METTL3-mediated m6A modification of HDGF mRNA promotes gastric cancer progression and has prognostic significance

Emerging importance of m6A modification in liver cancer and its potential therapeutic role

Liver cancer refers to malignant tumors that form in the liver and is usually divided into several types, the most common of which is hepatocellular carcinoma (HCC), which originates in liver cells. Other rare types of liver cancer include intrahepatic cholangiocarcinoma (iCCA). m6A modification is a chemical modification of RNA that usually manifests as the addition of a methyl group to adenine in the RNA molecule to form N6-methyladenosine. This modification exerts a critical role in various biological processes by regulating the metabolism of RNA, affecting gene expression. Recent studies have shown that m6A modification is closely related to the occurrence and development of liver cancer, and m6A regulators can further participate in the pathogenesis of liver cancer by regulating the expression of key genes and the function of specific cells. In this review, we provided an overview of the latest advances in m6A modification in liver cancer research and explored in detail the specific functions of different m6A regulators. Meanwhile, we deeply analyzed the mechanisms and roles of m6A modification in liver cancer, aiming to provide novel insights and references for the search for potential therapeutic targets. Finally, we discussed the prospects and challenges of targeting m6A regulators in liver cancer therapy.

The microbiota-m6A-metabolism axis: Implications for therapeutic strategies in gastrointestinal cancers

Gastrointestinal (GI) cancers remain a leading cause of cancer-related mortality worldwide, with metabolic reprogramming recognized as a central driver of tumor progression and therapeutic resistance. Among the key regulatory layers, N6-methyladenosine (m6A) RNA modification-mediated by methyltransferases (writers such as METTL3/14), RNA-binding proteins (readers like YTHDFs and IGF2BPs), and demethylases (erasers including FTO and ALKBH5), plays a pivotal role in controlling gene expression and metabolic flux in the tumor context. Concurrently, the gut microbiota profoundly influences GI tumorigenesis and immune evasion by modulating metabolite availability and remodeling the tumor microenvironment. Recent evidence has uncovered a bidirectional crosstalk between microbial metabolites and m6A methylation: microbiota-derived signals dynamically regulate m6A deposition on metabolic and immune transcripts, while m6A modifications, in turn, regulate the stability and translation of key mRNAs such as PD-L1 and FOXP3. This reciprocal interaction forms self-reinforcing epigenetic circuits that drive tumor plasticity, immune escape, and metabolic adaptation. In this review, we dissect the molecular underpinnings of the microbiota-m6A-metabolism axis in GI cancers and explore its potential to inform novel strategies in immunotherapy, metabolic intervention, and microbiome-guided precision oncology.

Recent advances in medicinal chemistry strategies for the development of METTL3 inhibitors

N6-methyladenosine (m6A), the most abundant RNA modification in eukaryotic cells, exerts a critical influence on RNA function and gene expression. It has attracted considerable attention within the rapidly evolving field of epitranscriptomics. METTL3 is a key enzyme for m6A modification and is essential for maintaining normal m6A levels. High expression of METTL3 is closely associated with various cancers, including gastric cancer, liver cancer, and leukemia. Inhibiting METTL3 has shown potential in slowing cancer progression, thereby driving the development of METTL3 inhibitors. In this work, we summarize recent advancements in the development of METTL3 inhibitor, with a focus on medicinal chemistry strategies employed during discovery and optimization phases. We explore the application of structure-activity relationship (SAR) studies and protein-targeted degradation techniques, while addressing key challenges associated with their characterization and clinical translation. This review underscores the therapeutic potential of METTL3 inhibitors in modulating epitranscriptomic pathways and aims to offer perspectives for future research in this rapidly evolving field.

Identification of biological markers and functional analysis in head and neck squamous cell carcinoma through Cuproptosis and methylation: molecular mechanism of action of METTL3 protein

Head and neck squamous cell carcinoma (HNSC) is a common malignant tumor. Gene methylation and cell death mechanisms such as cupping death play an important role in the development of the tumor. The purpose of this study was to investigate the role of METTL3 protein in HNSC and its potential biomarker value. In this study, we collected and preprocessed relevant gene expression data, including cup-death and methylation-related gene datasets, and pan-cancer datasets. Differential expression analysis was used to compare gene expression in HNSC tumor tissue with adjacent normal tissue, followed by diagnostic and prognostic analysis, including survival analysis and marker evaluation. The genes co-expressed with METTL3 were screened by functional enrichment analysis, and the GO and KEGG pathways were analyzed. To evaluate the immunoinfiltration of HNSC and its relevance in pan-cancer. The results showed that METTL3 was highly expressed in HNSC tissues, which was closely related to the malignant degree of tumor and the prognosis of patients. The results of survival analysis showed that the expression level of METTL3 was significantly correlated with the survival of patients. METTL3 is associated with infiltration levels of multiple immune cell types, suggesting that it plays an important role in regulating the tumor microenvironment. Through functional enhancement analysis, it was determined that the signaling pathway involved in the co-expression of METTL3 genes was related to cell proliferation and apoptosis. As an important biomarker of HNSC, METTL3 not only has good diagnostic and prognostic evaluation ability, but also plays a key role in the tumor immune microenvironment. Its molecular mechanism of action can affect the occurrence and development of tumors by regulating tumor-related pathways and the function of immune cells, and it is worth further study to improve its potential in clinical application.

N6-methyladenosine RNA modification in stomach carcinoma: Novel insights into mechanisms and implications for diagnosis and treatment

N6-methyladenosine (m6A) RNA methylation is crucially involved in the genesis and advancement of gastric cancer (GC) by controlling various pathobiological aspects including gene expression, signal transduction, metabolism, cell death, epithelial-mesenchymal transition, angiogenesis, and exosome function. Despite its importance, the exact mechanisms by which m6A modification influences GC biology remain inadequately explored. This review consolidates the latest advances in uncovering the mechanisms and diverse roles of m6A in GC and proposes new research and translational directions. Key regulators (writers, readers, and erasers) of m6A, such as METTL3/14/16 and WTAP, significantly affect cancer progression, anticancer immune response, and treatment outcomes. m6A modification also impacts immune cell infiltration and the tumor microenvironment, highlighting its potential as a diagnostic and prognostic marker. Interactions between m6A methylation and non-coding RNAs offer further novel insights into GC development and therapeutic targets. Targeting m6A regulators could enhance immunotherapy response, overcome treatment resistance, and improve oncological and clinical outcomes. Models based on m6A can precisely predict treatment response and prognosis in GC. Additional investigation is needed to fully understand the mechanisms of m6A methylation and its potential clinical applications and relevance (e.g., as precise markers for early detection, prediction of outcome, and response to therapy and as therapeutic targets) in GC. Future research should focus on in vivo studies, potential clinical trials, and the examination of m6A modification in other types of cancers.

Blood Biomarker-Based Predictive Indicator for Liver Metastasis in Alpha-Fetoprotein-Producing Gastric Cancer and Multi-Omics Tumor Microenvironment Insights

Alpha-fetoprotein-producing gastric cancer (AFPGC) is a rare but highly aggressive subtype of gastric cancer. Patients with AFPGC are at high risk of liver metastasis, and the tumor microenvironment (TME) is complex. A multicenter retrospective study is conducted from January 2011 to December 2021 and included 317 AFPGC patients. Using a multivariable logistic regression model, a nomogram for predicting liver metastasis is built. By combining AFP and the neutrophil-lymphocyte ratio (NLR), we developed a novel and easily applicable predictive indicator, termed ANLiM score, for liver metastasis in AFPGC. An integrated multi-omics analysis, including whole-exome sequencing and proteomic analysis, is conducted and revealed an immunosuppressive TME in AFPGC with liver metastasis. Single-cell RNA sequencing and multiplex immunofluorescence identified the potential roles of tumor-associated neutrophils and tertiary lymphoid structures in shaping the immune microenvironment. These findings are validated in a real-world cohort receiving anti-programmed cell death 1 (anti-PD-1) therapy, which showed concordant effectiveness. In addition, the ANLiM score is also identified as a promising biomarker for predicting immunotherapy efficacy. Overall, a blood biomarker-based predictive indicator is developed for liver metastasis and immunotherapy response in AFPGC. The findings on immune microenvironmental alterations for AFPGC with liver metastasis provide new insights for optimizing immunotherapy strategies.

Multi-omics analysis identifies LANCL2 as a potential biomarker for the diagnosis and prognosis of gastric cancer

Gastric cancer (GC) constitutes a significant global public health burden due to its high morbidity rates and poor prognosis, underscoring the critical need for identifying novel therapeutic targets and elucidating their mechanisms. As a key member of the lanthionine synthetase C-like enzyme family, LANCL2 has shown aberrant expression in multiple malignancies. However, its biological significance in GC remains unclear. To this end, a series of exploration and research were conducted. Through integrated analyses of multi-omics databases and experimental validation, LANCL2 was up-regulated in STAD at both mRNA and protein levels. Moreover, elevated LANCL2 is closely associated with poor prognosis, and the constructed nomogram exhibited reliable predictive performance for 1, 3, and 5-year overall survival (OS) in the GC cohort. In addition, the genetic alteration status of LANCL2 was associated with new neoplasm event post initial therapy indicator, MSIsensor score, tumor mutation burden (TMB), and survival prognosis. Functional enrichment analysis indicated that LANCL2 is primarily associated with the regulation of immune checkpoints, the cell cycle and DNA repair. Furthermore, the expression of LANCL2 displayed significant correlations with immune infiltration, m6A methylation, ferroptosis, tumor cell stemness and drug reactivity. Finally, in vitro studies confirmed that silencing or overexpression of LANCL2 can significantly influence the changes of proliferation and cell cycle of GC cells. Overall, this study indicated LANCL2 as a critical regulator in GC pathogenesis, and highlighted its potential as a prognostic biomarker for gastric cancer management.

Switching from messenger RNAs to noncoding RNAs, METTL3 is a novel colorectal cancer diagnosis and treatment target

N6-methyladenosine (m6A) modification, one of the most prevalent RNA epigenetic modifications in eukaryotes, constitutes over 60% of all RNA methylation modifications. This dynamic modification regulates RNA processing, maturation, nucleocytoplasmic transport, translation efficiency, phase separation, and stability, thereby linking its dysregulation to diverse physiological and pathological processes. METTL3, a core catalytic component of the methyltransferase complex responsible for m6A deposition, is frequently dysregulated in diseases, including colorectal cancer (CRC). Although METTL3’s involvement in CRC pathogenesis has been documented, its precise molecular mechanisms and functional roles remain incompletely understood. METTL3 mediates CRC progression-encompassing proliferation, invasion, drug resistance, and metabolic reprogramming-through m6A-dependent modulation of both coding RNAs and noncoding RNAs. Its regulatory effects are primarily attributed to interactions with key signaling pathways at multiple stages of CRC development. Emerging evidence highlights METTL3 as a promising biomarker for CRC diagnosis and prognosis, as well as a potential therapeutic target. By synthesizing recent advances in METTL3 research within CRC, this review provides critical insights into novel strategies for clinical diagnosis and targeted therapy.

The m6 A modification of CDKN2 A inhibites ferroptosis and affects the resistance of cervical squamous cell carcinoma to cisplatin

Cervical squamous cell carcinoma (CESC) is the fourth most common malignancy and the fourth leading cause of cancer deaths in women worldwide. Despite advances in treatment, cisplatin-based radiotherapy remains the primary treatment option. However, cisplatin resistance is a major challenge, leading to poor prognosis. Therefore, understanding the molecular mechanisms underlying cisplatin resistance is crucial for developing novel therapeutic strategies. Through bioinformatics analysis, we investigated the expression of CDKN2A in the CESC database. WB, IHC, qPCR, and CCK-8 were used for clinical analysis of CDKN2A expression and its correlation with CESC cell proliferation. Through qPCR, CCK-8, ROS, MDA, Fe2+ and WB, we explored how CDKN2A promotes cisplatin resistance by inhibiting ferroptosis. In nude mouse tumor experiments, we investigated how CDKN2A participates in ferroptosis and cisplatin resistance in CESC through the JAK2/STAT3 pathway. Furthermore, we explored CDKN2A as a target of METTL3 and how YTHDF1 enhances the stability of m6A-modified CDKN2A. We investigated the role of CDKN2A in CESC and its involvement in cisplatin resistance. We found that CDKN2A expression was associated with CESC cell ferroptosis and cisplatin resistance. Mechanistically, CDKN2A was identified as a target of METTL3, and YTHDF1 enhanced the stability of m6A-modified CDKN2A. Furthermore, METTL3 inhibited ferroptosis through m6A modification of YTHDF1/CDKN2A, influencing cisplatin resistance in CESC. Our findings provide new insights into the molecular mechanisms of cisplatin resistance in CESC and suggest that targeting the METTL3/YTHDF1/CDKN2A axis may be a promising strategy to overcome this resistance and improve treatment outcomes.

The RNA-binding protein YTHDF3 affects gastric cancer cell migration and response to paclitaxel by regulating EZRIN

BACKGROUND

Gastric cancer (GC) is the fourth most common cause of cancer-related mortality and the fifth most common cancer worldwide. Despite efforts, the identification of biomarkers and new therapeutic approaches for GC remains elusive. Recent studies have begun to reveal the role of N6-adenosine methylation (m6A) in the regulation of gene expression.

METHODS

The expression of the reader YT521-B homology domain-containing family 3 (YTHDF3) in GC was assessed in 331 patients using immunohistochemistry. GC cell lines depleted of YTHDF3 using CRISPR-Cas9 were evaluated for migration, metastasis, orientation of the mitotic spindle, and response to paclitaxel. The association between YTHDF3 and EZRIN (EZR) mRNA was shown using RNA sequencing, immunofluorescence, real-time PCR, and RNA immunoprecipitation. The single-base elongation- and ligation-based qPCR amplification (SELECT) method was used to map m6A in the EZR transcript.

RESULTS

YTHDF3 was significantly overexpressed in GC, and high levels of YTHDF3 were predictive of the response to chemotherapy. In GC cell lines, YTHDF3 was the most highly expressed reader protein. YTHDF3 depletion impaired cytoskeleton organization, cell migration and metastasis, and orientation of the mitotic spindle, leading to an increased response to paclitaxel. EZR was one of the downregulated targets in the YTHDF3 knockout cell models and was associated with the observed phenotype.

CONCLUSION

YTHDF3 contributes to cell motility and response to paclitaxel in GC cell lines, at least in part through EZR regulation. The YTHDF3-EZR regulatory axis is a novel molecular player in GC, with clinical relevance and potential therapeutic utility.

Epitranscriptome-epigenome interactions in development and disease mechanisms

Crosstalk between epitranscriptomic modifications to RNA and epigenomic modifications to DNA and histones plays fundamental roles in development and disease. Here, we summarize two major regulatory modes of the crosstalk between the epigenome and epitranscriptome. In the 'cis mode', the crosstalk occurs co-transcriptionally, with direct interactions observed between epigenetic modifications mediated by their regulators. In the 'trans mode', the modification of an epigenetic layer regulates the expression of another epigenetic layer's writers/erasers and subsequently induces downstream epigenetic alteration. Additionally, we focus on the functional roles of the crosstalk mechanism in physiological and pathological contexts, including development, differentiation, cancer, and complex genetic diseases. Lastly, we discuss the potential future directions for a systematic understanding of epigenetic crosstalk in development and disease.

Recent Advance in Sensitive Detection of Demethylase FTO

Methylation modification is a critical regulatory mechanism in epigenetics and plays a significant role in various biological processes. N6-methyladenosine (m6A) is the most common modification found in RNA. The fat mass and obesity-associated protein (FTO) facilitate the demethylation of m6A in RNA, and its abnormal expression is closely linked to the development of several diseases. As a result, FTO has the potential to serve as an important biomarker for clinical disease diagnosis. Despite its significance, there has been a lack of comprehensive reviews addressing advancements in detection methods for the demethylase FTO. This review provides an overview of the progress in FTO detection methods, ranging from traditional approaches to innovative techniques, with a particular emphasis on recently reported advancements. These novel detection methods can be categorized into strategies based on enzymes, functional nucleic acids (FNA), and conformational changes. We summarize the principles and applications of these detection methods and discuss the current challenges and prospects in this field.

Lactylation as a metabolic epigenetic modification: Mechanistic insights and regulatory pathways from cells to organs and diseases

In recent years, lactylation, a novel post-translational modification, has demonstrated a unique role in bridging cellular metabolism and epigenetic regulation. This modification exerts a dual-edged effect in both cancer and non-cancer diseases by dynamically integrating the supply of metabolic substrates and the activity of modifying enzymes: on one hand, it promotes tissue homeostasis and repair through the activation of repair genes; on the other, it exacerbates pathological progression by driving malignant phenotypes. In the field of oncology, lactylation regulates key processes such as metabolic reprogramming, immune evasion, and therapeutic resistance, thereby shaping the heterogeneity of the tumor microenvironment. In non-cancerous diseases, including neurodegeneration and cardiovascular disorders, its aberrant activation can lead to mitochondrial dysfunction, fibrosis, and chronic inflammation. Existing studies have revealed a dynamic regulatory network formed by the cooperation of modifying and demodifying enzymes, and have identified mechanisms such as subcellular localization and RNA metabolism intervention that influence disease progression. Nevertheless, several challenges remain in the field. This article comprehensively summarizes the disease-specific regulatory mechanisms of lactylation, with the aim of providing a theoretical foundation for its targeted therapeutic application.

FOXA1-dependent NSUN2 facilitates the advancement of prostate cancer by preserving TRIM28 mRNA stability in a m5C-dependent manner

RNA epigenetics is gaining increased attention for its role in the initiation, metastasis, and drug resistance of tumors. These studies have primarily focused on m6A modification. However, despite being the second most abundant modification found in RNA, the role of m5C modification in prostate cancer remains largely unexplored. Here, we predict an RNA m5C methyltransferase, NSUN2, as a potential therapeutic target for prostate cancer using various bioinformatics approaches, and verify the potential of NSUN2 as a target through multiple preclinical models. Mechanistically, NSUN2 enhances the stability of TRIM28 mRNA by adding m5C modification, promoting the expression of TRIM28. Concurrently, FOXA1, a prostate cancer lineage-specific transcription factor, transcriptionally activates the expression of NSUN2. Our study confirms the clinical potential of targeting RNA epigenetics for the treatment of prostate cancer and elucidates, mechanistically, how RNA epigenetics participates in the complex biological activities within tumors via the FOXA1-NSUN2-TRIM28 axis.

METTL3 enhances esophageal squamous cell carcinoma progression by suppressing ferroptosis through the PBX3/CA9 cascade

BACKGROUND

N6-methyladenosine (m6A) modification controls various processes during tumorigenesis. Although METTL3 functions as a pro-tumorigenic driver in esophageal squamous cell carcinoma (ESCC), its mechanisms are largely unknown.

METHODS

mRNA expression was detected by quantitative PCR, and protein expression was assessed by immunoblotting. Cell motility, invasiveness, and apoptosis were analyzed by wound-healing assay, transwell assay and flow cytometry, respectively. Cell ferroptosis was assessed by detecting the contents of ROS, MDA and Fe2+. The METTL3/PBX3 and PBX3/CA9 relationships were validated by luciferase, MeRIP or ChIP assay. The effect of METTL3 on tumor growth was tested by xenograft studies.

RESULTS

METTL3 was enhanced in ESCC tumors and cells, and its deficiency suppressed ESCC cell migration and invasion and promoted cell apoptosis and ferroptosis. Additionally, METTL3 deficiency caused growth inhibition of ESCC xenografts in vivo. METTL3 enhanced m6A modification of PBX3 mRNA. PBX3 was identified as a mediator of METTL3 function in modulating ESCC cell phenotypes. PBX3 promoted CA9 transcription, and METTL3 positively regulated CA9 through PBX3. PBX3 deficiency impeded ESCC cell migration and invasion and enhanced cell apoptosis and ferroptosis by downregulating CA9.

CONCLUSION

Our study elucidates a novel mechanism, the METTL3/PBX3/CA9 cascade, underlying the oncogenic activity of METTL3 in ESCC. The novel cascade may represent the potential target for ESCC therapy in the future.

ALKBH3-Mediated M1A Demethylation of METTL3 Endows Pathological Fibrosis:Interplay Between M1A and M6A RNA Methylation

Epigenetic modifications serve as crucial molecular switches for pathological fibrosis; howbeit the role of m1A in this condition remains enigmatic. Herein, it is found that ALKBH3 exerts a pro-fibrotic effect in pathological skin fibrosis by reshaping N6-methyladenosine (m6A) RNA modification pattern. First, ALKBH3 exhibited specific upregulation within hypertrophic scars (HTS), accompanied by N1-methyladenosine (m1A) hypomethylation. Moreover, multiomics analyses identified METTL3, a critical writer enzyme involved in m6A modification, as a downstream candidate target of ALKBH3. Therapeutically, ablation of ALKBH3 inhibited the progression of HTS both in vitro and in vivo, while exogenous replenishment of METTL3 counteracted this antifibrotic effect. Mechanistically, ALKBH3 recognizes the m1A methylation sites and prevents YTHDF2-dependent mRNA decay of METTL3 transcript. Subsequently, METTL3 stabilizes collagen type I alpha 1 chain (COL1A1) and fibronectin1 (FN1) mRNAs, two major components of extracellular matrix, and therefore eliciting the pathological transformation of HTS. This observation bridges the understanding of the link between m1A and m6A methylation, the two fundamental RNA modifications, underscoring the participation of "RNA methylation crosstalk" in pathological events.

The regulatory role of m6A in cancer metastasis

Metastasis remains a primary cause of cancer-related mortality, with its intricate mechanisms continuing to be uncovered through advancing research. Among the various regulatory processes involved, RNA modification has emerged as a critical epitranscriptomic mechanism influencing cancer metastasis. N6-methyladenosine (m6A), recognized as one of the most prevalent and functionally significant RNA modifications, plays a central role in the regulation of RNA metabolism. In this review, we explore the multifaceted role of m6A in the different stages of cancer metastasis, including epithelial-mesenchymal transition, invasion, migration, and colonization. In addition to summarizing the current state of our understanding, we offer insights into how m6A modifications modulate key oncogenic pathways, highlighting the implications of recent discoveries for therapeutic interventions. Furthermore, we critically assess the limitations of previous studies and propose areas for future research, including the potential for targeting m6A as a novel approach in anti-metastatic therapies. Our analysis provides a comprehensive understanding of the regulatory landscape of m6A in metastasis, offering directions for continued exploration in this rapidly evolving field.

Research progress on m6A and drug resistance in gastrointestinal tumors

Gastrointestinal (GI) tumors represent a significant global health burden and are among the leading causes of cancer-related mortality worldwide. their drug resistance is one of the major challenges in cancer therapy. In recent years, epigenetic modifications, especially N6-methyladenosine (m6A) RNA modifications, have become a hot research topic. m6A modification plays an important role in gene expression and cancer progression by regulating RNA splicing, translation, stability, and degradation, which are regulated by "writers," "erasers" and "readers." In GI tumors, resistance to chemotherapy, targeted therapy, and immunotherapy is closely associated with m6A RNA modification. Therefore, the molecular mechanism of m6A modification and its targeted drug development provide new therapeutic strategies for overcoming drug resistance and therapeutic efficacy in GI tumors. In this review, the biological functions of m6A were explored, the specific resistance mechanisms of m6A in different types of GI tumors were explored, new ideas and targets for future treatment resistance were identified, and the limitations of this field were highlighted.

m6A-Mediated TMCO3 Promotes Hepatocellular Carcinoma Progression by Facilitating the Membrane Translocation and Activation of AKT

The transmembrane and coiled-coil domains 3 (TMCO3) are highly expressed in many tumors. However, the underlying mechanisms governing the way in which TMCO3 affects the progression of hepatocellular carcinoma (HCC) remain unclear. This study screens out the molecule TMCO3 with high N6-methyladenosine (m6A) modification level in tumor samples compared to the adjacent non-cancerous tissues of three pairs of HCC patients through Methylated RNA Immunoprecipitation Sequencing (MeRIP-seq) and RNA sequencing (RNA-seq). Subsequently, the oncogenic effect of TMCO3 in HCC is verified through in vivo and in vitro experiments. AlkB Homolog 5 (ALKBH5), an m6A demethylase of TMCO3 is then screened out. The following experiments demonstrate that TMCO3 can activate AKT directly through the Phosphatidylinositol-3-Kinase (PI3K) pathway, thus promoting the progression of HCC. Meanwhile, the phosphorylation site on TMCO3: the 85th amino acid-serine, and mutation of this site can directly impair the activity and membrane translocation of AKT is found. Finally, the carcinogenic effect of TMCO3 is further elucidated in HCC through the orthotopic treatment model and the hydrodynamic tail vein injection treatment model. The findings can provide a potential target for targeted AKT treatment in patients with HCC and verify a possible prognostic marker in HCC.

The landscape of N6-methyladenosine in localized primary prostate cancer

N6-methyladenosine (m6A), the most abundant internal RNA modification in humans, regulates most aspects of RNA processing. Prostate cancer is characterized by widespread transcriptomic dysregulation; therefore, we characterized the m6A landscape of 162 localized prostate tumors with matched DNA, RNA and protein profiling. m6A abundance varied dramatically across tumors, with global patterns emerging via complex germline-somatic cooperative regulation. Individual germline polymorphisms regulated m6A abundance, cooperating with somatic mutation of cancer driver genes and m6A regulators. The resulting complex patterns were associated with prognostic clinical features and established the biomarker potential of global and locus-specific m6A patterns. Tumor hypoxia dysregulates m6A profiles, bridging prior genomic and proteomic observations. Specific m6A sites, such as those in VCAN, drive disease aggression, associating with poor outcomes, tumor growth and metastasis. m6A dysregulation is thus associated with key events in the natural history of prostate cancer: germline risk, microenvironmental dysregulation, somatic mutation and metastasis.

ABCF1-K430-Lactylation promotes HCC malignant progression via transcriptional activation of HIF1 signaling pathway

Lysine lactylation plays critical roles in various diseases, including cancer. Our previous study showed that lactylation of non-histone ABCF1 may be involved in hepatocellular carcinoma (HCC) progression. In this study, we evaluated the prognostic value of ABCF1-K430la in HCC using immunohistochemical staining and performed amino acid point mutations, multi-omics crossover, and biochemical experiments to investigate its biological role and underlying mechanism. Additionally, we performed molecular docking on lactylation sites. ABCF1-K430la was highly expressed in HCC tissues and correlated with poor patient prognosis. Functionally, ABCF1-K430la promoted HCC growth and lung metastasis. Mechanistically, upon lactylation, E2 ubiquitin ligase activity of ABCF1 remained unaffected, and ABCF1 entered the nucleus, bound to the KDM3A promoter to upregulate its expression, and activated the KDM3A-H3K9me2-HIF1A axis, challenging the notion that ABCF1 functions exclusively in cytoplasmic protein translation. Notably, we discovered the existence of a lactate-ABCF1(430Kla)-HIF1A-lactate in HCC. A small-molecule drug screen targeting ABCF1-K430la revealed that tubuloside A inhibits ABCF1-K430la and suppresses HCC development. These findings demonstrate that elevated ABCF1-K430la expression promotes HCC development, suggesting it as a potential prognostic biomarker and therapeutic target for HCC.

PCIF1 drives oesophageal squamous cell carcinoma progression via m6Am-mediated suppression of MTF2 translation

Oesophageal squamous cell carcinoma (OSCC) represents a highly aggressive malignancy with limited therapeutic options and poor prognosis. This study uncovers PCIF1 as a critical driver of OSCC progression via m6Am RNA modification, leading to translational repression of the tumour suppressor MTF2. Our results demonstrate that PCIF1 selectively suppresses MTF2 translation, activating oncogenic pathways that promote OSCC growth. In vitro and in vivo models confirm that PCIF1 knockdown reduces OSCC progression, whereas MTF2 knockdown counteracts this effect, highlighting the importance of the PCIF1-MTF2 axis. Clinical analyses further reveal that high PCIF1 expression and low MTF2 expression correlate with advanced tumour stage, poor treatment response and decreased overall survival. Furthermore, in a preclinical mouse model, PCIF1 knockout enhanced the efficacy of anti-PD1 immunotherapy, reducing tumour burden and improving histological outcomes. Notably, flow cytometry analysis indicated that PCIF1 primarily exerts its effects through tumour-intrinsic mechanisms rather than direct modulation of the immune microenvironment, distinguishing its mode of action from PD1 blockade. These findings establish PCIF1 and MTF2 as promising prognostic markers and therapeutic targets for OSCC, offering new avenues for treatment strategies and patient stratification. KEY POINTS: PCIF1 promotes OSCC progression via m6Am methylation at the MTF2 mRNA 5' cap. m6Am methylation suppresses MTF2 translation, enhancing tumour cell proliferation and invasion. Targeting PCIF1 holds therapeutic potential for OSCC treatment.

METTL3/IGF2BP1 promotes the development of triple-negative breast cancer by mediating m6A methylation modification of PRMT7

BACKGROUND

PRMT7 is upregulated in breast cancer and promotes tumor metastasis. Here we aimed to explore the function and mechanism of PRMT7 in triple-negative breast cancer (TNBC).

METHODS

The expression of PRMT7, METTL3 and IGF2BP1 was detected by immunohistochemistry (IHC), qRT-PCR and western blot. Cell viability and proliferation were measured using MTT and EdU assay. Flow cytometry and TUNEL assays were used to evaluate apoptosis. Invasion and migration were assessed by transwell and wound healing assays, respectively. Glucose consumption and lactate production were measured to assess glycolysis. In addition, the interaction between METTL3 and PRMT was verified by methylated RNA immunoprecipitation. The roles of METTL3 and PRMT in vivo were investigated through a xenograft model.

RESULTS

PRMT7 was upregulated in TNBC tissues and cells, and the knockdown of PRMT7 inhibited cell proliferation, invasion, migration and glycolysis, but induced apoptosis in TNBC cells. METTL3/IGF2BP1 enhanced PRMT7 expression by mediating the m6A methylation modification of PRMT7. Besides, METTL3 knockdown suppressed the progression of TNBC cells and regulated the WNT/β-catenin pathway via PRMT7. Moreover, silencing METTL3 restrained TNBC tumor growth in vivo through regulating PRMT7.

CONCLUSION

METTL3/IGF2BP1 facilitates the progression of TNBC by mediating m6A methylation modification of PRMT7.

Mechanistic study of METTL3 inducing ferroptosis to promote cervical cancer progression through mediating m6A modification of COTE-1

Cervical Cancer (CC) is one of the leading causes of tumor-related deaths among women worldwide, and the mechanisms underlying the anti-ferroptosis of CC cells are still unclear. Methyltransferase like 3 (METTL3) is widely expressed various types of tissues and plays a crucial role in tumorigenesis in part by mediating cell death. However, its regulatory function in CC progression and especially the underlying mechanisms have not been fully elucidated. This study aims to explore the role of METTL3 in the ferroptosis of CC cells. Mechanistically, by MeRIP-seq, we identified COTE-1 as a target of METTL3 mediated m6A modification, and revealed that METTL3-mediated COTE-1 expression was dependent on the m6A reader-dependent manner. Functionally, in vitro and in vivo experiments that METTL3 promotes proliferation and metastasis of CC cells by regulating COTE-1 expression. In addition, the study verified the effect of the METTL3/COTE-1 axis on autophagy-dependent ferroptosis. In summary, METTL3 influences CC progression by mediating COTE-1 to influence autophagy-dependent ferroptosis, representing a potential therapeutic approach for treating CC.

NAT10 Promotes Gastric Cancer Liver Metastasis by Modulation of M2 Macrophage Polarization and Metastatic Tumor Cell Hepatic Adhesion

The relationship between patterns of RNA modifications and gastric cancer (GC) liver metastasis (GCLM) remains unclear. Here, by single-cell sequencing, clinical sample analysis, and mouse model studies, an abnormal increase in the expression of the RNA acetyltransferase N-acetyltransferase 10 (NAT10) in liver metastatic GC cells is identified. NAT10-mediated N4-acetylcytidine modification of CXCL2 and KLF5 mRNA increases their stability. Then, secreted CXCL2 is found to promote the infiltration and polarization of M2-like macrophages to produce oncostatin M, which transcriptionally activates NAT10 expression via STAT3 signaling. In addition, organoid models confirm that NAT10 promotes the adhesion of GC cells to hepatocytes. Mechanistically, KLF5 transcriptionally activates ITGαV, facilitating GC cell attachment to hepatocytes. Intriguingly, high expression of NAT10/KLF5 axis is associated with poor prognosis of GC patients and targeting this axis significantly reduces GCLM in preclinical murine models. Collectively, these findings suggest the clinical significance of NAT10 in developing targeted therapies for GC patients with liver metastasis.

Knockdown of SLC7A5 inhibits malignant progression and attenuates oxaliplatin resistance in gastric cancer by suppressing glycolysis

BACKGROUND

Chemotherapy resistance is a major challenge in the treatment of intermediate and advanced gastric cancer (GC). This study aimed to recognize oxaliplatin resistance-related genes (OXARGs) in GC and to explore their role and mechanism in oxaliplatin resistance of GC.

METHODS

OXARGs with prognostic value in GC were analyzed using GC oxaliplatin resistance data from the GEO and TCGA databases. RT-qPCR and WB assay were applied to verify the expression of MT2A, NOTCH1 and SLC7A5 in oxaliplatin-resistant GC cells (HGC27R and MKN45R). The effect of SLC7A5 on the malignant phenotype of oxaliplatin-resistant GC cells was verified by CCK-8, EDU, TUNEL, colony formation, wound healing, transwell assay, tumor bearing experiments and WB assay.

RESULTS

Bioinformatics analysis and experimental validation indicate that SLC7A5 was a target for oxaliplatin-resistance in GC. Knockdown of SLC7A5 obviously decreased the viability, migration, and invasion of oxaliplatin-resistant GC cells in vitro and tumor growth in vivo. It also increased the apoptosis levels and BAX expression, and reduced the expression of BCL2, MMP 2 and MMP9. Additionally, the knockdown of SLC7A5 enhanced the sensitivity of oxaliplatin-resistant GC cells to oxaliplatin both in vitro and in vivo. Furthermore, knockdown of SLC7A5 downregulated the expression of HK2, LDHA, Glut1, and PDK1 both in vivo and in vitro, leading to increased extracellular glucose levels and decreased lactate levels. However, glutathione significantly attenuated the regulatory effect of SLC7A5 knockdown on the malignant phenotype of oxaliplatin-resistant GC cells.

TRIAL REGISTRATION

Not Applicable.

CONCLUSION

Knockdown of SLC7A5 inhibits malignant progression and attenuates oxaliplatin resistance in GC by suppressing glycolysis.

Targeting NAT10 attenuates homologous recombination via destabilizing DNA:RNA hybrids and overcomes PARP inhibitor resistance in cancers

AIMS

RNA metabolism has been extensively studied in DNA double-strand break (DSB) repair. The RNA acetyltransferase N-acetyltransferase 10 (NAT10)-mediated N4-acetylcytidine (ac4C) modification in DSB repair remains largely elusive. In this study, we aim to decipher the role for ac4C modification by NAT10 in DSB repair in hepatocellular carcinoma (HCC).

METHODS

Laser micro-irradiation and chromatin immunoprecipitation (ChIP) were used to assess the accumulation of ac4C modification and NAT10 at DSB sites. Cryo-electron microscopy (cryo-EM) was used to determine the structures of NAT10 in complex with its inhibitor, remodelin. Hepatocyte-specific deletion of NAT10 mouse models were adopted to detect the effects of NAT10 on HCC progression. Subcutaneous xenograft, human HCC organoid and patient-derived xenograft (PDX) model were exploited to determine the therapy efficiency of the combination of a poly (ADP-ribose) polymerase 1 (PARP1) inhibitor (PARPi) and remodelin.

RESULTS

NAT10 promptly accumulates at DSB sites, where it executes ac4C modification on RNAs at DNA:RNA hybrids dependent on PARP1. This in turn enhances the stability of DNA:RNA hybrids and promotes homologous recombination (HR) repair. The ablation of NAT10 curtails HCC progression. Furthermore, the cryo-EM yields a remarkable 2.9 angstroms resolution structure of NAT10-remodelin, showcasing a C2 symmetric architecture. Remodelin treatment significantly enhanced the sensitivity of HCC cells to a PARPi and targeting NAT10 also restored sensitivity to a PARPi in ovarian and breast cancer cells that had developed resistance.

CONCLUSION

Our study elucidated the mechanism of NAT10-mediated ac4C modification in DSB repair, revealing that targeting NAT10 confers synthetic lethality to PARP inhibition in HCC. Our findings suggest that co-inhibition of NAT10 and PARP1 is an effective novel therapeutic strategy for patients with HCC and have the potential to overcome PARPi resistance.

The N6-methyladenosine reader IGF2BP3 promotes bladder cancer progression through enhancing HSP90AB1 expression

N6-methyladenosine (m6A) is the most abundant RNA modification in mammalian cells, and has emerged as an important player in tumour development through post-transcriptional gene regulation. In this study, we found that the m6A reader protein IGF2BP3 was the most upregulated m6A modifier in bladder cancer through the proteomic analysis of 17 pairs of human bladder cancer tissues and adjacent normal bladder tissues, for which the expression was also positively correlated with higher tumour stage and poorer prognosis. In vitro and in vivo assays demonstrated the powerful oncogenic function of IGF2BP3 in bladder cancer. Further combined analyses of RNA-sequencing, m6A-sequencing, and RIP (RNA Binding Protein Immunoprecipitation)-sequencing, as well as site-directed mutagenesis assays and RIP-qPCR identified m6A-tagged HSP90AB1 mRNA as a direct target of IGF2BP3. Mechanistically, through in vitro and in vivo assays, as well as clinical sample analysis, we demonstrated that IGF2BP3 modulated the expression of HSP90AB1 in an m6A modification-dependent manner, thus activating the PI3K/AKT-signaling pathway, and promoting the development of bladder cancer. Collectively, our study highlights the critical role of the IGF2BP3-HSP90AB1-signaling axis in bladder cancer progression, which may serve as a promising therapeutic approach for bladder cancer.

M6A-modified BFSP1 induces aerobic glycolysis to promote liver cancer growth and metastasis through upregulating tropomodulin 4

RNA N6-methyladenosine (m6A) is a common RNA modification in eukaryotes, and its abnormal regulation is closely related to cancer progression. Aerobic glycolysis is a main way for cancer cells to obtain energy. It was found that beaded filament structural protein 1 (BFSP1) is a m6A related gene in liver cancer. However, the effect of m6A-modified BFSP1 on aerobic glycolysis and how it is regulated in liver cancer progression have not been explored. Here, we found that BFSP1 was upregulated in liver cancer cells and tissues. Overexpression of BFSP1 promoted the viability, invasion, and aerobic glycolysis of liver cancer cells, whereas knockdown of BFSP1 showed the opposite effects. Co-immunoprecipitation, immunofluorescence and GST pull down analyses showed that BFSP1 directly interacted with tropomodalin 4 (TMOD4), and knockdown of TMOD4 reversed BFSP1 overexpression-induced malignant phenotypes and aerobic glycolysis in liver cancer cells. Moreover, methyltransferase-like 3 (METTL3) enhanced BFSP1 stability by augmenting m6A modification of BFSP1 mRNA, which is achieved in a YTHDF1-dependent manner. In vivo experiments in mice confirmed that METTL3 increased BFSP1 stability by promoting m6A modification of BFSP1 mRNA, and knockdown of BFSP1 inhibited tumor growth and metastasis. In summary, METTL3-mediated m6A methylation of BFSP1 mRNA plays an important role in the aerobic glycolysis and progression of liver cancer, providing a potential therapeutic strategy for liver cancer.

Targeting m6A RNA Modification in Tumor Therapeutics

The prevalent eukaryotic RNA modification N6-methyladenosine (m6A), which is distributed in more than 50% of cases, has demonstrated significant implications in both normal development and disease progression, particularly in the context of cancer. This review aims to discuss the potential efficacy of targeting tumor cells through modulation of m6A RNA levels. Specifically, we discuss how the upregulation or downregulation of integral or specific targets is effective in treating different tumor types and patients. Additionally, we will cover the factors influencing the efficacy of m6A RNA targeting in tumor treatment. Our review will focus on the impact of targeting m6A mRNA on genes and cells and assess its potential as a therapeutic strategy for tumors. Despite the challenges involved, further research on m6A RNA in tumors and its integration with existing tumor therapy approaches is warranted.

MCT4: a key player influencing gastric cancer metastasis and participating in the regulation of the metastatic immune microenvironment

BACKGROUND

MCT4 is a lactate transporter associated with glycolysis, which has been found to be associated with various tumorigenesis and development processes. Gastric cancer is a malignant disease with high incidence and mortality. The role of MCT4 in the occurrence and development of gastric cancer has not been clarified.

METHODS

In this study, we comprehensively utilized single-cell sequencing and external transcriptome sequencing databases to deeply analyze the mechanism of the impact of MCT4 on gastric cancer and its microenvironment. We verified the function of MCT4 in gastric cancer through in vitro cell line experiments and in vivo experiments using gastric cancer liver metastasis and subcutaneous tumor models. Meanwhile, we collected tumor and normal tissue samples from clinical gastric cancer patients and employed immunohistochemistry and multiplex immunofluorescence techniques to detect the expression and localization of relevant indicators, thereby validating the results of computer simulation analysis and providing a basis for revealing the internal relationship between MCT4 and gastric cancer.

RESULTS

The expression of MCT4 is upregulated in gastric cancer patients, and the upregulation is more significant than that in patients with gastric cancer metastasis. MCT4 can mediate the proliferation and migration of gastric cancer cells in vitro. MCT4 can mediate the metastasis of gastric cancer cells in vivo. Multi-omics analysis showed that the expression of MCT4 was related to the composition of the immune microenvironment, and it could mediate the emergence of the inhibitory immune microenvironment. The results of immunofluorescence and immunohistochemistry proved the robustness of the multi-omics analysis.

CONCLUSION

Our study found that MCT4 plays an important role in the occurrence and development of gastric cancer, which may mediate the occurrence of gastric cancer metastasis and shape the immunosuppressive tumor microenvironment.

MAZ-mediated N6-methyladenosine modification of ZEB1 promotes hepatocellular carcinoma progression by regulating METTL3

BACKGROUND

Hepatocellular carcinoma (HCC) has a hidden onset and high malignancy. Its high metastasis, high recurrence, and short survival time have always been a difficult and hot spot in clinical practice. Our previous study revealed that myc-associated zinc finger protein (MAZ) is highly upregulated in HCC tissues and may promote the proliferation and metastasis of HCC cells by inducing the epithelial-mesenchymal transformation (EMT) process. However, the specific regulatory mechanism by which MAZ functions as an oncogene in HCC has still not been fully elucidated.

METHODS

Immunohistochemical staining and bioinformatics analyses were conducted to measure the expression of MAZ, key m6A enzymes, and ZEB1 in HCC tissues. RNA sequencing (RNA-seq) of MAZ knockdown HCC cells and human mRNA m6A sequencing (m6A-seq) of HCC tissues were intersected to screen the downstream targets for both MAZ and m6A methylation. The correlations between MAZ and its targets were analyzed by dual-luciferase assays and cell rescue experiments.

RESULTS

Here, we report for the first time that MAZ is involved in m6A methylation of HCC by targeting the transcriptional regulation of key m6A enzymes. MAZ expression was significantly correlated with the expression of key m6A enzymes in HCC tissues and cell lines. Moreover, MAZ could bind to the promoters of key m6A enzymes, and multivariate Cox regression analysis suggested that MAZ and METTL3 expression were independent risk factors for the survival of HCC patients. Through RNA-seq and m6A-seq, we screened out EMT regulators ZEB1 and TRIM50 as the downstream targets for both MAZ and m6A methylation. Mechanistically, m6A sites with high confidence in ZEB1 and TRIM50 mRNA were identified by SRAMP, and there were significant relationships between ZEB1 and METTL3 in HCC tissues and cells. A nomogram model was established to better display the combined effect of MAZ, METTL3, and ZEB1 on HCC prognosis.

CONCLUSIONS

Our study revealed a promising clinical application of MAZ, METTL3, and ZEB1 in HCC prognosis, further suggesting that MAZ can be used as a potential molecular biomarker for HCC diagnosis and prognosis.

METTL3-Mediated m6A Methylation Stabilizes IFI27 to Drive Esophageal Squamous Cell Carcinoma Progression Through an IGF2BP2-Dependent Mechanism

Dysregulation of m6A modification has emerged as a vital factor in the development of esophageal squamous cell carcinoma (ESCC). Here, we sought to explore the critical role of m6A methylation mediated by the m6A methyltransferase METTL3 in ESCC. Protein expression analysis was performed by immunohistochemistry and immunoblot assays. The mRNA levels of METTL3 and IFI27 were detected by quantitative PCR. Cell sphere formation potential, migration, invasiveness, apoptosis, proliferation and viability were assessed by standard sphere formation, wound healing, transwell, flow cytometry, EdU and CCK-8 assays, respectively. The impact of METTL3 or IGF2BP2 on IFI27 mRNA was evaluated by methylated RNA immunoprecipitation (MeRIP), RIP or mRNA stability analysis. Xenograft assays were used to detect the in vivo function of METTL3. Elevated levels of METTL3 were observed in ESCC tumors and cells, and these increased levels were associated with the declined prognosis of ESCC. MELLT3 depletion impeded ESCC cell growth, invasiveness, migration, and sphere formation, and induced cell apoptosis in vitro. Elevated IFI27 expression was positively correlated with METTL3 levels in ESCC. Moreover, METTL3 mediated m6A methylation of IFI27 mRNA to stabilize the mRNA. The m6A reader IGF2BP2 also affected m6A methylation and expression of IFI27 mRNA. Additionally, IFI27 re-expression had a counteracting impact on the effects of METTL3 deficiency on in vitro ESCC cell behaviors and in vivo KYSE30 xenograft growth. Our findings demonstrate that METTL3-mediated IFI27 mRNA m6A methylation drives ESCC development through an IGF2BP2-dependent mechanism. Blocking the METTL3/IFI27 axis may be effective for preventing ESCC.

RNA methylation homeostasis in ocular diseases: All eyes on Me

RNA methylation is a pivotal epigenetic modification that adjusts various aspects of RNA biology, including nuclear transport, stability, and the efficiency of translation for specific RNA candidates. The methylation of RNA involves the addition of methyl groups to specific bases and can occur at different sites, resulting in distinct forms, such as N6-methyladenosine (m6A), N1-methyladenosine (m1A), 5-methylcytosine (m5C), and 7-methylguanosine (m7G). Maintaining an optimal equilibrium of RNA methylation is crucial for fundamental cellular activities such as cell survival, proliferation, and migration. The balance of RNA methylation is linked to various pathophysiological conditions, including senescence, cancer development, stress responses, and blood vessel formation, all of which are pivotal for comprehending a spectrum of eye diseases. Recent findings have highlighted the significant role of diverse RNA methylation patterns in ophthalmological conditions such as age-related macular degeneration, diabetic retinopathy, cataracts, glaucoma, uveitis, retinoblastoma, uveal melanoma, thyroid eye disease, and myopia, which are critical for vision health. This thorough review endeavors to dissect the influence of RNA methylation on common and vision-impairing ocular disorders. It explores the nuanced roles that RNA methylation plays in key pathophysiological mechanisms, such as oxidative stress and angiogenesis, which are integral to the onset and progression of these diseases. By synthesizing the latest research, this review offers valuable insights into how RNA methylation could be harnessed for therapeutic interventions in the field of ophthalmology.

HDGF Knockout Suppresses Colorectal Cancer Progression and Drug Resistance by Modulating the DNA Damage Response

Colorectal cancer (CRC) is a highly heterogeneous gastrointestinal malignancy. Despite significant advances in molecular targeted therapies for CRC in recent years, the increase in the overall survival rates for CRC patients remains limited. Therefore, there is an urgent need to explore novel drug targets. Herein, we show that heparin binding growth factor (HDGF) is highly expressed in CRC, and that its overexpression is associated with a poor disease-free interval. Additionally, we reveal that HDGF knockout reduces proliferation, migration, and invasion, while enhancing apoptosis in CRC cells, thereby validating HDGF as a potential therapeutic target for CRC. Mechanistically, we found that HDGF modulates DNA damage response and, by recruiting C-terminal binding protein-interacting protein (CtIP), it facilitates homologous recombination repair to influence CRC drug sensitivity. Furthermore, we propose that HDGF may serve as a recognition protein for H3K36me3, participating in the repair of damaged transcriptionally active genes, thus maintaining genomic stability in CRC.

Exploring m6A modifications in gastric cancer: from molecular mechanisms to clinical applications

The significance of m6A modifications in several biological processes has been increasingly recognized, particularly in the context of cancer. For instance, m6A modifications in gastric cancer (GC) have been significantly implicated in tumor progression, metastasis, and treatment resistance. GC is characterized by the differential expression of m6A regulators. High expression writers such as METTL3 and WTAP are associated with poor prognosis and aggressive clinical features. Conversely, low expression of METTL14 is linked to worse clinical outcomes, whereas elevated levels of demethylases, such as FTO and ALKBH5, correlate with better survival rates. These m6A regulators influence several cellular biological functions, including proliferation, invasion, migration, glycolysis, and chemotherapy resistance, thereby affecting tumor growth and therapeutic outcomes. The assessment of m6A modification patterns and the expression profiles of m6A-related genes hold substantial potential for improving the clinical diagnosis and treatment of GC. In this review, we provide an updated and comprehensive summary of the role of m6A modifications in GC, emphasizing their molecular mechanisms, clinical significance, and translational applications in developing novel diagnostic and therapeutic strategies.

Deciphering the secret codes in N7-methylguanosine modification: Context-dependent function of methyltransferase-like 1 in human diseases

N7-methylguanosine (m7G) is one of the most prevalent post-transcriptional modifications of RNA and plays a critical role in RNA translation and stability. As a pivotal m7G regulator, methyltransferase-like 1 (METTL1) is responsible for methyl group transfer during the progression of m7G modification and contributes to the structure and functional regulation of RNA. Accumulating evidence in recent years has revealed that METTL1 plays key roles in various diseases depending on its m7G RNA methyltransferase activity. Elevated levels of METTL1 are typically associated with disease development and adverse consequences. In contrast, METTL1 may act as a disease suppressor in several disorders. While the roles of m7G modifications in disease have been extensively reviewed, the critical functions of METTL1 in various types of disease and the potential targeting of METTL1 for disease treatment have not yet been highlighted. This review describes the various biological functions of METTL1, summarises recent advances in understanding its pathogenic and disease-suppressive functions and discusses the underlying molecular mechanisms. Given that METTL1 can promote or inhibit disease processes, the possibility of applying METTL1 inhibitors and agonists is further discussed, with the goal of providing novel insights for future disease diagnosis and potential intervention targets. KEY POINTS: METTL1-mediated m7G modification is crucial for various biological processes, including RNA stability, maturation and translation. METTL1 has emerged as a critical epigenetic modulator in human illnesses, with its dysregulated expression correlating with multiple diseases progression and presenting opportunities for both diagnostic biomarker development and molecular-targeted therapy. Enormous knowledge gaps persist regarding context-dependent regulatory networks of METTL1 and dynamic m7G modification patterns, necessitating mechanistic interrogation to bridge basic research with clinical translation in precision medicine.

METTL3-mediated NFAT5 Upregulation Promotes Cervical Cancer Progression Through Enhancing the Mitochondrial Function by Transcriptional Regulation of PRDX1

Nuclear factor of activated T-cells 5 (NFAT5) is recognized as an oncogene in a variety of tumors. However, the role of NFAT5 in cervical cancer (CC) cell phenotypic alterations remains to be elucidated. Here, we demonstrated that NFAT5 expression was elevated in CC samples and cells using quantitative real-time reverse transcription PCR, Western blot analysis, and immunohistochemistry assays, and high NFAT5 expression showed a poor prognosis. After C-33A cells were transfected with pcDNA-NFAT5 or NFAT5-short hairpin RNA (shRNA), cell proliferation, invasion, and apoptosis were evaluated using CCK-8 and EdU assays, transwell assays, and flow cytometry, respectively. Biomarkers indicating mitochondrial function, including the expression of the d-loop, ATP levels, and mitochondrial membrane potential, were detected. NFAT5 knockdown restrained cell proliferation and invasion, impaired mitochondrial function, and increased the ratio of cell apoptosis; however, NFAT5 overexpression showed the opposite results. RNA immunoprecipitation (RIP) and methylated RIP (MeRIP) assays were performed to identify interactions among NFAT5, methyltransferase-like 3 (METTL3), and insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3). Chromatin immunoprecipitation and dual-luciferase reporter gene assays demonstrated that NFAT5 binds to the peroxiredoxin 1 (PRDX1) promoter to drive PRDX1 transcription. METTL3 enhanced NFAT5 mRNA stability through IGF2BP3-mediated N6-Methyladenosine (m6A) modification, and NFAT5 transcriptionally regulated PRDX1 expression. Moreover, the reintroduction of METTL3 or PRDX1 promoted cell growth and mitochondrial function damage in NFAT5-silenced cells. In vivo experiments further demonstrated that NFAT5 promotes CC tumor growth. Taken together, NFAT5 upregulation mediated by the METTL3/IGF2BP3 complex in an m6A-dependent manner facilitates CC cell growth by transcriptionally regulating PRDX1 expression, providing a novel target for CC therapy.

Comprehensive analysis of ceRNA Networks in UCEC: Prognostic and therapeutic implications

Endometrial cancer (UCEC) is the most prevalent gynecological malignancy in high-income countries, and its incidence is rising globally. Although early-stage UCEC can be treated with surgery, advanced cases have a poor prognosis, highlighting the need for effective molecular biomarkers to improve diagnosis and prognosis. In this study, we analyzed mRNA and miRNA sequencing data from UCEC tissues and adjacent non-cancerous tissues from the TCGA database. Differential expression analysis was conducted using the DESeq2 package, identifying differentially expressed lncRNAs, miRNAs, and mRNAs (DElncRNAs, DEmiRNAs, and DEmRNAs). Key molecules were screened using LASSO regression, and a ceRNA network was constructed by predicting lncRNA-miRNA and miRNA-mRNA interaction, which were visualized with Cytoscape. Functional enrichment analysis elucidated the roles and mechanisms of the network. The prognostic potential of the identified RNAs was assessed through survival and Cox regression analyses, while methylation and immune infiltration analyses explored regulatory mechanisms and immune interactions. We identified a prognostic lncRNA-miRNA-mRNA ceRNA network in UCEC, centered on the CDKN2B-AS1-hsa-miR-497-5p-IGF2BP3 axis. Survival analyses confirmed the prognostic significance of this network, with univariate Cox regression demonstrating a strong association between its aberrant expression and overall prognosis in UCEC. However, multivariate Cox regression suggested that other clinical factors may modulate this relationship. Methylation analysis revealed low methylation levels of IGF2BP3, possibly contributing to its overexpression. Furthermore, immune infiltration studies highlighted significant correlations between CDKN2B-AS1, IGF2BP3, and multiple immune cell types, suggesting that this axis regulates the tumor immune microenvironment. These findings suggest that the CDKN2B-AS1-hsa-miR-497-5p-IGF2BP3 axis is a key regulatory element in UCEC and a potential therapeutic target.

Semaphorin-4D signaling in recruiting dental stem cells for vascular stabilization

BACKGROUND

Achieving a stable vasculature is crucial for tissue regeneration. Endothelial cells initiate vascular morphogenesis, followed by mural cells that stabilize new vessels. This study investigated the in vivo effects of Sema4D-Plexin-B1 signaling on stem cells from human exfoliated deciduous teeth (SHED)-supported angiogenesis, focusing on its mechanism in PDGF-BB secretion. We also explored macrophages as an endogenous source of Sema4D for vascular stabilization.

METHODS

The in vivo Matrigel plug angiogenesis assay was conducted to examine the impact of Sema4D on vessel formation and stabilization supported by SHED. Knockdown of Plexin-B1 in human umbilical vein endothelial cells (HUVECs) and PDGFR-β inhibitors were utilized to explore the fundamental regulatory mechanisms. Furthermore, the m6A methylation levels of total RNA and the expression of Methyltransferase-like 3 (METTL3) were assessed under conditions of Sema4D treatment in vitro. An ELISA was employed to measure the levels of Sema4D in the supernatants derived from THP-1 cell-mediated macrophages. Additionally, a three-dimensional vasculature-on-a-chip microfluidic device was used to investigate the role of M2c macrophage-derived Sema4D in the stabilization of vascular structures.

RESULTS

Sema4D induced the formation of a greater number of perfused vessels by HUVECs and enhanced the coverage of these vessels by SM22α-positive SHED (SM22α+SHED). Conversely, the knockdown of the Plexin-B1 receptor in HUVECs or inhibition of PDGFR-β reversed the Sema4D-induced vascular stabilization, thereby confirming the regulatory role of the Plexin-B1/PDGF-BB axis in the recruitment of mural cells mediated by Sema4D. Mechanistically, Sema4D was found to upregulate the expression of methyltransferases, specifically METTL3, and to elevate the level of m6A modification in HUVECs. This modification was determined to be critical for enhancing PDGF-BB secretion, suggesting that Sema4D activates an epigenetic regulatory mechanism. Additionally, we investigated the secretion of Sema4D by various macrophage phenotypes, identifying that M2c macrophages secrete significant levels of Sema4D. This secretion recruited SM22α+SHED as mural cells by inducing endothelial PDGF production on a vasculature-on-a-chip platform, indicating a potential role for macrophages in facilitating vascular stabilization.

CONCLUSIONS

Sema4D acts on Plexin-B1, inducing METTL3-mediated PDGF-BB secretion to recruit SHED to stabilize vessels. Macrophages could be a key source of Sema4D for vascular stabilization.

3-Acetyldeoxynivalenol induces pyroptosis in leydig cells via METTL3-mediated N6-methyladenosine modification of NLRP3

3-acetyldeoxynivalenol (3-ADON), an acetylated derivative of deoxynivalenol, is a prevalent contaminant found in food products contaminated with mycotoxins. While the toxicological effects of 3-ADON on human and animal health are well-documented, its specific impact on the reproductive system remains underexplored. In this study, we comprehensively examined the toxicological effects of 3-ADON on TM3 Leydig cells through both in vivo and in vitro experimental models. Our results demonstrate that 3-ADON exposure leads to substantial testicular damage in vivo and significantly reduces cell viability while increasing mortality in TM3 cells in vitro (P = 0.012). Mechanistic investigations further revealed that 3-ADON exposure triggers pyroptosis in TM3 cells, as evidenced by upregulation of NLRP3, activation of caspase-1, ASC, and GSDMD. Moreover, 3-ADON treatment resulted in a significant upregulation of METTL3 expression and increased global mRNA m6A modification levels. m6A sequencing and functional assays established that METTL3-mediated m6A modification of NLRP3 mRNA enhances its stability and expression. RNA immunoprecipitation (RIP) assays further demonstrated that IGF2BP1 selectively recognizes m6A-modified NLRP3 mRNA, contributing to its stabilization. Notably, IGF2BP1 was found to inhibit the recruitment of the BTG2/CCR4-NOT complex by competitively binding to PABPC1, thereby preventing the deadenylation of NLRP3 mRNA and maintaining its expression. Additionally, we identified that METTL3 also methylates and stabilizes c-MyB mRNA, which subsequently binds to the promoter region of NLRP3, thereby enhancing its transcription. Collectively, our findings reveal a novel mechanism by which 3-ADON exerts its reproductive toxicity, underscoring the pivotal role of METTL3-mediated m6A modifications in regulating Leydig cell dysfunction.

Bola-Amphiphilic Dendrimer Enhances Imatinib to Target Metastatic Ovarian Cancer via β-Catenin-HRP2 Signaling Axis

Ovarian cancer is the leading cause of death among all gynecological malignancies, and drug resistance renders the current chemotherapy agents ineffective for patients with advanced metastatic tumors. We report an effective treatment strategy for targeting metastatic ovarian cancer involving a nanoformulation (Bola/IM)─bola-amphiphilic dendrimer (Bola)-encapsulated imatinib (IM)─to target the critical mediator of ovarian cancer stem cells (CSCs) CD117 (c-Kit). Bola/IM offered significantly more effective targeting of CSCs compared to IM alone, through a novel and tumor-specific β-catenin/HRP2 axis, allowing potent inhibition of cancer cell survival, stemness, and metastasis in metastatic and drug-resistant ovarian cancer cells. Promising results were also obtained in clinically relevant patient-derived ascites and organoids alongside high tumor-oriented accumulation and favorable pharmacokinetic properties in mouse models. Furthermore, Bola/IM displayed synergistic anticancer activity when combined with the first-line chemotherapeutic drug cisplatin in patient-derived xenograft mouse models without any adverse effects. Our findings support the use of Bola/IM as a nanoformulation to empower IM, providing targeted and potent treatment of metastatic ovarian cancer. Our study thus represents a significant advancement toward addressing the unmet medical need for improved therapies targeting this challenging disease.

m6A methylation modification: Potential pathways to suppress osteosarcoma metastasis

Osteosarcoma is a highly aggressive malignant bone tumor prone to metastasis, and its metastatic process is one of the main reasons for treatment failure and poor prognosis. Recent studies have demonstrated that modification of m6A methylation plays an important role in osteosarcoma metastasis, influencing both invasion and metastasis through various signaling pathways. Therefore, clarification of the specific effects of m6A methylation modification in osteosarcoma may reveal ways to improve the prognosis of osteosarcoma patients. The roles of various components involved in the m6A methylation modification process in osteosarcoma have been investigated, with studies focusing more on their effects than on their mechanisms. In this review, we focus on the interactions between the "writers," "erasers," and "readers" of m6A methylation and tumor metastasis-related factors to enhance the understanding of osteosarcoma and m6A methylation modification, with the aim of identifying clinical diagnostic biomarkers and potential therapeutic targets for osteosarcoma metastasis.

m6A Reader PRRC2A Promotes Colorectal Cancer Progression via CK1ε-Mediated Activation of WNT and YAP Signaling Pathways

Colorectal cancer (CRC) is the third most common cancer type and the second highest mortality rate among cancers. However, the mechanisms underlying CRC progression remain to be fully understood. In this work, a recently identified m6A-modified RNA reader protein Proline-rich Coiled-coil 2a (PRRC2A) is markedly upregulated in CRC, and intestinal epithelium-specific deletion of Prrc2a significantly suppressed tumor cell growth, stemness, and migratory capacity, while its overexpression promoted these behaviors. Through multiomics analysis, PRRC2A directly targeted CSNK1E (encoding CK1ε), maintaining its RNA stability in an m6A-dependent manner, and that elevated CK1ε can concomitantly result in activation of the WNT and YAP signaling pathways. Interestingly, PRRC2A is directly regulated by the transcription factor ATF1 in its promoter. In summary, the work reveals a novel mechanism by which m6A reader PRRC2A promotes colorectal cancer progression via CK1ε and aberrant upregulation of WNT and YAP signaling. Therefore, PRRC2A and CK1ε can be potential therapeutic targets for treating CRC.

Rapid and direct detection of m6A methylation by DNAzyme-based and smartphone-assisted electrochemical biosensor

m6A methylation detection is crucial for understanding RNA functions, revealing disease mechanisms, guiding drug development and advancing epigenetics research. Nevertheless, high-throughput sequencing and liquid chromatography-based traditional methods still face challenges to rapid and direct detection of m6A methylation. Here we report a DNAzyme-based and smartphone-assisted electrochemical biosensor for rapid detection of m6A. We initially identified m6A methylation-sensitive DNAzyme mutants through site mutation screening. These mutants were then combined with tetrahedral DNA to modify the electrodes, creating a 3D sensing interface. The detection of m6A was accomplished by using DNAzyme to capture and cleave the m6A sequence. The electrochemical biosensor detected the m6A sequence at nanomolar concentrations with a low detection limit of 0.69 nM and a wide detection range from 10 to 104 nM within 60 min. As a proof of concept, the 3'-UTR sequence of rice was selected as the m6A analyte. Combined with a smartphone, our biosensor shows good specificity, sensitivity, and easy-to-perform features, which indicates great prospects in the field of RNA modification detection and epigenetic analysis.

WTAP/IGF2BP3 Mediated m6A Modification of SOD2 mRNA Aggravates the Tumourigenesis of Colorectal Cancer

Wilms tumor 1-associated protein (WTAP) has been validated to be a crucial regulator in the tumorigenesis and advancement of diverse malignancies. This study intended to probe the impacts of WTAP on colorectal cancer (CRC) progression from the perspective of N6-methyladenosine (m6A) modification. The differential expression patterns of WTAP in clinical CRC samples and cultured cell lines were validated via qRT-PCR and western blot. Cell function tests were conducted with colony formation, transwell, and CCK-8. MeRIP-qPCR was conducted to identify the WTAP-mediated SOD2 (Superoxide dismutase 2) mRNA modification in CRC cells. Animal experiments were adopted to evaluate the function of WTAP in vivo. WTAP exhibited high expression pattern in CRC samples along with cells. Silencing of WTAP potently restrained the growth of CRC tumorigenesis in virto and in vivo. Mechanically, SOD2 was identified as an m6A target of WTAP. WTAP-mediated m6A modification of SOD2 mRNA elevated its stability in an IGF2BP3-dependent manner. Meanwhile, SOD2 overexpression could reverse the tumor suppressive effect induced by WTAP silencing. Molecular therapy targeting WTAP-SOD2 may offer novel insights and perspectives for the treatment of CRC.

Engineering a nano-drug delivery system to regulate m6A modification and enhance immunotherapy in gastric cancer

Cancer cell membrane-derived nanoparticle drug delivery system enables precise drug delivery to tumor tissues and is a new effective way to treat solid tumors. The aim of this study is to develop a safe and effective cancer cell membrane-derived nano-delivery system targeting gastric cancer. We previously reported that EPH receptor A2 (EphA2) is an important target for gastric cancer. RNA m6A methyltransferases METTL3 is upregulated in multiple cancers and promotes cancer development by increasing the expression of multiple oncogenes. We design a new nano-delivery system PLGA-STM-TAT: nanoparticles PLGA (poly lactic acid-hydroxyacetic acid) loaded with METTL3 inhibitor STM2457 and cell-penetrating peptide TAT, and then covered with gastric cancer cell membranes equipped with YSA peptides by means of click chemistry, which targeting EphA2. The nanoparticles are specifically enriched in gastric cancer tissues, significantly increased drug accumulation, and inhibited cancer cell proliferation by decreasing key oncogenes c-MYC and BRD4. During drug administration, we found that the expression of the immune checkpoint molecule PD-L1 was suppressed, and the anti-tumor immune effect was enhanced by the nano-delivery system in combination with anti-PD1. This cancer cell membrane-derived nano-delivery system provides a new biological strategy to treat gastric cancer through effective m6A modulation and EphA2 targeting. STATEMENT OF SIGNIFICANCE: M6A modifications have important biological roles, especially in tumors. Targeting highly modified m6A in gastric cancer becomes a challenge. We developed a nano-drug delivery system for modulating m6A that could produce an effective anti-cancer therapeutic effect and that the nanoparticles enhanced antitumor immunity when combined with anti-PD1.This cancer cell membrane-derived new nano-drug delivery system shows great promise as an antitumor approach by modulating m6A modification and targeting EphA2 in gastric cancers.

M6A-mediated molecular patterns and tumor microenvironment infiltration characterization in nasopharyngeal carcinoma

N6-methyladenosine (m6A) is the most predominant RNA epigenetic regulation in eukaryotic cells. Numerous evidence revealed that m6A modification exerts a crucial role in the regulation of tumor microenvironment (TME) cell infiltration in several tumors. Nevertheless, the potential role and mechanism of m6A modification in nasopharyngeal carcinoma (NPC) remains unknown. mRNA expression data and clinical information from GSE102349, and GSE53819 datasets obtained from Gene Expression Omnibus (GEO) was used for differential gene expression and subsequent analysis. Consensus clustering was used to identify m6A-related molecular patterns of 88 NPC samples based on prognostic m6A regulators using Univariate Cox analysis. The TME cell-infiltrating characteristics of each m6A-related subclass were explored using single-sample gene set enrichment (ssGSEA) algorithm and CIBERSORT algotithm. DEGs between two m6A-related subclasses were screened using edgeR package. The prognostic signature and predicated nomogram were constructed based on the m6A-related DEGs. The cell infiltration and expression of prognostic signature in NPC was determined using immunohistochemistry (IHC) analysis. Chi-square test was used to analysis the significance of difference of the categorical variables. And survival analysis was performed using Kaplan-Meier plots and log-rank tests. The NPC samples were divided into two m6A-related subclasses. The TME cell-infiltrating characteristics analyses indicated that cluster 1 is characterized by immune-related and metabolism pathways activation, better response to anit-PD1 and anti-CTLA4 treatment and chemotherapy. And cluster 2 is characterized by stromal activation, low expression of HLA family and immune checkpoints, and a worse response to anti-PD1 and anti-CTLA4 treatment and chemotherapy. Furthermore, we identified 1558 DEGs between two m6A-related subclasses and constructed prognostic signatures to predicate the progression-free survival (PFS) for NPC patients. Compared to non-tumor samples, REEP2, TMSB15A, DSEL, and ID4 were upregulated in NPC samples. High expression of REEP2 and TMSB15A showed poor survival in NPC patients. The interaction between REEP2, TMSB15A, DSEL, ID4, and m6A regulators was detected. Our finding indicated that m6A modification plays an important role in the regulation of TME heterogeneity and complexity.

Patent landscape of small molecule inhibitors of METTL3 (2020-present)

INTRODUCTION

Methyltransferase-like protein 3 (METTL3), in complex with METTL14, is the key 'writer' protein for RNA m6A methylation, accounting for almost all mRNA m6A modifications. Recent studies reveal that METTL3 is implicated in the development and progression of various types of cancers. Targeting METTL3 with small molecule inhibitors represents a promising therapeutic strategy for cancer.

AREAS COVERED

This review provides an overview of the patent literature covering METTL3 inhibitors. A literature search was conducted in SciFinder by using 'METTL3 inhibitor' as a keyword and was refined by narrowing the criteria to patents.

EXPERT OPINION

Efforts to develop METTL3/METTL14 inhibitors have led to the advancement of the drug candidate STC-15 to clinical trials. Preclinical studies of STC-15 show promise in inhibiting tumor growth via direct anti-tumor effects and anti-cancer immune responses. The clinical trial outcomes of STC-15 will shape future METTL3/METTL14 inhibitor development. However, critical questions remain. The role of METTL3/METTL14 in m6A RNA methylation is essential for cellular activity, raising concerns about the potential adverse effects of targeting this complex. Furthermore, depending on the context, METTL3/METTL14 can function as a tumor suppressor. This underscores the need for a deeper understanding of the molecular mechanisms by which RNA modifications regulate cancer.

Multimodal tumor suppression by METTL3 gene knockdown in melanoma and colon cancer cells

METTL3, an m6A methyltransferase, is integral to the regulation of messenger RNA (mRNA) biogenesis, degradation, and translation through the N6-methyladenosine (m6A) modification. Alterations in m6A homeostasis have been implicated in the development, progression, invasion, and metastasis of certain cancers. The present research aims to examine the consequences of METTL3 knockdown using short hairpin RNA (shRNA) on the proliferation and invasive capabilities of human colorectal and melanoma cancer cell lines. A specific shRNA against METTL3 mRNA was designed and inserted into an expression vector. Highly invasive colorectal cancer cell line SW480 and melanoma cell line A375 were cultured and transfected by METTL3-shRNA and scramble-control vectors and kept under culture condition for 2 weeks. The cells were harvested for analysis of gene expression by quantitative polymerase chain reaction (qPCR), invasion assay using three-dimensional (3D) spheroid assay and cell cycle and apoptosis analyses. In the METTL3-shRNA transfected cells, the expression of METTL3, VIM, SNAI1, SNAI2, ZEB1, CDH1, and TGFB1 genes were downregulated significantly compared with the scramble-control transfected cells. Expression of b-catenin, N-cadherin, vimentin, ZEB1, pro- and active MMP2, OCT4A, SOX2, and MYC proteins were also downregulated following METTL3 knockdown. Transfection by METTL3-shRNA reduced proliferation rate of the cells and increased the apoptotic rate significantly. Both migration and invasion rate of the cancer cells transfected with METTL3-shRNA were significantly decreased. These findings highlight the pro-oncogenic function of METTL3 in colorectal and melanoma cancer cells, indicating that inhibiting METTL3 could be a promising approach for tumor suppression across multiple cancer types; nonetheless, further investigation is essential to confirm these observations.