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KIAA1429 is an important 'writer' of the N6‐methyladenine (m6A) modification, which is involved in tumour progression. This study was conducted to explore the mechanism of action of KIAA1429 in colon adenocarcinoma (COAD). KIAA1429‐silenced COAD cell and xenograft tumour models were constructed, and the function of KIAA1429 was explored through a series of in vivo and in vitro assays. The downstream mechanisms of KIAA1429 were explored using transcriptome sequencing. Dimethyloxalylglycine (DMOG), an activator of HIF‐1α, was used for feedback verification. The expression of KIAA1429 in COAD tumour tissues and cells was elevated, and KIAA1429 exhibited differential expression at different stages of the tumour. Silencing of KIAA1429 inhibited the proliferation, migration, and invasion of HT29 and HCT116 cells. The expression levels of NLRP3, GSDMD and Caspase‐1 were decreased in KIAA1429‐silenced HT29 cells, indicating the pyroptotic activity was inhibited. Additionally, KIAA1429 silencing inhibited the growth of tumour xenograft. Transcriptome sequencing and reverse transcription quantitative polymerase chain reaction revealed that after KIAA1429 silencing, the expression of AKR1C1, AKR1C2, AKR1C3 and RDH8 was elevated, and the expression of VIRMA, GINS1, VBP1 and ARF3 was decreased. In HT29 cells, KIAA1429 silencing blocked the HIF‐1 signalling pathway, accompanied by the decrease in AKT1 and HIF‐1α protein levels. The activation of HIF‐1 signalling pathway, mediated by DMOG, reversed the antitumour role of KIAA1429 silencing. KIAA1429 silencing inhibits COAD development by blocking the HIF‐1 signalling pathway. [ABSTRACT FROM AUTHOR]

N6-methyladenine （m6A） modification is involved in a variety of biological processes and dynamically regulates RNA stability. When m6A modification is changed， it affects the development of follicles， granulosa cell proliferation and oocyte development， and participates in the occurrence and development of benign ovaria-related diseases， such as polycystic ovary syndrome， premature ovarian dysfunction， and endometriosis， resulting in decreased female fertility. This article reviews the role and research progress of m6A modification in benign ovaria-related diseases， aiming to provide new diagnosis and treatment ideas for subsequent research on improving fertility. [ABSTRACT FROM AUTHOR]

Methylation of adenine at the N6 position is a crucial epigenetic modification that profoundly influences gene regulation and expression. Moreover, this modification intricately alters the excited state dynamics of adenine nucleobases. To explore the impact of N6‐methyladenine on the excited state dynamics within oligonucleotides, we conducted a comprehensive investigation of two dinucleotides containing N6‐methyladenosine, in conjunction with adenosine or guanosine. Using steady‐state and time‐resolved absorption and fluorescence spectroscopy techniques, we not only observed the customary monomer‐like and charge transfer emissive states, as reported in previous dinucleotides, but also identified an additional low‐energy emissive state. This unique state exhibits an extraordinary Stokes Shift exceeding 2.3 eV and has a relatively long lifetime of 4–5 ns. We propose that this state corresponds to a bonded exciplex state, governed by ground‐state geometries. [ABSTRACT FROM AUTHOR]

Chronic myeloid leukemia (CML) is a common adult leukemia. Both the acute phase of the disease and the adverse effects of anti-cancer treatments can lead to a poor prognosis. The N6-methyladenine (m6A) modification plays an important regulatory role in various physiological and pathological processes. KIAA1429 is a known m6A regulator, but the biological role of KIAA1429 in CML is unclear. In this study, we observed that the m6A levels and KIAA1429 expression were significantly up-regulated in patients with blast phase CML. Notably, KIAA1429 regulated the total level of RNA m6A modification in the CML cells and promoted the malignant biological behaviors of CML cells, including proliferation, migration, and imatinib resistance. Inhibiting KIAA1429 in CML cells reduced the stability of RAB27B mRNA through the m6A/YTHDF1 axis, consequently inhibiting CML proliferation and drug efflux, ultimately increasing the sensitivity of CML cells to imatinib. Moreover, the knockdown of RAB27B also inhibited the proliferation and drug resistance of CML cells and promoted their apoptosis. Rucaparib, a recently developed anti-cancer agent, suppressed the expression of KIAA1429 and CML cell proliferation and promoted cell apoptosis. Rucaparib also inhibited the tumorigenesis of CML cells in vivo. The combined use of rucaparib and imatinib enhanced the sensitivity of CML cells to imatinib. Our study provides evidence that elevated KIAA1429 expression in the blast phase of CML enhances the stability of RAB27B mRNA through the m6A/YTHDF1 axis to up-regulate RAB27B expression, thereby promoting CML progression. Rucaparib exerts inhibitory effects on KIAA1429 expression and thus reduces CML progression.

AlkB homolog 1 (ALKBH1) is a member of the AlkB family of dioxygenases that are dependent on Fe(II) and α-ketoglutarate. Mounting evidence demonstrates that ALKBH1 exhibits enzymatic activity against various substrates, including N6-methyladenosine (m6A), N1-methyladenosine (m1A), N3-methylcytidine (m3C), 5-methylcytosine (m5C), N6-methyladenine (N6-mA, 6mA), and H2A, indicating its dual roles in different biological processes and involvement in human diseases. Up to the present, there is ongoing debate regarding ALKBH1's enzymatic activity. In this review, we present a comprehensive summary of recent research on ALKBH1, including its substrate diversity and pathological roles in a wide range of human disorders, the underlying mechanisms of its functions, and its dysregulation. We also explored the potential of ALKBH1 as a prognostic target.

Objective: To explore potential role and mechanism of N6‑methyladenine (m6A) RNA methylation regulators in prognosis and tumor immune microenvironment of cervical cancer. Methods: Clinical and survival data as well as RNA sequencing data were acquired from TCGA and GEO database. Expressions and correlation among m6A RNA methylation regulators were analyzed by bioinformatics analysis and tissue validation experiments. LASSO Cox regression analysis was used to generate a prognostic risk signature based on m6A regulators. Two m6A-modification patterns were identified based on m6A regulators and their abundance of immune cell inflitration were analyzed by ssGSEA. Results: Compared with normal tissues, RBM15, IGF2BP2, IGF2BP3, FMR1, YTHDF1, METTL3 and YTHDF2 expressions were significantly up-regulated in cervical cancer tissues, while ZC3H13, METTL4, YTHDC1, FTO and ALKBH3 expressions were significantly down-regulated. Five m6A regulators HNRNPC, LRPPRC, METTL3, ELAVL1 and FMR1 were selected to establish prognostic risk signature, whose expressions in cervical cancer were verified by HPA database and qRT-PCR with good predictive value, and could be used as independent poor prognostic factor (AUC=0.734). Based on expressions of 25 m6A regulators, two m6A modification patterns m6Acluster A and m6Acluster B were determined. There were differences between two groups in biological functions, signal pathways and immune cells infiltration levels in tumor microenvironment. Conclusion: m6A RNA methylation regulators are closely related to prognosis and immune infiltration of cervical cancer, which provides guidance for immunotherapy strategy. [ABSTRACT FROM AUTHOR]

Abstract Background Diversified histone deacetylation inhibitors (HDACis) have demonstrated encouraging outcomes in multiple malignancies. N6‐methyladenine (m6A) is the most prevalent messenger RNA modification that plays an essential role in the regulation of tumorigenesis. Howbeit, an in‐depth understanding of the crosstalk between histone acetylation and m6A RNA modifications remains enigmatic. This study aimed to explore the role of histone acetylation and m6A modifications in the regulation of tumorigenesis of ocular melanoma. Methods Histone modification inhibitor screening was used to explore the effects of HDACis on ocular melanoma cells. Dot blot assay was used to detect the global m6A RNA modification level. Multi‐omics assays, including RNA‐sequencing, cleavage under targets and tagmentation, single‐cell sequencing, methylated RNA immunoprecipitation‐sequencing (meRIP‐seq), and m6A individual nucleotide resolution cross‐linking and immunoprecipitation‐sequencing (miCLIP‐seq), were performed to reveal the mechanisms of HDACis on methyltransferase‐like 14 (METTL14) and FAT tumor suppressor homolog 4 (FAT4) in ocular melanoma. Quantitative real‐time polymerase chain reaction (qPCR), western blotting, and immunofluorescent staining were applied to detect the expression of METTL14 and FAT4 in ocular melanoma cells and tissues. Cell models and orthotopic xenograft models were established to determine the roles of METTL14 and FAT4 in the growth of ocular melanoma. RNA‐binding protein immunoprecipitation‐qPCR, meRIP‐seq, miCLIP‐seq, and RNA stability assay were adopted to investigate the mechanism by which m6A levels of FAT4 were affected. Results First, we found that ocular melanoma cells presented vulnerability towards HDACis. HDACis triggered the elevation of m6A RNA modification in ocular melanoma. Further studies revealed that METTL14 served as a downstream candidate for HDACis. METTL14 was silenced by the hypo‐histone acetylation status, whereas HDACi restored the normal histone acetylation level of METTL14, thereby inducing its expression. Subsequently, METTL14 served as a tumor suppressor by promoting the expression of FAT4, a tumor suppressor, in a m6A‐YTH N6‐methyladenosine RNA‐binding protein 1‐dependent manner. Taken together, we found that HDACi restored the histone acetylation level of METTL14 and subsequently elicited METTL14‐mediated m6A modification in tumorigenesis. Conclusions These results demonstrate that HDACis exert anti‐cancer effects by orchestrating m6A modification, which unveiling a “histone‐RNA crosstalk” of the HDAC/METTL14/FAT4 epigenetic cascade in ocular melanoma.

Changes in epitranscriptome with N6-methyladenine (m6A) modification could be involved in the development of multiple diseases, which might be a prevalent modification of messenger RNAs (mRNAs) in eukaryotes. The m6A modification might be performed through the action of methyltransferases, demethylases, and methylation-binding proteins. Importantly, the m6A methylation may be associated with various neurological disorders including Alzheimer’s disease (AD), Parkinson’s disease (PD), depression, aging-related diseases, and/or aging itself. In addition, the m6A methylation might functionally regulate the eukaryotic transcriptome by influencing the splicing, export, subcellular localization, translation, stability, and decay of mRNAs. Neurodegenerative diseases may possess a wide variety of phenotypes, depending on the neurons that degenerate on occasion. Interestingly, an increasing amount of evidence has indicated that m6A modification could modulate the expression of autophagy-related genes and promote autophagy in neuronal cells. Oxidative stresses such as reactive oxygen species (ROS) could stimulate the m6A RNA methylation, which may also be related to the regulation of autophagy and/or the development of neurodegenerative diseases. Both m6A modification and autophagy could also play critical roles in regulating the health condition of neurons. Therefore, a comprehensive understanding of the m6A and autophagy relationship in human diseases may benefit in developing therapeutic strategies in the future. This paper reviews advances in the understanding of the regulatory mechanisms of m6A modification in the occurrence and development of neurodegenerative diseases and/or aging, discussing the possible therapeutic procedures related to mechanisms of m6A RNA methylation and autophagy.

Ultraviolet (UV) radiation is the primary exogenous inducer of skin pigmentation, although the mechanism has not been fully elucidated. N6‐methyladenosine (m6A) modification is one of the key epigenetic form of gene regulation that affects multiple biological processes. The aim of this study was to explore the role and underlying mechanisms of m6A modification in UVB‐induced melanogenesis. Low‐dose UVB increased global m6A modification in melanocytes (MCs) and MNT1 melanoma cell line. The GEPIA database predicted that methyltransferase METTL3 is positively correlated with the melanogenic transcription factor MITF in the sun‐exposed skin tissues. After METTL3 respectively overexpressed and knocked down in the MNT1, the melanin content and melanogenesis‐related genes were significantly upregulated after overexpression of METTL3, especially with UVB irradiation, and downregulated after METTL3 knockdown. METTL3 levels were also higher in melanocytic nevi with high melanin content. METTL3 overexpression and knockdown also altered the protein level of YAP1. SRAMP analysis predicted four high‐potential m6A modification sites on YAP1 mRNA, of which three were confirmed by methylated RNA immunoprecipitation. Inhibition of YAP1 expression can partially reverse melanogenesis induced by overexpression of METTL3. In conclusion, UVB irradiation promotes global m6A modification in MCs and upregulates METTL3, which increases the expression level of YAP1 through m6A modification, thereby activating the co‐transcription factor TEAD1 and promoting melanogenesis. [ABSTRACT FROM AUTHOR]

Changes in epitranscriptome with N6-methyladenine (m6A) modification could be involved in the development of multiple diseases, which might be a prevalent modification of messenger RNAs (mRNAs) in eukaryotes. The m6A modification might be performed through the action of methyltransferases, demethylases, and methylation-binding proteins. Importantly, the m6A methylation may be associated with various neurological disorders including Alzheimer's disease (AD), Parkinson's disease (PD), depression, aging-related diseases, and/or aging itself. In addition, the m6A methylation might functionally regulate the eukaryotic transcriptome by influencing the splicing, export, subcellular localization, translation, stability, and decay of mRNAs. Neurodegenerative diseases may possess a wide variety of phenotypes, depending on the neurons that degenerate on occasion. Interestingly, an increasing amount of evidence has indicated that m6A modification could modulate the expression of autophagy-related genes and promote autophagy in neuronal cells. Oxidative stresses such as reactive oxygen species (ROS) could stimulate the m6A RNA methylation, which may also be related to the regulation of autophagy and/or the development of neurodegenerative diseases. Both m6A modification and autophagy could also play critical roles in regulating the health condition of neurons. Therefore, a comprehensive understanding of the m6A and autophagy relationship in human diseases may benefit in developing therapeutic strategies in the future. This paper reviews advances in the understanding of the regulatory mechanisms of m6A modification in the occurrence and development of neurodegenerative diseases and/or aging, discussing the possible therapeutic procedures related to mechanisms of m6A RNA methylation and autophagy. [ABSTRACT FROM AUTHOR]

ABSTRACT Methylated DNA adenines (6mA) are a critical epigenetic modification in bacteria that affect cell processes like replication, stress response, and pathogenesis. While much work has been done characterizing the influence of 6mA on specific loci, very few studies have examined the evolutionary dynamics of 6mA over long time scales. We used third-generation sequencing technology to analyze 6mA methylation across the Escherichia coli K-12 substr. MG1655 genome. 6mA levels were consistently high across GATC sites; however, we identified regions where 6mA is decreased, particularly in intergenic regions, especially around the −35 promoter element, and within cryptic prophages and IS elements. We further examined 6mA in WT and methyl-directed mismatch repair-deficient (MMR-) populations after 2,400 generations of experimental evolution. We find that, after evolution, MMR- populations acquire significantly more epimutations resulting in a genome-wide decrease in 6mA methylation. Here, clones from evolved MMR- populations display non-deterministic sets of epimutations, consistent with reduced selection on these modifications. Thus, we show that characterization of 6mA in bacterial populations is complementary to genetic sequencing and informative for molecular evolution. IMPORTANCE Methylation greatly influences the bacterial genome by guiding DNA repair and regulating pathogenic and stress-response phenotypes. But, the rate of epigenetic changes and their consequences on molecular phenotypes are underexplored. Through a detailed characterization of genome-wide adenine methylation in a commonly used laboratory strain of Escherichia coli, we reveal that mismatch repair deficient populations experience an increase in epimutations resulting in a genome-wide reduction of 6mA methylation in a manner consistent with genetic drift. Our findings highlight how methylation patterns evolve and the constraints on epigenetic evolution due to post-replicative DNA repair, contributing to a deeper understanding of bacterial genome evolution and how epimutations may introduce semi-permanent variation that can influence adaptation.

N6-methyladenine (6mA) plays a critical role in various epigenetic processing including DNA replication, DNA repair, silencing, transcription, and diseases such as cancer. To understand such epigenetic mechanisms, 6 mA has been detected by high-throughput technologies on a genome-wide scale at single-base resolution, together with conventional methods such as immunoprecipitation, mass spectrometry and capillary electrophoresis, but these experimental approaches are time-consuming and laborious. To complement these problems, we have developed a CNN-based 6 mA site predictor, named CNN6mA, which proposed two new architectures: a position-specific 1-D convolutional layer and a cross-interactive network. In the position-specific 1-D convolutional layer, position-specific filters with different window sizes were applied to an inquiry sequence instead of sharing the same filters over all positions in order to extract the position-specific features at different levels. The cross-interactive network explored the relationships between all the nucleotide patterns within the inquiry sequence. Consequently, CNN6mA outperformed the existing state-of-the-art models in many species and created the contribution score vector that intelligibly interpret the prediction mechanism. The source codes and web application in CNN6mA are freely accessible at https://github.com/kuratahiroyuki/CNN6mA.git and http://kurata35.bio.kyutech.ac.jp/CNN6mA/, respectively.

Periprosthetic joint infection (PJI) is a devastating complication. This study aimed to unravel the veil of the N6-methyladenine (m6A) modification in PJI. Synovium, synovial fluid, sonication fluid and bone samples were collected intraoperatively from Staphylococcus aureus PJI and aseptic failure (AF) patients. The overall m6A level was detected by the m6A RNA methylation quantification kit, and the expression of m6A-related genes was quantified by real-time PCR and Western blot. Finally, an epitranscriptomic microarray and bioinformatics analysis were performed. We showed that there was a significant difference in overall m6A level between the PJI group and the AF group (PJI group had a higher overall m6A level). The expression level of METTL3 was higher in the PJI group than that in the AF group. There were 2802 differential m6A-modified mRNAs. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that differential m6A-modified mRNAs were significantly enriched in the NOD-like receptor signaling pathway, Th17 cell differentiation and the IL-17 signaling pathway, which indicates that the m6A modification might be involved in the processes of infection and immune response, bone metabolism and programmed cell death in PJI. In summary, the present work demonstrated that m6A modification plays a role in PJI and might be a therapeutic target for developing effective treatment strategies. [ABSTRACT FROM AUTHOR]

Abstract Doxorubicin (Dox) is the standard treatment approach for osteosarcoma (OS), while acquired drug resistance seriously attenuates its treatment efficiency. The present study aimed to investigate the potential roles of metabolic reprogramming and the related regulatory mechanism in Dox-resistant OS cells. The results showed that the ATP levels, lactate generation, glucose consumption and oxygen consumption rate were significantly increased in Dox-resistant OS cells compared with parental cells. Furthermore, the results revealed that the increased expression of estrogen-related receptor alpha (ERRα) was involved in metabolic reprogramming in chemotherapy resistant OS cells, since targeted inhibition of ERRα restored the shifting of metabolic profiles. Mechanistic analysis indicated that the mRNA stability, rather than ERRα transcription was markedly increased in chemoresistant OS cells. Therefore, it was hypothesized that the 3ʹ-untranslated region of ERRα mRNA was methylated by N6-methyladenine, which could further recruit insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) to suppress mRNA decay and increase mRNA stability. IGF2BP1 knockdown downregulated ERRα and reversed the metabolic alteration of resistant OS cells. Additionally, the oncogenic effect of the IGF2BP1/ERRα axis on Dox-resistant OS cells was verified by in vitro and in vivo experiments. Clinical analysis also revealed that the expression levels of IGF2BP1 and ERRα were associated with the clinical progression of OS. Collectively, the current study suggested that the IGF2BP1/ERRα axis could regulate metabolic reprogramming to contribute to the chemoresistance of OS cells.

DNA N6-methyladenine (6mA) has recently been found to play regulatory roles in gene expression that links to various biological processes in eukaryotic species. The functional identification of 6mA methyltransferase will be important for understanding the underlying molecular mechanism of epigenetic 6mA methylation. It has been reported that the methyltransferase METTL4 can catalyze the methylation of 6mA; however, the function of METTL4 remains largely unknown. In this study, we aim to investigate the role of the Bombyx mori homolog METTL4 (BmMETTL4) in silkworm, a lepidopteran model insect. By using CRISPR-Cas9 system, we somatically mutated BmMETTL4 in silkworm individuates and found that disruption of BmMETTL4 caused the developmental defect of late silkworm embryo and subsequent lethality. We performed RNA-Seq and identified that there were 3192 differentially expressed genes in BmMETTL4 mutant including 1743 up-regulated and 1449 down-regulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that genes involved in molecular structure, chitin binding, and serine hydrolase activity were significantly affected by BmMETTL4 mutation. We further found that the expression of cuticular protein genes and collagens were clearly decreased while collagenases were highly increased, which had great contributions to the abnormal embryo and decreased hatchability of silkworm. Taken together, these results demonstrated a critical role of 6mA methyltransferase BmMETTL4 in regulating embryonic development of silkworm. [ABSTRACT FROM AUTHOR]

N6-methyladenine (6mA) is a type of post-replication modification that exists across a wide range of DNA sequences. It has emerged as a key element in various biological processes, and due to this fact, has attracted great attention for its ability to be a target for disease treatment. Identifying 6mA sites has been the prelude to understand multiple biological functions including DNA replication, transcription, and repairing. Aside from a few numbers of experimental methods, a series of predictors were developed to distinguish 6mA sites in the whole genome. In this study, a 6mA site predictor named iDNA6mA-Pred was designed, which used a variety of valid feature descriptors to obtain informative characteristics. To improve computational efficiency and reduce the amount of redundant information, 34-dimensional features were selected with the aid of the F-score and were employed to learn support vector machine model. This study resulted an support vector machine (SVM)-based predictor to recognize 6mA sites of the rice genome, where nucleic acid composition (NAC), dinucleotide Composition (DNC), and Position-Specific Trinucleotide Propensity (PSTNP) were used to characterize the DNA sequences. Jackknife test results showed that the property of iDNA6mA-Pred was accurate with an accuracy rate of 92.16%. This predictor could be used for accurate identification of 6mA sites. [ABSTRACT FROM AUTHOR]

Shao-hua Ren,1,2 Ya-fei Qin,1,2 Hong Qin,1,2 Hong-da Wang,1,2 Guang-ming Li,1,2 Yang-lin Zhu,1,2 Cheng-lu Sun,1,2 Bo Shao,1,2 Jing-yi Zhang,1,2 Jing-peng Hao,3 Hao Wang1,2 1Department of General Surgery, Tianjin Medical University General Hospital, Tianjin, People’s Republic of China; 2Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, People’s Republic of China; 3Department of Anorectal Surgery, The Second Hospital of Tianjin Medical University, Tianjin, People’s Republic of ChinaCorrespondence: Hao Wang, Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, 300052, People’s Republic of China, Tel/Fax +01186-22-60362502, Email hwangca272@hotmail.comBackground: The prognostic value of m6A-related genes in hepatocellular carcinoma (HCC) and its correlation with the immune microenvironment still requires further investigation.Methods: Consensus clustering by m6A related genes was used to classify 374 patients with HCC from The Cancer Genome Atlas (TCGA) database. Then we performed the least absolute shrinkage and selection operator (LASSO) to construct the m6A related genes model. The International Cancer Genome Consortium (ICGC) and Gene Expression Omnibus (GEO) datasets were used to verify and evaluate the model. ESTIMATE, CIBERSORTx, the expression levels of immune checkpoint genes, and TIDE were used to investigate the tumor microenvironment (TME) and the response to immunotherapy. Gene set enrichment analyses (GSEA), tumor-associated macrophages (TAMs), and gene-drug sensitivity were also analyzed.Results: By expression value and regression coefficient of five m6A related genes, we constructed the risk score of each patient. The patients with a higher risk score had a considerably poorer prognosis in the primary and validated cohort. For further discussing TME and the response to immunotherapy, we divided the entire set into two groups based on the risk score. Our findings implied that the tumor-infiltrating lymphocytes (TILs) were proportional to the risk scores, which seemed to contradict that patients with higher scores had a poor prognosis. Further, we found that the high-risk group had higher expression of PD-L1, CTLA-4, and PDCD1, indicating immune dysfunction, which may be a fundamental reason for poor prognosis. This was further reinforced by the fact that the low-risk group responded better than the high-risk group to monotherapy and combination therapy.Conclusion: The m6A related risk score is a new independent prognostic factor that correlates with immunotherapy response. It can provide a new therapeutic strategy for improving individual immunotherapy in HCC.Keywords: hepatocellular carcinoma, N6-methyladenine, tumor immune microenvironment, immunotherapy, drug sensitivity

N6-methyladenosine (6mA) plays a pivotal role in diverse biological processes, including cancer, bacterial toxin secretion, and bacterial drug resistance. However, to date there has not been a selective, sensitive, and simple method for quantitative detection of 6mA at single base resolution. Herein, we present a series piezoelectric quartz crystal (SPQC) sensor based on the specific recognition of transcription-activator-like effectors (TALEs) for locus-specific detection of 6mA. Detection sensitivity is enhanced through the use of a hybridization chain reaction (HCR) in conjunction with silver staining. The limit of detection (LOD) of the sensor was 0.63 pM and can distinguish single base mismatches. We demonstrate the applicability of the sensor platform by quantitating 6mA DNA at a specific site in biological matrix. The SPQC sensor presented herein offers a promising platform for in-depth study of cancer, bacterial toxin secretion, and bacterial drug resistance. [Display omitted] • A novel SPQC sensor based on the specific recognition of TALEs for locus-specific detection of 6mA in DNA is developed. • This SPQC sensor can locus-specific detect 6mA and distinguish single base mismatches. • The hybridization chain reaction and silver staining are utilized to enhance detection sensitivity, the LOD is 0.63 pM. • The SPQC sensor is competent for 6mA target analysis in the real cell samples. [ABSTRACT FROM AUTHOR]

The aim of this study is to explore the role of circCELF1/miR-636/DKK2 pathway in myocardial fibrosis (MF). RT-qPCR and western blot were used to detect the expression of circCELF1, miR-636, and DKK2 in activated cardiac fibroblasts (CFs) and the hearts of acute myocardial infarction (AMI) mice. The m6A level of DKK2 was detected by RIP and RT-qPCR. The regulation of circCELF1/miR-636/DKK2 pathway on CF viability, activation, apoptosis, and migration was verified by CCK-8, western blot, flow cytometry, and Transwell. Ang II induced downregulation of circCELF1 expression, while circCELF1 enhanced the expression of DKK2 by adsorbing miR-636. circCELF1 also reduced DKK2 m6A level by upregulating FTO expression, thereby inhibiting the binding of miR-636 to DKK2 and promoting DKK2 expression. Ang II promoted CF viability, activation, and migration through the circCELF1/miR-636/DKK2 pathway. Both miR-636 inhibitors and DKK2 effectively reduced MF and improved cardiac function in AMI mice. [ABSTRACT FROM AUTHOR]

Abstract Background N6-methyladenine (m6A) is the most common modification of mRNA and IncRNA in higher organisms. m6A has been confirmed to be related to the formation and progression of tumors and m6A-related genes can be used as prognostic biomarkers in a variety of tumors. However, there have been no similar studies on lung squamous cell carcinoma. The main purpose of this study was aimed to explore the differential expression of m6A-related genes in lung squamous cell carcinoma tissues and its relationship with patient clinical prognosis. Methods We integrated three m6A writers that catalyze the methylation of adenine on mRNA molecules. The training set including 501 patients with LUSC was collected from The Cancer Genome Atlas (TCGA) database and the test set including 181 patients with LUSC was collected from the Gene Expression Omnibus (GEO) database. Based on the expression level of the m6A methylase gene, we established a tumor subgroup and risk-prognosis model to quantify the risk index and long-term patient prognosis, which were confirmed by principal component analysis (PCA) and receiver operating characteristic (ROC) curve analysis. After lung squamous cell carcinoma tissue specimens were obtained during surgery, immunohistochemistry (IHC) was used to verify the results in vitro. Results The results of the study showed that the expression of the three m6A methylases in tumor tissues and normal tissues was significantly different (P

Pancreatic cancer is the deadliest malignancy of the digestive system and is the seventh most common cause of cancer-related deaths worldwide. The incidence and mortality of pancreatic cancer continue to increase, and its 5-year survival rate remains the lowest among all cancers. N6-methyladenine (m6A) is the most abundant reversible RNA modification in various eukaryotic messenger and long noncoding RNAs and plays crucial roles in the occurrence and development of cancers. However, the role of m6A in pancreatic cancer remains unclear. The present study aimed to explore the role of m6A and its regulators in pancreatic cancer and assess its underlying molecular mechanism associated with pancreatic cancer cell proliferation, invasion, and metastasis. Reduced expression of the m6A demethylase, fat mass and obesity-associated protein (FTO), was responsible for the high levels of m6A RNA modification in pancreatic cancer. Moreover, FTO demethylated the m6A modification of praja ring finger ubiquitin ligase 2 (PJA2), thereby reducing its mRNA decay, suppressing Wnt signaling, and ultimately restraining the proliferation, invasion, and metastasis of pancreatic cancer cells. Altogether, this study describes new, potential molecular therapeutic targets for pancreatic cancer that could pave the way to improve patient outcome.

Doxorubicin (Dox) is the standard treatment approach for osteosarcoma (OS), while acquired drug resistance seriously attenuates its treatment efficiency. The present study aimed to investigate the potential roles of metabolic reprogramming and the related regulatory mechanism in Dox-resistant OS cells. The results showed that the ATP levels, lactate generation, glucose consumption and oxygen consumption rate were significantly increased in Dox-resistant OS cells compared with parental cells. Furthermore, the results revealed that the increased expression of estrogen-related receptor alpha (ERRα) was involved in metabolic reprogramming in chemotherapy resistant OS cells, since targeted inhibition of ERRα restored the shifting of metabolic profiles. Mechanistic analysis indicated that the mRNA stability, rather than ERRα transcription was markedly increased in chemoresistant OS cells. Therefore, it was hypothesized that the 3'-untranslated region of ERRα mRNA was methylated by N6-methyladenine, which could further recruit insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) to suppress mRNA decay and increase mRNA stability. IGF2BP1 knockdown downregulated ERRα and reversed the metabolic alteration of resistant OS cells. Additionally, the oncogenic effect of the IGF2BP1/ERRα axis on Dox-resistant OS cells was verified by in vitro and in vivo experiments. Clinical analysis also revealed that the expression levels of IGF2BP1 and ERRα were associated with the clinical progression of OS. Collectively, the current study suggested that the IGF2BP1/ERRα axis could regulate metabolic reprogramming to contribute to the chemoresistance of OS cells. [ABSTRACT FROM AUTHOR]

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DNA methylation is treated as an important epigenetic mark in various biological activities. In the past, a large number of articles focused on 5 mC while lacking attention to N6-methyladenine (6 mA). The presence of 6 mA modification was previously discovered only in prokaryotes. Recently, with the development of detection technologies, 6 mA has been found in several eukaryotes, including protozoans, metazoans, plants, and fungi. The importance of 6 mA in prokaryotes and single-celled eukaryotes has been widely accepted. However, due to the incredibly low density of 6 mA and restrictions on detection technologies, the prevalence of 6 mA and its role in biological processes in eukaryotic organisms are highly debated. In this review, we first summarize the advantages and disadvantages of 6 mA detection methods. Then, we conclude existing reports on the prevalence of 6 mA in eukaryotic organisms. Next, we highlight possible methyltransferases, demethylases, and the recognition proteins of 6 mA. In addition, we summarize the functions of 6 mA in eukaryotes. Last but not least, we summarize our point of view and put forward the problems that need further research. [ABSTRACT FROM AUTHOR]

According to the latest global cancer statistics, cancer has become a major threat to human health, but cancer treatment has encountered many bottlenecks. As an emerging topic in epigenetics, N6-methyladenosine (m6A) is the most common internal modification on eukaryotic mRNA, which has attracted increasing attention in recent years. Accumulating studies have shown that aberrant m6A modifications have profound effects on the characteristics of tumors, which undoubtedly led to a significant breakthrough in cancer treatment. Although m6A function as an oncogene or tumor suppressor is not fully revealed, determining its precise function in the development and evolution of malignant tumors is crucial in improving clinical decisions involving targeted therapies. In this review, we briefly introduce the composition of the m6A methylation machinery and mainly summarize the biological mechanism of m6A in cancer cell death, angiogenesis, epithelial-mesenchymal transition (EMT), and therapeutic resistance. Subsequently, we present the exogenous regulatory factors of m6A and highlight the role of m6A on immune cells and cancer immunotherapy. The potential therapeutic strategies of m6A in human cancer are also discussed, considering research gaps and future applications.

DNA methylation is treated as an important epigenetic mark in various biological activities. In the past, a large number of articles focused on 5 mC while lacking attention to N6-methyladenine (6 mA). The presence of 6 mA modification was previously discovered only in prokaryotes. Recently, with the development of detection technologies, 6 mA has been found in several eukaryotes, including protozoans, metazoans, plants, and fungi. The importance of 6 mA in prokaryotes and single-celled eukaryotes has been widely accepted. However, due to the incredibly low density of 6 mA and restrictions on detection technologies, the prevalence of 6 mA and its role in biological processes in eukaryotic organisms are highly debated. In this review, we first summarize the advantages and disadvantages of 6 mA detection methods. Then, we conclude existing reports on the prevalence of 6 mA in eukaryotic organisms. Next, we highlight possible methyltransferases, demethylases, and the recognition proteins of 6 mA. In addition, we summarize the functions of 6 mA in eukaryotes. Last but not least, we summarize our point of view and put forward the problems that need further research.

N6-methyladenine (6mA) DNA methylation has emerged as an important epigenetic modification in eukaryotes. Nevertheless, the evolution of the 6mA methylation of homologous genes after species and after gene duplications remains unclear in plants. To understand the evolution of 6mA methylation, we detected the genome-wide 6mA methylation patterns of four lotus plants (Nelumbo nucifera) from different geographic origins by nanopore sequencing and compared them to patterns in Arabidopsis and rice. Within lotus, the genomic distributions of 6mA sites are different from the widely studied 5mC methylation sites. Consistently, in lotus, Arabidopsis and rice, 6mA sites are enriched around transcriptional start sites, positively correlated with gene expression levels, and preferentially retained in highly and broadly expressed orthologs with longer gene lengths and more exons. Among different duplicate genes, 6mA methylation is significantly more enriched and conserved in whole-genome duplicates than in local duplicates. Overall, our study reveals the convergent patterns of 6mA methylation evolution based on both lineage and duplicate gene divergence, which underpin their potential role in gene regulatory evolution in plants.

Cancer-associated fibroblasts (CAFs) exhibit notable versatility, plasticity, and robustness, actively participating in cancer progression through intricate interactions within the tumor microenvironment (TME). N6-methyladenosine (m6A) modification is the most prevalent modification in eukaryotic mRNA, playing essential roles in mRNA metabolism and various biological processes. Howbeit, the precise involvement of m6A in CAF activation remains enigmatic. In this study, we revealed that the m6A demethylase FTO supports CAF-mediated angiogenesis through activation of EGR1 and VEGFA in conjunctival melanoma (CoM). First, single-cell transcriptome analysis revealed that FTO was specifically upregulated in the CAF population, thereby contributing to the hypo-m6A status in the TME of CoM. Moreover, CAFs of CoM displayed extensive proangiogenic potential, which was largely compromised by FTO inhibition, both in vitro and in vivo. By employing multi-omics analysis, we showed that FTO effectively eliminates the m6A modifications of VEGFA and EGR1. This process subsequently disrupts the YTHDF2-dependent mRNA decay pathway, resulting in increased mRNA stability and upregulated expression of these molecules. Collectively, our findings initially indicate that the upregulation of FTO plays a pivotal role in tumor development by promoting CAF-mediated angiogenesis. Therapeutically, targeting FTO may show promise as a potential antiangiogenic strategy to optimize cancer treatment. • We reveal for the first time that the upregulation of FTO plays a pivotal role in tumor development by promoting CAF-mediated angiogenesis. • Our finding reveals that FTO efficiently removes the m6A modification of several neovascularization targets, which prevents YTHDF2-dependent mRNA decay and therefore induces angiogenesis in CoM progression. • As Angiogenesis is a crucial factor in tumor development, our study offers novel insight into the targeted correction of m6A homeostasis, which serves as an important antiangiogenic strategy in cancer therapy. [ABSTRACT FROM AUTHOR]

N 6-methyladenine (m6A) is the most abundant RNA modification in eukaryotic RNA. Further, m6A has been identified in the genomic DNA of both eukaryotes and prokaryotes. The G-quadruplex (G4) structure is a non-canonical nucleic acid structure formed by the stacking of G:G:G:G tetrads. In this study, we evaluated the effect of m6A modifications on G4 structures formed by GGA repeat oligonucleotides, d(GGA) 8 , d(GGA) 4 , and r(GGA) 4. The d(GGA) 8 forms an intramolecular tetrad:heptad:heptad:tetrad G4 structure, while d(GGA) 4 forms a dimerized intermolecular tetrad:heptad:heptad:tetrad G4 structure. r(GGA) 4 forms a dimerized intermolecular tetrad:hexad:hexad:tetrad G4 structure. Circular dichroism melting analysis demonstrated that (1) m6A modifications destabilized the G4 structure formed by d(GGA) 8 , (2) m6A modification at A3 disrupted the G4 structure formed by d(GGA) 4 , and (3) m6A modification at A3 destabilized the G4 structure formed by r(GGA) 4. m6A modifications may be involved in controlling G4 structure formation to regulate biological functions. [Display omitted] • m6A modifications destabilize the G4 structure formed by d(GGA) 8. • m6A modification at A3 inhibits formation of the G4 structure formed by d(GGA) 4. • m6A modification at A3 destabilizes the G4 structure formed by r(GGA) 4. [ABSTRACT FROM AUTHOR]

DNA N6-Methyladenine (6mA) is a common epigenetic modification, which plays some significant roles in the growth and development of plants. It is crucial to identify 6mA sites for elucidating the functions of 6mA. In this article, a novel model named i6mA-vote is developed to predict 6mA sites of plants. Firstly, DNA sequences were coded into six feature vectors with diverse strategies based on density, physicochemical properties, and position of nucleotides, respectively. To find the best coding strategy, the feature vectors were compared on several machine learning classifiers. The results suggested that the position of nucleotides has a significant positive effect on 6mA sites identification. Thus, the dinucleotide one-hot strategy which can describe position characteristics of nucleotides well was employed to extract DNA features in our method. Secondly, DNA sequences of Rosaceae were divided into a training dataset and a test dataset randomly. Finally, i6mA-vote was constructed by combining five different base-classifiers under a majority voting strategy and trained on the Rosaceae training dataset. The i6mA-vote was evaluated on the task of predicting 6mA sites from the genome of the Rosaceae, Rice, and Arabidopsis separately. In Rosaceae, the performances of i6mA-vote were 0.955 on accuracy (ACC), 0.909 on Matthew correlation coefficients (MCC), 0.955 on sensitivity (SN), and 0.954 on specificity (SP). Those indicators, in the order of ACC, MCC, SN, SP, were 0.882, 0.774, 0.961, and 0.803 on Rice while they were 0.798, 0.617, 0.666, and 0.929 on Arabidopsis. According to the indicators, our method was effectiveness and better than other concerned methods. The results also illustrated that i6mA-vote does not only well in 6mA sites prediction of intraspecies but also interspecies plants. Moreover, it can be seen that the specificity is distinctly lower than the sensitivity in Rice while it is just the opposite in Arabidopsis. It may be resulted from sequence similarity among Rosaceae, Rice and Arabidopsis. [ABSTRACT FROM AUTHOR]

Background: The role of N6-methyladenine (m6A) RNA methylation in a variety of biological processes is gradually being revealed. Methods: Here, we systematically describe the correlation between the expression pattern of m6A RNA methylation regulatory factors and clinical phenotype, immunity, drug sensitivity, stem cells and prognosis in more than 10,000 samples of 33 types of cancer. Results: The results show that there are significant differences in the expression of 20 m6A RNA methylation regulatory factors in different cancers, and there was a significant correlation with the analysis indicators. Conclusion: In this study, the m6A RNA methylation regulatory factor was found not only to potentially assist in stratifying the prognosis but also to predict or improve the sensitivity of clinical drug therapy. [ABSTRACT FROM AUTHOR]

DNA N6-Methyladenine (6mA) is a common epigenetic modification, which plays some significant roles in the growth and development of plants. It is crucial to identify 6mA sites for elucidating the functions of 6mA. In this article, a novel model named i6mA-vote is developed to predict 6mA sites of plants. Firstly, DNA sequences were coded into six feature vectors with diverse strategies based on density, physicochemical properties, and position of nucleotides, respectively. To find the best coding strategy, the feature vectors were compared on several machine learning classifiers. The results suggested that the position of nucleotides has a significant positive effect on 6mA sites identification. Thus, the dinucleotide one-hot strategy which can describe position characteristics of nucleotides well was employed to extract DNA features in our method. Secondly, DNA sequences of Rosaceae were divided into a training dataset and a test dataset randomly. Finally, i6mA-vote was constructed by combining five different base-classifiers under a majority voting strategy and trained on the Rosaceae training dataset. The i6mA-vote was evaluated on the task of predicting 6mA sites from the genome of the Rosaceae, Rice, and Arabidopsis separately. In Rosaceae, the performances of i6mA-vote were 0.955 on accuracy (ACC), 0.909 on Matthew correlation coefficients (MCC), 0.955 on sensitivity (SN), and 0.954 on specificity (SP). Those indicators, in the order of ACC, MCC, SN, SP, were 0.882, 0.774, 0.961, and 0.803 on Rice while they were 0.798, 0.617, 0.666, and 0.929 on Arabidopsis. According to the indicators, our method was effectiveness and better than other concerned methods. The results also illustrated that i6mA-vote does not only well in 6mA sites prediction of intraspecies but also interspecies plants. Moreover, it can be seen that the specificity is distinctly lower than the sensitivity in Rice while it is just the opposite in Arabidopsis. It may be resulted from sequence similarity among Rosaceae, Rice and Arabidopsis.

DNA N6-methyladenine (6mA) has recently been found to play regulatory roles in gene expression that links to various biological processes in eukaryotic species. The functional identification of 6mA methyltransferase will be important for understanding the underlying molecular mechanism of epigenetic 6mA methylation. It has been reported that the methyltransferase METTL4 can catalyze the methylation of 6mA; however, the function of METTL4 remains largely unknown. In this study, we aim to investigate the role of the Bombyx mori homolog METTL4 (BmMETTL4) in silkworm, a lepidopteran model insect. By using CRISPR-Cas9 system, we somatically mutated BmMETTL4 in silkworm individuates and found that disruption of BmMETTL4 caused the developmental defect of late silkworm embryo and subsequent lethality. We performed RNA-Seq and identified that there were 3192 differentially expressed genes in BmMETTL4 mutant including 1743 up-regulated and 1449 down-regulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that genes involved in molecular structure, chitin binding, and serine hydrolase activity were significantly affected by BmMETTL4 mutation. We further found that the expression of cuticular protein genes and collagens were clearly decreased while collagenases were highly increased, which had great contributions to the abnormal embryo and decreased hatchability of silkworm. Taken together, these results demonstrated a critical role of 6mA methyltransferase BmMETTL4 in regulating embryonic development of silkworm.

AlkB homolog 1 (ALKBH1) is a member of the AlkB family of dioxygenases that are dependent on Fe(II) and α-ketoglutarate. Mounting evidence demonstrates that ALKBH1 exhibits enzymatic activity against various substrates, including N6-methyladenosine (m 6 A), N1-methyladenosine (m 1 A), N3-methylcytidine (m 3 C), 5-methylcytosine (m 5 C), N6-methyladenine (N 6 -mA, 6mA), and H2A, indicating its dual roles in different biological processes and involvement in human diseases. Up to the present, there is ongoing debate regarding ALKBH1's enzymatic activity. In this review, we present a comprehensive summary of recent research on ALKBH1, including its substrate diversity and pathological roles in a wide range of human disorders, the underlying mechanisms of its functions, and its dysregulation. We also explored the potential of ALKBH1 as a prognostic target., Competing Interests: The authors declare no conflict of interests., (© 2024 The Authors. Published by Elsevier Ltd.)

Background: N6-methyladenine (m6A) is the most common modification of mRNA and IncRNA in higher organisms. m6A has been confirmed to be related to the formation and progression of tumors and m6A-related genes can be used as prognostic biomarkers in a variety of tumors. However, there have been no similar studies on lung squamous cell carcinoma. The main purpose of this study was aimed to explore the differential expression of m6A-related genes in lung squamous cell carcinoma tissues and its relationship with patient clinical prognosis.Methods: We integrated three m6A writers that catalyze the methylation of adenine on mRNA molecules. The training set including 501 patients with LUSC was collected from The Cancer Genome Atlas (TCGA) database and the test set including 181 patients with LUSC was collected from the Gene Expression Omnibus (GEO) database. Based on the expression level of the m6A methylase gene, we established a tumor subgroup and risk-prognosis model to quantify the risk index and long-term patient prognosis, which were confirmed by principal component analysis (PCA) and receiver operating characteristic (ROC) curve analysis. After lung squamous cell carcinoma tissue specimens were obtained during surgery, immunohistochemistry (IHC) was used to verify the results in vitro.Results: The results of the study showed that the expression of the three m6A methylases in tumor tissues and normal tissues was significantly different (P < 0.05). The survival-prognostic model based on METTL3 gene expression showed better predictive performance (AUC: 0.706). Patients in the high-risk and low-risk groups exhibited significant differences in terms of survival time and 5-year and 10-year survival rates. Immunohistochemistry revealed that patients with high METTL3 expression exhibited a longer survival time than those with low METTL3 expression.Conclusions: Our study showed that the molecular phenotype based on the expression of METTL3 may be an independent risk factor affecting the prognosis of lung squamous cell carcinoma. These findings not only prove the important role of m6A methylase in lung squamous cell carcinoma, but are also expected to provide more accurate prognostic assessment and individualized treatment for patients with lung squamous cell carcinoma. [ABSTRACT FROM AUTHOR]

DNA modification plays a pivotal role in regulating gene expression in cell development. As prevalent markers on DNA, 5‐methylcytosine (5mC), N6‐methyladenine (6mA), and N4‐methylcytosine (4mC) can be recognized by specific methyltransferases, facilitating cellular defense and the versatile regulation of gene expression in eukaryotes and prokaryotes. Recent advances in DNA sequencing technology have permitted the positions of different modifications to be resolved at the genome‐wide scale, which has led to the discovery of several novel insights into the complexity and functions of multiple methylations. In this review, we summarize differences in the various mapping approaches and discuss their pros and cons with respect to their relative read depths, speeds, and costs. We also discuss the development of future sequencing technologies and strategies for improving the detection resolution of current sequencing technologies. Lastly, we speculate on the potentially instrumental role that these sequencing technologies might play in future research. [ABSTRACT FROM AUTHOR]

As the most abundant and reversible chemical modification in eukaryotic mRNA, the epitranscriptomic mark N6-methyladenine (m6A) regulates plant development and stress response. We have previously characterized that ALKBH10B is an Arabidopsis mRNA m6A demethylase and regulates floral transition. However, it is unclear whether ALKBH10B plays a role in abiotic stress response. Here, we found that the expression of ALKBH10B is increased in response to abscisic acid (ABA), osmotic, and salt stress. The alkbh10b mutants showed hypersensitive to ABA, osmotic, and salt stress during seed germination. Transcriptome analysis revealed that the expression of several ABA response genes is upregulated in alkbh10b-1 than that of wild type, indicating ALKBH10B negatively affects the ABA signaling. Furthermore, m6A sequencing showed that ABA signaling genes, including PYR1, PYL7, PYL9, ABI1, and SnRK2.2 are m6A hypermethylated in alkbh10b-1 after ABA treatment. Taken together, our work demonstrated that ALKBH10B negatively modulates ABA response during seed germination in Arabidopsis.

A promising electrochemical strategy for assay of N6-methyladenosine (m6A)/N6-methyladenine (6mA) in RNA/DNA is proposed. The key of this strategy is the end-labeling of nucleic acid, which makes it possible to detect methylation level in unknown sequence. Firstly, the end of m6A-RNA or 6mA-DNA was labeled with sulfhydryl group through T4 polynucleotide kinase (T4 PNK) and then directly assembled on a gold nanoparticle–modified glassy carbon electrode (AuNPs/GCE). Secondly, methylation sites in RNA/DNA were specifically recognized by anti-m6A-antibody, and then, horseradish peroxidase–labeled goat anti-rabbit IgG (HRP-IgG) was further conjugated on the antibody. Thirdly, HRP-IgG catalyzed the hydroquinone oxidation reaction to generate amplified current signal which correlates with the amount of m6A/6mA in nucleic acid. This method showed a wide linear range from 0.0001 to 10 nM for m6A-RNA, 0.001 to 100 nM for 6mA-dsDNA, and 0.0001 to 10 nM for 6mA-ssDNA. The method was successfully applied to detection of m6A/6mA in RNA/DNA from HeLa cells and E. coli cells and validation of the decrease of m6A-RNA in HeLa cells after treatment with FTO protein. [ABSTRACT FROM AUTHOR]

Epigenetic modifications in DNA bases and histone proteins play important roles in the regulation of gene expression and genome stability. Chemical modification of DNA base (e.g., addition of a methyl group at the fifth carbon of cytosine residue) switches on/off the gene expression during developmental process and environmental stresses. The dynamics of DNA base methylation depends mainly on the activities of the writer/eraser guided by non-coding RNA (ncRNA) and regulated by the developmental/environmental cues. De novo DNA methylation and active demethylation activities control the methylation level and regulate the gene expression. Identification of ncRNA involved in de novo DNA methylation, increased DNA methylation proteins guiding DNA demethylase, and methylation monitoring sequence that helps maintaining a balance between DNA methylation and demethylation is the recent developments that may resolve some of the enigmas. Such discoveries provide a better understanding of the dynamics/functions of DNA base methylation and epigenetic regulation of growth, development, and stress tolerance in crop plants. Identification of epigenetic pathways in animals, their existence/orthologs in plants, and functional validation might improve future strategies for epigenome editing toward climate-resilient, sustainable agriculture in this era of global climate change. The present review discusses the dynamics of DNA methylation (cytosine/adenine) in plants, its functions in regulating gene expression under abiotic/biotic stresses, developmental processes, and genome stability. [ABSTRACT FROM AUTHOR]

N6-methyladenine (m6A) is one of the crucial epigenetic modifications and is related to the control of various DNA processes. Carrying out a genome-wide m6A analysis via wet experiments is fundamental but takes a long time. As complementary methods, computing tools, especially those based on machine learning, are urgently needed. A new protocol, iRicem6A-CNN, for identifying m6A sites in the rice genome was developed. This protocol was designed to use dinucleotide one-hot encoding to generate input tensors for predictions by convolutional neutral networks, and achieved five-fold cross-validation and independent testing accuracy values of 93.82% and 96.19%, respectively, performing better than those of other available predictors. The experiment results demonstrates that only the ability of iRicem6A-CNN based on 2-mer one-hot encoding is to display high performance but also to perform more stably and robustly than models using 1-mer one-hot encoding. A webserver is accessible at http://iRicem6A-CNN.aibiochem.net [ABSTRACT FROM AUTHOR]

DNA N6-methyladenine (6mA) modifications play a pivotal role in the regulation of growth, development, and diseases in organisms. As a significant epigenetic marker, 6mA modifications extensively participate in the intricate regulatory networks of the genome. Hence, gaining a profound understanding of how 6mA is intricately involved in these biological processes is imperative for deciphering the gene regulatory networks within organisms. In this study, we propose PSAC-6mA (Position-self-attention Capsule-6mA), a sequence-location-based self-attention capsule network. The positional layer in the model enables positional relationship extraction and independent parameter setting for each base position, avoiding parameter sharing inherent in convolutional approaches. Simultaneously, the self-attention capsule network enhances dimensionality, capturing correlation information between capsules and achieving exceptional results in feature extraction across multiple spatial dimensions within the model. Experimental results demonstrate the superior performance of PSAC-6mA in recognizing 6mA motifs across various species., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Zilong Zhang reports was provided by National Natural Science Foundation of China (No. 62101100, No. 62262015). If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Summary: Due to DNA heterozygosity and repeat content, assembly of non‐model plant genomes is challenging. Herein, we report a high‐quality genome reference of one of the oldest known domesticated species, fig (Ficus carica L.), using Pacific Biosciences single‐molecule, real‐time sequencing. The fig genome is ~333 Mbp in size, of which 80% has been anchored to 13 chromosomes. Genome‐wide analysis of N6‐methyladenine and N4‐methylcytosine revealed high methylation levels in both genes and transposable elements, and a prevalence of methylated over non‐methylated genes. Furthermore, the characterization of N6‐methyladenine sites led to the identification of ANHGA, a species‐specific motif, which is prevalent for both genes and transposable elements. Finally, exploiting the contiguity of the 13 pseudomolecules, we identified 13 putative centromeric regions. The high‐quality reference genome and the characterization of methylation profiles, provides an important resource for both fig breeding and for fundamental research into the relationship between epigenetic changes and phenotype, using fig as a model species. Significance Statement: We report a significant improvement of the Ficus carica L. genome sequence and annotation. Furthermore, we performed a genome‐wide analysis of N6‐methyladenine and N4‐methylcytosine. The characterization of N6‐methyladenine sites led to the identification of ANHGA, a species‐specific motif. Finally, we identified the putative centromeric regions. The characterization of two unconventional DNA modifications provides an important resource for investigating the relationship between epigenetic changes and the phenotype of plants. [ABSTRACT FROM AUTHOR]

N6-methyladenine (m6dA) has been recently discovered in eukaryotic genomic DNA. However, there have been few reports on its biological roles. G-quadruplex (G4) is a non-canonical nucleic acid structure formed by the stacking of G-tetrads. G4-forming sequences are enriched with cis -regulatory elements in genomic DNA and the G4 structures have important roles in various cellular functions. We previously reported that CpG methylation stabilized vascular endothelial growth factor (VEGF) G4 structure. Here we report that m6dA modification destabilizes the human c-kit 1 G4 structure. These results suggest that epigenetic modifications may affect G4 formation in order to regulate the biological functions. • N6-methyladenosine (m6dA) modifications decrease thermal stability of c-kit1 G4. • Two A-G base pairs in c-kit1 G4 are destabilized by m6dA modifications. • Gene expression of c-kit might be regulated by m6dA modifications. [ABSTRACT FROM AUTHOR]

DNA N6-methyladenine (6mA) is a dominant DNA modification form and involved in many biological functions. The accurate genome-wide identification of 6mA sites may increase understanding of its biological functions. Experimental methods for 6mA detection in eukaryotes genome are laborious and expensive. Therefore, it is necessary to develop computational methods to identify 6mA sites on a genomic scale, especially for plant genomes. Based on this consideration, the study aims to develop a machine learning-based method of predicting 6mA sites in the rice genome. We initially used mono-nucleotide binary encoding to formulate positive and negative samples. Subsequently, the machine learning algorithm named Random Forest was utilized to perform the classification for identifying 6mA sites. Our proposed method could produce an area under the receiver operating characteristic curve of 0.964 with an overall accuracy of 0.917, as indicated by the fivefold cross-validation test. Furthermore, an independent dataset was established to assess the generalization ability of our method. Finally, an area under the receiver operating characteristic curve of 0.981 was obtained, suggesting that the proposed method had good performance of predicting 6mA sites in the rice genome. For the convenience of retrieving 6mA sites, on the basis of the computational method, we built a freely accessible web server named iDNA6mA-Rice at http://lin-group.cn/server/iDNA6mA-Rice.

DNA methylation is a prevalent regulatory modification in prokaryotes and eukaryotes. N1-methyladenine (m1A) and N6-methyladenine (m6A) have been found to be capable of altering DNA structures via disturbing Watson–Crick base pairing. However, little has been known about their influences on non-B DNA structures, which are associated with genetic instabilities. In this work, we investigated the effects of m1A and m6A on both the structure and thermodynamic stability of a newly reported DNA minidumbbell formed by two TTTA tetranucleotide repeats. As revealed by the results of nuclear magnetic resonance spectroscopic studies, both m1A and m6A favored the formation of a T·m1A and T·m6A Hoogsteen base pair, respectively. More intriguingly, the m1A and m6A modifications brought about stabilization and destabilization effects on the DNA minidumbbell, respectively. This work provides new biophysical insights into the effects of adenine methylation on the structure and thermodynamic stability of DNA.

N6-methyladenine is the most common covalent modification in cellular RNA species, with demonstrated functional consequences. At the molecular level this methylation could alter local RNA structure, and/or modulate the binding of specific proteins. We have previously shown that trans-Hoogsteen-sugar (sheared) A:G base pairs can be completely disrupted by methylation, and that this occurs in a sub-set ofD/D k-turn structures. In this work we have investigated to what extent sequence context affects the severity with which inclusion of N6-methyladenine into different A:G base pairs of a standard k-turn affects RNA folding and L7Ae protein binding. We find that local sequence has a major influence, ranging from complete absence of folding and protein binding to a relatively mild effect. We have determined the crystal structure of one of these species both free and protein-bound, showing the environment of the methyl group and the way the modification is accommodated into the k-turn structure. [ABSTRACT FROM AUTHOR]

DNA methylation is an elementary epigenetic process. The N6-methyladenine is related to a large kind of biological processes i.e., transcription, DNA replication, and repair. In genome, the N6-methyladenine (6 mA) site distribution is non-random; therefore, precise discrimination of 6 mA is necessary to understand its biological functions. Through biochemical experiments, the N6-methyladenine produced a positive outcome, still, these wet lab processes are very time consuming and high pricy. In view of this, it is of high priority to introduce a powerful, accurate, and fast computational model to identify N6-methyladenine sites. In this connection, we propose an intelligent computational model called iDNA6mA (5-step rule) using deep learning approach to identify N6-methyladenine sites from DNA sequences in the rice genome. Existing methods used handcrafted features to identify N6-methyladenine sites; however, the proposed computational model automatically extracts the key features from DNA input sequences via the proposed convolution neural network (CNN) model. The intelligent computational model iDNA6mA (5-step rule) obtained 86.64% of accuracy, 86.70% of sensitivity, 86.59% of specificity, 0.732 of MCC, and 0.931 of auROC. The results demonstrate that the proposed intelligent computational model achieved better performance in terms of all evaluation parameters than existing techniques. It is observed that iDNA6mA (5-step rule) model will become a useful tool in the fields of computational biology, bioinformatics, and for the academic research on N6-methyladenine sites prediction. A user-friendly webserver has been established and freely accessible at https://home.jbnu.ac.kr/NSCL/iDNA6mA.htm. • Intelligent computational model is developed for prediction of DNA N6-methyladenine sites. • Convolution neural network is used. • A user-friendly webserver for the proposed tool has been developed and made available freely. • Achieved promising outcomes than existing methods. [ABSTRACT FROM AUTHOR]

Abstract N6-methyladenine (6mA) is one kind of post-replication modification (PTM or PTRM) occurring in a wide range of DNA sequences. Accurate identification of its sites will be very helpful for revealing the biological functions of 6mA, but it is time-consuming and expensive to determine them by experiments alone. Unfortunately, so far, no bioinformatics tool is available to do so. To fill in such an empty area, we have proposed a novel predictor called iDNA6mA-PseKNC that is established by incorporating nucleotide physicochemical properties into Pseudo K-tuple Nucleotide Composition (PseKNC). It has been observed via rigorous cross-validations that the predictor's sensitivity (Sn), specificity (Sp), accuracy (Acc), and stability (MCC) are 93%, 100%, 96%, and 0.93, respectively. For the convenience of most experimental scientists, a user-friendly web server for iDNA6mA-PseKNC has been established at http://lin-group.cn/server/iDNA6mA-PseKNC , by which users can easily obtain their desired results without the need to go through the complicated mathematical equations involved. Highlights • A bioinformatics tool called iDNA6mA-PseKNC was developed for identifying N6-methyladenine (6mA) sites in DNA sequences. • This is the first computational tool ever established for this purpose • Rigorous cross-validations have indicated that the predictor's sensitivity, specificity, accuracy, and stability are all quite high. • A user-friendly web-server for the predictor has been established by which users can easily obtain their desired results without the need to go through the complicated mathematical equations involved. [ABSTRACT FROM AUTHOR]