m6A mRNA Methylation Regulates LKB1 to Promote Autophagy of Hepatoblastoma Cells through Upregulated Phosphorylation of AMPK

TRPML1 ameliorates seizures-related neuronal injury by regulating autophagy and lysosomal biogenesis via Ca2+/TFEB signaling pathway

Alterations in autophagy have been observed in epilepsy, although their exact etiopathogenesis remains elusive. Transient Receptor Potential Mucolipin Protein 1 (TRPML1) is an ion channel protein that regulates autophagy and lysosome biogenesis. To explore the role of TRPML1 in seizures-induced neuronal injury and the potential mechanisms involved, an hyperexcitable neuronal model induced by Mg2+-free solution was used for the study. Our results revealed that TRPML1 expression was upregulated after seizures, which was accompanied by intracellular ROS accumulation, mitochondrial damage, and neuronal apoptosis. Activation of TRPML1 by ML-SA1 diminished intracellular ROS, restored mitochondrial function, and subsequently alleviated neuronal apoptosis. Conversely, inhibition of TRPML1 had the opposite effect. Further examination revealed that the accumulation of ROS and damaged mitochondria was associated with interrupted mitophagy flux and enlarged defective lysosomes, which were attenuated by TRPML1 activation. Mechanistically, TRPML1 activation allows more Ca2+ to permeate from the lysosome into the cytoplasm, resulting in the dephosphorylation of TFEB and its nuclear translocation. This process further enhances autophagy initiation and lysosomal biogenesis. Additionally, the expression of TRPML1 is positively regulated by WTAP-mediated m6A modification. Our findings highlighted crucial roles of TRPML1 and autophagy in seizures-induced neuronal injury, which provides a new target for epilepsy treatment.

Autophagy: a critical mechanism of N6-methyladenosine modification involved in tumor progression and therapy resistance

N6-Methyladenosine (m6A) is an evolutionarily highly conserved epigenetic modification that affects eukaryotic RNAs, especially mRNAs, and m6A modification is commonly linked to tumor proliferation, progression, and therapeutic resistance by participating in RNA metabolism. Autophagy is an intracellular degradation and recycling biological process by which cells remove damaged organelles, protein aggregates, and other intracellular wastes, and release nutrients to maintain cell survival when energy is scarce. Recent studies have shown that m6A modification plays a critical role in the regulation of autophagy, affecting the initiation of autophagy, the formation and assembly of autophagosomes, and lysosomal function by regulating critical regulatory molecules involved in the process of autophagy. Moreover, autophagy can also affect the expression of the three types of regulators related to m6A, which in turn affects the levels of their target genes via m6A modification. Thus, m6A modification and autophagy form a sophisticated regulatory network through mutual regulation, which plays an important role in tumor progression and therapeutic resistance. In this manuscript, we reviewed the effects of m6A modification on autophagy as well as the effects of autophagy on m6A modification and the roles of the m6A-autophagy axis in tumor progression and therapy resistance. Additionally, we summarized the value and application prospects of key molecules in the m6A-autophagy axis in tumor diagnosis and therapy.

Role of N6-methyladenosine RNA modification in cancer

N6-methyladenosine (m6A) is the most abundant modification of RNA in eukaryotic cells. Previous studies have shown that m6A is pivotal in diverse diseases especially cancer. m6A corelates with the initiation, progression, resistance, invasion, and metastasis of cancer. However, despite these insights, a comprehensive understanding of its specific roles and mechanisms within the complex landscape of cancer is still elusive. This review begins by outlining the key regulatory proteins of m6A modification and their posttranslational modifications (PTMs), as well as the role in chromatin accessibility and transcriptional activity within cancer cells. Additionally, it highlights that m6A modifications impact cancer progression by modulating programmed cell death mechanisms and affecting the tumor microenvironment through various cancer-associated immune cells. Furthermore, the review discusses how microorganisms can induce enduring epigenetic changes and oncogenic effect in microorganism-associated cancers by altering m6A modifications. Last, it delves into the role of m6A modification in cancer immunotherapy, encompassing RNA therapy, immune checkpoint blockade, cytokine therapy, adoptive cell transfer therapy, and direct targeting of m6A regulators. Overall, this review clarifies the multifaceted role of m6A modification in cancer and explores targeted therapies aimed at manipulating m6A modification, aiming to advance cancer research and improve patient outcomes.

The role of RNA modifications in hepatocellular carcinoma: functional mechanism and potential applications

Hepatocellular carcinoma (HCC) is a highly aggressive cancer with a poor prognosis. The molecular mechanisms underlying its development remain unclear. Recent studies have highlighted the crucial role of RNA modifications in HCC progression, which indicates their potential as therapeutic targets and biomarkers for managing HCC. In this review, we discuss the functional role and molecular mechanisms of RNA modifications in HCC through a review and summary of relevant literature, to explore the potential therapeutic agents and biomarkers for diagnostic and prognostic of HCC. This review indicates that specific RNA modification pathways, such as N6-methyladenosine, 5-methylcytosine, N7-methylguanosine, and N1-methyladenosine, are erroneously regulated and are involved in the proliferation, autophagy, innate immunity, invasion, metastasis, immune cell infiltration, and drug resistance of HCC. These findings provide a new perspective for understanding the molecular mechanisms of HCC, as well as potential targets for the diagnosis and treatment of HCC by targeting specific RNA-modifying enzymes or recognition proteins. More than ten RNA-modifying regulators showed the potential for use for the diagnosis, prognosis and treatment decision utility biomarkers of HCC. Their application value for HCC biomarkers necessitates extensive multi-center sample validation in the future. A growing number of RNA modifier inhibitors are being developed, but the lack of preclinical experiments and clinical studies targeting RNA modification in HCC poses a significant obstacle, and further research is needed to evaluate their application value in HCC treatment. In conclusion, this review provides an in-depth understanding of the complex interplay between RNA modifications and HCC while emphasizing the promising potential of RNA modifications as therapeutic targets and biomarkers for managing HCC.

Crosstalk between m6A modification and autophagy in cancer

Autophagy is a cellular self-degradation process that plays a crucial role in maintaining metabolic functions in cells and organisms. Dysfunctional autophagy has been linked to various diseases, including cancer. In cancer, dysregulated autophagy is closely associated with the development of cancer and drug resistance, and it can have both oncogenic and oncostatic effects. Research evidence supports the connection between m6A modification and human diseases, particularly cancer. Abnormalities in m6A modification are involved in the initiation and progression of cancer by regulating the expression of oncogenes and oncostatic genes. There is an interaction between m6A modification and autophagy, both of which play significant roles in cancer. However, the molecular mechanisms underlying this relationship are still unclear. m6A modification can either directly inhibit autophagy or promote its initiation, but the complex relationship between m6A modification, autophagy, and cancer remains poorly understood. Therefore, this paper aims to review the dual role of m6A and autophagy in cancer, explore the impact of m6A modification on autophagy regulation, and discuss the crucial role of the m6A modification-autophagy axis in cancer progression and treatment resistance.

The m6 RNA methylation regulator KIAA1429 is associated with autophagy-mediated drug resistance in lung cancer

N6-methyladenosine (m6A) modification plays a crucial role in cancer progression. However, the role of m6A modification-mediated autophagy underlying non-small cell lung cancer (NSCLC) gefitinib resistance remains unknown. Here, we discovered that m6A methyltransferase KIAA1429 was highly expressed in NSCLC gefitinib-resistant cells (PC9-GR) as well as tissues, and KIAA1429 high expression was associated with poor survival. In addition, silent KIAA1429 repressed gefitinib resistance in NSCLC and reduced tumor growth in vivo. Mechanistically, KIAA1429 stabilized WTAP, a significant player in autophagy, by binding to the 3' untranslated regions (3'-UTR) of WTAP. In a word, our findings indicated that KIAA1429 could elevate NSCLC gefitinib resistance, which may provide a promising targeted therapy for NSCLC patients.

The role of m6A modification in type 2 diabetes: A systematic review and integrative analysis

This study focuses on the latest developments in the studies of m6A modification and provides an up-to-date summary of the association between m6A modification and type 2 diabetes (T2D). The possible mechanisms of m6A related to T2D were summarized by literature review. The differentially expressed genes (DEGs) of m6A methylase in T2D were analyzed from 12 datasets in Gene Expression Omnibus (GEO). The associations between m6A level and T2D were explored in four electronic databases, including PubMed, EmBase, Web of Science and CNKI. Standard mean difference (SMD) and 95 % confidence interval (95 %CI) was calculated to assess the total effect in integrative analysis. Differential expression genes detected in at least three of six tissues were ZC3H13, YTHDC1/2, and IGF2BP2. LRPPRC were differentially expressed in five tissues except in arterial tissue. A total of 6 studies were included for integrative analysis. The mean m6A levels were significantly lower in T2D than those in normal controls (SMD = -1.35, 95 %CI: -2.58 to -0.11). This systematic review and integrative analysis summarize the previous studies on the association between m6A modification and T2D and the possible role of m6A modification in the progression of T2D, such as abnormal blood glucose, abnormal pancreatic β-cell function, insulin resistance, and abnormal lipid metabolism. The integrative analysis showed that decreased level of m6A was associated with T2D. These findings provide new targets for early detection and treatment for T2D.

Everolimus inhibits hepatoblastoma by inducing autophagy-dependent ferroptosis

Everolimus, a known inhibitor of the mammalian target of rapamycin (mTOR), has shown uncertain efficacy in treating hepatoblastoma. This study delves into the potential anti-hepatoblastoma properties of everolimus and its intricate relationship with autophagy and ferroptosis, both in vitro and in vivo. In vivo, tumor tissue from hepatoblastoma patient and human hepatoblastoma cell line HuH-6 were xenografted into nude mice to establish xenograft models for observing the effect of everolimus on tumor growth. In vitro, HuH-6 cells were cultured to evaluate the anti-hepatoblastoma activity of everolimus. Transmission electron microscopy and microtubule-associated proteins 1 light chain 3 (LC3), beclin 1, and p62 protein expressions were employed to investigate autophagy. Additionally, indicators of cell apoptosis, reactive oxygen species (ROS) and proteins associated with ferroptosis were measured to evaluate ferroptosis. The results demonstrate that everolimus treatment effectively induced the formation of autophagosomes in hepatoblastoma cells, upregulated the LC3II/I ratio and beclin 1 expression, and downregulated p62 expression, indicating an enhanced autophagy level both in vitro and in vivo. Furthermore, everolimus treatment induced cell apoptosis, increased ROS level, elevated concentrations of malondialdehyde, 4-hydroxynonenal, and iron content, while reducing the ratio of glutathione/oxidized glutathione, and downregulating the protein expression of glutathione peroxidase 4 and solute carrier family 7 member 11, suggesting its ability to induce ferroptosis in hepatoblastoma cells. Importantly, the induction of ferroptosis by everolimus was significantly reversed in the presence of autophinib, an autophagy inhibitor, indicating the autophagy-dependent of everolimus-induced ferroptosis. Taken together, these findings suggest that everolimus holds promise as an effective anti-hepatoblastoma drug, with its mechanism of action potentially involving the induction of autophagy-dependent ferroptosis in hepatoblastoma cells.

Novel insights into the regulatory role of N6-methyladenosine methylation modified autophagy in sepsis

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. It is characterized by high morbidity and mortality and one of the major diseases that seriously hang over global human health. Autophagy is a crucial regulator in the complicated pathophysiological processes of sepsis. The activation of autophagy is known to be of great significance for protecting sepsis induced organ dysfunction. Recent research has demonstrated that N6-methyladenosine (m6A) methylation is a well-known post-transcriptional RNA modification that controls epigenetic and gene expression as well as a number of biological processes in sepsis. In addition, m6A affects the stability, export, splicing and translation of transcripts involved in the autophagic process. Although it has been suggested that m6A methylation regulates the biological metabolic processes of autophagy and is more frequently seen in the progression of sepsis pathogenesis, the underlying molecular mechanisms of m6A-modified autophagy in sepsis have not been thoroughly elucidated. The present article fills this gap by providing an epigenetic review of the processes of m6A-modified autophagy in sepsis and its potential role in the development of novel therapeutics.

Epigenetic targeting of autophagy for cancer: DNA and RNA methylation

Autophagy, a crucial cellular mechanism responsible for degradation and recycling of intracellular components, is modulated by an intricate network of molecular signals. Its paradoxical involvement in oncogenesis, acting as both a tumor suppressor and promoter, has been underscored in recent studies. Central to this regulatory network are the epigenetic modifications of DNA and RNA methylation, notably the presence of N6-methyldeoxyadenosine (6mA) in genomic DNA and N6-methyladenosine (m6A) in eukaryotic mRNA. The 6mA modification in genomic DNA adds an extra dimension of epigenetic regulation, potentially impacting the transcriptional dynamics of genes linked to autophagy and, especially, cancer. Conversely, m6A modification, governed by methyltransferases and demethylases, influences mRNA stability, processing, and translation, affecting genes central to autophagic pathways. As we delve deeper into the complexities of autophagy regulation, the importance of these methylation modifications grows more evident. The interplay of 6mA, m6A, and autophagy points to a layered regulatory mechanism, illuminating cellular reactions to a range of conditions. This review delves into the nexus between DNA 6mA and RNA m6A methylation and their influence on autophagy in cancer contexts. By closely examining these epigenetic markers, we underscore their promise as therapeutic avenues, suggesting novel approaches for cancer intervention through autophagy modulation.

Correction: Li et al. m6A mRNA Methylation Regulates LKB1 to Promote Autophagy of Hepatoblastoma Cells through Upregulated Phosphorylation of AMPK. Genes 2021, 12, 1747

In the original publication [...].

N6-methyladenosine RNA modification: an emerging molecule in type 2 diabetes metabolism

Type 2 diabetes (T2D) is a metabolic disease with an increasing rate of incidence worldwide. Despite the considerable progress in the prevention and intervention, T2D and its complications cannot be reversed easily after diagnosis, thereby necessitating an in-depth investigation of the pathophysiology. In recent years, the role of epigenetics has been increasingly demonstrated in the disease, of which N6-methyladenosine (m6A) is one of the most common post-transcriptional modifications. Interestingly, patients with T2D show a low m6A abundance. Thus, a comprehensive analysis and understanding of this phenomenon would improve our understanding of the pathophysiology, as well as the search for new biomarkers and therapeutic approaches for T2D. In this review, we systematically introduced the metabolic roles of m6A modification in organs, the metabolic signaling pathways involved, and the effects of clinical drugs on T2D.

The Emerging, Multifaceted Role of WTAP in Cancer and Cancer Therapeutics

Cancer is a grave and persistent illness, with the rates of both its occurrence and death toll increasing at an alarming pace. N6-methyladenosine (m⁶A), the most prevalent mRNA modification in eukaryotic organisms, is catalyzed by methyltransferases and has a significant impact on various aspects of cancer progression. WT1-associated protein (WTAP) is a crucial component of the m⁶A methyltransferase complex, catalyzing m⁶A methylation on RNA. It has been demonstrated to participate in numerous cellular pathophysiological processes, including X chromosome inactivation, cell proliferation, cell cycle regulation, and alternative splicing. A better understanding of the role of WTAP in cancer may render it a reliable factor for early diagnosis and prognosis, as well as a key therapeutic target for cancer treatment. It has been found that WTAP is closely related to tumor cell cycle regulation, metabolic regulation, autophagy, tumor immunity, ferroptosis, epithelial mesenchymal transformation (EMT), and drug resistance. In this review, we will focus on the latest advances in the biological functions of WTAP in cancer, and explore the prospects of its application in clinical diagnosis and therapy.

The emerging importance role of m6A modification in liver disease

N6-methyladenosine (m6A) modification, as one of the most common types of inner RNA modification in eukaryotes, plays a multifunctional role in normal and abnormal biological processes. This type of modification is modulated by m6A writer, eraser and reader, which in turn impact various processes of RNA metabolism, such as RNA processing, translation, nuclear export, localization and decay. The current academic view holds that m6A modification exerts a crucial role in the post-transcriptional modulation of gene expression, and is involved in multiple cellular functions, developmental and disease processes. However, the potential molecular mechanism and specific role of m6A modification in the development of liver disease have not been fully elucidated. In our review, we summarized the latest research progress on m6A modification in liver disease, and explored how these novel findings reshape our knowledge of m6A modulation of RNA metabolism. In addition, we also illustrated the effect of m6A on liver development and regeneration to prompt further exploration of the mechanism and role of m6A modification in liver physiology and pathology, providing new insights and references for the search of potential therapeutic targets for liver disease.

Current and potential roles of RNA modification-mediated autophagy dysregulation in cancer

Autophagy, a cellular lysosomal degradation and survival pathway, supports nutrient recycling and adaptation to metabolic stress and participates in various stages of tumor development, including tumorigenesis, metastasis, and malignant state maintenance. Among the various factors contributing to the dysregulation of autophagy in cancer, RNA modification can regulate autophagy by directly affecting the expression of core autophagy proteins. We propose that autophagy disorder mediated by RNA modification is an important mechanism for cancer development. Therefore, this review mainly discusses the role of RNA modification-mediated autophagy regulation in tumorigenesis. We summarize the molecular basis of autophagy and the core proteins and complexes at different stages of autophagy, especially those involved in cancer development. Moreover, we describe the crosstalk of RNA modification and autophagy and review the recent advances and potential role of the RNA modification/autophagy axis in the development of multiple cancers. Furthermore, the dual role of the RNA modification/autophagy axis in cancer drug resistance is discussed. A comprehensive understanding and extensive exploration of the molecular crosstalk of RNA modifications with autophagy will provide important insights into tumor pathophysiology and provide more options for cancer therapeutic strategies.

Roles of RNA Methylations in Cancer Progression, Autophagy, and Anticancer Drug Resistance

RNA methylations play critical roles in RNA processes, including RNA splicing, nuclear export, nonsense-mediated RNA decay, and translation. Regulators of RNA methylations have been shown to be differentially expressed between tumor tissues/cancer cells and adjacent tissues/normal cells. N6-methyladenosine (m6A) is the most prevalent internal modification of RNAs in eukaryotes. m6A regulators include m6A writers, m6A demethylases, and m6A binding proteins. Since m6A regulators play important roles in regulating the expression of oncogenes and tumor suppressor genes, targeting m6A regulators can be a strategy for developing anticancer drugs. Anticancer drugs targeting m6A regulators are in clinical trials. m6A regulator-targeting drugs could enhance the anticancer effects of current chemotherapy drugs. This review summarizes the roles of m6A regulators in cancer initiation and progression, autophagy, and anticancer drug resistance. The review also discusses the relationship between autophagy and anticancer drug resistance, the effect of high levels of m6A on autophagy and the potential values of m6A regulators as diagnostic markers and anticancer therapeutic targets.

Association between autophagy and acute pancreatitis

Autophagy pathway involves maintaining intracellular homeostasis by regulating the degradation of cytoplasmic components. Disfunction of autophagic process has been confirmed to be critical mechanism in many diseases, including cancer, inflammation, infection, degeneration and metabolic disorders. Recent studies have shown that autophagy is one of the early events in acute pancreatitis. Impaired autophagy promotes the abnormal activation of zymogen granules and results in apoptosis and necrosis of exocrine pancreas. Furthermore, multiple signal paths involve progression of acute pancreatitis by regulating autophagy pathway. This article provides a comprehensive review of the recent advances in epigenetic regulation of autophagy and the role of autophagy in acute pancreatitis.

Novel insights into the interplay between m6A modification and programmed cell death in cancer

N6-methyladenosine (m6A) methylation, the most prevalent and abundant RNA modification in eukaryotes, has recently become a hot research topic. Several studies have indicated that m6A modification is dysregulated during the progression of multiple diseases, especially in cancer development. Programmed cell death (PCD) is an active and orderly method of cell death in the development of organisms, including apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis. As the study of PCD has become increasingly profound, accumulating evidence has revealed the mutual regulation of m6A modification and PCD, and their interaction can further influence the sensitivity of cancer treatment. In this review, we summarize the recent advances in m6A modification and PCD in terms of their interplay and potential mechanisms, as well as cancer therapeutic resistance. Our study provides promising insights and future directions for the examination and treatment of cancers.

Recent Advances in RNA m6A Modification in Solid Tumors and Tumor Immunity

An analogous field to epigenetics is referred to as epitranscriptomics, which focuses on the study of post-transcriptional chemical modifications in RNA. RNA molecules, including mRNA, tRNA, rRNA, and other non-coding RNA molecules, can be edited with numerous modifications. The most prevalent modification in eukaryotic mRNA is N6-methyladenosine (m6A), which is a reversible modification found in over 7000 human genes. Recent technological advances have accelerated the characterization of these modifications, and they have been shown to play important roles in many biological processes, including pathogenic processes such as cancer. In this chapter, we discuss the role of m6A mRNA modification in cancer with a focus on solid tumor biology and immunity. m6A RNA methylation and its regulatory proteins can play context-dependent roles in solid tumor development and progression by modulating RNA metabolism to drive oncogenic or tumor-suppressive cellular pathways. m6A RNA methylation also plays dynamic roles within both immune cells and tumor cells to mediate the anti-tumor immune response. Finally, an emerging area of research within epitranscriptomics studies the role of m6A RNA methylation in promoting sensitivity or resistance to cancer therapies, including chemotherapy, targeted therapy, and immunotherapy. Overall, our understanding of m6A RNA methylation in solid tumors has advanced significantly, and continued research is needed both to fill gaps in knowledge and to identify potential areas of focus for therapeutic development.

The role of RNA modification in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly mortal type of primary liver cancer. Abnormal epigenetic modifications are present in HCC, and RNA modification is dynamic and reversible and is a key post-transcriptional regulator. With the in-depth study of post-transcriptional modifications, RNA modifications are aberrantly expressed in human cancers. Moreover, the regulators of RNA modifications can be used as potential targets for cancer therapy. In RNA modifications, N6-methyladenosine (m6A), N7-methylguanosine (m7G), and 5-methylcytosine (m5C) and their regulators have important regulatory roles in HCC progression and represent potential novel biomarkers for the confirmation of diagnosis and treatment of HCC. This review focuses on RNA modifications in HCC and the roles and mechanisms of m6A, m7G, m5C, N1-methyladenosine (m1A), N3-methylcytosine (m3C), and pseudouridine (ψ) on its development and maintenance. The potential therapeutic strategies of RNA modifications are elaborated for HCC.

Role of WTAP in Cancer: From Mechanisms to the Therapeutic Potential

Wilms' tumor 1-associating protein (WTAP) is required for N⁶-methyladenosine (m⁶A) RNA methylation modifications, which regulate biological processes such as RNA splicing, cell proliferation, cell cycle, and embryonic development. m⁶A is the predominant form of mRNA modification in eukaryotes. WTAP exerts m⁶A modification by binding to methyltransferase-like 3 (METTL3) in the nucleus to form the METTL3-methyltransferase-like 14 (METTL14)-WTAP (MMW) complex, a core component of the methyltransferase complex (MTC), and localizing to the nuclear patches. Studies have demonstrated that WTAP plays a critical role in various cancers, both dependent and independent of its role in m⁶A modification of methyltransferases. Here, we describe the recent findings on the structural features of WTAP, the mechanisms by which WTAP regulates the biological functions, and the molecular mechanisms of its functions in various cancers. By summarizing the latest WTAP research, we expect to provide new directions and insights for oncology research and discover new targets for cancer treatment.

Exploration of Potential Biomarkers and Immune Landscape for Hepatoblastoma: Evidence from Machine Learning Algorithm

This study aimed to investigate the immune landscape in hepatoblastoma (HB) based on deconvolution methods and identify a biomarkers panel for diagnosis based on a machine learning algorithm. Firstly, we identified 277 differentially expressed genes (DEGs) and differentiated and functionally identified the modules in DEGs. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and GO (gene ontology) were used to annotate these DEGs, and the results suggested that the occurrence of HB was related to DNA adducts, bile secretion, and metabolism of xenobiotics by cytochrome P450. We selected the top 10 genes for our final diagnostic panel based on the random forest tree method. Interestingly, TNFRSF19 and TOP2A were significantly down-regulated in normal samples, while other genes (TRIB1, MAT1A, SAA2-SAA4, NAT2, HABP2, CYP2CB, APOF, and CFHR3) were significantly down-regulated in HB samples. Finally, we constructed a neural network model based on the above hub genes for diagnosis. After cross-validation, the area under the ROC curve was close to 1 (AUC = 0.972), and the AUC of the validation set was 0.870. In addition, the results of single-sample gene-set enrichment analysis (ssGSEA) and deconvolution methods revealed a more active immune responses in the HB tissue. In conclusion, we have developed a robust biomarkers panel for HB patients.

The Role of N6-Methyladenosine in the Promotion of Hepatoblastoma: A Critical Review

Simple Summary

Hepatoblastoma is the most common malignant pediatric tumor of the liver. Unlike hepatocellular carcinoma (HCC) which has been associated with hepatitis B virus infection or cirrhosis, the etiology of hepatoblastoma remains vague. Genetic syndromes, including familial adenomatous polyposis (FAP), Beckwith-Wiedemann syndrome (BWS), and trisomy 18 syndrome, have been associated with hepatoblastoma. BWS is an overgrowth syndrome which exhibits an alteration of genomic imprinting on chromosome 11p15.5. N⁶-Methyladenosine (M⁶A) is an RNA modification with rampant involvement in the metabolism of cells and malignant diseases. It has been observed to impact the development of various cancers via its governance of gene expression. Here, we explore the role of m⁶A and its genetic associates in promoting HB, and the impact this may have on our future management of the disease.

Abstract

Hepatoblastoma (HB) is a rare primary malignancy of the developing fetal liver. Its course is profoundly influenced by genetics, in the context of sporadic mutation or genetic syndromes. Conventionally, subtypes of HB are histologically determined based on the tissue type that is recapitulated by the tumor and the direction of its differentiation. This classification is being reevaluated based on advances on molecular pathology. The therapeutic approach comprises surgical intervention, chemotherapy (in a neoadjuvant or post-operative capacity), and in some cases, liver transplantation. Although diagnostic modalities and treatment options are evolving, some patients experience complications, including relapse, metastatic spread, and suboptimal response to chemotherapy. As yet, there is no consistent framework with which such outcomes can be predicted. N⁶-methyladenosine (m⁶A) is an RNA modification with rampant involvement in the normal processing of cell metabolism and neoplasia. It has been observed to impact the development of a variety of cancers via its governance of gene expression. M⁶A-associated genes appear prominently in HB. Literature data seem to underscore the role of m⁶A in promotion and clinical course of HB. Illuminating the pathogenetic mechanisms that drive HB are promising additions to the understanding of the clinically aggressive tumor behavior, given its potential to predict disease course and response to therapy. Implicated genes may also act as targets to facilitate the evolving personalized cancer therapy. Here, we explore the role of m⁶A and its genetic associates in the promotion of HB, and the impact this may have on the management of this neoplastic disease.

Roles of RNA Modifications in Diverse Cellular Functions

Chemical modifications of RNA molecules regulate both RNA metabolism and fate. The deposition and function of these modifications are mediated by the actions of writer, reader, and eraser proteins. At the cellular level, RNA modifications regulate several cellular processes including cell death, proliferation, senescence, differentiation, migration, metabolism, autophagy, the DNA damage response, and liquid-liquid phase separation. Emerging evidence demonstrates that RNA modifications play active roles in the physiology and etiology of multiple diseases due to their pervasive roles in cellular functions. Here, we will summarize recent advances in the regulatory and functional role of RNA modifications in these cellular functions, emphasizing the context-specific roles of RNA modifications in mammalian systems. As m6A is the best studied RNA modification in biological processes, this review will summarize the emerging advances on the diverse roles of m6A in cellular functions. In addition, we will also provide an overview for the cellular functions of other RNA modifications, including m5C and m1A. Furthermore, we will also discuss the roles of RNA modifications within the context of disease etiologies and highlight recent advances in the development of therapeutics that target RNA modifications. Elucidating these context-specific functions will increase our understanding of how these modifications become dysregulated during disease pathogenesis and may provide new opportunities for improving disease prevention and therapy by targeting these pathways.