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BACKGROUND: Circular RNA (circRNA), a subclass of non-coding RNA, plays a critical role in cancer tumorigenesis and metastasis. It has been suggested that circRNA acts as a microRNA sponge or a scaffold to interact with protein complexes; however, its full range of functions remains elusive. Recently, some circRNAs have been found to have coding potential. METHODS: To investigate the role of circRNAs in gastric cancer (GC), parallel sequencing was performed using five paired GC samples. Differentially expressed circAXIN1 was proposed to encode a novel protein. FLAG-tagged circRNA overexpression plasmid construction, immunoblotting, mass spectrometry, and luciferase reporter analyses were applied to confirm the coding potential of circAXIN1. Gain- and loss-of-function studies were conducted to study the oncogenic role of circAXIN1 and AXIN1-295aa on the proliferation, migration, invasion, and metastasis of GC cells in vitro and in vivo. The competitive interaction between AXIN1-295aa and adenomatous polyposis coli (APC) was investigated by immunoprecipitation analyses. Wnt signaling activity was observed using a Top/Fopflash assay, real-time quantitative RT-PCR, immunoblotting, immunofluorescence staining, and chromatin immunoprecipitation. RESULTS: CircAXIN1 is highly expressed in GC tissues compared with its expression in paired adjacent normal gastric tissues. CircAXIN1 encodes a 295 amino acid (aa) novel protein, which was named AXIN1-295aa. CircAXIN1 overexpression enhances the cell proliferation, migration, and invasion of GC cells, while the knockdown of circAXIN1 inhibits the malignant behaviors of GC cells in vitro and in vivo. Mechanistically, AXIN1-295aa competitively interacts with APC, leading to dysfunction of the "destruction complex" of the Wnt pathway. Released ß-catenin translocates to the nucleus and binds to the TCF consensus site on the promoter, inducing downstream gene expression. CONCLUSION: CircAXIN1 encodes a novel protein, AXIN1-295aa. AXIN1-295aa functions as an oncogenic protein, activating the Wnt signaling pathway to promote GC tumorigenesis and progression, suggesting a potential therapeutic target for GC.
Assuntos
Proteína Axina/genética , Regulação Neoplásica da Expressão Gênica , RNA Circular/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Via de Sinalização Wnt , Sequência de Aminoácidos , Animais , Proteína Axina/química , Proteína Axina/metabolismo , Carcinogênese/genética , Linhagem Celular Tumoral , Biologia Computacional , Modelos Animais de Doenças , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Humanos , Metástase Linfática , Camundongos , Modelos Biológicos , Estadiamento de Neoplasias , Conformação Proteica , Neoplasias Gástricas/patologiaRESUMO
Although great progress has been made in surgical techniques, traditional radiotherapy, and chemotherapy, gastric cancer (GC) is still the most common malignant tumor and has a high mortality, which highlights the importance of novel diagnostic markers. Emerging studies suggest that different microRNAs (miRNAs) are involved in tumorigenesis of GC. In this study, we found that miRNA-192 and -215 are significantly upregulated in GC and promote cell proliferation and migration. Adenomatous polyposis coli (APC), a well-known negative regulator in Wnt signaling, has been proved to be a target of miRNA-192 and -215. Inhibition of miRNA-192 or -215 reduced the Topflash activities and repressed the expression of Wnt signaling pathway proteins, while APC small interfering RNAs reversed the inhibitory effects, suggesting that miRNA-192 and -215 activate Wnt signaling via APC. In addition, APC mediates the cell proliferation and migration regulated by miRNA-192 and -215. Furthermore, APC is downregulated in GC tissues and negatively correlated with the expression of miRNA-192 and -215. In summary, miRNA-192 and -215 target APC and function as oncogenic miRNAs by activating Wnt signaling in GC, revealing to be potential therapeutic targets.
Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , MicroRNAs/genética , Neoplasias Gástricas/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Neoplasias Gástricas/patologia , Via de Sinalização WntRESUMO
BACKGROUND: Interleukin-37 (IL-37) has been known to play an immunosuppressive role in various inflammatory disorders, but whether it participates in the regulation of pathogenesis of ankylosing spondylitis (AS) has not been investigated. Here, we examined the serum levels of IL-37 and its clinical association in AS, and explored the anti-inflammatory effects of IL-37 on peripheral blood mononuclear cells (PBMCs) from AS patients. METHODS: The mRNA levels of IL-37, TNF-α, IL-6, IL-17, and IL-23 in PBMCs and their serum concentrations from 46 AS patients were examined by real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunoassay (ELISA), respectively. The correlations between serum IL-37 levels with disease activity, laboratory values and pro-inflammatory cytokines in AS were analyzed by Spearman correlation test. PBMCs from 46 AS patients were stimulated with recombinant IL-37 protein, expressions of TNF-α, IL-6, IL-17 and IL-23 were determined by RT-PCR and ELISA. RESULTS: Compared to healthy controls (HC), AS patients and active AS patients showed higher levels of IL-37 in PBMCs and serum respectively. Strikingly, serum IL-37 levels were higher in AS patients with osteoporosis than those without. Serum levels of IL-37 were correlated with laboratory values as well as TNF-α, IL-6 and IL-17, but not IL-23 in patients with AS. The productions of pro-inflammatory cytokines such as TNF-α, IL-6, IL-17, IL-23 in PBMCs from AS patients were obviously attenuated after recombinant IL-37 stimulation, but not in the HC. CONCLUSION: The higher levels of IL-37 were found in AS patients, which were correlated with disease activity and AS related pro-inflammatory cytokines. More importantly, IL-37 inhibits the expressions of the pro-inflammatory cytokines from PBMCs in AS patients, indicating the potential anti-inflammatory role of IL-37 in AS.
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Interleucina-1/sangue , Espondilite Anquilosante/sangue , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Mediadores da Inflamação/metabolismo , Interleucina-1/genética , Leucócitos Mononucleares/metabolismo , Masculino , Osteoporose/sangue , Osteoporose/complicações , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/metabolismo , Espondilite Anquilosante/complicações , Espondilite Anquilosante/genéticaRESUMO
Current automation-assisted technologies for screening cervical cancer mainly rely on automated liquid-based cytology slides with proprietary stain. This is not a cost-efficient approach to be utilized in developing countries. In this article, we propose the first automation-assisted system to screen cervical cancer in manual liquid-based cytology (MLBC) slides with hematoxylin and eosin (H&E) stain, which is inexpensive and more applicable in developing countries. This system consists of three main modules: image acquisition, cell segmentation, and cell classification. First, an autofocusing scheme is proposed to find the global maximum of the focus curve by iteratively comparing image qualities of specific locations. On the autofocused images, the multiway graph cut (GC) is performed globally on the a* channel enhanced image to obtain cytoplasm segmentation. The nuclei, especially abnormal nuclei, are robustly segmented by using GC adaptively and locally. Two concave-based approaches are integrated to split the touching nuclei. To classify the segmented cells, features are selected and preprocessed to improve the sensitivity, and contextual and cytoplasm information are introduced to improve the specificity. Experiments on 26 consecutive image stacks demonstrated that the dynamic autofocusing accuracy was 2.06 µm. On 21 cervical cell images with nonideal imaging condition and pathology, our segmentation method achieved a 93% accuracy for cytoplasm, and a 87.3% F-measure for nuclei, both outperformed state of the art works in terms of accuracy. Additional clinical trials showed that both the sensitivity (88.1%) and the specificity (100%) of our system are satisfyingly high. These results proved the feasibility of automation-assisted cervical cancer screening in MLBC slides with H&E stain, which is highly desirable in community health centers and small hospitals.
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Automação , Detecção Precoce de Câncer , Neoplasias do Colo do Útero/diagnóstico , Automação/economia , Automação/métodos , Núcleo Celular/patologia , Análise Custo-Benefício , Citoplasma/metabolismo , Amarelo de Eosina-(YS) , Feminino , Hematoxilina , Humanos , Sensibilidade e Especificidade , Coloração e Rotulagem/métodosRESUMO
BACKGROUND: Esophageal cancer ranks eighth among frequent cancers worldwide. Our aim was to investigate whether and at which neoplastic stage promoter hypermethylation of CAV1 is involved in human esophageal carcinogenesis. METHODS: Using real-time quantitative methylation-specific PCR (qMSP), we examined CAV1 promoter hypermethylation in 260 human esophageal tissue specimens. Real-time RT-PCR and qMSP were also performed on OE33 esophageal cancer cells before and after treatment with the demethylating agent, 5-aza-2'-deoxycytidine (5-Aza-dC). RESULTS: CAV1 hypermethylation showed highly discriminative ROC curve profiles, clearly distinguishing esophageal adenocarcinomas (EAC) and esophageal squamous cell carcinomas (ESCC) from normal esophagus (NE) (EAC vs. NE, AUROC = 0.839 and p < 0.0001; ESCC vs. NE, AUROC = 0.920 and p < 0.0001). Both CAV1 methylation frequency and normalized methylation value (NMV) were significantly higher in Barrett's metaplasia (BE), low-grade and high-grade dysplasia occurring in BE (D), EAC, and ESCC than in NE (all p < 0.01, respectively). Meanwhile, among 41 cases with matched NE and EAC or ESCC, CAV1 NMVs in EAC and ESCC (mean = 0.273) were significantly higher than in corresponding NE (mean = 0.146; p < 0.01, Student's paired t-test). Treatment of OE33 EAC cells with 5-Aza-dC reduced CAV1 methylation and increased CAV1 mRNA expression. CONCLUSIONS: CAV1 promoter hypermethylation is a frequent event in human esophageal carcinomas and is associated with early neoplastic progression in Barrett's esophagus.
Assuntos
Adenocarcinoma/metabolismo , Esôfago de Barrett/metabolismo , Carcinoma de Células Escamosas/metabolismo , Caveolina 1/metabolismo , Metilação de DNA , Neoplasias Esofágicas/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/patologia , Área Sob a Curva , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Esôfago de Barrett/genética , Esôfago de Barrett/patologia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Caveolina 1/genética , Linhagem Celular Tumoral , Metilases de Modificação do DNA/antagonistas & inibidores , Metilases de Modificação do DNA/metabolismo , Decitabina , Progressão da Doença , Inibidores Enzimáticos/farmacologia , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Curva ROC , Fatores de TempoRESUMO
BACKGROUND: Endoglin (ENG) is a 180-kilodalton transmembrane glycoprotein that functions as a component of the transforming growth factor-ß receptor complex. Recently, ENG promoter hypermethylation was reported in several human cancers. METHODS: The authors examined ENG promoter hypermethylation using real-time, quantitative, methylation-specific polymerase chain reaction in 260 human esophageal tissues. RESULTS: ENG hypermethylation demonstrated highly discriminative receiver operating characteristic curve profiles, clearly distinguishing esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) from normal esophagus (P<.01). It is interesting to note that ENG normalized methylation values were significantly higher in ESCC compared with normal tissue (P<.01) or EAC (P<.01). The ENG hypermethylation frequency was 46.2% in ESCC and 11.9% in normal esophageal tissue, but increased early and sequentially during EAC-associated neoplastic progression to 13.3% in Barrett metaplasia (BE), 25% in dysplastic BE, and 26.9% in frank EAC. ENG hypermethylation was significantly higher in normal esophageal tissue from patients with ESCC (mean, 0.0186) than in normal tissue from patients with EAC (mean, 0.0117; P<.05). Treatment of KYSE220 ESCC cells with the demethylating agent 5-aza-2'-deoxycytidine was found to reverse ENG methylation and reactivate ENG mRNA expression. CONCLUSIONS: Promoter hypermethylation of ENG appears to be a frequent, tissue-specific event in human ESCC and exhibits a field defect with promising biomarker potential for the early detection of ESCC. In addition, ENG hypermethylation occurs in a subset of human EAC, and early during BE-associated esophageal neoplastic progression.
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Antígenos CD/genética , Biomarcadores Tumorais/genética , Metilação de DNA , Neoplasias Esofágicas/genética , Esôfago/metabolismo , Regiões Promotoras Genéticas/genética , Receptores de Superfície Celular/genética , Adenocarcinoma/genética , Adenocarcinoma/patologia , Idoso , Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Estudos de Casos e Controles , Decitabina , Endoglina , Neoplasias Esofágicas/patologia , Esôfago/patologia , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/genética , Curva ROC , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais CultivadasRESUMO
Bioactive coatings containing Ca and P with self-sealing structures were fabricated on the surface of pure magnesium using micro-arc oxidation technique (MAO) in a specific calcium hydroxide based electrolyte system. Coatings were prepared at three applied voltages, i.e. 360, 410 and 450 V, and the morphology, chemical composition, corrosion resistance and the degradation properties in Hank's solution of the MAO-coated samples with three different applied voltages were investigated. It was found that all the three coatings showed similar surface morphologies that the majority of micro-pores were filled with compound particles. Both the porous structures and the compound particles were found to contain consistent chemical compositions which were mainly composed of O, Mg, F, Ca and P. Electrochemical tests showed a significant increase in corrosion resistance for the three coatings, meanwhile the coating obtained at 450 V exhibited the superior corrosion resistance owing to the largest coating thickness. The long term immersion tests in Hank's solution also revealed an effective reduction in corrosion rate for the MAO coated samples, and the pH values of the coated samples always maintained a lower level. Besides, all the three coatings were subjected to a mild and uniform degradation, while the coating obtained at 360 V showed a relatively obvious degradation characteristic and appreciable Ca and P contents on the surfaces of the three coatings were observed after immersion in Hank's solution. The results of the present study confirmed that the MAO coatings containing bioactive Ca and P elements with self-sealing structures could significantly enhance the corrosion resistance of magnesium substrate in Hanks' solution with great potential for medical application.
Assuntos
Cálcio/química , Magnésio/química , Fósforo/química , Estrutura MolecularRESUMO
Circular RNAs (circRNAs) form a class of endogenous single-stranded RNA transcripts that are widely expressed in eukaryotic cells. These RNAs mediate post-transcriptional control of gene expression and have multiple functions in biological processes, such as transcriptional regulation and splicing. They serve predominantly as microRNA sponges, RNA-binding proteins, and templates for translation. More importantly, circRNAs are involved in cancer progression, and may serve as promising biomarkers for tumor diagnosis and therapy. Although traditional experimental methods are usually time-consuming and laborious, substantial progress has been made in exploring potential circRNA-disease associations by using computational models, summarized signaling pathway data, and other databases. Here, we review the biological characteristics and functions of circRNAs, including their roles in cancer. Specifically, we focus on the signaling pathways associated with carcinogenesis, and the status of circRNA-associated bioinformatics databases. Finally, we explore the potential roles of circRNAs as prognostic biomarkers in cancer.
Assuntos
Neoplasias , RNA Circular , Humanos , RNA Circular/genética , Neoplasias/genética , Carcinogênese/genética , Biologia Computacional , Transdução de Sinais/genéticaRESUMO
The majority of glucose in tumor cells is converted to lactate despite the presence of sufficient oxygen and functional mitochondria, a phenomenon known as the "Warburg effect" or "aerobic glycolysis". Aerobic glycolysis supplies large amounts of ATP, raw material for macromolecule synthesis, and also lactate, thereby contributing to cancer progression and immunosuppression. Increased aerobic glycolysis has been identified as a key hallmark of cancer. Circular RNAs (circRNAs) are a type of endogenous single-stranded RNAs characterized by covalently circular structures. Accumulating evidence suggests that circRNAs influence the glycolytic phenotype of various cancers. In gastrointestinal (GI) cancers, circRNAs are related to glucose metabolism by regulating specific glycolysis-associated enzymes and transporters as well as some pivotal signaling pathways. Here, we provide a comprehensive review of glucose-metabolism-associated circRNAs in GI cancers. Furthermore, we also discuss the potential clinical prospects of glycolysis-associated circRNAs as diagnostic and prognostic biomarkers and therapeutic targets in GI cancers.
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Lipopolysaccharide (LPS) can exacerbate asthma; however, the mechanisms are not fully understood. This study investigated the effect of LPS on antigen-stimulated mast cell degranulation and the underlying mechanisms. We found that LPS enhanced degranulation in RBL-2H3 cells and mouse peritoneal mast cells upon FcεRI activation, in a dose- and time-dependent manner. Parallel to the alteration of degranulation, LPS increased FcεRI-activated Ca(2+) mobilization, as well as Ca(2+) entry through store-operated calcium channels (SOCs) evoked by thapsigargin. Blocking Ca(2+) entry through SOCs completely abolished LPS enhancement of mast cell degranulation. Consistent with functional alteration of SOCs, LPS increased mRNA and protein levels of Orai1 and STIM1, two major subunits of SOCs, in a time-dependent manner. In addition, LPS increased the mRNA level of Toll-like receptor 4 (TLR4) in a time-dependent manner. Blocking TLR4 with Cli-095 inhibited LPS, increasing transcription and expression of SOC subunits. Concomitantly, the effect of LPS enhancement of Ca(2+) mobilization and mast cell degranulation was largely reduced by Cli-095. Administration of LPS (1 µg) in vivo aggravated airway hyperreactivity and inflammatory reactions in allergic asthmatic mice. Histamine levels in serum and bronchoalveolar lavage fluid were increased by LPS treatment. In addition, Ca(2+) mobilization was enhanced in peritoneal mast cells isolated from LPS-treated asthmatic mice. Taken together, these results imply that LPS enhances mast cell degranulation, which potentially contributes to LPS exacerbating allergic asthma. Lipopolysaccharide increases Ca(2+) entry through SOCs by upregulating transcription and expression of SOC subunits, mainly through interacting with TLR4 in mast cells, resulting in enhancement of mast cell degranulation upon antigen stimulation.
Assuntos
Asma/induzido quimicamente , Hiper-Reatividade Brônquica/induzido quimicamente , Canais de Cálcio/efeitos dos fármacos , Sinalização do Cálcio/efeitos dos fármacos , Degranulação Celular/efeitos dos fármacos , Lipopolissacarídeos/toxicidade , Mastócitos/efeitos dos fármacos , Receptores de IgE/metabolismo , Animais , Asma/imunologia , Asma/metabolismo , Asma/fisiopatologia , Hiper-Reatividade Brônquica/imunologia , Hiper-Reatividade Brônquica/metabolismo , Hiper-Reatividade Brônquica/fisiopatologia , Líquido da Lavagem Broncoalveolar/imunologia , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , ATPases Transportadoras de Cálcio/antagonistas & inibidores , ATPases Transportadoras de Cálcio/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Feminino , Histamina/metabolismo , Mastócitos/imunologia , Mastócitos/metabolismo , Glicoproteínas de Membrana/efeitos dos fármacos , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Proteína ORAI1 , Ovalbumina , RNA Mensageiro/metabolismo , Ratos , Molécula 1 de Interação Estromal , Fatores de Tempo , Receptor 4 Toll-Like/efeitos dos fármacos , Receptor 4 Toll-Like/metabolismoRESUMO
Circular RNA (circRNA) is characterized by a specific covalently closed ring structure. The back-splicing of precursor mRNA is the main way of circRNA generation, and various cis/trans-acting elements are involved in regulating the process. circRNAs exhibit multiple biological functions, including serving as sponges of microRNAs, interacting with proteins to regulate their stabilities and abilities, and acting as templates for protein translation. Autophagy participates in many physiological and pathological processes, especially it plays a vital role in tumorigenesis and carcinoma progression. Increasing numbers of evidences have revealed that circRNAs are implicated in regulating autophagy during tumor development. Until now, the roles of autophagy-associated circRNAs in carcinoma progression and their molecular mechanisms remain unclear. Here, the emerging regulatory roles and mechanisms of circRNAs in autophagy were summarized. Furtherly, the effects of autophagy-associated circRNAs on cancer development were described. We also prospected the potential of autophagy-associated circRNAs as novel therapeutic targets of tumors and as biomarkers for cancer diagnosis and prognosis.
RESUMO
Circular RNAs (circRNAs) have been reported to play essential roles in tumorigenesis and progression. This study aimed to identify dysregulated circRNAs in gastric cancer (GC) and investigate the functions and underlying mechanism of these circRNAs in GC development. Here, we identify circ_CEA, a circRNA derived from the back-splicing of CEA cell adhesion molecule 5 (CEA) gene, as a novel oncogenic driver of GC. Circ_CEA is significantly upregulated in GC tissues and cell lines. Circ_CEA knockdown suppresses GC progression, and enhances stress-induced apoptosis in vitro and in vivo. Mechanistically, circ_CEA interacts with p53 and cyclin-dependent kinases 1 (CDK1) proteins. It serves as a scaffold to enhance the association between p53 and CDK1. As a result, circ_CEA promotes CDK1-mediated p53 phosphorylation at Ser315, then decreases p53 nuclear retention and suppresses its activity, leading to the downregulation of p53 target genes associated with apoptosis. These findings suggest that circ_CEA protects GC cells from stress-induced apoptosis, via acting as a protein scaffold and interacting with p53 and CDK1 proteins. Combinational therapy of targeting circ_CEA and chemo-drug caused more cell apoptosis, decreased tumor volume and alleviated side effect induced by chemo-drug. Therefore, targeting circ_CEA might present a novel treatment strategy for GC.
Assuntos
MicroRNAs , Neoplasias Gástricas , Apoptose/genética , Antígeno Carcinoembrionário/genética , Antígeno Carcinoembrionário/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , RNA Circular/genética , Neoplasias Gástricas/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Peptidylarginine deiminase 4 (PAD4), a Ca2+-dependent enzyme, catalyzes the conversion of arginine to citrulline and has been strongly associated with many malignant tumors. However, the molecular mechanisms of PAD4 in the development and progression of colorectal cancer (CRC) remain unclearly defined. In our study, PAD4 expression was increased in CRC tissues and cells, and was closely related to tumor size, lymph node metastasis. Moreover, the transcription factor KLF9 directly bound to PADI4 gene promoter, leading to overexpression of PAD4 in CRC cells, which augmented cell growth and migration. We revealed that PAD4 interacted with and citrullinated glycogen synthase kinase-3ß (GSK3ß) in CRC cells, and GSK3ß Arg-344 was the dominating PAD4-citrullination site. Furthermore, IgL2 and catalytic domains of PAD4 directly bound to the kinase domain of GSK3ß in CRC cells. Mechanistically, PAD4 promoted the transport of GSK3ß from the cytoplasm to the nucleus, thereby increasing the ubiquitin-dependent proteasome degradation of nuclear cyclin-dependent kinase inhibitor 1 (CDKN1A). Our study is the first to reveal the details of a critical PAD4/GSK3ß/CDKN1A signaling axis for CRC progression, and provides evidence that PAD4 is a potential diagnosis biomarker and therapeutic target in CRC.
Assuntos
Citrulinação , Neoplasias Colorretais , Arginina/genética , Biomarcadores/metabolismo , Citrulina/genética , Citrulina/metabolismo , Neoplasias Colorretais/genética , Inibidor de Quinase Dependente de Ciclina p21 , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/metabolismo , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Hidrolases/genética , Hidrolases/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteína-Arginina Desiminase do Tipo 4 , Desiminases de Arginina em Proteínas/genética , Desiminases de Arginina em Proteínas/metabolismo , Fatores de Transcrição/genética , Ubiquitinas/genéticaRESUMO
Circular RNAs (circRNAs) are covalently closed, endogenous molecules that are widespread in eukaryotes. Recent evidence indicates that circRNAs play important roles in carcinogenesis. Several circRNAs have been reported to comprise translatable RNA; however, whether circRNAs encode functional proteins remains unknown. In our study, circRNA sequencing was carried out using five pathologically diagnosed gastric carcinoma (GC) samples and their paired adjacent normal tissues, we characterized the circRNA GSPT1 (circGSPT1), which is expressed at low levels in GC. Antibody detections, and mass spectrometry were used to validate active circRNA translation. The spanning junction open reading frame in circGSPT1, driven by an internal ribosome entry site (IRES), encodes a functional peptide, termed GSPT1-238aa. Interestingly, GSPT1-238aa tends to select the start codon used to initiate translation. This is the first finding of selective translation driven by IRES. CircGSPT1 and GSPT1-238aa halted the proliferation, migration, and invasion in GC cells in vitro. We also confirmed that the vimentin/Beclin1/14-3-3 complex interacts with GSPT1-238aa and modulates autophagy via the PI3K/AKT/mTOR signaling pathway in GC cells. Our study reveals that GSPT1-238aa, a novel protein encoded by circGSPT1, halts GC tumorigenesis. We also provide insights into the function and underlying molecular mechanisms of GSPT1-238aa in GC and suggest that this protein represents a novel target for GC treatment.
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Carcinoma , Neoplasias Gástricas , Autofagia/genética , Carcinogênese/genética , Carcinoma/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Sítios Internos de Entrada Ribossomal , Fatores de Terminação de Peptídeos , Fosfatidilinositol 3-Quinases/genética , RNA Circular/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Proteínas Supressoras de Tumor/genética , Vimentina/genéticaRESUMO
17ß-hydroxysteroid dehydrogenase-13 is a hepatocyte-specific, lipid droplet-associated protein. A common loss-of-function variant of HSD17B13 (rs72613567: TA) protects patients against non-alcoholic fatty liver disease with underlying mechanism incompletely understood. In the present study, we identify the serine 33 of 17ß-HSD13 as an evolutionally conserved PKA target site and its phosphorylation facilitates lipolysis by promoting its interaction with ATGL on lipid droplets. Targeted mutation of Ser33 to Ala (S33A) decreases ATGL-dependent lipolysis in cultured hepatocytes by reducing CGI-58-mediated ATGL activation. Importantly, a transgenic knock-in mouse strain carrying the HSD17B13 S33A mutation (HSD17B1333A/A) spontaneously develops hepatic steatosis with reduced lipolysis and increased inflammation. Moreover, Hsd17B1333A/A mice are more susceptible to high-fat diet-induced nonalcoholic steatohepatitis. Finally, we find reproterol, a potential 17ß-HSD13 modulator and FDA-approved drug, confers a protection against nonalcoholic steatohepatitis via PKA-mediated Ser33 phosphorylation of 17ß-HSD13. Therefore, targeting the Ser33 phosphorylation site could represent a potential approach to treat NASH.
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Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Fosforilação , Serina/metabolismo , 17-Hidroxiesteroide Desidrogenases/genética , Hepatócitos/metabolismo , Fígado/metabolismoRESUMO
With the increase of unconventional oil production and transportation, the detection methods of light crude oil have been challenged. Mid-Infrared spectroscopy can reflect the functional group of the oil related samples, which has strong absorption signals with distinguishable peaks featured as a fast, economy, and robust technique. Nevertheless, the previous study and application of oil relevant samples, such as petroleum chemical industry online monitoring, are mainly based on Near-infrared spectroscopy. Recently, the rapid development of the spectral instrument manufacturing and the data analysis methods provides a more comprehensive technical support for the rapid and accurate identification of marine oil spill by Mid-infrared spectroscopy. In this paper, 10 crude oil samples were selected for infrared spectroscopy detection, and the results were analysed and compared with those of gas chromatography flame ionization detection method. The character information of the IR spectra and GC/FID chromatograms were extracted and classified both by principal component analysis and partial least squares regression. Under the condition of small sample size, the recognition accuracy was up to 100%. The results show that the mid-infrared method combined with chemometrics can be expected to achieve rapid, accurate and economical identification of heavy oil species.
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Poluição por Petróleo , Petróleo , Ionização de Chama , Petróleo/análise , Poluição por Petróleo/análise , Espectrofotometria Infravermelho , TecnologiaRESUMO
Previous research has found that miRNA-20b is highly expressed in gastric cancer (GC), however, its function and underlying mechanism are not clear. Wnt signaling pathway, implicated in tumorigeneisis, is activated in more than 30% of GC. We would like to characterize the biological behavior of miRNA-20b in terms of modulating Wnt/ß-catenin signaling and EMT. We showed that miRNA-20b inhibitors suppressed Topflash/Fopflash dependent luciferase activity and the ß-catenin nuclear translocation, resulting in inhibition of Wnt pathway activity and EMT. SUFU, negatively regulating Wnt and Hedgehog signaling pathway, was proved to be targeted by miRNA-20b. Moreover, additional knockdown of SUFU alleviated the inhibitory effect on Wnt pathway activity, EMT, cell proliferation/migration and colony formation caused by miRNA-20b inhibition. In summary, miRNA-20b is an oncogenic miRNA and promoted cell proliferation, migration and EMT in GC partially by activating Wnt pathway via targeting SUFU.
RESUMO
Mounting evidence has shown that miRNA-150 expression is upregulated in gastric cancer (GC) and is associated with gastric carcinogenesis, but the underlying oncogenic mechanism remains elusive. Here, we discovered that miRNA-150 targets the tumor suppressor SUFU to promote cell proliferation, migration, and the epithelial-mesenchymal transition (EMT) via the dual activation of Hedgehog (Hh) and Wnt signaling. MiRNA-150 was highly expressed in GC tissues and cell lines, and the level of this miRNA was negatively related to that of SUFU. In addition, both the miRNA-150 and SUFU levels were associated with tumor differentiation. Furthermore, miRNA-150 activated GC cell proliferation and migration in vitro. We found that miRNA-150 inhibitors repressed not only Wnt signaling by promoting cytoplasmic ß-catenin localization, but also repressed Hh signaling and EMT. MiRNA-150 inhibition also resulted in significant tumor volume reductions in vivo, suggesting the potential application of miRNA-150 inhibitors in GC therapy. The expression of genes downstream of Hh and Wnt signaling was also reduced in tumors treated with miRNA-150 inhibitors. Notably, anti-SUFU siRNAs rescued the inhibitory effects of miRNA-150 inhibitors on Wnt signaling, Hh activation, EMT, cell proliferation, cell migration, and colony formation. Taken together, these findings indicate that miRNA-150 is oncogenic and promotes GC cell proliferation, migration, and EMT by activating Wnt and Hh signaling via the suppression of SUFU expression.
Assuntos
Proteínas Hedgehog/genética , MicroRNAs/genética , Proteínas Repressoras/genética , Neoplasias Gástricas/genética , Via de Sinalização Wnt/fisiologia , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação para Baixo , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Hedgehog/metabolismo , Humanos , Camundongos , MicroRNAs/metabolismo , Proteínas Repressoras/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologiaRESUMO
Type-I clathrate compounds Yb x Ba8-x Ga16Ge30 have been synthesized by the high-pressure and high-temperature (HPHT) method rapidly. The effects of the synergy of atom filling and pressure regulation on the microstructure and thermal and electrical properties have been investigated. With the content of Yb atom increasing, the carrier concentration is improved, the electrical resistivity and the absolute Seebeck coefficient are decreased, while the thermal conductivity is reduced significantly. A series of extremely low lattice thermal conductivities are achieved, attributed to the enhancement of multiscale phonon scattering for the "rattling" of the filled guest atoms, the heterogeneous distribution of nano- and microstructures, grain boundaries, abundant lattice distortions, lattice deformations, and dislocations. As a result, a maximum ZT of about 1.07 at 873 K has achieved for the Yb0.5Ba7.5Ga16Ge30 sample.
RESUMO
Gastric cancer (GC) is the most common cancer throughout the world. Despite advances of the treatments, detailed oncogenic mechanisms are largely unknown. In our previous study, we investigated microRNA (miR) expression profiles in human GC using miR microarrays. We found miR-192/215 were upregulated in GC tissues. Then gene microarray was implemented to discover the targets of miR-192/215. We compared the expression profile of BGC823 cells transfected with miR-192/215 inhibitors, and HFE145 cells transfected with miR-192/-215 mimics, respectively. SET8 was identified as a proposed target based on the expression change of more than twofold. SET8 belongs to the SET domain-containing methyltransferase family and specifically catalyzes monomethylation of H4K20me. It is involved in diverse functions in tumorigenesis and metastasis. Therefore, we focused on the contributions of miR-192/215/SET8 axis to the development of GC. In this study, we observe that functionally, SET8 regulated by miR-192/215 is involved in GC-related biological activities. SET8 is also found to trigger oncogene-induced senescence (OIS) in GC in vivo and in vitro, which is dependent on the DDR (DNA damage response) and p53. Our findings reveal that SET8 functions as a negative regulator of metastasis via the OIS-signaling pathway. Taken together, we investigated the functional significance, molecular mechanisms, and clinical impact of miR-192/215/SET8/p53 in GC.