m6A RNA Modification Research Articles

NSUN2-mediated m5C modification of HBV RNA positively regulates HBV replication.

Chronic hepatitis B virus (HBV) infection is a major cause of liver cirrhosis and liver cancer, despite strong prevention and treatment efforts. The study of the epigenetic modification of HBV has become a research hotspot, including the N6-methyladenosine (m6A) modification of HBV RNA, which plays complex roles in the HBV life cycle. In addition to m6A modification, 5-methylcytosine (m5C) is another major modification of eukaryotic mRNA. In this study, we explored the roles of m5C methyltransferase and demethyltransferase in the HBV life cycle. The results showed that m5C methyltransferase NSUN2 deficiency could negatively regulate the expression of HBV while m5C demethyltransferase TET2 deficiency positively regulates the expression of HBV. Subsequently, we combined both in vitro bisulfite sequencing and high-throughput bisulfite sequencing methods to determine the distribution and stoichiometry of m5C modification in HBV RNA. Two sites: C2017 and C131 with the highest-ranking methylation rates were identified, and mutations at these two sites could lead to the decreased expression and replication of HBV, while the mutation of the "fake" m5C site had no effect. Mechanistically, NSUN2-mediated m5C modification promotes the stability of HBV RNA. In addition, compared with wild-type HepG2-NTCP cells and primary human hepatocytes, the replication level of HBV after NSUN2 knockdown decreased, and the ability of the mutant virus to infect and replicate in wild-type HepG2-NTCP cells and PHHs was substantially impaired. Similar results were found in the experiments using C57BL/6JGpt-Nsun2+/- mice. Interestingly, we also found that HBV expression and core protein promoted the endogenous expression of NSUN2, which implied a positive feedback loop. In summary, our study provides an accurate and high-resolution m5C profile of HBV RNA and reveals that NSUN2-mediated m5C modification of HBV RNA positively regulates HBV replication by maintaining RNA stability.

Comprehensive analysis of m6A reader YTHDF2 prognosis, immune infiltration, and related regulatory networks in hepatocellular carcinoma

BackgroundN6-Methyladenosine (m6A) RNA modification is the most prevalent internal modification pattern in eukaryotic mRNAs and plays critical roles in diverse physiological and pathological processes. However, the expression of m6A regulator YTHDF2, its prognostic value, its biological function, its correlation with tumor microenvironment (TME) immune infiltrates, and related regulatory networks in hepatocellular carcinoma (HCC) remain determined. MethodsTCGA, GTEx, and GEO databases were used to investigate the expression profile of YTHDF2 in HCC. We performed differentially expressed genes (DEGs) analysis and constructed a PPI network to explore the biological processes of YTHDF2 in HCC. Kaplan-Meier curves and Cox regression analysis were used to assess the prognostic value of YTHDF2 and then a clinical prognostic nomogram was constructed. Additionally, ssGSEA was performed to assess the correlation between YTHDF2 and immune infiltration levels. The TISIDB database was applied to explore the expression of YTHDF2 in immune and molecular subtypes of HCC. GSEA identifies the YTHDF2-related signaling pathways. Finally, we utilized miRNet and starBase database to construct regulatory networks for HCC based on lncRNA-miRNA and miRNA-YTHDF2 interactions. ResultsYTHDF2 was significantly upregulated in HCC tumor tissues compared with the adjacent normal tissues. HCC patients in the high YTHDF2 expression group had poorer survival. Multivariate Cox analysis suggested that YTHDF2 may be a new independent prognostic indicator for HCC patients, with the prognostic nomogram exhibiting satisfactory results. YTHDF2 expression was significantly correlated with TME immune cell-infiltrating characteristics. Strong correlations were also shown in immune subtypes, molecular subtypes and immune checkpoints. Further analysis revealed that the combination of YTHDF2 expression and immune cell score was considerably associated with survival outcome in HCC patients. GESA analysis demonstrated that high YTHDF2 expression is associated with multiple biological processes and oncogenic pathways. Moreover, 14 possible regulatory networks were constructed, which are associated with HCC progression. ConclusionOur findings revealed that YTHDF2 may serve as a promising prognostic biomarker for HCC and may regulate the tumor immune microenvironment to provide effective therapeutic strategies.

M6A reader YTHDF1 promotes malignant progression of laryngeal squamous carcinoma through activating the EMT pathway by EIF4A3

Laryngeal squamous cell carcinoma (LSCC) is one of the common malignant tumors in the head and neck region, and its high migration and invasion seriously threaten the survival and health of patients. In cancer development, m6A RNA modification plays a crucial role in regulating gene expression and signaling. This study delved into the function and mechanism of the m6A reading protein YTHDF1 in LSCC. It was found that YTHDF1 was highly expressed in the GEO database and LSCC tissues. Cell function experiments confirmed that the downregulation of YTHDF1 significantly inhibited the proliferation, migration, and invasion ability of LSCC cells. Further studies revealed that EIF4A3 was a downstream target gene of YTHDF1, and knockdown of EIF4A3 similarly significantly inhibited the malignant progression of LSCC in both in vivo and in vitro experiments. The molecular mechanism studies suggested that YTHDF1-EIF4A3 may promote the malignant development of LSCC by activating the EMT signaling pathway. This study provides important clues for an in-depth understanding of the pathogenesis of LSCC and is a solid foundation for the discovery of new therapeutic targets and approaches.

Roles of rRNA N-methyladenosine modification in the function of ribosomes.

The N-methyladenosine (m6A) modification of ribosomal RNA (rRNA) plays critical roles in regulating the function of ribosomes, the essential molecular machines that translate genetic information from mRNA into proteins. Specifically, m6A modification affects ribosome biogenesis, stability, and function by regulating the processing and maturation of rRNA, the assembly and composition of ribosomes, and the accuracy and efficiency of translation. Furthermore, m6A modification allows for dynamic regulation of translation in response to environmental and cellular signals. Therefore, a deeper understanding of the mechanisms and functions of m6A modification in rRNA will advance our knowledge of ribosome-mediated gene expression and facilitate the development of new therapeutic strategies for ribosome-related diseases.

Electromagnetic field (50 Hz) enhance metabolic potential and induce adaptive/reprogramming response mediated by the increase of N6-methyladenosine RNA methylation in adipose-derived mesenchymal stem cells in vitro

BackgroundElectromagnetic fields (EMF) have an impact on numerous cellular processes. It can positively and negatively affect adipose-derived stem cells (ASCs) thus their fate through the influence of specific factors and protein secretion. EMF can be a great factor for preconditioning ASCs for regenerative medicine purposes, however, understanding the cell's biological response to its effects in vitro is essential. MethodsASCs were exposed to the EMF (50 Hz; 1.5 mT) for 24 and 48 h, and then cell biological response was analyzed. Results24 h exposure of ASCs to EMF, significantly increased N6-methyladenosine (m6A) RNA methylation, indicating epitranscriptomic changes as an important factor in ASCs preconditioning. Furthermore, the expression of stem cell markers such as Nanog, Oct-4, Sox-2, CD44, and CD105 increased after 24 h of EMF exposure. Besides, western blot analysis showed upregulation of p21 and DNMT2/TRDMT1 protein levels compared to control cells with no differences in the p53 profile. Moreover, after 24 h of exposure to EMF, cell membrane flexibility, the metabolic potential of cells as well as the distribution, morphology, and metabolism of mitochondria were altered. ConclusionASCs undergo a process of mobilization and adaptation under the EMF influence through the increased m6A RNA modifications. These conditions may “force” ASCs to redefine their stem cell fate mediated by RNA-modifying enzymes and alter their reprogramming decision of as differentiation begins.

METTL3-mediated m6A RNA methylation induces the differentiation of lung resident mesenchymal stem cells into myofibroblasts via the miR-21/PTEN pathway

BackgroundThe accumulation of myofibroblasts is the key pathological feature of pulmonary fibrosis (PF). Aberrant differentiation of lung-resident mesenchymal stem cells (LR-MSCs) has been identified as a critical source of myofibroblasts, but the molecular mechanisms underlying this process remain largely unknown. In recent years, N6-methyladenosine (m6A) RNA modification has been implicated in fibrosis development across diverse organs; however, its specific role in promoting the differentiation of LR-MSCs into myofibroblasts in PF is not well defined.MethodsIn this study, we examined the levels of m6A RNA methylation and the expression of its regulatory enzymes in both TGF-β1-treated LR-MSCs and fibrotic mouse lung tissues. The downstream target genes of m6A and their related pathways were identified according to a literature review, bioinformatic analysis and experimental verification. We also assessed the expression levels of myofibroblast markers in treated LR-MSCs and confirmed the involvement of the above-described pathway in the aberrant differentiation direction of LR-MSCs under TGF-β1 stimulation by overexpressing or knocking down key genes within the pathway.ResultsOur results revealed that METTL3-mediated m6A RNA methylation was significantly upregulated in both TGF-β1-treated LR-MSCs and fibrotic mouse lung tissues. This process directly led to the aberrant differentiation of LR-MSCs into myofibroblasts by targeting the miR-21/PTEN pathway. Moreover, inhibition of METTL3 or miR-21 and overexpression of PTEN could rescue this abnormal differentiation.ConclusionOur study demonstrated that m6A RNA methylation induced aberrant LR-MSC differentiation into myofibroblasts via the METTL3/miR-21/PTEN signaling pathway. We indicated a novel mechanism to promote PF progression. Targeting METTL3-mediated m6A RNA methylation and its downstream targets may present innovative therapeutic approaches for the prevention and treatment of PF.

Ferroptosis-related genes prognostic signature for pancreatic cancer and immune infiltration: potential biomarkers for predicting overall survival.

Pancreatic adenocarcinoma (PAAD) constitutes a lethal malignancy, notorious for its elevated mortality rates due to the difficulties in early diagnosis and rapid metastasis. The emerging paradigm of ferroptosis-an iron-catalyzed, regulated cell death distinguished by the accrual of lipid peroxides-has recently garnered scholarly focus. However, the expression landscape of ferroptosis-related genes (FRGs) in PAAD and their prognostic implications remain enigmatic. We undertook a rigorous quantification of FRGs in PAAD samples, sourcing data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. These repositories also provided extensive metadata, encompassing mesenchymal stemness index (mRNAsi), genomic mutations, copy number variations (CNV), tumor mutational burden (TMB), and other clinical attributes. A predictive model was constructed utilizing Lasso regression analysis, and a co-expression study was executed to elucidate the complex interconnections between FRGs and other gene sets. Intriguingly, FRGs were substantially upregulated in the high-risk cohort, even in the absence of clinically manifest symptoms, emphasizing their utility as prognostic biomarkers. Gene set enrichment analysis (GSEA) revealed significant enrichment of immune and tumor-related pathways in this high-risk demographic. Striking heterogeneities in immune function and N6-methyladenosine (m6A) RNA modification were observed between the low- and high-risk groups. Our analysis further implicated a cohort of genes-including LINC01559, C11orf86, SERPINB5, DSG3, MSLN, EREG, FAM83A, CXCL5, LY6D, and PSCA-as cardinal mediators in PAAD pathogenesis. A convergence of our predictive model with an analysis of CNVs, single nucleotide polymorphisms (SNPs), and drug sensitivities, revealed an intricate relationship with the FRGs. Our findings accentuate the salient role of FRGs as critical modulators in the pathogenesis and progression of PAAD. Importantly, our composite prognostic framework offers invaluable insights into PAAD clinical trajectory. Moreover, the complex crosstalk between FRGs and immune cell landscapes in the tumor microenvironment (TME) may elucidate prospective therapeutic strategies. The clinical translational utility of these insights, however, requires further in-depth empirical exploration. Accordingly, the FRG signature introduces a compelling new avenue for risk stratification and targeted therapeutic interventions in this devastating malignancy.

Interpretable prediction models for widespread m6A RNA modification across cell lines and tissues.

RNA N6-methyladenosine (m6A) in Homo sapiens plays vital roles in a variety of biological functions. Precise identification of m6A modifications is thus essential to elucidation of their biological functions and underlying molecular-level mechanisms. Currently available high-throughput single-nucleotide-resolution m6A modification data considerably accelerated the identification of RNA modification sites through the development of data-driven computational methods. Nevertheless, existing methods have limitations in terms of the coverage of single-nucleotide-resolution cell lines and have poor capability in model interpretations, thereby having limited applicability. In this study, we present CLSM6A, comprising a set of deep learning-based models designed for predicting single-nucleotide-resolution m6A RNA modification sites across eight different cell lines and three tissues. Extensive benchmarking experiments are conducted on well-curated datasets and accordingly, CLSM6A achieves superior performance than current state-of-the-art methods. Furthermore, CLSM6A is capable of interpreting the prediction decision-making process by excavating critical motifs activated by filters and pinpointing highly concerned positions in both forward and backward propagations. CLSM6A exhibits better portability on similar cross-cell line/tissue datasets, reveals a strong association between highly activated motifs and high-impact motifs, and demonstrates complementary attributes of different interpretation strategies. The webserver is available at http://csbio.njust.edu.cn/bioinf/clsm6a. The datasets and code are available at https://github.com/zhangying-njust/CLSM6A/.

RNA m6A modification facilitates DNA methylation during maize kernel development.

N6-methyladenosine (m6A) in mRNA and 5-methylcytosine (5mC) in DNA have critical functions for regulating gene expression and modulating plant growth and development. However, the interplay between m6A and 5mC is an elusive territory and remains unclear mechanistically in plants. We reported an occurrence of crosstalk between m6A and 5mC in maize (Zea mays) via the interaction between mRNA adenosine methylase (ZmMTA), the core component of the m6A methyltransferase complex, and decrease in DNA methylation 1 (ZmDDM1), a key chromatin-remodeling factor that regulates DNA methylation. Genes with m6A modification were coordinated with a much higher level of DNA methylation than genes without m6A modification. Dysfunction of ZmMTA caused severe arrest during maize embryogenesis and endosperm development, leading to a significant decrease in CHH methylation in the 5' region of m6A-modified genes. Instead, loss of function of ZmDDM1 had no noteworthy effects on ZmMTA-related activity. This study establishes a direct link between m6A and 5mC during maize kernel development and provides insights into the interplay between RNA modification and DNA methylation.

Identification and validation of m6A RNA regulatory network in pulpitis

BackgroundN6-methyladenosine (m6A) RNA modification regulators play an important role in many human diseases, and its abnormal expression can lead to the occurrence and development of diseases. However, their significance in pulpitis remains largely unknown. Here, we sought to identify and validate the m6A RNA regulatory network in pulpitis.MethodsGene expression data for m6A regulators in human pulpitis and normal pulp tissues from public GEO databases were analyzed. Bioinformatics analysis including Gene ontology (GO) functional, and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses were performed by R package, and Cytoscape software was used to study the role of m6A miRNA-mRNA regulatory network in pulpitis. Quantitative real-time PCR (qRT-PCR) was performed to validate the expression of key m6A regulators in collected human pulpitis specimens.ResultsDifferential genes between pulpitis and normal groups were found from the GEO database, and further analysis found that there were significant differences in the m6A modification-related genes ALKBH5, METTL14, METTL3, METTL16, RBM15B and YTHDF1. And their interaction relationships and hub genes were determined. The hub m6A regulator targets were enriched in immune cells differentiation, glutamatergic synapse, ephrin receptor binding and osteoclast differentiation in pulpitis. Validation by qRT-PCR showed that the expression of methylases METTL14 and METTL3 was decreased, thus these two genes may play a key role in pulpitis.ConclusionOur study identified and validated the m6A RNA regulatory network in pulpitis. These findings will provide valuable resource to guide the mechanistic and therapeutic analysis of the role of key m6A modulators in pulpitis.

Mettl3-Mediated m6A Methylation Controls Pancreatic Bipotent Progenitor Fate and Islet Formation.

The important role of m6A RNA modification on β cell function has been established, yet how it regulates pancreas development and endocrine differentiation remains unknown. Here, we generated transgenic mice lacking RNA methyltransferase-like 3 (Mettl3) specifically in Pdx1+ pancreatic progenitor cells and found the mutant mice developed hyperglycemia and hypo-insulinemia at 2 weeks of age, with atrophic pancreas, reduced islet mass and abnormal increase in duct formation. At E15.5, Mettl3 deletion caused a significant loss of Ngn3+ endocrine progenitor cells, which was accompanied by increased Sox9+ duct precursor cells. We identified histone deacetylase 1(Hdac1) as the critical direct m6A target in bipotent progenitor, whose degeneration caused abnormal activation of Wnt/Notch signaling pathway and blocked endocrine differentiation. This transformation could be manipulated in embryonic pancreas culture in vitro through the regulation of the axis of Mettl3-Hdac1-Wnt/Notch signaling. Our finding that Mettl3 determines endocrine lineage through modulating Hdac1 activity during the transition of bipotent progenitor might help in the development of targeted endocrine cell protocols for diabetes treatment.

Plant–virus arms race beyond RNA interference

Plants use RNA interference for basal antiviral immunity, but emerging evidence suggests that additional RNA-targeting defense mechanisms also defend against invading viruses. Recent advancements in the understanding of RNA decay, RNA quality control, and N6-methyladenosine (m6A) RNA modifications have unveiled new insights into the molecular arms race between plants and viruses.

FTO facilitates cancer metastasis by modifying the m6A level of FAP to induce integrin/FAK signaling in non-small cell lung cancer

BackgroundEmerging evidence suggests the critical roles of N6-methyladenosine (m6A) RNA modification in tumorigenesis and tumor progression. However, the role of m6A in non-small cell lung cancer (NSCLC) is still unclear. This study aimed to explore the role of the m6A demethylase fat mass and obesity-associated protein (FTO) in the tumor metastasis of NSCLC.MethodsA human m6A epitranscriptomic microarray analysis was used to identify downstream targets of FTO. Quantitative real-time PCR (qRT‒PCR) and western blotting were employed to evaluate the expression levels of FTO and FAP in NSCLC cell lines and tissues. Gain-of-function and loss-of-function assays were conducted in vivo and in vitro to assess the effects of FTO and FAP on NSCLC metastasis. M6A-RNA immunoprecipitation (MeRIP), RNA immunoprecipitation (RIP), luciferase reporter assays, and RNA stability assays were used to explore the mechanism of FTO action. Co-immunoprecipitation (co-IP) assays were used to determine the mechanism of FAP in NSCLC metastasis.ResultsFTO was upregulated and predicted poor prognosis in patients with NSCLC. FTO promoted cell migration and invasion in NSCLC, and the FAK inhibitor defactinib (VS6063) suppressed NSCLC metastasis induced by overexpression of FTO. Mechanistically, FTO facilitated NSCLC metastasis by modifying the m6A level of FAP in a YTHDF2-dependent manner. Moreover, FTO-mediated metastasis formation depended on the interactions between FAP and integrin family members, which further activated the FAK signaling.ConclusionOur current findings provided valuable insights into the role of FTO-mediated m6A demethylation modification in NSCLC metastasis. FTO was identified as a contributor to NSCLC metastasis through the activation of the FAP/integrin/FAK signaling, which may be a potential therapeutic target for NSCLC.EwEnNquqUtx8DT1YGQrFDqVideo

The m6A reader IGF2BP2 promotes the progression of esophageal squamous cell carcinoma cells by increasing the stability of OCT4 mRNA.

Esophageal squamous cell carcinoma (ESCC) is a common malignancy with high morbidity and mortality. Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) serves as a reader of RNA m6A (N6 methyladenosine) modification to regulate gene expression at the post-transcriptional level. Emerging evidence suggests that IGF2BP2 plays critical roles in tumorigenesis and malignant development. However, the biological function and molecular mechanism of IGF2BP2 in ESCC are not well understood. Here, we found that IGF2BP2 expression was upregulated in esophageal cancer tissues and ESCC cells, and IGF2BP2 overexpression enhanced proliferation, migration, invasion, and stem cell-like properties of ESCC cells. Conversely, the knockdown of IGF2BP2 expression inhibited malignant phenotype of ESCC cells. Mechanistically, IGF2BP2 upregulated octomer-binding transcription factor 4 (OCT4) mRNA expression, and RNA immunoprecipitation (RIP) assay proved that IGF2BP2 could interact with OCT4 mRNA. Moreover, OCT4 was modified at m6A confirmed by methylated m6A RNA immunoprecipitation (Me-RIP)-qPCR assay, and IGF2BP2 knockdown reduced OCT4 mRNA stability. These results suggested that IGF2BP2 served as a reader for m6A-modified OCT4, thus increased OCT4 mRNA expression by regulating its stability. Furthermore, the knockdown of OCT4 could reverse the effects of IGF2BP2 on ESCC cells. In conclusion, these data indicate that IGF2BP2, as a reader for m6A, plays an oncogenic role by regulating OCT4 expression in ESCC, which provides new insights into targeting IGF2BP2/OCT4 axis for the therapy of ESCC.

The emerging roles of N6-methyladenosine RNA modifications in thyroid cancer.

Thyroid cancer (TC) is the most predominant malignancy of the endocrine system, with steadily growing occurrence and morbidity worldwide. Although diagnostic and therapeutic methods have been rapidly developed in recent years, the underlying molecular mechanisms in the pathogenesis of TC remain enigmatic. The N6-methyladenosine(m6A) RNA modification is designed to impact RNA metabolism and further gene regulation. This process is intricately regulated by a variety of regulators, such as methylases and demethylases. Aberrant m6A regulators expression is related to the occurrence and development of TC and play an important role in drug resistance. This review comprehensively analyzes the effect of m6A methylation on TC progression and the potential clinical value of m6A regulators as prognostic markers and therapeutic targets in this disease.

The emerging role of m6A modification of non-coding RNA in gastrointestinal cancers: a comprehensive review.

Gastrointestinal (GI) cancer is a series of malignant tumors with a high incidence globally. Although approaches for tumor diagnosis and therapy have advanced substantially, the mechanisms underlying the occurrence and progression of GI cancer are still unclear. Increasing evidence supports an important role for N6-methyladenosine (m6A) modification in many biological processes, including cancer-related processes via splicing, export, degradation, and translation of mRNAs. Under distinct cancer contexts, m6A regulators have different expression patterns and can regulate or be regulated by mRNAs and non-coding RNAs, especially long non-coding RNAs. The roles of m6A in cancer development have attracted increasing attention in epigenetics research. In this review, we synthesize progress in our understanding of m6A and its roles in GI cancer, especially esophageal, gastric, and colorectal cancers. Furthermore, we clarify the mechanism by which m6A contributes to GI cancer, providing a basis for the development of diagnostic, prognostic, and therapeutic targets.

METTL3-regulated m6A modification impairs the decidualization of endometrial stromal cells by regulating YTHDF2-mediated degradation of FOXO1 mRNA in endometriosis-related infertility

BackgroundEndometriosis-related infertility is a common worldwide reproductive health concern. Despite ongoing research, the causes of infertility remain unclear. Evidence suggests that epigenetic regulation is crucial in reproduction. However, the role of N6-methyladenosine (m6A) modification of RNA in endometriosis-related infertility requires further investigation.MethodsWe examined the expression of m6A and methyltransferase-like 3 (METTL3) in endometrial samples taken from normal fertile women in the proliferative phase (the NP group) or the mid-secretory phase (the NS group) or from women with endometriosis-related infertility at the mid-secretory phase (the ES group). We treated primary endometrial stromal cells (ESCs) with medroxyprogesterone acetate and 8-Bromo-cyclic adenosine monophosphate for in vitro decidualization and detected the expression of m6A, METTL3, and decidual markers. We analyzed the expression of m6A, METTL3, and forkhead box O1 (FOXO1) in ESCs from normal fertile women (the ND group) or women with endometriosis-related infertility (the ED group). We also assessed the expression of m6A, METTL3, and decidual markers, as well as the embryo adhesion rate, upon METTL3 overexpression or knockdown. Additionally, we investigated the role of METTL3 in embryo implantation in vivo by applying mice with endometriosis. Furthermore, we performed RNA stability assays, RNA immunoprecipitation (RIP), and methylated RIP assays to explore the mechanisms underlying the regulation of FOXO1 by METTL3-mediated m6A.ResultsThe expression of m6A and METTL3 was reduced only in the NS group; the NP and ES groups demonstrated increased m6A and METTL3 levels. m6A and METTL3 levels decreased in ESCs with prolonged decidual treatment. Compared to the ND group, m6A and METTL3 levels in the ED group increased after decidual treatment, whereas the expression of FOXO1 decreased. METTL3 overexpression suppressed the expression of decidual markers and embryo implantation in vitro; METTL3 knockdown exhibited the opposite effect. Inhibition of METTL3 promoted embryo implantation in vivo. Furthermore, we observed that METTL3-mediated m6A regulated the degradation of FOXO1 mRNA through YTHDF2, a m6A binding protein.ConclusionsMETTL3-regulated m6A promotes YTHDF2-mediated decay of FOXO1 mRNA, thereby affecting cellular decidualization and embryo implantation. These findings provide novel insights into the development of therapies for women with endometriosis-related infertility.

IGF2BP2 promotes glycolysis and hepatocellular carcinoma stemness by stabilizing CDC45 mRNA via m6A modification

ABSTRACT A growing number of studies haveshown the prognostic importance of Cell division cycle protein 45 (CDC45) inhepatocellular carcinoma (HCC). This study aims to investigate the biologicalfunction and mechanism of CDC45 in HCC. The differential expression and prognostic significance ofCDC45 in HCC and normal tissues were analyzed by bioinformatics. CDC45 wasknocked down and the biological effects of CDC45 in HCC in vitro andin vivo were measured. Subsequently, using RNA m6A colorimetry and Methylated RNA Immunoprecipitation (MeRIP),the levels of m6A modification of total RNA and CDC45 were evaluated in cells.RIP was applied to establish that CDC45 and insulin-like growth factor 2mRNA-binding protein 2 (IGF2BP2) interact. A test using actinomycin D wasperformed to gauge the stability of the CDC45 mRNA. Furthermore, the regulatoryrole of IGF2BP2 on CDC45 expression in HCC progression was explored byoverexpressing IGF2BP2. Highexpression of CDC45 was correlated with poor prognosis in HCC patients.Knocking down CDC45 inhibited HCC cell proliferation, migration, invasion, EMT,stemness, and glycolysis, and promoted apoptosis, which was verified through invitro experiments. Additionally, IGF2BP2 was highly expressed in HCC cells,and it was found to interact with CDC45. Knocking down IGF2BP2 resulted inreduced stability of CDC45 mRNA. Moreover, overexpression of IGF2BP2 promotedHCC cell proliferation, migration, invasion, EMT, stemness, and glycolysis,while inhibiting apoptosis, which was reversed by knocking down CDC45. In general, IGF2BP2 promoted HCC glycolysis and stemness bystabilizing CDC45 mRNA via m6A modification.

Genome-Wide Identification and Characterization of the YTH Domain-Containing RNA-Binding Protein Family in Liriodendron chinense.

N6-methyladenosine (m6A) is becoming one of the most important RNA modifications in plant growth and development, including defense, cell differentiation, and secondary metabolism. YT521-B homology (YTH) domain-containing RNA-binding proteins, identified as m6A readers in epitranscriptomics, could affect the fate of m6A-containing RNA by recognizing and binding the m6A site. Therefore, the identification and study of the YTH gene family in Liriodendron chinense (L. chinense) can provide a molecular basis for the study of the role of m6A in L. chinense, but studies on the YTH gene in L. chinense have not been reported. We identified nine putative YTH gene models in the L. chinense genome, which can be divided into DF subgroups and DC subgroups. Domain sequence analysis showed that the LcYTH protein had high sequence conservation. A LcYTH aromatic cage bag is composed of tryptophan and tryptophan (WWW). PrLDs were found in the protein results of YTH, suggesting that these genes may be involved in the process of liquid-liquid phase separation. LcYTH genes have different tissue expression patterns, but the expression of LcYTHDF2 is absolutely dominant in all tissues. In addition, the expression of the LcYTH genes is changed in response to ABA and MeJA. In this study, We identified and analyzed the expression pattern of LcYTH genes. Our results laid a foundation for further study of the function of the LcYTH gene and further genetic and functional analyses of m6A RNA modification in forest trees.

Crosstalk Between m6A RNA Methylation and miRNA Biogenesis in Cancer: An Unholy Nexus.

N6-methyladenosine (m6A) is one of the most prevalent internal reversible chemical modification of RNAs in eukaryotes, which has attracted widespread attention recently owing to its regulatory roles in a plethora of normal developmental processes and human diseases like cancer. Deposition of the m6A mark on RNAs is mediated by the dynamic interplay between m6A regulatory proteins such as m6A RNA methyltransferases (m6A writers), m6A RNA demethylases (m6A erasers) and m6A RNA binding proteins (m6A readers). m6A regulators are ectopically expressed in various cancer types, often leading to aberrant expression of tumor-suppressor and oncogenic mRNAs either directly or indirectly via regulating the biogenesis of non-coding RNAs like miRNAs. miRNAs are tiny regulators of gene expression, which often impact various hallmarks of cancer and thus influence tumorigenesis. It is becoming increasingly clear that m6A RNA modification impacts biogenesis and function of miRNAs, and recent studies have interestingly, uncovered many miRNAs whose biogenesis and function are regulated by m6A writers, erasers and readers. In this review, we discuss various mechanisms by which m6A RNA methylation regulates miRNA biogenesis, the functional crosstalk between m6A RNA methylation and miRNAs and how it modulates various aspects of tumorigenesis. The potential of m6A RNA methylation regulated miRNAs as biomarkers and novel therapeutic targets to treat various cancers is also addressed.