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1.
Zhonghua Zhong Liu Za Zhi ; 41(9): 675-680, 2019 Sep 23.
Artigo em Chinês | MEDLINE | ID: mdl-31550857

RESUMO

Objective: To investigate the inhibitory effect of programmed cell death factor 4 (PDCD4) on arsenic trioxide (As(2)O(3))-induced cell growth and nuclear factor kappa B (NF-κB) signaling pathway in neuroblastoma. Methods: The PDCD4 overexpression vector was transfected into neuroblastoma cells and detected by fluorescence quantitative PCR and Western blot. As(2)O(3) was used to treat PDCD4 overexpressing neuroblastoma cells. MTT assay was used to measure the proliferation. Colony formation assay was used to determine the cell clone forming ability. Apoptosis was measured by flow cytometry. Western blot was used to detect the expression of NF-κB p65 and cleaved caspase-3 protein in cells. Results: The transfection of PDCD4 overexpression vector significantly increased the expression level of PDCD4 in neuroblastoma cells. The cell survival rates of the control group, PDCD4 group, As(2)O(3) group and As(2)O(3)+ PDCD4 group were 100%, (72.14±5.20)%, (62.58±3.14)% and (40.87±2.47)%, respectively. The colony formation rates in these four groups were (91.25±8.36)%, (65.32±7.14)%, (57.23±5.28)% and (37.14±3.64)%, respectively. In addition, the cell apoptotic rates of these four groups were (3.57±0.24)%, (28.64±3.20)%, (36.41±4.58)% and (49.65±5.27)%, respectively. Therefore, overexpression of PDCD4 in the absence or presence of As(2)O(3) inhibited cell proliferation and clone formation ability, while promoted apoptosis. Furthermore, the expression levels of cleaved caspase-3 in the control group, PDCD4 group, As(2)O(3) group and As(2)O(3)+ PDCD4 group were 0.21±0.03, 0.30±0.02, 0.43±0.05 and 0.57±0.06, respectively. And the expression levels of NF-κB p65 protein were 0.68±0.04, 0.52±0.03, 0.43±0.04, and 0.32±0.02, respectively. Compared with the control group, the expression levels of NF-κB p65 protein in PDCD4 group, As(2)O(3) group and As(2)O(3)+ PDCD4 group were significantly decreased (P<0.05), whereas the expression level of cleaved Caspase-3 protein was significantly increased (P<0.05). The changes in As(2)O(3)+ PDCD4 group were more significant than those in PDCD4 group and As(2)O(3) groups (both P<0.05). Conclusion: PDCD4 enhances the inhibitory effect of As(2)O(3) on the growth and NF-κB signaling pathway in neuroblastoma cells.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Apoptose/efeitos dos fármacos , Trióxido de Arsênio/farmacologia , NF-kappa B/fisiologia , Neuroblastoma/tratamento farmacológico , Proteínas de Ligação a RNA/genética , Transdução de Sinais/efeitos dos fármacos , Antineoplásicos , Proteínas Reguladoras de Apoptose/metabolismo , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Proteínas de Ligação a RNA/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
2.
Cancer Sci ; 110(11): 3533-3542, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31489722

RESUMO

Clear cell renal cell carcinoma (ccRCC) is one of the most common malignant tumors in the urinary system. Surgical intervention is the preferred treatment for ccRCC, but targeted biological therapy is required for postoperative recurrent or metastatic ccRCC. Autophagy is an intracellular degradation system for misfolded/aggregated proteins and dysfunctional organelles. Defective autophagy is associated with many diseases. Mul1 is a mitochondrion-associated E3 ubiquitin ligase and involved in the regulation of divergent pathophysiological processes such as mitochondrial dynamics, and thus affects the development of various diseases including cancers. Whether Mul1 regulates ccRCC development and what is the mechanism remain unclear. Histochemical staining and immunoblotting were used to analyze the levels of Mul1 protein in human renal tissues. Statistical analysis of information associated with tissue microarray and The Cancer Genome Atlas (TCGA) database was conducted to show the relationship between Mul1 expression and clinical features and survival of ccRCC patients. Impact of Mul1 on rates of cell growth and migration and autophagy flux were tested in cultured cancer cells. Herein we show that Mul1 promoted autophagy flux to facilitate the degradation of P62-associated protein aggresomes and adipose differentiation-related protein (ADFP)-associated lipid droplets and suppressed the growth and migration of ccRCC cells. Levels of Mul1 protein and mRNA were significantly reduced so that autophagy flux was likely blocked in ccRCC tissues, which is potentially correlated with enhancement of malignancy of ccRCC and impairment of patient survival. Therefore, Mul1 may promote autophagy to suppress the development of ccRCC.


Assuntos
Autofagia , Carcinoma de Células Renais/enzimologia , Neoplasias Renais/enzimologia , Mitocôndrias/enzimologia , Ubiquitina-Proteína Ligases/metabolismo , Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Humanos , Rim/enzimologia , Neoplasias Renais/mortalidade , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/metabolismo , Proteólise , Proteínas de Ligação a RNA/metabolismo , Ubiquitina-Proteína Ligases/análise
3.
Anticancer Res ; 39(9): 4947-4955, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31519600

RESUMO

BACKGROUND/AIM: Insulin-like growth factor II mRNA-binding protein 3 (IMP3) plays an important role in the adhesion, invasion, and metastasis of tumor cells. Although emerging evidence suggests that IMP3 promotes tumor progression in several malignancies, the expression of IMP3 and its prognostic implication in adenocarcinoma of the ampulla of Vater (AVAC) has not been clarified to date. MATERIALS AND METHODS: The IMP3 expression status in 87 AVAC tissues was examined using immunostaining, and its association with various clinicopathological features and outcome of patients with AVAC was investigated. RESULTS: The vast majority (87.4%) of AVAC cases displayed at least focal cytoplasmic and membranous IMP3 immunoreactivity in tumor cells, whereas IMP3 expression was consistently absent from normal biliary epithelial cells. Tumor-specific IMP3 expression was associated with submucosal and pancreatic invasion, which were not identified in the corresponding hematoxylin and eosin-stained slides. This finding led to up-staging of the pathological tumor stage in two cases of well-differentiated AVAC. In addition, high IMP3 expression was significantly associated with a poorly differentiated histology (p=0.026). Survival analyses revealed that high IMP3 expression independently predicted shorter recurrence-free (p=0.003) and overall (p=0.029) survival. CONCLUSION: Our study demonstrated tumor-specific IMP3 expression in AVAC, which will be helpful in determining invasion depth and tumor extent in patients with well-differentiated tumors, as well as indicating worse survival of patients with AVAC. Our data highlight IMP3 expression status as a potential diagnostic and prognostic marker for AVAC.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Ampola Hepatopancreática/patologia , Neoplasias do Ducto Colédoco/genética , Neoplasias do Ducto Colédoco/mortalidade , Regulação Neoplásica da Expressão Gênica , Proteínas de Ligação a RNA/metabolismo , Adenocarcinoma/diagnóstico , Adenocarcinoma/metabolismo , Adulto , Idoso , Biomarcadores Tumorais , Neoplasias do Ducto Colédoco/diagnóstico , Neoplasias do Ducto Colédoco/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Proteínas de Ligação a RNA/genética , Carga Tumoral
4.
J Biochem ; 166(5): 375-382, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31511872

RESUMO

In human genome, there are approximately 1,500 RNA-binding proteins (RBPs). They can regulate mRNA stability or translational efficiency via ribosomes and these processes are known as 'post-transcriptional regulation'. Accumulating evidences indicate that post-transcriptional regulation is the determinant of the accurate levels of cytokines mRNAs. While transcriptional regulation of cytokines mRNAs has been well studied and found to be important for the rapid induction of mRNA and regulation of the acute phase of inflammation, post-transcriptional regulation by RBPs is essential for resolving inflammation in the later phase, and their dysfunction may lead to severe autoimmune diseases such as rheumatoid arthritis or systemic lupus erythematosus. For post-transcriptional regulation, RBPs recognize and directly bind to cis-regulatory elements in 3' untranslated region of mRNAs such as AU-rich or constitutive decay elements and play various roles. In this review, we summarize the recent findings regarding the role of RBPs in the regulation of inflammation.


Assuntos
Inflamação/genética , RNA Mensageiro/genética , Proteínas de Ligação a RNA/metabolismo , Transcrição Genética/genética , Animais , Humanos , Inflamação/imunologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/imunologia
5.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(7): 613-618, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31537246

RESUMO

Objective To investigate the effect of baicalein (BAI) on autophagy in gastric cancer cell line MGC-803. Methods MGC-803 cells were treated with 0, 5, 15, 25, 50 µmol/L BAI for 24, 48, 72 hours. The proliferation activity of MGC-803 cells was detected by MTT assay. Acridine orange (AO) staining combined with immunofluorescence cytochemical staining was performed to observe the expression of microtubule-associated protein 1 light chain 3 (LC3) and P62 to determine autophagy in MGC-803 cells. The protein levels of LC3, P62, phosphatidylinositol 3-kinase (PI3K), phosphorylated PI3K (p-PI3K), AKT, and p-AKT were detected by Western blot analysis. Results Compared with the control group, BAI significantly inhibited the proliferation of MGC-803 cells in a time- and dose-dependent manner. BAI-treated MGC-803 cells showed a significant increase in acid lysosomes and increased LC3 expression. BAI treatment significantly decreased phosphorylation of PI3K and AKT proteins, increased the ratio of LC3-II/LC3-I and up-regulated the expression of P62 protein. Conclusion Baicalein could inhibit PI3K/AKT signaling pathway and induce autophagy in MGC-803 cells.


Assuntos
Autofagia , Flavanonas/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas de Ligação a RNA/metabolismo
6.
Mol Biol (Mosk) ; 53(4): 663-673, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31397440

RESUMO

Malignant cutaneous melanoma (CM) is an extremely aggressive cancer characterized by a high level of metastatic activity and unfavorable prognosis due to a high incidence of relapses, as well as resistance to standard chemotherapy. Cutaneous melanoma accounts for 80% of deaths from malignant skin tumors. Nucleolin/C23 and nucleophosmin/B23, which constitute altogether ~70% of the nucleolus volume, are promising targets for molecular therapy of melanoma. These proteins perform many important functions in the cell, so disruption of the NCL and/or NPM gene structure and abnormal expression of the C23 and B23 proteins they encode, can lead to unlimited cell proliferation and progression of a tumor. Therefore, investigation of the structure and expression of these genes is a topical problem, which is important for understanding the mechanisms of CM carcinogenesis and for the development of new therapeutic approaches. This paper describes new NCL and NPM polymorphisms, as well as the levels of C23 and B23 expression in normal tissues, CM and mucosal melanoma.


Assuntos
Melanoma/genética , Melanoma/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Nucléolo Celular/química , Nucléolo Celular/metabolismo , Proliferação de Células , Humanos , Melanoma/tratamento farmacológico , Terapia de Alvo Molecular , Proteínas Nucleares/biossíntese , Proteínas Nucleares/química , Fosfoproteínas/biossíntese , Fosfoproteínas/química , Polimorfismo Genético , Proteínas de Ligação a RNA/biossíntese , Proteínas de Ligação a RNA/química , Neoplasias Cutâneas/tratamento farmacológico
8.
Genes Dev ; 33(17-18): 1221-1235, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371437

RESUMO

TRIM71/LIN-41, a phylogenetically conserved regulator of development, controls stem cell fates. Mammalian TRIM71 exhibits both RNA-binding and protein ubiquitylation activities, but the functional contribution of either activity and relevant primary targets remain poorly understood. Here, we demonstrate that TRIM71 shapes the transcriptome of mouse embryonic stem cells (mESCs) predominantly through its RNA-binding activity. We reveal that TRIM71 binds targets through 3' untranslated region (UTR) hairpin motifs and that it acts predominantly by target degradation. TRIM71 mutations implicated in etiogenesis of human congenital hydrocephalus impair target silencing. We identify a set of primary targets consistently regulated in various human and mouse cell lines, including MBNL1 (Muscleblind-like protein 1). MBNL1 promotes cell differentiation through regulation of alternative splicing, and we demonstrate that TRIM71 promotes embryonic splicing patterns through MBNL1 repression. Hence, repression of MBNL1-dependent alternative splicing may contribute to TRIM71's function in regulating stem cell fates.


Assuntos
Processamento Alternativo/genética , Regulação da Expressão Gênica/genética , Proteínas de Ligação a RNA/genética , Proteínas com Motivo Tripartido/genética , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Animais , Linhagem Celular Tumoral , Células-Tronco Embrionárias , Humanos , Camundongos , Camundongos Knockout , Mutação , Motivos de Nucleotídeos , Ligação Proteica , Domínios Proteicos/genética , Interferência de RNA , Proteínas de Ligação a RNA/metabolismo
9.
Adv Exp Med Biol ; 1157: 29-39, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31342436

RESUMO

Post-transcriptional regulation of gene expression is fundamental for all forms of life, as it critically contributes to the composition and quantity of a cell's proteome. These processes encompass splicing, polyadenylation, mRNA decay, mRNA editing and modification and translation and are modulated by a variety of RNA-binding proteins (RBPs). Alterations affecting RBP expression and activity contribute to the development of different types of cancer. In this chapter, we discuss current research shedding light on the role of different RBPs in gliomas. These studies place RBPs as modulators of critical signaling pathways, establish their relevance as prognostic markers and open doors for new therapeutic strategies.


Assuntos
Glioma , Proteínas de Ligação a RNA , Glioma/fisiopatologia , Humanos , Poliadenilação , Processamento de RNA , Estabilidade de RNA , Proteínas de Ligação a RNA/metabolismo
10.
BMC Evol Biol ; 19(1): 149, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337330

RESUMO

BACKGROUND: Adenosine deaminase enzymes of the ADAR family are conserved in metazoans. They convert adenine into inosine in dsRNAs and thus alter both structural properties and the coding potential of their substrates. Acting on exogenous dsRNAs, ADAR1 exerts a pro- or anti-viral role in vertebrates and Drosophila. RESULTS: We traced 4 ADAR homologs in 14 lophotrochozoan genomes and we classified them into ADAD, ADAR1 or ADAR2, based on phylogenetic and structural analyses of the enzymatic domain. Using RNA-seq and quantitative real time PCR we demonstrated the upregulation of one ADAR1 homolog in the bivalve Crassostrea gigas and in the gastropod Haliotis diversicolor supertexta during Ostreid herpesvirus-1 or Haliotid herpesvirus-1 infection. Accordingly, we demonstrated an extensive ADAR-mediated editing of viral RNAs. Single nucleotide variation (SNV) profiles obtained by pairing RNA- and DNA-seq data from the viral infected individuals resulted to be mostly compatible with ADAR-mediated A-to-I editing (up to 97%). SNVs occurred at low frequency in genomic hotspots, denoted by the overlapping of viral genes encoded on opposite DNA strands. The SNV sites and their upstream neighbor nucleotide indicated the targeting of selected adenosines. The analysis of viral sequences suggested that, under the pressure of the ADAR editing, the two Malacoherpesviridae genomes have evolved to reduce the number of deamination targets. CONCLUSIONS: We report, for the first time, evidence of an extensive editing of Malacoherpesviridae RNAs attributable to host ADAR1 enzymes. The analysis of base neighbor preferences, structural features and expression profiles of molluscan ADAR1 supports the conservation of the enzyme function among metazoans and further suggested that ADAR1 exerts an antiviral role in mollusks.


Assuntos
Antivirais/metabolismo , Vírus de DNA/genética , Moluscos/virologia , Edição de RNA/genética , RNA Viral/genética , Proteínas de Ligação a RNA/metabolismo , Animais , Teorema de Bayes , Vírus de DNA/fisiologia , Regulação da Expressão Gênica , Genoma Viral , Modelos Moleculares , Moluscos/genética , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Domínios Proteicos , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Transcriptoma/genética
11.
Eur J Pharm Biopharm ; 142: 473-479, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31325486

RESUMO

Nucleic acid aptamers have emerged as an attractive class of carrier molecules due to their ability to bind with high affinity to specific ligands; their high chemical flexibility; as well as tissue penetration capability. RNA G-quadruplex (rG4) sequences have been described as structures with high stability and selectivity towards cancer cells. Recently, precursor microRNAs (pre-miRNAs) have been described as new G4 forming molecules. Surface nucleolin (NCL) is a known target of aptamer G4 AS1411 and is overexpressed on prostate cancer cells when compared with normal cells. We have shown that the sequence 5' GGGAGGGAGGGACGGG 3' found in pre-miR-149 forms a rG4 parallel structure, which can bind NCL. Also, another rG4 sequence with a longer loop was evaluated in terms of G4 formation, stabilization and binding affinity to NCL. Both rG4s sequences were studied as supramolecular carriers for the cancer-selective delivery of acridine ligand C8. The rG4s-C8 complexes showed high affinity (KD = 10-6 M) and stabilization (Tm > 30 °C). The affinity of the rG4s-C8 complexes against NCL was in the low nanomolar range, indicating that C8 did not affect NCL binding. Noteworthy, the short loop rG4-C8 complex showed selective antiproliferative effects in prostate cancer cells when compared with normal prostatic cells. The stability and nuclease resistance of rG4 and rG4-C8 complex were evaluated in biological conditions and revealed the maintenance of G4 structure and complex stability. Furthermore, confocal microscopy studies confirmed the potential of rG4s-C8 complexes in the targeting of prostate cancer cells. Overall, it is here demonstrated that the rG4 found in pre-miR-149 can be used as a cancer-selective delivery carrier of C8 to prostate cancer cells.


Assuntos
Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/metabolismo , Portadores de Fármacos/química , MicroRNAs/química , MicroRNAs/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Quadruplex G , Humanos , Ligantes , Masculino , Oligodesoxirribonucleotídeos/química , Oligonucleotídeos/química , Células PC-3 , Fosfoproteínas/metabolismo , Proteínas de Ligação a RNA/metabolismo
12.
Nucleic Acids Res ; 47(16): 8675-8692, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31329932

RESUMO

The RNA guanine-N7 methyltransferase (RNMT) in complex with RNMT-activating miniprotein (RAM) catalyses the formation of a N7-methylated guanosine cap structure on the 5' end of nascent RNA polymerase II transcripts. The mRNA cap protects the primary transcript from exonucleases and recruits cap-binding complexes that mediate RNA processing, export and translation. By using microsecond standard and accelerated molecular dynamics simulations, we provide for the first time a detailed molecular mechanism of allosteric regulation of RNMT by RAM. We show that RAM selects the RNMT active site conformations that are optimal for binding of substrates (AdoMet and the cap), thus enhancing their affinity. Furthermore, our results strongly suggest the likely scenario in which the cap binding promotes the subsequent AdoMet binding, consistent with the previously suggested cooperative binding model. By employing the network community analyses, we revealed the underlying long-range allosteric networks and paths that are crucial for allosteric regulation by RAM. Our findings complement and explain previous experimental data on RNMT activity. Moreover, this study provides the most complete description of the cap and AdoMet binding poses and interactions within the enzyme's active site. This information is critical for the drug discovery efforts that consider RNMT as a promising anti-cancer target.


Assuntos
Metiltransferases/química , Capuzes de RNA/química , Proteínas de Ligação a RNA/química , S-Adenosil-Homocisteína/química , S-Adenosilmetionina/química , Regulação Alostérica , Sequência de Aminoácidos , Sítios de Ligação , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Humanos , Cinética , Metiltransferases/genética , Metiltransferases/metabolismo , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Capuzes de RNA/genética , Capuzes de RNA/metabolismo , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Termodinâmica , Transcrição Genética
13.
Emerg Microbes Infect ; 8(1): 989-999, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31267843

RESUMO

It has recently been proposed that the Eurasian avian-like H1N1 (EA H1N1) swine influenza virus (SIV) is one of the most likely zoonotic viruses to cause the next influenza pandemic. Two main genotypes EA H1N1 viruses have been recognized to be infected humans in China. Our study finds that one of the genotypes JS1-like viruses are avirulent in mice. However, the other are HuN-like viruses and are virulent in mice. The molecular mechanism underlying this difference shows that the NP gene determines the virulence of the EA H1N1 viruses in mice. In addition, a single substitution, Q357K, in the NP protein of the EA H1N1 viruses alters the virulence phenotype. This substitution is a typical human signature marker, which is prevalent in human viruses but rarely detected in avian influenza viruses. The NP-Q357K substitution is readily to be occurred when avian influenza viruses circulate in pigs, and may facilitate their infection of humans and allow viruses also carrying NP-357K to circulate in humans. Our study demonstrates that the substitution Q357K in the NP protein plays a key role in the virulence phenotype of EA H1N1 SIVs, and provides important information for evaluating the pandemic risk of field influenza strains.


Assuntos
Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/virologia , Mutação de Sentido Incorreto , Infecções por Orthomyxoviridae/veterinária , Proteínas de Ligação a RNA/genética , Doenças dos Suínos/virologia , Proteínas do Core Viral/genética , Animais , China , Feminino , Genótipo , Humanos , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Orthomyxoviridae/virologia , Filogenia , Proteínas de Ligação a RNA/metabolismo , Suínos , Proteínas do Core Viral/metabolismo , Virulência , Replicação Viral
14.
Biochim Biophys Acta Gene Regul Mech ; 1862(8): 759-770, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31269460

RESUMO

The majority of melanomas carry an oncogenic BRAF mutation (BRAFV600E), which results in constitutive kinase activity driving melanoma proliferation. While inhibitors of BRAFV600E (BRAFi) effectively lead to rapid tumor shrinkage, most patients treated with BRAFi develop acquired resistance. Identification of factors as regulators of melanoma growth and as potential sources of resistance is thus crucial for the design of improved therapies to treat advanced melanoma with more durable responses. Here, we show that KH-type splicing regulatory protein (KSRP) is critical for proliferation of melanoma cells without and with acquired resistance to vemurafenib. Silencing KSRP reduces cell proliferation and augments the growth suppressive effects of vemurafenib. We identify killin (KLLN), a p53-regulated DNA replication inhibitor, as a downstream effector of growth inhibition by KSRP silencing and demonstrate that KSRP promotes decay of KLLN mRNA through an RNA-protein interaction. Using heterologous mRNA reporters, we show that a U-rich element within the 3' untranslated region of KLLN is responsible for KSRP-dependent mRNA decay. These findings implicate that KSRP is an important regulator of melanoma cell growth in part through controlling KLLN mRNA stability.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Melanoma/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Transativadores/genética , Transativadores/metabolismo , Proteínas Supressoras de Tumor/genética , Vemurafenib/uso terapêutico , Regiões 3' não Traduzidas , Animais , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Melanoma/genética , Camundongos , Estabilidade de RNA , RNA Mensageiro/química , Proteínas Supressoras de Tumor/química , Regulação para Cima
15.
Cell Mol Life Sci ; 76(21): 4233-4243, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31270581

RESUMO

Circular RNAs (circRNAs) are single-stranded and covalently closed back-splicing products of pre-mRNAs. They can be derived from exons, introns, or exons with intron retained between exons of transcripts, as well as antisense transcripts. CircRNAs have been reported to function as microRNA sponges, regulate gene transcription mediated by RNA polymerase II, and modulate the splicing or stability of mRNA. However, emerging studies demonstrate that they affect the behavior of proteins via direct interactions with them. Here, we summarize that by binding directly with proteins; circRNAs can facilitate their nuclear or cytoplasmic localizations, regulate their functions or stability, promote or inhibit the interactions between them, or influence the interactions between them and DNA. Furthermore, these circRNA-binding proteins contain transcription factors, RNA processing proteins, proteases, and some other RNA-binding proteins. As a consequence, circRNAs are involved in the regulation of multiple physiological or pathological processes, including tumorigenesis, atherosclerosis, wound repair, cardiac senescence, myocardial ischemia/reperfusion injury, and so forth. Nonetheless, it is worthwhile to further explore more types of proteins that interact with circRNAs, which would be helpful in revealing other unknown biological functions of circRNAs that guide the variation in behavior of cellular proteins.


Assuntos
Proteínas/metabolismo , RNA/fisiologia , Animais , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica/fisiologia , Humanos , Ligação Proteica , Estabilidade Proteica , Transporte Proteico/genética , RNA/metabolismo , Proteínas de Ligação a RNA/metabolismo
16.
Mol Immunol ; 112: 387-393, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31288148

RESUMO

Programmed cell death 4 (Pdcd4) was found to be related to apoptosis upon first discovery. It was later found to play the role of tumor suppressor gene in a variety of tumors by inhibiting transcription and translation. Recently, it has been proposed that it may play an important role in some inflammatory diseases and in the immune response. In our previous study, deficiency of Pdcd4 was found to attenuate the formation of atherosclerotic plaques. This might be because deficiency of Pdcd4 may increase IL-10 expression and lipoautophagy by macrophages and attenuate the formation of foam cells. However, the effect of Pdcd4 on the subsets of T cells in hyperlipidemic mice still remained unclear. In the present study, results showed that Pdcd4 deficiency decreased the percentage of CD8+ T cells and increased that of regulatory T cells (Tregs) under hyperlipidemic conditions both in vitro and in vivo, which may be due to the reduced expression of co-stimulatory molecules CD28 and CD137, and the enhancive expression of co-inhibitory molecules CTLA-4. These results indicated that endogenous Pdcd4 promotes immune response mediated by T cells through regulation of the co-stimulatory molecules expression, which may contribute to the development of advanced atherosclerotic plaques. The current work provides new data to understand the role of Pdcd4 in different T cell subsets under hyperlipidemic microenvironment.


Assuntos
Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/metabolismo , Hiperlipidemias/metabolismo , Proteínas de Ligação a RNA/metabolismo , Subpopulações de Linfócitos T/metabolismo , Animais , Apoptose/fisiologia , Antígenos CD28/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Células Espumosas/metabolismo , Interleucina-10/metabolismo , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Placa Aterosclerótica/metabolismo , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo
17.
Nat Commun ; 10(1): 3020, 2019 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-31289263

RESUMO

Human cytomegalovirus (HCMV) can persistently infect humans, but how HCMV avoids humoral immunity is not clear. The neonatal Fc receptor (FcRn) controls IgG transport from the mother to the fetus and prolongs IgG half-life. Here we show that US11 inhibits the assembly of FcRn with ß2m and retains FcRn in the endoplasmic reticulum (ER), consequently blocking FcRn trafficking to the endosome. Furthermore, US11 recruits the ubiquitin enzymes Derlin-1, TMEM129 and UbE2J2 to engage FcRn, consequently initiating the dislocation of FcRn from the ER to the cytosol and facilitating its degradation. Importantly, US11 inhibits IgG-FcRn binding, resulting in a reduction of IgG transcytosis across intestinal or placental epithelial cells and IgG degradation in endothelial cells. Hence, these results identify the mechanism by which HCMV infection exploits an ER-associated degradation pathway through US11 to disable FcRn functions. These results have implications for vaccine development and immune surveillance.


Assuntos
Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Evasão da Resposta Imune , Imunidade Humoral , Proteínas de Ligação a RNA/metabolismo , Receptores Fc/metabolismo , Proteínas Virais/metabolismo , Linhagem Celular , Citomegalovirus/patogenicidade , Infecções por Citomegalovirus/virologia , Degradação Associada com o Retículo Endoplasmático/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mutagênese Sítio-Dirigida , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/imunologia , Receptores Fc/imunologia , Enzimas de Conjugação de Ubiquitina/genética , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Virais/genética , Proteínas Virais/imunologia
18.
Nature ; 571(7765): 424-428, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31292544

RESUMO

N6-methyladenosine (m6A) is the most prevalent modified nucleotide in mRNA1,2, with around 25% of mRNAs containing at least one m6A. Methylation of mRNA to form m6A is required for diverse cellular and physiological processes3. Although the presence of m6A in an mRNA can affect its fate in different ways, it is unclear how m6A directs this process and why the effects of m6A can vary in different cellular contexts. Here we show that the cytosolic m6A-binding proteins-YTHDF1, YTHDF2 and YTHDF3-undergo liquid-liquid phase separation in vitro and in cells. This phase separation is markedly enhanced by mRNAs that contain multiple, but not single, m6A residues. Polymethylated mRNAs act as a multivalent scaffold for the binding of YTHDF proteins, juxtaposing their low-complexity domains and thereby leading to phase separation. The resulting mRNA-YTHDF complexes then partition into different endogenous phase-separated compartments, such as P-bodies, stress granules or neuronal RNA granules. m6A-mRNA is subject to compartment-specific regulation, including a reduction in the stability and translation of mRNA. These studies reveal that the number and distribution of m6A sites in cellular mRNAs can regulate and influence the composition of the phase-separated transcriptome, and suggest that the cellular properties of m6A-modified mRNAs are governed by liquid-liquid phase separation principles.


Assuntos
Adenosina/análogos & derivados , Compartimento Celular , RNA Mensageiro/química , RNA Mensageiro/metabolismo , Adenosina/metabolismo , Animais , Transporte Biológico , Linhagem Celular , Grânulos Citoplasmáticos/química , Grânulos Citoplasmáticos/metabolismo , Humanos , Metilação , Metiltransferases/deficiência , Camundongos , Transição de Fase , RNA Mensageiro/análise , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Estresse Fisiológico
19.
Cell Prolif ; 52(5): e12615, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31310044

RESUMO

OBJECTIVES: It has been widely reported that long non-coding RNAs (lncRNAs) can participate in multiple biological processes of human cancers. lncRNA HLA complex group 11 (HCG11) has been reported in human cancers as a tumour suppressor. This study focused on investigating the function and mechanism of HCG11 in glioma. MATERIALS AND METHODS: Based on The Cancer Genome Atlas (TCGA) data set and qRT-PCR analysis, the expression pattern of HCG11 was identified in glioma samples. The mechanism associated with HCG11 downregulation was determined by mechanism experiments. Gain-of-function assays were conducted for the identification of HCG11 function in glioma progression. Mechanism investigation based on the luciferase reporter assay, RIP assay and pull-down assay was used to explore the downstream molecular mechanism of HCG11. The role of molecular pathway in the progression of glioma was analysed in accordance with the rescue assays. RESULTS: HCG11 was expressed at low level in glioma samples compared with normal samples. FOXP1 could bind with HCG11 and transcriptionally inactivated HCG11. Overexpression of HCG11 efficiently suppressed cell proliferation, induced cell cycle arrest and promoted cell apoptosis. HCG11 was predominantly enriched in the cytoplasm of glioma cells and acted as a competing endogenous RNAs (ceRNAs) by sponging micro-496 to upregulate cytoplasmic polyadenylation element binding protein 3 (CPEB3). CEPB3 and miR-496 involved in HCG11-mediated glioma progression. CONCLUSIONS: HCG11 inhibited glioma progression by regulating miR-496/CPEB3 axis.


Assuntos
Glioma/patologia , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Antagomirs/metabolismo , Apoptose , Pontos de Checagem do Ciclo Celular , Linhagem Celular , Movimento Celular , Proliferação de Células , Progressão da Doença , Fatores de Transcrição Forkhead/química , Fatores de Transcrição Forkhead/metabolismo , Glioma/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Interferência de RNA , RNA Longo não Codificante/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/genética , Proteínas Repressoras/química , Proteínas Repressoras/metabolismo
20.
Int J Mol Sci ; 20(13)2019 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-31261900

RESUMO

The insulin-like growth factor 2 (IGF2) mRNA binding protein IMP2 (IGF2BP2) is an oncogenic protein known to be overexpressed in different tumor types. Pancreatic cancer is a very lethal cancer that requires early diagnosis and new treatment options. The aim of our study was to investigate the role of IMP2 in the initiation and progression of pancreatic ductal adenocarcinoma (PDAC). IMP2 was significantly overexpressed in a human precursor (PanIN) lesions suggesting IMP2 as a marker for early stages of PDAC. In a PDAC cohort of matched normal and tumor samples IMP2 showed overexpression in tumor tissues compared with normal pancreatic tissue. Strict correlation analysis (threshold R2 > 0.75) revealed 22 genes highly positively and 9 genes highly negatively correlating with IMP2. Besides genes involved in the inhibition of apoptosis (Bcl-XL), especially factors involved in ubiquitination were strongly correlated with IMP2 expression: SMURF1 and FBXO45. Moreover, protein kinase C (PKC) signaling pathway was distinctly affected: DXS1179E encoding PKC iota, PKC substrate PLEK2, and inositol triphosphate receptor IP3R3 were positively correlated with IMP2 expression. Besides tumor initiation, IMP2 also seemed to have an impact on tumor progression. TGF-ß treatment of Panc-1 pancreatic cancer cells to induce epithelial-mesenchymal transition (EMT) was accompanied by increased IMP2 expression. EMT is important for cancer cells to gain migratory and invasive potential, which is essential for metastasis. Concordantly, circulating tumor cells showed higher IMP2 levels as compared with normal tissue from tumor origin and with normal hematological cells. Accordingly, IMP2 protein levels correlated with poor survival. In conclusion, as IMP2 seems to promote tumor progression of PDAC, it might be an interesting diagnostic and prognostic marker as well as a novel target for the treatment of PDAC.


Assuntos
Adenocarcinoma/metabolismo , Biomarcadores Tumorais/genética , Neoplasias Pancreáticas/metabolismo , Proteínas de Ligação a RNA/genética , Adenocarcinoma/genética , Adenocarcinoma/patologia , Biomarcadores Tumorais/metabolismo , Transição Epitelial-Mesenquimal , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Proteína Quinase C/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Regulação para Cima
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