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

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.

METTL14 promotes neuroblastoma formation by inhibiting YWHAH via an m6A-YTHDF1-dependent mechanism

Neuroblastoma (NB) is a common childhood tumor with a high incidence worldwide. The regulatory role of RNA N6-methyladenosine (m6A) in gene expression has attracted significant attention, and the impact of methyltransferase-like 14 (METTL14) on tumor progression has been extensively studied in various types of cancer. However, the specific influence of METTL14 on NB remains unexplored. Using data from the Target database, our study revealed significant upregulation of METTL14 expression in high-risk NB patients, with strong correlation with poor prognosis. Furthermore, we identified ETS1 and YY1 as upstream regulators that control the expression of METTL14. In vitro experiments involving the knockdown of METTL14 in NB cells demonstrated significant inhibition of cell proliferation, migration, and invasion. In addition, suppressing METTL14 inhibited NB tumorigenesis in nude mouse models. Through MeRIP-seq and RNA-seq analyses, we further discovered that YWHAH is a downstream target gene of METTL14. Mechanistically, we observed that methylated YWHAH transcripts, particularly those in the 5' UTR, were specifically recognized by the m6A "reader" protein YTHDF1, leading to the degradation of YWHAH mRNA. Moreover, the downregulation of YWHAH expression activated the PI3K/AKT signaling pathway, promoting NB cell activity. Overall, our study provides valuable insights into the oncogenic effects of METTL14 in NB cells, highlighting its role in inhibiting YWHAH expression through an m6A-YTHDF1-dependent mechanism. These findings also suggest the potential utility of a biomarker panel for prognostic prediction in NB patients.

Functional TET2 gene polymorphisms increase the risk of neuroblastoma in Chinese children

The 5-methylcytosine (m5C) is the key chemical modification in RNAs. As one of the demethylases in m5C, TET2 has been shown as a tumor suppressor. However, the impact of TET2 gene polymorphisms on neuroblastoma has not been elucidated. 402 neuroblastoma patients and 473 controls were genotyped for TET2 gene polymorphisms using the TaqMan method. The impact of TET2 gene polymorphisms on neuroblastoma susceptibility was determined using multivariate logistic regression analysis. We also adopted genotype-tissue expression database to explore the impact of TET2 gene polymorphisms on the expression of host and nearby genes. We used the R2 platform and Sangerbox tool to analyze the relationship between gene expression and neuroblastoma risk and prognosis through non-parametric testing and Kaplan-Meier analysis, respectively. We found the TET2 gene polymorphisms (rs10007915 G > C and rs7670522 A > C) and the combined 2-5 risk genotypes can significantly increase neuroblastoma risk. Stratification analysis showed that these significant associations were more prominent in certain subgroups. TET2 rs10007915 G > C and rs7670522 A > C are significantly associated with reduced expression of TET2 mRNA. Moreover, lower expression of TET2 gene is associated with high risk, MYCN amplification, and poor prognosis of neuroblastoma. The rs10007915 G > C and rs7670522 A > C are significantly related to the increased expression of inorganic pyrophosphatase 2 mRNA, and higher expression of PPA2 gene is associated with high risk, MYCN amplification, and poor prognosis of neuroblastomas. In summary, TET2 rs10007915 G > C and rs7670522 A > C significantly confer neuroblastoma susceptibility, and further research is needed to investigate the underlying mechanisms.

HNRNPA2B1 and HNRNPR stabilize ASCL1 in an m6A-dependent manner to promote neuroblastoma progression

HNRNPA2B1 and HNRNPR stabilize ASCL1 mRNA in neuroblastoma, but whether their regulatory effects depend on m6A modification and whether their function involves ASCL1 remain unknown. This study investigated the m6A-dependent binding of HNRNPA2B1 and HNRNPR to ASCL1 and subsequent regulation, as well as the expression, clinical significance, and function of HNRNPA2B1 and HNRNPR in neuroblastoma. We revealed that METTL14 mediated ASCL1 m6A modification to stabilize ASCL1. HNRNPA2B1 and HNRNPR significantly enriched ASCL1 mRNA by binding to the 5' and 3' untranslated regions, respectively, and METTL14 knockdown reduced this enrichment. Mutations in m6A sites in the untranslated regions of ASCL1 mRNA considerably decreased probe capacity to engage HNRNPA2B1 and HNRNPR. HNRNPR interacts with IGF2BP1, and knocking down either impaired binding to ASCL1 mRNA. HNRNPA2B1 and HNRNPR knockdown suppressed neuroblastoma cell growth and invasion, while ASCL1 overexpression restored these effects. The high HNRNPA2B1 and HNRNPR expression in neuroblastoma correlated with ASCL1 expression. Thus, HNRNPA2B1 and HNRNPR bind and stabilize ASCL1 mRNA in an m6A-dependent manner to promote neuroblastoma progression. This study not only discovered a new mechanism underlying the high ASCL1 expression in neuroblastoma but also identified the HNRNPA2B1/HNRNPR/ASCL1 axis as a promising target for inhibiting neuroblastoma progression.

Altered N6-Methyladenosine Modification Patterns and Transcript Profiles Contributes to Cognitive Dysfunction in High-Fat Induced Diabetic Mice

N6-methyladenosine (m6A) constitutes the paramount post-transcriptional modification within eukaryotic mRNA. This modification is subjected to stimulus-dependent regulation within the central nervous system of mammals, being influenced by sensory experiences, learning processes, and injuries. The patterns of m6A methylation within the hippocampal region of diabetes cognitive impairment (DCI) has not been investigated. A DCI model was established by feeding a high-fat diet to C57BL/6J mice. m6A and RNA sequencing was conducted to profile the m6A-tagged transcripts in the hippocampus. Methylated RNA immunoprecipitation with next-generation sequencing and RNA sequencing analyses yielded differentially m6A-modified and expressed genes in the hippocampus of DCI mice, which were enriched in pathways involving synaptic transmission and axonal guidance. Mechanistic analyses revealed a remarkable change in m6A modification levels through alteration of the mRNA expression of m6A methyltransferases (METTL3 and METTL14) and demethylase (FTO) in the hippocampus of DCI mice. We identified a co-mediated specific RNA regulatory strategy that broadens the epigenetic regulatory mechanism of RNA-induced neurodegenerative disorders associated with metabolic and endocrine diseases.

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.

A potential relationship between MMP-9 rs2250889 and ischemic stroke susceptibility

Purpose

Ischemic stroke (IS), a serious cerebrovascular disease, greatly affects people's health and life. Genetic factors are indispensable for the occurrence of IS. As a biomarker for IS, the MMP-9 gene is widely involved in the pathophysiological process of IS. This study attempts to find out the relationship between MMP-9 polymorphisms and IS susceptibility.

Methods

A total of 700 IS patients and 700 healthy controls were recruited. The single nucleotide polymorphism (SNP) markers of the MMP-9 gene were genotyped by the MassARRAY analyzer. Multifactor dimensionality reduction (MDR) was applied to generate SNP-SNP interaction. Furthermore, the relationship between genetic variations (allele and genotype) of the MMP-9 gene and IS susceptibility was analyzed by calculating odds ratios (ORs) and 95% confidence intervals (CIs).

Results

Our results demonstrated that rs2250889 could significantly increase the susceptibility to IS in the codominant, dominant, overdominant, and log-additive models (p < 0.05). Further stratification analysis showed that compared with the control group, rs2250889 was associated with IS risk in different case groups (age, female, smoking, and non-drinking) (p < 0.05). Based on MDR analysis, rs2250889 was the best model for predicting IS risk (cross-validation consistency: 10/10, OR = 1.56 (1.26-1.94), p < 0.001).

Conclusion

Our study preliminarily confirmed that SNP rs2250889 was significantly associated with susceptibility to IS.

Coordination of RNA modifications in the brain and beyond

Gene expression regulation is a critical process throughout the body, especially in the nervous system. One mechanism by which biological systems regulate gene expression is via enzyme-mediated RNA modifications, also known as epitranscriptomic regulation. RNA modifications, which have been found on nearly all RNA species across all domains of life, are chemically diverse covalent modifications of RNA nucleotides and represent a robust and rapid mechanism for the regulation of gene expression. Although numerous studies have been conducted regarding the impact that single modifications in single RNA molecules have on gene expression, emerging evidence highlights potential crosstalk between and coordination of modifications across RNA species. These potential coordination axes of RNA modifications have emerged as a new direction in the field of epitranscriptomic research. In this review, we will highlight several examples of gene regulation via RNA modification in the nervous system, followed by a summary of the current state of the field of RNA modification coordination axes. In doing so, we aim to inspire the field to gain a deeper understanding of the roles of RNA modifications and coordination of these modifications in the nervous system.

RNA N6-methyladenosine reader IGF2BP3 interacts with MYCN and facilitates neuroblastoma cell proliferation

Neuroblastoma (NB) is a kind of typical life-threatening extracranial tumor in children. N6-methyladenosine (m6A) modification is closely related to multiple cancer pathological processes. Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) is a top-ranked prognostic risk gene in NB; however, its function is uncertain. The expression of m6A-associated enzymes in patients with NB was analyzed using the Gene Expression Omnibus (GEO) and Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. The IGF2BP3 level in NB cell lines and primary samples was tested using quantitative real-time polymerase chain reaction (qRT-PCR), western blot method, and immunohistochemical analysis. The IGF2BP3 function in cell proliferation was clarified based on many functional in vitro and in vivo experiments. The interaction between IGF2BP3 and N-myc was researched via RNA immunoprecipitation (RIP), m6A RNA immunoprecipitation (MeRIP), and chromatin immunoprecipitation (ChIP) assays. The 16 m6A-regulated enzymes in NB were researched, and the result indicated that IGF2BP3 overexpression was related to cancer progression, COG risk, and survival based on the GEO and TARGET databases. Besides, the IGF2BP3 and MYCN levels were positively correlated. IGF2BP3 expression levels increased in MYCN-amplified NB clinical samples and cells. Knockdown of IGF2BP3 inhibited N-myc expression and NB cell proliferation in vitro and in vivo. IGF2BP3 regulates MYCN RNA stability by modifying m6A. In addition, we demonstrated that N-myc is a transcription factor that directly promotes IGF2BP3 expression in NB cells. IGF2BP3 regulates the proliferation of NB cells via m6A modification of MYCN. N-myc also acts as a transcription factor that regulates IGF2BP3 expression. A positive feedback loop between IGF2BP3 and N-myc facilitates NB cell proliferation.

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.

NSUN2 gene rs13181449 C>T polymorphism reduces neuroblastoma risk

Neuroblastoma is the most common tumor in infants. RNA m5C modification regulates the survival, differentiation, and migration of cells affecting RNA function. However, the effects of the m5C modification methyltransferase gene NSUN2 polymorphism on neuroblastoma susceptibility have not been reported. TaqMan method was used to determine genotypes of four NSUN2 polymorphisms (rs4702373 C>T, rs13181449 C>T, rs166049 T>G, and rs8192120 A>C) in 402 patients with neuroblastoma and 473 cancer-free controls from Jiangsu province, China. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association of NSUN2 polymorphisms with neuroblastoma susceptibility. The association was also further assessed in subgroups stratified by age, sex, tumor origin, and stage. GTEx was used to analyze the effect of these polymorphisms on NSUN2 expression. We found the rs13181449 C>T was significantly associated with reduced neuroblastoma risk (CT vs. CC: adjusted OR = 0.68, 95% CI = 0.51-0.92, P = 0.012; CT/TT vs. CC: adjusted OR = 0.70, 95% CI = 0.53-0.92, P = 0.010). Compared with 0-2 protective genotypes, those with 3-4 protective genotypes could significantly reduce the neuroblastoma risk (adjusted OR = 0.68, 95% CI = 0.52 to 0.90, P = 0.006). Stratification analysis showed that the protective effect of rs13181449 polymorphism remained significant in children with age >18 months, boys, and those with early INSS stages. Moreover, children with more protective genotypes in the same subgroups also exhibited significantly reduced neuroblastoma risk. GTEx analysis showed that the rs13181449 T genotype was related with decreased NSUN2 gene expression. In conclusions, NSUN2 rs13181449 polymorphism is associated with decreased neuroblastoma risk, and the underlying mechanism in neuroblastoma needs further study.

Association of RNA m7G Modification Gene Polymorphisms with Pediatric Glioma Risk

Glioma stemming from glial cells of the central nervous system (CNS) is one of the leading causes of cancer death in childhood. The genetic predisposition of glioma is not fully understood. METTL1-WDR4 methyltransferase complex is implicated in tumorigenesis by catalyzing N7-methylguanosine (m⁷G) modification of RNA. This study is aimed at determining the association of glioma risk with three polymorphisms (rs2291617, rs10877013, and rs10877012) in METTL1 and five polymorphisms (rs2156315 rs2156316, rs6586250, rs15736, and rs2248490) in WDR4 gene in children of Chinese Han. We enrolled 314 cases and 380 controls from three independent hospitals. Genotypes of these polymorphisms were determined using the TaqMan assay. We found the WDR4 gene rs15736 was significantly associated with reduced glioma risk (GA/AA vs. GG: adjusted odds ratio = 0.63, 95%confidence interval = 0.42 - 0.94, P = 0.023) out of the eight studied polymorphisms. Stratified analyses showed that the association of rs15736 with the risk of glioma remained significant in children aged 60 months or older, girls, the subgroups with astrocytic tumors, or grade I + II glioma. We also found the combined effects of five WDR4 gene polymorphisms on glioma risk. Finally, expression quantitative trait locus (eQTL) analyses elucidated that the rs15736 polymorphism was related to the expression level of WDR4 and neighboring gene cystathionine-beta-synthase (CBS). Our finding provided evidence of a causal association between WDR4 gene polymorphisms and glioma susceptibility in Chinese Han children.

Roles of the m6A methyltransferases METTL3, METTL14, and WTAP in pulmonary tuberculosis

Objective

The aim of the current study was to investigate the contributing role of gene variation and transcription levels among the m6A methyltransferases METTL3, METTL14, and WTAP in pulmonary tuberculosis (PTB).

Methods

A case-control study including 461 PTB patients and 467 normal controls was designed for genotyping. Three SNPs in METTL3 (rs1061027, rs1139130, rs1061026), three SNPs in METTL14 (rs62328061, rs4834698, rs1064034), and two SNPs in WTAP (rs1853259, rs11752345) were genotyped via the SNPscan™ technique. METTL3, METTL14, and WTAP transcription levels were determined in 78 PTB patients and 86 controls via quantitative real-time reverse-transcription PCR.

Results

Frequencies of the METTL14 rs62328061 GG genotype, WTAP rs11752345 CT genotype, and T allele were significantly increased in PTB patients compared to controls. An increased risk of rs62328061 was detected in a recessive model, and a decreased risk of rs11752345 was detected in a dominant model in the PTB group. METTL3 gene variation was not associated with PTB risk. The METTL3 rs1139130 GG genotype was significantly increased with drug resistance, and the G allele was significantly decreased with drug-induced liver injury in PTB patients. A reduced frequency of the METTL14 rs62328061 G allele was associated with leukopenia, a reduced frequency of the WTAP rs11752345 T allele was associated with sputum smear positivity, and a higher frequency of the METTL14 rs4834698 TC genotype was evident in PTB patients with hypoproteinemia. Compared to controls, METTL3, METTL14, and WTAP transcription levels in PTB patients were significantly decreased, and the level of WTAP was increased in PTB patients with drug resistance. METTL3 level was negatively associated with erythrocyte sedimentation rate and aspartate aminotransferase, and METTL14 level was negatively correlated with alanine aminotransferase and aspartate aminotransferase.

Conclusion

METTL14 rs62328061 and WTAP rs11752345 variants were associated with the genetic background of PTB, and METTL3, METTL14, and WTAP levels were abnormally decreased, suggesting that these m6A methyltransferases may play important roles in PTB.

FTO rs62033406 A>G associated with the risk of osteonecrosis of the femoral head among the Chinese Han population

BACKGROUND

Fat mass and obesity-related (FTO) mRNA was downregulated in osteonecrosis patients. The study aimed to evaluate the correlation between FTO polymorphisms and the susceptibility of osteonecrosis of the femoral head (ONFH).

METHODS

Six polymorphisms in FTO were genotyped via the Agena MassARRAY in 498 ONFH patients and 498 healthy controls. Multiple genetic models were used to assess the correlation between FTO polymorphisms and ONFH risk by SNPStats. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using a logistic regression model adjusted by age, gender, smoking and drinking.

RESULTS

The risk-increasing association of rs62033406 A>G with ONFH was found (OR = 1.25, 95% CI 1.05-1.50, p = 0.014). Specially, FTO rs62033406 A>G was related to the risk of ONFH in the subgroup at age > 51 years (OR = 1.25, p = 4.00 × 10^-4), females (OR = 1.74, p = 1.00 × 10^-4), smokers (OR = 1.82, p = 0.005) and drinkers (OR = 1.89, p = 0.002), respectively. The best multi-loci model was the five-loci model, a combination of rs9930333 T>G, rs1558902 T>A, rs56094641 A>G, rs3751812 G>T, and rs62033406 A>G (testing accuracy, 0.5351; p = 0.0004; cross-validation consistency, 10/10).

CONCLUSION

Our study first revealed that FTO rs62033406 A>G was a risk factor for ONFH among the Chinese Han population, which might provide the new candidate gene for elucidating the pathogenesis of ONFH.

The Impact of BCL11A Polymorphisms on Endometrial Cancer Risk Among Chinese Han Females

Background

Endometrial carcinoma (EC) is one of the most common malignant gynecological malignancies. BCL11A gene may have a tumor-suppressor role in EC. Until now, no studies have reported the effect of BCL11A variants on EC predisposition in Chinese population.

Methods

Six BCL11A polymorphisms were genotyped using Agena MassARRAY system among 509 EC patients and 506 matched healthy women. Risk assessment of the BCL11A polymorphisms for EC risk was performed by calculating odds ratios (OR) with 95% confidence intervals (CI) through logistic regression models.

Results

We found that rs7581162 (OR = 1.29, p = 0.012), rs10189857 (OR = 1.26, p = 0.028), rs1427407 (OR = 1.30, p = 0.015), rs766432 (OR = 1.27, p = 0.025), and rs6729815 (OR = 1.32, p = 0.008) in BCL11A were associated with higher susceptibility to EC in Chinese Han women. Age and BMI stratified analysis displayed that the risk association between BCL11A variants and EC predisposition might be age- and BMI-dependent. Haplotype analysis revealed that A_rs10189857T_rs1427407 and G_rs10189857G_rs1427407 haplotypes were related to an increased risk of EC. MDR analysis indicated that rs1427407 was the most influential attributor on EC risk in the single-locus model, and the best combination was the two-locus model containing rs7581162 and rs766432.

Conclusion

Our study provided the first evidence that rs7581162, rs10189857, rs1427407, rs766432, and rs6729815 in BCL11A were risk factors for EC in Chinese Han women. These findings add our understanding of the role of BCL11A gene in EC pathogenesis.

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.

Functions, mechanisms, and therapeutic implications of METTL14 in human cancer

RNA modification plays a crucial role in many biological functions, and its abnormal regulation is associated with the progression of cancer. Among them, N⁶-methyladenine (m⁶A) is the most abundant RNA modification. Methyltransferase-like 14 (METTL14) is the central component of the m⁶A methylated transferase complex, which is involved in the dynamic reversible process of m⁶A modification. METTL14 acts as both an oncogene and tumor suppressor gene to regulate the occurrence and development of various cancers. The abnormal m⁶A level induced by METTL14 is related to tumorigenesis, proliferation, metastasis, and invasion. To date, the molecular mechanism of METTL14 in various malignant tumors has not been fully studied. In this paper, we systematically summarize the latest research progress on METTL14 as a new biomarker for cancer diagnosis and its biological function in human tumors and discuss its potential clinical application. This study aims to provide new ideas for targeted therapy and improved prognoses in cancer.

METTL14 gene polymorphisms influence hepatoblastoma predisposition in Chinese children: Evidences from a seven-center case-control study

Hepatoblastoma as the most prevalent hepatic malignancy in children, its etiology remains unclear. N⁶-Methyladenosine (m⁶A) modification which can modify various physiological processes, plays a critical role in tumorigenesis. Methyltransferase-like 14 (METTL14), an important component of the m⁶A methyltransferase complex, remains elusive during hepatoblastoma occurrence and development. We explored the relationship between METTL14 gene polymorphisms (rs1064034 T > A, rs298982 G > A, rs62328061 A > G, rs9884978 G > A, and rs4834698 T > C) and hepatoblastoma susceptibility from 313 patients and 1446 controls. The role of METTL14 polymorphisms in hepatoblastoma was evaluated by odds ratios (ORs) and 95% confidence intervals (CIs). Of the included subjects, 308 patients and 1444 controls were successfully genotyped. We did not find any significant correlation between the risk of hepatoblastoma and the five potentially functional METTL14 polymorphisms individually. However, the presence of 4-5 risk genotypes exhibited a significant increased hepatoblastoma risk (adjusted OR = 1.32, 95% CI = 1.03-1.69, P = 0.031) compared to those carriers with 0-3 risk genotypes. Furthermore, the stratified analysis demonstrated that the rs1064034 AA genotype, rs62328061 AG/GG genotypes, rs4834698 TC/CC genotypes, and 4-5 risk genotypes were related to hepatoblastoma susceptibility in certain subgroups. The expression quantitative trait loci (eQTL) analysis revealed that rs1064034 T > A and rs4834698 T > C were correlated with the expression levels of METTL14 and its surrounding genes. Prospectively, these findings suggested that METTL14 polymorphisms may correlation with hepatoblastoma susceptibility and provide a fresh insight into the genetic underpinnings of m⁶A modification in hepatoblastoma.

Genetic variants in splicing factor genes and susceptibility to bladder cancer

BACKGROUND

Genome-wide association studies have demonstrated that genetic variants are closely related to tumorigenesis and progression of cancer. However, the correlation between genetic variants in splicing factor genes and bladder cancer susceptibility remains unclear.

METHOD

A case-control study with 580 cases of bladder cancer and 1,101 controls was conducted to explore the association of single-nucleotide polymorphisms (SNPs) in splicing factors with bladder cancer susceptibility by logistic regression models, and multiple testing errors were justified by the false discovery rate (FDR) method. Next, we used the Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) datasets to further analyze the differential expression of candidate genes.

RESULTS

We found that rs978416 G>A in RBFOX3 contributed to a reduced risk of bladder cancer [adjusted odds ratio (OR) = 0.72, 95% confidence internal (CI) = 0.62-0.84, P = 3.54 × 10^-5], especially in individuals who never smoked (P = 7.83 × 10^-5). Stratified analysis showed that the protective effect of rs978416 was more significant in the subgroup of low grade and non-muscle invasive bladder cancer. Furthermore, the RBFOX3 mRNA expression was decreased in bladder tumor tissues. However, the relatively high expression of RBFOX3 was related to a higher bladder cancer stage.

CONCLUSIONS

Our findings indicated that SNP rs978416 G>A in RBFOX3 may be related to bladder cancer predisposition in Chinese population and might serve as a novel biomarker for bladder cancer risk.

Polymorphisms in IL-17A Gene and Susceptibility of Colorectal Cancer in Bangladeshi Population: A Case-Control Analysis

OBJECTIVE

Interleukin-17A (IL-17A) genetic polymorphisms are associated with multiple cancer types, including colorectal cancer (CRC). However, no previous study was performed in the Bangladeshi population to evaluate the association. Our study aimed to find the association between two IL-17A variants (rs10484879 C/A and rs3748067 G/A) and susceptibility of CRC.

METHODS AND MATERIALS

This retrospective case-control study comprised 292 CRC patients and 288 age, sex, and BMI matched healthy volunteers. Genotyping of both variants was done by the tetra-primer ARMS-PCR method, and the results were analyzed by the SPSS software package (version-25.0).

RESULTS

Logistic regression analysis indicated that in case of IL-17A rs10484879 polymorphism, AC and AA genotype carriers showed 2.44- and 3.27-times significantly increased risk for CRC development (OR = 2.44, P = .0008 and OR = 3.27, P = .0133, individually). A significant association was also observed for AC + AA genotype (OR = 2.58, P = .0001). Again, over-dominant and allelic model revealed statistically significant link to CRC risk (OR = 2.13, P = .0035 and OR = 2.22, P = .001). For rs3748067 polymorphism, AG and AA genotype carriers showed 2.30- and 2.45-times enhanced risk for CRC (OR = 2.30, P = .005 and OR = 2.45, P = .031). A statistically significant association was also observed for AG + AA genotype (OR = 2.35, P = .001), over-dominant model (OR = 2.05, P = .014), and allelic model (OR = 2.11, P = .0004).

CONCLUSION

This study highlights that IL-17A rs10484879 and rs3748067 polymorphisms may be associated with CRC development. However, further functional research with larger samples may reveal more statistically significant outcomes.

Genetic Variants in METTL14 are Associated with the Risk of Acute Lymphoblastic Leukemia in Southern Chinese Children: A Five-Center Case-Control Study

Background/Aim

Acute lymphoblastic leukemia (ALL) is the most common form of pediatric cancer. METTL14, an N⁶-methyladenosine (m⁶A) modification protein, plays several roles in cancer development and is involved in the pathogenesis of various types of cancers. However, the role of METTL14 gene single nucleotide polymorphisms (SNPs) in pediatric ALL susceptibility remains to be investigated.

Methods

A case-control design and multinomial logistic regression were used to develop models to estimate the overall risk for pediatric ALL and three METTL14 gene SNPs (rs298982 G/A, rs298981 A/G and rs1064034 T/A) in 808 cases and 1340 controls, which were genotyped using a TaqMan assay. The associations were estimated by odds ratios (ORs) with their 95% confidence intervals (CIs). Furthermore, stratified analysis was performed to explore associations of rs298982 and rs1064034 with pediatric ALL susceptibility in terms of age, sex, immunophenotype, minimal residual disease (MRD), and other clinical characteristics.

Results

Among the three analyzed SNPs, rs298982 G/A and rs1064034 T/A exhibited a significant association with decreased childhood ALL risk, while rs298981 A/G exhibited no difference. In stratified analysis, rs298982 GA/AA and rs1064034 TA/AA had a protective effect in children <120 months of age and males, common B ALL, TEL-AML, non gene fusion, normal diploid, and high WBC. However, the rs1064034 TA/AA genotype was associated with an increased risk of mixed immunophenotyping. Compared with the reference haplotype GAT, haplotypes CAA, CGT and CGA were significantly associated with elevated ALL risk, while haplotype GGT was significantly associated decreased ALL risk. Moreover, subjects carrying rs298982 A or rs1064034 A exhibited less minimal MRD after induced chemotherapy. Functional annotations revealed that METTL14 gene SNPs rs298982 G/A and rs1064034 T/A could be potential functional variants.

Conclusion

In conclusion, METTL14 gene polymorphisms influence the risk of ALL in southern Chinese children and might be potential biomarkers for pediatric ALL susceptibility and chemotherapeutics.

BDP1 Variants I1264M and V1347M Significantly Associated with Clinical Outcomes of Pediatric Neuroblastoma Patients Imply a New Prognostic Biomarker: A 121-Patient Cancer Genome Study

Background: Neuroblastoma (N.B.) is the most common tumor in children. The gene BDP1 (B Double Prime 1) plays a role in cancers but is less known in N.B. Thus, we conducted this study to investigate the value of BDP1 mutations in N.B. prognosis. Methods: A dataset of 121 NB patients from the Cancer Genome Atlas database was used to analyze BDP1 gene mutations by RNA sequencing. Kaplan-Meier estimates were performed for overall survival (O.S.) analysis on BDP1 variants, and Cox’s proportional hazards regression model was used for multivariate analysis. Results: In 121 NB patients, we identified two variants of BDP1 associated with N.B., located at chr5:71511131 and chr5:71510884. The prevalence of these BDP1 variants, I1264M and V1347M, was 52.9% (64/121) and 45.5% (55/121), respectively. O.S. analysis showed a significant difference between subgroups with or without BDP1 variants (p < 0.05). Multivariate analysis further revealed that BDP1ariants were independent prognostic variables in N.B. (p < 0.05). Conclusion: Our results suggest BDP1 variants are associated with significantly improved clinical outcomes in N.B., thus providing clinicians with a new tool.

BDP1 Variants I1264M and V1347M Significantly Associated with Clinical Outcomes of Pediatric Neuroblastoma Patients Imply a New Prognostic Biomarker: A 121-Patient Cancer Genome Study

Background: Neuroblastoma (N.B.) is the most common tumor in children. The gene BDP1 (B Double Prime 1) plays a role in cancers but is less known in N.B. Thus, we conducted this study to investigate the value of BDP1 mutations in N.B. prognosis. Methods: A dataset of 121 NB patients from the Cancer Genome Atlas database was used to analyze BDP1 gene mutations by RNA sequencing. Kaplan-Meier estimates were performed for overall survival (O.S.) analysis on BDP1 variants, and Cox’s proportional hazards regression model was used for multivariate analysis. Results: In 121 NB patients, we identified two variants of BDP1 associated with N.B., located at chr5:71511131 and chr5:71510884. The prevalence of these BDP1 variants, I1264M and V1347M, was 52.9% (64/121) and 45.5% (55/121), respectively. O.S. analysis showed a significant difference between subgroups with or without BDP1 variants (p < 0.05). Multivariate analysis further revealed that BDP1ariants were independent prognostic variables in N.B. (p < 0.05). Conclusion: Our results suggest BDP1 variants are associated with significantly improved clinical outcomes in N.B., thus providing clinicians with a new tool.

YTHDC1 gene polymorphisms and neuroblastoma susceptibility in Chinese children

Neuroblastoma (NB) is the most common extracranial tumor in children. YTHDC1, a member of RNA methylation modification binding proteins, plays critical roles in tumor occurrence and metastasis. However, it is unclear whether YTHDC1 gene polymorphisms are related to NB susceptibility. Herein, we aimed to evaluate the association between YTHDC1 gene polymorphisms (rs2293596 T>C, rs2293595 T>C, rs3813832 T>C) and susceptibility of NB by logistic regression models. In this eight-center case-control study, 898 patients with NB and 1734 healthy controls were genotyped by TaqMan assay. The results showed that rs3813832 TC genotype could significantly reduce the susceptibility of NB compared with the TT genotype [adjusted odds ratio (AOR) = 0.81, 95% confidence interval (CI) = 0.68-0.96, P = 0.018]. Combined genotype analysis revealed that individuals with 3 protective genotypes had a prominently lower NB risk than those with 0-2 protective genotypes (AOR = 0.80, 95% CI = 0.68-0.94, P = 0.006). The stratified analysis also demonstrated the protective effect of rs3813832 TC/CC and 3 protective genotypes in certain subgroups. Further functional experiments revealed that YTHDC1 siRNA-554, targeting the area near the rs3813832 T>C polymorphism site, could observably inhibit the proliferation and migration of NB cells. In conclusion, our findings highlight the involvement of YTHDC1 gene and its genetic variants in the etiology of NB.

METTL14 gene polymorphisms decrease Wilms tumor susceptibility in Chinese children

BACKGROUND

Wilms tumor is a highly heritable malignancy. Aberrant METTL14, a critical component of N6-methyladenosine (m⁶A) methyltransferase, is involved in carcinogenesis. The association between genetic variants in the METTL14 gene and Wilms tumor susceptibility remains to be fully elucidated. We aimed to assess whether variants within this gene are implicated in Wilms tumor susceptibility.

METHODS

A total of 403 patients and 1198 controls were analyzed. METTL14 genotypes were assessed by TaqMan genotyping assay.

RESULT

Among the five SNPs analyzed, rs1064034 T > A and rs298982 G > A exhibited a significant association with decreased susceptibility to Wilms tumor. Moreover, the joint analysis revealed that the combination of five protective genotypes exerted significantly more protective effects against Wilms tumor than 0-4 protective genotypes with an OR of 0.69. The stratified analysis further identified the protective effect of rs1064034 T > A, rs298982 G > A, and combined five protective genotypes in specific subgroups. The above significant associations were further validated by haplotype analysis and false-positive report probability analysis. Preliminary mechanism exploration indicated that rs1064034 T > A and rs298982 G > A are correlated with the expression and splicing event of their surrounding genes.

CONCLUSIONS

Collectively, our results suggest that METTL14 gene SNPs may be genetic modifiers for the development of Wilms tumor.

Environmental and occupational determinants of myelodysplastic syndrome: A case-control study from Pakistan

Background

Myelodysplastic syndromes (MDS) are heterogeneous group of haematopoietic stem cell disorders and have variable reduction in the production of red cells, platelets and mature granulocytes.

Aim

We conducted a case–control study evaluating the environmental and occupational determinants as risk factors of MDS.

Methods

A case–control study was conducted including 150 de novo MDS cases and 450 age and gender‐matched controls. Disease characteristics, sociodemographics and exposure to environmental and occupational determinants were collected through a questionnaire. Chi‐square test was applied to observe association, and binary logistic regression was applied to predict the odds of having MDS.

Results

A total of 600 participants were analysed. Those who were exposed to arsenic (OR 31.81, CI: 19.0–53.0, P‐value: .000), benzene (OR 1.564, CI: 1.07–2.27, P‐value: .01) using natural source of water (OR 3.563, CI: 2.29–5.53, P‐value: .000) and smokers (OR 3.1, P‐value: .000) were more likely to have MDS. Unmarried were less likely to acquire MDS than married (OR 0.239, CI: 0.15–0.36, P‐value: .000), Sindhi speaking were 1.419 times more likely to have MDS than participants speaking other languages. Uneducated participants were more likely to have MDS than educated and powder milk users were more likely to have MDS than dairy milk users.

Conclusion

Our results revealed that arsenic, use of natural source of water and benzene exposure might lead to higher risk of acquiring MDS. This study would be helpful to understand the aetiology of disease in Pakistani population.

A novel m6A-related prognostic signature for predicting the overall survival of hepatocellular carcinoma patients

Liver hepatocellular carcinoma (LIHC) comprises most cases of liver cancer with a poor prognosis. N⁶‐methyladenosine (m6A) plays important biological functions in cancers. Thus, the present research was aimed to determine biomarkers of m6A regulators that could effectively predict the prognosis of LIHC patients. Based on the data collected from the Cancer Genome Atlas (TCGA) database, the correlation between the mRNA expression levels and copy number variation (CNV) patterns were determined. Higher mRNA expression resulted from the increasing number of 9 genes. Using the univariate Cox regression analysis, 11 m6A regulators that had close correlations with the LIHC prognosis were identified. In addition, under the support of the multivariate Cox regression models and the least absolute shrinkage and selection operator, a 4‐gene (YTHDF2, IGF2BP3, KIAA1429, and ALKBH5) signature of m6A regulators was constructed. This signature was expected to present a prognostic value in LIHC (log‐rank test p value < 0.0001). The GSE76427 (n = 94) and ICGC‐LIRI‐JP (n = 212) datasets were used to validate the prognostic signature, suggesting strong power to predict patients' prognosis for LIHC. To sum up, genetic alterations in m6A regulatory genes were identified as reliable and effective biomarkers for predicting the prognosis of LIHC patients.

IGF2BP2 promotes the progression of colorectal cancer through a YAP-dependent mechanism

To explore the effect of insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) on colorectal cancer (CRC) by recognizing the m6A modification of YAP mRNA thus activating ErbB2 expression. High expressions of IGF2BP2, YAP, and ErbB2 promoted the proliferation, migration and invasion of CRC cells and reduced their apoptosis. IGF2BP2 recognized the m6A on YAP mRNA and promoted the translation of mRNA. YAP regulated ErbB2 expression by promoting TEAD4 enrichment in ErbB2 promoter region. Therefore, IGF2BP2 promoted the expression of ErbB2 to enhance the proliferation, invasion and migration of CRC cells, to repress cell apoptosis, and to promote solid tumor formation in nude mice. IGF2BP2 activates the expression of ErbB2 by recognizing the m6A of YAP, thus affecting the cell cycle of CRC, inhibiting cell apoptosis, and promoting proliferation.

The RNA m6A writer METTL14 in cancers: Roles, structures, and applications

N⁶-methyladenosine (m⁶A) is the most abundant and diverse epigenetic modification of mRNAs in eukaryotes, and it regulates biological metabolism, cell differentiation and cycles, and responses to heat shock stress, cancers and other diseases. RNA methyltransferase-like 3 (METTL3), methyltransferase-like 14 (METTL14) and other proteins possessing methyltransferase (MTase) capability including Wilms tumor 1-associated protein (WTAP), RNA-binding motif protein 15(RBM15), KIAA 1429 and zinc finger CCCH-type containing 13 (ZC3H13) constitute the m⁶A writer complex. Although METTL3 is the catalytic subunit, its activity is strongly dependent on METTL14, which is crucial in maintaining complex integrity and recognizing special RNA substrates. Currently, the roles of m⁶A modification in cancers are being extensively reviewed. The critical functions of METTL14 in the occurrence and development of a variety of cancers as well as the potential targeting of METTL14 as a cancer treatment have not yet been highlighted. Therefore, in this review, we summarize the m⁶A modification and focus on the structure and functions of METTL14 as well as its roles in oncogenesis, metastasis progression, treatment and prognosis in cancer.

Integrative genomic analysis of N6-methyladenosine-single nucleotide polymorphisms (m6A-SNPs) associated with breast cancer

Due to the important role of N6-methyladenosine (m⁶A) in breast cancer, single nucleotide polymorphisms (SNPs) in genes with m⁶A modification may also be involved in breast cancer pathogenesis. In this study, we used a public genome-wide association study dataset to identify m⁶A-SNPs associated with breast cancer and to further explore their potential functions. We found 113 m⁶A-SNPs associated with breast cancer that reached the genome-wide suggestive threshold (5.0E-05), and 86 m⁶A-SNPs had eQTL signals. Only six genes were differentially expressed between controls and breast cancer cases in GEO datasets (GSE15852, GSE115144, and GSE109169), and the SNPs rs4829 and rs9610915 were located next to the m⁶A modification sites in the 3ʹUTRs of TOM1L1 and MAFF, respectively. In addition, we found that polyadenylate-binding protein cytoplasmic 1 might have a potential interaction with rs4829 (TOM1L1) and rs9610915 (MAFF). In summary, these findings indicated that the SNPs rs4829 and rs9610915 are potentially associated with breast cancer because they had eQTL signals, altered gene expression, and were located next to the m⁶A modification sites in the 3ʹUTRs of their coding genes. However, further studies are still needed to clarify how genetic variation affects the epigenetic modification, m⁶A, and its subsequent functions in the pathogenesis of breast cancer.

LRRC3B Polymorphisms Contributed to Breast Cancer Susceptibility in Chinese Han Population

Purpose

LRRC3B gene, as a tumor suppressor gene was involved in the development and progress of breast cancer (BC). However, the effect of LRRC3B polymorphisms on BC has rarely been reported. In the study, we aimed to evaluate the relation between LRRC3B variants and BC risk.

Methods

Among 563 BC patients and 552 healthy controls, ten single-nucleotide polymorphisms (SNPs) in LRRC3B were genotyped by Agena MassARRAY. Odds ratios (ORs) and 95% confidence interval (CI) were calculated using logistic regression model.

Results

Our study demonstrated that rs1907168 polymorphism (heterozygous: OR = 0.71, p = 0.017) was related to the reduced risk of BC in the overall. In stratified analyses by age, rs1907168 was associated with the decreased (heterozygous: OR = 0.53, p = 0.002) while rs78205284 (homozygote: OR = 2.83, p = 0.034) increased BC susceptibility among the population at age ≤51 years. Rs6551122 (recessive: OR = 0.51, p = 0.028) and rs12635768 (homozygote, OR = 0.36, p = 0.023) polymorphisms were related to the smaller BC tumor size (<2 cm). In addition, rs112276562 (heterozygote OR = 0.56, p = 0.002), rs6551122 (heterozygote OR = 0.63, p = 0.016), and rs73150416 (heterozygote OR = 0.57, p = 0.005) variants contributed to the lower incidence of PR-positive BC. Moreover, rs6788033 was associated with a lower expression level of Ki-67 (log-additive: OR = 0.68, p = 0.024). Furthermore, we found an association of ‘GATT’ haplotype with an increased risk for BC. In addition, LRRC3B gene was down-regulated in BC tumor and had a poor prognosis in BC in in silico analysis.

Conclusion

Our study firstly found LRRC3B SNPs contributed to the risk of BC, suggesting LRRC3B variants might help to predict BC progression.

E-cadherin (CDH1) gene -160C/A polymorphism and the risk of colorectal cancer: A meta-analysis involving 17,291 subjects

BACKGROUND

The E-cadherin (CDH1) polymorphism has been implicated in the susceptibility to colorectal cancer (CRC). However, the results remain inconclusive. The present meta-analysis aimed to investigate the association between the CDH1-160C/A polymorphism and CRC risk.

METHODS

Relevant studies were retrieved by searching PubMed, Web of Science, Google Scholar, the Cochrane Library, Embase, CNKI and Wanfang databases up to 11 March 2021. Pooled odds ratio and 95% confidence interval were calculated using either the fixed- or random-effects model. Quality evaluation was carried out using Newcastle-Ottawa Scale (NOS). A trial sequential analysis (TSA) was conducted to reduce the risk of type I error.

RESULTS

In total, 16 studies from 14 articles with 8699 patients and 8592 controls were included. In general, all studies were of high quality (NOS score higher than 6). Overall, no significant associations between the CDH1 -160C/A polymorphism and CRC risk were detected. In subgroup analysis by ethnicity, source of control, genotyping method and location, significant associations were found between the CDH1-160C/A polymorphism and the risk of CRC in the Caucasians and the hospital-based subgroup. Furthermore, 10 studies with 8019 subjects reported the association between the polymorphism and clinical characteristics in CRC patients, and we found that the CDH1-160C/A polymorphism might show a protective role in the distal CRC subgroup. By TSA, the findings in the present study were based on sufficient evidence in Caucasians, but not in Asians.

CONCLUSIONS

This meta-analysis suggests that the CDH1-160C/A polymorphism may be an important protective factor for CRC in Caucasians and a hospital-based subgroup. Moreover, the polymorphism show a protective role in the distal CRC group. However, large and well-designed studies are warranted to validate our findings, especially for Asians.

Regulatory Mechanisms of the RNA Modification m6A and Significance in Brain Function in Health and Disease

RNA modifications have emerged as an additional layer of regulatory complexity governing the function of almost all species of RNA. N⁶-methyladenosine (m⁶A), the addition of methyl groups to adenine residues, is the most abundant and well understood RNA modification. The current review discusses the regulatory mechanisms governing m⁶A, how this influences neuronal development and function and how aberrant m⁶A signaling may contribute to neurological disease. M⁶A is known to regulate the stability of mRNA, the processing of microRNAs and function/processing of tRNAs among other roles. The development of antibodies against m⁶A has facilitated the application of next generation sequencing to profile methylated RNAs in both health and disease contexts, revealing the extent of this transcriptomic modification. The mechanisms by which m⁶A is deposited, processed, and potentially removed are increasingly understood. Writer enzymes include METTL3 and METTL14 while YTHDC1 and YTHDF1 are key reader proteins, which recognize and bind the m⁶A mark. Finally, FTO and ALKBH5 have been identified as potential erasers of m⁶A, although there in vivo activity and the dynamic nature of this modification requires further study. M⁶A is enriched in the brain and has emerged as a key regulator of neuronal activity and function in processes including neurodevelopment, learning and memory, synaptic plasticity, and the stress response. Changes to m⁶A have recently been linked with Schizophrenia and Alzheimer disease. Elucidating the functional consequences of m⁶A changes in these and other brain diseases may lead to novel insight into disease pathomechanisms, molecular biomarkers and novel therapeutic targets.

Genetic variants in m6A modification core genes are associated with glioma risk in Chinese children

Glioma is a highly heritable disease with a strong genetic component. The N6-methyladenosine (m⁶A) modification core genes play important roles in the context of cancer. However, the effects of polymorphisms in the m⁶A modification core genes on the risk of pediatric glioma remain undefined. Here, we intended to demonstrate the relationship between 24 functional single-nucleotide polymorphisms (SNPs) in eight m⁶A modification core genes and glioma risk. Case-control design and multinomial logistic regression were used to develop models to estimate the risk of glioma while accounting for the subtypes of glioma. A total of 171 glioma cases and 228 controls from South China were genotyped using a TaqMan assay. The WTAP rs7766006, YTHDF2 rs3738067, and FTO rs9939609 variants conferred a statistically significant increased risk of glioma, respectively. YTHDC1 rs2293595, YTHDC1 rs3813832, and FTO rs8047395 were associated with a significant inverse association with risk of glioma, respectively. The significant associations were more predominant in stratification analyses of certain subgroups. Functional annotations revealed that WTAP rs7766006 and YTHDF2 rs3738067 could be potential functional variants by increasing expression of WTAP and YTHDF2 mRNA, respectively. Overall, these findings implicate variants in the m⁶A modification core genes as playing a role in pediatric glioma etiology.

Noriega L, Tovar A, Alegría-Torres JA. Polymorphisms of the genes ABCG2, SLC22A12 and XDH and their relation with hyperuricemia and hypercholesterolemia in Mexican young adults

Background: Hyperuricemia is a pathological condition associated with risk factors of cardiovascular disease. In this study, three genetic polymorphisms were genotyped as predisposing factors of hyperuricemia. Methods: A total of 860 Mexicans (129 cases and 731 controls) between 18 and 25 years of age were genotyped for the ABCG2 (Q191K),  SLC22A12 (517G>A), and  XDH (518T>C) polymorphisms, as predisposing factors of hyperuricemia. Biochemical parameters were measured by spectrophotometry, while genetic polymorphisms were analyzed by real-time PCR. An analysis of the risk of hyperuricemia in relation to the variables studied was carried out using a logistic regression. Results: Male sex, being overweight or obese, having hypercholesterolemia or having hypertriglyceridemia were factors associated with hyperuricemia ( p ≤ 0.05). The ABCG2 polymorphism was associated with hyperuricemia (OR = 2.43, 95% CI: 1.41-4.17, p = 0.001) and hypercholesterolemia (OR = 4.89, 95% CI: 1.54-15.48, p = 0.003), employing a dominant model, but only in male participants. Conclusions: The ABCG2 (Q191K) polymorphism increases the risk of hyperuricemia and hypercholesterolemia in young Mexican males.

Association of LCT -13910C>T polymorphism and hip fracture in a cohort of older adult population from Northern Spain

Hip fracture is a common health problem very frequent in the older adult population and is associated with significant morbidity, mortality, and societal costs. There are several factors that increase the risk of suffering a hip fracture, however, the effect of genetic lactase non-persistence is not clear-cut yet. For this reason, we investigated if the LCT -13910C>T polymorphism is a potential risk factor for osteoporotic hip fractures in older adult people from the Northern Spain population. A total of 740 individuals were included in this study. Of them, 364 belonged to the group of patients whit osteoporotic hip fracture while the control group consisted of 376 individuals without hip fracture. The genotypes for the LCT -13910C>T polymorphism were analyzed by using polymerase chain reaction and high resolution melting. The prevalence of the CC genotype, which is related to lactase non-persistence, did not differ significantly in both groups. Likewise, no differences were observed between groups when they were compared with regard to the C or the T allele, or when they were analyzed considering gender. Additionally, our results were compared with those obtained in a control group of 207 nonagenarian individuals originally from Northern Spain and no differences were observed. In conclusion, no significant association was observed between the LCT -13910C>T polymorphism and the risk for suffering hip fracture in the older adult population of Northern Spain.

KRAS gene polymorphisms are associated with the risk of glioma: a two-center case-control study

BACKGROUND

Glioma, also known as neuroglioma, is the most common primary tumors of the central nervous system. Many previous studies have reported associations between RAS gene polymorphisms and multiple tumors. However, the role of RAS gene polymorphisms on glioma risk has not been investigated.

METHODS

We conducted a two-center case-control study to investigate whether the RAS gene polymorphisms predispose individuals to gliomas in 248 healthy controls and 191 glioma patients. RAS gene polymorphisms (rs12587 G>T, rs7973450 A>G, rs7312175 G>A in KRAS, rs2273267 A>T in NRAS) were genotyped by the TaqMan assay. The relationship between RAS gene functional single nucleotide polymorphisms (SNPs) and the risk of glioma was evaluated based on odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Individuals with KRAS rs7312175 GA genotype were more likely to develop glioma than those with GG genotype (adjusted OR =1.66, 95% CI: 1.05-2.64, P=0.030). However, the other three SNPs could not affect glioma risk. In stratified analysis of age, gender, subtypes, and clinical stages, rs7312175 GA carriers were more likely to develop glioma in the following subgroups: children less than 60 months, tumor derived from the astrocytic tumors, and clinical stages I.

CONCLUSIONS

The study showed that polymorphism rs7312175 GA in the KRAS gene was associated with increased glioma susceptibility. Further investigation is warranted to confirm these findings and to better elucidate the involved biological pathways.

YTHDF2 Gene rs3738067 A>G Polymorphism Decreases Neuroblastoma Risk in Chinese Children: Evidence From an Eight-Center Case-Control Study

Neuroblastoma is a primary malignancy mainly occurring in children. We have reported that polymorphisms of several N6-methyladenosine (m6A) RNA modification-related genes contributed to neuroblastoma risk in previous studies. YTHDF2, a "reader" of RNA m6A modification, is involved in cancer progression. Here, we estimated the association between a YTHDF2 gene rs3738067 A>G polymorphism and neuroblastoma susceptibility in 898 neuroblastoma patients and 1,734 healthy individuals from China. We found that the rs3738067 A>G could decrease neuroblastoma risk [AG vs. AA: adjusted odds ratio (OR) = 0.76, 95% confidence interval (CI) = 0.64-0.90, P = 0.002; AG/GG vs. AA: adjusted OR = 0.81, 95% CI = 0.69-0.95, P = 0.011). Besides, the rs3738067 AG/GG genotype was related to reduced neuroblastoma risk in the following subgroups: children aged 18 months and under, boys, patients with tumors originating from retroperitoneal, patients at clinical stage IV, and cases at clinical stages III plus IV. Importantly, false-positive report probability analysis proved our significant results worthy of close attention of. The expression quantitative trait locus analysis results revealed that the rs3738067 was associated with the expression of YTHDF2.

The contribution of YTHDF2 gene rs3738067 A>G to the Wilms tumor susceptibility

YTHDF2 is responsible for maintaining the dynamic N⁶-methyladenosine (m⁶A) modification balance and influences a variety of cancers. We tested whether YTHDF2 gene rs3738067 A>G polymorphism is related to Wilms tumor by genotyping samples of Chinese children (450 cases and 1317 controls). However, the rs3738067 A>G polymorphism showed no statistical significance with Wilms tumor susceptibility. Stratification analysis also revealed that there was no remarkable association of rs3738067 variant AG/GG genotype with Wilms tumor risk in every subgroup (age, gender, and clinical stages). In all, the results indicated YTHDF2 gene rs3738067 A>G polymorphism could not alter Wilms tumor risk significantly.

Epitranscriptomic regulation of transcriptome plasticity in development and diseases of the brain

Proper development of the nervous system is critical for its function, and deficits in neural development have been impli-cated in many brain disorders. A precise and predictable developmental schedule requires highly coordinated gene expression programs that orchestrate the dynamics of the developing brain. Especially, recent discoveries have been showing that various mRNA chemical modifications can affect RNA metabolism including decay, transport, splicing, and translation in cell type- and tissue-specific manner, leading to the emergence of the field of epitranscriptomics. Moreover, accumulating evidences showed that certain types of RNA modifications are predominantly found in the developing brain and their dysregulation disrupts not only the developmental processes, but also neuronal activities, suggesting that epitranscriptomic mechanisms play critical post-transcriptional regulatory roles in development of the brain and etiology of brain disorders. Here, we review recent advances in our understanding of molecular regulation on transcriptome plasticity by RNA modifications in neurodevelopment and how alterations in these RNA regulatory programs lead to human brain disorders.