Targeting the RNA m6A Reader YTHDF2 Selectively Compromises Cancer Stem Cells in Acute Myeloid Leukemia

CRM1 mediates the nuclear export of YTHDF2

Precise intracellular localization is crucial for protein function. YTHDF2, a reader protein for N6-methyladenosine (m6A), has been reported to shuttle between the cytoplasm and nucleus through an unknown mechanism. Here, we identify a functional nuclear export sequence (NES) in YTHDF2 that mediates its nuclear export. Mutation of the NES leads to nuclear accumulation of YTHDF2. Wild-type YTHDF2, but not the NES-mutant, interacts with the nuclear export receptor CRM1. Inhibition of CRM1 using the specific inhibitor leptomycin B or CRM1 knockdown effectively blocks YTHDF2 nuclear export. Using a tethering reporter system, we demonstrate that NES mutation impairs the mRNA degradation activity of YTHDF2. These findings provide mechanistic insights into the regulation of YTHDF2 subcellular localization and may have therapeutic implications for YTHDF2-associated diseases.

YTHDF2: a key RNA reader and antitumor target

N6-methyladenosine (m6A) is a key mRNA modification influencing mRNA stability and translation. YTHDF2, a major m6A 'reader', was initially recognized for promoting mRNA decay but is now also known to enhance translation by binding to methylated mRNAs. YTHDF2 maintains the function of immune suppressive cells, including tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), and regulatory T cells (Tregs), while also supporting cytotoxic immune cells, including natural killer (NK) and CD8+ T cells. Additionally, YTHDF2 acts as a tumor-intrinsic regulator orchestrating tumor immune evasion. Its multifaceted roles in tumor immunity make YTHDF2 a promising yet challenging therapeutic target. This review explores the complex roles and mechanisms of YTHDF2 in cancers, immune regulation, and tumor immune evasion and highlights emerging therapeutic strategies that target YTHDF2.

m6A/IGF2BP3-driven serine biosynthesis fuels AML stemness and metabolic vulnerability

Metabolic reprogramming of amino acids represents a vulnerability in cancer cells, yet the mechanisms underlying serine metabolism in acute myeloid leukemia (AML) and leukemia stem/initiating cells (LSCs/LICs) remain unclear. Here, we identify RNA N6-methyladenosine (m6A) modification as a key regulator of serine biosynthesis in AML. Using a CRISPR/Cas9 screen, we find that depletion of m6A regulators IGF2BP3 or METTL14 sensitizes AML cells to serine and glycine (SG) deprivation. IGF2BP3 recognizies m6A on mRNAs of key serine synthesis pathway (SSP) genes (e.g., ATF4, PHGDH, PSAT1), stabilizing these transcripts and sustaining serine production to meet the high metabolic demand of AML cells and LSCs/LICs. IGF2BP3 silencing combined with dietary SG restriction potently inhibits AML in vitro and in vivo, while its deletion spares normal hematopoiesis. Our findings reveal the critical role of m6A modification in the serine metabolic vulnerability of AML and highlight the IGF2BP3/m6A/SSP axis as a promising therapeutic target.

Phase separation participates in the genetic regulation mechanism of hematopoietic stem cells: potential therapeutic methods

Hematopoietic stem cells (HSCs) are the primitive cells that give rise to common precursors for all blood cell lineages. Abnormalities in their number and/or function are important factors leading to the decline of immune function and the occurrence of various systemic diseases. Phase separation refers to a physicochemical mechanism in which intracellular liquid-liquid phase separation (LLPS) forms membrane-less organelles. It participates in various physiological activities and is related to the occurrence of diseases. Studies have shown that the functional activity of HSCs is regulated by complex mechanisms, and phase separation is closely related to these complex mechanisms such as genetic regulation, epigenetic regulation, microenvironment regulation, gene expression, autophagy degradation, and cell proliferation. With the deepening of research, the importance of phase separation in the pathogenesis and treatment of diseases such as leukemia and tumors has gradually emerged, but the deep mechanism of its regulation of HSCs genetic regulation still lacks exploration, and the direction of clinical targeted therapy is not yet clear. Here, we will summarize and elaborate the genetic regulation mechanism of HSCs, discuss the relationship between phase separation and the functional regulation of HSCs, and analyze the possibility of phase separation participating in the genetic regulation of HSCs to treat diseases, in order to provide help for the clinical implementation of targeted therapy for HSCs regulation.

Key epigenetic enzymes modulated by natural compounds contributes to tumorigenicity

Dysregulation of epigenetic regulation is observed in numerous tumor cells. The therapeutic effects of natural products on tumors were investigated through a comprehensive analysis of active ingredients derived from various structured natural products. The analysis focuses on regulating key enzymes involved in epigenetic control. To study the modulation of these enzymes for tumor treatment, the structural characteristics of natural products that impact tumorigenesis were identified. The presence of specific patterns suggests that compounds sharing structural similarities can potentially induce therapeutic effects on identical tumors through modulation of distinct modifying enzymes. Structurally analogous natural products can likewise achieve therapeutic effects across diverse tumor types via their interaction with a common epigenetic enzyme. There exist numerous flavonoids with the capability to modulate METTL3, thereby influencing the development of various tumors. The normalization process was implemented to account for a common phenomenon, wherein structurally distinct compounds effectively target the same tumor by modulating a shared key enzyme. By summarizing, valuable insights into the role of compound-epigenetic enzymes in tumor development have been obtained. This discovery establishes a crucial scientific foundation for the prevention and treatment of tumor development through the utilization of structurally similar natural active ingredients.

YTHDF2 promotes the metastasis of oral squamous cell carcinoma through the JAK-STAT pathway

RNA-binding proteins act as crucial mediators between N6-methyladenosine (m6A) modification and RNA function, playing a significant role in the recurrence and metastasis of oral squamous cell carcinoma (OSCC). YTHDF2, the first identified RNA-binding protein, has been shown to be closely associated with the prognosis of certain types of cancer. However, the role of YTHDF2 in OSCC and its underlying molecular mechanisms remain poorly understood and require further investigation. First, we analysed the expression levels of YTHDF2 and examined its correlation with clinical features using public databases and OSCC patient samples. Subsequently, a series of in vitro functional experiments were conducted to assess the effects of YTHDF2 on the proliferation, migration, and invasion capabilities of OSCC cells. Additionally, RNA-seq analysis was utilized to investigate the signalling pathways modulated by YTHDF2, which was further supported by experimental validation. Our findings revealed that YTHDF2 expression was significantly elevated in OSCC tissues and cells, with levels closely correlated with the clinical stage, pathological grade, and survival time of patients. The knockdown of YTHDF2 resulted in a significant reduction in the proliferation, migration, and invasion abilities of OSCC cells. Furthermore, RNA sequencing data indicated that silencing YTHDF2 suppressed the JAK-STAT signalling pathway, and the use of STAT3 activators reversed this suppressive effect in OSCC cells. Our study demonstrated that YTHDF2 promotes the proliferation, metastasis, and invasion of OSCC by positively regulating the JAK-STAT signalling pathway, suggesting that YTHDF2 could serve as a potential prognostic marker for the diagnosis and treatment of OSCC.

YTHDF1 and YTHDC1 m6A reader proteins regulate HTLV-1 tax and hbz activity

Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus responsible for adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a progressive neurodegenerative disease. Regulation of viral gene expression plays a key role in viral persistence and pathogenesis. However, the molecular mechanisms underlying this fine-tuned regulation remain poorly understood. Little is known regarding RNA chemical modifications of HTLV-1 RNA and how these affect viral biology and disease development. Post-transcriptional chemical modification of RNA is common in eukaryotes, with N6-methyladenosine (m6A) being the most prevalent. In this study, we investigated the role of m6A RNA modifications on HTLV-1 gene expression. Using MeRIP-Seq, we mapped the sites of m6A modification to the 3' end of the viral genome. We found HTLV-1 RNA, as well as viral oncogene transcripts tax and hbz, contained m6A modifications. m6A-depletion in HTLV-1-transformed cells decreased sense-derived viral genes (Tax, Gag, and Env) and increased antisense-derived Hbz expression. Tax and hbz transcripts were bound by reader proteins YTHDF1 and YTHDC1 in a panel of HTLV-1 T-cell lines. Using expression vectors and shRNA-mediated knockdown, we found that YTHDF1 had opposing effects on viral gene expression, decreasing sense-derived viral genes and increasing antisense-derived Hbz. Upon further study, the YTHDF1 effects on tax abundance were dependent on tax m6A deposition. The nuclear m6A reader protein YTHDC1 affected the abundance of both sense- and antisense-derived viral transcripts and specifically enhanced the nuclear export of tax transcript. Collectively, our results demonstrate global m6A levels and m6A reader proteins YTHDF1 and YTHDC1 regulate HTLV-1 gene expression.IMPORTANCEHuman T-cell leukemia virus type 1 (HTLV-1) persistence and pathogenesis are controlled through tight regulation of viral gene expression. The fate of RNA can be controlled by epigenetic modifications that impact gene expression without altering the DNA sequence. Our study details the impact of N6-methyladenosine (m6A) RNA chemical modifications on HTLV-1 gene expression. We found that reductions in global m6A levels affected viral gene expression, decreasing Tax and other sense-derived viral genes, whereas increasing the antisense-derived Hbz. Our results suggest the oncogenic viral transcripts, tax and hbz, are m6A-modified in cells. We found that these viral RNA modifications are interpreted by reader proteins YTHDF1 and YTHDC1, which dictate the fate of the viral RNA. Understanding HTLV-1 RNA chemical modifications offers potential insights into novel therapeutic strategies for HTLV-1-associated diseases.

Modifications of RNA in cancer: a comprehensive review

RNA modifications play essential roles in post-transcriptional gene regulation and have emerged as significant contributors to cancer biology. Major chemical modifications of RNA include N6-methyladenosine (m6A), 5-methylcytosine (m5C), N1-methyladenosine (m1A), pseudouridine (ψ), and N7-methylguanosine (m7G). Their dynamic regulation highlights their roles in gene expression modulation, RNA stability, and translation. Advanced high-throughput detection methods, ranging from liquid chromatography-mass spectrometry and high-performance liquid chromatography to next-generation sequencing (NGS) and nanopore direct RNA sequencing, have enabled detailed studies of RNA modifications in cancer cells. Aberrant RNA modifications are associated with the dysregulation of tumor suppressor genes and oncogenes, influencing cancer progression, therapy resistance, and immune evasion. Emerging research suggests the therapeutic potential of targeting RNA-modifying enzymes and their inhibitors in cancer treatment. This review compiles and analyzes the latest findings on RNA modifications, presenting an in-depth discussion of the diverse chemical alterations that occur in RNA and their profound implications in cancer biology. It integrates fundamental principles with cutting-edge research, offering a holistic perspective on how RNA modifications influence gene expression, tumor progression, and therapeutic resistance. It emphasizes the need for further studies to elucidate the complex roles of RNA modifications in cancer, as well as the potential for multimodality therapeutic strategies that exploit the dynamic and reversible nature of these epitranscriptomic marks. It also attempts to highlight the challenges, gaps, and limitations of RNA modifications in cancer that should be tackled before their functional implications. Understanding the interplay between RNA modifications, cancer pathways, and their inhibitors will be crucial for developing promising RNA-based therapeutic approaches to cancer and personalized medicine strategies.

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.

Specific sDMA modifications on the RGG/RG motif of METTL14 regulate its function in AML

BACKGROUND

Protein arginine methylations are crucial post-translational modifications (PTMs) in eukaryotes, playing a significant regulatory role in diverse biological processes. Here, we present our investigation into the detailed arginine methylation pattern of the C-terminal RG-rich region of METTL14, a key component of the m6A RNA methylation machinery, and its functional implications in biology and disease.

METHODS

Using ETD-based mass spectrometry and in vitro enzyme reactions, we uncover a specific arginine methylation pattern on METTL14. RNA methyltransferase activity assays were used to assess the impact of sDMA on METTL3:METTL14 complex activity. RNA immunoprecipitation was used to evaluate mRNA-m6A reader interactions. MeRIP-seq analysis was used to study the genome-wide effect of METTL14 sDMA on m6A modification in acute myeloid leukemia cells.

RESULTS

We demonstrate that PRMT5 catalyzes the site-specific symmetric dimethylation at R425 and R445 within the extensively methylated RGG/RG motifs of METTL14. We show a positive regulatory role of symmetric dimethylarginines (sDMA) in the catalytic efficiency of the METTL3:METTL14 complex and m6A-specific gene expression in HEK293T and acute myeloid leukemia cells, potentially through the action of m6A reader protein YTHDF1. In addition, the combined inhibition of METTL3 and PRMT5 further reduces the expression of several m6A substrate genes essential for AML proliferation, suggesting a potential therapeutic strategy for AML treatment.

CONCLUSIONS

The study confirms the coexistence of sDMA and aDMA modifications on METTL14's RGG/RG motifs, with sDMA at R425 and R445 enhancing METTL3:METTL14's catalytic efficacy and regulating gene expression through m6A deposition in cancer cells.

The epigenetic hallmarks of immune cells in cancer

Targeting the dysregulation of epigenetic mechanisms in cancer has emerged as a promising therapeutic strategy. Although the significant rationale progress of epigenetic therapies in blocking cancer cells, how epigenetic regulation shapes tumor microenvironment (TME) and establishes antitumor immunity remains less understood. Recent study focus has been put on the epigenetic-mediated changes in the fate of immune cells, including the differentiation, expansion, recruitment, functionalization, and exhaustion of T cells, natural killer (NK) cells, tumor-associated macrophages (TAMs), dendritic cells (DCs), myeloid-derived suppressor cells (MDSCs), and B cells within the TME. Here, we review the latest molecular and clinical insights into how DNA modifications, histone modification, and epitranscriptome-related regulations shape immune cells of various cancers. We also discuss opportunities for leveraging epigenetic therapies to improve cancer immunotherapies. This review provides the epigenetic foundations of cancer immunity and proposes the future direction of combination therapies.

RNA methylation: where to from here for hematologic malignancies?

RNA methylation and the machinery that regulates or "reads" its expression has recently been implicated in the pathogenesis of acute myeloid leukemia (AML) and other hematologic malignancies. Modulation of these epigenetic marks has started to become a reality as several companies around the world seek to leverage this knowledge therapeutically in the clinic. Although the bases of observed activity in AML have been described by numerous groups, the exact context in which these therapies will ultimately be used remains to be properly determined. While context is likely to be of great importance here, a more "global" mechanism of action might allow for more widespread applicability to multiple disease subtypes. In other areas such as the myelodysplastic and other preleukemic syndromes, data remain sparse. Ongoing work is needed to determine whether therapeutic modulation of RNA modifications is a viable and biologically plausible approach in these cases. Regardless of the outcomes, this is an exciting era for "epitranscriptomics" as we navigate a pathway forward. Here, I describe the current knowledge around RNA methylation and hematologic malignancies at the end of 2024 including some of the relevant questions that are yet to be answered.

m6A reader YTHDF2 governs the onset of atrial fibrillation by modulating Cacna1c translation

Atrial fibrillation (AF) is the most common arrhythmia, which is tightly associated with the abnormal expression and function of ion channels in the atrial cardiomyocytes. N6-methyladenosine (m6A), a widespread chemical modification in eukaryotic mRNA, is known to play a significant regulatory role in the pathogenesis of heart disease. However, the significance of m6A regulatory proteins in the onset of AF remains unclear. Here, we demonstrate that the m6A reader protein YTHDF2 regulates atrial electrical remodeling and AF onset by modulating the Cav1.2 expression. Firstly, YTHDF2 expression was selectively upregulated in rat atrial cardiomyocytes with AF. Secondly, YTHDF2 knockout reduced AF susceptibility in mice. Thirdly, the knockout of YTHDF2 increased Cav1.2 protein levels in an m6A-in-dependent manner, ultimately prolonging the atrial myocardial refractory period, a critical electrophysiological substrate for the onset of AF. Fourthly, the N-terminal domain of YTHDF2 was identified as critical for Cacna1c mRNA translation regulation. Overall, our findings unveil that YTHDF2 can alter Cav1.2 protein expression in an m6A-independent manner, thereby facilitating the onset of AF. Our study suggests that YTHDF2 may be a potential intervention target for AF.

The role of YTHDF2 in anti-tumor immunity

RNA N 6-methyladenosine (m6A) modification has been identified as the most abundant RNA modification and plays crucial roles in both physiological and pathological processes. YTHDF2 was the first identified reader protein that can recognize m6A modification and recent studies also revealed its ability to bind 5-methylcytidine (m5C) modification. YTHDF2 shows a dual binding capacity to both m6A and m5C, which leads to opposite mRNA outcomes. Multiple studies have highlighted the critical roles of YTHDF2 in tumor development and tumor microenvironment. Emerging findings showed that YTHDF2 plays critical roles in immune regulation, impacting T cell, B cell, NK cell, macrophage, innate/adaptive anti-tumor immune responses, and T-cell based immunotherapy. Inhibitors have been developed to target YTHDF2, which showed potential efficacy in tumor treatment. Herein, we reviewed the molecular mechanism of YTHDF2 and its roles in tumors, immune cells, and tumor microenvironment.

Discovery of a Novel Selective and Cell-Active N6-Methyladenosine RNA Demethylase ALKBH5 Inhibitor

N6-methyladenosine (m6A), the most abundant methylation on mRNA, plays pivotal roles in regulating mRNA biological functions, which affect cell functions. ALKBH5, an m6A demethylase, was found to be an oncogene in several cancer types, including triple-negative breast cancer (TNBC). Here, we report a novel and selective ALKBH5 covalent inhibitor, W23-1006, through virtual screening and structure optimization. It covalently bonds to the ALKBH5 C200 residue with an IC50 value of 3.848 μM, representing roughly 30- and 8-fold stronger inhibitory activity than that against FTO and ALKBH3, respectively. Cellular experiments demonstrated that W23-1006 could efficiently enhance the m6A level on fibronectin 1 (FN1) mRNA, leading to strong suppression of TNBC cell proliferation and migration in vitro as well as tumor growth and metastasis in vivo. Collectively, our study developed a novel, selective, and cell-active ALKBH5 covalent inhibitor, W23-1006, which could be a potential therapeutic option for cancer, such as TNBC treatment.

Silencing YTHDF2 Induces Apoptosis of Neuroblastoma Cells In a Cell Line-Dependent Manner via Regulating the Expression of DLK1

Neuroblastoma (NB) is the most common extracranial malignant solid tumor in children. The complications caused by traditional chemoradiotherapy seriously affect the quality of life of patients with NB. In this study, NGP, KCNR, and SH-SY5Y (SY5Y) cell lines were used. Retinoic acid (RA, 5 µM) was used to treat NB cells for 48 h. siRNAs were used to silence the expression of DLK1 or YTHDF2. Cell confluence was analyzed using IncuCyte ZOOM to evaluate cell proliferation of NB cells. RT-qPCR and western blotting were performed to detect the expression of target molecules. Annexin V/PI staining and Caspase-Glo 3/7 assay were performed to detect cell apoptosis. RNA m6A quantification, MeRIP-qPCR, and RIP-qPCR were performed. Results showed that RA treatment decreased the expression of DLK1 and YTHDF2 in NB cells, and low expression of DLK1 was correlated with good prognosis of patients. Knockdown of the expression of DLK1 or YTHDF2 inhibited cell proliferation and induced apoptosis of SY5Y cells, but not NGP and KCNR cells. Furthermore, we found that there are m6A modification sites in DLK1 mRNA, and the expression of m6A modified DLK1 mRNA increased after RA treatment, and YTHDF2 regulates the expression level of DLK1, and the expression of YTHDF2-bound DLK1 mRNA decreased after RA treatment. These suggest that YTHDF2 may regulate the proliferation and apoptosis of NB cells in a cell line-dependent manner by binding to the m6A modification site of DLK1 mRNA to affect its expression, and YTHDF2 and DLK1 are potential therapeutic targets for patients with NB.

N 6-methyladenosine reader YTHDF2 in cell state transition and antitumor immunity

Recent studies have revealed that the YTHDF family proteins bind preferentially to the N 6-methyladenosine (m6A)-modified mRNA and regulate the functions of these RNAs in different cell types. YTHDF2, the first identified m6A reader in mammals, has garnered significant attention because of its profound effect to regulate the m6A epitranscriptome in multiple biological processes. Here, we review current knowledge on the mechanisms by which YTHDF2 exerts its functions and discuss recent advances that underscore the multifaceted role of YTHDF2 in development, stem cell expansion, and immune evasion. We also highlight potential therapeutic interventions targeting the m6A/YTHDF2 axis to improve the response to current antitumor therapies.

Epigenetic regulation in female reproduction: the impact of m6A on maternal-fetal health

With the development of public health, female diseases have become the focus of current concern. The unique reproductive anatomy of women leads to the development of gynecological diseases gradually become an important part of the socio-economic burden. Epigenetics plays an irreplaceable role in gynecologic diseases. As an important mRNA modification, m6A is involved in the maturation of ovum cells and maternal-fetal microenvironment. At present, researchers have found that m6A is involved in the regulation of gestational diabetes and other reproductive system diseases, but the specific mechanism is not clear. In this manuscript, we summarize the components of m6A, the biological function of m6A, the progression of m6A in the maternal-fetal microenvironment and a variety of gynecological diseases as well as the progression of targeted m6A treatment-related diseases, providing a new perspective for clinical treatment-related diseases.

The diverse landscape of RNA modifications in cancer development and progression

BACKGROUND

RNA modifications, a central aspect of epitranscriptomics, add a regulatory layer to gene expression by modifying RNA function without altering nucleotide sequences. These modifications play vital roles across RNA species, influencing RNA stability, translation, and interaction dynamics, and are regulated by specific enzymes that add, remove, and interpret these chemical marks.

OBJECTIVE

This review examines the role of aberrant RNA modifications in cancer progression, exploring their potential as diagnostic and prognostic biomarkers and as therapeutic targets. We focus on how altered RNA modification patterns impact oncogenes, tumor suppressor genes, and overall tumor behavior.

METHODS

We performed an in-depth analysis of recent studies and advances in RNA modification research, highlighting key types and functions of RNA modifications and their roles in cancer biology. Studies involving preclinical models targeting RNA-modifying enzymes were reviewed to assess therapeutic efficacy and potential clinical applications.

RESULTS

Aberrant RNA modifications were found to significantly influence cancer initiation, growth, and metastasis. Dysregulation of RNA-modifying enzymes led to altered gene expression profiles in oncogenes and tumor suppressors, correlating with tumor aggressiveness, patient outcomes, and response to immunotherapy. Notably, inhibitors of these enzymes demonstrated potential in preclinical models by reducing tumor growth and enhancing the efficacy of existing cancer treatments.

CONCLUSIONS

RNA modifications present promising avenues for cancer diagnosis, prognosis, and therapy. Understanding the mechanisms of RNA modification dysregulation is essential for developing targeted treatments that improve patient outcomes. Further research will deepen insights into these pathways and support the clinical translation of RNA modification-targeted therapies.

Biomolecular condensates in immune cell fate

Fate decisions during immune cell development require temporally precise changes in gene expression. Evidence suggests that the dynamic modulation of these changes is associated with the formation of diverse, membrane-less nucleoprotein assemblies that are termed biomolecular condensates. These condensates are thought to orchestrate fate-determining transcriptional and post-transcriptional processes by locally and transiently concentrating DNA or RNA molecules alongside their regulatory proteins. Findings have established a link between condensate formation and the gene regulatory networks that ensure the proper development of immune cells. Conversely, condensate dysregulation has been linked to impaired immune cell fates, including ageing and malignant transformation. This Review explores the putative mechanistic links between condensate assembly and the gene regulatory frameworks that govern normal and pathological development in the immune system.

YTHDF2 promotes ATP synthesis and immune evasion in B cell malignancies

Long-term durable remission in patients with B cell malignancies following chimeric antigen receptor (CAR)-T cell immunotherapy remains unsatisfactory, often due to antigen escape. Malignant B cell transformation and oncogenic growth relies on efficient ATP synthesis, although the underlying mechanisms remain unclear. Here, we report that YTHDF2 facilitates energy supply and antigen escape in B cell malignancies, and its overexpression alone is sufficient to cause B cell transformation and tumorigenesis. Mechanistically, YTHDF2 functions as a dual reader where it stabilizes mRNAs as a 5-methylcytosine (m5C) reader via recruiting PABPC1, thereby enhancing their expression and ATP synthesis. Concomitantly, YTHDF2 also promotes immune evasion by destabilizing other mRNAs as an N6-methyladenosine (m6A) reader. Small-molecule-mediated targeting of YTHDF2 suppresses aggressive B cell malignancies and sensitizes them to CAR-T cell therapy.

Role of N6-methyladenosine methylation in nasopharyngeal carcinoma: current insights and future prospective

Nasopharyngeal carcinoma (NPC) is a distinct type of head and neck squamous cell carcinoma prevalent in Southern China, Southeast Asia, and North Africa. Despite advances in treatment options, the prognosis for advanced NPC remains poor, underscoring the urgent need to explore its underlying mechanisms and develop novel therapeutic strategies. Epigenetic alterations have been shown to play a key role in NPC progression. Recent studies indicate that dysregulation of RNA modifications in NPC specifically affects tumor-related transcripts, influencing various oncogenic processes. This review provides a comprehensive overview of altered RNA modifications and their regulators in NPC, with a focus on m6A and its regulatory mechanisms. We discuss how m6A RNA modification influences gene expression and affects NPC initiation and progression at the molecular level, analyzing its impact on cancer-related biological functions. Understanding these modifications could reveal new biomarkers and therapeutic targets for NPC, offering promising directions for future research and precision medicine.

Epitranscriptomic RNA m6A Modification in Cancer Therapy Resistance: Challenges and Unrealized Opportunities

Significant advances in the development of new cancer therapies have given rise to multiple novel therapeutic options in chemotherapy, radiotherapy, immunotherapy, and targeted therapies. Although the development of resistance is often reported along with temporary disease remission, there is often tumor recurrence of an even more aggressive nature. Resistance to currently available anticancer drugs results in poor overall and disease-free survival rates for cancer patients. There are multiple mechanisms through which tumor cells develop resistance to therapeutic agents. To date, efforts to overcome resistance have only achieved limited success. Epitranscriptomics, especially related to m6A RNA modification dysregulation in cancer, is an emerging mechanism for cancer therapy resistance. Here, recent studies regarding the contributions of m6A modification and its regulatory proteins to the development of resistance to different cancer therapies are comprehensively reviewed. The promise and potential limitations of targeting these entities to overcome resistance to various anticancer therapies are also discussed.

Single-cell transcriptome profiling of m6A regulator-mediated methylation modification patterns in elderly acute myeloid leukemia patients

Millions of people worldwide die of acute myeloid leukaemia (AML) each year. Although N6-methyladenosine (m6A) modification has been reported to regulate the pathogenicity of AML, the mechanisms by which m6A induces dysfunctional hematopoietic differentiation in elderly AML patients remain elusive. This study elucidates the mechanisms of the m6A landscape and the specific roles of m6A regulators in hematopoietic cells of elderly AML patients. Notably, fat mass and obesity-associated protein (FTO) was found to be upregulated in hematopoietic stem cells (HSCs), myeloid cells, and T-cells, where it inhibits their differentiation via the WNT signaling pathway. Additionally, elevated YT521-B homology domain family proteins 2 (YTHDF2) expression in erythrocytes was observed to negatively regulate differentiation through oxidative phosphorylation, resulting in leukocyte activation. Moreover, IGF2BP2 was significantly upregulated in myeloid cells, contributing to an aberrant chromosomal region and disrupted oxidative phosphorylation. m6A regulators were shown to induce abnormal cell-cell communication within hematopoietic cells, mediating ligand-receptor interactions across various cell types through the HMGB1-mediated pathway, thereby promoting AML progression. External validation was conducted using an independent single-cell RNA sequencing (scRNA-Seq) dataset. The THP-1 and MV411 cell lines were utilized to corroborate the m6A regulator profile; in vitro experiments involving short hairpin RNA (shRNA) targeting FTO demonstrated inhibition of cell proliferation, migration, and oxidative phosphorylation, alongside induction of cell cycle arrest and apoptosis. In summary, these findings suggest that the upregulation of m6A regulators in HSCs, erythrocytes, myeloid cells, and T-cells may contribute to the malignant differentiation observed in AML patients. This research provides novel insights into the pathogenesis of AML in elderly patients and identifies potential therapeutic targets.

m6A reader YTHDF2 orchestrates CD8+ T cell infiltration to promote pancreatic cancer progression and predicts clinical outcome

Pancreatic cancer has emerged as one of the most lethal malignancies, characterized by rising morbidity and mortality rates. Research has demonstrated that N6-methyladenosine (m6A) modification of RNA significantly influences RNA metabolism, and dysregulation of m6A is implicated in various human diseases. A clearer picture of how the divergent m6A methylation patterns affect immunological microenvironment in pancreatic cancer is still unknown. Based on an analysis of RNA-sequencing (RNA-seq) data from the TCGA, GEO, and GTEx databases, we predicted and validated the expression of YTHDF2. Apoptosis and cell cycle analyses of YTHDF2 were conducted using flow cytometry, and a subcutaneous transplantation tumor model was established in BALB/c nude mice. The immune infiltration status and Weighted Gene Co-expression Network Analysis (WGCNA) were employed to evaluate cellular immunity and identify downstream target genes associated with the CD8+ T cell module. Additionally, machine learning-based integrative approaches were utilized to generate a predictive signature. The Western blot technique was employed to quantify YTHDF2 expression levels in PDAC cell lines and tissues. WGCNA and PPI unveiled TFG as the core gene regulation network conducting the function of the CD8+ T cell. Quantitative reverse transcription PCR (qRT-PCR) assays were conducted to confirm the reduction in TFG expression subsequent to YTHDF2 knockdown. Integrative analyses using large-scale genomic data sets were conducted to reveal that YTHDF2 could affect pancreatic cancer cell apoptosis and the cell cycle, promote malignant biologic processes, and gene regulation in immune cells. YTHDF2 potentially modulates crucial molecular subgroups of immune checkpoint molecules in CD8+ T cells, thereby enhancing tumor immunogenicity and promoting anti-tumor immune responses.

The three YTHDF paralogs and VIRMA are strong cross-histotype tumor driver candidates among m6A core genes

N6-Methyladenosine (m6A) is the most abundant internal modification in mRNAs. Despite accumulating evidence for the profound impact of m6A on cancer biology, there are conflicting reports that alterations in genes encoding the m6A machinery proteins can either promote or suppress cancer, even in the same tumor type. Using data from The Cancer Genome Atlas, we performed a pan-cancer investigation of 15 m6A core factors in nearly 10000 samples from 31 tumor types to reveal underlying cross-tumor patterns. Altered expression, largely driven by copy number variations at the chromosome arm level, results in the most common mode of dysregulation of these factors. YTHDF1, YTHDF2, YTHDF3 and VIRMA are the most frequently altered factors and the only ones to be uniquely altered when tumors are grouped according to the expression pattern of the m6A factors. These genes are also the only ones with coherent, pan-cancer predictive power for progression-free survival. On the contrary, METTL3, the most intensively studied m6A factor as a cancer target, shows much lower levels of alteration and no predictive power for patient survival. Therefore, we propose the non-enzymatic YTHDF and VIRMA genes as preferred subjects to dissect the role of m6A in cancer and as priority cancer targets.

Biological functions of the m6A reader YTHDF2 and its role in central nervous system disorders

N6-methyladenosine (m6A) is a prevalent mRNA modification in eukaryotic cells, characterized by its reversible nature. YTH structural domain family protein 2 (YTHDF2), a key reader of m6A, plays a crucial role in identifying and binding m6A-containing RNAs, thereby influencing RNA metabolism through various functional mechanisms. The upstream and downstream targets of YTHDF2 are critical in the pathogenesis of various central nervous system (CNS) diseases, affecting disease development by regulating signaling pathways and gene expression. This paper provides an overview of current research on the role of YTHDF2 in CNS diseases and investigates the regulatory mechanisms by which YTHDF2 influences the development of these conditions. This exploration aims to improve understanding of disease pathogenesis and offer novel insights for the targeted prevention and treatment of neurological disorders.

Comprehensive analysis of m6A methylome alterations after azacytidine plus venetoclax treatment for acute myeloid leukemia by nanopore sequencing

N6 adenosine methylation (m6A), one of the most prevalent internal modifications on mammalian RNAs, regulates RNA transcription, stabilization, and splicing. Growing evidence has focused on the functional role of m6A regulators on acute myeloid leukemia (AML). However, the global m6A levels after azacytidine (AZA) plus venetoclax (VEN) treatment in AML patients remain unclear. In our present study, bone marrow (BM) sample pairs (including pre-treatment [AML] and post-treatment [complete remission (CR)] samples) were harvested from three AML patients who had achieved CR after AZA plus VEN treatment for Nanopore direct RNA sequencing. Notably, the amount of m6A sites and the m6A levels in CR BMs was significantly lower than those in the AML BMs. Such a significant reduction in the m6A levels was also detected in AZA-treated HL-60 cells. Thirteen genes with decreased m6A and expression levels were identified, among which three genes (HPRT1, SNRPC, and ANP32B) were closely related to the prognosis of AML. Finally, we speculated the mechanism via which m6A modifications affected the mRNA stability of these three genes. In conclusion, we illustrated for the first time the global landscape of m6A levels in AZA plus VEN treated AML (CR) patients and revealed that AZA had a significant demethylation effect at the RNA level in AML patients. In addition, we identified new biomarkers for AZA plus VEN-treated AML via Nanopore sequencing technology in RNA epigenetics.

RNA modifications: emerging players in the regulation of reproduction and development

The intricate world of RNA modifications, collectively termed the epitranscriptome, covers over 170 identified modifications and impacts RNA metabolism and, consequently, almost all biological processes. In this review, we focus on the regulatory roles and biological functions of a panel of dominant RNA modifications (including m 6A, m 5C, Ψ, ac 4C, m 1A, and m 7G) on three RNA types-mRNA, tRNA, and rRNA-in mammalian development, particularly in the context of reproduction as well as embryonic development. We discuss in detail how those modifications, along with their regulatory proteins, affect RNA processing, structure, localization, stability, and translation efficiency. We also highlight the associations among dysfunctions in RNA modification-related proteins, abnormal modification deposition and various diseases, emphasizing the roles of RNA modifications in critical developmental processes such as stem cell self-renewal and cell fate transition. Elucidating the molecular mechanisms by which RNA modifications influence diverse developmental processes holds promise for developing innovative strategies to manage developmental disorders. Finally, we outline several unexplored areas in the field of RNA modification that warrant further investigation.

Metabolic regulation of the glioblastoma stem cell epitranscriptome by malate dehydrogenase 2

Tumors reprogram their metabolism to generate complex neoplastic ecosystems. Here, we demonstrate that glioblastoma (GBM) stem cells (GSCs) display elevated activity of the malate-aspartate shuttle (MAS) and expression of malate dehydrogenase 2 (MDH2). Genetic and pharmacologic targeting of MDH2 attenuated GSC proliferation, self-renewal, and in vivo tumor growth, partially rescued by aspartate. Targeting MDH2 induced accumulation of alpha-ketoglutarate (αKG), a critical co-factor for dioxygenases, including the N6-methyladenosine (m6A) RNA demethylase AlkB homolog 5, RNA demethylase (ALKBH5). Forced expression of MDH2 increased m6A levels and inhibited ALKBH5 activity, both rescued by αKG supplementation. Reciprocally, targeting MDH2 reduced global m6A levels with platelet-derived growth factor receptor-β (PDGFRβ) as a regulated transcript. Pharmacological inhibition of MDH2 in GSCs augmented efficacy of dasatinib, an orally bioavailable multi-kinase inhibitor, including PDGFRβ. Collectively, stem-like tumor cells reprogram their metabolism to induce changes in their epitranscriptomes and reveal possible therapeutic paradigms.

YTHDF2 upregulation and subcellular localization dictate CD8 T cell polyfunctionality in anti-tumor immunity

RNA methylation is an important regulatory process to determine immune cell function but how it affects the anti-tumor activity of CD8 T cells is not fully understood. Here we show that the N6-methyladenosine (m6A) RNA reader YTHDF2 is highly expressed in early effector or effector-like CD8 T cells. We find that YTHDF2 facilitates nascent RNA synthesis, and m6A recognition is fundamental for this distinctively nuclear function of the protein, which also reinforces its autoregulation at the RNA level. Loss of YTHDF2 in T cells exacerbates tumor progression and confers unresponsiveness to PD-1 blockade in mice and in humans. In addition to initiating RNA decay that is necessary for mitochondrial fitness, YTHDF2 orchestrates chromatin changes that promote T cell polyfunctionality. YTHDF2 interacts with IKZF1/3, which is important for sustained transcription of their target genes. Accordingly, immunotherapy-induced efficacy could be largely restored in YTHDF2-deficient T cells through combinational use of IKZF1/3 inhibitor lenalidomide in a mouse model. Thus, YTHDF2 coordinates epi-transcriptional and transcriptional networks to potentiate T cell immunity, which could inform therapeutic intervention.

A primer for junior trainees: Recognition of RNA modifications by RNA-binding proteins

The complexity of RNA cannot be fully expressed with the canonical A, C, G, and U alphabet. To date, over 170 distinct chemical modifications to RNA have been discovered in living systems. RNA modifications can profoundly impact the cellular outcomes of messenger RNAs (mRNAs), transfer and ribosomal RNAs, and noncoding RNAs. Additionally, aberrant RNA modifications are associated with human disease. RNA modifications are a rising topic within the fields of biochemistry and molecular biology. The role of RNA modifications in gene regulation, disease pathogenesis, and therapeutic applications increasingly captures the attention of the scientific community. This review aims to provide undergraduates, junior trainees, and educators with an appreciation for the significance of RNA modifications in eukaryotic organisms, alongside the skills required to identify and analyze fundamental RNA-protein interactions. The pumilio RNA-binding protein and YT521-B homology (YTH) family of modified RNA-binding proteins serve as examples to highlight the fundamental biochemical interactions that underlie the specific recognition of both unmodified and modified ribonucleotides, respectively. By instilling these foundational, textbook concepts through practical examples, this review contributes an analytical toolkit that facilitates engagement with RNA modifications research at large.

RNA modification in normal hematopoiesis and hematologic malignancies

N6-methyladenosine (m6A) is the most abundant RNA modification in eukaryotic cells. Previous studies have shown that m6A plays a critical role under both normal physiological and pathological conditions. Hematopoiesis and differentiation are highly regulated processes, and recent studies on m6A mRNA methylation have revealed how this modification controls cell fate in both normal and malignant hematopoietic states. However, despite these insights, a comprehensive understanding of its complex roles between normal hematopoietic development and malignant hematopoietic diseases remains elusive. This review first provides an overview of the components and biological functions of m6A modification regulators. Additionally, it highlights the origin, differentiation process, biological characteristics, and regulatory mechanisms of hematopoietic stem cells, as well as the features, immune properties, and self-renewal pathways of leukemia stem cells. Last, the article systematically reviews the latest research advancements on the roles and mechanisms of m6A regulatory factors in normal hematopoiesis and related malignant diseases. More importantly, this review explores how targeting m6A regulators and various signaling pathways could effectively intervene in the development of leukemia, providing new insights and potential therapeutic targets. Targeting m6A modification may hold promise for achieving more precise and effective leukemia treatments.

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.

The m6A methyltransferase METTL14 promotes cell proliferation via SETBP1-mediated activation of PI3K-AKT signaling pathway in myelodysplastic neoplasms

N6-methyladenosine (m6A) is the most prevalent epitranscriptomic modification in mammalian mRNA. Recent studies have revealed m6A is involved in the pathogenesis of various malignant tumors including hematologic neoplasms. Nevertheless, the specific roles of m6A modification and m6A regulators in myelodysplastic neoplasms (MDS) remain poorly understood. Herein, we demonstrated that m6A level and the expression of m6A methyltransferase METTL14 were elevated in MDS patients with bone marrow blasts ≥5%. Additionally, m6A level and METTL14 expression were upregulated as the disease risk increased and significantly associated with adverse clinical outcomes. Knockdown of METTL14 inhibited cell proliferation and colony formation ability of MDS cells. Moreover, in vivo experiments showed METTL14 knockdown remarkably reduced tumor burden and prolonged the survival of mice. Mechanistically, METTL14 facilitated the m6A modification of SETBP1 mRNA by formation of METTL3-METTL14 complex, leading to increased stabilization of SETBP1 mRNA and subsequent activation of the PI3K-AKT signaling pathway. Overall, this study elucidated the involvement of the METTL14/m6A/SETBP1/PI3K-AKT signaling axis in MDS, highlighting the therapeutic potential of targeting METTL3-METTL14 complex-mediated m6A modification for MDS therapy.

Dynamic RNA methylation modifications and their regulatory role in mammalian development and diseases

Among over 170 different types of chemical modifications on RNA nucleobases identified so far, RNA methylation is the major type of epitranscriptomic modifications existing on almost all types of RNAs, and has been demonstrated to participate in the entire process of RNA metabolism, including transcription, pre-mRNA alternative splicing and maturation, mRNA nucleus export, mRNA degradation and stabilization, mRNA translation. Attributing to the development of high-throughput detection technologies and the identification of both dynamic regulators and recognition proteins, mechanisms of RNA methylation modification in regulating the normal development of the organism as well as various disease occurrence and developmental abnormalities upon RNA methylation dysregulation have become increasingly clear. Here, we particularly focus on three types of RNA methylations: N6-methylcytosine (m6A), 5-methylcytosine (m5C), and N7-methyladenosine (m7G). We summarize the elements related to their dynamic installment and removal, specific binding proteins, and the development of high-throughput detection technologies. Then, for a comprehensive understanding of their biological significance, we also overview the latest knowledge on the underlying mechanisms and key roles of these three mRNA methylation modifications in gametogenesis, embryonic development, immune system development, as well as disease and tumor progression.

Metabolic dependencies of acute myeloid leukemia stem cells

Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy primarily driven by an immature population of AML cells termed leukemia stem cells (LSCs) that are implicated in AML development, chemoresistance, and relapse. An emerging area of research in AML focuses on identifying and targeting the aberrant metabolism in LSCs. Dysregulated metabolism is involved in sustaining functional properties of LSCs, impeding myeloid differentiation, and evading programmed cell death, both in the process of leukemogenesis and in response to chemotherapy. This review discusses recent discoveries regarding the aberrant metabolic processes of AML LSCs that have begun to change the therapeutic landscape of AML.

Functions of N6-methyladenosine (m6A) RNA modifications in acute myeloid leukemia

N6-methyladenosine is the most common modification of eukaryotic RNA. N6-methyladenosine participates in RNA splicing, nuclear export, translation, and degradation through regulation by methyltransferases, methylation readers, and demethylases, affecting messenger RNA stability and translation efficiency. Through the dynamic and reversible regulatory network composed of "writers, erasers, and readers," N6-methyladenosine modification plays a unique role in the process of hematopoiesis. Acute myeloid leukemia is a heterogeneous disease characterized by malignant proliferation of hematopoietic stem cells/progenitor cells. Many studies have shown that N6-methyladenosine-related proteins are abnormally expressed in acute myeloid leukemia and play an important role in the occurrence and development of acute myeloid leukemia, acting as carcinogenic or anticancer factors. Here, we describe the mechanisms of action of reversing N6-methyladenosine modification in hematopoiesis and acute myeloid leukemia occurrence and progression to provide a basis for further research on the role of N6-methyladenosine methylation and its regulatory factors in normal hematopoiesis and acute myeloid leukemia, to ultimately estimate its potential clinical value.

METTL14-mediated N6-methyladenosine modification of TCP1 mRNA promotes acute myeloid leukemia progression

BACKGROUND

Acute myeloid leukemia (AML) is a prevalent hematologic malignancy characterized by a steady rise in morbidity and mortality rates over time. The upregulation of methyltransferase-like 14 (METTL14) expression in AML has been identified; however, its specific contributions to AML progression and underlying molecular mechanisms have yet to be elucidated.

METHOD

METTL14-bound mRNAs were predicted using bioinformatics methods, analyzed, and screened to identify T-complex protein 1 (TCP1). The regulatory impact of METTL14 on TCP1 was observed. TCP1 expression in AML clinical samples was assessed using quantitative real-time PCR and western blot analysis. The involvement of TCP1 in AML malignant progression was assessed through in vitro and in vivo functional assays. The String database was utilized for predicting proteins that interact with TCP1, while western blot assays and immunoprecipitation were employed to validate the associated signaling pathways.

RESULTS

METTL14 overexpression upregulates TCP1 expression in AML cells. AML patients exhibit high levels of TCP1 expression. Elevated TCP1 levels in HL60 and U937 cells in vitro lead to increased proliferation, migration, invasion, and inhibition of apoptosis, while in vivo, it accelerates AML proliferation and tumorigenesis. Mechanistically, METTL14 modulates AML progression by influencing TCP1 transcript stability via m6A methylation, thereby regulating TCP1 expression. Additionally, PPP2R2C potentially serves as a crucial functional target of TCP1 implicated in the malignant progression of AML.

CONCLUSION

Upregulation of TCP1 expression in AML through METTL14-mediated m6A modification accelerates the malignant progression of the disease. Therefore, targeting the m6A modification of TCP1 could be a potential therapeutic strategy to enhance the treatment of AML.

Epigenetic modifications in hematopoietic ecosystem: a key tuner from homeostasis to acute myeloid leukemia

Hematopoietic stem cells (HSCs) maintain homeostasis in the hematopoietic ecosystem, which is tightly regulated at multiple layers. Acute myeloid leukemia (AML) is a severe hematologic malignancy driven by genetic and epigenetic changes that lead to the transformation of leukemia stem cells (LSCs). Since somatic mutations in DNA methylation-related genes frequently occur in AML, DNA methylation is widely altered and functions as a starting engine for initiating AML. Additionally, RNA modifications, especially N6-methyladenosine (m6A), also play an important role in the generation and maintenance of the hematopoietic ecosystem, and AML development requires reprogramming of m6A modifications to facilitate cells with hallmarks of cancer. Given the complex pathogenesis and poor prognosis of AML, it is important to fully understand its pathogenesis. Here, we mainly focus on DNA methylation and RNA m6A modification in hematopoiesis and AML and summarize recent advances in this field.

Role of RNA modifications in blood development and regeneration

Blood development and regeneration require rapid turnover of cells, and ribonucleic acid (RNA) modifications play a key role in it via regulating stemness and cell fate regulation. RNA modifications affect gene activity via posttranscriptional and translation-mediated mechanisms. Diverse molecular players involved in RNA-modification processes are abundantly expressed by hematopoietic stem cells and lineages. Close to 150 RNA chemical modifications have been reported, but only N6-methyl adenosine (m6A), inosine (I), pseudouridine (Ψ), and m1A-a handful-have been studied in-cell fate regulation. The role of RNA modification in blood diseases and disorders is an emerging field and offers potential for therapeutic interventions. Knowledge of RNA-modification and enzymatic activities could be used to design therapies in the future. Here, we summarized the recent advances in RNA modification and the epitranscriptome field and discussed their regulation of blood development and regeneration.

Wilms' Tumor 1-Associating Protein Promotes Nonsmall-Cell Lung Cancer Through the Expression of Carcinoembryonic Antigen-Related Cell Adhesion Molecule 5

OBJECTIVE

This study aimed to analyze the functional roles and molecular mechanism of Wilms' tumor 1-associating protein (WTAP) in the tumorigenesis of nonsmall-cell lung cancer (NSCLC).

METHODS

Retrospective analysis was used. Tumor tissues and surrounding nontumor tissues of 150 patients with NSCLS who were surgically resected in the Fourth Hospital of Hebei Medical University from January 2016 to January 2018 were selected. The expression of WTAP in NSCLC tissues was detected by immunohistochemistry. Clinicopathologic parameters were then subjected to univariate and multivariate Cox regression analysis in purpose of uncovering the independent risk factors for overall survival time. MTS (3-[4,5-dimethylthiazol-zyl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazoliuzolium, inner salt) assay, colony formation assay, and transwell assays were performed to estimate cell proliferation, migration, and invasion. Meanwhile, the relationship between WTAP and the cell migration and invasion marker-related proteins were evaluated by Western blot analysis and RT-qPCR. WTAP expression was knocked-down in cell lines by shRNA, and RNA-Seq was performed to investigate the pathways regulated by WTAP.

RESULTS

In NSCLC patients, WTAP was highly expressed in tumor tissues and the higher expression was significantly associated with poor overall survival (OS) ( P <0.01). Compared with the control group in vitro, the overexpression of WTAP could significantly promote cell proliferation, migration, and invasion ( P <0.01), while knock-down WTAP significantly reduces the above effects ( P <0.01). In a mouse orthotopic implantation model, higher WTAP abundance could significantly promote tumor enlargement compared with the control group ( P <0.01). Compared with the control group, the knock-down of WTAP significantly inhibit the expression of carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) in cell lines ( P <0.01). Besides, in NSCLC, knocked-down CEACAM5 significantly reduced the impact of WTAP on cell proliferation, migration, and invasion compared with the control group ( P <0.05).

CONCLUSIONS

This study suggests that high expression of WTAP was associated with poor clinical outcomes. CEACAM5 may play a synergistic role with WTAP to jointly promote NSCLC progression by enhancing cell proliferation, invasion, and migration.

Reading the m6A-encoded epitranscriptomic information in development and diseases

N6-methyladenosine (m6A) represents the most prevalent internal and reversible modification on RNAs. Different cell types display their unique m6A profiles, which are determined by the functions of m6A writers and erasers. M6A modifications lead to different outcomes such as decay, stabilization, or transport of the RNAs. The m6A-encoded epigenetic information is interpreted by m6A readers and their interacting proteins. M6A readers are essential for different biological processes, and the defects in m6A readers have been discovered in diverse diseases. Here, we review the latest advances in the roles of m6A readers in development and diseases. These recent studies not only highlight the importance of m6A readers in regulating cell fate transitions, but also point to the potential application of drugs targeting m6A readers in diseases.

RNA modifications in physiology and pathology: Progressing towards application in clinical settings

The potential to modify individual nucleotides through chemical means in order to impact the electrostatic charge, hydrophobic properties, and base pairing of RNA molecules is harnessed in the medical application of stable synthetic RNAs like mRNA vaccines and synthetic small RNA molecules. These modifications are used to either increase or decrease the production of therapeutic proteins. Additionally, naturally occurring biochemical alterations of nucleotides play a role in regulating RNA metabolism and function, thereby modulating essential cellular processes. Research elucidating the mechanisms through which RNA modifications govern fundamental cellular functions in multicellular organisms has enhanced our comprehension of how irregular RNA modification profiles can lead to human diseases. Collectively, these fundamental scientific findings have unveiled the molecular and cellular functions of RNA modifications, offering new opportunities for therapeutic intervention and paving the way for a variety of innovative clinical strategies.

Targeting YTHDF2 inhibits tumorigenesis of diffuse large B-cell lymphoma through ACER2-mediated ceramide catabolism

INTRODUCTION

Epigenetic alterations play crucial roles in diffuse large B-cell lymphoma (DLBCL). Disturbances in lipid metabolism contribute to tumor progression. However, studies in epigenetics, especially its critical regulator YTH N6-methyladenosine RNA binding protein 2 (YTHDF2), on lipid metabolism regulation in DLBCL are unidentified.

OBJECTIVES

Elucidate the prognostic value and biological functions of YTHDF2 in DLBCL and illuminate the underlying epigenetic regulation mechanism of lipid metabolism by YTHDF2 in DLBCL development.

METHODS

The expression and clinical value of YTHDF2 in DLBCL were performed in public databases and clinical specimens. The biological functions of YTHDF2 in DLBCL were determined in vivo and in vitro through overexpression and CRISPR/Cas9-mediated knockout of YTHDF2. RNA sequencing, lipidomics, methylated RNA immunoprecipitation sequencing, RNA immunoprecipitation-qPCR, luciferase activity assay, and RNA stability experiments were used to explore the potential mechanism by which YTHDF2 contributed to DLBCL progression.

RESULTS

YTHDF2 was highly expressed in DLBCL, and related to poor prognosis. YTHDF2 overexpression exerted a tumor-promoting effect in DLBCL, and knockdown of YTHDF2 restricted DLBCL cell proliferation, arrested cell cycle in the G2/M phase, facilitated apoptosis, and enhanced drug sensitivity to ibrutinib and venetoclax. In addition, YTHDF2 knockout drastically suppressed tumor growth in xenograft DLBCL models. Furthermore, a regulatory role of YTHDF2 in ceramide metabolism was identified in DLBCL cells. Exogenous ceramide effectively inhibited the malignant phenotype of DLBCL cells in vitro. The binding of YTHDF2 to m6A sites on alkaline ceramidase 2 (ACER2) mRNA promoted its stability and expression. Enhanced ACER2 expression hydrolyzed ceramides, disrupting the balance between ceramide and sphingosine-1-phosphate (S1P), activating the ERK and PI3K/AKT pathways, and leading to DLBCL tumorigenesis.

CONCLUSION

This study demonstrated that YTHDF2 contributed to the progression of DLBCL by regulating ACER2-mediated ceramide metabolism in an m6A-dependent manner, providing novel insights into targeted therapies.

Functions and mechanisms of RNA m6A regulators in breast cancer (Review)

Breast cancer (BC) is a major malignant tumor in females and the incidence rate of BC has increased worldwide in recent years. N6‑methyladenosine (m6A) is a methylation modification that occurs extensively in eukaryotic RNA. The abnormal expression of m6A and related regulatory proteins can activate or inhibit certain signal pathways or oncogenes, thus affecting the proliferation, metastasis and prognosis of BC. Numerous studies have shown that m6A regulator disorder exists in BC, and this disorder can be reversed. Therefore, m6A is predicted as a potential therapeutic target for BC. However, the molecular mechanism of m6A RNA methylation regulating the occurrence and development of BC has not been comprehensively elucidated. In this review article, the functions of various m6A regulators and the specific mechanisms of certain regulators of the progress of BC were summarized. Furthermore, the dual role of RNA methylation in tumor progression was discussed, concluding that RNA methylation can not only lead to tumorigenesis but at times give rise to inhibition of tumor formation. In addition, further comprehensive analysis on mechanisms of m6A regulators in BC is conducive to screening effective potential targets and formulating targeted treatment strategies, which will provide new methods for the prevention and treatment of BC.

RNA m6A methylation regulators in sepsis

N6-methyladenosine (m6A) modification is a class of epitope modifications that has received significant attention in recent years, particularly in relation to its role in various diseases, including sepsis. Epigenetic research has increasingly focused on m6A modifications, which is influenced by the dynamic regulation of three protein types: ‟Writers" (such as METTL3/METTL14/WTAP)-responsible for m6A modification; ‟Erasers" (FTO and ALKBH5)-involved in m6A de-modification; and ‟Readers" (YTHDC1/2, YTHDF1/2/3)-responsible for m6A recognition. Sepsis, a severe and fatal infectious disease, has garnered attention regarding the crucial effect of m6A modifications on its development. In this review, we attempted to summarize the recent studies on the involvement of m6A and its regulators in sepsis, as well as the significance of m6A modifications and their regulators in the development of novel drugs and clinical treatment. The potential value of m6A modifications and modulators in the diagnosis, treatment, and prognosis of sepsis has also been discussed.

The potential of RNA methylation in the treatment of cardiovascular diseases

RNA methylation has emerged as a dynamic regulatory mechanism that impacts gene expression and protein synthesis. Among the known RNA methylation modifications, N6-methyladenosine (m6A), 5-methylcytosine (m5C), 3-methylcytosine (m3C), and N7-methylguanosine (m7G) have been studied extensively. In particular, m6A is the most abundant RNA modification and has attracted significant attention due to its potential effect on multiple biological processes. Recent studies have demonstrated that RNA methylation plays an important role in the development and progression of cardiovascular disease (CVD). To identify key pathogenic genes of CVD and potential therapeutic targets, we reviewed several common RNA methylation and summarized the research progress of RNA methylation in diverse CVDs, intending to inspire effective treatment strategies.

RNA binding protein-directed control of leukemic stem cell evolution and function

Strict control over hematopoietic stem cell decision making is essential for healthy life-long blood production and underpins the origins of hematopoietic diseases. Acute myeloid leukemia (AML) in particular is a devastating hematopoietic malignancy that arises from the clonal evolution of disease-initiating primitive cells which acquire compounding genetic changes over time and culminate in the generation of leukemic stem cells (LSCs). Understanding the molecular underpinnings of these driver cells throughout their development will be instrumental in the interception of leukemia, the enabling of effective treatment of pre-leukemic conditions, as well as the development of strategies to target frank AML disease. To this point, a number of precancerous myeloid disorders and age-related alterations are proving as instructive models to gain insights into the initiation of LSCs. Here, we explore this myeloid dysregulation at the level of post-transcriptional control, where RNA-binding proteins (RBPs) function as core effectors. Through regulating the interplay of a myriad of RNA metabolic processes, RBPs orchestrate transcript fates to govern gene expression in health and disease. We describe the expanding appreciation of the role of RBPs and their post-transcriptional networks in sustaining healthy hematopoiesis and their dysregulation in the pathogenesis of clonal myeloid disorders and AML, with a particular emphasis on findings described in human stem cells. Lastly, we discuss key breakthroughs that highlight RBPs and post-transcriptional control as actionable targets for precision therapy of AML.

Knockdown of YTHDF2 initiates ERS-induced apoptosis and cancer stemness suppression by sustaining GLI2 stability in cervical cancer

Cervical cancer ranks fourth in women in terms of incidence and mortality. The RNA-binding protein YTH N6-methyladenosine RNA-binding protein F2 (YTHDF2) contributes to cancer progression by incompletely understood mechanisms. We show how YTHDF2 controls the fate of cervical cancer cells and whether YTHDF2 could be a valid target for the therapy of cervical cancer. Sphere formation and alkaline phosphatase staining assays were performed to evaluate tumor stemness of cervical cancer cells following YTHDF2 knockdown. Apoptosis was detected by flow cytometry and TUNEL assay. The compounds 4PBA and SP600125 were used to investigate the correlation between JNK, endoplasmic reticulum stress, tumor stemness, and apoptosis. Data from The Cancer Genome Atlas (TCGA) databases and Gene Expression Omnibus (GEO) revealed that GLI family zinc finger 2 (GLI2) might be the target of YTHDF2. The transcription inhibitor actinomycin D and dual-luciferase reporter gene assays were employed to investigate the association between the GLI2 mRNA and YTHDF2. Nude mouse xenografts were generated to assess the effects of YTHDF2 knockdown on cervical cancer growth in vivo. Knockdown of YTHDF2 up-regulated the expression of GLI2, leading to JNK phosphorylation and endoplasmic reticulum stress. These processes inhibited the proliferation of cervical cancer cells and their tumor cell stemness and promotion of apoptosis. In conclusion, the knockdown of YTHDF2 significantly affects the progression of cervical cancer cells, making it a potential target for treating cervical cancer.