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

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.

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.

FUS and METTL3 collaborate to regulate RNA maturation, preventing unfolded protein response and promoting gastric cancer progression

FUS-mediated alternative splicing and METTL3-regulated RNA methylation play crucial roles in RNA processing. The purpose of this study was to investigate the interactive roles of FUS and METTL3 in gastric cancer (GC) progression. RNA sequencing data were obtained from the TCGA-STAD dataset. Differentially expressed genes (DEGs) were analyzed across groups stratified by the medians of FUS, METTL3, and NEAT1, respectively. Endoplasmic reticulum (ER) stress markers PERK, IRE1, pIRE1, Bip, and CHOP, as well as related apoptosis stress markers PARP, cleaved-PARP, (Cleaved) Caspase 7, and (Cleaved) Caspase 3, were assessed through western blotting. Alternative splicing and N6-methyladenosine (m(6)A) methylation of specific genes were detected with MeRIP-PCR. Finally, in vivo experiments were conducted using nude mice bearing sh-FUS-transfected HGC27 xenograft tumors. FUS and METTL3 expression levels were elevated in GC tissues. A significant overlap of DEGs was observed between the FUS- and METTL3-stratified groups. These overlapping DEGs were predominantly enriched in mRNA processing and protein processing in the ER. ER stress and apoptosis were induced by sh-FUS or sh-METTL3, which was further enhanced by ER stress inducer tunicamycin in both MKN45 and HGC27 cells. Similarly, DEGs for NEAT1 high- and low-expressed groups were enriched in protein processing in the ER and spliceosome. To a lesser extent, ER stress was also induced by sh-NEAT1 and enhanced by tunicamycin in HGC27 cells. Furthermore, sh-FUS or sh-METTL3 influenced alternative splicing and methylation of specific mRNAs, including FUS, NEAT1, PCNA, MCM2, and BIRC5. Tumor progression was inhibited by sh-FUS in mice, and ER stress and apoptosis were induced, which were further enhanced by tunicamycin. FUS and METTL3 collaborate to facilitate RNA maturation. Inhibiting FUS or METTL3 promoted ER stress and apoptosis and inhibited progression in GC.

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.

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.

The role of N6-methyladenosine modification in tumor angiogenesis

Tumor angiogenesis is a characteristics of malignant cancer progression that facilitates cancer cell growth, diffusion and metastasis, and has an indispensable role in cancer development. N6-methyladenosine (m6A) is among the most prevalent internal modifications in eukaryotic RNAs, and has considerable influence on RNA metabolism, including its transcription, splicing, localization, translation, recognition, and degradation. The m6A modification is generated by m6A methyltransferases ("writers"), removed by m6A demethylases ("erasers"), and recognized by m6A-binding proteins ("readers"). There is accumulating evidence that abnormal m6A modification is involved in the pathogenesis of multiple diseases, including cancers, and promotes cancer occurrence, development, and progression through its considerable impact on oncoprotein expression. Furthermore, increasing studies have demonstrated that m6A modification can influence angiogenesis in cancers through multiple pathways to regulate malignant processes. In this review, we elaborate the role of m6A modification in tumor angiogenesis-related molecules and pathways in detail, providing insights into the interactions between m6A and tumor angiogenesis. Moreover, we describe how targeting m6A modification in combination with anti-angiogenesis drugs is expected to be a promising anti-tumor treatment strategy, with potential value for addressing the challenge of drug resistance.

Oncogenic mechanisms of COL10A1 in cancer and clinical challenges (Review)

Collagen type X α1 chain (COL10A1), a gene encoding the α‑1 chain of type X collagen, serves a key role in conferring tensile strength and structural integrity to tissues. Upregulation of COL10A1 expression has been observed in different malignancies, including lung, gastric and pancreatic cancer, and is associated with poor prognosis. The present review provides an updated synthesis of the evolving biological understanding of COL10A1, with a particular focus on its mechanisms of action and regulatory functions within the context of tumorigenesis. For example, it has been established that increased COL10A1 expression promotes cancer progression by activating multiple signaling pathways, including the TGF‑β1/Smad, MEK/ERK and focal adhesion kinase signaling pathways, thereby inducing proliferation, invasion and migration. Additionally, COL10A1 has been demonstrated to induce epithelial‑mesenchymal transition and reshapes the extracellular matrix within tumor tissues. Furthermore, on the basis of methyltransferase‑like 3‑mediated N6‑methyladenosine methylation, COL10A1 intricately regulates the epitranscriptomic machinery, thereby augmenting its oncogenic role. However, although COL10A1 serves a pivotal role in gene transcription and the orchestration of tumor growth, the question of whether COL10A1 would serve as a viable therapeutic target remains a subject of scientific hypothesis requiring rigorous examination. Variables such as distinct tumor microenvironments and treatment associations necessitate further experimental validation. Therefore, a comprehensive assessment and understanding of the functional and mechanistic roles of COL10A1 in cancer may pave the way for the development of innovative cancer treatment strategies.

METTL3-Mediated m6A Modification of FMRP Drives Hepatocellular Carcinoma Progression and Indicates Poor Prognosis

Accumulating studies reveal that m6A RNA methylation plays a critical role in cancer pathogenesis and progression. METTL3 as a m6A methyltransferase acts as an oncogene in multiple malignancies including hepatocellular carcinoma (HCC). However, the role and underlying mechanism by which METTL3 contributes to HCC remains unclear. The association of METTL3 expression with clinicopathological characteristics and prognosis in patients with HCC was assessed by reverse transcription polymerase chain reaction, Western blot, and public TCGA dataset. MTT, colony formation, Transwell assays, and xenograft tumor models were executed to reveal the role of METTL3 in HCC. m6A dot blot, RNA immunoprecipitation (RIP), m6A methylated RIP, and Western blot assays were used to uncover the regulatory mechanism of METTL3 in HCC cells. We found that METTL3 was dramatically upregulated in HCC tissue samples and acted as an independent prognostic factor for poor survival and tumor recurrence in patients with HCC. Silencing of METTL3 repressed cell growth and invasion in vitro and in vivo, but restored expression of METTL3 boosted these effects. Mechanistical investigations revealed that METTL3 could directly interact with FMRP and harbor a positive correlation with FMRP expression. Knockdown of METTL3 reduced FMRP m6A levels as well as its mRNA and protein expression. FMRP overexpression drove cell colony formation and cell invasion and abolished METTL3 knockdown-induced antitumor effects and AKT/mTORC1 signaling inactivation. Elevated expression of FMRP could act as an independent prognostic factor for poor survival and tumor recurrence in patients with HCC. Our findings demonstrate that METTL3-mediated m6A modification of FMRP promotes growth and invasion of HCC cells and may provide a promising therapeutic target for HCC.

METTL3 as a potential therapeutic target in gastric cancer

Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide. N6-methyladenosine (m6A) modification is the most prominent epigenetic modification of eukaryotic mRNAs, and methyltransferase-like 3 (METTL3), a core component of the methyltransferase complex, catalyzes m6A modification. The results of previous studies indicate that the expression level of METTL3 is significantly elevated in gastric cancer tissues and cells. In addition, fluctuations in m6A levels induced by METTL3 are closely associated with the malignant progression of tumors as well as the poor prognosis of patients with gastric cancer. In this review, we focus on the potential mechanism of METTL3 in gastric cancer, and through our analysis, we suggest that targeting METTL3 could be a new therapeutic tool for treating GC.

m6A and beyond: RNA modifications shaping angiogenesis

RNA modifications are crucial post-transcriptional processes that significantly influence gene expression, RNA stability, nuclear transport, and translational capacity. Angiogenesis, the formation of new blood vessels, is a physiological process that is dysregulated in many pathological conditions, including ocular diseases, immune disorders, and cancer. In this review, we compile the current understanding of the intricate relationship between various RNA modifications and angiogenic mechanisms, spotlighting emerging evidence that underscore their pivotal regulatory roles in both physiological and pathological angiogenesis. Furthermore, we delve into recent advances in innovative therapeutic approaches that target RNA modifications to modulate angiogenesis, offering insights into their potential as novel treatment modalities.

Peptide Degrader-Based Targeting of METTL3/14 Improves Immunotherapy Response in Cutaneous Melanoma

METTL3 has emerged as a promising therapeutic target in cancer treatment, although its oncogenic functions in melanoma development and potential for therapeutic targeting drug have not been fully explored. In this study, we define the oncogenic role of METTL3 in melanoma development and progression. Building on this insight, we examine our recently designed peptide inhibitor RM3, which targets the binding interface of METTL3/14 complex for disruption and subsequent ubiquitin-mediated proteasomal degradation via the E3 ligase STUB1. RM3 treatment reduces proliferation, migration, and invasion, and induces apoptosis in melanoma cells in vitro and in vivo. Subsequent transcriptomic analysis identified changes in immuno-related genes following RM3-mediated suppression of METTL3/14 N6-methyladenosine (m6A) methyltransferase activity, suggesting a potential for interaction with immunotherapy. A combination treatment of RM3 with anti-PD-1 antibody results in significantly higher beneficial tumor response in vivo, with a good safety profile. Collectively, these findings not only delineate the oncogenic role of METTL3 in melanoma but also showcase RM3, acting as a peptide degrader, as a novel and promising strategy for melanoma treatment.

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.

m6A regulator-mediated methylation modifications define the immune infiltration characteristics of the tumor microenvironment in prostate adenocarcinoma

Prostate adenocarcinoma (PRAD) persists as the predominant non-cutaneous malignancy diagnosed in males, which is a primary contributor to cancer-related mortality globally. It is reported that the progression of prostate adenocarcinoma is associated with various factors, including genetics, age, obesity, etc. Contemporary research indicates that epigenetic inheritance is a leading factor in the initiation and progression of cancer. RNA methylation modification is the most prevalent form of RNA modification, with N6-methyladenosine (m6A) representing the most common modification on mRNA and lncRNAs. However, the biological mechanisms underpinning this association in prostate adenocarcinoma and its correlation with patients' prognostic survival outcomes remain elusive. Our study elucidates the roles of the tumor microenvironment (TME) and genetic mutations during the initiation and progression of prostate adenocarcinoma. Additionally, we stratify prostate adenocarcinoma into distinct subtypes based on m6A scoring. This approach enhances our comprehension of the functional role of m6A in the development of prostate adenocarcinoma, offering novel insights into the clinical strategies and understanding the biological significance between prostate adenocarcinoma and m6A modification.

KMT2A regulates the autophagy-GATA4 axis through METTL3-mediated m6A modification of ATG4a to promote NPCs senescence and IVDD progression

Intervertebral disc degeneration (IVDD), a disease associated with ageing, is characterised by a notable increase in senescent nucleus pulposus cells (NPCs) as IVDD progresses. However, the specific mechanisms that regulate the senescence of NPCs remain unknown. In this study, we observed impaired autophagy in IVDD-NPCs, which contributed to the upregulation of NPCs senescence and the senescence-associated secretory phenotype (SASP). The dysregulated SASP disrupted NPCs viability and initiated extracellular matrix degradation. Conversely, the restoration of autophagy reversed the senescence phenotype by inhibiting GATA binding protein 4 (GATA4). Moreover, we made the novel observation that a cross-talk between histone H3 lysine 4 trimethylation (H3K4me3) modification and N6-methyladenosine(m6A)-methylated modification regulates autophagy in IVDD-NPCs. Mechanistically, lysine methyltransferase 2A (KMT2A) promoted the expression of methyltransferase-like 3 (METTL3) through H3K4me3 modification, whereas METTL3-mediated m6A modification reduced the expression of autophagy-associated 4a (ATG4a) by attenuating its RNA stability, leading to autophagy damage in NPCs. Silencing KMT2A and METTL3 enhanced autophagic flux and suppressed SASP expression in IVDD-NPCs. Therefore, targeting the H3K4me3-regulated METTL3/ATG4a/GATA4 axis may represent a promising new therapeutic strategy for IVDD.

A novel interaction between RNA m6A methyltransferase METTL3 and RREB1

Regulation of gene expression is achieved through the modulation of regulatory inputs both pre- and post-transcriptionally. Methyltransferase-like 3 (METTL3) is a key player in pre-mRNA processing, actively catalyzing N6-methyladenosine (m6A). Among the most enriched mRNA targets of METTL3 is the Ras Responsive Element Binding Protein 1 (RREB1), a transcription factor which functions to govern cell fate, proliferation and DNA repair. Here, we show a novel interaction between METTL3 and RREB1. Further examination of this interaction indicates that METTL3's N-terminus is the primary interacting domain. Our findings uncover a novel interacting partner of METTL3, providing further insights into METTL3's regulatory network.

Shenqi Qiangjing Granules Ameliorate Asthenozoospermia in Mice by Regulating Ferroptosis through the METTL3/GPX4 Signaling Axis

Asthenozoospermia is a leading cause of male infertility, yet current pharmacotherapies yield suboptimal outcomes, underscoring the urgent need for novel treatment modalities. Herein, we induced asthenozoospermic mouse models using busulfan and investigated the therapeutic effects of Shenqi Qiangjing Granules (SQ) on testicular pathology, serum sex hormone and steroidogenic enzyme levels, and ferroptosis. Furthermore, utilizing GC-1 spg cell lines, we elucidated the role of the METTL3-mediated m6A modification in GPX4 mRNA stability. Treatment with SQ or Fer-1 (an inhibitor of ferroptosis) significantly ameliorated testicular pathological injury, restored abnormal serum sex hormone levels, and enhanced testicular steroidogenic enzyme expression, highlighting the therapeutic potential of targeting ferroptosis in asthenozoospermia. In elucidating the molecular mechanism of METTL3 in ferroptosis, we found that METTL3 regulates GPX4 mRNA stability, subsequently impacting ferroptosis and sperm quality. Knockdown of METTL3 mimicked the effects of SQ treatment, while overexpression of METTL3 partially reversed SQ-mediated effects on ferroptosis and asthenozoospermia, underscoring the pivotal role of METTL3 in SQ therapy. In conclusion, the METTL3-GPX4-ferroptosis axis emerges as a novel regulatory pathway in the pathogenesis of asthenozoospermia. Targeting this axis, particularly through interventions such as SQ treatment, holds promise for the management of male infertility.

METTL3 alters AK3 RNA expression in an m6A-dependent manner to affect the proliferation and metastasis of hepatocellular carcinoma

In recent years, the significance of N6-methyladenosine (m6A) modification in the process of tumorigenesis has garnered substantial attention from researchers in the field. Among the myriad of factors involved, METTL3, which functions as an m6A methyltransferase, has emerged as a critical player in this context. This enzyme has been shown to participate actively in the regulation of RNA stability and expression across a diverse array of tumors. To achieve this, we employed quantitative polymerase chain reaction (qPCR) and Western blot analysis techniques to measure the expression levels of both METTL3 and AK3 in various hepatocellular carcinoma cell lines. We utilized small interfering RNA (siRNA) technology to inhibit the expression of METTL3, subsequently observing the resulting changes in AK3 expression. We analyzed the levels of m6A modification using the MeRIP-Seq method to obtain a comprehensive understanding of the underlying molecular interactions. Through MeRIP-Seq analysis, we discovered that METTL3 directly modulates the stability of AK3, thereby promoting its expression via m6A modification. This finding is pivotal as it underscores the regulatory role that METTL3 plays in AK3 RNA expression, facilitated through the M6A modification pathway.

Leonurine improves atherosclerosis by activating foam cell autophagy and metabolic remodeling via METTL3-mediated AKT1S1 mRNA stability modulation

BACKGROUND

Atherosclerosis (AS) is the most prevalent cardiovascular disease and remains the major contributor to death and mortality globally. Leonurine (LEO) is a unique alkaloid compound with protective effects on the cardiovascular system. However, the exact mechanisms underlying its cardiovascular-protecting action are still not fully elucidated. The methyltransferase 3 (METTL3), the catalytic core of the N6-methyladenosine modification (m6A) methyltransferase complex, has been shown to inhibit autophagy and exacerbate the process of AS via regulation of m6A modification of mRNA.

PURPOSE

We aimed to determine whether the inhibited effect of LEO on AS is related to METTL3-mediated AKT1S1 stability.

METHODS

The apolipoprotein E (ApoE) knockout mice was subjected to a high-fat diet (HFD), and THP-1 derived macrophages was exposed to oxidized low-density lipoprotein (ox-LDL), to establish the animal and cellular models of AS, respectively.

RESULTS

We found that LEO effectively improved AS and reduced the plaque area and inflammation via diminishing macrophage lipid accumulation and remodeling the lipid metabolism profile. LEO activated ox-LDL-induced macrophage autophagy, enhancing lipid metabolism decrease, according to the lipidomic and molecular biology analyses. Additionally, LEO caused a marked increase in autophagy marker levels in mouse models with advanced AS. Furthermore, we found that LEO reactivated autophagy and reversed lipid accumulation by suppressing METTL3 expression. The m6A-seq from ox-LDL-induced macrophages showed that a total of five autophagy-related mRNA transcripts (AKT1S1, AKT1, RB1CC1, CFLAR, and MTMR4) were altered, and AKT1S1 was significantly upregulated by LEO. Mechanistically, LEO-mediated regulation of METTL3 decreased AKT1S1 expression by attenuating its mRNA stability. Silencing AKT1S1 inhibited LEO-METTL3 axis-mediated autophagy and enhanced lipid accumulation in ox-LDL-induced macrophages.

CONCLUSION

The study first revealed that LEO exerts anti-atherosclerotic effect by activating METTL3-mediated macrophage autophagy in vivo and in vitro. The mechanism of LEO was further found to be the enhancement of METTL3-mediated AKT1S1 stability to activate autophagy thereby reducing lipid accumulation. This study provides a new perspective of natural medicines on the treatment of AS via an epigenetic manner.

METTL3-driven m6A modification of lncRNA FAM230B suppresses ferroptosis by modulating miR-27a-5p/BTF3 axis in gastric cancer

Our previous research revealed the apoptosis-inhibiting effect of lncRNA FAM230B in gastric cancer (GC). While its role on ferroptosis of GC remain unexplored. In this study, the m6A level and RNA stability regulation of METTL3 on FAM230B was detected by m6A quantification, stability assays, MeRIP, and their interaction was confirmed by RIP, and RNA pull-down assays. The level of ferroptosis was detected by flow cytometry, MDA and GSH level assessments, and electron microscopy. Gene expression was detected by quantitative real-time PCR, western blot, and immunofluorescence. The miR-27a-5p and BTF3 interaction was predicted with TargetScan and confirmed by dual-luciferase assay. Here, elevated levels of METTL3 and FAM230B were observed in GC tissues and cell lines. METTL3 was confirmed to bind with FAM230B RNA. Furthermore, silencing METTL3 reduced FAM230B m6A levels and stability, leading to decreased FAM230B and increased miR-27a-5p expressions. FAM230B knockdown favored ferroptosis and increased BTF3 expression, while its overexpression mitigated erastin-induced ferroptosis in GC cells. Additionally, BTF3 overexpression was found to negate miR-27a-5p's ferroptosis-promoting effects in GC cells. Collectively, our study demonstrates that the m6A modification of FAM230B by METTL3 plays a crucial role in promoting GC progression by reducing ferroptosis, through the modulation of the miR-27a-5p/BTF3 axis.

m6A-Dependent ITIH1 Regulated by TGF-β Acts as a Target for Hepatocellular Carcinoma Progression

Both the transforming growth factor beta (TGF-β) signaling pathway and N6-methyladenosine (m6A) modification for mRNA play an important role in hepatocellular carcinoma (HCC) progression. However, the relationship between TGF-β and m6A in hepatocellular carcinoma (HCC) remains unclear. Here, it is found that TGF-β can promote the liquid phase separation of METTL3, which further leads to the reduction of mRNA stability of ITIH1. As a secreted protein, ITIH1 can act as a ligand of integrin α5β1 to antagonize fibronectin, induce the inhibition of focal adhesion kinase signaling pathway, and inhibit the progression of HCC. In the preclinical model (mouse model, patient-derived organoid, patient-derived xenografts), purified recombinant ITIH1 (r-ITIH1) protein can be targeted for HCC. More importantly, r-ITIH1 can play a synergistic role in targeting HCC with TGF-β inhibitor. The downstream ITIH1 regulatory mechanism of TGF-β and m6A modification is revealed, and ITIH1 can be translational as a potential target for HCC.

A review of current developments in RNA modifications in lung cancer

Lung cancer has the highest incidence and mortality rates worldwide and is the primary cause of cancer-related death. Despite the rapid development of diagnostic methods and targeted drugs in recent years, many lung cancer patients do not benefit from effective therapies. The emergence of drug resistance has led to a reduction in the therapeutic effectiveness of targeted drugs, highlighting a crucial need to explore novel therapeutic targets. Many studies have found that epigenetic plays an important role in the occurrence of lung cancer. This review describes the biological function of epigenetic RNA modifications, such as m6A, m5C, m7G, and m1A, and recent advancements in their role in the development, progression, and prognosis of lung cancer. This review aims to provide new guidance for the treatment of lung cancer.

The interaction between m6A modification and noncoding RNA in tumor microenvironment on cancer progression

Cancer development is thought to be closely related to aberrant epigenetic regulation, aberrant expression of specific non-coding RNAs (ncRNAs), and tumor microenvironment (TME). The m6A methylation is one of the most abundant RNA modifications found in eukaryotes, and it can determine the fate of RNA at the post-transcriptional level through a variety of mechanisms, which affects important biological processes in the organism. The m6A methylation modification is involved in RNA processing, regulation of RNA nuclear export or localisation, RNA degradation and RNA translation. This process affects the function of mRNAs and ncRNAs, thereby influencing the biological processes of cancer cells. TME accelerates and promotes cancer generation and progression during tumor development. The m6A methylation interacting with ncRNAs is closely linked to TME formation. Mutual regulation and interactions between m6A methylation and ncRNAs in TME create complex networks and mediate the progression of various cancers. In this review, we will focus on the interactions between m6A modifications and ncRNAs in TME, summarising the molecular mechanisms by which m6A interacts with ncRNAs to affect TME and their roles in the development of different cancers. This work will help to deepen our understanding of tumourigenesis and further explore new targets for cancer therapy.

R-loops' m6A modification and its roles in cancers

R-loops are three-stranded nucleic acid structures composed of an RNA-DNA hybrid and a displaced DNA strand. They are widespread and play crucial roles in regulating gene expression, DNA replication, and DNA and histone modifications. However, their regulatory mechanisms remain unclear. As R-loop detection technology advances, changes in R-loop levels have been observed in cancer models, often associated with transcription-replication conflicts and genomic instability. N6-methyladenosine (m6A) is an RNA epigenetic modification that regulates gene expression by affecting RNA localization, splicing, translation, and degradation. Upon reviewing the literature, we found that R-loops with m6A modifications are implicated in tumor development and progression. This article summarizes the molecular mechanisms and detection methods of R-loops and m6A modifications in gene regulation, and reviews recent research on m6A-modified R-loops in oncology. Our goal is to provide new insights into the origins of genomic instability in cancer and potential strategies for targeted therapy.

Interactive Structural Analysis of KH3-4 Didomains of IGF2BPs with Preferred RNA Motif Having m6A Through Dynamics Simulation Studies

m6A modification is the most common internal modification of messenger RNA in eukaryotes, and the disorder of m6A can trigger cancer progression. The GGACU is considered the most frequent consensus sequence of target transcripts which have a GGAC m6A core motif. Newly identified m6A 'readers' insulin-like growth factor 2 mRNA-binding proteins modulate gene expression by binding to the m6A binding sites of target mRNAs, thereby affecting various cancer-related processes. The dynamic impact of the methylation at m6A within the GGAC motif on human IGF2BPs has not been investigated at the structural level. In this study, through in silico analysis, we mapped IGF2BPs binding sites for the GGm6AC RNA core motif of target mRNAs. Subsequent molecular dynamics simulation analysis at 400 ns revealed that only the KH4 domain of IGF2BP1, containing the 503GKGG506 motif and its periphery residues, was involved in the interaction with the GGm6AC backbone. Meanwhile, the methyl group of m6A is accommodated by a shallow hydrophobic cradle formed by hydrophobic residues. Interestingly, in IGF2BP2 and IGF2BP3 complexes, the RNA was observed to shift from the KH4 domain to the KH3 domain in the simulation at 400 ns, indicating a distinct dynamic behavior. This suggests a conformational stabilization upon binding, likely essential for the functional interactions involving the KH3-4 domains. These findings highlight the potential of targeting IGF2BPs' interactions with m6A modifications for the development of novel oncological therapies.

N6-Methyladenosine (m6A) Reader IGF2BP1 Accelerates Gastric Cancer Development and Immune Escape by Targeting PD-L1

N6-methyladenosine (m6A) functions as an important regulator in various human cancers, including gastric cancer. The immunotherapy targeting PD-1/PD-L1 has brought hope for advanced gastric cancer therapeutic. Here, present research aims to investigate the roles of m6A reader IGF2BP1 on gastric cancer tumor development and immune escape. Results indicated that IGF2BP1 up-regulated in the gastric cancer tissue and correlated with poor prognosis of gastric cancer patients. IGF2BP1 overexpression augmented the proliferation of co-cultured gastric cancer cells, and mitigated the CD8+ T cells mediated anti-tumor response, including IFN-γ secretion, surface PD-L1 level, and cytotoxicity of CD8+ T cells. Meanwhile, IGF2BP1 silencing exerted the opposite effects. In silico analysis revealed that there was a remarkable m6A modified site on PD-L1 mRNA. Moreover, the IGF2BP1 overexpression enhanced the stability of PD-L1 mRNA, thereby deteriorating the immune escape of gastric cancer cells. Collectively, these results describe a novel regulatory mechanism of IGF2BP1 by regulating PD-L1 through m6A epigenetic modification, which might provide insights for gastric cancer immunotherapies.

Prognostic roles of dysregulated METTL3 protein expression in cancers and potential anticancer value by inhibiting METTL3 function

BACKGROUND

Many studies have demonstrated the relationship between METTL3 protein expression and clinical outcomes in various cancers and elucidated the mechanism by which METTL3 disrupts the behavior of cancer cells. Here, we attempted to define the prognostic value of METTL3 protein in patients with cancer via systematic analysis and explored the potential effect of inhibiting METTL3 using its specific inhibitor.

METHODS

We searched PubMed, Embase, and the Web of Science databases for studies that elucidated the prognostic value of METTL3 protein expression in all cancer types and then calculated the pooled hazard ratios with 95% confidence intervals for the overall survival (OS) of all cancer types and subgroups. Data from The Cancer Genome Atlas dataset were used to study METTL3 mRNA expression in cancers. Further, the effects of a METTL3-specific inhibitor were studied in cancer cells via the colony formation assay, the cell proliferation assay, and apoptosis detection.

RESULTS

Meta-analysis of the 33 cohorts in 32 studies (3666 patients in total) revealed that higher METTL3 protein expression indicated poor OS in the majority of cancers. Bioinformatics analysis of METTL3 mRNA expression and cancer prognosis did not show the extremely prominent prognostic value of METTL3 mRNA. Nevertheless, the METTL3-specific inhibitor attenuated cell proliferation and cell cloning formation and promoted apoptosis.

CONCLUSIONS

METTL3 protein expression is associated with poor prognosis in most cancer types and could be a biomarker for OS. Further, METTL3 inhibition might be a potential treatment strategy for cancers.

Genomic biology and therapeutic strategies of liver metastasis from gastric cancer

The liver is a frequent site of metastasis in advanced gastric cancer (GC). Despite significant advancements in diagnostic and therapeutic techniques, the overall survival rate for patients afflicted with gastric cancer liver metastasis (GCLM) remains dismally low. Precision oncology has made significant progress in identifying therapeutic targets and enhancing our understanding of metastasis mechanisms through genome sequencing and molecular characterization. Therefore, it is crucial to have a comprehensive understanding of the various molecular processes involved in GCLM and the fundamental principles of systemic therapy to develop new treatment approaches. This paper aims to review recent findings on the diagnosis, potential biomarkers, and therapies targeting the multiple molecular processes of GCLM, with the goal of improving treatment strategies for patients with GCLM.

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.

Eight types of RNA modification regulators define clinical outcome and immune response in gastric cancer

Background

RNA modifications represent a novel category of biological molecule alterations, characterized by three primary classes of proteins: writers, erasers, and readers. Numerous studies indicate that the dysregulation of these RNA modifications is linked to cancer development and may offer new therapeutic avenues for treatment. In our research, we focused on eight specific genes associated with RNA modifications (RMRGs) to comprehensively analyze their distinct functions in gastric cancer (GC). Furthermore, we aimed to elucidate the roles of RMRGs concerning clinicopathological characteristics, tumor microenvironment, and patient prognosis.

Methods

In this study, we examined the expression and mutations of RMRGs in gastric cancer (GC) using data from TCGA-STAD (The Cancer Genome Atlas; Stomach adenocarcinoma) and the gene expression omnibus (GSE66229). We identified two subtypes of RMRGs and three gene clusters through consensus clustering analysis, assessing their differences in prognosis and immune cell infiltration patterns. Subsequently, we developed an RMRGs score to evaluate GC prognosis and highlight general immune features within the tumor microenvironment (TME). Lastly, we focused on MAMDC2 to validate its expression in GC and explore the effects of a MAMDC2 inhibitor on GC tumor cells.

Results

We discovered 94 differentially expressed RMRGs common to both the TCGA-STAD and GEO datasets. Notable differences in prognosis and immune cell infiltration were observed between the two RMRGs subtypes and three gene clusters. The RMRGs score emerged as an independent prognostic factor related to the tumor microenvironment (TME) characteristics in gastric cancer (GC). Reducing MAMDC2 levels enhanced cell migration and invasion while decreasing proliferation in vitro.

Conclusions

In conclusion, this study comprehensively analyzed the role of RMRGs on GC. Our study firstly proposed RMRGs score and demonstrated its potential to be biomarkers for prognosis and immune characteristics. Consequently, RMRGs score is of great clinical significance and can be utilized to develop individualized.

Targeting NAT10 inhibits osteosarcoma progression via ATF4/ASNS-mediated asparagine biosynthesis

Despite advances in treatment, the prognosis of patients with osteosarcoma remains unsatisfactory, and searching for potential targets is imperative. Here, we identify N4-acetylcytidine (ac4C) acetyltransferase 10 (NAT10) as a candidate therapeutic target in osteosarcoma through functional screening. NAT10 overexpression is correlated with a poor prognosis, and NAT10 knockout inhibits osteosarcoma progression. Mechanistically, NAT10 enhances mRNA stability of activating transcription factor 4 (ATF4) through ac4C modification. ATF4 induces the transcription of asparagine synthetase (ASNS), which catalyzes asparagine (Asn) biosynthesis, facilitating osteosarcoma progression. Utilizing virtual screening, we identify paliperidone and AG-401 as potential NAT10 inhibitors, and both inhibitors are found to bind to NAT10 proteins. Inhibiting NAT10 suppresses osteosarcoma progression in vivo. Combined treatment using paliperidone and AG-401 produces synergistic inhibition for osteosarcoma in patient-derived xenograft (PDX) models. Our findings demonstrate that NAT10 facilitates osteosarcoma progression through the ATF4/ASNS/Asn axis, and pharmacological inhibition of NAT10 may be a feasible therapeutic approach for osteosarcoma.

Regulatory effect of N6-methyladenosine on tumor angiogenesis

Previous studies have demonstrated that genetic alterations governing epigenetic processes frequently drive tumor development and that modifications in RNA may contribute to these alterations. In the 1970s, researchers discovered that N6-methyladenosine (m6A) is the most prevalent form of RNA modification in advanced eukaryotic messenger RNA (mRNA) and noncoding RNA (ncRNA). This modification is involved in nearly all stages of the RNA life cycle. M6A modification is regulated by enzymes known as m6A methyltransferases (writers) and demethylases (erasers). Numerous studies have indicated that m6A modification can impact cancer progression by regulating cancer-related biological functions. Tumor angiogenesis, an important and unregulated process, plays a pivotal role in tumor initiation, growth, and metastasis. The interaction between m6A and ncRNAs is widely recognized as a significant factor in proliferation and angiogenesis. Therefore, this article provides a comprehensive review of the regulatory mechanisms underlying m6A RNA modifications and ncRNAs in tumor angiogenesis, as well as the latest advancements in molecular targeted therapy. The aim of this study is to offer novel insights for clinical tumor therapy.

Interference with ENO2 promotes ferroptosis and inhibits glycolysis in clear cell renal cell carcinoma by regulating Hippo‑YAP1 signaling

Glycolytic enzyme enolase 2 (ENO2) is dysregulated in various cancer types. Nevertheless, the role and underlying mechanism of ENO2 in clear cell renal cell carcinoma (ccRCC) remain unclear. Therefore, the current study investigated the effect and mechanism of ENO2 in ccRCC. ENO2 expression in a ccRCC cell line was assessed using reverse transcription-quantitative PCR and western blotting. Analysis of glycolysis was performed by estimating the extracellular acidification rate, lactic acid concentration, glucose uptake and the expression of glucose transporter 1, pyruvate kinase muscle isozyme M2 and hexokinase 2. Moreover, ferroptosis was assessed by detecting the level of total iron, lipid peroxide, reactive oxygen species and the expression of ferroptosis-related protein. In addition, mitochondrial function was assessed using JC-1 staining and detection kits. The results indicated that ENO2 is expressed at high levels in ccRCC cell lines, and interference with ENO2 expression inhibits glycolysis, promotes ferroptosis and affects mitochondrial function in ccRCC cells. Further investigation demonstrated that interference with ENO2 expression affected ferroptosis levels in ccRCC cells by inhibiting the glycolysis process. Mechanistically, the present results indicated that ENO2 may affect ferroptosis, glycolysis and mitochondrial functions by regulating Hippo-yes-associated protein 1 (YAP1) signaling in ccRCC cells. In conclusion, the present study showed that ENO2 affects ferroptosis, glycolysis and mitochondrial functions in ccRCC cells by regulating Hippo-YAP1 signaling, hence demonstrating its potential as a therapeutic target in ccRCC.

ZC3H13 knockdown enhances the inhibitory effect of sevoflurane on gastric cancer cell malignancy by regulating the N6-methyladenosine modification of the lncRNA DLX6-AS1

Sevoflurane, an inhalation anesthetic, has been shown to suppress cancer development. In this study, we investigated the specific mechanisms involving sevoflurane, zinc-finger CCCH-type containing 13 (ZC3H13), and lncRNA DLX6-AS1 in gastric cancer (GC) progression, focusing on the N6-methyladenosine (m6A) modification of long non-coding RNAs (lncRNAs). We used quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analyses to measure the levels of ZC3H13 and lncRNA DLX6-AS1 in GC tissues and cells. Furthermore, we conducted Cell Counting Kit-8, colony formation, Transwell, and tumor xenograft assays to evaluate changes in GC cell malignancy following cell transfection and sevoflurane treatment. Additionally, actinomycin D, methylated RNA immunoprecipitation, and qRT-PCR assays were performed to examine the regulatory effects of ZC3H13 on the DLX6-AS1 m6A modification. We detected elevated levels of ZC3H13 in GC samples, while ZC3H13 silencing inhibited GC cell proliferation, migration, and invasion. Silencing ZC3H13 also enhanced the inhibitory effects of sevoflurane on GC cell malignancy. Moreover, we found that the increased expression of DLX6-AS1 in GC cells could be suppressed by ZC3H13 through the mediation of the m6A modification of DLX6-AS1, thereby reducing DLX6-AS1 stability. In conclusion, ZC3H13 knockdown enhances the inhibitory effect of sevoflurane on GC cell malignancy by inducing DLX6-AS1 m6A modification. Our findings may help identify potential therapeutic targets for the treatment of GC.

Regulatory role of N6-Methyladenosine on skeletal muscle development in Hu sheep

N6-Methyladenosine (m6A) RNA modification plays an essential role in many biological processes. To investigate the regulatory role of m6A on the skeletal muscle development in Hu sheep, this study took newborn Hu sheep (b_B Group) and six-month-old Hu sheep (s_B Group) as the objects. MeRIP-seq and RNA-Seq analysis techniques were used to detect differentially methylated genes (DMGs) and differentially expressed genes (DEGs) in the longissimus dorsi muscle of Hu sheep at different months of age. Then, conjoint analysis was further employed to screen for key genes involved in skeletal muscle development that are modified by m6A and expressed by mRNA. According to the results of the MeRIP-seq analysis, there were 285 m6A differentially methylated peaks (DMPs) in total between b_B Group and s_B Group, with 192 significant upregulated peaks and 93 significant downregulated peaks. GO and KEGG analysis revealed that DMGs are mainly enriched in actin-binding, cellular transport, and metabolic pathways. According to the results of the RNA-seq analysis, there were 4,349 DEGs in total between b_B Group and s_B Group, with 2010 upregulated genes and 2,339 downregulated genes. DEGs are found to be mainly enriched in the regulation of actin cytoskeleton tissue, AMPK and FoxO signaling pathways, etc. The conjoint analysis demonstrated that 283 genes were both modified by m6A and expressed by mRNA. Among them, three genes relevant to muscle growth (RGMB, MAPK8IP3, and RSPO3) were selected as candidates for quantitative validation, and the results were in line with the sequencing results. The results mentioned above all suggest that m6A plays a certain role in the skeletal muscle development in Hu sheep.

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

Background

Cancers arise from genetic and epigenetic abnormalities that affect oncogenes and tumor suppressor genes, compounded by gene mutations. The N6-methyladenosine (m6A) RNA modification, regulated by methylation regulators, has been implicated in tumor proliferation, differentiation, tumorigenesis, invasion, and metastasis. However, the role of m6A modification patterns in the tumor microenvironment of gastric cancer (GC) remains poorly understood.

Materials and methods

In this study, we analyzed m6A modification patterns in 267 GC samples utilizing 31 m6A regulators. Using consensus clustering, we identified two unique subgroups of GC. Patients with GC were segregated into high- and low-infiltration cohorts to evaluate the infiltration proportions of the five prognostically significant immune cell types. Leveraging the differential genes in GC, we identified a "green" module via Weighted Gene Co-expression Network Analysis. A risk prediction model was established using the LASSO regression method.

Results

The "green" module was connected to both the m6A RNA methylation cluster and immune infiltration patterns. Based on "Module Membership" and "Gene Significance", 37 hub genes were identified, and a risk prediction model incorporating nine hub genes was established. Furthermore, methylated RNA immunoprecipitation and RNA Immunoprecipitation assays revealed that YTHDF1 elevated the expression of DNMT3B, which synergistically promoted the initiation and development of GC. We elucidated the molecular mechanism underlying the regulation of DNMT3B by YTHDF1 and explored the crosstalk between m6A and 5mC modification.

Conclusion

m6A RNA methylation regulators are instrumental in malignant progression and the dynamics of tumor microenvironment infiltration of GC. Assessing m6A modification patterns and tumor microenvironment infiltration characteristics in patients with GC holds promise as a valuable prognostic biomarker.

METTL3-Regulated lncRNA SNHG7 Drives MNNG-Induced Epithelial-Mesenchymal Transition in Gastric Precancerous Lesions

As a representative item of chemical carcinogen, MNNG is closely associated with the onset of gastric cancer (GC), where N6-methyladonosine (m6A) RNA methylation is recognized as a critical epigenetic event. In our previous study, we found that the m6A modification by methyltransferase METTL3 was up-regulated in MNNG-exposed malignant GES-1 cells (MC cells) compared to control cells in vitro, and long non-coding RNA SNHG7 as a downstream target of the METTL3. However, the functional role of METTL3 in mediating the SNHG7 axis in MNNG-induced GC remains unclear. In the present study, we continuously investigate the functional role of METTL3 in mediating the SNHG7 axis in MNNG-induced GC. RIP-PCR and m6A-IP-qPCR were used to examine the molecular mechanism underlying the METTL3/m6A/SNHG7 axis in MNNG-induced GC. A METTL3 knockout mice model was constructed and exposed by MNNG. Western blot analysis, IHC analysis, and RT-qPCR were used to measure the expression of METTL3, SNHG7, and EMT markers. In this study, we demonstrated that in MNNG-induced GC tumorigenesis, the m6A modification regulator METTL3 facilitates cellular EMT and biological functions through the m6A/SNHG7 axis using in vitro and in vivo models. In conclusion, our study provides novel insights into critical epigenetic molecular events vital to MNNG-induced gastric carcinogenesis. These findings suggest the potential therapeutic targets of METTL3 for GC treatment.

Role of N6-methyladenosine in tumor neovascularization

Tumor neovascularization is essential for the growth, invasion, and metastasis of tumors. Recent studies have highlighted the significant role of N6-methyladenosine (m6A) modification in regulating these processes. This review explores the mechanisms by which m6A influences tumor neovascularization, focusing on its impact on angiogenesis and vasculogenic mimicry (VM). We discuss the roles of m6A writers, erasers, and readers in modulating the stability and translation of angiogenic factors like vascular endothelial growth factor (VEGF), and their involvement in key signaling pathways such as PI3K/AKT, MAPK, and Hippo. Additionally, we outline the role of m6A in vascular-immune crosstalk. Finally, we discuss the current development of m6A inhibitors and their potential applications, along with the contribution of m6A to anti-angiogenic therapy resistance. Highlighting the therapeutic potential of targeting m6A regulators, this review provides novel insights into anti-angiogenic strategies and underscores the need for further research to fully exploit m6A modulation in cancer treatment. By understanding the intricate role of m6A in tumor neovascularization, we can develop more effective therapeutic approaches to inhibit tumor growth and overcome treatment resistance. Targeting m6A offers a novel approach to interfere with the tumor's ability to manipulate its microenvironment, enhancing the efficacy of existing treatments and providing new avenues for combating cancer progression.

Helicobacter Pylori-Enhanced hnRNPA2B1 Coordinates with PABPC1 to Promote Non-m6A Translation and Gastric Cancer Progression

Helicobacter pylori (H. pylori) infection is the primary risk factor for the pathogenesis of gastric cancer (GC). N6-methyladenosine (m6A) plays pivotal roles in mRNA metabolism and hnRNPA2B1 as an m6A reader is shown to exert m6A-dependent mRNA stabilization in cancer. This study aims to explore the role of hnRNPA2B1 in H. pylori-associated GC and its novel molecular mechanism. Multiple datasets and tissue microarray are utilized for assessing hnRNPA2B1 expression in response to H. pylori infection and its clinical prognosis in patients with GC. The roles of hnRNPA2B1 are investigated through a variety of techniques including glucose metabolism analysis, m6A-epitranscriptomic microarray, Ribo-seq, polysome profiling, RIP-seq. In addition, hnRNPA2B1 interaction with poly(A) binding protein cytoplasmic 1 (PABPC1) is validated using mass spectrometry and co-IP. These results show that hnRNPA2B1 is upregulated in GC and correlated with poor prognosis. H. pylori infection induces hnRNPA2B1 upregulation through recruiting NF-κB to its promoter. Intriguingly, cytoplasm-anchored hnRNPA2B1 coordinated PABPC1 to stabilize its relationship with cap-binding eIF4F complex, which facilitated the translation of CIP2A, DLAT and GPX1 independent of m6A modification. In summary, hnRNPA2B1 facilitates the non-m6A translation of epigenetic mRNAs in GC progression by interacting with PABPC1-eIF4F complex and predicts poor prognosis for patients with GC.

RNA epigenetic modifications in digestive tract cancers: Friends or foes

Digestive tract cancers are among the most common malignancies worldwide and have high incidence and mortality rates. Thus, the discovery of more effective diagnostic and therapeutic targets is urgently required. The development of technologies to accurately detect RNA modification has led to the identification of numerous RNA chemical modifications in humans (epitranscriptomics) that are involved in the occurrence and development of digestive tract cancers. RNA modifications can cooperatively regulate gene expression to facilitate normal physiological functions of the digestive system. However, the dysfunction of relevant RNA-modifying enzymes ("writers," "erasers," and "readers") can lead to the development of digestive tract cancers. Consequently, targeting dysregulated enzyme activity could represent a potent therapeutic strategy for the treatment of digestive tract cancers. In this review, we summarize the most widely studied roles and mechanisms of RNA modifications (m6A, m1A, m5C, m7G, A-to-I editing, pseudouridine [Ψ]) in relation to digestive tract cancers, highlight the crosstalk between RNA modifications, and discuss their roles in the interactions between the digestive system and microbiota during carcinogenesis. The clinical significance of novel therapeutic methods based on RNA-modifying enzymes is also discussed. This review will help guide future research into digestive tract cancers that are resistant to current therapeutics.

METTL5: A Potential Biomarker for Nonsmall Cell Lung Cancer That Promotes Cancer Cell Proliferation by Interacting with IGF2BP3

Objective: To examine if METTL5 promotes the proliferation of nonsmall cell lung cancer (NSCLC) cells by interacting with IGF2BP3. Methods: The expression patterns of METTL5 and IGF2BP3 in NSCLC tissues, their relationship with survival rate, and their correlation were analyzed using bioinformatics and clinical sample analyses. The effects of METTL5 overexpression and IGF2BP3 knockdown, as well as those of METTL5 knockdown and IGF2BP3 overexpression, on the proliferation of NSCLC cells were analyzed by transfecting appropriate constructs. The interaction between METTL5 and IGF2BP3 was verified using the co-immunoprecipitation (Co-IP) assay. The in vivo effects of METTL5 and IGF2BP3 on NSCLC growth were analyzed using the tumor-bearing nude mouse model. Results: METTL5 and IGF2BP3 expression levels were positively correlated and were associated with poor clinical prognosis. The METTL5 and IGF2BP3 expression levels were upregulated in the clinical NSCLC samples. IGF2BP3 expression did not affect METTL5 expression but was regulated by METTL5. IGF2BP3 overexpression mitigated the METTL5 knockdown-induced impaired cell proliferation. Meanwhile, IGF2BP3 knockdown suppressed METTL5-mediated NSCLC cell proliferation. The Co-IP assay results revealed the interaction between METTL5 and IGF2BP3 in NSCLC cells. IGF2BP3 knockdown suppressed tumor growth, whereas IGF2BP3 overexpression enhanced tumor volume and quality. Conclusion: METTL5 induces NSCLC cell proliferation by interacting with IGF2BP3. Thus, METTL5 is a potential biomarker and a therapeutic target for NSCLC.

N6-methyladenosine RNA modifications: a potential therapeutic target for AML

N6-methyladenosine (m6A) RNA modification has recently emerged as an essential regulator of normal and malignant hematopoiesis. As a reversible epigenetic modification found in messenger RNAs and non-coding RNAs, m6A affects the fate of the modified RNA molecules. It is essential in most vital bioprocesses, contributing to cancer development. Here, we review the up-to-date knowledge of the pathological functions and underlying molecular mechanism of m6A modifications in normal hematopoiesis, leukemia pathogenesis, and drug response/resistance. At last, we discuss the critical role of m6A in immune response, the therapeutic potential of targeting m6A regulators, and the possible combination therapy for AML.

N6-Methyladenosine enhances the translation of ENO1 to promote the progression of bladder cancer by inhibiting PCNA ubiquitination

The mechanism underlying N6-methyladenosine (m6A) modification in bladder cancer (BC) remains elusive. We identified that the RBM15/METTL3 complex enhances m6A modification and promotes the ENO1 protein translation efficiency through its 359A site by depending on YTHDF1 in BC cells. In the tumor microenvironment, TGF-β effectively stimulates RBM15/METTL3 expression to improve ENO1 mRNA m6A modification through the Smad2/3 pathway. Reduced ENO1 m6A levels hamper tumor proliferation both in vitro and in vivo. Mechanistically, ENO1 augments PCNA protein stability by reducing its K48-linked ubiquitination and thus prevents protein degradation through the endoplasmic reticulum-associated degradation pathway. According to the subsequent experiments, the ENO1 inhibitor significantly reduced tumor proliferation both in vitro and in vivo. Our study highlights the significance of RBM15/METTL3 complex-mediated ENO1 mRNA m6A modification in ENO1 expression. It also reveals a novel mechanism by which ENO1 promotes BC progression, thereby suggesting that ENO1 can be a therapeutic target for BC.

A m6A regulators-related classifier for prognosis and tumor microenvironment characterization in hepatocellular carcinoma

Background

Increasing evidence have highlighted the biological significance of mRNA N6-methyladenosine (m6A) modification in regulating tumorigenicity and progression. However, the potential roles of m6A regulators in tumor microenvironment (TME) formation and immune cell infiltration in liver hepatocellular carcinoma (LIHC or HCC) requires further clarification.

Method

RNA sequencing data were obtained from TCGA-LIHC databases and ICGC-LIRI-JP databases. Consensus clustering algorithm was used to identify m6A regulators cluster subtypes. Weighted gene co-expression network analysis (WGCNA), LASSO regression, Random Forest (RF), and Support Vector Machine-Recursive Feature Elimination (SVM-RFE) were applied to identify candidate biomarkers, and then a m6Arisk score model was constructed. The correlations of m6Arisk score with immunological characteristics (immunomodulators, cancer immunity cycles, tumor-infiltrating immune cells (TIICs), and immune checkpoints) were systematically evaluated. The effective performance of nomogram was evaluated using concordance index (C-index), calibration plots, decision curve analysis (DCA), and receiver operating characteristic curve (ROC).

Results

Two distinct m6A modification patterns were identified based on 23 m6A regulators, which were correlated with different clinical outcomes and biological functions. Based on the constructed m6Arisk score model, HCC patients can be divided into two distinct risk score subgroups. Further analysis indicated that the m6Arisk score showed excellent prognostic performance. Patients with a high m6Arisk score was significantly associated with poorer clinical outcome, lower drug sensitivity, and higher immune infiltration. Moreover, we developed a nomogram model by incorporating the m6Arisk score and clinicopathological features. The application of the m6Arisk score for the prognostic stratification of HCC has good clinical applicability and clinical net benefit.

Conclusion

Our findings reveal the crucial role of m6A modification patterns for predicting HCC TME status and prognosis, and highlight the good clinical applicability and net benefit of m6Arisk score in terms of prognosis, immunophenotype, and drug therapy in HCC patients.

m6A-mediated lnc-OXAR promotes oxaliplatin resistance by enhancing Ku70 stability in non-alcoholic steatohepatitis-related hepatocellular carcinoma

BACKGROUND

The escalating prevalence of metabolic diseases has led to a rapid increase in non-alcoholic steatohepatitis (NASH)-related hepatocellular carcinoma (NASH-HCC). While oxaliplatin (OXA)-based hepatic arterial infusion chemotherapy (HAIC) has shown promise in advanced-stage HCC patients, its efficacy in NASH-HCC remains uncertain. This study aims to assess the effectiveness of OXA-based HAIC and elucidate the mechanisms underlying OXA resistance in NASH-HCC.

METHODS

The key lncRNAs were screened through RNA-seq analysis of NASH/non-NASH and OXA-sensitive/OXA-resistant (OXA-S/R) HCC tissues. The biological functions of the lnc-OXAR (OXA resistance-related lncRNA in NASH-HCC) in NASH-HCC were verified through a series of in vitro and in vivo experiments. The molecular mechanism of lnc-OXAR was elucidated by fluorescence in situ hybridization, immunoprecipitation-mass spectrometry (FISH), Immunoprecipitation-Mass Spectrometry (IP-MS), RNA pulldown, RNA immunoprecipitation (RIP), methylated RNA immunoprecipitation sequencing (MeRIP-Seq) and a dual-luciferase reporter assay.

RESULTS

NASH-HCC exhibited reduced responsiveness to OXA-based HAIC compared to non-NASH HCC. We identified and validated a novel transcript namedlnc-OXAR, which played a crucial role in conferring OXA resistance to NASH-HCC. Inhibition of lnc-OXAR suppressed HCC cell growth and restored OXA sensitivity both in NASH-HCC mouse models and in vitro. Mechanistically, lnc-OXAR recruited Ku70 and cystatin A (CSTA), preventing Ku70 degradation and facilitating DNA double-strand break (DSB) repair, thereby promoting OXA resistance in NASH-HCC. Additionally, WTAP-mediated m6A modification enhanced the stability of lnc-OXAR in an IGF2BP2-dependent manner. Notably, silencing lnc-OXAR significantly enhanced the response to OXA in patient-derived xenograft (PDX) models derived from NASH-HCC.

CONCLUSIONS

The reduced responsiveness of NASH-HCC to OXA treatment can be attributed to the upregulation of lnc-OXAR. Our findings provide a rationale for stratifying HCC patients undergoing OXA-based HAIC based on etiology. Lnc-OXAR holds promise as a novel target for overcoming OXA resistance in NASH-HCC and improving prognosis.

Progression of m6A in the tumor microenvironment: hypoxia, immune and metabolic reprogramming

Recently, N6-methyladenosine (m6A) has aroused widespread discussion in the scientific community as a mode of RNA modification. m6A comprises writers, erasers, and readers, which regulates RNA production, nuclear export, and translation and is very important for human health. A large number of studies have found that the regulation of m6A is closely related to the occurrence and invasion of tumors, while the homeostasis and function of the tumor microenvironment (TME) determine the occurrence and development of tumors to some extent. TME is composed of a variety of immune cells (T cells, B cells, etc.) and nonimmune cells (tumor-associated mesenchymal stem cells (TA-MSCs), cancer-associated fibroblasts (CAFs), etc.). Current studies suggest that m6A is involved in regulating the function of various cells in the TME, thereby affecting tumor progression. In this manuscript, we present the composition of m6A and TME, the relationship between m6A methylation and characteristic changes in TME, the role of m6A methylation in TME, and potential therapeutic strategies to provide new perspectives for better treatment of tumors in clinical work.