The biologic basis for neuroblastoma heterogeneity and risk stratification

Comparison of 177Lu-octreotate and 177Lu-octreotide for treatment in human neuroblastoma-bearing mice

Background

Patients with high-risk neuroblastoma (NB) have a 5-year event-free survival of less than 50 %, and novel and improved treatment options are needed. Radiolabeled somatostatin analogs (SSTAs) could be a treatment option. The aims of this work were to compare the biodistribution and the therapeutic effects of 177Lu-octreotate and 177Lu-octreotide in mice bearing the human CLB-BAR NB cell line, and to evaluate their regulatory effects on apoptosis-related genes.

Methods

The biodistribution of 177Lu-octreotide in mice bearing CLB-BAR tumors was studied at 1, 24, and 168 h after administration, and the absorbed dose was estimated to tumor and normal tissues. Further, animals were administered different amounts of 177Lu-octreotate or 177Lu-octreotide. Tumor volume was measured over time and compared to a control group given saline. RNA was extracted from tumors, and the expression of 84 selected genes involved in apoptosis was quantified with qPCR.

Results

The activity concentration was generally lower in most tissues for 177Lu-octreotide compared to 177Lu-octreotate. Mean absorbed dose per administered activity to tumor after injection of 1.5 MBq and 15 MBq was 0.74 and 0.03 Gy/MBq for 177Lu-octreotide and 2.9 and 0.45 Gy/MBq for 177Lu-octreotate, respectively. 177Lu-octreotide treatment resulted in statistically significant differences compared to controls. Fractionated administration led to a higher survival fraction than after a single administration. The pro-apoptotic genes TNSFS8, TNSFS10, and TRADD were regulated after administration with 177Lu-octreotate. Treatment with 177Lu-octreotide yielded regulation of the pro-apoptotic genes CASP5 and TRADD, and of the anti-apoptotic gene IL10 as well as the apoptosis-related gene TNF.

Conclusion

177Lu-octreotide gave somewhat better anti-tumor effects than 177Lu-octreotate. The similar effect observed in the treated groups with 177Lu-octreotate suggests saturation of the somatostatin receptors. Pronounced anti-tumor effects following fractionated administration merited receptor saturation as an explanation. The gene expression analyses suggest apoptosis activation through the extrinsic pathway for both radiopharmaceuticals.

Navigating the landscape of theranostics in nuclear medicine: current practice and future prospects

Theranostics refers to the combination of diagnostic biomarkers with therapeutic agents that share a specific target expressed by diseased cells and tissues. Nuclear medicine is an exciting component explored for its applicability in theranostic concepts in clinical and research investigations. Nuclear theranostics is based on the employment of radioactive compounds delivering ionizing radiation to diagnose and manage certain diseases employing binding with specifically expressed targets. In the realm of personalized medicine, nuclear theranostics stands as a beacon of potential, potentially revolutionizing disease management. Studies exploring the theranostic profile of radioactive compounds have been presented in this review along with a detailed explanation of radioactive compounds and their theranostic applicability in several diseases. It furnishes insights into their applicability across diverse diseases, elucidating the intricate interplay between these compounds and disease pathologies. Light is shed on the important milestones of nuclear theranostics beginning with radioiodine therapy in thyroid carcinomas, MIBG labelled with iodine in neuroblastoma, and several others. Our perspectives have been put forth regarding the most important theranostic agents along with emerging trends and prospects.

Lineage specific transcription factor waves reprogram neuroblastoma from self-renewal to differentiation

Temporal regulation of super-enhancer (SE) driven transcription factors (TFs) underlies normal developmental programs. Neuroblastoma (NB) arises from an inability of sympathoadrenal progenitors to exit a self-renewal program and terminally differentiate. To identify SEs driving TF regulators, we use all-trans retinoic acid (ATRA) to induce NB growth arrest and differentiation. Time-course H3K27ac ChIP-seq and RNA-seq reveal ATRA coordinated SE waves. SEs that decrease with ATRA link to stem cell development (MYCN, GATA3, SOX11). CRISPR-Cas9 and siRNA verify SOX11 dependency, in vitro and in vivo. Silencing the SOX11 SE using dCAS9-KRAB decreases SOX11 mRNA and inhibits cell growth. Other TFs activate in sequential waves at 2, 4 and 8 days of ATRA treatment that regulate neural development (GATA2 and SOX4). Silencing the gained SOX4 SE using dCAS9-KRAB decreases SOX4 expression and attenuates ATRA-induced differentiation genes. Our study identifies oncogenic lineage drivers of NB self-renewal and TFs critical for implementing a differentiation program.

Comparing Tribbles Homolog 3 (TRIB3) Protein Expression Levels with Clinicopathological Characteristics and Survival Among Neuroblastoma Patients

Background

Tribbles Homolog 3 (TRIB3) is a member of the pseudokinase family of tribbles and acts as an adaptor protein to regulate different cellular processes. Upregulation of TRIB3 expression was shown either as a favorable or an adverse prognostic factor in various adult malignancies. However, TRIB3 expression has not been examined in pediatric cancers. Neuroblastoma is the most common malignant solid tumor of childhood, which affects mostly children under 5 years old. Risk stratification of patients defined by International Neuroblastoma Risk Group was used to determine prognosis and treatment of the disease. This study aimed to examine the relationship between TRIB3 protein expression levels and clinicopathological features and survival of patients.

Methods

TRIB3 protein expression was analyzed using immunohistochemical staining on formalin-fixed paraffin-embedded tissue samples of neuroblastoma patients (n = 56). Survival analyses were performed with Kaplan-Meier method and log-rank tests. Association between TRIB3 expression and clinicopathological characteristics were analyzed with Spearman's correlation.

Results

Of the patients, 32.1% were in the low-risk group, 21.4% in the medium-risk group, and 46.4% in the high-risk group. Survival analysis was performed in the entire neuroblastoma patient group and sub-risk groups of neuroblastoma patients. In the entire patient group, there was no significant difference in overall survival (P = .202) and event-free survival (P = .172) between TRIB3-positive and -negative patients. However, when survival analyses were performed in each risk group, TRIB3 expression was significantly associated with higher overall survival (P = .034) and event-free survival (P = .032) in low-risk group neuroblastoma patients. Nevertheless, no association was found between TRIB3 expression and overall survival (P = .799) and event-free survival (P = .448) in high-risk neuroblastoma patients. Furthermore, a significant correlation was identified between 1p36 loss-of-heterozygosity and TRIB3 expression (P = .030). However, TRIB3 expression did not correlate with other clinicopathological features.

Conclusion

TRIB3 expression is a potential predictive biomarker for low-risk neuroblastoma patients.

Potential Benefits of Dietary Plant Compounds on Normal and Tumor Brain Cells in Humans: In Silico and In Vitro Approaches

Neuroblastoma can be accessed with compounds of larger sizes and wider polarities, which do not usually cross the blood-brain barrier. Clinical data indicate cases of spontaneous regression of neuroblastoma, suggesting a reversible point in the course of cell brain tumorigenesis. Dual specificity tyrosine-phosphorylation-regulated kinase2 (DYRK2) is a major molecular target in tumorigenesis, while curcumin was revealed to be a strong inhibitor of DYRK2 (PBD ID: 5ZTN). Methods: in silico studies by CLC Drug Discovery Workbench (CLC) and Molegro Virtual Docker (MVD) Software on 20 vegetal compounds from the human diet tested on 5ZTN against the native ligand curcumin, in comparison with anemonin. In vitro studies were conducted on two ethanolic extracts from Anemone nemorosa tested on normal and tumor human brain cell lines NHA and U87, compared with four phenolic acids (caffeic, ferulic, gentisic, and para-aminobenzoic/PABA). Conclusions: in silico studies revealed five dietary compounds (verbascoside, lariciresinol, pinoresinol, medioresinol, matairesinol) acting as stronger inhibitors of 5ZTN compared to the native ligand curcumin. In vitro studies indicated that caffeic acid has certain anti-proliferative effects on U87 and small benefits on NHA viability. A. nemorosa extracts indicated potential benefits on NHA viability, and likely dangerous effects on U87.

Prognostic value of texture analysis of the primary tumour in high-risk neuroblastoma: An 18 F-DOPA PET study

PURPOSE

To evaluate the prognostic value of texture analysis of the primary tumour with ¹⁸ fluorine-dihydroxyphenylalanine positron emission tomography/X-ray computed tomography (¹⁸ F-DOPA PET/CT) in patients affected by high-risk neuroblastoma (HR-NBL).

METHODS

We retrospectively analysed 18 patients with HR-NBL, which had been prospectively enrolled in the course of a previous trial investigating the diagnostic role of ¹⁸ F-DOPA PET/CT at the time of the first onset. Texture analysis of the primary tumour was carried out on the PET images using LifeX. Conventional indices, histogram parameters, grey level co-occurrence (GLCM), run-length (GLRLM), neighbouring difference (NGLDM) and zone-length (GLZLM) matrices parameter were extracted; their values were compared with the overall metastatic load, expressed by means of whole-body metabolic burden (WBMB) score and the progression-free/overall survival (PFS and OS).

RESULTS

There was a direct correlation between WBMB and radiomics parameter describing uptake intensity (SUV_mean : p = .004) and voxel heterogeneity (entropy: p = .026; GLCM_Contrast: p = .001). Conversely, texture indices of homogeneity showed an inverse correlation with WBMB (energy: p = .026; GLCM_Homogeneity: p = .006). On the multivariate model, WBMB (p < .01) and the first standardised uptake value (SUV) quartile (p < .001) predicted PFS; OS was predicted by WBMB and the N-myc proto-oncogene protein (MYCN) amplification (p < .05) for both.

CONCLUSIONS

Textural parameters describing heterogeneity and metabolic intensity of the primary HR-NBL are closely associated with its overall metastatic burden. In turn, the whole-body tumour load appears to be one of the most relevant predictors of progression-free and overall survival.

Pharmacophore-Model-Based Virtual-Screening Approaches Identified Novel Natural Molecular Candidates for Treating Human Neuroblastoma

The mortality of cancer patients with neuroblastoma is increasing due to the limited availability of specific treatment options. Few drug candidates for combating neuroblastoma have been developed, and identifying novel therapeutic candidates against the disease is an urgent issue. It has been found that muc-N protein is amplified in one-third of human neuroblastomas and expressed as an attractive drug target against the disease. The myc-N protein interferes with the bromodomain and extraterminal (BET) family proteins. Pharmacologically inhibition of the protein potently depletes MYCN in neuroblastoma cells. BET inhibitors target MYCN transcription and show therapeutic efficacy against neuroblastoma. Therefore, the study aimed to identify potential inhibitors against the BET family protein, specifically Brd4 (brodamine-containing protein 4), to hinder the activity of neuroblastoma cells. To identify effective molecular candidates against the disease, a structure-based pharmacophore model was created for the binding site of the Brd4 protein. The pharmacophore model generated from the protein Brd4 was validated to screen potential natural active compounds. The compounds identified through the pharmacophore-model-based virtual-screening process were further screened through molecular docking, ADME (absorption, distribution, metabolism, and excretion), toxicity, and molecular dynamics (MD) simulation approach. The pharmacophore-model-based screening process initially identified 136 compounds, further evaluated based on molecular docking, ADME analysis, and toxicity approaches, identifying four compounds with good binding affinity and lower side effects. The stability of the selected compounds was also confirmed by dynamic simulation and molecular mechanics with generalized Born and surface area solvation (MM-GBSA) methods. Finally, the study identified four natural lead compounds, ZINC2509501, ZINC2566088, ZINC1615112, and ZINC4104882, that will potentially inhibit the activity of the desired protein and help to fight against neuroblastoma and related diseases. However, further evaluations through in vitro and in vivo assays are suggested to identify their efficacy against the desired protein and disease.

EIF4EBP1 is transcriptionally upregulated by MYCN and associates with poor prognosis in neuroblastoma

Neuroblastoma (NB) accounts for 15% of cancer-related deaths in childhood despite considerable therapeutic improvements. While several risk factors, including MYCN amplification and alterations in RAS and p53 pathway genes, have been defined in NB, the clinical outcome is very variable and difficult to predict. Since genes of the mechanistic target of rapamycin (mTOR) pathway are upregulated in MYCN-amplified NB, we aimed to define the predictive value of the mTOR substrate-encoding gene eukaryotic translation initiation factor 4E-binding protein 1 (EIF4EBP1) expression in NB patients. Using publicly available data sets, we found that EIF4EBP1 mRNA expression is positively correlated with MYCN expression and elevated in stage 4 and high-risk NB patients. In addition, high EIF4EBP1 mRNA expression is associated with reduced overall and event-free survival in the entire group of NB patients in three cohorts, as well as in stage 4 and high-risk patients. This was confirmed by monitoring the clinical value of 4EBP1 protein expression, which revealed that high levels of 4EBP1 are significantly associated with prognostically unfavorable NB histology. Finally, functional analyses revealed that EIF4EBP1 expression is transcriptionally controlled by MYCN binding to the EIF4EBP1 promoter in NB cells. Our data highlight that EIF4EBP1 is a direct transcriptional target of MYCN whose high expression is associated with poor prognosis in NB patients. Therefore, EIF4EBP1 may serve to better stratify patients with NB.

Improved Outcome in Children With Newly Diagnosed High-Risk Neuroblastoma Treated With Chemoimmunotherapy: Updated Results of a Phase II Study Using hu14.18K322A

PURPOSE

We evaluated whether combining a humanized antidisialoganglioside monoclonal antibody (hu14.18K322A) throughout therapy improves early response and outcomes in children with newly diagnosed high-risk neuroblastoma.

PATIENTS AND METHODS

We conducted a prospective, single-arm, three-stage, phase II clinical trial. Six cycles of induction chemotherapy were coadministered with hu14.18K322A, granulocyte-macrophage colony-stimulating factor (GM-CSF), and low-dose interleukin-2 (IL-2). The consolidation regimen included busulfan and melphalan. When available, an additional cycle of parent-derived natural killer cells with hu14.18K322A was administered during consolidation (n = 31). Radiation therapy was administered at the end of consolidation. Postconsolidation treatment included hu14.18K322A, GM-CSF, IL-2, and isotretinoin. Early response was assessed after the first two cycles of induction therapy. End-of-induction response, event-free survival (EFS), and overall survival (OS) were evaluated.

RESULTS

Sixty-four patients received hu14.18K322A with induction chemotherapy. This regimen was well tolerated, with continuous infusion narcotics. Partial responses (PRs) or better after the first two chemoimmunotherapy cycles occurred in 42 of 63 evaluable patients (66.7%; 95% CI, 55.0 to 78.3). Primary tumor volume decreased by a median of 75% (range, 100% [complete disappearance]-5% growth). Median peak hu14.18K322A serum levels in cycle one correlated with early response to therapy (P = .0154, one-sided t-test). Sixty of 62 patients (97%) had an end-of-induction partial response or better. No patients experienced progressive disease during induction. The 3-year EFS was 73.7% (95% CI, 60.0 to 83.4), and the OS was 86.0% (95% CI, 73.8 to 92.8), respectively.

CONCLUSION

Adding hu14.18K322A to induction chemotherapy improved early objective responses, significantly reduced tumor volumes in most patients, improved end-of-induction response rates, and yielded an encouraging 3-year EFS. These results, if validated in a larger study, may be practice changing.

MYCN in Neuroblastoma: "Old Wine into New Wineskins"

MYCN Proto-Oncogene, BHLH Transcription Factor (MYCN) has been one of the most studied genes in neuroblastoma. It is known for its oncogenetic mechanisms, as well as its role in the prognosis of the disease and it is considered one of the prominent targets for neuroblastoma therapy. In the present work, we attempted to review the literature, on the relation between MYCN and neuroblastoma from all possible mechanistic sites. We have searched the literature for the role of MYCN in neuroblastoma based on the following topics: the references of MYCN in the literature, the gene's anatomy, along with its transcripts, the protein's anatomy, the epigenetic mechanisms regulating MYCN expression and function, as well as MYCN amplification. MYCN plays a significant role in neuroblastoma biology. Its functions and properties range from the forming of G-quadraplexes, to the interaction with miRNAs, as well as the regulation of gene methylation and histone acetylation and deacetylation. Although MYCN is one of the most primary genes studied in neuroblastoma, there is still a lot to be learned. Our knowledge on the exact mechanisms of MYCN amplification, etiology and potential interventions is still limited. The knowledge on the molecular mechanisms of MYCN in neuroblastoma, could have potential prognostic and therapeutic advantages.

Serine-Threonine Kinase Receptor-Associated Protein (STRAP) Knockout Decreases the Malignant Phenotype in Neuroblastoma Cell Lines

Background: Serine-threonine kinase receptor-associated protein (STRAP) plays an important role in neural development but also in tumor growth. Neuroblastoma, a tumor of neural crest origin, is the most common extracranial solid malignancy of childhood and it continues to carry a poor prognosis. The recent discovery of the role of STRAP in another pediatric solid tumor, osteosarcoma, and the known function of STRAP in neural development, led us to investigate the role of STRAP in neuroblastoma tumorigenesis. Methods: STRAP protein expression was abrogated in two human neuroblastoma cell lines, SK-N-AS and SK-N-BE(2), using transient knockdown with siRNA, stable knockdown with shRNA lentiviral transfection, and CRISPR-Cas9 genetic knockout. STRAP knockdown and knockout cells were examined for phenotypic alterations in vitro and tumor growth in vivo. Results: Cell proliferation, motility, and growth were significantly decreased in STRAP knockout compared to wild-type cells. Indicators of stemness, including mRNA abundance of common stem cell markers Oct4, Nanog, and Nestin, the percentage of cells expressing CD133 on their surface, and the ability to form tumorspheres were significantly decreased in the STRAP KO cells. In vivo, STRAP knockout cells formed tumors less readily than wild-type tumor cells. Conclusion: These novel findings demonstrated that STRAP plays a role in tumorigenesis and maintenance of neuroblastoma stemness.

Monoclonal Antibody Therapies for High Risk Neuroblastoma

Monoclonal antibodies (mAbs) are part of the standard of care for the treatment of many adult solid tumors. Until recently none have been approved for use in children with solid tumors. Neuroblastoma (NB) is the most common extracranial solid tumor in children. Those with high-risk disease, despite treatment with very intensive multimodal therapy, still have poor overall survival. Results of treatment with an immunotherapy regimen using a chimeric (human/mouse) mAb against a cell surface disialoganglioside (GD2) have changed the standard of care for these children and resulted in the first approval of a mAb for use in children with solid tumors. This article will review the use of the various anti-GD2 mAbs in children with NB, methods that have been or are being evaluated for enhancing their efficacy, as well as review other promising antigenic targets for the therapeutic use of mAbs in children with NB.

Liquid biomarkers for the management of paediatric neuroblastoma: an approach to personalised and targeted cancer therapy

Background:

Neuroblastoma is the most common extracranial solid tumour of infancy and accounts for about 6–10% of paediatric cancers. It has a biologically and clinically heterogeneous behaviour that ranges from spontaneous regression to cases of highly aggressive metastatic disease that could be unresponsive to standard therapy. In recent years, there have been several investigations into the development of various diagnostic, predictive and prognostic biomarkers towards personalised and targeted management of the disease.

Materials and Methods:

This paper reports on the review of current clinical and emerging biomarkers used in risk assessment, screening for early detection and diagnosis, prognostication and monitoring of the response of treatment of neuroblastoma in paediatric patients.

Conclusions:

Tumour markers can significantly improve diagnosis; however, the invasive, unpleasant and inconvenient nature of current tissue biopsies limits their applications, especially in paediatric patients. Therefore, the development of a non-invasive, reliable high accurate and personalised diagnostic tool capable of early detection and rapid response is the most promising step towards advanced cancer management from tumour diagnosis, therapy to patient monitoring and represents an important step towards the promise of precision, personalised and targeted medicine. Liquid biopsy assay with wide ranges of clinical applications is emerging to hold incredible potential for advancing cancer treatment and has greater promise for diagnostic purposes, identification and tracking of tumour-specific alterations during the course of the disease and to guide therapeutic decisions.

The MicroRNA Landscape of MYCN-Amplified Neuroblastoma

MYCN gene amplification and upregulated expression are major hallmarks in the progression of high-risk neuroblastoma. MYCN expression and function in modulating gene synthesis in neuroblastoma is controlled at virtually every level, including poorly understood regulation at the post-transcriptional level. MYCN modulates the expression of various microRNAs including the miR-17-92 cluster. MYCN mRNA expression itself is subjected to the control by miRNAs, most prominently the miR-17-92 cluster that balances MYCN expression by feed-back regulation. This homeostasis seems disturbed in neuroblastoma where MYCN upregulation coincides with severely increased expression of the miR-17-92 cluster. In the presented study, we applied high-throughput next generation sequencing to unravel the miRNome in a cohort of 97 neuroblastomas, representing all clinical stages. Aiming to reveal the MYCN-dependent miRNome, we evaluate miRNA expression in MYCN-amplified as well as none amplified tumor samples. In correlation with survival data analysis of differentially expressed miRNAs, we present various putative oncogenic as well as tumor suppressive miRNAs in neuroblastoma. Using microRNA trapping by RNA affinity purification, we provide a comprehensive view of MYCN-regulatory miRNAs in neuroblastoma-derived cells, confirming a pivotal role of the miR-17-92 cluster and moderate association by the let-7 miRNA family. Attempting to decipher how MYCN expression escapes elevated expression of inhibitory miRNAs, we present evidence that RNA-binding proteins like the IGF2 mRNA binding protein 1 reduce miRNA-directed downregulation of MYCN in neuroblastoma. Our findings emphasize the potency of post-transcriptional regulation of MYCN in neuroblastoma and unravel new avenues to pursue inhibition of this potent oncogene.

EZH2 inhibition decreases neuroblastoma proliferation and in vivo tumor growth

Investigation of the mechanisms responsible for aggressive neuroblastoma and its poor prognosis is critical to identify novel therapeutic targets and improve survival. Enhancer of Zeste Homolog 2 (EZH2) is known to play a key role in supporting the malignant phenotype in several cancer types and knockdown of EZH2 has been shown to decrease tumorigenesis in neuroblastoma cells. We hypothesized that the EZH2 inhibitor, GSK343, would affect cell proliferation and viability in human neuroblastoma. We utilized four long-term passage neuroblastoma cell lines and two patient-derived xenolines (PDX) to investigate the effects of the EZH2 inhibitor, GSK343, on viability, motility, stemness and in vivo tumor growth. Immunoblotting confirmed target knockdown. Treatment with GSK343 led to significantly decreased neuroblastoma cell viability, migration and invasion, and stemness. GSK343 treatment of mice bearing SK-N-BE(2) neuroblastoma tumors resulted in a significant decrease in tumor growth compared to vehicle-treated animals. GSK343 decreased viability, and motility in long-term passage neuroblastoma cell lines and decreased stemness in neuroblastoma PDX cells. These data demonstrate that further investigation into the mechanisms responsible for the anti-tumor effects seen with EZH2 inhibitors in neuroblastoma cells is warranted.

Immunotherapy approaches targeting neuroblastoma

PURPOSE OF REVIEW

In the era of immune-oncology, a breakthrough in the field of pediatric solid tumor research has been the demonstration that immunotherapy for patients with high-risk neuroblastoma improves the event-free and overall survival. Immunotherapeutic approaches including a monoclonal antibody targeting the cell surface glycosphingolipid disialoganglioside and cytokines successfully eliminate minimal residual disease.

RECENT FINDINGS

Since this seminal discovery, clinical trials evaluating immunotherapy in combination with chemotherapy and cellular therapies have begun to demonstrate effectiveness in treatment of bulky disease. Broader knowledge has also been gained regarding immunotherapy-limiting side-effects. Furthermore, biologic studies in actively treated patients have contributed to our growing understanding of the underlying immunologic processes and mechanisms of tumor response and immune evasion.

SUMMARY

The example of neuroblastoma is beginning to demonstrate that various immunotherapies combined with more conventional anticancer treatments can be synergistic. These advancements pose new challenges to both clinical researchers and medical provider and herald a new era in pediatric cancer therapy.

Association of Genetic Polymorphisms and Serum Levels of IL-6 and IL-8 with the Prognosis in Children with Neuroblastoma

Simple Summary

Neuroblastoma (NB) presents diverse biological and clinical characteristics, from spontaneous regression to highly malignant and aggressive unfavorable tumors that condition the therapeutic failure of conventional treatments. The tumorigenesis of NB can be the result of different genetic variants, which can influence the clinical outcome, and the survival of patients who have metastatic tumors is low. The role of cytokines such as interleukin (IL)-6 has been described in the NB microenvironment promoting tumor progression and metastasis. Single nucleotide polymorphism (SNP)-174 G > C in IL-6 and -251 T > A and +781 C > T in IL-8 regulate the expression of these cytokines, and could be associated with the clinical outcome in patients with NB. Our objective was to evaluate the association of the genetic polymorphisms of IL-6 and IL-8, as well as the serum levels of these cytokines in patients with NB, as this will allow the genetic bases of NB to be characterized and understood, in order to predict the outcome of the disease and develop new therapeutic strategies.

Abstract

There is evidence that high circulating levels of IL-6 and IL-8 are markers of a poor prognosis in various types of cancer, including NB. The participation of these cytokines in the tumor microenvironment has been described to promote progression and metastasis. Our objective was to evaluate the prognostic role of genetic polymorphisms and serum levels of IL-6 and IL-8 in a cohort of Mexican pediatric patients with NB. The detection of the SNPs rs1800795 IL-6 and rs4073 and rs2227306 IL-8 was carried out by PCR-RFLP and the levels of cytokines were determined by the ELISA method. We found elevated circulating levels of IL-8 and IL-6 in NB patients compared to the control group. The genotype frequencies of the rs1800795 IL-6 and rs4073 IL-8 variants were different between the patients with NB and the control group. Likewise, the survival analysis showed that the GG genotypes of rs1800795 IL-6 (p = 0.014) and AA genotypes of rs4073 IL-8 (p = 0.002), as well as high levels of IL-6 (p = 0.009) and IL-8 (p = 0.046), were associated with lower overall survival. We confirmed the impact on an adverse prognosis in a multivariate model. This study suggests that the SNPs rs1800795 IL-6 and rs4073 IL-8 and their serum levels could be promising biomarkers of a poor prognosis, associated with overall survival, metastasis, and a high risk in Mexican children with NB.

Theranostic approaches in nuclear medicine: current status and future prospects

Introduction: Theranostics is an emerging field in which diagnosis and specific targeted therapy are combined to achieve a personalized treatment approach to the patient. In nuclear medicine clinical practice, theranostics is often performed utilizing the same molecule labeled with two different radionuclides, one radionuclide for imaging and another for therapy.Areas covered: The authors review the clinical applications of different radiopharmaceuticals in the field of interest, including the well-established use of radioactive iodine in differentiated thyroid cancer, radiolabeled metaiodobenzylguanidine (MIBG) in neuroblastoma and the clinical impact of peptide radionuclide receptorial therapy (PRRT) in the management of neuroendocrine tumors. Furthermore, the more cutting-edge and recently introduced theranostic approaches will be reviewed, such as the radioligand therapy with ¹⁷⁷Lu-prostate specific membrane antigen (PSMA) and targeted alpha therapy in castration-resistant prostate cancer. Finally, the main applications of PET for the imaging of biomarkers suitable for the non-radionuclide targeted therapy will be covered.Expert opinion: Theranostics is envisaging a revolutionary clinical approach which is deeply connected with the concept of personalized medicine and ruled by a 'patient-centered' vision. In this perspective, the theranostic applications will need well-trained specialists, capable to manage not only the technological aspects of the discipline, but also to deal with the more innovative oncological therapies in a multidisciplinary setting.

Impact of MYCN status on response of high-risk neuroblastoma to neoadjuvant chemotherapy

BACKGROUND/PURPOSE

MYCN-amplification in neuroblastoma is associated with an aggressive clinical phenotype. We evaluated the association of MYCN amplification with tumor response to neoadjuvant chemotherapy.

METHODS

Primary tumor response, assessed by percentage volume change on CT scan and degree of tumor resection, assessed by the operating surgeon, were retrospectively compared in 84 high-risk neuroblastoma patients. There were thirty-four (40%) with MYCN-amplified tumors and fifty (60%) with non-amplified tumors treated at our institution from 1999 to 2016. Metastatic disease response was assessed on MIBG scan by change in Curie score.

RESULTS

MYCN-amplification was associated with a greater mean percentage reduction in primary tumor volume after neoadjuvant chemotherapy (72.27% versus 46.83% [non-amplified tumors], p = 0.001). The percentage of patients with a Curie score > 2 at diagnosis who then had a score ≤ 2 after neoadjuvant chemotherapy was not significantly different (8 [61.5%] and 8 [34.8%], respectively, p = 0.37). Twenty-eight (85.7%) patients with MYCN-amplification had ≥90% surgical resection compared to 45 (91.84%) patients with non-amplified tumors (p = 0.303).

CONCLUSIONS

MYCN-amplification in high-risk neuroblastoma was associated with a better response of the primary tumor to neoadjuvant chemotherapy, but not metastatic sites, than in patients with non-amplified tumors. This did not significantly impact the ability to resect ≥90% of the primary tumor/locoregional disease.

TYPE OF STUDY

Treatment Study LEVEL OF EVIDENCE: Level III.

A Phase II Trial of Hu14.18K322A in Combination with Induction Chemotherapy in Children with Newly Diagnosed High-Risk Neuroblastoma

PURPOSE

We sought to evaluate whether combining a humanized antidisialoganglioside mAb (hu14.18K322A) with induction chemotherapy improves early responses and outcomes in children with newly diagnosed high-risk neuroblastoma.

PATIENTS AND METHODS

We conducted a prospective nonrandomized, single-arm, two-stage, phase II clinical trial. Six courses of induction chemotherapy were coadministered with hu14.18K322A and followed with granulocyte-macrophage colony-stimulating factor (GM-CSF) and low-dose IL2. Consolidation was performed with a busulfan/melphalan preparative regimen. An additional course of hu14.18K322A was administered with parent-derived natural killer cells, when available, during consolidation. Hu14.18K322A, GM-CSF, IL2, and isotretinoin were then administered. Secondary outcomes included reduced tumor volume and semiquantitative ¹²³I-metaiodobenzylguanidine scoring [i.e., Curie scores (CS)] at the end of induction.

RESULTS

Forty-two patients received hu14.18K322A and induction chemotherapy. This regimen was well tolerated, with continuous-infusion narcotics adjusted to patient tolerance. Partial responses (PR) or better after the first two chemoimmunotherapy courses occurred in 32 patients [76.2%; 95% confidence interval (CI), 60.6-88.0]. This was accompanied by primary tumor volume reductions (median, -76%; range, -100% to 5%). Of 35 patients with stage IV disease who completed induction, 31 had end-of-induction CSs of 2 or less. No patients experienced progression during induction. Two-year event-free survival (EFS) was 85.7% (95% CI, 70.9-93.3).

CONCLUSIONS

Adding hu14.18K322A to induction chemotherapy produced early PR or better in most patients, reduced tumor volumes, improved CSs at the end of induction, and yielded an encouraging 2-year EFS. These results, if validated in a larger study, may change the standard of care for children with high-risk neuroblastoma.

Neuroblastoma in relation to joint effects of vitamin A and maternal and offspring variants in vitamin A-related genes: A report of the Children's Oncology Group

BACKGROUND

There is evidence vitamin A plays a role in neuroblastoma. Not only is 13-cis-retinoic acid used as maintenance therapy for high-risk cases, but prenatal vitamin intake use may decrease neuroblastoma risk. We hypothesized that single nucleotide polymorphisms (SNPs) in vitamin A-related genes are may be associated with neuroblastoma risk and potentially be modified by vitamin A intake.

METHODS

The Neuroblastoma Epidemiology in North America (NENA) study recruited 563 case-parent sets through the Children's Oncology Group's Childhood Cancer Research Network. We ascertained dietary nutrient intake through questionnaires and genotyped 463 SNPs in vitamin A-related genes from saliva DNA. Offspring and maternal log-additive risk ratios (RR) and stratum-specific RR for gene-environment interaction were estimated with a log-linear model. We avoided false positives due to multiple testing by using the false discovery rate (FDR).

RESULTS

When all neuroblastoma cases were considered together, no offspring variants met the significance criteria (FDR Q-value < 0.2). One maternal SNP (rs12442054) was associated with decreased risk of neuroblastoma (RR: 0.61; 95% Confidence Interval (CI): 0.47-0.79, Q = 0.076). When the cases were categorized according to prognostic risk category and age at onset, nine offspring SNPs were significantly associated with intermediate-risk neuroblastoma. Maternal rs6776706 was associated with (RR: 0.49; 95% CI: 0.33-0.72, Q = 0.161) high-risk neuroblastoma and maternal rs11103603 (RR: 0.60; 95% CI: 0.45-0.79, Q = 0.127) was associated with neuroblastoma aged <1 year. For gene-environment interaction, maternal rs729147 was associated with decreased risk of neuroblastoma among mothers with vitamin A consumption above the recommendation.

CONCLUSIONS

Although there is biologic plausibility for the role of vitamin A in neuroblastoma, we found weak evidence of a relationship between vitamin A related genes and neuroblastoma.

Ginsenoside Rk1 Induces Apoptosis in Neuroblastoma Cells Through Loss of Mitochondrial Membrane Potential and Activation of Caspases

Neuroblastoma (NB) is the most common childhood cancer, with a very poor prognosis. More than 60% of children with NB die within five years; therefore, a more effective therapy for NB is required. Although ginsenoside has been shown to significantly inhibit the growth of various cancers, the effect of ginsenoside Rk1 on neuroblastoma has not been known yet. Hence, we examined the anticancer effects of highly pure Rk1 on neuroblastoma cell lines. The apoptotic effects of Rk1 on neuroblastoma cells were examined using cell viability assay, flow cytometry and cell staining assay, and the change in gene expression levels were analysed using RT-PCR, western blots, and immunohistochemistry. The metastatic effect of Rk1 was monitored by wound healing assay, invasion and migration with Matrigels. Rk1 inhibited neuroblastoma cell viability dose-dependently. Rk1-induced apoptosis was investigated through nuclear condensation and mitochondrial membrane potential loss, and it showed that Rk1 can induce cell cycle arrest at the G0/G1 phase but also inhibit the metastatic ability of neuroblastoma cells. Moreover, Rk1 (30 mg/kg) injections markedly inhibited xenograft tumor growth. These findings demonstrate that Rk1 might be valuable in the development of anti-cancer agents for neuroblastoma treatment.

The Influence of Sarcopenia on High-Risk Neuroblastoma

PURPOSE

Sarcopenia is a syndrome that is defined by the loss of skeletal muscle mass, quality, and strength. In adult patients with malignancies, the presence of sarcopenia is known to be correlated with a poor prognosis; however, there have been no reports on the influence of sarcopenia on malignant tumors in pediatric patients. In the present study, we investigated whether or not sarcopenia affects the prognosis of high-risk neuroblastoma.

MATERIALS AND METHODS

Thirteen patients with high-risk neuroblastoma who were treated according to the standard protocol at our hospital from 2007 to 2016 were divided into a progression-free survival group (n = 8) and a relapse/death group (n = 5). The rate of change in sarcopenia was calculated by comparing the psoas muscle area (PMA) of the L3-level lumbar spine on computed tomography before and after treatment with the standard protocol. The rate of change in the PMA, Kaup index, and serum albumin level were compared. Furthermore, we determined the cutoff rate of change in the PMA and compared the overall and progression-free survival.

RESULTS

The rates of change in the PMA were 1.24 and 0.84 in the progression-free survival and relapse/death groups, respectively (P = 0.0472). There were no significant differences in the rates of change in the Kaup index or the serum albumin level of the two groups. The patients whose rate of change in the PMA was >1.00 showed a prolonged overall (P = 0.0078) and progression-free survival (P = 0.006).

CONCLUSIONS

A decrease in the skeletal muscle mass was suggested to be a significant prognostic factor for high-risk neuroblastoma.

Investigation of PP2A and Its Endogenous Inhibitors in Neuroblastoma Cell Survival and Tumor Growth

High-risk neuroblastoma continues to carry a poor prognosis. Nearly 50% of these tumors relapse following extensive treatment regimens. Protein phosphatase 2A (PP2A), a tumor suppressor, has been shown to be downregulated in many human cancers via multiple mechanisms including upregulation of its endogenous inhibitors, I2PP2A or CIP2A. We hypothesized that inhibition of the endogenous PP2A inhibitors or activation of PP2A would decrease tumorigenicity in human neuroblastoma cells. Four human neuroblastoma cell lines were utilized. Expression of PP2A and its endogenous inhibitors I2PP2A and CIP2A was confirmed by immunoblotting. PP2A activation was measured via phosphatase activation assay. Multiple parallel methods including siRNA inhibition of the endogenous PP2A inhibitors and pharmacologic activation of PP2A were utilized. Cell viability, proliferation, migration, and invasion assays were performed. In vivo studies were utilized to determine the effects of PP2A activation on neuroblastoma tumor growth. Inhibition of the endogenous inhibitors of PP2A or pharmacologic activation of PP2A with the PP2A activator FTY720 led to decreased neuroblastoma cell viability, proliferation, migration, and invasion. Treatment of mice bearing SK-N-AS or SK-N-BE(2) neuroblastoma tumors with FTY720 resulted in a significant decrease in tumor growth compared to vehicle-treated animals. In conclusion, activation of PP2A may provide a novel therapeutic target for neuroblastoma.

CLINICAL AND EPIDEMIOLOGICAL CHARACTERISTICS AND SURVIVAL OUTCOMES OF CHILDREN WITH NEUROBLASTOMA: 21 YEARS OF EXPERIENCE AT THE INSTITUTO DE ONCOLOGIA PEDIÁTRICA, IN SÃO PAULO, BRAZIL

Objective:

To describe the clinical and epidemiological characteristics and survival outcomes of children with neuroblastoma (NB) treated at a pediatric oncology center from 1991 to 2012.

Methods:

A retrospective study with clinical and epidemiological data from 258 patients with neuroblastoma treated at a pediatric oncology center from 1991 to 2012, using medical records.

Results:

The average age of the children at diagnosis was 40.5±46.4 months with a median age of 28.9 months (interquartile range 42.2). The male:female ratio was 1.3:1, and 1% of the patients were asymptomatic. The most frequent manifestations were: fever (25%), abdominal pain (22%), abdominal mass (19%), and bone pain (19%). The mean time from symptom onset to diagnosis was 3.0±4.8 months. The most common location of the tumor was the abdomen (63%). Metastases occurred in the bone marrow (37%) and in the bone (33%). Overall survival (OS) and event-free survival (EFS) in five years were 62 and 52%, respectively. The main cause of death was the progression of the disease (72%).

Conclusions:

The clinical features of children with neuroblastoma are variable and mostly nonspecific, which makes clinical recognition difficult and, in general, too late. In children less than 5 years old, with an abdominal mass and/or bone pain, irritability, and a fever from an unknown cause, neuroblastoma should be considered as a possible diagnosis.

Clinical evaluation of integrated panel testing by next-generation sequencing for somatic mutations in neuroblastomas with MYCN unamplification

Neuroblastomas (NBs) exhibit heterogeneity and show clinically significant prognosis classified by genetic alterations. Among prognostic genes or genome factors, MYCN amplification (MNA) is the most established genomic marker of poor prognosis in patients with NB. However, the prognostic classification of more than 60% of patients without MNA has yet to be clarified. In this study, the application of target next-generation sequencing (NGS) was extended on the basis of a comprehensive panel of regions where copy number variations (CNVs) or point mutations occurred to improve the prognostic evaluation of these patients and obtain the sequence of 33 patients without MNA. A mean coverage depth of 887× was determined in the target regions in all of the samples, and the mapped read percentage was more than 99%. Somatic mutations in patients without MNA could be precisely defined on the basis of these findings, and 17 unique somatic aberrations, including 14 genes, were identified in 11 patients. Among these variations, most were CNVs with a number of 13. The 3-year event-free survival (EFS) of CNV(−) patients was 60.0% compared with the EFS (16.7%) of CNV(+) patients (P = 0.015, HR = 0.1344, 95%, CI = 0.027 to 0.678). CNVs were also associated with unfavorable histological characteristics (P = 0.003) and likely to occur in stage 4 (P = 0.041). These results might further indicate the role of CNVs in NB chemotherapy resistance (P = 0.059) and show CNVs as a therapeutic target. In multivariate analysis, the presence of CNVs was a clinically negative prognostic marker that impaired the outcome of patients without MNA and associated with poor prognosis in this tumor subset. Comprehensive genetic/genomic profiling instead of focusing on single genetic marker should be performed through in-depth NGS that could reveal prognostic information, improve NB target therapy, and provide a basis for investigations on NB pathogenesis.

Late Effects in Pediatric High-risk Neuroblastoma Survivors After Intensive Induction Chemotherapy Followed by Myeloablative Consolidation Chemotherapy and Triple Autologous Stem Cell Transplants

Multimodal treatment in high-risk neuroblastoma has modestly improved survival; limited data exist on the late effects from these regimens. We report the sequelae of treatment incorporating 3 consecutive cycles of high-dose therapy and autologous stem cell transplants (ASCTs) without the use of total body irradiation (TBI). We reviewed the medical records of 61 patients treated on or following the Chicago Pilot 2 protocol between 1991 and 2008. Of the 25 patients who are alive (41%), 19 had near complete data to report. Specific treatment modalities and therapy-related side effects were collected. Fourteen of these 19 patients (74%) received 3 cycles of high-dose therapy with ASCT; follow-up occurred over a median of 13.9 years (range, 5.8 to 18.8 y). The majority of late effects were endocrine-related, including growth failure, hypothyroidism, and hypogonadism. Patients also developed secondary neoplasms and skeletal deformities. The most frequent sequela was hearing loss, seen in 17/19 patients. We found a high prevalence of various late effects in survivors of high-risk neuroblastoma using a non-TBI-based regimen including 3 cycles of high-dose therapy with ASCTs. As current treatment regimens recommend tandem ASCT without TBI, it is imperative that we understand and monitor for the sequelae from these modalities.

Molecular Classification Substitutes for the Prognostic Variables Stage, Age, and MYCN Status in Neuroblastoma Risk Assessment

BACKGROUND: Current risk stratification systems for neuroblastoma patients consider clinical, histopathological, and genetic variables, and additional prognostic markers have been proposed in recent years. We here sought to select highly informative covariates in a multistep strategy based on consecutive Cox regression models, resulting in a risk score that integrates hazard ratios of prognostic variables. METHODS: A cohort of 695 neuroblastoma patients was divided into a discovery set (n = 75) for multigene predictor generation, a training set (n = 411) for risk score development, and a validation set (n = 209). Relevant prognostic variables were identified by stepwise multivariable L1-penalized least absolute shrinkage and selection operator (LASSO) Cox regression, followed by backward selection in multivariable Cox regression, and then integrated into a novel risk score. RESULTS: The variables stage, age, MYCN status, and two multigene predictors, NB-th24 and NB-th44, were selected as independent prognostic markers by LASSO Cox regression analysis. Following backward selection, only the multigene predictors were retained in the final model. Integration of these classifiers in a risk scoring system distinguished three patient subgroups that differed substantially in their outcome. The scoring system discriminated patients with diverging outcome in the validation cohort (5-year event-free survival, 84.9 ± 3.4 vs 63.6 ± 14.5 vs 31.0 ± 5.4; P < .001), and its prognostic value was validated by multivariable analysis. CONCLUSION: We here propose a translational strategy for developing risk assessment systems based on hazard ratios of relevant prognostic variables. Our final neuroblastoma risk score comprised two multigene predictors only, supporting the notion that molecular properties of the tumor cells strongly impact clinical courses of neuroblastoma patients.

Sub-micromolar concentrations of retinoic acid induce morphological and functional neuronal phenotypes in SK-N-SH neuroblastoma cells

Neuroblastoma cells are neural crest derivatives that can differentiate into neuron-like cells in response to exogenous agents, and are known to be particularly sensitive to retinoic acid. The spectrum of neuroblastoma responses, ranging from proliferation, migration, differentiation, or apoptosis, is difficult to predict due to the heterogeneity of these tumors and to the broad effective range of retinoic acid. Our study focused on the effects of nanomolar concentrations of retinoic acid on neuroblastoma differentiation in two cell lines cells: SK-N-SH (HTB-11) and IMR-32. Each cell line was treated with retinoic acid from 1 to 100 nM for up to 6 d. Morphological changes were quantified; immunocytochemistry was used to observe changes in neuronal protein expression and localization, while live-cell calcium imaging utilizing pharmacological agents was conducted to identify neuron-like activity. Retinoic acid-treated HTB-11 but not IMR-32 cells developed specific neuronal phenotypes: acquisition of long neurite-like processes, expression of neurofilament-200, increased responsiveness to acetylcholine, and decreased responsiveness to nicotine and epinephrine. In addition, nanomolar levels of retinoic acid elicited increased nuclear trafficking of the CRABP2, which is traditionally associated with gene expression of cellular pathways related to neuronal differentiation. Collectively, these results show that nanomolar concentrations of retinoic acid are capable of inducing both structural and functional neuron-like features in HTB-11 cells using CRABP2, suggesting differentiation in neuroblastoma cells into neuronal phenotypes. These have important implications for both chemotherapeutic design and for the use of neuroblastomas as in vitro models for neuron differentiation.

Consolidation Therapy for Newly Diagnosed Pediatric Patients with High-Risk Neuroblastoma Using Busulfan/Melphalan, Autologous Hematopoietic Cell Transplantation, Anti-GD2 Antibody, Granulocyte-Macrophage Colony-Stimulating Factor, Interleukin-2, and Haploidentical Natural Killer Cells

The treatment of pediatric high-risk neuroblastoma is intensive and multimodal. Despite the introduction of immunotherapy for minimal residual disease, survival rates remain suboptimal and new therapies are needed. As part of a phase 2 trial, we are using a consolidation therapy regimen that combines a busulfan/melphalan conditioning schema, autologous hematopoietic cell transplantation (AHCT), and experimental immunotherapy with hu14.18K322A (a humanized anti-GD2 monoclonal antibody), granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-2, with or without the adoptive transfer of haploidentical natural killer cells (NKs). Here we report on 30 patients who have undergone AHCT with this experimental immunotherapy regimen, 21 of whom received haploidentical NKs. The median time to neutrophil engraftment was 13 days (range, 10 to 28 days) and to platelet engraftment of at least 20  ×  103/mm³ was 36.5 days (range, 0 to 102 days); no clinical difference was seen in those who did or did not receive NKs. Eight patients developed veno-occlusive disease, with 3 having multiorgan dysfunction. Toxicities were similar for patients who did or did not receive NKs. We conclude that this consolidation regimen is feasible and has an acceptable acute toxicity profile.

Optimization of liposomal topotecan for use in treating neuroblastoma

The purpose of this work was to develop an optimized liposomal formulation of topotecan for use in the treatment of patients with neuroblastoma. Drug exposure time studies were used to determine that topotecan (Hycamtin) exhibited great cytotoxic activity against SK-N-SH, IMR-32 and LAN-1 neuroblastoma human cell lines. Sphingomyelin (SM)/cholesterol (Chol) and 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)/Chol liposomes were prepared using extrusion methods and then loaded with topotecan by pH gradient and copper-drug complexation. In vitro studies showed that SM/Chol liposomes retained topotecan significantly better than DSPC/Chol liposomes. Decreasing the drug-to-lipid ratio engendered significant increases in drug retention. Dose-range finding studies on NRG mice indicated that an optimized SM/Chol liposomal formulation of topotecan prepared with a final drug-to-lipid ratio of 0.025 (mol: mol) was better tolerated than the previously described DSPC/Chol topotecan formulation. Pharmacokinetic studies showed that the optimized SM/Chol liposomal topotecan exhibited a 10-fold increase in plasma half-life and a 1000-fold increase in AUC0-24 h when compared with Hycamtin administered at equivalent doses (5 mg/kg). In contrast to the great extension in exposure time, SM/Chol liposomal topotecan increased the life span of mice with established LAN-1 neuroblastoma tumors only modestly in a subcutaneous and systemic model. The extension in exposure time may still not be sufficient and the formulation may require further optimization. In the future, liposomal topotecan will be assessed in combination with high-dose radiotherapy such as 131 I-metaiodobenzylguanidine, and immunotherapy treatment modalities currently used in neuroblastoma therapy.

ALK Protein Expression Is Related to Neuroblastoma Aggressiveness But Is Not Independent Prognostic Factor

PURPOSE

In this study, anaplastic lymphoma kinase (ALK) mutation and amplification, ALK protein expression, loss of the nuclear alpha thalassemia/mental retardation syndrome X-linked (ATRX) protein, and telomerase reverse transcriptase (TERT) protein expressionwere studied to investigate potential correlations between these molecular characteristics and clinical features or outcomes in neuroblastoma.

MATERIALS AND METHODS

Seventy-two patients were enrolled in this study. Polymerase chain reaction amplification and direct sequencing were used for mutation analysis. ALK and MYCN amplifications were detected by fluorescence in situ hybridization. Protein expressionwas evaluated by immunohistochemical (IHC) staining.

RESULTS

ALK mutation was found in only two patients (4.1%); ALK amplification was not detected. ALK positivity, loss of nuclear ATRX protein, TERT positivity by IHC were detected in 40 (55.6%), nine (13.0%), and 42 (59.2%) patients, respectively. The incidence of ALK expression increased in accordance with increasing tumor stage (p=0.001) and risk group (p < 0.001). The relapse rate was significantly higher in ALK⁺ patients compared to that of other patients (47.5% vs. 11.3%, p=0.007). However, there was no significant difference in relapse rate when the survival analysis was confined to the high-risk patients.

CONCLUSION

Although ALK mutation was rare and no amplification was observed, ALK protein expression was found in a significant number of patients and was correlated with advanced stage and high-risk neuroblastoma. ALK protein expression could be considered as a marker related to the aggressive neuroblastoma, but it was not the independent prognostic factor for the outcome.

Esthesioneuroblastoma in a boy with 47, XYY karyotype

Neuroblastomas are sometimes associated with abnormal constitutional karyotypes, but the XYY karyotype has been rarely described in neuroblastomas. Here, we report a case of an esthesioneuroblastoma in a boy with a 47, XYY karyotype. A 6-year-old boy was admitted to our hospital because of nasal obstruction and palpable cervical lymph node, which he first noticed several days previously. A polypoid mass in the right nasal cavity was detected through sinuscopy. Biopsy of the right nasal polyp was performed. Based on the result, the patient was diagnosed with a high-grade esthesioneuroblastoma. Nuclear imaging revealed increased uptake in both the right posterior nasal cavity and the right cervical IB-II space, suggesting metastatic lymph nodes. Cytogenetic analysis revealed a 47, XYY karyotype. Twelve courses of concurrent chemotherapy were administered. Three years after the completion of chemotherapy, the patient had had no disease recurrence. He manifested behavioral violence and temper tantrums, so we started methylphenidate for correction of the behavior.

Role of diets rich in omega-3 and omega-6 in the development of cancer

Over the past decade, some studies have addressed the therapeutic effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and the opposite effects of omega-6 (ω-6) PUFAs on several diseases, including cardiovascular disorders, diabetes, neurodegenerative diseases, and cancer. Research demonstrates the safety of these naturally occurring ingredients. Of particular interest, several studies have shown that ω-3 PUFAs possess a therapeutic role against certain types of cancer. It is also known that ω-3 PUFAs can improve the efficacy and tolerability of chemotherapy. Previous reports have indicated that suppression of nuclear factor-κB, activation of AMPK/SIRT1, modulation of cyclooxygenase (COX) activity, and up-regulation of novel anti-inflammatory lipid mediators such as protectins, maresins, and resolvins, are the main mechanisms of the antineoplastic effect of ω-3 PUFAs. In contrast, several studies have demonstrated that ω-6 PUFAs induce progression in certain types of cancer. In this review, we discuss epidemiological and experimental studies addressing the relationship between the development of some types of cancer, including colon and colorectal carcinoma, breast cancer, prostate cancer, lung cancer and neuroblastoma, and the ingestion to ω-3 and ω-6 (PUFAs). We also discuss the clinical data, addressing the therapeutic role of omega-3 PUFA against different types of cancer.

Autophagy is associated with chemoresistance in neuroblastoma

Background

Neuroblastoma (NB) is a frequent pediatric tumor characterized by a poor prognosis where a majority of tumors progress despite intensive multimodality treatments. Autophagy, a self-degradative process in cells, could be induced by chemotherapy and be associated with chemoresistance. The aim of this study was to determine whether: 1) autophagy is present in NB, 2) chemotherapy modified its levels, and 3) its inhibition decreased chemoresistance.

Methods

Immunohistochemical stainings were performed on samples from 184 NB patients in order to verify the expression of LC3B, a specific marker for autophagy, and Beclin 1, a positive regulator of autophagy. In addition, we performed an in vitro study with six NB cell lines and six drugs (vincristine, doxorubicin, cisplatin temozolomide, LY294002 and syrolimus). Inhibition of autophagy was performed using ATG5 knockdown cells or hydroxychloroquine (HCQ). Cell survival was measured using the MTT cell proliferation assay. Autophagy was detected by monodansylcadaverine, confocal microscopy and Western blot. In vivo study with tumor xenografts in NSG mice was performed.

Results

Our results have indicated that autophagy was present at low levels in NB and was not a prognostic factor, while Beclin 1 was highly expressed in children with poor NB prognosis. However, autophagy levels increased after chemotherapy in vitro and in vivo. Tumor progression was significantly decreased in mice treated with a combination of HCQ and vincristine.

Conclusions

Taken together, autophagy is present in NB, induced by chemotherapy and associated with chemoresistance, which is significantly reduced by its inhibition. Therefore, targeting autophagy represents a very attractive approach to develop new therapeutic strategies in NB.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2906-9) contains supplementary material, which is available to authorized users.

The zebrafish as a model for studying neuroblastoma

Neuroblastoma is a tumor arising in the peripheral sympathetic nervous system and is the most common cancer in childhood. Since most of the cellular and molecular mechanisms underlying neuroblastoma onset and progression remain unknown, the generation of new in vivo models might be appropriate to better dissect the peripheral sympathetic nervous system development in both physiological and disease states. This review is focused on the use of zebrafish as a suitable and innovative model to study neuroblastoma development. Here, we briefly summarize the current knowledge about zebrafish peripheral sympathetic nervous system formation, focusing on key genes and cellular pathways that play a crucial role in the differentiation of sympathetic neurons during embryonic development. In addition, we include examples of how genetic changes known to be associated with aggressive neuroblastoma can mimic this malignancy in zebrafish. Thus, we note the value of the zebrafish model in the field of neuroblastoma research, showing how it can improve our current knowledge about genes and biological pathways that contribute to malignant transformation and progression during embryonic life.

Neuroblastoma (Peripheral neuroblastic tumours)

Peripheral neuroblastic tumours (PNTs), a family of tumours arising in the embryonal remnants of the sympathetic nervous system, account for 7-10% of all tumours in children. In two-thirds of cases, PNTs originate in the adrenal glands or the retroperitoneal ganglia. At least one third present metastases at onset, with bone and bone marrow being the most frequent metastatic sites. Disease extension, MYCN oncogene status and age are the most relevant prognostic factors, and their influence on outcome have been considered in the design of the recent treatment protocols. Consequently, the probability of cure has increased significantly in the last two decades. In children with localised operable disease, surgical resection alone is usually a sufficient treatment, with 3-year event-free survival (EFS) being greater than 85%. For locally advanced disease, primary chemotherapy followed by surgery and/or radiotherapy yields an EFS of around 75%. The greatest problem is posed by children with metastatic disease or amplified MYCN gene, who continue to do badly despite intensive treatments. Ongoing trials are exploring the efficacy of new drugs and novel immunological approaches in order to save a greater number of these patients.

Identification of Neuroblastoma Subgroups Based on Three-Dimensional Telomere Organization

Using 3D telomere quantitative fluorescence in situ hybridization, we determined the 3D telomere organization of 74 neuroblastoma tissue samples. Hierarchical cluster analysis of the measured telomere parameters identified three subgroups from our patient cohort. These subgroups have unique telomere profiles based on telomere length and nuclear architecture. Subgroups with higher levels of telomere dysfunction were comprised of tumors with greater numbers of telomeres, telomeric aggregates, and short telomeres (P<.0001). Tumors with greater telomere dysfunction were associated with unfavorable tumor characteristics (greater age at diagnosis, unfavorable histology, higher stage of disease, MYCN amplification, and higher MYCN expression) and poor prognostic risk (P<.001). Subgroups with greater telomere dysfunction also had higher intratumor heterogeneity. MYCN overexpression in two neuroblastoma cell lines with constitutively low MYCN expression induced changes in their telomere profile that were consistent with increased telomere dysfunction; this illustrates a functional relationship between MYCN and 3D telomere organization. This study demonstrates the ability to classify neuroblastomas based on the level of telomere dysfunction, which is a novel approach for this cancer.

High-dose chemotherapy and autologous haematopoietic stem cell rescue for children with high-risk neuroblastoma

BACKGROUND

Despite the development of new treatment options, the prognosis of high-risk neuroblastoma patients is still poor; more than half of patients experience disease recurrence. High-dose chemotherapy and haematopoietic stem cell rescue (i.e. myeloablative therapy) might improve survival. This review is the second update of a previously published Cochrane review.

OBJECTIVES

Primary objectiveTo compare the efficacy, that is event-free and overall survival, of high-dose chemotherapy and autologous bone marrow or stem cell rescue with conventional therapy in children with high-risk neuroblastoma. Secondary objectivesTo determine adverse effects (e.g. veno-occlusive disease of the liver) and late effects (e.g. endocrine disorders or secondary malignancies) related to the procedure and possible effects of these procedures on quality of life.

SEARCH METHODS

We searched the electronic databases The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, issue 11), MEDLINE/PubMed (1966 to December 2014) and EMBASE/Ovid (1980 to December 2014). In addition, we searched reference lists of relevant articles and the conference proceedings of the International Society for Paediatric Oncology (SIOP) (from 2002 to 2014), American Society for Pediatric Hematology and Oncology (ASPHO) (from 2002 to 2014), Advances in Neuroblastoma Research (ANR) (from 2002 to 2014) and American Society for Clinical Oncology (ASCO) (from 2008 to 2014). We searched for ongoing trials by scanning the ISRCTN register (www.isrct.com) and the National Institute of Health Register (www.clinicaltrials.gov). Both registers were screened in April 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the efficacy of myeloablative therapy with conventional therapy in high-risk neuroblastoma patients.

DATA COLLECTION AND ANALYSIS

Two authors independently performed study selection, data extraction and risk of bias assessment. If appropriate, we pooled studies. The risk ratio (RR) and 95% confidence interval (CI) was calculated for dichotomous outcomes. For the assessment of survival data, we calculated the hazard ratio (HR) and 95% CI. We used Parmar's method if hazard ratios were not reported in the study. We used a random-effects model.

MAIN RESULTS

We identified three RCTs including 739 children. They all used an age of one year as the cut-off point for pre-treatment risk stratification. The first updated search identified a manuscript reporting additional follow-up data for one of these RCTs, while the second update identified an erratum of this study. There was a significant statistical difference in event-free survival in favour of myeloablative therapy over conventional chemotherapy or no further treatment (three studies, 739 patients; HR 0.78, 95% CI 0.67 to 0.90). There was a significant statistical difference in overall survival in favour of myeloablative therapy over conventional chemotherapy or no further treatment (two studies, 360 patients; HR 0.74, 95% CI 0.57 to 0.98). However, when additional follow-up data were included in the analyses the difference in event-free survival remained statistically significant (three studies, 739 patients; HR 0.79, 95% CI 0.70 to 0.90), but the difference in overall survival was no longer statistically significant (two studies, 360 patients; HR 0.86, 95% CI 0.73 to 1.01). The meta-analysis of secondary malignant disease and treatment-related death did not show any significant statistical differences between the treatment groups. Data from one study (379 patients) showed a significantly higher incidence of renal effects, interstitial pneumonitis and veno-occlusive disease in the myeloablative group compared to conventional chemotherapy, whereas for serious infections and sepsis no significant difference between the treatment groups was identified. No information on quality of life was reported. In the individual studies we evaluated different subgroups, but the results were not univocal in all studies. All studies had some methodological limitations.

AUTHORS' CONCLUSIONS

Based on the currently available evidence, myeloablative therapy seems to work in terms of event-free survival. For overall survival there is currently no evidence of effect when additional follow-up data are included. No definitive conclusions can be made regarding adverse effects and quality of life, although possible higher levels of adverse effects should be kept in mind. A definitive conclusion regarding the effect of myeloablative therapy in different subgroups is not possible. This systematic review only allows a conclusion on the concept of myeloablative therapy; no conclusions can be made regarding the best treatment strategy. Future trials on the use of myeloablative therapy for high-risk neuroblastoma should focus on identifying the most optimal induction and/or myeloablative regimen. The best study design to answer these questions is a RCT. These RCTs should be performed in homogeneous study populations (e.g. stage of disease and patient age) and have a long-term follow-up. Different risk groups, using the most recent definitions, should be taken into account.It should be kept in mind that recently the age cut-off for high risk disease was changed from one year to 18 months. As a result it is possible that patients with what is now classified as intermediate-risk disease have been included in the high-risk groups. Consequently the relevance of the results of these studies to the current practice can be questioned. Survival rates may be overestimated due to the inclusion of patients with intermediate-risk disease.

Neuroblastoma Arginase Activity Creates an Immunosuppressive Microenvironment That Impairs Autologous and Engineered Immunity

Neuroblastoma is the most common extracranial solid tumor of childhood, and survival remains poor for patients with advanced disease. Novel immune therapies are currently in development, but clinical outcomes have not matched preclinical results. Here, we describe key mechanisms in which neuroblastoma inhibits the immune response. We show that murine and human neuroblastoma tumor cells suppress T-cell proliferation through increased arginase activity. Arginase II is the predominant isoform expressed and creates an arginine-deplete local and systemic microenvironment. Neuroblastoma arginase activity results in inhibition of myeloid cell activation and suppression of bone marrow CD34(+) progenitor proliferation. Finally, we demonstrate that the arginase activity of neuroblastoma impairs NY-ESO-1-specific T-cell receptor and GD2-specific chimeric antigen receptor-engineered T-cell proliferation and cytotoxicity. High arginase II expression correlates with poor survival for patients with neuroblastoma. The results support the hypothesis that neuroblastoma creates an arginase-dependent immunosuppressive microenvironment in both the tumor and blood that leads to impaired immunosurveillance and suboptimal efficacy of immunotherapeutic approaches.

Combined Scintigraphy and Tumor Marker Analysis Predicts Unfavorable Histopathology of Neuroblastic Tumors with High Accuracy

Objectives

Our aim was to improve the prediction of unfavorable histopathology (UH) in neuroblastic tumors through combined imaging and biochemical parameters.

Methods

¹²³I-MIBG SPECT and MRI was performed before surgical resection or biopsy in 47 consecutive pediatric patients with neuroblastic tumor. Semi-quantitative tumor-to-liver count-rate ratio (TLCRR), MRI tumor size and margins, urine catecholamine and NSE blood levels of neuron specific enolase (NSE) were recorded. Accuracy of single and combined variables for prediction of UH was tested by ROC analysis with Bonferroni correction.

Results

34 of 47 patients had UH based on the International Neuroblastoma Pathology Classification (INPC). TLCRR and serum NSE both predicted UH with moderate accuracy. Optimal cut-off for TLCRR was 2.0, resulting in 68% sensitivity and 100% specificity (AUC-ROC 0.86, p < 0.001). Optimal cut-off for NSE was 25.8 ng/ml, resulting in 74% sensitivity and 85% specificity (AUC-ROC 0.81, p = 0.001). Combination of TLCRR/NSE criteria reduced false negative findings from 11/9 to only five, with improved sensitivity and specificity of 85% (AUC-ROC 0.85, p < 0.001).

Conclusion

Strong ¹²³I-MIBG uptake and high serum level of NSE were each predictive of UH. Combined analysis of both parameters improved the prediction of UH in patients with neuroblastic tumor. MRI parameters and urine catecholamine levels did not predict UH.

MYCN overexpression is associated with unbalanced copy number gain, altered nuclear location, and overexpression of chromosome arm 17q genes in neuroblastoma tumors and cell lines

MYCN amplification and MYCN overexpression are poor prognostic factors in neuroblastoma. Tumors with unbalanced chromosome arm 17q gain are often associated with MYCN amplification; however, the relationship between chromosome 17 copy number status and MYCN expression is not known. We investigated the relationship between MYCN expression and chromosome 17 copy number, nuclear location, and gene expression. By performing dual-colored fluorescence in situ hybridization on 16 primary neuroblastomas, we found that those with unbalanced gain of 17q have high MYCN expression, those with no gain have medium expression, and those with numerical gain have low expression (P < 0.0001). We also found that the nuclear location of 17q correlates with chromosome 17 copy number status: copies in tumors with unbalanced gain and no gain of chromosome 17 occupy a more central location than those in tumors with balanced gain (P < 0.0001). We show that a more central nuclear location of 17q coincides with increased expression of genes found within this chromosome arm. To further understand the association between MYCN expression and chromosome 17, we overexpressed MYCN in two low-expressing MYCN cell lines, SHEP and GIMEN. We found that both cell lines had an unbalanced gain of chromosome 17q, a more central nuclear location of the region and increased expression of the 17q genes. Therefore, this study indicates, for the first time, a functional relationship between MYCN overexpression and the gain of 17q in neuroblastoma.

The role of chest computed tomography (CT) as a surveillance tool in children with high-risk neuroblastoma

BACKGROUND

Standardization of imaging obtained in children with neuroblastoma is not well established. This study examines chest CT in pediatric patients with high-risk neuroblastoma.

PROCEDURE

Medical records and imaging from 88 patients with high-risk neuroblastoma, diagnosed at St. Jude Children's Research Hospital between January, 2002 and December, 2009, were reviewed. Surveillance imaging was conducted through 2013. Ten patients with thoracic disease at diagnosis were excluded. Event free survival (EFS) and overall survival (OS) were estimated. Size specific dose estimates for CT scans of the chest, abdomen, and pelvis were used to estimate absolute organ doses to 23 organs. Organ dosimetry was used to calculate cohort effective dose.

RESULTS

The 5 year OS and EFS were 51.9% ± 6.5% and 42.6% ± 6.5%, respectively. Forty-six (58.9%) patients progressed/recurred and 41 (52.6%) died of disease. Eleven patients (14%) developed thoracic disease progression/recurrence identified by chest CT (1 paraspinal mass, 1 pulmonary nodules, and 9 nodal). MIBG (metaiodobenzylguanidine) scans identified thoracic disease in six patients. Five of the 11 had normal chest MIBG scans; three were symptomatic and two were asymptomatic with normal chest MIBG scans but avid bone disease. The estimated radiation dose savings from surveillance without CT chest imaging was 42%, 34% when accounting for modern CT acquisition (2011-2013).

CONCLUSIONS

Neuroblastoma progression/recurrence in the chest is rare and often presents with symptoms or is identified using standard non-CT imaging modalities. For patients with non-thoracic high-risk neuroblastoma at diagnosis, omission of surveillance chest CT imaging can save 35-42% of the radiation burden without compromising disease detection.

Preclinical Evaluation of a Novel RXR Agonist for the Treatment of Neuroblastoma

Neuroblastoma remains a common cause of pediatric cancer deaths, especially for children who present with advanced stage or recurrent disease. Currently, retinoic acid therapy is used as maintenance treatment to induce differentiation and reduce tumor recurrence following induction therapy for neuroblastoma, but unavoidable side effects are seen. A novel retinoid, UAB30, has been shown to generate negligible toxicities. In the current study, we hypothesized that UAB30 would have a significant impact on multiple neuroblastoma cell lines in vitro and in vivo. Cellular survival, cell-cycle analysis, migration, and invasion were studied using AlamarBlue assays, FACS, and Transwell assays, respectively, in multiple cell lines following treatment with UAB30. In addition, an in vivo murine model of human neuroblastoma was utilized to study the effects of UAB30 upon tumor xenograft growth and animal survival. We successfully demonstrated decreased cellular survival, invasion, and migration, cell-cycle arrest, and increased apoptosis after treatment with UAB30. Furthermore, inhibition of tumor growth and increased survival was observed in a murine neuroblastoma xenograft model. The results of these in vitro and in vivo studies suggest a potential therapeutic role for the low toxicity synthetic retinoid X receptor selective agonist, UAB30, in neuroblastoma treatment.