Common genetic variants in NEFL influence gene expression and neuroblastoma risk

TET3 gene rs828867 G>A polymorphism reduces neuroblastoma risk in Chinese children

Objective

Neuroblastoma (NB) is a prevalent pediatric tumor originating from primordial neural crest cells. As one of the latest epigenetics investigations focuses, RNA 5-methylcytosine (m5C) is closely related to cancer risk. TET methylcytosine dioxygenase 3 (TET3) is a demethylase for m5C modification. Whether there is an association between TET3 gene polymorphisms and neuroblastoma risk remains unclear.

Methods

We conducted an epidemiological study in 402 patients and 473 controls to evaluate the relationship between TET3 gene SNPs (rs7560668 T > C, rs828867 G > A, and rs6546891 A > G) and NB susceptibility.

Results

Our results showed that rs828867 G > A significantly reduced NB risk in Chinese children [GA vs. GG, adjusted odds ratio (OR) = 0.72, 95% confidence interval (CI) = 0.52-0.98, P=0.040; GA/AA vs. GG, adjusted OR = 0.74, 95% CI = 0.55-0.998, P=0.048]. Individuals with 2-3 risk genotypes had a significantly higher NB risk than those with 0-1 risk genotypes (adjusted OR = 1.40, 95% CI = 1.04-1.88, P=0.027). The stratified analysis showed that the rs828867 G > A associated with decreased NB risk is remarkable among children aged >18 months (adjusted OR = 0.67, 95% CI = 0.46-0.96, P=0.029) and patients at clinical III + IV stages (adjusted OR = 0.67, 95% CI = 0.45-0.98, P=0.040). Compared with the 0-1 risk genotype, the concurrence of 2-3 risk genotypes significantly increased NB risk in the following subgroups: children aged >18 months and patients at clinical III + IV stages. GTEx analysis suggested that rs828867 G > A was significantly associated with RP11-287D1.4 and POLE4 mRNA expression.

Conclusions

Overall, our results revealed that rs828867 G > A in the TET3 gene is significantly associated with predisposition to NB.

Genetic variants of m7G modification genes influence neuroblastoma susceptibility

Objective

Neuroblastoma is a life-threatening pediatric solid tumor whose etiology remains unclear. N7-methylguanosine (m7G) is one of the most important epigenetic modifications of RNA, which plays a crucial role in tumorigenesis. The m7G-mediated genes METTL1 and WDR4 also have been reported to be dysregulated in various cancers. However, the implications of METTL1 and WDR4 in neuroblastoma have not been clarified.

Methods

Given the oncogenic potential of m7G modification, we performed a case-control study to assess the association of METTL1 and WDR4 genes polymorphisms with neuroblastoma risk in a Chinese population consisting of 402 cases and 473 controls. Odds ratios (ORs) and 95 % confidence intervals (CIs) were applied to evaluate the associations between studied polymorphisms and neuroblastoma risk. The adjusted odds ratio (AOR) was adjusted for age and gender.

Results

Overall, four polymorphisms were significantly associated with neuroblastoma risk, including METTL1 rs2291617 (recessive model: adjusted OR = 1.59, 95 % CI = 1.08-2.34, P = 0.019), WDR4 rs2156316 (dominant model: adjusted OR = 0.74, 95 % CI = 0.57-0.97, P = 0.028), WDR4 rs6586250 (dominant model: adjusted OR = 0.59, 95 % CI = 0.42-0.84, P = 0.004) and WDR4 rs15736 (dominant model: adjusted OR = 0.60, 95 % CI = 0.42-0.85, P = 0.004). Stratified analysis showed stronger correlations between significant polymorphisms and neuroblastoma risk among subgroups divided by age, gender, tumor origin, and clinical stage. Furthermore, expression quantitative trait loci (eQTL) analysis revealed that significant polymorphisms were associated with the expression of the adjacent genes.

Conclusions

Our study indicated that four polymorphisms in m7G-mediated genes contribute to neuroblastoma susceptibility in the eastern Chinese population. However, our findings should be verified further by large-scale and well-designed studies.

Variant rs8400 enhances ALKBH5 expression through disrupting miR-186 binding and promotes neuroblastoma progression

Objective

AlkB homolog 5 (ALKBH5) has been proven to be closely related to tumors. However, the role and molecular mechanism of ALKBH5 in neuroblastomas have rarely been reported.

Methods

The potential functional single-nucleotide polymorphisms (SNPs) in ALKBH5 were identified by National Center for Biotechnology Information (NCBI) dbSNP screening and SNPinfo software. TaqMan probes were used for genotyping. A multiple logistic regression model was used to evaluate the effects of different SNP loci on the risk of neuroblastoma. The expression of ALKBH5 in neuroblastoma was evaluated by Western blotting and immunohistochemistry (IHC). Cell counting kit-8 (CCK-8), plate colony formation and 5-ethynyl-2'-deoxyuridine (EdU) incorporation assays were used to evaluate cell proliferation. Wound healing and Transwell assays were used to compare cell migration and invasion. Thermodynamic modelling was performed to predict the ability of miRNAs to bind to ALKBH5 with the rs8400 G/A polymorphism. RNA sequencing, N6-methyladenosine (m6A) sequencing, m6A methylated RNA immunoprecipitation (MeRIP) and a luciferase assay were used to identify the targeting effect of ALKBH5 on SPP1.

Results

ALKBH5 was highly expressed in neuroblastoma. Knocking down ALKBH5 inhibited the proliferation, migration and invasion of cancer cells. miR-186-3p negatively regulates the expression of ALKBH5, and this ability is affected by the rs8400 polymorphism. When the G nucleotide was mutated to A, the ability of miR-186-3p to bind to the 3'-UTR of ALKBH5 decreased, resulting in upregulation of ALKBH5. SPP1 is the downstream target gene of the ALKBH5 oncogene. Knocking down SPP1 partially restored the inhibitory effect of ALKBH5 downregulation on neuroblastoma. Downregulation of ALKBH5 can improve the therapeutic efficacy of carboplatin and etoposide in neuroblastoma.

Conclusions

We first found that the rs8400 G>A polymorphism in the m6A demethylase-encoding gene ALKBH5 increases neuroblastoma susceptibility and determines the related mechanisms. The aberrant regulation of ALKBH5 by miR-186-3p caused by this genetic variation in ALKBH5 promotes the occurrence and development of neuroblastoma through the ALKBH5-SPP1 axis.

Dual-specificity phosphatase 12 attenuates oxidative stress injury and apoptosis in diabetic cardiomyopathy via the ASK1-JNK/p38 signaling pathway

Diabetic cardiomyopathy (DCM) is ventricular dysfunction that occurs in patients with diabetes mellitus (DM), independent of recognized risk factors, such as coronary artery disease, hypertension, and valvular heart disease. Dual-specificity phosphatase 12 (DUSP12) is a dual-specificity phosphatase expressed in all tissues. Genome-wide linkage studies have found an association between DUSP12 and type 2 diabetes (T2D). However, the role of DUSP12 in DCM remains largely unknown. Ubiquitously expressed DUSP12 is involved in nonalcoholic fatty liver disease, bacterial infection, and myocardial hypertrophy and plays a critical role in tumorigenesis. Herein, we observed an increased expression of DUSP12 in a hyperglycemia cell model and a high-fat diet (HFD) mouse model. Heart-specific DUSP12-deficient mice showed severe cardiac dysfunction and remodeling induced by an HFD. DUSP12 deficiency exacerbated oxidative stress injury and apoptosis, whereas DUSP12 overexpression had the opposite effect. At the molecular level, DUSP12 physically bound to apoptotic signal-regulated kinase 1 (ASK1), promoted its dephosphorylation, and inhibited its action on c-Jun N-terminal kinase and p38 mitogen-activated protein kinase. Rescue experiments have shown that oxidative stress injury and apoptosis, exacerbated by DUSP12 deficiency, are alleviated by ASK1 inhibition. Therefore, we consider DUSP12 an important signaling pathway in DCM.

NEFL is overexpressed and it modulates invasion and migration in neuroendocrine-like PC3-ML2 prostate cancer cells

Prostate cancer clinical outcomes are varied, from non-aggressive asymptomatic to lethal aggressive neuroendocrine forms which represent a critical challenge in the management of the disease. The neurofilament light ( NEFL ) is proposed to be a tumor suppressor gene. Studies have shown that expression of the gene is decreased in various cancers. We have used quantitative RT-PCR, immunoblotting, methylation specific PCR, siRNA knockdown followed by migration/invasion assays to determine associations between NEFL expression and disease phenotype in a panel of prostate cells. We demonstrate that NEFL is overexpressed and it modulates invasion and migration in PC3-ML2 prostate cancers cells which have an aggressive neuroendocrine-like phenotype.

Exploration of genetic ancestry and socioeconomic status in the incidence of neuroblastoma: An ecological study

Although global differences in the incidence of neuroblastoma have been examined, the underlying mechanism has yet to be elucidated. Previous studies have suggested genetic ancestry and human development index (HDI) as contributing factors, but few studies have been conducted at the international level. Here, we aimed to examine whether the frequency of common genomic variation associated with neuroblastoma can affect its risk at the ecological level with consideration of the HDI. Minor allele frequencies (MAFs) for 22 single-nucleotide polymorphisms (SNPs) were abstracted from the Geography of Genetic Variants Browser. The number of incident neuroblastomas for each population was obtained from the Cancer Incidence in Five Continents series. Further, population pseudo-polygenic risk scores (pp-PRSs) were calculated as a sum of MAFs at the population level, each of which was weighted by effect sizes from prior studies. Negative binomial regression was used to estimate the incidence rate ratios (IRRs) and the 95% confidence intervals (CIs) to examine whether differences in MAFs across the population influence the risk of neuroblastoma, with and without adjustment for HDI and whether pp-PRSs can be a predictor of the risk of neuroblastoma. Overall, our results indicated that the neuroblastoma risk associated with variation in SNP frequency could not be differentiated from that of HDI at the ecological level. Additionally, pp-PRSs were not significantly associated with the risk of neuroblastoma (IRR: 0.99, 95% CI: 0.62-1.60). Further study using individual-level data is warranted to minimize the bias related to the use of population-level data in this study.

AC-265347 Inhibits Neuroblastoma Tumor Growth by Induction of Differentiation without Causing Hypocalcemia

Neuroblastoma is the most common extracranial solid tumor of childhood, with heterogeneous clinical manifestations ranging from spontaneous regression to aggressive metastatic disease. The calcium-sensing receptor (CaSR) is a G protein-coupled receptor (GPCR) that senses plasmatic fluctuation in the extracellular concentration of calcium and plays a key role in maintaining calcium homeostasis. We have previously reported that this receptor exhibits tumor suppressor properties in neuroblastoma. The activation of CaSR with cinacalcet, a positive allosteric modulator of CaSR, reduces neuroblastoma tumor growth by promoting differentiation, endoplasmic reticulum (ER) stress and apoptosis. However, cinacalcet treatment results in unmanageable hypocalcemia in patients. Based on the bias signaling shown by calcimimetics, we aimed to identify a new drug that might exert tumor-growth inhibition similar to cinacalcet, without affecting plasma calcium levels. We identified a structurally different calcimimetic, AC-265347, as a promising therapeutic agent for neuroblastoma, since it reduced tumor growth by induction of differentiation, without affecting plasma calcium levels. Microarray analysis suggested biased allosteric modulation of the CaSR signaling by AC-265347 and cinacalcet towards distinct intracellular pathways. No upregulation of genes involved in calcium signaling and ER stress were observed in patient-derived xenografts (PDX) models exposed to AC-265347. Moreover, the most significant upregulated biological pathways promoted by AC-265347 were linked to RHO GTPases signaling. AC-265347 upregulated cancer testis antigens (CTAs), providing new opportunities for CTA-based immunotherapies. Taken together, this study highlights the importance of the biased allosteric modulation when targeting GPCRs in cancer. More importantly, the capacity of AC-265347 to promote differentiation of malignant neuroblastoma cells provides new opportunities, alone or in combination with other drugs, to treat high-risk neuroblastoma patients.

Association between NER pathway gene polymorphisms and neuroblastoma risk in an eastern Chinese population

Neuroblastoma is a common childhood malignancy. Nucleotide excision repair (NER) polymorphisms have been shown to influence cancer susceptibility by modifying DNA repair efficiency. To investigate the association of NER gene polymorphisms with neuroblastoma risk, we constructed a three-center case-control study. A total of 19 candidate single-nucleotide polymorphisms (SNPs) in NER genes were analyzed. Odds ratios (ORs) and 95% confidential intervals (CIs) were calculated to evaluate the associations. We identified five independent SNPs that were significantly associated with neuroblastoma risk, including XPA rs1800975 (dominant model: adjusted OR = 0.73, 95% CI = 0.55-0.98, p = 0.033), XPA rs3176752 (recessive model: adjusted OR = 2.78, 95% CI = 1.12-6.91, p = 0.028), XPD rs3810366 (dominant: adjusted OR = 1.44, 95% CI = 1.05-1.97, p = 0.022; recessive: adjusted OR = 1.58, 95% CI = 1.18-2.11, p = 0.002), XPD rs238406 (dominant: adjusted OR = 0.64, 95% CI = 0.48-0.84, p = 0.002; recessive: adjusted OR = 0.67, 95% CI = 0.48-0.94, p = 0.021), and XPG rs2094258 (recessive: adjusted OR = 1.44, 95% CI = 1.03-2.04, p = 0.036). Stratified analysis was carried out. Furthermore, these findings were strengthened by false-positive report probability (FPRP) analysis and expression quantitative trait loci (eQTL) analysis. In conclusion, our study indicates that five SNPs in NER genes are correlated with neuroblastoma susceptibility in the eastern Chinese population, providing novel insight into the genetic underpinnings of neuroblastoma. However, further large-scale studies are required to verify these findings.

YTHDF1 gene polymorphisms and neuroblastoma susceptibility in Chinese children: an eight-center case-control study

Neuroblastoma is one of the most common life-threatening extracranial tumors that mainly occurs in children, and its genetic etiology remains largely obscure. RNA m6A modification has been thought to play a key role in cancer progression. YTHDF1 is the critical downstream gene by which RNA m6A modification exerts its functions. Single nucleotide polymorphisms in the YTHDF1 gene may affect its expression and biological activity, thereby leading to abnormalities in the regulation of downstream m6A-modified RNA and eventually promoting the initiation and development of tumors. Here, we attempted to evaluate the contributions of two polymorphisms (rs6011668 C>T and rs6090311 A>G) in the YTHDF1 gene to neuroblastoma susceptibility in 898 cases and 1734 controls that originated in China. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in the logistic regression models to evaluate the associations between selected polymorphisms and neuroblastoma risk. Overall, either in a single locus or combination analysis, no significant association with neuroblastoma risk was found for either of the two selected polymorphisms. However, the stratified analysis showed that rs6090311AG/GG genotypes significantly reduced the neuroblastoma risk in males (adjusted OR=0.77, 95% CI=0.62-0.96, P=0.018). Moreover, we found that subjects with 2 protective genotypes had a lower tumor risk in males than in those with 0-1 protective genotypes (adjusted OR=0.77, 95% CI=0.62-0.96, P=0.018). In summary, our study indicates that YTHDF1 gene polymorphisms may weakly contribute to neuroblastoma susceptibility. Our findings should be further verified by well-designed studies with larger sample sizes.

Identification of novel prognostic markers of survival time in high-risk neuroblastoma using gene expression profiles

Neuroblastoma is the most common extracranial solid tumor in childhood. Patients in high-risk group often have poor outcomes with low survival rates despite several treatment options. This study aimed to identify a genetic signature from gene expression profiles that can serve as prognostic indicators of survival time in patients of high-risk neuroblastoma, and that could be potential therapeutic targets. RNA-seq count data was downloaded from UCSC Xena browser and samples grouped into Short Survival (SS) and Long Survival (LS) groups. Differential gene expression (DGE) analysis, enrichment analyses, regulatory network analysis and machine learning (ML) prediction of survival group were performed. Forty differentially expressed genes (DEGs) were identified including genes involved in molecular function activities essential for tumor proliferation. DEGs used as features for prediction of survival groups included EVX2, NHLH2, PRSS12, POU6F2, HOXD10, MAPK15, RTL1, LGR5, CYP17A1, OR10AB1P, MYH14, LRRTM3, GRIN3A, HS3ST5, CRYAB and NXPH3. An accuracy score of 82% was obtained by the ML classification models. SMIM28 was revealed to possibly have a role in tumor proliferation and aggressiveness. Our results indicate that these DEGs can serve as prognostic indicators of survival in high-risk neuroblastoma patients and will assist clinicians in making better therapeutic and patient management decisions.

Genetic predisposition and chromosome instability in neuroblastoma

Neuroblastoma (NB) is a pediatric tumor of embryonic origin. About 1-2% of all NBs are familial cases, and genetic predisposition is suspected for the remaining cases. During the last decade, genome-wide association studies (GWAS) and high-throughput sequencing approaches have been used to identify associations among common and rare genetic variants and NB risk. Substantial data has been produced by large patient cohorts that implicate various genes in NB tumorigenesis, such as CASC15, BARD1, CHEK2, LMO1, LIN28B, AXIN2, BRCA1, TP53, SMARCA4, and CDK1NB. NB, as well as other pediatric cancers, has few recurrent mutations but several copy number variations (CNVs). Almost all NBs show both numerical and structural CNVs. The proportion between numerical and structural CNVs differs between localized and metastatic tumors, with a greater prevalence of structural CNVs in metastatic NB. This genomic chaos frequently identified in NBs suggests that chromosome instability (CIN) could be one of the major actors in NB oncogenesis. Interestingly, many NB-predisposing variants occur in genes involved in the control of genome stability, mitosis, and normal chromosome separation. Here, we discuss the relationship between genetic predisposition and CIN in NB.

Genetic Predisposition to Solid Pediatric Cancers

Progresses over the past years have extensively improved our capacity to use genome-scale analyses—including high-density genotyping and exome and genome sequencing—to identify the genetic basis of pediatric tumors. In particular, exome sequencing has contributed to the evidence that about 10% of children and adolescents with tumors have germline genetic variants associated with cancer predisposition. In this review, we provide an overview of genetic variations predisposing to solid pediatric tumors (medulloblastoma, ependymoma, astrocytoma, neuroblastoma, retinoblastoma, Wilms tumor, osteosarcoma, rhabdomyosarcoma, and Ewing sarcoma) and outline the biological processes affected by the involved mutated genes. A careful description of the genetic basis underlying a large number of syndromes associated with an increased risk of pediatric cancer is also reported. We place particular emphasis on the emerging view that interactions between germline and somatic alterations are a key determinant of cancer development. We propose future research directions, which focus on the biological function of pediatric risk alleles and on the potential links between the germline genome and somatic changes. Finally, the importance of developing new molecular diagnostic tests including all the identified risk germline mutations and of considering the genetic predisposition in screening tests and novel therapies is emphasized.

METTL14 Gene Polymorphisms Confer Neuroblastoma Susceptibility: An Eight-Center Case-Control Study

Neuroblastoma is the primary cause of cancer death in childhood. METTL14 is tightly linked to cancer. However, whether single-nucleotide polymorphisms (SNPs) in the METTL14 gene could predispose to neuroblastoma susceptibility lacks evidence. With an epidemiology case-control study, associations between METTL14 gene SNPs and overall risk for neuroblastoma were estimated in 898 cases and 1,734 controls. Following that, stratified analysis was performed. Among the five analyzed SNPs, rs298982 G>A and rs62328061 A>G exhibited a significant association with decreased susceptibility to neuroblastoma, whereas the associations with increased neuroblastoma susceptibility were observed for rs9884978 G>A and rs4834698 T>C. Moreover, subjects carrying two to five risk genotypes were more inclined to develop neuroblastoma than those with zero to one risk genotypes. The stratified analysis further demonstrated the protective effect of rs298982 G>A and rs62328061 A>G, as well as the predisposing effect of rs4834698 T>C and two to five risk genotypes, in certain subgroups. Haplotype analysis was performed. Moreover, false-positive report probability analysis validated the reliability of the significant results. The expression quantitative trait locus analysis revealed that rs298982 is correlated with the expression levels of its surrounding genes. Our results suggest that some SNPs in the METTL14 gene are associated with predisposition to neuroblastoma.

Association between METTL3 gene polymorphisms and neuroblastoma susceptibility: A nine-centre case-control study

Neuroblastoma ranks as the most commonly seen and deadly solid tumour in infancy. The aberrant activity of m6 A-RNA methyltransferase METTL3 is involved in human cancers. Therefore, functional genetic variants in the METTL3 gene may contribute to neuroblastoma risk. In the current nine-centre case-control study, we aimed to analyse the association between the METTL3 gene single nucleotide polymorphisms (SNPs) and neuroblastoma susceptibility. We genotyped four METTL3 gene SNPs (rs1061026 T>G, rs1061027 C>A, rs1139130 A>G, and rs1263801 G>C) in 968 neuroblastoma patients and 1814 controls in China. We found significant associations between these SNPs and neuroblastoma risk in neither single-locus nor combined analyses. Interestingly, in the stratified analysis, we observed a significant risk association with rs1061027 AA in subgroups of children ≤ 18 months of age (adjusted OR = 1.87, 95% CI = 1.03-3.41, P = .040) and females (adjusted OR = 1.86, 95% CI = 1.07-3.24, P = .028). Overall, we identified a significant association between METTL3 gene rs1061027 C>A polymorphism and neuroblastoma risk in children ≤18 months of age and females. Our findings provide novel insights into the genetic determinants of neuroblastoma.

Genome-Wide Association Study for the Identification of Novel Genetic Variants Associated with the Risk of Neuroblastoma in Korean Children

Purpose

Neuroblastoma (NB) is the most common extracranial solid tumor found in children. To identify significant genetic factors for the risk of NB, several genetic studies was conducted mainly for Caucasians and Europeans. However, considering racial differences, there is a possibility that genetic predispositions that contribute to the development of NB are different, and genome-wide association study has not yet been conducted on Korean NB patients.

Materials and Methods

To identify the genetic variations associated with the risk of pediatric NB in Korean children, we performed a genome-wide association analysis with 296 NB patients and 1,000 unaffected controls (total n=1,296) after data cleaning and filtering as well as imputation of non-genotyped single nucleotide polymorphisms (SNPs) using IMPUTE v2.3.2.

Results

After adjusting for multiple comparisons, we found 21 statistically significant SNPs associated with the risk of NB (P^corr < 0.05) within 12 genes (RPTN, MRPS18B, LRRC45, KANSL1L, ARHGEF40, IL15RA, L1TD1, ANO7, LAMA5, OR7G2, SALL4, and NEUROG2). Interestingly, out of these, 12 markers were nonsynonymous SNPs. The SNP rs76015112 was most significantly associated with the risk of NB (p = 8.1E-23, P^corr = 2.3E-17) and was located in the RPTN gene. In addition, significant nonsynonymous SNPs in ADGRE1 were found in patients with MYCN amplification (rs7256147, p = 2.6E-05). In high-risk group, rs7256147 was observed as a significant SNP (p = 5.9E-06).

Conclusion

Our findings might facilitate improved understanding of the mechanism of pediatric NB pathogenesis. However, functional evaluation and replication of these results in other populations are still needed.

Association of PARP1 polymorphisms with response to chemotherapy in patients with high-risk neuroblastoma

The genetic aetiology and the molecular mechanisms that characterize high‐risk neuroblastoma are still little understood. The majority of high‐risk neuroblastoma patients do not take advantage of current induction therapy. So far, one of the main reasons liable for cancer therapeutic failure is the acquisition of resistance to cytotoxic anticancer drugs, because of the DNA repair system of tumour cells. PARP1 is one of the main DNA damage sensors involved in the DNA repair system and genomic stability. We observed that high PARP1 mRNA level is associated with unfavourable prognosis in 3 public gene expression NB patients’ datasets and in 20 neuroblastomas analysed by qRT‐PCR. Among 4983 SNPs in PARP1, we selected two potential functional SNPs. We investigated the association of rs907187, in PARP1 promoter, and rs2048426 in non‐coding region with response chemotherapy in 121 Italian patients with high‐risk NB. Results showed that minor G allele of rs907187 associated with induction response of patients (P = .02) and with decrease PARP1 mRNA levels in NB cell line (P = .003). Furthermore, rs907187 was predicted to alter the binding site of E2F1 transcription factor. Specifically, allele G had low binding affinity with E2F1 whose expression positively correlates with PARP1 expression and associated with poor prognosis of patients with NB. By contrast, we did not find genetic association for the SNP rs2048426. These data reveal rs907187 as a novel potential risk variant associated with the failure of induction therapy for high‐risk NB.

NRAS rs2273267 A>T polymorphism reduces neuroblastoma risk in Chinese children

Neuroblastoma is an extracranial solid tumor that mainly occurs in childhood. Mutations of NRAS gene have been described in several cancers. However, whether NRAS gene polymorphisms can predict the risk of neuroblastoma have not been investigated. We hypothesized that variations of NRAS gene contribute to neuroblastoma predisposition. Therefore, we conducted a multi-center case-control study using 263 cases and 715 controls to examine the association of NRAS gene rs2273267 A>T polymorphism and neuroblastoma risk. We calculated odds ratios (ORs) and corresponding 95% confidence intervals (CIs) to assess the strength of the associations. Relative to those with AA genotype, subjects with AT/TT genotype had reduced neuroblastoma risk (adjusted OR = 0.72, 95% CI = 0.54-0.96, P = 0.024). Stratified analysis revealed that rs2273267 AT/TT carriers were less likely to develop neuroblastoma for patients with tumor originating from the adrenal gland (adjusted OR = 0.67, 95% CI = 0.45-0.99, P = 0.047) and clinical stages III + IV (adjusted OR = 0.57, 95% CI = 0.36-0.90, P = 0.015). Our findings underline the likely importance of NRAS gene rs2273267 A>T in the risk of neuroblastoma. Further independent case-control studies with functional analysis are needed to verify the role of NRAS gene rs2273267 A>T polymorphism in the risk of neuroblastoma.

Functional characterization of full-length BARD1 strengthens its role as a tumor suppressor in neuroblastoma

BARD1 is associated with the development of high-risk neuroblastoma patients. Particularly, the expression of full length (FL) isoform, FL BARD1, correlates to high-risk neuroblastoma development and its inhibition is sufficient to induce neuroblastoma cells towards a worst phenotype. Here we have investigated the mechanisms of FL BARD1 in neuroblastoma cell lines depleted for FL BARD1 expression. We have shown that FL BARD1 expression protects the cells from spontaneous DNA damage and from damage accumulated after irradiation. We demonstrated a role for FL BARD1 as tumor suppressor to prevent unscheduled mitotic entry of DNA damaged cells and to lead to death cells that have bypassed cell cycle checkpoints. FL BARD1-depleted cells that have survived to checkpoints acquire features of aggressiveness. Overall, our results show that FL BARD1 may defend cells against cancer and prevent malignant transformation of cells.

LIN28A gene polymorphisms modify neuroblastoma susceptibility: A four-centre case-control study

Neuroblastoma ranks the most common seen solid tumour in childhood. Overexpression of LIN28A gene has been linked to the development of multiple human malignancies, but the relationship between LIN28A single nucleotide polymorphisms (SNPs) and neuroblastoma susceptibility is still under debate. Herein, we evaluated the correlation of four potentially functional LIN28A SNPs (rs3811464 G>A, rs3811463 T>C, rs34787247 G>A, and rs11247957 G>A) and neuroblastoma susceptibility in 505 neuroblastoma patients and 1070 controls from four independent hospitals in China. The correlation strengths were determined by using odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Among these SNPs, rs34787247 G>A exhibited a significant association with increased susceptibility in neuroblastoma (GA vs GG: adjusted OR = 1.30, 95% CI = 1.03-1.64; AA vs GG: adjusted OR = 2.51, 95% CI = 1.36-4.64, AA/GA vs GG: adjusted OR = 1.42, 95% CI = 1.12-1.80, AA vs GG/GA: adjusted OR = 2.39, 95% CI = 1.29-4.42). Furthermore, the combined analysis of risk genotypes revealed that subjects carrying three risk genotypes (adjusted OR = 1.64, 95% CI = 1.02-2.63) are more inclined to develop neuroblastoma than those without risk genotype, and so do carriers of 1-4 risk genotypes (adjusted OR = 1.26, 95% CI = 1.01-1.56). Stratification analysis further revealed risk effect of rs3811464 G>A, rs34787247 G>A and 1-4 risk genotypes in some subgroups. Haplotype analysis of these four SNPs yields two haplotypes significantly correlated with increased neuroblastoma susceptibility. Overall, our finding indicated that LIN28A SNPs, especially rs34787247 G>A, may increase neuroblastoma risk.

HMGA2 Gene rs8756 A>C Polymorphism Reduces Neuroblastoma Risk in Chinese Children: A Four-Center Case-Control Study

BACKGROUND

Neuroblastoma, mainly affecting children, is a lethal malignancy arising from the developing sympathetic nervous system. The genetic etiology of neuroblastoma remains mostly obscure. High mobility group AT-hook 2 (HMGA2), an oncogenic gene, is up-regulated in many tumors. Single nucleotide polymorphisms (SNPs) often modify cancer susceptibility. However, no studies are investigating the association between HMGA2 SNPs and neuroblastoma susceptibility.

METHODS

We conducted a four-center case-control study to evaluate the association between three HMGA2 polymorphisms (rs6581658 A>G, rs8756 A>C and rs968697 T>C) and neuroblastoma susceptibility in a Chinese population with 505 cases and 1070 controls. Logistic regression was performed to evaluate the strength of the association.

RESULTS

We found that the rs8756 AC/CC genotypes were associated with a reduced neuroblastoma risk when compared to rs8756 AA genotype [Adjusted odds ratio (OR)=0.74, 95% confidence interval (CI)=0.56-0.99, P=0.039]. Carriers with 3 protective genotypes have lower neuroblastoma susceptibility than those without or with 0-2 protective genotypes. The stratified analysis revealed that the protective effects of rs8756 AC/CC genotypes were more predominant among children of age > 18 months, males, and subgroups with the tumor in the mediastinum. Furthermore, haplotype analysis uncovered that haplotype ACC significantly reduced neuroblastoma risk.

CONCLUSION

Our study indicated HMGA2 rs8756 A>C polymorphism is significantly associated with decreased neuroblastoma risk.

Association of miR-34b/c rs4938723 and TP53 Arg72Pro Polymorphisms with Neuroblastoma Susceptibility: Evidence from Seven Centers

Neuroblastoma is a pediatric malignancy arising from the developing peripheral nervous system. p53 and downstream effector miR-34b/c have critical tumor suppressing functions. TP53 Arg72Pro (rs1042522 C > G) and miR-34b/c rs4938723 (T > C) polymorphisms have been known to modify cancer susceptibility. This study was performed to validate the association of these two polymorphisms and neuroblastoma risk with 819 cases and 1780 controls. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to assess the strength of the associations. False positive report possibility analysis was adopted to dissect out real significant associations from chance findings. We found that both TP53 Arg72Pro (CG/GG vs. CC: adjusted OR = 0.82, 95% CI = 0.69-0.98) and miR-34b/c rs4938723 (TC/CC vs. TT: adjusted OR = 0.64, 95% CI = 0.54-0.75) were associated with decreased neuroblastoma susceptibility. Stratify analyses further confirmed the protective effect among some subgroups. Moreover, subjects with variant alleles of both polymorphisms were associated with more significantly decreased neuroblastoma risk (CG/TC vs. CC/TT: adjusted OR = 0.38, 95% CI = 0.28-0.50; GG/TC vs. CC/TT: adjusted OR = 0.43, 95% CI = 0.30-0.63) than those carrying variant allele of either one polymorphism (CC/TC vs. CC/TT: adjusted OR = 0.51, 95% CI = 0.37-0.69; CG/TT vs. CC/TT: adjusted OR = 0.71, 95% CI = 0.55-0.92), suggesting cumulative effects of the polymorphisms. False positive report possibility analysis further verified that our findings are noteworthy. Overall, we confirmed that miR-34b/c rs4938723 and TP53 Arg72Pro conferred decreased neuroblastoma risk and two polymorphisms exerted stronger protective effects against neuroblastoma than either one alone.

Exploring Shared Susceptibility between Two Neural Crest Cells Originating Conditions: Neuroblastoma and Congenital Heart Disease

In the past years, genome wide association studies (GWAS) have provided evidence that inter-individual susceptibility to diverse pathological conditions can reveal a common genetic architecture. Through the analysis of congenital heart disease (CHD) and neuroblastoma (NB) GWAS data, we aimed to dissect the genetic susceptibility shared between these conditions, which are known to arise from neural crest cell (NCC) migration or development abnormalities, via identification and functional characterization of common regions of association. Two loci (2q35 and 3q25.32) harbor single nucleotide polymorphisms (SNPs) that are associated at a p-value < 10^-3 with conotruncal malformations and ventricular septal defect respectively, as well as with NB. In addition, the lead SNP in 4p16.2 for atrial septal defect and the lead SNP in 3q25.32 for tetralogy of Fallot are less than 250 Kb distant from the lead SNPs for NB at the same genomic regions. Some of these shared susceptibility loci regulate the expression of relevant genes involved in NCC formation and developmental processes (such as BARD1, MSX1, and SHOX2) and are enriched in several epigenetic markers from NB and fetal heart cell lines. Although the clinical correlation between NB and CHD is unclear, our exploration of a possible common genetic basis between NB and a subset of cardiac malformations can help shed light on their shared embryological origin and pathogenetic mechanisms.

Emodin relieves hypoxia-triggered injury via elevation of microRNA-25 in PC-12 cells

Emodin (EMO) possesses extensive pharmacological activities, which has been proven to exert the protective impact in diverse nervous system diseases. Nonetheless, whether EMO emerges a neuro-protective activity in hypoxic-evoked ischemic brain injury is still further probed. The intention of the research is to disclose whether EMO emerges neuro-protective activity in hypoxic-evoked ischemic brain injury. PC-12 received hypoxia administration, and then cell viability, apoptosis and autophagy were estimated. After EMO disposition, the above-involved cellular processes were evaluated again. MiR-25 functions in EMO-affected cells were also estimated. The interrelation between miR-25 and neurofilament light-chain polypeptide gene (NEFL) and the conceivable roles of NEFL in hypoxia-disposed cells were investigated. The latent mechanism was uncovered by mTOR and Notch pathways determination. Hypoxia triumphantly triggered apoptosis and autophagy, but EMO repressed these functions in PC-12 cells. Increased miR-25 was induced by EMO, and inhibited miR-25 abated the impacts of EMO on hypoxia-disposed PC-12 cells. NEFL as a neoteric target gene of miR-25 was predicated, and overexpressed NEFL annulled the functions of EMO in hypoxia-injured cells. EMO activated mTOR and Notch pathways through repressing NEFL. The investigations corroborated that EMO weakened hypoxia-triggered injury via elevating miR-25 by targeting NEFL in PC-12 cells.

Association of miR-146a, miR-149 and miR-196a2 polymorphisms with neuroblastoma risk in Eastern Chinese population: a three-center case-control study

Neuroblastoma is one of the most common malignancy in childhood, which originates from the developing sympathetic nervous system. Single nucleotide polymorphisms (SNPs) in primary miRNA (pri-miRNA) have shown to associate with cancer susceptibility, including neuroblastoma. Three precursor miRNA (pre-miRNA) SNPs (pre-miR-146a rs2910164, pre-miR-149 rs2292832 and pre-miR-196a2 rs11614913) were found to contribute to pathogenesis of various diseases. Here, to evaluate the association among these three pre-miRNA SNPs and neuroblastoma susceptibility in Eastern Chinese children, we carried out a three-center case-control study involving 312 neuroblastoma cases and 762 healthy controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the association of these three polymorphisms with neuroblastoma risk. However, no significant association was observed among these three SNPs and neuroblastoma susceptibility, in either overall or subgroups analysis by tumor sites, gender and age. Further larger studies consisting of diverse ethnic populations are required to clarify the associations among these three pre-miRNAs polymorphisms and neuroblastoma risk.

Functional Polymorphisms in BARD1 Association with Neuroblastoma in a regional Han Chinese Population

Neuroblastoma (NB) is a sympathetic nervous system cancer for children, occupying approximately 15% of pediatric oncology deaths. BARD1, a tumor suppressor, is essential for genome stability by interaction with BRCA1. Here, we performed a systematic investigation for the association between SNPs in BARD1 and the risk of NB in Chinese population. After SNP screening in BARD1 gene, we performed case-control study of eleven selected SNPs in BARD1 with 339 NB patients and 778 cancer-free controls. The OR and 95% CI of these candidate SNPs were computed by logistic regression. After adjusted gender and age, seven out of eleven SNPs in BARD1 were significant associated with the risk of NB, including one SNP in 5'-UTR (rs17489363 G > A), two SNPs in exon (rs2229571 G > C and rs3738888 C > T), and four SNPs in intron (rs3768716 A > G, rs6435862 T > G, rs3768707 C > T and rs17487792 C > T). When stratified by the INPC, primary tumor site and the INSS, these seven SNPs were significant associated with GNB/NB, stage III/IV and adrenal origin of NB. Dual-luciferase reporter assay showed rs17489363 A allele-containing haplotypes (TAC, CAC, TAG and CAG), composed with rs34732883 T > C, and rs1129804 C > G, dramatically reduced the transcriptional activity of reporter gene. The major of our study showed that seven SNPs of BARD1 associated with increased NB risk in Chinese population, and four haplotypes could reduce transcription activity of BARD1.

Additional data support the role of LINC00673 rs11655237 C>T in the development of neuroblastoma

Neuroblastoma is the most frequently diagnosed neural tumor of childhood. Abnormal function of the long intergenic non-coding RNA (lincRNA) LINC00673 has been implicated in various human malignancies. Genome-wide association studies revealed the LINC00673 rs11655237 C>T polymorphism to be associated with the risk of neuroblastoma, though the effect was not well defined, in part due to the small sample size in our earlier study. Herein, we verified the impact of LINC00673 rs11655237 C>T on the risk of neuroblastoma in 700 cases and 1516 controls from six centers in China. After pooling all enrolled patients, we observed a significant association between LINC00673 rs11655237 C>T and risk of neuroblastoma (TT vs. CC: adjusted odds ratio [OR]=1.58, 95% confidence interval [CI]=1.06-2.35, P=0.024; additive model: adjusted OR=1.20, 95% CI=1.03-1.39, P=0.020; recessive model: adjusted OR=1.50, 95% CI=1.02-2.22, P=0.040). Stratification analysis revealed a significant relationship between rs11655237 CT/TT and neuroblastoma risk in subgroups of males, patients whose tumor originated in the adrenal gland, and patients with clinical stage IV disease. These findings add new evidence of the importance of LINC00673 rs11655237 C>T to the risk of developing neuroblastoma.

MicroRNA-7a ameliorates neuropathic pain in a rat model of spinal nerve ligation via the neurofilament light polypeptide-dependent signal transducer and activator of transcription signaling pathway

Neuropathic pain is a type of chronic pain induced by either central or peripheral nerve injury. MicroRNAs have been recently linked to many diseases, including neuropathic pain. However, the role of miR-7a in neuropathic pain still remains elusive. Thus, we aim to investigate the effects of miR-7a on neuropathic pain based on the spinal nerve ligation rat model. After establishment of spinal nerve ligation rat models, rats were infected with adeno-associated virus-neurofilament light polypeptide, adeno-associated virus-miR-7a or treated with metformin. The paw withdrawal threshold and paw withdrawal latency were assessed afterward, and the expression of miR-7a and neurofilament light polypeptide as well as their interaction was determined. Subsequently, miR-7a was overexpressed or silenced in dorsal root ganglion cells to investigate the role of miR-7a in neuropathic pain. Furthermore, the regulatory effect of neurofilament light polypeptide on neuropathic pain was detected using plasmid overexpressing neurofilament light polypeptide. Spinal nerve ligation rat model exhibited upregulation of neurofilament light polypeptide but downregulation of miR-7a. In addition, neurofilament light polypeptide accumulation or miR-7a inhibition decreased paw withdrawal threshold and paw withdrawal latency. Then, neurofilament light polypeptide accumulation or miR-7a inhibition was observed to increase the phosphorylation level of signal transducer and activator of transcription. miR-7a was found to directly target neurofilament light polypeptide and downregulate neurofilament light polypeptide. In addition, inhibiting the signal transducer and activator of transcription signaling pathway was also revealed to increase paw withdrawal threshold and paw withdrawal latency. Collectively, our study demonstrated that miR-7a ameliorated neuropathic pain via blocking the signal transducer and activator of transcription signaling pathway by repressing neurofilament light polypeptide. These findings, if taken further, can be of important clinical significance in treating patients with neuropathic pain.

Neuroblastoma-A Neural Crest Derived Embryonal Malignancy

Neuroblastoma is a neural crest derived malignancy of the peripheral nervous system and is the most common and deadliest tumor of infancy. It is characterized by clinical heterogeneity with a disease spectrum ranging from spontaneous regression without any medical intervention to treatment resistant tumors with metastatic spread and poor patient survival. The events that lead to the development of neuroblastoma from the neural crest have not been fully elucidated. Here we discuss factors and processes within the neural crest that when dysregulated have the potential to be initiators or drivers of neuroblastoma development. A more precise biological understanding of neuroblastoma causes and cell of origin is highly warranted. This will give valuable information for the development of medicines that specifically target molecules within neuroblastoma cells and also give hint about the mechanisms behind treatment resistance that is frequently seen in neuroblastoma.

APEX1 Polymorphisms and Neuroblastoma Risk in Chinese Children: A Three-Center Case-Control Study

Neuroblastoma is a life-threatening extracranial solid tumor, preferentially occurring in children. However, its etiology remains unclear. APEX1 is a critical gene in the base excision repair (BER) system responsible for maintaining genome stability. Given the potential effects of APEX1 polymorphisms on the ability of the DNA damage repair, many studies have investigated the association between these variants and susceptibility to several types of cancer but not neuroblastoma. Here, we conducted a three-center case-control study to evaluate the association between APEX1 polymorphisms (rs1130409 T>G, rs1760944 T>G, and rs3136817 T>C) and neuroblastoma risk in Chinese children, consisting of 469 cases and 998 controls. Odds ratio (OR) and 95% confidence intervals (CIs) were calculated to evaluate the associations. No significant association with neuroblastoma risk was found for the studied APEX1 polymorphisms in the single locus or combination analysis. Interestingly, stratified analysis showed that rs1130409 GG genotype significantly reduced the risk of tumor in males. Furthermore, we found that carriers with 1-3 protective genotypes had a lower neuroblastoma risk in the children older than18 months and male, when compared to those without protective genotypes. In summary, our data indicate that APEX1 gene polymorphisms may have a weak effect on neuroblastoma susceptibility. These findings should be further validated by well-designed studies with larger sample size.

Association of NEFL Gene Polymorphisms with Wilms' Tumor Susceptibility in Chinese Children

Wilms' tumor is renal tumor of childhood, characterized by the appearance of embryonic renal tissue and other kidney malformations. The genetic etiology of sporadic Wilms' tumor remains largely unknown. Neurofilament light (NEFL) is a tumor suppressor. We evaluated the association between three NEFL gene polymorphisms (rs11994014 G>A, rs2979704 T>C and rs1059111 A>T) and Wilms' tumor susceptibility in a Chinese population consisting of 145 cases and 531 controls. In the single locus analysis, rs2979704 CC variant genotype was associated with a decreased risk of Wilms' tumor [CC vs. TT: adjusted odds ratio (OR)=0.48, 95% confidence interval (CI)=0.24-0.94; CC vs. TT+CT: adjusted OR=0.51, 95% CI=0.27-0.97]. We also observed that carriers of the three protective genotypes had significantly decreased risk of Wilms' tumor when compared to those with 0-2 protective genotypes (adjusted OR=0.49, 95% CI=0.25-0.95). The association between rs11994014 G>A or rs1059111 A>T polymorphisms and Wilms' tumor susceptibility did not reach statistical significance. No significant association was detected in the stratified analyses. Our findings suggested that the NEFL rs2979704 T>C polymorphism may be associated with Wilms' tumor susceptibility in the Chinese population.

miR-34b/c rs4938723 T>C Decreases Neuroblastoma Risk: A Replication Study in the Hunan Children

Neuroblastoma is the most common seen solid neural tumor in children less than age one. As mutation in the miR-34b/c gene is observed in several types of human malignancies, there likely to be similar events that contribute to the pathogenesis of neuroblastoma. We hypothesize that polymorphism in the miR-34b/c gene might predispose to neuroblastoma. Here, we conducted this replication study by genotyping rs4938723 T>C from miR-34b/c in Hunan children (162 subjects with neuroblastoma and 270 control subjects) and examined its effect on the risk of neuroblastoma. We determined such association using logistic regression, adjusted for age and gender. Relative to those with TT genotype, subjects with C allele had reduced neuroblastoma risk (TC vs. TT: adjusted OR = 0.46, 95%CI = 0.30-0.71; additive model: adjusted OR = 0.64, 95%CI = 0.47-0.88; TC/CC vs. TT: adjusted OR = 0.49, 95%CI = 0.33-0.73). Stratified analysis revealed that rs4938723 TC/CC carriers were less likely to develop neuroblastoma for patients in the subgroups of age ≤ 18 months, age > 18 months, females, males, tumors in retroperitoneal, tumors in other sites, and clinical stages II, III, IV, and III+IV. Our findings verified miR-34b/c rs4938723 C variant allele as a protective factor for the risk of neuroblastoma. Further investigation of how miR-34b/c rs4938723 T>C might modify neuroblastoma risk is warranted.

H19 gene polymorphisms and neuroblastoma susceptibility in Chinese children: a six-center case-control study

Neuroblastoma is the most common seen solid tumor in children less than one year old. Given that polymorphisms in the lncRNA H19 gene are observed in several types of human malignancies, there likely to be similar events that contribute to the pathogenesis of neuroblastoma. We hypothesize that single nucleotide polymorphisms (SNPs) in the H19 gene might predispose to neuroblastoma. Here, we genotyped three SNPs (rs2839698 G>A, rs3024270 C>G, rs217727 G>A) from H19 gene in a Chinese population (700 subjects with neuroblastoma and 1516 control subjects) enrolled from six hospitals and examined the effect of individual and combined SNPs on the risk of neuroblastoma. Odds ratios (ORs) and 95% confidence intervals (CIs) calculated from logistic regression were adopted to assess such association, adjusted for age and gender. Among them, 700 controls and 1514 cases were successfully genotyped. None of these three SNPs were found to be relevant to the risk of neuroblastoma, either in overall analysis or stratification analysis. Findings from this study excluded the participation of lncRNA H19 gene SNPs in the risk of neuroblastoma. More independent case-control studies are encouraged to better elucidate this relationship.

TP53 gene rs1042522 allele G decreases neuroblastoma risk: a two-centre case-control study

The TP53 gene plays a crucial role in the prevention of cancer formation, which is closely related to TP53 mutation. TP53 gene polymorphism rs1042522 C>G was largely investigated in various cancers, but its contribution to neuroblastoma is as yet undefined. Here, we evaluated the effect of the TP53 gene rs1042522 C>G polymorphism on the development of neuroblastoma in two different regions, with patients from hospitals in both North and South China. The clinical data involved 374 patients and 812 controls. The resulting odds ratios (ORs) and 95% confidence intervals (CIs) were used with a logistic regression model to determine the intensity of associations between the factors of interest. We found that the TP53 gene rs1042522 allele G was associated with a reduced risk of developing neuroblastoma. In our stratified analysis of age, sex, primary sites and clinical stages, we observed that male children, older than 18 months, with tumours derived from the mediastinum who had the rs1042522 CG/GG genotypes were at a decreased risk of developing neuroblastoma. These results indicate that the TP53 gene rs1042522 allele G may be a potential protective factor against neuroblastoma in Chinese children.

PARP1 gene polymorphisms and neuroblastoma susceptibility in Chinese children

Neuroblastoma is a heterogeneous cancer frequently occurring in childhood. Germline mutations of PARP1 oncogene are implicated in several types of cancer. However, whether common single nucleotide polymorphisms (SNPs) in PARP1 gene are associated with neuroblastoma risk has received relatively few attentions. In this multi-center study, we aimed to elucidate the contributing role of PARP1 SNPs in neuroblastoma risk. We successfully genotyped three potentially functional PARP1 SNPs (rs1136410 A>G, rs2666428 T>C, rs8679 A>G) in 469 neuroblastoma cases and 998 controls. We did not detect any significant association between the analyzed SNPs and neuroblastoma risk in single SNP analysis. However, stratified analysis revealed that rs1136410 AG/GG carriers were more likely to develop tumors arising from mediastinum (AG/GG vs. AA: adjusted OR=1.65, 95% CI=1.06-2.56, P=0.028). Moreover, rs2666428 TC/CC carriers were at significantly lower risk to develop tumors from "other sites" (TC/CC vs. TT: adjusted OR=0.44, 95% CI=0.20-0.96, P=0.040). Our findings failed to provide evidence of the conferring role of the PARP1 gene polymorphisms in the risk of neuroblastoma. Further investigations of the association between PARP1 gene SNPs and neuroblastoma risk are warranted.

KRAS rs7973450 A>G increases neuroblastoma risk in Chinese children: a four-center case-control study

BACKGROUND

Neuroblastoma is one of the most common extracranial solid pediatric tumors. KRAS plays an important role in regulating cell proliferation, differentiation, and apoptosis. Single nucleotide polymorphisms (SNPs) in KRAS have been shown to modify susceptibility to multiple tumors, but no specific molecular epidemiology study was reported regarding neuroblastoma.

METHODS

We conducted a four-center case-control study to explore the association between KRAS gene polymorphisms (rs12587 G>T, rs7973450 A>G, rs7312175 G>A) and neuroblastoma susceptibility with 505 Chinese children and 1070 matched controls.

RESULTS

We found that rs7973450 A>G was associated with significantly increased neuroblastoma risk [GG vs. AA: adjusted odds ratio (OR)=4.26, 95% confidence interval (CI)=1.28-14.19, P=0.018; GG vs. AA/AG: adjusted OR=4.27, 95% CI=1.28-14.24, P=0.018]. The stratified analysis further demonstrated that rs7973450 GG genotype carriers had a higher risk to develop neuroblastoma in the subgroups of males, tumor originated from the adrenal gland and clinical stages III+IV.

CONCLUSIONS

Overall, our results suggested that rs7973450 A>G was associated with increased neuroblastoma risk.

Association of the TP53 rs1042522 C>G polymorphism and hepatoblastoma risk in Chinese children

The TP53 gene encodes an important class of cell cycle and tumor-suppressing factors that play critical roles in maintaining genomic stability. The TP53 Arg72Pro (rs1042522 C>G) polymorphism has been reported to be associated with the risk of several types of adult cancers; however, its risk for pediatric cancers remains unclear. Here, we analyzed the association of the TP53 gene rs1042522 C>G polymorphism with hepatoblastoma (HB) susceptibility in a hospital-based study among Chinese children. A total of 213 HB patients and 958 healthy controls were enrolled in the study. Genotypes were determined by a TaqMan assay, and the strength of the association was assessed by the odds ratios and 95% confidence intervals generated from logistic regression models, adjusted for age, gender, and clinical stage. No significant association between the TP53 rs1042522 C>G polymorphism and HB susceptibility was detected in the main analysis or in stratification analyses of age, gender, and clinical stages. Overall, the TP53 gene rs1042522 C>G polymorphism is not associated with HB susceptibility in the Chinese population, other polymorphisms alone or in combination should be investigated to further clarify HB susceptibility.

Fine mapping of 2q35 high-risk neuroblastoma locus reveals independent functional risk variants and suggests full-length BARD1 as tumor-suppressor

A previous genome-wide association study (GWAS) identified common variation at the BARD1 locus as being highly associated with susceptibility to high-risk neuroblastoma, but the mechanisms underlying this association have been not extensively investigated. Here, we performed a fine mapping analysis of BARD1 locus (2q35) using GWAS data from 556 high-risk neuroblastoma patients and 2,575 controls of European-American ancestry, and identified two independent genome-wide neuroblastoma-associated loci. Functional single-nucleotide polymorphism (SNP) prioritization identified two causative variants that independently contributed to neuroblastoma risk, and each replicated robustly in multiple independent cohorts comprising 445 high-risk cases and 3,170 controls (rs17489363: combined p = 1.07 × 10-31 , OR:1.79, 95% CI:1.62-1.98 and rs1048108: combined p = 7.27 × 10-14 , OR:0.65, 95% CI:0.58-0.73). Particularly, the T risk allele of rs17489363 in the canonical promoter region of full-length BARD1 altered binding site of the transcription factor HSF1 and correlated with low expression of full-length BARD1 mRNA and protein. Low-level expression of full-length BARD1 associated with advanced neuroblastoma. In human neuroblastoma cells, attenuating full-length BARD1 increased proliferation and invasion capacity. In conclusion, we have identified two potentially causative SNPs at the BARD1 locus associated with predisposition to high-risk neuroblastoma, and have shown that full-length BARD1 may act as tumor suppressor.

XRCC1 gene polymorphisms and risk of neuroblastoma in Chinese children

Neuroblastoma is a common pediatric extra-cranial tumor of the sympathetic nervous system. XRCC1 is a scaffold protein that participates in DNA single-strand break repair by complexing with other proteins. XRCC1 gene polymorphisms are being increasingly explored in cancer epidemiology studies. However, the contribution of XRCC1 gene polymorphisms to neuroblastoma risk remains unclarified. Herein, we conducted a case-control study with 393 neuroblastoma patients and 812 controls to explore the association of XRCC1 gene polymorphisms (rs1799782 G>A, rs25487 C>T, rs25489 C>T and rs915927 T>C) with neuroblastoma risk. Results showed that none of the studied polymorphisms was associated with neuroblastoma risk. However, individuals with 2 risk genotypes seemed to be at significantly higher risk for neuroblastoma compared with those without risk genotype (adjusted odds ratio=1.69; 95% confidence interval=1.06-2.69). Stratified analysis revealed that the XRCC1 rs25489 CT/TT was strongly associated with reduced risk of neuroblastoma in the children ≤ 18 months of age and subgroup with clinical stage I+II+4s diseases, compared with CC genotypes. We also identified an increased neuroblastoma risk for carrier of 2-3 risk genotypes among children ≤ 18 months of age and subgroup with clinical stage I+II+4s. More evidence of the association between XRCC1 gene polymorphisms and neuroblastoma risk is needed.

Serum Interleukin-6 Level and the rs1800795 Polymorphism in its Gene Associated with Neuroblastoma Risk in Chinese Children

Background

The pro-inflammatory cytokine, interleukin-6 (IL-6), stimulates the metastasis of several neoplasms. An association of its serum level and the single nucleotide polymorphism (SNP) rs1800795 with neuroblastoma (NB) has been reported in American and Italian cohorts. This study was to clarify whether the same association exists in Chinese children.

Methods

A total of 130 NB patients, with 77 boys (59%), 53 girls (41%), mean age 41 ± 5 months, were assigned to two groups: high risk (HR) versus intermediate-low risk (non-HR), and 50 healthy children were randomly selected as the age- and gender-matched controls. Peripheral blood samples were analyzed to determine serum IL-6 level using enzyme linked immunosorbent assay and rs1800795 SNPs phenotype using polymerase chain reaction and gene sequencing.

Results

There were 87 NB patients in the HR group and 43 NB patients in the non-HR group. A comparison of allele and genotype frequencies of the rs1800795 polymorphism between patients and controls found no association with NB risk (P > 0.05). The frequency of GG+GC genotype was higher in HR-NB patients than in non-HR-NB patients (64.4% vs. 48.8%, P = 0.02), and serum IL-6 level was much higher in HR-NB patients with GG+GC genotype than in HR-NB patients with CC genotype (4.36 ± 1.1 pg/ml vs. 1.83 ± 0.5 pg/ml; P = 0.02), but not in Non-HR-NB patients.

Conclusions

The polymorphism rs1800795 is associated with serum IL-6 level and level of NB risk. GG genotype might indicate that the tumor is highly malignant (prone to metastasis) and associated with poor prognosis.

Genetic Predisposition to Neuroblastoma

Neuroblastoma is the most common solid tumor in children under the age of one. It displays remarkable phenotypic heterogeneity, resulting in differences in outcomes that correlate with clinical and biologic features at diagnosis. While neuroblastoma accounts for approximately 5% of all cancer diagnoses in pediatrics, it disproportionately results in about 9% of all childhood deaths. Research advances over the decades have led to an improved understanding of neuroblastoma biology. However, the initiating events that lead to the development of neuroblastoma remain to be fully elucidated. It has only been recently that advances in genetics and genomics have allowed researchers to unravel the predisposing factors enabling the development of neuroblastoma and fully appreciate the interplay between the genetics of tumor and host. In this review, we outline the current understanding of familial neuroblastoma and highlight germline variations that predispose children to sporadic disease. We also discuss promising future directions in neuroblastoma genomic research and potential clinical applications for these advances.

Relevance of XPD polymorphisms to neuroblastoma risk in Chinese children: a four-center case-control study

Neuroblastoma is a lethal tumor that commonly occurs in children. Polymorphisms in XPD reportedly influence risk for several types of cancer, though their roles in neuroblastoma remain unclear. Here we endeavored to determine the relevance of XPD gene polymorphisms and neuroblastoma susceptibility in Chinese children genotyping three XPD polymorphisms (rs3810366, rs13181 and rs238406) in 505 cases and 1070 controls and assessing their contributions to neuroblastoma risk. Overall, we detected no significant association between any single XPD genotype and neuroblastoma risk. When risk genotypes were combined, however, we found that patients with 2-3 risk genotypes were more likely to develop neuroblastoma (adjusted odds ratio =1.31; 95% confidence interval =1.06-1.62, P=0.013) than those with 0-1 risk genotypes. Stratification analysis of rs3810366 revealed significant relationships between the subgroups age ≤18 months and clinical stage I+II+4s and neuroblastoma risk. Moreover, the presence of 2-3 risk genotypes was significantly associated with increased neuroblastoma risk in the subgroups age ≤18 months, male, tumor originated from others, and clinical stage I+II+4s. Our findings provide novel insight into the genetic underpinnings of neuroblastoma and demonstrate that XPD polymorphisms may have a cumulative effect on neuroblastoma risk.

RSRC1 and CPZ gene polymorphisms with neuroblastoma susceptibility in Chinese children

Two new neuroblastoma susceptibility loci at 3q25 (RSRC1 rs6441201 G > A) and 4p16 (CPZ rs3796725 T > C and rs3796727 A > G) were identified by a genome-wide association study (GWAS) involving Italians, African Americans and European Americans. In this case-control study with 393 neuroblastoma cases and 812 controls, we investigated the association between these three polymorphisms and neuroblastoma susceptibility in Chinese population. We found that participants harboring the RSRC1 rs6441201A allele were associated with an increased risk of neuroblastoma (AA vs. GG: adjusted OR = 1.55, 95% CI = 1.03-2.34, P = 0.036). No significant association between the CPZ polymorphisms (rs3796725 T > C and rs3796727A > G) and neuroblastoma susceptibility was observed. In conclusion, our results confirm that the RSRC1 rs6441201A allele is associated with neuroblastoma susceptibility in Chinese population.

HOTAIR gene polymorphisms contribute to increased neuroblastoma susceptibility in Chinese children

BACKGROUND

Neuroblastoma is the most frequently diagnosed extracranial solid tumor in children. Previous studies have shown that single-nucleotide polymorphisms in some genes are associated with the risk of multiple cancers, including neuroblastoma. Although Hox transcript antisense intergenic RNA (HOTAIR) gene polymorphisms have been investigated in a variety of cancers, to the authors' knowledge the relationships between HOTAIR gene polymorphisms and neuroblastoma susceptibility have not been reported to date. The objective of the current study was to evaluate the correlation between HOTAIR gene polymorphisms and neuroblastoma risk in Chinese children.

METHODS

The authors genotyped 6 polymorphisms (rs920778 A>G, rs12826786 C>T, rs4759314 A>G, rs7958904 G>C, rs874945 C>T, and rs1899663 C>A) of the HOTAIR gene in 2 Chinese populations including 393 neuroblastoma cases and 812 healthy controls. The strength of the associations was evaluated using odds ratios and 95% confidence intervals. Further stratification analyses were conducted to explore the association between the HOTAIR gene polymorphisms rs12826786 C>T, rs874945 C>T, and rs1899663 C>A with neuroblastoma susceptibility in terms of age, sex, clinical stage of disease, and sites of origin.

RESULTS

The authors found that the rs12826786 C>T (P =.013), rs874945 C>T (P =.020), and rs1899663 C>A (P =.029) polymorphisms were significantly associated with increased neuroblastoma risk. In stratification analyses, these associations were more predominant in females and among patients with tumor in the retroperitoneal region or mediastinum. The remaining 3 polymorphisms were not found to be related to neuroblastoma susceptibility.

CONCLUSIONS

The results of the current study verified that HOTAIR gene polymorphisms are associated with increased neuroblastoma risk and suggest that HOTAIR gene polymorphisms might be a potential biomarker for neuroblastoma susceptibility. Cancer 2018;124:2599-606. © 2018 American Cancer Society.

Lack of associations between AURKA gene polymorphisms and neuroblastoma susceptibility in Chinese children

Previous studies have demonstrated that polymorphisms in the AURKA gene are associated with various types of cancer. In neuroblastoma, AURKA protein product regulates N-myc protein levels and plays a critical role in tumorigenesis. To investigate the association between three AURKA polymorphisms (rs1047972 C>T, rs2273535 T>A, and rs8173 G>C) and neuroblastoma susceptibility in Chinese populations, we performed this two-center case-control study including 393 neuroblastoma cases and 812 controls. Two study populations were recruited from two different regions in China. No significant associations were identified amongst any of the three AURKA polymorphisms and the risk of neuroblastoma. Similar observations were found in the stratified analysis. In conclusion, our results indicate that none of the AURKA polymorphisms are associated with neuroblastoma susceptibility in two distinct Chinese populations. Further studies with larger sample sizes and different ethnicities are warranted to validate our results.

Genetic dissection of the BRCA2 promoter and transcriptional impact of DNA variants

PURPOSE

Promoter mutations may affect transcription and can be associated with human diseases. However, the promoters of the breast cancer (BC) genes are not regularly screened. Our goal was to investigate the BRCA2 promoter in order to study a possible correlation between impaired transcription and disease.

METHODS

The proximal and core promoter of the BRCA2 gene was sequenced in 95 high-risk BC patients. A BRCA2-promoter insert [- 938 to + 312 from the transcription start site (TSS)] was generated and cloned into the firefly luciferase vector pGL4.10. Promoter variants and deletions were introduced by site-directed mutagenesis and quantified by Dual-Luciferase assays and semi-quantitative RT-PCR.

RESULTS

Three different variants were detected in high-risk BC patients: rs3092989, rs206118, and rs563971900. Functional mapping of 13 overlapping deletions revealed four down-regulating segments (TSS positions): -59_-10del/µdel3 (16% of activity of the wild-type construct), -104_-55del/µdel4 (62%), -239_-190del/µdel7 (39%), -464_-415/µdel12 (78%), suggesting the presence therein of putative transcriptional activator motifs. Additionally, six microdeletions rendered luciferase overexpression: +32_+81del/µdel1 (356%), -14_+36del/µdel2 (180%), -194_-145del/µdel6 (154%), -284_-235del/µdel8 (168%), -329_-280del/µdel9 (111%), and -509_-460del/µdel13 (139%), which is indicative of repressor elements. Functional assays of 15 promoter variants (including those detected in patients) showed that ten of them significantly altered expression with seven up-regulating (113-163%) and three down-regulating (rs551887850_G, rs570548398_T, rs55880202_T; 72-83%) SNPs. Eight of them were located in an ENCODE-DNase Hypersensitive Cluster (TSS - 185 to + 105) where most active transcriptional motifs are known to be placed.

CONCLUSIONS

BRCA2 expression is highly sensitive to promoter variations as most of them induced relevant changes. Moreover, we mapped critical regions of the BRCA2 promoter that may constitute potential targets for regulatory variants. Three SNPs moderately decreased luciferase activity, but confirmation of its potential pathogenicity requires further analysis. These data reinforce the need to screen the promoter regions of breast cancer genes with a view to discovering novel deleterious mutations.

RAN/RANBP2 polymorphisms and neuroblastoma risk in Chinese children: a three-center case-control study

The genetic etiology of sporadic neuroblastoma remains largely obscure. RAN and RANBP2 genes encode Ras-related nuclear protein and Ran-binding protein 2, respectively. These two proteins form Ran-RanBP2 complex that regulate various cellular activities including nuclear transport. Aberrant functions of the two proteins are implicated in carcinogenesis. Given the unknown role of RAN/RANBP2 single nucleotide polymorphisms (SNPs) in neuroblastoma risk, we performed a multi-center case-control study in Chinese children to assess the association of the RAN/RANBP2 SNPs with neuroblastoma risk. We analyzed three potentially functional SNPs in RAN gene (rs56109543 C>T, rs7132224 A>G, rs14035 C>T) and one in RANBP2 (rs2462788 C>T) in 429 cases and 884 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to access the association between these four polymorphisms and neuroblastoma risk. No single variant was found to statistically significantly associate with neuroblastoma risk. However, individuals with 3 protective genotypes were less likely to develop neuroblastoma, in comparison to non-carriers (adjusted OR=0.33; 95% CI=0.12-0.96; P=0.042), as well as those with 0-2 protective genotypes (adjusted OR=0.33; 95% CI=0.11-0.94; P=0.038). Stratified analysis revealed no significant association for any of the four polymorphisms. Further studies are warranted to validate the weak impact of RAN/RANBP2 SNPs on neuroblastoma risk.

Functional Polymorphisms at ERCC1/XPF Genes Confer Neuroblastoma Risk in Chinese Children

Variations in nucleotide excision repair pathway genes may predispose to initiation of cancers. However, polymorphisms of ERCC1/XPF genes and neuroblastoma risk have not been investigated before. To evaluate the relevance of polymorphisms of ERCC1/XPF genes in influencing neuroblastoma susceptibility, we genotyped four polymorphisms in ERCC1/XPF genes using a Chinese population of 393 cases and 812 controls. The results showed that ERCC1 rs2298881 and rs11615 predisposed to enhanced neuroblastoma risk [CA vs. AA: adjusted odds ratio (OR)=1.94, 95% confidence interval (CI)=1.30-2.89, P=0.0012; CC vs. AA: adjusted OR=2.18, 95% CI=1.45-3.26, P=0.0002 for rs2298881, and AG vs. GG: adjusted OR=1.31, 95% CI=1.02-1.69, P=0.038 for rs11615]. Moreover, XPF rs2276466 was also associated with increased neuroblastoma risk (GG vs. CC: adjusted OR=1.66, 95% CI=1.02-2.71, P=0.043). In the combined analysis of ERCC1, we found that carriers with 2-3 risk genotypes were more likely to get risk of neuroblastoma, when compared to those with 0-1 risk genotype (adjusted OR=1.75; 95% CI=1.25-2.45, P=0.0012). Our study indicates that common genetic variations in ERCC1/XPF genes predispose to neuroblastoma risk, which needs to be further validated by ongoing efforts.

Associations between lncRNA MEG3 polymorphisms and neuroblastoma risk in Chinese children

Neuroblastoma is the third most common childhood cancer after leukemias and cancer of the central nervous system. Long noncoding RNA MEG3 polymorphisms have been shown to confer cancer susceptibility; however, their roles in the genetic predisposition to neuroblastoma remain unclarified. To answer this question, we genotyped two MEG3 polymorphisms, rs7158663 G>A and rs4081134 G>A, in 392 neuroblastoma children and 783 controls by TaqMan method. The results showed that neither single locus nor the combination analysis supported an association between MEG3 polymorphism and neuroblastoma risk. Interestingly, we found that subjects carrying rs4081134 AG/AA genotypes significantly tended to develop neuroblastoma among subgroups with age >18 month (adjusted OR=1.36, 95% CI=1.01-1.84) and clinical stage III+IV disease (adjusted OR=1.47, 95% CI=1.08-1.99), when compared with reference group. In the combined analysis of MEG3 polymorphisms, we found that carriers of 2 risk genotypes were more likely to have higher risk of developing neuroblastoma than those with 0-1 risk genotype among children more than 18 months of age (adjusted OR=1.36, 95% CI=1.01-1.84, P=0.042), and with clinical stages III+IV disease (adjusted OR=1.47, 95% CI=1.08-2.00, P=0.014). Our data suggest MEG3 as a weak-effect neuroblastoma susceptibility gene. Well-designed studies with large sample studies are needed to further validate this finding.

Genetic susceptibility to neuroblastoma: current knowledge and future directions

Neuroblastoma, a malignancy of the developing peripheral nervous system that affects infants and young children, is a complex genetic disease. Over the past two decades, significant progress has been made toward understanding the genetic determinants that predispose to this often lethal childhood cancer. Approximately 1-2% of neuroblastomas are inherited in an autosomal dominant fashion and a combination of co-morbidity and linkage studies has led to the identification of germline mutations in PHOX2B and ALK as the major genetic contributors to this familial neuroblastoma subset. The genetic basis of "sporadic" neuroblastoma is being studied through a large genome-wide association study (GWAS). These efforts have led to the discovery of many common susceptibility alleles, each with modest effect size, associated with the development and progression of sporadic neuroblastoma. More recently, next-generation sequencing efforts have expanded the list of potential neuroblastoma-predisposing mutations to include rare germline variants with a predicted larger effect size. The evolving characterization of neuroblastoma's genetic basis has led to a deeper understanding of the molecular events driving tumorigenesis, more precise risk stratification and prognostics and novel therapeutic strategies. This review details the contemporary understanding of neuroblastoma's genetic predisposition, including recent advances and discusses ongoing efforts to address gaps in our knowledge regarding this malignancy's complex genetic underpinnings.

A comprehensive characterization of rare mitochondrial DNA variants in neuroblastoma

Background

Neuroblastoma, a tumor of the developing sympathetic nervous system, is a common childhood neoplasm that is often lethal. Mitochondrial DNA (mtDNA) mutations have been found in most tumors including neuroblastoma. We extracted mtDNA data from a cohort of neuroblastoma samples that had undergone Whole Exome Sequencing (WES) and also used snap-frozen samples in which mtDNA was entirely sequenced by Sanger technology. We next undertook the challenge of determining those mutations that are relevant to, or arisen during tumor development. The bioinformatics pipeline used to extract mitochondrial variants from matched tumor/blood samples was enriched by a set of filters inclusive of heteroplasmic fraction, nucleotide variability, and in silico prediction of pathogenicity.

Results

Our in silico multistep workflow applied both on WES and Sanger-sequenced neuroblastoma samples, allowed us to identify a limited burden of somatic and germline mitochondrial mutations with a potential pathogenic impact.

Conclusions

The few singleton germline and somatic mitochondrial mutations emerged, according to our in silico analysis, do not appear to impact on the development of neuroblastoma. Our findings are consistent with the hypothesis that most mitochondrial somatic mutations can be considered as ‘passengers’ and consequently have no discernible effect in this type of cancer.