FTO m6A Demethylase in Obesity and Cancer: Implications and Underlying Molecular Mechanisms

FTO triggers NLRP3/GSDMD-dependent pyroptosis to enhance cisplatin-sensitivity in ovarian cancer

Chemotherapy resistance is still the major impediment to poor prognosis of ovarian cancer (OC). The fat mass and obesity associated protein (FTO), as the first recognized RNA N6-methyladenosine (m6A) demethylase, was dysregulated in various tumors, but its effect on chemoresistance of OC remains unexplored. In this study, FTO expression in tissues and cells was measured by qPCR, IHC, and Western blot. Functional assays were performed, including CCK-8, colony formation, flow cytometry, Transwell assays, and LDH release. Pyroptosis-related proteins were detected by Western blot. MeRIP-qPCR was conducted to measure the m6A level. Finally, the effect of FTO on tumor growth and cisplatin (DDP) sensitivity of OC was checked in a mouse model. We found that FTO was significantly downregulated in OC tissues compared to adjacent normal tissues. In addition, the protein level of FTO was much lower in cisplatin (DDP)-resistant cells than in DDP-sensitive cells. Then, FTO overexpression in DDP-resistant cells decreased IC50 of DDP, increased cell apoptosis, and inhibited cell proliferation, migration, and invasion, whereas FTO silencing cells showed the opposite phenotypes. Moreover, FTO promoted the protein expressions of pyroptosis-related proteins, including NLRP3, cleaved-caspase-1, and GSDMD-NT, to enhance DDP sensitivity, as indicated by lower IC50. Furthermore, FTO activated NLRP3/Caspase-1/GSDMD-mediated pyroptosis in DDP-resistant cells. Mechanically, FTO successfully reduced the total m6A level and NLRP3 mRNA m6A modification to further increase DDP sensitivity in resistant cells. Finally, FTO overexpression promoted DDP-sensitivity and NLRP3 expression to inhibit tumorigenesis in a nude mice xenograft model. Together, our study inferred that FTO triggered NLRP3/Caspase-1/GSDMD-dependent pyroptosis by mediating NLRP3 m6A demethylation to enhance DDP-sensitivity and inhibit the progression of OC. This project indicates that FTO overexpression may be a potential strategy to overcome DDP resistance in OC.

Configural path of obesity: linkage of physical activity and lifestyle based on fuzzy-set qualitative comparative analysis

Obesity plays a significant role in the burden of various health conditions, it is not only a global health issue but challenges the national public health system. Some regions of China still face a high prevalence of obesity, and it is broadly recognized that physical activities interact with lifestyle in different pathways would affect obesity. We aim to capture different configurational paths that lead to obesity, using the fuzzy set Qualitative Comparative Analysis. Eight obesity-related variables were involved, and data were collected between January 1, 2021, and January 31, 2022. The study shows six configurational paths result in obesity, in which the necessary condition is "educational status," and core conditions of "the time of exercise" and "weekly sitting time*sleeping time less than 6 h*second hand smoking exposure on average of 4-6 days per week *keep excising on average of 4 times per week* exercise intensity on the shortness of breath, markedly increased heart rate, heavy sweating" play an important role in the obesity outcome, and the solution exhibits acceptable consistency is 0.50. The six configurational paths solution consistency is 0.76, and the solution coverage is 0.31. Besides the necessary condition and core factors that play(s) an important role in the development of obesity, we have to consider the multiple factors of physical activity and lifestyle have a cross-cutting effect on obesity. This can offer a better understanding of the mechanisms that cause obesity by identifying and characterizing the regional population, which would help develop an effective protective measure for obesity.

Irradiation of 125I seeds blocks glycolysis in pancreatic cancer by inhibiting KLF5 m6A methylation through the suppression of RBM15

This paper investigated whether 125I seed irradiation for pancreatic cancer treatment was mediated through the RBM15/KLF5 pathway in glycolysis. The study collected peripheral blood from pancreatic cancer patients, and detected the expression of RBM15 and KLF5 expression in the serum of pancreatic cancer patients before and after 125I seed irradiation. An in vitro study was conducted to investigate the effects 125I seed irradiation on the malignant behavior and glycolysis of pancreatic cancer cells. The underlying mechanisms were thoroughly examined through a series of logical experiments, including Western blot analysis, Dot-blot experiment, methylated RNA immunoprecipitation assay, and RNA pull down assay. A xenograft tumor model in nude mice was established and treated with 125I seed irradiation, which was employed to research the in vivo effect and mechanism of 125I seed irradiation for pancreatic cancer. The overexpressed RBM15 and KLF5 in serum of pancreatic cancer patients were reduced after 125I seed treatment. 125I seed treatment impaired pancreatic cancer cell proliferation and invasion; enhanced apoptosis; attenuated glycolysis; and reduced RBM15 and KLF5 expression. RBM15 overexpression partially reversed these influences of 125I seed treatment on pancreatic cancer cells. RBM15 was capable of increasing KLF5 expression, which might be achieved by promoting m6A methylation of KLF5. In vivo, 125I seed treatment blocked the growth of pancreatic cancer cells and decreased RBM15 and KLF5 expression in xenograft tumor, whereas RBM15 overexpression abolished these effects. 125I seed irradiation suppressed glycolysis in pancreatic cancer by inhibiting KLF5 m6A methylation through down-regulation of RBM15. This discovery established a solid foundation for the use of in the treatment of pancreatic cancer.

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.

Emerging importance of m6A modification in liver cancer and its potential therapeutic role

Liver cancer refers to malignant tumors that form in the liver and is usually divided into several types, the most common of which is hepatocellular carcinoma (HCC), which originates in liver cells. Other rare types of liver cancer include intrahepatic cholangiocarcinoma (iCCA). m6A modification is a chemical modification of RNA that usually manifests as the addition of a methyl group to adenine in the RNA molecule to form N6-methyladenosine. This modification exerts a critical role in various biological processes by regulating the metabolism of RNA, affecting gene expression. Recent studies have shown that m6A modification is closely related to the occurrence and development of liver cancer, and m6A regulators can further participate in the pathogenesis of liver cancer by regulating the expression of key genes and the function of specific cells. In this review, we provided an overview of the latest advances in m6A modification in liver cancer research and explored in detail the specific functions of different m6A regulators. Meanwhile, we deeply analyzed the mechanisms and roles of m6A modification in liver cancer, aiming to provide novel insights and references for the search for potential therapeutic targets. Finally, we discussed the prospects and challenges of targeting m6A regulators in liver cancer therapy.

FTO inhibition mitigates high-fat diet-induced metabolic disturbances and cognitive decline in SAMP8 mice

This study investigated the effects of fat mass and obesity-associated (FTO) inhibition on cognitive function and metabolic parameters of senescence-accelerated mouse prone 8 (SAMP8) mice fed a high-fat diet (HFD). SAMP8 mice fed an HFD exhibited increased body weight, impaired glucose tolerance, and elevated serum leptin levels. In epididymal white adipose tissue (eWAT), pharmacological treatment with FB23, a well-established FTO inhibitor, increased leptin production and modulated genes involved in lipid metabolism (Cpt1a, Atgl, Hsl, Fas), oxidative stress (OS) (Bip, Edem), and inflammation (Mcp1, Tnfα). Expression of hepatic genes related to lipid metabolism (Cpt1a, Atgl, Mgl, Dgat2, Srebp, Plin2) and OS (catalase, Edem) were modulated by FB23, although hepatic steatosis remained unchanged. Remarkably, FB23 treatment increased m6A RNA methylation in the brain, accompanied by changes in N6-methyladenosine (m6A)-regulatory enzymes and modulation of neuroinflammatory markers (Il6, Mcp1, iNOS). FTO inhibition reduced the activity of matrix metalloproteases (Mmp2, Mmp9) and altered IGF1 signaling (Igf1, Pten). Notably, enhanced leptin signaling was observed through increased expression of immediate early genes (Arc, Fos) and the transcription factor Stat3. Improved synaptic plasticity was evident, as shown by increased levels of neurotrophic factors (Bdnf, Ngf) and restored neurite length and spine density. Consistent with these findings, behavioral tests demonstrated that FB23 treatment effectively rescued cognitive impairments in SAMP8 HFD mice. The novel object recognition test (NORT) and object location test (OLT) revealed that treated mice exhibited enhanced short- and long-term memory and spatial memory compared to the HFD control group. Additionally, the open field test showed a reduction in anxiety-like behavior after treatment with FB23. In conclusion, pharmacological FTO inhibition ameliorated HFD-induced metabolic disturbances and cognitive decline in SAMP8 mice. These results suggest that targeting FTO may be a promising therapeutic approach to counteract obesity-induced cognitive impairment and age-related neurodegeneration.

Comparative transcriptomic and metabolomic analysis of FTO knockout and wild-type porcine iliac artery endothelial cells

The fat mass and obesity associated (FTO) gene, previously identified as a pivotal genetic locus associated with adiposity, has recently been linked to various cancers. In this study, we established an FTO knockout (KO) cell line in porcine iliac artery endothelial cells (PIECs) utilizing CRISPR/Cas9 technology to systematically investigate the gene's function and effect through transcriptomic and metabolomic analysis. Our results revealed significant gene expression and metabolic profiles differences between the FTO KO and wild-type (WT) cells. Furthermore, enrichment analysis highlighted the involvement of differentially expressed genes in metabolic processes, cellular components, and molecular functions, as well as in complement and coagulation cascades, mineral absorption, glutathione metabolism, insulin signaling, fluid shear stress, and atherosclerosis pathways. The metabolomic profiling revealed clear distinctions between the FTO KO and WT cells, indicating profound modifications in cellular metabolism. Correlation analysis of transcriptomic and metabolomic data revealed a significant association between six metabolites and twenty genes, with melatonin showing specific correlations with the expression of several genes, indicating a complex regulatory network between gene expression and metabolic changes. This study provides a foundation for further research on the FTO gene's role in cellular processes and molecular mechanisms underlying physiological and pathological conditions.

2-Oxoglutarate-dependent dioxygenases as oxygen sensors: their importance in health and disease

Since low oxygen conditions below physiological levels, hypoxia, are associated with various diseases, it is crucial to understand the molecular basis behind cellular response to hypoxia. Hypoxia-inducible factors (HIFs) have been revealed to primarily orchestrate the hypoxic response at the transcription level and have continuously attracted great attention over the past three decades. In addition to these hypoxia-responsive effector proteins, 2-oxoglutarate-dependent dioxygenase (2-OGDD) superfamily including prolyl-4-hydroxylase domain-containing proteins (PHDs) and factor inhibiting HIF-1 (FIH-1) has attracted even greater attention in recent years as factors that act as direct oxygen sensors due to their necessity of oxygen for the regulation of the expression and activity of the regulatory subunit of HIFs. Herein, we present a detailed classification of 2-OGDD superfamily proteins, such as Jumonji C-domain-containing histone demethylases, ten-eleven translocation enzymes, AlkB family of DNA/RNA demethylases and lysyl hydroxylases, and discuss their specific functions and associations with various diseases. By introducing the multifaceted roles of 2-OGDD superfamily proteins in the hypoxic response, this review aims to summarize the accumulated knowledge about the complex mechanisms governing cellular adaptation to hypoxia in various physiological and pathophysiological contexts.

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

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

METTL14/IGF2BP2-MEDIATED M6A MODIFICATION OF STEAP1 AGGRAVATES ACUTE LUNG INJURY INDUCED BY SEPSIS

ABSTRACT

Background: Acute lung injury (ALI) is a severe complication of sepsis, characterized by inflammation, edema, and injury to alveolar cells, leading to high mortality rates. Septic ALI is a complex disease involving multiple factors and signaling pathways. STEAP family member 1 (STEAP1) has been reported to be upregulated in a sepsis-induced ALI model. However, the role of STEAP1 in the regulation of septic ALI is not yet fully understood. Methods: The study stimulated human pulmonary microvascular endothelial cells (HPMECs) using lipopolysaccharides (LPS) to establish an in vitro ALI model. The study used quantitative real-time polymerase chain reaction to measure mRNA expression, and western blotting assay or immunohistochemistry assay to analyze protein expression. Cell Counting Kit-8 assay was performed to assess cell viability. Flow cytometry was conducted to analyze cell apoptosis. Tube formation assay was used to analyze the tube formation rate of human umbilical vein endothelial cells. Enzyme-linked immunosorbent assays were used to measure the levels of interleukin 1beta and tumor necrosis factor alpha. The levels of Fe 2+ and reactive oxygen species were determined using colorimetric and fluorometric assays, respectively. The glutathione level was also determined using a colorimetric assay. m6A RNA immunoprecipitation assay, dual-luciferase reporter assay, and RNA immunoprecipitation assay were performed to identify the association of STEAP1 with methyltransferase 14, N6-adenosine-methyltransferase noncatalytic subunit (METTL14) and insulin like growth factor 2 mRNA binding protein 2 (IGF2BP2). The transcript half-life of STEAP1 was analyzed by actinomycin D assay. Finally, a rat model of polymicrobial sepsis was established to analyze the effects of STEAP1 knockdown on lung injury in vivo . Results: We found that the mRNA expression levels of STEAP1 and METTL14 were upregulated in the blood of ALI patients induced by sepsis compared to healthy volunteers. LPS treatment increased the protein levels of STEAP1 and METTL14 in HPMECs. STEAP1 depletion attenuated LPS-induced promoting effects on HPMECs' apoptosis, inflammatory response, and ferroptosis, as well as LPS-induced inhibitory effect on tube formation. We also found that METTL14 and IGF2BP2 stabilized STEAP1 mRNA expression through the m6A methylation modification process. Moreover, METTL14 silencing attenuated LPS-induced effects by decreasing STEAP1 expression in HPMECs, and STEAP1 silencing ameliorated cecal ligation and puncture-induced lung injury of mice. Conclusion: METTL14/IGF2BP2-mediated m6A modification of STEAP1 aggravated ALI induced by sepsis. These findings suggest potential therapeutic targets for the treatment of this disease.

Curcumin-induced exosomal FTO from bone marrow stem cells alleviates sepsis-associated acute kidney injury by modulating the m6A methylation of OXSR1

Curcumin and bone marrow stem cells (BMSCs)-derived exosomes are considered to be useful for the treatment of many human diseases, including sepsis-associated acute kidney injury (SA-AKI). However, the role and underlying molecular mechanism of curcumin-loaded BMSCs-derived exosomes in the progression of SA-AKI remain unclear. Exosomes (BMSCs-EXOCurcumin or BMSCs-EXOControl) were isolated from curcumin or DMSO-treated BMSCs, and then co-cultured with LPS-induced HK2 cells. Cell proliferation and apoptosis were determined by cell counting kit 8 (CCK8) assay, 5-ethynyl-2-deoxyuridine (EdU) assay, and flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used for examining inflammatory factors. The levels of SOD, MDA, and ROS were tested to assess oxidative stress. The levels of fat mass and obesity-associated protein (FTO) and oxidative stress responsive 1 (OXSR1) were detected by quantitative real-time PCR and western blot. Methylated RNA immunoprecipitation (MeRIP) assay and RNA immunoprecipitation (RIP) assay were used for measuring the interaction between FTO and OXSR1. BMSCs-EXOCurcumin treatment could inhibit LPS-induced HK2 cell apoptosis, inflammation, and oxidative stress. FTO was downregulated in SA-AKI patients and LPS-induced HK2 cells, while was upregulated in BMSCs-EXOCurcumin. Exosomal FTO from curcumin-induced BMSCs suppressed apoptosis, inflammation, and oxidative stress in LPS-induced HK2 cells. FTO decreased OXSR1 expression through m6A modification, and the inhibitory effect of FTO on LPS-induced HK2 cell injury could be eliminated by OXSR1 overexpression. In animal experiments, BMSCs-EXOCurcumin alleviated kidney injury in SA-AKI mice models by regulating FTO/OXSR1 axis. In conclusion, exosomal FTO from curcumin-induced BMSCs reduced OXSR1 expression to alleviate LPS-induced HK2 cell injury and improve kidney function in CLP-induced mice models, providing a new target for SA-AKI.

Therapeutic Potential of FTO Demethylase in Metabolism and Disease Pathways

The crucial involvement of the Fat Mass and Obesity-associated (FTO) protein in both metabolic and non-metabolic diseases has been documented since its discovery. This enzyme, known as FTO, is a demethylase that belongs to the 2-oxoglutarate-dependent nucleic acid demethylases. Its primary function is to target N6-methyladenosine (m6A) in RNA, which is crucial in regulating RNA stability, processing, and expression. This review facilitates understanding the FTO gene variations linked to Body Mass Index (BMI) and obesity, resulting in increased vulnerability to type 2 diabetes. While prior reviews have already discussed the link between FTO and BMI and its impact on type 2 diabetes, the current review additionally examines the emerging evidence suggesting a direct influence of the FTO gene on metabolism. Additionally, the paper discusses the alternative role of FTO and emphasizes the endophenotypes in neurological circuits and the demethylase function of FTO in neurodegenerative disorders. The review further examines the impact of FTO on several physiological systems and emphasizes the need to study FTO as a potential multitarget for future research and therapies.

Diet-induced Obesity: Pathophysiology, Consequences and Target Specific Therapeutic Strategies

Diet has emerged as a pivotal factor in the current time for diet-induced obesity (DIO). A diet overloaded with fats and carbohydrates and unhealthy dietary habits contribute to the development of DIO through several mechanisms. The prominent ones include the transition of normal gut microbiota to obese microbiota, under-expression of AMPK, and abnormally high levels of adipogenesis. DIO is the root of many diseases. The present review deals with various aspects of DIO and its target proteins that can be specifically used for its treatment. Also, the currently available treatment strategies have been explored. It was found that the expression of five proteins, namely, PPARγ, FTO, CDK4, 14-3-3 ζ protein, and Galectin-1, is upregulated in DIO. They can be used as potential targets for drug-designing studies. Thus, with these targets, the treatment strategy for DIO using natural bioactive compounds can be a safer alternative to medications and bariatric surgeries.

Unraveling the genetic and epigenetic landscape governing intramuscular fat deposition in rabbits: Insights and implications

Intramuscular fat (IMF) content is a predominant factor recognized to affect rabbit meat quality, directly impacting flavor, juiciness, and consumer preference. Despite its significance, the major interplay of genetic and epigenetic factors regulating IMF in rabbits remains largely unexplored. This review sheds light on this critical knowledge gap, offering valuable insights and future directions. We delve into the potential role of established candidate genes from other livestock (e.g. PPARγ, FABP4, and SCD) in rabbits, while exploring the identified novel genes of IMF in rabbits. Furthermore, we explored the quantitative trait loci studies in rabbit IMF and genomic selection approaches for improving IMF content in rabbits. Beyond genetics, this review unveils the exciting realm of epigenetic mechanisms modulating IMF deposition. We explored the potential of DNA methylation patterns, histone modifications, and non-coding RNA-mediation as fingerprints for selecting rabbits with desirable IMF levels. Additionally, we explored the possibility of manipulating the epigenetic landscape through nutraceuticals interventions to promote favorable IMF depositions. By comprehensively deciphering the genomic and epigenetic terrain of rabbit intramuscular fat regulation, this study aims to assess the existing knowledge regarding the genetic and epigenetic factors that control the deposition of intramuscular fat in rabbits. By doing so, we identified gaps in the current research, and suggested potential areas for further investigation that would enhance the quality of rabbit meat. This can enable breeders to develop targeted breeding strategies, optimize nutrition, and create innovative interventions to enhance the quality of rabbit meat, meet consumer demands and increase market competitiveness.

FTO in health and disease

Fat mass and obesity-associated (FTO) protein, a key enzyme integral to the dynamic regulation of epitranscriptomic modifications in RNAs, significantly influences crucial RNA lifecycle processes, including splicing, export, decay, and translation. The role of FTO in altering the epitranscriptome manifests across a spectrum of physiological and pathological conditions. This review aims to consolidate current understanding regarding the implications of FTO in health and disease, with a special emphasis on its involvement in obesity and non-communicable diseases associated with obesity, such as diabetes, cardiovascular disease, and cancer. It also summarizes the established molecules with FTO-inhibiting activity. Given the extensive impact of FTO on both physiology and pathophysiology, this overview provides illustrative insights into its roles, rather than an exhaustive account. A proper understanding of FTO function in human diseases could lead to new treatment approaches, potentially unlocking novel avenues for addressing both metabolic disorders and malignancies. The evolving insights into FTO's regulatory mechanisms hold great promise for future advancements in disease treatment and prevention.

The Putative Antilipogenic Role of NRG4 and ERBB4: First Expression Study on Human Liver Samples

BACKGROUND

Epidermal growth factor receptor 4 (ERBB4) and neuregulin 4 (NRG4) have been shown to reduce steatosis and prevent the development of non-alcoholic steatohepatitis in mouse models, but little to nothing is known about their role in non-alcoholic fatty liver disease (NAFLD) in humans. This study is the first to investigate the expression of ERBB4 and NRG4 mRNAs and their role in lipid metabolism in the livers of individuals with obesity, type 2 diabetes and biopsy-proven NAFLD.

METHODS

Liver biospecimens were obtained intraoperatively from 80 individuals. Quantitative reverse transcription polymerase chain reaction was used to measure the expression levels of mRNAs ERBB4 and NRG4, as well as key lipogenesis genes in the liver tissue of the donors. Histological analysis was conducted on liver biopsies from 36 subjects, and the levels of the examined transcripts were compared with the stage of NAFLD.

RESULTS

In individuals with elevated body mass index (BMI), ERBB4 and NRG4 levels decreased, while ACACA levels increased. A strong negative correlation was observed between NRG4 and ACACA levels. No deregulation of the analyzed transcripts was detected in NAFLD.

CONCLUSIONS

The study demonstrates a decrease in ERBB4 and NRG4 mRNA expression in the livers of subjects with high BMI but not in those with NAFLD. The correlation of the studied transcripts with major lipogenesis genes was assessed, and on this basis a putative scheme for NRG4-mediated suppression of hepatic de novo lipogenesis was hypothesised, offering new research vectors in this field.

The roles of lactate and the interplay with m6A modification in diseases

Lactate exhibits various biological functions, including the mediation of histone and non-histone lactylation to regulate gene transcription, influencing the activity of T lymphocytes, NK cells, and macrophages in immune suppression, activating G protein-coupled receptor 81 for signal transduction, and serving as an energy substrate. The m6A modification represents the most prevalent post-transcriptional epigenetic alteration. It is regulated by m6A-related regulatory enzymes (including methyltransferases, demethylases, and recognition proteins) that control the transcription, splicing, stability, and translation of downstream target RNAs. Lactate-mediated lactylation at histone H3K18 can modulate downstream target m6A modifications by enhancing the transcriptional expression levels of m6A-related regulatory enzymes. These enzymes play a crucial role in the progression of diseases such as cancer, fibrosis (in both liver and lung), myocardial ischemia, cerebral hemorrhage, and sepsis. Furthermore, m6A-related regulatory enzymes are also subject to lactylation by lactate. In turn, these regulatory enzymes can influence key glycolytic pathway enzymes or modify lactate transporter MCT4 via m6A alterations to impact lactate levels and subsequently affect lactylation processes.

FTO attenuates TNF-α-induced damage of proximal tubular epithelial cells in acute pancreatitis-induced acute kidney injury via targeting AQP3 in an N6-methyladenosine-dependent manner

BACKGROUND

Acute kidney injury (AKI) is a frequent complication of severe acute pancreatitis (SAP). Previous investigations have revealed the involvement of FTO alpha-ketoglutarate-dependent dioxygenase (FTO) and aquaporin 3 (AQP3) in AKI. Therefore, the aim of this study is to explore the association of FTO and AQP3 on proximal tubular epithelial cell damage in SAP-induced AKI.

METHODS

An in-vitro AKI model was established in human proximal tubular epithelial cells (PTECs) HK-2 via tumor necrosis factor-α (TNF-α) induction (20 ng/mL), after which FTO and AQP3 expression was manipulated and quantified by quantitative real-time PCR and Western blotting. The viability and apoptosis of PTECs under various conditions, and reactive oxygen species (ROS), superoxide dismutase (SOD), and malonaldehyde (MDA) levels within these cells were measured using commercial assay kits and flow cytometry. Methylated RNA immunoprecipitation and mRNA stability assays were performed to elucidate the mechanism of FTO-mediated N6-methyladenosine (m6A) modification. Western blotting was performed to quantify β-catenin protein levels in the PTECs.

RESULTS

FTO overexpression attenuated the TNF-α-induced decrease in viability and SOD levels, elevated apoptosis, increased levels of ROS and MDA, and diminished TNF-α-induced AQP3 expression and reduced β-catenin expression, but its silencing led to contradictory results. FTO negatively modulates AQP3 levels in RTECs in an m6A-depednent manner and compromises AQP3 stability. In addition, all FTO overexpression-induced effects in TNF-α-induced PTECs were neutralized following AQP3 upregulation.

CONCLUSION

FTO alleviates TNF-α-induced damage to PTECs in vitro by targeting AQP3 in an m6A-dependent manner.

FTO promotes gefitinib-resistance by enhancing PELI3 expression and autophagy in non-small cell lung cancer

The established recognition of N6-methyladenosine (m6A) modification as an indispensable regulatory agent in human cancer is widely accepted. However, the understanding of m6A's role and the mechanisms underlying its contribution to gefitinib resistance is notably limited. Herein, using RT-qPCR, Western blot, Cell proliferation and apoptosis, as well as RNA m6A modification assays, we substantiated that heightened FTO (Fat Mass and Obesity-associated protein) expression substantially underpins the emergence of gefitinib resistance in NSCLC cells. This FTO-driven gefitinib resistance is hinged upon the co-occurrence of PELI3 (Pellino E3 Ubiquitin Protein Ligase Family Member 3) expression and concurrent autophagy activation. Manipulation of PELI3 expression and autophagy activation, including its attenuation, was efficacious in both inducing and overcoming gefitinib resistance within NSCLC cells, as validated in vitro and in vivo. In summary, this study has successfully elucidated the intricate interplay involving FTO-mediated m6A modification, its consequential downstream effect on PELI3, and the concurrent involvement of autophagy in fostering the emergence of gefitinib resistance within the therapeutic context of NSCLC.

Glycolysis modulation: New therapeutic strategies to improve pulmonary hypertension (Review)

Pulmonary hypertension (PH) is a progressive life‑threatening cardiopulmonary vascular disease involving various pathological mechanisms, including hypoxia, cellular metabolism, inflammation, abnormal proliferation and apoptosis. Specifically, metabolism has attracted the most attention. Glucose metabolism is essential to maintain the cardiopulmonary vascular function. However, once exposed to a noxious stimulus, intracellular glucose metabolism changes or switches to an alternative pathway more suitable for adaptation, which is known as metabolic reprogramming. By promoting the switch from oxidative phosphorylation to glycolysis, cellular metabolic reprogramming plays an important role in PH development. Suppression of glucose oxidation and secondary upregulation of glycolysis are responsible for various features of PH, including the proliferation and apoptosis resistance of pulmonary artery endothelial and smooth muscle cells. In the present review, the roles and importance of the glucose metabolism shift were discussed to aid in the development of new treatment approaches for PH.

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

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

The shared genetic landscape of polycystic ovary syndrome and breast cancer: convergence on ER + breast cancer but not ER- breast cancer

BACKGROUND

The clinically high comorbidity between polycystic ovary syndrome (PCOS) and breast cancer (BC) has been extensively reported. However, limited knowledge exists regarding their shared genetic basis and underlying mechanisms.

METHOD

Leveraging summary statistics from the largest genome-wide association studies (GWASs) to date, we conducted a comprehensive genome-wide cross-trait analysis of PCOS and BC. A variety of genetic statistical methods were employed to uncover potential shared genetic causes.

RESULTS

Our analysis revealed genetic overlap between the three trait pairs. After partitioning the genome into 2,495 independent regions, we identified two loci, chr8: 75,011,700-76,295,483 and chr17: 6,305,079-7,264,458, with significant localized genetic correlations. Pleiotropic analysis under a composite null hypothesis identified 1,183 significant pleiotropic single nucleotide polymorphisms (SNPs) across three trait pairs. FUMA mapped 26 pleiotropic loci, with regions 16q12.2 and 6q25.1 duplicated across all three trait pairs, while COLOC detected three loci with colocalization evidence. Gene-based analysis identified 23 unique candidate pleiotropic genes, including the FTO shared by all trait pairs, as well as SER1, RALB, and others in two trait pairs. Pathway enrichment analysis further highlighted key biological pathways, primarily involving the significant biological pathways were the metabolism of regulation of autophagy, regulation of cellular catabolic process, and positive regulation of catabolic process. Latent Heritable Confounder Mendelian randomization (LHC-MR) supported a positive causal relationship between PCOS and both BCALL and ERPBC but not with ERNBC.

CONCLUSION

In conclusion, our genome-wide cross-trait analysis identified a shared genetic basis between PCOS and BC, specific identical genetic mechanisms and causality between PCOS and various BC subtypes, which could better explains the genetics of the co-morbidity of PCOS and ERPBC rather than PCOS and ERNBC. These findings provide new insights into the biological mechanisms underlying the co-morbidity of these two complex diseases, which have important implications for clinical disease intervention, treatment, and improved prognosis.

Current insights on m6A RNA modification in acute leukemia: therapeutic targets and future prospects

RNA modification is the critical mechanism for regulating post-transcriptional processes. There are more than 150 RNA modifications reported so far, among which N6-Methyladenosine is the most prevalent one. M6A RNA modification complex consists of 'writers', 'readers' and 'erasers' which together in a group catalyze, recognize and regulate the methylation process of RNA and thereby regulate the stability and translation of mRNA. The discovery of erasers also known as demethylases, revolutionized the research on RNA modifications as it revealed that this modification is reversible. Since then, various studies have focused on discovering the role of m6A modification in various diseases especially cancers. Aberrant expression of these 'readers', 'writers', and 'erasers' is found to be altered in various cancers resulting in disturbance of cellular homeostasis. Acute leukemias are the most common cancer found in pediatric patients and account for 20% of adult cases. Dysregulation of the RNA modifying complex have been reported in development and progression of hematopoietic malignancies. Further, targeting m6A modification is the new approach for cancer immunotherapy and is being explored extensively. This review provides detailed information about current information on the role of m6A RNA modification in acute leukemia and their therapeutic potential.

Role of m6A Methylation Regulators in the Diagnosis and Subtype Classification of COPD Based on the GEO Database

N6-methyladenosine (m6A) is a prevalent mRNA modifier, yet its role in chronic obstructive pulmonary disease (COPD) remains unexplored. We sourced expression levels of m6A methylation regulators from the GSE76925 dataset. These regulators' differential expression (DEMs) predicted COPD risk via random forest and support vector machine models. Additionally, a nomogram model using DEMs estimated COPD prevalence. We employed consistent cluster analysis of m6A methylation regulators to categorise COPD samples into distinct subtypes. Analyses of immune cell infiltration in these subtypes and differential gene expression (DEGs) across m6A methylation subtypes were conducted. A cell model validated several m6A regulators and their associated pathways. Fifteen m6A methylation regulators showed differential expression and were used in random forest and support vector machine models. Eleven were selected for a nomogram model, which decision curve analysis suggested could benefit patients. Consensus cluster analysis divided the COPD samples into two subtypes: Cluster A and Cluster B. Cluster B was associated with neutrophil and eosinophil-dominated immunity, while Cluster A was linked with monocyte-dominated immunity. Validation of some research findings was achieved through cell experiments. m6A methylation regulators appear instrumental in diagnosing and classifying subtypes of COPD.

RNA modification in normal hematopoiesis and hematologic malignancies

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

The Advances in the Development of Epigenetic Modifications Therapeutic Drugs Delivery Systems

Epigenetic dysregulation can significantly trigger the onset and progression of various diseases, epigenetic therapy is a new treatment strategy by changing DNA methylation, histone modification, N6-methyladenosine, chromatin modification and other epigenetic modifications to regulate gene expression levels for therapeutic purposes. However, small-molecule epigenetic drugs face challenges in disease treatment, such as lack of selectivity, limited therapeutic efficacy, and insufficient safety. Nanomedicine delivery systems offer significant advantages in addressing these issues by enhancing drug targeting, improving bioavailability, and reducing nonspecific distribution. This help minimize side effects while increasing both therapeutic effectiveness and safety of epigenetic drugs. In this review, we focus on the mechanism and role of epigenetic regulatory factors in diseases, as well as the challenges faced by small molecule inhibitors in treatment strategies, especially the research advancements in epigenetic drug delivery systems, review and discuss the therapeutic potential and challenges of using nanotechnology to develop epigenetic drug delivery systems.

Crosstalk of methylation and tamoxifen in breast cancer (Review)

Tamoxifen is a widely used anti‑estrogen drug in the endocrine therapy of breast cancer (BC). It blocks estrogen signaling by competitively binding to estrogen receptor α (ERα), thereby inhibiting the growth of BC cells. However, with the long‑term application of tamoxifen, a subset of patients with BC have shown resistance to tamoxifen, which leads to low overall survival and progression‑free survival. The molecular mechanism of resistance is mainly due to downregulation of ERα expression and abnormal activation of the PI3K/AKT/mTOR signaling pathway. Moreover, the downregulation of targeted gene expression mediated by DNA methylation is an important regulatory mode to control protein expression. In the present review, methylation and tamoxifen are briefly introduced, followed by a focus on the effect of methylation on tamoxifen resistance and sensitivity. Finally, the clinical application of methylation for tamoxifen is described, including its use as a prognostic indicator. Finally, it is hypothesized that when methylation is used in combination with tamoxifen, it could recover the resistance of tamoxifen.

Meta-analysis of FTO expression on the clinicopathologic characteristics and prognosis of gastric cancer

BACKGROUND

Fat mass and obesity-related gene (FTO) is aberrantly expressed in various cancers including highly expressed in gastric cancer tissues. The aim of this meta-analysis was to explore the effect of FTO expression on clinicopathological and prognostic outcome of gastric cancer.

METHODS

China National Knowledge Infrastructure (CNK), Wanfang database, VIP database, Chinese biomedical literature database (CBM), PubMed, Web of Science, the Cochrane library and EMBASE database were searched to screen the literatures according to the inclusion criteria. The search time was the database establishment until May 2023. The two researchers independently searched and screened the literature, extracted pathological data, and conducted The Newcastle-Ottawa scale (NOS) quality evaluation. Analyze the correlation between FTO and pathological indicators of gastric cancer patients and the impact on prognosis, use and Stata 12.0, software for Meta-analysis.

RESULTS

A total of 1619 patients were studied in this study. The results of the Meta-analysis showed that higher expression levels of FTO were associated with TMN stage (OR = 1.83, 95% CI: 1.11-3.03, P = .019), liver metastases (OR = 3.73, 95% CI: 1.49-9.31, P = .005), vascular invasion (OR = 2.22, 95% CI: 1.36-3.61, P = .001), poorer overall survival (OS) (HR = 0.46, 95% CI: 0.34-0.58, P < .001) and recurrence-free survival (HR = 0.56, 95% CI: 0.40-0.73, P < .001) in gastric cancer patients. There was no significant relationship with the degree of differentiation (OR = 1.08, 95% CI: 0.49-2.35, P = .852), age (OR = 0.89, 95% CI: 0.71-1.11, P = .306), and gender (OR = 0.92, 95% CI: 0.74-1.14, P = .432).

CONCLUSION

High expression of FTO was associated with risk of distant metastases and poor prognosis for patients with gastric cancer. FTO may be a potential prognostic biomarker for gastric cancer, but due to the limited number of literature, the above results need further research.

TARGET based m6A methylation-related genes predict prognosis relapsed B-cell acute lymphoblastic leukemia

PURPOSE

The current study aims to investigate the significance of N6-methyladenosine (m6A) methylationrelated genes in the clinical prognosis of childhood relapsed B-cell acute lymphoblastic leukemia (B-ALLL) patient.

METHODS

Transcriptome data and corresponding clinical data on m6A methylation-related genes (including 20 genes) were obtained from the Therapeutically Applicable Research To Generate Effective Treatments (TARGET) database.

RESULTS

The bone marrow (BM) samples of 134 newly diagnosed (naive) and 116 relapsed B-ALL from TARGET were enrolled in the current study. Three genes (FTO, HNRNPC, RBM15B) showed significant up-regulation in relapsed B-ALL compared with that in naive B-ALL.The three genes had a significantly worse survival (P < 0.05). The LASSO Cox regression model was used to select the most predictive genes as prognostic indicators, and YTHDC1 and FTO were identified as prognostic factors for relapsed B-ALL. Finally, the results of multivariate regression analysis showed that the risk score of m6A methylation-related genes was an independent prognostic factor in relapsed B-ALL (P < 0.05).

CONCLUSION

We found that the expression levels of m6A methylation-related genes were different in naive and relapsed patients with B-ALL and correlated with survival and prognosis.This implies that m6A methylation-related genes may be promising prognostic indicators or therapeutic targets for relapsed B-ALL.

Comprehensive analysis of the expression patterns and function of the FTO-LINE1 axis in yak tissues and muscle satellite cells

Background

The long interspersed nuclear element 1 (LINE1) retrotransposon has been identified as a specific substrate for fat mass and obesity-related gene (FTO), which facilitates the removal of N6-methyladenosine modifications from its targeted RNAs.

Methods

This study examined the dynamic interaction between FTO and LINE1 in yak tissues and muscle satellite cells, utilizing RT-qPCR, RNA immunoprecipitation (RIP), immunofluorescence staining, and techniques involving overexpression and interference of FTO and LINE1 to elucidate the relationship between FTO and LINE1 in yak tissues and muscle satellite cells.

Results

Cloning and analysis of the FTO coding sequence in Jiulong yak revealed a conserved protein structure across various Bos breeds, with notable homology observed with domestic yak, domestic cattle, and Java bison. Comprehensive examination of FTO and LINE1 gene expression patterns in Jiulong yaks revealed consistent trends across tissues in both sexes. FTO mRNA levels were markedly elevated in the heart and kidney, while LINE1 RNA was predominantly expressed in the heart. Immunoprecipitation confirmed the direct interaction between the FTO protein and LINE1 RNA in yak tissues and muscle satellite cells. The FTO-LINE1 axis was confirmed by a significant decrease in LINE1 RNA enrichment following its expression interference in yak muscle satellite cells. Overexpression of FTO substantially reduced the expression of recombinant myogenic factor 5 (MYF5). However, FTO interference had no discernible effect on MYF5 and myoblast determination protein 1 (MYOD1) mRNA levels. Immunofluorescence analysis revealed no alterations in Ki-67 protein expression following FTO interference or overexpression. However, phalloidin staining demonstrated enhancement in the myotube fusion rate of yak muscle satellite cells upon LINE1 interference.

Conclusion

This comprehensive mapping of the FTO and LINE1 mRNA expression patterns establishes a direct interaction between the FTO protein and LINE1 RNA in yak. The findings suggest that FTO overexpression promotes muscle satellite cells differentiation, whereas LINE1 negatively regulates myotube fusion. The study provides fundamental insights into the role of the FTO-LINE1 axis in determining the fate of muscle satellite cells in yak, laying a solid theoretical foundation for future investigations.

N6-methyladenine RNA methylation epigenetic modification and diabetic microvascular complications

N6-methyladensine (m6A) has been identified as the best-characterized and the most abundant mRNA modification in eukaryotes. It can be dynamically regulated, removed, and recognized by its specific cellular components (respectively called "writers," "erasers," "readers") and have become a hot research field in a variety of biological processes and diseases. Currently, the underlying molecular mechanisms of m6A epigenetic modification in diabetes mellitus (DM) and diabetic microvascular complications have not been extensively clarified. In this review, we focus on the effects and possible mechanisms of m6A as possible potential biomarkers and therapeutic targets in the treatment of DM and diabetic microvascular complications.

Regulatory effect of N6-methyladenosine on tumor angiogenesis

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

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.

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

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

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.

Fat mass and obesity-associated protein (FTO)-induced upregulation of flotillin-2 (FLOT2) contributes to cancer aggressiveness in diffuse large B-cell lymphoma (DLBCL) via activating the PI3K/Akt/mTOR signal pathway

The role of fat mass and obesity-associated protein (FTO)-mediated N6-methyladenosine (m6A)-demethylation has been investigated in various types of cancers, but it is still unclear whether FTO participates in the progression of diffuse large B-cell lymphoma (DLBCL). Here, by conducting Real-Time qPCR and Western Blot analysis, we verified that FTO was especially enriched in the DLBCL cells (RCK-8, LY-3, DHL-6 and U2932) compared to normal WIL2S cells. Then, the overexpression and silencing vectors for FTO were delivered into the LY-3 and U2932 cells, and our functional experiments confirmed that silencing of FTO suppressed cell viability and division, and induced apoptotic cell death in the DLBCL cells, whereas FTO-overexpression exerted opposite effects. Further mechanical experiments showed that FTO demethylated m6A modifications in flotillin-2 (FLOT2) mRNA to sustain its stability for FLOT2 upregulation, and elevated FLOT2 subsequently increased the expression levels of phosphorylated PI3K (p-PI3K), p-Akt and p-mTOR to activate the tumor-initiating PI3K/Akt/mTOR signal pathway. Of note, FLOT2 also serve as an oncogene to enhance cancer malignancy in DLBCL, and the rescuing experiments showed that FTO-ablation induced suppressing effects on the malignant phenotypes in DLBCL were all abrogated by overexpressing FLOT2. Taken together, those data hinted that FTO-mediated m6A-demethylation upregulated FLOT2 to activate the downstream PI3K/Akt/mTOR signal pathway, leading to the aggressiveness of DLBCL, which potentially provided diagnostic, therapeutic and prognostic biomarkers for DLBCL.

RNA N6-methyladenosine modifications in urological cancers: from mechanism to application

The N6-methyladenosine (m6A) modification is the most common modification of messenger RNAs in eukaryotes and has crucial roles in multiple cancers, including in urological malignancies such as renal cell carcinoma, bladder cancer and prostate cancer. The m6A RNA modification is controlled by three types of regulators, including methyltransferases (writers), demethylases (erasers) and RNA-binding proteins (readers), which are responsible for gene regulation at the post-transcriptional level. This Review summarizes the current evidence indicating that aberrant or dysregulated m6A modification is associated with urological cancer development, progression and prognosis. The complex and context-dependent effects of dysregulated m6A modifications in urological cancers are described, along with the potential for aberrantly expressed m6A regulators to provide valuable diagnostic and prognostic biomarkers as well as new therapeutic targets.

Risk of Fat Mass- and Obesity-Associated Gene-Dependent Obesogenic Programming by Formula Feeding Compared to Breastfeeding

It is the purpose of this review to compare differences in postnatal epigenetic programming at the level of DNA and RNA methylation and later obesity risk between infants receiving artificial formula feeding (FF) in contrast to natural breastfeeding (BF). FF bears the risk of aberrant epigenetic programming at the level of DNA methylation and enhances the expression of the RNA demethylase fat mass- and obesity-associated gene (FTO), pointing to further deviations in the RNA methylome. Based on a literature search through Web of Science, Google Scholar, and PubMed databases concerning the dietary and epigenetic factors influencing FTO gene and FTO protein expression and FTO activity, FTO's impact on postnatal adipogenic programming was investigated. Accumulated translational evidence underscores that total protein intake as well as tryptophan, kynurenine, branched-chain amino acids, milk exosomal miRNAs, NADP, and NADPH are crucial regulators modifying FTO gene expression and FTO activity. Increased FTO-mTORC1-S6K1 signaling may epigenetically suppress the WNT/β-catenin pathway, enhancing adipocyte precursor cell proliferation and adipogenesis. Formula-induced FTO-dependent alterations of the N6-methyladenosine (m6A) RNA methylome may represent novel unfavorable molecular events in the postnatal development of adipogenesis and obesity, necessitating further investigations. BF provides physiological epigenetic DNA and RNA regulation, a compelling reason to rely on BF.

MICAL1 promotes the proliferation in acute myeloid leukemia and is associated with clinical prognosis and immune infiltration

Acute myeloid leukemia (AML) is one of the most common hematopoietic malignancies that has a poor prognosis and a high rate of relapse. Dysregulated metabolism plays an important role in AML progression. This study aimed to conduct a comprehensive analysis of MRGs using TCGA and GEO datasets and further explore the potential function of critical MRGs in AML progression. In this study, we identified 17 survival-related differentially expressed MRGs in AML using TCGA and GEO datasets. The 150 AML samples were divided into three molecular subtypes using 17 MRGs, and we found that three molecular subtypes exhibited a different association with ferroptosis, cuproptosis and m6A related genes. Moreover, a prognostic signature that comprised nine MRGs and had good predictive capacity was established by LASSO-Cox stepwise regression analysis. Among the 17 MRGs, our attention focused on MICAL1 which was highly expressed in many types of tumors, including AML and its overexpression was also confirmed in several AML cell lines. We also found that the expression of MICAL1 was associated with several immune cells. Moreover, functional experiments revealed that knockdown of MICAL1 distinctly suppressed the proliferation of AML cells. Overall, this study not only contributes to a deeper understanding of the molecular mechanisms underlying AML but also provides potential targets and prognostic markers for AML treatment. These findings offer robust support for further research into therapeutic strategies and mechanisms related to AML, with the potential to improve the prognosis and quality of life for AML patients. Nevertheless, further research is needed to validate these findings and explore more in-depth molecular mechanisms.

RNA demethylase FTO participates in malignant progression of gastric cancer by regulating SP1-AURKB-ATM pathway

Gastric cancer (GC) is the 5th most prevalent cancer and the 4th primary cancer-associated mortality globally. As the first identified m6A demethylase for removing RNA methylation modification, fat mass and obesity-associated protein (FTO) plays instrumental roles in cancer development. Therefore, we study the biological functions and oncogenic mechanisms of FTO in GC tumorigenesis and progression. In our study, FTO expression is obviously upregulated in GC tissues and cells. The upregulation of FTO is associated with advanced nerve invasion, tumor size, and LNM, as well as the poor prognosis in GC patients, and promoted GC cell viability, colony formation, migration and invasion. Mechanistically, FTO targeted specificity protein 1 and Aurora Kinase B, resulting in the phosphorylation of ataxia telangiectasia mutated and P38 and dephosphorylation of P53. In conclusion, the m6A demethylase FTO promotes GC tumorigenesis and progression by regulating the SP1-AURKB-ATM pathway, which may highlight the potential of FTO as a diagnostic biomarker for GC patients' therapy response and prognosis.

N6-Methyladenosine-Modified KREMEN2 Promotes Tumorigenesis and Malignant Progression of High-Grade Serous Ovarian Cancer

High-grade serous ovarian cancer (HGSOC) remains the most lethal female cancer by far. Herein, clinical HGSOC samples had higher N6-methyladenosine (m6A) modification than normal ovarian tissue, and its dysregulation had been reported to drive aberrant transcription and translation programs. However, Kringle-containing transmembrane protein 2 (KREMEN2) and its m6A modification have not been fully elucidated in HGSOC. In this study, the data from the high-throughput messenger RNA (mRNA) sequencing of clinical samples were processed using the weighted correlation network analysis and functional enrichment analysis. Results revealed that KREMEN2 was a driver gene in the tumorigenesis of HGSOC and a potential target of m6A demethylase fat-mass and obesity-associated protein (FTO). KREMEN2 and FTO levels were upregulated and downregulated, respectively, and correlation analysis showed a significant negative correlation in HGSOC samples. Importantly, upregulated KREMEN2 was remarkably associated with lymph node metastasis, distant metastasis, peritoneal metastasis, and high International Federation of Gynecology and Obstetrics stage (Ⅲ/Ⅳ), independent of the age of patients. KREMEN2 promoted the growth of HGSOC in vitro and in vivo, which was dependent on FTO. The methylated RNA immunoprecipitation qPCR and RNA immunoprecipitation assays were performed to verify the m6A level and sites of KREMEN2. FTO overexpression significantly decreased m6A modification in the 3' and 5' untranslated regions of KREMEN2 mRNA and downregulated its expression. In addition, we found that FTO-mediated m6A modification of KREMEN2 mRNA was recognized and stabilized by the m6A reader IGF2BP1 rather than by IGF2BP2 or IGF2BP3. This study highlights the m6A modification of KREMEN2 and extends the importance of RNA epigenetics in HGSOC.

The Impact of Haplotypes of the FTO Gene, Lifestyle, and Dietary Patterns on BMI and Metabolic Syndrome in Polish Young Adult Men

BACKGROUND

Variants in fat mass and the obesity-associated protein (FTO) gene have long been recognized as the most significant genetic predictors of body fat mass and obesity. Nevertheless, despite the overall evidence, there are conflicting reports regarding the correlation between different polymorphisms of the FTO gene and body mass index (BMI). Additionally, it is unclear whether FTO influences metabolic syndrome (MetS) through mechanisms other than BMI's impact. In this work, we aimed to analyze the impact of the following FTO polymorphisms on the BMI as well as MetS components in a population of young adult men.

METHODS

The patient group consisted of 279 Polish young adult men aged 28.92 (4.28) recruited for the MAGNETIC trial. The single-nucleotide polymorphisms (SNPs), located in the first intron of the FTO gene, were genotyped, and the results were used to identify "protective" and "risk" haplotypes and diplotypes based on the literature data. Laboratory, as well as anthropometric measurements regarding MetS, were performed. Measured MetS components included those used in the definition in accordance with the current guidelines. Data regarding dietary patterns were also collected, and principal components of the dietary patterns were identified.

RESULTS

No statistically significant correlations were identified between the analyzed FTO diplotypes and BMI (p = 0.53) or other MetS components (waist circumference p = 0.55; triglycerides p = 0.72; HDL cholesterol p = 0.33; blood glucose p = 0.20; systolic blood pressure p = 0.06; diastolic blood pressure p = 0.21). Stratification by the level of physical activity or adherence to the dietary patterns also did not result in any statistically significant result.

CONCLUSIONS

Some studies have shown that FTO SNPs such as rs1421085, rs1121980, rs8050136, rs9939609, and rs9930506 have an impact on the BMI or other MetS components; nevertheless, this was not replicated in this study of Polish young adult males.

Construction of a label-free fluorescent biosensor for homogeneous detection of m6A eraser FTO in breast cancer tissues

Fat mass and obesity-associated protein (FTO) is a crucial eraser of RNA N6- methyladenosine (m6A) modification, and abnormal FTO expression level is implicated in pathogenesis of numerous cancers. Herein, we demonstrate the construction of a label-free fluorescent biosensor for homogeneous detection of m6A eraser FTO in breast cancer tissues. When FTO is present, it specifically erases the methyl group in m6A, inducing the cleavage of demethylated DNA by endonuclease DpnII and the generation of a single-stranded DNA (ssDNA) with a 3'-hydroxyl group. Subsequently, terminal deoxynucleotidyl transferase (TdT) promotes the incorporation of dTTPs into the ssDNA to obtain a long polythymidine (T) DNA sequence. The resultant long poly (T) DNA sequence can act as a template to trigger hyperbranched strand displacement amplification (HSDA), yielding numerous DNA fragments that may be stained by SYBR Gold to produce an enhanced fluorescence signal. This biosensor processes ultrahigh sensitivity with a detection limit of 1.65 × 10-10 mg/mL (2.6 fM), and it can detect the FTO activity in a single MCF-7 cell. Moreover, this biosensor can screen the FTO inhibitors, evaluate enzyme kinetic parameters, and discriminate the FTO expression levels in the tissues of breast cancer patients and healthy persons.

Palmatine inhibits expression fat mass and obesity associated protein (FTO) and exhibits a curative effect in dextran sulfate sodium (DSS)-induced experimental colitis

BACKGROUND

Ulcerative colitis (UC) is an inflammatory disease whose pathogenesis and mechanisms have not been fully described. The m6A methylation modification is a general mRNA modification in mammalian cells and is closely associated with the onset and progression of inflammatory bowel disease (IBD). Palmatine (PAL) is a biologically active alkaloid with anti-inflammatory and protective effects in animal models of colitis. Accordingly, we examined the role of PAL on colitis by regulating N6-methyladenosine (m6A) methylation.

METHODS

A rat experimental colitis model was established by 5 % dextran sulfate sodium (DSS) in drinking water for seven days, then PAL treatment was administered for seven days. The colonic tissue pathology was assessed using hematoxylin-eosin (HE) and disease activity index (DAI). In in vitro studies, a human, spontaneously immortalized non-cancerous colon mucosal epithelial cell line (NCM460) was exposed to 2 % DSS and treated with PAL and cell viability was assayed using Cell Counting Kit-8 (CCK-8). The levels of tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6, and IL-8 were detected by enzyme-linked immunosorbent assay (ELISA) kits. The level of Zonula occludens-1 (ZO-1) was dectected by immunofluorescence. Transepithelial electrical resistance (TEER) of cells was also assessed. The methyltransferase-like 3 (METTL3), METTL14, AlkB homologate 5 (ALKBH5), and fat mass and obesity-associated protein (FTO) expression levels were assessed by western blotting. The localized expression of m6A was measured by immunofluorescence.

RESULTS

PAL significantly prevented bodyweight loss and shortening of the colon in experimental colitis rats, as well as decreasing the DAI and histological damage scores. Furthermore, PAL inhibited the levels of inflammatory factors (TNF-α, IL-6, IL-8, and IL-1β) in both DSS treated rats and NCM460 cells. In addition, PAL enhanced the expression level of ZO-1, and increased the transepithelial electrical resistance to repaire intestinal barrier dysfunction. Colitis occurred due to decreased m6A levels, and the increased FTO expression led to a colitis phenotype. PAL markedly enhanced the METTL3 and METTL14 expression levels while decreasing ALKBH5 and FTO expression levels.

CONCLUSIONS

The findings demonstrated that PAL improved DSS-induced experimental colitis. This effect was associated with inhibiting FTO expression and regulating m6A methylation.

FTO promotes the progression of retinoblastoma through YTHDF2-dependent N6-methyladenosine modification in E2F3

Early treatment of retinoblastoma (RB) has significantly improved clinical outcomes. N6-methyladenosine (m6A) methylation is crucial for cancer progression. Thus, we investigated the role of FTO-dependent demethylation in RB and its underlying mechanisms. The biological behavior of RB cells was analyzed using cell counting kit-8, colony formation analysis, transwell assay, flow cytometry, and western blot analysis. m6A modification was evaluated using methylated RNA immunoprecipitation and dual-luciferase reporter assays, and E2F3 stability was assessed using Actinomycin D. The roles of FTO and E2F3 were also elucidated in vivo. These results indicated that FTO was highly expressed in RB cells with low m6A levels. FTO knockdown inhibited RB cell growth, migration, invasion, and epithelial-mesenchymal transition and arrested the cell cycle at the G0/G1 phase. Mechanistically, FTO interference promoted m6A methylation of E2F3, which was recognized by YTHDF2, thereby reducing mRNA stability. E2F3 overexpression partially rescued the effects of FTO knockdown on biological behavior. Moreover, FTO knockdown reduced tumor weight, tumor volume, ki67 expression, and tumor cell infiltration by mediating E2F3. Taken together, FTO silencing inhibited the malignant processes of RB by suppressing E2F3 in an m6A-YTHD2-dependent manner. These findings suggest that FTO is a novel therapeutic target for RB.

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.

Mechanism of Fat Mass and Obesity-Related Gene-Mediated Heme Oxygenase-1 m6A Modification in the Recovery of Neurological Function in Mice with Spinal Cord Injury

OBJECTIVES

This study examined the mechanism of fat mass and obesity-related gene (FTO)-mediated heme oxygenase-1 (HO-1) m6A modification facilitating neurological recovery in spinal cord injury (SCI) mice. FTO/HO-1 was identified as a key regulator of SCI as well as a potential target for treatment of SCI.

METHODS

An SCI mouse was treated with pcDNA3.1-FTO/pcDNA3.1-NC/Dac51. An oxygen/glucose deprivation (OGD) cell model simulated SCI, with cells treated with pcDNA3.1-FTO/si-HO-1/Dac51. Motor function and neurobehavioral evaluation were assessed using the Basso, Beattie, and Bresnahan (BBB) scale and modified neurological severity score (mNSS). Spinal cord pathology and neuronal apoptosis were assessed. Further, FTO/HO-1 mRNA and protein levels, HO-1 mRNA stability, the interaction of YTHDF2 with HO-1 mRNA, neuronal viability/apoptosis, and HO-1 m6A modification were evaluated.

RESULTS

Spinal cord injury mice exhibited reduced BBB, elevated mNSS scores, disorganized spinal cord cells, scattered nuclei, and severe nucleus pyknosis. pcDNA3.1-FTO elevated FTO mRNA, protein expression, and BBB score; reduced the mNSS score of SCI mice; decreased neuronal apoptosis; improved the cell arrangement; and improved nucleus pyknosis in spinal cord tissues. OGD decreased FTO expression. FTO upregulation ameliorated OGD-induced neuronal apoptosis. pcDNA3.1-FTO reduced HO-1 mRNA and protein and HO-1 m6A modification, while increasing HO-1 mRNA stability and FTO in OGD-treated cells. FTO upregulated HO-1 by modulating m6A modification. HO-1 downregulation attenuated the effect of FTO. pcDNA3.1-FTO/Dac51 increased the HO-1 m6A level in mouse spinal cord tissue homogenate, reduced BBB, boosted mNSS scores of SCI mice, aggravated nucleus pyknosis, and increased neuronal apoptosis in spinal cord tissues, confirming that FTO mediated HO-1 m6A modification facilitated neurological recovery in SCI mice.

CONCLUSION

The fat mass and obesity-related gene modulates HO-1 mRNA stability by regulating m6A modification levels, thereby influencing HO-1 expression and promoting neurological recovery in SCI mice.

METTL14 promotes neuroblastoma formation by inhibiting YWHAH via an m6A-YTHDF1-dependent mechanism

Neuroblastoma (NB) is a common childhood tumor with a high incidence worldwide. The regulatory role of RNA N6-methyladenosine (m6A) in gene expression has attracted significant attention, and the impact of methyltransferase-like 14 (METTL14) on tumor progression has been extensively studied in various types of cancer. However, the specific influence of METTL14 on NB remains unexplored. Using data from the Target database, our study revealed significant upregulation of METTL14 expression in high-risk NB patients, with strong correlation with poor prognosis. Furthermore, we identified ETS1 and YY1 as upstream regulators that control the expression of METTL14. In vitro experiments involving the knockdown of METTL14 in NB cells demonstrated significant inhibition of cell proliferation, migration, and invasion. In addition, suppressing METTL14 inhibited NB tumorigenesis in nude mouse models. Through MeRIP-seq and RNA-seq analyses, we further discovered that YWHAH is a downstream target gene of METTL14. Mechanistically, we observed that methylated YWHAH transcripts, particularly those in the 5' UTR, were specifically recognized by the m6A "reader" protein YTHDF1, leading to the degradation of YWHAH mRNA. Moreover, the downregulation of YWHAH expression activated the PI3K/AKT signaling pathway, promoting NB cell activity. Overall, our study provides valuable insights into the oncogenic effects of METTL14 in NB cells, highlighting its role in inhibiting YWHAH expression through an m6A-YTHDF1-dependent mechanism. These findings also suggest the potential utility of a biomarker panel for prognostic prediction in NB patients.

METTL3 recruiting M2-type immunosuppressed macrophages by targeting m6A-SNAIL-CXCL2 axis to promote colorectal cancer pulmonary metastasis

BACKGROUND

The regulatory role of N6-methyladenosine (m6A) modification in the onset and progression of cancer has garnered increasing attention in recent years. However, the specific role of m6A modification in pulmonary metastasis of colorectal cancer remains unclear.

METHODS

This study identified differential m6A gene expression between  primary colorectal cancer and its pulmonary metastases using transcriptome sequencing and immunohistochemistry. We investigated the biological function of METTL3 gene both in vitro and in vivo using assays such as CCK-8, colony formation, wound healing, EDU, transwell, and apoptosis, along with a BALB/c nude mouse model. The regulatory mechanisms of METTL3 in colorectal cancer pulmonary metastasis were studied using methods like methylated RNA immunoprecipitation quantitative reverse transcription PCR, RNA stability analysis, luciferase reporter gene assay, Enzyme-Linked Immunosorbent Assay, and quantitative reverse transcription PCR.

RESULTS

The study revealed high expression of METTL3 and YTHDF1 in the tumors of patients with pulmonary metastasis of colorectal cancer. METTL3 promotes epithelial-mesenchymal transition in colorectal cancer by m6A modification of SNAIL mRNA, where SNAIL enhances the secretion of CXCL2 through the NF-κB pathway. Additionally, colorectal cancer cells expressing METTL3 recruit M2-type macrophages by secreting CXCL2.

CONCLUSION

METTL3 facilitates pulmonary metastasis of colorectal cancer by targeting the m6A-Snail-CXCL2 axis to recruit M2-type immunosuppressive macrophages. This finding offers new research directions and potential therapeutic targets for colorectal cancer treatment.