Ewing's sarcoma with distant metastasis: A brief note on management and emerging therapies

Ewing’s sarcoma is an aggressive fatal malignancy of bones and soft-tissue. It predominantly affects the young population, with a worldwide incidence of three cases per million. The pelvis, extremities, and ribs are the most common sites. We present a case of massive Ewing’s sarcoma of the right femur with metastasis to bones and lungs. The patient was treated with chemotherapy. However, he succumbed to his illness before completion of therapy. In conclusion, Ewing’s sarcoma with distant metastasis is a high risk case with poor prognosis. Integrating novel molecular targets with conventional chemotherapeutic agents holds a promise for high-risk Ewing’s sarcoma patients.

Emerging trends in immunotherapy for pediatric sarcomas

While promising, immunotherapy has yet to be fully unlocked for the preponderance of cancers where conventional chemoradiation reigns. This remains particularly evident in pediatric sarcomas where standard of care has not appreciably changed in decades. Importantly, pediatric bone sarcomas, like osteosarcoma and Ewing’s sarcoma, possess unique tumor microenvironments driven by distinct molecular features, as do rhabdomyosarcomas and soft tissue sarcomas. A better understanding of each malignancy’s biology, heterogeneity, and tumor microenvironment may lend new insights toward immunotherapeutic targets in novel platform technologies for cancer vaccines and adoptive cellular therapy. These advances may pave the way toward new treatments requisite for pediatric sarcomas and patients in need of new therapies.

LncRNA SOX2 overlapping transcript acts as a miRNA sponge to promote the proliferation and invasion of Ewing's sarcoma

Long non-coding RNAs (lncRNAs) function as critical regulator in human cancers. However, the biological regulatory mechanisms of lncRNAs in Ewing's sarcoma are still elusive. This study tries to investigate the clinical significance and pathological role of lncRNA SOX2 overlapping transcript (SOX2OT) in Ewing's sarcoma progression. SOX2OT was identified to be up-regulated in Ewing's sarcoma tissue and cells. In vitro, SOX2OT knockdown suppressed Ewing's sarcoma cells proliferation and invasion, and triggered apoptosis. In vivo xenograft assays, SOX2OT knockdown significantly inhibited Ewing's sarcoma growth. With the help of bioinformatics analysis and luciferase assay, SOX2OT was validated to harbor miR-363, acting as miRNA sponge or competing endogenous RNA (ceRNA). Furthermore, FOXP4 was validated to be the target protein of miR-363. Western blot and RT-PCR confirmed that SOX2OT was positively correlated with FOXP4 protein via sponging miR-363, forming a negative cascade regulation. In conclusion, our study realizes that SOX2OT acted as oncogene in the tumorigenesis of Ewing's sarcoma, suggesting the SOX2OT/miR-363/FOXP4 pathway in Ewing's sarcoma.

Identification of key genes and pathways in Ewing's sarcoma patients associated with metastasis and poor prognosis

Background: Ewing sarcoma (ES) is the second commonest primary malignant bone neoplasm. Metastatic status at diagnosis strongly predicted poor prognosis of Ewing sarcoma patients. Yet little was known about the underlying mechanism of ES metastasis.

Purpose:This study intended to identify the relationship between key genes/pathways and metastasis/poor prognosis in Ewing's sarcoma patients by using bioinformatic method.

Methods: In this study, multi-center sequencing data were obtained from the GEO database, including gene and miRNA expression profile and prognosis information of ES patients. Differentially expressed genes (DEGs) were identified between primary and metastasis ES samples by the GEO2R online tool. Gene ontology (Go) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analyses of DEGs were performed. And PPI network analyses were conducted. The ES patient’s prognostic information was employed for survival analysis, and the potential relationship between miRNAs and key genes was analyzed.

Results: The results showed that a total of 298 and 428 DEGs were screened out in metastasis samples based on GSE17618 and GSE12102 dataset compared to primary samples respectively. The most significantly enriched KEGG pathway was the mismatch repair (MMR) pathway. MSH2, MSH6, RPA2, and RFC2 that belong to the MMR pathway were identified as key genes. Moreover, the expression of key genes was increased in metastasis samples compared with primary ones and was associated with poor event-free and overall survival of ES patients. The negative correlation of the expression level of the key genes with patients prognosis also supported by TCGA sarcoma database. Furthermore, knockdown of EWSR/FLI1 fusion in ES cell line A673 down-regulates the expression of the 4 key genes was revealed by GDS4962.

Conclusion: In conclusion, the present study indicated that the key genes promote our understanding of the molecular mechanisms underlying the development of ES metastasis, and might be used as molecular targets and diagnostic biomarkers for the treatment of ES.

Efficacy and tolerability of stereotactic body radiotherapy for lung metastases in three patients with pediatric malignancies

Purpose: To report a case series of 3 pediatric patients treated with Stereotactic Body Radiation Therapy (SBRT) for lung metastases.

Patients and methods: Three patients (ages 9, 11, and 21) received SBRT for rhabdoid tumor, Ewing sarcoma, and Wilms tumor histologies, respectively. SBRT doses were 37.5–50 Gy in 3–5 fractions treating twelve lesions.

Results: Three patients (ages 9, 11, and 21) received photon SBRT for pulmonary metastases. The patients were as follows: 1) 21-year-old male with favorable histology Wilms tumor and 1 lesion treated, 2) 11-year-old female with Ewing sarcoma and 1 lesion treated for relapse after previous whole lung radiation (15 Gy), and 3) 9-year-old female with rhabdoid tumor of the left thigh with 10 lesions treated over a two-year period. Median dose delivered was 40 Gy (range, 37.5–50 Gy), delivered in a median of 4 fractions (range, 4–5) of a median of 10 Gy per fraction (range, 9.4–10 Gy). Within a minimum follow-up of 1.9 years (range 1.9–4 years), local control for all 13 treated metastases is 100% without any observed acute toxicities. One possible late toxicity (grade 2 rib fracture) developed 1.3 years following SBRT for treatment of a peripheral lesion (rhabdoid tumor) in an area of disease progression and was managed conservatively. Two patients are surviving 2.9 years (Wilms tumor) and 1.9 years (Ewing sarcoma) after SBRT, and one (rhabdoid tumor) expired 2 years after her final course (4 years after initial SBRT). Two patients (rhabdoid tumor and Ewing sarcoma) suffered disease progression outside of the treated lesions and one patient (Wilms tumor) is without evidence of disease and has not required whole lung irradiation or further systemic therapy.

Conclusion: SBRT appears effective and well tolerated for pediatric lung metastases, however further studies are warranted.

Extraskeletal Ewing's Sarcoma of Neck in a Child- A Case Report

INTRODUCTION

Ewing's sarcoma (ES) is an extremely rare bone malignancy observed in otorhinolaryngeal practice. In otorhinolaryngology, it sometimes involves the facial bones and cervical vertebrae. In children, ES is the second most common primary malignancy of bone after osteosarcoma. Extraskeletal Ewing's sarcoma (EES) is an extremely rare malignancy of mesenchymal cell origin. The EES is observed in the trunk and lower extremities. The neck is an extremely rare primary site for EES.

CASE REPORT

A 3-year-old female child referred with a rapidly enlarging right-sided neck swelling since 2 months ago. Physical examination and preoperative investigations suggested the diagnosis of a carotid body tumor and histopathological findings were similar. However, the results of immunohistochemistry revealed a confirmatory diagnosis of ES.

CONCLUSION

Hereby, we presented a case of EES of the neck in a child, which was completely misdiagnosed preoperatively due to its rare incidence. The incidence of EES in the head and neck region can be successfully managed with radical excision and radiotherapy.

Ewing's sarcoma of the sternum necessitating complex resection and reconstruction

We present a 30-year-old man with a sternal Ewing’s sarcoma, who was treated by complex resection of the sternal body and reconstruction by a methyl methacrylate sandwich graft and a pedicled latissimus dorsi flap.

Ewing's Sarcoma with Extension into Superior Vena Cava and Right Atrium

Ewing sarcoma is rarely shown to develop this intravascular extension so the decision of the initial treatment is more difficult. We report a 7-year-old boy of this sarcoma with extension into superior vena cava (SVC) and right atrium (RA), who was successfully treated with initial surgery. Intravascular extension was observed from the azygous vein to SVC and finally RA. The removal of the intravascular extension was done, 7 days before chemotherapy was started. The initial surgery for the intravascular extension may have decreased a risk of pulmonary tumor embolism and this made the chemotherapy done safe in this patient.

Vascular endothelial growth factor expression as a biomarker of prognosis in patients with chondrosarcoma, Ewing's sarcoma and osteosarcoma. Current concepts

With the advent of the molecularly targeted therapies, identifying molecular therapeutic targets and molecolar marker is increasingly important, especially in neoplastic diseases. Several studies show VEGF is involved in neo-angiogenesis in many solid cancers, as breast, lung, renal, gastric carcinomas, through promoting endothelial cell growth and migration. Conversely the relationship between VEFG and tumours of the musculoskeletal system is yet unclear, in particular the role of VEGF has not yet been completely understood in these tumours. Chondrosarcoma, Ewing's Sarcoma and Osteosarcoma are the tumours of the musculoskeletal system in which the activity of VEGF has been closely studied. The present study aims to give an overview focused on the relationship between VEGF and these three cancers.

Primary intracranial extraosseous Ewing's sarcoma

INTRODUCTION

Common sites of occurrence of extraosseous Ewing's sarcoma include the soft tissues and bones of the lower extremity, 12 paravertebral, and retroperitoneal regions. Primary intracranial Ewing's sarcoma/pPNET is usually intraparenchymal located 13 when supratentorially, and an extraaxial epidural tumor radiographically mimicking a meningioma is extremely rare.

CASE PRESENTATION

A 20-year14 old male presented to the emergency department with a 1-day history of drowsiness, headache, and fever. Neurological exam15 ination revealed decreased muscle strength (4/5) in the left lower limb. Head computed tomography scan showed an epidural 16 space-occupying lesion in the right temporoparietal region, which was assumed to be a meningioma by radiographic criteria. However, the surgical specimen was diagnosed as Ewing's sarcoma.

CONCLUSION

Primary intracranial extraosseous Ewing's sarcoma is a rare condition that may mimic a meningioma on imaging. Physicians must be cognizant of this possibility, particularly in any young individual with a solitary contrast-enhancing dural-based lesion.

Prognostic factors and survival in Ewing's sarcoma treated by limb salvage surgery

PURPOSE

Survival in Ewing's sarcoma (ES) has increased with the use of chemotherapy. Surgical techniques such as limb salvage (LS) have been developed. Survival and adverse events have been widely studied in general series of ES, but there are few specific series of ES cases treated by LS, despite this being the most commonly used (surgical) approach. The aim of this study was to determine survival and prognostic factors in ES patients undergoing LS.

PATIENTS AND METHODS

We analysed all ES patients treated between January 1984 and May 2008 and selected all those treated by systemic multimodal therapy and LS. We assessed the influence of patient characteristics, tumour parameters and therapeutic results in event-free survival (EFS).

RESULTS

Ninety patients were included. Fifty of them were treated by systemic multimodal therapy and locally by LS. ean age was 20 years. Overall survival (OS) was 68.8% and EFS was 60.6% at years. In the univariate analysis, pelvic location, age and response to chemotherapy were associated with poor prognosis. After multivariate analysis, poor response to treatment, pelvis location and age between 12 and 17 years were found to be independent prognostic factors. Dissemination at diagnosis was not a prognostic factor.

CONCLUSIONS

OS and EFS in ES treated by LS were similar to findings in previous ES studies. factors are no different, except for the presence of metastasis at diagnosis.

Regorafenib regressed a doxorubicin-resistant Ewing's sarcoma in a patient-derived orthotopic xenograft (PDOX) nude mouse model

PURPOSE

Ewing's sarcoma (ES) is a rare and recalcitrant disease which is in need of a development of a novel effective therapy. The aim of this study was to investigate the efficacy of regorafenib on an ES tumor in a patient-derived orthotopic xenograft (PDOX) model.

METHODS

The ES PDOX models were established orthotopically in the right chest wall of nude mice to match the site of the tumor in the donor patient. The ES PDOX models were randomized into three groups (G) when the tumor volume reached 75 mm³: G1: untreated control; G2: doxorubicin (DOX) (i.p., 3 mg/kg, weekly, 2 weeks); G3: regorafenib (REG) (p.o., 30 mg/kg, daily, 2 weeks). Tumor volume and body weight were measured twice a week. All mice were sacrificed on day 15.

RESULTS

DOX was ineffective compared to the control group (P = 0.229). REG regressed the tumor size (P < 0.001 and P < 0.001, relative to control and DOX, respectively).

CONCLUSIONS

Our findings suggest that REG has clinical potential for ES patients whose tumors respond to REG in a PDOX model.

Combining Tumor-Selective Bacterial Therapy with Salmonella typhimurium A1-R and Cancer Metabolism Targeting with Oral Recombinant Methioninase Regressed an Ewing's Sarcoma in a Patient-Derived Orthotopic Xenograft Model

BACKGROUND

Ewing's sarcoma (ES) is a recalcitrant disease in need of transformative therapeutics.

OBJECTIVES

The aim of this study was to investigate the efficacy of tumor-selective Salmonella typhimurium A1-R combined with tumor metabolism targeting with oral administration of recombinant methioninase (o-rMETase), on an ES patient-derived orthotopic xenograft (PDOX) model.

METHODS

The ES PDOX models were previously established in the right chest wall. The ES PDOX models were randomized into 5 groups when the tumor volume reached 80 mm3: G1: untreated control; G2: doxorubicin; G3: S. typhimurium A1-R; G4: o-rMETase; G5: S. typhimurium A1-R combined with o-rMETase. All mice were sacrificed on day 15. Body weight and tumor volume were assessed twice a week.

RESULTS

S. typhimurium A1-R and o-rMETase respectively suppressed tumor growth as monotherapies (p = 0.050 and p = 0.032). S. typhimurium A1-R combined with o-rMETase regressed tumor growth significantly compared to untreated group on day 15 (p < 0.032). S. typhimurium A1-R combined with o-rMETase group was significantly more effective than S. typhimurium A1-R or o-rMETase monotherapy (p = 0.032, p = 0.032).

CONCLUSIONS

The present results suggest that the combination of S. typhimurium A1-R and o-rMETase has promise to be a transformative therapy for ES.

Long noncoding RNA DLX6-AS1 targets miR-124-3p/CDK4 to accelerate Ewing's sarcoma

Ewing's sarcoma is one of leading cause of malignancy occurred in the children and adolescents worldwide. Given the emerging critical role of long noncoding RNA (lncRNA) in the human cancer, as well as Ewing's sarcoma, we aim to identify the biological role of DLX6-AS1 in the tumorigenesis. Results unveil that DLX6-AS1 expression was increased in the tissue sample and cells. Functionally, the silencing of DLX6-AS1 could repress the proliferation and accelerate the apoptosis of Ewing's sarcoma cells. Mechanically, DLX6-AS1 functioned as the sponge of miR-124-3p, and then miR-124-3p targeted the 3'-UTR of CDK4 mRNA, forming the DLX6-AS1/miR-124-3p/CDK4 regulatory pathway. In conclusion, the critical role of DLX6-AS1 might unveil a potential therapeutic target for Ewing's sarcoma.

Extraosseous Ewing's Sarcoma of the Parapharyngeal Space - A Rare Entity - with Review of Literature

INTRODUCTION

Extraosseous Ewing's sarcoma (EES) of the head and neck region is a rare occurrence, and Ewing's sarcoma of the parapharyngeal space is even rarer. To the best of our knowledge, only three cases of EES of the parapharyngeal space have been reported in the literature.

CASE REPORT

We report a rare case of EES of the parapharyngeal space in an 8-year-old girl. She presented with complaints of earache, difficulty in breathing and swallowing and bleeding from the mouth. Investigations revealed a large parapharyngeal mass causing narrowing of the nasopharyngeal and oropharyngeal airway with skeletal and lung metastasis. Biopsy from the parapharyngeal mass was suggestive of malignant small round cell tumor. The patient was treated with chemotherapy and radiotherapy, but developed brain metastasis and succumbed to disease approximately 1 year after diagnosis. Herein, we describe the characteristic clinicopathological features and treatment with a comprehensive review of the literature.

CONCLUSION

EES in this unusual location behaves aggressively, with a high rate of recurrence and distant metastasis. Aggressive multimodal treatment comprising of multi-agent chemotherapy, surgical resection if feasible, and radiotherapy should be considered.

The efficacy and safety of apatinib in Ewing's sarcoma: a retrospective analysis in one institution

BACKGROUND

Ewing's sarcoma (ES) is a highly aggressive and metastatic neoplasm occurring mainly in children and young adults. The standard treatment of localized ES requires a combination of surgery, chemotherapy, and radiotherapy. Although the 5-year survival rate for local ES has improved, the survival rate and prognosis are still very poor for metastatic or recurrent ES patients. The aim of this study was to investigate the efficacy and safety of apatinib, a specific vascular endothelial growth factor receptor 2 inhibitor, in ES patients.

METHODS

This retrospective analysis involved eleven patients with ES not amenable to curative treatment. All patients suffered poor responses to two cycles of chemotherapy (vincristine, doxorubicin, and cyclophosphamide). Apatinib 500 mg (or 250 mg) was given daily. Tumor responses were assessed according to the Response Evaluation Criteria in Solid Tumors 1.1. Survival analysis was performed by the Kaplan-Meier test. The safety profile was also recorded.

RESULTS

The mean age of the patients was 18 (range, 10-31) years. The 12-month overall survival and progression-free survival rates were 90% and 72%, respectively. Four patients achieved partial response, and four patients achieved stable disease, with objective response rate of 40%. The median follow-up in our study was 16 months (range, 3-26 months). The most common adverse events included hand-foot skin reaction (n=5; 45%), oral ulcers (n=4; 36%), and gastrointestinal discomfort (n=4; 36%).

CONCLUSION

Apatinib may provide as second- or first-line treatment options for ES patients, particularly in chemoresistant cases. Further studies with more cases and longer follow-up will be necessary to determine the clinical efficacy and safety of apatinib in ES patients.

Congenital Ewing's Sarcoma, a Rare and Difficult Diagnosis: A Case Report

We have interestedly read the article written by Thalia Wong BS in July 2015, which is about Pediatric Blood Cancer, including clinical findings and results of infants <1 year of age with Ewing sarcoma. We report a case with congenital Ewing's sarcoma that easily interfered with rabdomyosarcoma in a pregnant woman. A 32-year-old multigravida with a big neck mass at 35 weeks was referred to our clinic. The final diagnosis of extraskeletal Ewing's sarcoma was made. Hepatic metastasis was detected and treatment by chemotherapy was initiated. Ewing's sarcoma is usually noted among adolescents or young adults and more rarely than among newborns. This case is important because of its rarity.

Ewing's Sarcoma of Scapula: a Rare Case Report

Neoplasms arising from scapula are rare. We herein, present a rare case of Ewing's sarcoma of scapula in a 9-year-old male child. Extensive literature search reveals that less than 20 similar cases have been reported so far. The index case had been treated with multimodal therapies-chemotherapy, surgery, and radiotherapy. This case is reported to highlight the rarity of the case and discuss the review of literature comprehensively.

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.

An unusual biconvex epidural lesion: acutely presenting extraosseous intracranial Ewing's sarcoma

Background

Ewing’s sarcoma family of tumors consists of small round cell neoplasms, inclusive of primitive neuroectodermal tumor (PNET), Askin’s tumor, and PNET of the bone. Extraosseous Ewing’s sarcoma occurs commonly at bones of lower extremities and paravertebral region of the spine. It rarely presents as a primary intracranial lesion. When intracranial, it can be misdiagnosed as central PNET (e.g., medulloblastoma, pinealoblastoma, or supratentorial PNET), other intracranial lesions, or even as an epidural hematoma.

Case presentation

We report the case of a 20-year-old patient who presented to the emergency department with complaints of drowsiness, headache, and fever for 1 day. On initial computed tomography (CT) scan of the brain, a right temporal biconvex epidural lesion involving squamous-temporal bone with periosteal reaction was noted.

The patient underwent urgent craniotomy, and a tumor was found and excised. Biopsy report confirmed Ewing’s sarcoma.

Conclusion

Ewing’s sarcoma is a rare intracranial malignancy with only a few cases reported in literature. In a young patient with a biconvex epidural lesion, in the absence of trauma or ongoing infection, the possibility of Ewing’s sarcoma should be considered as well.

Identification of driver genes associated with chemotherapy resistance of Ewing's sarcoma

Background

The aim of this study was to identify the driver genes associated with chemotherapy resistance of Ewing’s sarcoma and potential targets for Ewing’s sarcoma treatment.

Methods

Two mRNA microarray datasets, GSE12102 and GSE17679, were downloaded from the Gene Expression Omnibus database, which contain 94 human Ewing’s sarcoma samples, including 65 from those who experienced a relapse and 29 from those with no evidence of disease. The differen tially expressed genes (DEGs) were identified using LIMMA package R. Subsequently, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed for DEGs using Database for Annotation, Visualization and Integrated Analysis. The protein–protein interaction network was constructed using Cytoscape software, and module analysis was performed using Molecular Complex Detection.

Results

A total of 206 upregulated DEGs and 141 downregulated DEGs were identified. Upregulated DEGs were primarily enriched in DNA replication, nucleoplasm and protein kinase binding for biological processes, cellular component and molecular functions, respectively. Downregulated DEGs were predominantly involved in receptor clustering, membrane raft, and ligand-dependent nuclear receptor binding. The protein–protein interaction network of DEGs consisted of 150 nodes and 304 interactions. Thirteen hub genes were identified, and biological analysis revealed that these genes were primarily enriched in cell division, cell cycle, and mitosis. Furthermore, based on closeness centrality, betweenness centrality, and degree centrality, the three most significant genes were identified as GAPDH, AURKA, and EHMT2. Furthermore, the significant network module was composed of nine genes. These genes were primarily enriched in mitotic nuclear division, mitotic chromosome condensation, and nucleoplasm.

Conclusion

These hub genes, especially GAPDH, AURKA, and EHMT2, may be closely associated with the progression of Ewing’s sarcoma chemotherapy resistance, and further experiments are needed for confirmation.

miR-185 suppresses progression of Ewing's sarcoma via inhibiting the PI3K/AKT and Wnt/β-catenin pathways

Background

miRNAs are confirmed to play essential roles in tumorigenesis and progression of cancers, including Ewing's sarcoma. miR-185 has been reported to be downregulated in some tumors, whereas the role of miR-185 in Ewing's sarcoma remains unclear.

Purpose

The objective of this study was to investigate the role of miR-185 in the progression and metastasis of Ewing's sarcoma and explore the associated mechanism.

Materials and methods

Ewing's sarcoma cell line RD-ES was transfected with pCMV-MIR-miR185 vector to upregulate the expression of miR-185. Cell Counting Kit 8 and colony formation assays were used to assess the effect of miR-185 on cell proliferation. The effect of miR-185 on cell migration and invasion was detected by transwell assay. Flow cytometry assay was performed to detect apoptosis rate of RD-ES cells. The protein levels of apoptosis-related proteins was determined using Western blot assay or immunohistochemistry assay. Dual-luciferase reporter assay was used to validate the regulation between miR-185 and its target gene.

Results

Upregulation of miR-185 caused significant inhibition on cell growth capacity, migration and invasion of Ewing's sarcoma cell RD-ES. Besides, upregulation of miR-185 was observed to accelerate cell apoptosis in a mitochondrial pathway through regulating Bcl-2/Bax, Caspase 3, and Caspase 9 in Ewing's sarcoma in vitro. Moreover, upregulation of miR-185 was found to suppress the PI3K/Akt/mTOR and Wnt/β-catenin pathways in RD-ES cells. Furthermore, we identified that E2F6 was a target gene for miR-185, and the suppression on cell proliferation caused by overexpression of miR-185 was significantly rescued by the upregulation of E2F6 in RD-ES cells.

Conclusion

miR-185 is involved in cell growth, motility and survival of Ewing's sarcoma as a tumor suppressor via suppressing PI3K/Akt/mTOR and Wnt/β-catenin pathways and targeting E2F6.

Establishment of a novel patient-derived Ewing's sarcoma cell line, NCC-ES1-C1

Ewing's sarcoma is an aggressive mesenchymal tumor characterized by the presence of a unique EWSR1-FLI1 translocation. Ewing's sarcoma primarily occurs in the bone and soft tissues. Cell lines enable researchers to investigate the molecular backgrounds of disease and the significance of genetic alterations in relevant cellular contexts. Here, we report the establishment and characterization of a novel Ewing's sarcoma cell line following primary Ewing's sarcoma tumor tissue culture. The established cell line was authenticated by DNA microsatellite short tandem repeat analysis, characterized by in vitro assays, and named NCC-ES1-C1. The NCC-ES1-C1 cell line grew well for 15 mo and was subcultured more than 50 times during this period. Characterization of the cells revealed that they were not adherent and showed floating features. In conclusion, we successfully established a novel Ewing's sarcoma cell line, NCC-ES1-C1, from primary tumor tissue. The cell line has the characteristic EWSR1-FLI1 gene fusion and exhibits aggressive growth in vitro. Thus, the NCC-ES1-C1 cell line will be a useful tool for investigating the mechanisms of disease and the biological role of the EWSR1-FLI1 fusion gene.

Curettage, phenolization, and cementation in paediatric Ewing's sarcoma with a complete radiological response to neoadjuvant chemotherapy

PURPOSE

Although wide resection is the standard treatment for Ewing's sarcoma (ES), it has complications especially in children. In this study, we compared the oncologic and functional outcomes of wide resection with extended curettage and local adjuvant therapy (phenolization and cementation), as a less extensive surgery for paediatric ES with a complete radiologic response to neoadjuvant chemotherapy.

METHODS

Children aged ≤ ten years, with ES of non-expendable long-bones and complete radiologic response to neoadjuvant chemotherapy, were included in this case-control study. Twenty-six patients were treated with extended curettage and local adjuvant therapy (case group) and 17 were managed with wide resection (control group). The average follow-up period was 60.1 ± 28.7 months (range 30-168 months). Functional outcome was assessed with the Musculoskeletal Tumor Society (MSTS) scoring system.

RESULTS

Three local recurrences (11.5%) and three distant metastases (11.5%) were observed in the case group. Two local recurrences (11.7%) and two metastases (11.7%) were recorded in the control group. The rate of local recurrence was not statistically different between the two study groups (p = 0.668). The rate of metastasis was not statistically different between the two study groups as well (p = 0.668). The complication rates were 15% in the case group and 53% in the control group (p = 0.005). The mean MSTS score was 98.3% and 74% in the case and control group, respectively (p < 0.001).

CONCLUSION

The oncologic outcome of extended curettage and local adjuvant therapy in paediatric ES with complete radiological response to neoadjuvant chemotherapy is comparable to wide resection, yet it offers considerably better functional results.

TRPC4/TRPC5 channels mediate adverse reaction to the cancer cell cytotoxic agent (-)-Englerin A

(-)-Englerin A (EA) is a natural product which has potent cytotoxic effects on renal cell carcinoma cells and other types of cancer cell but not non-cancer cells. Although selectively cytotoxic to cancer cells, adverse reaction in mice and rats has been suggested. EA is a remarkably potent activator of ion channels formed by Transient Receptor Potential Canonical 4 and 5 proteins (TRPC4 and TRPC5) and TRPC4 is essential for EA-mediated cancer cell cytotoxicity. Here we specifically investigated the relevance of TRPC4 and TRPC5 to the adverse reaction. Injection of EA (2 mg.kg^-1 i.p.) adversely affected mice for about 1 hour, manifesting as a marked reduction in locomotor activity, after which they fully recovered. TRPC4 and TRPC5 single knockout mice were partially protected and double knockout mice fully protected. TRPC4/TRPC5 double knockout mice were also protected against intravenous injection of EA. Importance of TRPC4/TRPC5 channels was further suggested by pre-administration of Compound 31 (Pico145), a potent and selective small-molecule inhibitor of TRPC4/TRPC5 channels which did not cause adverse reaction itself but prevented adverse reaction to EA. EA was detected in the plasma but not the brain and so peripheral mechanisms were implicated but not identified. The data confirm the existence of adverse reaction to EA in mice and suggest that it depends on a combination of TRPC4 and TRPC5 which therefore overlaps partially with TRPC4-dependent cancer cell cytotoxicity. The underlying nature of the observed adverse reaction to EA, as a consequence of TRPC4/TRPC5 channel activation, remains unclear and warrants further investigation.