated that GPR56-siRNA down-regulated the expression of GTP-RhoA and Ki67. GTP-RhoA participates in the cell migration process, while Ki67 plays important roles in cell proliferation, indicating GPR56 may function in tumor development. Correspondingly, we show that GPR56 regulates the proliferation and invasion capacity of osteosarcoma cells. Our study has revealed the prognostic value of GPR56 expression in osteosarcoma.

Pediatric Sarcomas

Pediatric sarcomas are a heterogeneous group of tumors accounting for approximately 10% of childhood solid tumors. Treatment is focused on multimodality therapy, which has improved the prognosis over the past two decades. Current regimens focus on decreasing treatment for low-risk patients to decrease the long-term side effects while maximizing therapy for patients with metastatic disease to improve survival. Pediatric sarcomas can be divided into soft tissue sarcomas and osseous tumors. Soft tissue sarcomas are further delineated into rhabdomyosarcomas, which affect young children and nonrhabdomyosarcomas, which are most common in adolescents. The most common bone sarcomas are osteosarcomas and Ewing's sarcoma.

Natural compounds targeting major cell signaling pathways: a novel paradigm for osteosarcoma therapy

Osteosarcoma is the most common primary bone cancer affecting children and adolescents worldwide. Despite an incidence of three cases per million annually, it accounts for an inordinate amount of morbidity and mortality. While the use of chemotherapy (cisplatin, doxorubicin, and methotrexate) in the last century initially resulted in marginal improvement in survival over surgery alone, survival has not improved further in the past four decades. Patients with metastatic osteosarcoma have an especially poor prognosis, with only 30% overall survival. Hence, there is a substantial need for new therapies. The inability to control the metastatic progression of this localized cancer stems from a lack of complete knowledge of the biology of osteosarcoma. Consequently, there has been an aggressive undertaking of scientific investigation of various signaling pathways that could be instrumental in understanding the pathogenesis of osteosarcoma. Here, we review these cancer signaling pathways, including Notch, Wnt, Hedgehog, phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/AKT, and JAK/STAT, and their specific role in osteosarcoma. In addition, we highlight numerous natural compounds that have been documented to target these pathways effectively, including curcumin, diallyl trisulfide, resveratrol, apigenin, cyclopamine, and sulforaphane. We elucidate through references that these natural compounds can induce cancer signaling pathway manipulation and possibly facilitate new treatment modalities for osteosarcoma.

BMPR2 and HIF1- overexpression in resected osteosarcoma correlates with distant metastasis and patient survival

Objective

Bone morphogenetic protein receptor 2 (BMPR2) and hypoxia-inducible factor 1-α (HIF1-α) existed abnormal expression in several types of cancer. However, their expressions and related roles in osteosarcoma are largely unknown.

Methods

To investigate the clinical significance of BMPR2 and HIF1-α in osteosarcoma, we analyzed their expression levels in 103 osteosarcoma specimens by immunochemistry. Meanwhile, we conducted a follow-up to examine the metastatic behavior and overall survival (OS) of osteosarcoma patients.

Results

Among 103 tissues, 61 cases had BMPR2-positive expression and 57 cases had HIF1-α positive expression. A significant correlation was noticed between BMPR2 and HIF1-α expression in osteosarcoma specimens (P=0.035). Receiver-operating characteristic (ROC) curves were calculated to investigate the predictive value of the two markers in tumor metastasis. By means of univariate and multivariate analysis, BMPR2 and HIF1-α expression, as well as higher tumor grade, were identified as significant risk factors for OS in patients with osteosarcoma. Kaplan-Meier survival analysis revealed that the patients with BMPR2 and HIF1-α positive expression had worse OS compared with patients with BMPR2-negative or HIF1-α-negative staining.

Conclusions

It can be concluded that BMPR2 and HIF1-α expression is highly correlated with metastatic behavior in patients with osteosarcoma and can serve as predictive markers for metastasis and OS of these patients.

Verification of TREX1 as a promising indicator of judging the prognosis of osteosarcoma

Background

The study aimed to explore the correlation between the expression of TREX1 and the metastasis and the survival time of patients with osteosarcoma as well as biological characteristics of osteosarcoma cells for the prognosis judgment of osteosarcoma.

Method

The correlation between the expression of TREX1 protein and the occurrence of pulmonary metastasis in 45 cases of osteosarcoma was analyzed. The CD133⁺ and CD133⁻ cell subsets of osteosarcoma stem cells were sorted by the flow cytometry. The tumorsphere culture, clone formation, growth curve, osteogenic and adipogenic differentiation, tumor-formation ability in nude mice, sensitivity of chemotherapeutic drugs, and other cytobiology behaviors were compared between the cell subsets in two groups; the expressions of stem cell-related genes Nanog and Oct4 were compared; The expressions of TREX1 protein and mRNA were compared between the cell subsets in two groups. The data was statistically analyzed. The measurement data between the two groups were compared using t test. The count data between the two groups were compared using χ² test and Kaplan–Meier survival analysis. A P value <0.05 indicated that the difference was statistically significant.

Results

The expression of TREX1 protein in patients with osteosarcoma in the metastasis group was significantly lower than that in the non-metastasis group. The difference was statistically significant (P < 0.05). Up to the last follow-up visit, the former average survival time was significantly lower than that of the latter, and the difference was statistically significant (P < 0.05). The expression of TREX1 in human osteosarcoma CD133⁺ cell subsets was significantly lower than that in CD133^- cell subsets. Stemness-related genes Nanog and Oct4 were highly expressed in human osteosarcoma CD133⁺ cell subsets with lower expression of TREX1; the biological characteristics identification experiment showed that human CD133⁺ cell subsets with low TREX1 expression could form tumorspheres, the number of colony forming was more, the cell proliferation ability was strong, the osteogenic and adipogenic differentiation potential was big, the tumor-forming ability in nude mice was strong, and the sensibility of chemotherapeutics drugs on cisplatin was low.

Conclusions

The expression of TREX1 may be related to metastasis in patients with osteosarcoma. The expression of TREX1 was closely related to the cytobiology characteristics of osteosarcoma stem cell. TREX1 can play an important role in the occurrence and development processes. And, TREX1 is expected to become an effective new index for the evaluation of the prognosis.

Review of Osteosarcoma and Current Management

Osteosarcoma is the most common primary malignancy of bone in children and young adults. This tumor has a very heterogeneous genetic profile and lacks any consistent unifying event that leads to the pathogenesis of osteosarcoma. In this review, some of the important genetic events involved in osteosarcoma will be highlighted. Additionally, the clinical diagnosis of osteosarcoma will be discussed, as well as contemporary chemotherapeutic and surgical management of this tumor. Finally, the review will discuss some of the novel approaches to treating this disease.

miR-10b promotes invasion by targeting KLF4 in osteosarcoma cells

OBJECTIVE

Osteosarcoma is a common malignancy with high rate of metastasis. miR-10b has been reported to be expressed in many types of tumors abnormally and be associated with cancer carcinogenesis and progression. But the function of miR-10b in osteosarcoma is still unknown. So this study was aimed to investigate the role of miR-10b in osteosarcoma development.

METHODS

miR-10b expression in osteosarcoma tissues and osteosarcoma cells were detected using real time PCR. The effects of miR-10b on osteosarcoma cells proliferation, apoptosis, migration and invasion were detected using CCK-8 assay, flow cytometry, wound-healing assay and transwell assay, respectively. The relationship between miR-10b and KLF4 was evaluated using dual-luciferase assay, correlation analysis.

RESULTS

miR-10b was highly expressed in osteosarcoma tissues and osteosarcoma cells. Furthermore, inhibition of miR-10b in osteosarcoma cells depressed the cells proliferation, migration and invasion but promoted cells apoptosis. In addition, KLF4 was down-regulated by miR-10b and miR-10b expression was negatively related to KLF4 expression in osteosarcoma tissue, miR-10b participated in the process of osteosarcoma cells invasion by regulating KLF4 expression.

CONCLUSION

miR-10b is overexpressed in osteosarcoma and KLF4 is the direct target gene of miR-10b. Furthermore, miR-10b promotes osteosarcoma cells progression by downregulating KLF4 expression. These results suggest that miR-10b functions as an oncomiR and play an important role in osteosarcoma cellular processes at least partially through regulating KLF4; miR-10b may be a therapeutic target for osteosarcoma treatment.

Effects of Arsenic Trioxide on Minor Progressive High-Grade Osteosarcoma of the Extremities Metastatic to the Lung: Results of 39 Patients Treated in a Single Institution

Patients who mildly progressed after first-line chemotherapy were administered arsenic trioxide (ATO) 5–10 mg intravenously daily. Thirty-nine patients were finally enrolled in the study, of whom 19 patients received first-line chemotherapy with ATO infusion while 20 patients did not. Progression-free survival at 4 months was 89.2 and 62.7% (p = 0.043) for the ATO group and the control group, respectively, while the 2-year overall survival was 61 and 16.4% (p = 0.032).

High Expression of HULC Is Associated with Poor Prognosis in Osteosarcoma Patients

Osteosarcoma (OS) is the most common primary bone cancer in childhood. OS is an aggressive disease, and metastatic patients evolve with very poor clinical outcomes. Genetically, OSs are extremely complex tumors, and the related metastatic process is not well understood in terms of the biology of the disease. In this context, long non-coding RNAs (lncRNAs) have emerged as an important class of gene expression regulators that play key roles in the invasion and metastasis of several human tumors. Here, we evaluated the expression of HULC, which is an lncRNA that is associated with the tumor metastatic process, and assessed its potential role as a prognostic marker in OS. HULC expression was evaluated in primary OS samples using real-time RT-PCR. HULC expression status was determined by receiver operating characteristic (ROC) analysis, and its association with survival was assessed using the Kaplan-Meier method. The HULC expression level was not significantly associated with the clinicopathological characteristics of the OS patients. However, our data demonstrated that higher levels of expression of HULC were associated with lower survival rates in OS patients, both in terms of overall and event-free survival. Elevated HULC expression was associated with poor clinical outcomes among the OS patients, which suggests that HULC could be a potential prognostic biomarker in OS.

Genetically engineered pre-microRNA-34a prodrug suppresses orthotopic osteosarcoma xenograft tumor growth via the induction of apoptosis and cell cycle arrest

Osteosarcoma (OS) is the most common primary malignant bone tumor in children, and microRNA-34a (miR-34a) replacement therapy represents a new treatment strategy. This study was to define the effectiveness and safety profiles of a novel bioengineered miR-34a prodrug in orthotopic OS xenograft tumor mouse model. Highly purified pre-miR-34a prodrug significantly inhibited the proliferation of human 143B and MG-63 cells in a dose dependent manner and to much greater degrees than controls, which was attributed to induction of apoptosis and G2 cell cycle arrest. Inhibition of OS cell growth and invasion were associated with release of high levels of mature miR-34a from pre-miR-34a prodrug and consequently reduction of protein levels of many miR-34a target genes including SIRT1, BCL2, c-MET, and CDK6. Furthermore, intravenous administration of in vivo-jetPEI formulated miR-34a prodrug significantly reduced OS tumor growth in orthotopic xenograft mouse models. In addition, mouse blood chemistry profiles indicated that therapeutic doses of bioengineered miR-34a prodrug were well tolerated in these animals. The results demonstrated that bioengineered miR-34a prodrug was effective to control OS tumor growth which involved the induction of apoptosis and cell cycle arrest, supporting the development of bioengineered RNAs as a novel class of large molecule therapeutic agents.

TRIM59 is upregulated and promotes cell proliferation and migration in human osteosarcoma

Osteosarcoma is a prevalent type of cancer and has a high metastatic ability, particularly for metastasis to the lungs. Effective treatment strategies have improved, however, the detailed molecular mechanism underlying the onset of this malignancy remains to be fully elucidated. The current study investigated the role of the tripartite motif (TRIM) family protein TRIM59 in osteosarcoma growth and metastasis. It was identified that TRIM59 was overexpressed in clinical osteosarcoma tissues and cultured osteosarcoma cell lines. In addition, the MTT assay demonstrated that in U2OS and MG63 cells, knockdown of TRIM59 by specific siRNA inhibited proliferation, whereas overexpression of TRIM59 promoted cell proliferation. Furthermore, overexpression of TRIM59 significantly increased the U2OS cell migrative and invasive abilities in a Transwell chamber assay. In addition, TRIM59 was able to negatively regulate the protein levels of P53 without significantly affecting the mRNA levels in U2OS and MG63 cells. These data suggest the oncogenic abilities of TRIM59 in osteosarcoma, which promote osteosarcoma cell proliferation, migration and invasion.

microRNA and Bone Cancer

MicroRNA molecules have a variety of roles in cellular development and proliferation processes, including normal osteogenesis. These effects are exerted through post-translational inhibition of target genes. Altered miRNA expression has been demonstrated in several cancers, both in the tumor tissue and in the peripheral circulation. This may influence carcinogenesis if the specific miRNA targets are encoded by tumor suppressor genes or oncogenes. To date, most research investigating the role of microRNAs and primary bone tumors has focused on osteosarcoma and Ewing sarcoma. Several microRNAs including the miR-34 family have been implicated in osteosarcoma tumorigenesis via effects on the Notch signaling pathway. Progression, invasion, and metastasis of osteosarcoma tumor cells is also influenced by microRNA expression. In addition, microRNA expression may affect the response to chemotherapy in osteosarcoma and thus hold potential for future use as either a prognostic indicator or a therapeutic target. The EWS-FLI1 fusion protein produced in Ewing sarcoma has been shown to induce changes in miRNA expression. MicroRNA expression profiling may have some potential for prediction of disease progression and survival in Ewing sarcoma. There is limited evidence to support a role for microRNAs in other primary bone tumors, either malignant or benign; however, early work is suggestive of involvement in chondrosarcoma, multiple osteochondromatosis, and giant cell tumors of bone.

Metastatic osteosarcoma: a challenging multidisciplinary treatment

Osteosarcoma is the most common malignant bone tumor, currently treated with pre-and postoperative chemotherapy in association with the surgical removal of the tumor. About 15-20% of patients have evidence of metastases at diagnosis, mostly in the lungs. Patients with metastatic disease still have a very poor prognosis, with approximately 20-30% of long-term survivors, as compared with 65-70% of patients with localized disease. The optimum management of these patients has not been standardized yet due to several patterns of metastatic disease harboring different prognosis. Complete surgical resection of all sites of disease is mandatory and predictive of survival. Patients with multiple sites of disease not amenable to complete surgery removal should be considered for innovative therapeutic approaches because of poor prognosis.

Combination therapy with bioengineered miR-34a prodrug and doxorubicin synergistically suppresses osteosarcoma growth

Osteosarcoma (OS) is the most common form of primary malignant bone tumor and prevalent among children and young adults. Recently we have established a novel approach to bioengineering large quantity of microRNA-34a (miR-34a) prodrug for miRNA replacement therapy. This study is to evaluate combination treatment with miR-34a prodrug and doxorubicin, which may synergistically suppress human OS cell growth via RNA interference and DNA intercalation. Synergistic effects were indeed obvious between miR-34a prodrug and doxorubicin for the suppression of OS cell proliferation, as defined by Chou-Talalay method. The strongest antiproliferative synergism was achieved when both agents were administered simultaneously to the cells at early stage, which was associated with much greater degrees of late apoptosis, necrosis, and G2 cell cycle arrest. Alteration of OS cellular processes and invasion capacity was linked to the reduction of protein levels of miR-34a targeted (proto-)oncogenes including SIRT1, c-MET, and CDK6. Moreover, orthotopic OS xenograft tumor growth was repressed to a significantly greater degree in mouse models when miR-34a prodrug and doxorubicin were co-administered intravenously. In addition, multiple doses of miR-34a prodrug and doxorubicin had no or minimal effects on mouse blood chemistry profiles. The results demonstrate that combination of doxorubicin chemotherapy and miR-34a replacement therapy produces synergistic antiproliferative effects and it is more effective than monotherapy in suppressing OS xenograft tumor growth. These findings support the development of mechanism-based combination therapy to combat OS and bioengineered miR-34a prodrug represents a new natural miRNA agent.

Second primary osteosarcomas in patients with retinoblastoma

OBJECTIVE

Second primary malignancies have become the leading cause of death in retinoblastoma survivors. Although osteosarcoma is the most common second malignancy, little is known about its clinical and therapeutic features.

METHODS

We retrospectively reviewed a database of patients with retinoblastoma and osteosarcoma occurring as a second malignancy between 1964 and 2010 at the National Cancer Center Hospital of Japan.

RESULTS

Among 857 patients with retinoblastoma registered in the database, 10 (1.1%) developed osteosarcoma as a second malignancy. The median age at the onset of retinoblastoma was 3 months, being bilateral in nine patients and unilateral in one. Systemic chemoreduction was performed in three patients and intra-arterial chemotherapy in six; all patients received external beam radiotherapy. The median age at the onset of second primary osteosarcoma was 11.2 years; four were radiation-related and six were located in an extremity. Among five patients treated at our institute, four patients with tumors on an extremity were treated by wide resection with neoadjuvant and adjuvant chemotherapy. Three of these four patients (75%) were good responders to high-dose methotrexate-based multi-agent chemotherapy and survived with no evidence of disease (median follow-up period, 17.3 years). One patient whose temporal bone was affected underwent radiotherapy with chemotherapy but died after local recurrence.

CONCLUSIONS

The clinical outcomes of second primary osteosarcoma in an extremity occurring in retinoblastoma survivors may be more favorable than those of conventional osteosarcoma. Early diagnosis of radiation-related osteosarcoma arising in the craniofacial region should be made at a stage where complete resection is possible.

Phase II multicenter clinical trial of pulmonary metastasectomy and isolated lung perfusion with melphalan in patients with resectable lung metastases

INTRODUCTION

The 5-year overall survival rate of patients undergoing complete surgical resection of pulmonary metastases (PM) from colorectal cancer (CRC) and sarcoma remains low (20-50%). Local recurrence rate is high (48-66%). Isolated lung perfusion (ILuP) allows the delivery of high-dose locoregional chemotherapy with minimal systemic leakage to improve local control.

METHODS

From 2006 to 2011, 50 patients, 28 male, median age 57 years (15-76), with PM from CRC (n = 30) or sarcoma (n = 20) were included in a phase II clinical trial conducted in four cardiothoracic surgical centers. In total, 62 ILuP procedures were performed, 12 bilaterally, with 45 mg of melphalan at 37°C, followed by resection of all palpable PM. Survival was calculated according to the Kaplan-Meier method.

RESULTS

Operative mortality was 0%, and 90-day morbidity was mainly respiratory (grade 3: 42%, grade 4: 2%). After a median follow-up of 24 months (3-63 mo), 18 patients died, two without recurrence. Thirty patients had recurrent disease. Median time to local pulmonary progression was not reached. The 3-year overall survival and disease-free survival were 57% ± 9% and 36% ± 8%, respectively. Lung function data showed a decrease in forced expiratory volume in 1 second and diffusing capacity of the alveolocapillary membrane of 21.6% and 25.8% after 1 month, and 10.4% and 11.3% after 12 months, compared with preoperative values.

CONCLUSION

Compared with historical series of PM resection without ILuP, favorable results are obtained in terms of local control without long-term adverse effects. These data support the further investigation of ILuP as additional treatment in patients with resectable PM from CRC or sarcoma.

Tumor Suppressor WWOX inhibits osteosarcoma metastasis by modulating RUNX2 function

Osteosarcoma (OS) is among the most frequently occurring primary bone tumors, primarily affecting adolescents and young adults. This malignant osteoid forming tumor is characterized by its metastatic potential, mainly to lungs. We recently demonstrated that WW domain-containing oxidoreductase (WWOX) is frequently inactivated in human OS and that WWOX restoration in WWOX-negative OS cells suppresses tumorigenicity. Of note, WWOX levels are reduced in paired OS samples of post-treatment metastastectomies as compared to pre-treatment biopsies suggesting that decreased WWOX levels are associated with a more aggressive phenotype at the metastatic site. Nevertheless, little is known about WWOX function in OS metastasis. Here, we investigated the role of tumor suppressor WWOX in suppressing pulmonary OS metastasis bothin vitroandin vivo. We demonstrated that ectopic expression of WWOX in OS cells, HOS and LM-7, inhibits OS invasion and cell migration in vitro. Furthermore, WWOX expression reduced tumor burden in vivo and inhibited metastases’ seeding and colonization. Mechanistically, WWOX function is associated with reduced levels of RUNX2 metastatic target genes implicated in adhesion and motility. Our results suggest that WWOX plays a critical role in determining the aggressive phenotype of OS, and its expression could be an attractive therapeutic target to combat this devastating adolescent disease.

Hedgehog signaling inhibitors as anti-cancer agents in osteosarcoma

Osteosarcoma is a rare type of cancer associated with a poor clinical outcome. Even though the pathologic characteristics of OS are well established, much remains to be understood, particularly at the molecular signaling level. The molecular mechanisms of osteosarcoma progression and metastases have not yet been fully elucidated and several evolutionary signaling pathways have been found to be linked with osteosarcoma pathogenesis, especially the hedgehog signaling (Hh) pathway. The present review will outline the importance and targeting the hedgehog signaling (Hh) pathway in osteosarcoma tumor biology. Available data also suggest that aberrant Hh signaling has pro-migratory effects and leads to the development of osteoblastic osteosarcoma. Activation of Hh signaling has been observed in osteosarcoma cell lines and also in primary human osteosarcoma specimens. Emerging data suggests that interference with Hh signal transduction by inhibitors may reduce osteosarcoma cell proliferation and tumor growth thereby preventing osteosarcomagenesis. From this perspective, we outline the current state of Hh pathway inhibitors in osteosarcoma. In summary, targeting Hh signaling by inhibitors promise to increase the efficacy of osteosarcoma treatment and improve patient outcome.