Secreted protein acidic and rich in cysteine (SPARC) induces lipotoxicity in neuroblastoma by regulating transport of albumin complexed with fatty acids

SPARC is a matrix protein that mediates interactions between cells and the microenvironment. In cancer, SPARC may either promote or inhibit tumor growth depending upon the tumor type. In neuroblastoma, SPARC is expressed in the stromal Schwannian cells and functions as a tumor suppressor. Here, we developed a novel in vivo model of stroma-rich neuroblastoma using non-tumorigenic SHEP cells with modulated levels of SPARC, mixed with tumorigenic KCNR cells. Tumors with stroma-derived SPARC displayed suppressed growth, inhibited angiogenesis and increased lipid accumulation. Based on the described chaperone function of SPARC, we hypothesized that SPARC binds albumin complexed with fatty acids and transports them to tumors. We show that SPARC binds albumin with Kd=18.9±2.3 uM, and enhances endothelial cell internalization and transendothelial transport of albumin in vitro. We also demonstrate that lipids induce toxicity in neuroblastoma cells and show that lipotoxicity is increased when cells are cultured in hypoxic conditions. Studies investigating the therapeutic potential of SPARC are warranted.

Identification of different ALK mutations in a pair of neuroblastoma cell lines established at diagnosis and relapse

Anaplastic Lymphoma Kinase (ALK) is a transmembrane receptor kinase that belongs to the insulin receptor superfamily and has previously been shown to play a role in cell proliferation, migration and invasion in neuroblastoma. Activating ALK mutations are reported in both hereditary and sporadic neuroblastoma tumours, and several ALK inhibitors are currently under clinical evaluation as novel treatments for neuroblastoma. Overall, mutations at codons F1174, R1275 and F1245 together account for ~85% of reported ALK mutations in neuroblastoma. NBLW and NBLW-R are paired cell lines originally derived from an infant with metastatic MYCN amplified Stage IVS (Evans Criteria) neuroblastoma, at diagnosis and relapse, respectively. Using both Sanger and targeted deep sequencing, this study describes the identification of distinct ALK mutations in these paired cell lines, including the rare R1275L mutation, which has not previously been reported in a neuroblastoma cell line. Analysis of the sensitivity of NBLW and NBLW-R cells to a panel of ALK inhibitors (TAE-684, Crizotinib, Alectinib and Lorlatinib) revealed differences between the paired cell lines, and overall NBLW-R cells with the F1174L mutation were more resistant to ALK inhibitor induced apoptosis compared with NBLW cells. This pair of cell lines represents a valuable pre-clinical model of clonal evolution of ALK mutations associated with neuroblastoma progression.

Data Commons to Support Pediatric Cancer Research

The falling costs and increasing fidelity of high-throughput biomedical research data have led to a renaissance in cancer surveillance and treatment. Yet, the amount, velocity, and complexity of these data have overcome the capacity of the increasing number of researchers collecting and analyzing this information. By centralizing the data, processing power, and tools, there is a valuable opportunity to share resources and thus increase the efficiency, power, and impact of research. Herein, we describe current data commons and how they operate in the oncology landscape, including an overview of the International Neuroblastoma Risk Group data commons as a paradigm case. We outline the practical steps and considerations in building data commons. Finally, we discuss the unique opportunities and benefits of creating a data commons within the context of pediatric cancer research, highlighting the particular advantages for clinical oncology and suggested next steps.

Evaluation of Genetic Predisposition for MYCN-Amplified Neuroblastoma

To investigate genetic predispositions for MYCN-amplified neuroblastoma, we performed a meta-analysis of three genome-wide association studies totaling 615 MYCN-amplified high-risk neuroblastoma cases and 1869 MYCN-nonamplified non-high-risk neuroblastoma cases as controls using a fixed-effects model with inverse variance weighting. All statistical tests were two-sided. We identified a novel locus at 3p21.31 indexed by the single nucleotide polymorphism (SNP) rs80059929 (odds ratio [OR] = 2.95, 95% confidence interval [CI] = 2.17 to 4.02, Pmeta = 6.47 × 10-12) associated with MYCN-amplified neuroblastoma, which was replicated in 127 MYCN-amplified cases and 254 non-high-risk controls (OR = 2.30, 95% CI = 1.12 to 4.69, Preplication = .02). To confirm this signal is exclusive to MYCN-amplified tumors, we performed a second meta-analysis comparing 728 MYCN-nonamplified high-risk patients to identical controls. rs80059929 was not statistically significant in MYCN-nonamplified high-risk patients (OR = 1.24, 95% CI = 0.90 to 1.71, Pmeta = .19). SNP rs80059929 is within intron 16 in the KIF15 gene. Additionally, the previously reported LMO1 neuroblastoma risk locus was statistically significant only in patients with MYCN-nonamplified high-risk tumors (OR = 0.63, 95% CI = 0.53 to 0.75, Pmeta = 1.51 × 10-8; Pmeta = .95). Our results indicate that common genetic variation predisposes to different neuroblastoma genotypes, including the likelihood of somatic MYCN-amplification.

Intravenous immunoglobulin with prednisone and risk-adapted chemotherapy for children with opsoclonus myoclonus ataxia syndrome associated with neuroblastoma (ANBL00P3): a randomised, open-label, phase 3 trial

Purpose

No previous clinical trial has been conducted for patients with neuroblastoma associated opsoclonus myoclonus ataxia syndrome (OMA), and current treatment is based on case reports. To evaluate the OMA response to prednisone and risk-adapted chemotherapy and determine if the addition of intravenous gammaglobulin (IVIG) further improves response, the Children’s Oncology Group designed a randomized therapeutic trial.

Patient and Methods

Eligible subjects were randomized to receive twelve cycles of IVIG (IVIG+) or no IVIG (NO-IVIG) in addition to prednisone and neuroblastoma risk-adapted chemotherapy. All low-risk patients were treated with cyclophosphamide. The severity of OMA symptoms was evaluated at 2, 6, and 12 months using a scale developed by Mitchell and Pike and baseline versus best response scores were compared. A single patient who did not undergo neurologic assessment was excluded from OMA response analysis. This study is registered with Clinical Trials.gov (identifier NCT00033293).

Results

Of the 53 patients enrolled in the study, 62% (33/53) were female. There were 44 low-risk, 7 intermediate-risk, and 2 high-risk neuroblastoma patients. Twenty-six subjects were randomized to receive IVIG+ and 27 were randomized to NO-IVIG. The neuroblastoma 3-year event-free survival (95% confidence interval (CI)) was 94.1% (87.3%, 100%) and overall survival was 98.0% (94.1%, 100%). Significantly higher rates of OMA response were observed in patients randomized to IVIG+ compared to NO-IVIG [21/26=80.8% for IVIG+; 11/27=40.7% for NO-IVIG (odds ratio=6.1; 95% CI: (1.5, 25.9), p=0.0029)]. For the majority of patients, the IVIG+ OMA regimen combined with cytoxan or other risk-based chemotherapy was well tolerated, although there was one toxic death in a high-risk subject.

Conclusion

This is the only randomized prospective therapeutic clinical trial in children with neuroblastoma-associated OMA. The addition of IVIG to prednisone and risk-adapted chemotherapy significantly improves OMA response rate. IVIG+ constitutes a back-bone upon which to build additional therapy.

Neuroblastoma Patients' KIR and KIR-Ligand Genotypes Influence Clinical Outcome for Dinutuximab-based Immunotherapy: A Report from the Children's Oncology Group

Purpose: In 2010, a Children's Oncology Group (COG) phase III randomized trial for patients with high-risk neuroblastoma (ANBL0032) demonstrated improved event-free survival (EFS) and overall survival (OS) following treatment with an immunotherapy regimen of dinutuximab, GM-CSF, IL2, and isotretinoin compared with treatment with isotretinoin alone. Dinutuximab, a chimeric anti-GD2 monoclonal antibody, acts in part via natural killer (NK) cells. Killer immunoglobulin-like receptors (KIR) on NK cells and their interactions with KIR-ligands can influence NK cell function. We investigated whether KIR/KIR-ligand genotypes were associated with EFS or OS in this trial.Experimental Design: We genotyped patients from COG study ANBL0032 and evaluated the effect of KIR/KIR-ligand genotypes on clinical outcomes. Cox regression models and log-rank tests were used to evaluate associations of EFS and OS with KIR/KIR-ligand genotypes.Results: In this trial, patients with the "all KIR-ligands present" genotype as well as patients with inhibitory KIR2DL2 with its ligand (HLA-C1) together with inhibitory KIR3DL1 with its ligand (HLA-Bw4) were associated with improved outcome if they received immunotherapy. In contrast, for patients with the complementary KIR/KIR-ligand genotypes, clinical outcome was not significantly different for patients who received immunotherapy versus those receiving isotretinoin alone.Conclusions: These data show that administration of immunotherapy is associated with improved outcome for neuroblastoma patients with certain KIR/KIR-ligand genotypes, although this was not seen for patients with other KIR/KIR-ligand genotypes. Further investigation of KIR/KIR-ligand genotypes may clarify their role in cancer immunotherapy and may enable KIR/KIR-ligand genotyping to be used prospectively for identifying patients likely to benefit from certain cancer immunotherapy regimens. Clin Cancer Res; 24(1); 189-96. ©2017 AACRSee related commentary by Cheung and Hsu, p. 3.

Revisions to the International Neuroblastoma Response Criteria: A Consensus Statement From the National Cancer Institute Clinical Trials Planning Meeting

Purpose More than two decades ago, an international working group established the International Neuroblastoma Response Criteria (INRC) to assess treatment response in children with neuroblastoma. However, this system requires modification to incorporate modern imaging techniques and new methods for quantifying bone marrow disease that were not previously widely available. The National Cancer Institute sponsored a clinical trials planning meeting in 2012 to update and refine response criteria for patients with neuroblastoma. Methods Multidisciplinary investigators from 13 countries reviewed data from published trials performed through cooperative groups, consortia, and single institutions. Data from both prospective and retrospective trials were used to refine the INRC. Monthly international conference calls were held from 2011 to 2015, and consensus was reached through review by working group leadership and the National Cancer Institute Clinical Trials Planning Meeting leadership council. Results Overall response in the revised INRC will integrate tumor response in the primary tumor, soft tissue and bone metastases, and bone marrow. Primary and metastatic soft tissue sites will be assessed using Response Evaluation Criteria in Solid Tumors (RECIST) and iodine-123 (123I) -metaiodobenzylguanidine (MIBG) scans or [18F]fluorodeoxyglucose-positron emission tomography scans if the tumor is MIBG nonavid. 123I-MIBG scans, or [18F]fluorodeoxyglucose-positron emission tomography scans for MIBG-nonavid disease, replace technetium-99m diphosphonate bone scintigraphy for osteomedullary metastasis assessment. Bone marrow will be assessed by histology or immunohistochemistry and cytology or immunocytology. Bone marrow with ≤ 5% tumor involvement will be classified as minimal disease. Urinary catecholamine levels will not be included in response assessment. Overall response will be defined as complete response, partial response, minor response, stable disease, or progressive disease. Conclusion These revised criteria will provide a uniform assessment of disease response, improve the interpretability of clinical trial results, and facilitate collaborative trial designs.

Data Commons to Support Pediatric Cancer Research

The falling costs and increasing fidelity of high-throughput biomedical research data have led to a renaissance in cancer surveillance and treatment. Yet, the amount, velocity, and complexity of these data have overcome the capacity of the increasing number of researchers collecting and analyzing this information. By centralizing the data, processing power, and tools, there is a valuable opportunity to share resources and thus increase the efficiency, power, and impact of research. Herein, we describe current data commons and how they operate in the oncology landscape, including an overview of the International Neuroblastoma Risk Group data commons as a paradigm case. We outline the practical steps and considerations in building data commons. Finally, we discuss the unique opportunities and benefits of creating a data commons within the context of pediatric cancer research, highlighting the particular advantages for clinical oncology and suggested next steps.

Emerging and investigational therapies for neuroblastoma

INTRODUCTION

Treatment for children with clinically aggressive, high-risk neuroblastoma remains challenging. Less than 50% of patients with high-risk neuroblastoma will survive long-term with current therapies, and survivors are at risk for serious treatment-related late toxicities. Here, we review new and evolving treatments that may ultimately improve outcome for children with high-risk neuroblastoma with decreased potential for late adverse events.

AREAS COVERED

New strategies for treating high-risk neuroblastoma are reviewed including: radiotherapy, targeted cytotoxics, biologics, immunotherapy, and molecularly targeted agents. Recently completed and ongoing neuroblastoma clinical trials testing these novel treatments are highlighted. In addition, we discuss ongoing clinical trials designed to evaluate precision medicine approaches that target actionable somatic mutations and oncogenic cellular pathways.

EXPERT OPINION

Advances in genomic medicine and molecular biology have led to the development of early phase studies testing biologically rational therapies targeting aberrantly activated cellular pathways. Because many of these drugs have a wider therapeutic index than standard chemotherapeutic agents, these treatments may be more effective and less toxic than current strategies. However, to effectively integrate these targeted strategies, robust predictive biomarkers must be developed that will identify patients who will benefit from these approaches and rapidly match treatments to patients at diagnosis.

The Role of Nursing Professionals in the Management of Patients With High-Risk Neuroblastoma Receiving Dinutuximab Therapy

Neuroblastoma, an embryonic cancer of the sympathetic nervous system, is the most common extracranial solid tumor in childhood. Dinutuximab (formerly called ch14.18), a monoclonal antibody targeting the disialoganglioside GD2, has been shown to significantly improve survival rates in patients with high-risk neuroblastoma. However, the safe and effective use of dinutuximab therapy in these high-risk patients requires medical expertise in patient selection, treatment administration, and the monitoring and management of adverse events. Findings of the randomized phase III study (ANBL0032) led to the approval of dinutuximab for the treatment of children with high-risk neuroblastoma. Multi-institutional nursing approaches to implementing standard protocols ensure the effective management of high-risk neuroblastoma patients receiving dinutuximab immunotherapy. Understanding and implementing recommendations for the management of the clinically important and most common adverse events are essential to ensuring patient continuation of therapy and improving patient outcomes.

Neuroblastoma survivors are at increased risk for second malignancies: A report from the International Neuroblastoma Risk Group Project

BACKGROUND

The incidence of second malignant neoplasm (SMN) within the first ten years of diagnosis in high-risk neuroblastoma patients treated with modern, intensive therapy is unknown. Further, the underlying germline genetics that contribute to SMN in these survivors are not known.

METHODS

The International Neuroblastoma Risk Group (INRG) database of patients diagnosed from 1990 to 2010 was analysed. SMN risk was accessed by cumulative incidence, standardised incidence ratios (SIRs) and absolute excess risk. A candidate gene-based association study evaluated genetic susceptibility to SMN in neuroblastoma survivors.

RESULTS

Of the 5987 patients in the INRG database with SMN data enrolled in a clinical trial, 43 (0.72%) developed a SMN. The 10-year cumulative incidence of SMN for high-risk patients was 1.8% (95% confidence interval [CI] 1.0-2.6%) compared with 0.38% (95% CI: 0.22-0.94%) for low-risk patients (P = 0.01). High-risk patients had an almost 18-fold higher incidence of SMN compared to age- and sex-matched controls (SIR = 17.5 (95% CI: 11.4-25.3), absolute excess risk = 27.6). For patients treated on high- and intermediate-risk clinical trials, the SIR of acute myelogenous leukaemia was 106.8 (95% CI: 28.7-273.4) and 127.7 (95%CI: 25.7-373.3), respectively. Variants implicating DNA repair genes XRCC3 (rs861539: P = 0.006; odds ratio: 2.04, 95%CI: 1.19-3.46) and MSH2 (rs17036651: P = 0.009; odds ratio: 0.26, 95% CI: 0.08-0.81) were associated with SMN.

CONCLUSION

The intensive multi-modality treatment strategy currently used to treat high-risk neuroblastoma is associated with a significantly increased risk of secondary acute myelogenous leukaemia. Defining the interactions of treatment exposures and genetic factors that promote the development of SMN is critical for optimising survivorship care.

A Phase I New Approaches to Neuroblastoma Therapy Study of Buthionine Sulfoximine and Melphalan With Autologous Stem Cells for Recurrent/Refractory High-Risk Neuroblastoma

BACKGROUND

Myeloablative therapy for high-risk neuroblastoma commonly includes melphalan. Increased cellular glutathione (GSH) can mediate melphalan resistance. Buthionine sulfoximine (BSO), a GSH synthesis inhibitor, enhances melphalan activity against neuroblastoma cell lines, providing the rationale for a Phase 1 trial of BSO-melphalan.

PROCEDURES

Patients with recurrent/resistant high-risk neuroblastoma received BSO (3 gram/m(2) bolus, then 24 grams/m(2) /day infusion days -4 to -2), with escalating doses of intravenous melphalan (20-125 mg/m(2) ) days -3 and -2, and autologous stem cells day 0 using 3 + 3 dose escalation.

RESULTS

Among 28 patients evaluable for dose escalation, one dose-limiting toxicity occurred at 20 mg/m(2) melphalan (grade 3 aspartate aminotransferase/alanine aminotransferase) and one at 80 mg/m(2) (streptococcal bacteremia, grade 4 hypotension/pulmonary/hypocalcemia) without sequelae. Among 25 patients evaluable for response, there was one partial response (PR) and two mixed responses (MRs) among eight patients with prior melphalan exposure; one PR and three MRs among 16 patients without prior melphalan; one stable disease with unknown melphalan history. Melphalan pharmacokinetics with BSO were similar to reports for melphalan alone. Melphalan Cmax for most patients was below the 10 μM concentration that showed neuroblastoma preclinical activity with BSO.

CONCLUSIONS

BSO (75 gram/m(2) ) with melphalan (125 mg/m(2) ) is tolerable with stem cell support and active in recurrent/refractory neuroblastoma. Further dose escalation is feasible and may increase responses.

Patient/Family Education for Newly Diagnosed Pediatric Oncology Patients

There is a paucity of data to support evidence-based practices in the provision of patient/family education in the context of a new childhood cancer diagnosis. Since the majority of children with cancer are treated on pediatric oncology clinical trials, lack of effective patient/family education has the potential to negatively affect both patient and clinical trial outcomes. The Children's Oncology Group Nursing Discipline convened an interprofessional expert panel from within and beyond pediatric oncology to review available and emerging evidence and develop expert consensus recommendations regarding harmonization of patient/family education practices for newly diagnosed pediatric oncology patients across institutions. Five broad principles, with associated recommendations, were identified by the panel, including recognition that (1) in pediatric oncology, patient/family education is family-centered; (2) a diagnosis of childhood cancer is overwhelming and the family needs time to process the diagnosis and develop a plan for managing ongoing life demands before they can successfully learn to care for the child; (3) patient/family education should be an interprofessional endeavor with 3 key areas of focus: (a) diagnosis/treatment, (b) psychosocial coping, and (c) care of the child; (4) patient/family education should occur across the continuum of care; and (5) a supportive environment is necessary to optimize learning. Dissemination and implementation of these recommendations will set the stage for future studies that aim to develop evidence to inform best practices, and ultimately to establish the standard of care for effective patient/family education in pediatric oncology.

Segmental Chromosomal Aberrations in Localized Neuroblastoma Can be Detected in Formalin-Fixed Paraffin-Embedded Tissue Samples and Are Associated With Recurrence

BACKGROUND

Array comparative genomic hybridization (CGH) analyses of frozen tumors have shown strong associations between the pattern of chromosomal aberrations and outcome in patients with advanced-stage neuroblastoma. New platforms for analyzing chromosomal aberrations using formalin-fixed paraffin-embedded (FFPE) tissue have recently been developed. We sought to determine whether chromosomal microarray analysis (CMA) using FFPE tumors is feasible and if segmental chromosomal aberrations were prognostic of recurrence in localized neuroblastoma.

METHODS

Patients with MYCN nonamplified International Neuroblastoma Staging System stage 1 and 2 disease who recurred were identified. CMA was performed with diagnostic FFPE samples using OncoScan™ FFPE Express 2.0. The prognostic significance of chromosomal pattern was validated in 105 patients with available CGH results.

RESULTS

In 26 evaluable patients, 11 recurred locally, nine had metastatic relapse, and six remained progression free >3 years from diagnosis. No chromosomal aberrations were identified in four tumors. Numerical chromosomal aberrations (NCAs) without segmental chromosomal aberration (SCA) were identified in 11 patients: six progressed locally, two had metastatic progression and 3 remained progression-free. Eleven patients had SCAs: four progressed locally, six developed metastatic progression and one remained progression-free. Five or more SCAs were only detected in tumors from patients who developed metastases (P = 0.0004). In the validation cohort, SCAs were associated with inferior event-free survival (EFS) compared to NCA (5-year EFS 68% ± 8.3% vs. 91% ± 3.6%, respectively; P = 0.0083).

CONCLUSIONS

It is feasible to evaluate chromosomal aberrations using FFPE neuroblastoma tissue. SCA is associated with inferior EFS in localized neuroblastoma patients, and multiple SCAs may be predictive of metastatic relapse.

Stem Cell Transplant-Associated Wernicke Encephalopathy in a Patient with High-Risk Neuroblastoma

Children undergoing intense cancer treatment frequently require total parenteral nutrition (TPN). Rarely, vitamins are removed due to hypersensitivity to the carrier vehicle in the formulation. We present the case of a 5-year-old patient with stage 4, high-risk neuroblastoma who developed altered mental status, ataxia, and tachycardia during consolidative autologous stem cell transplantation. Skin findings and brain MRI were consistent with thiamine (vitamin B1) deficiency and Wernicke encephalopathy. Vitamin B1 administration rapidly reversed all skin and neurologic symptoms. This case highlights the importance of close monitoring of micronutrients in pediatric patients receiving prolonged courses of chemotherapy and stem cell transplantation.

Abstract A2-55: Identification of evolutionarily conserved hypoxia-induced genomic pathways responsible for aggressive neuroblastoma phenotypes

Background: In cancer, hypoxia leads to a clinically aggressive phenotype by inducing angiogenesis, altering metabolism, and promoting cell infiltration, invasion and metastasis. Hypoxia also results in specific adaptive genetic changes in Drosophila melanogaster and many other species. We hypothesized that an evolutionarily conserved transcriptional program exists in Drosophila, neuroblastoma cell lines, and primary neuroblastoma tumors conferring both a survival advantage in Drosophila bred in hypoxia and aggressive tumor behavior.

Methods: RNA-seq data from neuroblastoma cells grown in normoxia or hypoxia were analyzed to identify differentially expressed genes (DEG). These data were compared to previously identified human orthologous DEG from Drospohila bred in normoxia or hypoxia. The analysis was validated using public microarray expression data from 11 additional neuroblastoma cell lines cultured in normal or hypoxic conditions (GEO accession GSE17714). In order to evaluate these genes in patients, gene expression microarray data from 479 primary neuroblastoma tumors (EMBL accession E-MTAB-179) were analyzed with respect to patient survival status.

Results: Pathway analysis of genes differentially expressed in Drosophila bred in hypoxia revealed enrichment for genes of the citric acid cycle (p = 13.1x10-17), pyruvate metabolism (p = 5.4x10-10), and glycolysis (p = 4.1x10-7). Analysis of neuroblastoma cells grown in hypoxia identified DEG in steroid biosynthesis (p = 1.3x10-13), HIF-1α transcription network (p = 3.3x10-13), and glycolysis (p = 3.2x10-6). 222 common DEG in neuroblastoma cells and Drosophila were enriched for glycolysis (p = 2.1x10-8), gluconeogenesis (p = 1.2x10-5) and the HIF-1α transcription network (p = 7.2x10-5). Up-regulation of glycolysis genes was also detected in the 11 additional neuroblastoma cell lines cultured in hypoxia. These cell lines showed additional differential expression in Ataxia telangiectasia and Rad3 (ATR) DNA damage sensing genes and general cell cycle related genes (p = 2.9x10-9 and p = 1.5x10-5, respectively). Of the 479 primary tumor samples with median follow up time of 3.75 years, there were 119 stage 1, 80 stage 2, 69 stage 3, 148 stage 4, and 62 stage 4S patients of whom 91 are deceased. In the analysis of primary tumors, decreased expression of cell cycle and metabolism genes (p = 4.8x10-13 and p = 1.6x10-12, respectively) was associated with survival. Thirty-nine of the DEG from patients, including multiple metabolism genes such as PGK1, GPI, and ACSS2, were common for both Drosophila and cell lines exposed to hypoxic conditions.

Conclusions: Hypoxia alters metabolism in Drosophila, and neuroblastoma cell lines, and similar changes are associated with clinically aggressive phenotype in primary neuroblastoma tumors. Changes in cell cycle gene expression were also common in neuroblastoma cell lines grown in hypoxia and in clinically aggressive primary tumors. Further analysis of these pathways and their regulation will allow us to identify patients at high risk and provide insight to personalize therapy.

Citation Format: Mark A. Applebaum, Aashish R. Jha, Alexandre Chlenski, Kyle Hernandez, Christopher J. Mariani, Barbara E. Stranger, Susan L. Cohn. Identification of evolutionarily conserved hypoxia-induced genomic pathways responsible for aggressive neuroblastoma phenotypes. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A2-55.

Abstract B1-15: Identification of evolutionarily conserved hypoxia-induced genomic pathways responsible for aggressive neuroblastoma phenotypes

Background: In cancer, hypoxia leads to a clinically aggressive phenotype by inducing angiogenesis, altering metabolism, and promoting cell infiltration, invasion and metastasis. Hypoxia also results in specific adaptive genetic changes in Drosophila melanogaster and many other species. We hypothesized that an evolutionarily conserved transcriptional program exists in Drosophila, neuroblastoma cell lines, and primary neuroblastoma tumors conferring both a survival advantage in Drosophila bred in hypoxia and aggressive tumor behavior.

Methods: RNA-seq data from neuroblastoma cells grown in normoxia or hypoxia were analyzed to identify differentially expressed genes (DEG). These data were compared to previously identified human orthologous DEG from Drospohila bred in normoxia or hypoxia. The analysis was validated using public microarray expression data from 11 additional neuroblastoma cell lines cultured in normal or hypoxic conditions (GEO accession GSE17714). In order to evaluate these genes in patients, gene expression microarray data from 479 primary neuroblastoma tumors (EMBL accession E-MTAB-179) were analyzed with respect to patient survival status.

Results: Pathway analysis of genes differentially expressed in Drosophila bred in hypoxia revealed enrichment for genes of the citric acid cycle (p = 13.1x10-17), pyruvate metabolism (p = 5.4x10-10), and glycolysis (p = 4.1x10-7). Analysis of neuroblastoma cells grown in hypoxia identified DEG in steroid biosynthesis (p = 1.3x10-13), HIF-1α transcription network (p = 3.3x10-13), and glycolysis (p = 3.2x10-6). 222 common DEG in neuroblastoma cells and Drosophila were enriched for glycolysis (p = 2.1x10-8), gluconeogenesis (p = 1.2x10-5) and the HIF-1α transcription network (p = 7.2x10-5). Up-regulation of glycolysis genes was also detected in the 11 additional neuroblastoma cell lines cultured in hypoxia. These cell lines showed additional differential expression in Ataxia telangiectasia and Rad3 (ATR) DNA damage sensing genes and general cell cycle related genes (p = 2.9x10-9 and p = 1.5x10-5, respectively). Of the 479 primary tumor samples with median follow up time of 3.75 years, there were 119 stage 1, 80 stage 2, 69 stage 3, 148 stage 4, and 62 stage 4S patients of whom 91 are deceased. In the analysis of primary tumors, decreased expression of cell cycle and metabolism genes (p = 4.8x10-13 and p = 1.6x10-12, respectively) was associated with survival. Thirty-nine of the DEG from patients, including multiple metabolism genes such as PGK1, GPI, and ACSS2, were common for both Drosophila and cell lines exposed to hypoxic conditions.

Conclusions: Hypoxia alters metabolism in Drosophila, and neuroblastoma cell lines, and similar changes are associated with clinically aggressive phenotype in primary neuroblastoma tumors. Changes in cell cycle gene expression were also common in neuroblastoma cell lines grown in hypoxia and in clinically aggressive primary tumors. Further analysis of these pathways and their regulation will allow us to identify patients at high risk and provide insight to personalize therapy.

Citation Format: Mark A. Aplebaum, Aashish R. Jha, Alexandre Chlenski, Kyle Hernandez, Christopher J. Mariani, Barbara E. Stranger, Susan L. Cohn. Identification of evolutionarily conserved hypoxia-induced genomic pathways responsible for aggressive neuroblastoma phenotypes. [abstract]. In: Proceedings of the AACR Special Conference on Computational and Systems Biology of Cancer; Feb 8-11 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 2):Abstract nr B1-15.

Abstract A37: Immunohistochemical detection of MYCN protein and MYC protein identifies highly aggressive neuroblastomas

Background:MYCN amplification with subsequent MYCN protein (MYCN-P) over-expression is a powerful indicator of a poor prognosis of neuroblastoma patients. Little is known regarding the prognostic significance of the homologous MYC protein (MYC-P) expression in this disease.

Methods: Immunohistochemical study for MYCN-P and MYC-P expression was conducted using a total of 357 cases of neuroblastoma, undifferentiated (20) or poorly differentiated (337) subtype with available unstained slides. The cases were collected and reviewed during one-year period of 2009 at the COG (Children's Oncology Group) Neuroblastoma Pathology Reference Laboratory. Relationship between these protein expressions and other prognostic markers [Clinical stage (stage 4, N=161 vs. non-stage 4, N=196); Age at diagnosis (<18months, N=210 vs. ≥18months, N=147);MYCN status (amplified, N=82 vs. non-amplified, N=272); International Neuroblastoma Pathology Classification (FH-favorable histology, N=176 vs. UH-unfavorable histology, N=181); MKI (mitosis-karyorrhexis index, Low, N=159; Intermediate, N=103 vs. High, N=81); and prominent nucleolar (PN) formation (+, N=110 vs. -, N=247)] were analyzed.

Findings: Of 357 cases, there were 67 (19%) MYCN-P (+) tumors, 37 (10%) MYC-P (+) tumors, and only one (0.3%) tumor expressing both proteins. Both MYCN-P (+) and MYC-P (+) tumors were more likely diagnosed in older children with stage 4 disease. MYCN-P (+) tumors were associated with amplified MYCN and UH, and often had High MKI. MYC-P (+) tumors were also frequently UH but not associated with MYCN amplification, and more likely to have Low or Intermediate MKI. PN formation was significantly associated with either MYCN-P or MYC-P expression. FH patients without MYC-P/MYCN-P expressions exhibited the best survival (N=167, 89.7+/-5.5% 3-year EFS, 97.0+/-3.2% 3-year OS), followed by UH patients without MYC-P/MYCN-P expressions (N=84, 63.1+/-13.6% 3-year EFS, 83.5+/-9.4% 3-year OS). While MYCN-P (+) patients and MYC-P (+) patients had similar and significantly low (p<0•0001) survival rates (46.2+/-12.0% 3-year EFS, 63.2+/-12.1% 3-year OS and 43.4+/-23.1% 3-year EFS, 63.5+/-19.2% 3-year OS, respectively). Notably, prognostic impact by MYC-P expression was independent from other factors.

Interpretation: In summary, about 30% of neuroblastoma cases in the undifferentiated and poorly differentiated subtypes expressed either MYCN protein (2/3 of the tumors) or MYC protein (1/3 of the tumors) in this series of cases. Those tumors were highly aggressive clinically: patients with MYC-protein expressing tumor had similarly low 3-year EFS and 3-year OS rate to those with MYCN-protein expressing tumor. MYCN-P expression was associated with MYCN amplification. In contrast, MYC-P expression was not associated with MYCN amplification, and its prognostic impact was independent from other standard prognostic factors in this disease. With the results of this report, we should move on to a prospective study of MYC-P expression as a new biomarker for high-risk neuroblastomas.

Citation Format: Larry L. Wang, Risa Teshiba, Naohiko Ikegaki, Xao X. Tang, Arlene Naranjo, Wendy B. London, Michael D. Hogarty, Julie M. Gastier-Foster, A. Thomas Look, Julie R. Park, John M. Maris, Susan L. Cohn, Robert C. Seeger, Shahab Asgharzadeh, Hiroyuki Shimada. Immunohistochemical detection of MYCN protein and MYC protein identifies highly aggressive neuroblastomas. [abstract]. In: Proceedings of the AACR Special Conference on Myc: From Biology to Therapy; Jan 7-10, 2015; La Jolla, CA. Philadelphia (PA): AACR; Mol Cancer Res 2015;13(10 Suppl):Abstract nr A37.

Advances in Risk Classification and Treatment Strategies for Neuroblastoma

Risk-based treatment approaches for neuroblastoma have been ongoing for decades. However, the criteria used to define risk in various institutional and cooperative groups were disparate, limiting the ability to compare clinical trial results. To mitigate this problem and enhance collaborative research, homogenous pretreatment patient cohorts have been defined by the International Neuroblastoma Risk Group classification system. During the past 30 years, increasingly intensive, multimodality approaches have been developed to treat patients who are classified as high risk, whereas patients with low- or intermediate-risk neuroblastoma have received reduced therapy. This treatment approach has resulted in improved outcome, although survival for high-risk patients remains poor, emphasizing the need for more effective treatments. Increased knowledge regarding the biology and genetic basis of neuroblastoma has led to the discovery of druggable targets and promising, new therapeutic approaches. Collaborative efforts of institutions and international cooperative groups have led to advances in our understanding of neuroblastoma biology, refinements in risk classification, and stratified treatment strategies, resulting in improved outcome. International collaboration will be even more critical when evaluating therapies designed to treat small cohorts of patients with rare actionable mutations.