Differential expression of minimal residual disease markers in peripheral blood and bone marrow samples from high-risk neuroblastoma patients

Distinct Expression Profiles of Neuroblastoma-Associated mRNAs in Peripheral Blood and Bone Marrow of Non-High-Risk and High-Risk Neuroblastoma Patients

Non-high-risk (non-HR) neuroblastoma (NB) patients have excellent outcomes, with more than a 90% survival rate, whereas HR NB patients expect less than a 50% survival rate. Metastatic disease is the principal cause of death among both non-HR and HR NB patients. Previous studies have reported the significant but limited prognostic value of quantitative PCR (qPCR)-based assays, measuring overlapping but different sets of neuroblastoma-associated mRNAs (NB-mRNAs), to detect metastatic disease in both non-HR and HR patient samples. A droplet digital PCR (ddPCR)-based assay measuring seven NB-mRNAs (CRMP1, DBH, DDC, GAP43, ISL1, PHOX2B, and TH mRNAs) was recently developed and exhibited a better prognostic value for HR patient samples than qPCR-based assays. However, it remained to be tested on non-HR patient samples. In the present study, we employed the ddPCR-based assay to study peripheral blood (PB) and bone marrow (BM) samples collected at diagnosis from eight non-HR and eleven HR cases and characterized the expression profiles of NB-mRNAs. The most highly expressed NB-mRNAs in PB and BM differed between non-HR and HR cases, with the CRMP1 mRNA being predominant in non-HR cases and the GAP43 mRNA in HR cases. The levels of NB-mRNAs in PB and BM were 5 to 1000 times lower in non-HR cases than in HR cases. The PB to BM ratio of NB-mRNAs was 10 to 100 times higher in non-HR cases compared to HR cases. The present case series suggests that non-HR and HR NB patients have the distinct expression profiles of NB-mRNAs in their PB and BM.

Discovery of Spatial Peptide Signatures for Neuroblastoma Risk Assessment by MALDI Mass Spectrometry Imaging

Simple Summary

The childhood tumor, neuroblastoma, has a broad clinical presentation. Risk assessment at diagnosis is particularly difficult in molecularly heterogeneous high-risk cases. Here we investigate the potential of imaging mass spectrometry to directly detect intratumor heterogeneity on the protein level in tissue sections. We show that this approach can produce discriminatory peptide signatures separating high- from low- and intermediate-risk tumors, identify 8 proteins aassociated with these signatures and validate two marker proteins using tissue immunostaining that have promise for further basic and translational research in neuroblastoma. We provide proof-of-concept that mass spectrometry-based technology could assist early risk assessment in neuroblastoma and provide insights into peptide signature-based detection of intratumor heterogeneity.

Abstract

Risk classification plays a crucial role in clinical management and therapy decisions in children with neuroblastoma. Risk assessment is currently based on patient criteria and molecular factors in single tumor biopsies at diagnosis. Growing evidence of extensive neuroblastoma intratumor heterogeneity drives the need for novel diagnostics to assess molecular profiles more comprehensively in spatial resolution to better predict risk for tumor progression and therapy resistance. We present a pilot study investigating the feasibility and potential of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to identify spatial peptide heterogeneity in neuroblastoma tissues of divergent current risk classification: high versus low/intermediate risk. Univariate (receiver operating characteristic analysis) and multivariate (segmentation, principal component analysis) statistical strategies identified spatially discriminative risk-associated MALDI-based peptide signatures. The AHNAK nucleoprotein and collapsin response mediator protein 1 (CRMP1) were identified as proteins associated with these peptide signatures, and their differential expression in the neuroblastomas of divergent risk was immunohistochemically validated. This proof-of-concept study demonstrates that MALDI-MSI combined with univariate and multivariate analysis strategies can identify spatially discriminative risk-associated peptide signatures in neuroblastoma tissues. These results suggest a promising new analytical strategy improving risk classification and providing new biological insights into neuroblastoma intratumor heterogeneity.

Minimal residual disease in high-risk neuroblastoma shows a dynamic and disease burden-dependent correlation between bone marrow and peripheral blood

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Bone marrow is the most frequent site of metastasis and relapse for neuroblastoma.

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Minimal residual disease has been identified in bone marrow and peripheral blood (BM-MRD and PB-MRD) by quantifying several sets of neuroblastoma-associated mRNAs.

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BM-MRD has significant prognostic information for high-risk neuroblastoma.

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BM-MRD and PB-MRD show a dynamic and disease burden-dependent correlation in high-risk neuroblastoma.

Neuroblastoma (NB) is the most common extracranial solid tumor in children and originates from sympathoadrenal or Schwann cell precursors derived from neural crest. These neural crest derivatives also constitute the hematopoietic and mesenchymal stem cells in bone marrow (BM) that is the most frequent site of NB metastasis and relapse. In NB patients, NB cells have been pathologically detected in BM and peripheral blood (PB), and minimal residual disease (MRD) in BM and PB (BM-MRD and PB-MRD) can be monitored by quantitating several sets of NB-associated mRNAs (NB-mRNAs). Although previous studies have shown varying degrees of correlation between BM-MRD and PB-MRD, the underlying factors and/or mechanisms remains unknown. In the present study, we determined the levels of BM-MRD and PB-MRD by quantitating seven NB-mRNAs in 133 pairs of concurrently collected BM and PB samples from 19 high-risk NB patients with clinical disease evaluation, and examined their correlation in overall and subgroups of sample pairs. The levels of BM-MRD and PB-MRD were moderately (r = 0.418, p < 0.001) correlated with each other in overall sample pairs. The correlation became strong (r = 0.725, p < 0.001), weak (r = 0.284, p = 0.008), and insignificant (p = 0.194) in progression, stable, and remission subgroups of sample pairs, respectively. It also became stronger in subgroups of sample pairs with poor treatment responses and poor prognostic factors. Present study suggests that MRD in high-risk NB shows a dynamic and disease burden-dependent correlation between BM and PB.

Increased plasma concentration of cell-free DNA precedes disease recurrence in children with high-risk neuroblastoma

Background

Neuroblastoma is the most common extracranial solid tumor of childhood. The high rate of recurrence is associated with a low survival rate for patients with high-risk neuroblastoma. There is thus an urgent need to identify effective predictive biomarkers of disease recurrence.

Methods

A total of 116 patients with high-risk neuroblastoma were recruited at Beijing Children’s Hospital between February 2015 and December 2017. All patients received multidisciplinary treatment, were evaluated for the therapeutic response, and then initiated on maintenance treatment. Blood samples were collected at the beginning of maintenance treatment, every 3 months thereafter, and at the time of disease recurrence. Plasma levels of cell-free DNA (cfDNA) were quantified by qPCR. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the ability of plasma cfDNA concentration to predict recurrence.

Results

Of the 116 patients, 36 (31.0%) developed recurrence during maintenance treatment. The median time to recurrence was 19.00, 9.00, and 8.00 months for patients who had achieved complete response (n = 6), partial response (n = 25), and stable disease (n = 5), respectively, after multidisciplinary treatment. The median plasma cfDNA concentration at the time of recurrence was significantly higher than the concentration in recurrence-free patients throughout maintenance treatment (29.34 ng/mL vs 10.32 ng/mL). Patients recorded a plasma cfDNA level ≥ 29 ng/mL an average of 0.55 months before diagnosis of disease recurrence. ROC analysis of the power of plasma cfDNA to distinguish between patients with or without recurrence yielded an area under the curve of 0.825, with optimal sensitivity and specificity of 80.6 and 71.3%, respectively, at a cfDNA level of 12.93 ng/mL.

Conclusions

High plasma cfDNA concentration is a potential molecular marker to signal disease recurrence in patients with high-risk neuroblastoma.

Cytokine-induced killer cells/natural killer cells combined with anti-GD2 monoclonal antibody increase cell death rate in neuroblastoma SK-N-SH cells

Neuroblastoma (NB) is one of the most common extracranial, solid, pediatric malignancies. Despite improvements in conventional therapies, including surgery, chemotherapy and radiation therapy, the prognosis of stage IV NB remains poor, indicating that novel treatment strategies are required. Immunotherapies, such as anti-GD2 monoclonal antibodies, used alone or in combination with cytokines, and peripheral blood mononuclear cells or cord blood mononuclear cells (CBMNCs), have been indicated to cause NB cell death and to prolong patient survival in high-risk NB; however, they remain limited by severe cytotoxicity and side effects. In the present study, it was determined that anti-GD2 monoclonal antibody alone or CBMNC-isolated cytokine-induced killer (CIK)/natural killer (NK) cells alone significantly induced cell death of NB SK-N-SH cells, and the combination of anti-GD2 antibody and CIK/NK cells could significantly increase the cell death rate compared with either treatment alone. In addition, based on a method referred to our previous study, it was identified that a two-cytokine culture system, using interleukin IL-2 and IL-7, effectively stimulated the proliferation of CIK/NK cells. These results serve to suggest a novel treatment strategy for relapsed/refractory NB with high efficiency and few side effects.

The role of β-catenin and paired-like homeobox 2B (PHOX2B) expression in neuroblastoma patients; predictive and prognostic value

BACKGROUND

The expression of β-catenin and paired-like homeobox 2B (PHOX2B) expression were assessed in Neuroblastoma (NB) patients as a diagnostic, prognostic and/or predictive markers.

METHODS

Bone marrow (BM) samples of 52 NB patients were assessed for the expression of β-catenin by immunohistochemistry (IHC), and PHOX2B by real time PCR (RT-PCR), compared to 12 healthy normal controls (NC). The data were correlated to the clinic-pathological features of the patients, response to treatment and disease relapse.

RESULTS

β-catenin was expressed in 40 (76.92%) patients (P < .001). While PHOX2B was expressed in 32/52 (61.5%) patients, with a fold change of 0.29 (0.01-40.0, P = .096). β-catenin expression associated significantly with advanced tumor stage, high risk, positive results by MIBG and bone scan (P = .002, P < .001, P = .006, P = .013; respectively). Also it associated significantly with synaptophysin expression in the BM biopsy (P < .001), with a significant concordance (K = 0.519, P < .001). The expression of β-catenin associated significantly with PHOX2B gene expression [28/32 (87.5%), P = .04], and its fold change (P = .027), with a significant measure of agreement (K = 0.297, P = .022). The fold change of PHOX2B gene expression associated significantly with the high risk of the patients (P = .04). Poor response to treatment associated significantly with the expression of neuron specific enolase (NSE), β-catenin and PHOX2B in NB patients (P = .021, P = .019 and P = .040; respectively). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of synaptophysin for the diagnosis of BM metastasis in NB patients were (69%, 65.2%, 71.4%, 62.5%; respectively, P = .024). While with β-catenin (93.1%, 43.5%, 67.5%, 83.3%; respectively, P = .003), and PHOX2B expression (65.5%, 34.5%, 59.4%, 50%; respectively, P = .574).

CONCLUSION

β-Catenin could be used as a sensitive and reliable marker for detection of BM metastasis and also a good predictor for resistance to treatment in NB patients. While, PHOX2B gene expression in BM aspirate could be a marker for high risk patients and poor response to treatment.

Dynamic alterations of plasma cell free DNA in response to chemotherapy in children with neuroblastoma

Background

To improve cure rates for neuroblastoma (NB), it is important and necessary to evaluate therapy response. Our investigation focuses on using plasma cell free DNA (cfDNA) as a biomarker to determine tumor burden and minimal residual disease (MRD) of NB patients during chemotherapy.

Methods

Total 58 NB patients were recruited from July 2016 to December 2017. Therapy regime and risk classification were based on COG standard and BCH‐NB‐2007 protocol. RECIST study was used to judge response to therapy at the end of fourth cycle of chemotherapy (CC4) and maintenance stage (MS) respectively. Serial quantifications of cfDNA, NSE, and LDH were examined at four stages, including newly diagnosed, second and CC4, and maintenance.

Results

During early chemotherapy, 65.5% of NB kids responded well. Consistently, cfDNA, NSE, and LDH levels were down‐regulated in NB patients with partial remission (PR) compared to those with stable disease (SD). In both training and predicting sets, the levels of cfDNA were significantly comparable between PR and SD only at CC4 stage. To predict the insufficient response to early chemotherapy, the optimal AUC value of cfDNA was 0.732 and 0.747 in training and predicting sets respectively, with a sensitivity of 63.2% and 80% specificity at 11.59 ng/ml and a sensitivity of 68.4% and 90% specificity at 10.35 ng/ml. At MS, responded NB patients were slightly increased up to 70%. This evaluation was confirmed by further decrease in cfDNA and NSE levels during intermediate chemotherapy in comparison with early stage.

Conclusion

The dynamic change of cfDNA was considered as a surrogate biomarker to evaluate tumor burden and MRD of NB during early and intermediate therapy periods.

Plasma cell-free DNA quantification is highly correlated to tumor burden in children with neuroblastoma

To evaluate plasma cell-free DNA (cfDNA) as a promising biomarker for neuroblastoma (NB) tumor burden. Seventy-nine eligible patients with newly diagnosed NB were recruited from Beijing Children's Hospital between April 2016 and April 2017. Additionally, from September 2011 to June 2017, 79 patients with stable NB were evaluated with a median follow-up time of 21 months. Approximately 2 mL of peripheral blood was drawn upon enrollment, and plasma cfDNA levels were measured via quantitative polymerase chain reaction (qPCR). Total cfDNA analysis was performed using the long interspersed nuclear element 1 (LINE-1) 79 bp fragment, and DNA integrity was calculated by the ratio of the LINE-1 300 bp fragment to the LINE-1 79 bp fragment. A total of 79 NB patients with a median age of 36 months comprised the group of newly diagnosed NB patients. The main primary tumor site was the retroperitoneal and adrenal region (81%). Three or more metastatic sites were found in 17.7% of patients. Stable NB patients older than 18 months comprised 98.7% of the stable NB patients. Neuron-specific enolase (NSE), lactate dehydrogenase (LDH), and cfDNA levels were dramatically increased in the newly diagnosed NB patients and significantly different from those in the stable NB patients. Moreover, the concentration of cfDNA was much higher in patients with larger tumors. By analyzing the area under the receiver operator characteristic (ROC) curve (AUC), the areas of total cfDNA, NSE, and LDH levels were 0.953, 0.929, and 0.906, respectively. The sensitivity and specificity data clarified that the level of circulating cfDNA in plasma can be considered as a reliable biomarker for describing tumor load in NB. The plasma cfDNA concentration was as good as the levels of LDH and NSE to discriminate the tumor burden in children with NB.