Search Results (297)

Ewing sarcoma (ES) is the second most common primary bone malignancy in children and adolescents and remains one of the most lethal pediatric cancers. Found in more than 85% of patients with ES, EWSR1::FLI1 results from the t(11;22)(q24;q12) chromosomal translocation. This fusion encodes an aberrant transcription factor that dysregulates gene expression and drives oncogenic transformation. Although this oncogene was identified over three decades ago, therapeutic progress has been limited, in part due to the lack of robust and permissive animal models. Prior efforts to generate transgenic mouse models have been unsuccessful, and while zebrafish have emerged as a promising system, a tissue context capable of supporting EWSR1::FLI1-driven tumorigenesis has not been defined. Here, we report that tissue-specific expression of EWSR1::FLI1 in zebrafish induces tumor formation that recapitulates the histologic and molecular hallmarks of human ES, including small round blue cell morphology and characteristic biomarker expression. Tumors were driven by the col2a1a promoter and resulted in ~70% incidence of notochord tumors within the first 72–96 h. Of the surviving fish, ~5% developed CD99-positive small round blue cell tumors at ~9 months post-fertilization. This work establishes a stable tissue-specific transgenic model of ES, providing a powerful in vivo platform to investigate disease pathogenesis and evaluate novel therapeutic strategies. Full article

Background/Objectives: To study the hypothesis that cognitive functions and learning skills are impaired in child/adolescent childhood cancer survivors (CCS). Secondary outcomes included psychosocial parameters and quality of life. Methods: This case–control study was conducted over four years (2017–2021) at the largest pediatric Aghia Sophia Children’s Hospital, in Greece. Eligible participants were children and adolescents in Greece. For CCS, ≥1 year should have elapsed from completion of cancer treatment. Assessments of neurocognitive function, learning and psychosocial skills and health-related quality of life (HRQoL) were performed with validated instruments (WISC-III, LAMDA software, Achenbach CBCL/6-18 and YSR, KIDSCREEN-52, respectively). Results: In total, 219 participants (47.49% males, mean age ± SD 11.72 ± 2.32 years), 70 CCS and 149 controls (matched for age, sex, family income), were included. Cases were CCS of acute lymphoblastic leukemia (n = 25)/brain tumors (n = 19)/lymphoma (n = 17)/nephroblastoma (n = 5)/Ewing sarcoma (n = 3)/rhabdomyosarcoma (n = 1). CCS had worse scores in full-scale Intelligence Quotient (FSIQ) (p = 0.004), verbal IQ (VIQ) (p = 0.005) and all its subscales, performance IQ (PIQ) (p = 0.021), and almost all learning parameters than controls. Attention, working memory, writing/visual–motor coordination, processing accuracy/speed, language acquisition/expression, all psychosocial scales, and HRQoL domains of mood and emotions, were negatively affected in CCS. Female CCS demonstrated lower FSIQ (p = 0.019) and VIQ (p = 0.014) than control females, whereas male CCS retained their total IQ unaffected. Among CCS, those with non-central nervous system (CNS) tumors, higher parental educational level or higher family income had significantly higher IQ than those with CNS tumors, lower parental educational level or lower family income, respectively. Conclusions: CCS in Greece carry a significant burden of cognitive and psychological morbidity. Cognitive/educational and psychosocial support to CCS is imperative. Full article

Survival rates for metastatic Ewing sarcoma (EwS) have remained persistently low over recent decades, highlighting the need for more effective chemotherapeutic options. Potential targets may be found within the Neuropeptide Y (NPY) signalling pathway that has been implicated in EwS cell survival. However, confounding factors include hypoxia that modulates NPY signalling, dipeptidyl peptidase-4 (DPP4/CD26) that cleaves NPY and interactions via NPY signalling from infiltrating immune cells. We investigated these interactions in A673 and SK-ES-1 EwS cell lines and THP-1 monocytes to identify therapeutic targets suitable for drug repurposing. Both EwS cell lines secreted NPY into conditioned media and extracellular vesicles. Recombinant NPY enhanced viability of both A673 and SK-ES-1 cells; however, the NPY1R antagonist BMS-193885 reduced viability in A673 cells only. Recombinant DPP4 widely promoted EwS viability and, under hypoxic conditions, it increased cell metabolism. The DPP4 inhibitor linagliptin, which is used clinically, consistently suppressed EwS viability with elevated sensitivity under hypoxia, where there was increased cell death of SK-ES-1 cells. Conversely, in THP-1 monocytes, NPY suppressed metabolism, BMS-193885 increased live-cell staining and DPP4 induced cell death. These findings suggest that NPY and DPP4 enhance EwS survival through autocrine/paracrine signalling while reducing monocyte viability. Thus, targeting the NPY/DPP4 signalling axis may provide therapeutic benefit by directly suppressing EwS growth and enhancing efficacy of immunotherapy. Full article

Background: DNA methylation profiling has become an important diagnostic tool in pediatric neuro-oncology, particularly for tumors with overlapping morphology or unusual immunophenotypes. Methods: We report four pediatric brain tumor cases evaluated by histopathology and immunohistochemistry, supplemented by targeted next-generation sequencing (NGS) and DNA methylation profiling using the DKFZ Brain Tumor Classifier (v12.8); one case also underwent DKFZ Sarcoma Classifier analysis (v13.2). Results: Methylation profiling provided clinically meaningful diagnostic insights across all cases. In two patients, methylation results supported integrated interpretation in diagnostically challenging settings without changing management. In two cases, methylation profiling prompted major diagnostic revisions with significant therapeutic consequences: (i) a tumor initially diagnosed as atypical teratoid/rhabdoid tumor was reclassified as CNS Ewing sarcoma, confirmed by an EWSR1-FLI1 fusion and immunophenotype, leading to a change to Ewing-based therapy; and (ii) a tumor interpreted as high-grade astrocytoma/glioblastoma was reclassified as a CNS tumor with BCOR internal tandem duplication, enabling a curative-intent approach and revised prognostic counseling. Conclusions: These cases illustrate that DNA methylation profiling can complement histopathology, resolve diagnostically ambiguous tumors, and in selected patients substantially alter treatment decisions and expected outcomes. Early integration of methylome profiling may improve precision diagnostics and reduce the risk of inappropriate therapy in pediatric brain tumors. Full article

Background/Objectives: Preclinical models that accurately reflect Ewing sarcoma (ES) will enable the prioritisation of clinically active targeted agents from bench to clinic. To expedite this process, we have established and characterised patient-derived ES cultures (PDES) in vitro. Methods: Fluorescence in situ hybridisation, RT-PCR and western blotting were used to examine expression of the pathognomonic EWSR1 fusions. Activation or repression of EWSR1 fusion downstream targets and proliferation was examined by immunofluorescence and immunohistochemistry. Using next-generation sequencing, the DNA and transcriptomic profiles of PDES and cell lines were compared. The response of PDES and cell lines to standard-of-care chemotherapeutics, ionising radiation and investigational drugs was examined. Results: All PDES contain EWSR1 fusion DNA, consistent with a diagnosis of ES. EWSR1 fusion gene RNA and protein were detected in 70% and 21% of PDES, respectively. Markers of proliferation and expression of EWSR1 fusion target genes were consistent with the tumours from which PDES were derived (R² = 0.74, p < 0.0001) and the paediatric mesenchymal lineage (SBS5 and SBS1, ID1 and ID2). In contrast, the transcriptome of PDES was significantly different from that of cell lines. PDES had a significantly increased doubling time (p < 0.00001), decreased expression of Ki67 (p < 0.0001) and increased migration (p < 0.02) compared to cell lines. Consistent with the longer doubling time, PDES were more resistant to doxorubicin, etoposide and vincristine and ionising radiation (p < 0.0001) than cell lines. PDES were sensitive to mTKIs (cabozantinib, lenvatinib, and regorafenib), and trabectedin. The response of PDES to drugs in vitro reflects the clinical experience of patients. Conclusions: Models incorporating PDES cells may positively contribute to the preclinical pipeline. Full article

Background/Objectives: Standard treatment of multiply relapsed Ewing sarcoma remains to be established. Recent studies evaluating tyrosine kinase inhibitors (TKIs) with anti-angiogenic properties have shown encouraging results. Therefore, we conducted a systematic review and meta-analysis to explore the efficacy and safety of TKIs in patients with Ewing sarcoma. Methods: We comprehensively searched PubMed, Embase, and Cochrane databases for clinical trials (CTs) and cohort studies assessing TKIs in the treatment of advanced Ewing sarcoma patients who received at least one prior line of therapy. The main outcome was objective response rate (ORR). All analyses were conducted using R software (v.4.2.2), employing random effects models with 95% confidence intervals (CIs). Results: We included 14 studies (seven phase II CT and seven retrospective cohorts), comprising 257 patients. The following TKIs were evaluated: cabozantinib, regorafenib, apatinib, anlotinib, sorafenib, lenvatinib, sunitinib, fruquintinib, and imatinib. In a pooled analysis of all Ewing sarcoma patients treated with TKIs, the ORR was 23% (95% CI, 11.2–37.1%) and the DCR was 61.1% (95% CI, 47.3–74.2%). Responses were numerically higher but statistically nonsignificant between clinical trials and real-world studies. The analysis including only single-agent TKIs showed better responses for anlotinib and apatinib, yet these drugs are not available in Western countries. Among the FDA-approved TKIs, superior outcomes were noted with single-agent cabozantinib. (ORR: 21.6%) and regorafenib (ORR: 11.3%). Several studies did not report toxicity data exclusively for Ewing sarcoma patients; thus, conclusions about toxicity are mostly based on the general population of studies and may not be fully representative of Ewing sarcoma patients. Conclusions: Anti-angiogenic TKIs have shown important anti-tumoral activity in patients with Ewing sarcoma. Efficacy was consistently seen in both clinical trials and real-world studies. Nonetheless, there are important differences in study design and population that may limit our interpretation of efficacy and toxicity findings. Full article

Background/Objectives: The oncoprotein EWS::FLI1 is a chimeric transcription factor that aberrantly brings transcriptional deregulation relevant to Ewing sarcoma. It is also regarded as a therapeutic target for suppressing oncogenic progression, but the inhibition and clearance of the EWS::FLI1 oncoprotein remain a challenge. Methods: We apply a polyglutamine (polyQ) fusion strategy to directly target EWS::FLI1 in suppression of its transcriptional malfunction in A673 cells derived from Ewing sarcoma. Based on the template of the N-terminal fragment of polyQ-expanded ataxin-7 (Atx7_93Q-N172) and the homologous peptides of EWS::FLI1, we have designed and constructed three polyQ fusion proteins, namely Atx7_93Q-N172-SYGQ1, Atx7_93Q-N172-SYGQ2, and Atx7_93Q-N172-LCD. Results: Supernatant/pellet fractionation and immunofluorescence imaging reveal that the polyQ fusion proteins co-precipitate and co-localize with EWS::FLI1 in A673 cells, indicating that the polyQ fusions we have designed can sequester endogenous EWS::FLI1 into insoluble aggregates and reduce its cellular availability. Moreover, these polyQ fusions, especially Atx7_93Q-N172-LCD, alter the expression of EWS::FLI1 downstream genes, with an increase in P21 (CDKN1A) and a decrease in c-Myc. Conclusions: These results demonstrate that the engineered polyQ fusions entrap endogenous EWS::FLI1 protein into aggregates and reduce its soluble fraction in Ewing sarcoma cells. This study provides an alternative potential for treating Ewing sarcoma and other tumors by directly targeting the oncogenic proteins in the future. Full article

Background/Objectives: Cutaneous metastases from primary bone sarcomas are exceedingly rare and poorly characterized, often posing diagnostic challenges due to their atypical presentation. This systematic review aimed to describe the clinical patterns, temporal relationships, and prognostic implications of cutaneous metastases across major bone sarcoma histologies. Methods: A comprehensive literature search was conducted to identify all reported cases of cutaneous metastases from osteosarcoma, chondrosarcoma, Ewing sarcoma, and chordoma. Data on patient demographics, primary tumor site, cutaneous lesion characteristics, latency periods, synchronous metastases, morphology, and clinical outcome were extracted and analyzed descriptively. Results: 102 cases were identified, with chordoma representing the most frequent histology. Cutaneous metastases showed histology-specific patterns: osteosarcoma and Ewing sarcoma typically presented with multiple lesions in the context of widespread systemic disease and poor prognosis, whereas chordoma more often exhibited solitary or skin-dominant metastases with longer latency and occasional favorable outcomes, including complete responses after local treatment. Conclusions: Cutaneous metastases in bone sarcomas display heterogeneous behavior, with chordoma demonstrating a more indolent and potentially manageable pattern compared to other histologies. Increased clinical awareness is essential to avoid diagnostic delays and optimize management. Full article

Background: Achieving adequate margins in pelvic bone tumor resection remains difficult, as conventional navigation provides no direct three-dimensional margin feedback. We proposed an innovative dangerous region generation method based on 3D image resampling and anisotropic distance transform, integrated with computer-assisted navigation, to enhance surgical margin accuracy. This study aimed to evaluate its oncological safety, functional outcomes, and perioperative efficacy in pelvic tumor surgery. Methods: The study was conducted on 19 patients (8 males, 11 females) with primary pelvic bone tumors between May 2018 and June 2024. The age range was 19 to 66 years (mean age: 62.67 years). Histological diagnoses included chondrosarcoma (n = 6), giant cell tumor (n = 4), osteosarcoma (n = 1), chordoma (n = 2), Ewing sarcoma (n = 3), spindle cell sarcoma (n = 1), chondromyxoid fibroma (n = 1), and peripheral nerve sheath tumor (n = 1). The feasibility of the dangerous region generation method for computer-assisted pelvic tumor resection surgery was assessed by general results, oncological and functional results. Results: All patients successfully underwent surgery with a mean operative time of 252 min and average intraoperative blood loss of 1358 mL. The mean hospital stay was 22 days, and all patients completed follow-up (mean, 37 months). Two patients developed postoperative wound complications, which resolved after debridement. Adequate surgical margins were achieved in all cases. The 5-year overall survival rate was 75.6%, increasing to 80.0% among patients with wide-margin resections. At the final follow-up, the mean MSTS score among 16 limb-salvage patients was 26.6, corresponding to an average functional recovery of 88.5%. Most patients exhibited a normal gait and were able to ambulate without assistive devices. Conclusions: This dangerous region generation method, when combined with computer-assisted techniques for pelvic bone tumor resection, is feasible and can achieve favorable clinical outcomes. Full article

Background: Sarcomas are rare, aggressive malignancies with limited therapeutic options in advanced stages. This is the first real-world study in the MENA region evaluating the clinical utility of Next-Generation Sequencing (NGS) in guiding sarcoma treatment and improving outcomes. Methods: We retrospectively reviewed sarcoma patients who underwent NGS at a major referral center (2021–2024), comparing clinical and molecular outcomes between those who received NGS-based treatment adjustments (NBTA) and those who did not. Results: Seventy-eight patients were included (60% male; median age 44 years). Soft tissue sarcomas accounted for 70.5% of cases (n = 55), while bone sarcomas represented 29.5% (n = 23). Prior to NGS, 64.1% of patients had received a median of one line of systemic therapy. NGS was performed late in the disease course in 73% of cases. At least one mutation was detected in 87% (median 3 mutations). Targetable alterations were identified in 33% at the time of testing, rising to 42% with updated genomic knowledge and therapeutic advances. Overall, 20.5% received NBTA. Among non-NBTA patients, 67% had no actionable targets, 17% had no detectable mutations, and 16% were ineligible due to cost, limited access, or clinical deterioration. Tumor Mutational Burden was low in 79%, intermediate in 19%, and high in 2%, and all tumors were microsatellite stable. Patients receiving NBTA had a longer median Progression-Free Survival (9 vs. 2 months; p = 0.023). Median Overall Survival was longer in the NBTA group (74 vs. 48 months), though not statistically significant (p = 0.207). Genomic alterations were subtype-specific: EWSR1 rearrangements (Ewing and Desmoplastic small round cell tumors), CDK4 and MDM2 amplifications (Liposarcoma and Osteosarcoma), TP53 and RB1 mutations (Leiomyosarcoma), CDKN2A/B deletions (Undifferentiated Pleomorphic Sarcoma and Chondrosarcoma), and SS18 rearrangements (Synovial Sarcoma). Conclusions: Genomics-guided therapy in sarcoma is feasible and impactful. Expanding timely access to molecular profiling is essential for advancing precision oncology in the MENA region. Full article

Background: Primary fibula tumours are rare, representing approximately 0.25% of all primary bone tumours. While benign lesions are often asymptomatic, malignant ones typically present with pain and functional impairment. Most tumours arise in the proximal third of the fibula, yet the literature regarding their epidemiology and clinicopathological features remains limited. This systematic review aims to synthesise current evidence on presentation, diagnosis, management, and prognosis of primary malignant tumours of the proximal fibula. Methods: A systematic review was conducted following PRISMA guidelines. PubMed, Scopus, and the Cochrane Register were searched on 28 October 2025 for English-language case reports and case series on primary malignant tumors of the proximal fibula. Two reviewers independently performed study selection and data extraction, collecting information on demographics, tumor characteristics, diagnostic approaches, treatments, and outcomes, with disagreements resolved by a third reviewer. Results: Thirty-three papers involving 228 patients (78 females, 128 males, 22 unknown) were included. The mean age at diagnosis was 22.8 years (range 4–79). The most common symptoms were painful mass and neurological complaints. Osteosarcoma and Ewing’s sarcoma were predominant histological types. Limb-sparing surgeries were most common, although 16 patients underwent amputation. At mean follow-up of 48.9 months, local recurrence occurred in 44 cases, and 12 developed distant metastases, most commonly in the lungs. Overall, 38 patients died, 37 due to disease progression. Conclusions: Primary malignant tumours of the proximal fibula, while rare, pose significant therapeutic challenges. Accurate diagnosis, appropriate multimodal treatment, and careful surgical planning are crucial to optimise oncological control and functional outcomes. Full article

Background: Ewing’s sarcoma (EwS) is a pediatric bone and soft tissue cancer driven by the oncogenic fusion protein EWS::FLI1. Currently, EwS lacks targeted therapies, necessitating the identification of novel regulatory mechanisms. While the role of microRNAs and long non-coding RNAs has been explored in EwS, the presence and functional significance of circular RNAs (circRNAs) in EwS is not reported. This is the first study to report the presence and role of oncogenic circRNA, circZNF609 in EwS tumor progression. Methods: Expression of circZNF609 was validated in 5 different EwS cell lines using qPCR. Cellular localization of circZNF609 was identified using circFISH. Functional assays for proliferation, migration and apoptosis were performed in wild type and circZNF609 knocked down (KD) cell lines to confirm its oncogenic role. The impact of circZNF609 on EWS::FLI1 protein levels was confirmed using western blots, immunofluorescence, and polysome fractionation. Mechanistic insights were gained utilizing bioinformatic, dual-luciferase reporter assays, rescue experiments, and microscopy to identify and validate the circRNA-miRNA-mRNA regulatory axis. Results: We report the first identification of circZNF609 in EwS, demonstrating that its expression is EWS::FLI1-dependent. Functional analysis reveals that circZNF609 promotes cell proliferation and metastasis while inhibiting apoptosis. Mechanistically, circZNF609 acts as a molecular sponge for miR-145-5p. By sequestering this miRNA, circZNF609 prevents the translational repression of EWS::FLI1, thereby sustaining oncogenic signaling. Conclusions: These findings identify circZNF609 as a novel post-transcriptional regulator of EWS::FLI1 and establish its critical role in EwS pathogenesis. Our results suggest that targeting the circZNF609/miR-145-5p/EWS::FLI1 axis may offer a promising therapeutic strategy for EwS. Full article

The manufacturing process contributes significantly to the proliferation, metabolic state, and functional persistence of chimeric antigen receptor (CAR)-T cells. However, how different culture systems regulate CAR-T cell metabolism and thereby influence their long-term antitumor activity remains poorly understood. In this study, we compared dynamic cultivation using a wave bioreactor with static expansion systems (gas-permeable and conventional T-flasks) for the production of CD99-specific CAR-T cells. CAR-T cells expanded by the wave bioreactor exhibited faster proliferation and stronger cytotoxicity during culture. Upon repeated antigen stimulation, they retained these enhanced functional properties and showed the reduced expression of immune checkpoint molecules, preferentially preserved memory-like subsets, and displayed transcriptional features consistent with memory maintenance and exhaustion resistance. Targeted metabolomic profiling revealed enhanced Tricarboxylic Acid (TCA) cycle activity and features consistent with sustained oxidative phosphorylation, supporting mitochondrial-centered metabolic reprogramming. In a Ewing sarcoma xenograft model, wave bioreactor-cultured CAR-T cells showed a greater percentage of memory-like tumor-infiltrating lymphocytes. Collectively, these results indicate that wave bioreactor-based dynamic cultivation promotes mitochondrial metabolic reprogramming, which is characterized by an enhanced TCA cycle and sustained oxidative phosphorylation, thereby sustaining CAR-T cell functionality and providing a robust platform for the manufacturing of potent and durable cellular therapeutics. Full article

Background/Objectives: Targeted gene sequencing (TGS) for Comprehensive Genomic Profiling (CGP) use in sarcomas has recently increased in clinical practice. We report on TGS real-world data over a period of 3 years (2022–2025) at the IRCCS Istituto Ortopedico Rizzoli, with the aim of identifying potential actionable targets and providing therapeutic indications for advanced sarcoma patients. Methods: We analyzed 22 advanced sarcoma patients by using the VariantPlex Pan Solid Tumor kit panel, including 185 genes. In nine cases, saliva samples for germinal DNA analysis were available. Sequencing was performed on the NextSeq-500 Platform and analyzed with Archer Analysis software. The Cancer Genome Interpreter and OncoKB Database tools were used to find potential actionable targets. Results: We found the most frequent genetic variants, including missense, deletion, duplication, and delins, in the NOTCH4, AR, BARD1, MUC16, and ROS1 genes. Copy Number alterations affected the CDKN2A, CDKN2B, TP53, RHOA, MYC, CCND3, and DDR2 genes mainly in osteosarcoma samples. In four patients, longitudinal analyses of subsequent lesions showed the maintenance of most genomic alterations and enrichment in missense or splice variants in PMS2, SMARCA4, ARID1A, AKT1, BMPR1A, and PTEN, indicating the occurrence of tumor evolution. Germline variants subtraction identified the specific somatic tumor mutations. Advantages and disadvantages of our approach were considered in order to refine the analysis setting and better select possible actionable targets. Conclusions: Early access to genomic analyses, routine germline assessment, and broad gene panels would help in identifying possible targeted drugs with sufficient evidence of activity beneficial to each patient. In the clinical management of advanced sarcoma patients, when analyzing cost-effectiveness and sustainability, the role of the Molecular Tumor Board in the governance of the complexity introduced by mutational oncology should be considered. Full article

Background: Ewing sarcoma (ES) is a rare, aggressive small round cell sarcoma (SRCS) that peaks in adolescence. Given its rarity, atypical age or site presentations increase the risk of misclassification. This study examines age-related clinicopathological patterns in molecularly confirmed canonical ES (FET::ETS-fused). Methods: Between 2016 and 2025, 90 tumors diagnosed as ES or Ewing-like SRCSs underwent targeted RNA sequencing and/or EWSR1 break-apart fluorescence in situ hybridization. Patients were stratified into three age groups: 0–18, 19–39, and ≥40 years. Clinical, anatomical, pathological, molecular, and treatment/outcome variables were compared across strata. Results: Canonical ES accounted for 84% (76/90) of SRCSs, dominated by EWSR1::FLI1 (89%). ES comprised 91% of SRCSs in children but declined to 75% in older adults. Tumors arose mainly in bone (63%), with a significant age association (p = 0.016): children and young adults were primarily skeletal (73% and 62%), whereas older adults were predominantly extraskeletal (78%). Renal ES clustered in adults ≥40 years (p = 0.003). Classic histology predominated; atypical patterns were more common in extraskeletal tumors but lacked age specificity. Ewing-like SRCSs (n = 14), with heterogeneous or absent fusions, displayed a broader age distribution—including infants and older adults—and a marked extraskeletal predominance (86%, p = 0.001). Metastatic presentation strongly predicted inferior survival (p = 0.025). Treatment was multimodal, with neoadjuvant chemotherapy more frequent in children (90%, p = 0.029). Conclusions: Age significantly influences anatomic presentation and certain treatment choices in ES, whereas histology and survival remain broadly similar across groups. Age-linked extraskeletal trends reinforce the importance of routine molecular testing, particularly in underreported Middle Eastern populations. Full article