Children's Oncology Group's 2013 blueprint for research: bone tumors

Inactivation of ICAM1 inhibits metastasis and improves the prognosis of Ewing's sarcoma

BACKGROUND

Ewing's sarcoma (ES) is a kind of malignant tumor, which often occurs in the long bone, pelvis, and other bone tissues, as well as some soft tissues. It often occurs in children and adolescents, second only to osteosarcoma and rhabdomyosarcoma. In the past 30 years, little progress has been made on the genomic mechanism of ES metastasis.

METHODS

The gene expression sequence of ES metastasis samples was compared with that of primary tumor samples to obtain differentially expressed genes (DEGs). Subsequently, we annotated the gene functions and enriched pathways of DEGs. Additionally, the protein and protein interaction network were constructed to screen key genes that can lead to the metastasis in ES. Then, cell and molecular biology experiments were conducted to verify the results obtained from the bioinformatics analysis. Finally, we assessed the correlation of expression between the key genes EWSR and FLI1, and conducted a survival analysis of ICAM1.

RESULTS

Our study revealed 153 DEGs. Of these, 82 (53.59%) were upregulated and the remaining 71 (46.41%) were downregulated. The bioinformatics analysis showed that ICAM1 was the key gene leading to the invasion and metastasis of ES. Through cell biology and molecular biology experiments, inactivation of ICAM1 inhibited the metastasis of ES cells. The survival and correlation analyses showed that ICAM1 was a risk factor in patients with ES, and that ICAM1 expression was correlated with EWSR and FLI1 expression.

CONCLUSION

Our study shows that inactivation of ICAM1 inhibits metastasis and improves the prognosis of ES. Additionally, our findings provide a better understanding of the underlying mechanisms of metastatic ES, a basis for an accurate diagnosis, and therapeutic targets for ES patients.

Oxyresveratrol induces apoptosis and inhibits cell viability via inhibition of the STAT3 signaling pathway in Saos‑2 cells

Oxyresveratrol (ORES) is a natural phenolic compound with multiple biological functions including antioxidation, anti-inflammation and neuroprotection; however, the inhibitory effect of ORES on osteosarcoma remains largely unknown. The present study aimed to determine the effects of ORES on osteosarcoma cell Saos-2. Cell Counting Kit-8 assay was performed to detect Soas-2 cell viability. Annexin-FITC/PI staining and JC-1 staining were used to measure cell apoptosis and the change of mitochondrial membrane potential. In addition, western blotting was conducted to determine the expression levels of apoptotic proteins and the phosphorylation of STAT3. It was found that ORES inhibited cell viability and induced apoptosis of osteosarcoma Saos-2 cells in a concentration-dependent manner. In addition, ORES increased the expression levels of apoptotic proteases caspase-9 and caspase-3 and reduced mitochondrial membrane potential. In response to ORES treatment, the expression levels of pro-apoptotic proteins, Bad and Bax, were enhanced, whereas those of anti-apoptotic proteins, Bcl-2 and Bcl-xL, were reduced. In addition, the phosphorylation of STAT3 was attenuated in Saos-2 cells after treatment with ORES. Inhibition of cell viability and apoptosis induction by ORES were rescued by enhancement of STAT3 activation upon treatment with IL-6. Collectively, the present study indicated that ORES induced apoptosis and inhibited cell viability, which may be associated with the inhibition of STAT3 activation; thus, ORES represents a promising agent for treating osteosarcoma.

Pharmacogenomics in Pediatric Oncology: Mitigating Adverse Drug Reactions While Preserving Efficacy

Cancer is the leading cause of death in American children older than 1 year of age. Major developments in drugs such as thiopurines and optimization in clinical trial protocols for treating cancer in children have led to a remarkable improvement in survival, from approximately 30% in the 1960s to more than 80% today. Short-term and long-term adverse effects of chemotherapy still affect most survivors of childhood cancer. Pharmacogenetics plays a major role in predicting the safety of cancer chemotherapy and, in the future, its effectiveness. Treatment failure in childhood cancer-due to either serious adverse effects that limit therapy or the failure of conventional dosing to induce remission-warrants development of new strategies for treatment. Here, we summarize the current knowledge of the pharmacogenomics of cancer drug treatment in children and of statistically and clinically relevant drug-gene associations and the mechanistic understandings that underscore their therapeutic value in the treatment of childhood cancer.

Fine Particulate Matter Air Pollution and Mortality among Pediatric, Adolescent, and Young Adult Cancer Patients

BACKGROUND

Air pollution is a carcinogen and causes pulmonary and cardiac complications. We examined the association of fine particulate matter pollution (PM_2.5) and mortality from cancer and all causes among pediatric, adolescent, and young adult (AYA) patients with cancer in Utah, a state with considerable variation in PM_2.5.

METHODS

We followed 2,444 pediatric (diagnosed ages 0-14) and 13,459 AYA (diagnosed ages 15-39) patients diagnosed in 1986-2015 from diagnosis to 5 and 10 years postdiagnosis, death, or emigration. We measured average monthly PM_2.5 by ZIP code during follow-up. Separate pediatric and AYA multivariable Cox models estimated the association of PM_2.5 and mortality. Among AYAs, we examined effect modification of PM_2.5 and mortality by stage while controlling for cancer type.

RESULTS

Increases in PM_2.5 per 5 μg/m³ were associated with cancer mortality in pediatric lymphomas and central nervous system (CNS) tumors at both time points, and all cause mortality in lymphoid leukemias [HR_5-year = 1.32 (1.02-1.71)]. Among AYAs, PM_2.5 per 5 μg/m³ was associated with cancer mortality in CNS tumors and carcinomas at both time points, and all cause mortality for all AYA cancer types [HR_5-year = 1.06 (1.01-1.13)]. PM_2.5 ≥12 μg/m³ was associated with cancer mortality among breast [HR_5-year = 1.50 (1.29-1.74); HR_10-year = 1.30 (1.13-1.50)] and colorectal cancers [HR_5-year = 1.74 (1.29-2.35); HR_10-year = 1.67 (1.20-2.31)] at both time points. Effect modification by stage was significant, with local tumors at highest risk.

CONCLUSIONS

PM_2.5 was associated with mortality in pediatric and AYA patients with specific cancers.

IMPACT

Limiting PM_2.5 exposure may be important for young cancer patients with certain cancers.See all articles in this CEBP Focus section, "Environmental Carcinogenesis: Pathways to Prevention."

An evolutionary framework for treating pediatric sarcomas

Lessons from extinction can be used in trials designed to pursue a cure for cancer. When cancer cannot be cured, similar strategies may be unwise, and strategies that leverage the adaptations of cancer to therapy should be considered.

Precision medicine in Ewing sarcoma: a translational point of view

Ewing sarcoma is a rare tumor that arises in bones of children and teenagers but, in 15% of the patients it is presented as a primary soft tissue tumor. Balanced reciprocal chimeric translocation t(11;22)(q24;q12), which encodes an oncogenic protein fusion (EWSR1/FLI1), is the most generalized and characteristic molecular event. Using conventional treatments, (chemotherapy, surgery and radiotherapy) long-term overall survival rate is 30% for patients with disseminated disease and 65-75% for patients with localized tumors. Urgent new effective drug development is a challenge. This review summarizes the preclinical and clinical investigational knowledge about prognostic and targetable biomarkers in Ewing sarcoma, finally suggesting a workflow for precision medicine committees.

Hippo pathway effectors YAP1/TAZ induce an EWS-FLI1-opposing gene signature and associate with disease progression in Ewing sarcoma

YAP1 and TAZ (WWTR1) oncoproteins are the final transducers of the Hippo tumor suppressor pathway. Deregulation of the pathway leads to YAP1/TAZ activation fostering tumorigenesis in multiple malignant tumor types, including sarcoma. However, oncogenic mutations within the core components of the Hippo pathway are uncommon. Ewing sarcoma (EwS), a pediatric cancer with low mutation rate, is characterized by a canonical fusion involving the gene EWSR1 and FLI1 as the most common partner. The fusion protein is a potent driver of oncogenesis, but secondary alterations are scarce, and little is known about other biological factors that determine the risk of relapse or progression. We have observed YAP1/TAZ expression and transcriptional activity in EwS cell lines. Analyses of 55 primary human EwS samples revealed that high YAP1/TAZ expression was associated with progression of the disease and predicted poorer outcome. We did not observe recurrent SNV or copy number gains/losses in Hippo pathway-related loci. However, differential CpG methylation of the RASSF1 locus (a regulator of the Hippo pathway) was observed in EwS cell lines compared with mesenchymal stem cells, the putative cell of origin of EwS. Hypermethylation of RASSF1 correlated with the transcriptional silencing of the tumor suppressor isoform RASFF1A, and transcriptional activation of the pro-tumorigenic isoform RASSF1C, which promotes YAP1/TAZ activation. Knockdown of YAP1/TAZ decreased proliferation and invasion abilities of EwS cells and revealed that YAP1/TAZ transcription activity is inversely correlated with the EWS-FLI1 transcriptional signature. This transcriptional antagonism could be explained partly by EWS-FLI1-mediated transcriptional repression of TAZ. Thus, YAP1/TAZ may override the transcriptional program induced by the fusion protein, contributing to the phenotypic plasticity determined by dynamic fluctuation of the fusion protein, a recently proposed model for disease dissemination in EwS. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Bioengineered miR-328-3p modulates GLUT1-mediated glucose uptake and metabolism to exert synergistic antiproliferative effects with chemotherapeutics

MicroRNAs (miRNAs or miRs) are small noncoding RNAs derived from genome to control target gene expression. Recently we have developed a novel platform permitting high-yield production of bioengineered miRNA agents (BERA). This study is to produce and utilize novel fully-humanized BERA/miR-328-3p molecule (hBERA/miR-328) to delineate the role of miR-328-3p in controlling nutrient uptake essential for cell metabolism. We first demonstrated successful high-level expression of hBERA/miR-328 in bacteria and purification to high degree of homogeneity (>98%). Biologic miR-328-3p prodrug was selectively processed to miR-328-3p to suppress the growth of highly-proliferative human osteosarcoma (OS) cells. Besides glucose transporter protein type 1, gene symbol solute carrier family 2 member 1 (GLUT1/SLC2A1), we identified and verified large neutral amino acid transporter 1, gene symbol solute carrier family 7 member 5 (LAT1/SLC7A5) as a direct target for miR-328-3p. While reduction of LAT1 protein levels by miR-328-3p did not alter homeostasis of amino acids within OS cells, suppression of GLUT1 led to a significantly lower glucose uptake and decline in intracellular levels of glucose and glycolytic metabolite lactate. Moreover, combination treatment with hBERA/miR-328 and cisplatin or doxorubicin exerted a strong synergism in the inhibition of OS cell proliferation. These findings support the utility of novel bioengineered RNA molecules and establish an important role of miR-328-3p in the control of nutrient transport and homeostasis behind cancer metabolism.

Alterations in Muscle Architecture: A Review of the Relevance to Individuals After Limb Salvage Surgery for Bone Sarcoma

Osteosarcoma and Ewing's sarcoma are the most common primary bone malignancies affecting children and adolescents. Optimal treatment requires a combination of chemotherapy and/or radiation along with surgical removal when feasible. Advances in multiple aspects of surgical management have allowed limb salvage surgery (LSS) to supplant amputation as the most common procedure for these tumors. However, individuals may experience significant impairment after LSS, including deficits in range of motion and strength that limit function and impact participation in work, school, and the community, ultimately affecting quality of life. Muscle force and speed of contraction are important contributors to normal function during activities such as gait, stairs, and other functional tasks. Muscle architecture is the primary contributor to muscle function and adapts to various stimuli, including periods of immobilization-protected weightbearing after surgery. The impacts of LSS on muscle architecture and how adaptations may impact deficits within the rehabilitation period and into long-term survivorship is not well-studied. The purpose of this paper is to [1] provide relevant background on bone sarcomas and LSS, [2] highlight the importance of muscle architecture, its measurement, and alterations as seen in other relevant populations and [3] discuss the clinical relevance of muscle architectural changes and the impact on muscle dysfunction in this population. Understanding the changes that occur in muscle architecture and its impact on long-term impairments in bone sarcoma survivors is important in developing new rehabilitation treatments that optimize functional outcomes.

TRIM3 Negatively Regulates Autophagy Through Promoting Degradation of Beclin1 in Ewing Sarcoma Cells

Background and aim

Ewing sarcoma (ES) is an aggressive neoplasm predominantly occurring in adolescents and has a poor prognosis when metastasized. In the current study, we were aiming to investigate the function of TRIM3 in autophagy in ES cells.

Methods

The expression of TRIM3 in Ewing sarcoma tissues and normal tissues was examined by quantitative PCR and western blot. The effect of TRIM3 on autophagy was detected by western blot and immunofluorescence assay. Target of TRIM3 was examined by western blot, immunoprecipitation and ubiquitination assay.

Results

We found the expression of TRIM3 was significantly up-regulated in Ewing sarcoma tissues compared with normal tissues, and this phenomenon was regulated by EWS-FLI1 expression. Furthermore, we observed that overexpression of TRIM3 markedly and consistently inhibited autophagy in ES cells, and autophagy was enhanced in TRIM3-silenced ES cells. Finally, we found in ES cells, TRIM3 could directly interact with Beclin1, and improved its K48-linked polyubiquitinaion, leading to the degradation of Beclin1 and then regulated autophagy.

Conclusion

In the present research, for the first time we revealed that TRIM3 negatively regulates autophagy through promoting degradation of Beclin1 in Ewing sarcoma cells, and these findings may provide ideas for ES research.

Small molecule inhibition of lysine-specific demethylase 1 (LSD1) and histone deacetylase (HDAC) alone and in combination in Ewing sarcoma cell lines

Ewing Sarcoma (ES) is characterized by recurrent translocations between EWSR1 and members of the ETS family of transcription factors. The transcriptional activity of the fusion oncoprotein is dependent on interaction with the nucleosome remodeling and deactylase (NuRD) co-repressor complex. While inhibitors of both histone deacetylase (HDAC) and lysine-specific demethylase-1 (LSD1) subunits of the NuRD complex demonstrate single agent activity in preclinical models, combination strategies have not been investigated. We selected 7 clinically utilized chemotherapy agents, or active metabolites thereof, for experimentation: doxorubicin, cyclophosphamide, vincristine, etoposide and irinotecan as well as the HDAC inhibitor romidepsin and the reversible LSD1 inhibitor SP2509. All agents were tested at clinically achievable concentrations in 4 ES cell lines. All possible 2 drug combinations were then tested for potential synergy. Order of addition of second-line conventional combination therapy agents was tested with the addition of SP2509. In two drug experiments, synergy was observed with several combinations, including when SP2509 was paired with topoisomerase inhibitors or romidepsin. Addition of SP2509 after treatment with second-line combination therapy agents enhanced treatment effect. Our findings suggest promising combination treatment strategies that utilize epigenetic agents in ES.

Histologic Response and Toxicity following Interval-Compressed Four-Drug Therapy Given Preoperatively in Children and Young Adults with Osteosarcoma: A Retrospective Study

OBJECTIVES

The histologic response to chemotherapy is an important prognostic factor in osteosarcoma. Thus, we attempted to develop an effective neoadjuvant regimen to achieve an improvement in histologic response.

METHODS

Twenty-nine patients with a high-grade osteosarcoma received 2 courses of neoadjuvant chemotherapy non-randomly with either the MAP regimen (methotrexate 12 g/m2, cisplatin 120 mg/m2, and doxorubicin 75 mg/m2) or MAPI regimen (MAP plus ifosfamide 9 g/m2). We applied interval compression to MAPI by shortening the preoperative period to be aligned with that of MAP. Adjuvant chemotherapy was tailored according to the necrosis rate of resected tumor specimens. Necrosis rate, toxicity, and survival outcome were compared retrospectively between the 2 groups.

RESULTS

The median interval between the beginning of neoadjuvant chemotherapy and surgery was 97.0 days in the MAPI group (17 patients) and 90.5 days in the MAP group (12 patients; p = 0.19). The good histologic response (>90% of necrosis) was observed in 71% of MAPI and in 42% of MAP (p = 0.12). Major toxicities of grade 3 or worse were not different between the 2 groups. The probability of 5-year progression-free survival and overall survival of the MAPI group were 74 and 83%, and those in the MAP group were 50 and 75%, showing no difference.

CONCLUSIONS

Interval-compressed MAPI therapy given in a similar duration of the preoperative phase to that of conventional MAP therapy showed a marginal trend toward a better histologic response without a significant increase in major toxicities. Regarding the proportion of good histologic response, 71% is one of the highest values ever reported in the literature. The results warrant further testing in a prospective way in a larger cohort.

Provocative questions in osteosarcoma basic and translational biology: A report from the Children's Oncology Group

Patients who are diagnosed with osteosarcoma (OS) today receive the same therapy that patients have received over the last 4 decades. Extensive efforts to identify more effective or less toxic regimens have proved disappointing. As we enter a postgenomic era in which we now recognize OS not as a cancer of mutations but as one defined by p53 loss, chromosomal complexity, copy number alteration, and profound heterogeneity, emerging threads of discovery leave many hopeful that an improving understanding of biology will drive discoveries that improve clinical care. Under the organization of the Bone Tumor Biology Committee of the Children's Oncology Group, a team of clinicians and scientists sought to define the state of the science and to identify questions that, if answered, have the greatest potential to drive fundamental clinical advances. Having discussed these questions in a series of meetings, each led by invited experts, we distilled these conversations into a series of seven Provocative Questions. These include questions about the molecular events that trigger oncogenesis, the genomic and epigenomic drivers of disease, the biology of lung metastasis, research models that best predict clinical outcomes, and processes for translating findings into clinical trials. Here, we briefly present each Provocative Question, review the current scientific evidence, note the immediate opportunities, and speculate on the impact that answered questions might have on the field. We do so with an intent to provide a framework around which investigators can build programs and collaborations to tackle the hardest problems and to establish research priorities for those developing policies and providing funding.

Survival Differences Between Males and Females Diagnosed With Childhood Cancer

BACKGROUND

Males have worse survival for childhood cancer, but whether this disparity exists among all childhood cancer types is undescribed.

METHODS

We estimated sex differences in survival for 18 cancers among children (0-19 years) in Surveillance, Epidemiology, and End Results 18 (2000-2014). We used Kaplan-Meier survival curves (log-rank P values) to characterize sex differences in survival and Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between sex and death for each cancer type. We used an inverse odds weighting method to determine whether the association between sex and death was mediated by stage of disease for solid tumors.

RESULTS

Males had worse overall survival and a higher risk of death for acute lymphoblastic leukemia (HR = 1.24, 95% CI = 1.12 to 1.37), ependymoma (HR = 1.36, 95% CI = 1.05 to 1.77), neuroblastoma (HR = 1.28, 95% CI = 1.09 to 1.51), osteosarcoma (HR = 1.29, 95% CI = 1.08 to 1.53), thyroid carcinoma (HR = 3.25, 95% CI = 1.45 to 7.33), and malignant melanoma (HR = 1.97, 95% CI = 1.33 to 2.92) (all log-rank P values < .02). The association between sex and death was mediated by stage of disease for neuroblastoma (indirect HR = 1.12, 95% CI = 1.05 to 1.19), thyroid carcinoma (indirect HR = 1.24, 95% CI = 1.03 to 1.48), and malignant melanoma (indirect HR = 1.28, 95% CI = 1.10 to 1.49). For these six tumors, if male survival had been as good as female survival, 21% of male deaths and 13% of total deaths after these cancer diagnoses could have been avoided.

CONCLUSIONS

Consideration of molecular tumor and clinical data may help identify mechanisms underlying the male excess in death after childhood cancer for the aforementioned cancers.

Bad to the Bone: The Role of the Insulin-Like Growth Factor Axis in Osseous Metastasis

Bone metastases are a frequent complication of cancer that are associated with considerable morbidity. Current treatments may temporarily palliate the symptoms of bone metastases but often fail to delay their progression. Bones provide a permissive environment because they are characterized by dynamic turnover, secreting factors required for bone maintenance but also stimulating the establishment and growth of metastases. Insulin-like growth factors (IGF) are the most abundant growth factors in bone and are required for normal skeletal development and function. Via activation of the IGF-1 receptors (IGF-1R) and variant insulin receptors, IGFs promote cancer progression, aggressiveness, and treatment resistance. Of specific relevance to bone biology, IGFs contribute to the homing, dormancy, colonization, and expansion of bone metastases. Furthermore, preclinical evidence suggests that tumor cells can be primed to metastasize to bone by a high IGF-1 environment in the primary tumor, suggesting that bone metastases may reflect IGF dependency. Therapeutic targeting of the IGF axis may therefore provide an effective method for treating bone metastases. Indeed, anti-IGF-1R antibodies, IGF-1R tyrosine kinase inhibitors, and anti-IGF-1/2 antibodies have demonstrated antitumor activity in preclinical models of prostate and breast cancer metastases, either alone or in combination with other agents. Several studies suggest that such treatments can inhibit bone metastases without affecting growth of the primary tumor. Although previous trials of anti-IGF-1R drugs have generated negative results in unselected patients, these considerations suggest that future clinical trials of IGF-targeted agents may be warranted in patients with bone metastases.

Treatment Outcomes of Pediatric Patients With Ewing Sarcoma in a War-Torn Nation: A Single-Institute Experience From Iraq

PURPOSE

Ewing sarcoma (ES) is a relatively rare, highly malignant tumor of the musculoskeletal system. It is the second most common malignant bone tumor in children and adolescents in the age group of 5 to 20 years. The aim of this study was to identify the treatment outcomes of pediatric patients with ES in Sulaimani governorate, Iraq.

PATIENTS AND METHODS

This was a retrospective study that reviewed the medical records of pediatric patients with ES who were managed between 2009 and 2015, with follow-up until late 2017. Patient- and tumor-related factors were correlated with clinical outcomes.

RESULTS

A total of 31 pediatric patients with ES were included in this study. All the patients received chemotherapy and radiotherapy, whereas only 14 patients underwent surgical resection and just eight had free surgical margins. The median age at diagnosis was 13 years, 58% were male, and 42% were female. The presenting symptoms at diagnosis were mostly pain (67.7%) and palpable mass (25.8%). The primary tumor was located in the extremities (51.6%), the thoracic cage (19.4%), the pelvis (16.1%), and the lumbar vertebrae (12.9%). Approximately two thirds of the patients (61.3%) had localized disease at the time of presentation. The 5-year overall survival was 19%, and the 5-year recurrence-free survival was 34%.

CONCLUSION

Clinical outcomes of ES in pediatric patients in our war-torn nation, Iraq, are still markedly inferior to the published outcomes from stable, developed nations. Additional large and multicenter national studies are required. Diagnostic and therapeutic measures need improvement, and multidisciplinary and comprehensive cancer-integrated approaches are vital for better outcomes.

USP19 deubiquitinates EWS-FLI1 to regulate Ewing sarcoma growth

Ewing sarcoma is the second most common pediatric bone and soft tissue tumor presenting with an aggressive behavior and prevalence to metastasize. The diagnostic translocation t(22;11)(q24;12) leads to expression of the chimeric oncoprotein EWS-FLI1 which is uniquely expressed in all tumor cells and maintains their survival. Constant EWS-FLI1 protein turnover is regulated by the ubiquitin proteasome system. Here, we now identified ubiquitin specific protease 19 (USP19) as a regulator of EWS-FLI1 stability using an siRNA based screening approach. Depletion of USP19 resulted in diminished EWS-FLI1 protein levels and, vice versa, upregulation of active USP19 stabilized the fusion protein. Importantly, stabilization appears to be specific for the fusion protein as it could not be observed neither for EWSR1 nor for FLI1 wild type proteins even though USP19 binds to the N-terminal EWS region to regulate deubiquitination of both EWS-FLI1 and EWSR1. Further, stable shUSP19 depletion resulted in decreased cell growth and diminished colony forming capacity in vitro, and significantly delayed tumor growth in vivo. Our findings not only provide novel insights into the importance of the N-terminal EWSR1 domain for regulation of fusion protein stability, but also indicate that inhibition of deubiquitinating enzyme(s) might constitute a novel therapeutic strategy in treatment of Ewing sarcoma.

Successful Treatment of Osteosarcoma Without Methotrexate in a 13-Year-Old Boy With Down Syndrome

Osteosarcoma is the most common primary bone tumor in children, and only 1 article in the literature describes a case of osteosarcoma in a patient with Down syndrome. Although osteosarcoma is generally treated with chemotherapy regimens that include high-dose methotrexate, patients with Down syndrome have heightened sensitivity to the toxicities of methotrexate. The patient from the aforementioned case study died from sepsis soon after treatment with high-dose methotrexate. This case report describes the successful treatment of osteosarcoma in a pediatric patient with Down syndrome without methotrexate.

Multi-level otsu method to define metabolic tumor volume in positron emission tomography

This study was to validate reliability and clinical utility of a PET tumor segmentation method using multi-level Otsu (MO-PET) in standard National Electrical Manufacturers Association (NEMA) image quality (IQ) phantom and patients with osteosarcoma. The NEMA IQ phantom was prepared with a lesion-to-background ratio (LBR) of either 8:1, 4:1, or 1.5:1. The artificial lesions in the phantom were segmented using MO-PET, gradient-based method (PETedge), relative threshold methods, and background threshold methods. Metabolic tumor volumes (MTVs) using MO-PET and PETedge were named as MTV (MO-PET) and MTV (PETedge), respectively. Among the MTVs using multiple methods, only MTV (MO-PET) and MTV (PETedge) showed excellent agreements with the actual volume of NEMA IQ phantom across the different LBRs (intraclass correlation coefficient, ICC = 0.987, 0.985 in LBR 8:1, 0.981, 0.993 in LBR 4:1 and 0.947, 0.994 in LBR 1.5:1). Repeated measurements of MTV (MO-PET) of the primary tumors showed excellent reproducibility with ICC of 0.994 (0.989-0.997) in patients with osteosarcoma. Also, MTV (MO-PET) was found to be predictive of Event Free Survival (EFS) [Hazard ratio (95% CI) = 6.1 (2.1-17.2), log rank P = 0.0003] in patients with osteosarcoma. We have validated in NEMA IQ phantom that the MTV (MO-PET) is accurate, and importantly, stable and consistent across a range of lesion sizes and LBRs representative of clinical tumor lesions. Furthermore, MTV (MO-PET) showed excellent reproducibility and was predictive for EFS in patients with osteosarcoma.

Preparation of adriamycin gelatin microsphere-loaded decellularized periosteum that is cytotoxic to human osteosarcoma cells

The purpose of this study was to develop a novel approach to treat bone osteosarcoma using a multipurpose scaffold aiming for local drug delivery. The slowly releasing microspheres was designed to deliver the chemotherapy drug adriamycin (ADM) and a decellularized (D) periosteum scaffold (which is known to be able to promote bone regeneration) was used to carry these microspheres. D-periosteum was obtained by physical and chemical decellularization. Histological results showed that the cellular components were effectively removed. The D-periosteum showed an excellent cytocompatibility and the ability to promote adhesion and growth of fibroblasts. Two kinds of slowly releasing microspheres, adriamycin gelatin microspheres (ADM-GMS) and adriamycin poly (dl-lactide-co-glycolide) gelatin microspheres (ADM-PLGA-GMS), were prepared and anchored to D-periosteum, resulting in two types of drug-releasing regenerative scaffolds. The effectiveness of these two scaffolds in killing human osteosarcoma cells was tested by evaluating cell viability overtime of the cancer cells cultured with the scaffolds. In summary, a gelatin/decellularized periosteum-based biologic scaffold material was designed aiming for local delivery of chemotherapy drugs for osteosarcoma, with the results showing ability of the scaffolds in sustaining release of the cancer drug and in suppressing growth of the cancer cells in vitro.

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.

Ewing's Sarcoma of the Head and Neck: Margins are not just for surgeons

Background, Methods

To describe the characteristics, treatments (systemic/local), and outcome (oncological/functional) of French patients with head and neck Ewing's sarcomas (HNES) registered in the Euro‐Ewing 99 (EE99) database. Specific patient‐level data were reviewed retrospective.

Results

Forty‐seven HNES patients in the EE99 database had a median age of 11 years, 89% had bone tumors (skull 55%, mandible 21%, maxilla 11%), 89% had small tumors (<200 mL), and they were rarely metastatic (9%). Local treatment was surgery radiotherapy (55%), exclusively surgery (28%), or radiotherapy (17%). Metastatic relapses occurred in five patients with high relapse risk factors (metastasis at diagnosis, poor histological response, large tumors). Local progression/relapses (LR) after exclusive radiotherapy occurred in three patients with persistent extra‐osseous residue and in four patients considered R0 margins (postchemotherapy surgery, without postoperative radiotherapy [PORT]), reclassified by pathological review as R1a. Pathological review reclassified 72% of R0 margins: 11/18 to R1a and 2/18 to R2. Five patients had confirmed R0 margins after postchemotherapy surgery without PORT and had no LR Eight patients had R2 margins (initial surgery without previous chemotherapy, with PORT) and had no LR With a median follow‐up of 9.3 years, the 3‐year LR rate, EFS, and OS were 84.8%, 78.6%, and 89.3%, respectively. Among the 5‐year survivors, 88% had long‐term sequelae.

Conclusion

To optimize HNES management, patients should be treated from diagnosis in expert centers with multidisciplinary committees to discuss treatment strategy (type of surgery, need for PORT) and validate surgical margins.

The Children's Oncology Group: Organizational Structure, Membership, and Institutional Characteristics

BACKGROUND

The Children's Oncology Group (COG) is the only organization within the National Cancer Institute's National Clinical Trials Network dedicated exclusively to pediatric cancer research. The purpose of this article is to provide an overview of COG's organizational structure, to characterize its institutional and individual membership, and to summarize enrollments onto COG clinical trials.

METHOD

Data from 2013 to 2015 were compiled from sources internal (Network Operations, Statistics and Data Center, Chair's Office) and external (American Hospital Association, American Nurses Credentialing Center) to COG, to present a comprehensive overview of COG's structure, individual and institutional membership, and group operations.

RESULTS

In 2016, COG comprised 8,785 individuals from 223 member institutions, across seven countries. An average of 9,661 new patients were registered with COG per year over the most recent (2013-2015) 3-year period. Over the same 3-year time frame, there were an average of 16,836 enrollments onto therapeutic (i.e., treatment) and nontherapeutic (e.g., epidemiology, survivorship, biology) trials per year.

CONCLUSIONS

COG institutions have diverse characteristics related to size, geographical location, and infrastructure. Individual membership also reflects diversity with representation from over 28 disciplines and groups. The diversity of COG institutions and individual members allows for unique perspectives and contributions to science unified under a common goal to enroll children/adolescents onto clinical trials. COG's collaborative, multidisciplinary approach to science functions to support the development of research that seeks to continually improve outcomes for children and adolescents with cancer.

Re‑irradiation plus hyperthermia for recurrent pediatric sarcoma; a simulation study to investigate feasibility

Recurrent pediatric tumors pose a challenge since treatment options may be limited, particularly after previous irradiation. Positive results have been reported for chemotherapy and hyperthermia, but the combination of re‑irradiation and hyperthermia has not been investigated thus far, although it is a proven treatment strategy in adults. The theoretical feasibility of re‑irradiation plus hyperthermia was investigated for infield recurrent pediatric sarcoma in the pelvic region and the extremities. A total of 46 recurrent pediatric sarcoma cases diagnosed at the Academic Medical Center (Amsterdam, The Netherlands) between 2002 and 2017 were evaluated. Patients not previously irradiated, outfield recurrences and locations other than the pelvis and extremities were excluded, ultimately yielding four eligible patients: Two with sarcomas in the pelvis and two in an extremity. Re‑irradiation and hyperthermia treatment plans were simulated for 23x2 Gy treatment schedules and weekly hyperthermia. The radiosensitizing effect of hyperthermia was quantified using biological modelling with a temperature‑dependent change in the parameters of the linear‑quadratic model. The possible effectiveness of re‑irradiation plus hyperthermia was estimated by calculating the equivalent radiotherapy dose distribution. Treatment planning revealed that tumors located in the pelvis and the extremities can be effectively heated in children. Equivalent dose distributions indicated that hyperthermic radiosensitization can be quantified as a target‑selective additional D95% of typically 10 Gy, thereby delivering a possibly curative dose of 54 Gy, without substantially increasing the equivalent dose to the organs at risk. Therefore, re‑irradiation plus hyperthermia is a theoretically feasible and possibly effective treatment option for recurrent pediatric sarcoma in the pelvic region and the extremities, and its clinical feasibility is worthy of evaluation.

Downregulation of microRNA‑660 inhibits cell proliferation and invasion in osteosarcoma by directly targeting forkhead box O1

The abnormal expression of microRNAs (miRNAs/miRs) has been observed in osteosarcoma (OS), and these differently expressed miRNAs contribute to the occurrence and development of OS by regulating various biological behaviours. Therefore, a comprehensive understanding of the detailed roles of aberrantly expressed miRNAs in OS progression may be favourable to the identification of promising therapeutic strategies for the treatment of patients with this malignancy. The present study demonstrated that miR‑660‑5p (miR‑660) expression was significantly upregulated in OS tissues and cell lines compared with that in normal adjacent tissues and normal human osteoblast hFOB1.19, respectively. miR‑660 downregulation led to a significant decrease in the proliferation and invasion of OS cells. Forkhead box O1 (FOXO1) was predicted as a potential target of miR‑660. The subsequent luciferase reporter assay indicated that miR‑660 directly binds to the 3'‑untranslated region of FOXO1. Furthermore, miR‑660 inhibition increased the FOXO1 expression in OS cells at mRNA and protein levels. Moreover, FOXO1 was downregulated in OS tissues and this downregulation was negatively correlated with miR‑660 levels. Besides, rescue experiments demonstrated that FOXO1 knockdown abolished the effects of miR‑660 knockdown on OS cell proliferation and invasion. These results suggest that miR‑660 may serve oncogenic roles in OS by directly targeting FOXO1. Targeting miR‑660 may be an effective candidate for the treatment of patients with OS.

miR-26a suppresses osteosarcoma migration and invasion by directly targeting HMGA1

Osteosarcoma (OS) is identified as the most commonly diagnosed malignant cancer of bone, and has approximately three million new cases annually. miR-26a plays an important role in the development of various types of cancer. We investigated whether miR-26a can regulate the migration and invasion of OS by targeting high-mobility group A1 HMGA1. Western blot analysis was used to identify the changes of protein levels. Reverse transcription-quantitative PCR was used to test expression levels of genes and miR-26a. Luciferase reporter assay was used to test the specific target gene of miR-26a. Transwell assay was employed to determine the migration and invasion of OS cell lines. In the present study, miRNA-26a was frequently downregulated in OS tissues and cells. Overexpression of miR-26a inhibited cell migration and invasion in vitro. In addition, miR-26a downregulated HMGA1 by targeting its 3′-UTR and knockdown of HMGA1 significantly suppressed the migration and invasion of two osteosarcoma cell lines in vitro. miR-26a suppressed the migration and invasion of OS cells by targeting HMGA1, suggesting that miR-26a/HMGA1 axis provides a new prospective therapeutic strategy for OS.

Disruption of mammalian SWI/SNF and polycomb complexes in human sarcomas: mechanisms and therapeutic opportunities

Soft-tissue sarcomas are increasingly characterized and subclassified by genetic abnormalities that represent underlying drivers of their pathology. Hallmark tumor suppressor gene mutations and pathognomonic gene fusions collectively account for approximately one-third of all sarcomas. These genetic abnormalities most often result in global transcriptional misregulation via disruption of protein regulatory complexes which govern chromatin architecture. Specifically, alterations to mammalian SWI/SNF (mSWI/SNF or BAF) ATP-dependent chromatin remodeling complexes and polycomb repressive complexes cause disease-specific changes in chromatin architecture and gene expression across a number of sarcoma subtypes. Understanding the functions of chromatin regulatory complexes and the mechanisms underpinning their roles in oncogenesis will be required for the design and development of new therapeutic strategies in sarcomas. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Co-targeting of DNA, RNA, and protein molecules provides optimal outcomes for treating osteosarcoma and pulmonary metastasis in spontaneous and experimental metastasis mouse models

Metastasis is a major cause of mortality for cancer patients and remains as the greatest challenge in cancer therapy. Driven by multiple factors, metastasis may not be controlled by the inhibition of single target. This study was aimed at assessing the hypothesis that drugs could be rationally combined to co-target critical DNA, RNA and protein molecules to achieve saturation attack against metastasis. Independent actions of the model drugs DNA-intercalating doxorubicin, RNA-interfering miR-34a and protein-inhibiting sorafenib on DNA replication, RNA translation and protein kinase signaling in highly metastatic, human osteosarcoma 143B cells were demonstrated by the increase of? H2A.X foci formation, reduction of c-MET expression and inhibition of Erk1/2 phosphorylation, respectively, and optimal effects were found for triple-drug combination. Consequently, triple-drug treatment showed a strong synergism in suppressing 143B cell proliferation and the greatest effects in reducing cell invasion. Compared to single- and dual-drug treatment, triple-drug therapy suppressed pulmonary metastases and orthotopic osteosarcoma progression to significantly greater degrees in orthotopic osteosarcoma xenograft/spontaneous metastases mouse models, while none showed significant toxicity. In addition, triple-drug therapy improved the overall survival to the greatest extent in experimental metastases mouse models. These findings demonstrate co-targeting of DNA, RNA and protein molecules as a novel therapeutic strategy for the treatment of metastasis.

Murine models of osteosarcoma: A piece of the translational puzzle

Osteosarcoma (OS) is the most common cancer of bone in children and young adults. Despite extensive research efforts, there has been no significant improvement in patient outcome for many years. An improved understanding of the biology of this cancer and how genes frequently mutated contribute to OS may help improve outcomes for patients. While our knowledge of the mutational burden of OS is approaching saturation, our understanding of how these mutations contribute to OS initiation and maintenance is less clear. Murine models of OS have now been demonstrated to be highly valid recapitulations of human OS. These models were originally based on the frequent disruption of p53 and Rb in familial OS syndromes, which are also common mutations in sporadic OS. They have been applied to significantly improve our understanding about the functions of recurrently mutated genes in disease. The murine models can be used as a platform for preclinical testing and identifying new therapeutic targets, in addition to testing the role of additional mutations in vivo. Most recently these models have begun to be used for discovery based approaches and screens, which hold significant promise in furthering our understanding of the genetic and therapeutic sensitivities of OS. In this review, we discuss the mouse models of OS that have been reported in the last 3-5 years and newly identified pathways from these studies. Finally, we discuss the preclinical utilization of the mouse models of OS for identifying and validating actionable targets to improve patient outcome.

miR-30d inhibits cell biological progression of Ewing's sarcoma by suppressing the MEK/ERK and PI3K/Akt pathways in vitro

MicroRNAs (miRNAs) are small, single-stranded, non-coding RNA molecules involved in cancer initiation and progression. The present study aimed to determine the effect of miRNA-30d (miR-30d) on the growth, malignant phenotype, and apoptosis of Ewing's sarcoma (ES) SK-ES-1 cells, and to elucidate the underlying molecular mechanism and signaling pathway involved. Cell proliferation, invasion, migration, morphological changes, cell cycle distribution and apoptosis were investigated. Furthermore, the expression of matrix metalloproteinase (MMP)-2, MMP-9, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase-3 and poly (ADP-ribose) polymerase (PARP) were examined, as was the activity of the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) and phosphoinositide 3-kinase (PI3K)/Akt pathways. It was found that the overexpression of miR-30d repressed the proliferation, migration and invasion, and promoted morphological changes, S-phase arrest and apoptosis of SK-ES-1 cells. Additionally, it was observed that increased miR-30d levels inhibited the expression of MMP-2 and MMP-9, and inhibited the activity of the MEK/ERK and PI3K/Akt pathways, but elevated the ratio of Bax/Bcl-2 and the cleavage of caspase-3 and PARP. Taken together, the results demonstrated that miR-30d suppressed the biological progression of SK-ES-1 cells by targeting MMP-2 and MMP9, the Bax/Bcl-2 and caspase-3 cascade, and the MEK/ERK and PI3K/Akt signaling pathways. Therefore, miR-30d is a promising target in the treatment of ES. However, further investigations are urgently required to investigate the underlying molecular mechanisms of the effects of miR-30d on ES for a comprehensive understanding of the tumorigenesis and progression of this cancer.

ΔNp63 mediates cellular survival and metastasis in canine osteosarcoma

p63 is a structural homolog within the 53 family encoding two isoforms, ΔNp63 and TAp63. The oncogenic activity of ΔNp63 has been demonstrated in multiple cancers, however the underlying mechanisms that contribute to tumorigenesis are poorly characterized. Osteosarcoma (OSA) is the most common primary bone tumor in dogs, exhibiting clinical behavior and molecular biology essentially identical to its human counterpart. The purpose of this study was to evaluate the potential contribution of ΔNp63 to the biology of canine OSA. As demonstrated by qRT-PCR, nearly all canine OSA cell lines and tissues overexpressed ΔNp63 relative to normal control osteoblasts. Inhibition of ΔNp63 by RNAi selectively induced apoptosis in the OSA cell lines overexpressing ΔNp63. Knockdown of ΔNp63 upregulated expression of the proapoptotic Bcl-2 family members Puma and Noxa independent of p53. However the effects of ΔNp63 required transactivating isoforms of p73, suggesting that ΔNp63 promotes survival in OSA by repressing p73-dependent apoptosis. In addition, ΔNp63 modulated angiogenesis and invasion through its effects on VEGF-A and IL-8 expression, and STAT3 phosphorylation. Lastly, the capacity of canine OSA cell lines to form pulmonary metastasis was directly related to expression levels of ΔNp63 in a murine model of metastatic OSA. Together, these data demonstrate that ΔNp63 inhibits apoptosis and promotes metastasis, supporting continued evaluation of this oncogene as a therapeutic target in both human and canine OSA.

BO-1055, a novel DNA cross-linking agent with remarkable low myelotoxicity shows potent activity in sarcoma models

DNA damaging agents cause rapid shrinkage of tumors and form the basis of chemotherapy for sarcomas despite significant toxicities. Drugs having superior efficacy and wider therapeutic windows are needed to improve patient outcomes. We used cell proliferation and apoptosis assays in sarcoma cell lines and benign cells; γ-H2AX expression, comet assay, immunoblot analyses and drug combination studies in vitro and in patient derived xenograft (PDX) models. BO-1055 caused apoptosis and cell death in a concentration and time dependent manner in sarcoma cell lines. BO-1055 had potent activity (submicromolar IC50) against Ewing sarcoma and rhabdomyosarcoma, intermediate activity in DSRCT (IC50 = 2-3μM) and very weak activity in osteosarcoma (IC50 >10μM) cell lines. BO-1055 exhibited a wide therapeutic window compared to other DNA damaging drugs. BO-1055 induced more DNA double strand breaks and γH2AX expression in cancer cells compared to benign cells. BO-1055 showed inhibition of tumor growth in A673 xenografts and caused tumor regression in cyclophosphamide resistant patient-derived Ewing sarcoma xenografts and A204 xenografts. Combination of BO-1055 and irinotecan demonstrated synergism in Ewing sarcoma PDX models. Potent activity on sarcoma cells and its relative lack of toxicity presents a strong rationale for further development of BO-1055 as a therapeutic agent.

Reactivation of TWIST1 contributes to Ewing sarcoma metastasis

BACKGROUND

Ewing sarcoma is a cancer of bone and soft tissue. Despite aggressive treatment, survival remains poor, particularly in patients with metastatic disease. Failure to treat Ewing sarcoma is due to the lack of understanding of the molecular pathways that regulate metastasis. In addition, no molecular prognostic markers have been identified for Ewing sarcoma to risk stratify patients.

PROCEDURE

Ewing sarcoma patients were divided into high or low Twist1 gene expression and survival curves were generated using the R2 microarray-based Genomic Analysis platform (http://r2.amc.nl). Tumors from Ewing sarcoma patients were also evaluated for TWIST1 expression by immunohistochemistry. Ewing sarcoma xenografts were established to evaluate the role of TWIST1 in metastasis. The effects of Twist1 on migration and invasion were evaluated using migration and invasion assays in A673 and RDES cells.

RESULTS

Twist1 expression was a negative prognostic marker for overall survival in a public Ewing sarcoma patient data set based on Twist1 mRNA levels and in patient tumor samples based on Twist1 immunohistochemistry. TWIST1 is detected in significantly higher percentage of patients with metastatic diseases than localized disease. Using Ewing sarcoma tumor xenografts in mice, we found that suppressing TWIST1 levels suppressed metastasis without affecting primary tumor development. Knockdown of Twist1 inhibited the migration and invasion capability, while overexpression of Twist1 promoted migration and invasion in Ewing sarcoma cells.

CONCLUSION

These results suggest that TWIST1 promotes metastasis in Ewing sarcoma and could be used as a prognostic marker for treatment stratification; however, further validation is required in a larger cohort of patients.

Beclin-1 knockdown decreases proliferation, invasion and migration of Ewing sarcoma SK-ES-1 cells via inhibition of MMP-9

Although Beclin-1, a well-known key regulator of autophagy, has been demonstrated to serve a function in a number of disorders, including cancer, aging and degenerative diseases, its biological function in Ewing sarcoma (ES) remains unresolved. The objective of the present study was to determine the in vitro effect of Beclin-1 knockdown on the growth and malignant phenotype of ES SK-ES-1 cells, which have increased endogenous expression of Beclin-1 compared with RD-ES cells, and to investigate the underlying molecular mechanism. Cell proliferation, invasion and migration were investigated using CCK-8, Boyden chamber Transwell, and wound healing assays, respectively. Western blot analysis was used to detect expression levels of matrix metalloproteinase (MMP)-2 and MMP-9, which are associated with the malignant phenotype. Beclin-1 knockdown significantly inhibited proliferation, invasion and migration of SK-ES-1 cells. Western blot analysis revealed that Beclin-1 knockdown caused a significant reduction in the expression of MMP-9; no marked changes in MMP-2 expression were observed in the si-Beclin-1 group compared with the control group. The results of the present study suggest that Beclin-1 serves a function in proliferation, tumor progression and inhibition of autophagy in ES, and demonstrates it's potential as a target to increase the efficacy of anticancer agents.

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.

Childhood osteosarcoma: Incidence and survival in Argentina. Report from the National Pediatric Cancer Registry, ROHA Network 2000-2013

BACKGROUND

Differences in incidence and survival in osteosarcoma reports are considerable worldwide.

PURPOSE

This study describes the incidence and survival of patients with osteosarcoma in Argentina with data from the National Pediatric Cancer Registry (ROHA), and the impact of age, gender, stage, regional, and socioeconomic indicators on outcome.

METHODS

Pediatric patients with osteosarcoma reported to ROHA from 2000 through 2013 were analyzed, the annual age-standardized incidence rate (ASR) was calculated using the National Vital Statistics, and survival was estimated. The extended human development index (EHDI) for each reporting region was used as an indicator of socioeconomic status.

RESULTS

There were 515 cases of osteosarcoma identified, yielding an ASR of 3.2/1,000,000 children (0-14 years old). The ASR did not vary significantly by year of diagnosis but ranged from 4.0/1,000,000 in the Cuyo/Western Central region to 2.7/1,000,000 in the northeast region (P < 0.000). The estimated 5-year survival rate was 45% (95% confidence interval [CI] 44-51%), with no difference by sex, diagnosis year, region, or EHDI score (P > 0.1 in all cases). Survival rate for localized disease was 52% (95% CI 45-57%) and for metastatic 22% (95% CI 15-30%).

CONCLUSIONS

In Argentina, ASR of osteosarcoma is similar to that in high-income countries, but survival is lower in all regions. Future work will focus on identification and reduction of causes of preventable treatment failure.

Metabolic modulation of Ewing sarcoma cells inhibits tumor growth and stem cell properties

Ewing sarcoma (EWS) is a highly aggressive and metabolically active malignant tumor. Metabolic activity can broadly be characterized by features of glycolytic activity and oxidative phosphorylation. We have further characterized metabolic features of EWS cells to identify potential therapeutic targets. EWS cells had significantly more glycolytic activity compared to their non-malignant counterparts. Thus, metabolic inhibitors of glycolysis such as 2-deoxy-D-glucose (2DG) and of the mitochondrial respiratory pathway, such as metformin, were evaluated as potential therapeutic agents against a panel of EWS cell lines in vitro. Results indicate that 2DG alone or in combination with metformin was effective at inducing cell death in EWS cell lines. The predominant mechanism of cell death appears to be through stimulating apoptosis leading into necrosis with concomitant activation of AMPK-α. Furthermore, we demonstrate that the use of metabolic modulators can target putative EWS stem cells, both in vitro and in vivo, and potentially overcome chemotherapeutic resistance in EWS. Based on these data, clinical strategies using drugs targeting tumor cell metabolism present a viable therapeutic modality against EWS.

ML327 induces apoptosis and sensitizes Ewing sarcoma cells to TNF-related apoptosis-inducing ligand

Ewing sarcomas are rare mesenchymal-derived bone and soft tissue tumors in children. Afflicted children with distant metastases have poor survival despite aggressive therapeutics. Epithelial-to-mesenchymal transition in epithelial carcinomas is associated with loss of E-cadherin and resistance to apoptosis. ML327 is a novel small molecule that we have previously shown to reverse epithelial-to-mesenchymal transition features in both epithelial and neural crest-derived cancers. Herein, we sought to evaluate the effects of ML327 on mesenchymal-derived Ewing sarcoma cells, hypothesizing that ML327 initiates growth arrest and sensitizes to TNF-related apoptosis-inducing ligand. ML327 induced protein expression changes, increased E-cadherin and decreased vimentin, consistent with partial induction of mesenchymal-to-epithelial transition in multiple Ewing Sarcoma cell lines (SK-N-MC, TC71, and ES-5838). Induction of epithelial features was associated with apoptosis, as demonstrated by PARP and Caspase 3 cleavage by immunoblotting. Cell cycle analysis validated these findings by marked induction of the subG₀ cell population. In vitro combination treatment with TRAIL demonstrated additive induction of apoptotic markers. Taken together, these findings establish a rationale for further in vivo trials of ML327 in cells of mesenchymal origin both alone and in combination with TRAIL.

Disparities in Adolescents and Young Adults With Cancer

BACKGROUND

Cancer care for adolescents and young adults (AYAs) focuses on the care of patients aged 15 to 39 years. Historically, this group has favorable outcomes based on a preponderance of diagnoses such as thyroid cancers and Hodgkin lymphoma. Improvements in outcomes among the AYA population have lagged behind compared with younger and older populations.

METHODS

We discuss and review recent progress in AYA patient care and highlight remaining disparities that exist, including financial disadvantages, need for fertility care, limited clinical trial availability, and other areas of evolving AYA-focused research.

RESULTS

Survival rates have not improved for this age group as they have for children and older adults. Disparities are present in the AYA population and have contributed to this lack of progress.

CONCLUSIONS

Recognizing disparities in the care of AYAs with cancer has led many medical specialty disciplines to improve the lives of these patients through advocacy, education, and resource development. Research addressing barriers to clinical trial enrollment in this population, quality-of-life issues, and the improvement of survivorship care is also under way.

The second European interdisciplinary Ewing sarcoma research summit--A joint effort to deconstructing the multiple layers of a complex disease

Despite multimodal treatment, long term outcome for patients with Ewing sarcoma is still poor. The second “European interdisciplinary Ewing sarcoma research summit” assembled a large group of scientific experts in the field to discuss their latest unpublished findings on the way to the identification of novel therapeutic targets and strategies. Ewing sarcoma is characterized by a quiet genome with presence of an EWSR1-ETS gene rearrangement as the only and defining genetic aberration. RNA-sequencing of recently described Ewing-like sarcomas with variant translocations identified them as biologically distinct diseases. Various presentations adressed mechanisms of EWS-ETS fusion protein activities with a focus on EWS-FLI1. Data were presented shedding light on the molecular underpinnings of genetic permissiveness to this disease uncovering interaction of EWS-FLI1 with recently discovered susceptibility loci. Epigenetic context as a consequence of the interaction between the oncoprotein, cell type, developmental stage, and tissue microenvironment emerged as dominant theme in the discussion of the molecular pathogenesis and inter- and intra-tumor heterogeneity of Ewing sarcoma, and the difficulty to generate animal models faithfully recapitulating the human disease. The problem of preclinical development of biologically targeted therapeutics was discussed and promising perspectives were offered from the study of novel in vitro models. Finally, it was concluded that in order to facilitate rapid pre-clinical and clinical development of novel therapies in Ewing sarcoma, the community needs a platform to maintain knowledge of unpublished results, systems and models used in drug testing and to continue the open dialogue initiated at the first two Ewing sarcoma summits.

LINGO-1 is a New Therapy Target and Biomarker for Ewing Sarcoma

Ewing sarcoma is a predominantly paediatric cancer with a high rate of metastasis and reoccurrence. A new surface marker called LINGO-1 was recently identified on Ewing tumours as a potential target for antibody-mediated therapies. However, such targeting requires caution because of LINGO-1 expression on some brain cells. Although the blood-brain-barrier exists, small amounts of antibody may cross this barrier and cause harmful side-effects. In this perspective, we suggest some options to alleviate this risk that can make targeting tumour cells expressing the LINGO-1 antigen a safe option.

Combinatorial Drug Screening Identifies Ewing Sarcoma-specific Sensitivities

Improvements in survival for Ewing sarcoma pediatric and adolescent patients have been modest over the past 20 years. Combinations of anticancer agents endure as an option to overcome resistance to single treatments caused by compensatory pathways. Moreover, combinations are thought to lessen any associated adverse side effects through reduced dosing, which is particularly important in childhood tumors. Using a parallel phenotypic combinatorial screening approach of cells derived from three pediatric tumor types, we identified Ewing sarcoma-specific interactions of a diverse set of targeted agents including approved drugs. We were able to retrieve highly synergistic drug combinations specific for Ewing sarcoma and identified signaling processes important for Ewing sarcoma cell proliferation determined by EWS-FLI1 We generated a molecular target profile of PKC412, a multikinase inhibitor with strong synergistic propensity in Ewing sarcoma, revealing its targets in critical Ewing sarcoma signaling routes. Using a multilevel experimental approach including quantitative phosphoproteomics, we analyzed the molecular rationale behind the disease-specific synergistic effect of simultaneous application of PKC412 and IGF1R inhibitors. The mechanism of the drug synergy between these inhibitors is different from the sum of the mechanisms of the single agents. The combination effectively inhibited pathway crosstalk and averted feedback loop repression, in EWS-FLI1-dependent manner. Mol Cancer Ther; 16(1); 88-101. ©2016 AACR.

Effects of long non-coding RNA SPRY4-IT1 on osteosarcoma cell biological behavior

Recent findings indicate that long noncoding RNAs (lncRNAs) were dysregulated in many kinds of tumors including osteosarcoma (OS). SPRY4-IT1 has been recently revealed as oncogenic regulator in various cancers, while its clinical value and potential function in OS are still unknown. To investigate the role of SPRY4-IT1 in OS, we evaluated the expression SPRY4-IT1 in OS tissues and cell lines, and investigated the effect of SPRY4-IT1 siRNA on cell proliferation, migration and invasion of OS in vitro. Our result showed that SPRY4-IT1 was upregulated in OS tissues. Further experiments revealed that SPRY4-IT1 knockdown significantly inhibited OS cells proliferation by causing G1 arrest and promoting apoptosis. Furthermore, inhibitory effects of SPRY4-IT1 on cell migration and invasion were partly associated with EMT process. In conclusion, these data suggest that SPRY4-IT1 could be an oncogene for OS, and may be served as a candidate target for new therapies in human OS.

The iron chelator Dp44mT suppresses osteosarcoma's proliferation, invasion and migration: in vitro and in vivo

Di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT), the novel iron chelator, has been reported to inhibit the tumorigenesis and progression of various cancer cells, including neuroblastoma, neuroepithelioma and prostate cancer. However, whether Dp44mT has anticancer effects in osteosarcoma is still unknown. Here, we investigated the antitumor action of Dp44mT in osteosarcoma and its underlying mechanisms. A human osteosarcoma 143B cell line in vitro and 143B xenograft in nude mice in vivo were utilized, the anticancer effects of Dp44mT were examined through methods of MTT assay, transwell, wound healing assay, flow cytometry, western blot, immunohistochemistry and H&E staining. We showed that Dp44mT inhibits cell proliferation, invasion and migration in vitro. In addition, flow cytometry further illustrated that Dp44mT suppression of 143B cell proliferation, invasion and migration were partially due to induction of cell apoptosis, cell cycle arrest in S phase and ROS production. Also in vitro and in vivo, the expression levels of Bcl2, Bax, Caspase3, Caspase9, LC3-II, β-catenin and its downstream targets such as C-myc and Cyclin D1 demonstrated that cell apoptosis and autophagy, as well as Wnt/β-catenin pathway were involved in Dp44mT induced osteosarcoma suppression. The Dp44mT inhibition of osteosarcoma was further verified via animal models. The findings indicated that in vivo Dp44mT showed a significant reduction in the 143B xenograft tumor growth and metastasis. In conclusion, our data demonstrated that Dp44mT has effective anticancer capability in osteosarcoma and that may represent a promising treatment strategy for osteosarcoma.

Advances in the management of osteosarcoma

Osteosarcoma, a bone cancer most commonly seen in adolescents and young adults, is usually a high-grade malignancy characterized by a very high risk for the development of pulmonary metastases. High-grade osteosarcomas are usually treated by preoperative and postoperative chemotherapy and surgery, with a very limited number of active agents available. Rarer lower-grade variants such as parosteal and periosteal osteosarcoma or low-grade central osteosarcoma are treated by surgery only. Imaging to search for possible metastases focuses on the lung. Computed tomography is the most sensitive method but cannot reliably distinguish small metastases from benign lesions. Advances of local imaging and surgical reconstruction now allow the use of limb-salvage in an ever-increasing proportion of patients. While still troubled by complications, non-invasive endoprosthesis-lengthening mechanisms have led to an increased uptake of limb-salvage, even for young, skeletally immature patients. Radiotherapy is employed when osteosarcomas cannot be removed with clear margins, but very high doses are required, and both proton and carbon-ion radiotherapy are under investigation. Unfortunately, the past 30 years have witnessed few, if any, survival improvements. Novel agents have not led to universally accepted changes of treatment standards. In patients with operable high-grade osteosarcomas, the extent of histological response to preoperative chemotherapy is a significant predictive factor for both local and systemic control. Attempts to improve prognosis by adapting postoperative treatment to response, recently tested in a randomized, prospective setting by the European and American Osteosarcoma Study Group, have not been proven to be beneficial. Many agree that only increased knowledge about osteosarcoma biology will lead to novel, effective treatment approaches and will be able to move the field forward.