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1.
Cell ; 186(15): 3208-3226.e27, 2023 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-37379838

RESUMO

N7-methylguanosine (m7G) modification, routinely occurring at mRNA 5' cap or within tRNAs/rRNAs, also exists internally in messenger RNAs (mRNAs). Although m7G-cap is essential for pre-mRNA processing and protein synthesis, the exact role of mRNA internal m7G modification remains elusive. Here, we report that mRNA internal m7G is selectively recognized by Quaking proteins (QKIs). By transcriptome-wide profiling/mapping of internal m7G methylome and QKI-binding sites, we identified more than 1,000 high-confidence m7G-modified and QKI-bound mRNA targets with a conserved "GANGAN (N = A/C/U/G)" motif. Strikingly, QKI7 interacts (via C terminus) with the stress granule (SG) core protein G3BP1 and shuttles internal m7G-modified transcripts into SGs to regulate mRNA stability and translation under stress conditions. Specifically, QKI7 attenuates the translation efficiency of essential genes in Hippo signaling pathways to sensitize cancer cells to chemotherapy. Collectively, we characterized QKIs as mRNA internal m7G-binding proteins that modulate target mRNA metabolism and cellular drug resistance.


Assuntos
DNA Helicases , RNA Helicases , DNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/genética , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , RNA Helicases/metabolismo , Grânulos de Estresse , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas de Ligação ao GTP/metabolismo , RNA Mensageiro/metabolismo , Grânulos Citoplasmáticos/metabolismo
2.
Cell ; 172(1-2): 90-105.e23, 2018 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-29249359

RESUMO

R-2-hydroxyglutarate (R-2HG), produced at high levels by mutant isocitrate dehydrogenase 1/2 (IDH1/2) enzymes, was reported as an oncometabolite. We show here that R-2HG also exerts a broad anti-leukemic activity in vitro and in vivo by inhibiting leukemia cell proliferation/viability and by promoting cell-cycle arrest and apoptosis. Mechanistically, R-2HG inhibits fat mass and obesity-associated protein (FTO) activity, thereby increasing global N6-methyladenosine (m6A) RNA modification in R-2HG-sensitive leukemia cells, which in turn decreases the stability of MYC/CEBPA transcripts, leading to the suppression of relevant pathways. Ectopically expressed mutant IDH1 and S-2HG recapitulate the effects of R-2HG. High levels of FTO sensitize leukemic cells to R-2HG, whereas hyperactivation of MYC signaling confers resistance that can be reversed by the inhibition of MYC signaling. R-2HG also displays anti-tumor activity in glioma. Collectively, while R-2HG accumulated in IDH1/2 mutant cancers contributes to cancer initiation, our work demonstrates anti-tumor effects of 2HG in inhibiting proliferation/survival of FTO-high cancer cells via targeting FTO/m6A/MYC/CEBPA signaling.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioma/tratamento farmacológico , Glutaratos/farmacologia , Leucemia/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Adenosina/análogos & derivados , Adenosina/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Animais , Antineoplásicos/uso terapêutico , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Linhagem Celular Tumoral , Glutaratos/uso terapêutico , Células HEK293 , Humanos , Células Jurkat , Camundongos , Proteínas Proto-Oncogênicas c-myc/metabolismo , Processamento Pós-Transcricional do RNA
3.
Mol Cell ; 81(5): 922-939.e9, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33434505

RESUMO

R-2-hydroxyglutarate (R-2HG), a metabolite produced by mutant isocitrate dehydrogenases (IDHs), was recently reported to exhibit anti-tumor activity. However, its effect on cancer metabolism remains largely elusive. Here we show that R-2HG effectively attenuates aerobic glycolysis, a hallmark of cancer metabolism, in (R-2HG-sensitive) leukemia cells. Mechanistically, R-2HG abrogates fat-mass- and obesity-associated protein (FTO)/N6-methyladenosine (m6A)/YTH N6-methyladenosine RNA binding protein 2 (YTHDF2)-mediated post-transcriptional upregulation of phosphofructokinase platelet (PFKP) and lactate dehydrogenase B (LDHB) (two critical glycolytic genes) expression and thereby suppresses aerobic glycolysis. Knockdown of FTO, PFKP, or LDHB recapitulates R-2HG-induced glycolytic inhibition in (R-2HG-sensitive) leukemia cells, but not in normal CD34+ hematopoietic stem/progenitor cells, and inhibits leukemogenesis in vivo; conversely, their overexpression reverses R-2HG-induced effects. R-2HG also suppresses glycolysis and downregulates FTO/PFKP/LDHB expression in human primary IDH-wild-type acute myeloid leukemia (AML) cells, demonstrating the clinical relevance. Collectively, our study reveals previously unrecognized effects of R-2HG and RNA modification on aerobic glycolysis in leukemia, highlighting the therapeutic potential of targeting cancer epitranscriptomics and metabolism.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Antineoplásicos/farmacologia , Glutaratos/farmacologia , Glicólise/genética , Lactato Desidrogenases/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Fosfofrutoquinase-1 Tipo C/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/antagonistas & inibidores , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica , Glicólise/efeitos dos fármacos , Células HEK293 , Humanos , Células K562 , Lactato Desidrogenases/antagonistas & inibidores , Lactato Desidrogenases/metabolismo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação Oxidativa/efeitos dos fármacos , Fosfofrutoquinase-1 Tipo C/antagonistas & inibidores , Fosfofrutoquinase-1 Tipo C/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Análise de Sobrevida , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Trends Genet ; 38(5): 454-467, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34991904

RESUMO

N6-methyladenine (6mA) is the most prevalent DNA modification in prokaryotes. However, its presence and significance in eukaryotes remain elusive. Recently, with methodology advances in detection and sequencing of 6mA in eukaryotes, 6mA is back in the spotlight. Although multiple studies have reported that 6mA is an important epigenetic mark in eukaryotes and plays a regulatory role in DNA transcription, transposon activation, stress response, and other bioprocesses, there are some discrepancies in the current literature. We review the recent advances in 6mA research in eukaryotes, especially in mammals. In particular, we describe the abundance/distribution of 6mA, its potential role in regulating gene expression, identified regulators, and pathological roles in human diseases, especially in cancer. The limitations faced by the field and future perspectives in 6mA research are also discussed.


Assuntos
Adenina , Metilação de DNA , Adenina/metabolismo , Animais , DNA/genética , Desoxiadenosinas , Eucariotos/genética , Humanos , Mamíferos/genética
5.
Nature ; 567(7748): 414-419, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30867593

RESUMO

DNA and histone modifications have notable effects on gene expression1. Being the most prevalent internal modification in mRNA, the N6-methyladenosine (m6A) mRNA modification is as an important post-transcriptional mechanism of gene regulation2-4 and has crucial roles in various normal and pathological processes5-12. However, it is unclear how m6A is specifically and dynamically deposited in the transcriptome. Here we report that histone H3 trimethylation at Lys36 (H3K36me3), a marker for transcription elongation, guides m6A deposition globally. We show that m6A modifications are enriched in the vicinity of H3K36me3 peaks, and are reduced globally when cellular H3K36me3 is depleted. Mechanistically, H3K36me3 is recognized and bound directly by METTL14, a crucial component of the m6A methyltransferase complex (MTC), which in turn facilitates the binding of the m6A MTC to adjacent RNA polymerase II, thereby delivering the m6A MTC to actively transcribed nascent RNAs to deposit m6A co-transcriptionally. In mouse embryonic stem cells, phenocopying METTL14 knockdown, H3K36me3 depletion also markedly reduces m6A abundance transcriptome-wide and in pluripotency transcripts, resulting in increased cell stemness. Collectively, our studies reveal the important roles of H3K36me3 and METTL14 in determining specific and dynamic deposition of m6A in mRNA, and uncover another layer of gene expression regulation that involves crosstalk between histone modification and RNA methylation.


Assuntos
Adenosina/análogos & derivados , Histonas/química , Histonas/metabolismo , Lisina/metabolismo , RNA Mensageiro/química , RNA Mensageiro/metabolismo , Transcrição Gênica , Adenosina/metabolismo , Animais , Diferenciação Celular , Linhagem Celular , Células-Tronco Embrionárias/metabolismo , Humanos , Lisina/química , Metilação , Metiltransferases/deficiência , Metiltransferases/genética , Metiltransferases/metabolismo , Camundongos , RNA Polimerase II/metabolismo , Elongação da Transcrição Genética , Transcriptoma/genética
6.
Small ; : e2311812, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38453675

RESUMO

Local high concentration electrolytes (LHCEs) have been proved to be one of the most promising systems to stabilize both high voltage cathodes and Li metal anode for next-generation batteries. However, the solvation structures and interactions among different species in LHCEs are still convoluted, which bottlenecks the further breakthrough on electrolyte development. Here, it is demonstrated that the hydrogen bonding interaction between diluent and solvent is crucial for the construction of LHCEs and corresponding interphase chemistries. The 2,2,2-trifluoroethyl trifluoromethane sulfonate (TFSF) is selected as diluent with the solvent dimethoxy-ethane (DME) to prepare a non-flammable LHCE for high voltage LMBs. This is first find that the hydrogen bonding interaction between TFSF and DME solvent tailors the electrolyte solvation structures by weakening the coordination of DME molecules to Li+ cations and allows more participation of anions in the first solvation shell, leading to the formation of aggregates (AGGs) clusters which are conducive to generating inorganic solid/cathodic electrolyte interphases (SEI/CEIs). The proposed TFSF based LHCE enables the Li||NCM811 (LiNi0.8 Mn0.1 O2 ) batteries to realize >80% capacity retention with a high average Coulombic efficiency of 99.8% for 230 cycles under aggressive conditions (NCM811 cathode: 3.4 mAh cm-2 , cut-off voltage: 4.4 V, and 20 µm Li foil).

7.
Semin Cancer Biol ; 86(Pt 2): 664-677, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35381329

RESUMO

RNA-binding proteins (RBPs) are key players in cellular physiology through posttranscriptional regulation of the expression of target RNA transcripts. By modulating the processing, stability and translation of cancer-related messenger RNA (mRNA) transcripts, a large set of RBPs play essential roles in various types of cancers. Perturbations in RBP activity have been causally associated with cancer development, tumor metabolism, drug resistance, cancer stem cell self-renewal, and tumor immune evasion. Here, we summarize the recent advances in cancer pathological roles and mechanisms of RBPs in regulating mRNA stability and translation with an emphasis on the emerging category of RNA modification-associated RBPs. The functional diversity of RBPs in different types of cancers and the therapeutic potential of targeting dysregulated RBPs for cancer treatment are also discussed.


Assuntos
Neoplasias , Proteínas de Ligação a RNA , Humanos , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Estabilidade de RNA/genética , Neoplasias/genética , Neoplasias/metabolismo , Regulação da Expressão Gênica , RNA
8.
Cancer Treat Res ; 190: 3-24, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38112997

RESUMO

RNA modifications have recently been recognized as essential posttranscriptional regulators of gene expression in eukaryotes. Investigations over the past decade have revealed that RNA chemical modifications have profound effects on tumor initiation, progression, refractory, and recurrence. Tumor cells are notorious for their robust plasticity in response to the stressful microenvironment and undergo metabolic adaptations to sustain rapid cell proliferation, which is termed as metabolic reprogramming. Meanwhile, cancer-associated metabolic reprogramming leads to substantial alterations of intracellular and extracellular metabolites, which further reshapes the tumor microenvironment (TME). Moreover, cancer cells compete with tumor-infiltrating immune cells for the limited nutrients to maintain their proliferation and function in the TME. In this chapter, we review recent interesting findings on the engagement of epitranscriptomic pathways, especially the ones associated with N6-methyladenosine (m6A), in the regulation of cancer metabolism and the surrounding microenvironment. We also discuss the promising therapeutic approaches targeting RNA modifications for anti-tumor therapy.


Assuntos
Neoplasias , Microambiente Tumoral , Humanos , Reprogramação Metabólica , Neoplasias/genética , RNA
9.
Molecules ; 28(9)2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37175126

RESUMO

Bone and cartilage disorders are the leading causes of musculoskeletal disability. There is no absolute cure for all bone and cartilage disorders. The exploration of natural compounds for the potential therapeutic use against bone and cartilage disorders is proving promising. Among these natural chemicals, naringin, a flavanone glycoside, is a potential candidate due to its multifaceted pharmacological activities in bone and cartilage tissues. Emerging studies indicate that naringin may promote osteogenic differentiation, inhibit osteoclast formation, and exhibit protective effects against osteoporosis in vivo and in vitro. Many signaling pathways, such as BMP-2, Wnt/ß-catenin, and VEGF/VEGFR, participate in the biological actions of naringin in mediating the pathological development of osteoporosis. In addition, the anti-inflammatory, anti-oxidative stress, and anti-apoptosis abilities of naringin also demonstrate its beneficial effects against bone and cartilage disorders, including intervertebral disc degeneration, osteoarthritis, rheumatoid arthritis, bone and cartilage tumors, and tibial dyschondroplasia. Naringin exhibits protective effects against bone and cartilage disorders. However, more efforts are still needed due to, at least in part, the uncertainty of drug targets. Further biological and pharmacological evaluations of naringin and its applications in bone tissue engineering, particularly its therapeutic effects against osteoporosis, might result in developing potential drug candidates.


Assuntos
Flavanonas , Osteoporose , Humanos , Osteogênese , Osso e Ossos , Flavanonas/farmacologia , Flavanonas/uso terapêutico , Flavanonas/química , Osteoporose/tratamento farmacológico , Osteoporose/etiologia
10.
Haematologica ; 105(1): 148-160, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30975912

RESUMO

Homoharringtonine, a plant alkaloid, has been reported to suppress protein synthesis and has been approved by the US Food and Drug Administration for the treatment of chronic myeloid leukemia. Here we show that in acute myeloid leukemia (AML), homoharringtonine potently inhibits cell growth/viability and induces cell cycle arrest and apoptosis, significantly inhibits disease progression in vivo, and substantially prolongs survival of mice bearing murine or human AML. Strikingly, homoharringtonine treatment dramatically decreases global DNA 5-hydroxymethylcytosine abundance through targeting the SP1/TET1 axis, and TET1 depletion mimics homoharringtonine's therapeutic effects in AML. Our further 5hmC-seq and RNA-seq analyses, followed by a series of validation and functional studies, suggest that FLT3 is a critical down-stream target of homoharringtonine/SP1/TET1/5hmC signaling, and suppression of FLT3 and its downstream targets (e.g. MYC) contributes to the high sensitivity of FLT3-mutated AML cells to homoharringtonine. Collectively, our studies uncover a previously unappreciated DNA epigenome-related mechanism underlying the potent antileukemic effect of homoharringtonine, which involves suppression of the SP1/TET1/5hmC/FLT3/MYC signaling pathways in AML. Our work also highlights the particular promise of clinical application of homoharringtonine to treat human AML with FLT3 mutations, which accounts for more than 30% of total cases of AML.


Assuntos
Epigenoma , Leucemia Mieloide Aguda , Animais , Linhagem Celular Tumoral , DNA , Proteínas de Ligação a DNA , Mepesuccinato de Omacetaxina , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Camundongos , Proteínas Proto-Oncogênicas/genética , Tirosina Quinase 3 Semelhante a fms
11.
Cancer Sci ; 108(6): 1203-1209, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28370702

RESUMO

A specific subtype of non-small-cell lung cancer (NSCLC) characterized with an EML4-ALK fusion gene, which drives constitutive oncogenic activation of anaplastic lymphoma kinase (ALK), shows a good clinical response to ALK inhibitors. We have reported multiple examples implying the biological significance of methylation on non-histone proteins including oncogenic kinases in human carcinogenesis. Through the process to search substrates for various methyltransferases using an in vitro methyltransferase assay, we found that a lysine methyltransferase, SET and MYND domain-containing 2 (SMYD2), could methylate lysine residues 1451, 1455, and 1610 in ALK protein. Knockdown of SMYD2 as well as treatment with a SMYD2 inhibitor in two NSCLC cell lines with an EML4-ALK gene significantly attenuated the phosphorylation levels of the EML4-ALK protein. Substitutions of each of these three lysine residues to an alanine partially or almost completely diminished in vitro methylation of ALK. In addition, we found that exogenous introduction of EML4-ALK protein with the substitution of lysine 1610 to an alanine in these two cell lines reduced the phosphorylation levels of AKT, one of the downstream oncogenic molecules in the EML4-ALK pathway, and suppressed the growth of the two cell lines. We further showed that the combination of a SMYD2 inhibitor and an ALK inhibitor additively suppressed the growth of these two NSCLC cells, compared with single-agent treatment. Our results shed light on a novel mechanism that modulates the kinase activity of the ALK fused gene product and imply that SMYD2-mediated ALK methylation might be a promising target for development of a novel class of treatment for tumors with the ALK fused gene.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Proliferação de Células/genética , Histona-Lisina N-Metiltransferase/genética , Neoplasias Pulmonares/genética , Proteínas de Fusão Oncogênica/genética , Transdução de Sinais/genética , Quinase do Linfoma Anaplásico , Apoptose/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/patologia , Metilação , Fosforilação/genética , Receptores Proteína Tirosina Quinases/genética
12.
J Sep Sci ; 39(12): 2229-37, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27324351

RESUMO

A specific, simple, and sensitive ultra high performance liquid chromatography with tandem mass spectrometry method utilizing the Triple Quad system has been developed and validated for the simultaneous determination and pharmacokinetic study of four triterpenoid components of Acanthopanax sessiliflorus in rat plasma. The components are 22-α-hydroxychiisanogenin, chiisanogenin, (1R,11α)1,4-epoxy-11-hrdroxy-3,4-secolupane-20(30)-ene-3,28-dioic acid, and 22-α-hydroxychiisanoside. Sample preparation involved a liquid-liquid extraction of the analytes with ethyl acetate. Chromatographic separation was accomplished using an Agilent SB-C18 column (1.8 µm, 2.1 mm × 50 mm) with 2.0 min isocratic elution. The compounds were detected with a triple quadrupole tandem mass spectrometer in multiple reaction monitoring mode and an ESI source in negative mode. The method was linear for all analytes over the investigated range, with all determined correlation coefficients exceeding 0.9906. The limit of quantification of each analyte was lower than 1 ng/mL. The intraday and interday precisions were less than 14.9%, and the accuracy ranged from -10.2 to 11.8%. The mean recoveries of the analytes were higher than 80.0%, and the matrix effects were between 100.4 and 107.1%. These results may contribute to determining the mechanism of action and guiding the clinical application of Acanthopanax sessiliflorus.


Assuntos
Eleutherococcus/química , Extratos Vegetais/sangue , Extratos Vegetais/farmacocinética , Triterpenos/sangue , Triterpenos/farmacocinética , Administração Oral , Animais , Cromatografia Líquida de Alta Pressão , Frutas/química , Masculino , Extratos Vegetais/administração & dosagem , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem , Triterpenos/administração & dosagem
13.
J Sep Sci ; 39(8): 1471-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26924270

RESUMO

This paper describes an improved liquid chromatography method combined with pulsed electrochemical detection for the analysis of etimicin sulfate. In total, 22 impurities could be separated. A TSK-GEL C18 column (250 mm × 4.6 mm i.d., 5 µm) is used, and the mobile phase is composed of 40 mL of acetonitrile and 960 mL of an aqueous solution containing trifluoroacetic acid (15 mL/L), pentafluoropropionic acid (500 µL/L), 50% sodium hydroxide (8 mL/L) and sodium sulfate (1.5 g/L). The pH of the aqueous solution is adjusted to 3.5 with 0.8 M sodium hydroxide. The influence of the different chromatographic parameters on the separation was investigated. A quadruple potential-time waveform was applied to the electrodes of the detection cell. 0.8 M sodium hydroxide was added post column to raise the pH to at least 12 before detection. A central composite experimental design was used to describe the relationship between factors and response values and to establish factorial analysis. Compared to previously published investigations, this improved method shows higher sensitivity, better separation ability and robustness and has been incorporated by the Chinese Pharmacopoeia 2015 for analysis of etimicin sulfate. A number of commercial samples of etimicin sulfate were also analyzed using this method.


Assuntos
Técnicas Eletroquímicas , Gentamicinas/análise , Configuração de Carboidratos , Cromatografia Líquida
14.
Clin Transl Med ; 14(6): e1666, 2024 Jun.
Artigo em Italiano | MEDLINE | ID: mdl-38880983

RESUMO

Dysregulated RNA modifications, stemming from the aberrant expression and/or malfunction of RNA modification regulators operating through various pathways, play pivotal roles in driving the progression of haematological malignancies. Among RNA modifications, N6-methyladenosine (m6A) RNA modification, the most abundant internal mRNA modification, stands out as the most extensively studied modification. This prominence underscores the crucial role of the layer of epitranscriptomic regulation in controlling haematopoietic cell fate and therefore the development of haematological malignancies. Additionally, other RNA modifications (non-m6A RNA modifications) have gained increasing attention for their essential roles in haematological malignancies. Although the roles of the m6A modification machinery in haematopoietic malignancies have been well reviewed thus far, such reviews are lacking for non-m6A RNA modifications. In this review, we mainly focus on the roles and implications of non-m6A RNA modifications, including N4-acetylcytidine, pseudouridylation, 5-methylcytosine, adenosine to inosine editing, 2'-O-methylation, N1-methyladenosine and N7-methylguanosine in haematopoietic malignancies. We summarise the regulatory enzymes and cellular functions of non-m6A RNA modifications, followed by the discussions of the recent studies on the biological roles and underlying mechanisms of non-m6A RNA modifications in haematological malignancies. We also highlight the potential of therapeutically targeting dysregulated non-m6A modifiers in blood cancer.


Assuntos
Neoplasias Hematológicas , Humanos , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/metabolismo , Neoplasias Hematológicas/patologia , Processamento Pós-Transcricional do RNA/genética , RNA/genética , RNA/metabolismo , Adenosina/análogos & derivados , Adenosina/metabolismo , Adenosina/genética
15.
Genes Dis ; 11(1): 382-396, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37588203

RESUMO

As the most common internal modification of mRNA, N6-methyladenosine (m6A) and its regulators modulate gene expression and play critical roles in various biological and pathological processes including tumorigenesis. It was reported previously that m6A methyltransferase (writer), methyltransferase-like 3 (METTL3) adds m6A in primary microRNAs (pri-miRNAs) and facilitates its processing into precursor miRNAs (pre-miRNAs). However, it is unknown whether m6A modification also plays a role in the maturation process of pre-miRNAs and (if so) whether such a function contributes to tumorigenesis. Here, we found that YTHDF2 is aberrantly overexpressed in acute myeloid leukemia (AML) patients, especially in relapsed patients, and plays an oncogenic role in AML. Moreover, YTHDF2 promotes expression of miR-126-3p (also known as miR-126, as it is the main product of precursor miR-126 (pre-miR-126)), a miRNA that was reported as an oncomiRNA in AML, through facilitating the processing of pre-miR-126 into mature miR-126. Mechanistically, YTHDF2 recognizes m6A modification in pre-miR-126 and recruits AGO2, a regulator of pre-miRNA processing, to promote the maturation of pre-miR-126. YTHDF2 positively and negatively correlates with miR-126 and miR-126's downstream target genes, respectively, in AML patients, and forced expression of miR-126 could largely rescue YTHDF2/Ythdf2 depletion-mediated suppression on AML cell growth/proliferation and leukemogenesis, indicating that miR-126 is a functionally important target of YTHDF2 in AML. Overall, our studies not only reveal a previously unappreciated YTHDF2/miR-126 axis in AML and highlight the therapeutic potential of targeting this axis for AML treatment, but also suggest that m6A plays a role in pre-miRNA processing that contributes to tumorigenesis.

16.
J Hematol Oncol ; 17(1): 7, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38302992

RESUMO

BACKGROUND: While liver cancer stem cells (CSCs) play a crucial role in hepatocellular carcinoma (HCC) initiation, progression, recurrence, and treatment resistance, the mechanism underlying liver CSC self-renewal remains elusive. We aim to characterize the role of Methyltransferase 16 (METTL16), a recently identified RNA N6-methyladenosine (m6A) methyltransferase, in HCC development/maintenance, CSC stemness, as well as normal hepatogenesis. METHODS: Liver-specific Mettl16 conditional KO (cKO) mice were generated to assess its role in HCC pathogenesis and normal hepatogenesis. Hydrodynamic tail-vein injection (HDTVi)-induced de novo hepatocarcinogenesis and xenograft models were utilized to determine the role of METTL16 in HCC initiation and progression. A limiting dilution assay was utilized to evaluate CSC frequency. Functionally essential targets were revealed via integrative analysis of multi-omics data, including RNA-seq, RNA immunoprecipitation (RIP)-seq, and ribosome profiling. RESULTS: METTL16 is highly expressed in liver CSCs and its depletion dramatically decreased CSC frequency in vitro and in vivo. Mettl16 KO significantly attenuated HCC initiation and progression, yet only slightly influenced normal hepatogenesis. Mechanistic studies, including high-throughput sequencing, unveiled METTL16 as a key regulator of ribosomal RNA (rRNA) maturation and mRNA translation and identified eukaryotic translation initiation factor 3 subunit a (eIF3a) transcript as a bona-fide target of METTL16 in HCC. In addition, the functionally essential regions of METTL16 were revealed by CRISPR gene tiling scan, which will pave the way for the development of potential inhibitor(s). CONCLUSIONS: Our findings highlight the crucial oncogenic role of METTL16 in promoting HCC pathogenesis and enhancing liver CSC self-renewal through augmenting mRNA translation efficiency.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Células-Tronco Neoplásicas , Animais , Humanos , Camundongos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Autorrenovação Celular/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Metiltransferases/genética , Metiltransferases/metabolismo , Células-Tronco Neoplásicas/patologia , Biossíntese de Proteínas , Ribossomos/metabolismo , RNA
17.
Electrophoresis ; 34(3): 463-70, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23161341

RESUMO

A selective and low-cost CD-MEKC method under acidic conditions was developed for investigating the N-oxygenation of tamoxifen (TAM) by flavin-containing monooxygenases (FMOs). The inhibitory effects of methimazole (MMI), nicotine and 5,6-dimethylxanthenone-4-acetic acid (DMXAA) on the given FMO reaction were also evaluated; 100 mM phosphate buffer (pH 8.6) was used for performing the enzymatic reaction and the separation of TAM and its metabolite tamoxifen N-oxide (TNO) was obtained with a BGE consisting of 100 mM phosphoric acid solution adjusted to pH 2.5 with triethanolamine containing 50 mM sodium taurodeoxycholate, 20 mM carboxymethyl ß-CD and 20% ACN. The proposed method was applied for the kinetics study of FMO1 using TAM as a substrate probe. A Michaelis-Menten constant (K(m)) of 164.1 µM was estimated from the corrected peak area of the product, TNO. The calculated value of the maximum reaction velocity (V(max)) was 3.61 µmol/min/µmol FMO1; 50% inhibitory concentration and inhibition constant (K(i)) of MMI, the most common alternate substrate FMO inhibitor, were evaluated and the inhibitory effects of two other important FMO substrates, nicotine and DMXAA, a novel anti-tumour agent, were investigated.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , Metimazol/farmacologia , Nicotina/farmacologia , Oxigenases/antagonistas & inibidores , Oxigenases/metabolismo , Tamoxifeno/análise , Xantonas/farmacologia , Ciclodextrinas/farmacologia , Humanos , Reprodutibilidade dos Testes , Tamoxifeno/metabolismo
18.
Ann Emerg Med ; 62(4): 380-387.e1, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23711878

RESUMO

STUDY OBJECTIVE: The aim of this study is to determine the content of 5 important emergency medical services (EMS) drugs after being stored at the recommended refrigerated temperature, room temperature, or in an emergency physician transport vehicle operating under real-world working conditions. METHODS: Adrenaline hydrochloride, cisatracurium besylate, lorazepam, methylergonovine maleate, and succinylcholine chloride were stored for 1 year under the 3 conditions. For each storage condition, samples of the drugs were taken after 1, 2, 3, and 4 weeks and after 2, 4, 6, 8, 10, and 12 months. For adrenaline hydrochloride, however, the samples were taken after 1, 2, 4, 6, 8, 10, and 12 months. The samples were analyzed with a validated high-performance liquid chromatography assay. A drug was considered stable if its content was above 90%. RESULTS: Adrenaline hydrochloride and methylergonovine maleate remained stable for 1 year at room temperature and in the emergency physician transport vehicle. At room temperature and in the emergency physician transport vehicle, lorazepam became unstable within 4 weeks. Succinylcholine chloride was stable for 2 months at room temperature and for 1 month in the emergency physician transport vehicle. Cisatracurium besylate became unstable within 4 months at room temperature. However, it remained stable for 4 months in the emergency physician transport vehicle. CONCLUSION: When stored at room temperature or in the emergency physician transport vehicle, lorazepam became unstable within weeks, whereas succinylcholine chloride and cisatracurium besylate became unstable within months. Adrenaline hydrochloride and methylergonovine maleate remained stable for several months, even under room temperature and emergency physician transport vehicle conditions. Thus, real-world EMS working conditions pose challenges for maintaining optimal efficacy of these important EMS drugs.


Assuntos
Estabilidade de Medicamentos , Temperatura , Ambulâncias , Atracúrio/análogos & derivados , Atracúrio/análise , Atracúrio/normas , Cromatografia Líquida de Alta Pressão , Armazenamento de Medicamentos/métodos , Armazenamento de Medicamentos/normas , Serviços Médicos de Emergência , Epinefrina/análise , Epinefrina/normas , Metilergonovina/análise , Metilergonovina/normas , Succinilcolina/análise , Succinilcolina/normas , Fatores de Tempo
19.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 38(1): 101-8, 2013 Jan.
Artigo em Zh | MEDLINE | ID: mdl-23406852

RESUMO

Hyperlipidemia is one of the most important risk factors for atherosclerosis, coronary heart disease and other cardiovascular diseases. It is the main effect of lipid-lowering drugs to reduce the plasma low-density lipoprotein or to enhance high-density lipoprotein. Niemann-Pick C1 like 1 protein (NPC1L1), acyl-coenzyme A: cholesterol acyltransferases (ACAT), ATP binding cassette transporter G member 5 and member 8 (ABCG5/G8), microsomal triglyceride transfer protein (MTP), monoacylglycerol acyltransferase, diacylglycerol acyltransferases (MAGT), peroxisome proliferator-activated receptor (PPAR), farnesoid X receptor (FXR), and proprotein convertase subtilisin/kexin type 9 (PCSK9) play key roles in the metabolism of lipid, which are regarded as the targets of anti-hyperlipidemia drugs and evidence for clinic choice of lipid-lowering drugs. These proteins are considered as breakthrough points for new lipid-lowering drug development.


Assuntos
Hiperlipidemias/tratamento farmacológico , Hipolipemiantes/farmacologia , Hipolipemiantes/uso terapêutico , Metabolismo dos Lipídeos/efeitos dos fármacos , Sítios de Ligação , Humanos , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos
20.
Cell Chem Biol ; 30(7): 703-705, 2023 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-37478827

RESUMO

Immunosuppression contributes to tumor-radiotherapy failure, but the mechanism remains elusive. Wang et al.1 reported that ionizing radiation (IR) induces YTHDF2 expression in myeloid-derived suppressor cells (MDSCs) via an IR-YTHDF2-NF-κB circuit, which contributes to MDSC expansion/migration and treatment failure. Genetic depletion or pharmacological inhibition of YTHDF2 overcomes immunosuppression and improves radiotherapy.


Assuntos
Células Supressoras Mieloides , Neoplasias , Humanos , Células Supressoras Mieloides/metabolismo , Neoplasias/radioterapia , Neoplasias/metabolismo , NF-kappa B/metabolismo , Proteínas de Ligação a RNA/metabolismo
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