IGF2BPs as novel m6A readers: Diverse roles in regulating cancer cell biological functions, hypoxia adaptation, metabolism, and immunosuppressive tumor microenvironment

Decoding intricate interactions between m6A modification with mRNAs and non-coding RNAs in cervical cancer: Molecular mechanisms and clinical implications

N6-methyladenosine (m6A) methylation is the most prevalent RNA modification that is regulated by three regulatory factors: "writers", "erasers" and "readers". m6A modification regulates RNA stability and other mechanisms, including translation, cleavage, and degradation. Current research has demonstrated that m6A methylation is involved in the regulation of occurrence and development of cancers by controlling the expression of cancer-related genes. This review summarizes the role of m6A modification on messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs) in cervical cancer (CC). We highlight the dual role of m6A regulatory factors, which act as oncogenes or tumor suppressors depending on the cellular context and downstream targets. Additionally, we examine how ncRNAs reciprocally regulate m6A modification in two ways: by guiding the deposition or removal of m6A modifications on RNA targets, and by modulating the expression of m6A regulatory factors. These interactions further contribute to tumor progression. Furthermore, the therapeutic potential of targeting m6A modification has been emphasized in CC. Moreover, recent advances in small-molecule inhibitors targeting m6A regulators and RNA-based therapies which may offer new treatment strategies have been summarized. Finally, we discuss the current challenges in m6A modification research and provide suggestions for future research directions. This review aims to deepen the understanding of m6A modification in CC and contribute to the development of targeted and personalized treatment strategies.

METTL3 regulates rifampicin-induced CYP3A4 expression by activating PXR translation and nuclear import and stabilizing CYP3A4 mRNA

The pregnane X receptor (PXR) activator rifampicin (RIF) plays a critical role in drug-drug interactions (DDIs) by inducing cytochrome P450 (CYP) 3A4 expression. Increasing evidence indicates that n6-methyladenosine (m6A) modification is involved in the regulation of CYP basal expression. Here, we showed its effect on RIF-induced CYP3A4 expression. This study found that m6A levels and methyltransferase-like 3 (METTL3) expression were upregulated in HepG2 and LS174T cells treated with RIF, as well as in mice treated with pregnenolone-16α-carbonitrile (PCN, a typical PXR activator in mice), associated with the expression of CYP3A4 and Cyp3a11 (mouse homolog of human CYP3A4). Specifically, knockdown or overexpression of METTL3 downregulated and upregulated the basal and RIF-induced expression of CYP3A4, respectively. Similar results were obtained in a mouse model with liver-specific knockdown of Mettl3 (homolog of human METTL3) treated with PCN, indicating the involvement of m6A methylation in RIF-induced CYP3A4 expression. Mechanistically, METTL3 promotes PXR nuclear translocation and protein translation, while potentially affecting CYP3A4 mRNA stability through its binding to CYP3A4 mRNA (enhanced by RIF), thereby contributing to RIF-induced upregulation of CYP3A4 expression. Functionally, we observed that METTL3 knockdown or treatment with the METTL3 inhibitor STM2457 reduced the cytotoxicity induced by RIF combined with ritonavir. In conclusion, this study identified a novel mechanism of m6A modification in the regulation of RIF-induced CYP3A4 expression, providing valuable insights into CYP3A4-mediated DDIs.

Long Non-Coding RNAs and RNA-Binding Proteins in Pancreatic Cancer Development and Progression

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and is responsible for about 467,000 cancer deaths annually. An oftentimes asymptomatic early phase of this disease results in a delayed diagnosis, and patients often present with advanced disease. Current treatment options have limited survival benefits, and only a minor patient population carries actionable genomic alterations. Hence, innovative personalized treatment strategies that consider molecular, cellular and functional analyses are urgently needed for pancreatic cancer patients. However, the majority of the genetic alterations found in PDAC are currently undruggable, or patients' response is not as expected. Therefore, non-genomic biomarkers and alternative molecular targets should be considered in order to advance the clinical management of PDAC patients. In line with this, recent gene expression and single-cell transcriptome analyses have identified molecular subtypes and transcriptional cell states that affect disease progression and drug efficiency. In this review, we will introduce long non-coding RNAs (lncRNAs) as well as RNA-binding proteins (RBPs) that are able to modulate the transcriptome of a cell through diverse mechanisms, thereby contributing to disease progression. We will provide a brief overview about the general functions of lncRNAs and RBPs, respectively. Subsequently, we will highlight selected lncRNAs and RBPs that have been shown to play a role in PDAC development, progression and drug response. Finally, we will present strategies aiming to interfere with the expression and function of lncRNAs and RBPs.

FTO controls CD8+ T cell survival and effector response by modulating m6A methylation of Fas

Functional CD8+ T cell immunity is essential for immune surveillance and host defense against infection and tumors. Epigenetic mechanisms, particularly RNA modification, in controlling CD8+ T cell immune response is not fully elucidated. Here, by T cell-specific deletion of fat mass and obesity-associated protein (FTO), a critical N6-methyladenosine (m6A) demethylase, we revealed that FTO was indispensable for adequate CD8+ T cell immune response and protective function. FTO ablation led to considerable cell death in activated CD8+ T cells, which was attributed to cell apoptosis. MeRIP-seq analysis revealed an increase in m6A methylation on Fas mRNA in FTO-deficient CD8+ T cells. The loss of FTO promoted Fas expression via enhancing the Fas mRNA stability, which depended on the m6A reader insulin-like growth factor-2 mRNA-biding proteins 3 (IGF2BP3). Mutation of the Fas m6A sites or knockdown IGF2BP3 could normalize the upregulated Fas expression and apoptosis levels caused by FTO ablation in CD8+ T cells. Our findings delineate a novel epigenetic regulatory mechanism of FTO-mediated m6A modification in supporting CD8+ T cell survival and effector responses, providing new insights into understanding the post-transcriptional regulation in CD8+ T cell immunological functions and the potential therapeutic intervention.

RNA Binding Protein IGF2BP3 Rehabilitates Glycolysis of Vascular Endothelial Cells to Protect the ox-LDL-induced Cellular Injury via Stabilizing LDHA mRNA

Vascular endothelial cells (VECs) dysfunction has been revealed to be a major cause of various cardiovascular diseases. Yet, the precise cellular and molecular mechanisms of VECs injury remain elusive. This study aims to investigate the roles and molecular mechanisms of RNA binding protein IGF2BP3 in vascular endothelial cell injury caused by oxidized low-density lipoprotein (ox-LDL). HUVECs were treated with ox-LDL to induce endothelial cell injury, and the cellular responses to ox-LDL were assessed using cell viability and apoptosis assays. IGF2BP3 was expressed at low levels in vascular tissues from atherosclerosis patients. Treatment with ox-LDL significantly decreased the expression of IGF2BP3 in HUVECs. Overexpression of IGF2BP3 effectively reduced the injury induced by ox-LDL. Glucose metabolism enzymes were significantly downregulated in vascular tissues from atherosclerosis patients and in HUVECs treated with ox-LDL, leading to suppressed glucose metabolism. IGF2BP3 upregulated the glucose metabolism enzyme LDHA to alleviate the injury caused by ox-LDL in HUVECs. Analysis of the LDHA sequence revealed the presence of an IGF2BP3 binding motif in its 3'UTR. Further experiments including RNA pull-down, RNA IP, and RNA stability assays confirmed the specific binding of IGF2BP3 to the 3'UTR region of LDHA, stabilizing its transcripts. Rescue experiments demonstrated that IGF2BP3 mitigated vascular endothelial cell injury by regulating LDHA-mediated glucose metabolism. The outcomes of this study elucidate the protective roles of IGF2BP3 in safeguarding vascular endothelial cells against injury.

A pan-cancer analysis reveals the oncogenic and immunological role of insulin-like growth factor 2 mRNA-binding protein family members

PURPOSE

To investigate the expression and clinical significance of insulin-like growth factor 2 mRNA-binding protein family members (IGF2BPs) in pan-cancer and evaluate their potential as targets for tumor immunotherapy.

METHODS

Based on data from the cancer genome atlas (TCGA) database, pan-cancer analysis was conducted to examine the clinical significance of IGF2BPs expression in twenty-two tumors.

RESULTS

Differential expression analysis showed high expression of IGF2BPs in most tumor tissues. Survival and mutation analyses suggested that the overexpression of IGF2BPs was associated with poor prognosis and mutation status of certain tumors. Methylation analysis revealed the methylation levels of IGF2BP1/2/3 in certain tumors were intricately linked to their mRNA expression, patient prognosis, and immune cell infiltration. Enrichment analysis indicated that abnormal expression of IGF2BPs was associated with various common tumor-related pathways in different tumors, including AMPK, Hippo, PI3K-Akt, EMT, and p53. In addition, immune correlation analysis revealed that IGF2BPs were closely related to immunotherapy-related indicators (immune cell infiltration, major histocompatibility complex (MHC), immune checkpoints, tumor mutation burden (TMB), and microsatellite instability (MSI)) in some tumors. Drug sensitivity analysis indicated that IGF2BPs were sensitive to some common chemotherapeutic drugs (alvocidib, dasatinib, trametinib, and selumetinib).

CONCLUSION

IGF2BPs exhibit significantly high expression in most tumors and are associated with prognosis, pathological stage, mutational status, methylation levels, and the relevant indicators of immunotherapy sensitivity in multiple tumors. Moreover, IGF2BPs may play an oncogenic role by activating common signaling pathways. Therefore, IGF2BPs may be potential prognostic markers for tumor therapy and targets for immunotherapy and drug therapy.

Triple‑negative breast cancer cell‑derived piR‑31115 promotes the proliferation and migration of endothelial cells via METTL3‑mediated m6A modification of YAP1

Triple‑negative breast cancer (TNBC), a highly malignant breast cancer subtype with a pronounced metastatic propensity, forms the focus of the present investigation. MDA‑MB‑231, a prevalently utilized TNBC cell line in cancer research, was employed. In accordance with the tumour angiogenesis theory, cancer cells are capable of instigating angiogenesis and the formation of a novel vascular system within the tumour microenvironment, which subsequently sustains malignant proliferation and metastasis. Consequently, impeding the growth of tumour blood vessels holds substantial significance in suppressing TNBC metastasis. Piwi‑interacting RNAs (piRNAs), a category of endogenous non‑coding RNAs, have been demonstrated to modulate cancer progression. However, studies regarding the role of piRNAs in regulating angiogenesis within cancer cells are relatively scant. In the present study, via cell co‑culture experiments, it was revealed that piR‑31115 (a kind of piRNA) in MDA‑MB‑231 cells notably enhanced the recruitment of a human microvascular endothelial cell line (HMEC‑1). Moreover, the conditioned medium (CM, which was obtained from MDA‑MB‑231 cells via a specific culturing methodology and was employed for the subsequent treatment of HMEC‑1 cells to explore its impacts on the biological behaviors such as the proliferation and migration of HMEC‑1 cells) derived from MDA‑MB‑231 cells with upregulated piR‑31115 expression stimulated the proliferation and migration of HMEC‑1 cells. These findings suggest that piR‑31115 in MDA‑MB‑231 cells may play a pivotal role in modulating tumour angiogenesis. Further studies disclosed that the CM from MDA‑MB‑231 cells augmented the N6‑methyladenosine (m6A) RNA modification level via METTL3 in HMEC‑1 cells. Transcriptome sequencing revealed that METTL3 functions as an m6A writer protein for Yes‑associated protein 1 (YAP1), which exerts a positive influence on promoting the proliferation and migration of HMEC‑1 cells. Concurrently, the IGF2BP plays a crucial role in stabilizing YAP1 protein expression. Collectively, the present findings identified a signalling pathway through which MDA‑MB‑231 cells induce HMEC‑1 cell proliferation and migration by regulating m6A RNA methylation.

IGF2BP3 promotes the proliferation and cisplatin resistance of bladder cancer by enhancing the mRNA stability of CDK6 in an m6A dependent manner

Cisplatin-based chemotherapy is a primary treatment for bladder cancer, yet the development of chemoresistance poses a significant therapeutic challenge. Insulin-like growth factor II mRNA binding protein 3 (IGF2BP3) is an RNA-binding protein and a key m6A reader that regulates various cancers through m6A-dependent mechanisms. However, its role in chemotherapy resistance in bladder cancer remains unclear. Our in vivo and in vitro experiments identified IGF2BP3 as a key regulator of cisplatin resistance in bladder cancer. We demonstrated that IGF2BP3 enhances the stability of CDK6 mRNA in an m6A-dependent manner, leading to increased CDK6 expression. This, in turn, promoted tumor cell proliferation and resistance to cisplatin chemotherapy. Moreover, we showed that the CDK6 inhibitor palbociclib effectively suppresses the pro-growth and chemoresistant effects induced by IGF2BP3 overexpression. These results suggested that the IGF2BP3/m6A/CDK6 axis plays a pivotal role in bladder cancer progression and chemoresistance, and that targeting this pathway with CDK6 inhibitors such as palbociclib may offer a promising therapeutic strategy for overcoming cisplatin resistance in bladder cancer.

m6A epitranscriptomic modification in hepatocellular carcinoma: implications for the tumor microenvironment and immunotherapy

Hepatocellular carcinoma (HCC) is the most prevalent primary liver malignancy and a leading cause of cancer-related deaths globally. The asymptomatic progression of early-stage HCC often results in diagnosis at advanced stages, significantly limiting therapeutic options and worsening prognosis. Immunotherapy, with immune checkpoint inhibitors (ICIs) at the forefront, has revolutionized HCC treatment. Nevertheless, tumor heterogeneity, immune evasion, and the presence of immunosuppressive components within the tumor immune microenvironment (TIME) continue to compromise its efficacy. Furthermore, resistance or non-responsiveness to ICIs in some patients underscores the urgent need to unravel the complexities of the TIME and to design innovative strategies that enhance immunotherapeutic outcomes. Emerging evidence has revealed the pivotal role of N6-methyladenosine (m6A), a prominent RNA methylation modification, in shaping the TIME in HCC. By regulating RNA stability and translation, m6A influences immune-related factors, including cytokines and immune checkpoint molecules. This modification governs PD-L1 expression, facilitating immune escape and contributing to resistance against ICIs. Advances in this field have also identified m6A-related regulators as promising biomarkers for predicting immunotherapy response and as potential therapeutic targets for optimizing treatment efficacy. This review examines the regulatory mechanisms of m6A modification within the TIME of HCC, with a focus on its impact on immune cells and cytokine dynamics. It also explores the therapeutic potential of targeting m6A pathways to improve immunotherapy efficacy and outlines emerging directions for future research. These insights aim to provide a foundation for developing novel strategies to overcome immune resistance and advance HCC treatment.

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

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

IGF2BP1 promotes multiple myeloma with chromosome 1q gain via increasing CDC5L expression in an m6A-dependent manner

Multiple myeloma (MM) patients with chromosome 1q gain (1q+) are clinically and biologically heterogeneous. The underlying molecular mechanisms are still under investigation, while the identification of targets for effective therapy of this subgroup of MM patients is urgently needed. We aimed to investigate the clinical significance and the regulatory mechanisms of insulin-like growth factor 2 messenger RNA (mRNA) binding protein 1 (IGF2BP1), a N6-methyladenosine (m6A) reader, in MM patients with 1q+. We found that MM patients with 1q+ exhibit a significantly higher level of IGF2BP1 mRNA than controls, while higher IGF2BP1 expression predicted a worse prognosis in MM patients with 1q+. IGF2BP1 overexpression promoted cell proliferation and G1-to-S phase transition of the cell cycle in NCI-H929 cells. Through comprehensive in silico analyses of existing public datasets and in-house generated high-throughput sequencing datasets, along with in vitro experiments, we identified CDC5L as a target of IGFBP1, which can bind to the m6A sites of CDC5L mRNA to up-regulate its protein abundance. Higher CDC5L expression also predicted a worse prognosis of MM patients with 1q+. Moreover, both knockdown and mutation of CDC5L attenuated the pro-proliferative effect of IGF2BP1. Furthermore, IGF2BP1 inhibitor BTYNB effectively inhibited CDC5L expression in MM cells with 1q+ and suppressed the proliferation of these cells in vitro and in vivo. Therefore, IGF2BP1 acts as a post-transcriptional enhancer of CDC5L in an m6A-dependent manner to promote the proliferation of MM cells with 1q+. Our work identified a novel IGF2BP1-CDC5L axis and provided new insight into developing targeted therapeutics for MM patients with 1q+.

IGF2BP2 promotes lung adenocarcinoma progression by regulating LOX1 and tumor-associated neutrophils

Lung adenocarcinoma (LUAD) is the common form of lung cancer and is prone to distant metastasis. IGF2BP2, an m6A modification regulator, is upregulated in lung cancer tissue, but its specific role within the LUAD tumor microenvironment (TME) is unknown. We explored the role of IGF2BP2 in the progression of LUAD. IGF2BP2 expression in LUAD patient specimens and controls was evaluated through bioinformatics, Western blot, and immunohistochemistry. LUAD subcutaneous and orthotopic xenograft tumor models were established, alongside a co-culture system of tumor-associated neutrophils (TANs) and A549 cells. Functional assays assessed IGF2BP2's role under treatment with JX5, an IGF2BP2 inhibitor. Mechanistic assays explored the interaction between IGF2BP2 and LOX1 in 293T cells. IGF2BP2 was significantly upregulated in LUAD tissues, with higher expression levels predicting worse prognosis for patients (p < 0.001). In subcutaneous and orthotopic xenograft models, treatment with JX5, an IGF2BP2 inhibitor, reduced tumor size, volume, and weight (p < 0.001). JX5 also significantly reduced the concentrations of pro-inflammatory cytokines in peripheral blood (p < 0.01 and p < 0.001). Flow cytometry analysis indicated JX5 reduced CD11b+Ly6G+/CD45+ cells (TANs) in the TME (p < 0.001). Mechanistically, JX5 downregulated LOX1 expression in vivo, and co-culture experiments further demonstrated that IGF2BP2 promotes LUAD progression through LOX1-mediated regulation of TAN activity (p < 0.01 and p < 0.001). Overexpression of LOX1 reversed the inhibitory effects of JX5 on TAN infiltration, tumor cell viability, and apoptosis (p < 0.01 and p < 0.001). Additionally, RNA immunoprecipitation revealed that IGF2BP2 binds to LOX1 mRNA at its m6A modification site, stabilizing LOX1 and enhancing its function in the TME. Knockdown of IGF2BP2 accelerated LOX1 mRNA degradation, confirming its role in maintaining LOX1 stability (p < 0.01 and p < 0.001). IGF2BP2 recognizes and stabilizes LOX1 through m6A modification, contributing to TAN-mediated LUAD progression. Overall, these findings offer new insights into LUAD progression and demonstrate that IGF2BP2 is a key regulator that promotes tumor advancement, highlighting the IGF2BP2-LOX1 axis as a potential therapeutic target for LUAD.

Role of the RNA binding protein IGF2BP1 in cancer multidrug resistance

The insulin-like growth factor-2 mRNA-binding protein 1 (IGF2BP1), a member of a conserved family of single-stranded RNA-binding proteins (IGF2BP1-3), is expressed in a broad range of fetal tissues, placenta and more than sixteen cancer types but only in a limited number of normal adult tissues. IGF2BP1is required for the transport from nucleus to cytoplasm of certain mRNAs that play essential roles in embryogenesis, carcinogenesis, and multidrug resistance (MDR), by affecting their stability, translation, or localization. The purpose of this review is to gather and present information on MDR mechanisms in cancer and the significance of IGF2BP1 in this context. Within this review, we will provide an overview of IGF2BP1, including its tissue distribution, expression, molecular targets in the context of tumorigenesis and its inhibitors. Our main focus will be on elucidating the interplay between IGF2BP1 and MDR, particularly with regard to chemoresistance mediated by ABC transporters.

Effect of supramolecular chirality on nano-protein/cell interaction: An experimental and computational investigation

Understanding the unique role of supramolecular chirality in nano-protein/cell interactions, as opposed to molecular chirality, is crucial for elucidating the origin of life. However, this aspect has received inadequate attention. In this study, L/D-glutamic acid-based amphiphiles (L/D-GluC16), which possess molecular chirality, were synthesized. Additionally, through the manipulation of solvent effects, left/right-handed helical nanofibers (M/P-GluC16), endowed with supramolecular chirality, were assembled from L/D-GluC16. With the aid of molecular dynamics (MD) simulations, the interaction between M/P-GluC16, L/D-GluC16, and a model protein (bovine serum albumin, BSA) was investigated at the thermodynamic and spatial orientational levels. Combined with the experimental result of protein adsorption efficiency, a more favorable chirality-dependent binding of M/P-GluC16 to protein compared to L/D-GluC16 was confirmed. Furthermore, driven by the binding-induced conformational changes and subsequent functional disruptions of proteins, M/P-GluC16 exhibited a greater chirality-specific cancer cell inhibitory efficacy compared to L/D-GluC16, highlighting the more significant impact of supramolecular chirality on nano-protein/cell interactions than molecular chirality.

FTO suppresses cardiac fibrosis after myocardial infarction via m6A-mediated epigenetic modification of EPRS

BACKGROUND

Cardiac fibrosis is common in myocardial infarction (MI), leading to progressive cardiac dysfunction. Studies suggested that the abnormal N6-methyladenosine (m6A) modification induced by fat mass and obesity protein (FTO) is vital in MI. However, the effects of FTO on post-infarction cardiac fibrosis have not been detected.

METHODS

Western blot and quantitative real-time PCR were performed to detect the expression of FTO in the fibrotic tissue of rats. The functions of FTO on collagen biosynthesis were analyzed in vitro and in vivo. The underlying targets of FTO were selected through RNA-seq with m6A-seq. The following dual luciferase reporter assay and RNA stability assay were conducted to investigate the mechanisms of FTO-mediated m6A regulation.

RESULTS

The expression of FTO was decreased in the fibrotic tissue of post-infarction rats. The HIF-1 signal pathway was enriched after MI. HIF-1α could bind to the promoter of FTO and inhibit its expression. Functionally, FTO inhibited collagen synthesis after MI in vitro and in vivo. Mechanistically, EPRS was selected as the underlying target of FTO-induced m6A regulation. IGF2BP3 recognized and bound to the m6A sites of EPRS mRNA, which improved its stability. EPRS was required for cardiac fibrosis induced by FTO silencing.

CONCLUSIONS

FTO, identified as a cardioprotective factor, suppressed collagen synthesis in post-infarction cardiac fibrosis via m6A modification, which provided a new therapeutic strategy for cardiac fibrosis.

The Emerging Role of IGF2BP2 in Cancer Therapy Resistance: From Molecular Mechanism to Future Potential

Tumor resistance is one of the primary reasons for cancer treatment failure, significantly limiting the options and efficacy of cancer therapies. Therefore, overcoming resistance has become a critical factor in improving cancer treatment outcomes. IGF2BP2, as a reader of m6A methylation, plays a pivotal role in the post-transcriptional regulation of RNA through the methylation of m6A sites. It not only contributes to cancer initiation and progression but also plays a key role in tumor drug resistance. This review provides a comprehensive summary of the mechanisms by which IGF2BP2 contributes to therapy resistance, with the aim of improving the efficacy of chemotherapy in cancer treatment. Advancing research in this area is crucial for developing more effective therapies that could significantly improve the quality of life for cancer patients.

Metabolic regulation of RNA methylation by the m6A-reader IGF2BP3

The interplay of RNA modifications - deposited by "writers", removed by "erasers" and identified by RNA binding proteins known as "readers" - forms the basis of the epitranscriptomic gene regulation hypothesis. Recent studies have identified the oncofetal RNA-binding protein IGF2BP3 as a "reader" of the N6-methyladenosine (m6A) modification and crucial for regulating gene expression. Yet, how its function as a reader overlaps with its critical oncogenic function in leukemia remains an open question. Here, we report the novel finding that the reader IGF2BP3 reprograms cellular metabolism, resulting in an altered ability of the "writers" to modify the epitranscriptome. In leukemia cells, IGF2BP3 supports increased glycolytic flux and one-carbon metabolism, leading to increased production of S-adenosyl methionine (SAM), a key substrate for methylation reactions within the cell. IGF2BP3 directly regulates the translation of MAT2B, the regulatory subunit of the methionine-adenosyltransferase complex, which is the final enzyme in a pathway leading to SAM production. This, in turn, results in increased m6A modifications on RNA, resulting in positive feedback regulation. This novel mechanism illustrates how metabolism mutually acts with epitranscriptomic modifications, underscoring the pervasive impact of IGF2BP3 in gene regulatory mechanisms governing a broad range of cancer-specific processes.

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

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

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

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

m6A-modified circXPO1 accelerates colorectal cancer progression via interaction with FMRP to promote WWC2 mRNA decay

BACKGROUND

Recent evidence has demonstrated the vital roles of circular RNAs (circRNAs) in the progression of colorectal cancer (CRC); however, their functions and mechanisms in CRC need to be further explored. This study aimed to uncover the biological function of circXPO1 in CRC progression.

METHODS

CircXPO1 was identified by Sanger sequencing, RNase R, and actinomycin D treatment assays. Colony formation, scratch, transwell assays, and mouse xenograft models were adopted to evaluate CRC cell growth and metastasis in vitro and in vivo. Subcellular expression of circXPO1 was detected by FISH and nuclear-cytoplasmic separation assays. Molecular mechanisms were investigated by MeRIP, RIP, and RNA pull-down assays. Target molecular expression was detected by RT-qPCR, Western blotting and immunohistochemical staining.

RESULTS

circXPO1 was up-regulated in CRC tissues and cells, which indicated a poor prognosis of CRC patients. circXPO1 deficiency delayed the growth, EMT, and metastasis of CRC cells. Mechanistical experiments indicated that down-regulation of ALKBH5 enhanced IGF2BP2-mediated m6A modification of circXPO1 to increase circXPO1 expression. Furthermore, circXPO1 interacted with FMRP to reduce the mRNA stability of WWC2, which consequently resulted in Hippo-YAP pathway activation. Rescue experiments suggested that WWC2 overexpression abrogated circXPO1-mediated malignant capacities of CRC cells. The in vivo growth and liver metastasis of CRC cells were restrained by circXPO1 depletion or WWC2 overexpression.

CONCLUSIONS

m6A-modified circXPO1 by ALKBH5/IGF2BP2 axis destabilized WWC2 via interaction with FMRP to activate Hippo-YAP pathway, thereby facilitating CRC growth and metastasis. Targeting circXPO1 might be a potential therapeutic strategy for CRC.

Refining the role of N6-methyladenosine in cancer

N6-methyladenosine (m6A) is the most abundant internal modification of eukaryotic mRNAs. m6A affects the fate of its targets in all aspects of the mRNA life cycle and has important roles in various physiological and pathophysiological processes. Aberrant m6A patterns have been observed in numerous cancers and appear closely linked to oncogenic phenotypes. However, most studies relied on antibody-dependent modification detection, which is known to suffer from important limitations. Novel, antibody-independent, quantitative approaches will be critical to investigate changes in the m6A landscape of cancers. Furthermore, pharmaceutical targeting of the m6A writer Methyltransferase-like 3 (METTL3) has demonstrated the potential to modulate cancer cell phenotypes. However, the enzyme also appears to be essential for the viability of healthy cells. Further refinement of therapeutic strategies is therefore needed to fully realize the potential of m6A-related cancer therapies.

Role of m6A RNA Methylation in Ischemic Stroke

Ischemic stroke is a prominent contributor to global morbidity and mortality rates. The intricate and diverse mechanisms underlying ischemia-reperfusion injury remain poorly comprehended. RNA methylation, an emerging epigenetic modification, plays a crucial role in regulating numerous biological processes, including immunity, DNA damage response, tumorigenesis, metastasis, stem cell renewal, adipocyte differentiation, circadian rhythms, cellular development and differentiation, and cell division. Among the various RNA modifications, N6-methyladenosine (m6A) modification stands as the most prevalent in mammalian mRNA. Recent studies have demonstrated the crucial involvement of m6A modification in the pathophysiological progression of ischemic stroke. This review aims to elucidate the advancements in ischemic stroke-specific investigations pertaining to m6A modification, consolidate the underlying mechanisms implicated in the participation of m6A modification during the onset of ischemic stroke, and deliberate on the potential of m6A modification as a viable therapeutic target for ischemic stroke.

Crosstalk between m6A modification and non-coding RNAs in HCC

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide, with high morbidity and occurrence. Although various therapeutic approaches have been rapidly developed in recent years, the underlying molecular mechanisms in the pathogenesis of HCC remain enigmatic. The N6-methyladenosine (m6A) RNA modification is believed to regulate RNA metabolism and further gene expression. This process is intricately regulated by multiple regulators, such as methylases and demethylases. Non-coding RNAs (ncRNAs) are involved in the regulation of the epigenetic modification, mRNA transcription and other biological processes, exhibiting crucial roles in tumor occurrence and development. The m6A-ncRNA interaction has been implicated in the malignant phenotypes of HCC and plays an important role in drug resistance. This review summarizes the effect of m6A-ncRNA crosstalk on HCC progression and their clinical implications as prognostic markers and therapeutic targets in this disease.

Targeting insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs) for the treatment of cancer

Insulin-like growth factor 2 mRNA-binding proteins (IMPs, IGF2BPs) are RNA-binding proteins that regulate a variety of biological processes. In recent years, several studies have found that IGF2BPs play multiple roles in various biological processes, especially in cancer, and speculated on their mechanism of anticancer effect. In addition, targeting IGF2BPs or their downstream target gene has also received extensive attention as an effective treatment for different types of cancer. In this review, we summarized the recent progress on the role of IGF2BPs in cancers and their structural characteristics. We focused on describing the development of inhibitors targeting IGF2BPs and the prospects for further applications.

Regulation of ULK1 by WTAP/IGF2BP3 axis enhances mitophagy and progression in epithelial ovarian cancer

There is a pressing need for innovative therapeutic strategies for patients with epithelial ovarian cancer (EOC). Previous studies have shown that UNC-51-like kinase 1 (ULK1), a serine/threonine kinase, is crucial in regulating cellular autophagy and mitophagy across various tumor types. However, the clinical implications, biological functions, and potential mechanisms of ULK1 in EOC remain poorly understood. This study demonstrates that ULK1 expression is upregulated in EOC tissue samples and EOC cell lines, with increased ULK1 expression correlating with poor prognosis. Functionally, overexpressed ULK1 enhances the proliferation and migration abilities of EOC cells both in vitro and in vivo. Mechanistically, ULK1 was identified as an m6A target of WTAP. WTAP-mediated m6A modification of ULK1 enhanced its mRNA stability in an IGF2BP3-dependent manner, leading to elevated ULK1 expression and enhanced mitophagy in EOC. In summary, our research reveals that the WTAP/IGF2BP3-ULK1 axis significantly influences protective mitophagy in EOC, contributing to its progression. Therefore, the regulatory mechanisms and biological function of ULK1 identify it as a potential molecular target for therapeutic intervention in EOC.

Hypoxia inducible factor-1ɑ as a potential therapeutic target for osteosarcoma metastasis

Osteosarcoma (OS) is a malignant tumor originating from mesenchymal tissue. Pulmonary metastasis is usually present upon initial diagnosis, and metastasis is the primary factor affecting the poor prognosis of patients with OS. Current research shows that the ability to regulate the cellular microenvironment is essential for preventing the distant metastasis of OS, and anoxic microenvironments are important features of solid tumors. During hypoxia, hypoxia-inducible factor-1α (HIF-1α) expression levels and stability increase. Increased HIF-1α promotes tumor vascular remodeling, epithelial-mesenchymal transformation (EMT), and OS cells invasiveness; this leads to distant metastasis of OS cells. HIF-1α plays an essential role in the mechanisms of OS metastasis. In order to develop precise prognostic indicators and potential therapeutic targets for OS treatment, this review examines the molecular mechanisms of HIF-1α in the distant metastasis of OS cells; the signal transduction pathways mediated by HIF-1α are also discussed.