High-risk Neuroblastoma Research Articles

Abstract 4670: True bench-to-bedside science: An international pilot study modeling hard-to-cure pediatric cancers to prioritize therapeutic intervention

Abstract There has been dramatic improvement in treatment outcomes for many pediatric cancers over the last three decades. However, for the 20% of young people with relapsed or refractory cancer, the prognosis remains grim. Canada’s PRecision Oncology For Young peopLE (PROFYLE) and Australia’s Zero Childhood Cancer (ZERO) programs, leverage nation-wide scientific and clinical oncology expertise to provide personalized precision medicine to children, adolescent and young adult (CAYA) cancer patients who lack treatment options. Beyond improving the lives of young cancer patients nationally, PROFYLE and ZERO have partnered to create an international pipeline for knowledge sharing and sample acquisition. A key component of both programs is the use of mice for patient-derived xenografts (PDXs). However, long lead times for mouse PDX generation make the timely return of preclinical drug response data challenging. PROFYLE has uniquely incorporated zebrafish larval xenografts, which have the potential to provide comparable information in a clinically actionable timeframe. In a pilot study, we compared retrospective matched ZERO patient and mouse PDX therapeutic response data with prospective zebrafish larval PDX data as a proof-of-principle that drug efficacy signals were maintained across model systems. Three ZERO avatars: high-risk neuroblastoma, Ewing’s sarcoma, and anaplastic large cell lymphoma were shipped from Australia to Canada and transplanted into 48h casper zebrafish. Following dose optimization, zebrafish PDXs were treated with targeted single and combination drug treatments by immersion therapy. Strikingly, in as little time as a week, cell proliferation rates and drug responses to single agents and combinatorial therapy in zebrafish PDXs recapitulated mouse and patient data. To expand on this pilot project, we tested additional patient samples, including multiple subtypes of sarcomas, T-cell acute lymphoblastic leukemia and an embryonal tumor with multilayered rosettes. Results further validated the practical utility of the zebrafish larval PDX model and in fact provided drug response data when mouse PDX data were unavailable. This study demonstrates the robustness and feasibility of the zebrafish larval PDX model as a preclinical tool for personalized precision therapeutic decision-making and highlights the value of international collaboration in improving outcomes of rare childhood cancers. Citation Format: Nadine Azzam, Nicole Melong, Lissandra Tuzi, Lisa Pinto, Jamie I. Fletcher, Alvin Kamili, Biljana Dumevska, Loretta Lau, Jennifer A. Chan, Donna L. Senger, Stephanie A. Grover, Michelle Haber, David Malkin, Jason N. Berman. True bench-to-bedside science: An international pilot study modeling hard-to-cure pediatric cancers to prioritize therapeutic intervention. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4670.

Abstract 3545: The Yes-associated protein (YAP) regulates GD2 immunotherapy response in high-risk neuroblastoma

Abstract Background Patients with the pediatric solid tumor high-risk neuroblastoma (HR NB) receive intense multimodal therapy yet 50% still relapse with chemotherapy-resistant disease. Relapsed NBs harbor increased RAS/MAPK pathway mutations and increased expression and downstream activity of the transcriptional co-regulator YAP. We have previously shown that YAP mediates resistance to chemotherapy and MEK inhibitors in RAS mutant NBs (Shim et al., Cancer Res 2020). Patients with relapsed NB are treated with the GD2-targeting monoclonal antibody dinutuximab in combination with chemotherapy. Given the increased expression and activity of YAP in relapsed HR NB, we posited that YAP might also play a role in GD2 immunotherapy response. Methods/Results We stably knocked down YAP in the human derived NRAS mutant SK-N-AS NB cell line with a scrambled short hairpin (sh) control or 2 YAP-targeting shRNAs to generate 3 distinct cell lines. Dinutuximab requires antibody-dependent cellular cytotoxicity (ADCC) and we have shown that gamma delta (γδ) T cells augment dinutuximab in aggressive NB models. We exposed the shYAP1, shYAP2, and control SK-N-AS cells to γδ T cells with/without dinutuximab. YAP knockdown sensitized both SK-N-AS shYAP cell lines to γδ T cell killing both in the presence and absence of dinutuximab. To investigate the mechanism of increased dinutuximab sensitivity, we evaluated a panel of NB cell lines (MYCN amplified and MYCN single copy) for YAP protein and GD2 cell surface expression and noted an inverse relationship. That same inverse correlation was found for GD2 and YAP gene expression in primary HR NB tumor datasets. We therefore evaluated GD2 expression following YAP knockdown in SK-N-AS and show that GD2 significantly increased on the cell surface following YAP inhibition. PRRX1 is a master transcription factor that induces a mesenchymal NB phenotype which is one of high YAP expression with very low to no GD2 surface expression. Interestingly, PRRX1 expression increased in YAP knockdown cells yet GD2 expression also increased, suggesting YAP regulates GD2 expression more directly than PRRX1. In the GD2 biosynthesis pathway, GM3 is converted into GD3 by GD3 synthase (GD3S). GD2 synthase then catalyzes GD3 into GD2. GD3S gene (ST8SIA1) expression significantly increased (>100-fold) upon YAP knockdown. Furthermore, shRNA stable inhibition of GD3S in shYAP NB cells reverted the phenotype and decreased GD2 cell surface expression back to baseline. We then treated established SK-N-AS control or shYAP xenografts with an 18-day course of human γδ T cells, dinutuximab, and cyclophosphamide. Pilot results show significantly extended survival in mice harboring SK-N-AS shYAP tumors. Conclusion These results support YAP regulation of GD2 expression through transcriptional suppression of GD3 synthase and identify YAP as a therapeutic target to augment GD2 immunotherapy responses in HR and relapsed NB. Citation Format: Adeiye A. Pilgrim, Hunter C. Jonus, Andrew Ho, Anna Cole, Jenny Shim, Kelly C. Goldsmith. The Yes-associated protein (YAP) regulates GD2 immunotherapy response in high-risk neuroblastoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3545.

Abstract 3552: YAP-TEAD2 binding mediates therapy resistance in RAS-driven neuroblastoma

Abstract Background/Objectives: Despite intensive multimodal therapy, greater than 50% of children with high-risk neuroblastoma (HR NB) relapse with incurable disease. Next generation sequencing of primary HR NB tumors identified an increase in activating mutations in the RAS/RAF/MAPK pathway. Moreover, gene set enrichment analyses showed a significant decrease in expression of genes suppressed by the Yes-Associated Protein (YAP) at relapse, suggesting increased YAP transcriptional repression. YAP binds with TEAD family transcription factors to regulate gene expression. We have shown that YAP promotes chemotherapy and MEK inhibitor resistance in RAS-mutated NB tumors in vivo by suppressing the expression of Harakiri (HRK), a BH3-only pro-apoptotic protein activated in response to tumor environmental stress such as serum starvation. Our overall objective is to elucidate how YAP represses HRK and tumor suppressor genes globally, and to enhance MEK inhibitor potency by combining MEK inhibition with agents that inhibit YAP or induce HRK to restore the tumor environmental stress response and apoptosis in RAS-mutated NB. Design/Methods: We used publicly available databases to identify TEAD binding sites on the HRK gene locus in NB. To assess the global state of methylation, we treated NB cells, SK-N-AS (NRASQ61K mutation, MYCN non-amplified) and NLF (NF1 deletion, MYCN amplified), with demethylating agent azacitidine and evaluated HRK expression. To identify the specific TEAD (1-4) binding partner to YAP, we performed siRNA and co-immunoprecipitation studies. We further tested novel YAP-TEAD small molecule inhibitors with varying TEAD1-4 inhibition specificity in SK-N-AS and NLF cells in vitro. Results: We observed that TEAD binds near cis-regulatory regions on the HRK gene locus in NB. We found that HRK expression is restored when SK-N-AS and NLF cells are treated with azacitidine despite YAP expression increasing. We also identified TEAD2 as the specific binding partner to YAP in NB and found that TEAD2 is necessary for HRK regulation. Novel YAP-TEAD small molecule inhibitors affect NB cell viability under serum-deprived conditions in vitro, especially the inhibitor with highest specificity against TEAD2, and affect YAP-TEAD downstream targets. Conclusions: YAP-TEAD2 binding is essential for HRK regulation in RAS-mutated NB and thus is a logical therapeutic target to restore therapy response. Further studies are ongoing to test YAP-TEAD small molecule inhibitors in combination with MEK inhibitors and in vivo. Citation Format: Jenny Shim, Andrew Ho, Hunter C. Jonus, Adeiye A. Pilgrim, Benjamin G. Barwick, Tracy T. Tang, Lawrence H. Boise, Kelly C. Goldsmith. YAP-TEAD2 binding mediates therapy resistance in RAS-driven neuroblastoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3552.

Abstract 4517: Novel prognostic and predictive biomarker for neuroblastoma

Abstract Recently we showed that Retinal degeneration protein 3 (RD3) is constitutively expressed in healthy adult and fetal tissues beyond retina and, its gradient expression from high to low in ganglioneuroma, ganglioneuroblastoma and neuroblastoma (NB). Crucially, our sequential in vitro and in vivo studies identified that RD3 regulates NB progression and metastasis, and its loss prompts the evolution of therapy defying progressive disease (PD). Here we investigated the prognostic significance of RD3 in NB, its predictive benefit and, its association to clinical outcomes. RNA-Seq data mining (4 independent study cohorts, total n = 1013) indicated that high RD3 can predict good NB prognosis. RD3 expression (immunohistochemistry) gauged in our NB patient cohort (n = 100) showed a positive correlation with longer overall survival (OS, P = 1.0E-04) and relapse-free survival (RFS, P = 2.1E-02). Similarly, high RD3 correlated with longer OS (P = 1.2E-03) and RFS (P = 2.1-02) in children presented with high-risk NB (HR-NB), irrespective of MYCN amplification status (MYCN amplified, P = 1.4E-02; non-amplified, P = 5.5E-03) and patient age (<2Y age, P = 2.8E-02; >2Y age, P = 1.0E-04) groups. Significantly, we observed a gradient loss of RD3 with NB progression, from stage 1 through stage 4 disease. Consistently, RD3 loss was substantial in metastatic disease when compared to the primary neuroblastomas, and this loss associated with poor OS in patients presented with metastatic disease (P = 4.0E-02). More importantly, RD3 is significantly lost in therapy resistant progressive NB and corroborated significantly (P = 9.5E-03) with the poor progression free survival. Multivariate analysis identified RD3 as an independent (P = 4.4E-02) prognostic factor for NB. These results demonstrate that RD3-loss can forecast poor prognosis in NB, and further imply that assessing RD3 loss could serve as the good predictor for therapy response and/or PD evolution. Together, these data identify a novel prognostic and predictive factor for neuroblastoma. Funding: This work was partially or in full, funded by Oklahoma Center for the Advancement of Science and Technology, OCAST-HR19-045; National Institutes of Health, NIH-P20GM103639 and Department of Defense DoD-CA210339 Citation Format: Dinesh Babu Somasundaram, Zhongxin Yu, Ashley Baker, Natarajan Aravindan. Novel prognostic and predictive biomarker for neuroblastoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4517.

Abstract 481: Investigating molecular glues as a new therapeutic approach to high-risk neuroblastoma

Abstract High-risk neuroblastoma (NB) is the most common extracranial solid tumor of childhood. Despite extensive study, treatments remain highly toxic and are often insufficient to cure. Thus, there is an urgent need to develop more effective and less toxic treatments for children with NB. NB commonly displays reliance on a relatively small cohort of transcription factors (TFs) and epigenetic proteins to drive cell growth, however, many of these targets are inaccessible with conventional small molecules. In recent years, new modalities such as targeted protein degradation (TPD) have emerged. TPD may permit small molecule degradation of traditionally “undruggable” targets, such as TFs. This makes TPD a particularly attractive modality for defining new therapeutic strategies for high-risk NB. One category of TPD agents are molecular glues (MGs). MGs are monovalent small molecules capable of simultaneously binding to an E3 ligase receptor such as CRBN (cereblon), and a target protein of interest. Importantly, in comparison to conventional protein inhibitors, MGs do not require a conventional binding pocket on the protein of interest to bind to it, and can be utilized in sub-stoichiometric concentrations. Thus, this may result in the recruitment, polyubiquitination, and subsequent proteasomal degradation of proteins previously thought to be “undruggable.” Here, we demonstrate that high-risk NB cells are critically sensitive to a cluster of previously unknown MGs. We performed high-throughput screening of a proprietary library (>4000 unique compounds) of MGs in two MYCN-amplified NB cell lines, Kelly and MHHNB11. These two cell lines demonstrate a strikingly close correlation in Cell-Titer Glo-based growth response to MGs, as compared with an outgroup of other MG-responsive cancer cell lines. We identified a unique subcluster of 112 common MGs that display >70% growth inhibition in both cell lines. To identify the mechanism of cell growth inhibition, we established Kelly cells with stable knockout of CRBN, and coupled these with screening to confirm that the majority of these MGs (84%; 94/112) require CRBN expression. To rule out common off-target effects of MGs, candidate compounds were then tested in cells transgenically expressing either wild-type or degradation-resistant GSPT1 (G575N) constructs, revealing a subset of MGs retaining cytotoxicity without effecting GSPT1 protein levels. Current studies are focused on determining the targets of these high confidence MGs, as a foundation for preclinical in vivo studies. These studies will identify new compounds with defined mechanisms of action, with an ultimate goal of developing new treatments that are more effective and less toxic for children with NB. Citation Format: Ian Delahunty, Gisele Nishiguchi, Yang Zhang, Abigail Fish, Anand Mayasundari, Jun Qi, Brian Abraham, Anang Shelat, Zoran Rankovic, Adam Durbin. Investigating molecular glues as a new therapeutic approach to high-risk neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 481.

Abstract 4923: Prostaglandin E2 receptor EP2: A novel target for high-risk neuroblastoma

Abstract Neuroblastoma (NB) is the most common pediatric extracranial solid tumor. Based on tumor stage and histological features, 50% of NBs are classified as high-risk diseases, a subtype characterized by a quite unsatisfactory long-term survival even with the striking advances in NB management that have been achieved in the past decades. Cyclooxygenase-2/prostaglandin E2 (COX-2/PGE2) cascade has been reported to foster a proinflammatory tumor-nourishing microenvironment in NB. However, the specific downstream PGE2 receptor (EP) subtype which directly mediates this tumor promoting effect remains elusive. Therefore, in our research, we aim to 1) elucidate the culprit EP receptor that is directly involved in NB development; 2) evaluate the feasibility of inhibiting the PGE2 receptor subtype as a novel treatment strategy for high-risk NB. To start with, we analyzed the gene expression profiles of the COX2/PGE2/EP pathway from four major NB datasets (Versteeg, Kocak, SEQC, and NRC) on R2 platform. It indicates that the COX-2/PGE2/EP2 signaling axis is highly associated with the expression of high-risk NB markers, as well as an abysmal overall survival rate. Moreover, a time resolved fluorescence resonance energy transfer (TR-FRET) method was adopted to reveal that EP2 receptor is the key Gαs-coupled receptor that mediates PGE2-initiated cAMP signaling in high-risk NB cell lines. Genetic interference of EP2 receptor expression by CRISPR/Cas9-mediated genome editing and doxycycline induced conditional knockdown significantly inhibited high-risk NB development and progression both in neuro-sphere formation assay and in nude mice xenograft models. Finally, we tested the anti-NB efficacy of our recently developed selective and bioavailable small-molecule EP2 antagonists. With a consecutive treatment of three weeks, decreased tumor size and weight have been observed in both high-risk NB xenograft model and immunocompetent allograft model, simultaneously with decreased inflammation, angiogenesis, and enhanced apoptosis. Collectively, our results suggest that the PGE2/EP2 pathway contributes to the growth and malignant potential of high-risk NB; pharmacological inhibition on EP2 receptor by our drug-like compounds might provide a novel therapeutic strategy for this deadly pediatric cancer. Citation Format: Ruida Hou, Ying Yu, Jun Yang, Jianxiong Jiang. Prostaglandin E2 receptor EP2: A novel target for high-risk neuroblastoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4923.

Abstract 3407: The italian personalized medicine program PREME for high-risk neuroblastoma

Abstract Background: In the era of precision medicine, the need for high-risk neuroblastoma (NB) patient-specific therapies is crucial. Methods: From November 2018 to February 2021, the Italian PeRsonalizEd MEdicine (PREME) program has enrolled 18 NB affected patients. Tumors and bone marrow-infiltrating NB cells underwent to histological (selection panel: CD45, CD56, TH, PHOX-2B, S100) and to flow cytometry (selection panel: CD45, CD56, GD2, B7-H3) immunophenotyping, respectively. The biological material was then used for: 1) DNA extraction for subsequent DNAseq (Whole Exome Sequencing, 100X mean coverage, or Deep Targeted Gene Panel Sequencing, 1000x mean coverage, when the percentage of the neoplastic counterpart within the sample was over or down 60%, respectively); 2) RNA extraction for subsequent RNAseq (30 millions of reads per sample); 3) Development of primary NB cell culture (3D/tumor-spheres) and of Patient-Derived Xenografts (PDX) models in mice (both stored in local Bio-banks). Results: 14 out of 18 patients (77.7%) had one or more potentially actionable somatic alterations in primary tumors. Among those, 4 had also one pathogenic germline variant in known cancer predisposition genes. In 11 of the 14 cases the Molecular Tumor Board identified molecular alterations potentially targetable by an approved or investigational agent, and 4 of those received the treatment. Out of 11 tumor samples implanted in mice, 5 gave rise to PDX, all preserved in a local PDX Bio-bank. Comparing all genomic variants of the 5 tumors with developed PDX samples up to second generation, we observed a high grade of similarity among primary tumors and subsequent PDX tumor models (Pearson coefficients>0.8). Considered the allele frequency distribution, a significant increase in the PDX tumor models at first generation (G1) (median=0.008) and second generations (G2) (median=0.038) with respect to the primary tumors (G0) (median=0.034) was observed. The validity and reproducibility of our PDX models was further demonstrated from high rates of conserved somatic variants at G1 compared to G0 tumors (mean=81.93%), at G2 compared to G1 (mean=84.04%) and at G2 compared to G0 tumors (mean=78.31%). Finally, we were able to identify all the potentially actionable genetic alterations of G0 tumors in the PDX generations G1 and G2. A high grade of similarity was confirmed when the histological, the immunophenotypic and the transcriptomic profiles among primary tumors and PDX generations were compared. Also, NB cells grown as 3D demonstrated good rates of conserved somatic variants, paving the way to the creation of a Bio-bank of patient-derived tumor-spheres. The development of a bioinformatics pipeline for RNAseq data analysis is ongoing. Conclusions: Until now, PREME program has reported a large number of NB patient samples, which harbor targetable genomic alterations and has allowed the development of a Bio-banks to be used for translational research. Citation Format: Mario Capasso, Chiara Brignole, Veronica Bensa, Vito Alessandro Lasorsa, Enrico Sebastiani, Sueva Cantalupo, Angela Rita Sementa, Katia Mazzocco, Barbara Cafferata, Valerio Gaetano Vellone, Michele Cilli, Enzo Calarco, Elena Giusto, Eleonora Ciampi, Patrizia Perri, Maria Valeria Corrias, Sanja Aveic, Doriana Fruci, Alessandro Quattrone, Annalisa Tondo, Roberto Luksch, Rossella Mura, Marco Rabusin, Francesco De Leonardis, Monica Cellini, Paola Coccia, Massimo Conte, Loredana Amoroso, Alberto Garaventa, Mirco Ponzoni, Fabio Pastorino. The italian personalized medicine program PREME for high-risk neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3407.

Abstract 2593: A MYCN-independent mechanism mediating secretome reprogramming and metastasis in MYCN-amplified neuroblastoma

Abstract MYCN amplification (MNA) is a defining feature of high-risk neuroblastoma (NB) that predicts poor prognosis. However, whether genes within or in close proximity to the MYCN amplicon also contribute to aggressiveness in MNA+ NB remains poorly understood. Here we identify that GREB1, a transcription factor encoding gene neighboring the MYCN locus, is frequently co-expressed with MYCN, and promotes gene expression independently of MYCN in MNA+ NB. We found that GREB1, as a crucial estrogen receptor (ER) regulatory factor, is highly expressed in MNA+ NB comparable to ER+ breast cancer. Among GREB1-regulated genes altered in MNA+ NB, we uncover that Myosin 1B (MYO1B) promotes aggressive features in MNA+ NB, including invasive capacity in vitro, as well as extravasation and distant metastasis in vivo. Global secretome and proteome profiling uncover MYO1B as a major regulator of secretome reprogramming in MNA+ NB cells. Moreover, we identify the cytokine MIF as an important pro-invasive and pro-metastatic mediator of MYO1B activity. Together, we have identified a putative GREB1-MYO1B-MIF axis as an unconventional mechanism that promotes the aggressiveness of MNA+ NB, and independently of MYCN. Furthermore, we found that MYO1B is also upregulated in association with other oncoproteins during cellular transformation, and is dramatically increased in multiple human cancer types, suggesting a crucial role of MYO1B in cancers in addition to MNA+ NB. Citation Format: Hai-Feng Zhang, Alberto Delaidelli, Sumreen Javed, Busra Turgu, Christopher S. Hughes, Xiaqiu Yang, Michael Lizardo, Daniel Martinez, John M. Maris, Kristopher R. Bosse, Karla C. Williams, Poul H. Sorensen. A MYCN-independent mechanism mediating secretome reprogramming and metastasis in MYCN-amplified neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2593.

Abstract 911: Butyrophilin 3A2 expression plays a critical role in phosphoantigen-mediated γδ T cell cytotoxicity of neuroblastoma cells

Abstract The clinical use of antibodies targeting the diaslganglioside GD2 improved survival and clearly identified a role for immunotherapy in the aggressive pediatric solid tumor neuroblastoma (NB). Even so, the 5-year survival rate for high risk patients remains 50%, warranting novel immunotherapeutic approaches. Given their MHC-independent cytotoxic activity towards transformed cells, γδ T cells are attractive tools for adoptive cellular immunotherapy. γδ T cell cytotoxicity is mediated through the expression of various activating receptors that contribute to multiple mechanisms of anti-tumor activity. Specifically, their expression of the γδ-TCR works in concert with tumor expression of members of the butyrophilin-3 (BTN3A) subfamily for cytotoxicity in response to phosphoantigens (pAg). In other cancers, stimulation of pAg production through zoledronate (ZOL) supplementation promotes γδ T cell recognition/killing. We have identified that γδ T cells are differentially cytotoxic towards NB cell lines, suggesting variations in expression of key players responsible for γδ T cell susceptibility. This work serves to understand the significance of BTN3A members in NB, and their impact on the susceptibility of NB to γδ-TCR mediated killing. It is hypothesized that the pAg-mediated response can be augmented by increasing intracellular pAg via use of ZOL or by manipulating BTN3A members. To test this, NB cells were pre-treated with either vehicle or ZOL for 24 hours and then co-incubated with expanded γδ T cells for 4 hours at various effector:target (E:T) ratios. Apoptotic death was then determined for NB cells using Annexin-V/7-AAD staining. Across 8 tested NB cell lines, Kelly, NB-1643, NGP, SK-N-AS, SH-SY5Y, NLF, and SMS-SAN cells were resistant to γδ T cells at a 10:1 E:T ratio when untreated with ZOL. IMR-5 demonstrated 12-18% lysis at a 5:1 E:T. When NB cells were pre-treated with ZOL, γδ T cell cytotoxicity was enhanced towards all models except SK-N-AS. We identified three NB cell lines with differential susceptibility to γδ T cell killing, SK-N-AS<NLF<IMR5. Using a high-risk NB gene expression dataset, expression of important BTN members was queried, revealing IMR5 to have BT3.2low expression, NLF to have BT3.2mod expression, and SK-N-AS to have BT3.2high expression. BT3.2 expression levels was confirmed via western blotting. It has been postulated that BT3.2 may be a decoy receptor that interacts with γδ T cells without intracellular signaling, given it lacks the intracellular pAg sensor. Due to its high expression in SK-N-AS, a lentiviral system was used to knockdown BT3.2. SK-N-A-S shBT3.2 models had 48-55% lysis at a 5:1 E:T when untreated and 65-72% lysis when pre-treated with ZOL. In summary, the anti-NB γδ T cell response can be augmented with ZOL pre-treatment. Additionally, the expression of BT3.2 may be responsible for differential sensitivity of NB cell lines to γδ T cells. Citation Format: Andrew Ho, Hunter C. Jonus, Kelly C. Goldsmith. Butyrophilin 3A2 expression plays a critical role in phosphoantigen-mediated γδ T cell cytotoxicity of neuroblastoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 911.

Hospitalizations in Australian children with neuroblastoma: A population-based study.

An increasing number of children diagnosed with both low- and high-risk neuroblastoma are surviving. Yet, treatment can be intensive and often multimodal, especially for high-risk neuroblastoma, resulting in significant long-term health problems. We aimed to describe neuroblastoma survivors' pediatric hospitalizations, readmissions, and their associated costs. We conducted a population-based study of all children (<18 years) residing in New South Wales (NSW), Australia, and hospitalized with a recorded diagnosis of neuroblastoma during 2001-2020. We used linked NSW Admitted Patient Data Collection and death registration data to examine the frequency, length of stay, and readmissions following the first admission when neuroblastoma was diagnosed (i.e., the index admission), and the associated hospitalization costs by age and timing postindex admission discharge. In total, 300 children (64% aged <3 years) were hospitalized for neuroblastoma over the study period. The median number of readmissions and length of stay within 2 years postdischarge were 17 (interquartile range IQR: 5.5-25) and 45.5 (IQR: 10-125) days, and median cost per child was AUD$124,058 (IQR $34,217-$264,627). Following discharge from the index admission, there were 7088 readmissions (median: 20 per child, IQR: 7-29). Fifty-eight percent of readmissions occurred within 1-year postdischarge, primarily due to fever, nausea, abdominal pain, and respiratory conditions. The burden of health problems requiring hospitalization among neuroblastoma survivors results in significant associated healthcare costs, warranting further efforts to optimize health care for neuroblastoma survivors that focuses on early intervention and long-term monitoring.

Clonal evolution during metastatic spread in high-risk neuroblastoma

Clonal evolution during metastatic spread in high-risk neuroblastoma

Survival effect of complete surgical resection of the primary tumor in patients with metastatic, high-risk neuroblastoma in a large Canadian cohort.

To determine whether extent of surgical resection of the primary tumor correlates with survival in patients with International Neuroblastoma Staging System (INSS) stage 4, high-risk neuroblastoma. Data were extracted for patients with newly diagnosed INSS stage 4, high-risk neuroblastoma between 2001 and 2019 from the national Cancer in Young People in Canada (CYPC) database. Complete resection was defined as gross total resection of primary tumor based on operative reports. Primary endpoints were 3 and 5-year event-free (EFS) and overall survival (OS). Survival analyses were completed using log-rank test and Cox proportional hazards regression including covariates of age, sex, decade of treatment (2001-2009vs. 2010-2019), immunotherapy, and tandem stem cell transplant (SCT). One-hundred and forty patients with complete surgical data were included. On univariate analysis, 3-year EFS and OS for patients that had complete versus incomplete resection was 71% (95% CI 57-80%) vs. 48% (36-60%) and 86% (75-93%) vs. 64% (51-74%), p=.008 and p=.002, respectively. 5-year EFS and OS for patients with complete resection also demonstrated significantly improved survival. On Cox Proportional Hazards models adjusted for age, immunotherapy, tandem SCT, and surgical resection, only complete resection was associated with statistically significant improved 3year EFS and OS, HR=0.48 (0.29-0.81; p=.006) and HR=0.42 (0.24-0.73; p=.002). In a large Canadian INSS stage 4 high-risk neuroblastoma cohort, complete surgical resection was associated with increased EFS and OS. Within the constraints of a retrospective study, these results suggest that the ability to achieve primary tumor complete resection in patients with metastatic high-risk disease is associated with improved survival.

BI-D1870 Induces Mitotic Dysfunction and Apoptosis in Neuroblastoma by Regulating the PI3K-Akt-mTORC1 Signal Axis

Introduction: Neuroblastoma (NB) is one of the most common extracranial solid malignant tumors in children. The 5-year survival rate of high-risk or refractory NB is less than 50%. Therefore, developing new effective therapeutics for NB remains an urgent challenge. Materials and Methods: Based on the NB dataset TARGET-NBL in the TCGA database, the prognosis-related genes were analyzed using univariate cox regression (p < 0.01). The protein network interaction of prognostic genes was analyzed using STRING to obtain 150 hub genes with HR > 1 and 150 hub genes with HR < 1. The Connectivity Map database was used to predict a therapeutic drug: BI-D1870, a ribosomal S6 kinase inhibitor. The inhibitory effect of BI-D1870 on NB was investigated through in vivo and in vitro experiments, and its inhibitory mechanism was explored. Results: Both the in vivo and in vitro experiments showed that BI-D1870 could inhibit tumor proliferation and induce tumor apoptosis. Furthermore, we proved that BI-D1870 caused G2/M phase arrest and mitosis damage in cells. RNA-seq of cells showed that BI-D1870 may inhibit the growth of NB by inhibiting the PI3K-Akt-mTOR axis. Western blot and immunofluorescence testing showed that BI-D1870 inhibited the PI3K-Akt-mTORC1 signal pathway to regulate the phosphorylation of RPS6 and 4E BP1 proteins, inhibit protein translation, and inhibit microtubule formation, thus preventing mitotic proliferation and inducing apoptosis. Conclusions: This study provides strong support that BI-D1870 may be a potential adjuvant therapy for NB.

Prognostic value of xenograft engraftment in patients with metastatic high-risk neuroblastoma.

Successful engraftment of human cancer biopsies in immunodeficient mice correlates with the poor prognosis of patients. This was reported 30 years ago for children with neuroblastoma, but the standard of care treatment evolved significantly during the last 15 years, leading to improved survival of these patients. Here, we evaluated the association of patient-derived xenograft (PDX) engraftment and prognosis in patients receiving up-to-date treatments for cancers classified as metastatic (stage M) high-risk neuroblastoma (HR-NB) by the International Neuroblastoma Risk Group Staging System (INRGSS). We obtained biopsies from patients with stage M HR-NB. We inoculated biopsy fragments subcutaneously in mice. We studied the association of PDX engraftment with event-free survival (EFS) and overall survival (OS) of patients. Since 2009, we established 17 PDX from 97 samples of 66 patients with stage M HR-NB, with a follow-up of at least two years. Factors associated with higher probability of engraftment were the death as outcome (p=.0006) and the amplification of the gene MYCN in tumors (p=.0271). Patients whose biopsies established a PDX had significantly shorter EFS and OS (p=.0039 and .0002, respectively) than patients whose samples did not engraft. The association of PDX engraftment and OS was significant in patients without MYCN amplification (p=.0041), but not in patients with MYCN amplification (p=.2707). Positive PDX engraftment is a factor related to poor prognosis and fatal outcome in patients with stage M HR-NB treated with up-to-date therapies.

Potential Treatment Options for Neuroblastoma with Polyphenols through Anti-Proliferative and Apoptotic Mechanisms.

Neuroblastoma (NB) is an extracranial tumor of the peripheral nervous system arising from neural crest cells. It is the most common malignancy in infants and the most common extracranial solid tumor in children. The current treatment for high-risk NB involves chemotherapy and surgical resection followed by high-dose chemotherapy with autologous stem-cell rescue and radiation treatment. However, those with high-risk NB are susceptible to relapse and the long-term side effects of standard chemotherapy. Polyphenols, including the sub-class of flavonoids, contain more than one aromatic ring with hydroxyl groups. The literature demonstrates their utility in inducing the apoptosis of neuroblastoma cells, mostly in vitro and some in vivo. This review explores the use of various polyphenols outlined in primary studies, underlines the pathways involved in apoptotic activity, and discusses the dosage and delivery of these polyphenols. Primary studies were obtained from multiple databases with search the terms "neuroblastoma", "flavonoid", and "apoptosis". The in vitro studies showed that polyphenols exert an apoptotic effect on several NB cell lines. These polyphenols include apigenin, genistein, didymin, rutin, quercetin, curcumin, resveratrol, butein, bisphenols, and various plant extracts. The mechanisms of the therapeutic effects include calpain-dependent pathways, receptor-mediated apoptosis, and, notably, and most frequently, mitochondrial apoptosis pathways, including the mitochondrial proteins Bax and Bcl-2. Overall, polyphenols demonstrate potency in decreasing NB proliferation and inducing apoptosis, indicating significant potential for further in vivo research.

Prognostic Values of Primary Tumor Textural Heterogeneity and Blood Biomarkers in High-risk Neuroblastoma.

The aim of this study was to evaluate the prognostic value of textural parameters of primary tumors, serum lactate dehydrogenase (LDH), D -dimer, and ferritin in high-risk neuroblastoma patients. The imaging findings of 22 neuroblastoma patients (14 girls and 8 boys; age, 36.6 ± 34.2 [range: 5 to 138] months) who underwent 18-fluorodeoxyglucose positron emission tomography/computed tomography for primary staging before therapy between 2009 and 2020 were retrospectively evaluated. Positron emission tomography-derived metabolic data (maximum standard uptake value, mean standard uptake value, metabolic tumor volume, and total lesion glycolysis) and textural features of primary tumors were obtained. Serum LDH, D -dimer, and ferritin levels at the time of diagnosis were recorded. Univariate and multivariate Cox proportional hazards regression models were used to identify predictors for progression-free survival (PFS) and overall survival (OS). Survival curves were estimated by using the Kaplan-Meier method. The median follow-up duration after diagnosis was 63 months (range: 5 to 141mo). The median PFS and OS in all patients were 19 and 72 months, respectively. In multivariate Cox regression analyses with backward stepwise selection, grey level size zone matrix_size zone emphasis (GLSZM_SZE) was found as an independent predictor for both PFS and OS. Serum ferritin level was also found as an independent predictor for PFS. The Kaplan-Meier survival analysis showed that higher serum LDH, D -dimer, GLSZM_SZE, and zone size nonuniformity were significantly associated with shorter OS. Serum LDH, D -dimer, ferritin levels, and GLSZM_SZE of primary tumors may be used as prognostic biomarkers to identify patients with worse prognoses in high-risk neuroblastoma. GLSZM textural features showing higher tumor heterogeneity are significantly associated with shorter PFS and OS.

Evaluating the RIST Molecular-Targeted Regimen in a Three-Dimensional Neuroblastoma Spheroid Cell Culture Model.

The outcome for patients with high-risk neuroblastoma remains poor and novel treatment strategies are urgently needed. The RIST protocol represents a novel metronomic and multimodal treatment strategy for high-risk neuroblastoma combining molecular-targeted drugs as 'pre-treatment' with a conventional chemotherapy backbone, currently evaluated in a phase II clinical trial. For preclinical drug testing, cancer cell growth as spheroid compared to mo-nolayer cultures is of advantage since it reproduces a wide range of tumor characteristics, including the three-dimensional architecture and cancer stem cell (CSC) properties. The objective of this study was to establish a neuroblastoma spheroid model for the rigorous assessment of the RIST treatment protocol. Evaluation of CSC marker expression was performed by mRNA and protein analysis and spheroid viability by luminescence-based assays. Aberrant expression of RNA-binding protein La in neuroblastoma was assessed by tissue microarray analysis and patients' data mining. Spheroid cultures showed increased expression of a subgroup of CSC-like markers (CXCR4, NANOG and BMI) and higher Thr389 phosphorylation of the neuroblastoma-associated RNA-binding protein La when compared to monolayer cultures. Molecular-targeted 'pre-treatment' of spheroids decreased neoplastic signaling and CSC marker expression. The RIST treatment protocol efficiently reduced the viability of neuroblastoma spheroids characterized by advanced CSC properties.

Monocyte and Macrophage in Neuroblastoma: Blocking Their Pro-Tumoral Functions and Strengthening Their Crosstalk with Natural Killer Cells.

Over the past decade, immunotherapy has represented an enormous step forward in the fight against cancer. Immunotherapeutic approaches have increasingly become a fundamental part of the combined therapies currently adopted in the treatment of patients with high-risk (HR) neuroblastoma (NB). An increasing number of studies focus on the understanding of the immune landscape in NB and, since this tumor expresses low or null levels of MHC class I, on the development of new strategies aimed at enhancing innate immunity, especially Natural Killer (NK) cells and macrophages. There is growing evidence that, within the NB tumor microenvironment (TME), tumor-associated macrophages (TAMs), which mainly present an M2-like phenotype, have a crucial role in mediating NB development and immune evasion, and they have been correlated to poor clinical outcomes. Importantly, TAM can also impair the antibody-dependent cellular cytotoxicity (ADCC) mediated by NK cells upon the administration of anti-GD2 monoclonal antibodies (mAbs), the current standard immunotherapy for HR-NB patients. This review deals with the main mechanisms regulating the crosstalk among NB cells and TAMs or other cellular components of the TME, which support tumor development and induce drug resistance. Furthermore, we will address the most recent strategies aimed at limiting the number of pro-tumoral macrophages within the TME, reprogramming the TAMs functional state, thus enhancing NK cell functions. We also prospectively discuss new or unexplored aspects of human macrophage heterogeneity.

Correlation between ARID1B gene mutation (p.A460, p.V215G) and prognosis of high-risk refractory neuroblastoma.

In a few reports, ARID1B/A mutation was found in neuroblastoma. We analyzed the clinical characteristics, clinical efficacy, and prognosis of three children with high-risk refractory neuroblastoma (NB) with somatic ARID1B gene mutation. The whole exon sequencing results showed that there were involved in transcription, DNA synthesis, and repair of ARID1B gene mutations. All mutation sites were located in the promoter region of the exon: ARID1B (p.A460) mutation was found in cases 1 and 2, and ARID1B (p.V215G) mutation was found in cases 1 and 3. The nucleic acid site of ARID1B (p.A460) mutation was c.1379 (exon1) C > G, and the nucleic acid site of ARID1B (p.V215G) mutation was c.644 (exon1) T > G. The meningeal metastasis in case 1 turned negative after 4 cycles of intrathecal injection combined with chemotherapy. However, the child died of agranulocytosis combined with sepsis during the 5th cycle of chemotherapy. Case 2 achieved complete remission (CR). Case 3 achieved CR after chemotherapy, surgery, metaiodobenzylguanidine, and 3F-8 (Naxitamab) immunotherapy after the initial diagnosis. The mediastinum and lymph node metastasis occurred during the 6-month observation period after stopping treatment. He achieved very good partial remission after individualized chemotherapy and surgical treatment. ARID1B is a component protein of the SWI/SNF chromatin-remodeling complex that participates in the occurrence of a variety of tumors by regulating DNA repair and synthesis. ARID1B nucleic acid mutation (p.A460, p.V215G) in the promoter region of three children may contribute to the poor prognosis of NB children.

SOX11 regulates SWI/SNF complex components as member of the adrenergic neuroblastoma core regulatory circuitry

The pediatric extra-cranial tumor neuroblastoma displays a low mutational burden while recurrent copy number alterations are present in most high-risk cases. Here, we identify SOX11 as a dependency transcription factor in adrenergic neuroblastoma based on recurrent chromosome 2p focal gains and amplifications, specific expression in the normal sympatho-adrenal lineage and adrenergic neuroblastoma, regulation by multiple adrenergic specific (super-)enhancers and strong dependency on high SOX11 expression in adrenergic neuroblastomas. SOX11 regulated direct targets include genes implicated in epigenetic control, cytoskeleton and neurodevelopment. Most notably, SOX11 controls chromatin regulatory complexes, including 10 SWI/SNF core components among which SMARCC1, SMARCA4/BRG1 and ARID1A. Additionally, the histone deacetylase HDAC2, PRC1 complex component CBX2, chromatin-modifying enzyme KDM1A/LSD1 and pioneer factor c-MYB are regulated by SOX11. Finally, SOX11 is identified as a core transcription factor of the core regulatory circuitry (CRC) in adrenergic high-risk neuroblastoma with a potential role as epigenetic master regulator upstream of the CRC.