YTHDC1 gene polymorphisms and hepatoblastoma susceptibility in Chinese children: A seven-center case-control study

Identification of hepatoblastoma susceptibility loci in the TRMT6 gene from a seven-center case-control study

Hepatoblastoma, the most frequently diagnosed primary paediatric liver tumour, bears the lowest somatic mutation burden among paediatric neoplasms. Therefore, it is essential to identify pathogenic germline genetic variants, especially those in oncogenic genes, for this disease. The tRNA methyltransferase 6 noncatalytic subunit (TRMT6) forms a tRNA methyltransferase complex with TRMT61A to catalyse adenosine methylation at position N1 of RNAs. TRMT6 has displayed tumour-promoting functions in several cancer types. However, the contribution of its genetic variants to hepatoblastoma remains unclear. In this study, we investigated the association between four TRMT6 polymorphisms (rs236170 A > G, rs451571 T > C, rs236188 G > A and rs236110 C > A) and the risk of hepatoblastoma in a cohort of 313 cases and 1446 healthy controls. Germline DNA was subjected to polymorphism genotyping via the TaqMan qPCR method. Odds ratio (OR) and 95% confidence interval (CI) were used to determine hepatoblastoma susceptibility variants. The rs236170 A > G, rs236188 G > A and rs236110 C > A polymorphisms were significantly associated with hepatoblastoma risk. Combination analysis of the four polymorphisms revealed that children bearing 1-4 risk genotypes were at significantly enhanced hepatoblastoma risk compared to those without risk genotype (adjusted OR = 1.52, 95% CI = 1.19-1.95, p = 0.0008). We also conducted stratification analyses by age, sex and clinical stage. Ultimately, we found that the rs236110 C > A was significantly associated with the downregulation of MCM8, a neighbouring gene of TRMT6. In conclusion, we identified three susceptibility loci in the TRMT6 gene for hepatoblastoma. Our findings warrant further validation by extensive case-control studies across different ethnicities.

TRMT61B rs4563180 G>C variant reduces hepatoblastoma risk: a case-control study of seven medical centers

N1-methyladenosine (m1A) is an essential chemical modification of RNA. Dysregulation of RNA m1A modification and m1A-related regulators is detected in several adult tumors. Whether aberrant RNA m1A modification is involved in hepatoblast carcinogenesis has not been reported. tRNA methyltransferase 61B (TRMT61B) is responsible for mitochondrial RNA m1A modification. Some evidence has shown that genetic variants of TRMT61B might contribute to cancer susceptibility; however, its roles in hepatoblastoma are unknown. This study attempted to discover novel hepatoblastoma susceptibility loci. With the TaqMan method, we examined genotypes of the TRMT61B rs4563180 G>C polymorphism among germline DNA samples from 313 cases and 1446 controls. The association of the rs4563180 G>C polymorphism with hepatoblastoma risk was estimated based on odds ratios (ORs) and 95% confidence intervals (CIs). We found that the TRMT61B rs4563180 G>C polymorphism correlated significantly with a reduction in hepatoblastoma risk (GC vs. GG: adjusted OR=0.65, 95% CI=0.49-0.85, P=0.002; GC/CC vs. GG: adjusted OR=0.66, 95% CI=0.51-0.85, P=0.002). In stratified analysis, significant associations were detected in children younger than 17 months old, girls, and subgroups with stage I+II or III+IV tumors. False-positive report probability analysis validated that children with the GC or CC genotype, particularly in those <17 months of age, had a decreased risk of hepatoblastoma. The rs4563180 G>C polymorphism also correlated with expression of TRMT61B and the nearby gene PPP1CB. We identified a high-quality biomarker measuring hepatoblastoma susceptibility, which may contribute to future screening programs.

Association of N6-methyladenosine readers' genes variation and expression level with pulmonary tuberculosis

N6-Methyladenosine (m6A) is associated with many biological processes and the development of multiple diseases. The aim of this study was to analyze the association of m6A readers' genes variation, as well as their expression levels, with pulmonary tuberculosis (PTB). A total of 11 single-nucleotide polymorphisms (SNPs) in m6A readers' genes (i.e., YTHDF1 rs6122103, rs6011668, YTHDF2 rs602345, rs3738067, YTHDF3 rs7464, rs12549833, YTHDC1 rs3813832, rs17592288, rs2293596, and YTHDC2 rs6594732, and rs2416282) were genotyped by SNPscan™ technique in 457 patients with PTB and 466 normal controls. The m6A readers' genes expression levels in peripheral blood mononuclear cells (PBMCs) from 78 patients with PTB and 86 normal controls were detected by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). There was no significant association between all SNPs in YTHDF1, YTHDF2, YTHDF3, YTHDC1, and YTHDC2 genes and PTB susceptibility. The increased frequencies of YTHDF2 rs3738067 GG genotype and YTHDC1 rs3813832 CC genotype, C allele, were, respectively, found in PTB patients with hypoproteinemia and fever. YTHDC2 rs6594732 variant was significantly associated with drug-induced liver damage and sputum smear-positive, and the rs2416282 variant was significantly associated with fever in patients with PTB. Compared with controls, the YTHDF1, YTHDF2, YTHDF3, YTHDC1, and YTHDC2 mRNA levels were significantly decreased in PTB. Moreover, YTHDF1 level was negatively associated with erythrocyte sedimentation rate (ESR), and YTHDF3 and YTHDC1 levels were negatively related to alanine aminotransferase (ALT) in patients with PTB. Our results demonstrated that YTHDF1, YTHDF2, YTHDF3, YTHDC1, and YTHDC2 genes SNPs did not contribute to PTB susceptibility, while their decreased levels in patients with PTB suggested that these m6A readers might play significant roles in PTB.

METTL1 gene polymorphisms synergistically confer hepatoblastoma susceptibility

INTRODUCTION

Hepatoblastoma is a rare but devastating pediatric liver malignancy. Overexpressed methyltransferase-like 1 (METTL1) is a methyltransferase that catalyzes essential N7-methylguanosine (m7G) modification of eukaryotic mRNA. Accumulating evidence has revealed the oncogenic potential of METTL1. However, whether METTL1 gene polymorphisms confer susceptibility to hepatoblastoma has not been reported. This study aimed to identify causal relationships between genetic variants of this gene and susceptibility to hepatoblastoma.

MATERIALS AND METHODS

Using the TaqMan assay, we genotyped three METTL1 polymorphisms (rs2291617 G > T, rs10877013 T > C, rs10877012 T > G) in germline DNA samples from 1759 Chinese children of Han ethnicity (313 cases vs. 1446 controls).

RESULTS

None of these polymorphisms were associated with hepatoblastoma risk. However, combination analysis showed that children with 1 to 3 risk genotypes were associated with increased hepatoblastoma risk (adjusted odds ratio = 1.47, 95% confidence interval  1.07-2.02; P = 0.018). Stratified analyses revealed significant effects of combined polymorphisms mainly among young children (< 17 months of age), boys, and those with advanced hepatoblastoma.

CONCLUSION

We identified some potential functional METTL1 gene polymorphisms that work together to increase the risk of hepatoblastoma among Chinese Han children; single polymorphism showed only weak effects. These METTL1 polymorphisms may be promising biomarkers for screening high-risk individuals for hepatoblastoma. These findings are inspiring and deserve to be validated among individuals of different ethnicities.

The Role of N6-Methyladenosine in the Promotion of Hepatoblastoma: A Critical Review

Simple Summary

Hepatoblastoma is the most common malignant pediatric tumor of the liver. Unlike hepatocellular carcinoma (HCC) which has been associated with hepatitis B virus infection or cirrhosis, the etiology of hepatoblastoma remains vague. Genetic syndromes, including familial adenomatous polyposis (FAP), Beckwith-Wiedemann syndrome (BWS), and trisomy 18 syndrome, have been associated with hepatoblastoma. BWS is an overgrowth syndrome which exhibits an alteration of genomic imprinting on chromosome 11p15.5. N⁶-Methyladenosine (M⁶A) is an RNA modification with rampant involvement in the metabolism of cells and malignant diseases. It has been observed to impact the development of various cancers via its governance of gene expression. Here, we explore the role of m⁶A and its genetic associates in promoting HB, and the impact this may have on our future management of the disease.

Abstract

Hepatoblastoma (HB) is a rare primary malignancy of the developing fetal liver. Its course is profoundly influenced by genetics, in the context of sporadic mutation or genetic syndromes. Conventionally, subtypes of HB are histologically determined based on the tissue type that is recapitulated by the tumor and the direction of its differentiation. This classification is being reevaluated based on advances on molecular pathology. The therapeutic approach comprises surgical intervention, chemotherapy (in a neoadjuvant or post-operative capacity), and in some cases, liver transplantation. Although diagnostic modalities and treatment options are evolving, some patients experience complications, including relapse, metastatic spread, and suboptimal response to chemotherapy. As yet, there is no consistent framework with which such outcomes can be predicted. N⁶-methyladenosine (m⁶A) is an RNA modification with rampant involvement in the normal processing of cell metabolism and neoplasia. It has been observed to impact the development of a variety of cancers via its governance of gene expression. M⁶A-associated genes appear prominently in HB. Literature data seem to underscore the role of m⁶A in promotion and clinical course of HB. Illuminating the pathogenetic mechanisms that drive HB are promising additions to the understanding of the clinically aggressive tumor behavior, given its potential to predict disease course and response to therapy. Implicated genes may also act as targets to facilitate the evolving personalized cancer therapy. Here, we explore the role of m⁶A and its genetic associates in the promotion of HB, and the impact this may have on the management of this neoplastic disease.

The Emerging Role of N6-Methyladenosine RNA Methylation as Regulators in Cancer Therapy and Drug Resistance

N6-methyladenosine (m6A) RNA methylation has been considered the most prevalent, abundant, and conserved internal transcriptional modification throughout the eukaryotic mRNAs. Typically, m6A RNA methylation is catalyzed by the RNA methyltransferases (writers), is removed by its demethylases (erasers), and interacts with m6A-binding proteins (readers). Accumulating evidence shows that abnormal changes in the m6A levels of these regulators are increasingly associated with human tumorigenesis and drug resistance. However, the molecular mechanisms underlying m6A RNA methylation in tumor occurrence and development have not been comprehensively clarified. We reviewed the recent findings on biological regulation of m6A RNA methylation and summarized its potential therapeutic strategies in various human cancers.

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.

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.

MiR-451a Promotes Cell Growth, Migration and EMT in Osteosarcoma by Regulating YTHDC1-mediated m6A Methylation to Activate the AKT/mTOR Signaling Pathway

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It’s first proved that miR-451a can promote the malignant progression of osteosarcoma cells through AKT/mTOR pathway.

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It’s first proved that YTHDC1 modifies the m6A methylation of PDPK1.

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It’s first proved that YTHDC1 can promote the malignant progression of osteosarcoma cells.

Background

Osteosarcoma is the most prevalent primary malignant bone tumor containing mesenchymal cells with poor prognosis. Being a hot spot of anti-tumor therapy researches, AKT/mammalian target of rapamycin (mTOR) signaling pathway could affect various cellular processes including transcription, protein synthesis, apoptosis, autophagy and growth.

Materials and methods

The levels of RNA and protein were detected by quantitative real-time polymerase chain reaction (q-PCR) and western blot analyses respectively. Functional assays were carried out to analyze the malignant phenotypes of osteosarcoma cells. RNA-binding protein immunoprecipitation (RIP), Co-immunoprecipitation (Co-IP), RNA pulldown, luciferase reporter and in vitro kinase assays were conducted to uncover the specific mechanism of microRNA-451a (miR-451a) in osteosarcoma cells.

Results

Functionally, miR-451a represses the malignant progression of osteosarcoma. Mechanically, miR-451a could curb the AKT/mTOR pathway via 3-phosphoinositide dependent protein kinase 1 (PDPK1)-mediated phosphorylation modification. After the certification that YTH domain containing 1 (YTHDC1) regulates the m6A phosphorylation modification of PDPK1 mRNA, we further proved that miR-451a-mediated YTHDC1 stabilizes PDPK1 mRNA via m6A-dependent regulation.

Conclusion

This study demonstrated that miR-451a regulates YTHDC1-mediated m6A methylation to activate the AKT/mTOR pathway, stimulating the malignancy of osteosarcoma.

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.

Polymorphisms in METTL3 gene and hepatoblastoma risk in Chinese children: A seven-center case-control study

Hepatoblastoma is the most common malignant liver cancer in childhood, yet its etiology remains unclear. As an m6A methylation modifier, methyltransferase like 3 (METTL3) has an active methyltransferase domain that functionally participates in various tumor occurrence and development. However, little is known about how METTL3 polymorphisms affect the occurrence of hepatoblastoma. Here, we attempted to investigate the associations between METTL3 gene polymorphisms and hepatoblastoma risk in a seven-center case-control study. We genotyped four METTL3 polymorphisms (rs1061026 T > G, rs1061027 C > A, rs1139130 A > G, rs1263801 G > C) by TaqMan technique in 313 cases and 1446 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the contributions of these four single nucleotide polymorphisms (SNPs) to hepatoblastoma susceptibility. In single genotype analysis, we detected no significant correlation between these four polymorphisms in METTL3 and hepatoblastoma risk. However, in the combined analysis, the presence of 2-4 risk genotypes of METTL3 was associated with an increased risk of hepatoblastoma compared with that of 0-1 risk genotypes (adjusted OR = 1.48, 95% CI = 1.03-2.12, P = 0.035). The stratified analysis further revealed that carriers of 2-4 risk genotypes are more susceptible to hepatoblastoma in the subgroups of subjects aged under 17 months (adjusted OR = 1.88, 95% CI = 1.12-3.16, P = 0.016) and females (adjusted OR = 1.79, 95% CI = 1.06-3.05, P = 0.031). Overall, our results revealed that none of these four SNPs could increase susceptibility to hepatoblastoma individually. Carriers with 2-4 risk genotypes in the combined analysis tend to increase the risk of hepatoblastoma.

The Genetic Changes of Hepatoblastoma

Hepatoblastoma is the most common malignant liver cancer in childhood. The etiology of hepatoblastoma remains obscure. Hepatoblastoma is closely related to genetic syndromes, hinting that hepatoblastoma is a genetic predisposition disease. However, no precise exposures or genetic events are reported to hepatoblastoma occurrence. During the past decade, significant advances have been made in the understanding of etiology leading to hepatoblastoma, and several important genetic events that appear to be important for the development and progression of this tumor have been identified. Advances in our understanding of the genetic changes that underlie hepatoblastoma may translate into better patient outcomes. Single nucleotide polymorphisms (SNPs) have been generally applied in the research of etiology's exploration, disease treatment, and prognosis assessment. Here, we reviewed and discussed the molecular epidemiology, especially SNPs progresses in hepatoblastoma, to provide references for future studies and promote the study of hepatoblastoma's etiology.

Role of RNA N6-Methyladenosine Modification in Male Infertility and Genital System Tumors

Epigenetic alterations, particularly RNA methylation, play a crucial role in many types of disease development and progression. Among them, N6-methyladenosine (m6A) is the most common epigenetic RNA modification, and its important roles are not only related to the occurrence, progression, and aggressiveness of tumors but also affect the progression of many non-tumor diseases. The biological effects of RNA m6A modification are dynamically and reversibly regulated by methyltransferases (writers), demethylases (erasers), and m6A binding proteins (readers). This review summarized the current finding of the RNA m6A modification regulators in male infertility and genital system tumors and discussed the role and potential clinical application of the RNA m6A modification in spermatogenesis and male genital system tumors.

Malignant Evaluation and Clinical Prognostic Values of M6A RNA Methylation Regulators in Prostate Cancer

Objective: M6A RNA modification is closely associated with tumor genesis and progression of several malignancies; however, its role in prostate cancer (PCa) remains poorly understood.

Materials and methods: Expression data and corresponding clinicopathologic information were available freely from the Cancer Genome Atlas (TCGA) dataset. We compared the expression level of m6A RNA methylation regulators in PCa with different clinicopathologic characteristics and identified subgroups based on their expressions with consensus clustering. To build the signature and assess its prognostic value, several methods were used for the analysis, including univariate Cox regression analysis, Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis, time-dependent receiver operating curve (ROC), and Kaplan-Meier (KM) survival analysis.

Results: Most of the m6A RNA methylation regulators were differentially expressed not only between normal and tumor tissue but also among PCa stratified by different clinicopathologic characteristics. There were obvious differences between two clusters, cluster 1 and 2, regarding clinicopathologic features, and the recurrence-free survival (RFS) in cluster 2 was significantly worse than cluster 1. We developed an eleven-gene signature which exhibited a high prognostic value and was able to independently predict RFS. Moreover, a nomogram which integrated clinical information and the gene signature was capable of distinguishing high-risk recurrent patients.

Conclusion: These methylation regulators are correlated to clinicopathologic characteristics in PCa and a prognostic model using m6A methylation-related genes is constructed and of high predictive value for recurrence after RP.

Genetic variations in base excision repair pathway genes and risk of hepatoblastoma: a seven-center case-control study

Hepatoblastoma is a rare childhood liver cancer without known explicit etiology. Base excision repair (BER) pathway genes have been implicated in the pathophysiology of cancer, yet the role of BER pathway gene single nucleotide polymorphisms (SNPs) on hepatoblastoma risk still awaits to be explored. This study aims to determine whether hepatoblastoma risk be modulated by polymorphisms in the BER pathway genes based on genotyped data from 313 cases and 1446 controls. We applied TaqMan assay to genotype these included samples. We comprehensively genotyped 20 SNPs across six genes of BER, and estimated odds ratio (ORs), 95% confidence intervals (CIs), and P-values of the selected SNPs' contribution to the risk of hepatoblastoma using logistic regression models. Only SNP rs293795 in the hOGG1 gene could significantly enhance hepatoblastoma risk under recessive model (adjusted OR=3.78, 95% CI=1.01-14.17, P=0.047). Stratified analysis revealed that rs159153 TC/CC genotype decreased hepatoblastoma risk in male subgroup. Moreover, rs293795 GG and 1-3 risk genotypes could increase hepatoblastoma risk in clinical stages I+II and male subgroups, respectively. False-positive report probability validated the reliability of the significant results. Our findings provide some clues of a potential risk effect of BER pathway gene hOGG1 SNPs on hepatoblastoma. Further investigation is warranted to confirm these findings and to better elucidate the biological pathways involved.