Current Advances in N6-Methyladenosine Methylation Modification During Bladder Cancer.
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ABSTRACT:
SUBMITTER: Liu Q
PROVIDER: S-EPMC8787278 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Purpose: To comprehensively analyze N6-methyladenosine modification patterns in bladder tumors and to further systematically explore the inherent relationships between these modification patterns and multiomic tumor characteristics. Materials and Methods: A total of 901 bladder tumor samples, including 405 samples from TCGA database, 188 samples from GSE13507 and 308 samples from GSE32894, were included in this systematic analysis. The N6-methyladenosine modification patterns were identified utilizing unsupervised clustering analysis. To quantify N6-methyladenosine modification patterns, the m6Ascore of individual sample was developed using principal component analysis algorithms. Relationships among immune infiltration, tumor mutation burden, various clinical characteristics, molecular subtypes, and the m6Ascore were systematically analyzed. The guiding value of m6Ascore in immunotherapy was further validated in an external trial cohort. Genomics of Drug Sensitivity in Cancer expression references were also utilized to perform drug sensitivity analysis for patients with distinct m6A modification patterns. Results: We determined three different N6-methyladenosine modification patterns for 901 bladder tumors. The quantitative m6Ascore of individual sample derived from N6-methyladenosine modification patterns could play a significant role in predicting overall survival, immune cell infiltration, and classic oncogene mutations. A low m6Ascore combined with high tumor mutation burden indicated better survival outcomes (p < 0.001). A higher m6Ascore also indicated a higher grade, higher T and N stage, elder ages, higher death rate, and higher PD1/PDL1/CTLA4 expressions (p < 0.01). The Basal type tended to exhibit significantly higher m6Ascores than the Luminal and Neuronal subtypes. External immunotherapy cohorts demonstrated that no difference in therapeutic effects was noted between the high and low m6Ascore groups when anti-PD1 immunotherapy was exclusively administered. When anti-PD1 and anti-CTLA4 immunotherapy were simultaneously administered, the high m6Ascore group had a significantly better prognosis than the low m6Ascore group (p < 0.001). High m6A groups were potentially sensitive to various medical treatments including Bleomycin, Bortezomib, Cisplatin, Cyclopamine, Dasatinib, Docetaxe, Rapamycin, and Vinblastine in this study. Conclusions: This study systematically revealed the important roles of m6A methylation modification patterns in bladder tumors. Detailed quantification of m6A modification patterns could improve our understanding of the bladder tumor microenvironments and could provide guidance for future immunotherapy strategies.
| S-EPMC8733309 | biostudies-literature
Project description:BackgroundUCA1 is frequently upregulated in a variety of cancers, including CRC, and it can play an oncogenic role by various mechanisms. However, how UCA1 is regulated in cancer is largely unknown. In this study, we aimed to determine whether RNA methylation at N6-methyladenosine (m6A) can impact UCA1 expression in colorectal cancer (CRC).MethodsqRT-PCR was performed to detect the level of UCA1 and IGF2BP2 in CRC samples. CRISPR/Cas9 was employed to knockout (KO) UCA1, METTL3 and WTAP in DLD-1 and HCT-116 cells, while rescue experiments were carried out to re-express METTL3 and WTAP in KO cells. Immunoprecipitation using m6A antibody was performed to determine the m6A modification of UCA1. In vivo pulldown assays using S1m tagging combined with site-direct mutagenesis was carried out to confirm the recognition of m6A-modified UCA1 by IGF2BP2. Cell viability was measured by MTT and colony formation assays. The expression of UCA1 and IGF2BP2 in TCGA CRC database was obtained from GEPIA ( http://gepia.cancer-pku.cn ).ResultsOur results revealed that IGF2BP2 serves as a reader for m6A modified UCA1 and that adenosine at 1038 of UCA1 is critical to the recognition by IGF2BP2. Importantly, we showed that m6A writers, METTL3 and WTAP positively regulate UCA1 expression. Mechanically, IGF2BP2 increases the stability of m6A-modified UCA1. Clinically, IGF2BP2 is upregulated in CRC tissues compared with normal tissues.ConclusionThese results suggest that m6A modification is an important factor contributing to upregulation of UCA1 in CRC tissues.
| S-EPMC8609784 | biostudies-literature
Project description:BackgroundSeveral studies have revealed that N6-methyladenosine (m6A) regulation is involved in various biological processes and cancer progression. Nevertheless, the potential effects of m6A modifications in the tumor immune microenvironment (TIME) and on immune regulation in pancreatic adenocarcinoma (PAAD) remains unclear.MethodsA consensus clustering algorithm was used to identify different m6A modification patterns and construct an m6A-associated gene signature based on 23 m6A regulators in PAAD. The CIBERSORT and ssGSEA algorithms were used to estimate the components of the immune cells in each sample. The PCA algorithm was used to develop the m6Ascore system for the evaluation of m6A modification patterns in each sample.ResultsTwo m6A modification patterns with different biological properties and prognoses were identified in 176 PAAD patient samples. The features of TIME between the two patterns were similar, with two definite immune phenotypes: immune-inflamed and immune-excluded. Based on the m6A phenotype-associated signature genes, we constructed an m6Ascore system to investigate the m6A modification pattern of each sample, profile the dissection of physiological processes, immune infiltration, clinical prognosis, immunotherapy, and genetic variation. Patients with low m6Ascore scores had better clinical outcomes, enhanced immune infiltration, and lower expression of immunotherapeutic drug targets, such as CD274 and PDCD1LG2. Further research indicated that the m6Ascore and tumor mutation burden were significantly correlated, and patients with low m6Ascore had higher mutation rates in SMAD4 and TTN. Moreover, TNFRSF21 was significantly upregulated in PAAD tumor tissues and cell lines. Lower expression of TNFRSF21 had a prominent advantage in survival and was correlated with a low level of immune infiltration. PAAD samples with different TNFRSF21 expression levels showed significantly distinct sensitivities to chemotherapeutic agents.ConclusionsThis study revealed that m6A modification patterns could play an important role in the diversity and complexity of TIME, and the m6Ascore system could serve as an independent and powerful prognostic biomarker and is latently related to PAAD immunotherapies. Quantitative determination of m6A modification patterns in individual patients will be instrumental in mapping the TIME landscape and further optimizing precision immunotherapy.
| S-EPMC9125922 | biostudies-literature
Project description:This study was conducted to investigate effect of N6-methyladenosine (m6A) RNA methylation on Heat shock proteins (HSPs) and dissect the profile of HSP RNA methylation. The results showed that m6A methyltransferases METTL3 mRNA was decreased in responses to heat shock stress in HepG2 cells, but m6A-specific binding protein YTHDF2 mRNA was upregulated in a manner similar to HSP70 induction. Immunofluorescence staining showed that the majority of YTHDF2 was present in the cytosol, however, nearly all YTHDF2 translocated from the cytosol into the nucleus after heat shock. METTL3 knockdown significantly changed HSP70, HSP60, and HSP27 mRNA expression in HepG2 cells using siRNA, however, mRNA lifetime was not impacted. Silence of YTHDF2 using siRNA did not change expression of HSP70, but significantly increased HSP90, HSP60, and HSPB1 mRNA expression. In addition, m6A-seq revealed that HSP m6A methylation peaks are mainly enriched on exons and around stop codons, and shows a unique distribution profile in the 5'UTR and 3'UTR. Knockdown of METTL3 changed the methylation patterns of HSPs transcript. In conclusion, m6A RNA methylation regulates HSP gene expression. Differential expression of HSPs modulated by m6A may depend on the m6A site and abundance of the target gene. This finding provides insights into new regulatory mechanisms of HSPs in normal and stress situations.
| S-EPMC6002042 | biostudies-literature
Project description:N6-methyladenosine (m6A) modification is a common RNA modification in the central nervous system and has been linked to various neurological disorders, including Alzheimer's disease (AD). However, the dynamic of mRNA m6A modification and m6A enzymes during the development of AD are not well understood. Therefore, this study examined the expression profiles of m6A and its enzymes in the development of AD. The results showed that changes in the expression levels of m6A regulatory factors occur in the early stages of AD, indicating a potential role for m6A modification in the onset of the disease. Additionally, the analysis of mRNA m6A expression profiles using m6A-seq revealed significant differences in m6A modification between AD and control brains. The genes with differential methylation were found to be enriched in GO and KEGG terms related to processes such as inflammation response, immune system processes. And the differently expressed genes (DEGs) are negatively lryassociated with genes involved in microglia hemostasis, but positively associated with genes related to "disease-associated microglia" (DAM) associated genes. These findings suggest that dysregulation of mRNA m6A modification may contribute to the development of AD by affecting the function and gene expression of microglia.
| S-EPMC10944207 | biostudies-literature
Project description:N6 -methyladenosine (m6 A) RNA modification, first discovered in 1974, is the most prevalent, abundant and penetrating messenger RNA (mRNA) modification in eukaryotes. This governs the fate of modified transcripts, regulates RNA metabolism and biological processes, and participates in pathogenesis of numerous human diseases, especially in cancer through the reciprocal regulation of m6 A methyltransferases ("writers") and demethylases ("erasers") and the binding proteins decoding m6 A methylation ("readers"). Accumulating evidence indicates a complicated regulation network of m6 A modification involving multiple m6 A-associated regulatory proteins whose biological functions have been further analysed. This review aimed to summarize the current knowledge on the potential significance and molecular mechanisms of m6 A RNA modification in the initiation and progression of cancer.
| S-EPMC7653258 | biostudies-literature
Project description:Since the breakthrough discoveries of DNA and histone modifications, the field of RNA modifications has gained increasing interest in the scientific community. The discovery of N6-methyladenosine (m6A), a predominantly internal epigenetic modification in eukaryotes mRNA, heralded the creation of the field of epi-transcriptomics. This post-transcriptional RNA modification is dynamic and reversible, and is regulated by methylases, demethylases and proteins that preferentially recognize m6A modifications. Altered m6A levels affect RNA processing, degradation and translation, thereby disrupting gene expression and key cellular processes, ultimately resulting in tumor initiation and progression. Furthermore, inhibitors and regulators of m6A-related factors have been explored as therapeutic approaches for treating cancer. In the present review, the mechanisms of m6A RNA modification, the clinicopathological relevance of m6A alterations, the type and frequency of alterations and the multiple functions it regulates in different types of cancer are discussed.
| S-EPMC7278081 | biostudies-literature
Project description:Accumulating evidence has revealed significant roles for N6-methyladenosine (m 6 A) modification in the development of various cancers. We previously demonstrated an oncogenic role of m 6 A-modified CUB domain containing protein 1 (CDCP1) in bladder cancer (BC) progression. However, the biological functions and underlying molecular mechanisms of engineered programmable m 6 A modification of CDCP1 mRNA in BC remain obscure. Here, we established a targeted m 6 A RNA methylation system by fusing the catalytic domain of methyltransferase like 3 (METTL3CD) to RCas9 as the RNA-targeting module. The constructed RCas9- METTL3 retained methylation activity and mediated efficient site-specific m 6 A installation in the presence of a cognate single guide RNA and short protospacer adjacent motif-containing ssDNA molecule . Subsequently, targeting m 6 A installation onto the 3' untranslated region of CDCP1 promoted CDCP1 mRNA translation and facilitated BC development in vitro and in vivo. Our findings demonstrate that the RCas9-METTL3 system mediates efficient sitespecific m 6 A installation on CDCP1 mRNA and promotes BC development. Thus, the RCas9-METTL3 system provides a new tool for studying m 6 A function and a potential strategy for BC epitranscriptome-modulating therapies.
| S-EPMC7712571 | biostudies-literature
Project description:Circular RNAs (circRNAs) are prevalent in eukaryotic cells and viral genomes. Mammalian cells possess innate immunity to detect foreign circRNAs, but the molecular basis of self versus foreign identity in circRNA immunity is unknown. Here, we show that N6-methyladenosine (m6A) RNA modification on human circRNAs inhibits innate immunity. Foreign circRNAs are potent adjuvants to induce antigen-specific T cell activation, antibody production, and anti-tumor immunity in vivo, and m6A modification abrogates immune gene activation and adjuvant activity. m6A reader YTHDF2 sequesters m6A-circRNA and is essential for suppression of innate immunity. Unmodified circRNA, but not m6A-modified circRNA, directly activates RNA pattern recognition receptor RIG-I in the presence of lysine-63-linked polyubiquitin chain to cause filamentation of the adaptor protein MAVS and activation of the downstream transcription factor IRF3. CircRNA immunity has considerable parallel to prokaryotic DNA restriction modification system that transforms nucleic acid chemical modification into organismal innate immunity.
| S-EPMC6778039 | biostudies-literature
Project description:Improvements in living standards have led to non-alcoholic fatty liver disease (NAFLD), one of the most common chronic liver diseases worldwide. Recent studies have shown that N6-methyladenosine (m6A), a type of RNA modification, is strongly associated with many important biological processes. However, the relationship between m6A methylation modifications and NAFLD remains poorly understood. In the present study, through methylated RNA immunoprecipitation sequencing and RNA transcriptome sequencing in high fructose diet-induced NAFLD mice, we found that hypermethylation-encoding genes were mainly enriched in lipid metabolism processes. We identified 266 overlapping and differentially expressed genes (DEGs) that changed at both the mRNA expression level and m6A modification level. Among them, 193 genes displayed increased expression and m6A modification, indicating that m6A RNA modifications tend to be positively correlated with NAFLD. We further compared the high fructose diet-induced NAFLD mouse model with leptin receptor-deficient mice and found that DEGs enriched in the lipid metabolism pathway were up-regulated in both groups. In contrast, DEGs associated with the immune inflammatory response were up-regulated in the high fructose diet group, but down-regulated in leptin receptor-deficient mice. Taken together, our results demonstrate that m6A methylation modifications may play an important role in the development of NAFLD.
| S-EPMC8688819 | biostudies-literature