Immunogenomic determinants of tumor microenvironment correlate with superior survival in high-risk neuroblastoma

Divergent HLA variations and heterogeneous expression but recurrent HLA loss-of- heterozygosity and common HLA-B and TAP transcriptional silencing across advanced pediatric solid cancers

The human leukocyte antigen (HLA) system is a major factor controlling cancer immunosurveillance and response to immunotherapy, yet its status in pediatric cancers remains fragmentary. We determined high-confidence HLA genotypes in 576 children, adolescents and young adults with recurrent/refractory solid tumors from the MOSCATO-01 and MAPPYACTS trials, using normal and tumor whole exome and RNA sequencing data and benchmarked algorithms. There was no evidence for narrowed HLA allelic diversity but discordant homozygosity and allele frequencies across tumor types and subtypes, such as in embryonal and alveolar rhabdomyosarcoma, neuroblastoma MYCN and 11q subtypes, and high-grade glioma, and several alleles may represent protective or susceptibility factors to specific pediatric solid cancers. There was a paucity of somatic mutations in HLA and antigen processing and presentation (APP) genes in most tumors, except in cases with mismatch repair deficiency or genetic instability. The prevalence of loss-of-heterozygosity (LOH) ranged from 5.9 to 7.7% in HLA class I and 8.0 to 16.7% in HLA class II genes, but was widely increased in osteosarcoma and glioblastoma (~15-25%), and for DRB1-DQA1-DQB1 in Ewing sarcoma (~23-28%) and low-grade glioma (~33-50%). HLA class I and HLA-DR antigen expression was assessed in 194 tumors and 44 patient-derived xenografts (PDXs) by immunochemistry, and class I and APP transcript levels quantified in PDXs by RT-qPCR. We confirmed that HLA class I antigen expression is heterogeneous in advanced pediatric solid tumors, with class I loss commonly associated with the transcriptional downregulation of HLA-B and transporter associated with antigen processing (TAP) genes, whereas class II antigen expression is scarce on tumor cells and occurs on immune infiltrating cells. Patients with tumors expressing sufficient HLA class I and TAP levels such as some glioma, osteosarcoma, Ewing sarcoma and non-rhabdomyosarcoma soft-tissue sarcoma cases may more likely benefit from T cell-based approaches, whereas strategies to upregulate HLA expression, to expand the immunopeptidome, and to target TAP-independent epitopes or possibly LOH might provide novel therapeutic opportunities in others. The consequences of HLA class II expression by immune cells remain to be established. Immunogenetic profiling should be implemented in routine to inform immunotherapy trials for precision medicine of pediatric cancers.

Strategies to overcome low MHC-I expression in paediatric and adult tumours

Immunotherapy has made significant advancements in cancer treatments, improving patients' survival rates and quality of life. Several challenges still need to be addressed, which include the considerable fraction of incomplete curative responses in cancer patients, the development of therapy resistance by tumours, and the occurrence of adverse effects, such as inflammatory and autoimmune complications. Paediatric tumours usually exhibit lower responsiveness to immunotherapies compared to adult tumours. Although the underlying reasons are not yet fully understood, one known mechanism by which tumours avoid immune recognition is through reduced cell surface expression of major histocompatibility complex class I (MHC-I) complexes. Accordingly, the reduced presentation of neoantigens by MHC-I hinders the recognition and targeting of tumour cells by CD8+ T cells, impeding T-cell-mediated cytotoxic anti-tumour responses. MHC-I downregulation indeed often correlates with a poorer prognosis and diminished response to immunotherapy. Understanding the mechanisms underlying MHC-I downregulation in different types of paediatric and adult tumours is crucial for developing strategies to restore MHC-I expression and enhance anti-tumour immune responses. We here discuss progress in MHC-I-based immunotherapies against cancers.

Integration of clinical characteristics and molecular signatures of the tumor microenvironment to predict the prognosis of neuroblastoma

This study aimed to analyze the clinical characteristics, cell types, and molecular characteristics of the tumor microenvironment to better predict the prognosis of neuroblastoma (NB). The gene expression data and corresponding clinical information of 498 NB patients were obtained from the Gene Expression Omnibus (GEO: GSE62564) and ArrayExpress (accession: E-MTAB-8248). The relative cell abundances were estimated using single-sample gene set enrichment analysis (ssGSEA) with the R gene set variation analysis (GSVA) package. We performed Cox regression analyses to identify marker genes indicating cell subsets and combined these with prognostically relevant clinical factors to develop a new prognostic model. Data from the E-MTAB-8248 cohort verified the predictive accuracy of the prognostic model. Single-cell RNA-seq data were analyzed by using the R Seurat package. Multivariate survival analysis for each gene, using clinical characteristics as cofactors, identified 34 prognostic genes that showed a significant correlation with both event-free survival (EFS) and overall survival (OS) (log-rank test, P value < 0.05). The pathway enrichment analysis revealed that these prognostic genes were highly enriched in the marker genes of NB cells with mesenchymal features and protein translation. Ultimately, USP39, RPL8, IL1RAPL1, MAST4, CSRP2, ATP5E, International Neuroblastoma Staging System (INSS) stage, age, and MYCN status were selected to build an optimized Cox model for NB risk stratification. These samples were divided into two groups using the median of the risk score as a cutoff. The prognosis of samples in the poor prognosis group (PP) was significantly worse than that of samples in the good prognosis group (GP) (log-rank test, P value < 0.0001, median EFS: 640.5 vs. 2247 days, median OS: 1279.5 vs. 2519 days). The risk model was also regarded as a prognostic indicator independent of MYCN status, age, and stage. Finally, through scRNA-seq data, we found that as an important prognostic marker, USP39 might participate in the regulation of RNA splicing in NB. Our study established a multivariate Cox model based on gene signatures and clinical characteristics to better predict the prognosis of NB and revealed that mesenchymal signature genes of NB cells, especially USP39, were more abundant in patients with a poor prognosis than in those with a good prognosis. KEY MESSAGES: Our study established a multivariate Cox model based on gene signatures and clinical characteristics to better predict the prognosis of NB and revealed that mesenchymal signature genes of NB cells, especially USP39, were more abundant in patients with a poor prognosis than in those with a good prognosis. USP39, RPL8, IL1RAPL1, MAST4, CSRP2, ATP5E, International Neuroblastoma Staging System (INSS) stage, age, and MYCN status were selected to build an optimized Cox model for NB risk stratification. These samples were divided into two groups using the median of the risk score as a cutoff. The prognosis of samples in the poor prognosis group (PP) was significantly worse than that of samples in the good prognosis group (GP). Finally, through scRNA-seq data, we found that as an important prognostic marker, USP39 might participate in the regulation of RNA splicing in NB.

Neuroblastoma Interaction with the Tumour Microenvironment and Its Implications for Treatment and Disease Progression

Neuroblastoma, a paediatric malignancy of the peripheral nervous system, displays a wide range of clinical outcomes, including regression to fatality despite extensive treatment. Neuroblastoma tumours display a complex interplay with their surrounding environment, known as the tumour microenvironment, which may affect disease progression and patient prognosis. This study aimed to dissect the ways in which neuroblastoma biology, treatment, prognosis, progression, and relapse are linked with the extracellular matrix, the dichotomous identities of neuroblastoma, various regulatory proteins and RNA, and extracellular vesicles within the backdrop of the tumour microenvironment. In addition, other aspects, such as immune cell infiltration, therapeutic options including monoclonal antibodies and small molecule inhibitors; and the ways in which these may affect disease progression and immunosuppression within the context of the neuroblastoma tumour microenvironment, are addressed. Such studies may shed light on useful therapeutic targets within the tumour microenvironment that may benefit groups of NB patients. Ultimately, a detailed understanding of these aspects will enable the neuroblastoma scientific community to improve treatment options, patient outcomes, and quality of life.

Adrenergic and mesenchymal signatures are identifiable in cell-free DNA and correlate with metastatic disease burden in children with neuroblastoma

Background

Cell free DNA (cfDNA) profiles of 5-hydroxymethylcytosine (5-hmC), an epigenetic marker of open chromatin and active gene expression, are correlated with metastatic disease burden in patients with neuroblastoma. Neuroblastoma tumors are comprised of adrenergic (ADRN) and mesenchymal (MES) cells, and the relative abundance of each in tumor biopsies has prognostic implications. We hypothesized that ADRN and MES specific signatures could be quantified in cfDNA 5-hmC profiles and would augment the detection of metastatic burden in patients with neuroblastoma.

Methods

We previously performed an integrative analysis to identify ADRN and MES specific genes (n=373 and n=159, respectively). Purified DNA from cell lines was serial diluted with healthy donor cfDNA. Using Gene Set Variation Analysis (GSVA), ADRN and MES signatures were optimized. We then quantified signature scores, and our prior neuroblastoma signature, in cfDNA from 84 samples from 46 high-risk patients including 21 patients with serial samples.

Results

Samples from patients with higher metastatic burden had increased GSVA scores for both ADRN and MES gene signatures (p < 0.001). While ADRN and MES signature scores tracked together in serially collected samples, we identified instances of patients with increases in either MES or ADRN score at relapse.

Conclusions

While it is feasible to identify ADRN and MES signatures using 5-hmC profiles of cfDNA from neuroblastoma patients and correlate these signatures to metastatic burden, additional data are needed to determine the optimal strategies for clinical implementation. Prospective evaluation in larger cohorts is ongoing.

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.

Tumor cell p38 inhibition to overcome immunotherapy resistance

Patients with tumors that do not respond to immune-checkpoint inhibition often harbor a non-T cell-inflamed tumor microenvironment, characterized by the absence of IFN-γ-associated CD8+ T cell and dendritic cell activation. Understanding the molecular mechanisms underlying immune exclusion in non-responding patients may enable the development of novel combination therapies. p38 MAPK is a known regulator of dendritic and myeloid cells however a tumor-intrinsic immunomodulatory role has not been previously described. Here we identify tumor cell p38 signaling as a therapeutic target to potentiate anti-tumor immunity and overcome resistance to immune-checkpoint inhibitors (ICI). Molecular analysis of tumor tissues from patients with human papillomavirus-negative head and neck squamous carcinoma reveals a p38-centered network enriched in non-T cell-inflamed tumors. Pan-cancer single-cell RNA analysis suggests that p38 activation may be an immune-exclusion mechanism across multiple tumor types. P38 knockdown in cancer cell lines increases T cell migration, and p38 inhibition plus ICI in preclinical models shows greater efficacy compared to monotherapies. In a clinical trial of patients refractory to PD1/L1 therapy, pexmetinib, a p38 inhibitor, plus nivolumab demonstrated deep and durable clinical responses. Targeting of p38 with anti-PD1 has the potential to induce the T cell-inflamed phenotype and overcome immunotherapy resistance.

T-cell inflammation is prognostic of survival in patients with high-risk neuroblastoma enriched for an adrenergic signature

Purpose

T-cell inflammation (TCI) has been shown to be a prognostic marker in neuroblastoma, a tumor comprised of cells that can exist in two epigenetic states, adrenergic (ADRN) and mesenchymal (MES). We hypothesized that elucidating unique and overlapping aspects of these biologic features could serve as novel biomarkers.

Patients and Methods

We detected lineage-specific, single-stranded super-enhancers defining ADRN and MES specific genes. Publicly available neuroblastoma RNA-seq data from GSE49711 (Cohort 1) and TARGET (Cohort 2) were assigned MES, ADRN, and TCI scores. Tumors were characterized as MES (top 33%) or ADRN (bottom 33%), and TCI (top 67% TCI score) or non-inflamed (bottom 33% TCI score). Overall survival (OS) was assessed using the Kaplan-Meier method, and differences were assessed by the log-rank test.

Results

We identified 159 MES genes and 373 ADRN genes. TCI scores were correlated with MES scores (R=0.56, p<0.001 and R=0.38, p<0.001) and anticorrelated with MYCN -amplification (R=-0.29, p<0.001 and -0.18, p=0.03) in both cohorts. Among Cohort 1 patients with high-risk, ADRN tumors (n=59), those with TCI tumors (n=22) had superior OS to those with non-inflammed tumors (n=37) (p=0.01), though this comparison did not reach significance in Cohort 2. TCI status was not associated with survival in patients with high-risk MES tumors in either cohort.

Conclusions

High inflammation scores were correlated with improved survival in some high-risk patients with, ADRN but not MES neuroblastoma. These findings have implications for approaches to treating high-risk neuroblastoma.

Targeted immune activation in pediatric solid tumors: opportunities to complement local control approaches

Surgery or radiation therapy is nearly universally applied for pediatric solid tumors. In many cases, in diverse tumor types, distant metastatic disease is present and evades surgery or radiation. The systemic host response to these local control modalities may lead to a suppression of antitumor immunity, with potential negative impact on the clinical outcomes for patients in this scenario. Emerging evidence suggests that the perioperative immune responses to surgery or radiation can be modulated therapeutically to preserve anti-tumor immunity, with the added benefit of preventing these local control approaches from serving as pro-tumorigenic stimuli. To realize the potential benefit of therapeutic modulation of the systemic response to surgery or radiation on distant disease that evades these modalities, a detailed knowledge of the tumor-specific immunology as well as the immune responses to surgery and radiation is imperative. In this Review we highlight the current understanding of the tumor immune microenvironment for the most common peripheral pediatric solid tumors, the immune responses to surgery and radiation, and current evidence that supports the potential use of immune activating agents in the perioperative window. Finally, we define existing knowledge gaps that limit the current translational potential of modulating perioperative immunity to achieve effective anti-tumor outcomes.

Biological Insight and Recent Advancement in the Treatment of Neuroblastoma

One of the most frequent solid tumors in children is neuroblastoma, which has a variety of clinical behaviors that are mostly influenced by the biology of the tumor. Unique characteristics of neuroblastoma includes its early age of onset, its propensity for spontaneous tumor regression in newborns, and its high prevalence of metastatic disease at diagnosis in individuals older than 1 year of age. Immunotherapeutic techniques have been added to the previously enlisted chemotherapeutic treatments as therapeutic choices. A groundbreaking new treatment for hematological malignancies is adoptive cell therapy, specifically chimeric antigen receptor (CAR) T cell therapy. However, due to the immunosuppressive nature of the tumor microenvironment (TME) of neuroblastoma tumor, this treatment approach faces difficulties. Numerous tumor-associated genes and antigens, including the MYCN proto-oncogene (MYCN) and disialoganglioside (GD2) surface antigen, have been found by the molecular analysis of neuroblastoma cells. The MYCN gene and GD2 are two of the most useful immunotherapy findings for neuroblastoma. The tumor cells devise numerous methods to evade immune identification or modify the activity of immune cells. In addition to addressing the difficulties and potential advancements of immunotherapies for neuroblastoma, this review attempts to identify important immunological actors and biological pathways involved in the dynamic interaction between the TME and immune system.

CD69 on Tumor-Infiltrating Cells Correlates With Neuroblastoma Suppression by Simultaneous PD-1 and PD-L1 Blockade

INTRODUCTION

Tumor-infiltrating cells play an important role in tumor immunology, and tumor-infiltrating lymphocytes (TILs) are critical in antitumor reaction related to immune checkpoint inhibition targeting programmed cell death protein 1 (PD-1) and programmed cell death ligand 1 (PD-L1).

METHODS

In nude mice, which are immune deficient because they lack T cells, and inbred A/J mice, which are syngeneic to neuroblastoma cells (Neuro-2a) and have normal T cell function, we investigated the importance of T lymphocytes in immune checkpoint inhibition in mouse neuroblastoma and analyzed the immune cells in the tumor microenvironment. Then, we subcutaneously injected mouse Neuro-2ainto nude mice and A/J mice, administered anti-PD-1 and anti-PD-L1 antibodies by intraperitoneal injection, and evaluated tumor growth. At 16 d after Neuro-2a cells injection, mice were euthanized, tumors and spleens were harvested, and immune cells were analyzed by flow cytometry.

RESULTS

The antibodies suppressed tumor growth in A/J but not in nude mice. The co-administration of antibodies did not affect regulatory T cells (culster of differentiation [CD]4⁺CD25⁺FoxP3⁺ cells) or activated CD4⁺ lymphocytes (expressing CD69). No changes in activated CD8⁺ lymphocytes (expressing CD69) were observed in spleen tissue. However, increased infiltration of activated CD8⁺ TILs was seen in tumors weighing less than 300 mg, and the amount of activated CD8⁺ TILs was negatively correlated with tumor weight.

CONCLUSIONS

Our study confirms that lymphocytes are essential for the antitumor immune reaction induced by blocking PD-1/PD-L1 and raises the possibility that promoting the infiltration of activated CD8⁺ TIL into tumors may be an effective treatment for neuroblastoma.

Analysis of m6A methylation patterns and tumor microenvironment in endometrial cancer

BACKGROUND

The N⁶-methyladenosine (m⁶A) modification is the most common epigenetic modification in eukaryotic mRNA. In recent years, lots of studies have shown that the tumor microenvironment (TME) plays a critical role in tumor growth and development. However, there are few studies on the interaction between m⁶A methylation and the TME in uterine corpus endometrial carcinoma (UCEC).

METHODS

Three distinct m⁶A modification patterns were based on 21 m⁶A regulators of UCEC patients and tumor-free individuals. We investigated the relationship between m⁶A modification patterns and associated features of the TME. Differentially expressed genes were selected and the m⁶A score was established to evaluate the prognosis and immunotherapeutic efficacy of UCEC patients.

RESULTS

We identified three different m⁶A modification patterns. The TME infiltrating characteristics were highly consistent with tumors with three distinct immune phenotypes. Besides, our analysis showed that the m⁶A score was shown to be useful in predicting clinical outcomes. Patients with the low m⁶A score seemed to have a better prognosis, a stronger immunotherapeutic response, and a higher tumor mutation burden.

CONCLUSION

Our study explored the influence of m⁶A modification and TME on the prognosis of cancer patients, which will contribute to the discovery of immunotherapy strategies to improve their prognosis.

Outcomes Following GD2-Directed Postconsolidation Therapy for Neuroblastoma After Cessation of Random Assignment on ANBL0032: A Report From the Children's Oncology Group

PURPOSE

Postconsolidation immunotherapy including dinutuximab, granulocyte-macrophage colony-stimulating factor, and interleukin-2 improved outcomes for patients with high-risk neuroblastoma enrolled on the randomized portion of Children's Oncology Group study ANBL0032. After random assignment ended, all patients were assigned to immunotherapy. Survival and toxicities were assessed.

PATIENTS AND METHODS

Patients with a pre-autologous stem cell transplant (ASCT) response (excluding bone marrow) of partial response or better were eligible. Demographics, stage, tumor biology, pre-ASCT response, and adverse events were summarized using descriptive statistics. Event-free survival (EFS) and overall survival (OS) from time of enrollment (up to day +200 from last ASCT) were evaluated.

RESULTS

From 2009 to 2015, 1,183 patients were treated. Five-year EFS and OS for the entire cohort were 61.1 ± 1.9% and 71.9 ± 1.7%, respectively. For patients ≥ 18 months old at diagnosis with International Neuroblastoma Staging System stage 4 disease (n = 662) 5-year EFS and OS were 57.0 ± 2.4% and 70.9 ± 2.2%, respectively. EFS was superior for patients with complete response/very good partial response pre-ASCT compared with those with PR (5-year EFS: 64.2 ± 2.2% v 55.4 ± 3.2%, P = .0133); however, OS was not significantly different. Allergic reactions, capillary leak, fever, and hypotension were more frequent during interleukin-2-containing cycles than granulocyte-macrophage colony-stimulating factor-containing cycles (P < .0001). EFS was superior in patients with higher peak dinutuximab levels during cycle 1 (P = .034) and those with a high affinity FCGR3A genotype (P = .0418). Human antichimeric antibody status did not correlate with survival.

CONCLUSION

Analysis of a cohort assigned to immunotherapy after cessation of random assignment on ANBL0032 confirmed previously described survival and toxicity outcomes. EFS was highest among patients with end-induction complete response/very good partial response. Among patients with available data, higher dinutuximab levels and FCGR3A genotype were associated with superior EFS. These may be predictive biomarkers for dinutuximab therapy.

Opsoclonus-myoclonus syndrome associated with neuroblastoma: Insights into antitumor immunity

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disorder. Half of these cases occur in children with neuroblastoma. Neuroblastoma patients with OMS usually have better oncological outcomes than those without OMS even after stratification by tumor stage and age, indicating that factors mediating OMS may also inhibit tumor cell proliferation. Although the mechanisms underlying OMS remain undefined, the cytokines and lymphocytes alterations in the cerebrospinal fluid support the concept that it is a pattern of neuroinflammation due to an autoimmune effect. The presence of lymphoid follicles consisting of follicular dendritic cells, CD20⁺ B lymphocytes, CD3⁺ T lymphocytes, and CD68⁺ macrophages in the tumor microenvironment in OMS-associated neuroblastoma support the autoimmune nature of this disorder. This review focuses on the clinical and genetic features of OMS-associated neuroblastoma, and we update readers on immune features of neuroblastoma with or without OMS to gain insights into antitumor immunity as it relates to tumor biology and prognosis.

Mesenchymal and adrenergic cell lineage states in neuroblastoma possess distinct immunogenic phenotypes

Apart from the anti-GD2 antibody, immunotherapy for neuroblastoma has had limited success due to immune evasion mechanisms, coupled with an incomplete understanding of predictors of response. Here, from bulk and single-cell transcriptomic analyses, we identify a subset of neuroblastomas enriched for transcripts associated with immune activation and inhibition and show that these are predominantly characterized by gene expression signatures of the mesenchymal lineage state. By contrast, tumors expressing adrenergic lineage signatures are less immunogenic. The inherent presence or induction of the mesenchymal state through transcriptional reprogramming or therapy resistance is accompanied by innate and adaptive immune gene activation through epigenetic remodeling. Mesenchymal lineage cells promote T cell infiltration by secreting inflammatory cytokines, are efficiently targeted by cytotoxic T and natural killer cells and respond to immune checkpoint blockade. Together, we demonstrate that distinct immunogenic phenotypes define the divergent lineage states of neuroblastoma and highlight the immunogenic potential of the mesenchymal lineage.

NAIRscore as a biomarker for the quality of immune response to neoantigens is related with an increased overall survival in multiple myeloma

Neoantigen provides a promising breakthrough in tumor immunotherapy, although only a subset of patients responds well due to the quality of their immune response. However, few biomarkers have been reported to measure the quality of immune response to neoantigens and to predict prognosis of patients with multiple myeloma (MM). Here, we first developed a neoantigen-prediction pipeline starting from outcomes of somatic mutations and gene-expression profiles. Given the expression of some specific marker genes, the human leukocyte antigen (HLA)-I score and the cytolytic score were evaluated respectively to reflect HLA-I molecular expression and CD8+ T/natural killer (NK) cell abundance. According to the process of the immune response to neoantigens, we comprehensively took neoantigen load, cytolytic score, and HLA-I score to construct a neoantigen immune response score (NAIRscore), in which the HLA-I score presented a hazard ratio (HR) of less than 1, while the cytolytic score and neoantigen load presented a HR of greater than 1. Meanwhile, NAIRscore presented a competitive advantage to stratify MM samples. Especially, those exhibiting high NAIRscore correlated with an increased overall survival (OS), echoing the underlying molecular signatures of lower driver-gene mutations and down-regulated immune response. Notably, an online tool based on this study is provided to identify neoantigens and predict OS.

Immunotherapy of Neuroblastoma: Facts and Hopes

While the adoption of multimodal therapy including surgery, radiation, and aggressive combination chemotherapy has improved outcomes for many children with high-risk neuroblastoma, we appear to have reached a plateau in what can be achieved with cytotoxic therapies alone. Most children with cancer, including high-risk neuroblastoma, do not benefit from treatment with immune checkpoint inhibitors (ICI) that have revolutionized the treatment of many highly immunogenic adult solid tumors. This likely reflects the low tumor mutation burden as well as the downregulated MHC-I that characterizes most high-risk neuroblastomas. For these reasons, neuroblastoma represents an immunotherapeutic challenge that may be a model for the creation of effective immunotherapy for other "cold" tumors in children and adults that do not respond to ICI. The identification of strong expression of the disialoganglioside GD2 on the surface of nearly all neuroblastoma cells provided a target for immune recognition by anti-GD2 mAbs that recruit Fc receptor-expressing innate immune cells that mediate cytotoxicity or phagocytosis. Adoption of anti-GD2 antibodies into both upfront and relapse treatment protocols has dramatically increased survival rates and altered the landscape for children with high-risk neuroblastoma. This review describes how these approaches have been expanded to additional combinations and forms of immunotherapy that have already demonstrated clear clinical benefit. We also describe the efforts to identify additional immune targets for neuroblastoma. Finally, we summarize newer approaches being pursued that may well help both innate and adaptive immune cells, endogenous or genetically engineered, to more effectively destroy neuroblastoma cells, to better induce complete remission and prevent recurrence.

Clinical Significance of a CD3/CD8-Based Immunoscore in Neuroblastoma Patients Using Digital Pathology

Background

Infiltrating immune cells have been reported as prognostic markers in many cancer types. We aimed to evaluate the prognostic role of tumor-infiltrating lymphocytes, namely CD3+ T cells, CD8+ cytotoxic T cells and memory T cells (CD45RO+), in neuroblastoma.

Patients and Methods

Immunohistochemistry was used to determine the expression of CD3, CD8 and CD45RO in the tumor samples of 244 neuroblastoma patients. We then used digital pathology to calculate the densities of these markers and derived an immunoscore based on such densities.

Results

Densities of CD3+ and CD8+ T cells in tumor were positively associated with the overall survival (OS) and event-free survival (EFS), whereas density of CD45RO+ T cells in tumor was negatively associated with OS but not EFS. An immunoscore with low density of CD3 and CD8 (CD3-CD8-) was indictive of a greater risk of death (hazard ratio 6.39, 95% confidence interval 3.09-13.20) and any event (i.e., relapse at any site, progressive disease, second malignancy, or death) (hazard ratio 4.65, 95% confidence interval 2.73-7.93). Multivariable analysis revealed that the CD3-CD8- immunoscore was an independent prognostic indicator for OS, even after adjusting for other known prognostic indicators.

Conclusions

The new immunoscore based on digital pathology evaluated densities of tumor-infiltrating CD3+ and CD8+ T cells contributes to the prediction of prognosis in neuroblastoma patients.

Targeting tumor microenvironment and metastasis in children with solid tumors

PURPOSE OF REVIEW

The prognosis of pediatric patients with metastatic solid tumors remains poor, necessitating development of novel therapeutic strategies. The biology of the pediatric tumor microenvironment (TME) presents obstacles for the efficacy of current therapeutic approaches including immunotherapies. Targeting various aspects of the TME in pediatric patients with solid tumors represents a therapeutic opportunity that may improve outcomes. Here we will discuss recent advances in characterization of the TME, and clinical advances in targeting the immune, vascular, and stromal aspects of the TME.

RECENT FINDINGS

Although immunotherapies have shown limited success in the treatment of pediatric solid tumor patients thus far, optimization of these approaches to overcome the TME shows promise. In addition, there is increasing focus on the myeloid compartment as a therapeutic target. Vascular endothelial growth factor (VEGF) targeting has resulted in responses in some refractory pediatric solid tumors. There has been relatively little focus on stromal targeting; however, emerging preclinical data are improving our understanding of underlying biology, paving the way for future therapies.

SUMMARY

Although translation of TME-targeting therapies for pediatric solid tumors is in the early stages, we are optimistic that continued exploration of approaches aimed at rebalancing the TME will lead to improved outcomes for this population.

Recent Advances in Pediatric Cancer Research

Over the past few years, the field of pediatric cancer has experienced a shift in momentum, and this has led to new and exciting findings that have relevance beyond pediatric malignancies. Here we present the current status of key aspects of pediatric cancer research. We have focused on genetic and epigenetic drivers of disease, cellular origins of different pediatric cancers, disease models, the tumor microenvironment, and cellular immunotherapies.

Deep analysis of neuroblastoma core regulatory circuitries using online databases and integrated bioinformatics shows their pan-cancer roles as prognostic predictors

AIM

Neuroblastoma is a heterogeneous childhood cancer derived from the neural crest. The dual cell identities of neuroblastoma include Mesenchymal (MES) and Adrenergic (ADRN). These identities are conferred by a small set of tightly-regulated transcription factors (TFs) binding super enhancers, collectively forming core regulatory circuitries (CRCs). The purpose of this study was to gain a deep understanding of the role of MES and ADRN TFs in neuroblastoma and other cancers as potential indicators of disease prognosis, progression, and relapse.

METHODS

To that end, we first investigated the expression and mutational profile of MES and ADRN TFs in neuroblastoma. Moreover, we established their correlation with neuroblastoma risk groups and overall survival while establishing their extended networks with long non-coding RNAs (lncRNAs). Furthermore, we analysed the pan-cancer expression and mutational profile of these TFs and their correlation with patient survival and finally their network connectivity, using a panel of bioinformatic tools including GEPIA2, human pathology atlas, TIMER2, Omicsnet, and Cytoscape.

RESULTS

We show the association of multiple MES and ADRN TFs with neuroblastoma risk groups and overall survival and find significantly higher expression of various MES and ADRN TFs compared to normal tissues and their association with overall survival and disease-free survival in multiple cancers. Moreover, we report the strong correlation of the expression of these TFs with the infiltration of stromal and immune cells in the tumour microenvironment and with stemness and metastasis-related genes. Furthermore, we reveal extended pan-cancer networks comprising these TFs that influence the tumour microenvironment and metastasis and may be useful indicators of cancer prognosis and patient survival.

CONCLUSION

Our meta-analysis shows the significance of MES and ADRN TFs as indicators of patient prognosis and the putative utility of these TFs as potential novel biomarkers.