m6A RNA Methylation Regulators Research Articles

Tumor Microenvironment in Clear Cell Renal Cell Carcinoma: A Comprehensive Analysis

Background: M6A RNA methylation and the tumor microenvironment (TME) have been reported to play important roles in the progression and prognosis of clear cell renal cell carcinoma (ccRCC). However, whether m6A RNA methylation regulators affect the TME in ccRCC remains unknown. Thus, we aimed to evaluate comprehensively the effect of m6A RNA methylation regulators on the TME in ccRCC. Methods: Transcriptome data of ccRCC were obtained from TCGA database. Consensus clustering analysis was conducted based on the expression of m6A RNA methylation regulators. Survival differences were evaluated by Kaplan–Meier analysis between the clusters. The DESeq2 package was used to analyze the differentially expressed genes (DEGs) between the clusters. GO and KEGG pathway analyses were performed by the ClusterProfiler R package. The CIBERSORT algorithm was used to evaluate immune infiltration. Results: The expression of 15 m6A regulators significantly differed between ccRCC and normal kidney tissues. Based on the expression of these 15 m6A regulators, two clusters were identified by consensus clustering, in which cluster 1 had better overall survival (OS). Overall, 4,429 DEGs were identified between the two clusters and were enriched in immune-related biological processes. Cluster 1 had lower immune and ESTIMATE scores, higher expression of HLA and lower expression of immune checkpoint molecules. Moreover, immune infiltration and expressions of Th1/IFNγ gene signature were also significantly different between the two clusters. Conclusion: Our study revealed m6A regulators were important participants in the development of ccRCC, with a close relationship with the TME.

Prognosis and immune infiltration analysis of m6A RNA methylation regulators in cutaneous melanoma and differential analysis with cuproptosis related genes

Objective: N6-methyladenosine (m6A) modification and cuproptosis play essential roles in the pathogenesis of various malignant tumors. However, the predictive role of m6A regulators and cuproptosis-related genes in cutaneous melanoma (CM) remains unclear. In this study, the aim was not only to explore the role of m6A modification in CM, but also to investigate the differential expression of cuproptosis-related genes in different risk group. Methods: We obtained transcriptome data from the XENA and GTEx databases. Univariate Cox regression analysis was performed to investigate the relationship between m6A-related genes and the outcomes of CM. LASSO regression analysis was utilized to construct a risk model. Moreover, we analyzed immune cell infiltration using CIBERSORT algorithms. Finally, we evaluated the expression levels of cuproptosis-related genes in CM samples and performed RT-qPCR to validate the expression of cuproptosis-associated genes in melanoma cells after YTHDF3 knockdown. Results: All m6A-related genes differed in melanoma tissues and normal tissues and a prognostic signature was developed. Immune infiltration revealed that low-risk group patients had a higher level of CD8 + T cells, memory activated CD4 + T cells, activated NK cells and M1 Macrophages than high-risk group (P<0.05). Moreover, the cuproptosis-related genes MTF-1, PDHB and FDX1 were significantly negatively associated with risk score (P=0.0007, P=0.0057 and P=0.04, respectively). We also found that downregulation YTHDF3 in melanoma cells affected the expression of cuproptosis-related genes. (P<0.01 and P<0.05). Conclusion: Our study demonstrated the prognostic value of m6A-related genes and cuproptosis-related genes in CM, providing new predictive models and potential therapeutic targets for CM.

Diagnostic biomarkers for ST-segment elevation myocardial infarction using RNA methylation regulators

AimsAdditional evidence has indicated a correlation between N6-methyladenosine (m6A) RNA methylation and cardiovascular disease. Nevertheless, the alterations in RNA methylation modification and the expression of numerous genes remains unclear. This study aimed to identify the role of m6A in ST-segment elevation myocardial infarction (STEMI).MethodsTwo microarray datasets (GSE123342 and GSE59867) were downloaded from the GEO database. After merging the data and batch normalization, differentially expressed regulators were identified using the limma package. Subtyping consistency analysis was performed to group samples. The random forest algorithm and support vector machine were used to identify diagnostic biomarkers. Immune infiltration and inflammation levels among the subtypes were assessed using a single-sample gene set enrichment analysis.ResultsA total of 15 key differential m6A regulators (RBM15B, ELAVL1, ALKBH5, METTL16, ZC3H13, RBM15, YTHDC1, YTHDC2, YTHDF3, HNRNPC, FMR1, LRPPRC, HNRNPA2B1, RBMX, FTO) were identified using the random forest classifier and were found to be highly correlated by PPI analysis. Two distinct RNA modification patterns (cluster A and B) were validated based on the expression levels of the 15 key m6A regulators. GO and KEGG annotations showed that immunity and inflammation pathways were enriched. Immune infiltration analysis revealed that cluster 2 had higher immune activation than cluster 1. Further analysis showed that cluster 2 had a higher inflammation level, with IL-4 and IL-33 showing differential expression (p < 0.05).ConclusionA set of 15 m6A RNA methylation regulators could alter the STEMI microenvironment to improve risk stratification and clinical treatment.

The m6A reader HNRNPC predicts adverse prognosis and promotes the progression of colorectal cancer.

As a critical m6A RNA methylation regulator, HNRNPC has been revealed to serve as potential biomarkers in various human cancers. The specific expression and significance of HNRNPC in colorectal cancer remain unknown. This study aimed to confirm HNRNPC expression level and evaluate its function in colorectal cancer progression. 101 paired tissue samples were collected from colorectal cancer patients. HNRNPC levels in colorectal cancer were detected using PCR. CCK8 and transwell assays were conducted to estimate the effect of HNRNPC on cell growth and metastasis with the regulation of HNRNPC by cell transfection. Upregulated HNRNPC was observed in colorectal cancer compared with normal tissues and cells. The higher HNRNPC levels in tumor tissues were associated with the advanced TNM stage and positive lymph node metastasis. Meanwhile, HNRNPC upregulation could indicate adverse outcomes of colorectal cancer patients. In vitro, the knockdown of HNRNPC significantly suppressed the proliferation, migration, and invasion of colorectal cancer cells. Upregulated HNRNPC served as a biomarker for the prognosis and development of colorectal cancer, which provides a novel therapeutic target for colorectal cancer.

Molecular characterization of m6A RNA methylation regulators with features of immune dysregulation in IgA nephropathy.

The role of RNA N6-methyladenosine (m6A) modification in immunity is being elucidated. This study aimed to explore the potential association between m6A regulators and the immune microenvironment in IgA nephropathy (IgAN). The expression profiles of 24 m6A regulators in 107 IgAN patients were obtained from the Gene Expression Omnibus (GEO) database. The least absolute shrinkage and selection operator (LASSO) regression and logistic regression analysis were utilized to construct a model for distinguishing IgAN from control samples. Based on the expression levels of m6A regulators, unsupervised clustering was used to identify m6A-induced molecular clusters in IgAN. Gene set enrichment analysis (GSEA) and immunocyte infiltration among different clusters were examined. The gene modules with the highest correlation for each of the three clusters were identified by weighted gene co-expression network analysis (WGCNA). A model containing 10 m6A regulators was developed using LASSO and logistic regression analyses. Three molecular clusters were determined using consensus clustering of 24 m6A regulators. A decrease in the expression level of YTHDF2 in IgAN samples was significantly negatively correlated with an increase in resting natural killer (NK) cell infiltration and was positively correlated with the abundance of M2 macrophage infiltration. The risk scores calculated by the nomogram were significantly higher for cluster-3, and the expression levels of m6A regulators in this cluster were generally low. Immunocyte infiltration and pathway enrichment results for cluster-3 differed significantly from those for the other two clusters. Finally, the expression of YTHDF2 was significantly decreased in IgAN based on immunohistochemical staining. This study demonstrated that m6A methylation regulators play a significant role in the regulation of the immune microenvironment in IgAN. Based on m6A regulator expression patterns, IgAN can be classified into multiple subtypes, which might provide additional insights into novel therapeutic methods for IgAN.

The significance of m6A RNA methylation regulators in diagnosis and subtype classification of HBV-related hepatocellular carcinoma.

In recent years, abnormal m6A alteration in hepatocellular carcinoma (HCC) has been a focus on investigating the biological implications. In this study, our objective is to determine whether m6A modification contributes to the progression of HBV-related HCC. To achieve this, we employed a random forest model to screen top 8 characteristic m6A regulators from 19 candidate genes. Subsequently, we developed a nomogram model that utilizes these 8 characteristic m6A regulators to predict the prevalence of HBV-related HCC. According to decision curve analysis, patients may benefit from the nomogram model. The clinical impact curves exhibited a robust predictive capability of the nomogram models. Additionally, consensus molecular subtyping was employed to identify m6A modification patterns and m6A-related gene signature. The quantification of immune cell subsets was accomplished through the implementation of ssGSEA algorithms. PCA algorithms were developed to compute the m6A score for individual tumors. Two distinct m6A modification patterns, namely cluster A and cluster B, exhibited significant correlations with distinct immune infiltration patterns and biological pathways. Notably, patients belonging to cluster B demonstrated higher m6A scores compared to those in cluster A, as determined by the m6A score metric. Furthermore, the expression of IGFBP3 proteins was validated through immunofluorescence, revealing their pronounced lower expression in tumor tissues. In summary, our study underscores the importance of m6A modification in the advancement of HBV-related HCC. This research has the potential to yield novel prognostic biomarkers and therapeutic targets for the identification of HBV-related HCC.

Expression patterns and prognostic role of m6A RNA methylation regulators in Non-small Cell Lung Cancer.

To investigate the expression pattern and prognostic role of m6A RNA methylation regulators in non-small cell lung cancer (NSCLC), we downloaded data from 422 patients from The Cancer Genome Atlas (TCGA) database. The relationship between the expression levels of m6A RNA methylation regulators and clinicopathological variables of NSCLC was analysed using R language. By analysing glioma data in TCGA, we found that a prognostic risk score model could be constructed based on 18 genes with m6A methylation modification. m6A gene alterations were significantly associated with tumour grade and tumour stage. Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression models were used to identify 2 m6A RNA methylation modifiers: IFG2BP2, and METTL14 to construct risk profiles. Based on the risk profile, patients were divided into high-risk and low-risk groups. The overall survival rate of the low-risk group was significantly higher than that of the high-risk group. The results suggest that the prognostic risk score model constructed by m6A methylation regulators can predict the prognosis of glioma patients. IFG2BP2 and METTL14 may be the key m6A methylation regulators involved in the development of NSCLC and can be used as the molecular markers for the prognosis of NSCLC.

Tumor microenvironment characteristics and prognostic role of m6A modification in lung squamous cell carcinoma

BackgroundIt has recently been determined that N6-methyladenosine (m6A) RNA methylation regulators have prominent effects on several cancers. However, the potential role of m6A modification in lung squamous cell carcinoma (LUSC) remains unclear. MethodsWe evaluated the modification pattern of m6A and studied the biological function of m6A regulators in LUSC. Then, we constructed the m6Ascore to predict the prognosis of LUSC and analyzed the relationship between the m6Ascore and tumor mutation burden, immune cell infiltration, and immunotherapy. ResultIn the unsupervised consensus cluster analysis, three different m6Aclusters were identified, which correspond to an immune activation state, a moderate immune activation state, and an immune tolerance state. Forty-two genes related to the m6A phenotype were used to construct the m6Ascore; subsequently, multiple validations of the m6Ascore were carried out to determine the relationship between the score and immune cell infiltration and response to CTLA-4/PD-1 inhibitor treatment. Further analysis revealed that the m6Ascore could effectively predict the prognosis of LUSC and that the m6A phenotype-related genes, FAM162A and LOM4, might be potential biomarkers. ConclusionThese findings highlight the potential role of m6A modification in the prognosis, TME, and immunotherapy of LUSC and have profound implications for developing more effective personalized treatment strategies for LUSC.

Expression patterns of m6A RNA methylation regulators under apoptotic conditions in various human cancer cell lines.

Cancer is a complex disease that involves both genetic and epigenetic factors. While emerging evidence clearly suggests that changes in epitranscriptomics play a crucial role in cancer pathogenesis, a comprehensive understanding of the writers, erasers, and readers of epitranscriptomic processes, particularly under apoptotic conditions remains lacking. The aim of this study was to uncover the changes in the expression of m6A RNA modifiers under apoptotic conditions across various cancer cell lines. Initially, we quantified the abundance of m6A RNA modifiers in cervical (HeLa and ME180), breast (MCF7 and MDA-MB-231), lung (A549 and H1299), and colon (Caco-2 and HCT116) cancer cell lines using qPCR. Subsequently, we induced apoptosis using cisplatin and tumor necrosis factor-alpha (TNF-α) to activate intrinsic and extrinsic pathways, respectively, and assessed apoptosis rates via flow cytometry. Further, we examined the transcript abundance of m6A RNA modifiers under apoptotic conditions in cervical, breast, and lung cancer cell lines using qPCR. Overall, treatment with cisplatin increased the abundance of m6A modifiers, whereas TNF-α treatment decreased their expression in cervical, breast, and lung cancer cell lines. Specifically, cisplatin-induced apoptosis, but not TNF-α-mediated apoptosis, resulted in decreased abundance of METTL14 and FTO transcripts. Additionally, cisplatin treatment drastically reduced the abundance of IGF2BP2 and IGF2BP3 readers. These results suggest that the differential response of cancer cells to apoptotic inducers may be partially attributed to the expression of m6A RNA modifiers.

Implication of m6A Methylation Regulators in the Immune Microenvironment of Bronchopulmonary Dysplasia.

N6-methyladenosine (m6A) regulates gene expression and governs many important biological processes. However, the function of m6A in the development of bronchopulmonary dysplasia (BPD) remains poorly characterized. Thus, the purpose of this investigation was to evaluate the effects of m6A RNA methylation regulators on the development of BPD. BPD-related transcriptome data were downloaded from the GEO database. Differentially expressed m6A methylation regulators between BPD and control group were identified. Consensus clustering was conducted for the classification of BPD and association between clusters and BPD phenotypes were explored. Analysis of differentially expressed genes (DEGs) and immune-related DEGs was performed. The GSEA, GO and KEGG analyses were used to interpret the functional enrichments. The composition of immune cell subtypes in BPD subsets was predicted by CIBERSORT analysis. Compared with the control group, expression of most m6A regulators showed significant alteration, especially for IGF2BP1/2/3. BPD was classified into 2 subsets, and cluster 1 was correlated with severe BPD. Furthermore, the results of functional enrichment analyses showed a disturbed immune-related signaling pathway. Based on CIBERSORT analysis, we found that the proportion of immune cell subsets changed between cluster 1 and cluster 2. Our study revealed the implication of m6A methylation regulators in the development of BPD, which might provide a novel insight for the diagnosis and treatment of BPD.

N6-Methyladenosine reader HNRNPC-mediated downregulation of circITCH prevents miR-224-3p sequestering and contributes to tumorigenesis in nasopharyngeal carcinoma.

N6-Methyladenosine (m6A) RNA methylation modulators are implicated in nasopharyngeal carcinoma (NPC). Circular RNAs (circRNAs) stimulate/inhibit the development of NPC by sponging microRNAs (miRNAs). Herein, m6A modifications affecting the circRNA/miRNA axis in NPC were explored. Twenty prognostic m6A RNA methylation regulators were identified from 504 head/neck squamous cell carcinoma and 44 normal samples from The Cancer Genome Atlas (TCGA). Differentially expressed miRNAs were screened from the TCGA and Gene Expression Omnibus (GEO) databases. RNA-binding protein (RBP)-circRNA and circRNA-miRNA interactive pairs were verified using RBPmap and RNAhybrid, respectively. The RBP/circRNA/miRNA network was constructed using Cytoscape. Furthermore, CircITCH (hsa_circ_00059948), HNRNPC, and miR-224-3p expressions were detected by western blotting and quantitative polymerase chain reaction. The role of circITCH in NPC was examined using apoptosis, scratch wound healing, transwell invasion, and cell counting kit-8 assays. Finally, CircITCH-miR-224-3p and circITCH-HNRNPC interactions were assessed by dual-luciferase reporter and RNA-immunoprecipitation (RIP) assays, respectively. Bioinformatics analysis revealed that high pathological grade, late-stage tumors, and low survival were associated with increased HNRNPC expression. MiR-224-3p was upregulated in NPC and sequestered by circITCH. Construction of the RBP/circRNA/miRNA network highlighted the HNRNPC/circITCH/miR-224-3p axis. In vitro experiments demonstrated decreased circITCH expression and increased HNRNPC and miR-224-3p expressions in NPC. In NPC cells overexpressing circITCH, HNRNPC and miR-224-3p expressions were significantly decreased. Dual-luciferase assays demonstrated a targeting relationship between circITCH and miR-224-3p, and RIP assays demonstrated interaction of HNRNPC targets with circITCH. CircITCH overexpression inhibited NPC progression by sequestering miR-224-3p, and HNRNPC reduced circITCH expression through direct interaction.

Prognostic analysis of patients with gastric cancer based on N6-methyladenosine modification patterns and tumor microenvironment characterization.

Cancers arise from genetic and epigenetic abnormalities that affect oncogenes and tumor suppressor genes, compounded by gene mutations. The N6-methyladenosine (m6A) RNA modification, regulated by methylation regulators, has been implicated in tumor proliferation, differentiation, tumorigenesis, invasion, and metastasis. However, the role of m6A modification patterns in the tumor microenvironment of gastric cancer (GC) remains poorly understood. In this study, we analyzed m6A modification patterns in 267 GC samples utilizing 31 m6A regulators. Using consensus clustering, we identified two unique subgroups of GC. Patients with GC were segregated into high- and low-infiltration cohorts to evaluate the infiltration proportions of the five prognostically significant immune cell types. Leveraging the differential genes in GC, we identified a "green" module via Weighted Gene Co-expression Network Analysis. A risk prediction model was established using the LASSO regression method. The "green" module was connected to both the m6A RNA methylation cluster and immune infiltration patterns. Based on "Module Membership" and "Gene Significance", 37 hub genes were identified, and a risk prediction model incorporating nine hub genes was established. Furthermore, methylated RNA immunoprecipitation and RNA Immunoprecipitation assays revealed that YTHDF1 elevated the expression of DNMT3B, which synergistically promoted the initiation and development of GC. We elucidated the molecular mechanism underlying the regulation of DNMT3B by YTHDF1 and explored the crosstalk between m6A and 5mC modification. m6A RNA methylation regulators are instrumental in malignant progression and the dynamics of tumor microenvironment infiltration of GC. Assessing m6A modification patterns and tumor microenvironment infiltration characteristics in patients with GC holds promise as a valuable prognostic biomarker.

Comprehensive analysis of m6A RNA methylation regulators in esophageal carcinoma.

N6-methyladenosine (m6A) is the most pervasive modification of RNA methylation in eukaryotic cells. m6A modification plays a pivotal role in tumorigenesis and progression in many types of cancers. Until now, the role of m6A modification in esophageal carcinoma (ESCA) has remained obscure. The aim of the study was to construct and validate prognostic signatures based on m6A regulators for ESCA. Transcriptomic data, somatic mutations and clinical information were obtained from The Cancer Genome Atlas (TCGA). Copy number variations were obtained from the UCSC (University of California, Santa Cruz) Xena database. We curated 21 m6A regulators and performed consensus clustering analysis to quantify the m6A modification pattern. Of the 184 patients, 23 (12.5%) were genetically altered in m6A regulators, with the highest frequency of mutations in ZC3H13 and LRPPRC. We constructed a m6A score system to investigate the prognosis of ESCA. The m6A score was closely related to immune cell infiltration in the tumor immune microenvironment. Patients with a high m6A score had an unfavorable prognosis. The combination of tumor mutation burden and m6A score would improve the prognostic value. Our study established and validated a strong prognostic signature based on m6A regulators. This can be used to accurately predict the prognosis of ESCA.

Landscape of m6A RNA methylation regulators in liver cancer and its therapeutic implications.

Liver cancer remains as the third leading cause of cancer-related death globally as of 2020. Despite the significant progress made in the field of liver cancer treatment, there is still a lack of effective therapies in patients with advanced cancer and the molecular mechanisms underlying liver cancer progression remain largely elusive. N6-methyladenosine (m6A) modification, as the most prevalent and abundant internal RNA modification in eukaryotic RNAs, plays an essential role in regulating RNA metabolism including RNA splicing, stability, translation, degradation. To date, there is mounting evidence showing that m6A dysregulation is closely associated with the onset and development of many tumors including hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC) and hepatoblastoma (HB). In this review, we summarize the last research progress regarding the functions of m6A-related regulators in liver cancer and its underlying mechanisms. Additionally, we also discuss the therapeutic applications of m6A-based inhibitors in liver cancer treatment.

Comprehensive Analysis of N6-Methyladenosine RNA Methylation Regulators in the Diagnosis and Subtype Classification of Rheumatoid Arthritis.

m6A modification is the most abundant mRNA modifications and plays an integral role in various biological processes in eukaryotes. However, the role of m6A regulators in rheumatoid arthritis remains unknown. To determine the expression of m6A RNA methylation regulators in rheumatoid arthritis and their possible functional and prognostic value. In this study, we performed differential analysis in the comprehensive gene expression database GSE93272 dataset between non-rheumatoid arthritis patients and rheumatoid arthritis patients to obtain 15 important m6A regulators. A random forest model and lasso regression were used to screen the five most important m6A regulators to predict the risk of developing rheumatoid arthritis. After further validation using in vitro qPCR experiments, a nomogram model was developed based on the four most important m6A regulators (ELAVL1, WTAP, YTHDF1, and ALKBH5). Immuno-infiltration analysis and consensus clustering analysis were then performed. An analysis of the decision curve showed that the nomogram model could be beneficial to patients. According to selected important m6A regulators, patients with rheumatoid arthritis were classified into two m6A models (ClusterA and ClusterB) via consensus approach. Activated B cells, CD56dim natural killer cells, immature B cells, monocytes, natural killer T cells, and T lymphocytes were associated with ClusterA in immune infiltration analysis. Importantly, immune infiltration in patients with high ELAVL1 expression was strikingly similar to ClusterA. m6A regulators play a non-negligible role in the development of rheumatoid arthritis. A study of m6A patterns may provide future therapeutic options for rheumatoid arthritis.

YTHDF3 Modulates EGFR/ATK/ERK/p21 Signaling Axis to Promote Cancer Progression and Osimertinib Resistance of Glioblastoma Cells.

Despite recent advances in EGFR-tyrosine kinase inhibitor (TKI) drugs for glioblastoma multiforme (GBM), intrinsic EGFR alterations in GBM have resulted in drug resistance and unsatisfactory clinical development of EGFR-TKIs. Determining the unknown mechanisms underlying EGFR-TKI drug resistance is an urgent, but unmet, medical need for GBM. Although several m6A RNA methylation regulators, such as reader YTHDF1/2, were recently predicted to be related to GBM recurrence, none was associated with resistance to the 3rd generation EGFR-TKI osimertinib. Osimertinib-resistant GBM cells (U87OSR) were established to ascertain the correlation between m6A expression and osimertinib resistance, prior to systemic analyses on m6A writers, erasers, and readers. YTHDF3-silencing was employed to reveal changes in IC50, cellular migration, cancer stemness, and p21-guided senescence in U87OSR cells. Signaling pathways and an in vivo xenograft model of U87OSR cells were investigated to delineate the influence of osimertinib-resistance and elevated YTHDF3 expression. YTHDF3 played a crucial role in inducing cellular proliferation, migration, and stemness in U87OSR GBM cells. Importantly, silencing of YTHDF3 markedly reduced the activation of certain signaling pathways, including EGFR- or ITGA7- AKT, and ERK in U87OSR cells. Our study also revealed the oncogenic function of YTHDF3 in inducing senescence escape via p21 down-regulation. In contrast, silencing of YTHDF3 resulted in increased p21 expression, senescence, and suppressed tumor growth in our osimertinib-resistant preclinical model. Overall, our research underscores the novel potential of YTHDF3 as a new pharmacological target in GBM treatment, specifically for patients with osimertinib-resistant or refractory tumors.

Sulforaphene suppressed cell proliferation and promoted apoptosis of COV362 cells in endometrioid ovarian cancer.

N6-methyladenosine (m6A) RNA methylation exerts a regulatory effect on endometrioid ovarian cancer (EOC), but the specific m6A regulator genes in EOC remain to be explored. This study investigated that sulforaphene (Sul) is implicated in EOC development by regulating methyltransferase-like 3 (METTL3). The dysregulated m6A RNA methylation genes in EOC were determined by methylated RNA immunoprecipitation (MeRIP-seq) and RNA sequencing. The roles of METTL3 and/or Sul on viability, proliferative ability, cell cycle, and apoptosis of EOC cells were determined by MTT, colony formation, flow cytometry, and TUNEL staining assay, respectively. The expression of METTL3 and apoptosis-related proteins in EOC cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot assays. Five m6A RNA methylation regulators (METTL3, ELF3, IGF2BP2, FTO, and METTL14) were differentially expressed in EOC, among which METTL3 had the highest expression level. Silencing METTL3 reduced the clonal expansion and viability of EOC cells, and caused the cells to arrest in the G0/G1 phase. This also promoted apoptosis in the EOC cells and activated the FAS/FADD and mitochondrial apoptosis pathways. In contrast, overexpressing METTL3 had the opposite effect. Sul, in a dose-dependent manner, reduced the viability of EOC cells but promoted their apoptosis. Sul also increased the levels of IGF2BP2 and FAS, while decreasing the levels of KRT8 and METTL3. Furthermore, Sul was able to reverse the effects of METTL3 overexpression on EOC cells. Sul could suppress cell proliferation and promote apoptosis of EOC cells by inhibiting the METTL3 to activate the FAS/FADD and apoptosis-associated pathways.

The role of m6A RNA methylation regulator in meningioma.

Meningiomas are common intracranial tumors, and the effect of surgical resection is often unsatisfactory. N6-Methyladenosine (m6A)-related regulator expression levels are related to cancer occurrence and development. This study aimed to investigate the roles of m6A RNA methylation regulators in meningiomas, as these are currently unclear. Two m6A methylation-regulated genes (METTL3 and IGF2BP2) were identified as survival-associated linear models for RiskScore through bioinformatics analysis. Univariate and multivariate Cox regression analyses showed that the overall survival of patients with meningioma in the high-risk group was substantially shorter than that in the low-risk group. Weighted gene co-expression network analysis constructed a co-expression network based on the m6A methylation model (RiskScore). Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes analyses identified the biological processes of hub module gene behavior, and Cytoscape constructed an m6A methylation-related gene regulatory network. In vitro experiments verified that the mRNA and protein expression levels of METTL3 and IGF2BP2 were lower in meningioma cells than in normal meningioma cells. Therefore, central regulators of m6A methylation (METTL3 and IGF2BP2) could potentially serve as novel therapeutic targets in meningioma. Subsequently, a novel methylation signature (RiskScore) was developed for prognostic prediction in patients with meningioma.

Hypothalamic FTO promotes high-fat diet-induced leptin resistance in mice through increasing CX3CL1 expression

Long-term consumption of a high-fat diet (HFD) disrupts energy homeostasis and leads to weight gain. The fat mass and obesity-associated (FTO) gene has been consistently identified to be associated with HFD-induced obesity. The hypothalamus is crucial for regulating energy balance, and HFD-induced hypothalamic leptin resistance contributes to obesity. FTO, an N6-methyladenosine (m6A) RNA methylation regulator, may be a key mediator of leptin resistance. However, the exact mechanisms remain unclear. Therefore, the present study aims to investigate the association between FTO and leptin resistance. After HFD or standard diet (SD) feeding in male mice for 22 weeks, m6A-sequencing and western blotting assays were used to identify target genes and assess protein level, and molecular interaction changes. CRISPR/Cas9 gene knockout system was employed to investigate the potential function of FTO in leptin resistance and obesity. Our data showed that chemokine (C-X3-C motif) ligand 1 (CX3CL1) was a direct downstream target of FTO-mediated m6A modification. Furthermore, upregulation of FTO/CX3CL1 and suppressor of cytokine signaling 3 (SOCS3) in the hypothalamus impaired leptin-signal transducer and activator of transcription 3 signaling, resulting in leptin resistance and obesity. Compared to wild-type (WT) mice, FTO deficiency in leptin receptor-expressing neurons of the hypothalamus significantly inhibited the upregulation of CX3CL1 and SOCS3, and partially ameliorating leptin resistance under HFD conditions. Our findings reveal that FTO involved in the hypothalamic leptin resistance and provides novel insight into the function of FTO in the contribution to hypothalamic leptin resistance and obesity.

Identification of the expression patterns and potential prognostic role of m6A-RNA methylation regulators in Wilms Tumor

BackgroundTo explore the potential role of m6A methylation modification in Wilms Tumor (WT) by m6A-RNA Methylation (m6A) regulators.MethodologyThe association of m6A modification patterns with immune and prognostic characteristics of tumors was systematically evaluated using 19 m6A regulators extracted from Wilms Tumor’s samples in public databases. A comprehensive model of “m6Ascore” was constructed using principal component analysis, and its prognostic value was evaluated.ResultsAlmost all m6A regulators were differentially expressed between WT and normal tissues. Unsupervised clustering identified three distinct m6A clusters that differed in both immune cell infiltration and biological pathways. The m6Ascore was constructed to quantify m6A modifications in individual patients. Our analysis suggests that m6Ascore is an independent prognostic factor for WT and can be used as a novel predictor of WT prognosis.ConclusionsThis study comprehensively explored and systematically characterized m6A modifications in WT. m6A modification patterns play a critical role in the tumor immune microenvironment (TIME) and WT prognosis. m6Ascore provides a more comprehensive understanding of m6A modifications in WT and offers a practical tool for predicting WT prognosis. This study will help clinicians to identify valid indicators of WT to improve the poor prognosis of this disease.Supplementary InformationThe online version contains supplementary material available at https://www.aliyundrive.com/drive/folder/64be739cd6956a741fb24670baeea53422be6024.