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1.
Int J Mol Sci ; 25(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38892173

RESUMO

A-to-I RNA editing, catalyzed by the ADAR protein family, significantly contributes to the diversity and adaptability of mammalian RNA signatures, aligning with developmental and physiological needs. Yet, the functions of many editing sites are still to be defined. The Unc80 gene stands out in this context due to its brain-specific expression and the evolutionary conservation of its codon-altering editing event. The precise biological functions of Unc80 and its editing, however, are still largely undefined. In this study, we first demonstrated that Unc80 editing occurs in an ADAR2-dependent manner and is exclusive to the brain. By employing the CRISPR/Cas9 system to generate Unc80 knock-in mouse models that replicate the natural editing variations, our findings revealed that mice with the "gain-of-editing" variant (Unc80G/G) exhibit heightened basal neuronal activity in critical olfactory regions, compared to the "loss-of-editing" (Unc80S/S) counterparts. Moreover, an increase in glutamate levels was observed in the olfactory bulbs of Unc80G/G mice, indicating altered neurotransmitter dynamics. Behavioral analysis of odor detection revealed distinctive responses to novel odors-both Unc80 deficient (Unc80+/-) and Unc80S/S mice demonstrated prolonged exploration times and heightened dishabituation responses. Further elucidating the olfactory connection of Unc80 editing, transcriptomic analysis of the olfactory bulb identified significant alterations in gene expression that corroborate the behavioral and physiological findings. Collectively, our research advances the understanding of Unc80's neurophysiological functions and the impact of its editing on the olfactory sensory system, shedding light on the intricate molecular underpinnings of olfactory perception and neuronal activity.


Assuntos
Adenosina Desaminase , Percepção Olfatória , Edição de RNA , Animais , Camundongos , Percepção Olfatória/fisiologia , Adenosina Desaminase/metabolismo , Adenosina Desaminase/genética , Bulbo Olfatório/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Neurônios/metabolismo , Sistemas CRISPR-Cas , Masculino , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo
2.
Commun Biol ; 7(1): 594, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760406

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is a chronic disease caused by hepatic steatosis. Adenosine deaminases acting on RNA (ADARs) catalyze adenosine to inosine RNA editing. However, the functional role of ADAR2 in NAFLD is unclear. ADAR2+/+/GluR-BR/R mice (wild type, WT) and ADAR2-/-/GluR-BR/R mice (ADAR2 KO) mice are fed with standard chow or high-fat diet (HFD) for 12 weeks. ADAR2 KO mice exhibit protection against HFD-induced glucose intolerance, insulin resistance, and dyslipidemia. Moreover, ADAR2 KO mice display reduced liver lipid droplets in concert with decreased hepatic TG content, improved hepatic insulin signaling, better pyruvate tolerance, and increased glycogen synthesis. Mechanistically, ADAR2 KO effectively mitigates excessive lipid production via AMPK/Sirt1 pathway. ADAR2 KO inhibits hepatic gluconeogenesis via the AMPK/CREB pathway and promotes glycogen synthesis by activating the AMPK/GSK3ß pathway. These results provide evidence that ADAR2 KO protects against NAFLD progression through the activation of AMPK signaling pathways.


Assuntos
Adenosina Desaminase , Dieta Hiperlipídica , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica , Proteínas de Ligação a RNA , Transdução de Sinais , Animais , Adenosina Desaminase/metabolismo , Adenosina Desaminase/genética , Adenosina Desaminase/deficiência , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/etiologia , Dieta Hiperlipídica/efeitos adversos , Masculino , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Resistência à Insulina , Camundongos Obesos , Obesidade/metabolismo , Obesidade/genética , Camundongos Endogâmicos C57BL , Fígado/metabolismo
3.
Cell Oncol (Dordr) ; 45(4): 621-638, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35849310

RESUMO

PURPOSE: Molecular composition of circulating small extracellular vesicles (EVs) does not merely reflect the cells of origin, but also is enriched in specific biomolecules directly associated with the cellular transformation. However, while most of the currently identified EV-miRs are only geared towards one-dimensional disease detection, their application for long-term tracking and treatment response monitoring has been largely elusive. METHODS: We established and optimized a rapid, sensitive and robust liquid biopsy sampling method, and further used small RNA sequencing to comprehensively catalogue EV-miRomes in association with the progression and outcome of metastatic colorectal cancer (mCRC). RESULTS: By cross-comparison of EV-miRomes (n = 290) from multi-stage and longitudinal cohorts, we uncovered a 15-EV-miR signature with dual detection and long-term monitoring of tumor size progression for mCRC. From this panel, EV-miR-320c was uncovered as a strong clinical marker - aside from its diagnostic power and a therapeutic monitoring performance superior to carcinoembryonic antigen (CEA), its high expression has also been linked to lower overall survival and a greater likelihood of disease recurrence. Further, integrative analyses of tissue transcriptomic and liquid biopsy implicated this 15-EV-miR signature in programming the mesenchymal-epithelial transition (MET) for distant localization of the metastasized cells and also in creating a tumor-favoring metastatic niche. CONCLUSION: Our clinically-oriented delineation of the mCRC-associated circulating EV-miRomes systematically revealed the functional significance of these liquid biopsy markers and further strengthen their translational potential in mCRC therapeutic monitoring.


Assuntos
Neoplasias do Colo , Vesículas Extracelulares , MicroRNAs , Neoplasias do Colo/metabolismo , Vesículas Extracelulares/genética , Humanos , Biópsia Líquida , MicroRNAs/genética , MicroRNAs/metabolismo , Análise de Sequência de RNA
4.
Cell Death Dis ; 13(7): 629, 2022 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-35858923

RESUMO

Recent findings have implicated long noncoding RNAs (lncRNAs) as pivotal gene regulators for diverse biological processes, despite their lack of protein-coding capabilities. Accumulating evidence suggests the significance of lncRNAs in mediating cell signaling pathways, especially those associated with tumorigenesis. Consequently, lncRNAs have emerged as novel functional regulators and indicators of cancer development and malignancy. Recent transcriptomic profiling has recognized a tumor-biased expressed lncRNA, the HOXA10-AS transcript, whose expression is associated with patient survival. Functional cell-based assays show that the HOXA10-AS transcript is essential in the regulation of oral cancer growth and metastasis. LncRNA expression is also associated with drug sensitivity. In this study, we identify that HOXA10-AS serves as a modular scaffold for TP63 mRNA processing and that such involvement regulates cancer growth. These findings provide a functional interpretation of lncRNA-mediated molecular regulation, highlighting the significance of the lncRNA transcriptome in cancer biology.


Assuntos
Neoplasias Bucais , RNA Longo não Codificante , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/genética , Proteínas Homeobox A10 , Humanos , Neoplasias Bucais/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Transcriptoma
6.
FASEB J ; 35(10): e21929, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34553421

RESUMO

Recent studies emphasize the importance of 5-HT2C receptor (5-HT2C R) signaling in the regulation of energy homeostasis. The 5-HT2C R is the only G-protein-coupled receptor known to undergo post-transcriptional adenosine to inosine (A-to-I) editing by adenosine deaminase acting on RNA (ADAR). 5-HT2C R has emerged as an important role in the modulation of pancreatic ß cell functions. This study investigated mechanisms behind the effects of palmitic acid (PA) on insulin secretion in different overexpressed 5-HT2C R edited isoforms in pancreatic MIN6 ß cells. Results showed that the expressions of 5HT2C R and ADAR2 were upregulated in the pancreatic islets of mice fed with high-fat diet (HFD) compared to control mice. PA treatment significantly induced the expressions of 5-HT2C R and ADAR2 in pancreatic MIN6 ß cells. PA treatment significantly induced the editing of 5-HT2C R in pancreatic MIN6 ß cells. There was no significant difference in cell viability between naïve cells and three overexpressed 5-HT2C R edited isoforms in pancreatic MIN6 ß cells. Overexpressed 5-HT2C R edited isoforms showed reduced glucose-stimulated insulin secretion (GSIS) compared with green fluorescent protein (GFP) expressed cells. Moreover, 5-HT2C R edited isoforms displayed reduced endoplasmic reticulum (ER) calcium release and store-operated calcium entry (SOCE) activation, probably through inhibition of stromal interaction molecule 1 trafficking under PA treatment. Altogether, our results show that PA-mediated editing of 5-HT2C R modulates GSIS through alteration of ER calcium release and SOCE activation in pancreatic MIN6 ß cells.


Assuntos
Sinalização do Cálcio , Cálcio/metabolismo , Secreção de Insulina/genética , Células Secretoras de Insulina/metabolismo , Edição de RNA , Receptor 5-HT2C de Serotonina/genética , Adenosina Desaminase/genética , Animais , Linhagem Celular , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Dieta Hiperlipídica , Retículo Endoplasmático/metabolismo , Glucose/metabolismo , Resistência à Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Masculino , Camundongos , Modelos Animais , Ácido Palmítico/farmacologia , Isoformas de Proteínas/genética , Proteínas de Ligação a RNA/genética , Transdução de Sinais , Molécula 1 de Interação Estromal/metabolismo , Regulação para Cima/efeitos dos fármacos
7.
Front Immunol ; 12: 743448, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35095836

RESUMO

Colorectal cancer (CRC) is a major cause of cancer mortality and morbidity. Despite advances in chemotherapy and targeted therapy, unsustainable clinical benefit was noted due to recurrence and therapy resistance. The immune status of the cancer patient may affect the effectiveness of disease treatments. The dynamic change in the T-cell receptor (TCR) repertoire might be a clinical parameter for monitoring treatment responses. In this study, we aimed to determine the characteristics and clinical significance of the TCR repertoire in patients with unresectable metastatic colorectal cancer (mCRC). Herein, we comprehensively profile 103 peripheral blood samples from 20 healthy controls and 16 CRC patients with a follow-up of 98 to 452 days to identify hypervariable rearrangements of the TCRα and TCRß repertoires using high-throughput sequencing. We found that TCRα repertoires, TCRß repertoires, and CDR3 clonotypes were altered in mCRC patients compared with healthy controls. The diversity of TCR repertoires and CDR3 clonotypes decreased in most mCRC patients after therapy. Furthermore, compared with baseline TCR diversity, patients whose TCR diversity dropped considerably during therapy had better treatment responses, including lower CEA and CA19-9 levels and smaller tumor sizes. TCR baseline diversity was also significantly associated with partial response (PR) status (odds ratio: 5.29, p = 0.04). In conclusion, the present study demonstrated the association between dynamic changes in TCR diversity during chemotherapy and clinical outcomes as well as the potential utility of the TCR repertoire in predicting the prognosis of cancer treatment.


Assuntos
Neoplasias Colorretais/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Adulto , Idoso , Antígenos Glicosídicos Associados a Tumores/genética , Estudos de Casos e Controles , Neoplasias Colorretais/patologia , Feminino , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
8.
Cells ; 9(8)2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32785098

RESUMO

Deep sequencing technologies have revealed the once uncharted non-coding transcriptome of circular RNAs (circRNAs). Despite the lack of protein-coding potential, these unorthodox yet highly stable RNA species are known to act as critical gene regulatory hubs, particularly in malignancies. However, their mechanistic implications in tumor outcome and translational potential have not been fully resolved. Using RNA-seq data, we profiled the circRNAomes of tumor specimens derived from oral squamous cell carcinoma (OSCC), which is a prevalently diagnosed cancer with a persistently low survival rate. We further catalogued dysregulated circRNAs in connection with tumorigenic progression. Using comprehensive bioinformatics analyses focused on co-expression maps and miRNA-interaction networks, we delineated the regulatory networks that are centered on circRNAs. Interestingly, we identified a tumor-associated, pro-tumorigenic circRNA, named circFLNB, that was implicated in maintaining several tumor-associated phenotypes in vitro and in vivo. Correspondingly, transcriptome profiling of circFLNB-knockdown cells showed alterations in tumor-related genes. Integrated in silico analyses further deciphered the circFLNB-targeted gene network. Together, our current study demarcates the OSCC-associated circRNAome, and unveils a novel circRNA circuit with functional implication in OSCC progression. These systems-based findings broaden mechanistic understanding of oral malignancies and raise new prospects for translational medicine.


Assuntos
Carcinoma de Células Escamosas/genética , Filaminas/genética , Neoplasias Bucais/genética , RNA Circular/genética , Transcriptoma , Animais , Biologia Computacional/métodos , Técnicas de Silenciamento de Genes , Redes Reguladoras de Genes , Células HeLa , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , MicroRNAs/genética , Interferência de RNA , RNA Mensageiro/genética , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Sci Rep ; 10(1): 4526, 2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32161294

RESUMO

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers worldwide. While both genetic and environmental factors have been linked to the incidence and mortality associated with CRC, an ethnic aspect of its etiology has also emerged. Since previous large-scale cancer genomics studies are mostly based on samples of European ancestry, the patterns of clinical events and associated mechanisms in other minority ethnic patients suffering from CRC are largely unexplored. We collected 104 paired and adjacent normal tissue and CRC tumor samples from Taiwanese patients and employed an integrated approach - paired expression profiles of mRNAs and microRNAs (miRNAs) combined with transcriptome-wide network analyses - to catalog the molecular signatures of this regional cohort. On the basis of this dataset, which is the largest ever reported for this type of systems analysis, we made the following key discoveries: (1) In comparison to the The Cancer Genome Atlas (TCGA) data, the Taiwanese CRC tumors show similar perturbations in expressed genes but a distinct enrichment in metastasis-associated pathways. (2) Recurrent as well as novel CRC-associated gene fusions were identified based on the sequencing data. (3) Cancer subtype classification using existing tools reveals a comparable distribution of tumor subtypes between Taiwanese cohort and TCGA datasets; however, this similarity in molecular attributes did not translate into the predicted subtype-related clinical outcomes (i.e., death event). (4) To further elucidate the molecular basis of CRC prognosis, we developed a new stratification strategy based on miRNA-mRNA-associated subtyping (MMAS) and consequently showed that repressed WNT signaling activity is associated with poor prognosis in Taiwanese CRC. In summary, our findings of distinct, hitherto unreported biosignatures underscore the heterogeneity of CRC tumorigenesis, support our hypothesis of an ethnic basis of disease, and provide prospects for translational medicine.


Assuntos
Transformação Celular Neoplásica/genética , Neoplasias Colorretais/etiologia , Perfilação da Expressão Gênica , Transcriptoma , Biomarcadores Tumorais , Neoplasias Colorretais/epidemiologia , Biologia Computacional/métodos , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , MicroRNAs/genética , Gradação de Tumores , Metástase Neoplásica , Estadiamento de Neoplasias , Prognóstico , Interferência de RNA , RNA Mensageiro/genética , Taiwan/epidemiologia
10.
FASEB J ; 34(1): 1107-1121, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31914708

RESUMO

The nucleolus is best known for its cellular role in regulating ribosome production and growth. More recently, an unanticipated role for the nucleolus in innate immunity has recently emerged whereby downregulation of fibrillarin and nucleolar contraction confers pathogen resistance across taxa. The mechanism of this downregulation, however, remains obscure. Here we report that rather than fibrillarin itself being the proximal factor in this pathway, the key player is a fibrillarin-stabilizing deubiquitinylase USP-33. This was discovered by a candidate-gene search of Caenorhabditis elegans in which CED-3 caspase was revealed to execute targeted cleavage of USP-33, thus destabilizing fibrillarin. We also showed that cep-1 and ced-3 mutant worms altered nucleolar size and decreased antimicrobial peptide gene, spp-1, expression rendering susceptibility to bacterial infection. These phenotypes were reversed by usp-33 knockdown, thus linking the CEP-1-CED-3-USP-33 pathway with nucleolar control and resistance to bacterial infection in worms. Parallel experiments with the human analogs of caspases and USP36 revealed similar roles in coordinating these two processes. In summary, our work outlined a conserved cascade that connects cell death signaling to nucleolar control and innate immune response.


Assuntos
Infecções Bacterianas/metabolismo , Caenorhabditis elegans/microbiologia , Nucléolo Celular/metabolismo , Enzimas Desubiquitinantes/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina/metabolismo , Animais , Apoptose , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Células HeLa , Humanos , Microscopia de Fluorescência , Infecções por Pseudomonas , Interferência de RNA , Infecções Estafilocócicas , Estaurosporina/farmacologia , Ubiquitina Tiolesterase/metabolismo
11.
EMBO Rep ; 20(5)2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30948460

RESUMO

Adenosine deaminase acting on RNA (ADAR)-catalyzed adenosine-to-inosine RNA editing is potentially dysregulated in neoplastic progression. However, how this transcriptome recoding process is functionally correlated with tumorigenesis remains largely elusive. Our analyses of RNA editome datasets identify hypoxia-related genes as A-to-I editing targets. In particular, two negative regulators of HIF-1A-the natural antisense transcript HIF1A-AS2 and the ubiquitin ligase scaffold LIMD1-are directly but differentially modulated by ADAR1. We show that HIF1A-AS2 antagonizes the expression of HIF-1A in the immediate-early phase of hypoxic challenge, likely through a convergent transcription competition in cis ADAR1 in turn suppresses transcriptional progression of the antisense gene. In contrast, ADAR1 affects LIMD1 expression post-transcriptionally, by interfering with the cytoplasmic translocation of LIMD1 mRNA and thus protein translation. This multi-tier regulation coordinated by ADAR1 promotes robust and timely accumulation of HIF-1α upon oxygen depletion and reinforces target gene induction and downstream angiogenesis. Our results pinpoint ADAR1-HIF-1α axis as a hitherto unrecognized key regulator in hypoxia.


Assuntos
Adenosina Desaminase/genética , Hipóxia Celular/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Proteínas de Ligação a RNA/genética , Transdução de Sinais/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Citoplasma/genética , Humanos , Proteínas com Domínio LIM/genética , Células MCF-7 , Edição de RNA/genética , RNA Mensageiro/genética , Transcrição Gênica/genética
12.
J Biol Chem ; 293(26): 10158-10171, 2018 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-29769310

RESUMO

Processing of the eukaryotic transcriptome is a dynamic regulatory mechanism that confers genetic diversity, and splicing and adenosine to inosine (A-to-I) RNA editing are well-characterized examples of such processing. Growing evidence reveals the cross-talk between the splicing and RNA editing, but there is a paucity of substantial evidence for its mechanistic details and contribution in a physiological context. Here, our findings demonstrate that tumor-associated differential RNA editing, in conjunction with splicing machinery, regulates the expression of variants of HNRPLL, a gene encoding splicing factor. We discovered an HNRPLL transcript variant containing an additional exon 12A (E12A), which is a substrate of ADAR1 and ADAR2. Adenosine deaminases acting on RNA (ADAR) direct deaminase-dependent expression of the E12A transcript, and ADAR-mediated regulation of E12A is largely splicing-based, and does not affect the stability or nucleocytoplasmic distribution of the transcript. Furthermore, ADAR-mediated modification of exon 12A generates an enhancer for the oncogenic splicing factor SRSF1 and consequently promotes the frequency of alternative splicing. Gene expression profiling by RNA-seq revealed that E12A acts distinctly from HNRPLL and regulates a set of growth-related genes, such as cyclin CCND1 and growth factor receptor TGFBR1 Accordingly, silencing E12A expression leads to impaired clonogenic ability and enhanced sensitivity to doxorubicin, thus highlighting the significance of this alternative isoform in tumor cell survival. In summary, we present the interplay of RNA editing and splicing as a regulatory mechanism of gene expression and also its physiological relevance. These findings extend our understanding of transcriptional dynamics and provide a mechanistic explanation to the link of RNA editors to tumorigenesis.


Assuntos
Processamento Alternativo , Ribonucleoproteínas Nucleares Heterogêneas/genética , Íntrons/genética , Edição de RNA , Antígenos de Superfície/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Ciclina D1/genética , Regulação Neoplásica da Expressão Gênica/genética , Células HEK293 , Células HeLa , Humanos , RNA Mensageiro/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Transcrição Gênica/genética
13.
Theranostics ; 8(2): 486-504, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29290822

RESUMO

During neoplastic development, a multitude of changes in genome-encoded information are progressively selected to confer growth and survival advantages to tumor cells. microRNAs-mRNAs regulatory networks, given their role as a critical layer of robust gene expression control, are frequently altered in neoplasm. However, whether and how these gene perturbations impact metabolic homeostasis remains largely unresolved. Methods: Through targeted miRNA expression screening, we uncovered an oral squamous cell carcinoma (OSCC)-associated miRNAome, among which miR-31-5p was identified based on extent of up-regulation, functional impact on OSCC cell migration and invasion, and direct regulation of the rate-limiting enzyme in peroxisomal ß-oxidation, ACOX1. Results: We further found that both miR-31-5p and ACOX1 underpin, in an antagonistic manner, the overall cellular lipidome profiles as well as the migratory and invasive abilities of OSCC cells. Interestingly, the extracellular levels of prostaglandin E2 (PGE2), a key substrate of ACOX1, were controlled by the miR-31-5p-ACOX1 axis, and were shown to positively influence the extent of cell motility in correlation with metastatic status. The promigratory effect of this metabolite was mediated by an elevation in EP1-ERK-MMP9 signaling. Of note, functional significance of this regulatory pathway was further corroborated by its clinicopathologically-correlated expression in OSCC patient specimens. Conclusions: Collectively, our findings outlined a model whereby misregulated miR-31-5p-ACOX1 axis in tumor alters lipid metabolomes, consequently eliciting an intracellular signaling change to enhance cell motility. Our clinical analysis also unveiled PGE2 as a viable salivary biomarker for prognosticating oral cancer progression, further underscoring the importance of lipid metabolism in tumorigenesis.


Assuntos
Acil-CoA Oxidase/genética , Carcinogênese/genética , Carcinoma de Células Escamosas/genética , Dinoprostona/metabolismo , MicroRNAs/genética , Neoplasias Bucais/genética , Biomarcadores Tumorais/genética , Carcinogênese/patologia , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Neoplasias Bucais/patologia , Transdução de Sinais/genética , Regulação para Cima/genética
14.
Nat Commun ; 8(1): 465, 2017 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-28878238

RESUMO

Oral squamous cell carcinoma is a prominent cancer worldwide, particularly in Taiwan. By integrating omics analyses in 50 matched samples, we uncover in Taiwanese patients a predominant mutation signature associated with cytidine deaminase APOBEC, which correlates with the upregulation of APOBEC3A expression in the APOBEC3 gene cluster at 22q13. APOBEC3A expression is significantly higher in tumors carrying APOBEC3B-deletion allele(s). High-level APOBEC3A expression is associated with better overall survival, especially among patients carrying APOBEC3B-deletion alleles, as examined in a second cohort (n = 188; p = 0.004). The frequency of APOBEC3B-deletion alleles is ~50% in 143 genotyped oral squamous cell carcinoma -Taiwan samples (27A3B -/-:89A3B +/-:27A3B +/+), compared to the 5.8% found in 314 OSCC-TCGA samples. We thus report a frequent APOBEC mutational profile, which relates to a APOBEC3B-deletion germline polymorphism in Taiwanese oral squamous cell carcinoma that impacts expression of APOBEC3A, and is shown to be of clinical prognostic relevance. Our finding might be recapitulated by genomic studies in other cancer types.Oral squamous cell carcinoma is a prevalent malignancy in Taiwan. Here, the authors show that OSCC in Taiwanese show a frequent deletion polymorphism in the cytidine deaminases gene cluster APOBEC3 resulting in increased expression of A3A, which is shown to be of clinical prognostic relevance.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Citidina Desaminase/genética , Neoplasias Bucais/genética , Polimorfismo Genético , Proteínas/genética , Adulto , Povo Asiático , Carcinoma de Células Escamosas/mortalidade , Estudos de Coortes , Citidina Desaminase/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Mutação em Linhagem Germinativa , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/mortalidade , Proteínas/metabolismo , Deleção de Sequência , Taiwan
15.
Aging Cell ; 16(4): 797-813, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28514051

RESUMO

Cellular senescence is a permanent proliferative arrest triggered by genome instability or aberrant growth stresses, acting as a protective or even tumor-suppressive mechanism. While several key aspects of gene regulation have been known to program this cessation of cell growth, the involvement of the epigenetic regulation has just emerged but remains largely unresolved. Using a systems approach that is based on targeted gene profiling, we uncovered known and novel chromatin modifiers with putative link to the senescent state of the cells. Among these, we identified SETD8 as a new target as well as a key regulator of the cellular senescence signaling. Knockdown of SETD8 triggered senescence induction in proliferative culture, irrespectively of the p53 status of the cells; ectopic expression of this epigenetic writer alleviated the extent doxorubicin-induced cellular senescence. This repressive effect of SETD8 in senescence was mediated by directly maintaining the silencing mark H4K20me1 at the locus of the senescence switch gene p21. Further in support of this regulatory link, depletion of p21 reversed this SETD8-mediated cellular senescence. Additionally, we found that PPARγ acts upstream and regulates SETD8 expression in proliferating cells. Downregulation of PPARγ coincided with the senescence induction, while its activation inhibited the progression of this process. Viewed together, our findings delineated a new epigenetic pathway through which the PPARγ-SETD8 axis directly silences p21 expression and consequently impinges on its senescence-inducing function. This implies that SETD8 may be part of a cell proliferation checkpoint mechanism and has important implications in antitumor therapeutics.


Assuntos
Senescência Celular/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Epigênese Genética , Fibroblastos/metabolismo , Histona-Lisina N-Metiltransferase/genética , PPAR gama/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Pontos de Checagem do Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Senescência Celular/efeitos dos fármacos , Senescência Celular/efeitos da radiação , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Dano ao DNA , Doxorrubicina/farmacologia , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/efeitos da radiação , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/efeitos da radiação , PPAR gama/metabolismo , Cultura Primária de Células , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Raios Ultravioleta
16.
Cell Death Dis ; 8(5): e2833, 2017 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-28542129

RESUMO

Adenosine-to-inosine RNA editing constitutes a crucial component of the cellular transcriptome and critically underpins organism survival and development. While recent high-throughput approaches have provided comprehensive documentation of the RNA editome, its functional output remains mostly unresolved, particularly for events in the non-coding regions. Gene ontology analysis of the known RNA editing targets unveiled a preponderance of genes related to apoptosis regulation, among which proto-oncogenes XIAP and MDM2 encode two the most abundantly edited transcripts. To further decode this potential functional connection, here we showed that the main RNA editor ADAR1 directly targets this 3' UTR editing of XIAP and MDM2, and further exerts a negative regulation on the expression of their protein products. This post-transcriptional silencing role was mediated via the inverted Alu elements in the 3' UTR but independent of alteration in transcript stability or miRNA targeting. Rather, we discovered that ADAR1 competes transcript occupancy with the RNA shuttling factor STAU1 to facilitate nuclear retention of the XIAP and MDM2 mRNAs. As a consequence, ADAR1 may acquire functionality in part by conferring spatial distribution and translation efficiency of the target transcripts. Finally, abrogation of ADAR1 expression or catalytic activity elicited a XIAP-dependent suppression of apoptotic response, whereas ectopic expression reversed this protective effect on cell death. Together, our results extended the known functions of ADAR1 and RNA editing to the critical fine-tuning of the intracellular apoptotic signaling and also provided mechanistic explanation for ADAR1's roles in development and tumorigenesis.


Assuntos
Regiões 3' não Traduzidas/genética , Adenosina Desaminase/metabolismo , Apoptose/genética , Edição de RNA/genética , Proteínas de Ligação a RNA/metabolismo , Adenosina Desaminase/genética , Elementos Alu/genética , Sequência de Bases , Citoproteção/genética , Proteínas do Citoesqueleto/metabolismo , Células HEK293 , Células Hep G2 , Humanos , Proteínas Proto-Oncogênicas c-mdm2/genética , Transporte de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Transcrição Gênica , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética
17.
Oncotarget ; 7(16): 22448-59, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-26968954

RESUMO

Triiodothyronine (T3) and its receptor (TR) modulate several physiological processes, including cell development, proliferation, differentiation and metabolism. The regulatory mechanism of T3/TR involves binding to the thyroid hormone response element (TRE) within the target gene promoter. However, the number of target genes directly regulated by TRα1 and the specific pathways of TR-regulated target genes remain largely unknown. Here, we expressed TRα1 in a HepG2 cell line and used chromatin immunoprecipitation coupled with microarray to determine the genes that are directly regulated by TRα1 and also involved in cell metabolism and proliferation. Our analysis identified E74-like factor 2 (ELF2), a transcription factor associated with tumor growth, as a direct target downregulated by T3/TR. Overexpression of ELF2 enhanced tumor cell proliferation, and conversely, its knockdown suppressed tumor growth. Additionally, ELF2 restored the proliferative ability of hepatoma cells inhibited by T3/TR. Our findings collectively support a potential role of T3/TR in tumor growth inhibition through regulation of ELF2.


Assuntos
Carcinoma Hepatocelular/patologia , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias Hepáticas/patologia , Receptores dos Hormônios Tireóideos/metabolismo , Fatores de Transcrição/metabolismo , Tri-Iodotironina/metabolismo , Imunoprecipitação da Cromatina/métodos , Células Hep G2 , Humanos
18.
Nucleus ; 7(2): 112-20, 2016 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-27003693

RESUMO

Exploiting a C. elegans mutant (ncl-1) exhibiting nucleolar abnormalities, we recently identified the let-7/ncl-1/fib-1 genetic cascade underlying proper rRNA abundance and nucleolar size. These 3 factors, let-7 (a miRNA), NCL-1 (a member of the TRIM-NHL family), and fibrillarin (a nucleolar methyltransferase), are evolutionarily conserved across metazoans. In this article, we provide several lines of bioinformatic evidence showing that human and Drosophila homologues of C. elegans NCL-1, TRIM-71 and Brat, respectively, likely act as translational suppressors of fibrillarin. Moreover, since their 3'-UTRs contain putative target sites, they may also be under the control of the let-7 miRNA. We hypothesize that let-7, TRIM and fibrillarin contribute activities in concert, and constitute a conserved network controlling nucleolar size in eukaryotes. We provide an in-depth literature review of various molecular pathways, including the let-7/ncl-1/fib-1 genetic cascade, implicated in the regulation of nucleolar size.


Assuntos
Nucléolo Celular , Evolução Molecular , Tamanho das Organelas/genética , Animais , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Humanos
19.
Hum Mutat ; 36(2): 167-74, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25196204

RESUMO

Next-generation sequencing (NGS) technologies have revolutionized the field of genetics and are trending toward clinical diagnostics. Exome and targeted sequencing in a disease context represent a major NGS clinical application, considering its utility and cost-effectiveness. With the ongoing discovery of disease-associated genes, various gene panels have been launched for both basic research and diagnostic tests. However, the fundamental inconsistencies among the diverse annotation sources, software packages, and data formats have complicated the subsequent analysis. To manage disease-associated NGS data, we developed Vanno, a Web-based application for in-depth analysis and rapid evaluation of disease-causative genome sequence alterations. Vanno integrates information from biomedical databases, functional predictions from available evaluation models, and mutation landscapes from TCGA cancer types. A highly integrated framework that incorporates filtering, sorting, clustering, and visual analytic modules is provided to facilitate exploration of oncogenomics datasets at different levels, such as gene, variant, protein domain, or three-dimensional structure. Such design is crucial for the extraction of knowledge from sequence alterations and translating biological insights into clinical applications. Taken together, Vanno supports almost all disease-associated gene tests and exome sequencing panels designed for NGS, providing a complete solution for targeted and exome sequencing analysis. Vanno is freely available at http://cgts.cgu.edu.tw/vanno.


Assuntos
Software , Curadoria de Dados , Exoma , Genoma Humano , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Anotação de Sequência Molecular , Análise de Sequência de DNA
20.
Nucleic Acids Res ; 43(Database issue): D849-55, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25398898

RESUMO

Whole-exome sequencing, which centres on the protein coding regions of disease/cancer associated genes, represents the most cost-effective method to-date for deciphering the association between genetic alterations and diseases. Large-scale whole exome/genome sequencing projects have been launched by various institutions, such as NCI, Broad Institute and TCGA, to provide a comprehensive catalogue of coding variants in diverse tissue samples and cell lines. Further functional and clinical interrogation of these sequence variations must rely on extensive cross-platforms integration of sequencing information and a proteome database that explicitly and comprehensively archives the corresponding mutated peptide sequences. While such data resource is a critical for the mass spectrometry-based proteomic analysis of exomic variants, no database is currently available for the collection of mutant protein sequences that correspond to recent large-scale genomic data. To address this issue and serve as bridge to integrate genomic and proteomics datasets, CMPD (http://cgbc.cgu.edu.tw/cmpd) collected over 2 millions genetic alterations, which not only facilitates the confirmation and examination of potential cancer biomarkers but also provides an invaluable resource for translational medicine research and opportunities to identify mutated proteins encoded by mutated genes.


Assuntos
Bases de Dados de Proteínas , Proteínas Mutantes/genética , Proteínas de Neoplasias/genética , Neoplasias/genética , Proteoma/genética , Linhagem Celular Tumoral , Humanos , Internet , Mutação
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