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.

Metastatic adrenal gland neuroblastoma in an infant with trisomy 18: A case report

I present a patient with trisomy 18 associated with neuroblastoma. To the best of my knowledge, this is the second report of such an individual in the relevant literature. A 19-month-old girl known to have trisomy 18 presented with respiratory distress secondary to pleural effusion. Work-up showed metastatic neuroblastoma to multiple sites, and the patient's clinical situation was critical. The physician-parent's decision was not to proceed with treatment of the malignancy. Based on this report, I recommend that physicians remain vigilant and have a high level of suspicion about the potential association between neuroblastoma and trisomy 18. Accordingly, it may be necessary to consider performing serial abdominal ultrasounds and biochemical tests to screen children with trisomy 18 who survive beyond infancy.

Categorizing Malignant Small Round Cell Tumors in Aspiration Cytology: An Institutional Experience

Aim and Objectives

The study aims to categorize malignant small round cell tumors (MSRCTs) originating in various sites of the body with the objective of utilization of cytomorphological features and ancillary techniques.

Study Design

It is a cross-sectional study conducted over a time span of 3 years (2017-2020). 33 cases of tumors with round cell morphology were evaluated by fine needle aspiration cytology (FNAC).

Materials and Methods

The application of cell block preparation supported by immunohistochemistry aided in the categorization of 23 cases with definite diagnosis and the rest were reported as MSRCTs.

Results

Among the categorized 23/33 cases, the most common diagnosis was Ewing's sarcoma (7/23) followed by 6 cases of lymphoma. There were 2 cases each of rhabdomyosarcoma and Langerhans cell histiocytosis (LCH) and 1 case each of neuroblastoma, desmoplastic small round cell tumor (DSRCT), myeloid sarcoma, neuroendocrine tumor of pancreas, plasmacytoma, and small cell carcinoma. Histopathology confirmation was available in 24/33 cases. Among the categorized tumors (23/33), biopsy correlation was available in 19 cases, of which concordant result was seen in 17 cases (89.47%), which were 6 cases of lymphoma, 5 cases of Ewing's sarcoma (EWS), 2 of rhabdomyosarcoma, and 1 each of neuroblastoma, small cell carcinoma, DSRCT, and LCH. Discordant result was seen in one case of rhabdomyosarcoma and a case of synovial sarcoma reported as extraskeletal EWS in cytology. Out of the uncategorized cases reported as MSRTCs, histopathology was available in 5 cases which were diagnosed as rhabdomyosarcoma (1 cases), lymphoma (1 case), amelanotic melanoma (1 case), and extraskeletal EWS (2 cases).

Conclusion

Categorization of MSRCTs should be done to implement appropriate therapeutic protocol. FNAC provides a rapid diagnosis contributing immensely for the timely management of the patient. Detailed cytomorphological evaluation serves as a guide for further evaluation by ancillary techniques leading to definitive diagnosis.

Model for predicting prognosis and immunotherapy based on CD+8 T cells infiltration in neuroblastoma

BACKGROUND

Neuroblastoma (NBL) is an extracranial malignant tumor in children deriving from the neural crest in the sympathetic nervous system. Although various immunotherapy interventions have made significant breakthroughs in many adult cancers, the efficacy of these immunotherapies was still limited in NBL. NBL has low immunogenicity which results in a lack of tumor-infiltrating T lymphocytes in the tumor microenvironment (TME). Moreover, tumor cells can wield many immune evasion strategies both in the TME and systemically to impede lymphocyte infiltration and activation. All these factors hamper the anti-tumor effects of CD8+ T cells during immunotherapy and the levels of infiltrating CD8+ T cells correlate with therapy response.

MATERIALS AND METHODS

In this study, we utilized multidimensional bioinformatic methods to establish a risk model based on CD8+ T cells -related genes (CD8+ TRGs).

RESULTS

We obtained 33 CD8+ TRGs with well-predictive ability for prognosis in both GSE49711 and E-MTAB-8248 cohorts. Then, 12 CD8+ TRGs including HK2, RP2, HPSE, ELL2, GFI1, SLC22A16, FCGR3A, CTSS, SH2D1A, RBP5, ATF5, and ADAM9 were finally identified for risk model construction and validation. This model revealed a stable performance in prognostic prediction of the overall survival (OS) and event-free survival (EFS) in patients with NBL. Additionally, our research indicated that the immune and stromal scores, immune-related pathways, immune cell infiltration, the expression of major histocompatibility complex (MHC) and immune checkpoint molecules, immunotherapy response, and drug susceptibility revealed significant differences between high and low-risk groups.

CONCLUSIONS

According to our analyses, the constructed CD8+ TRGs-based risk model may be promising for the clinical prediction of anti-tumor therapy responses and prognoses in NBL.

The deubiquitinase USP28 maintains the expression of the transcription factor MYCN and is essential in neuroblastoma cells

Neuroblastoma (NB) is one of the most common extracranial solid tumors in children. MYCN gene amplification is highly associated with poor prognosis in high-risk NB patients. In non-MYCN-amplified high-risk NB patients, the expression of c-MYC (MYCC) and its target genes is highly elevated. USP28 as a deubiquitinase is known to regulate the stability of MYCC. We show here USP28 also regulates the stability of MYCN. Genetic depletion or pharmacologic inhibition of the deubiquitinase strongly destabilizes MYCN and stops the growth of NB cells that overexpress MYCN. In addition, MYCC could be similarly destabilized in non-MYCN NB cells by compromising USP28 function. Our results strongly suggest USP28 as a therapeutic target for NB with or without MYCN amplification/overexpression.

CRISPR/Cas9-based genome-wide screening of the deubiquitinase subfamily identifies USP3 as a protein stabilizer of REST blocking neuronal differentiation and promotes neuroblastoma tumorigenesis

BACKGROUND

The repressor element-1 silencing transcription factor (REST), a master transcriptional repressor, is essential for maintenance, self-renewal, and differentiation in neuroblastoma. An elevated expression of REST is associated with impaired neuronal differentiation, which results in aggressive neuroblastoma formation. E3 ligases are known to regulate REST protein abundance through the 26 S proteasomal degradation pathway in neuroblastoma. However, deubiquitinating enzymes (DUBs), which counteract the function of E3 ligase-mediated REST protein degradation and their impact on neuroblastoma tumorigenesis have remained unexplored.

METHODS

We employed a CRISPR/Cas9 system to perform a genome-wide knockout of ubiquitin-specific proteases (USPs) and used western blot analysis to screen for DUBs that regulate REST protein abundance. The interaction between USP3 and REST was confirmed by immunoprecipitation and Duolink in situ proximity assays. The deubiquitinating effect of USP3 on REST protein degradation, half-life, and neuronal differentiation was validated by immunoprecipitation, in vitro deubiquitination, protein-turnover, and immunostaining assays. The correlation between USP3 and REST expression was assessed using patient neuroblastoma datasets. The USP3 gene knockout in neuroblastoma cells was performed using CRISPR/Cas9, and the clinical relevance of USP3 regulating REST-mediated neuroblastoma tumorigenesis was confirmed by in vitro and in vivo oncogenic experiments.

RESULTS

We identified a deubiquitinase USP3 that interacts with, stabilizes, and increases the half-life of REST protein by counteracting its ubiquitination in neuroblastoma. An in silico analysis showed a correlation between USP3 and REST in multiple neuroblastoma cell lines and identified USP3 as a prognostic marker for overall survival in neuroblastoma patients. Silencing of USP3 led to a decreased self-renewal capacity and promoted retinoic acid-induced differentiation in neuroblastoma. A loss of USP3 led to attenuation of REST-mediated neuroblastoma tumorigenesis in a mouse xenograft model.

CONCLUSION

The findings of this study indicate that USP3 is a critical factor that blocks neuronal differentiation, which can lead to neuroblastoma. We envision that targeting USP3 in neuroblastoma tumors might provide an effective therapeutic differentiation strategy for improved survival rates of neuroblastoma patients.

Chromosome 1p status in neuroblastoma correlates with higher expression levels of miRNAs targeting neuronal differentiation pathway

Neuroblastoma (NB) is characterized by acquired segmental and numerical chromosome aberrations. Although deletions of distal 1p and 11q are frequent alterations, no candidate tumor suppressor gene residing in these chromosomal sites could be identified so far. In the present study, we detected the genomic imbalances of six neuroblastoma cell lines using the multiplex ligation-dependent probe amplification (MLPA) technique and the microRNA (miRNA) expression profiles of the cell lines by a microarray study. According to MLPA results, we aimed to assess the miRNA expression profiles of the cell lines harboring 11q and 1p deletions. The cell lines with 1p deletions revealed statistically significant higher levels of expression for 29 miRNAs in contrast to the cell lines without 1p deletion in microarray study. We also performed GO enrichment analysis for predicted targets of the differentially expressed miRNAs. According to GO enrichment analysis, miRNAs that showed the high change in expression was associated with neuronal differentiation. We showed that hsa-miR-494, hsa-miR-495, and hsa-miR-543 target most of mRNAs in neuronal differentiation pathway. Although limited to the cell lines, our results highly suggest that NBs with different segmental chromosome abnormalities may have different dysregulated miRNA expression signatures that target the genes involved in neuronal differentiation.

[18F]mFBG PET-CT for detection and localisation of neuroblastoma: a prospective pilot study

PURPOSE

Meta-[¹⁸F]fluorobenzylguanidine ([¹⁸F]mFBG) is a positron emission tomography (PET) radiotracer that allows for fast and high-resolution imaging of tumours expressing the norepinephrine transporter. This pilot study investigates the feasibility of [¹⁸F]mFBG PET-CT for imaging in neuroblastoma.

METHODS

In a prospective, single-centre study, we recruited children with neuroblastoma, referred for meta-[¹²³I]iodobenzylguanidine ([¹²³I]mIBG) scanning, consisting of total body planar scintigraphy in combination with single-photon emission computed tomography-CT (SPECT-CT). Within two weeks of [¹²³I]mIBG scanning, total body PET-CTs were performed at 1 h and 2 h after injection of [¹⁸F]mFBG (2 MBq/kg). Detected tumour localisations on scan pairs were compared. Soft tissue disease was quantified by number of lesions and skeletal disease by SIOPEN score.

RESULTS

Twenty paired [¹²³I]mIBG and [¹⁸F]mFBG scans were performed in 14 patients (median age 4.9 years, n = 13 stage 4 disease and n = 1 stage 4S). [¹⁸F]mFBG injection was well tolerated and no related adverse events occurred in any of the patients. Mean scan time for [¹⁸F]mFBG PET-CT (9.0 min, SD 1.9) was significantly shorter than for [¹²³I]mIBG scanning (84.5 min, SD 10.5), p < 0.01. Most tumour localisations were detected on the 1 h versus 2 h post-injection [¹⁸F]mFBG PET-CT. Compared to [¹²³I]mIBG scanning, [¹⁸F]mFBG PET-CT detected a higher, equal, and lower number of soft tissue lesions in 40%, 55%, and 5% of scan pairs, respectively, and a higher, equal, and lower SIOPEN score in 55%, 30%, and 15% of scan pairs, respectively. On average, two more soft tissue lesions and a 6-point higher SIOPEN score were detected per patient on [¹⁸F]mFBG PET-CT compared to [¹²³I]mIBG scanning.

CONCLUSION

Results of this study demonstrate feasibility of [¹⁸F]mFBG PET-CT for neuroblastoma imaging. More neuroblastoma localisations were detected on [¹⁸F]mFBG PET-CT compared to [¹²³I]mIBG scanning. [¹⁸F]mFBG PET-CT shows promise for future staging and response assessment in neuroblastoma.

TRIAL REGISTRATION

Dutch Trial Register NL8152.

Aspectos Clínicos e Fatores Prognósticos do Neuroblastoma: Relato de Caso

Introdução: O neuroblastoma é um tumor extracraniano originado de falhas das células da crista neural. É a neoplasia maligna mais comum dos lactentes e apresenta perfil clínico bastante heterogêneo. O objetivo deste artigo é relatar o caso de um neuroblastoma em estádio avançado e sobrevida satisfatória, a despeito dos fatores prognósticos desfavoráveis. Relato do caso: Paciente feminina, 1 ano e 4 meses, iniciou quadro de irritabilidade, distensão abdominal e febre intermitente com três meses de evolução. Ao exame físico, apresentou alopecia sugestiva de tricotilomania, linfonodomegalia cervical, inguinal e axilar e distensão abdominal. A tomografia computadorizada de abdome evidenciou massa expansiva, medindo 6,8 x 5,8 x 4,0 cm, localizada no espaço pararrenal anterior esquerdo. À cintilografia óssea e ressonância nuclear magnética, foram visualizadas imagens sugestivas de implantes secundários a distância. Após exérese tumoral total, foi confirmado neuroblastoma pouco diferenciado, com gene MYCN não amplificado e histologia desfavorável. Biópsia da crista ilíaca bilateral revelou áreas compatíveis com infiltração medular. Por se tratar de neuroblastoma estádio IV, estabeleceu-se terapêutica multimodal, com quimioterapia adjuvante após cirurgia, seguida de transplante autólogo de medula óssea, radioterapia no sítio primário da lesão e nos locais de metástases ósseas e uso de ácido 13-cis-retinoico. Conclusão: Apesar de apresentar diversos indicadores de mau prognóstico (idade, metástases ósseas, estadiamento IV, infiltração medular), a paciente permanece em remissão completa da doença há 39 meses.

PCLAF promotes neuroblastoma G1/S cell cycle progression via the E2F1/PTTG1 axis

PCLAF (PCNA clamp-associated factor), also known as PAF15/ KIAA0101, is overexpressed in most human cancers and is a predominant regulator of tumor progression. However, its biological function in neuroblastoma remains unclear. PCLAF is extremely overexpressed in neuroblastoma and is associated with poor prognosis. Through the analysis of various data sets, we found that the high expression of PCLAF is positively correlated with increased stage and high risk of neuroblastoma. Most importantly, knocking down PCLAF could restrict the proliferation of neuroblastoma cells in vitro and in vitro. By analyzing RNA-seq data, we found that the enrichment of cell cycle-related pathway genes was most significant among the differentially expressed downregulated genes after reducing the expression of PCLAF. In addition, PCLAF accelerated the G1/S transition of the neuroblastoma cell cycle by activating the E2F1/PTTG1 signaling pathway. In this study, we reveal the mechanism by which PCLAF facilitates cell cycle progression and recommend that the PCLAF/E2F1/PTTG1 axis is a therapeutic target in neuroblastoma.

Synthetic Heterocyclic Derivatives as Kinase Inhibitors Tested for the Treatment of Neuroblastoma

In the last few years, small molecules endowed with different heterocyclic scaffolds have been developed as kinase inhibitors. Some of them are being tested at preclinical or clinical levels for the potential treatment of neuroblastoma (NB). This disease is the most common extracranial solid tumor in childhood and is responsible for 10% to 15% of pediatric cancer deaths. Despite the availability of some treatments, including the use of very toxic cytotoxic chemotherapeutic agents, high-risk (HR)-NB patients still have a poor prognosis and a survival rate below 50%. For these reasons, new pharmacological options are urgently needed. This review focuses on synthetic heterocyclic compounds published in the last five years, which showed at least some activity on this severe disease and act as kinase inhibitors. The specific mechanism of action, selectivity, and biological activity of these drug candidates are described, when established. Moreover, the most remarkable clinical trials are reported. Importantly, kinase inhibitors approved for other diseases have shown to be active and endowed with lower toxicity compared to conventional cytotoxic agents. The data collected in this article can be particularly useful for the researchers working in this area.

Antitumor Effect of Saikosaponin A on Human Neuroblastoma Cells

Objective

Neuroblastoma (NB) is a highly metastatic tumor in children that develops in the sympathetic nervous system and has a low curative rate. Saikosaponin A (SSA), an active ingredient isolated from the root of Radix Bupleuri, is a natural compound with various pharmacological activities and shows good application prospects in antitumors. This study investigated the antihuman NB activity of SSA and underlying mechanisms associated with its actions.

Materials and Methods

The MTT method was used to detect the activity of SSA in inhibiting human NB cell SK-N-AS proliferation. Cell morphology was observed. The flow cytometry technology was used in analyzing the cell apoptosis rate. The Transwell assay evaluated cell migration and invasion following SSA treatment, apoptosis-related protein expression, and angiogenesis-related protein expression, and EMT-related proteins were detected by western blot analysis.

Results

SSA showed an inhibitory effect on SK-N-AS cells with the IC₅₀ values of 14.14 μM at 24 h and 12.41 μM at 48 h. Results indicated that SSA has proapoptotic activity, and its proapoptotic activity is positively correlated with the Bax/Bcl-2/caspase-9/caspase-7/PARP pathway. Furthermore, SSA inhibited the invasion and migration of SK-N-AS cells via regulating the angiogenesis-related VEGFR2/Src/Akt pathway and the epithelial-mesenchymal transition- (EMT-) related protein expression.

Conclusion

SSA exerts an antihuman NB effect and thus provides foundations for NB treatment.

Diagnostic Performance of 18F-FDG PET(CT) in Bone-Bone Marrow Involvement in Pediatric Neuroblastoma: A Systemic Review and Meta-Analysis

Objective

We sought to perform a systemic review and meta-analysis of the diagnostic performance of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (computed tomography) (PET(CT)) in detection of bone and/or bone marrow involvement (BMI) in pediatric neuroblastoma (NB).

Materials and Methods

We searched electronic databases Pubmed and Embase to retrieve relevant references. We calculated pooled sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR−), diagnostic odds ratio (DOR), and the area under the curve (AUC). Moreover, a summary receiver operating characteristic (SROC) curve and likelihood ratio dot plot were plotted. Study-between statistical heterogeneity was evaluated via I-square index (I²). Subgroup analyses were used to explore heterogeneity.

Results

Seven studies including 127 patients were involved in this meta-analysis. The overall sensitivity and specificity were 0.87 (95% CI: 0.65–0.96) with heterogeneity I² = 88.1% (p < 0.001) and 0.96 (95% CI: 0.67–1.00) with heterogeneity I² = 77.8% (p < 0.001), respectively. The pooled LR+, LR−, and DOR were 21.3 (95% CI: 2.1–213.9), 0.14 (95% CI: 0.05–0.40), and 157 (95% CI: 16–1532), respectively. The area under the SROC curve was 0.97 (95% CI: 0.95–0.98).

Conclusions

Through a meta-analysis, this study suggested that ¹⁸F-FDG PET(CT) has a good overall diagnostic accuracy in the detection of bone/BMI in pediatric neuroblastoma.

Plasticity in Neuroblastoma Cell Identity Defines a Noradrenergic-to-Mesenchymal Transition (NMT)

Neuroblastoma, a pediatric cancer of the peripheral sympathetic nervous system, is characterized by an important clinical heterogeneity, and high-risk tumors are associated with a poor overall survival. Neuroblastoma cells may present with diverse morphological and biochemical properties in vitro, and seminal observations suggested that interconversion between two phenotypes called N-type and S-type may occur. In 2017, two main studies provided novel insights into these subtypes through the characterization of the transcriptomic and epigenetic landscapes of a panel of neuroblastoma cell lines. In this review, we focus on the available data that define neuroblastoma cell identity and propose to use the term noradrenergic (NOR) and mesenchymal (MES) to refer to these identities. We also address the question of transdifferentiation between both states and suggest that the plasticity between the NOR identity and the MES identity defines a noradrenergic-to-mesenchymal transition, reminiscent of but different from the well-established epithelial-to-mesenchymal transition.

Neuromedin U and neurotensin may promote the development of the tumour microenvironment in neuroblastoma

Stage 4S neuroblastoma, as defined by the International Neuroblastoma Staging System committee (INSS), is known to regress spontaneously and have a more favourable outcome compared with stage 4 tumours. Comparing the molecular differences between these two stages may provide insights into the progression of neuroblastoma. Our study aimed to explore the molecular differences in the tumour microenvironment (TME) between INSS stage 4S and stage 4 tumours to provide an insight into the mechanisms underlying the biological processes of neuroblastoma. We downloaded the datasets GSE120572 and GSE73517 from the GEO database and pre-processed them using the limma package. CIBERSORT deconvolution agorithm was applied to analyse the differences in 22 infiltrating immune leukocyte subsets between the two stages. We used gene ontology (GO) enrichment analysis to determine the biological process (BP) annotation of differentially expressed genes (DEGs) using the online WebGestalt tool. Hub genes were determined in the STRING database and Cytoscape, and the expression of these genes was verified in the Oncomine database. Then these critical genes were performed survival analysis in TARGET database. We further validated the hub genes using a transwell assay and wound healing assay to detect the function of the genes in the neuroblastoma cell line SK-N-BE(2). GO analysis revealed that the 216 DEGs between stage 4S and stage 4 were enriched in aggressive biological processes. Neuromedin U (NMU) and neurotensin (NTS), which were significantly associated with patients’ overall survival rate, were verified to be elevated in stage 4, and to promote the proliferation and invasion of the SK-N-BE(2) cell. Tumour infiltrating leukocyte analysis showed a high infiltration of regulatory T cells and type 2 tumour-associated macrophages in stage 4 but not in stage 4S. Results of gene co-expression correlation, and the results of previous studies, suggest that NMU and NTS may play certain roles in modulating TME, thus facilitating the progression of neuroblastoma.

Bioinformatic Identification of Neuroblastoma Microenvironment-Associated Biomarkers with Prognostic Value

The microenvironment plays a vital role in the tumor recurrence of neuroblastoma. This research aimed at exploring prognostic genes that are involved in neuroblastoma microenvironment. We used “estimate” R package to calculate the immune/stromal/ESTIMATE scores of each sample of ArrayExpress dataset E-MTAB-8248 based on the ESTIMATE algorithm. Then we found that immune/stromal/ESTIMATE scores were not correlated with age/chromosome 11q, but tumor stage, MYCN gene amplifications, and chromosome 1p. Samples were then divided into high- and low-score groups, and 280 common differentially expressed genes (DEGs) were identified. 64 potential prognostic genes were harvested through overall survival analysis from the common DEGs. 14 prognostic genes (ABCA6, SEPP1, SLAMF8, GPR171, ABCA9, ARHGAP15, IL7R, HLA-DPB1, GZMA, GPR183, CCL19, ITK, FGL2, and CD1C) were obtained after screening in two independent cohorts. GO and KEGG analysis discovered that common DEGs and 64 potential prognostic genes are mainly involved in T-cell activation, lymphocyte activation regulation, leukocyte migration, and the interaction of cytokines and cytokine receptors. Correlation analysis showed that all prognostic genes were negatively correlated with MYCN amplification. Cox analysis identified 5 independent prognostic genes (ARHGAP15, ABCA9, CCL19, SLAMF8, and CD1C).

Novel Mannich base 3FB3FA8H induces apoptosis by upregulating P53 pathway in neuroblastoma cells

P53 plays an important role in maintaining genetic stability and development of resistance against tumors. Dysregulation of P53 gene is one of the key factors contributing to the etiology of neuroblastoma which causes cells to evade apoptosis. Activating P53 pathway can be a therapeutic alternative to the currently available medicinal strategies. Mannich bases have been known to possess various biological activities including the anticancer activity. In this study, we have targeted the P53 pathway by novel Mannich base (3FB3FA8H) which can be a future prospect to cure neuroblastoma. 3FB3FA8H has shown modulation of P53 pathway leading to apoptosis of neuroblastoma cells. Mitochondrial membrane permeability is also increased by 3FB3FA8H which may be a consequence of P53 pathway modulation. 3FB3FA8H increases the mRNA levels of P53 leading to activation of BAX. Inclining BAX/BCL2 ratio towards apoptotic BAX leads to cleavage of caspase 3, ultimately, causing apoptosis. Series of experiments provide the evidence that Mannich base 3FB3FA8H leads to P53-mediated apoptosis. Inducing apoptosis by this mechanism could be of central importance in reducing tumor burden which can be a good prospect for neuroblastoma patients.

Polycomb repressive complex 1: Regulators of neurogenesis from embryonic to adult stage

Development of vertebrate nervous system is a complex process which involves differential gene expression and disruptions in this process or in the mature brain, may lead to neurological disorders and diseases. Extensive work that spanned several decades using rodent models and recent work on stem cells have helped uncover the intricate process of neuronal differentiation and maturation. There are various morphological changes, genetic and epigenetic modifications which occur during normal mammalian neural development, one of the chromatin modifications that controls vital gene expression are the posttranslational modifications on histone proteins, that controls accessibility of translational machinery. Among the histone modifiers, polycomb group proteins (PcGs), such as Ezh2, Eed and Suz12 form large protein complexes-polycomb repressive complex 2 (PRC2); while Ring1b and Bmi1 proteins form core of PRC1 along with accessory proteins such as Cbx, Hph, Rybp and Pcgfs catalyse histone modifications such as H3K27me3 and H2AK119ub1. PRC1 proteins are known to play critical role in X chromosome inactivation in females but they also repress the expression of key developmental genes and tightly regulate the mammalian neuronal development. In this review we have discussed the signalling pathways, morphogens and nuclear factors that initiate, regulate and maintain cells of the nervous system. Further, we have extensively reviewed the recent literature on the role of Ring1b and Bmi1 in mammalian neuronal development and differentiation; as well as highlighted questions that are still unanswered.

Pediatric neuroblastic tumors: A critical evaluation of cytomorphological features for risk stratification on aspiration cytology

BACKGROUND

Neuroblastic tumor (NT) is the most common extracranial solid tumor of childhood with variable outcome which again depends on risk stratification related to distinct biology of the tumor. The use of fine-needle aspiration (FNA) material for evaluation of cytomorphological parameters and risk stratification in NTs using cytology prognostic score (PS) is limited in routine practice.

METHODS

We reviewed 38 FNA cytology cases diagnosed as pediatric small round cell tumor between time period June 2017 to December 2019 for clinical, cytomorphological and immunohistochemical features.

RESULTS

Ten out of 38 small round cell tumors were NTs. All 10 cases were further subclassified according to International Neuroblastoma Pathology Classification into undifferentiated neuroblastoma (n = 1), poorly differentiated neuroblastoma (n = 5), differentiating neuroblastoma (n = 2), and ganglioneuroblastoma (n = 2). Cytologic PS was done using the morphological criteria as described previously in literature. The patients were divided into favorable and unfavorable cytomorphological prognostic categories with a cut off scoring of 12. A score of more than 12 is associated with high risk morphology and advanced stage. All cases with PS > 12 (n-4) (unfavorable cytomorphology) had a poor outcome compared to six patients with PS < 12 (n-6) (favorable cytomorphology).

CONCLUSION

Aspiration cytology can be used as a first line investigation to evaluate the cytomorphological features for risk stratification and diagnosis in patients with NTs using cytological prognostic scoring system. A larger multi-centric validation study necessitates for cytological risk stratification.

Nanotechnological based miRNA intervention in the therapeutic management of neuroblastoma

Neuroblastoma (NB) is a widely diagnosed cancer in children, characterized by amplification of the gene encoding the MYCN transcription factor, which is highly predictive of poor clinical outcome and metastatic disease. microRNAs (a class of small non-coding RNAs) are regulated by MYCN transcription factor in neuroblastoma cells. The current research is focussed on identifying differential role of miRNAs and their interactions with signalling proteins, which are intricately linked with cellular processes like apoptosis, proliferation or metastasis. However, the therapeutic success of miRNAs is limited by pharmaco-technical issues which are well counteracted by nanotechnological advancements. The nanoformulated miRNAs unload anti-cancer drugs in a controlled and prespecified manner at target sites, to influence the activity of target protein in amelioration of NB. Recent advances and developments in the field of miRNAs-based systems for clinical management of NBs and the role of nanotechnology to overcome challenges with drug delivery of miRNAs have been reviewed in this paper.

WNT Signaling in Neuroblastoma

The term WNT (wingless-type MMTV integration site family) signaling comprises a complex molecular pathway consisting of ligands, receptors, coreceptors, signal transducers and transcriptional modulators with crucial functions during embryonic development, including all aspects of proliferation, morphogenesis and differentiation. Its involvement in cancer biology is well documented. Even though WNT signaling has been divided into mainly three distinct branches in the past, increasing evidence shows that some molecular hubs can act in various branches by exchanging interaction partners. Here we discuss developmental and clinical aspects of WNT signaling in neuroblastoma (NB), an embryonic tumor with an extremely broad clinical spectrum, ranging from spontaneous differentiation to fatal outcome. We discuss implications of WNT molecules in NB onset, progression, and relapse due to chemoresistance. In the light of the still too high number of NB deaths, new pathways must be considered.

Inhibition of Ubiquitin-Specific Protease 14 Suppresses Cell Proliferation and Synergizes with Chemotherapeutic Agents in Neuroblastoma

Neuroblastoma is the most common extracranial malignant solid tumor in children, and drug resistance is a major reason for poor outcomes. Elevated proteasome activity plays an important role in neuroblastoma tumor development and resistance to conventional chemotherapy. Ubiquitin-specific protease 14 (USP14), one of three deubiquitinases associated with the regulatory subunit of the proteasome, is emerging as a potential therapeutic target in multiple tumor types. However, the role of USP14 in neuroblastoma is yet to be elucidated. We found that USP14 inhibition in neuroblastoma via knockdown or a specific inhibitor such as b-AP15 suppressed cell proliferation by inducing cell apoptosis. Furthermore, b-AP15 significantly inhibited neuroblastoma tumor growth in NGP and SH-SY5Y xenograft mouse models. For combination treatment, b-AP15 plus conventional chemotherapeutic agents such as doxorubicin or VP-16 resulted in synergistic antitumor effects on neuroblastoma. Our study demonstrates that USP14 is required for cell viability and is a novel therapeutic target in neuroblastoma. Moreover, USP14 inhibition may add value in combination therapy due to its powerful synergistic effects in treating neuroblastoma.

[68Ga]-Dota Peptide PET/CT in Neuroendocrine Tumors: Main Clinical Applications

Objective:

Neuroendocrine Neoplasms (NENs) are generally defined as rare and heterogeneous tumors. The gastrointestinal system is the most frequent site of NENs localization, however they can be found in other anatomical regions, such as pancreas, lungs, ovaries, thyroid, pituitary, and adrenal glands. Neuroendocrine neoplasms have significant clinical manifestations depending on the production of active peptide.

Methods:

Imaging modalities play a fundamental role in initial diagnosis as well as in staging and treatment monitoring of NENs, in particular they vastly enhance the understanding of the physiopathology and diagnosis of NENs through the use of somatostatin analogue tracers labeled with appropriate radioisotopes. Additionally, the use of somatostatin analogues provides the ability to in-vivo measure the expression of somatostatin receptors on NEN cells, a process that might have important therapeutic implications.

Results:

A large body of evidences showed improved accuracy of molecular imaging based on PET/CT radiotracer with SST analogues (e.g. [68Ga]-DOTA peptide) for the detection of NEN lesions in comparison to morphological imaging modalities. So far, the role of imaging technologies in assessing treatment response is still under debate.

Conclusion:

This review offers the systems of classification and grading of NENs and summarizes the more useful recommendations based on data recently published for the management of patients with NENs, with special focus on the role of imaging modalities based on SST targeting with PET / CT radiotracers.

Innate immune sensor laboratory of genetics and physiology 2 suppresses tumor cell growth and functions as a prognostic marker in neuroblastoma

The innate immune receptors, such as toll-like receptor 3 (TLR3), melanoma differentiation-associated 5 (MDA5) and retinoic acid-inducible gene-I (RIG-I), have been shown to be differentially expressed in neuroblastoma (NB) and promote dsRNA poly (I:C)-induced NB suppression in vitro and in vivo. However, the role of another important innate immune cytosolic sensor, laboratory of genetics and physiology 2 (LGP2), in the cancer behavior of NB remains unclear. Here, we demonstrated that the expression levels of LGP2 were either low or undetectable in all NB cell lines tested with or without MYCN amplification. LGP2 expression levels were significantly increased only in NB cells without MYCN amplification, including SK-N-AS and SK-N-FI after poly (I:C) treatment in vitro and in mouse xenograft models. Ectopic expression of LGP2 in NB cells significantly enhanced poly (I:C)-induced NB cell death associated with downregulation of MDA5, RIG-I, MAVS and Bcl-2, as well as upregulation of Noxa and tBid. By immunofluorescence analyses, LGP2 localized mainly in the cytoplasm of NB cells after poly (I:C) treatment. In human NB tissue samples, cytoplasmic LGP2 expression was positively correlated with histological differentiation and inversely correlated with MYCN amplification. Positive cytoplasmic LGP2 expression in tumor tissues could predict a favorable outcome in NB patients independent of other prognostic factors. In short, LGP2 was effective in promoting poly (I:C)-induced NB suppression and cytoplasmic LGP2 can serve as an independent favorable prognostic factor in NB patients.

MiRNA Influences in Neuroblast Modulation: An Introspective Analysis

Neuroblastoma (NB) is the most common occurring solid paediatric cancer in children under the age of five years. Whether of familial or sporadic origin, chromosome abnormalities contribute to the development of NB and cause dysregulation of microRNAs (miRNAs). MiRNAs are small non-coding, single stranded RNAs that target messenger RNAs at the post-transcriptional levels by repressing translation within all facets of human physiology. Such gene 'silencing' activities by miRNAs allows the development of regulatory feedback loops affecting multiple functions within the cell, including the possible differentiation of neural stem cell (NSC) lineage selection. Neurogenesis includes stages of self-renewal and fate specification of NSCs, migration and maturation of young neurones, and functional integration of new neurones into the neural circuitry, all of which are regulated by miRNAs. The role of miRNAs and their interaction in cellular processes are recognised aspects of cancer genetics, and miRNAs are currently employed as biomarkers for prognosis and tumour characterisation in multiple cancer models. Consequently, thorough understanding of the mechanisms of how these miRNAs interplay at the transcriptomic level will definitely lead to the development of novel, bespoke and efficient therapeutic measures, with this review focusing on the influences of miRNAs on neuroblast modulations leading to neuroblastoma.

Neuroblastoma pathogenesis: deregulation of embryonic neural crest development

Neuroblastoma (NB) is an aggressive pediatric cancer that originates from neural crest tissues of the sympathetic nervous system. NB is highly heterogeneous both from a clinical and a molecular perspective. Clinically, this cancer represents a wide range of phenotypes ranging from spontaneous regression of 4S disease to unremitting treatment-refractory progression and death of high-risk metastatic disease. At a cellular level, the heterogeneous behavior of NB likely arises from an arrest and deregulation of normal neural crest development. In the present review, we summarize our current knowledge of neural crest development as it relates to pathways promoting 'stemness' and how deregulation may contribute to the development of tumor-initiating CSCs. There is an emerging consensus that such tumor subpopulations contribute to the evolution of drug resistance, metastasis and relapse in other equally aggressive malignancies. As relapsed, refractory disease remains the primary cause of death for neuroblastoma, the identification and targeting of CSCs or other primary drivers of tumor progression remains a critical, clinically significant goal for neuroblastoma. We will critically review recent and past evidence in the literature supporting the concept of CSCs as drivers of neuroblastoma pathogenesis.

Protein glycosylation in cancers and its potential therapeutic applications in neuroblastoma

Glycosylation is the most complex post-translational modification of proteins. Altered glycans on the tumor- and host-cell surface and in the tumor microenvironment have been identified to mediate critical events in cancer pathogenesis and progression. Tumor-associated glycan changes comprise increased branching of N-glycans, higher density of O-glycans, generation of truncated versions of normal counterparts, and generation of unusual forms of terminal structures arising from sialylation and fucosylation. The functional role of tumor-associated glycans (Tn, sTn, T, and sLe^a/x) is dependent on the interaction with lectins. Lectins are expressed on the surface of immune cells and endothelial cells or exist as extracellular matrix proteins and soluble adhesion molecules. Expression of tumor-associated glycans is involved in the dysregulation of glycogenes, which mainly comprise glycosyltransferases and glycosidases. Furthermore, genetic and epigenetic mechanisms on many glycogenes are associated with malignant transformation. With better understanding of all aspects of cancer-cell glycomics, many tumor-associated glycans have been utilized for diagnostic, prognostic, and therapeutic purposes. Glycan-based therapeutics has been applied to cancers from breast, lung, gastrointestinal system, melanomas, and lymphomas but rarely to neuroblastomas (NBs). The success of anti-disialoganglioside (GD2, a glycolipid antigen) antibodies sheds light on glycan-based therapies for NB and also suggests the possibility of protein glycosylation-based therapies for NB. This review summarizes our understanding of cancer glycobiology with a focus of how protein glycosylation and associated glycosyltransferases affect cellular behaviors and treatment outcome of various cancers, especially NB. Finally, we highlight potential applications of glycosylation in drug and cancer vaccine development for NB.

Improved selectivity of mIBG uptake into neuroblastoma cells in vitro and in vivo by inhibition of organic cation transporter 3 uptake using clinically approved corticosteroids

INTRODUCTION

Radiolabeled meta-iodobenzylguanidine (mIBG) is used for imaging and therapy of neuroblastoma as well as pheochromocytoma. However, non-tumorous tissues also incorporate mIBG mainly by organic cation transporters (OCTs). In this study, we tested different clinically approved corticosteroids as potential inhibitors of the OCT3-mediated uptake in vitro and in vivo, to achieve a more selective mIBG tumor uptake.

METHODS

The in vitro incorporation of [(3)H]norepinephrine ([(3)H]NE), [(3)H]dopamine ([(3)H]DA) and [(123)I]mIBG in neuroblastoma cells (SK-N-SH, Kelly, IMR-32) and in HEK-293 cells transfected with human OCT3 was measured with and without supplemental corticosteroids (hydrocortisone, prednisolone, dexamethasone, corticosterone). The in vivo biodistribution of [(123)I]mIBG in absence and presence of corticosteroids was studied in non-tumor bearing NOD scid gamma mice. Retrospectively, we selected patients with and without corticosteroid treatment prior to [(123)I]mIBG scintigraphy.

RESULTS

A concentration-dependent inhibitory effect of different corticosteroids on the [(3)H]NE and [(3)H]DA uptake via OCT3 was illustrated in vitro. The highest OCT3 inhibition was observed for corticosterone, but clinically used corticosteroids, showed also promising inhibitory effects. In contrast, the uptake in neuroblastoma cells was reduced only moderately. Hydrocortisone or prednisolone had only minor effects on [(123)I]mIBG uptake of both neuroblastoma cells, but reduced uptake in OCT3 expressing cells significantly. In mice tissues, [(123)I]mIBG uptake was inhibited by corticosteroids especially in the small intestine and kidney. Finally, in one patient with hydrocortisone treatment performed prior to [(123)I]mIBG scan, heart and liver uptake was reduced compared to untreated patients.

CONCLUSIONS

The OCT3 is widely spread in many organs and responsible for non-targeted uptake of radiolabeled mIBG. In our study, clinically approved corticosteroids inhibited mIBG uptake in OCT3 expressing cells effectively, whereas tracer accumulation in NT (norepinephrine transporter) expressing neuroblastoma cells showed consistency. We conclude, that a single dose of hydrocortisone or prednisolone prior to [(123)I]mIBG scintigraphy may improve specificity and reduce radiation dose to non-target organs.

Rac GTPase regulation of 3D invasion in neuroblastomas lacking MYCN amplification

Neuroblastomas are highly invasive tumors that occur in pediatric patients and treatment of invasive disease remains a challenge. The study of cells invading in 3-dimensional (3D) hydrogels has revealed morphologically distinct modes of invasion by which cancer cells adapt to the local tissue environment in order to invade local tissue. Specifically, the small G protein Rac GTPase has been implicated as regulating the elongated/mesenchymal mode of cell invasion. In the present study we demonstrate an inverse association between Rac expression and amplification of MYCN, a well-established prognostic indicator in neuroblastoma. Moreover, the association further tracks with previously described morphological variants of neuroblastoma. Importantly, while MYCN amplification is associated with universally poor prognosis, the clinical course of patients whose tumors lack MYCN amplification are more difficult to predict. Therefore, we analyzed the role that Rac plays in regulating the invasive behavior of neuroblastoma cells lacking MYCN amplification. Using siRNA targeting Rac in single cell suspensions in 3D collagen gels and Rac inhibition of multicellular spheroids (MCS) embedded in collagen gels, we find that the high Rac-expressing lines differ in their morphological response to Rac depletion and inhibition. Live cell imaging of embedded MCS reveals distinct individual and collective modes of invasion between the cell lines. Critically, Rac inhibition blocked both individual and collective invasion in 2 of the 3 high Rac expressing cell lines. Our study suggests that Rac activity may be an important determinant of metastatic capability in subsets of neuroblastoma cells lacking MYCN amplification.

123I-MIBG scintigraphy and 18F-FDG-PET imaging for diagnosing neuroblastoma

BACKGROUND

Neuroblastoma is an embryonic tumour of childhood that originates in the neural crest. It is the second most common extracranial malignant solid tumour of childhood.Neuroblastoma cells have the unique capacity to accumulate Iodine-123-metaiodobenzylguanidine (¹²³I-MIBG), which can be used for imaging the tumour. Moreover, ¹²³I-MIBG scintigraphy is not only important for the diagnosis of neuroblastoma, but also for staging and localization of skeletal lesions. If these are present, MIBG follow-up scans are used to assess the patient's response to therapy. However, the sensitivity and specificity of ¹²³I-MIBG scintigraphy to detect neuroblastoma varies according to the literature.Prognosis, treatment and response to therapy of patients with neuroblastoma are currently based on extension scoring of ¹²³I-MIBG scans. Due to its clinical use and importance, it is necessary to determine the exact diagnostic accuracy of ¹²³I-MIBG scintigraphy. In case the tumour is not MIBG avid, fluorine-18-fluorodeoxy-glucose ((18)F-FDG) positron emission tomography (PET) is often used and the diagnostic accuracy of this test should also be assessed.

OBJECTIVES

PRIMARY OBJECTIVES

1.1 To determine the diagnostic accuracy of ¹²³I-MIBG (single photon emission computed tomography (SPECT), with or without computed tomography (CT)) scintigraphy for detecting a neuroblastoma and its metastases at first diagnosis or at recurrence in children from 0 to 18 years old.1.2 To determine the diagnostic accuracy of negative ¹²³I-MIBG scintigraphy in combination with (18)F-FDG-PET(-CT) imaging for detecting a neuroblastoma and its metastases at first diagnosis or at recurrence in children from 0 to 18 years old, i.e. an add-on test.

SECONDARY OBJECTIVES

2.1 To determine the diagnostic accuracy of (18)F-FDG-PET(-CT) imaging for detecting a neuroblastoma and its metastases at first diagnosis or at recurrence in children from 0 to 18 years old.2.2 To compare the diagnostic accuracy of ¹²³I-MIBG (SPECT-CT) and (18)F-FDG-PET(-CT) imaging for detecting a neuroblastoma and its metastases at first diagnosis or at recurrence in children from 0 to 18 years old. This was performed within and between included studies. ¹²³I-MIBG (SPECT-CT) scintigraphy was the comparator test in this case.

SEARCH METHODS

We searched the databases of MEDLINE/PubMed (1945 to 11 September 2012) and EMBASE/Ovid (1980 to 11 September 2012) for potentially relevant articles. Also we checked the reference lists of relevant articles and review articles, scanned conference proceedings and searched for unpublished studies by contacting researchers involved in this area.

SELECTION CRITERIA

We included studies of a cross-sectional design or cases series of proven neuroblastoma, either retrospective or prospective, if they compared the results of ¹²³I-MIBG (SPECT-CT) scintigraphy or (18)F-FDG-PET(-CT) imaging, or both, with the reference standards or with each other. Studies had to be primary diagnostic and report on children aged between 0 to 18 years old with a neuroblastoma of any stage at first diagnosis or at recurrence.

DATA COLLECTION AND ANALYSIS

One review author performed the initial screening of identified references. Two review authors independently performed the study selection, extracted data and assessed the methodological quality.We used data from two-by-two tables, describing at least the number of patients with a true positive test and the number of patients with a false negative test, to calculate the sensitivity, and if possible, the specificity for each included study.If possible, we generated forest plots showing estimates of sensitivity and specificity together with 95% confidence intervals.

MAIN RESULTS

Eleven studies met the inclusion criteria. Ten studies reported data on patient level: the scan was positive or negative. One study reported on all single lesions (lesion level). The sensitivity of ¹²³I-MIBG (SPECT-CT) scintigraphy (objective 1.1), determined in 608 of 621 eligible patients included in the 11 studies, varied from 67% to 100%. One study, that reported on a lesion level, provided data to calculate the specificity: 68% in 115 lesions in 22 patients. The sensitivity of ¹²³I-MIBG scintigraphy for detecting metastases separately from the primary tumour in patients with all neuroblastoma stages ranged from 79% to 100% in three studies and the specificity ranged from 33% to 89% for two of these studies.One study reported on the diagnostic accuracy of (18)F-FDG-PET(-CT) imaging (add-on test) in patients with negative ¹²³I-MIBG scintigraphy (objective 1.2). Two of the 24 eligible patients with proven neuroblastoma had a negative ¹²³I-MIBG scan and a positive (18)F-FDG-PET(-CT) scan.The sensitivity of (18)F-FDG-PET(-CT) imaging as a single diagnostic test (objective 2.1) and compared to ¹²³I-MIBG (SPECT-CT) (objective 2.2) was only reported in one study. The sensitivity of (18)F-FDG-PET(-CT) imaging was 100% versus 92% of ¹²³I-MIBG (SPECT-CT) scintigraphy. We could not calculate the specificity for both modalities.

AUTHORS' CONCLUSIONS

The reported sensitivities of ¹²³-I MIBG scintigraphy for the detection of neuroblastoma and its metastases ranged from 67 to 100% in patients with histologically proven neuroblastoma.Only one study in this review reported on false positive findings. It is important to keep in mind that false positive findings can occur. For example, physiological uptake should be ruled out, by using SPECT-CT scans, although more research is needed before definitive conclusions can be made.As described both in the literature and in this review, in about 10% of the patients with histologically proven neuroblastoma the tumour does not accumulate ¹²³I-MIBG (false negative results). For these patients, it is advisable to perform an additional test for staging and assess response to therapy. Additional tests might for example be (18)F-FDG-PET(-CT), but to be certain of its clinical value, more evidence is needed.The diagnostic accuracy of (18)F-FDG-PET(-CT) imaging in case of a negative ¹²³I-MIBG scintigraphy could not be calculated, because only very limited data were available. Also the detection of the diagnostic accuracy of index test (18)F-FDG-PET(-CT) imaging for detecting a neuroblastoma tumour and its metastases, and to compare this to comparator test ¹²³I-MIBG (SPECT-CT) scintigraphy, could not be calculated because of the limited available data at time of this search.At the start of this project, we did not expect to find only very limited data on specificity. We now consider it would have been more appropriate to use the term "the sensitivity to assess the presence of neuroblastoma" instead of "diagnostic accuracy" for the objectives.

MDA5 complements TLR3 in suppression of neuroblastoma

Toll-like receptor3 (TLR3) has been confirmed to be differentially expressed in neuroblastoma (NB), and predicts a favorable prognosis with a high expression in tumor tissues. Treatment with TLR3 agonist--polyinosinic-polycytidylic acid [poly(I:C)] could induce significant but limited apoptosis in TLR3-expressing NB cells, suggesting that other viral RNA sensors, including melanoma differentiation-associated gene 5 (MDA5) and retinoic acid-inducible gene-I (RIG-I) in the cytosolic compartment might also be implicated in poly(I:C)-induced NB cell death. MDA5 and RIG-I were induced by poly(I:C) to express in two of six NB cell lines, SK-N-AS (AS) and SK-N-FI, which were associated with up-regulation of caspase9 and active caspase3. While knockdown of either MDA5 or RIG-I alone is ineffective to decrease caspase9 and active caspase3, simultaneously targeting MDA5 and TLR3 showed the best effect to rescue poly(I:C) induced up-regulation of mitochondrial antiviral signaling protein (MAVS), caspase9, active caspase3, and apoptosis in AS cells. Over-expression of MDA5 in FaDu cells resulted in significantly less colony formation and more poly(I:C)-induced cell death. Further studies in human NB tissue samples revealed that MDA5 expression in NB tissues predicted a favorable prognosis synergistically with TLR3. Our findings indicate that MDA5 may serve as a complementary role in the TLR3 activated suppression of NB.

Image-defined risk factor assessment of neurogenic tumors after neoadjuvant chemotherapy is useful for predicting intra-operative risk factors and the completeness of resection

BACKGROUND

Patients with neuroblastoma are now stratified at diagnosis according to the presence and number of image-defined risk factors (IDRFs). We examined the added value of IDRF assessment after neoadjuvant chemotherapy for predicting surgical resection.

MATERIAL AND METHODS

From 2009-2012, 39 out of 91 patients operated on in our institution for neuroblastic tumors received neoadjuvant chemotherapy based on ongoing SIOPEN protocols or treatment guidelines. IDRFs were assessed both at diagnosis and preoperatively on CT and/or MRI.

RESULTS

Median age at diagnosis was 30 months [range 2-191]. The tumor locations were adrenal (n = 20), paravertebral (n = 13) and perivascular (n = 6). INRGSS stages were L2 (n = 13), M (n = 25) and Ms (n = 1). Eleven tumors (28%) were MYCN-amplified. Chemotherapy reduced the number of IDRFs in 54% of patients overall (21/39): 61.5% (16/26) of M and Ms patients, and 38.5% (5/13) of non metastatic patients (P < 0.001). The number of IDRFs lost after chemotherapy was proportional to the degree of tumor shrinkage (P = 0.002), independent of the primary tumor location (P = 0.73), although the number was higher in patients with left versus right adrenal locations (P = 0.004). Patients with neuroblastoma on post-surgical histology lost more IDRFs (median: 1[0-9]) than patients with ganglioneuroblastoma (median: 0[0-4]) (P < 0.001). The completeness of resection was related only to the number of preoperative IDRFs (P = 0.028).

CONCLUSION

IDRF assessment after neoadjuvant chemotherapy is useful for predicting completeness of resection of neurogenic tumors. A larger international study is needed to confirm these results and to explore a possible correlation between preoperative IDRF status and survival.

PI3K Inhibitor Combined With Chemotherapy Can Enhance the Apoptosis of Neuroblastoma Cells In Vitro and In Vivo

Activation of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway is a novel poor prognostic indicator of neuroblastoma (NB), and the positive effects of chemotherapy on NB have been confirmed. In this study, we investigated the effect of small molecule PI3K inhibitor PI103 on chemosensitivity. The PI3K inhibitor cooperates with doxorubicin to synergistically induce apoptosis and to reduce tumor growth of NB in in vitro and in vivo models. Human NB cells, SH-SY5Y and SK-N-BE(2), were treated with PI103 combined doxorubicin-enhanced Bid cleavage, activated Bax, and caspase 3. Activation of caspase 3 was also observed in xenografts of NB in nude mice upon combination of doxorubicin with the specific PI3K inhibitor PI103. Cell viability was assessed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Both PI103 and doxorubicin inhibited growth of NB in vitro and PI103 induced a G1 arrest of NB cells. PI103 combined doxorubicin significantly inhibits the growth of established NB tumors, induced apoptosis of tumor cells, and improved the survival of mice in vivo Taken together, our findings suggest that PI3K inhibition seems to be a promising option to sensitize tumor cells for chemotherapy in NB, which may be effective in the treatment of NBs.

Chemoresistance, cancer stem cells, and miRNA influences: the case for neuroblastoma

Neuroblastoma is a type of cancer that develops most often in infants and children under the age of five years. Neuroblastoma originates within the peripheral sympathetic ganglia, with 30% of the cases developing within the adrenal medulla, although it can also occur within other regions of the body such as nerve tissue in the spinal cord, neck, chest, abdomen, and pelvis. MicroRNAs (miRNAs) regulate cellular pathways, differentiation, apoptosis, and stem cell maintenance. Such miRNAs regulate genes involved in cellular processes. Consequently, they are implicated in the regulation of a spectrum of signaling pathways within the cell. In essence, the role of miRNAs in the development of cancer is of utmost importance for the understanding of dysfunctional cellular pathways that lead to the conversion of normal cells into cancer cells. This review focuses on highlighting the recent, important implications of miRNAs within the context of neuroblastoma basic research efforts, particularly concerning miRNA influences on cancer stem cell pathology and chemoresistance pathology for this condition, together with development of translational medicine approaches for novel diagnostic tools and therapies for this neuroblastoma.

Second malignancies in patients with neuroblastoma: the effects of risk-based therapy

BACKGROUND

To investigate the incidence of second malignant neoplasms (SMN) for patients with neuroblastoma, we analyzed patients from the SEER database according to three treatment eras (Era 1: 1973-1989, Era 2: 1990-1996, and Era 3: 1997-2006) corresponding to the introduction of multi-agent chemotherapy, risk-based treatment, and stem cell transplant.

PROCEDURES

The SEER database was mined for all patients with neuroblastoma or ganglioneuroblastoma. Cumulative incidence of SMN was calculated with death as a competing risk. A poisson regression model was used to estimate incidence rate ratios and 95% confidence intervals to compare the rates of SMN between patients in different Eras.

RESULTS

The analytic cohort included 2,801 patients. Thirty-four patients developed a SMN, accounting for 1.2% of all patients. Of the patients who developed a SMN, 47.1% received radiation for their primary neuroblastoma. Fourteen of the SMN were carcinomas, and 10 were hematologic malignancies, with six cases of acute myelogenous leukemia. There was no difference in the incidence of SMN in Era 1 compared to Era 3 (P = 0.48). The cumulative incidence of SMN at 30 years for high-risk patients was 10.44% (95% CI 3.98-20.52%) compared to 3.57% (95% CI 1.87-6.12%) for non-high-risk patients (P < 0.001).

CONCLUSIONS

This study showed no increase in the incidence of SMNs for children treated in the most recent treatment era as compared to earlier Eras. However, as the risk for developing SMN does not plateau, the number of SMNs will likely continue to rise in the cohort of patients treated after 1996. Comprehensive follow-up care for these survivors will be important.

Nothing but NET: a review of norepinephrine transporter expression and efficacy of 131I-mIBG therapy

Neuroblastoma is unique amongst common pediatric cancers for its expression of the norepinephrine transporter (NET), enabling tumor-selective imaging and therapy with radioactive analogues of norepinephrine. The majority of neuroblastoma tumors are avid for (123)I-metaiodobenzaguanidine (mIBG) on imaging, yet the therapeutic response to (131) I-mIBG is only 30% in clinical trials, and off-target effects cause short- and long-term morbidity. We review the contemporary understanding of the tumor-selective uptake, retention, and efflux of meta-iodobenzylguanidine (mIBG) and strategies currently in development for improving its efficacy. Combination treatment strategies aimed at enhancing NET are likely necessary to reach the full potential of (131)I-mIBG therapy.

GALNT2 suppresses malignant phenotypes through IGF-1 receptor and predicts favorable prognosis in neuroblastoma

Aberrant expression of the simple mucin-type carbohydrate antigens such as Tn antigen is associated with malignant transformation and cancer progression. N-acetylgalactosaminyltransferase 2 (GALNT2), one of the enzymes that mediate the initial step of mucin-type O-glycosylation, is responsible for forming Tn antigen. GALNT2 is expressed differentially in nervous tissues during mouse embryogenesis; however, the role of GALNT2 in neuroblastoma (NB) remains unclear. Here we showed that increased GALNT2 expression evaluated using immunohistochemistry in NB tumor tissues correlated well with the histological grade of differentiation as well as younger age at diagnosis, early clinical stage, primary tumor originated from the extra-adrenal site, favorable INPC histology, and MYCN non-amplification. Multivariate analysis showed that GALNT2 expression is an independent prognostic factor for better survival for NB patients. GALNT2 overexpression suppressed IGF-1-induced cell growth, migration, and invasion of NB cells, whereas GALNT2 knockdown enhanced these NB phenotypes. Mechanistic investigations demonstrated that GALNT2 overexpression modified O-glycans on IGF-1R, which suppressed IGF-1-triggered IGF-1R dimerization and subsequent downstream signaling events. Conversely, these properties were reversed by GALNT2 knockdown in NB cells. Our findings suggest that GALNT2 regulates malignant phenotypes of NB cells through the IGF-1R signaling pathway, suggesting a critical role for GALNT2 in the pathogenesis of NB.

Adult neuroblastoma complicated by increased intracranial pressure: a case report and review of the literature

Neuroblastoma is the third most commonly occurring malignancy of the pediatric population, although it is extremely rare in the adult population. In adults, neuroblastoma is often metastatic and portends an extremely poor overall survival. Our case report documents metastatic neuroblastoma occurring in a healthy 29-year-old woman whose course was complicated by an unusual presentation of elevated intracranial pressures. The patient was treated with systemic chemotherapy, I¹³¹ metaiodobenzylguanidine (MIBG) radiotherapy, and autologous stem cell transplant (SCT). Unfortunately the patient's response to therapy was limited and she subsequently died. We aim to review neuroblastoma in the context of increased intracranial pressure and the limited data of neuroblastoma occurring in the adult population, along with proposed treatment options.

Clinical experience with (18)F-fluorodeoxyglucose positron emission tomography and (123)I-metaiodobenzylguanine scintigraphy in pediatric neuroblastoma: complementary roles in follow-up of patients

Purpose

To evaluate the potential utility of ¹²³I-metaiodobenzylguanine (¹²³I-MIBG) scintigraphy and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) for the detection of primary and metastatic lesions in pediatric neuroblastoma (NBL) patients, and to determine whether ¹⁸F-FDG PET is as beneficial as ¹²³I-MIBG imaging.

Methods

We selected 8 NBL patients with significant residual mass after operation and who had paired ¹²³I-MIBG and ¹⁸F-FDG PET images that were obtained during the follow-up. We retrospectively reviewed the clinical charts and the findings of 45 paired scans.

Results

Both scans correlated relatively well with the disease status as determined by standard imaging modalities during follow-up; the overall concordance rates were 32/45 (71.1%) for primary tumor sites and 33/45 (73.3%) for bone-bone marrow (BM) metastatic sites. In detecting primary tumor sites, ¹²³I-MIBG might be superior to ¹⁸F-FDG PET. The sensitivity of ¹²³I-MIBG and ¹⁸F-FDG PET were 96.7% and 70.9%, respectively, and their specificity were 85.7% and 92.8%, respectively. ¹⁸F-FDG PET failed to detect 9 true NBL lesions in 45 follow-up scans (false negative rate, 29%) with positive ¹²³I-MIBG. For bone-BM metastatic sites, the sensitivity of ¹²³I-MIBG and ¹⁸F-FDG PET were 72.7% and 81.8%, respectively, and the specificity were 79.1% and 100%, respectively. ¹²³I-MIBG scan showed higher false positivity (20.8%) than ¹⁸F-FDG PET (0%).

Conclusion

¹²³I-MIBG is superior for delineating primary tumor sites, and ¹⁸F-FDG PET could aid in discriminating inconclusive findings on bony metastatic NBL. Both scans can be complementarily used to clearly determine discrepancies or inconclusive findings on primary or bone-BM metastatic NBL during follow-up.

Laparoscopic resection of adrenal neuroblastoma without image-defined risk factors: a prospective study on 21 consecutive pediatric patients

BACKGROUND

Over the last 20 years MIS has progressively gained popularity in children with cancer. We therefore aimed at evaluating the safety of Minimally Invasive Surgery (MIS) resection in a series of children affected by adrenal neuroblastoma (NB) presenting without Image-Defined Risk Factors (IDRFs).

METHODS

An Institutional protocol for MIS resection of adrenal NB in pediatric patients without IDRFs has been applied since 2008. Absence of IDRFs represented the main indication for MIS in NB, regardless of tumor size. All pediatric patients who underwent MIS for NB between January 2008 and May 2013 were included. Specific technical considerations, demographic data, and outcome have been recorded.

RESULTS

Twenty-one patients underwent MIS resection for IDRFs-negative adrenal NB. Nine of these patients experienced preoperative downgrading of IDRFs after chemotherapy. Radiological median diameter of the mass was 30 mm (range 10-83 mm). Median operative time was 90 min. Median hospital stay was 4 days. All patients were treated successfully, without serious intraoperative complications. One mild intraoperative hemorrhage occurred and was treated without the need for conversion to open surgery nor blood transfusion was required. No postoperative complications, including port-site or peritoneal metastases were experienced.

CONCLUSIONS

This study demonstrated the safety and effectiveness of MIS for the resection of adrenal NB without IDRFs in children. Pediatric surgeons dedicated to oncology should be aware of this alternative approach to open resection.

TAK1 inhibitor 5Z-7-oxozeaenol sensitizes neuroblastoma to chemotherapy

Treatment failure in high risk neuroblastoma is largely due to development of chemoresistance. NF-κB activation is one of the resistance mechanisms for cancer cells to escape from chemotherapy-induced cell-death. TAK1 is an essential component in genotoxic stresses-induced NF-κB activation; however, the role of TAK1 in the development of chemoresistance in neuroblastoma remains unknown. Using a panel of neuroblastoma cell lines, we found that TAK1 inhibitor 5Z-7-oxozeaenol significantly augmented the cytotoxic effects of doxorubicin (Dox) and etoposide (VP-16) on neuroblastoma cell lines. TAK1 inhibition also enhanced the inhibitory effect of Dox and VP-16 on anchorage-independent growth. Treatment of neuroblastoma cells with 5Z-7-oxozeaenol blocked Dox- and VP16-induced NF-κB activation and enhanced Dox- and VP16-induced apoptosis. Moreover, 5Z-7-oxozeaenol was able to overcome the established chemoresistance in LA-N-6 neuroblastoma cells. Using an orthotopic neuroblastoma mouse model, we found that 5Z-7-oxozeaenol significantly enhanced chemotherapeutic efficacy in vivo. Together, our results provide a proof-of-concept that TAK1 inhibition significantly increases the sensitivity of neuroblastoma cells to chemotherapy-induced cell-death and can serve as an effective adjunct to current chemotherapeutic regimens for high risk diseases.

(68)Ga-DOTATATE positron emission tomography/computed tomography scan in the detection of bone metastases in pediatric neuroendocrine tumors

AIM

The aim of this study is to evaluate the role of (68)Ga-DOTATATE positron emission tomography/computed tomography (PET/CT) scan for the detection of bone metastases in pediatric neuroendocrine tumors (NETs) and to compare it with CT scan.

MATERIALS AND METHODS

A total of 30 patients (18 were males and 12 were females; age range: 1-18 years; mean age 7.6 years) with histologically confirmed NETs referred to our department were retrospectively analyzed. All patients underwent (68)Ga-DOTATATE PET/CT scan at the time of diagnosis for primary staging. Contrast enhanced CT (CECT) performed at the time of PET scan acquisition was used for comparison with PET data. Imaging results were analyzed on a per-patient and on a per-lesion basis. Clinical follow-up of all patients and repeat PET/CT imaging (n = 10) was taken as the reference standard.

RESULTS

Out of the 30 patients, 17 had no evidence of bone metastases on any imaging modality or on clinical follow-up while the rest of 13 patients showed evidence of bone metastases (nine showing positivity both on (68)Ga-DOTATATE PET and CT scan while four showing positivity only on (68)Ga-DOTATATE PET). Compared with CT scan, (68)Ga-DOTATATE PET detected bone metastases at a significantly higher rate (P = 0.0039). On a per lesion analysis, out of a total of 225 lesions detected by (68)Ga-DOTATATE PET, only 84 lesions could be detected by CT scan.

CONCLUSION

(68)Ga-DOTATATE PET/CT scan is more useful than CECT scan for the early detection of bone metastases in pediatric NETs.

Development of a simple and rapid solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry method for the analysis of dopamine, serotonin and norepinephrine in human urine

The work aims at developing a simple and rapid method for the quantification of dopamine (DA), serotonin (5-HT) and norepinephrine (NE) in human urine. The urinary levels of these biogenic amines can be correlated with several pathological conditions concerning heart disease, stress, neurological disorders and cancerous tumors. The proposed analytical approach is based on the use of solid phase microextraction (SPME) combined with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) after a fast derivatization of both aliphatic amino and phenolic moieties by propyl chloroformate. The variables influencing the derivatization reaction were reliably optimized by the multivariate approach of "Experimental design". The optimal conditions were obtained by performing derivatization with 100μL of propyl chloroformate and 100μL of pyridine. The extraction ability of five commercially available SPME fibers was evaluated in univariate mode and the best results were obtained using the polyacrylate fiber. The variables affecting the efficiency of SPME analysis were again optimized by the multivariate approach of "Experimental design" and, in particular, a central composite design (CCD) was applied. The optimal values were extraction in 45min at room temperature, desorption temperature at 300°C, no addition of NaCl. Assay of derivatized analytes was performed by using a gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) system in selected reaction monitoring (SRM) acquisition. An evaluation of all analytical parameters demonstrates that the developed method provides satisfactory results. Indeed, very good linearities were achieved in the tested calibration range with correlation coefficient values of 0.9995, 0.9999 and 0.9997 for DA, 5-HT and NE, respectively. Accuracies and RSDs calculated for between-run and tested at concentrations of 30, 200, and 800μg L(-1) were in the range from 92.8% to 103.0%, and from 0.67 to 4.5%, respectively. Finally, the LOD values obtained can be considered very good (0.587, 0.381 and 1.23μg L(-1) for DA, 5-HT and NE, respectively).

B3GNT3 expression suppresses cell migration and invasion and predicts favorable outcomes in neuroblastoma

Aberrant expression of the simple mucin-type carbohydrate antigens such as T, Tn, sialyl-T and sialyl-Tn is associated with poor prognosis in several cancers. β1,3-N-acetylglucosaminyltransferase-3 (B3GNT3), a member of the β3GlcNAcT family, is responsible for forming extended core 1 (T antigen) oligosaccharides. The role of B3GNT3, which is expressed in various tissues including human fetal brain, in regulating neuroblastoma (NB) formation and cell behaviors remains unclear. Here, we showed that increased B3GNT3 expression evaluated using immunohistochemistry in NB tumor tissues correlated well with the histological grade of differentiation as well as a favorable Shimada's subset of pathology. Univariate and multivariate analyses revealed that positive B3GNT3 expression in tumor tissues predicted a favorable prognosis in NB patients independent of other prognostic markers. B3GNT3 overexpression suppresses T antigen formation and malignant phenotypes including migration and invasion of SK-N-SH cells, whereas B3GNT3 knockdown enhances these phenotypes of SK-N-SH cells. Moreover, B3GNT3 expression decreased phosphorylation of focal adhesion kinase (FAK), Src, paxillin, Akt and ERK1/2. We conclude that B3GNT3 predicts a favorable cancer behavior of NB and suppresses malignant phenotypes by modulating mucin-type O-glycosylation and signaling in NB cells.

131I-MIBG followed by consolidation with busulfan, melphalan and autologous stem cell transplantation for refractory neuroblastoma

BACKGROUND

(131) I-metaiodobenzylguanidine (MIBG) produces a 37% response rate in relapsed/refractory neuroblastoma, and could be used to improve remission status prior to myeloablative chemotherapy with autologous stem cell transplant (ASCT). The purpose of our report was to evaluate safety and response with MIBG therapy followed by myeloablative busulfan and melphalan (BuMel) with ASCT in patients with refractory neuroblastoma.

METHODS

Retrospective chart review was done on patients treated with MIBG (18 mCi/kg) on Day 1 and ASCT on day 14. Six to eight weeks after MIBG, patients without progressive disease received IV busulfan on days -6 to -2 (target Css 700-900), melphalan (140 mg/m2 IV) on day -1, and ASCT on Day 0. Response and toxicity were evaluated after MIBG and again after myeloablative therapy.

RESULTS

Eight patients completed MIBG/ASCT followed by BuMel/ASCT. MIBG was well tolerated, with grade 3 or 4 non-hematologic toxicity limited to one patient with sepsis. Grade 3 mucositis occurred in six patients after BuMel/ASCT. One patient developed sinusoidal obstructive syndrome (SOS) and died 50 days post-ASCT following myeloablative conditioning. All patients engrafted neutrophils (median 16.5 days) and platelets (median 32 days) after BuMel, excluding the patient with SOS. After all therapy, there were three complete, two partial, and one minor response in seven evaluable patients.

CONCLUSIONS

MIBG at doses up to 18 mCi/kg can be safely administered 6 weeks prior to a BuMel consolidative regimen for refractory neuroblastoma. Preceding MIBG did not impair engraftment following BuMel. This regimen is being further evaluated in a Children's Oncology Group (COG) trial.

Toll-like receptor 3 expression inhibits cell invasion and migration and predicts a favorable prognosis in neuroblastoma

To evaluate the clinical significance of TLR3 expression on neuroblastomas, we performed immunohistochemical study on archival tissues and in vitro studies on neuroblastoma cell lines. The results showed that positive TLR3 expression was associated with favorable histology and prognosis. Activation of TLR3 by polyinosinic:polycytidylic acid [poly(I:C)] treatment is effective to suppress cell migration and invasion and to decrease organized assembly of F-actin and filopodia formation, in TLR3-expressing SK-N-AS cells, which could be reversed by TLR3-targeting siRNA treatment. TLR3 agonist poly(I:C) promotes GAP-43 expression also in SK-N-AS cells only. Taken together, TLR3 could serve to predict favorable behavior in neuroblastomas.