ALKBH5 gene polymorphisms and risk of neuroblastoma in Chinese children from Jiangsu Province.

Background: Neuroblastoma is one of the most common extracranial malignant solid tumors in children. AlkB homolog 5 (ALKBH5) is an RNA N6-methyladenosine (m6A) demethylase that plays a critical role in tumorigenesis and development. We assessed the association between single nucleotide polymorphisms (SNPs) in ALKBH5 and the risk of neuroblastoma in a case-control study including 402 patients and 473 non-cancer controls. Methods: Genotyping was determined by the TaqMan method. The association between ALKBH5 polymorphisms (rs1378602 and rs8400) and the risk of neuroblastoma was evaluated using the odds ratio (OR) and 95% confidence interval (CI). Results: We found no strong association of ALKBH5 rs1378602 and rs8400 with neuroblastoma risk. Further stratification analysis by age, sex, primary site, and clinical stage showed that the rs1378602 AG/AA genotype was associated with a lower risk of neuroblastoma in males (adjusted OR = 0.58, 95% CI = 0.35-0.97, p = 0.036) and children with retroperitoneal neuroblastoma (adjusted OR = 0.58, 95% CI = 0.34-0.98, p = 0.040). Conclusions: ALKBH5 SNPs do not seem to be associated with neuroblastoma risk. More studies are required to confirm this negative result and reveal the relationship between gene polymorphisms of the m6A modifier ALKBH5 and neuroblastoma.

Neuroblastoma susceptibility and association of N7-methylguanosine modification gene polymorphisms: multi-center case-control study.

BACKGROUND: Neuroblastoma (NB) is a common extracranial solid malignancy in children. The N7-methylguanosine (m7G) modification gene METTL1/WDR4 polymorphisms may serve as promising molecular markers for identifying populations susceptible to NB. METHODS: TaqMan probes was usded to genotype METTL1/WDR4 single nucleotide polymorphisms (SNPs) in 898 NB patients and 1734 healthy controls. A logistic regression model was utilized to calculate the odds ratio (OR) and 95% confidence interval (CI), evaluating the association between genotype polymorphisms and NB susceptibility. The analysis was also stratified by age, sex, tumor origin site, and clinical stage. RESULTS: Individual polymorphism of the METTL1/WDR4 gene investigated in this study did not show significant associations with NB susceptibility. However, combined genotype analysis revealed that carrying all 5 WDR4 protective genotypes was associated with a significantly lower NB risk compared to having 0-4 protective genotypes (AOR = 0.82, 95% CI = 0.69-0.96, P = 0.014). Further stratified analyses revealed that carrying 1-3 METTL1 risk genotypes, the WDR4 rs2156316 CG/GG genotype, the WDR4 rs2248490 CG/GG genotype, and having all five WDR4 protective genotypes were all significantly correlated with NB susceptibility in distinct subpopulations. CONCLUSIONS: In conclusion, our findings suggest significant associations between m7G modification gene METTL1/WDR4 SNPs and NB susceptibility in specific populations. IMPACT: Genetic variation in m7G modification gene is associated with susceptibility to NB. Single nucleotide polymorphisms in METTL1/WDR4 are associated with susceptibility to NB. Single nucleotide polymorphisms of METTL1/WDR4 can be used as a biomarker for screening NB susceptible populations.

ALKBH1 rs2267755 C>T polymorphism decreases neuroblastoma risk in Chinese children.

Neuroblastoma is a highly malignant extracranial solid tumor in pediatrics. ALKBH1 as a recently discovered DNA N6-methyldeoxyadenosine (6mA) demethylase closely links to tumorigenesis. Whether the ALKBH1 polymorphism contributes to neuroblastoma risk remains unclear. In the present study, we genotyped the ALKBH1 single nucleotide polymorphisms (SNPs) in 402 neuroblastoma patients and 473 healthy controls by TaqMan assay. Odds ratios (ORs) and 95% confidence intervals (CIs) were also calculated to evaluate the strength of the association. Our result exhibited that the rs2267755 C>T (CT vs. CC, adjusted OR=0.69, 95% CI=0.50-0.94, P=0.019) is significantly associated with reduced neuroblastoma risk. And its protective effect is particularly significant in children with tumors originating from the retroperitoneal. Combined genotype analysis revealed that carriers with 1-2 protective genotypes are more susceptible to neuroblastoma than those with 3-4 protective genotypes (adjusted OR=0.71, 95% CI=0.53-0.97, P=0.028). Moreover, the rs2267755 C>T is significantly associated with messenger RNA (mRNA) expression of ALKBH1 and three of its surrounding genes, including SNWQ, ADCK1, and RPL21P10. These results suggest that the rs2267755 C>T may be a genetic variant to reduce neuroblastoma risk.

MUC15 is an independent prognostic factor that promotes metastases of MYCN non-amplified neuroblastoma.

Background: Neuroblastoma (NB) is a cancer that arises from neural-crest-derived sympathoadrenal lineage. Less is known about the pathogenesis and molecular characteristics of MYCN non-amplified (MYCN-NA) NB. Methods: We constructed a signature model targeting mucin family according to RNA sequencing data from GSE49710 dataset, and validated the prognostic performance. We also analyzed the gene expression matrix using DESeq2 R packages to screen the most differential mucin in high-risk NB samples. We further assessed its prognostic value, particularly in MYCN-NA NB samples. Moreover, we performed functional experiments to evaluate the impact of MUC15 overexpression on the migration of MYCN-NA NB cell lines. Results: The 8-mucin signature model showed good prognostic performance in the GSE49710 dataset. Among the mucin genes, MUC15 was significantly upregulated in the high-risk NB cohort and was associated with poor prognosis, especially in MYCN-NA NB samples. Furthermore, MUC15 overexpression and exogenous MUC15 protein enhanced the migration of MYCN-NA NB cell lines. Mechanistically, MUC15 promoted the phosphorylation of focal adhesion kinase (FAK) by inhibiting the expression of MYCT1, a target of c-Myc. Conclusions: Our findings suggested a potential network in controlling NB cell metastasis. Targeting MUC15 in MYCN-NA NB patients could be a promising therapeutic strategy.

Progress in building clinically relevant patient-derived tumor xenograft models for cancer research.

Patient-derived tumor xenograft (PDX) models, a method involving the surgical extraction of tumor tissues from cancer patients and subsequent transplantation into immunodeficient mice, have emerged as a pivotal approach in translational research, particularly in advancing precision medicine. As the first stage of PDX development, the patient-derived orthotopic xenograft (PDOX) models implant tumor tissue in mice in the corresponding anatomical locations of the patient. The PDOX models have several advantages, including high fidelity to the original tumor, heightened drug sensitivity, and an elevated rate of successful transplantation. However, the PDOX models present significant challenges, requiring advanced surgical techniques and resource-intensive imaging technologies, which limit its application. And then, the humanized mouse models, as well as the zebrafish models, were developed. Humanized mouse models contain a human immune environment resembling the tumor and immune system interplay. The humanized mouse models are a hot topic in PDX model research. Regarding zebrafish patient-derived tumor xenografts (zPDX) and patient-derived organoids (PDO) as promising models for studying cancer and drug discovery, zPDX models are used to transplant tumors into zebrafish as novel personalized medical animal models with the advantage of reducing patient waiting time. PDO models provide a cost-effective approach for drug testing that replicates the in vivo environment and preserves important tumor-related information for patients. The present review highlights the functional characteristics of each new phase of PDX and provides insights into the challenges and prospective developments in this rapidly evolving field.

The application of Aptamer in biomarker discovery.

Biomarkers are detectable molecules that can reflect specific physiological states of cells, organs, and organisms and therefore be regarded as indicators for specific diseases. And the discovery of biomarkers plays an essential role in cancer management from the initial diagnosis to the final treatment regime. Practically, reliable clinical biomarkers are still limited, restricted by the suboptimal methods in biomarker discovery. Nucleic acid aptamers nowadays could be used as a powerful tool in the discovery of protein biomarkers. Nucleic acid aptamers are single-strand oligonucleotides that can specifically bind to various targets with high affinity. As artificial ssDNA or RNA, aptamers possess unique advantages compared to conventional antibodies. They can be flexible in design, low immunogenicity, relative chemical/thermos stability, as well as modifying convenience. Several SELEX (Systematic Evolution of Ligands by Exponential Enrichment) based methods have been generated recently to construct aptamers for discovering new biomarkers in different cell locations. Secretome SELEX-based aptamers selection can facilitate the identification of secreted protein biomarkers. The aptamers developed by cell-SELEX can be used to unveil those biomarkers presented on the cell surface. The aptamers from tissue-SELEX could target intracellular biomarkers. And as a multiplexed protein biomarker detection technology, aptamer-based SOMAScan can analyze thousands of proteins in a single run. In this review, we will introduce the principle and workflow of variations of SELEX-based methods, including secretome SELEX, ADAPT, Cell-SELEX and tissue SELEX. Another powerful proteome analyzing tool, SOMAScan, will also be covered. In the second half of this review, how these methods accelerate biomarker discovery in various diseases, including cardiovascular diseases, cancer and neurodegenerative diseases, will be discussed.

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.

PTBP2-Mediated Alternative Splicing of IRF9 Controls Tumor-Associated Monocyte/Macrophage Chemotaxis and Repolarization in Neuroblastoma Progression.

The recurrence and metastasis of children with mediastinal neuroblastoma (NB) are also occurred after surgery, chemotherapy, or radiotherapy. Strategies targeting the tumor microenvironment have been reported to improve survival; however, thorough investigations of monocytes and tumor-associated macrophages (Mϕs) with specialized functions in NB are still lacking. Our data first demonstrated polypyrimidine tract binding protein 2 (PTBP2) as a possible identifier in patients with mediastinal NB screened by proteomic profiling and that PTBP2 predicted good outcomes. Functional studies revealed that PTBP2 in NB cells induced the chemotactic activity and repolarization of tumor-associated monocytes and Mϕs, which, in turn, inhibited NB growth and dissemination. Mechanistically, PTBP2 prevents interferon regulatory factor 9 alternative splicing and upregulates signal transducers and activators of transcription 1 to stimulate C-C motif chemokine ligand 5 (CCL5) and interferon-stimulated gene factor-dependent type I interferon secretion, to induce monocyte/Mϕs chemotaxis, and to sustain monocytes in a proinflammatory phenotype. Our study defined a critical event of PTBP2-induced monocytes/Mϕs in NB progression and revealed that RNA splicing occurred by PTBP2 benefits immune compartmentalization between NB cells and monocytes. This work revealed the pathological and biological role of PTBP2 in NB development and indicates that PTBP2-induced RNA splicing benefits immune compartmentalization and predicted a favorable prognosis in mediastinal NB.

Erratum: In vitro and in vivo antiangiogenic activity of desacetylvinblastine monohydrazide through inhibition of VEGFR2 and Axl pathways.

[This corrects the article on p. 843 in vol. 6, PMID: 27186435.].

Nucleic acid therapy in pediatric cancer.

The overall survival, progress free survival, and life quality of cancer patients have improved due to the advance in minimally invasive surgery, precision radiotherapy, and various combined chemotherapy in the last decade. Furthermore, the discovery of new types of therapeutics, such as immune checkpoint inhibitors and immune cell therapies have facilitated both patients and doctors to fight with cancers. Moreover, in the context of the development in biocompatible and cell type targeting nano-carriers as well as nucleic acid-based drugs for initiating and enhancing the anti-tumor response have come to the age. The treatment paradigms utilization of nucleic acids, including short interfering RNA (siRNA), antisense oligonucleotides (ASO), and messenger RNA (mRNA), can target specific protein expression to achieve the therapeutic effects. Over ten nucleic acid therapeutics have been approved by the FDA and EMA in rare diseases and genetic diseases as well as dozens of registered clinical trails for varies cancers. Though generally less dangerous of pediatric cancers than adult cancers was observed during the past decades, yet pediatric cancers accounted for a significant proportion of child deaths which hurt those family very deeply. Therefore, it is necessary to pay more attention for improving the treatment of pediatric cancer and discovering new nucleic acid therapeutics which may help to improve the therapeutic effect and prognoses in turns to ameliorate the survival period and quality of life for children patient. In this review, we focus on the nucleic acid therapy in pediatric cancers.

Therapeutic aptamer targeting sclerostin loop3 for promoting bone formation without increasing cardiovascular risk in osteogenesis imperfecta mice.

Rationale: Sclerostin inhibition demonstrated bone anabolic potential in osteogenesis imperfecta (OI) mice, whereas humanized therapeutic sclerostin antibody romosozumab for postmenopausal osteoporosis imposed clinically severe cardiac ischemic events. Therefore, it is desirable to develop the next generation sclerostin inhibitors to promote bone formation without increasing cardiovascular risk for OI. Methods and Results: Our data showed that sclerostin suppressed inflammatory responses, prevented aortic aneurysm (AA) and atherosclerosis progression in hSOSTki.Col1a2+/G610C.ApoE-/- mice. Either loop2&3 deficiency or inhibition attenuated sclerostin's suppressive effects on expression of inflammatory cytokines and chemokines in vitro, whilst loop3 deficiency maintained the protective effect of sclerostin on cardiovascular system both in vitro and in vivo. Moreover, loop3 was critical for sclerostin's antagonistic effect on bone formation in Col1a2+/G610C mice. Accordingly, a sclerostin loop3-specific aptamer aptscl56 was identified by our lab. It could recognize both recombinant sclerostin and sclerostin in the serum of OI patients via targeting loop3. PEG40k conjugated aptscl56 (Apc001PE) demonstrated to promote bone formation, increase bone mass and improve bone microarchitecture integrity in Col1a2+/G610C mice via targeting loop3, while did not show influence in inflammatory response, AA and atherosclerosis progression in Col1a2+/G610C.ApoE-/- mice with Angiotensin II infusion. Further, Apc001PE had no influence in the protective effect of sclerostin on cardiovascular system in hSOSTki.Col1a2+/G610C.ApoE-/- mice, while it inhibited the antagonistic effect of sclerostin on bone formation in hSOSTki.Col1a2+/G610C mice via targeting loop3. Apc001PE was non-toxic to healthy rodents, even at ultrahigh dose. Apc001PE for OI was granted orphan drug designation by US-FDA in 2019 (DRU-2019-6966). Conclusion: Sclerostin loop3-specific aptamer Apc001PE promoted bone formation without increasing cardiovascular risk in OI mice.

TTF1 suppresses neuroblastoma growth and induces neuroblastoma differentiation by targeting TrkA and the miR-204/TrkB axis.

Neuroblastoma (NB) is the most common extracranial malignant solid tumor in children. We found that TTF1, TrkA, and miR-204 were lowly expressed, whereas TrkB was highly expressed in undifferentiated NB tissues. Meanwhile, TTF1 expression correlated positively with TrkA and miR-204 expression but negatively with TrkB expression. The TTF1 promoter was hypermethylated in undifferentiated NB tissues and SK-N-BE cells, leading to TTF1 downregulation. We also identified miR-204, which directly targets TrkB, as a transcriptional target of TTF1. Functionally, TTF1 suppressed proliferation, migration, and invasion of NB cells, whereas induced cell cycle arrest, apoptosis, and autophagy of NB cells by regulating TrkA and the miR-204-TrkB axis. Furthermore, TTF1 suppressed tumor growth and promoted neurogenic differentiation in a NB xenograft mouse model. Our study demonstrates that TTF1 reduces tumor growth and induces neurogenic differentiation in NB by directly targeting TrkA and the miR-204/TrkB axis.

Targeting loop3 of sclerostin preserves its cardiovascular protective action and promotes bone formation.

Sclerostin negatively regulates bone formation by antagonizing Wnt signalling. An antibody targeting sclerostin for the treatment of postmenopausal osteoporosis was approved by the U.S. Food and Drug Administration, with a boxed warning for cardiovascular risk. Here we demonstrate that sclerostin participates in protecting cardiovascular system and inhibiting bone formation via different loops. Loop3 deficiency by genetic truncation could maintain sclerostin's protective effect on the cardiovascular system while attenuating its inhibitory effect on bone formation. We identify an aptamer, named aptscl56, which specifically targets sclerostin loop3 and use a modified aptscl56 version, called Apc001PE, as specific in vivo pharmacologic tool to validate the above effect of loop3. Apc001PE has no effect on aortic aneurysm and atherosclerotic development in ApoE-/- mice and hSOSTki.ApoE-/- mice with angiotensin II infusion. Apc001PE can promote bone formation in hSOSTki mice and ovariectomy-induced osteoporotic rats. In summary, sclerostin loop3 cannot participate in protecting the cardiovascular system, but participates in inhibiting bone formation.

CASC15 Gene Polymorphisms and Glioma Susceptibility in Chinese Children.

OBJECTIVE: Gliomas are the most common tumors in the central nervous system. The cancer susceptibility candidate 15 (CASC15) gene has been reported to be a susceptibility gene for several types of cancer. No studies have been carried out on the predisposing effect of CASC15 gene single nucleotide polymorphisms (SNPs) on glioma risk. METHODS: In order to determine whether CASC15 gene SNPs are involved in glioma susceptibility, the first association study in a relatively large sample, which consisted of 171 patients and 228 healthy controls recruited from China, was performed. The contribution of SNPs (rs6939340 A>G, rs4712653 T>C and rs9295536 C>A) to the risk of glioma was evaluated by multinomial logistic regression, based on the calculation of the odds ratio (OR) and 95% confidence interval (CI). RESULTS: In the single locus and combined analysis, it was revealed that the genetic risk score had no significant associations between CASC15 gene SNPs and glioma risk. However, in the stratified analysis, a significant decrease in risk of glioma was observed in subjects of <60 months old with the rs4712653 TT genotype, when compared to those with the CC/CT genotype (OR=0.12, 95% CI=0.02-0.91, P=0.041). CONCLUSION: The present study provides referential evidence on the association between the genetic predisposition of the CASC15 gene and glioma risk in Chinese children. However, more well-designed case-control studies and functional experiments are needed to further explore the role of CASC15 gene SNPs.

LncRNAs and CircRNAs in cancer.

It is well known that noncoding RNAs (ncRNAs) cannot encode proteins, but they can play important regulatory roles in tumors by combining with proteins, RNAs, and DNAs. As more and more studies reveal the important roles and underlying mechanisms of long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) in cancer, their huge application potential in cancer therapy cannot be ignored. For example, lncRNAs can be involved in tumor-related signal transduction pathways, cell cycle control, DNA damage, epigenetic regulation, and microRNA control. A group of studies confirmed that abnormal expression of lncRNAs can affect cancer progression. Furthermore, as covalently closed continuous circular ncRNAs, many recent studies have shown that circRNAs have regulatory effects and other important biological significances in cancer. Interestingly, circRNAs were found to have translational functions. This has greatly attracted people's attention to circRNAs research. In this review, we introduce the important roles of lncRNAs and circRNAs in some representative cancers, respectively. Furthermore, we focus on the biological functions and important clinical therapeutic implications of lnRNAs and circRNAs in neuroblastoma. Our review also focuses on providing rationale and relevant references for novel biomarkers for neuroblastoma diagnosis, prognosis, and treatment.

FTO gene polymorphisms and hepatoblastoma susceptibility among Chinese children.

Current knowledge on the etiology of hepatoblastoma remains limited. FTO gene has been documented as a susceptibility gene for several types of cancer. However, its role has not been characterized in hepatoblastoma. Herein, we intended to explore whether FTO gene single nucleotide polymorphisms (SNPs) contribute to the risk of hepatoblastoma. A multi-center case-control study was conducted including 358 cases and 1512 controls recruited from the night hospitals in China. Odds ratios (ORs) and 95% confidence intervals (CIs), for the association of FTO gene SNPs with hepatoblastoma risk, were estimated using conditional logistic regression models, adjusted for relevant confounding variables. Four SNPs (rs1477196 G > A, rs9939609 T > A, rs7206790 C > G, and rs8047395 A > G) in the FTO gene were genotyped. We detected a significant association between rs9939609 T > A and decreased risk of hepatoblastoma (TA vs. TT: adjust OR = 0.73, 95% CI = 0.54-0.99, P = 0.041; TA/AA vs. TT: adjust OR = 0.73, 95% CI = 0.55-0.97, P = 0.032). Compared to 0-3 protective genotypes, carriers with four protective genotypes showed enough strength to protect from hepatoblastoma (adjust OR = 0.65, 95% CI = 0.47-0.91, P = 0.012). In stratification analysis, we also detected a significantly decreased risk of hepatoblastoma in subjects with rs9939609 TA/AA or with four protective genotypes in some subgroups. Our results provided some clues for an association of FTO gene SNPs with hepatoblastoma risk in Chinese children.Abbreviations: GWAS, genome-wide association study; FTO, The fat mass and obesity-associated gene; SNP, single nucleotide polymorphism; m6A, N6-methyladenosine; mRNA, messenger RNA; LD, linkage disequilibrium; HWE, Hardy-Weinberg equilibrium; OR, odds ratio; CI, confidence interval; AML, acute myeloid leukemia; GSC, glioblastoma stem(-like) cell; HER2, human epidermal growth factor receptor 2.

The role of m6A modification in pediatric cancer.

With the development of RNA modification research, the importance of N6-methyladenosine (m6A) in tumors cannot be ignored. m6A promotes the self-renewal of tumor stem cells and the proliferation of tumor cells. It affects post-transcriptional gene expression through epigenetic mechanisms, combining various factors to determine proteins' fate and altering the biological function. This modification process runs through the entire tumors, and genes affected by m6A modification may be the critical targets for cancers breakthroughs. Though generally less dangerous than adult cancer, pediatric cancer accounts for a significant proportion of child deaths. What is more alarming is that the occurrences of adult tumors are highly associated with the poor prognoses of pediatric tumors. Therefore, it is necessary to pay attention to the importance of pediatric cancer and discover new therapeutic targets, which will help improve the therapeutic effect and prognoses of the diseases. We collected and investigated m6A modification in pediatric cancers based on mRNA and non-coding RNA, finding that m6A factors were involved in glioma, hepatoblastoma, nephroblastoma, neuroblastoma, osteosarcoma, medulloblastoma, retinoblastoma, and acute lymphoblastic leukemia. Consequently, we summarized the relationships between the m6A factors and these pediatric cancers.