IGFBP7 regulates cell proliferation and migration through JAK/STAT pathway in gastric cancer and is regulated by DNA and RNA methylation.

New biomarkers for early diagnosis of gastric cancer (GC), the second leading cause of cancer-related death, are urgently needed. IGFBP7, known to play various roles in multiple tumours, is complexly regulated across diverse cancer types, as evidenced by our pancancer analysis. Bioinformatics analysis revealed that IGFBP7 expression was related to patient prognosis, tumour clinicopathological characteristics, tumour stemness, microsatellite instability and immune cell infiltration, as well as the expression of oncogenes and immune checkpoints. GSEA links IGFBP7 to several cancer-related pathways. IGFBP7 deficiency inhibited GC cell proliferation and migration in vitro. Furthermore, an in vivo nude mouse model revealed that IGFBP7 downregulation suppressed the tumorigenesis of GC cells. Western blotting analysis showed that the JAK1/2-specific inhibitor ruxolitinib could rescue alterations induced by IGFBP7 overexpression in GC cells. Additionally, our bioinformatics analysis and in vitro assays suggested that IGFBP7 is regulated by DNA methylation at the genetic level and that the RNA m6A demethylase FTO modulates it at the posttranscriptional level. This study emphasizes the clinical relevance of IGFBP7 in GC and its influence on cell proliferation and migration via the JAK/STAT signalling pathway. This study also highlights the regulation of IGFBP7 in GC by DNA and m6A RNA methylation.

[m6A RNA methylation is a potential biological target for neuropathic pain].

N6-methyladenosine (m6A) is the most common type of RNA modification in eukaryotes, which affects intracellular RNA metabolism and controls gene expression of related pathophysiological processes through dynamic reversible regulation of methyltransferases, demethylases and m6A-binding proteins. In recent years, the involvement of m6A methylation in the study of neuropathic pain has become a hot topic, some new understandings have been emerging, and m6A methylation has become a potential biological target for the treatment of neuropathic pain. Therefore, this article reviews the role and regulation of m6A methylation in neuropathic pain, in order to provide new enlightenment for the drug development and treatment of neuropathic pain.

Fat mass and obesity-related protein contributes to the development and maintenance of bone cancer pain in rats by abrogating m6A methylation of RNA.

Effective prevention and treatment options for bone cancer-related pain (BCP) are lacking. In recent years, numerous studies have investigated the association between m6A epigenetic modifications and pain, revealing their significant role in pain initiation and maintenance. This study aimed to provide theoretical support for the treatment of BCP and to identify target drugs for future development. Specifically, we investigated the involvement of fat mass and obesity-related protein (FTO) in rat models of BCP by administering varying doses (1/5/10 mg/kg) of the FTO inhibitor meclofenamic acid (MA) and assessing changes in mechanical sensitivity through domain analysis, gait analysis, and open-field experiments. After successfully establishing the BCP model, we verified it by performing mechanical sensitivity assessments. We observed significantly increased expression levels of the demethylase FTO within the spinal dorsal horn accompanied by decreased m6A methylation levels in the model. Compared with untreated BCP rats, remarkably improved behavioral responses indicative of reduced pain were observed in the model rats after administration of 10 mg/kg MA, concomitant with decreased expression levels of FTO and increased m6A methylation levels. Compared with untreated BCP rats, the expression levels of p-ERK and pro-inflammatory cytokines were also significantly decreased after MA administration. Taken together, FTO can downregulate m6A methylation level and activate ERK/inflammatory cytokines signaling pathway to maintain BCP in rats.

Transcriptome-wide RNA m6A methylation profiles in an endemic osteoarthropathy, Kashin-Beck disease.

Kashin-Beck disease (KBD) is a chronic degenerative, disabling disease of the bones and joints and its exact aetiology and pathogenesis remain uncertain. This study is to investigate the role of m6A modification in the pathogenesis of KBD. Combined analysis of m6A MeRIP-Seq and RNA-Seq were used to analyse human peripheral blood samples from three KBD patients and three normal controls (NC). Bioinformatic methods were used to analyse m6A-modified differential genes and RT-qPCR was performed to validate the mRNA expression of several KBD-related genes. The results indicated that the total of 16,811 genes were modified by m6A in KBD group, of which 4882 genes were differential genes. A large number of differential genes were associated with regulation of transcription, signal transduction and protein binding. KEGG analysis showed that m6A-enriched genes participated the pathways of Vitamin B6 metabolism, endocytosis and Rap 1 signalling pathway. There was a positive association between m6A abundance and levels of gene expression, that there were 6 hypermethylated and upregulated genes (hyper-up), 23 hypomethylated and downregulated genes (hypo-down) in KBD group compared with NC. In addition, the mRNA expression of levels of MMP8, IL32 and GPX1 were verified and the protein-protein interaction networks of these key factors were constructed. Our study showed that m6A modifications may play a vital role in modulating gene expression, which represents a new clue to reveal the pathogenesis of KBD.

RNA methylation patterns of tumor microenvironment cells regulate prognosis and immunotherapeutic responsiveness in patients with triple-negative breast cancer.

Immunotherapy research focuses on reshaping the tumor microenvironment (TME) to enhance its antitumor immune responses, with an emphasis on understanding the impact of RNA methylation in triple-negative breast cancer (TNBC) TME regulation. This study explored the influence of various RNA methyltransferases on TME cells in TNBC and their correlation with prognosis and immunotherapy response. Using non-negative matrix factorization on single-cell RNA-sequencing data, distinct TME cell clusters were identified based on the expression of 30 RNA methyltransferases. Various analyses, including pseudotime, cell communication, transcription factor regulatory network, and gene enrichment, were conducted on these clusters. The roles of RNA methyltransferase-mediated TME clusters in prognosis and immunotherapy response were determined using TNBC bulk RNA-Seq data, and the findings were validated through immunofluorescence analysis of a tissue microarray comprising 87 samples. Spatial transcriptomic analysis further revealed the distribution of TME cell clusters. Different methyltransferase-mediated cell clusters exhibited unique metabolic, immune, transcriptional, and intercellular communication patterns. Survival analysis indicated prognostic significance in specific TME cell clusters, and immunofluorescence analysis confirmed the prognostic value of m6A_WTAP + CD8T + cells. In conclusion, our study illustrated the involvement of these cell subgroups in tumor growth and antitumor immunity modulation, providing insights into the enhancement of TNBC immunotherapy.

RNA methylation sequencing shows different gene expression signatures for response to azacytidine therapy in high-grade myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are myeloid malignancies with heterogeneous genotypes and phenotypes, characterized by ineffective haematopoiesis and a high risk of progression towards acute myeloid leukaemia (AML). Prognosis for patients treated with hypomethylating agents (HMAs), as is azacytidine, the main drug used as frontline therapy for MDS is mostly based on cytogenetics and next generation sequencing (NGS) of the initial myeloid clone. Although the critical influence of the epigenetic landscape upon cancer cells survival and development as well on tumour environment establishment is currently recognized and approached within current clinical practice in MDS, the heterogenous response of the patients to epigenetic therapy is suggesting a more complex mechanism of action, as is the case of RNA methylation. In this sense, the newly emerging field of epitranscriptomics could provide a more comprehensive perspective upon the modulation of gene expression in malignancies, as is the proof-of-concept of MDS. We initially did RNA methylation sequencing on MDS patients (n = 6) treated with azacytidine and compared responders with non-responders. Afterwards, the genes identified were assessed in vitro and afterwards validated on a larger cohort of MDS patients treated with azacytidine (n = 58). Our data show that a more accurate prognosis could be based on analysing the methylome and thus we used methylation sequencing to differentially split high-grade MDS patients with identical demographical and cytogenetic features, between azacytidine responders and non-responders.

NSUN2-mediated RNA methylation: Molecular mechanisms and clinical relevance in cancer.

Cancer remains a leading cause of morbidity and mortality worldwide, necessitating the ongoing investigation of molecular targets for improved diagnosis, prognosis, and therapy. Among these targets, RNA modifications, particularly N5-methylcytosine (m5C) in RNA, have emerged as critical regulators of gene expression and cellular functions. NOP2/Sun RNA methyltransferase family member 2 (NSUN2) is a key enzyme in m5C modification, significantly influencing various biological processes and tumorigenesis. NSUN2 methylates multiple RNA species, including transfer RNAs (tRNAs), messenger RNAs (mRNAs), and non-coding RNAs, impacting RNA stability, translation efficiency, and cellular stress responses. These modifications, in turn, affect cell proliferation, differentiation, and survival. In cancer, NSUN2 is frequently upregulated, associated with aggressive tumor phenotypes, poor prognosis, and therapy resistance. Its role in oncogenic signaling pathways further underscores its importance in cancer biology. This review offers a comprehensive overview of NSUN2's role in cancer, focusing on its involvement in RNA methylation and its implications for tumor initiation and progression. Additionally, we explore the potential of NSUN2 as a biomarker for cancer diagnosis and prognosis, and its promise as a therapeutic target.

Methyltransferase-Like 3-Mediated N6-Methyladenosine RNA Methylation Regulates Hypoxia-Induced Pulmonary Arterial Smooth Muscle Cell Pyroptosis by Targeting PTEN.

BACKGROUND: Pulmonary hypertension is a rare, progressive disorder that can lead to right ventricular hypertrophy, right heart failure, and even sudden death. N6-methyladenosine modification and the main methyltransferase that mediates it, methyltransferase-like (METTL) 3, exert important effects on many biological and pathophysiological processes. However, the role of METTL3 in pyroptosis remains unclear. METHODS AND RESULTS: Here, we characterized the role of METTL3 and the underlying cellular and molecular mechanisms of pyroptosis, which is involved in pulmonary hypertension. METTL3 was downregulated in a pulmonary hypertension mouse model and in hypoxia-exposed pulmonary artery smooth muscle cell. The small interfering RNA-induced silencing of METTL3 decreased the m6A methylation levels and promoted pulmonary artery smooth muscle cell pyroptosis, mimicking the effects of hypoxia. In contrast, overexpression of METTL3 suppressed hypoxia-induced pulmonary artery smooth muscle cell pyroptosis. Mechanistically, we identified the phosphate and tension homology deleted on chromosome 10 (PTEN) gene as a target of METTL3-mediated m6A modification, and methylated phosphate and tension homology deleted on chromosome 10 mRNA was subsequently recognized by the m6A "reader" protein insulin-like growth factor 2 mRNA-binding protein 2, which directly bound to the m6A site on phosphate and tension homology deleted on chromosome 10 mRNA and enhanced its stability. CONCLUSIONS: These results identify a new signaling pathway, the METTL3/phosphate and tension homology deleted on chromosome 10/insulin-like growth factor 2 mRNA-binding protein 2 axis, that participates in the regulation of hypoxia-induced pyroptosis.

The novel roles of RNA m6A modification in regulating the development, infection, and oxidative DNA damage repair of Phytophthora sojae.

N6-methyladenosine (m6A), a vital post-transcriptional regulator, is among the most prevalent RNA modifications in eukaryotes. Nevertheless, the biological functions of m6A in oomycetes remain poorly understood. Here, we showed that the PsMTA1 and PsMTA2 genes are orthologs of human METTL4, while the PsMET16 gene is an ortholog of human METTL16. These genes are implicated in m6A modification and play a critical role in the production of sporangia and oospores, the release of zoospores, and the virulence of Phytophthora sojae. In P. sojae, m6A modifications are predominantly enriched in the coding sequence and the 3' untranslated region. Notably, the PsMTA1 knockout mutant exhibited reduced virulence, attributed to impaired tolerance to host defense-generated ROS stress. Mechanistically, PsMTA1-mediated m6A modification positively regulates the mRNA lifespan of DNA damage response (DDR) genes in reaction to plant ROS stress during infection. Consequently, the mRNA abundance of the DDR gene PsRCC1 was reduced in the single m6A site mutant ΔRCC1/RCC1A2961C, resulting in compromised DNA damage repair and reduced ROS adaptation-associated virulence in P. sojae. Overall, these results indicate that m6A-mediated RNA metabolism is associated with the development and pathogenicity of P. sojae, underscoring the roles of epigenetic markers in the adaptive flexibility of Phytophthora during infection.

Increased m6A RNA methylation and METTL3 expression may contribute to the synovitis progression of rheumatoid arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial hyperplasia and progressive bone destruction. The tumor-like growth of fibroblast-like synoviocytes (FLSs) plays a crucial role in the pathogenesis of RA. The N6 methyladenine (m6A) mRNA methylation modification, regulated by methyltransferases (METTL3) and demethylation enzymes, is a novel epigenetic regulator in the development of RA. However, there is limited research on m6A methylation modifications in RA synovitis and a lack of mechanistic studies on their impact on the function of RA-FLSs. METHODS: This study utilized clinical synovial tissue specimens and FLSs as research subjects. The m6A methylation level and the expression of methyltransferases and demethylation enzymes were detected. RNA interference and gene overexpression methods were employed to investigate the mechanism of METTL3 in RA-FLSs. The study also examined the proliferation, apoptosis, migration, invasion, and cytokine levels of RA-FLSs, as well as the expression of METTL3 in RA animal models. RESULTS: In this study, we found that m6A methylation levels were elevated in synovial tissues and FLSs of RA patients. Immunohistochemical staining showed that METTL3 and METTL14 levels were up-regulated in synovial tissues of RA, the mRNA levels of METTL3, METTL14, WTAP, FTO, and ALKBH5 were significantly higher in synovial tissues and FLSs of RA patients. Overexpression of METTL3 could promote the proliferation, migration, and secretion of IL-6, RANKL of RA-FLSs; inhibition of METTL3 expression could inhibit the abnormal proliferation, migration, invasion, and secretion of IL-6, RANKL, at the same time promoted the apoptosis and secretion of OPG, thus inhibited RA-FLSs tumor-like growth. In CIA mice, the use of MTX and STM2457 reduced METTL3 expression, synovial hyperplasia and bone destruction. CONCLUSION: Abnormal modification of m6A methylation exists in synovial tissues and FLSs of RA patients, and inhibition of METTL3 can reduce synovitis and bone destruction. Our findings suggest that m6A methylation might control FLS-mediated tumor-like phenotype, and be a novel target for RA treatment.

Modulation of m6A RNA modification by DAP3 in cancer cells.

N6-methyladenosine (m6A) RNA methylation is a prevalent RNA modification that significantly impacts RNA metabolism and cancer development. Maintaining the global m6A levels in cancer cells relies on RNA accessibility to methyltransferases and the availability of the methyl donor S-adenosylmethionine (SAM). Here, we reveal that death associated protein 3 (DAP3) plays a crucial role in preserving m6A levels through two distinct mechanisms. First, although DAP3 is not a component of the m6A writer complex, it directly binds to m6A target regions, thereby facilitating METTL3 binding. Second, DAP3 promotes MAT2A's last intron splicing, increasing MAT2A protein, cellular SAM, and m6A levels. Silencing DAP3 hinders tumorigenesis, which can be rescued by MAT2A overexpression. This evidence suggests DAP3's role in tumorigenesis, partly through m6A regulation. Our findings unveil DAP3's complex role as an RNA-binding protein and tumor promoter, impacting RNA processing, splicing, and m6A modification in cancer transcriptomes.

RNA m6A modification in ferroptosis: implications for advancing tumor immunotherapy.

The pursuit of innovative therapeutic strategies in oncology remains imperative, given the persistent global impact of cancer as a leading cause of mortality. Immunotherapy is regarded as one of the most promising techniques for systemic cancer therapies among the several therapeutic options available. Nevertheless, limited immune response rates and immune resistance urge us on an augmentation for therapeutic efficacy rather than sticking to conventional approaches. Ferroptosis, a novel reprogrammed cell death, is tightly correlated with the tumor immune environment and interferes with cancer progression. Highly mutant or metastasis-prone tumor cells are more susceptible to iron-dependent nonapoptotic cell death. Consequently, ferroptosis-induction therapies hold the promise of overcoming resistance to conventional treatments. The most prevalent post-transcriptional modification, RNA m6A modification, regulates the metabolic processes of targeted RNAs and is involved in numerous physiological and pathological processes. Aberrant m6A modification influences cell susceptibility to ferroptosis, as well as the expression of immune checkpoints. Clarifying the regulation of m6A modification on ferroptosis and its significance in tumor cell response will provide a distinct method for finding potential targets to enhance the effectiveness of immunotherapy. In this review, we comprehensively summarized regulatory characteristics of RNA m6A modification on ferroptosis and discussed the role of RNA m6A-mediated ferroptosis on immunotherapy, aiming to enhance the effectiveness of ferroptosis-sensitive immunotherapy as a treatment for immune-resistant malignancies.

m6A modification of RNA in cervical cancer: role and clinical perspectives.

N6-methyladenosine (m6A) is widely recognized as the predominant form of RNA modification in higher organisms, with the capability to finely regulate RNA metabolism, thereby influencing a series of crucial physiological and pathological processes. These processes include regulation of gene expression, cell proliferation, invasion and metastasis, cell cycle control, programmed cell death, interactions within the tumour microenvironment, energy metabolism, and immune regulation. With advancing research into the mechanisms of RNA methylation, the pivotal role of m6A modification in the pathophysiology of reproductive system tumours, particularly cervical cancer, has been progressively unveiled. This discovery has opened new research avenues and presented significant potential for the diagnosis, prognostic evaluation, and treatment of diseases. This review delves deeply into the biological functions of m6A modification and its mechanisms of action in the onset and progression of cervical cancer. Furthermore, it explores the prospects of m6A modification in the precision diagnosis and treatment of cervical cancer, aiming to provide new perspectives and a theoretical basis for innovative and advanced treatment strategies for cervical cancer.

FTO-overexpressing extracellular vesicles from BM-MSCs reverse cellular senescence and aging to ameliorate osteoarthritis by modulating METTL3/YTHDF2-mediated RNA m6A modifications.

Extracellular vesicles secreted by bone marrow mesenchymal stem cells (BM-MSCs) exert therapeutic effects in osteoarthritis (OA). As an important N6-Methyladenosine (m6A) demethylase, it is reported that fat mass and obesity-associated protein (FTO) involves in regulating OA progression. Here, we generated MSCs-derived FTO-overexpressing EVs (FTO-EVs) to investigate whether FTO-EVs could be used for the potential treatment of OA. Our experiments verify that FTO-EVs suppressed cellular senescence, aging, apoptosis, and enhanced cell autophagy in LPS-treated chondrocytes in vitro and monosodium iodoacetate (MIA)-treated mice tissues in vivo. Also, ROS scavenger NAC reversed LPS-induced detrimental effects in chondrocytes. Mechanical experiments illustrated that FTO-EVs induced m6A-demethylation in autophagy-associated genes (Atg5 and Atg7) and pro-apoptosis gene (BNIP3), subsequently inducing the upregulation of Atg5/Atg7 and downregulation of BNIP3 in a YTHDF2-dependent manner, and the effects of FTO-EVs on the expressions of Atg5/Atg7 and BNIP3 were all reversed by upregulating m6A methyltransferase METTL3. Furthermore, FTO-EVs-induced suppressing effects on LPS-treated chondrocytes senescence and aging were abolished by Atg5/Atg7 knockdown and BNIP3 overexpression. In conclusion, this study evidenced that BM-MSCs-derived FTO-EVs suppressed cellular senescence and apoptosis, and triggered protective autophagy to suppress OA development through demethylating m6A modifications, and the engineering FTO-EVs could be potentially used to treat OA in clinic.

Targeting treatment resistance: unveiling the potential of RNA methylation regulators and TG-101,209 in pan-cancer neoadjuvant therapy.

BACKGROUND: Tumor recurrence and mortality rates remain challenging in cancer patients despite comprehensive treatment. Neoadjuvant chemotherapy and immunotherapy aim to eliminate residual tumor cells, reducing the risk of recurrence. However, drug resistance during neoadjuvant therapy is a significant hurdle. Recent studies suggest a correlation between RNA methylation regulators (RMRs) and response to neoadjuvant therapy. METHODS: Using a multi-center approach, we integrated advanced techniques such as single-cell transcriptomics, whole-genome sequencing, RNA sequencing, proteomics, machine learning, and in vivo/in vitro experiments. Analyzing pan-cancer cohorts, the association between neoadjuvant chemotherapy/immunotherapy effectiveness and RNA methylation using single-cell sequencing was investigated. Multi-omics analysis and machine learning algorithms identified genomic variations, transcriptional dysregulation, and prognostic relevance of RMRs, revealing distinct molecular subtypes guiding pan-cancer neoadjuvant therapy stratification. RESULTS: Our analysis unveiled a strong link between neoadjuvant therapy efficacy and RNA methylation dynamics, supported by pan-cancer single-cell sequencing data. Integration of omics data and machine learning algorithms identified RMR genomic variations, transcriptional dysregulation, and prognostic implications in pan-cancer. High-RMR-expressing tumors displayed increased genomic alterations, an immunosuppressive microenvironment, poorer prognosis, and resistance to neoadjuvant therapy. Molecular investigations and in vivo/in vitro experiments have substantiated that the JAK inhibitor TG-101,209 exerts notable effects on the immune microenvironment of tumors, rendering high-RMR-expressing pan-cancer tumors, particularly in pancreatic cancer, more susceptible to chemotherapy and immunotherapy. CONCLUSIONS: This study emphasizes the pivotal role of RMRs in pan-cancer neoadjuvant therapy, serving as predictive biomarkers for monitoring the tumor microenvironment, patient prognosis, and therapeutic response. Distinct molecular subtypes of RMRs aid individualized stratification in neoadjuvant therapy. Combining TG-101,209 adjuvant therapy presents a promising strategy to enhance the sensitivity of high-RMR-expressing tumors to chemotherapy and immunotherapy. However, further validation studies are necessary to fully understand the clinical utility of RNA methylation regulators and their impact on patient outcomes.

A Novel RNA Methylation-Related Prognostic Signature and its Tumor Microenvironment Characterization in Hepatocellular Carcinoma.

INTRODUCTION: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors of the digestive system. RNA methylation plays an important role in tumorigenesis and metastasis, which could alter gene expression and even function at multiple levels, such as RNA splicing, stability, translocation, and translation. In this study, we aimed to conduct a comprehensive analysis of RNA methylation-related genes (RMGs) in HCC and their relationship with survival and clinical features. METHODS: A retrospective analysis was performed using publicly available HCC-related datasets. The differentially expressed genes (DEGs) between HCC and controls were identified from TCGA-LlHC and intersected with RMGs to obtain differentially expressed RNA methylation-related genes (DERMGs). Regression analysis was used to screen for prognostic genes and construct risk models. Simultaneously, clinical, immune infiltration and therapeutic efficacy analyses were performed. Finally, multivariate cox regression was used to identify independent risk factors, and quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the expression levels of the core genes of the model. RESULTS: A 21-gene risk model for HCC was established with excellent performance based on ROC curves and survival analysis. Risk scores correlated with tumor grade, pathologic T, and TNM stage. Immune infiltration analysis showed correlations with immune scores, 11 immune cells, and 30 immune checkpoints. Low-risk patients showed a higher susceptibility to immunotherapy. The risk score and TNM stage were independent prognostic factors. qRT-PCR confirmed higher expression of PRDM9, ALPP, and GAD1 in HCC. CONCLUSIONS: This study identified RNA methylation-related signature genes in HCC and constructed a risk model that predicts patient outcomes and reflects the immune microenvironment. Prognostic genes are involved in complex regulatory mechanisms, which may be useful for cancer diagnosis, prognosis, and therapy.

Expression patterns and clinical value of key m6A RNA modification regulators in smoking patients with coronary artery disease.

Even though N6-methyladenosine (m6A) RNA modifications are increasingly being implicated in human disease, their mechanisms are not fully understood in smokers with coronary artery disease (CAD). Thirty m6A-related regulators' expression (MRRE) in CAD individuals (smokers and non-smokers) were analyzed from GEO. Support Vector Machine, random forest, and nomogram models were constructed to assess its clinical value. Consensus clustering, principal component analysis, and ssGSEA were used to construct a full picture of m6A-related regulators in smokers with CAD. Oxygen-glucose deprivation (OGD) and qRT-PCR were used to validate hypoxia's effect on MRRE. A comparison between smokers with CAD and controls revealed lower expression levels of RBM15B, YTHDC2, and ZC3H13. Based on three key MRREs, all models showed good clinical value, and smokers with CAD were divided into two distinct molecular subgroups. The correlations were found between key MRRE and the degree of immune infiltration. Three key MRREs in HUVECs and FMC84 mouse cardiomyocytes were reduced in the OGD group. Through hypoxia, smoking might reduce the expression levels of RBM15B, YTHDC2, and ZC3H13 in smokers with CAD. Our findings provide an important theoretical basis for the treatment of smokers with CAD.

Identification of key genes with abnormal RNA methylation modification and selected m6A regulators in ankylosing spondylitis.

BACKGROUND: N6-methyladenosine (m6A) has been identified as the most abundant modification of RNA molecules and the aberrant m6A modifications have been associated with the development of autoimmune diseases. However, the role of m6A modification in ankylosing spondylitis (AS) has not been adequately investigated. Therefore, we aimed to explore the significance of m6A regulator-mediated RNA methylation in AS. METHODS: The methylated RNA immunoprecipitation sequencing (meRIP-seq) and digital RNA sequencing (Digital RNA-seq) were conducted using the peripheral blood mononuclear cells from three AS cases and three healthy controls, to identify genes affected by abnormal RNA methylation. The genes associated with different peaks were cross-referenced with AS-related genes obtained from the GeneCards Suite. Subsequently, the expression levels of shared differentially expressed genes (DEGs) and key m6A regulators in AS were evaluated using data from 68 AS cases and 36 healthy controls from two data sets (GSE25101 and GSE73754). In addition, the results were validated through quantitative polymerase chain reaction (qPCR). RESULTS: The meRIP-seq and Digital RNA-seq analyses identified 28 genes with upregulated m6A peaks but with downregulated expression, and 52 genes with downregulated m6A peaks but with upregulated expression. By intersecting the genes associated with different peaks with 2184 AS-related genes from the GeneCards Suite, we identified a total of five shared DEGs: BCL11B, KAT6B, IL1R1, TRIB1, and ALDH2. Through analysis of the data sets and qPCR, we found that BCL11B and IL1R1 were differentially expressed in AS. Moreover, two key m6A regulators, WTAP and heterogeneous nuclear ribonucleoprotein C, were identified. CONCLUSIONS: In conclusion, the current study revealed that m6A modification plays a crucial role in AS and might hence provide a new treatment strategy for AS disease.

FTO-mediated RNA m6A methylation regulates synovial aggression and inflammation in rheumatoid arthritis.

Fibroblast-like synoviocytes (FLS) plays an important role in synovial inflammation and joint damage in rheumatoid arthritis (RA). As the most abundant mRNA modification, N6-methyladenosine (m6A) is involved in the development of various diseases; however, its role in RA remains to be defined. In this study, we reported the elevated expression of the m6A demethylase fat mass and obesity-associated protein (FTO) in FLS and synovium from RA patients. Functionally, FTO knockdown or treatment with FB23-2, an inhibitor of the mRNA m6A demethylase FTO, inhibited the migration, invasion and inflammatory response of RA FLS, however, FTO-overexpressed RA FLS exhibited increased migration, invasion and inflammatory response. We further demonstrated that FTO promoted ADAMTS15 mRNA stability in an m6A-IGF2BP1 dependent manner. Notably, the severity of arthritis was significantly reduced in CIA mice with FB23-2 administration or CIA rats with intra-articular injection of FTO shRNA. Our results illustrate the contribution of FTO-mediated m6A modification to joint damage and inflammation in RA and suggest that FTO might be a potential therapeutic target in RA.

RNA m6A modification regulates cell fate transition between pluripotent stem cells and 2-cell-like cells.

N6-methyladenosine (m6A) exerts essential roles in early embryos, especially in the maternal-to-zygotic transition stage. However, the landscape and roles of RNA m6A modification during the transition between pluripotent stem cells and 2-cell-like (2C-like) cells remain elusive. Here, we utilised ultralow-input RNA m6A immunoprecipitation to depict the dynamic picture of transcriptome-wide m6A modifications during 2C-like transitions. We found that RNA m6A modification was preferentially enriched in zygotic genome activation (ZGA) transcripts and MERVL with high expression levels in 2C-like cells. During the exit of the 2C-like state, m6A facilitated the silencing of ZGA genes and MERVL. Notably, inhibition of m6A methyltransferase METTL3 and m6A reader protein IGF2BP2 is capable of significantly delaying 2C-like state exit and expanding 2C-like cells population. Together, our study reveals the critical roles of RNA m6A modification in the transition between 2C-like and pluripotent states, facilitating the study of totipotency and cell fate decision in the future.