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1.
Genome Biol ; 25(1): 157, 2024 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877540

RESUMO

Methylation-based liquid biopsies show promises in detecting cancer using circulating cell-free DNA; however, current limitations impede clinical application. Most assays necessitate substantial DNA inputs, posing challenges. Additionally, underrepresented tumor DNA fragments may go undetected during exponential amplification steps of traditional sequencing methods. Here, we report linear amplification-based bisulfite sequencing (LABS), enabling linear amplification of bisulfite-treated DNA fragments in a genome-wide, unbiased fashion, detecting cancer abnormalities with sub-nanogram inputs. Applying LABS to 100 patient samples revealed cancer-specific patterns, copy number alterations, and enhanced cancer detection accuracy by identifying tissue-of-origin and immune cell composition.


Assuntos
Metilação de DNA , Neoplasias , Análise de Sequência de DNA , Sulfitos , Humanos , Neoplasias/genética , Análise de Sequência de DNA/métodos , Ácidos Nucleicos Livres , Técnicas de Amplificação de Ácido Nucleico/métodos , Variações do Número de Cópias de DNA , DNA de Neoplasias/genética , DNA Tumoral Circulante/genética
2.
Nat Commun ; 15(1): 4881, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849358

RESUMO

N6-methyladenosine (m6A) plays critical roles in regulating mRNA metabolism. However, comprehensive m6A methylomes in different plant tissues with single-base precision have yet to be reported. Here, we present transcriptome-wide m6A maps at single-base resolution in different tissues of rice and Arabidopsis using m6A-SAC-seq. Our analysis uncovers a total of 205,691 m6A sites distributed across 22,574 genes in rice, and 188,282 m6A sites across 19,984 genes in Arabidopsis. The evolutionarily conserved m6A sites in rice and Arabidopsis ortholog gene pairs are involved in controlling tissue development, photosynthesis and stress response. We observe an overall mRNA stabilization effect by 3' UTR m6A sites in certain plant tissues. Like in mammals, a positive correlation between the m6A level and the length of internal exons is also observed in plant mRNA, except for the last exon. Our data suggest an active m6A deposition process occurring near the stop codon in plant mRNA. In addition, the MTA-installed plant mRNA m6A sites correlate with both translation promotion and translation suppression, depicting a more complicated regulatory picture. Our results therefore provide in-depth resources for relating single-base resolution m6A sites with functions in plants and uncover a suppression-activation model controlling m6A biogenesis across species.


Assuntos
Adenosina , Arabidopsis , Regulação da Expressão Gênica de Plantas , Oryza , RNA Mensageiro , Oryza/genética , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Adenosina/análogos & derivados , Adenosina/metabolismo , RNA Mensageiro/metabolismo , RNA Mensageiro/genética , Transcriptoma/genética , RNA de Plantas/genética , RNA de Plantas/metabolismo , Regiões 3' não Traduzidas/genética , Perfilação da Expressão Gênica/métodos , Estabilidade de RNA/genética , Éxons/genética , Códon de Terminação/genética
3.
Nat Cell Biol ; 26(3): 421-437, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38409327

RESUMO

Type 1 diabetes (T1D) is characterized by the destruction of pancreatic ß-cells. Several observations have renewed the interest in ß-cell RNA sensors and editors. Here, we report that N6-methyladenosine (m6A) is an adaptive ß-cell safeguard mechanism that controls the amplitude and duration of the antiviral innate immune response at T1D onset. m6A writer methyltransferase 3 (METTL3) levels increase drastically in ß-cells at T1D onset but rapidly decline with disease progression. m6A sequencing revealed the m6A hypermethylation of several key innate immune mediators, including OAS1, OAS2, OAS3 and ADAR1 in human islets and EndoC-ßH1 cells at T1D onset. METTL3 silencing enhanced 2'-5'-oligoadenylate synthetase levels by increasing its mRNA stability. Consistently, in vivo gene therapy to prolong Mettl3 overexpression specifically in ß-cells delayed diabetes progression in the non-obese diabetic mouse model of T1D. Mechanistically, the accumulation of reactive oxygen species blocked upregulation of METTL3 in response to cytokines, while physiological levels of nitric oxide enhanced METTL3 levels and activity. Furthermore, we report that the cysteines in position C276 and C326 in the zinc finger domains of the METTL3 protein are sensitive to S-nitrosylation and are important to the METTL3-mediated regulation of oligoadenylate synthase mRNA stability in human ß-cells. Collectively, we report that m6A regulates the innate immune response at the ß-cell level during the onset of T1D in humans.


Assuntos
Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Animais , Humanos , Camundongos , Adenosina Desaminase/metabolismo , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/metabolismo , Imunidade Inata , Células Secretoras de Insulina/metabolismo , Metiltransferases/genética , Metiltransferases/metabolismo , Oxirredução
4.
Nat Plants ; 9(12): 2042-2058, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38066290

RESUMO

Light regulates chlorophyll homeostasis and photosynthesis via various molecular mechanisms in plants. The light regulation of transcription and protein stability of nuclear-encoded chloroplast proteins have been extensively studied, but how light regulation of mRNA metabolism affects abundance of nuclear-encoded chloroplast proteins and chlorophyll homeostasis remains poorly understood. Here we show that the blue light receptor cryptochrome 2 (CRY2) and the METTL16-type m6A writer FIONA1 (FIO1) regulate chlorophyll homeostasis in response to blue light. In contrast to the CRY2-mediated photo-condensation of the mRNA adenosine methylase (MTA), photoexcited CRY2 co-condenses FIO1 only in the presence of the CRY2-signalling protein SUPPRESSOR of PHYTOCHROME A (SPA1). CRY2 and SPA1 synergistically or additively activate the RNA methyltransferase activity of FIO1 in vitro, whereas CRY2 and FIO1, but not MTA, are required for the light-induced methylation and translation of the mRNAs encoding multiple chlorophyll homeostasis regulators in vivo. Our study demonstrates that the light-induced liquid-liquid phase separation of the photoreceptor/writer complexes is commonly involved in the regulation of photoresponsive changes of mRNA methylation, whereas the different photo-condensation mechanisms of the CRY/FIO1 and CRY/MTA complexes explain, at least partially, the writer-specific functions in plant photomorphogenesis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Homeostase , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ciclo Celular/metabolismo , Clorofila/metabolismo , Proteínas de Cloroplastos/metabolismo , Criptocromos/genética , Criptocromos/metabolismo , Regulação da Expressão Gênica de Plantas , Luz , Fatores de Transcrição/metabolismo , RNA Mensageiro/metabolismo , Metilação de RNA
5.
Mol Cell ; 83(15): 2692-2708.e7, 2023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37478845

RESUMO

N6-methyladenosine (m6A) of mRNAs modulated by the METTL3-METTL14-WTAP-RBM15 methyltransferase complex and m6A demethylases such as FTO play important roles in regulating mRNA stability, splicing, and translation. Here, we demonstrate that FTO-IT1 long noncoding RNA (lncRNA) was upregulated and positively correlated with poor survival of patients with wild-type p53-expressing prostate cancer (PCa). m6A RIP-seq analysis revealed that FTO-IT1 knockout increased mRNA m6A methylation of a subset of p53 transcriptional target genes (e.g., FAS, TP53INP1, and SESN2) and induced PCa cell cycle arrest and apoptosis. We further showed that FTO-IT1 directly binds RBM15 and inhibits RBM15 binding, m6A methylation, and stability of p53 target mRNAs. Therapeutic depletion of FTO-IT1 restored mRNA m6A level and expression of p53 target genes and inhibited PCa growth in mice. Our study identifies FTO-IT1 lncRNA as a bona fide suppressor of the m6A methyltransferase complex and p53 tumor suppression signaling and nominates FTO-IT1 as a potential therapeutic target of cancer.


Assuntos
Neoplasias , RNA Longo não Codificante , Masculino , Camundongos , Animais , RNA Longo não Codificante/genética , Proteína Supressora de Tumor p53/genética , Adenosina/metabolismo , RNA Mensageiro/genética , Metiltransferases/genética , Metiltransferases/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo
6.
bioRxiv ; 2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36824909

RESUMO

Type 1 Diabetes (T1D) is characterized by autoimmune-mediated destruction of insulin-producing ß-cells. Several observations have renewed interest in the innate immune system as an initiator of the disease process against ß-cells. Here, we show that N 6 -Methyladenosine (m 6 A) is an adaptive ß-cell safeguard mechanism that accelerates mRNA decay of the 2'-5'-oligoadenylate synthetase (OAS) genes to control the antiviral innate immune response at T1D onset. m 6 A writer methyltransferase 3 (METTL3) levels increase drastically in human and mouse ß-cells at T1D onset but rapidly decline with disease progression. Treatment of human islets and EndoC-ßH1 cells with pro-inflammatory cytokines interleukin-1 ß and interferon α mimicked the METTL3 upregulation seen at T1D onset. Furthermore, m 6 A-sequencing revealed the m 6 A hypermethylation of several key innate immune mediators including OAS1, OAS2, and OAS3 in human islets and EndoC-ßH1 cells challenged with cytokines. METTL3 silencing in human pseudoislets or EndoC-ßH1 cells enhanced OAS levels by increasing its mRNA stability upon cytokine challenge. Consistently, in vivo gene therapy, to prolong Mettl3 overexpression specifically in ß-cells, delayed diabetes progression in the non-obese diabetic (NOD) mouse model of T1D by limiting the upregulation of Oas pointing to potential therapeutic relevance. Mechanistically, the accumulation of reactive oxygen species blocked METTL3 upregulation in response to cytokines, while physiological levels of nitric oxide promoted its expression in human islets. Furthermore, for the first time to our knowledge, we show that the cysteines in position C276 and C326 in the zinc finger domain of the METTL3 protein are sensitive to S-nitrosylation (SNO) and are significant for the METTL3 mediated regulation of OAS mRNA stability in human ß-cells in response to cytokines. Collectively, we report that m 6 A regulates human and mouse ß-cells to control the innate immune response during the onset of T1D and propose targeting METTL3 to prevent ß-cell death in T1D.

7.
ACS Chem Biol ; 17(12): 3306-3312, 2022 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-36398936

RESUMO

Methods for the precise detection and quantification of RNA modifications are critical to uncover functional roles of diverse RNA modifications. The internal m7G modification in mammalian cytoplasmic tRNAs is known to affect tRNA function and impact embryonic stem cell self-renewal, tumorigenesis, cancer progression, and other cellular processes. Here, we introduce m7G-quant-seq, a quantitative method that accurately detects internal m7G sites in human cytoplasmic tRNAs at single-base resolution. The efficient chemical reduction and mild depurination can almost completely convert internal m7G sites into RNA abasic sites (AP sites). We demonstrate that RNA abasic sites induce a mixed variation pattern during reverse transcription, including G → A or C or T mutations as well as deletions. We calculated the total variation ratio to quantify the m7G modification fraction at each methylated site. The calibration curves of all relevant motif contexts allow us to more quantitatively determine the m7G methylation level. We detected internal m7G sites in 22 human cytoplasmic tRNAs from HeLa and HEK293T cells and successfully estimated the corresponding m7G methylation stoichiometry. m7G-quant-seq could be applied to monitor the tRNA m7G methylation level change in diverse biological processes.


Assuntos
Guanosina , RNA , Animais , Humanos , Células HEK293 , RNA de Transferência/genética , Mamíferos/genética
8.
Medicine (Baltimore) ; 101(41): e30982, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36254009

RESUMO

The highly malignant nature of lung adenocarcinoma (LUAD) makes its early diagnosis and prognostic assessment particularly important. However, whether the CXC subfamily of chemokine receptors (CXCR) is involved in the development and prognosis of LUAD remains unclear. Here, differentially expressed genes (DEGs) associated with overall survival (OS) were selected from the cancer genome atlas (TCGA) dataset using univariate Cox analysis and least absolute shrinkage and selection operator (LASSO) regression analysis. Then, a prognostic gene signature was constructed, which was evaluated using Kaplan-Meier curves, receiver operating characteristics curves, nomogram curves, and an external gene expression omnibus (GEO) dataset. Finally, we verified the functions of the genes comprising the signature using the gene expression profiling interactive analysis (GEPIA) and the immune system interaction database (TISIDB) web portals. We constructed a 7-gene signature (SHC1, PRKCD, VEGFC, RPS6KA1, CAT, CDC25C, and GPI) that stratified patients into high- and low-risk categories. Notably, the risk score of the signature was a separate and effective predictor for OS (P < .001). Patients in the low-risk category had a better prognosis than those in the high-risk category. The receiver operating characteristics and nomogram curves verified the predictive power of the signature. Moreover, in both categories, biological processes and pathways associated with cell migration were enriched. Immune infiltration statuses differed between the 2 risk categories. Critically, the results from the GEPIA and TISIDB web portals indicated that the expression of the 7-gene signature was associated with survival, clinical stage, and immune subtypes of LUAD patients. We identified a CXCR-related gene signature that could assess prognosis and provide a reference for the diagnosis and treatment of LUAD.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Adenocarcinoma de Pulmão/patologia , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/patologia , Prognóstico , Receptores de Quimiocinas
9.
Science ; 376(6596): 968-973, 2022 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-35511947

RESUMO

N6-methyladenosine (m6A) is the most abundant internal modification on mammalian messenger RNA. It is installed by a writer complex and can be reversed by erasers such as the fat mass and obesity-associated protein FTO. Despite extensive research, the primary physiological substrates of FTO in mammalian tissues and development remain elusive. Here, we show that FTO mediates m6A demethylation of long-interspersed element-1 (LINE1) RNA in mouse embryonic stem cells (mESCs), regulating LINE1 RNA abundance and the local chromatin state, which in turn modulates the transcription of LINE1-containing genes. FTO-mediated LINE1 RNA m6A demethylation also plays regulatory roles in shaping chromatin state and gene expression during mouse oocyte and embryonic development. Our results suggest broad effects of LINE1 RNA m6A demethylation by FTO in mammals.


Assuntos
Adenosina/análogos & derivados , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Cromatina , Regulação da Expressão Gênica no Desenvolvimento , Elementos Nucleotídeos Longos e Dispersos , Células-Tronco Embrionárias Murinas , Oócitos , RNA Mensageiro , Adenosina/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Animais , Cromatina/metabolismo , Desmetilação , Elementos Nucleotídeos Longos e Dispersos/genética , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Oócitos/crescimento & desenvolvimento , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
11.
Nat Biotechnol ; 40(8): 1210-1219, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35288668

RESUMO

Functional studies of the RNA N6-methyladenosine (m6A) modification have been limited by an inability to map individual m6A-modified sites in whole transcriptomes. To enable such studies, here, we introduce m6A-selective allyl chemical labeling and sequencing (m6A-SAC-seq), a method for quantitative, whole-transcriptome mapping of m6A at single-nucleotide resolution. The method requires only ~30 ng of poly(A) or rRNA-depleted RNA. We mapped m6A modification stoichiometries in RNA from cell lines and during in vitro monocytopoiesis from human hematopoietic stem and progenitor cells (HSPCs). We identified numerous cell-state-specific m6A sites whose methylation status was highly dynamic during cell differentiation. We observed changes of m6A stoichiometry as well as expression levels of transcripts encoding or regulated by key transcriptional factors (TFs) critical for HSPC differentiation. m6A-SAC-seq is a quantitative method to dissect the dynamics and functional roles of m6A sites in diverse biological processes using limited input RNA.


Assuntos
Processamento Pós-Transcricional do RNA , Transcriptoma , Animais , Humanos , Mamíferos/genética , Metilação , RNA/genética , RNA/metabolismo , Processamento Pós-Transcricional do RNA/genética , RNA Mensageiro/genética , Transcriptoma/genética
12.
Nat Cell Biol ; 24(2): 205-216, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35145225

RESUMO

METTL16 has recently been identified as an RNA methyltransferase responsible for the deposition of N6-methyladenosine (m6A) in a few transcripts. Whether METTL16 methylates a large set of transcripts, similar to METTL3 and METTL14, remains unclear. Here we show that METTL16 exerts both methyltransferase activity-dependent and -independent functions in gene regulation. In the cell nucleus, METTL16 functions as an m6A writer to deposit m6A into hundreds of its specific messenger RNA targets. In the cytosol, METTL16 promotes translation in an m6A-independent manner. More specifically, METTL16 directly interacts with the eukaryotic initiation factors 3a and -b as well as ribosomal RNA through its Mtase domain, thereby facilitating the assembly of the translation-initiation complex and promoting the translation of over 4,000 mRNA transcripts. Moreover, we demonstrate that METTL16 is critical for the tumorigenesis of hepatocellular carcinoma. Collectively, our studies reveal previously unappreciated dual functions of METTL16 as an m6A writer and a translation-initiation facilitator, which together contribute to its essential function in tumorigenesis.


Assuntos
Adenosina/análogos & derivados , Carcinogênese/metabolismo , Carcinoma Hepatocelular/enzimologia , Neoplasias Hepáticas/enzimologia , Metiltransferases/metabolismo , Biossíntese de Proteínas , Processamento Pós-Transcricional do RNA , RNA Mensageiro/metabolismo , Adenosina/metabolismo , Animais , Carcinogênese/genética , Carcinogênese/patologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Citosol/enzimologia , Fator de Iniciação 3 em Eucariotos/genética , Fator de Iniciação 3 em Eucariotos/metabolismo , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Metiltransferases/genética , Camundongos Endogâmicos NOD , Camundongos SCID , RNA Mensageiro/genética , RNA Ribossômico/genética , RNA Ribossômico/metabolismo , Transdução de Sinais , Carga Tumoral
13.
PLoS Pathog ; 17(12): e1010142, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34929018

RESUMO

Human respiratory syncytial virus (RSV) is the leading cause of respiratory tract infections in humans. A well-known challenge in the development of a live attenuated RSV vaccine is that interferon (IFN)-mediated antiviral responses are strongly suppressed by RSV nonstructural proteins which, in turn, dampens the subsequent adaptive immune responses. Here, we discovered a novel strategy to enhance innate and adaptive immunity to RSV infection. Specifically, we found that recombinant RSVs deficient in viral RNA N6-methyladenosine (m6A) and RSV grown in m6A methyltransferase (METTL3)-knockdown cells induce higher expression of RIG-I, bind more efficiently to RIG-I, and enhance RIG-I ubiquitination and IRF3 phosphorylation compared to wild-type virion RNA, leading to enhanced type I IFN production. Importantly, these m6A-deficient RSV mutants also induce a stronger IFN response in vivo, are significantly attenuated, induce higher neutralizing antibody and T cell immune responses in mice and provide complete protection against RSV challenge in cotton rats. Collectively, our results demonstrate that inhibition of RSV RNA m6A methylation enhances innate immune responses which in turn promote adaptive immunity.


Assuntos
Adenosina/análogos & derivados , RNA Viral , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sincicial Respiratório Humano/imunologia , Imunidade Adaptativa , Animais , Imunidade Inata , Metilação , Camundongos , Ratos
14.
World J Surg Oncol ; 19(1): 275, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521431

RESUMO

BACKGROUND: Squamous cell carcinoma (SCC) is a disease with distinct management complexities as it displays a remarkably heterogeneous molecular subtype. However, the landscape of angiogenesis for SCC is not fully investigated. METHOD AND MATERIALS: The angiogenesis-related subtypes of SCC were established by using the ConsensusClusterPlus package based on angiogenesis-related genes and TCGA data. We analyzed the alteration of genes and miRNAs as well as pathways associated with angiogenesis subtypes. Next, the regulation network, the correlation with genomic characteristics, immune microenvironment, and clinical features of the angiogenesis subtypes were further investigated. Finally, the prognostic impact of the angiogenesis-related subtypes for SCC was also analyzed. RESULTS: A total of 1368 SCC samples were included in this study. Two angiogenesis subtypes were then identified based on the one hundred and sixty-three angiogenesis-related genes with subtype1 (angiogenesis subtype) of 951 SCC patients and subtype2 (non-angiogenesis subtype) of 417 SCC. GSEA revealed that angiogenesis and epithelial-mesenchymal transition, inflammatory response, and hypoxia were enriched in the angiogenesis subtype. Eight of the 15 immune checkpoints (ADORA2A, BTLA, CD276, CYBB, HAVCR2, SIGLEC7, SIGLEC9, and VTCN1) were significantly upregulated while C10orf54 were significantly downregulated in the angiogenesis subtype. The survival analysis revealed that the patients in the angiogenesis subtype have poorer survival outcomes than those in the non-angiogenesis subtype (P = 0.017 for disease-free interval and P = 0.00013 for overall survival). CONCLUSION: Our analysis revealed a novel angiogenesis subtype classification in SCC and provides new insights into a hallmark of SCC progression.


Assuntos
Carcinoma de Células Escamosas , MicroRNAs , Antígenos CD , Antígenos B7 , Carcinoma de Células Escamosas/genética , Humanos , Prognóstico , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico , Análise de Sobrevida , Microambiente Tumoral
15.
Proc Natl Acad Sci U S A ; 118(35)2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34452996

RESUMO

Global genome repair (GGR), a subpathway of nucleotide excision repair, corrects bulky helix-distorting DNA lesions across the whole genome and is essential for preventing mutagenesis and skin cancer. Here, we show that METTL14 (methyltransferase-like 14), a critical component of the N6-methyladenosine (m6A) RNA methyltransferase complex, promotes GGR through regulating m6A mRNA methylation-mediated DDB2 translation and suppresses ultraviolet B (UVB) radiation-induced skin tumorigenesis. UVB irradiation down-regulates METTL14 protein through NBR1-dependent selective autophagy. METTL14 knockdown decreases GGR and DDB2 abundance. Conversely, overexpression of wild-type METTL14 but not its enzymatically inactive mutant increases GGR and DDB2 abundance. METTL14 knockdown decreases m6A methylation and translation of the DDB2 transcripts. Adding DDB2 reverses the GGR repair defect in METTL14 knockdown cells, indicating that METTL14 facilitates GGR through regulating DDB2 m6A methylation and translation. Similarly, knockdown of YTHDF1, an m6A reader promoting translation of m6A-modified transcripts, decreases DDB2 protein levels. Both METTL14 and YTHDF1 bind to the DDB2 transcript. In mice, skin-specific heterozygous METTL14 deletion increases UVB-induced skin tumorigenesis. Furthermore, METTL14 as well as DDB2 is down-regulated in human and mouse skin tumors and by chronic UVB irradiation in mouse skin, and METTL14 level is associated with the DDB2 level, suggesting a tumor-suppressive role of METTL14 in UVB-associated skin tumorigenesis in association with DDB2 regulation. Taken together, these findings demonstrate that METTL14 is a target for selective autophagy and acts as a critical epitranscriptomic mechanism to regulate GGR and suppress UVB-induced skin tumorigenesis.


Assuntos
Carcinogênese/genética , Reparo do DNA/fisiologia , Metiltransferases/fisiologia , Neoplasias Cutâneas/genética , Animais , Autofagia , Linhagem Celular Tumoral , Dano ao DNA , Reparo do DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Genes Supressores de Tumor/efeitos da radiação , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Glicoproteínas de Membrana/metabolismo , Metilação , Metiltransferases/genética , Camundongos , Proteínas do Tecido Nervoso/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Neoplasias Cutâneas/etiologia , Raios Ultravioleta
16.
Front Oncol ; 11: 691915, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34447695

RESUMO

BACKGROUND: The epidermal growth factor receptor (EGFR) is a primary target of molecular targeted therapy for lung adenocarcinoma (LUAD). The mechanisms that lead to epigenetic abnormalities of EGFR in LUAD are still unclear. The purpose of our study was to evaluate the abnormal methylation of EGFR CpG sites as potential biomarkers for LUAD. METHODS: To assess the differentially methylation CpG sites of EGFR in LUAD, we used an integrative study of Illumina HumanMethylation450K and RNA-seq data from The Cancer Genome Atlas (TCGA). We evaluated and compared EGFR multiple-omics data to explore the role of CpG sites located in EGFR promoter regions and gene body regions and the association with transcripts, protein expression levels, mutations, and somatic copy number variation. We calculated the correlation coefficients between CpG sites of EGFR and immune infiltration fraction (by MCPcounter and ESTIMATE) and immune-related pathways in LUAD. Finally, we validated the differential methylation of clinically and prognostically relevant CpG sites using quantitative methylation-specific PCR (qMSP). RESULTS: We found that the methylation level of many EGFR CpGs in the promoter region was negatively correlated with the transcription level, protein expression, and SCNV, while the methylation at the gene body region was positively correlated with these features. The methylation level of EGFR CpGs in the promoter region was positively correlated with the level of immune infiltration and IFN-γ signature, while the opposite was found for methylation of the gene body region. The qMSP results showed that cg02316066 had a high methylation level, while cg02166842 had a low methylation level in LUAD. There was a high degree of co-methylation between cg02316066 and cg03046247. CONCLUSION: Our data indicate that EGFR is an epigenetic regulator in LUAD acting through DNA methylation. Our research provides a theoretical basis for the further detection of EGFR DNA methylation as a predictive biomarker for LUAD survival and immunotherapy.

17.
Nat Cell Biol ; 23(7): 684-691, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34253897

RESUMO

Members of the mammalian AlkB family are known to mediate nucleic acid demethylation1,2. ALKBH7, a mammalian AlkB homologue, localizes in mitochondria and affects metabolism3, but its function and mechanism of action are unknown. Here we report an approach to site-specifically detect N1-methyladenosine (m1A), N3-methylcytidine (m3C), N1-methylguanosine (m1G) and N2,N2-dimethylguanosine (m22G) modifications simultaneously within all cellular RNAs, and discovered that human ALKBH7 demethylates m22G and m1A within mitochondrial Ile and Leu1 pre-tRNA regions, respectively, in nascent polycistronic mitochondrial RNA4-6. We further show that ALKBH7 regulates the processing and structural dynamics of polycistronic mitochondrial RNAs. Depletion of ALKBH7 leads to increased polycistronic mitochondrial RNA processing, reduced steady-state mitochondria-encoded tRNA levels and protein translation, and notably decreased mitochondrial activity. Thus, we identify ALKBH7 as an RNA demethylase that controls nascent mitochondrial RNA processing and mitochondrial activity.


Assuntos
Enzimas AlkB/metabolismo , Mitocôndrias/enzimologia , Proteínas Mitocondriais/metabolismo , Processamento Pós-Transcricional do RNA , RNA Mitocondrial/metabolismo , Adenosina/análogos & derivados , Adenosina/metabolismo , Enzimas AlkB/genética , Citidina/análogos & derivados , Citidina/metabolismo , Guanosina/análogos & derivados , Guanosina/metabolismo , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Biossíntese de Proteínas , RNA Mitocondrial/genética , RNA de Transferência/genética , RNA de Transferência/metabolismo
18.
Blood ; 138(26): 2838-2852, 2021 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-34255814

RESUMO

YTHDC1 has distinct functions as a nuclear N6-methyladenosine (m6A) reader in regulating RNA metabolism. Here we show that YTHDC1 is overexpressed in acute myeloid leukemia (AML) and that it is required for the proliferation and survival of human AML cells. Genetic deletion of Ythdc1 markedly blocks AML development and maintenance as well as self-renewal of leukemia stem cells (LSCs) in vivo in mice. We found that Ythdc1 is also required for normal hematopoiesis and hematopoietic stem and progenitor cell (HSPC) maintenance in vivo. Notably, Ythdc1 haploinsufficiency reduces self-renewal of LSCs but not HSPCs in vivo. YTHDC1 knockdown has a strong inhibitory effect on proliferation of primary AML cells. Mechanistically, YTHDC1 regulates leukemogenesis through MCM4, which is a critical regulator of DNA replication. Our study provides compelling evidence that shows an oncogenic role and a distinct mechanism of YTHDC1 in AML.


Assuntos
Regulação Leucêmica da Expressão Gênica , Leucemia Mieloide Aguda/genética , Proteínas de Manutenção de Minicromossomo/genética , Proteínas do Tecido Nervoso/genética , Fatores de Processamento de RNA/genética , Adenosina/análogos & derivados , Adenosina/genética , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Replicação do DNA , Humanos , Camundongos Transgênicos , Componente 4 do Complexo de Manutenção de Minicromossomo/genética , Regulação para Cima
19.
Bioengineered ; 12(1): 4556-4568, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34323652

RESUMO

There are few studies on the role of iron metabolism genes in predicting the prognosis of lung adenocarcinoma (LUAD). Therefore, our research aims to screen key genes and to establish a prognostic signature that can predict the overall survival rate of lung adenocarcinoma patients. RNA-Seq data and corresponding clinical materials of 594 adenocarcinoma patients from The Cancer Genome Atlas(TCGA) were downloaded. GSE42127 of Gene Expression Omnibus (GEO) database was further verified. The multi-gene prognostic signature was constructed by the Cox regression model of the Least Absolute Shrinkage and Selection Operator (LASSO). We constructed a prediction signature with 12 genes (HAVCR1, SPN, GAPDH, ANGPTL4, PRSS3, KRT8, LDHA, HMMR, SLC2A1, CYP24A1, LOXL2, TIMP1), and patients were split into high and low-risk groups. The survival graph results revealed that the survival prognosis between the high and low-risk groups was significantly different (TCGA: P < 0.001, GEO: P = 0.001). Univariate and multivariate Cox regression analysis confirmed that the risk value is a predictor of patient OS (P < 0.001). The area under the time-dependent ROC curve (AUC) indicated that our signature had a relatively high true positive rate when predicting the 1-year, 3-year, and 5-year OS of the TCGA cohort, which was 0.735, 0.711, and 0.601, respectively. In addition, immune-related pathways were highlighted in the functional enrichment analysis. In conclusion, we developed and verified a 12-gene prognostic signature, which may be help predict the prognosis of lung adenocarcinoma and offer a variety of targeted options for the precise treatment of lung cancer.


Assuntos
Adenocarcinoma de Pulmão , Ferro/metabolismo , Neoplasias Pulmonares , Adenocarcinoma de Pulmão/diagnóstico , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/mortalidade , Biomarcadores Tumorais/genética , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Transcriptoma/genética
20.
Nucleic Acids Res ; 49(10): 5779-5797, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-34048572

RESUMO

Faithful genome integrity maintenance plays an essential role in cell survival. Here, we identify the RNA demethylase ALKBH5 as a key regulator that protects cells from DNA damage and apoptosis during reactive oxygen species (ROS)-induced stress. We find that ROS significantly induces global mRNA N6-methyladenosine (m6A) levels by modulating ALKBH5 post-translational modifications (PTMs), leading to the rapid and efficient induction of thousands of genes involved in a variety of biological processes including DNA damage repair. Mechanistically, ROS promotes ALKBH5 SUMOylation through activating ERK/JNK signaling, leading to inhibition of ALKBH5 m6A demethylase activity by blocking substrate accessibility. Moreover, ERK/JNK/ALKBH5-PTMs/m6A axis is activated by ROS in hematopoietic stem/progenitor cells (HSPCs) in vivo in mice, suggesting a physiological role of this molecular pathway in the maintenance of genome stability in HSPCs. Together, our study uncovers a molecular mechanism involving ALKBH5 PTMs and increased mRNA m6A levels that protect genomic integrity of cells in response to ROS.


Assuntos
Homólogo AlkB 5 da RNA Desmetilase/metabolismo , Dano ao DNA , Reparo do DNA , Espécies Reativas de Oxigênio/metabolismo , Homólogo AlkB 5 da RNA Desmetilase/genética , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , Desmetilação/efeitos dos fármacos , Proteínas de Grupos de Complementação da Anemia de Fanconi/genética , Proteínas de Grupos de Complementação da Anemia de Fanconi/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metilação/efeitos dos fármacos , Camundongos , Fosforilação , Processamento de Proteína Pós-Traducional , RNA Interferente Pequeno , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , RNA-Seq , Sumoilação/efeitos dos fármacos , Espectrometria de Massas em Tandem , Proteína Nuclear Ligada ao X/genética , Proteína Nuclear Ligada ao X/metabolismo
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