3D proteome-wide scale screening and activity evaluation of a new ALKBH5 inhibitor in U87 glioblastoma cell line

Small molecules that regulate the N6-methyladenosine RNA modification as potential anti-cancer agents

Epitranscriptomics, the field of post-translational RNA modifications, is a burgeoning domain of research that has recently received significant attention for its role in multiple diseases, including cancer. N6-methyladenosine (m6A) is the most prominent post-translational RNA modification and plays a critical role in RNA transcription, processing, translation, and metabolism. The m6A modification is controlled by three protein classes known as writers (methyltransferases), erasers (demethylases), and readers (m6A-binding proteins). Each class of m6A regulatory proteins has been implicated in cancer initiation and progression. As such, many of these proteins have been identified as potential targets for anti-cancer chemotherapeutics. In this work, we provide an overview of the role m6A-regulating proteins play in cancer and discuss the current state of small molecule therapeutics targeting these proteins.

Methylation modifications in tRNA and associated disorders: Current research and potential therapeutic targets

High-throughput sequencing has sparked increased research interest in RNA modifications, particularly tRNA methylation, and its connection to various diseases. However, the precise mechanisms underpinning the development of these diseases remain largely elusive. This review sheds light on the roles of several tRNA methylations (m1A, m3C, m5C, m1G, m2G, m7G, m5U, and Nm) in diverse biological functions, including metabolic processing, stability, protein interactions, and mitochondrial activities. It further outlines diseases linked to aberrant tRNA modifications, related enzymes, and potential underlying mechanisms. Moreover, disruptions in tRNA regulation and abnormalities in tRNA-derived small RNAs (tsRNAs) contribute to disease pathogenesis, highlighting their potential as biomarkers for disease diagnosis. The review also delves into the exploration of drugs development targeting tRNA methylation enzymes, emphasizing the therapeutic prospects of modulating these processes. Continued research is imperative for a comprehensive comprehension and integration of these molecular mechanisms in disease diagnosis and treatment.

Regulations of m6A and other RNA modifications and their roles in cancer

RNA modification is an essential component of the epitranscriptome, regulating RNA metabolism and cellular functions. Several types of RNA modifications have been identified to date; they include N6-methyladenosine (m6A), N1-methyladenosine (m1A), 5-methylcytosine (m5C), N7-methylguanosine (m7G), N6,2'-O-dimethyladenosine (m6Am), N4-acetylcytidine (ac4C), etc. RNA modifications, mediated by regulators including writers, erasers, and readers, are associated with carcinogenesis, tumor microenvironment, metabolic reprogramming, immunosuppression, immunotherapy, chemotherapy, etc. A novel perspective indicates that regulatory subunits and post-translational modifications (PTMs) are involved in the regulation of writer, eraser, and reader functions in mediating RNA modifications, tumorigenesis, and anticancer therapy. In this review, we summarize the advances made in the knowledge of different RNA modifications (especially m6A) and focus on RNA modification regulators with functions modulated by a series of factors in cancer, including regulatory subunits (proteins, noncoding RNA or peptides encoded by long noncoding RNA) and PTMs (acetylation, SUMOylation, lactylation, phosphorylation, etc.). We also delineate the relationship between RNA modification regulator functions and carcinogenesis or cancer progression. Additionally, inhibitors that target RNA modification regulators for anticancer therapy and their synergistic effect combined with immunotherapy or chemotherapy are discussed.

Ferroptosis: a critical mechanism of N6-methyladenosine modification involved in carcinogenesis and tumor progression

Ferroptosis is an iron-dependent regulatory cell necrosis induced by iron overload and lipid peroxidation. It occurs when multiple redox-active enzymes are ectopically expressed or show abnormal function. Hence, the precise regulation of ferroptosis-related molecules is mediated across multiple levels, including transcriptional, posttranscriptional, translational, and epigenetic levels. N6-methyladenosine (m6A) is a highly evolutionarily conserved epigenetic modification in mammals. The m6A modification is commonly linked to tumor proliferation, progression, and therapy resistance because it is involved in RNA metabolic processes. Intriguingly, accumulating evidence suggests that dysregulated ferroptosis caused by the m6A modification drives tumor development. In this review, we summarized the roles of m6A regulators in ferroptosis-mediated malignant tumor progression and outlined the m6A regulatory mechanism involved in ferroptosis pathways. We also analyzed the potential value and application strategies of targeting m6A/ferroptosis pathway in the clinical diagnosis and therapy of tumors.

Clinical Perspectives in Epitranscriptomics

Epitranscriptomics, the study of reversible and dynamic chemical marks on the RNA, is rapidly emerging as a pivotal field in post-transcriptional gene expression regulation. Increasing knowledge about epitranscriptomic landscapes implicated in disease pathogenesis proves an invaluable opportunity for the identification of epitranscriptomic biomarkers and the development of new potential therapeutic drugs. Hence, recent advances in the characterization of these marks and associated enzymes in both health and disease blaze a trail toward the use of epitranscriptomics approaches for clinical applications. Here, we review the latest studies to provide a wide and comprehensive perspective of clinical epitranscriptomics and emphasize its transformative potential in shaping future health care paradigms.

Small molecule inhibitors targeting m6A regulators

As the most common form of epigenetic regulation by RNA, N6 methyladenosine (m6A) modification is closely involved in physiological processes, such as growth and development, stem cell renewal and differentiation, and DNA damage response. Meanwhile, its aberrant expression in cancer tissues promotes the development of malignant tumors, as well as plays important roles in proliferation, metastasis, drug resistance, immunity and prognosis. This close association between m6A and cancers has garnered substantial attention in recent years. An increasing number of small molecules have emerged as potential agents to target m6A regulators for cancer treatment. These molecules target the epigenetic level, enabling precise intervention in RNA modifications and efficiently disrupting the survival mechanisms of tumor cells, thus paving the way for novel approaches in cancer treatment. However, there is currently a lack of a comprehensive review on small molecules targeting m6A regulators for anti-tumor. Here, we have comprehensively summarized the classification and functions of m6A regulators, elucidating their interactions with the proliferation, metastasis, drug resistance, and immune responses in common cancers. Furthermore, we have provided a comprehensive overview on the development, mode of action, pharmacology and structure-activity relationships of small molecules targeting m6A regulators. Our aim is to offer insights for subsequent drug design and optimization, while also providing an outlook on future prospects for small molecule development targeting m6A.

Internal m 6 A and m 7 G RNA modifications in hematopoietic system and acute myeloid leukemia

ABSTRACT

Epitranscriptomics focuses on the RNA-modification-mediated post-transcriptional regulation of gene expression. The past decade has witnessed tremendous progress in our understanding of the landscapes and biological functions of RNA modifications, as prompted by the emergence of potent analytical approaches. The hematopoietic system provides a lifelong supply of blood cells, and gene expression is tightly controlled during the differentiation of hematopoietic stem cells (HSCs). The dysregulation of gene expression during hematopoiesis may lead to severe disorders, including acute myeloid leukemia (AML). Emerging evidence supports the involvement of the mRNA modification system in normal hematopoiesis and AML pathogenesis, which has led to the development of small-molecule inhibitors that target N6-methyladenosine (m 6 A) modification machinery as treatments. Here, we summarize the latest findings and our most up-to-date information on the roles of m 6 A and N7-methylguanine in both physiological and pathological conditions in the hematopoietic system. Furthermore, we will discuss the therapeutic potential and limitations of cancer treatments targeting m 6 A.

Demethylases in tumors and the tumor microenvironment: Key modifiers of N6-methyladenosine methylation

RNA methylation modifications are widespread in eukaryotes and prokaryotes, with N6-methyladenosine (m6A) the most common among them. Demethylases, including Fat mass and obesity associated gene (FTO) and AlkB homolog 5 (ALKBH5), are important in maintaining the balance between RNA methylation and demethylation. Recent studies have clearly shown that demethylases affect the biological functions of tumors by regulating their m6A levels. However, their effects are complicated, and even opposite results have appeared in different articles. Here, we summarize the complex regulatory networks of demethylases, including the most important and common pathways, to clarify the role of demethylases in tumors. In addition, we describe the relationships between demethylases and the tumor microenvironment, and introduce their regulatory mechanisms. Finally, we discuss evaluation of demethylases for tumor diagnosis and prognosis, as well as the clinical application of demethylase inhibitors, providing a strong basis for their large-scale clinical application in the future.

Targeting non-coding RNAs and N6-methyladenosine modification in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common form of primary liver cancers, accounts for a significant portion of cancer-related death globally. However, the molecular mechanisms driving the onset and progression of HCC are still not fully understood. Emerging evidence has indicated that non-protein-coding regions of genomes could give rise to transcripts, termed non-coding RNA (ncRNA), forming novel functional driving force for aberrant cellular activity. Over the past decades, overwhelming evidence has denoted involvement of a complex array of molecular function of ncRNAs at different stages of HCC tumorigenesis and progression. In this context, several pre-clinical studies have highlighted the potentials of ncRNAs as novel therapeutic modalities in the management of human HCC. Moreover, N6-methyladenosine (m6A) modification, the most prevalent form of internal mRNA modifications in mammalian cells, is essential for the governance of biological processes within cells. Dysregulation of m6A in ncRNAs has been implicated in human carcinogenesis, including HCC. In this review, we will discuss dysregulation of several hallmark ncRNAs (miRNAs, lncRNAs, and circRNAs) in HCC and address the latest advances for their involvement in the onset and progression of HCC. We also focus on dysregulation of m6A modification and various m6A regulators in the etiology of HCC. In the end, we discussed the contemporary preclinical and clinical application of ncRNA-based and m6A-targeted therapies in HCC.

Abnormal changes in metabolites caused by m6A methylation modification: The leading factors that induce the formation of immunosuppressive tumor microenvironment and their promising potential for clinical application

BACKGROUND

N6-methyladenosine (m6A) RNA methylation modifications have been widely implicated in the metabolic reprogramming of various cell types within the tumor microenvironment (TME) and are essential for meeting the demands of cellular growth and maintaining tissue homeostasis, enabling cells to adapt to the specific conditions of the TME. An increasing number of research studies have focused on the role of m6A modifications in glucose, amino acid and lipid metabolism, revealing their capacity to induce aberrant changes in metabolite levels. These changes may in turn trigger oncogenic signaling pathways, leading to substantial alterations within the TME. Notably, certain metabolites, including lactate, succinate, fumarate, 2-hydroxyglutarate (2-HG), glutamate, glutamine, methionine, S-adenosylmethionine, fatty acids and cholesterol, exhibit pronounced deviations from normal levels. These deviations not only foster tumorigenesis, proliferation and angiogenesis but also give rise to an immunosuppressive TME, thereby facilitating immune evasion by the tumor.

AIM OF REVIEW

The primary objective of this review is to comprehensively discuss the regulatory role of m6A modifications in the aforementioned metabolites and their potential impact on the development of an immunosuppressive TME through metabolic alterations.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review aims to elaborate on the intricate networks governed by the m6A-metabolite-TME axis and underscores its pivotal role in tumor progression. Furthermore, we delve into the potential implications of the m6A-metabolite-TME axis for the development of novel and targeted therapeutic strategies in cancer research.

A covalent compound selectively inhibits RNA demethylase ALKBH5 rather than FTO

N 6-Methyladenosine (m6A) is the most prevalent mRNA modification and is required for gene regulation in eukaryotes. ALKBH5, an m6A demethylase, is a promising target, particularly for anticancer drug discovery. However, the development of selective and potent inhibitors of ALKBH5 rather than FTO remains challenging. Herein, we used a targeted covalent inhibition strategy and identified a covalent inhibitor, TD19, which selectively inhibits ALKBH5 compared with FTO demethylase in protein-based and tumor cell-based assays. TD19 irreversibly modifies the residues C100 and C267, preventing ALKBH5 from binding to m6A-containing RNA. Moreover, TD19 displays good anticancer efficacy in acute myeloid leukemia and glioblastoma multiforme cell lines. Thus, the ALKBH5 inhibitor developed in this study, which selectively targets ALKBH5 compared with FTO, can potentially be used as a probe for investigating the biological functions of RNA demethylase and as a lead compound in anticancer research.

D-2-HG Inhibits IDH1mut Glioma Growth via FTO Inhibition and Resultant m6A Hypermethylation

IDH1mut gliomas produce high levels of D-2-hydroxyglutarate (D-2-HG), an oncometabolite capable of inhibiting α-ketoglutarate-dependent dioxygenases critical to a range of cellular functions involved in gliomagenesis. IDH1mut gliomas also exhibit slower growth rates and improved treatment sensitivity compared with their IDH1wt counterparts. This study explores the mechanism driving apparent reduced growth in IDH1mut gliomas. Specifically, we investigated the relationship between IDH1mut and the RNA N6-methyladenosine (m6A) demethylases FTO and ALKBH5, and their potential for therapeutic targeting. We investigated the role of D-2-HG and m6A in tumor proliferation/viability using glioma patient tumor samples, patient-derived gliomaspheres, and U87 cells, as well as with mouse intracranial IDH1wt gliomasphere xenografts. Methylation RNA immunoprecipitation sequencing (MeRIP-seq) RNA sequencing was used to identify m6A-enriched transcripts in IDH1mut glioma. We show that IDH1mut production of D-2-HG is capable of reducing glioma cell growth via inhibition of the m6A epitranscriptomic regulator, FTO, with resultant m6A hypermethylation of a set of mRNA transcripts. On the basis of unbiased MeRIP-seq epitranscriptomic profiling, we identify ATF5 as a hypermethylated, downregulated transcript that potentially contributes to increased apoptosis. We further demonstrate how targeting this pathway genetically and pharmacologically reduces the proliferative potential of malignant IDH1wt gliomas, both in vitro and in vivo. Our work provides evidence that selective inhibition of the m6A epitranscriptomic regulator FTO attenuates growth in IDH1wt glioma, recapitulating the clinically favorable growth phenotype seen in the IDH1mut subtype.

SIGNIFICANCE

We show that IDH1mut-generated D-2-HG can reduce glioma growth via inhibition of the m6A demethylase, FTO. FTO inhibition represents a potential therapeutic target for IDH1wt gliomas and possibly in conjunction with IDH1mut inhibitors for the treatment of IDH1mut glioma. Future studies are necessary to demonstrate the role of ATF5 downregulation in the indolent phenotype of IDH1mut gliomas, as well as to identify other involved gene transcripts deregulated by m6A hypermethylation.

Emerging Roles and Mechanisms of RNA Modifications in Neurodegenerative Diseases and Glioma

Despite a long history of research, neurodegenerative diseases and malignant brain tumor gliomas are both considered incurable, facing challenges in the development of treatments. Recent evidence suggests that RNA modifications, previously considered as static components of intracellular RNAs, are in fact dynamically regulated across various RNA species in cells and play a critical role in major biological processes in the nervous system. Innovations in next-generation sequencing have enabled the accurate detection of modifications on bases and sugars within various RNA molecules. These RNA modifications influence the stability and transportation of RNA, and crucially affect its translation. This review delves into existing knowledge on RNA modifications to offer a comprehensive inventory of these modifications across different RNA species. The detailed regulatory functions and roles of RNA modifications within the nervous system are discussed with a focus on neurodegenerative diseases and gliomas. This article presents a comprehensive overview of the fundamental mechanisms and emerging roles of RNA modifications in these diseases, which can facilitate the creation of innovative diagnostics and therapeutics for these conditions.

The epigenetic downregulation of LncGHRLOS mediated by RNA m6A methylase ZCCHC4 promotes colorectal cancer tumorigenesis

BACKGROUND

m6A modification is currently recognized as a major driver of RNA function that maintains cancer cell homeostasis. Long non-coding (Lnc) RNAs control cell proliferation and play an important role in the occurrence and progression of colorectal cancer (CRC). ZCCHC4 is a newly discovered m6A methyltransferase whose role and mechanism in tumors have not yet been elucidated.

METHODS

The EpiQuik m6A RNA methylation kit was used to detect the level of total RNA m6A in six types of digestive tract tumors. The Kaplan-Meier method and receiver operating characteristic curve were used to evaluate the prognostic and diagnostic value of the newly discovered m6A methyltransferase, ZCCHC4, in CRC. The effects on CRC growth in vitro and in vivo were studied using gain- and loss-of-function experiments. The epigenetic mechanisms underlying ZCCHC4 upregulation in CRC were studied using RIP, MeRIP-seq, RNA pull-down, and animal experiments.

RESULTS

We reported that the ZCCHC4-LncRNAGHRLOS-KDM5D axis regulates the growth of CRC in vitro and in vivo. We found that ZCCHC4 was upregulated in primary CRC samples and could predict adverse clinical outcomes in patients with CRC. Mechanistically, ZCCHC4 downregulated LncRNAGHRLOS to promote CRC tumorigenesis. As a downstream molecule of LncRNAGHRLOS, KDM5D directly controls CRC cell proliferation, migration, and invasion.

CONCLUSION

This study suggests that the ZCCHC4 axis contributes to the tumorigenesis and progression of CRC and that ZCCHC4 may be a potential biomarker for this malignancy.

N6-methyladenosine methylation in ophthalmic diseases: From mechanisms to potential applications

N6-methyladenosine (m6A) modification, as the most common modification method in eukaryotes, is widely involved in numerous physiological and pathological processes, such as embryonic development, malignancy, immune regulation, and premature aging. Under pathological conditions of ocular diseases, changes in m6A modification and its metabolism can be detected in aqueous and vitreous humor. At the same time, an increasing number of studies showed that m6A modification is involved in the normal development of eye structures and the occurrence and progress of many ophthalmic diseases, especially ocular neovascular diseases, such as diabetic retinopathy, age-related macular degeneration, and melanoma. In this review, we summarized the latest progress regarding m6A modification in ophthalmic diseases, changes in m6A modification-related enzymes in various pathological states and their upstream and downstream regulatory networks, provided new prospects for m6A modification in ophthalmic diseases and new ideas for clinical diagnosis and treatment.

A review on the role of RNA methylation in aging-related diseases

Senescence is the underlying mechanism of organism aging and is robustly regulated at the post-transcriptional level. This regulation involves the chemical modifications, of which the RNA methylation is the most common. Recently, a rapidly growing number of studies have demonstrated that methylation is relevant to aging and aging-associated diseases. Owing to the rapid development of detection methods, the understanding on RNA methylation has gone deeper. In this review, we summarize the current understanding on the influence of RNA modification on cellular senescence, with a focus on mRNA methylation in aging-related diseases, and discuss the emerging potential of RNA modification in diagnosis and therapy.

Research Advances in the Roles of N6-Methyladenosine Modification in Ovarian Cancer

Ovarian cancer (OC) is the most lethal gynecological tumor, characterized by its insidious and frequently recurring metastatic progression. Owing to limited early screening methods, over 70% of OC cases are diagnosed at advanced stages, typically stage III or IV. Recently, N6-methyladenosine (m6A) modification has emerged as a hotspot of epigenetic research, representing a significant endogenous RNA modification in higher eukaryotes. Numerous studies have reported that m6A-related regulatory factors play pivotal roles in tumor development through diverse mechanisms. Moreover, recent studies have indicated the aberrant expression of multiple regulatory factors in OC. Therefore, this paper comprehensively reviews research advancements concerning m6A in OC, aiming to elucidate the regulatory mechanism of m6A-associated regulators on pivotal aspects, such as proliferation, invasion, metastasis, and drug resistance, in OC. Furthermore, it discusses the potential of m6A-associated regulators as early diagnostic markers and therapeutic targets, thus contributing to the diagnosis and treatment of OC.

Discovery of Pyrazolo[1,5-a]pyrimidine Derivative as a Novel and Selective ALKBH5 Inhibitor for the Treatment of AML

M6A (N6-methyladenosine) plays a significant role in regulating RNA processing, splicing, nucleation, translation, and stability. AlkB homologue 5 (ALKBH5) is an Fe(II)/2-oxoglutarate (2-OG)-dependent dioxygenase that demethylates mono- or dimethylated adenosines. ALKBH5 can be regarded as an oncogenic factor for various human cancers. However, the discovery of potent and selective ALKBH5 inhibitors remains a challenge. We identified DDO-2728 as a novel and selective inhibitor of ALKBH5 by structure-based virtual screening and optimization. DDO-2728 was not a 2-oxoglutarate analogue and could selectively inhibit the demethylase activity of ALKBH5 over FTO. DDO-2728 increased the abundance of m6A modifications in AML cells, reduced the mRNA stability of TACC3, and inhibited cell cycle progression. Furthermore, DDO-2728 significantly suppressed tumor growth in the MV4-11 xenograft mouse model and showed a favorable safety profile. Collectively, our results highlight the development of a selective probe for ALKBH5 that will pave the way for the further study of ALKBH5 targeting therapies.

Role of N6-methyladenosine methylation in glioma: recent insights and future directions

Glioma is the most pervasive intracranial tumor in the central nervous system (CNS), with glioblastoma (GBM) being the most malignant type having a highly heterogeneous cancer cell population. There is a significantly high mortality rate in GBM patients. Molecular biomarkers related to GBM malignancy may have prognostic values in predicting survival outcomes and therapeutic responses, especially in patients with high-grade gliomas. In particular, N6-methyladenine (m6A) mRNA modification is the most abundant form of post-transcriptional RNA modification in mammals and is involved in regulating mRNA translation and degradation. Cumulative findings indicate that m6A methylation plays a crucial part in neurogenesis and glioma pathogenesis. In this review, we summarize recent advances regarding the functional significance of m6A modification and its regulatory factors in glioma occurrence and progression. Significant advancement of m6A methylation-associated regulators as potential therapeutic targets is also discussed.

N6-methyladenosine (m6A) methylation in kidney diseases: Mechanisms and therapeutic potential

The N6-methyladenosine (m6A) modification is regulated by methylases, commonly referred to as "writers," and demethylases, known as "erasers," leading to a dynamic and reversible process. Changes in m6A levels have been implicated in a wide range of cellular processes, including nuclear RNA export, mRNA metabolism, protein translation, and RNA splicing, establishing a strong correlation with various diseases. Both physiologically and pathologically, m6A methylation plays a critical role in the initiation and progression of kidney disease. The methylation of m6A may also facilitate the early diagnosis and treatment of kidney diseases, according to accumulating research. This review aims to provide a comprehensive overview of the potential role and mechanism of m6A methylation in kidney diseases, as well as its potential application in the treatment of such diseases. There will be a thorough examination of m6A methylation mechanisms, paying particular attention to the interplay between m6A writers, m6A erasers, and m6A readers. Furthermore, this paper will elucidate the interplay between various kidney diseases and m6A methylation, summarize the expression patterns of m6A in pathological kidney tissues, and discuss the potential therapeutic benefits of targeting m6A in the context of kidney diseases.

m6 A mRNA methylation: Biological features, mechanisms, and therapeutic potentials in type 2 diabetes mellitus

As the most common internal post-transcriptional RNA modification in eukaryotic cells, N6-methyladenosine (m6 A) performs a dynamic and reversible role in a variety of biological processes mediated by methyltransferases (writers), demethylases (erasers), and m6 A binding proteins (readers). M6 A methylation enables transcriptome conversion in different signals that regulate various physiological activities and organ development. Over the past few years, emerging studies have identified that mRNA m6 A regulators defect in β-cell leads to abnormal regulation of the target mRNAs, thereby resulting in β-cell dysfunction and loss of β-cell identity and mass, which are strongly associated with type 2 diabetes mellitus (T2DM) pathogenesis. Also, mRNA m6 A modification has been implicated with insulin resistance in muscles, fat, and liver cells/tissues. In this review, we elaborate on the biological features of m6 A methylation; provide a comprehensive overview of the underlying mechanisms that how it controls β-cell function, identity, and mass as well as insulin resistance; highlight its connections to glucose metabolism and lipid metabolism linking to T2DM; and further discuss its role in diabetes complications and its therapeutic potentials for T2DM diagnosis and treatment.

The potential role of RNA modification in skin diseases, as well as the recent advances in its detection methods and therapeutic agents

RNA modification is considered as an epigenetic modification that plays an indispensable role in biological processes such as gene expression and genome editing without altering nucleotide sequence, but the molecular mechanism of RNA modification has not been discussed systematically in the development of skin diseases. This article mainly presents the whole picture of theoretical achievements on the potential role of RNA modification in dermatology. Furthermore, this article summarizes the latest advances in clinical practice related with RNA modification, including its detection methods and drug development. Based on this comprehensive review, we aim to illustrate the current blind spots and future directions of RNA modification, which may provide new insights for researchers in this field.

N6-methyladenosine (m6A) in cancer therapeutic resistance: Potential mechanisms and clinical implications

Cancer therapy resistance (CTR) is the development of cancer resistance to multiple therapeutic strategies, which severely affects clinical response and leads to cancer progression, recurrence, and metastasis. N6-methyladenosine (m6A) has been identified as the most common, abundant, and conserved internal transcriptional alterations of RNA modifications, regulating RNA splicing, translation, stabilization, degradation, and gene expression, and is involved in the development and progression of a variety of diseases, including cancer. Recent studies have shown that m6A modifications play a critical role in both cancer development and progression, especially in reversing CTR. Although m6A modifications have great potential in CTR, the specific molecular mechanisms are not fully elucidated. In this review, we summarize the potential molecular mechanisms of m6A modification in CTR. In addition, we update recent advances in natural products from Traditional Chinese Medicines (TCM) and small-molecule lead compounds targeting m6A modifications, and discuss the great potential and clinical implications of these inhibitors targeting m6A regulators and combinations with other therapies to improve clinical efficacy and overcome CTR.

The role of N6-methyladenosine modification in rodent models of neuropathic pain: from the mechanism to therapeutic potential

Neuropathic pain (NP) is a common chronic pain condition resulted from lesions or diseases of somatosensory nervous system, but the pathogenesis remains unclear. A growing body of evidence supports the relationship between pathogenesis and N6-methyladenosine (m6A) modifications of RNA. However, studies on the role of m6A modifications in NP are still at an early stage. Elucidating different etiologies is important for understanding the specific pathogenesis of NP. This article provides a comprehensive review on the role of m6A methylation modifications including methyltransferases ("writers"), demethylases ("erasers"), and m6A binding proteins ("readers") in NP models. Further analysis of the pathogenic mechanism relationship between m6A and NP provided novel theoretical and practical significance for clinical treatment of NP.

The role of N6-methyladenosine (m6A) in kidney diseases

Chemical modifications are a specific and efficient way to regulate the function of biological macromolecules. Among them, RNA molecules exhibit a variety of modifications that play important regulatory roles in various biological processes. More than 170 modifications have been identified in RNA molecules, among which the most common internal modifications include N6-methyladenine (m6A), n1-methyladenosine (m1A), 5-methylcytosine (m5C), and 7-methylguanine nucleotide (m7G). The most widely affected RNA modification is m6A, whose writers, readers, and erasers all have regulatory effects on RNA localization, splicing, translation, and degradation. These functions, in turn, affect RNA functionality and disease development. RNA modifications, especially m6A, play a unique role in renal cell carcinoma disease. In this manuscript, we will focus on the biological roles of m6A in renal diseases such as acute kidney injury, chronic kidney disease, lupus nephritis, diabetic kidney disease, and renal cancer.

RNA N6-methyladenosine (m6A) modification in HNSCC: molecular mechanism and therapeutic potential

Head and neck squamous cell carcinoma ranks seventh in incidence of malignant tumours in the world. Although there are treatments including surgery, radiotherapy and chemotherapy, targeted therapy and immunotherapy, drug resistance to treatment is caused by various reasons, and the survival rate of patients remains frustrating. To overcome the bottleneck of treatment at this stage, it is urgent to identify possible diagnostic and prognostic markers. N6-methyladenosine is a methylation modification on the sixth N atom of adenine which is the most abundant epitope transcriptome modification in mammalian genes. N6-methyladenosine modification is reversible and results from the interaction among writers, erasers and readers. A large number of studies have proven that N6-methyladenosine modification has important significance in promoting the progression and treatment of tumours and have made great progress in research. In this review, we introduce how N6-methyladenosine modification promotes the occurrence and development of tumours, the mechanism of drug resistance, and new findings of N6-methyladenosine modification in radiotherapy and chemotherapy, immunotherapy, and targeted therapy. N6-methyladenosine modification provides more possibilities for improving the overall survival rate and prognosis of patients.

m6A methylation: a potential key player in understanding and treating COVID-2019 infection

Since its discovery in 2019, coronavirus disease 2019 (COVID-2019) spans a wide clinical spectrum from the asymptomatic stage, mild infection, to severe pneumonia. In patients with COVID-2019, factors such as advanced age, diabetes, or hypertension are associated with a significantly increased risk of severe diseases and death. Of note, the mechanisms underlying differences in the risk and symptoms of COVID-2019 among different populations are still poorly characterized. Accordingly, it is imperative to elucidate potential pathophysiological mechanisms and develop targeted therapeutic approaches for COVID-2019 infection. N6-methyladenosine (m6A) is one of the most common modifications in mammalian RNA transcripts and is widely found in messenger RNAs and some non-coding RNAs. It has been reported that m6A methylation modifications are present in viral RNA transcripts, which are of great significance for the regulation of the viral life cycle. Furthermore, m6A methylation has recently been found to be strongly associated with COVID-2019 infection. Therefore, this article reviews recent advances in studies related to the role of m6A methylation in COVID-2019 infection.

m6A-regulated tumor glycolysis: new advances in epigenetics and metabolism

Glycolytic reprogramming is one of the most important features of cancer and plays an integral role in the progression of cancer. In cancer cells, changes in glucose metabolism meet the needs of self-proliferation, angiogenesis and lymphangiogenesis, metastasis, and also affect the immune escape, prognosis evaluation and therapeutic effect of cancer. The n6-methyladenosine (m6A) modification of RNA is widespread in eukaryotic cells. Dynamic and reversible m6A modifications are widely involved in the regulation of cancer stem cell renewal and differentiation, tumor therapy resistance, tumor microenvironment, tumor immune escape, and tumor metabolism. Lately, more and more evidences show that m6A modification can affect the glycolysis process of tumors in a variety of ways to regulate the biological behavior of tumors. In this review, we discussed the role of glycolysis in tumor genesis and development, and elaborated in detail the profound impact of m6A modification on different tumor by regulating glycolysis. We believe that m6A modified glycolysis has great significance and potential for tumor treatment.

The roles and implications of RNA m6A modification in cancer

N6-Methyladenosine (m6A), the most prevalent internal modification in eukaryotic mRNA, has been extensively and increasingly studied over the past decade. Dysregulation of RNA m6A modification and its associated machinery, including writers, erasers and readers, is frequently observed in various cancer types, and the dysregulation profiles might serve as diagnostic, prognostic and/or predictive biomarkers. Dysregulated m6A modifiers have been shown to function as oncoproteins or tumour suppressors with essential roles in cancer initiation, progression, metastasis, metabolism, therapy resistance and immune evasion as well as in cancer stem cell self-renewal and the tumour microenvironment, highlighting the therapeutic potential of targeting the dysregulated m6A machinery for cancer treatment. In this Review, we discuss the mechanisms by which m6A modifiers determine the fate of target RNAs and thereby influence protein expression, molecular pathways and cell phenotypes. We also describe the state-of-the-art methodologies for mapping global m6A epitranscriptomes in cancer. We further summarize discoveries regarding the dysregulation of m6A modifiers and modifications in cancer, their pathological roles, and the underlying molecular mechanisms. Finally, we discuss m6A-related prognostic and predictive molecular biomarkers in cancer as well as the development of small-molecule inhibitors targeting oncogenic m6A modifiers and their activity in preclinical models.

ALKBH5-mediated m6A demethylation fuels cutaneous wound re-epithelialization by enhancing PELI2 mRNA stability

BACKGROUND

Impaired wound re-epithelialization contributes to cutaneous barrier reconstruction dysfunction. Recently, N⁶-methyladenosine (m⁶A) RNA modification has been shown to participate in the determination of RNA fate, and its aberration triggers the pathogenesis of numerous diseases. Howbeit, the function of m⁶A in wound re-epithelialization remains enigmatic.

METHODS

Alkbh5^‒/‒ mouse was constructed to study the rate of wound re-epithelialization after ALKBH5 ablation. Integrated high-throughput analysis combining methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA-seq was used to identify the downstream target of ALKBH5. In vitro and in vivo rescue experiments were conducted to verify the role of the downstream target on the functional phenotype of ALKBH5-deficient cells or animals. Furthermore, the interacting reader protein and regulatory mechanisms were determined through RIP-qPCR, RNA pull-down, and RNA stability assays.

RESULTS

ALKBH5 was specifically upregulated in the wound edge epidermis. Ablation of ALKBH5 suppressed keratinocyte migration and resulted in delayed wound re-epithelialization in Alkbh5^‒/‒ mouse. Integrated high-throughput analysis revealed that PELI2, an E3 ubiquitin protein ligase, serves as the downstream target of ALKBH5. Concordantly, exogenous PELI2 supplementation partially rescued keratinocyte migration and accelerated re-epithelialization in ALKBH5-deficient cells, both in vitro and in vivo. In terms of its mechanism, ALKBH5 promoted PELI2 expression by removing the m⁶A modification from PELI2 mRNA and enhancing its stability in a YTHDF2-dependent manner.

CONCLUSIONS

This study identifies ALKBH5 as an endogenous accelerator of wound re-epithelialization, thereby benefiting the development of a reprogrammed m⁶A targeted therapy for refractory wounds.

Biomaterial-based in vitro 3D modeling of glioblastoma multiforme

Adult-onset brain cancers, such as glioblastomas, are particularly lethal. People with glioblastoma multiforme (GBM) do not anticipate living for more than 15 months if there is no cure. The results of conventional treatments over the past 20 years have been underwhelming. Tumor aggressiveness, location, and lack of systemic therapies that can penetrate the blood-brain barrier are all contributing factors. For GBM treatments that appear promising in preclinical studies, there is a considerable rate of failure in phase I and II clinical trials. Unfortunately, access becomes impossible due to the intricate architecture of tumors. In vitro, bioengineered cancer models are currently being used by researchers to study disease development, test novel therapies, and advance specialized medications. Many different techniques for creating in vitro systems have arisen over the past few decades due to developments in cellular and tissue engineering. Later-stage research may yield better results if in vitro models that resemble brain tissue and the blood-brain barrier are used. With the use of 3D preclinical models made available by biomaterials, researchers have discovered that it is possible to overcome these limitations. Innovative in vitro models for the treatment of GBM are possible using biomaterials and novel drug carriers. This review discusses the benefits and drawbacks of 3D in vitro glioblastoma modeling systems.

The Regulation of m6A Modification in Glioblastoma: Functional Mechanisms and Therapeutic Approaches

Glioblastoma is the most prevalent primary brain tumour and invariably confers a poor prognosis. The immense intra-tumoral heterogeneity of glioblastoma and its ability to rapidly develop treatment resistance are key barriers to successful therapy. As such, there is an urgent need for the greater understanding of the tumour biology in order to guide the development of novel therapeutics in this field. N6-methyladenosine (m6A) is the most abundant of the RNA modifications in eukaryotes. Studies have demonstrated that the regulation of this RNA modification is altered in glioblastoma and may serve to regulate diverse mechanisms including glioma stem-cell self-renewal, tumorigenesis, invasion and treatment evasion. However, the precise mechanisms by which m6A modifications exert their functional effects are poorly understood. This review summarises the evidence for the disordered regulation of m6A in glioblastoma and discusses the downstream functional effects of m6A modification on RNA fate. The wide-ranging biological consequences of m6A modification raises the hope that novel cancer therapies can be targeted against this mechanism.

Role of N6-methyladenosine modification in central nervous system diseases and related therapeutic agents

N6-methyladenosine (m6A) is a ubiquitous mRNA modification in eukaryotes. m6A occurs through the action of methyltransferases, demethylases, and methylation-binding proteins. m6A methylation of RNA is associated with various neurological disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), depression, cerebral apoplexy, brain injury, epilepsy, cerebral arteriovenous malformations, and glioma. Furthermore, recent studies report that m6A-related drugs have attracted considerable concerns in the therapeutic areas of neurological disorders. Here, we mainly summarized the role of m6A modification in neurological diseases and the therapeutic potential of m6A-related drugs. The aim of this review is expected to be useful to systematically assess m6A as a new potential biomarker and develop innovative modulators of m6A for the amelioration and treatment of neurological disorders.

The emerging role of N6-methyladenine RNA methylation in metal ion metabolism and metal-induced carcinogenesis

N⁶-methyladenine (m⁶A) is the most common and abundant internal modification in eukaryotic mRNAs, which can regulate gene expression and perform important biological tasks. Metal ions participate in nucleotide biosynthesis and repair, signal transduction, energy generation, immune defense, and other important metabolic processes. However, long-term environmental and occupational exposure to metals through food, air, soil, water, and industry can result in toxicity, serious health problems, and cancer. Recent evidence indicates dynamic and reversible m⁶A modification modulates various metal ion metabolism, such as iron absorption, calcium uptake and transport. In turn, environmental heavy metal can alter m⁶A modification by directly affecting catalytic activity and expression level of methyltransferases and demethylases, or through reactive oxygen species, eventually disrupting normal biological function and leading to diseases. Therefore, m⁶A RNA methylation may play a bridging role in heavy metal pollution-induced carcinogenesis. This review discusses interaction among heavy metal, m⁶A, and metal ions metabolism, and their regulatory mechanism, focuses on the role of m⁶A methylation and heavy metal pollution in cancer. Finally, the role of nutritional therapy that targeting m⁶A methylation to prevent metal ion metabolism disorder-induced cancer is summarized.

Aberrant RNA m6A modification in gastrointestinal malignancies: versatile regulators of cancer hallmarks and novel therapeutic opportunities

Gastrointestinal (GI) cancer is one of the most common malignancies, and a leading cause of cancer-related death worldwide. However, molecular targeted therapies are still lacking, leading to poor treatment efficacies. As an important layer of epigenetic regulation, RNA N6-Methyladenosine (m⁶A) modification is recently linked to various biological hallmarks of cancer by orchestrating RNA metabolism, including RNA splicing, export, translation, and decay, which is partially involved in a novel biological process termed phase separation. Through these regulatory mechanisms, m⁶A dictates gene expression in a dynamic and reversible manner and may play oncogenic, tumor suppressive or context-dependent roles in GI tumorigenesis. Therefore, regulators and effectors of m⁶A, as well as their modified substrates, represent a novel class of molecular targets for cancer treatments. In this review, we comprehensively summarize recent advances in this field and highlight research findings that documented key roles of RNA m⁶A modification in governing hallmarks of GI cancers. From a historical perspective, milestone findings in m⁶A machinery are integrated with a timeline of developing m⁶A targeting compounds. These available chemical compounds, as well as other approaches that target core components of the RNA m⁶A pathway hold promises for clinical translational to treat human GI cancers. Further investigation on several outstanding issues, e.g. how oncogenic insults may disrupt m⁶A homeostasis, and how m⁶A modification impacts on the tumor microenvironment, may dissect novel mechanisms underlying human tumorigenesis and identifies next-generation anti-cancer therapeutics. In this review, we discuss advances in our understanding of m⁶A RNA modification since its discovery in the 1970s to the latest progress in defining its potential clinic relevance. We summarize the molecular basis and roles of m⁶A regulators in the hallmarks of GI cancer and discuss their context-dependent functions. Furthermore, the identification and characterization of inhibitors or activators of m⁶A regulators and their potential anti-cancer effects are discussed. With the rapid growth in this field there is significant potential for developing m⁶A targeted therapy in GI cancers.

RNA N6-methyladenosine modification in regulating cancer stem cells and tumor immune microenvironment and its implication for cancer therapy

Therapy resistance is a well-known phenomenon in cancer treatment. It can be intrinsic or acquired, accountable for frequent tumor relapse and death worldwide. The interplay between cancer cells and their neighboring environment can activate complex signaling mechanisms influencing epigenetic changes and maintain cancer cell survival leading to the malignant phenotype. Cancer stem cells (CSCs) are tumor-initiating cells (TICs) and constitute the primary source of drug resistance and tumor recurrence. Studies have shown that cancer cells exhibit dysregulated RNA N6-methyladenosine (m6A) "writers," "erasers," and "readers" levels after acquiring drug resistance. The present review provides novel insight into the role of m6A modifiers involved in CSC generation, cancer cell proliferation, and therapy resistance. m6A RNA modifications in the cross-talk between CSC and the tumor immune microenvironment (TIME) have also been highlighted. Further, we have discussed the therapeutic potential of targeting m6A machinery for cancer diagnosis and the development of new therapies for cancer treatment.

The potential role of m6A modifications on immune cells and immunotherapy

N6-methyladenosine (m6A), is the most prevalent and reversible post-transcriptional epigenetic modification of RNA in mammals. Dysregulation of m6A modifications impacts RNA procession, degradation, translocation, and translation, disrupting immune cell homeostasis and promoting tumor initiation and development. Here, we discuss an -up-to-date summary of the mechanisms by which m6A modifications regulate immune cell anti-tumor as well as self-homeostasis. We also present how the dysregulation of m6A modifications intrinsic to tumor cells regulates the function of immune cells in the tumor microenvironment. Meanwhile, we described some specific inhibitors targeting m6A modulators and discussed their potential use in cancer treatments.

Targeting RNA N6-methyladenosine to synergize with immune checkpoint therapy

Cancer immunotherapy, especially immune checkpoint therapy, has revolutionized therapeutic options by reactivating the host immune system. However, the efficacy varies, and only a small portion of patients develop sustained antitumor responses. Hence, illustrating novel strategies that improve the clinical outcome of immune checkpoint therapy is urgently needed. N6-methyladenosine (m⁶A) has been proved to be an efficient and dynamic posttranscriptional modification process. It is involved in numerous RNA processing, such as splicing, trafficking, translation and degradation. Compelling evidence emphasizes the paramount role of m⁶A modification in the regulation of immune response. These findings may provide a foundation for the rational combination of targeting m⁶A modification and immune checkpoints in cancer treatment. In the present review, we summarize the current landscape of m⁶A modification in RNA biology, and highlight the latest findings on the complex mechanisms by which m⁶A modification governs immune checkpoint molecules. Furthermore, given the critical role of m⁶A modification in antitumor immunity, we discuss the clinical significance of targeting m⁶A modification to improve the efficacy of immune checkpoint therapy for cancer control.

m6A Modification-Association with Oxidative Stress and Implications on Eye Diseases

Oxidative stress (OS) refers to a state of imbalance between oxidation and antioxidation. OS is considered to be an important factor leading to aging and a range of diseases. The eyes are highly oxygen-consuming organs. Due to its continuous exposure to ultraviolet light, the eye is particularly vulnerable to the impact of OS, leading to eye diseases such as corneal disease, cataracts, glaucoma, etc. The N6-methyladenosine (m6A) modification is the most investigated RNA post-transcriptional modification and participates in a variety of cellular biological processes. In this study, we review the role of m6A modification in oxidative stress-induced eye diseases and some therapeutic methods to provide a relatively overall understanding of m6A modification in oxidative stress-related eye diseases.

Understanding the Epitranscriptome for Avant-Garde Brain Tumour Diagnostics

RNA modifications are diverse, dynamic, and reversible transcript alterations rapidly gaining attention due to their newly defined RNA regulatory roles in cellular pathways and pathogenic mechanisms. The exciting emerging field of 'epitranscriptomics' is predominantly centred on studying the most abundant mRNA modification, N6-methyladenine (m⁶A). The m⁶A mark, similar to many other RNA modifications, is strictly regulated by so-called 'writer', 'reader', and 'eraser' protein species. The abundance of genes coding for the expression of these regulator proteins and m⁶A levels shows great potential as diagnostic and predictive tools across several cancer fields. This review explores our current understanding of RNA modifications in glioma biology and the potential of epitranscriptomics to develop new diagnostic and predictive classification tools that can stratify these highly complex and heterogeneous brain tumours.

N6-methyladenosine in macrophage function: a novel target for metabolic diseases

N6-methyladenosine (m⁶A) is one of the most prevalent internal transcriptional modifications. Evidence has highlighted changes in m⁶A in metabolic disorders and various metabolic diseases. However, the precise mechanisms of these m⁶A changes in such conditions are not understood. Macrophages are crucial for the innate immune system and exert either beneficial or harmful roles in metabolic disease. Notably, m⁶A was found to be closely related to macrophage phenotype and dysfunction. In this review, we summarize m⁶A in macrophage function from the perspective of macrophage development, activation, and polarization, pyroptosis, and metabolic disorders. Furthermore, we discuss how m⁶A-mediated macrophage function affects metabolic diseases, including atherosclerosis and nonalcoholic fatty liver disease (NAFLD). Finally, we discuss challenges and prospects for m⁶A in macrophage and metabolic diseases with the aim of providing guidance for the treatment of metabolic diseases.

m6A modification on the fate of colorectal cancer: functions and mechanisms of cell proliferation and tumorigenesis

N6-methyladenosine (m6A) is the most pervasive RNA modification in eukaryotic cells. The dynamic and reversible m6A modification of RNA plays a critical role in the occurrence and progression of tumors by regulating RNA metabolism, including translocation, mRNA stability or decay, pre-mRNA splicing, and lncRNA processing. Numerous studies have shown that m6A modification is involved in the development of various cancers. This review aims to summarize the significant role of m6A modification in the proliferation and tumorigenesis of CRC, as well as the potential of modulating m6A modification for tumor treatment. These findings may offer new therapeutic strategies for clinical implementation of m6A modification in CRC in the near future.

N6-methyladenosine Modification of Noncoding RNAs: Mechanisms and Clinical Applications in Cancer

N6-methyladenosine (m6A) modification remains the most pivotal epigenetic modification on RNA. As we know, m6A not only affects physiological processes but is also involved in carcinoma. Noncoding RNAs play an indispensable role in the occurrence and development of carcinoma. However, a large amount of research is focused on mRNA currently. Insufficient research has been done on the relationship between noncoding RNA (ncRNA) methylation and cancer. Therefore, this review aims to introduce the theoretical knowledge of m6A modification in noncoding RNA, discuss its function in tumorigenesis and progression, and ultimately summarize its potential clinical applications.

RNA m6 A methylation in cancer

N⁶ -methyladenosine (m⁶ A) is one of the most abundant internal modifications in eukaryotic messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs). It is a reversible and dynamic RNA modification that has been observed in both internal coding segments and untranslated regions. Studies indicate that m⁶ A modifications play important roles in translation, RNA splicing, export, degradation and ncRNA processing control. In this review, we focus on the profiles and biological functions of RNA m⁶ A methylation on both mRNAs and ncRNAs. The dynamic modification of m⁶ A and its potential roles in cancer development are discussed. Moreover, we discuss the possibility of m⁶ A modifications serving as potential biomarkers for cancer diagnosis and targets for therapy.

N 6-methyladenosine RNA methylation: From regulatory mechanisms to potential clinical applications

Epitranscriptomics has emerged as another level of epigenetic regulation similar to DNA and histone modifications. N 6-methyladenosine (m6A) is one of the most prevalent and abundant posttranscriptional modifications, widely distributed in many biological species. The level of N 6-methyladenosine RNA methylation is dynamically and reversibly regulated by distinct effectors including methyltransferases, demethylases, histone modification and metabolites. In addition, N 6-methyladenosine RNA methylation is involved in multiple RNA metabolism pathways, such as splicing, localization, translation efficiency, stability and degradation, ultimately affecting various pathological processes, especially the oncogenic and tumor-suppressing activities. Recent studies also reveal that N 6-methyladenosine modification exerts the function in immune cells and tumor immunity. In this review, we mainly focus on the regulatory mechanisms of N 6-methyladenosine RNA methylation, the techniques for detecting N 6-methyladenosine methylation, the role of N 6-methyladenosine modification in cancer and other diseases, and the potential clinical applications.

New roles of N6-methyladenosine methylation system regulating the occurrence of non-alcoholic fatty liver disease with N6-methyladenosine-modified MYC

Non-alcoholic fatty liver disease (NAFLD) has become a major chronic disease in contemporary society, affected by N6-methyladenosine (m6A) RNA methylation, one of the most common RNA modifications. Compared with healthy control, m6A RNA methyltransferase 3 (METTL3) and METTL14 increased, while Wilms tumor 1-associated protein (WTAP) and RNA-binding motif protein 15 (RBM15) decreased significantly in NAFLD, and the m6A demethylases fat mass and obesity-associated protein (FTO) elevated. Meanwhile, the m6A binding proteins, YT521-B homology (YTH) domain-containing 1 (YTHDC1), YTHDC2, insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1), heterogeneous nuclear ribonucleoprotein C (HNRNPC), and HNRNPA2B1 were decreased, while eukaryotic translation initiation factor 3 subunit H (EIF3H) was increased significantly. All these changes of m6A regulators had significant differences between healthy control and NAFLD, but no differences between the NAFL and NASH group. The expression level of RBM15, HNRNPC, and HNRNPA2B1 were related to body fat index. RBM15, YTHDC2, HNRNPC, HNRNPA2B1, and EIF3H were related to steatosis. Also, KIAA1429 and YTH domain family 1 (YTHDF1) were related to lobular inflammation. Taken together, m6A regulators were involved in the occurrence of NAFLD. More importantly, abnormal MYC was determined as a key link to m6A regulation of NAFLD. The higher MYC mRNA level was accompanied by higher HDL cholesterol and unsaturated fatty acid proportions, as well as lower fat mass, glucose, and transaminase. Taken together, dysregulation of m6A methylation caused steatosis and fibrosis, affecting the occurrence of NAFLD, and MYC might be its potential target.

The role of N6-methyladenosine-modified non-coding RNAs in the pathological process of human cancer

Non-coding RNAs (ncRNAs) account for the majority of the widespread transcripts of mammalian genomes. They rarely encode proteins and peptides, but their regulatory role is crucial in numerous physiological and pathological processes. The m6A (N6-methyladenosine) modification is one of the most common internal RNA modifications in eukaryotes and is associated with all aspects of RNA metabolism. Accumulating researches have indicated a close association between m6A modification and ncRNAs, and suggested m6A-modified ncRNAs played a crucial role in tumor progression. The correlation between m6A modification and ncRNAs offers a novel perspective for investigating the potential mechanisms of cancer pathological processes, which suggests that both m6A modification and ncRNAs are critical prognostic markers and therapeutic targets in numerous malignancies. In the present report, we summarized the interaction between m6A modification and ncRNA, emphasizing how their interaction regulates pathological processes in cancer.

Crosstalk among m6A RNA methylation, hypoxia and metabolic reprogramming in TME: from immunosuppressive microenvironment to clinical application

The tumor microenvironment (TME), which is regulated by intrinsic oncogenic mechanisms and epigenetic modifications, has become a research hotspot in recent years. Characteristic features of TME include hypoxia, metabolic dysregulation, and immunosuppression. One of the most common RNA modifications, N6-methyladenosine (m⁶A) methylation, is widely involved in the regulation of physiological and pathological processes, including tumor development. Compelling evidence indicates that m⁶A methylation regulates transcription and protein expression through shearing, export, translation, and processing, thereby participating in the dynamic evolution of TME. Specifically, m⁶A methylation-mediated adaptation to hypoxia, metabolic dysregulation, and phenotypic shift of immune cells synergistically promote the formation of an immunosuppressive TME that supports tumor proliferation and metastasis. In this review, we have focused on the involvement of m⁶A methylation in the dynamic evolution of tumor-adaptive TME and described the detailed mechanisms linking m⁶A methylation to change in tumor cell biological functions. In view of the collective data, we advocate treating TME as a complete ecosystem in which components crosstalk with each other to synergistically achieve tumor adaptive changes. Finally, we describe the potential utility of m⁶A methylation-targeted therapies and tumor immunotherapy in clinical applications and the challenges faced, with the aim of advancing m⁶A methylation research.

Discovery of two novel ALKBH5 selective inhibitors that exhibit uncompetitive or competitive type and suppress the growth activity of glioblastoma multiforme

A group of RNA methylation enzymes is currently of interest as a new target for cancer therapy. Alpha-ketoglutarate-dependent dioxygenase B (AlkB) homolog 5 (ALKBH5) is an N⁶ -methyladenosine (m⁶ A) demethylation enzyme, and by high-throughput screening from pure small molecule compounds, we identified two novel inhibitors, Ena15 and Ena21, against it. Each compound showed either uncompetitive or competitive inhibition for 2-oxoglutarate (2OG). In addition, Ena21 had little inhibitory activity for fat mass and obesity-associated protein (FTO), which is another N⁶ -methyladenosine demethylation enzyme, while Ena15 enhanced the demethylase activity of FTO. The predicted binding poses of both compounds with the crystal structure of ALKBH5 (PDB ID: 4NRO) were comparable with these observations pertaining to the interaction of the 2OG catalytic site in this enzyme kinetics. Furthermore, either knockdown of ALKBH5 or inhibition with Ena15 or Ena21 inhibited cell proliferation of glioblastoma multiforme-derived cell lines, decreased cell population in the synthesis phase of the cell cycle, increased m⁶ A RNA level, and stabilized FOXM1 mRNA. Based on these results, Ena15 and Ena21 were found to be potential candidates that might help in further research into the biological function of ALKBH5.