Treatment of high-risk neuroblastoma with intensive chemotherapy, radiotherapy, autologous bone marrow transplantation, and 13-cis-retinoic acid. Children's Cancer Group

The Warburg effect: The hacked mitochondrial-nuclear communication in cancer

Mitochondrial-nuclear communication is vital for maintaining cellular homeostasis. This communication begins with mitochondria sensing environmental cues and transmitting signals to the nucleus through the retrograde cascade, involving metabolic signals such as substrates for epigenetic modifications, ATP and AMP levels, calcium flux, etc. These signals inform the nucleus about the cell's metabolic state, remodel epigenome and regulate gene expression, and modulate mitochondrial function and dynamics through the anterograde feedback cascade to control cell fate and physiology. Disruption of this communication can lead to cellular dysfunction and disease progression, particularly in cancer. The Warburg effect is the metabolic hallmark of cancer, characterized by disruption of mitochondrial respiration and increased lactate generation from glycolysis. This metabolic reprogramming rewires retrograde signaling, leading to epigenetic changes and dedifferentiation, further reprogramming mitochondrial function and promoting carcinogenesis. Understanding these processes and their link to tumorigenesis is crucial for uncovering tumorigenesis mechanisms. Therapeutic strategies targeting these disrupted pathways, including metabolic and epigenetic components, provide promising avenues for cancer treatment.

Assessing bone mineral density and cortical geometry using high-resolution peripheral quantitative computed tomography in pediatric survivors of high-risk neuroblastoma with severe growth failure

INTRODUCTION

Survival of children with high-risk neuroblastoma (HR-NBL) has increased with multimodal therapy. cis-Retinoic acid (cis-RA), cornerstone of HR-NBL therapy, can cause osteoporosis and premature physeal closure. This study utilized high-resolution peripheral quantitative computed tomography (HR-pQCT), for 3D measures of volumetric bone mineral density (BMD) and microarchitecture, to assess impact of HR-NBL therapy on skeletal structure.

METHODS

We prospectively enrolled 20 HR-NBL survivors and 20 age-, sex-, and race-matched healthy reference participants. We assessed leg lean mass adjusted for leg length by DXA and strength using a Biodex dynamometer. Tibia bone microarchitecture was assessed via HR-pQCT scans at 4 % of tibia length and a cortical site at 30 %. We compared tibia length (cm), cortical and trabecular vBMD (mg HA/cm3), geometric and structural parameters between groups. Linear regression models assessed group differences in bone microarchitecture adjusted for leg lean mass.

RESULTS

Compared to reference participants, tibia length was significantly shorter in HR-NBL survivors (31.6 cm [27.7,39.5] vs. 36.1 cm [30.4,40], p < 0.005), consistent with significantly lower height Z-score in the HR-NBL cohort (p < 0.001). HR-NBL survivors demonstrated lower cortical area (178.3mm2 [121.9273.5] vs. 214.6mm2 [159.4326.9], p < 0.05) and cortical perimeter (60.0 mm [51.9,82.5] vs. 68.8 mm [57.7,90.8], p < 0.01). After adjusting for tibia length, these differences were no longer significant. Total, cortical, and trabecular volumetric BMD, were not significantly different between groups. Cortical geometry and peak torque deficits were associated with muscle deficits when adjusted for leg lean mass (p < 0.001).

CONCLUSION

Bone density was not severely impacted in HR-NBL survivors. Muscle deficits persisted years after treatment and underscored cortical geometry deficits.

GPOH Guidelines for Diagnosis and First-line Treatment of Patients with Neuroblastic Tumors, update 2025

The clinical course of neuroblastoma is more heterogeneous than any other malignant disease. Many low-risk patients experience regression after limited or even no chemotherapy. However, more than half of high-risk patients die from disease despite intensive multimodal treatment. Precise disease characterization for each patient at diagnosis is key for risk-adapted treatment. The guidelines presented here incorporate results from national and international clinical trials to produce recommendations for diagnosing and treating neuroblastoma patients in German hospitals outside of clinical trials.

Emerging clinical and research approaches in targeted therapies for high-risk neuroblastoma

Neuroblastoma is a pediatric cancer that originates from neural crest cells and is the most common extracranial solid tumor in children under five years of age. While low-risk neuroblastoma often regresses spontaneously, high-risk neuroblastoma poses a significant clinical challenge. Recent advances in understanding neuroblastoma's molecular mechanisms have led to the development of targeted therapies that aim to selectively inhibit specific pathways involved in tumor growth and progression, improving patient outcomes while minimizing side effects. This review provides a comprehensive review of neuroblastoma biology and emerging therapeutic strategies. Key topics include (a) immunotherapies and immunotargets, (b) non-coding RNAs (long non-coding RNA, microRNA, and circular RNA), (c) molecular biomarkers and pathways, and (d) limitations and future directions.

Bone morphogenetic protein (BMP) signaling determines neuroblastoma cell fate and sensitivity to retinoic acid

Retinoic acid (RA) is a standard-of-care neuroblastoma drug thought to be effective by inducing differentiation. Curiously, RA has little effect on primary human tumors during upfront treatment but can eliminate neuroblastoma cells from the bone marrow during post-chemo maintenance therapy-a discrepancy that has never been explained. To investigate this, we treat a large cohort of neuroblastoma cell lines with RA and observe that the most RA-sensitive cells predominantly undergo apoptosis or senescence, rather than differentiation. We conduct genome-wide CRISPR knockout screens under RA treatment, which identify bone morphogenic protein (BMP) signaling as controlling the apoptosis/senescence vs differentiation cell fate decision and determining RA's overall potency. We then discover that BMP signaling activity is markedly higher in neuroblastoma patient samples at bone marrow metastatic sites, providing a plausible explanation for RA's ability to clear neuroblastoma cells specifically from the bone marrow, by seemingly mimicking interactions between BMP and RA during normal development.

Neuropathiazol induces neuronal-like differentiation in neuroblastoma cells via upregulation of PEG5

BACKGROUND

Differentiation therapy is emerging as a promising strategy for treating neuroblastoma. However, the effects of neuropathiazol, a small molecule known to induce neuronal differentiation, have not been explored in neuroblastoma.

PROCEDURE

Neuroblastoma cell lines were used to investigate the effects of neuropathiazol and retinoic acid on cell morphology, proliferation, and invasion in vitro. In vivo, neuroblastoma cells were implanted in nude mice to assess neuropathiazol's therapeutic potential. Silver staining and markers of mature neurons were employed to evaluate neuropathiazol's ability to promote neuronal differentiation.

RESULTS

Neuropathiazol significantly inhibited the proliferation and invasion of neuroblastoma cells in vitro. It also enhanced synaptic growth and increased the expression of mature neuron markers more effectively than retinoic acid. Neuropathiazol treatment upregulated PEG5 expression, suggesting its role in promoting neuronal differentiation. Silencing PEG5 reversed these differentiation effects, reducing neuronal features. In vivo, neuropathiazol suppressed tumor growth and induced neuron-like differentiation in tumor tissues. However, its efficacy was diminished when PEG5 was knocked down. Additionally, neuropathiazol synergized with cyclophosphamide, enhancing its anti-neuroblastoma effects.

CONCLUSION

Neuropathiazol induces neuroblastoma differentiation, partly through PEG5 upregulation. As a promising differentiating agent for neuroblastoma, the combination of neuropathiazol and cyclophosphamide offers a potential treatment strategy for the disease.

IMPACT

Neuropathiazol significantly inhibits neuroblastoma cell proliferation and invasion in vitro. Neuropathiazol promotes synaptic growth and upregulates mature neuronal marker expression more effectively than retinoic acid. Neuropathiazol induces significant neuronal-like differentiation of neuroblastoma cells in vivo, leading to tumor growth suppression. PEG5 is identified as a critical mediator of neuropathiazol's differentiation-inducing effects. Knockdown of PEG5 reverses these effects, underscoring its pivotal role. The combination of neuropathiazol with cyclophosphamide synergistically enhances anti-neuroblastoma effects, offering a compelling pharmacotherapeutic strategy.

Strategies to manage the adverse effects of immunotherapy with dinutuximab beta in neuroblastoma: an Italian experience and literature review

PURPOSE

Patients with high-risk neuroblastoma (HR NB) frequently present with metastases in the bone marrow and bone. Approximately 15% of these patients are refractory to induction therapy, and 50% relapse. Dinutuximab beta is an anti-GD2 monoclonal antibody approved in Europe for maintenance therapy of pediatric patients with HR NB. Immunotherapy with anti-GD2 antibodies improves the survival of children with HR NB and relapsed or refractory disease. It is associated with adverse events, such as pain, fever, allergic reactions, capillary leak syndrome, and diarrhea. This manuscript aims to propose a practical guide in support and prevention treatment of adverse events.

METHODS

MEDLINE was searched using the terms "GD2," "ch14.18/CHO," "anti-GD2 antibody," "dinutuximab beta," and "neuroblastoma." The experts reappraised available evidence discussing different clinical Italian experiences.

RESULTS

Neuropathic pain is the main toxicity associated with dinutuximab beta and can be prevented with analgesics, including intravenous opioids and gabapentin by mouth. The intensity of the supportive treatment decreases from course to course.

CONCLUSION

In the experience of the authors, adverse events associated with dinutuximab beta may be prevented and managed in experienced centers. The supportive therapy may be reduced after the first cycle to improve the quality of life.

Assessment of Chemo-Immunotherapy Regimens in Patients with Refractory or Relapsed Neuroblastoma: A Systematic Review with Meta-Analysis of Critical Oncological Outcomes

Background: Neuroblastoma is a highly aggressive pediatric cancer, particularly in children with refractory or relapsed disease, where survival outcomes remain poor despite advancements in treatment. Combining anti-GD2 antibodies, such as dinutixumab beta, dinutixumab, and naxitanab, with conventional chemotherapy has emerged as a promising approach to improve clinical outcomes in this high-risk population. This chemo-immunotherapy regimen meta-analysis aimed to investigate the efficacy of these combination regimens by analyzing objective response rate (ORR), overall survival (OS), and event-free survival (EFS) outcomes across multiple studies. Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines. PubMed, Web of Science, and Scopus databases were searched, yielding studies comprising the related reports. Both randomized controlled trials and non-randomized studies were included. The primary outcome of interest was ORR, and the secondary outcome of interest was EFS. A random-effects model using the DerSimonian-Laird method and Knapp-Hartung-Sidik-Jonkman adjustments was employed to pool effect sizes, and heterogeneity was assessed using I2 statistics. Results: A total of ten reports from eight studies were deemed eligible and included in the meta-analysis. The pooled ORR across the studies was 0.45 (95% CI: 0.35-0.54, p < 0.001), indicating that approximately 45% of patients showed a favorable treatment response, with moderate heterogeneity (I2 = 52.78%). The pooled analysis showed an OS of 75% (95% CI: 53-96, p < 0.001), and the pooled EFS effect size was 0.59 (95% CI: 0.45-0.73, p < 0.001), despite substantial heterogeneity (I2 = 60.54%). Conclusions: anti-GD2 antibodies combined with conventional chemotherapy may significantly improve response rates and event-free survival in children with refractory or relapsed neuroblastoma. Future research should focus on identifying predictive biomarkers to tailor therapies to individual patients, enhancing both efficacy and safety in this vulnerable population.

Trends in childhood cancer: Incidence and survival analysis over 45 years of SEER data

BACKGROUND

The SEER Registry contains U.S. cancer statistics. To assess trends in incidence and survival and the impact of demographic factors among pediatric patients with cancer, we assessed nearly 5 decades (1975-2019) of data.

METHODS

All patients below the age of 20 with histology-confirmed malignancy were studied. Kaplan-Meier survival curves were generated to evaluate survival trends across treatment periods and ICCC classes. JoinPoint analysis was conducted to identify changes in incidence and survival.

RESULTS

The incidence of childhood cancer increased from 14.23 cases per 100,000 children in 1975-1979 to 18.89 in 2010-2019, with an average annual percent change of 0.73. This rise was more pronounced in several cancers, including leukemias, lymphomas, brain tumors, hepatic tumors, and gonadal germ cell tumors. Age-adjusted cancer mortality decreased from 4.9 to 2.3 per 100,000. Cancer-related mortality was consistently higher in boys than in girls, and in Black children than in White children. Survival significantly improved, with 5- and 10-year survival rates rising from 63.1% to 85.2% and from 58.8% to 82.7%, respectively. Leukemias showed a substantial increase in 5-year survival from 48.2% ± 1.7% to 85.1% ± 0.4% in 2010-2019. Lymphomas also showed significant improvement, with survival increasing from 72.9% ± 1.7% to 94.2% ± 0.3%. Despite these improvements, the survival of CNS tumors, bone tumors, and sarcomas remained suboptimal, with 5-year survival estimates of approximately 60%. Our joinpoint analysis confirmed our findings but revealed an interesting increase in the incidence of lymphomas limited to the years between 2005 and 2014.

CONCLUSION

This research elucidates advancements in survival among pediatric patients with cancer. The results offer critical perspectives on pediatric oncology, highlighting the imperative for ongoing innovation in therapeutics. Although the increase in incidence may partially stem from enhanced diagnostic capabilities and more comprehensive registration processes, the underlying causes remain unclear.

Global, regional, and national epidemiology of childhood neuroblastoma (1990-2021): a statistical analysis of incidence, mortality, and DALYs

Background

Neuroblastoma is the most prevalent extracranial solid tumor in pediatric populations worldwide, representing 8-10% of childhood malignancies and contributing to approximately 15% of pediatric cancer-related fatalities. This study aims to report global trends in the incidence, mortality, and disability-adjusted life years (DALYs) of childhood neuroblastoma from 1990 to 2021.

Methods

The study utilized data from the Global Burden of Disease (GBD) database to analyze neuroblastoma incidence, mortality, and DALYs in children aged 0-14 years. Rates for incidence, mortality, and DALYs were calculated per 100,000 population, with 95% uncertainty intervals (UIs). Data from 204 countries and territories were stratified by age, sex, and location. Trends were assessed using Joinpoint regression models to compute the annual percent change (APC) and log-transformed linear regression models to calculate the estimated average annual percentage change (EAPC).

Findings

Globally, the incidence of neuroblastoma in children in 2021 was 5560 cases (95% UI, 3734.21-7560.03), with 1977 deaths (95% UI, 1445.04-2528.54), and 174,186.30 DALYs (95% UI, 127,104.64-223,265.92). From 1990 to 2021, the incidence increased by 30.26% (95% UI, -1.24% to 72.51%), mortality by 20.35% (95% UI, -12.44% to 63.30%), and DALYs by 20.08% (95% UI, -12.89% to 63.27%). The incidence rate rose from 0.25 (95% UI, 0.18-0.33) per 100,000 individuals in 1990 to 0.28 (95% UI, 0.19-0.38) per 100,000 individuals in 2021, an overall increase of 12.60% (95% UI, -14.62% to 49.12%). Among the five Sociodemographic Index (SDI) regions, the highest EAPCs were observed in the low-to-mid SDI regions for incidence (1.87%; 95% CI, 1.64%-2.10%), mortality (1.22%; 95% CI, 1.09%-1.34%), and DALYs (1.36%; 95% CI, 1.15%-1.57%). Regionally, Central Asia exhibited the fastest annual increase in incidence (EAPC = 2.76%; 95% CI, 2.18%-3.34%). At the national level, India had the highest number of neuroblastoma cases globally in 2021, with 685 cases (95% UI, 404.16-1007.67).

Interpretation

The global trends for incidence, mortality, and DALYs related to pediatric neuroblastoma initially increased and then decreased, although an overall increasing trend was observed. However, the burden of disease remains significant in low-, low-middle-, and middle-SDI regions. A comprehensive understanding of the epidemiology of neuroblastoma in children is crucial for enhancing disease prevention and control efforts.

Funding

This research was funded by the Guangxi Natural Science Foundation (Grant No. 2024GXNSFAA010420) and the Youth Science Foundation of Guangxi Medical University (Grant No. GXMUYSF202404).

Restoring Mitochondrial Quantity and Quality to Reverse Warburg Effect and Drive Tumor Differentiation

Reduced mitochondrial quality and quantity in tumors is associated with dedifferentiation and increased malignancy. However, it remains unclear how to restore mitochondrial quantity and quality in tumors, and whether mitochondrial restoration can drive tumor differentiation. Our study shows that restoring mitochondrial function using retinoic acid (RA) to boost mitochondrial biogenesis and a mitochondrial uncoupler to enhance respiration synergistically drives neuroblastoma differentiation and inhibits proliferation. U-13C-glucose/glutamine isotope tracing revealed a metabolic shift from the pentose phosphate pathway to oxidative phosphorylation, accelerating the TCA cycle and switching substrate preference from glutamine to glucose. These effects were reversed by ETC inhibitors or in ρ0 cells lacking mtDNA, emphasizing the necessity of mitochondrial function for differentiation. Dietary RA and uncoupler treatment promoted tumor differentiation in an orthotopic neuroblastoma xenograft model, evidenced by neuropil production and Schwann cell recruitment. Single-cell RNA sequencing analysis of the orthotopic xenografts revealed that this strategy effectively eliminated the stem cell population, promoted differentiation, and increased mitochondrial gene signatures along the differentiation trajectory, which could potentially significantly improve patient outcomes. Collectively, our findings establish a mitochondria-centric therapeutic strategy for inducing tumor differentiation, suggesting that maintaining/driving differentiation in tumor requires not only ATP production but also continuous ATP consumption and sustained ETC activity.

Population Pharmacokinetics of Tamibarotene in Pediatric and Young Adult Patients with Recurrent or Refractory Solid Tumors

Tamibarotene is a synthetic retinoid that inhibits tumor cell proliferation and promotes differentiation. We previously reported on the safety and tolerability of tamibarotene in patients with recurrent or refractory solid tumors. Therefore, in this study, we aimed to evaluate the pharmacokinetic properties of tamibarotene and construct a precise pharmacokinetic model. We also conducted a non-compartmental analysis and population pharmacokinetic (popPK) analysis based on the results of a phase I study. Targeted pediatric and young adult patients with recurrent or refractory solid tumors were administered tamibarotene at doses of 4, 6, 8, 10, and 12 g/m2/day. Serum tamibarotene concentrations were evaluated after administration, and a popPK model was constructed for tamibarotene using Phoenix NLME. During model construction, we considered the influence of various parameters (weight, height, body surface area, and age) as covariates. Notably, 22 participants were included in this study, and 109 samples were analyzed. A two-compartment model incorporating lag time was selected as the base model. In the final model, the body surface area was included as a covariate for apparent total body clearance, the central compartment volume of distribution, and the peripheral compartment volume of distribution. Visual prediction checks and bootstrap analysis confirmed the validity and predictive accuracy of the final model as satisfactory.

Accurate Measurement of Cell Number-Normalized Differential Gene Expression in Cells Treated With Retinoic Acid

Genome-wide gene expression analysis is a commonly used method to quantitatively examine the transcriptional signature of any tissue or cell state. Standard bulk cell RNA sequencing (RNA-seq) quantifies RNAs in the cells of the tissue type of interest through massive parallel sequencing of cDNA synthesized from the cellular RNA. The subsequent analysis of global RNA expression and normalization of RNA expression levels between two or more samples generally assumes that cells from all samples produce equivalent amounts of RNA per cell. This assumption may be invalid in cells where MYC or MYCN expression levels are markedly different and thus, overall mRNA expression per cell is altered. Here, we describe an approach for RNA-seq analysis of MYCN-amplified neuroblastoma cells during treatment with retinoic acid, which causes dramatic downregulation of MYCN expression and induces growth arrest and differentiation of the cells. Our procedure employs spiked-in RNA standards added in ratio to the number of cells in each sample prior to RNA extraction. In the analysis of differential gene expression, the expression level of each gene is standardized to the spiked-in RNA standard to accurately assess gene expression levels per cell in conditions of high and low MYCN expression. Our protocol thus provides a step-by-step experimental approach for normalizing RNA-seq expression data on a per-cell-number basis, allowing accurate assessment of differential gene expression in cells expressing markedly different levels of MYC or MYCN. Key features • High levels of MYC and MYCN expression in cancer cells cause substantial increases in the levels of overall mRNA expression per cell. • RNA-seq using control RNAs spiked-in on a per-cell basis more accurately reflects global expression changes, when comparing cell populations with substantially different MYCN expression levels. • In MYCN-amplified neuroblastoma, retinoic acid dramatically decreases MYCN expression levels, resulting in large changes in overall RNA expression levels per cell.

Epac activation reduces trans-endothelial migration of undifferentiated neuroblastoma cells and cellular differentiation with a CDK inhibitor further enhances Epac effect

Neuroblastoma (NB) is the most common solid extracranial neoplasm found in children and is derived from primitive sympathoadrenal neural precursor. The disease accounts for 15% of all cancer deaths in children. The mortality rate is high in patients presenting with a metastatic tumour even with extensive treatments. This signifies the need for further research towards the development of new additional therapies that can combat not only tumour growth but metastasis, especially amongst the high-risk groups. During metastasis, primary tumour cells become migratory and travel towards a capillary within the tumour. They then degrade the matrix surrounding the pericytes and endothelial cells traversing the endothelial barrier twice to establish a secondary. This led to the hypothesis that modulation of the endothelial cell junctional stability could have an influence on tumour metastasis. To test this hypothesis, agents that modulate endothelial permeability on NB cell line migration and invasion were assessed in vitro in a tissue culture model. The cAMP agonist and its antagonists were found to have no obvious effect on both SK-N-BE2C and SK-N-AS migration, invasion and proliferation. Next, NB cells were cocultured with HDMEC cells and live cell imaging was used to assess the effect of an Epac agonist on trans-endothelial cell migration of NB cells. Epac1 agonist remarkably reduced the trans-endothelial migration of both SK-N-BE2C and SK-N-AS cells. These results demonstrate that an Epac1 agonist may perhaps serve as an adjuvant to currently existing therapies for the high-risk NB patients.

Advances in the approaches used to repurpose drugs for neuroblastoma

INTRODUCTION

Neuroblastoma (NB) remains a challenging pediatric malignancy with limited treatment options, particularly for high-risk cases. Drug repurposing offers a convenient and cost-effective strategy for treating rare diseases like NB. Using existing drugs with known safety profiles accelerates the availability of new treatments, reduces development costs, and mitigates risks, offering hope for improved patient outcomes in challenging conditions.

AREAS COVERED

This review provides an overview of the advances in approaches used to repurpose drugs for NB therapy. The authors discuss strategies employed in drug repurposing, including computational and experimental methods, and rational drug design, highlighting key examples of repurposed drugs with promising clinical results. Additionally, the authors examine the challenges and opportunities associated with drug repurposing in NB and discuss future directions and potential areas for further research.

EXPERT OPINION

The fact that only one new drug has been approved in the last 30 years for the treatment of neuroblastoma plus a significant proportion of high-risk NB patients that remain uncurable, evidences the need for new fast and cost-effective alternatives. Drug repurposing may accelerate the treatment development process while reducing expenses and risks. This approach can swiftly bring effective NB therapies to market, enhancing survival rates and patient quality of life.

Integrative genomic analyses identify neuroblastoma risk genes involved in neuronal differentiation

Genome-Wide Association Studies (GWAS) have been decisive in elucidating the genetic predisposition of neuroblastoma (NB). The majority of genetic variants identified in GWAS are found in non-coding regions, suggesting that they can be causative of pathogenic dysregulations of gene expression. Nonetheless, pinpointing the potential causal genes within implicated genetic loci remains a major challenge. In this study, we integrated NB GWAS and expression Quantitative Trait Loci (eQTL) data from adrenal gland to identify candidate genes impacting NB susceptibility. We found that ZMYM1, CBL, GSKIP and WDR81 expression was dysregulated by NB predisposing variants. We further investigated the functional role of the identified genes through computational analysis of RNA sequencing (RNA-seq) data from single-cell and whole-tissue samples of NB, neural crest, and adrenal gland tissues, as well as through in vitro differentiation assays in NB cell cultures. Our results indicate that dysregulation of ZMYM1, CBL, GSKIP, WDR81 may lead to malignant transformation by affecting early and late stages of normal program of neuronal differentiation. Our findings enhance the understanding of how specific genes contribute to NB pathogenesis by highlighting their influence on neuronal differentiation and emphasizing the impact of genetic risk variants on the regulation of genes involved in critical biological processes.

Enhanced anti-tumor activity mediated by combination chimeric antigen receptor T cells targeting GD2 and GPC2 in high-risk neuroblastoma

BACKGROUND AIMS

Chimeric antigen receptor T (CAR-T) cells targeting single antigens show limited activity against solid tumors due to poor T cell persistence, low efficiency infiltration, and exhaustion together with heterogeneous tumor-associated antigen (TAA) expression. This is also true in high-risk neuroblastoma (HRNB), a lethal pediatric extracranial malignancy. To overcome these obstacles, a combinational strategy using GD2-specific and GPC2-specific CAR-T cells was developed to improve immunotherapeutic efficacy.

METHODS

We individually developed GD2-specific and GPC2-specific CARs containing a selective domain (sCAR) which was a peptide of 10 amino acids derived from human nuclear autoantigen La/SS-B. These constructs allowed us to generate two different HRNB antigen-specific CAR-T cells with enhanced biological activity through stimulating sCAR-engrafted T cells via a selective domain-specific monoclonal antibody (SmAb). Binding affinity and stimulation of GD2- and GPC2-specific sCARs by SmAb were measured, and transient and persistent anti-tumor cytotoxicity of GD2sCAR-T and GPC2sCAR-T cells were quantified in neuroblastoma cell lines expressing different TAA levels. The anti-tumor pharmaceutical effects and cellular mechanisms mediated by single or combinational sCAR-T cells were evaluated in vitro and in vivo.

RESULTS

GD2- and GPC2-specific sCARs had antigen-specific binding affinity similar to their parental counterparts and were recognized by SmAb. SmAb-mediated stimulation selectively activated sCAR-T proliferation and increased central memory T cells in the final products. SmAb-stimulated sCAR-T cells had enhanced transient cytolytic activity, and combination therapy extended long-term anti-tumor activity in vitro through TNF-α and IL-15 release. Stimulated sCAR-T cells overcame heterogeneous antigen expression in HRNB, and the multi-TAA-targeting strategy was especially efficacious in vivo, inducing apoptosis through the caspase-3/PARP pathway and inhibiting the release of several tumor-promoting cytokines.

CONCLUSIONS

These data suggest that combined targeting of multiple TAAs is a promising strategy to overcome heterogenous antigen expression in solid tumors and extend CAR-T cell persistence for HRNB immunotherapy.

Unveiling Tumorigenesis Mechanisms and Drug Therapy in Neuroblastoma by Mass Spectrometry Based Proteomics

Neuroblastoma (NB) is the most common type of extracranial solid tumors in children. Despite the advancements in treatment strategies over the past years, the overall survival rate in patients within the high-risk NB group remains less than 50%. Therefore, new treatment options are urgently needed for this group of patients. Compared with genomic aberrations, proteomic alterations are more dynamic and complex, as well as more directly related to pathological phenotypes and external perturbations such as environmental changes and drug treatments. This review focuses on specific examples of proteomics application in various fundamental aspects of NB research, including tumorigenesis, drug treatment, drug resistance, and highlights potential protein signatures and related signaling pathways with translational values for clinical practice. Moreover, emerging cutting-edge proteomic techniques, such as single cell and spatial proteomics, as well as mass spectrometry imaging, are discussed for their potentials to probe intratumor heterogeneity of NB.

Immune reconstitution after transplantation of autologous peripheral stem cells in children: a comparison between CD34+ selected and nonmanipulated grafts

BACKGROUND AND AIMS

High-dose chemotherapy (HDC) followed by autologous stem cell transplantation (ASCT) improves the prognosis in pediatric patients with several solid tumors and lymphomas. Little is known about the reconstitution of the immune system after ASCT and the influence of CD34+ cell selection on the reconstitution in pediatric patients.

METHODS

Between 1990 and 2001, 94 pediatric patients with solid tumors and lymphomas received autologous CD34+ selected or unmanipulated peripheral stem cells after HDC. CD34+ selection was carried out with magnetic microbeads. The absolute numbers of T cells, B cells and natural killer (NK) cells were measured and compared in both groups at various time points post-transplant.

RESULTS

Recovery of T cells was significantly faster in the unmanipulated group at day 30, with no significant difference later on. Reconstitution of B and NK cells was similar in both groups without significant differences at any time. The CD34+-selected group was divided into patients receiving less or more than 5.385 × 106/kg CD34+ cells. Patients in the CD34+ high-dose group displayed significantly faster reconstitutions of neutrophiles and lymphocyte subsets than the CD34+ low-dose group.

CONCLUSIONS

Engraftment and reconstitution of leukocytes, B cells and NK cells after transplantation of CD34+ selected stem cells were comparable to that in patients receiving unmanipulated grafts. T-cell recovery was faster in the unmanipulated group only within the first month. However, this delay could be compensated by transplantation of >5.385 × 106 CD34+ cells/kg. Especially for patients receiving immunotherapy after HDC large numbers of immune effector cells such as NK and T cells are necessary to mediate antibody-dependent cellular cytotoxicity. Therefore, in patients receiving autologous CD34+-selected grafts, our data emphasize the need to administer high stem cell counts.

Germline functional variants contribute to somatic mutation and outcomes in neuroblastoma

Germline genetic context may play a significant role in the development and evolution of cancer, particularly in childhood cancers such as neuroblastoma. This study investigates the role of putatively functional germline variants in neuroblastoma, even if they do not directly increase disease risk. Our whole-exome sequencing analysis of 125 patients with neuroblastoma reveals a positive correlation between germline variant burden and somatic mutations. Moreover, patients with higher germline variant burden exhibit worse outcomes. Similar findings are observed in the independent neuroblastoma cohort where a higher germline variant burden correlates with a higher somatic mutational burden and a worse overall survival outcome. However, contrasting results emerge in adult-onset cancer, emphasizing the importance of germline genetics in neuroblastoma. The enrichment of putatively functional germline variants in cancer predisposition genes is borderline significant when compared to healthy populations (P = 0.077; Odds Ratio, 1.45; 95% confidence intervals, 0.94-2.21) and significantly more pronounced against adult-onset cancers (P = 0.016; Odds Ratio, 2.13; 95% confidence intervals, 1.10-3.91). Additionally, the presence of these variants proves to have prognostic significance in neuroblastoma (log-rank P < 0.001), and combining germline with clinical risk factors notably improves survival predictions.

Molecular profiling of core immune-escape genes highlights TNFAIP3 as an immune-related prognostic biomarker in neuroblastoma

BACKGROUND

Neuroblastoma (NB) is the most prevalent and deadliest pediatric solid tumor. With of over 50% of high-risk neuroblastoma cases relapse, the imperative for novel drug targets and therapeutic strategies is accentuated. In neuroblastoma, the existence of tumor-associated macrophages (TAMs) correlates with an unfavorable patient prognosis. However, the clinical relevance and prognostic implications of regulatory genes linked to TAMs infiltration in neuroblastoma remain unclear, and further study is required.

METHODS

We conducted a comprehensive analysis utilizing transcriptome expression profiles from three primary datasets associated with neuroblastoma (GSE45547, GSE49710, TARGET) to identify hub genes implicated in immune evasion within neuroblastoma. Subsequently, we utilized single-cell RNA sequencing analysis on 17 clinical neuroblastoma samples to investigate the expression and distribution of these hub genes, leading to the identification of TNFAIP3. The above three public databases were merged to allowed for the validation of TNFAIP3's molecular functions through GO and KEGG analysis. Furthermore, we assessed TNFAIP3's correlation with immune infiltration and its potential immunotherapeutic impact by multiple algorithms. Our single-cell transcriptome data revealed the role of TNFAIP3 in macrophage polarization. Finally, preliminary experimental verifications to confirm the biological functions of TNFAIP3-mediated TAMs in NB.

RESULTS

A total of 6 genes related to immune evasion were screened and we found that TNFAIP3 exhibited notably higher expression in macrophages than other immune cell types, based on the scRNA-sequencing data. GO and KEGG analysis showed that low expression of TNFAIP3 significantly correlated with the activation of multiple oncogenic pathways as well as immune-related pathways. Then validation affirmed that individuals within the TNFAIP3 high-expression cohort could potentially derive greater advantages from immunotherapeutic interventions, alongside exhibiting heightened immune responsiveness. Deciphering the pseudotime trajectory of macrophages, we revealed the potential of TNFAIP3 in inducing the polarization of macrophages towards the M1 phenotype. Finally, we confirmed that patients in the TNFAIP3 high expression group might benefit more from immunotherapy or chemotherapy as substantiated by RT-qPCR and immunofluorescence examinations. Moreover, the role of TNFAIP3 in macrophage polarization was validated. Preliminary experiment showed that TNFAIP3-mediated TAMs inhibit the proliferation, migration and invasion capabilities of NB cells.

CONCLUSIONS

Our results suggest that TNFAIP3 was first identified as a promising biomarker for immunotherapy and potential molecular target in NB. Besides, the presence of TNFAIP3 within TAMs may offer a novel therapeutic strategy for NB.

Effects and mechanisms of puerarin against neuroblastoma: insights from bioinformatics and in vitro experiments

BACKGROUND

Neuroblastoma, a prevalent solid tumor in children, often manifests with hidden onset sites, rapid growth, and high metastatic potential. The prognosis for children with high-risk neuroblastoma remains poor, highlighting the urgent need for novel prognostic models and therapeutic avenues. In recent years, puerarin, as a kind of small molecule drug extracted from Chinese medicine Pueraria lobata, has demonstrated significant anticancer effects on various cancer cell types. In this study, through bioinformatics analysis and in vitro experiments, the potential and mechanism of puerarin in the treatment of neuroblastoma were investigated, and a prognostic model was established.

METHODS

A total of 9 drug-disease related targets were observed by constructing a database of drug targets and disease genes. Besides, GO and KEGG enrichment analysis was performed to explore the potential mechanism of its therapeutic effect. To construct the prognostic model, risk regression analysis and LASSO analysis were carried out for validation. Finally, the prognostic genes were identified. Parachute test and immunofluorescence staining were performed to verify the potential mechanism of puerarin in neuroblastoma treatment.

RESULTS

Three prognostic genes, i.e., BIRC5, TIMP2 and CASP9, were identified. In vitro studies verified puerarin's impact on BIRC5, TIMP2, and CASP9 expression, inhibiting proliferation in neuroblastoma SH-SY5Y cells. Puerarin disrupts the cytoskeleton, boosts gap junctional communication, curtailing invasion and migration, and induces mitochondrial damage in SH-SY5Y cells.

CONCLUSIONS

Based on network pharmacology and bioinformatics analysis, combined with in vitro experimental verification, puerarin was hereby observed to enhance GJIC in neuroblastoma, destroy cytoskeleton and thus inhibit cell invasion and migration, cause mitochondrial damage of tumor cells, and inhibit cell proliferation. Overall, puerarin, as a natural medicinal compound, does hold potential as a novel therapy for neuroblastoma.

The miR-29 family facilitates the activation of NK-cell immune responses by targeting the B7-H3 immune checkpoint in neuroblastoma

Neuroblastoma (NB) is a highly aggressive pediatric cancer that originates from immature nerve cells, presenting significant treatment challenges due to therapy resistance. Despite intensive treatment, approximately 50% of high-risk NB cases exhibit therapy resistance or experience relapse, resulting in poor outcomes often associated with tumor immune evasion. B7-H3 is an immune checkpoint protein known to inhibit immune responses. MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation. Our study aims to explore the impact of miRNAs on B7-H3 regulation, the anti-tumor immune response, and tumorigenicity in NB. Analysis of NB patients and patient-derived xenograft tumors revealed a correlation between higher B7-H3 expression and poorer patient survival. Notably, deceased patients exhibited a depletion of miR-29 family members (miR-29a, miR-29b, and miR-29c), which displayed an inverse association with B7-H3 expression in NB patients. Overexpression and knockdown experiments demonstrated that these miRNAs degrade B7-H3 mRNA, resulting in enhanced NK cell activation and cytotoxicity. In vivo, experiments provided further evidence that miR-29 family members reduce tumorigenicity, macrophage infiltration, and microvessel density, promote infiltration and activation of NK cells, and induce tumor cell apoptosis. These findings offer a rationale for developing more effective combination treatments that leverage miRNAs to target B7-H3 in NB patients.

Neuroprotective effects of flavonoids: endoplasmic reticulum as the target

The incidence of neurological disorders, particularly age-related neurodegenerative pathologies, exhibits an alarming upward trend, while current pharmacological interventions seldom achieve curative outcomes. Despite their diverse clinical presentations, neurological diseases often share a common pathological thread: the aberrant accumulation of misfolded proteins within the endoplasmic reticulum (ER). This phenomenon, known as ER stress, arises when the cell's intrinsic quality control mechanisms fail to cope with the protein-folding burden. Consequently, misfolded proteins accumulate in the ER lumen, triggering a cascade of cellular stress responses. Recognizing this challenge, researchers have intensified their efforts over the past two decades to explore natural compounds that could potentially slow or even reverse these devastating pathologies. Flavonoids constitute a vast and heterogeneous class of plant polyphenols, with over 10,000 identified from diverse natural sources such as wines, vegetables, medicinal plants, and organic products. Flavonoids are generally divided into six different subclasses: anthocyanidins, flavanones, flavones, flavonols, isoflavones, and flavonols. The diverse family of flavonoids, featuring a common phenolic ring backbone adorned with varying hydroxyl groups and additional modifications, exerts its antioxidant activity by inhibiting the formation of ROS, as evidenced by research. Also, studies suggest that polyphenols such as flavonoids can regulate ER stress through apoptosis and autophagy. By understanding these mechanisms, we can unlock the potential of flavonoids as novel therapeutic agents for neurodegenerative disorders. Therefore, this review critically examines the literature exploring the modulatory effects of flavonoids on various steps of the ER stress in neurological disorders.

Impact of risk-based therapy on late morbidity and mortality in neuroblastoma survivors: a report from the Childhood Cancer Survivor Study

BACKGROUND

Early efforts at risk-adapted therapy for neuroblastoma are predicted to result in differential late effects; the magnitude of these differences has not been well described.

METHODS

Late mortality, subsequent malignant neoplasms (SMNs), and severe/life-threatening chronic health conditions (CHCs), graded according to CTCAE v4.03, were assessed among 5-year Childhood Cancer Survivor Study (CCSS) survivors of neuroblastoma diagnosed 1987-1999. Using age, stage at diagnosis, and treatment, survivors were classified into risk groups (low [n = 425]; intermediate [n = 252]; high [n = 245]). Standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) of SMNs were compared with matched population controls. Cox regression models estimated hazard ratios (HRs) and 95% confidence intervals for CHC compared with 1029 CCSS siblings.

RESULTS

Among survivors (49.8% male; median age = 21 years, range = 7-42; median follow-up = 19.3 years, range = 5-29.9), 80% with low-risk disease were treated with surgery alone, whereas 79.1% with high-risk disease received surgery, radiation, chemotherapy ± autologous stem cell transplant (ASCT). All-cause mortality was elevated across risk groups (SMRhigh = 27.7 [21.4-35.8]; SMRintermediate = 3.3 [1.7-6.5]; SMRlow = 2.8 [1.7-4.8]). SMN risk was increased among high- and intermediate-risk survivors (SIRhigh = 28.0 [18.5-42.3]; SIRintermediate = 3.7 [1.2-11.3]) but did not differ from the US population for survivors of low-risk disease. Compared with siblings, survivors had an increased risk of grade 3-5 CHCs, particularly among those with high-risk disease (HRhigh = 16.1 [11.2-23.2]; HRintermediate = 6.3 [3.8-10.5]; HRlow = 1.8 [1.1-3.1]).

CONCLUSION

Survivors of high-risk disease treated in the early days of risk stratification carry a markedly elevated burden of late recurrence, SMN, and organ-related multimorbidity, whereas survivors of low/intermediate-risk disease have a modest risk of late adverse outcomes.

Wnt/β-Catenin Signaling Pathway in Pediatric Tumors: Implications for Diagnosis and Treatment

The evolutionarily conserved Wnt signaling has a significant and diverse role in maintaining cell homeostasis and tissue maintenance. It is necessary in the regulation of crucial biological functions such as embryonal development, proliferation, differentiation, cell fate, and stem cell pluripotency. The deregulation of Wnt/β-catenin signaling often leads to various diseases, including cancer and non-cancer diseases. The role of Wnt/β-catenin signaling in adult tumors has been extensively studied in literature. Although the Wnt signaling pathway has been well explored and recognized to play a role in the initiation and progression of cancer, there is still a lack of understanding on how it affects pediatric tumors. This review discusses the recent developments of this signaling pathway in pediatric tumors. We also focus on understanding how different types of variations in Wnt signaling pathway contribute to cancer development and provide an insight of tissue specific mutations that lead to clinical progression of these tumors.

A nationwide phase II study of delayed local treatment for children with high-risk neuroblastoma: The Japan Children's Cancer Group Neuroblastoma Committee Trial JN-H-11

PURPOSE

Survival rates of patients with high-risk neuroblastoma are unacceptable. A time-intensified treatment strategy with delayed local treatment to control systemic diseases has been developed in Japan. We conducted a nationwide, prospective, single-arm clinical trial with delayed local treatment. This study evaluated the safety and efficacy of delayed surgery to increase treatment intensity.

PATIENTS AND METHODS

Seventy-five patients with high-risk neuroblastoma were enrolled in this study between May 2011 and September 2015. Delayed local treatment consisted of five courses of induction chemotherapy (cisplatin, pirarubicin, vincristine, and cyclophosphamide) and myeloablative high-dose chemotherapy (melphalan, etoposide, and carboplatin), followed by local tumor extirpation with surgery and irradiation. The primary endpoint was progression-free survival (PFS). The secondary endpoints were overall survival (OS), response rate, adverse events, and surgical complications.

RESULTS

Seventy-five patients were enrolled, and 64 were evaluable (stage 3, n = 8; stage 4, n = 56). The estimated 3-year PFS and OS rates (95% confidence interval [CI]) were 44.4% [31.8%-56.3%] and 80.7% [68.5%-88.5%], resspectively. The response rate of INRC after completion of the treatment protocol was 66% (42/64; 95% CI: 53%-77%; 23 CR [complete response], 10 VGPR [very good partial response], and nine PR [partial response]). None of the patients died during the protocol treatment or within 30 days of completion. Grade 4 adverse effects, excluding hematological adverse effects, occurred in 48% of patients [31/64; 95% CI: 36%-61%]. Major Surgical complications were observed in 25% of patients [13/51; 95% CI: 14%-40%].

CONCLUSION

This study indicates that delayed local treatment is feasible and shows promising efficacy, suggesting that this treatment should be considered further in a comparative study of high-risk neuroblastoma.

Bone morphogenetic protein (BMP) signaling determines neuroblastoma cell fate and sensitivity to retinoic acid

Retinoic acid (RA) is a standard-of-care neuroblastoma drug thought to be effective by inducing differentiation. Curiously, RA has little effect on primary human tumors during upfront treatment but can eliminate neuroblastoma cells from the bone marrow during post-chemo consolidation therapy-a discrepancy that has never been explained. To investigate this, we treated a large cohort of neuroblastoma cell lines with RA and observed that the most RA-sensitive cells predominantly undergo apoptosis or senescence, rather than differentiation. We conducted genome-wide CRISPR knockout screens under RA treatment, which identified BMP signaling as controlling the apoptosis/senescence vs differentiation cell fate decision and determining RA's overall potency. We then discovered that BMP signaling activity is markedly higher in neuroblastoma patient samples at bone marrow metastatic sites, providing a plausible explanation for RA's ability to clear neuroblastoma cells specifically from the bone marrow, seemingly mimicking interactions between BMP and RA during normal development.

Phase II Study of Allogeneic Hematopoietic Stem Cell Transplantation for Children with High-Risk Neuroblastoma Using a Reduced-Intensity Conditioning Regimen: Results from the AIEOP Trial

Despite aggressive multimodal treatment, the outcomes of pediatric patients with high-risk (HR) neuroblastoma (NB) remain poor. The rationale for allogeneic hematopoietic stem cell transplantation (allo-HCT) to treat NB was based on the possible graft-versus-tumor effect; however, toxicity limits its efficacy. We sought to prospectively assess the feasibility and efficacy of allo-HCT using a reduced-intensity conditioning regimen in pediatric patients with HR NB in a multicenter phase II trial. Primary endpoints were the rate of neutrophil and platelet engraftment, 5-year transplantation-related mortality (TRM), and disease-free survival (DFS). Secondary endpoint measures included the incidence of acute graft-versus-host disease (aGVHD) and chronic GVHD. Fifty-one patients were enrolled in the study. The 5-year cumulative incidence (CuI) of TRM was 29.4 ± 6.4%, and that of DFS was 11.8 ± 4.5%. Patients undergoing allo-HCT within 1 year of diagnosis or with bone marrow as their stem cell source had a higher DFS probability. The CuI of neutrophil engraftment, platelet engraftment, and grade II-IV aGVHD was 97.9 ± 2.1%, 93.8 ± 3.5%, and 47.1 ± 7.0%, respectively. The development of new therapeutic strategies could further improve disease control.

Recent advances in the development of 225Ac- and 211At-labeled radioligands for radiotheranostics

Radiotheranostics utilizes a set of radioligands incorporating diagnostic or therapeutic radionuclides to achieve both diagnosis and therapy. Imaging probes using diagnostic radionuclides have been used for systemic cancer imaging. Integration of therapeutic radionuclides into the imaging probes serves as potent agents for radionuclide therapy. Among them, targeted alpha therapy (TAT) is a promising next-generation cancer therapy. The α-particles emitted by the radioligands used in TAT result in a high linear energy transfer over a short range, inducing substantial damage to nearby cells surrounding the binding site. Therefore, the key to successful cancer treatment with minimal side effects by TAT depends on the selective delivery of radioligands to their targets. Recently, TAT agents targeting biomolecules highly expressed in various cancer cells, such as sodium/iodide symporter, norepinephrine transporter, somatostatin receptor, αvβ3 integrin, prostate-specific membrane antigen, fibroblast-activation protein, and human epidermal growth factor receptor 2 have been developed and have made remarkable progress toward clinical application. In this review, we focus on two radionuclides, 225Ac and 211At, which are expected to have a wide range of applications in TAT. We also introduce recent fundamental and clinical studies of radiopharmaceuticals labeled with these radionuclides.

Targeting of neuroblastoma cells through Kynurenine-AHR pathway inhibition

Neuroblastoma poses significant challenges in clinical management. Despite its relatively low incidence, this malignancy contributes disproportionately to cancer-related childhood mortality. Tailoring treatments based on risk stratification, including MYCN oncogene amplification, remains crucial, yet high-risk cases often confront therapeutic resistance and relapse. Here, we explore the aryl hydrocarbon receptor (AHR), a versatile transcription factor implicated in diverse physiological functions such as xenobiotic response, immune modulation, and cell growth. Despite its varying roles in malignancies, AHR's involvement in neuroblastoma remains elusive. Our study investigates the interplay between AHR and its ligand kynurenine (Kyn) in neuroblastoma cells. Kyn is generated from tryptophan (Trp) by the activity of the enzymes indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO2). We found that neuroblastoma cells displayed sensitivity to the TDO2 inhibitor 680C91, exposing potential vulnerabilities. Furthermore, combining TDO2 inhibition with retinoic acid or irinotecan (two chemotherapeutic agents used to treat neuroblastoma patients) revealed synergistic effects in select cell lines. Importantly, clinical correlation analysis using patient data established a link between elevated expression of Kyn-AHR pathway genes and adverse prognosis, particularly in older children. These findings underscore the significance of the Kyn-AHR pathway in neuroblastoma progression, emphasizing its potential role as a therapeutic target.

EGCG Disrupts the LIN28B/Let-7 Interaction and Reduces Neuroblastoma Aggressiveness

Neuroblastoma (NB) is the most commonly diagnosed extracranial solid tumor in children, accounting for 15% of all childhood cancer deaths. Although the 5-year survival rate of patients with a high-risk disease has increased in recent decades, NB remains a challenge in pediatric oncology, and the identification of novel potential therapeutic targets and agents is an urgent clinical need. The RNA-binding protein LIN28B has been identified as an oncogene in NB and is associated with a poor prognosis. Given that LIN28B acts by negatively regulating the biogenesis of the tumor suppressor let-7 miRNAs, we reasoned that selective interference with the LIN28B/let-7 miRNA interaction would increase let-7 miRNA levels, ultimately leading to reduced NB aggressiveness. Here, we selected (-)-epigallocatechin 3-gallate (EGCG) out of 4959 molecules screened as the molecule with the best inhibitory activity on LIN28B/let-7 miRNA interaction and showed that treatment with PLC/PLGA-PEG nanoparticles containing EGCG (EGCG-NPs) led to an increase in mature let-7 miRNAs and a consequent inhibition of NB cell growth. In addition, EGCG-NP pretreatment reduced the tumorigenic potential of NB cells in vivo. These experiments suggest that the LIN28B/let-7 miRNA axis is a good therapeutic target in NB and that EGCG, which can interfere with this interaction, deserves further preclinical evaluation.

Stemness and Cell Cycle Regulators and Their Modulation by Retinoic Acid in Ewing Sarcoma

Retinoic acid (RA) regulates stemness and differentiation in human embryonic stem cells (ESCs). Ewing sarcoma (ES) is a pediatric tumor that may arise from the abnormal development of ESCs. Here we show that RA impairs the viability of SK-ES-1 ES cells and affects the cell cycle. Cells treated with RA showed increased levels of p21 and its encoding gene, CDKN1A. RA reduced mRNA and protein levels of SRY-box transcription factor 2 (SOX2) as well as mRNA levels of beta III Tubulin (TUBB3), whereas the levels of CD99 increased. Exposure to RA reduced the capability of SK-ES-1 to form tumorspheres with high expression of SOX2 and Nestin. Gene expression of CD99 and CDKN1A was reduced in ES tumors compared to non-tumoral tissue, whereas transcript levels of SOX2 were significantly higher in tumors. For NES and TUBB3, differences between tumors and control tissue did not reach statistical significance. Low expression of CD99 and NES, and high expression of SOX2, were significantly associated with a poorer patient prognosis indicated by shorter overall survival (OS). Our results indicate that RA may display rather complex modulatory effects on multiple target genes associated with the maintenance of stem cell's features versus their differentiation, cell cycle regulation, and patient prognosis in ES.

Global research trends in Total Body Irradiation: a bibliometric analysis

Objectives

This manuscript presents a bibliometric and visualization analysis of Total Body Irradiation (TBI) research, aiming to elucidate trends, gaps, and future directions in the field. This study aims to provide a comprehensive overview of the global research landscape of TBI, highlighting its key contributions, evolving trends, and potential areas for future exploration.

Methods

The data for this study were extracted from the Web of Science Core Collection (WoSCC), encompassing articles published up to May 2023. The analysis included original studies, abstracts, and review articles focusing on TBI-related research. Bibliometric indicators such as total publications (TP), total citations (TC), and citations per publication (C/P) were utilized to assess the research output and impact. Visualization tools such as VOS Viewer were employed for thematic mapping and to illustrate international collaboration networks.

Results

The analysis revealed a substantial body of literature, with 7,315 articles published by 2,650 institutions involving, 13,979 authors. Full-length articles were predominant, highlighting their central role in the dissemination of TBI research. The authorship pattern indicated a diverse range of scholarly influences, with both established and emerging researchers contributing significantly. The USA led in global contributions, with significant international collaborations observed. Recent research trends have focused on refining TBI treatment techniques, investigating long-term patient effects, and advancing dosimetry and biomarker studies for radiation exposure assessments.

Conclusions

TBI research exhibits a dynamic and multifaceted landscape, driven by global collaboration and innovation. It highlights the clinical challenges of TBI, such as its adverse effects and the need for tailored treatments in pediatric cases. Crucially, the study also acknowledges the fundamental science underpinning TBI, including its effects on inflammatory and apoptotic pathways, DNA damage, and the varied sensitivity of cells and tissues. This dual focus enhances our understanding of TBI, guiding future research toward innovative solutions and comprehensive care.

Effects of Anionic Liposome Delivery of All-Trans-Retinoic Acid on Neuroblastoma Cell Differentiation

All-trans-retinoic acid (ATRA) has long been known to affect cell growth and differentiation. To improve ATRA's therapeutic efficacy and pharmacodynamics, several delivery systems have been used. In this study, free ATRA and anionic-liposome-encapsulated ATRA were compared for their effects on SK-N-SH human neuroblastoma cell growth and differentiation. Anionic liposomes made of L-α-phosphatidylcholine (PC) and L-α-phosphatidic acid (PA), empty (PC-PA) and loaded with ATRA (PC-PA-ATRA), were characterized by dynamic light scattering (DLS) and electrophoretic mobility measurements, and drug entrapment efficiency (EE%) was measured to evaluate the applicability of the new colloidal formulation. The results of brightfield microscopy and cell growth curves indicated that ATRA, whether free or encapsulated, reduced growth and induced differentiation, resulting in SK-N-SH cells changing from epithelioid to neuronal-like morphologies, and producing a significant increase in neurite growth. To further characterize the neuro-differentiation of SK-N-SH cells, the expression of βIII-Tubulin and synaptophysin and mitochondria localization were analyzed via immunofluorescence. Increased expression of neuronal markers and a peculiar localization of mitochondria in the neuritic extensions were apparent both in ATRA- and PC-PA-ATRA-differentiated cells. As a whole, our results strongly indicate that ATRA treatment, by any means, can induce the differentiation of parent SK-N-SH, and they highlight that its encapsulation in anionic liposomes increases its differentiation ability in terms of the percentage of neurite-bearing cells. Interestingly, our data also suggest an unexpected differentiation capability of anionic liposomes per se. This work highlights the importance of developing and carefully testing novel delivery nanocarriers, which are a necessary first "step" in the development of new therapeutic settings.

Impaired Aortic Growth in Neuroblastoma Patients After Intensive Treatment

PURPOSE

This study evaluated the abdominal aortic diameter in high-risk neuroblastoma (NB) patients and the risk of aortic narrowing following intensive treatment.

METHODS

We measured the aortic diameter at four specific levels of the abdominal aorta (diaphragmatic crus, celiac axis, and the root of the superior (SMA) and inferior (IMA) mesenteric arteries) on contrast CT scans. The control group consisted of 56 children with non-oncologic disorders, while the NB group included 35 patients with high-risk abdominal NB. We used regression analysis of age and aortic diameter to determine the regression formula for each level in each group and performed intergroup comparisons using t-test.

RESULTS

We evaluated a total of 160 contrast-enhanced CTs performed in the 35 eligible cases. The aortic diameter of pretreated NB patients was not significantly different from the controls. After receiving any treatment, the aortic diameter was significantly smaller in the NB group (p < 0.01 each). Patients who underwent radical surgery, particularly gross total resection (n = 26), had smaller aortic diameters at all levels compared to controls (p < 0.01 each). Patients treated with radiotherapy (RT) had smaller aortic diameters than controls. External beam radiotherapy (EBRT) patients (n = 24) had smaller aortic diameters at all levels except the celiac axis (crus, SMA, IMA; p < 0.01 each), and intraoperative radiotherapy (IORT) ± EBRT patients (n = 5) had smaller aortic diameters at all levels (p < 0.01 each).

CONCLUSION

Patients with NB may experience impaired development of the abdominal aorta after multimodal therapy, particularly after RT. Close observation and long-term follow-up is essential to monitor for catastrophic vascular complications.

LEVEL OF EVIDENCE

LEVEL III.

Survival Benefit of Myeloablative Therapy with Autologous Stem Cell Transplantation in High-Risk Neuroblastoma: A Systematic Literature Review

BACKGROUND

Multimodal treatment of newly diagnosed high-risk neuroblastoma (HRNB) includes induction chemotherapy, consolidation with myeloablative therapy (MAT) and autologous stem cell transplantation (ASCT), followed by anti-disialoganglioside 2 (GD2) immunotherapy, as recommended by the Children's Oncology Group (COG) and the Society of Paediatric Oncology European Neuroblastoma (SIOPEN). Some centres proposed an alternative approach with induction chemotherapy followed by anti-GD2 immunotherapy, without MAT+ASCT.

OBJECTIVE

The aim of this systematic literature review was to compare survival outcomes in patients with HRNB treated with or without MAT+ASCT and with or without subsequent anti-GD2 immunotherapy.

PATIENTS AND METHODS

The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE via PubMed and EMBASE databases were systematically searched for randomised controlled trials (RCT) and observational comparative studies in patients with HRNB using search terms for 'neuroblastoma' and ('myeloablative therapy' OR 'stem cell transplantation'). Reporting of at least one survival outcome [event-free survival (EFS), progression-free survival, relapse-free survival and/or overall survival (OS)] was required for inclusion. Outcomes from RCTs were synthesized in meta-analysis, while meta-analysis of non-RCTs was not planned owing to expected heterogeneity.

RESULTS

Literature searches produced 2587 results with 41 publications reporting 34 comparative studies included in the review. Of these, 7 publications reported 4 RCTs, and 34 publications reported 30 non-RCT studies. Studies differed with respect to included populations, induction regimen, response to induction, additional treatments and transplantation procedures. Subsequent treatments of relapse were rarely reported and could not be compared. In the meta-analysis, EFS was in favour of MAT+ASCT over conventional chemotherapy or no further treatment [hazard ratio (HR) = 0.78, 95% confidence interval (CI) 0.67-0.91, p = 0.001] with a trend favouring MAT+ASCT for OS (HR = 0.86, 95% CI 0.73-1.00, p = 0.05). Tandem MAT+ASCT was found to improve EFS compared with the single procedure, with improvement in both EFS and OS in patients treated with anti-GD2 therapy. Non-RCT comparative studies were broadly consistent with evidence from the RCTs; however, not all reported survival benefits of MAT+ASCT (single or tandem). Limited comparative evidence on treatment without MAT+ASCT in patients treated with anti-GD2 immunotherapy suggests an increased risk of relapse. In relapsed patients, MAT+ASCT appears to improve OS, but evidence remains scarce.

CONCLUSIONS

Survival benefits in patients treated with MAT+ASCT confirm that the procedure should remain an integral part of multimodal therapy. In patients treated with anti-GD2 immunotherapy, limited evidence suggests that omitting MAT+ASCT is associated with an increased risk of relapse, and therefore, a change in clinical practice can currently not be recommended. Evidence suggests the use of tandem MAT+ASCT compared with the single procedure, with greater benefits observed in patients treated with anti-GD2 immunotherapy. Limited evidence also suggests improved survival following MAT+ASCT in relapsed patients, which needs to be viewed in light of emerging chemoimmunotherapy in this setting.

Visual conservation treatment dilemmas in neuroblastoma with bilateral blindness

OBJECTIVE

To investigate the clinical features, treatment strategies, and prognosis of neuroblastoma with bilateral blindness.

METHODS

The clinical data of five patients with bilateral blindness neuroblastoma admitted to Beijing Children's Hospital from April 2018 to September 2020 were retrospectively collected to summarize their clinical characteristics.

RESULTS

All patients were female and the median age at presentation was 25 (23, 41) months. The median intervention time from the onset of symptoms of bilateral blindness to the start of treatment was 10 (10, 12) days. All five cases were staged as stage M and grouped as high risk. Four cases were MYCN gene amplification and one case was MYCN acquisition. Five children were treated according to a high-risk neuroblastoma treatment protocol. Four children did not recover their vision after treatment, and one case improved to have light perception. All patients were effectively followed up for a median of 20 (12, 31) months, with three deaths, one tumor-free survival, and one recurrent tumor-bearing survival.

CONCLUSION

Neuroblastoma with bilateral blindness is rare in the clinic, mostly in children of young age, and is often associated with MYCN amplification and multiple metastases. Early hormone shock therapy and optic nerve decompression are beneficial for preserving the child's vision. A joint multi-disciplinary treatment may help in the formulation of treatment decisions. Achieving a balance between good visual preservation and survival within the short optic nerve neurotherapeutic window is extremely challenging.

Retinoid Therapy for Neuroblastoma: Historical Overview, Regulatory Challenges, and Prospects

Retinoids are vitamin A derivatives and include trans-retinoic acid, isotretinoin, tamibarotene, and bexarotene, all of which are currently available for clinical use. The clinical development of retinoid therapy for neuroblastoma has a history spanning more than four decades. The most promising agent is isotretinoin, which can contribute to improving event-free survival in patients with high-risk neuroblastoma by approximately 10% when administered over six months as maintenance therapy. Although isotretinoin is regarded as an essential component in the standard clinical management of high-risk neuroblastoma, its use for this purpose in the US and EU is off-label. To promote isotretinoin use in Japan as a treatment for neuroblastoma, our clinical research team is planning to launch an investigator-initiated, registration-directed clinical trial. The present review article discusses the basic science behind retinoid therapy, pre-clinical/clinical evidence on neuroblastoma, the concept of the proposed clinical trial, and prospects for this therapy.

Mitochondrial uncoupler and retinoic acid synergistically induce differentiation and inhibit proliferation in neuroblastoma

Neuroblastoma is a leading cause of death in childhood cancer cases. Unlike adult malignancies, which typically develop from aged cells through accumulated damage and mutagenesis, neuroblastoma originates from neural crest cells with disrupted differentiation. This distinct feature provides novel therapeutic opportunities beyond conventional cytotoxic methods. Previously, we reported that the mitochondrial uncoupler NEN (niclosamide ethanolamine) activated mitochondria respiration to reprogram the epigenome, promoting neuronal differentiation. In the current study, we further combine NEN with retinoic acid (RA) to promote neural differentiation both in vitro and in vivo. The treatment increased the expression of RA signaling and neuron differentiation-related genes, resulting in a global shift in the transcriptome towards a more favorable prognosis. Overall, these results suggest that the combination of a mitochondrial uncoupler and the differentiation agent RA is a promising therapeutic strategy for neuroblastoma.

No-ozone cold plasma induces apoptosis in human neuroblastoma cell line via increased intracellular reactive oxygen species (ROS)

BACKGROUND

This study aimed to evaluate the effect of argon-based No-ozone Cold Plasma (NCP) on neuroblastoma cancer cell apoptosis.

METHODS

Experiments were performed with SK-N-SH and HS 68. Cell cultures were treated with NCP for 1, 3, and 5 min. NCP was applied using three different strategies: direct NCP application to cell cultures, to only media, and to only cells. Evaluation of cell viability and the level of the reactive oxygen species (ROS) was performed. N-acetyl-L-cysteine (NAC) was also used to antagonize intracellular ROS. Cleaved caspase 3, PARP, aquaporin (AQP) 3 and 8 were detected.

RESULTS

NCP induced a gradual decrease in the SK-N-SH cell viability. In contrast, the viability of HS 68 cells did not change. SK-N-SH cells viability was reduced the most when the only media-NCP application strategy was employed. Intracellular ROS levels were significantly increased with time. Cleaved caspase 3 and PARP were increased at 6 h after NCP application. SK-N-SH cells remained viable with NAC after NCP application. AQP 3 and 8 were over-expressed in SK-N-SH cells.

CONCLUSION

These findings demonstrate the anti-cancer effect of NCP on neuroblastoma cells. NCP enhanced the selective apoptosis of neuroblastoma cells due to the increased intracellular ROS.

Reactivation of the G1 enhancer landscape underlies core circuitry addiction to SWI/SNF

Several cancer core regulatory circuitries (CRCs) depend on the sustained generation of DNA accessibility by SWI/SNF chromatin remodelers. However, the window when SWI/SNF is acutely essential in these settings has not been identified. Here we used neuroblastoma (NB) cells to model and dissect the relationship between cell-cycle progression and SWI/SNF ATPase activity. We find that SWI/SNF inactivation impairs coordinated occupancy of non-pioneer CRC members at enhancers within 1 hour, rapidly breaking their autoregulation. By precisely timing inhibitor treatment following synchronization, we show that SWI/SNF is dispensable for survival in S and G2/M, but becomes acutely essential only during G1 phase. We furthermore developed a new approach to analyze the oscillating patterns of genome-wide DNA accessibility across the cell cycle, which revealed that SWI/SNF-dependent CRC binding sites are enriched at enhancers with peak accessibility during G1 phase, where they activate genes involved in cell-cycle progression. SWI/SNF inhibition strongly impairs G1-S transition and potentiates the ability of retinoids used clinically to induce cell-cycle exit. Similar cell-cycle effects in diverse SWI/SNF-addicted settings highlight G1-S transition as a common cause of SWI/SNF dependency. Our results illustrate that deeper knowledge of the temporal patterns of enhancer-related dependencies may aid the rational targeting of addicted cancers.

Reprogramming neuroblastoma by diet-enhanced polyamine depletion

Neuroblastoma is a highly lethal childhood tumor derived from differentiation-arrested neural crest cells1,2. Like all cancers, its growth is fueled by metabolites obtained from either circulation or local biosynthesis3,4. Neuroblastomas depend on local polyamine biosynthesis, with the inhibitor difluoromethylornithine showing clinical activity5. Here we show that such inhibition can be augmented by dietary restriction of upstream amino acid substrates, leading to disruption of oncogenic protein translation, tumor differentiation, and profound survival gains in the TH-MYCN mouse model. Specifically, an arginine/proline-free diet decreases the polyamine precursor ornithine and augments tumor polyamine depletion by difluoromethylornithine. This polyamine depletion causes ribosome stalling, unexpectedly specifically at adenosine-ending codons. Such codons are selectively enriched in cell cycle genes and low in neuronal differentiation genes. Thus, impaired translation of these codons, induced by the diet-drug combination, favors a pro-differentiation proteome. These results suggest that the genes of specific cellular programs have evolved hallmark codon usage preferences that enable coherent translational rewiring in response to metabolic stresses, and that this process can be targeted to activate differentiation of pediatric cancers.

Ten-Year Trends of Hematopoietic Stem Cell Transplantation in Korean Pediatric Cancer from the National Health Insurance Claims Data

PURPOSE

We aimed to determine the current application and survival trends of hematopoietic stem cell transplantation (HSCT) among Korean children and adolescents with cancer.

MATERIALS AND METHODS

Data of patients aged < 20 years with KCD-10 (Korean Classifications of Diseases, 10th revision) C codes and specific designation codes were collected from the National Health Insurance Service database. Thirty claim codes for HSCT were included, and data from 2009 to 2019 were analyzed.

RESULTS

The operational definition of pediatric cancer yielded an annual average of 2,000, with annual cases decreasing. In 2019, 221 HSCTs were performed, a decrease from the ten-year average of 276. Allografts outnumbered autografts with a ratio of 1.5:1. The source of allograft was bone marrow in 15% of patients in 2009; however, it substantially decreased to 3.3% in 2019. Furthermore, 70.5% of allogeneic HSCT used peripheral blood stem cell (PBSC) grafts, which increased to 89.3% by 2015. Cord blood utilization markedly decreased to 2.7% in 2018. The 5-year overall survival (OS) rate of all patients was 85.1%. Overall mortality decreased among patients who underwent recent HSCT, and they exhibited a higher 5-year OS rate.

CONCLUSION

In Korea, the number of pediatric patients with cancer is declining; however, the ratio of transplants to all patients remains constant. Patients who recently underwent transplantation showed better survival rates, possibly due to HSCT optimization. Korea showed a substantially greater PBSC utilization in pediatric HSCT. An in-depth examination encompassing donor relations and cause of death with a prospective registry is required in future studies.

Advances in the Management of Neuroblastoma

Neuroblastoma is a malignant tumor of neuroblasts, immature nerve cells found in several areas of the body. It usually affects children under age of 5. As usual, the tumor has ability to grow rapidly and to expand vastly which ultimately leads to death. Mostly, management decisions can be drawn by the prediction of the stage of the disease as well as age at the time of its diagnosis. There are four main stages of neuroblastoma, and treatment is according to the low and high risk of the disease. Several cytotoxic agents along with other therapies (antibody therapy, gene therapy, and even immunological therapies, antiangiogenic therapy, etc.) are used. Immunotherapy also has an important treatment option used nowadays for neuroblastoma. The discovery of major neuroblastoma-predisposition gene anaplastic lymphoma kinase cause somatic transformation or gene strengthening in diagnosed neuroblastoma. Promising new antiangiogenic strategies have also been introduced for the treatment of neuroblastoma with multiple mylomas. To manage numerous myelomas and cancers, including neuroblastoma, bone marrow transplantation and peripheral blood stem cell transplantation may be used.

Stage 4N neuroblastoma before and during the era of anti-GD2 immunotherapy

Patients with stage 4N neuroblastoma (distant metastases limited to lymph nodes) stand out as virtually the only survivors of high-risk neuroblastoma (HR-NB) before myeloablative therapy (MAT) and immunotherapy with anti-GD2 monoclonal antibodies (mAbs) became standard. Because no report presents more recent results with 4N, we analyzed our large 4N experience. All 51 pediatric 4N patients (<18 years old) diagnosed 1985 to 2021 were reviewed. HR-NB included MYCN-nonamplified 4N diagnosed at age ≥18 months and MYCN-amplified 4N. Among 34 MYCN-nonamplified high-risk patients, 20 are relapse-free 1.5+ to 37.5+ (median 12.5+) years post-diagnosis, including 13 without prior MAT and 5 treated with little (1 cycle; n = 2) or no mAb (n = 3), while 14 patients (7 post-MAT, 8 post-mAbs) relapsed (all soft tissue). Of 15 MYCN-amplified 4N patients, 7 are relapse-free 2.1+ to 26.4+ (median 11.6+) years from the start of chemotherapy (all received mAbs; 3 underwent MAT) and 4 are in second remission 4.2+ to 21.8+ years postrelapse (all soft tissue). Statistical analyses showed no significant association of survival with either MAT or mAbs for MYCN-nonamplified HR-NB; small numbers prevented these analyses for MYCN-amplified patients. The two patients with intermediate-risk 4N (14-months-old) are relapse-free 7+ years postresection of primary tumors; distant disease spontaneously regressed. The natural history of 4N is marked by NB confined to soft tissue without early relapse in bones or bone marrow, where mAbs have proven efficacy. These findings plus curability without MAT, as seen elsewhere and at our center, support consideration of treatment reduction for MYCN-nonamplified 4N.

Persistence of Racial and Ethnic Disparities in Risk and Survival for Patients with Neuroblastoma over Two Decades

BACKGROUND

Racial/ethnic survival disparities in neuroblastoma were first reported more than a decade ago. We sought to investigate if these disparities have persisted with current era therapy.

METHODS

Two patient cohorts were identified in the International Neuroblastoma Risk Group Data Commons (INRGdc) (Cohort 1: diagnosed 2001-2009, n=4359; Cohort 2: diagnosed 2010-2019, n=4891). Chi-squared tests were used to assess the relationship between race/ethnicity and clinical and biologic features. Survival was estimated by the Kaplan-Meier method. Cox proportional hazards regression analyses were performed to investigate the association between racial/ethnic groups and prognostic markers.

RESULTS

Significantly higher 5-year event-free survival (EFS) and overall survival (OS) were observed for Cohort 2 compared to Cohort 1 (P<0.001 and P<0.001, respectively). Compared to White patients, Black patients in both cohorts had a higher proportion of high-risk disease (Cohort 1: P<0.001; Cohort 2: P<0.001) and worse EFS (Cohort 1: P<0.001; Cohort 2 P<0.001) and OS (Cohort 1: P<0.001; Cohort 2: P<0.001). In Cohort 1, Native Americans also had a higher proportion of high-risk disease (P=0.03) and inferior EFS/OS. No significant survival disparities were observed for low- or intermediate-risk patients in either cohort or high-risk patients in Cohort 1. Hispanic patients with high-risk disease in Cohort 2 had significantly inferior OS (P=0.047). Significantly worse OS, but not EFS, (P=0.006 and P=0.02, respectively) was also observed among Black and Hispanic patients assigned to receive post-Consolidation dinutuximab on clinical trials (n=885).

CONCLUSION

Racial/ethnic survival disparities have persisted over time and were observed among high-risk patients assigned to receive post-Consolidation dinutuximab.

Differentiated neuroblastoma cells remain epigenetically poised for de-differentiation to an immature state

Neuroblastoma is the most common extracranial solid tumor of childhood and accounts for a significant share of childhood cancer deaths. Prior studies utilizing RNA sequencing of bulk tumor populations showed two predominant cell states characterized by high and low expression of neuronal genes. Although cells respond to treatment by altering their gene expression, it is unclear whether this reflects shifting balances of distinct subpopulations or plasticity of individual cells. Using mouse and human neuroblastoma cell lines lacking MYCN amplification, we show that the antigen CD49b (also known as ITGA2) distinguishes these subpopulations. CD49b expression marked proliferative cells with an immature gene expression program, whereas CD49b-negative cells expressed differentiated neuronal marker genes and were non-cycling. Sorted populations spontaneously switched between CD49b expression states in culture, and CD49b-negative cells could generate rapidly growing, CD49b-positive tumors in mice. Although treatment with the chemotherapy drug doxorubicin selectively killed CD49b-positive cells in culture, the CD49b-positive population recovered when treatment was withdrawn. We profiled histone 3 (H3) lysine 27 acetylation (H3K27ac) to identify enhancers and super enhancers that were specifically active in each population and found that CD49b-negative cells maintained the priming H3 lysine 4 methylation (H3K4me1) mark at elements that were active in cells with high expression of CD49b. Improper maintenance of primed enhancer elements might thus underlie cellular plasticity in neuroblastoma, representing potential therapeutic targets for this lethal tumor.

Aryl hydrocarbon receptor is a tumor promoter in MYCN-amplified neuroblastoma cells through suppression of differentiation

Neuroblastoma is the most common extracranial solid tumor in children. MYCN amplification is detected in almost half of high-risk cases and is associated with poorly differentiated tumors, poor patient prognosis and poor response to therapy, including retinoids. We identify the aryl hydrocarbon receptor (AhR) as a transcription factor promoting the growth and suppressing the differentiation of MYCN-amplified neuroblastoma. A neuroblastoma specific AhR transcriptional signature reveals an inverse correlation of AhR activity with patients' outcome, suggesting AhR activity is critical for disease progression. AhR modulates chromatin structures, reducing accessibility to regions responsive to retinoic acid. Genetic and pharmacological inhibition of AhR results in induction of differentiation. Importantly, AhR antagonism with clofazimine synergizes with retinoic acid in inducing differentiation both in vitro and in vivo. Thus, we propose AhR as a target for MYCN-amplified neuroblastoma and that its antagonism, combined with current standard-of-care, may result in a more durable response in patients.

PAX3-FOXO1 dictates myogenic reprogramming and rhabdomyosarcoma identity in endothelial progenitors

Fusion-positive rhabdomyosarcoma (FP-RMS) driven by the expression of the PAX3-FOXO1 (P3F) fusion oncoprotein is an aggressive subtype of pediatric rhabdomyosarcoma. FP-RMS histologically resembles developing muscle yet occurs throughout the body in areas devoid of skeletal muscle highlighting that FP-RMS is not derived from an exclusively myogenic cell of origin. Here we demonstrate that P3F reprograms mouse and human endothelial progenitors to FP-RMS. We show that P3F expression in aP2-Cre expressing cells reprograms endothelial progenitors to functional myogenic stem cells capable of regenerating injured muscle fibers. Further, we describe a FP-RMS mouse model driven by P3F expression and Cdkn2a loss in endothelial cells. Additionally, we show that P3F expression in TP53-null human iPSCs blocks endothelial-directed differentiation and guides cells to become myogenic cells that form FP-RMS tumors in immunocompromised mice. Together these findings demonstrate that FP-RMS can originate from aberrant development of non-myogenic cells driven by P3F.