Neuroblastoma

Targeting the MYCN-MDM2 pathways for cancer therapy: Are they druggable?

Targeting oncogenes and their interactive partners is an effective approach to developing novel targeted therapies for cancer and other chronic diseases. We and others have long suggested the MDM2 oncogene being an excellent target for cancer therapy, based on its p53-dependent and -independent oncogenic activities in a variety of cancers. The MYC family proteins are transcription factors that also regulate diverse biological functions. Dysregulation of MYC, such as amplification of MYCN, is associated with tumorigenesis, especially for neuroblastoma. Although the general survival rate of neuroblastoma patients has significantly improved over the past few decades, high-risk neuroblastoma still presents a poor prognosis. Therefore, innovative and more potent therapeutic strategies are needed to eradicate these aggressive neoplasms. This review focuses on the oncogenic properties of MYCN and its molecular regulation and summarizes the major therapeutic strategies being developed based on preclinical findings. We also highlight the potential benefits of targeting both the MYCN and MDM2 oncogenes, providing preclinical evidence of the efficacy and safety of this approach. In conclusion, the development of effective small molecules that inhibit both MYCN and MDM2 represents a promising new strategy for the treatment of neuroblastoma and other cancers.

FOXR2 Targets LHX6+/DLX+ Neural Lineages to Drive Central Nervous System Neuroblastoma

Central nervous system neuroblastoma with forkhead box R2 (FOXR2) activation (NB-FOXR2) is a high-grade tumor of the brain hemispheres and a newly identified molecular entity. Tumors express dual neuronal and glial markers, leading to frequent misdiagnoses, and limited information exists on the role of FOXR2 in their genesis. To identify their cellular origins, we profiled the transcriptomes of NB-FOXR2 tumors at the bulk and single-cell levels and integrated these profiles with large single-cell references of the normal brain. NB-FOXR2 tumors mapped to LHX6+/DLX+ lineages derived from the medial ganglionic eminence, a progenitor domain in the ventral telencephalon. In vivo prenatal Foxr2 targeting to the ganglionic eminences in mice induced postnatal cortical tumors recapitulating human NB-FOXR2-specific molecular signatures. Profiling of FOXR2 binding on chromatin in murine models revealed an association with ETS transcriptional networks, as well as direct binding of FOXR2 at key transcription factors that coordinate initiation of gliogenesis. These data indicate that NB-FOXR2 tumors originate from LHX6+/DLX+ interneuron lineages, a lineage of origin distinct from that of other FOXR2-driven brain tumors, highlight the susceptibility of ventral telencephalon-derived interneurons to FOXR2-driven oncogenesis, and suggest that FOXR2-induced activation of glial programs may explain the mixed neuronal and oligodendroglial features in these tumors. More broadly, this work underscores systematic profiling of brain development as an efficient approach to orient oncogenic targeting for in vivo modeling, critical for the study of rare tumors and development of therapeutics. Significance: Profiling the developing brain enabled rationally guided modeling of FOXR2-activated CNS neuroblastoma, providing a strategy to overcome the heterogeneous origins of pediatric brain tumors that hamper tumor modeling and therapy development. See related commentary by Orr, p. 195.

TERT Expression and Clinical Outcome in Pulmonary Carcinoids

PURPOSE

The clinical course of pulmonary carcinoids ranges from indolent to fatal disease, suggesting that specific molecular alterations drive progression toward the fully malignant state. A similar spectrum of clinical phenotypes occurs in pediatric neuroblastoma, in which activation of telomerase reverse transcriptase (TERT) is decisive in determining the course of disease. We therefore investigated whether TERT expression defines the clinical fate of patients with pulmonary carcinoid.

METHODS

TERT expression was examined by RNA sequencing in a test cohort and a validation cohort of pulmonary carcinoids (n = 88 and n = 105, respectively). A natural TERT expression cutoff was determined in the test cohort on the basis of the distribution of TERT expression, and its prognostic value was assessed by Kaplan-Meier survival estimates and multivariable analyses. Telomerase activity was validated by telomere repeat amplification protocol assay.

RESULTS

Similar to neuroblastoma, TERT expression exhibited a bimodal distribution in pulmonary carcinoids, separating tumors into TERT-high and TERT-low subgroups. A natural TERT cutoff discriminated unfavorable from favorable clinical courses with high accuracy both in the test cohort (5-year overall survival [OS], 0.547 ± 0.132 v 1.0; P < .001) and the validation cohort (5-year OS, 0.788 ± 0.063 v 0.913 ± 0.048; P < .001). In line with these findings, telomerase activity was largely absent in TERT-low tumors, whereas it was readily detectable in TERT-high carcinoids. In multivariable analysis considering TERT expression, histology (typical v atypical carcinoid), and stage (≤IIA v ≥IIB), high TERT expression was an independent prognostic marker for poor survival, with a hazard ratio of 5.243 (95% CI, 1.943 to 14.148; P = .001).

CONCLUSION

Our data demonstrate that high TERT expression defines clinically aggressive pulmonary carcinoids with fatal outcome, similar to neuroblastoma, indicating that activation of TERT may be a defining feature of lethal cancers.

Long-Term Risk of Subsequent Neoplasms in 5-Year Survivors of Childhood Neuroblastoma: A Dutch Childhood Cancer Survivor Study-LATER 3 Study

PURPOSE

Neuroblastoma survivors have an increased risk of developing subsequent malignant neoplasms (SMNs), but the risk of subsequent nonmalignant neoplasms (SNMNs) and risk factors are largely unknown. We analyzed the long-term risks and associated risk factors for developing SMNs and SNMNs in a well-characterized cohort of 5-year neuroblastoma survivors.

METHODS

We included 563 5-year neuroblastoma survivors from the Dutch Childhood Cancer Survivor Study (DCCSS)-LATER cohort, diagnosed during 1963-2014. Subsequent neoplasms were ascertained by linkages with the Netherlands Cancer Registry and the Dutch Nationwide Pathology Databank (Palga) and medical chart review. We calculated standardized incidence ratios (SIRs), absolute excess risk (AER), and cumulative incidences. Multivariable competing risk regression analysis was used to evaluate risk factors.

RESULTS

In total, 23 survivors developed an SMN and 60 an SNMN. After a median follow-up of 23.7 (range, 5.0-56.3) years, the risk of SMN was elevated compared with the general population (SIR, 4.0; 95% CI, 2.5 to 5.9; AER per 10,000 person-years, 15.1). The 30-year cumulative incidence was 3.4% (95% CI, 1.9 to 6.0) for SMNs and 10.4% (95% CI, 7.3 to 14.8) for SNMNs. Six survivors developed an SMN after iodine-metaiodobenzylguanidine (131IMIBG) treatment. Survivors treated with 131IMIBG had a higher risk of developing SMNs (subdistribution hazard ratio [SHR], 5.7; 95% CI, 1.8 to 17.8) and SNMNs (SHR, 2.6; 95% CI, 1.2 to 5.6) compared with survivors treated without 131IMIBG; results for SMNs were attenuated in high-risk patients only (SMNs SHR, 3.6; 95% CI, 0.9 to 15.3; SNMNs SHR, 1.5; 95% CI, 0.7 to 3.6).

CONCLUSION

Our results demonstrate that neuroblastoma survivors have an elevated risk of developing SMNs and a high risk of SNMNs. 131IMIBG may be a treatment-related risk factor for the development of SMN and SNMN, which needs further validation. Our results emphasize the need for awareness of subsequent neoplasms and the importance of follow-up care.

Adults and Adolescents With Neuroblastoma: An Analysis of the National Cancer Database

BACKGROUND AND OBJECTIVES

Neuroblastoma, the most common extracranial solid tumor in children, is rare in adults. This study compares patient characteristics, disease patterns, and treatments among adults, adolescents, and children with neuroblastoma.

METHODS

We queried the National Cancer Database (2004-2019) for neuroblastoma cases. Patient and tumor characteristics, treatments, and 5-year overall survival (5-OS) were compared between adults (≥ 18 years), adolescents (10-17 years), and children (0-9 years). Kaplan-Meier curves and Cox regression assessed survival differences.

RESULTS

Among 6350 neuroblastoma patients, 256 (4.0%) were adults, 222 (3.5%) were adolescents, and 5872 (92.5%) were children. Tumors were largest in adolescents (9.7 cm), followed by adults (8.0 cm) and children (6.7 cm) (p < 0.001). Adults were less likely to have tumors in the adrenal glands (34.0% vs. children: 54.7%, adolescents: 43.2%, p < 0.001) and had lower rates of metastasis (10.9% vs. 19.3% and 19.4%, p < 0.001). Compared to children, adults received less chemotherapy, immunotherapy, and bone marrow transplants (p < 0.001). 5-OS was worse in adults (65.8%), followed by adolescents (70.4%) and children (78.2%) (p < 0.001). After adjustment, adults (aHR: 2.27; 95% CI, 1.71-3.01) and adolescents (aHR: 2.02; 95% CI, 1.54-2.64) had higher hazards of death compared to children.

CONCLUSIONS

Adults and adolescents with neuroblastoma have distinct clinical features and lower survival than children, underscoring the need for tailored treatment approaches for older patients.

LEVEL OF EVIDENCE

III.

Rare germline structural variants increase risk for pediatric solid tumors

Pediatric solid tumors are a leading cause of childhood disease mortality. In this work, we examined germline structural variants (SVs) as risk factors for pediatric extracranial solid tumors using germline genome sequencing of 1765 affected children, their 943 unaffected parents, and 6665 adult controls. We discovered a sex-biased association between very large (>1 megabase) germline chromosomal abnormalities and increased risk of solid tumors in male children. The overall impact of germline SVs was greatest in neuroblastoma, where we uncovered burdens of ultrarare SVs that cause loss of function of highly expressed, mutationally constrained genes, as well as noncoding SVs predicted to disrupt chromatin domain boundaries. Collectively, we estimate that rare germline SVs explain 1.1 to 5.6% of pediatric cancer liability, establishing them as an important component of disease predisposition.

Natural killer cell-based therapies in neuroblastoma

Neuroblastoma (NB) is the most common extracranial solid tumor of childhood forming around 15 % of all pediatric tumors. Despite advances in the treatment of NB, high-risk patients still face a grave prognosis. Adoptive cell therapies based on NK cells are becoming an assistive treatment for such cases. Moreover, there is also evidence that NKT-based therapies have promising results in the management of NB. Lower complications in comparison with adoptive T cell therapies, various cell sources, and miscellaneous tumor recognition mechanisms are some of the advantages of NK- and NKT-based therapies. This review is dedicated to searching for recent advances in this field.

Detection of circulating tumor cells using a microfluidic chip for diagnostics and therapeutic prediction in mediastinal neuroblastoma

Circulating tumor cells (CTCs) have served as noninvasive tumor biomarkers in many types of cancer. Here, we detected CTCs in mediastinal neuroblastoma (mNB) patients for use as diagnostic and treatment response predictive biomarkers. We employed a cascaded filter deterministic lateral displacement microfluidic chip (CFD-Chip) to enrich CTCs in peripheral blood from 32 mNB patients and 7 healthy children. CTCs were identified by immunofluorescence staining and integrated neoplastic cell morphology. In total, 66.67% of newly diagnosed mNB patients were positive for CTCs while no CTCs were detected in healthy children. Moreover, CTC count differed significantly across different International Neuroblastoma Staging System, International Neuroblastoma Risk Group staging system, and risk stratifications. CTC count was also significantly higher in children with metastasis than those without metastasis. Additionally, CTC demonstrated a significant difference among patients with different clinical responses to therapy. CTC count decreased or fluctuated at low levels in patients with complete and partial response, compared to considerably increased in patients with stable and progressive diseases.Conclusion: CTCs may serve as non-invasive indicators for mNB diagnosis, staging, and metastasis prediction, and demonstrate promising potential as a liquid biopsy biomarker for the dynamic monitoring of therapeutic efficacy.

DDX21 at the Nexus of RNA Metabolism, Cancer Oncogenesis, and Host-Virus Crosstalk: Decoding Its Biomarker Potential and Therapeutic Implications

DDX21, a member of the DEAD-box RNA helicase family, plays a pivotal role in various aspects of RNA metabolism, including ribosomal RNA (rRNA) processing, transcription, and translation. Its diverse functions in cancer progression and viral infections have attracted considerable attention. DDX21 exerts a pivotal function through ribosomal DNA (rDNA) transcription and rRNA processing. DDX21 is involved in different biological processes of mRNA transcription. It interacts with transcription factors, modulates RNA polymerase II elongation, binds R-loops to regulate transcription, and participates in alternative splicing. The elevated expression of DDX21 has been observed in most cancers, where it influences tumorigenesis by affecting ribosome biogenesis, transcription, genome stability, and cell cycle regulation. Additionally, DDX21 plays a key role in the antiviral defense of host by interacting with viral proteins to regulate essential stages of the infection process. This review provides a thorough examination of the biological functions of DDX21, its involvement in cancer progression and viral infections, and its potential as both a biomarker and a therapeutic target. Future studies should aim to clarify the specific mechanisms of the activity of DDX21, advance the development of targeted therapies, and assess its clinical relevance across various cancer types and stages.

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.

Progress Toward Epigenetic Targeted Therapies for Childhood Cancer

Among the most significant discoveries from cancer genomics efforts has been the critical role of epigenetic dysregulation in cancer development and progression. Studies across diverse cancer types have revealed frequent mutations in genes encoding epigenetic regulators, alterations in DNA methylation and histone modifications, and a dramatic reorganization of chromatin structure. Epigenetic changes are especially relevant to pediatric cancers, which are often characterized by a low rate of genetic mutations. The inherent reversibility of epigenetic lesions has led to an intense interest in the development of epigenetic targeted therapies. Additionally, the recent appreciation of the interplay between the epigenome and immune regulation has sparked interest in combination therapies and synergistic immunotherapy approaches. Further, the recent appreciation of epigenetic variability as a driving force in cancer evolution has suggested new roles for epigenetic therapies in limiting plasticity and resistance. Here, we review recent progress and emerging directions in the development of epigenetic targeted therapeutics and their promise across the landscape of childhood cancers.

Neuroblastoma response to RAS-MAPK inhibitors and APR-246 (eprenetapopt) co-treatment is dependent on SLC7A11

Background

We previously demonstrated that APR-246 (eprenetapopt) could be an efficient treatment option against neuroblastoma (NB), the most common pediatric extracranial solid tumor. APR-246's mechanism of action is not completely understood and can differ between cell types. Here we investigate the involvement of well-known oncogenic pathways in NB's response to APR-246.

Methods

A proteome profiler kinase assays and western blot analysis were used to identify the molecular pathways involved in the responses to APR-246. Bulk ATP levels were used to determine the viability of cells and the IC50 for APR-246. Cystine-FITC was used to measure the cellular uptake of cysteine. PmRNA5 was used to activate ERK1/2 and pshRNA1 was used to silence HSP27. An IMR-32 xenograft zebrafish embryo model was used to assess APR-246 and sulfasalazine efficacy in vivo.

Results

After APR-246 treatment, the most deregulated signaling protein identified was ERK1/2, an end-point kinase of the RAS-MAPK pathway. Induction of phospho-ERK1/2 resulted in increased glutathione (GSH) levels, increased cystine uptake, and increased resistance of NB cells to APR-246. Using ERK1/2 inhibitors in combination with APR-246, we were able to categorize cells into synergistic and antagonistic groups. After co-treatment, these two groups differ by their levels of SLC7A11 and Hsp27 phosphorylation, cystine uptake, and BIM expression. Using erastin and sulfasalazine, both inhibitors of SLC7A11 and activators of ferroptosis, we were able to reverse the antagonistic effects of ERK1/2 inhibitors and demonstrate a strong synergistic action in vitro and in vivo in zebrafish models.

Conclusions

These results demonstrated a pivotal role of the RAS-MAPK pathway in the NB cellular response to APR-246 via the modulation of intracellular concentrations of GSH and the transport of cystine through SLC7A11, phosphorylation of Hsp27, and programmed cell death. Combining APR-246 with RAS-MAPK pathway inhibitors can, in some cases, lead to antagonistic action, which can be reversed by combining APR-246 with the clinically approved drug sulfasalazine.

Natural killer cells in neuroblastoma: immunological insights and therapeutic perspectives

Natural killer (NK) cells have multifaceted roles within the complex tumor milieu. They are pivotal components of innate immunity and shape the dynamic landscape of tumor-immune cell interactions, and thus can be leveraged for use in therapeutic interventions. NK-based immunotherapies have had remarkable success in hematological malignancies, but these therapies are met with many challenges in solid tumors, including neuroblastoma (NB), a childhood tumor arising from the sympathetic nervous system. With a focus on NB, this review outlines the mechanisms employed by NK cells to recognize and eliminate malignant cells, delving into the dynamic relationship between ligand-receptor interactions, cytokines, and other molecules that facilitate the cross talk between NK and NB cells. We discuss the immunomodulatory functions of NK cells and the mechanisms that contribute to loss of this immunosurveillance in NB, with a focus on how this dynamic has been utilized in recent immunotherapy advancements for NB.

Multicellular model of neuroblastoma proposes unconventional therapy based on multiple roles of p53

Neuroblastoma is the most common extra-cranial solid tumour in children. Over half of all high-risk cases are expected to succumb to the disease even after chemotherapy, surgery, and immunotherapy. Although the importance of MYCN amplification in this disease is indisputable, the mechanistic details remain enigmatic. Here, we present a multicellular model of neuroblastoma comprising a continuous automaton, discrete cell agents, and a centre-based mechanical model, as well as the simulation results we obtained with it. The continuous automaton represents the tumour microenvironment as a grid-like structure, where each voxel is associated with continuous variables such as the oxygen level therein. Each discrete cell agent is defined by several attributes, including its cell cycle position, mutations, gene expression pattern, and more with behaviours such as cell cycling and cell death being stochastically dependent on these attributes. The centre-based mechanical model represents the properties of these agents as physical objects, describing how they repel each other as soft spheres. By implementing a stochastic simulation algorithm on modern GPUs, we simulated the dynamics of over one million neuroblastoma cells over a period of months. Specifically, we set up 1200 heterogeneous tumours and tracked the MYCN-amplified clone's dynamics in each, revealed the conditions that favour its growth, and tested its responses to 5000 drug combinations. Our results are in agreement with those reported in the literature and add new insights into how the MYCN-amplified clone's reproductive advantage in a tumour, its gene expression profile, the tumour's other clones (with different mutations), and the tumour's microenvironment are inter-related. Based on the results, we formulated a hypothesis, which argues that there are two distinct populations of neuroblastoma cells in the tumour; the p53 protein is pro-survival in one and pro-apoptosis in the other. It follows that alternating between inhibiting MDM2 to restore p53 activity and inhibiting ARF to attenuate p53 activity is a promising, if unorthodox, therapeutic strategy. The multicellular model has the advantages of modularity, high resolution, and scalability, making it a potential foundation for creating digital twins of neuroblastoma patients.

diaPASEF-Powered Chemoproteomics Enables Deep Kinome Interaction Profiling

Protein-protein interactions (PPIs) underlie most biological functions. Devastating human conditions like cancers, neurological disorders, and infections, hijack PPI networks to initiate disease, and to drive disease progression. Understanding precisely how diseases remodel PPI networks can, therefore, help clarify disease mechanisms and identify therapeutic targets. Protein kinases control most cellular processes through protein phosphorylation. The 518 human kinases, known as the kinome, are frequently dysregulated in disease and highly druggable with ATP-competitive inhibitors. Kinase activity, localization, and substrate recognition are regulated by dynamic PPI networks composed of scaffolding and adapter proteins, other signaling enzymes like small GTPases and E3 ligases, and phospho-substrates. Accordingly, mapping kinase PPI networks can help determine kinome activation states, and, in turn, cellular activation states; this information can be used for studying kinase-mediated cell signaling, and for prioritizing kinases for drug discovery. Previously, we have developed a high-throughput method for kinome PPI mapping based on mass spectrometry (MS)-based chemoproteomics that we named kinobead competition and correlation analysis (kiCCA). Here, we introduce 2 nd generation (gen) kiCCA which utilizes data-independent acquisition (dia) with parallel accumulation serial fragmentation (PASEF) MS and a re-designed CCA algorithm with improved selection criteria and the ability to predict multiple kinase interaction partners of the same proteins. Using neuroblastoma cell line models of the noradrenergic-mesenchymal transition (NMT), we demonstrate that 2 nd gen kiCCA (1) identified 6.1-times more kinase PPIs in native cell extracts compared to our 1 st gen approach, (2) determined kinase-mediated signaling pathways that underly the neuroblastoma NMT, and (3) accurately predicted pharmacological targets for manipulating NMT states. Our 2 nd gen kiCCA method is broadly useful for cell signaling research and kinase drug discovery.

Novel PP2A-Activating Compounds in Neuroblastoma

BACKGROUND

Neuroblastoma (NB) remains one of the deadliest pediatric solid tumors. Recent advancements aimed at improving outcomes have been insufficient, and patients with high-risk NB continue to have a poor prognosis. Protein phosphatase 2A (PP2A) is a tumor suppressor protein downregulated in many cancers, including NB. PP2A activation has been shown to affect the malignant phenotype in other solid tumors. The present studies aim to investigate the effects of two novel PP2A activators as a NB therapeutic.

METHODS

Four established NB cell lines and a patient-derived xenoline were utilized to study the effect on cell viability, proliferation, motility, and in vivo tumor growth using two novel tricyclic sulfonamide PP2A activators, ATUX-3364 and ATUX-8385.

RESULTS

ATUX-3364 and ATUX-8385 increased PP2A activity. These PP2A activators led to decreased viability, proliferation, and motility of NB cells. Treatment of animals bearing NB tumors with ATUX-3364 or ATUX-8385 resulted in decreased tumor growth in MYCN-amplified SK-N-BE(2) tumors. At the molecular level, PP2A-based reactivation led to dephosphorylation of MYCN-S62 and decreased MYCN protein expression.

CONCLUSIONS

PP2A activators decreased NB cell viability, proliferation, and motility. In vivo experiments show that PP2A activators have more significant effects on tumorigenesis in MYCN-amplified tumors. Finally, phosphorylation of MYCN protein was decreased following treatment with novel sulfonamide PP2A activators. These data and mechanistic insights may be useful for developing new PP2A-based therapies that target MYCN for the treatment of NB.

Integrating multi-omics data reveals neuroblastoma subtypes in the tumor microenvironment

Neuroblastoma (NB) is a severe pediatric tumor originating from the developing sympathetic nervous system, characterized by diverse clinical outcomes, including spontaneous regression and aggressive metastasis. This variability suggests the existence of different NB subtypes, necessitating accurate classification for effective targeted treatment. In this study, we employed the similarity network fusion (SNF) algorithm and identified three NB subtypes, including mesenchymal-like (MES), MYCN-like (MYCN), and neurogenic-like (Neurogenic). The MES subtype exhibited the highest activation of immune-related pathways. The MYCN subtype demonstrated the worst prognosis, with enrichment in cell growth and proliferation pathways. Conversely, the Neurogenic subtype showed the best prognosis, with enrichment in sympathetic nervous system development processes. Through single-cell RNA sequencing (scRNA-seq) analysis, we examined the tumor microenvironments of these distinct NB subtypes, revealing divergent differentiation trajectories for adrenergic cells within the MYCN and Neurogenic subtypes. We also identified a significant presence of naïve T cells in the MES subtype, as well as mesenchymal cell subtypes associated with the unique plasticity observed in both the MES and MYCN subtypes. Drug sensitivity prediction analysis suggested that the MES subtype may respond favorably to MEK inhibitors, while the MYCN subtype may be susceptible to Bcl-2 inhibitors. Our integrative multi-omics approach enabled precise stratification of NB into biologically distinct subtypes, potentially facilitating the development of subtype-specific therapeutic strategies for improved patient management and survival outcomes.

m6Am sequesters PCF11 to suppress premature termination and drive neuroblastoma differentiation

N6,2'-O-dimethyladenosine (m6Am) is an abundant mRNA modification that impacts multiple diseases, but its function remains controversial because the m6Am reader is unknown. Using quantitative proteomics, we identified transcriptional terminator premature cleavage factor II (PCF11) as a m6Am-specific reader in human cells. Direct quantification of mature versus nascent RNAs reveals that m6Am does not regulate mRNA stability but promotes nascent transcription. Mechanistically, m6Am functions by sequestering PCF11 away from proximal RNA polymerase II (RNA Pol II). This suppresses PCF11 from dissociating RNA Pol II near transcription start sites, thereby promoting full-length transcription of m6Am-modified RNAs. m6Am's unique relationship with PCF11 means m6Am function is enhanced when PCF11 is reduced, which occurs during all-trans-retinoic-acid (ATRA)-induced neuroblastoma-differentiation therapy. Here, m6Am promotes expression of ATF3, which represses neuroblastoma biomarker MYCN. Depleting m6Am suppresses MYCN repression in ATRA-treated neuroblastoma and maintains their tumor-stem-like properties. Collectively, we characterize m6Am as an anti-terminator RNA modification that suppresses premature termination and modulates neuroblastoma's therapeutic response.

Characterisation of Paediatric Neuroblastic Tumours by Quantitative Structural and Diffusion-Weighted MRI

Purpose: To determine the diagnostic accuracy of quantitative diffusion-weighted (DW) MRI apparent diffusion coefficient (ADC) and tumour volumes to differentiate between malignant (neuroblastoma (NB)) and benign types of neuroblastic tumours (ganglioneuroma (GN) and ganglioneuroblastoma (GNB)) using different region-of-interest (ROI) sizes. Materials and Methods: This single-centre retrospective study included malignant and benign paediatric neuroblastic tumours that had undergone DW MRI at diagnosis. The outcome was diagnostic accuracy of the tumour volume from structural and ADC DW MRI, in comparison to histopathology (reference standard). Results: Data from 40 patients (NB, n = 24; GNB, n = 6; GN, n = 10), 18 (45%) females and 22 (55%) males, with a median age at diagnosis of 21 months (NB), 64 months (GNB), and 133 months (GN), respectively, ranging from 0 to 193 months, were evaluated. The area under the receiver operating characteristic (AUROC) curve for ADC for discriminating between neuroblastic tumours' histopathology for a small ROI was 0.86 (95% CI: 0.75-0.98), and for a large ROI, 0.83 (95% CI: 0.71-0.96). An ADC cut-off value of 1.06 × 10-3 mm2/s was able to distinguish malignant from benign tumours with 83% (68-98%) sensitivity and 75% (95% CI: 54-98%) specificity. Tumour volume was not indicative of malignant vs. benign tumour diagnosis. Conclusions: In this study, both small and large ROIs used to derive ADC DW MRI metrics demonstrated high accuracy to differentiate malignant from benign neuroblastic tumours, with the ADC AUROC for the averaged multiple small ROIs being slightly greater than that of large ROIs, but with overlapping 95% CIs. This should be taken into consideration for standardisation of ROI-related data analysis by international initiatives.

Identification of novel markers for neuroblastoma immunoclustering using machine learning

Background

Due to the unique heterogeneity of neuroblastoma, its treatment and prognosis are closely related to the biological behavior of the tumor. However, the effect of the tumor immune microenvironment on neuroblastoma needs to be investigated, and there is a lack of biomarkers to reflect the condition of the tumor immune microenvironment.

Methods

The GEO Database was used to download transcriptome data (both training dataset and test dataset) on neuroblastoma. Immunity scores were calculated for each sample using ssGSEA, and hierarchical clustering was used to categorize the samples into high and low immunity groups. Subsequently, the differences in clinicopathological characteristics and treatment between the different groups were examined. Three machine learning algorithms (LASSO, SVM-RFE, and Random Forest) were used to screen biomarkers and synthesize their function in neuroblastoma.

Results

In the training set, there were 362 samples in the immunity_L group and 136 samples in the immunity_H group, with differences in age, MYCN status, etc. Additionally, the tumor microenvironment can also affect the therapeutic response of neuroblastoma. Six characteristic genes (BATF, CXCR3, GIMAP5, GPR18, ISG20, and IGHM) were identified by machine learning, and these genes are associated with multiple immune-related pathways and immune cells in neuroblastoma.

Conclusions

BATF, CXCR3, GIMAP5, GPR18, ISG20, and IGHM may serve as biomarkers that reflect the conditions of the immune microenvironment of neuroblastoma and hold promise in guiding neuroblastoma treatment.

Promoting application of enhanced recovery after surgery protocols during perioperative localized abdominal and thoracic neuroblastomas

AIM

To investigate the safety and efficacy of the application of enhanced recovery after surgery (ERAS) protocols in the perioperative period of abdominal and thoracic localized neuroblastomas (NBs).

METHODS

In this retrospective study, 68 children with NBs who underwent surgical resection of the tumor were enrolled. The ERAS protocols for NB excision were implemented in the ERAS group (n = 39) and the consequences were compared with children treated with traditional care (n = 29, TRAD group). The main outcomes of our interest included the incidence of surgery-related complications, the postoperative length of stay (LOS), and the Face/Legs/Activity/Cry/Consolability (FLACC) quantitative table from postoperative days (POD) 1-5. We also evaluated the median intraoperative fluid volume and anesthesia recovery time; blood glucose levels at the beginning of anesthesia, POD1, and 3; WBC counts, CRP values, and the concentration of plasma nutritional indicators on POD1 and 3; time of early ambulation, first anal exhaust, total enteral nutrition (TEN), and discontinue intravenous infusion postoperatively; usage proportion and duration of abdominal and thoracic drainages, nasogastric decompression tubes and urinary catheters; cost of hospitalization, parental satisfaction rate, and readmission rate of surgery ward within 30 days.

RESULTS

Compared to the TRAD group, the ERAS group had lower surgery-related complications, albeit not significantly (P > 0.05); the median postoperative LOS decreased from 11.0 to 8.0 days (P < 0.001), the LOS of abdominal NB was significantly shortened (P < 0.001) compared to thoracic NB (P = 0.07) between the two groups; the FLACC scores decreased significantly from POD1-5 (all P < 0.01). The ERAS group had an improved median intraoperative infusion speed (5.0 mL/kg/h vs 8.0 mL/kg/h), time of early ambulation (1.0 days vs 3.0 days), first anal exhaust (2.0 days vs 2.0 days), TEN (5.0 vs 7.0 days), discontinuation of intravenous infusion (5.0 days vs 8.0 days), and total cost of hospitalization (33,897.2 Yuan vs 38,876.3 Yuan); (all P < 0.01). The usage proportion and duration of surgical drainages and tubes were apparently reduced. The mean blood glucose level was higher at the beginning of anesthesia but lower on POD1 and 3 in the ERAS group (P < 0.01). No statistically significant difference was detected in WBC counts and concentrations of hemoglobin and albumin between the two groups of patients (P > 0.05), while the concentrations of prealbumin on POD3 were higher and the CRP level on POD1 was lower in the ERAS group than the TRAD group (P < 0.01). The satisfaction rate of parents was only slightly higher, but the difference was not statistically significant (P = 0.730). No obvious differences were observed in the aspects of NB resection (P = 0.462) and 30-day readmissions of surgery ward (P = 1.000).

CONCLUSION

The application of ERAS protocols has a significant potential to accelerate perioperative rehabilitation in children undergoing abdominal and thoracic NBs' surgical resection.

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.

SUV39H1 epigenetically modulates the MCPIP1-AURKA signaling axis to enhance neuroblastoma tumorigenesis

Epigenetic regulation is a pivotal factor during neuroblastoma (NB) pathogenesis and investigations into cancer epigenetics are actively underway to identify novel therapeutic strategies for NB patients. SUV39H1, a member of the H3K9 methyltransferase family, contributing to tumorigenesis across multiple malignancies. However, its specific role in NB remains unexplored. In this study, we conducted a high-throughput screen utilizing a compound library containing 288 epigenetic drugs, leading to the identification of chaetocin as the most potent NB inhibitor by targeting SUV39H1. Genetic manipulation and therapeutic inhibition of SUV39H1 significantly impacted proliferation, migration, cell cycle phases, and apoptosis in NB cells. Concurrently, chaetocin demonstrated robust anti-tumor efficacy in vivo with tolerable toxicity. RNA-seq unveiled that SUV39H1 knockdown and inhibition down-regulated cell cycle pathways, impacting vital genes such as AURKA. Besides, MCPIP1 emerged as a novel tumor suppressor following SUV39H1 inhibition, which decreased AURKA expression in NB. In detail, SUV39H1 mediated the enrichment of H3K9me3 at the promoter region of MCPIP1, repressing the MCPIP1-mediated degradation of AURKA and facilitating the subsequent accumulation of AURKA, which revealed the oncogenic role of SUV39H1 via the SUV39H1-MCPIP1-AURKA signaling axis in NB. Therapeutic inhibition of SUV39H1 using chaetocin emerges as an effective and safe strategy for NB patients. Illustration of the oncogenic pathway regulated by SUV39H1 in NB.

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.

Combined inhibition of histone methyltransferases EZH2 and DOT1L is an effective therapy for neuroblastoma

BACKGROUND

The child cancer, neuroblastoma (NB), is characterised by a low incidence of mutations and strong oncogenic embryonal driver signals. Many new targeted epigenetic modifier drugs have failed in human trials as monotherapy.

METHODS

We performed a high-throughput, combination chromatin-modifier drug screen against NB cells. We screened 13 drug candidates in 78 unique combinations.

RESULTS

We found that the combination of two histone methyltransferase (HMT) inhibitors: GSK343, targeting EZH2, and SGC0946, targeting DOT1L, demonstrated the strongest synergy across 8 NB cell lines, with low normal fibroblast toxicity. High mRNA expression of both EZH2 and DOT1L in NB tumour samples correlated with the poorest patient survival. Combination HMT inhibitor treatment caused activation of ATF4-mediated endoplasmic reticulum (ER) stress responses. In addition, glutathione and several amino acids were depleted by HMT inhibitor combination on mass spectrometry analysis. The combination of SGC0946 and GSK343 reduced tumour growth in comparison to single agents.

CONCLUSION

Our results support further investigation of HMT inhibitor combinations as a therapeutic approach in NB.

Combining ERAP1 silencing and entinostat therapy to overcome resistance to cancer immunotherapy in neuroblastoma

BACKGROUND

Checkpoint immunotherapy unleashes tumor control by T cells, but it is undermined in non-immunogenic tumors, e.g. with low MHC class I expression and low neoantigen burden, such as neuroblastoma (NB). Endoplasmic reticulum aminopeptidase 1 (ERAP1) is an enzyme that trims peptides before loading on MHC class I molecules. Inhibition of ERAP1 results in the generation of new antigens able of inducing potent anti-tumor immune responses. Here, we identify a novel non-toxic combinatorial strategy based on genetic inhibition of ERAP1 and administration of the HDAC inhibitor (HDACi) entinostat that increase the immunogenicity of NB, making it responsive to PD-1 therapy.

METHODS

CRISPR/Cas9-mediated gene editing was used to knockout (KO) the ERAP1 gene in 9464D NB cells derived from spontaneous tumors of TH-MYCN transgenic mice. The expression of MHC class I and PD-L1 was evaluated by flow cytometry (FC). The immunopeptidome of these cells was studied by mass spectrometry. Cocultures of splenocytes derived from 9464D bearing mice and tumor cells allowed the assessment of the effect of ERAP1 inhibition on the secretion of inflammatory cytokines and activation and migration of immune cells towards ERAP1 KO cells by FC. Tumor cell killing was evaluated by Caspase 3/7 assay and flow cytometry analysis. The effect of ERAP1 inhibition on the immune content of tumors was analyzed by FC, immunohistochemistry and multiple immunofluorescence.

RESULTS

We found that inhibition of ERAP1 makes 9464D cells more susceptible to immune cell-mediated killing by increasing both the recall and activation of CD4+ and CD8+ T cells and NK cells. Treatment with entinostat induces the expression of MHC class I and PD-L1 molecules in 9464D both in vitro and in vivo. This results in pronounced changes in the immunopeptidome induced by ERAP1 inhibition, but also restrains the growth of ERAP1 KO tumors in vivo by remodelling the tumor-infiltrating T-cell compartment. Interestingly, the absence of ERAP1 in combination with entinostat and PD-1 blockade overcomes resistance to PD-1 immunotherapy and increases host survival.

CONCLUSIONS

These findings demonstrate that ERAP1 inhibition combined with HDACi entinostat treatment and PD-1 blockade remodels the immune landscape of a non-immunogenic tumor such as NB, making it responsive to checkpoint immunotherapy.

NBAtlas: A harmonized single-cell transcriptomic reference atlas of human neuroblastoma tumors

Neuroblastoma, a rare embryonic tumor arising from neural crest development, is responsible for 15% of pediatric cancer-related deaths. Recently, several single-cell transcriptome studies were performed on neuroblastoma patient samples to investigate the cell of origin and tumor heterogeneity. However, these individual studies involved a small number of tumors and cells, limiting the conclusions that could be drawn. To overcome this limitation, we integrated seven single-cell or single-nucleus datasets into a harmonized cell atlas covering 362,991 cells across 61 patients. We use this atlas to decipher the transcriptional landscape of neuroblastoma at single-cell resolution, revealing associations between transcriptomic profiles and clinical outcomes within the tumor compartment. In addition, we characterize the complex immune-cell landscape and uncover considerable heterogeneity among tumor-associated macrophages. Finally, we showcase the utility of our atlas as a resource by expanding it with additional data and using it as a reference for data-driven cell-type annotation.

P2X7 receptor in macrophage polarization and its implications in neuroblastoma tumor behavior

Tumor-associated macrophages (TAMs) exhibit antitumor or protumor responses related to inflammatory (or M1) and alternative (or M2) phenotypes, respectively. The P2X7 receptor plays a key role in macrophage polarization, influencing inflammation and immunosuppression. In this study, we investigated the role of the P2X7 receptor in TAMs. Using P2X7 receptor-deficient macrophages, we analyzed gene expression profiles and their implications for neuroblastoma invasion and chemoresistance. Our results showed that P2X7 receptor deficiency altered the expression of classical polarization markers, such as nitric oxide synthase 2 (Nos2) and tumor necrosis factor-α (Tnf), as well as alternative phenotype markers, including mannose receptor C-type 1 (Mrc1) and arginase 1 (Arg1). P2X7 deficiency also influenced the expression of the ectonucleotidases Entpd1 and Nt5e and other purinergic receptors, especially P2ry2, suggesting compensatory mechanisms involved in macrophage polarization. In particular, TAMs deficient in P2X7 showed a phenotype with characteristics intermideiate between resting macrophages (M0) and M1 polarization rather than the M2-type phenotype like and wild-type TAM macrophages. In addition, P2rx7-/- TAMs regulated the expression of P2X7 receptor isoforms in neuroblastoma cells, with downregulation of the P2X7 A and B isoforms leading to a decrease in chemotherapy-induced cell death. However, TAMs expressing P2X7 downregulated only the B isoform, suggesting that TAMs play a role in modulating tumor behavior through P2X7 receptor isoform regulation. Taken together, our data underscore the regulatory function of the P2X7 receptor in orchestrating alternative macrophage polarization and in the interplay between tumor cells and TAMs. These findings help to clarify the complex interplay of purinergic signaling in cancer progression and open up avenues for future research and therapeutic interventions.

Copy-number dosage regulates telomere maintenance and disease-associated pathways in neuroblastoma

Telomere maintenance in neuroblastoma is linked to poor outcome and caused by either telomerase reverse transcriptase (TERT) activation or through alternative lengthening of telomeres (ALT). In contrast to TERT activation, commonly caused by genomic rearrangements or MYCN amplification, ALT is less well understood. Alterations at the ATRX locus are key drivers of ALT but only present in ∼50% of ALT tumors. To identify potential new pathways to telomere maintenance, we investigate allele-specific gene dosage effects from whole genomes and transcriptomes in 115 primary neuroblastomas. We show that copy-number dosage deregulates telomere maintenance, genomic stability, and neuronal pathways and identify upregulation of variants of histone H3 and H2A as a potential alternative pathway to ALT. We investigate the interplay between TERT activation, overexpression and copy-number dosage and reveal loss of imprinting at the RTL1 gene associated with poor clinical outcome. These results highlight the importance of gene dosage in key oncogenic mechanisms in neuroblastoma.

Event-free survival in neuroblastoma with MYCN amplification and deletion of 1p or 11q may be associated with altered immune status

BACKGROUND

Neuroblastoma exhibits substantial heterogeneity, which is intricately linked to various genetic alterations. We aimed to explore immune status in the peripheral blood and prognosis of patients with neuroblastoma with different genetic characteristics.

METHODS

We enrolled 31 patients with neuroblastoma and collected samples to detect three genetic characteristics. Peripheral blood samples were tested for immune cells and cytokines by fluorescent microspheres conjugated with antibodies and flow cytometry. Event-free survival (EFS) was analyzed using the Kaplan‒Meier method.

RESULTS

Twenty-two patients had genetic aberrations, including MYCN amplification in 6 patients, chromosome 1p deletion in 9 patients, and chromosome 11q deletion in 14 patients. Two genetic alterations were present in seven patients. The EFS was worse in patients with MYCN amplification or 1p deletion than in the corresponding group, whereas 11q deletion was a prognostic factor only in patients with unamplified MYCN. Changes in immune status revealed a decrease in the proportion of T cells in blood, and an increase in regulatory T cells and immunosuppression-related cytokines such as interleukin (IL)-10. The EFS of the IL-10 high-level group was lower than that of the low-level group. Patients with concomitant genetic alterations and a high level of IL-10 had worse EFS than other patients.

CONCLUSIONS

Patients with neuroblastoma characterized by these genetic characteristics often have suppressed T cell response and an overabundance of immunosuppressive cells and cytokines in the peripheral blood. This imbalance is significantly associated with poor EFS. Moreover, if these patients show an elevated levels of immunosuppressive cytokines such as IL-10, the prognosis will be worse.

Research status and development trends of omics in neuroblastoma a bibliometric and visualization analysis

Background

Neuroblastoma (NB), a prevalent extracranial solid tumor in children, stems from the neural crest. Omics technologies are extensively employed in NB, and We analyzed published articles on NB omics to understand the research trends and hot topics in NB omics.

Method

We collected all articles related to NB omics published from 2005 to 2023 from the Web of Science Core Collection database. Subsequently, we conducted analyses using VOSviewer, CiteSpace, Bibliometrix, and the Bibliometric online analysis platform (https://bibliometric.com/ ).

Results

We included a total of 514 articles in our analysis. The increasing number of publications in this field since 2020 indicates growing attention to NB omics, gradually entering a mature development stage. These articles span 50 countries and 1,000 institutions, involving 3,669 authors and 292 journals. The United States has the highest publication output and collaboration with other countries, with Germany being the most frequent collaborator. Capital Medical University and the German Cancer Research Center are the institutions with the highest publication count. The Journal of Proteome Research and the Journal of Biological Chemistry are the most prolific journal and most co-cited journal, respectively. Wang, W, and Maris, JM are the scholars with the highest publication count and co-citations in this field. "Neuroblastoma" and "Expression" are the most frequent keywords, while "classification," "Metabolism," "Cancer," and "Diagnosis" are recent key terms. The article titled "Neuroblastoma" by John M. Maris is the most cited reference in this analysis.

Conclusion

The continuous growth in NB omics research underscores its increasing significance in the scientific community. Omics technologies have facilitated the identification of potential biomarkers, advancements in personalized medicine, and the development of novel therapeutic strategies. Despite these advancements, the field faces significant challenges, including tumor heterogeneity, data standardization issues, and the translation of research findings into clinical practice.

A temporal (phospho-)proteomic dataset of neurotrophic receptor tyrosine kinase signalling in neuroblastoma

Neurotrophic receptor tyrosine kinases (TrkA, TrkB, TrkC), despite their homology, contribute to the clinical heterogeneity of the childhood cancer neuroblastoma. TrkA expression is associated with low-stage disease and is often seen with spontaneous tumour regression. Conversely, TrkB is present in unfavourable neuroblastomas that often harbour amplification of the MYCN oncogene. The role of TrkC is less clearly defined, although some studies suggest its association with a favourable outcome. Understanding the differences in activity of Trk receptors that drive divergent clinical phenotypes as well as the influence of MYCN amplification on downstream Trk receptor signalling remains poorly understood. Here, we present a comprehensive label-free mass spectrometry-based total proteomics and phosphoproteomics dataset (432 raw files with FragPipe search outputs; available on PRIDE with accession number PXD054441) where we identified and quantified 4,907 proteins, 16,744 phosphosites and 5,084 phosphoproteins, derived from NGF/BDNF/NT-3 treated TrkA/B/C-overexpressing neuroblastoma cells with differential MYCN status. Analysing our dataset offers valuable insights into TrkA/B/C receptor signalling in neuroblastoma and its modulation by MYCN status; and holds potential for advancing therapeutic strategies in this challenging childhood cancer.

Repurposing of c-MET Inhibitor Tivantinib Inhibits Pediatric Neuroblastoma Cellular Growth

Background: Dysregulation of receptor tyrosine kinase c-MET is known to promote tumor development by stimulating oncogenic signaling pathways in different cancers, including pediatric neuroblastoma (NB). NB is an extracranial solid pediatric cancer that accounts for almost 15% of all pediatric cancer-related deaths, with less than a 50% long-term survival rate. Results: In this study, we analyzed a large cohort of primary NB patient data and revealed that high MET expression strongly correlates with poor overall survival, disease progression, relapse, and high MYCN levels in NB patients. To determine the effects of c-MET in NB, we repurposed a small molecule inhibitor, tivantinib, and found that c-MET inhibition significantly inhibits NB cellular growth. Tivantinib significantly blocks NB cell proliferation and 3D spheroid tumor formation and growth in different MYCN-amplified and MYCN-non-amplified NB cell lines. Furthermore, tivantinib blocks the cell cycle at the G2/M phase transition and induces apoptosis in different NB cell lines. As expected, c-MET inhibition by tivantinib inhibits the expression of multiple genes in PI3K, STAT, and Ras cell signaling pathways. Conclusions: Overall, our data indicate that c-MET directly regulates NB growth and 3D spheroid growth, and c-MET inhibition by tivantinib may be an effective therapeutic approach for high-risk NB. Further developing c-MET targeted therapeutic approaches and combining them with current therapies may pave the way for effectively translating novel therapies for NB and other c-MET-driven cancers.

Super-enhancer-driven IRF2BP2 enhances ALK activity and promotes neuroblastoma cell proliferation

BACKGROUND

Super-enhancers (SEs) typically govern the expression of critical oncogenes and play a fundamental role in the initiation and progression of cancer. Focusing on genes that are abnormally regulated by SE in cancer may be a new strategy for understanding pathogenesis. In the context of this investigation, we have identified a previously unreported SE-driven gene IRF2BP2 in neuroblastoma (NB).

METHODS

The expression and prognostic value of IRF2BP2 were detected in public databases and clinical samples. The effect of IRF2BP2 on NB cell growth and apoptosis was evaluated through in vivo and in vitro functional loss experiments. The molecular mechanism of IRF2BP2 was investigated by the study of chromatin regulatory regions and transcriptome sequencing.

RESULTS

The sustained high expression of IRF2BP2 results from the activation of a novel SE established by NB master transcription factors MYCN, MEIS2, and HAND2, and they form a new complex that regulates the gene network associated with the proliferation of NB cell populations. We also observed a significant enrichment of the AP-1 family at the binding sites of IRF2BP2. Remarkably, within NB cells, AP-1 plays a pivotal role in shaping the chromatin accessibility landscape, thereby exposing the binding site for IRF2BP2. This orchestrated action enables AP-1 and IRF2BP2 to collaboratively stimulate the expression of the NB susceptibility gene ALK, thereby upholding the highly proliferative phenotype characteristic of NB.

CONCLUSIONS

Our findings indicate that SE-driven IRF2BP2 can bind to AP-1 to maintain the survival of tumor cells via regulating chromatin accessibility of the NB susceptibility gene ALK.

Radiomics models to predict bone marrow metastasis of neuroblastoma using CT

Background

Bone marrow is the leading site for metastasis from neuroblastoma and affects the prognosis of patients with neuroblastoma. However, the accurate diagnosis of bone marrow metastasis is limited by the high spatial and temporal heterogeneity of neuroblastoma. Radiomics analysis has been applied in various cancers to build accurate diagnostic models but has not yet been applied to bone marrow metastasis of neuroblastoma.

Methods

We retrospectively collected information from 187 patients pathologically diagnosed with neuroblastoma and divided them into training and validation sets in a ratio of 7:3. A total of 2632 radiomics features were retrieved from venous and arterial phases of contrast-enhanced computed tomography (CT), and nine machine learning approaches were used to build radiomics models, including multilayer perceptron (MLP), extreme gradient boosting, and random forest. We also constructed radiomics-clinical models that combined radiomics features with clinical predictors such as age, gender, ascites, and lymph gland metastasis. The performance of the models was evaluated with receiver operating characteristics (ROC) curves, calibration curves, and risk decile plots.

Results

The MLP radiomics model yielded an area under the ROC curve (AUC) of 0.97 (95% confidence interval [CI]: 0.95-0.99) on the training set and 0.90 (95% CI: 0.82-0.95) on the validation set. The radiomics-clinical model using an MLP yielded an AUC of 0.93 (95% CI: 0.89-0.96) on the training set and 0.91 (95% CI: 0.85-0.97) on the validation set.

Conclusions

MLP-based radiomics and radiomics-clinical models can precisely predict bone marrow metastasis in patients with neuroblastoma.

Low Expression of CASP8 Could be a Prognostic Biomarker in Neuroblastoma Patients

The aim of study was to investigate whether CASP8 (CASPASE8) could be a biomarker for prognosis in neuroblastoma. The prognostic value of CASP8 was determined by analyzing CASP8 methylation status and gene expressions in the tumor tissues of 37 neuroblastoma patients. Bisulfite and quantitative multiplex-methylation-specific polymerase chain reaction (PCR) were used to identify the methylation status. CASP8 messenger ribonucleic acid (RNA) expression levels were determined using reverse transcriptase-quantitative PCR. CASP8 expression levels associated with prognostic value were also analyzed using the TARGET NBL (141 cases) database through PDX for Childhood Cancer Therapeutics (PCAT) and SEQC (498 cases) via the R2 platform. CASP8 methylation status was associated with risk groups, MYCN amplification, and 17q gain status. CASP8 expression was found to be statistically different between high- and low-risk neuroblastoma groups. Low expression of CASP8 was associated with MYCN amplification status. Low expression of CASP8 has shown statistically significant prognostic value through TARGET NBL and SEQC-498 data sets. CASP8 messenger RNA expressions and methylation status were associated with the MYCN amplified high-risk group in neuroblastoma. CASP8 messenger RNA expressions may be considered as a clinical prognostic marker in neuroblastoma.

A subset of image-defined risk factors predict completeness of resection in children with high-risk neuroblastoma: An international multicenter study

BACKGROUND

Image-defined risk factors (IDRFs) were promulgated for predicting the feasibility and safety of complete primary tumor resection in children with neuroblastoma (NB). There is limited understanding of the impact of individual IDRFs on resectability of the primary tumor or patient outcomes. A multicenter database of patients with high-risk NB was interrogated to answer this question.

DESIGN/METHODS

Patients with high-risk NB (age <20 years) were eligible if cross-sectional imaging was performed at least twice prior to resection. IDRFs and primary tumor measurements were recorded for each imaging study. Extent of resection was determined from operative reports.

RESULTS

There were 211 of 229 patients with IDRFs at diagnosis, and 171 patients with IDRFs present pre-surgery. A ≥90% resection was significantly more likely in the absence of tumor invading or encasing the porta hepatis, hepatoduodenal ligament, superior mesenteric artery (SMA), renal pedicles, abdominal aorta/inferior vena cava (IVC), iliac vessels, and/or diaphragm at diagnosis or an overlapping subset of IDRFs (except diaphragm) at pre-surgery. There were no significant differences in event-free survival (EFS) and overall survival (OS) when patients were stratified by the presence versus absence of any IDRF either at diagnosis or pre-surgery.

CONCLUSION

Two distinct but overlapping subsets of IDRFs present either at diagnosis or after induction chemotherapy significantly influence the probability of a complete resection in children with high-risk NB. The presence of IDRFs was not associated with significant differences in OS or EFS in this cohort.

Pharmacologically Targeting Ferroptosis and Cuproptosis in Neuroblastoma

Neuroblastoma is a deadly pediatric cancer that originates from the neural crest and frequently develops in the abdomen or adrenal gland. Although multiple approaches, including chemotherapy, radiotherapy, targeted therapy, and immunotherapy, are recommended for treating neuroblastoma, the tumor will eventually develop resistance, leading to treatment failure and cancer relapse. Therefore, a firm understanding of the molecular mechanisms underlying therapeutic resistance is vital for the development of new effective therapies. Recent research suggests that cancer-specific modifications to multiple subtypes of nonapoptotic regulated cell death (RCD), such as ferroptosis and cuproptosis, contribute to therapeutic resistance in neuroblastoma. Targeting these specific types of RCD may be viable novel targets for future drug discovery in the treatment of neuroblastoma. In this review, we summarize the core mechanisms by which the inability to properly execute ferroptosis and cuproptosis can enhance the pathogenesis of neuroblastoma. Therefore, we focus on emerging therapeutic compounds that can induce ferroptosis or cuproptosis, delineating their beneficial pharmacodynamic effects in neuroblastoma treatment. Cumulatively, we suggest that the pharmacological stimulation of ferroptosis and ferroptosis may be a novel and therapeutically viable strategy to target neuroblastoma.

Modern surgical strategies in pediatric neuroblastoma: Evolving approaches and treatment principles

Neuroblastoma, the most common extracranial solid tumor in children under the age of 5, has been described as early as the 19th century, and its complexity has continued to intrigue researchers, as well as medical and surgical specialists. At one end of the phenotypic spectrum, neuroblastoma is self-limiting with minimal to no intervention required, while on the opposite end exists the challenge of refractory disease despite aggressive management and toxic systemic treatments. The goal of this review is to describe a comprehensive surgical perspective and contemporary approach to neuroblastoma.

Identification and validation of a novel five-gene signature in high-risk MYCN-not-amplified neuroblastoma

OBJECTIVE

High-risk neuroblastoma patients often have poor outcomes despite multi-treatment options. The risk stratification of high-risk MYCN-not-amplified (HR-MYCN-NA) patients remains difficult. This study aims to identify a gene set signature that can help further stratify HR-MYCN-NA patients for a potential personalized therapeutic strategy.

METHODS

Three microarrays and one single-cell RNA sequence dataset were acquired and analyzed. Firstly, the prognostic-related genes (PRGs) in HR-MYCN-NA tumor cells were identified using TARGET-NB and GSE137804 datasets. Then, the prognostic model was established by LASSO-Cox regression, and verified in external cohort (GSE49710, GSE45547). Moreover, a time-dependent receiver operating characteristic curve (ROC) and area under the ROC (AUC) was used to assess survival prediction. A nomogram was established to predict the 1-, 3- and 5-year overall survival (OS) of HR-MYCN-NA patients.

RESULTS

In the training set, a five-PRGs signature, which include GAL, GFRA3, MARCKS, PSMD13, and ZNHIT3 genes, was identified and successfully stratified HR-MYCN-NA patients into ultra-high risk (UHR) and high-risk (HR) subtypes (HR = 4.29, P < 0.001). ROC curve analysis confirmed its predictive power (AUC = 0.74-0.82), suggesting a good predictive efficacy. Consistently, high-risk scores also predicted worse OS (HR = 2, P = 0.033) in the external validation dataset (AUC = 0.67-0.71). Moreover, the overall C-index of the nomogram was 0.75 (P < 0.001), which indicated good agreement between the observed and predicted survival rates. Further integrating the five PRGs signature with clinical factors, these 5 gene signature (HR = 4.45, P < 0.001) and tumor grade (HR = 4.15, P = 0.02) were found to be independent prognostic factors for HR-MYCN-NA patients.

CONCLUSION

The novel five PRGs signature could well predict the survival of HR-MYCN-NA patients, which may provide constructive information for these subsets.

Neuroblastoma with high ASPM reveals pronounced heterogeneity and poor prognosis

OBJECTIVE

We explored the preliminary value of abnormal spindle-like microcephaly- associated (ASPM) protein in aiding precise risk sub-stratification, prediction of metabolic heterogeneity, and prognosis of neuroblastoma (NB).

METHODS

This retrospective study enrolled newly diagnosed patients with NB who underwent positron emission tomography/computed tomography (PET/CT) before therapy, and tumor tissue was collected after surgery. Regression analysis was used to evaluate ASPM expression and risk stratification in patients with NB. The expression levels of ASPM, clinical information, and PET/CT text features were analyzed using univariate and multivariate survival analyses. Finally, a correlation analysis was used to explore the relationship between ASPM and tumor metabolic heterogeneity.

RESULTS

There were 48 patients with NB in this study (35 boys and 13 girls); 22 patients progressed and 16 died. We found that the level of ASPM was highly associated with risk stratification (OR = 5.295, 95%IC: 1.348-41.722, p = 0.021). Patients with NB and high-risk stratification with high ASPM level had a lower 3-year progression-free survival (PFS) rate (14.28%) and 1-year PFS rate (57.14%) than those with low ASPM level (57.14% and 93.75%, respectively). Using univariate and multivariate survival analyses, this study revealed that ASPM and LDH were independent risk factors for both PFS and overall survival (OS), whales GLZLM_ZLNU was only a risk factor for PFS.

CONCLUSION

ASPM holds promise as a novel biomarker for refining current risk stratification and predicting prognosis in neuroblastoma. Elevated levels of ASPM, LDH, and GLZLM_ZLNU may be associated with poorer survival outcomes in neuroblastoma patients.

The Remarkable and Selective In Vitro Cytotoxicity of Synthesized Bola-Amphiphilic Nanovesicles on Etoposide-Sensitive and -Resistant Neuroblastoma Cells

Neuroblastoma (NB) is a solid tumor occurring in infancy and childhood. Its high-risk form has currently a survival rate <50%, despite aggressive treatments. This worrying scenario is worsened by drug-induced secondary tumorigenesis and the emergency of drug resistance, calling for the urgent development of new extra-genomic treatments. Triphenyl phosphonium salts (TPPs) are mitochondria-targeting compounds that exert anticancer effects, impair mitochondria functions, and damage DNA at the same time. Despite several biochemical applications, TPP-based bola-amphiphiles self-assembling nanoparticles (NPs) in water have never been tested as antitumor agents. Here, with the aim of developing new antitumor devices to also counteract resistant forms of HR-NB, the anticancer effects of a TPP-based bola-amphiphile molecule have been investigated in vitro for the first time. To this end, we considered the previously synthesized and characterized sterically hindered quaternary phosphonium salt (BPPB). It embodies both the characteristics of mitochondria-targeting compounds and those of bola-amphiphiles. The anticancer effects of BPPB were assessed against HTLA-230 human stage-IV NB cells and their counterpart, which is resistant to etoposide (ETO), doxorubicin (DOX), and many other therapeutics (HTLA-ER). Very low IC50 values of 0.2 µM on HTLA-230 and 1.1 µM on HTLA-ER (538-fold lower than that of ETO) were already determined after 24 h of treatment. The very low cell viability observed after 24 h did not significantly differ from that observed for the longest exposure timing. The putative future inclusion of BPPB in a chemotherapeutic cocktail for HR-NB was assessed by investigating in vitro its cytotoxic effects against mammalian cell lines. These included monkey kidney cells (Cos-7, IC50 = 4.9 µM), human hepatic cells (HepG2, IC50 = 9.6 µM), a lung-derived fibroblast cell line (MRC-5, IC50 = 2.8 µM), and red blood cells (RBCs, IC50 = 14.9 µM). Appreciable to very high selectivity indexes (SIs) have been determined after 24 h treatments (SIs = 2.5-74.6), which provided evidence that both NB cell populations were already fully exterminated. These in vitro results pave the way for future investigations of BPPB on animal models and upon confirmation for the possible development of BPPB as a novel therapeutic to treat MDR HR-NB cells.

Salvage chemotherapy regimens with arsenic trioxide for relapsed or refractory neuroblastoma: a promising approach

In patients with relapsed or refractory neuroblastoma (NB), the limited efficacy of conventional chemotherapies necessitates the exploration of new treatment options. Previous studies have highlighted the anti-tumor properties of arsenic trioxide (ATO) in high-risk NB (HR-NB). This study aims to assess the effectiveness and safety of ATO combined with salvage chemotherapy regimens, featuring cyclophosphamide and topotecan, as a foundational treatment for children with relapsed or refractory NB. Eleven patients (four relapsed, seven refractory NB) were retrospectively analyzed for efficacy and treatment relevance. Salvage treatments, incorporating ATO (0.18 mg/kg daily for 8 h intravenously on days 1 to 10), were administered upon disease progression or relapse, with assessments conducted every two cycles. Treatments had 63.6% efficacy, with six cases of partial response, one case of stable disease, and four cases of disease progression. The overall response rate was 54.5%, and the disease control rate was 63.6%. Importantly, the systemic toxicity experienced by patients following salvage chemotherapy with ATO was mild. Salvage chemotherapy regimens featuring ATO demonstrated potential for prolonging disease stabilization for relapsed or refractory HR-NB patients, exhibiting both favorable efficacy and safety profiles. This suggests further clinical exploration and promotion of this therapeutic approach in the treatment of NB.

Heterogeneous SSTR2 target expression and a novel KIAA1549::BRAF fusion clone in a progressive metastatic lesion following 177Lutetium-DOTATATE molecular radiotherapy in neuroblastoma: a case report

In this case report, we present the treatment outcomes of the first patient enrolled in the LuDO-N trial. The patient is a 21-month-old girl diagnosed with high-risk neuroblastoma (NB) and widespread skeletal metastasis. The patient initially underwent first-line therapy according to SIOPEN HRNBL-1 but was switched to second-line treatments due to disease progression, and she was finally screened for enrollment in the LuDO-N trial due to refractory disease. Upon enrollment, the patient received two rounds of the radiolabeled somatostatin analogue lutetium-177 octreotate (177Lu-DOTATATE), which was well tolerated. A dosimetry analysis revealed a heterogeneous uptake across tumor lesions, resulting in a significant absorbed dose of 54 Gy in the primary tumor, but only 2 Gy at one of the metastatic sites in the distal femur. While the initial treatment response showed disease stabilization, the distal femoral metastasis continued to progress, leading to the eventual death of the patient. A tissue analysis of the biopsies collected throughout the course of the disease revealed heterogeneous drug target expression of somatostatin receptor 2 (SSTR2) across and within tumor lesions. Furthermore, genomic profiling revealed a novel KIAA1549::BRAF fusion oncogene amplification in the distal femoral metastasis at recurrence that might be related with resistance to radiation, possibly through the downregulation of SSTR2. This case report demonstrates a mixed response to molecular radiotherapy (MRT) with 177Lu-DOTATATE. The observed variation in SSTR2 expression between tumor lesions suggests that heterogeneous target expression may have been the reason for treatment failure in this patient's case. Further investigation within the LuDO-N trial will give a more comprehensive understanding of the correlation between SSTR2 expression levels and treatment outcomes, which will be important to advance treatment strategies based on MRT for children with high-risk NB.

Investigating the molecular mechanisms of Fuzheng Yiliu Shenji prescription in SH-SY5Y neuroblastoma cells

Background

Neuroblastoma is the most common extracranial solid tumor in childhood. Fuzheng Yiliu Shenji Prescription (FYSP) has shown potential in treating malignant pediatric tumors in clinical settings. This study aims to explore the molecular mechanisms behind its effects, specifically in the context of neuroblastoma cell lines.

Objective

To elucidate the active compounds in FYSP and their mechanisms of action in inhibiting neuroblastoma cell viability, inducing apoptosis, and affecting the cell cycle in SH-SY5Y cells through network pharmacology and empirical validation.

Materials and methods

We identified the major compounds in FYSP and their predicted targets, constructing a protein-protein interaction (PPI) network and performing GO and KEGG pathway analyses. The effects of FYSP were empirically validated through assays on cell viability, cell cycle, apoptosis, and protein expression in SH-SY5Y cells.

Results

The study identified 172 active chemical components in FYSP, with 188 common targets related to neuroblastoma. Network analysis highlighted the PI3K-Akt pathway as a significant target. Experimental validation in SH-SY5Y cells confirmed that FYSP could inhibit cell viability, induce G2/M cell cycle arrest, and promote apoptosis through modulation of the PI3K-Akt pathway, specifically upregulating caspase-3 and downregulating Bcl-2/Bax expression.

Conclusion

The study elucidates the molecular basis of FYSP's effects on neuroblastoma cells in vitro, demonstrating its ability to modulate key pathways involved in cell cycle and apoptosis. While these findings suggest a potential therapeutic role for FYSP, they are limited to in vitro observations, and further research, including in vivo studies, is necessary to explore its clinical applicability.

Whole-Exome Sequencing Reveals Novel Candidate Driver Mutations and Potential Druggable Mutations in Patients with High-Risk Neuroblastoma

Neuroblastoma is the most prevalent solid tumor in early childhood, with a 5-year overall survival rate of 40-60% in high-risk cases. Therefore, the identification of novel biomarkers for the diagnosis, prognosis, and therapy of neuroblastoma is crucial for improving the clinical outcomes of these patients. In this study, we conducted the whole-exome sequencing of 48 freshly frozen tumor samples obtained from the Biobank. Somatic variants were identified and selected using a bioinformatics analysis pipeline. The mutational signatures were determined using the Mutalisk online tool. Cancer driver genes and druggable mutations were predicted using the Cancer Genome Interpreter. The most common mutational signature was single base substitution 5. MUC4, MUC16, and FLG were identified as the most frequently mutated genes. Using the Cancer Genome Interpreter, we identified five recurrent cancer driver mutations spanning MUC16, MUC4, ALK, and CTNND1, with the latter being novel and containing a missense mutation, R439C. We also identified 11 putative actionable mutations including NF1 Q1798*, Q2616*, and S636X, ALK F1174L and R1275Q, SETD2 P10L and Q1829E, BRCA1 R612S, NOTCH1 D1670V, ATR S1372L, and FGFR1 N577K. Our findings provide a comprehensive overview of the novel information relevant to the underlying molecular pathogenesis and therapeutic targets of neuroblastoma.

USP44 Overexpression Drives a MYC-Like Gene Expression Program in Neuroblastoma through Epigenetic Reprogramming

Neuroblastoma is an embryonic cancer that contributes disproportionately to death in young children. Sequencing data have uncovered few recurrently mutated genes in this cancer, although epigenetic pathways have been implicated in disease pathogenesis. We used an expression-based computational screen that examined the impact of deubiquitinating enzymes on patient survival to identify potential new targets. We identified the histone H2B deubiquitinating enzyme USP44 as the enzyme with the greatest impact on survival in patients with neuroblastoma. High levels of USP44 significantly correlate with metastatic disease, unfavorable histology, advanced patient age, and MYCN amplification. The subset of patients with tumors expressing high levels of USP44 had significantly worse survival, including those with tumors lacking MYCN amplification. We showed experimentally that USP44 regulates neuroblastoma cell proliferation, migration, invasion, and neuronal development. Depletion of the histone H2B ubiquitin ligase subunit RNF20 resulted in similar findings, strongly implicating this histone mark as the target of USP44 activity in this disease. Integration of transcriptome and epigenome in analyses demonstrates a distinct set of genes that are regulated by USP44, including those in Hallmark MYC target genes in both murine embryonic fibroblasts and the SH-SY5Y neuroblastoma cell line. We conclude that USP44 is a novel epigenetic regulator that promotes aggressive features and may be a novel target in neuroblastoma. Implications: This study identifies a new genetic marker of aggressive neuroblastoma and identifies the mechanisms by which its overactivity contributes to the pathophysiology of this disease.

FTO diversely influences sensitivity of neuroblastoma cells to various chemotherapeutic drugs

Chemotherapy resistance is a significant factor in treatment failure in patients with neuroblastoma (NB), and it directly affects patient prognosis. Therefore, identifying novel therapeutic targets to enhance chemosensitivity is essential to improve the cure rate and prognosis of patients with NB. In this study, we investigated the role of FTO in chemosensitivity of NB cells to various chemotherapeutic drugs. Our results showed that high FTO expression was positively correlated with increased survival probability and favorable prognostic factors in patients with NB. FTO overexpression inhibited cell proliferation, whereas FTO knockdown promoted cell proliferation in NB cells. FTO expression alteration had contrasting effects on NB cells' sensitivity to etoposide but had no significant impact on sensitivity to cisplatin. Downregulation of FTO reduced the sensitivity of NB cells to paclitaxel, whereas upregulation of FTO enhanced its sensitivity. Additionally, the sensitivities between patients with lower and higher FTO expression to various chemotherapeutic drugs or small-molecule inhibitors were different. Thus, FTO affects the sensitivities of NB cells differently depending on the different chemotherapeutic drugs and small-molecule inhibitors. This finding may guide physicians and patients choose the appropriate chemotherapeutic drugs or small-molecule inhibitors for treatment.

Long-Lasting Response to Lorlatinib in Patients with ALK-Driven Relapsed or Refractory Neuroblastoma Monitored with Circulating Tumor DNA Analysis

Patients with anaplastic lymphoma kinase (ALK)-driven neuroblastoma may respond to tyrosine kinase inhibitors, but resistance to treatment occurs and methods currently used for detection of residual disease have limited sensitivity. Here, we present a national unselected cohort of five patients with relapsed or refractory ALK-driven neuroblastoma treated with lorlatinib as monotherapy and test the potential of targeted circulating tumor DNA (ctDNA) analysis as a guide for treatment decisions in these patients. We developed a sequencing panel for ultrasensitive detection of ALK mutations associated with neuroblastoma or resistance to tyrosine kinase inhibitors and used it for ctDNA analysis in 83 plasma samples collected longitudinally from the four patients who harbored somatic ALK mutations. All four patients with ALK p.R1275Q experienced major responses and were alive 35 to 61 months after starting lorlatinib. A fifth patient with ALK p.F1174L initially had a partial response but relapsed after 10 months of treatment. In all cases, ctDNA was detected at the start of lorlatinib single-agent treatment and declined gradually, correlating with clinical responses. In the two patients exhibiting relapse, ctDNA increased 9 and 3 months, respectively, before clinical detection of disease progression. In one patient harboring HRAS p.Q61L in the relapsed tumor, retrospective ctDNA analysis showed that the mutation appeared de novo after 8 months of lorlatinib treatment. We conclude that some patients with relapsed or refractory high-risk neuroblastoma show durable responses to lorlatinib as monotherapy, and targeted ctDNA analysis is effective for evaluation of treatment and early detection of relapse in ALK-driven neuroblastoma.

SIGNIFICANCE

We present five patients with ALK-driven relapsed or refractory neuroblastoma treated with lorlatinib as monotherapy. All patients responded to treatment, and four of them were alive after 3 to 5 years of follow-up. We performed longitudinal ctDNA analysis with ultra-deep sequencing of the ALK tyrosine kinase domain. We conclude that ctDNA analysis may guide treatment decisions in ALK-driven neuroblastoma, also when the disease is undetectable using standard clinical methods.