RNA N6-methyladenosine demethylase FTO promotes breast tumor progression through inhibiting BNIP3

Antitumor activity and mechanistic study of steroidal saponins from the rhizomes of Paris polyphylla var. yunnanensis

Through phytochemical analysis of the large roots of Paris polyphylla var. yunnanensis, three previously undescribed steroidal saponins (Polypharsis A-C, 1-3) and four known steroidal saponins (4-7) were isolated. The structures of 1-3 were elucidated by 1D/2D NMR, HR-ESI-MS, acid hydrolysis and ECD calculations. The cytotoxic activity tests of seven compounds against three tumor cell lines (HepG2, MCF-7, and A549) were conducted. Among them, compounds 6 and 7 belong to the protodioscin class of compounds. Compound 6 exhibits significant inhibition of HepG2 cell growth with an IC50 value of 7.53 ± 2.07 μM, comparable to that of Doxorubicin (6.82 ± 1.59 μM). Compound 7 shows a strong inhibitory effect on the growth of the MCF-7 cell line with an IC50 value of 0.69 ± 0.26 μM, which is more potent than Doxorubicin (5.56 ± 0.08 μM). Subsequently, the antitumor efficacy of compound 6 against HepG2 cells and compound 7 against MCF-7 cells was investigated through in vitro experiments, and their respective mechanisms of action were further predicted using network pharmacology and molecular docking.

Targeting RNA adenosine editing and modification enzymes for RNA therapeutics

Adenosine-to-inosine (A-to-I) RNA editing, and N6 methyladenosine (m6A) are among the most abundant modifications in eukaryotic messenger RNA, affecting various aspects of RNA metabolism and cellular function, including proliferation, differentiation, responses to stressors, and cell death. Recent preclinical evidence suggests that both modifications play a significant role in multiple disorders, including infections, chronic inflammatory diseases, and cancer, sparking great interest in their therapeutic potential. Structural characterization of ADARs (adenosine deaminases acting on RNA) and key m6A enzymes has enabled the development of small molecule inhibitors modulating their expression, enzymatic activity, or binding to target RNAs. Herein, we review preclinical evidence supporting the therapeutic benefits of targeting ADARs and m6A enzymes in diverse disease contexts. Small molecule inhibitors of RNA modification enzymes have shown potent anti-proliferative and pro-apoptotic effects in cancer cells, and have successfully inhibited tumor growth in vivo, without evident toxicity, while their combination with immuno-/chemotherapeutics displayed synergistic anti-neoplastic action. Adenosine RNA editing via recruitment of endogenous ADARs and usage of guide RNAs showed remarkable efficacy in correcting G-to-A point mutations and restoring the associated protein expression with limited off-target activity. Future studies are warranted to evaluate the safety and clinical efficacy of RNA editing or modification-targeting therapeutics in patients.

Baicalein disrupts TGF-β-induced EMT in pancreatic cancer by FTO-dependent m6A demethylation of ZEB1

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy associated with poor prognosis. Baicalein, a flavonoid extracted from the roots of Scutellaria baicalensis, traditionally used in Chinese medicine, has demonstrated potential in inhibiting cancer development and progression. However, its mechanism of action remains poorly understood, particularly regarding epigenetic gene regulation through m6A RNA methylation. In this study, three human PDAC cell lines and one nonmalignant cell line were employed. The effects of baicalein were examined using multiple assays, including RT-qPCR, MeRIP-qPCR, Western blotting, spheroid formation, RNA stability, and MTT, to evaluate cellular functions and m6A regulation. Baicalein significantly reduced cell viability, migration, invasion, and colony formation. It also downregulated FTO, an enzyme critical for m6A RNA demethylation. Knockdown of FTO replicated the effects of baicalein, underscoring its oncogenic role in PDAC. Bioinformatic analysis identified ZEB1-a key transcription factor in epithelial-to-mesenchymal transition-as an m6A-modified target regulated by FTO. Both baicalein treatment and FTO knockdown enhanced m6A modification and decreased ZEB1 mRNA stability, thereby suppressing stemness-related features. Rescue experiments further confirmed that baicalein disrupts the TGF-β/FTO/ZEB1 signaling axis, highlighting its therapeutic potential in PDAC. This study offers fundamental insights for the development of novel therapeutic strategies targeting PDAC.

FTO-mediated m6A Demethylation of OTUB1 stabilizes SLC7A11 to alleviate Ferroptosis in cerebral ischemia/reperfusion injury

BACKGROUD

Therapeutic strategies for cerebral ischemia/reperfusion (I/R) injury, an important contributor to neurological impairment and disability, exhibit limited efficacy. Reperfusion therapy intensifies neuronal damage by promoting iron deposition, ferroptosis (lipid peroxidation-associated iron-dependent cellular death), and reactive oxygen species (ROS) accumulation.

METHODS

we investigated the role of the m6A demethylase FTO in modulating ferroptosis during cerebral I/R injury, using middle cerebral artery occlusion/reperfusion (MCAO/R) model rats and neuronal cells subjected to oxygen glucose deprivation/reoxygenation (OGD/R) as in vivo and in vitro experimental platforms, respectively. Neurological scores and cerebral infarction volumes were measured by TTC staining. FTO, OTUB1, and SLC7A11 levels, and FTO demethylase activity, were assessed by qRT-PCR, western blotting, and immunohistochemistry. MeRIP was applied to ascertain the m6A methylation status of OTUB1 mRNA. Apoptotic rates and cell viability were quantitatively aalyzed by flow cytometry and CCK-8 assay, respectively, while brain tissue apoptosis was evaluated using TUNEL staining.

RESULTS

MCAO/R rat brains and OGD/R cells showed decreased FTO expression and increased OTUB1 m6A methylation. FTO overexpression upregulated OTUB1 by diminishing m6A methylation, consequently stabilizing SLC7A11 and reducing ferroptosis. FTO or OTUB1 silencing increased ferroptosis, while their co-overexpression enhanced neuroprotective effects. FTO overexpression reduced infarct volume and cell apoptosis, and improved neurological outcomes in vivo.

CONCLUSIONS

FTO enhanced OTUB1 expression via m6A demethylation, stabilizing SLC7A11, and inhibiting ferroptosis to alleviate cerebral I/R injury. The FTO/OTUB1/SLC7A11 pathway is a viable therapeutic target for ischemic stroke, providing novel perspectives on the molecular mechanisms underlying neuroprotection and proposing innovative m6A-based therapies.

Mechanistic role of FTO in cancer pathogenesis, immune evasion, chemotherapy resistance, and immunotherapy response

Fat mass and obesity-associated protein (FTO), an N6-methyladenosine (m6A) RNA demethylase, plays a key role in cancer biology by regulating mRNA modifications. Its deregulation affects tumor cell proliferation, metastasis, immune evasion, and therapeutic resistance. By removing m6A methylation marks, FTO can alter the stability and translation of key oncogenes and tumor suppressor genes. These modifications directly influence essential cellular pathways involved in cancer progression, such as the phosphatidylinositol 3-kinases/ protein kinase B (PI3K/AKT), Wnt/β-catenin, and mammalian target of rapamycin (mTOR) signaling pathways. This review explores the mechanistic roles of FTO in cancer pathogenesis, focusing on its dual impact on immune regulation and chemotherapy response. In terms of immunity, FTO has been shown to promote immune evasion by modulating the expression of immune checkpoints and influencing the tumor microenvironment. Additionally, FTO's influence on autophagy, glycolysis, and apoptosis resistance further complicates the effectiveness of chemotherapy treatments. By discussing the molecular details of how FTO regulates these processes, we provide insights into how FTO could serve as a promising therapeutic target to overcome cancer-related challenges, including immune resistance and chemotherapy failure. Finally, we evaluate current and emerging strategies for targeting FTO in cancer therapy, highlighting its potential to enhance immunotherapy and chemotherapy outcomes.

FTO Promotes Hepatocellular Carcinoma Progression by Mediating m6A Modification of BUB1 and Targeting TGF-βR1 to Activate the TGF-β Signaling Pathway

Background and Aims

Fat mass and obesity-associated protein (FTO) has been linked to various cancers, though its role in hepatocellular carcinoma (HCC) remains unclear. This study aimed to investigate FTO expression, its clinical relevance, functional role in HCC progression, and the underlying molecular mechanisms.

Methods

Quantitative reverse-transcription polymerase chain reaction and immunohistochemical analysis were used to assess FTO expression in HCC. Functional assays, including proliferation, invasion, and epithelial-mesenchymal transition studies, were conducted using HCC cell lines with FTO knockdown. N6-methyladenosine (m6A) RNA immunoprecipitation and RNA stability assays further elucidated the role of FTO in BUB1 mRNA methylation and stability. Co-immunoprecipitation studies were employed to confirm the interaction between BUB1 and TGF-βR1. In vivo studies in nude mice were conducted to evaluate tumor growth following FTO knockdown.

Results

FTO was significantly upregulated in HCC tissues compared to normal liver tissues, with higher expression observed in advanced tumor-node-metastasis stages and metastatic HCC. Elevated FTO correlated with poor overall survival in patients. Silencing FTO decreased HCC cell proliferation, colony formation, invasion, epithelial-mesenchymal transition, and tumor growth in nude mice. Mechanistically, FTO downregulation led to increased m6A modification of BUB1 mRNA, thereby promoting its degradation via the YTH domain family 2-dependent pathway and reducing BUB1 protein levels. Additionally, BUB1 physically interacted with TGF-βR1, activating downstream TGF-β signaling.

Conclusions

FTO is overexpressed in HCC and is associated with poor clinical outcomes. Mechanistically, FTO promotes HCC progression by stabilizing BUB1 mRNA through an m6A-YTH domain family 2-dependent pathway, which activates TGF-β signaling. Targeting the FTO-BUB1-TGF-βR1 regulatory network may offer a promising therapeutic strategy for HCC.

N6-methyladenosine RNA base modification regulates NKG2D-dependent and cytotoxic genes expression in natural killer cells

BACKGROUND

Breast cancer (BC) is the most commonly diagnosed cancer in women. N6-methyladenosine (m6A) is the most prevalent internal modification in mammalian mRNAs and plays a crucial role in various biological processes. However, its function in Natural killer (NK) cells in BC remains unclear. NK cells are essential for cancer immunosurveillance. This study aims to assess m6A levels in transcripts involved in the NKG2D cytotoxicity signaling pathway in NK cells of BC patients compared to controls and find out its impact on mRNA levels. Additionally, it evaluates how deliberately altering m6A levels in NK cells affects mRNA and protein expression of NKG2D pathway genes and NK cell functionality.

METHODS

m6A methylation in transcripts of NKG2D-pathway-related genes in BC patients and controls was determined using methylated RNA immunoprecipitation-reverse transcription-PCR (MERIP-RT-PCR). To deliberately alter m6A levels in primary cultured human NK cells, the m6A demethylases, FTO and ALKBH5, were knocked out using the CRISPR-CAS9 system, and FTO was inhibited using Meclofenamic acid (MA). The impact of m6A alteration on corresponding mRNA and protein levels was assessed using RT-qPCR and Western blot analysis or flow cytometry, respectively. Additionally, NK cell functionality was evaluated through degranulation and 51Cr release cytotoxicity assays.

RESULTS

Transcripts of NKG2D, an activating receptor that detects stressed non-self tumour cells, had significantly higher m6A levels in the 3' untranslated region (3'UTR) accompanied by a marked reduction in their corresponding mRNA levels in BC patients compared to controls. Conversely, transcripts of ERK2 and PRF1 exhibited significantly lower m6A levels escorted with higher mRNA expression in BC patients relative to controls. The mRNA levels of PI3K, PAK1 and GZMH were also significantly elevated in BC patients. Furthermore, artificially increasing transcripts' m6A levels via MA in cultured primary NK cells reduced mRNA levels of NKG2D pathway genes and death receptor ligands but did not affect protein expression or NK cell functionality.

CONCLUSION

Transcripts with higher m6A levels in the 3'UTR region were less abundant, and vice versa. However, changes in mRNA levels of the target genes didn't impact their corresponding protein levels or NK cell functionality.

METTL3-dependent m6A modification of SNAP29 induces "autophagy-mitochondrial crisis" in the ischemic microenvironment after soft tissue transplantation

Necrosis at the ischemic distal end of flap transplants increases patients' pain and economic burden. Reactive oxygen species (ROS) and mitochondrial damage are crucial in regulating parthanatos, but the mechanisms linking disrupted macroautophagic/autophagic flux to parthanatos in ischemic flaps remain unclear. The results of western blotting, immunofluorescence staining, and a proteomic analysis revealed that the autophagic protein SNAP29 was deficient in ischemic flaps, resulting in disrupted autophagic flux, increased ROS-induced parthanatos, and aggravated ischemic flap necrosis. The use of AAV vector to restore SNAP29 in vivo mitigated the disruption of autophagic flux and parthanatos. Additionally, quantification of the total m6A level and RIP-qPCR, MeRIP-qPCR, and RNA stability assessments were performed to determine differential Snap29 mRNA m6A methylation levels and mRNA stability in ischemic flaps. Various in vitro and in vivo tests were conducted to verify the ability of METTL3-mediated m6A methylation to promote SNAP29 depletion and disrupt autophagic flux. Finally, we concluded that restoring SNAP29 by inhibiting METTL3 and YTHDF2 reversed the "autophagy-mitochondrial crisis", defined for the first time as disrupted autophagic flux, mitochondrial damage, mitochondrial protein leakage, and the occurrence of parthanatos. The reversal of this crisis ultimately promoted the survival of ischemic flaps.Abbreviations: AAV = adeno-associated virus; ACTA2/α-SMA = actin alpha 2, smooth muscle, aorta; AIFM/AIF = apoptosis-inducing factor, mitochondrion-associated; ALKBH5 = alkB homolog, RNA demythelase; Baf A1 = bafilomycin A1; CQ = chloroquine; DHE = dihydroethidium; ECs = endothelial cells; F-CHP = 5-FAM-conjugated collagen-hybridizing peptide; GO = gene ontology; HUVECs = human umbilical vein endothelial cells; KEGG = Kyoto Encyclopedia of Genes and Genomes; LC-MS/MS = liquid chromatography-tandem mass spectrometry; LDBF = laser doppler blood flow; m6A = N6-methyladenosine; MAP1LC3/LC3 = microtubule-associated protein 1 light chain 3; MeRIP = methylated RNA immunoprecipitation; METTL3 = methyltransferase 3, N6-adenosine-methyltransferase complex catalytic subunit; NAC = N-acetylcysteine; OGD = oxygen glucose deprivation; PAR = poly (ADP-ribose); PARP1 = poly (ADP-ribose) polymerase family, member 1; PECAM1/CD31 = platelet/endothelial cell adhesion molecule 1; ROS = reactive oxygen species; RT-qPCR = reverse transcription quantitative polymerase chain reaction; RIP = RNA immunoprecipitation; SNAP29 = synaptosomal-associated protein 29; SNARE = soluble N-ethylmaleimide-sensitive factor attachment protein receptor; SQSTM1 = sequestosome 1; SRAMP = sequence-based RNA adenosine methylation site predicting; STX17 = syntaxin 17; TMT = tandem mass tag; TUNEL = terminal deoxynucleotidyl transferase dUTP nick end labeling; VAMP8 = vesicle-associated membrane protein 8; WTAP = WT1 associating protein; YTHDF2 = YTH N6-methyladenosine RNA binding protein 2; 3' UTR = 3'-untranslated region.

FTO alleviated the diabetic nephropathy progression by regulating the N6-methyladenosine levels of DACT1

Diabetic nephropathy (DN) is one of the most important microvascular complications of diabetes. The role of epigenetic regulation in DN has attracted much attention recently. This research was performed to explore the role of FTO in the DN progression. The renal tissues of DN patients were collected and the podocytes were stimulated with high glucose (HG) to establish the DN model in vitro. Western blot along with reverse transcription quantitative polymerase chain reaction assays was performed to analyze the mRNA as well as protein expressions. Immunohistochemistry and immunofluorescence were carried out to measure the FTO and DACT1 levels. The interaction between FTO/IGF2BP1 and DACT1 was verified by double luciferase reports and RNA-binding protein immunoprecipitation assays. FTO was declined, and DACT1 was enhanced in the HG-treated podocytes as well as renal tissues of DN patients. Overexpressed FTO declined the mRNA levels of MCP-1, IL-6, TNF-α, and the apoptosis rate of HG-treated podocytes. The N6-methyladenosine (m6A) levels, mRNA expression, and stability of FTO were depleted after FTO overexpression. DACT1 overexpression reversed the function of oe-FTO in podocytes stimulated with HG. Furthermore, IGF2BP1 knockdown declined the mRNA expression as well as the stability of FTO. In conclusion, FTO-medicated m6A modification of DACT1 was dependent on IGF2BP1 in DN progression.

m6A Methylation Mediated Autophagy and Nucleotide-Binding Oligomerization Domain-like Receptors Signaling Pathway Provides New Insight into the Mitigation of Oxidative Damage by Mulberry Leaf Polysaccharides

m6A methylation modification is an important genetic modification involved in biological processes such as sexual maturation, antibacterial, and antiviral in aquatic animals. However, few studies have been conducted in aquatic animals on the relationship between m6A methylation modification and autophagy-inflammation induced by lipid metabolism disorders. In the present study, a high-fat (HF) group and HF-MLP group (1 g mulberry leaf polysaccharides (MLPs)/1 kg HF diet) were set up. The mid-hind intestines of Megalobrama amblycephala juveniles from the two groups were collected for MeRIP-seq and RNA-seq after an 8-week feeding trial. The m6A peaks in the HF and HF-MLP groups were mainly enriched in the 3' Untranslated Region (3'UTR), Stop codon, and coding sequence (CDS) region. Compared with the HF group, the m6A peaks in the HF-MLP group were shifted toward the 5'UTR region. 'RRACH' was the common m6A methylation motif in the HF and HF-MLP groups. Methyltransferase mettl14 and wtap expression in the intestines of the HF-MLP group were significantly higher compared with the HF group (p < 0.05). A total of 21 differentially expressed genes(DEGs) with different peaks were screened by the combined MeRIP-seq and RNA-seq analysis. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis enriched BCL2 interacting protein 3 (bnip3) to autophagy-animal and mitophagy-animal signaling pathways, etc., and nucleotide-binding domain leucine-rich repeat protein 1 (nlrp1) was enriched to the Nucleotide-binding oligomerization domain (NOD)-like receptor signaling pathway. Combined MeRIP-seq and RNA-seq analysis indicated that the expression pattern of bnip3 was hyper-up and that of nlrp1 was hyper-down. Gene Set Enrichment Analysis (GSEA) analysis confirmed that the intestinal genes of HF-MLP group positively regulate lysosomal and autophagy-animal signaling pathways. In the present study, we demonstrated that m6A methylation modification plays a role in regulating autophagy-inflammatory responses induced by HF diets by MLPs, and further explored the molecular mechanisms by which MLPs work from the epigenetic perspective.

Phosducin inhibits the cell proliferation and promotes the antitumor effect of temozolomide in glioma

Malignant gliomas are the most lethal form of brain cancer, characterized by rapid cell growth, substantial molecular heterogeneity, and a propensity for invasion into critical brain regions. Phosducin (PDC) is recognized for its involvement in sensory signal transmission, blood pressure regulation, and thyroid gland endocrine functions. However, the role of PDC in cell proliferation, drug sensitization, and its connection to RNA m6A modification in gliomas remains unclear. In this study, RNA sequencing analysis was performed on U251 glioma cells with knockdown and overexpression of fat mass and obesity-associated protein (FTO). The results revealed that FTO negatively regulates PDC expression. This finding was corroborated in U87, U251, and A172 glioma cells via qRT-PCR and western blot analysis. Additionally, MTT and EdU assays revealed that PDC overexpression inhibited cell proliferation, while PDC knockdown accelerated it. Moreover, the proliferation-enhancing effect of FTO overexpression was reduced by PDC overexpression, and the proliferation-inhibiting effect of FTO knockdown was reversed by PDC knockdown. These findings suggest that PDC serves as a functional target of FTO. Furthermore, PDC enhanced the antitumor efficacy of temozolomide (TMZ). In summary, this study demonstrates for the first time that PDC plays a crucial role in regulating cell proliferation and TMZ sensitivity in glioma cells, providing a potential therapeutic target to improve treatment outcomes for the patients with glioma.

The m6A demethylase FTO promotes C/EBPβ-LIP translation to perform oncogenic functions in breast cancer cells

N6-methyladenosine (m6A) is a prevalent posttranscriptional mRNA modification involved in the regulation of transcript turnover, translation, and other aspects of RNA fate. The modification is mediated by multicomponent methyltransferase complexes (so-called writers) and is reversed through the action of the m6A-demethylases fat mass and obesity-associated (FTO) and alkB homolog 5 (ALKBH5) (so-called erasers). FTO promotes cell proliferation, colony formation and metastasis in models of triple-negative breast cancer (TNBC). However, little is known about genome-wide or specific downstream regulation by FTO. Here, we examined changes in the genome-wide transcriptome and translatome following FTO knockdown in TNBC cells. Unexpectedly, FTO knockdown had a limited effect on the translatome, while transcriptome analysis revealed that genes related to extracellular matrix (ECM) and epithelial-mesenchymal transition (EMT) are regulated through yet unidentified mechanisms. Differential translation of CEBPB mRNA into the C/EBPβ transcription factor isoform C/EBPβ-LIP is known to act in a pro-oncogenic manner in TNBC cells through regulation of EMT genes. Here we show that FTO is required for efficient C/EBPβ-LIP expression, suggesting that FTO has oncogenic functions through regulation of C/EBPβ-LIP.

Helicobacter pylori CagA elevates FTO to induce gastric cancer progression via a "hit-and-run" paradigm

BACKGROUND

Helicobacter pylori (H. pylori) infection contributes significantly to gastric cancer (GC) progression. The intrinsic mechanisms of H. pylori-host interactions and their role in promoting GC progression need further investigation. In this study, we explored the potential role of fat mass and obesity-associated protein (FTO) in mediating Cytotoxin-associated gene A (CagA)-induced GC progression.

METHODS

The effects of H. pylori infection on N6-methyladenosine (m6A) modification were evaluated in both human samples and GC cell lines. The function of FTO in the progression of GC was elucidated through in vitro and in vivo studies. A series of techniques, including methylated RNA immunoprecipitation sequencing, RNA sequencing, RNA binding protein immunoprecipitation, and chromatin immunoprecipitation assays, were utilized to investigate the mechanism by which FTO mediates the capacity of cagA-positive H. pylori to promote GC progression. Furthermore, the therapeutic potential of the FTO inhibitor meclofenamic acid (MA) in impeding GC progression was evaluated across GC cells, animal models, and human GC organoids.

RESULTS

Infection with cagA-positive H. pylori upregulated the expression of FTO, which was essential for CagA-mediated GC metastasis and significantly associated with a poor prognosis in GC patients. Mechanistically, CagA delivered by H. pylori enhanced FTO transcription via Jun proto-oncogene. Elevated FTO induced demethylation of m6A and inhibited the degradation of heparin-binding EGF-like growth factor (HBEGF), thereby facilitating the epithelial-mesenchymal transition (EMT) process in GC cells. Interestingly, eradication of H. pylori did not fully reverse the increases in FTO and HBEGF levels induced by cagA-positive H. pylori. However, treatment with a combination of antibiotics and MA substantially inhibited cagA-positive H. pylori-induced EMT and prevented GC metastasis.

CONCLUSION

Our study revealed that FTO mediates the "hit-and-run" mechanism of CagA-induced GC progression, which suggests that the therapeutic targeting of FTO could offer a promising approach to the prevention of CagA-induced cancer progression.

The Role of N6-Methyladenosine in Mitochondrial Dysfunction and Pathology

Mitochondria are indispensable in cells and play crucial roles in maintaining cellular homeostasis, energy production, and regulating cell death. Mitochondrial dysfunction has various manifestations, causing different diseases by affecting the diverse functions of mitochondria in the body. Previous studies have mainly focused on mitochondrial-related diseases caused by nuclear gene mutations or mitochondrial gene mutations, or mitochondrial dysfunction resulting from epigenetic regulation, such as DNA and histone modification. In recent years, as a popular research area, m6A has been involved in a variety of important processes under physiological and pathological conditions. However, there are few summaries on how RNA methylation, especially m6A RNA methylation, affects mitochondrial function. Additionally, the role of m6A in pathology through influencing mitochondrial function may provide us with a new perspective on disease treatment. In this review, we summarize several manifestations of mitochondrial dysfunction and compile examples from recent years of how m6A affects mitochondrial function and its role in some diseases.

Discovery of the 2,3-Dihydrobenzopyrane-4-one as a Potent FTO Inhibitor against Obesity-Related Metabolic Diseases

The involvement of the fat mass and obesity-associated gene (FTO) in the development and advancement of metabolic disorders is widely recognized. However, the existing FTO inhibitor entacapone has been limited in clinical application due to its low potency and short plasma elimination half-life. Here, through drug library screening and in depth structure-activity relationship analysis, title compound 40, eriodictyol was identified as a potent FTO inhibitor, and showed good binding to FTO by surface plasmon resonance (SPR) and Microscale thermophoresis (MST) detection. The residues Arg96, Tyr108, Ser229, Asp233, and Glu234 of FTO are essential for binding. Meanwhile, eriodictyol attenuated obesity-related metabolic diseases by enhancing glucose metabolism pathways via the FTO-FOXO1-G6PC/PCK1 axis and increasing adipose tissue heat production for weight loss via the FTO-FOXO1-Ucp1 axis in vivo. Surprisingly, eriodictyol showed good pharmacokinetic properties and no obvious toxicity. These results could provide the reference for design of new FTO inhibitors against obesity-related metabolic diseases.

Key epigenetic enzymes modulated by natural compounds contributes to tumorigenicity

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

Pan-cancer analysis of co-inhibitory molecules revealing their potential prognostic and clinical values in immunotherapy

Background

The widespread use of immune checkpoint inhibitors (anti-CTLA4 or PD-1) has opened a new chapter in tumor immunotherapy by providing long-term remission for patients. Unfortunately, however, these agents are not universally available and only a minority of patients respond to them. Therefore, there is an urgent need to develop novel therapeutic strategies targeting other co-inhibitory molecules. However, comprehensive information on the expression and prognostic value of co-inhibitory molecules, including co-inhibitory receptors and their ligands, in different cancers is not yet available.

Methods

We investigated the expression, correlation, and prognostic value of co-inhibitory molecules in different cancer types based on TCGA, UCSC Xena, TIMER, CellMiner datasets. We also examined the associations between the expression of these molecules and the extent of immune cell infiltration. Besides, we conducted a more in-depth study of VISTA.

Result

The results of differential expression analysis, correlation analysis, and drug sensitivity analysis suggest that CTLA4, PD-1, TIGIT, LAG3, TIM3, NRP1, VISTA, CD80, CD86, PD-L1, PD-L2, PVR, PVRL2, FGL1, LGALS9, HMGB1, SEMA4A, and VEGFA are associated with tumor prognosis and immune cell infiltration. Therefore, we believe that they are hopefully to serve as prognostic biomarkers for certain cancers. In addition, our analysis indicates that VISTA plays a complex role and its expression is related to TMB, MSI, cancer cell stemness, DNA/RNA methylation, and drug sensitivity.

Conclusions

These co-inhibitory molecules have the potential to serve as prognostic biomarkers and therapeutic targets for a broad spectrum of cancers, given their strong associations with key clinical metrics. Furthermore, the analysis results indicate that VISTA may represent a promising target for cancer therapy.

The Role of M6A LncRNA Modification in Papillary Thyroid Cancer

Thyroid Cancer (TC) is the most common endocrine cancer, of which papillary thyroid cancer (PTC), a well-differentiated type of TC, accounts for 80-90%. Long non-coding RNAs (lncRNAs), which comprise non-protein-coding segments of the genome, have been found to play a crucial role in various biological processes, including cancer development. The activity of lncRNAs is modified through epigenetic modifications, with N6-Methyladenosine (m6A) modifications implicated in the progression of several malignancies. The activity of m6A is further regulated by modifying enzymes classified as "readers", writers", and "erasers", of which specific enzymes have been found to play a role in various aspects of PTC. Recent research has highlighted the significance of m6A modification in regulating the expression and function of lncRNAs associated with PTC pathogenesis. Dysregulation of this process implicates tumor proliferation, invasion, and metastasis, with subsequent impact on prognosis. Therefore, understanding the interplay between m6A modification and lncRNAs provides valuable insights into the molecular mechanisms underlying PTC progression. This narrative review aims to explore the established role of several prominent m6A modifying enzymes and lncRNAs on cancer pathogenesis and seeks to clarify the function of these enzymes in PTC pathogenesis.

Modifications of RNA in cancer: a comprehensive review

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

Demethylase FTO mediates m6A modification of ENST00000619282 to promote apoptosis escape in rheumatoid arthritis and the intervention effect of Xinfeng Capsule

Introduction

The pathological mechanisms of rheumatoid arthritis (RA) are closely associated with the apoptosis escape of fibroblast-like synoviocytes (FLS). The m6A modification of long non-coding RNAs (lncRNAs) plays a critical regulatory role in RA pathogenesis. Xinfeng Capsule (XFC), a clinically effective traditional Chinese medicine formulation, has been shown to alleviate RA by inhibiting FLS apoptosis escape. However, its molecular mechanisms remain unclear. This study aimed to elucidate the mechanism by which the demethylase FTO promoted FLS apoptosis escape through the m6A modification of lncRNA ENST00000619282 and to reveal the therapeutic targets of XFC in treating RA by intervening in this m6A-dependent pathway.

Methods

A retrospective analysis was conducted on 1603 RA patients using association rule mining and random walk algorithms to evaluate the efficacy of XFC. The proliferation and apoptosis of co-cultured RA-FLS were assessed using CCK-8, flow cytometry (FCM), and molecular biology techniques. Bioinformatics prediction, MeRIP-qPCR, RIP, and RNA pull-down assays were employed to identify the m6A modification sites of ENST00000619282 and their interactions with FTO/YTHDF1. Additionally, FISH, luciferase reporter assays, and rescue experiments were performed to validate the regulatory role of ENST00000619282 and its sponge-like function in RA-FLS. Clinical samples were analyzed to determine the correlation between FTO/YTHDF1/ENST00000619282/Bax/Bcl-2 and immune-inflammatory markers. Furthermore, the binding affinity of XFC active components to NF-κB was assessed through molecular docking.

Results

Retrospective data mining demonstrated that XFC significantly improved immune-inflammatory markers in RA patients. Mechanistically, FTO reduced the m6A modification level of ENST00000619282, enhancing its stability and promoting YTHDF1-dependent expression, which in turn inhibited PUF60 and activated the NF-κB pathway, ultimately leading to FLS apoptosis escape. XFC downregulated FTO, increased the m6A modification of ENST00000619282, blocked the NF-κB signaling, inhibited RA-FLS proliferation, as well as induced their apoptosis. Clinical validation revealed that FTO/YTHDF1/ENST00000619282/Bax/Bcl-2 was closely associated with immune-inflammatory markers in RA patients. After XFC treatment, FTO, ENST00000619282, and Bcl-2 expressions were decreased, while YTHDF1 and Bax expressions were increased (all P<0.05). Molecular docking confirmed that the active components of XFC (calycosin-7-O-beta-D-glucoside, calycosin, and formononetin) exhibited strong binding affinity to NF-κB p65.

Conclusion

FTO promoted FLS apoptosis escape and RA progression by activating the NF-κB pathway through the m6A-dependent ENST00000619282/YTHDF1 axis. XFC inhibited this pathway by modulating FTO-mediated m6A modification, providing a novel RNA epigenetic regulatory strategy for RA treatment.

Research progress on N6-Methyladenosine modification in angiogenesis, vasculogenic mimicry, and therapeutic implications in breast cancer

N6-methyladenosine (m6A) modification is the most common epitranscriptomic modification in eukaryotic RNA and has garnered extensive attention in the context of breast cancer research. The m6A modification significantly impacts tumorigenesis and tumor progression by regulating RNA stability, splicing, translation, and degradation. In this review we summarize recent advances in understanding the roles of m6A modification in the mechanisms underlying angiogenesis and vasculogenic mimicry in breast cancer. We review how m6A modification and associated transcripts influence relevant factors by affecting key factors and signaling pathways, highlighting the interactions among m6A "writers," "erasers," and "readers," and their overall impact on tumor angiogenesis and vasculogenic mimicry, as well as potential new therapeutic targets.

The epigenetic landscape of brain metastasis

Brain metastasis represents a significant challenge in oncology, driven by complex molecular and epigenetic mechanisms that distinguish it from primary tumors. While recent research has focused on identifying genomic mutation drivers with potential clinical utility, these strategies have not pinpointed specific genetic mutations responsible for site-specific metastasis to the brain. It is now clear that successful brain colonization by metastatic cancer cells requires intricate interactions with the brain tumor ecosystem and the acquisition of specialized molecular traits that facilitate their adaptation to this highly selective environment. This is best exemplified by widespread transcriptional adaptation during brain metastasis, resulting in aberrant gene programs that promote extravasation, seeding, and colonization of the brain. Increasing evidence suggests that epigenetic mechanisms play a significant role in shaping these pro-brain metastasis traits. This review explores dysregulated chromatin patterns driven by chromatin remodeling, histone modifications, DNA/RNA methylation, and other epigenetic regulators that underpin brain metastatic seeding, initiation, and outgrowth. We provide novel insights into how these epigenetic modifications arise within both the brain metastatic tumor and the surrounding brain metastatic tumor ecosystem. Finally, we discuss how the inherent plasticity and reversibility of the epigenomic landscape in brain metastases may offer new therapeutic opportunities.

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

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

A novel mechanism of FTO modulating the progression of endometriosis through mediating the m6A methylation of GEF-H1 in a YTHDF1-dependent manner

BACKGROUND

Endometriosis (EMs) is a condition characterized by the growth of endometrial tissue outside the uterine cavity. Although this condition is benign, it has cancer-like features. N6-methyladenosine (m6A) is a common RNA modification involved in diverse biological processes, but its role in EMs remains unclear.

METHODS

A human endometrial stromal cell line (HESCs), primary eutopic endometrial stromal cells (Eu-ESCs), primary ectopic endometrial stromal cells (Ec-ESCs), and clinical samples were used in this study. A colorimetric assay was used to measure methylation levels in clinical and mouse EMs samples. Functional assays (CCK-8, EdU, Transwell, and wound healing) were used to evaluate phenotypic changes. m6A immunoprecipitation sequencing (MeRIP-seq) identified downstream targets. Mechanistic studies were conducted via qRT‒PCR, Western blot, RNA immunoprecipitation (RIP), dual-luciferase reporter, and RNA stability assays.

RESULTS

We detected aberrantly low levels of m6A within endometriotic lesions, which was attributed to increased expression of the m6A eraser fat mass and obesity-associated protein (FTO). Notably, estrogen and inflammatory factors, which are recognized as pathogenic agents in EMs amplify FTO expression while suppressing m6A levels. In vitro experiments demonstrated that overexpression of FTO in endometrial stromal cells leads to a reduction in m6A levels and concomitantly promotes their proliferation, migration, and invasion. Furthermore, both genetic deletion of Fto and chemical inhibition of FTO impeded the growth of ectopic endometrial lesions in vivo. By utilizing m6A-seq, we identified GEF-H1 (a Rho guanine nucleotide exchange factor) as a pivotal downstream target of FTO. Specifically, diminished m6A methylation at a certain site within the 3'UTR of GEF-H1 promotes its expression in a YTH N6-methyladenosine RNA-binding protein F1 (YTHDF1)-dependent manner, thereby activating the RhoA pathway. Subsequent experiments revealed that GEF-H1 mediates the effects of FTO in promoting migration and invasion.

CONCLUSIONS

This study revealed that FTO decreases the m6A level of GEF-H1, thereby increasing its stability, which in turn activates the GEF-H1-RhoA pathway to promote the migration and invasion of endometrial stromal cells, thereby inducing EMs. Our findings suggest potential therapeutic avenues for targeting FTO to alleviate EMs progression.

Exploring m6A modifications in gastric cancer: from molecular mechanisms to clinical applications

The significance of m6A modifications in several biological processes has been increasingly recognized, particularly in the context of cancer. For instance, m6A modifications in gastric cancer (GC) have been significantly implicated in tumor progression, metastasis, and treatment resistance. GC is characterized by the differential expression of m6A regulators. High expression writers such as METTL3 and WTAP are associated with poor prognosis and aggressive clinical features. Conversely, low expression of METTL14 is linked to worse clinical outcomes, whereas elevated levels of demethylases, such as FTO and ALKBH5, correlate with better survival rates. These m6A regulators influence several cellular biological functions, including proliferation, invasion, migration, glycolysis, and chemotherapy resistance, thereby affecting tumor growth and therapeutic outcomes. The assessment of m6A modification patterns and the expression profiles of m6A-related genes hold substantial potential for improving the clinical diagnosis and treatment of GC. In this review, we provide an updated and comprehensive summary of the role of m6A modifications in GC, emphasizing their molecular mechanisms, clinical significance, and translational applications in developing novel diagnostic and therapeutic strategies.

The Emerging Role of m6A and Programmed Cell Death in Cardiovascular Diseases

N6-methyladenosine (m6A) is the most prevalent internal chemical modification in eukaryotic messenger RNA (mRNA), significantly impacting its lifecycle through dynamic and reversible processes involving methyltransferase, demethylase, and binding proteins. These processes regulate mRNA stability, splicing, nuclear export, translation, and degradation. Programmed cell death (PCD), a tightly controlled process encompassing apoptosis, pyroptosis, ferroptosis, autophagy, and necroptosis, plays a crucial role in maintaining cellular homeostasis, tissue development, and function. Recently, m6A modification has emerged as a significant research area due to its role in regulating PCD and its implications in cardiovascular diseases (CVDs). In this review, we delve into the intricate relationship between various PCD types and m6A modification, emphasizing their pivotal roles in the initiation and progression of CVDs such as myocardial ischemia-reperfusion (I/R), atherosclerosis (AS), pulmonary hypertension (PH), cardiomyopathy, doxorubicin (Dox)-induced cardiotoxicity (DIC), heart failure (HF), and myocardial infarction (MI). Our findings underscore the potential of elucidating the roles of m6A and PCD in CVD to pave new pathways for prevention and treatment strategies.

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.

N6-methyladenosine (m6A) RNA methylation of LncRNA LINC01214 accelerates the progression of non-small cell lung cancer (NSCLC) by targeting miR-195-5p/ROCK1 axis

Long non-coding RNA LINC01214 is reported to be up-regulated in non-small cell lung cancer (NSCLC), however, its function in NSCLC has not been elucidated yet. In our study, we verified that LINC01214 was aberrantly higher in the tumor tissues and cell lines than that in the normal controls, and was relevant to the severity and prognosis of NSCLC through using real-time quantitative PCR. Then, 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide assay and flow cytometry illustrated that knocking down LINC01214 restrained cell proliferation and promoted apoptosis in A549 and H1299 cells. Additionally, western blot results confirmed that LINC01214 silence reduced the protein expression of CDK2, CDK6, CyclinD1 and Bcl2, but increased the protein expression of Bax and Caspase-3. Of note, compared to normal cells, NSCLC cells had higher enrichment level of N6-methyladenosine (m6A) modification of LINC01214, while reducing m6A modification of LINC01214 weakened the stability of LINC01214 and diminished its level in A549 and H1299 through down-regulating methyltransferase METTL3 or overexpressing demethylase ALKBH5. Subsequently, molecular experiments proved that LINC01214 acted as a sponge for miR-195-5p to elevate ROCK1 expression in NSCLC. Furthermore, data from functional recovery experiments showed that elevating miR-195-5p also exerted tumor-suppressive effects in NSCLC; meanwhile, the effects were reversed by overexpressing ROCK1 or inhibiting miR-195-5p. In short, m6A modification-mediated up-regulation of LINC01214 advances cell proliferation and tumorigenesis to promote NSCLC progression through inhibiting miR-195-5p to up-regulate ROCK1.

Hypoxia-Inducible Factor-1α Regulates BNIP3-Dependent Mitophagy and Mediates Metabolic Reprogramming Through Histone Lysine Lactylation Modification to Affect Glioma Proliferation and Invasion

OBJECTIVE

Gliomas are the predominant form of malignant brain tumors. We investigated the mechanism of hypoxia-inducible factor-1α (HIF-1α) affecting glioma metabolic reprogramming, proliferation and invasion.

METHODS

Human glioma cell U87 was cultured under hypoxia and treated with small interfering (si)HIF-1α, si-B cell lymphoma-2/adenovirus E1B 19-kDa interacting protein 3 (siBNIP3), si-YT521-B homology domain 2 (siYTHDF2), 3-methyladenine and 2-deoxyglucose, with exogenous sodium lactate-treated normally-cultured cells as a lactate-positive control. Cellular hexokinase 2, lactate dehydrogenase A and pyruvate dehydrogenase kinase 1 enzyme activities, glucose uptake, and levels of lactic acid and adenosine triphosphate (ATP), and HIF-1α, glycolysis-related proteins, mitophagy-related proteins, histone H3 lysine 18 lactylation (H3K18la) and YTHDF2 were determined by ELISA, 2-NBDG, kits, and Western blot. Extracellular acidification rate (ECAR), and cell proliferation, invasion, apoptosis and mitophagy were evaluated by extracellular flux analysis, CCK-8, Transwell, flow cytometry, and immunofluorescence staining. H3K18la-YTHDF2 relationship and YTHDF2-BNIP3 interaction were assessed by ChIP and Co-IP assays.

RESULTS

Hypoxia-induced highly-expressed HIF-1α in glioma cells increased glycolysis-related protein levels, glycolytic enzyme activities, glucose uptake, lactic acid production, ATP level and ECAR, thereby promoting metabolic reprogramming, invasion and proliferation. HIF-1α mediated metabolic reprogramming, proliferation and invasion through BNIP3-dependent mitophagy, which were partly negated by mitophagy inhibition. HIF-1α induced histone Kla modification to upregulate YTHDF2. YTHDF2 downregulation impeded YTHDF2-BNIP3 interaction and inhibited HIF-1α-induced BNIP3-dependent mitophagy, curbing glioma cell metabolic reprogramming, proliferation and invasion.

CONCLUSIONS

Hypoxia-induced high HIF-1α expression upregulated YTHDF2 through hH3K18la modification, enhanced YTHDF2-BNIP3 interaction, and regulated BNIP3-dependent mitophagy-mediated metabolic reprogramming to affect glioma proliferation and invasion.

FTO-mediated m6A demethylation of SERPINE1 mRNA promotes tumor progression in hypopharyngeal squamous cell carcinoma

Background

The fat mass and obesity-associated protein (FTO) is implicated in various diseases and acts as a demethylase for the most abundant modification of mRNA, namely N6-methyladenosine (m6A) modification. It is known that FTO may play an oncogenic role or a tumor-suppressor role in different malignancies. The aim of this study was to investigate the functional roles of FTO in regulating biological processes related to hypopharyngeal squamous cell carcinoma (HSCC).

Methods

Using immunohistochemistry, quantitative real-time polymerase chain reaction (RT-qPCR), and Western blot analysis, we compared the expression levels of FTO in HSCC tissues to adjacent non-cancerous tissues. Furthermore, we evaluated the prognosis of patients with hypopharyngeal cancer in relation to FTO expression levels. In vitro, the Cell Counting Kit-8 (CCK8), wound healing assay, migration and invasion assays were used to identify roles of FTO in HSCC cells FaDu. Tumor xenografts in nude mice were used to disclose the effect of FTO in vivo. Then, transcriptome RNA sequencing (RNA-seq) assays were applied to screen for possible target genes. To confirm the specific site for modulating the expression of the target gene, we used the SRAMP database and methylated RNA immunoprecipitation PCR (MeRIP-PCR).

Results

The results showed that FTO was highly expressed in hypopharyngeal cancer tissues and was correlated with clinicopathology of patients. FTO promoted the proliferation, invasion and migration of hypopharyngeal cancer cells in vitro through its demethylase action. In vivo experiments showed that FTO promoted the growth of subcutaneously implanted tumors of hypopharyngeal cancer cells and their metastasis. Moreover, we revealed that FTO affected the malignant biological behavior of hypopharyngeal cancer cells by regulating the m6A modification level of SERPINE1 mRNA. FTO promoted epithelial-mesenchymal transformation (EMT) of hypopharyngeal cancer cells through the SERPINE1 signaling axis.

Conclusions

Our study highlighted the functional significance of the FTO/SERPINE1 axis in tumorigenesis of HSCC. Targeting FTO holds promise as a new therapeutic strategy for HSCC.

Comprehensive Analysis Reveals Midnolin as a Potential Prognostic, Therapeutic, and Immunological Cancer Biomarker

Background/Objectives: MIDN (midnolin) is newly discovered method for critically regulating a ubiquitin-independent proteasomal degradation pathway. This study aims to examine the expression, prognostic value, genomic changes, interacting proteins, methylation status, and correlations with the tumor immune microenvironment of MIDN in various cancers. Methods: The GTEx, Depmap, GEPIA2, and Kaplan-Meier Plotter databases are applied to evaluate the MIDN level in tumor and normal tissues and the MIDN prognostic value in cancers. The genetic alterations of MIDN in cancers are investigated using the cBioPortal database. The STRING, GeneMANIA, DAVID, and Human Protein Atlas are harnessed to identify and analyze MIDN-interacted proteins. The Sangerbox 3.0 platform (a pan-cancer analysis module) is used to measure the correlations between the MIDN level and the tumor immune microenvironment, stemness, immune cell infiltration, tumor mutational burden, immune checkpoint genes, and RNA modification genes. Immunofluorescence, qRT-PCR, and Western blotting assays were used to evaluate the biological roles of MIDN in breast and gastric cancer cells. Results: MIDN expression was dysregulated in many cancers and associated with prognosis in several cancers, such as esophageal cancer. MIDN was mutated in 1.7% of cancers, and deep deletion was the dominant mutation type. NR4A1, PSMC1, and EGR1 were selected as MIDN-interacted proteins, and these four molecules were co-expressed in pancreatic cancer, liver cancer, urothelial cancer, melanoma, and breast cancer. MIDN expression was significantly correlated with the infiltration of CD8+ T cell, CD4+ T cell, B cell, macrophage, neutrophil, and DC both in prostate adenocarcinoma and liver hepatocellular carcinoma. The MIDN level was correlated with several immune checkpoint genes, such as VEGFA, and RNA modification genes such as YTHDF1, YTHDF2, YTHDF3, and YTHDC1 in cancers. Furthermore, in breast cancer cells, the downregulation of MIDN suppressed the colony formation abilities and lessened cell-cycle-associated and stemness-associated genes; in gastric cancer, the knockdown of MIDN diminished the mRNA levels of Nanog and LDHA. Strikingly, silence of MIDN upregulated FTO protein expression in both breast and gastric cancer cells. Conclusions: Our findings demonstrate the expression, prognostic value, mutation status, interacting proteins, methylation status, and correlations with the tumor immune microenvironment of MIDN. MIDN will be developed as a potential therapeutic target and a prognosis biomarker.

hnRNPU-mediated pathogenic alternative splicing drives gastric cancer progression

BACKGROUND

Alternative splicing (AS) is a process that facilitates the differential inclusion of exonic sequences from precursor messenger RNAs, significantly enhancing the diversity of the transcriptome and proteome. In cancer, pathogenic AS events are closely related to cancer progression. This study aims to investigate the role and regulatory mechanisms of AS in gastric cancer (GC).

METHODS

We analyzed AS events in various tumor samples and identified hnRNPU as a key splicing factor in GC. The effects of hnRNPU on cancer progression were assessed through in vitro and in vivo experiments. Gene knockout models and the FTO inhibitor (meclofenamic acid) were used to validate the interaction between hnRNPU and FTO and their impact on AS.

RESULTS

We found that hnRNPU serves as a key splicing factor in GC, and its high expression is associated with poor clinical prognosis. Genetic depletion of hnRNPU significantly reduced GC progression. Mechanistically, the m6A demethylase FTO interacts with hnRNPU transcripts, decreasing the m6A modification levels of hnRNPU, which leads to exon 14 skipping of the MET gene, thereby promoting GC progression. The FTO inhibitor meclofenamic acid effectively inhibited GC cell growth both in vitro and in vivo.

CONCLUSION

The FTO/hnRNPU axis induces aberrant exon skipping of MET, thereby promoting GC cell growth. Targeting the FTO/hnRNPU axis may interfere with abnormal AS events and provide a potential diagnostic and therapeutic strategy for GC.

miRNA-214-3p targets BNIP3 to affect autophagy and thus drive gastric cancer progression

With a fourth-place death rate among all malignancies, gastric cancer (GC) is one of the most prevalent tumors globally. As a primary malignant characteristic of GC, metastasis contributes substantially to a high death rate and unfavorable prognosis. miRNA-214-3p can influence cell apoptosis since it is an autophagy-regulating molecule. Its significance in GC malignant development has not, however, been investigated in terms of mechanism. qRT-PCR was utilized to confirm expression of miRNA-214-3p in GC tissues and cells. Bioinformatics analysis was then implemented to examine BNIP3 expression in GC as well as binding interaction between BNIP3 and miRNA-214-3p. The targeting capability of miRNA-214-3p on BNIP3 was confirmed using the dual-luciferase assay. Capacities of cells to proliferate, migrate, and invade were assayed using Transwell assays and colony formation. In order to determine if GC cells were capable of autophagy, immunofluorescence and western blot were employed. In GC, miRNA-214-3p was substantially expressed in GC tissues and cells, but BNIP3 was downregulated, as shown by bioinformatics analysis and verified by cell tests. MiRNA-214-3p targeted BNIP3, as shown by further bioinformatics analysis, and dual-luciferase experiment verified this binding connection. MicroRNA-214-3p facilitated cell invasion, migration, and proliferation, as shown by Transwell tests and colony formation. MiRNA-214-3p accelerated malignant development of GC by targeting BNIP3 to impact autophagy, as demonstrated by immunofluorescence and western blot analyses. By targeting BNIP3 to affect autophagy, miRNA-214-3p aided in the malignant growth of GC. This suggested that miRNA-214-3p may function as a likely therapeutic target or biomarker for the disease, with significant implications for early diagnosis and treatment of patients.

FTO activates PD-L1 promotes immunosuppression in breast cancer via the m6A/YTHDF3/PDK1 axis under hypoxic conditions

INTRODUCTION

Altered epigenetic reprogramming enables breast cancer cells to adapt to hypoxic stress. Hypoxic microenvironment can alter immune cell infiltration and function, limiting the effectiveness of immunotherapy.

OBJECTIVES

The study aimed to identify how fat mass and obesity-associated protein (FTO) helps breast cancer cells cope with the hypoxic microenvironment and the mechanisms behind breast cancer cell resistance to tumor immunity.

METHODS

Clinical samples were utilized to analyze the impact of FTO on breast cancer progression and the effect of programmed cell death protein 1/ programmed cell death 1 ligand 1(PD-1/PD-L1) immune checkpoint inhibitor treatment. Utilized MeRIP-seq and mRNA-seq to analyze the downstream genes regulated by FTO under hypoxia. Methylation modification regulation of PDK1 by FTO was clarified using RIP. Then mouse models were utilized to analyze the efficacy of inhibiting FTO and 3-Phosphoinositide-dependent protein kinase 1(PDK1) in combination with PD-1/PD-L1 immune checkpoint inhibitor treatment.

RESULT

N6-Methyladenosine(m6A) demethylase FTO was transcriptionally activated by hypoxia inducible factor 1α(HIF-1α). PDK1 was identified as a potential target of FTO under hypoxic conditions through high-throughput sequencing. Mechanistically, overexpression of FTO decreases m6A modification sites on PDK1 mRNA, preventing YTH domain family 3(YTHDF3) from recognizing and binding to these sites, thereby inhibiting the degradation of PDK1 mRNA. Overexpression of PDK1 activates the AKT/STAT3 pathway, leading to enhanced PD-L1 expression. Targeting the FTO and PDK1-AKT pathways with FB23 and BX-912 inhibit breast cancer growth, enhance cytotoxic T lymphocyte (CTL) activity, and enhance the effectiveness of the PD-1/PD-L1 checkpoint inhibitor Atezolizumab.

CONCLUSION

This study reveals that HIF-1α promotes FTO transcription under hypoxic conditions, thereby increasing PD-L1 expression through the PDK1/AKT/STAT3 axis. Inhibition of FTO and PDK1 under hypoxic conditions could serve as a promising immunotherapeutic strategy for breast cancer.

Assembly of Dandelion-Like Nanoprobe for Sensitive Detection of N6-Methyladenosine Demethylase by Single-Molecule Counting

N6-methyladenosine (m6A) demethylase is essential for enzymatically removing methyl groups from m6A modifications and is significantly implicated in the pathogenesis and advancement of various cancers, which makes it a promising biomarker for cancer detection and research. As a proof of concept, we select the fat mass and obesity-associated protein (FTO) as the target m6A demethylase and develop a dandelion-like nanoprobe-based sensing platform by employing biobar-code amplification (BCA) for signal amplification. We construct two meticulously designed three-dimensional structures: reporter-loaded gold nanoparticles (Reporter@Au NPs) and substrate-loaded magnetic microparticles (Substrate@MMPs), which can self-assemble to form dandelion-like nanoprobes via complementary base pairing. In the presence of FTO, the m6A-containing substrates are demethylated, triggering the MazF-assisted cleavage reaction and thereby releasing the Reporter@Au NPs. Furthermore, upon digestion by exonucleases, the Reporter@Au NPs may liberate a significant quantity of Cy3 signals. Remarkably, the combined effects of Au NPs' superior enrichment capacity, MMPs' exceptional magnetic separation efficiency, and the precision of the single-molecule detection platform endow the FTO sensor with exceptional sensitivity and specificity with a detection limit of 7.46 × 10-16 M. Additionally, this method offers a versatile platform for the detection of m6A demethylase and the screening of corresponding inhibitors, thereby advancing clinical diagnosis and drug development.

FTO-mediated demethylation of MTUS1/ATIP1 promotes tumor progression in head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) has been recognized as the seventh most prevalent malignant tumor globally. It is a malignant neoplasm that arises from the mucosal epithelium of head and neck region. In our previous research, we have demonstrated that MTUS1/ATIP1 exhibits anti-cancer properties in HNSCC. Nevertheless, the underlying mechanism responsible for the reduction of MTUS1/ATIP1 expression has not been investigated.

METHODS

HNSCC and adjacent normal tissues were collected and examined using m6A MeRIP-seq, qRT-PCR, and IHC to investigate the relationship between MTUS1/ATIP1 and FTO. MeRIP-qPCR, m6A dot blot, RNA and protein stability assays, and RNC-qRT-PCR were employed to elucidate the mechanism by which FTO mediates demethylation of MTUS1/ATIP1 in HNSCC. Functional assays, subcutaneous tumorigenesis, and in situ tongue cancer models were conducted to assess the impact of the FTO-MTUS1/ATIP1 pathway on proliferative capacity of HNSCC tumors.

RESULTS

FTO was observed to be markedly upregulated and showed a negative correlation with MTUS1/ATIP1 expression in HNSCC. FTO was responsible for mediating m6A demethylation in the 3'UTR of MTUS1/ATIP1, leading to its degradation. Additionally, silencing MTUS1/ATIP1 successfully reversed the tumor-promoting effects on HNSCC triggered by FTO in in vitro and in vivo.

CONCLUSIONS

Our research elucidated the functional importance of FTO-mediated m6A demethylation of MTUS1/ATIP1, suggesting that targeting the FTO-MTUS1/ATIP1 axis could be a prospective novel approach for treating HNSCC.

Implications of obesity and insulin resistance for the treatment of oestrogen receptor-positive breast cancer

Breast cancer is the most common cancer in women, and incidence rates are rising, it is thought in part, due to increasing levels of obesity. Endocrine therapy (ET) remains the cornerstone of systemic therapy for early and advanced oestrogen receptor-positive (ER + ) breast cancer, but despite treatment advances, it is becoming more evident that obesity and insulin resistance are associated with worse outcomes. Here, we describe the current understanding of the relationship between both obesity and diabetes and the prevalence and outcomes for ER+ breast cancer. We also discuss the mechanisms associated with resistance to ET and the relationship to treatment toxicity.

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.

RNA methylation and breast cancer: insights into m6A, m7G and m5C

Breast cancer remains the most commonly diagnosed cancer in female worldwide, marked by its molecular diversity and complex subtypes. Despite progress in targeted therapies, tumor heterogeneity and treatment resistance continue to present major challenges. Recent studies emphasize the crucial role of RNA modifications in cancer biology, with nearly 200 distinct modifications identified. Among these, methylation is particularly significant, with methylation-related factors emerging as key regulators of RNA metabolism, influencing cancer progression, metastasis, and treatment resistance. This review focuses on the roles of key RNA methylation in breast cancer, particularly N6-methyladenosine (m6A), N7-methylguanosine (m7G), 5-methylcytosine (m5C), N1-methyladenosine (m1A), and N3-methylcytidine (m3C). We examine the functions of m6A "writers" like METTL3 and METTL14, and "readers" such as the YTH domain family in modulating tumor behavior. Dysregulation of m6A "erasers" like FTO and ALKBH5 are noticed too, highlighting their impact on cancer stem cell phenotypes, chemoresistance, and immune evasion. Additionally, the role of m7G modifications in mRNA stability and translation, facilitated by METTL1/WDR4 and RNMT, is discussed as a potential therapeutic target. The involvement of m5C, m1A, and m3C modifications, particularly those mediated by NSUN2 and NSUN6, in breast cancer tumorigenesis and prognosis is also reviewed. Despite coding RNAs, the interplay between these RNA methylations and non-coding RNAs, such as lncRNAs and miRNAs, is explored, shedding light on their roles in cancer cell proliferation, invasion, and immune response modulation. This review highlights the potential of RNA methylations as novel therapeutic targets in breast cancer, offering insights for precision medicine and improved patient outcomes.

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.

Addressing the mean-variance relationship in spatially resolved transcriptomics data with spoon

An important task in the analysis of spatially resolved transcriptomics data is to identify spatially variable genes (SVGs), or genes that vary in a 2D space. Current approaches rank SVGs based on either p-values or an effect size, such as the proportion of spatial variance. However, previous work in the analysis of RNA-sequencing identified a technical bias, referred to as the "mean-variance relationship", where highly expressed genes are more likely to have a higher variance. Here, we demonstrate the mean-variance relationship in spatial transcriptomics data. Furthermore, we propose spoon, a statistical framework using Empirical Bayes techniques to remove this bias, leading to more accurate prioritization of SVGs. We demonstrate the performance of spoon in both simulated and real spatial transcriptomics data. A software implementation of our method is available at https://bioconductor.org/packages/spoon.

High intensity interval training as a therapy: Mitophagy restoration in breast cancer

Recent studies have highlighted the role of mitophagy in tumorigenesis. This study aimed to investigate the effects of high-intensity interval training (HIIT) on mitophagy in tumor tissues of mice with breast cancer. Twenty-eight female BALB/c mice were randomly assigned to four groups: Healthy Control (CO), Cancer (CA), Exercise (EX), and Cancer + Exercise (CA + EX). Mammary tumors were induced in the CA and CA + EX groups via 4T1 cell injections. Upon confirmation of tumor formation, the EX and CA + EX groups underwent 8 weeks (40 sessions) of HIIT, comprising 4-10 intervals of running at 80-100 % of maximum speed. The expression levels of mitophagy-related proteins, including parkin, PTEN-induced putative kinase 1 (PINK1), NIP3-like protein X (NIX), BCL2 interacting protein-3 (BINP3), microtubule-associated protein light chain 3-I (LC3-I), microtubule-associated protein light chain 3-II (LC3-II), AMP-activated protein kinase (AMPK), Unc-51 like autophagy activating kinase-1 (ULK1), and sirtuin-1 (SIRT1), were measured in breast and tumor tissues. Tumor volume relative to body weight was assessed weekly during the eight-week HIIT intervention. Protein expression of parkin, PINK1, NIX, BINP3, LC3-II, LC3-I, AMPK, ULK1, and SIRT1 was reduced in the breast tissue of the CA group, while HIIT restored expression levels across all measured variables (P < 0.01). Additionally, tumor volume relative to body weight was significantly lower in the CA + EX group compared to the CA group from weeks 3-8 (P < 0.01). These findings suggest that breast cancer suppresses mitophagy, yet HIIT effectively reverses this suppression, potentially reducing tumor burden. HIIT may thus represent a promising therapeutic strategy for managing breast cancer.

WTAP weakens oxaliplatin chemosensitivity of colorectal cancer by preventing PANoptosis

As the most abundant post-transcriptional modification in eukaryotes, N6-methyladenosine (m6A) plays a crucial role in cancer cell proliferation, invasion and chemoresistance. However, its specific effects on chemosensitivity to oxaliplatin-based regimens and the impact of these drugs on m6A methylation levels in colorectal cancer (CRC) remain largely unexplored. In this study, we demonstrated that the m6A methyltransferase Wilms tumor 1-associating protein (WTAP) weakens oxaliplatin chemosensitivity in HCT116 and DLD1 cells. Mechanistically, oxaliplatin treatment upregulated WTAP expression, preventing multiple forms of cell death simultaneously, a process known as PANoptosis, by decreasing intracellular oxidative stress through maintaining the expression of nuclear factor erythroid-2-related factor 2 (NRF2), a major antioxidant response element, in an m6A-dependent manner. In addition, high WTAP expression in CRC patients is associated with a poor prognosis and reduced benefit from standard chemotherapy by clinical data analysis of The Cancer Genome Atlas (TCGA) database and patient cohort study. These findings suggest that targeting WTAP-NRF2-PANoptosis axis could enhance the antitumor efficacy of oxaliplatin-based chemotherapy in CRC treatment.

Fat Mass and Obesity-Associated Protein Regulates Granulosa Cell Aging by Targeting Matrix Metalloproteinase-2 Gene Via an N6-Methyladenosine-YT521-B Homology Domain Family Member 2-Dependent Pathway in Aged Mice

In this study, we aimed to investigate the molecular mechanisms of RNA N6-methyladenosine (m6A) modification and how its associated proteins affect granulosa cell aging. A granulosa cell senescence model was constructed to detect the differences in total RNA m6A modification levels and the expression of related enzymes. Changes in downstream molecular expression and the effects on the cellular senescence phenotype were explored by repeatedly knocking down and overexpressing the key genes fat mass and obesity-associated protein (FTO), YT521-B homology domain family member 2 (YTHDF2), and matrix metalloproteinase-2 (MMP2). There was an increased total RNA m6A modification and decreased expression of the demethylase FTO and target gene MMP2 in senescent granulosa cells. FTO and MMP2 knockdown promoted granulosa cell senescence, whereas FTO and MMP2 overexpression retarded it. YTHDF2 and FTO can bind to the messenger RNA of MMP2. The extracellular signal-regulated kinase (ERK) pathway, which is downstream of MMP2, retarded the process of granulosa cell senescence through ERK activators. In granulosa cells, FTO can regulate the expression of MMP2 in an m6A-YTHDF2-dependent manner, influencing the activation status of the ERK pathway and contributing to the aging process of granulosa cells.

The RNA N6-methyladenosine demethylase FTO regulates ATG5 to inhibit malignant progression of uveal melanoma

PURPOSE

This research aimed to identify the function of fat mass- and obesity-associated protein (FTO), an eraser of N6-methyladenosine (m6A), and explore its possible mechanisms in uveal melanoma (UVM).

METHODS

We performed quantitative real-time PCR (qPCR), Western blotting and gene correlation analysis with GEPIA2 to assess FTO expression and identify its potential targets in UVM. CCK-8, colony formation, cell cycle, cell apoptosis, wound healing and Transwell invasion assays were utilized to assess cell viability, cell cycle distribution, apoptosis, migration and invasion. Western blotting, qPCR and methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) were carried out to explore the underlying mechanism of FTO in 2 UVM cell lines.

RESULTS

FTO, a key m6A demethylase, was found to be upregulated in human UVM tissues compared with normal choroid tissues. Knockdown of FTO in Mel270 and OMM2.3 cells significantly promoted proliferation and migration and suppressed apoptosis. Mechanistically, knockdown of FTO decreased the expression of ATG5, an autophagy-related gene, leading to attenuation of autophagosome formation, thereby inhibiting autophagy. Upon FTO knockdown, increased levels of methylated ATG5 and decreased ATG5 stability were detected. Furthermore, ATG5 dramatically alleviated FTO downregulation-induced tumor growth and metastasis.

CONCLUSIONS

Our research highlights the importance of the m6A demethylase FTO in UVM by demonstrating that it direct regulates ATG5-induced autophagy in an m6A-dependent manner. These findings suggest that FTO may serve as a potential therapeutic target for UVM.

Mitophagy: insights into its signaling molecules, biological functions, and therapeutic potential in breast cancer

Mitophagy, a form of selective autophagy that removes damaged or dysfunctional mitochondria, plays a crucial role in maintaining mitochondrial and cellular homeostasis. Recent findings suggest that defective mitophagy is closely associated with various diseases, including breast cancer. Moreover, a better understanding of the multifaceted roles of mitophagy in breast cancer progression is crucial for the treatment of this disease. Here, we will summarize the molecular mechanisms of mitophagy process. In addition, we highlight the expression patterns and roles of mitophagy-related signaling molecules in breast cancer progression and the potential implications of mitophagy for the development of breast cancer, aiming to provide better therapeutic strategies for breast cancer treatment.

N6-Methyladenosine methylation modification in breast cancer: current insights

Breast cancer is the most common cancer type among women. Despite advanced treatment strategies, some patients still face challenges in disease control, prompting the exploration of new therapeutic approaches. N6-Methyladenosine (m6A) methylation modification regulates RNA and plays a crucial role in various tumor biological processes, closely linked to breast cancer occurrence, development, prognosis, and treatment. M6A regulators impact breast cancer progression, development, and drug resistance by modulating RNA metabolism and tumor-related pathways. Researchers have begun to understand the regulatory mechanisms of m6A methylation in breast cancer. This paper discusses the roles of m6A regulators in breast cancer progression, prognosis, and treatment, offering new perspectives for breast cancer diagnosis and treatment.

Regulation of m6A (N6-Methyladenosine) methylation modifiers in solid cancers

Solid cancers constitute a tremendous burden on global healthcare, requiring a deeper understanding of the molecular mechanisms underlying cancer development and progression. Epigenetic changes, notably N6-methyladenosine (m6A) RNA methylation, have emerged as important contributors to the biology of solid tumors in recent years. This epigenetic mark dynamically affects gene expression at the post-transcriptional level and modulates a variety of cellular processes, making it a focus of research in the context of solid tumors. m6A modification patterns are dysregulated in a variety of solid cancers, including ovarian, breast, lung, colorectal, pancreatic, and others. This dysregulated m6A landscape has been shown to induce significant changes in the expression of oncogenes, tumor suppressors, and genes involved in cancer stem cells, metastasis, and treatment resistance. In solid tumors, the interaction of m6A "writers" (e.g., METTL3, METTL14, and others), "erasers" (e.g., ALKBH5, FTO), and "readers" (e.g., members of YTHDF proteins and others) delicately changes the m6A methylome. Targeting m6A regulators as a potential therapeutic method to control gene expression and prevent tumor development seems a novel strategy. To enhance treatment results, advances in this area of research have led to the development of targeted treatments aiming at restoring or altering m6A alteration patterns in solid tumors.

R-loops' m6A modification and its roles in cancers

R-loops are three-stranded nucleic acid structures composed of an RNA-DNA hybrid and a displaced DNA strand. They are widespread and play crucial roles in regulating gene expression, DNA replication, and DNA and histone modifications. However, their regulatory mechanisms remain unclear. As R-loop detection technology advances, changes in R-loop levels have been observed in cancer models, often associated with transcription-replication conflicts and genomic instability. N6-methyladenosine (m6A) is an RNA epigenetic modification that regulates gene expression by affecting RNA localization, splicing, translation, and degradation. Upon reviewing the literature, we found that R-loops with m6A modifications are implicated in tumor development and progression. This article summarizes the molecular mechanisms and detection methods of R-loops and m6A modifications in gene regulation, and reviews recent research on m6A-modified R-loops in oncology. Our goal is to provide new insights into the origins of genomic instability in cancer and potential strategies for targeted therapy.

MiR-150-5p inhibits cell proliferation and metastasis by targeting FTO in osteosarcoma

Background

Osteosarcoma (OS), recognized as the predominant malignant tumor originating from bones, necessitates an in-depth comprehension of its intrinsic mechanisms to pinpoint novel therapeutic targets and enhance treatment methodologies. The role of fat mass and obesity-associated (FTO) in OS, particularly its correlation with malignant traits, and the fundamental mechanism, remains to be elucidated.

Materials and Methods

1. The FTO expression and survival rate in tumors were analyzed. 2. FTO in OS cell lines was quantified utilizing western blot and PCR. 3. FTO was upregulated and downregulated separately in MG63. 4. The impact of FTO on the proliferation and migration of OS cells was evaluated using CCK-8, colony formation, wound healing, and Transwell assays. 5. The expression of miR-150-5p in OS cells-derived exosomes was identified. 6. The binding of miR-150-5p to FTO was predicted by TargetScan and confirmed by luciferase reporter assay. 7. The impact of exosome miR-150-5p on the proliferation and migration of OS cells was investigated.

Results

The expression of FTO was higher in OS tissues compared to normal tissues correlating with a worse survival rate. Furthermore, the downregulation of FTO significantly impeded the growth and metastasis of OS cells. Additionally, miR-150-5p, which was downregulated in both OS cells and their derived exosomes, was found to bind to the 3'-UTR of FTO through dual luciferase experiments. Exosomal miR-150-5p was found to decrease the expression of FTO and inhibit cell viability.

Conclusions

We identified elevated levels of FTO in OS, which may be attributed to insufficient miR-150-5p levels in both the cells and exosomes. It suggests that the dysregulation of miR-150-5p and its interaction with FTO could potentially promote the development of OS.