Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.027
Filtrar
1.
Anticancer Res ; 39(11): 6379-6387, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31704871

RESUMO

BACKGROUND/AIM: In the present retrospective study, we assessed the molecular profile and clinicopathological correlations of Greek colorectal carcinoma (CRC) patients. PATIENTS AND METHODS: Data from 157 CRC patients were collected. High Resolution Melting Analysis and Pyrosequencing/Sanger sequencing were applied to identify KRAS, BRAF, NRAS mutations and microsatellite instability (MSI) status. Immunohistochemistry was performed to characterize the associated Mismatch Repair Protein loss. Statistical calculations were performed using the statistical package SPSS v21.0. RESULTS: KRAS mutations were detected in 39.3% of cases, BRAF in 10.9% and NRAS in 4.9%. MSI status was recognized in 11.5% of CRC patients and was associated with right colon tumors. MSI phenotype was inversely correlated with stage, N status and KRAS mutations and positively correlated with BRAF mutations. CONCLUSION: MSI positive CRCs in the Greek population are more often right-sided, free of metastasis, KRAS wild type and BRAF mutated. Providing more detailed clinicopathological and molecular data for specific populations will enable better clinical management and individualized therapy in the future.


Assuntos
Neoplasias do Colo/genética , GTP Fosfo-Hidrolases/genética , Proteínas de Membrana/genética , Instabilidade de Microssatélites , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Colo/patologia , Feminino , Grécia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores Sexuais , Neoplasias do Colo Sigmoide/genética , Neoplasias do Colo Sigmoide/patologia
2.
Bratisl Lek Listy ; 120(11): 832-838, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31747763

RESUMO

Head and neck squamous cell carcinomas (HNSCC) are a highly heterogenous disease which can be induced by two main carcinogens - tobacco and/or alcohol, or by HR HPV infection. This work examined 60 paraffin-embedded biopsies of head and neck carcinomas after histological verification. HPV infection, including its specific types in various HNSCC areas, was studied using multiplex qPCR. Expression levels of p16INK4A and p53 were detected by subsequent IHC analysis as being potential diagnostic markers. Based on the assumption that patients with HNSCC could benefit from anti-EGFR therapy (cetuximab), but the predictors are not yet defined, analyses of point mutations of ras genes (Kras, Nras) were carried out using multiplex qPCR and sequence analysis of the Braf gene. All statistical data were processed by Chí-x2 test.HPV infection was detected in 23.34 % of cases with HNSCC, of which 100 % were HPV 16, which is the most frequently infection found in the oropharyngeal region. Using IHC analysis, a positive expression of P16INK4A was detected in 100 % of HPV-positive HNSCC while this expression was discovered to be highly correlated with HPV infection. Furthermore, a correlation between p53 and HPV-negative HNSCC was proved. The mutation incidence was the highest in the Kras gene (codon 12 and codon 146), Nras (codon 12) and Braf. A correlation between tumor location in the oropharyngeal region and Kras mutations was proved. The HPV infection correlated with Kras mutations in case of codon 146 but on the grounds of low amount of output data, these figures could be irrelevant. In one case, c.1808 G>A, protein 603 Arg>Gln mutation was found in the Braf gene but its correlation with head and neck carcinomas has not been described yet (Tab. 2, Fig. 2, Ref. 24). Keywords: head and neck carcinomas, biopsy, HPV types, PCR, p16INK4A, p53, molecular predictors, Kras, Nras, Braf.


Assuntos
Carcinoma de Células Escamosas/genética , Neoplasias de Cabeça e Pescoço/genética , Infecções por Papillomavirus/complicações , Carcinoma de Células Escamosas/virologia , Inibidor p16 de Quinase Dependente de Ciclina/genética , GTP Fosfo-Hidrolases/genética , Neoplasias de Cabeça e Pescoço/virologia , Papillomavirus Humano 16 , Humanos , Imuno-Histoquímica , Proteínas de Membrana/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteína Supressora de Tumor p53/genética
3.
DNA Cell Biol ; 38(8): 796-807, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31295012

RESUMO

Myocardial hypertrophy is an important cause of heart failure and sudden death. Studies have shown that Mitofusin-2 (MFN2) is downregulated in myocardial hypertrophy, but the upstream regulation mechanism underlying its downexpression in cardiomyocytes is still unclear. This study aims to identify the expression profile of microRNAs (miRNAs) in hypertrophic cardiomyopathy (HCM) and explore the function of miRNA-20 in inducing cardiomyocyte hypertrophy through regulating MFN2. Through miRNA + mRNA microarray analysis, 1451 miRNAs were identified, 367 miRNAs expressed differently between groups. Meanwhile, a number of 24,718 mRNAs were identified, among which 5850 mRNAs were upregulated and 3005 mRNAs were downregulated in HCM group compared with the control group. Expression of hsa-miRNA-20a-5p was 2.26 times higher in the HCM group compared with the control group and 7 target gene prediction programs predicted MFN2 as a target of miRNA-20. In vitro model of hypertrophic cardiomyocytes displayed high expression level of miRNA-20, atrial natriuretic peptide (ANP) mRNA, and protein, accompanying low expression level of Mfn2 mRNA and protein, which meant miRNA-20 played a role in cardiomyocyte hypertrophy and might interact with MFN2 to function. Thereafter, overexpression of miRNA-20 led to cell hypertrophy accompanied with lowly expressed Mfn2 mRNA and protein. When transfected with miRNA-20 inhibitors, the expression of miRNA-20 and ANP gene was attenuated and MFN2 was the other way around. The cell surface area of Ang II group and mimic group was significantly larger compared with the control group, and in the inhibitor+Ang II group, the area was significantly decreased compared with the Ang II group. Dual-luciferase assays showed that miRNA-20 bound to 3' untranslated region of MFN2 and inhibited its expression. In conclusion, hypertrophic myocardium and normal myocardium have different miRNA expression profiles and the effect of miRNA-20 reducing the expression of MFN2 plays a role in promoting cardiomyocyte hypertrophy.


Assuntos
Cardiomiopatia Hipertrófica/genética , GTP Fosfo-Hidrolases/genética , MicroRNAs/genética , Proteínas Mitocondriais/genética , Miócitos Cardíacos/patologia , Regiões 3' não Traduzidas , Adulto , Angiotensina II/farmacologia , Animais , Estudos de Casos e Controles , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Proteínas de Membrana/genética , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Miócitos Cardíacos/efeitos dos fármacos , Ratos Wistar
4.
Int J Mol Sci ; 20(13)2019 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-31261893

RESUMO

BACKGROUND: Parkinson's disease (PD) is one of the most common neurodegenerative disorders involving devastating loss of dopaminergic neurons in the substantia nigra. Early steps in PD pathogenesis include mitochondrial dysfunction, and mutations in mitochondrial genes have been linked to familial forms of the disease. However, low penetrance of mutations indicates a likely important role for environmental factors in PD risk through gene by environment interactions. Herein, we study how genetic deficiencies in mitochondrial dynamics processes including fission, fusion, and mitophagy interact with environmental exposures to impact neurodegeneration. METHODS: We utilized the powerful model organism Caenorhabditis elegans to study ultraviolet C radiation (UVC)- and 6-hydroxydopamine-induced degeneration of fluorescently-tagged dopaminergic neurons in the background of fusion deficiency (MFN1/2 homolog, fzo-1), fission deficiency (DMN1L homolog, drp-1), and mitochondria-specific autophagy (mitophagy) deficiency (PINK1 and PRKN homologs, pink-1 and pdr-1). RESULTS: Overall, we found that deficiency in either mitochondrial fusion or fission sensitizes nematodes to UVC exposure (used to model common environmental pollutants) but protects from 6-hydroxydopamine-induced neurodegeneration. By contrast, mitophagy deficiency makes animals more sensitive to these stressors with an interesting exception-pink-1 deficiency conferred remarkable protection from 6-hydroxydopamine. We found that this protection could not be explained by compensatory antioxidant gene expression in pink-1 mutants or by differences in mitochondrial morphology. CONCLUSIONS: Together, our results support a strong role for gene by environment interactions in driving dopaminergic neurodegeneration and suggest that genetic deficiency in mitochondrial processes can have complex effects on neurodegeneration.


Assuntos
Neurônios Dopaminérgicos/metabolismo , Dinâmica Mitocondrial , Doença de Parkinson/genética , Tolerância a Radiação/genética , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/efeitos da radiação , Dinaminas/genética , GTP Fosfo-Hidrolases/genética , Degradação Mitocondrial , Oxidopamina/toxicidade , Doença de Parkinson/etiologia , Proteínas Serina-Treonina Quinases/genética , Ubiquitina-Proteína Ligases/genética , Raios Ultravioleta/efeitos adversos
5.
Biochemistry (Mosc) ; 84(4): 416-425, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31228933

RESUMO

The Q61R mutation of the NRAS gene is one of the most frequent driver mutations of thyroid cancer. Tumors with this mutation are characterized by invasion into blood vessels and formation of distant metastases. To study the role of this mutation in the growth of thyroid cancer, we developed a model system on the basis of thyroid epithelial cell line Nthy-ori 3-1 transduced by a lentiviral vector containing the NRAS gene with the Q61R mutation. It was found that the expression of NRAS(Q61R) in thyroid epithelial cells has a profound influence on groups of genes involved in the formation of intercellular contacts, as well as in processes of epithelial-mesenchymal transition and cell invasion. The alteration in the expression of these genes affects the phenotype of the model cells, which acquire traits of mesenchymal cells and demonstrate increased ability for survival and growth without attachment to the substrate. The key regulators of these processes are transcription factors belonging to families SNAIL, ZEB, and TWIST, and in different types of tumors the contribution of each individual factor can vary greatly. In our model system, phenotype change correlates with an increase in the expression of SNAIL2 and TWIST2 factors, which indicates their possible role in regulating invasive growth of thyroid cancer with the mutation of NRAS(Q61R).


Assuntos
Transição Epitelial-Mesenquimal , GTP Fosfo-Hidrolases/metabolismo , Proteínas de Membrana/metabolismo , Neoplasias da Glândula Tireoide/genética , Transcriptoma , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , GTP Fosfo-Hidrolases/genética , Humanos , Proteínas de Membrana/genética , Mutagênese Sítio-Dirigida , Fenótipo , Transdução de Sinais , Fatores de Transcrição da Família Snail/metabolismo , Células Epiteliais da Tireoide/citologia , Células Epiteliais da Tireoide/metabolismo , Fatores de Transcrição Twist/metabolismo
6.
Dis Colon Rectum ; 62(7): 832-839, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31188184

RESUMO

BACKGROUND: Mutation analyses provide the basis of selecting an appropriate target agent for the treatment of metastatic colorectal cancer. However, metachronous metastases developed after the treatment of primary tumor could create significant opportunities for different genetic profiles relative to the primary tumors. OBJECTIVE: The purpose of this study was to assess the necessity of genetic evaluation of metachronous metastases; we performed a quantitative analysis of genetic discordance between metachronous metastases and radically resected primary colorectal cancers using next-generation sequencing. DESIGN: This was a retrospective study. SETTINGS: Patients from a single-institution tertiary care center were studied. PATIENTS: We enrolled 33 patients who underwent resection of metachronous metastases between January 2014 and December 2016, ≥6 months after radical resection of primary colorectal cancer and whose tissue was available for analysis. MAIN OUTCOME MEASURES: Tumor samples were analyzed by next-generation sequencing. The mutant allele frequency was analyzed to evaluate the proportion of mutations in the tumor tissue. RESULTS: The mutant allele frequency of KRAS in metachronous metastases was higher in 6 cases (mean difference =% 25.5% (range, 9.5%-58.0%)) and lower in 3 cases (mean difference = 9.3% (range, 8.0-10.0%) compared with each of their primary tumors. In 1 case, the KRAS mutant-type (mutant allele frequency = 22.6%) metachronous metastasis had developed from the KRAS wild-type primary tumor. LIMITATIONS: Tumor sample may not represent perfectly the whole tumor of the patient because of heterogeneity. CONCLUSIONS: Genetic discordance can exist between metachronous metastases and radically resected primary colorectal cancers. For appropriate target therapy, genetic evaluation of metachronous metastases needs to be considered when possible. See Video Abstract at http://links.lww.com/DCR/A932.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/terapia , Análise Mutacional de DNA , Intervalo Livre de Doença , Feminino , GTP Fosfo-Hidrolases/genética , Frequência do Gene , Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Metástase Neoplásica , Proteínas Proto-Oncogênicas B-raf/genética , Estudos Retrospectivos , Proteína Supressora de Tumor p53/genética
7.
J Dairy Sci ; 102(8): 7536-7547, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31178189

RESUMO

High blood concentrations of nonesterified fatty acids (NEFA) and altered lipid metabolism are key characteristics of fatty liver in dairy cows. In nonruminants, the mitochondrial membrane protein mitofusin 2 (MFN2) plays important roles in regulating mitochondrial function and intrahepatic lipid metabolism. Whether MFN2 is associated with hepatic lipid metabolism in dairy cows with moderate fatty liver is unknown. Therefore, to investigate changes in MFN2 expression and lipid metabolic status in dairy cows with moderate fatty liver, blood and liver samples were collected from healthy dairy cows (n = 10) and cows with moderate fatty liver (n = 10). To determine the effects of MFN2 on lipid metabolism in vitro, hepatocytes isolated from healthy calves were used for small interfering RNA-mediated silencing of MFN2 or adenovirus-mediated overexpression of MFN2 for 48 h, or treated with 0, 0.6, 1.2, or 2.4 mM NEFA for 12 h. Milk production and plasma glucose concentrations in dairy cows with moderate fatty liver were lower, but concentrations of NEFA and ß-hydroxybutyrate (BHB) were greater in dairy cows with moderate fatty liver. Dairy cows with moderate fatty liver displayed hepatic lipid accumulation and lower abundance of hepatic MFN2, peroxisome proliferator-activated receptor-α (PPARα), and carnitine palmitoyltransferase 1A (CPT1A). However, sterol regulatory element-binding protein 1c (SREBP-1c), acetyl CoA carboxylase 1 (ACACA), fatty acid synthase (FASN), and diacylglycerol acyltransferase 1 (DGAT1) were more abundant in the livers of dairy cows with moderate fatty liver. In vitro, exogenous NEFA treatment upregulated abundance of SREBP-1c, ACACA, FASN, and DGAT1, and downregulated the abundance of PPARα and CPT1A. These changes were associated with greater lipid accumulation in calf hepatocytes, and MFN2 silencing aggravated this effect. In contrast, overexpression of MFN2-ameliorated exogenous NEFA-induced lipid accumulation by downregulating the abundance of SREBP-1c, ACACA, FASN, and DGAT1, and upregulating the abundance of PPARα and CPT1A in calf hepatocytes. Overall, these data suggest that one cause for the negative effect of excessive NEFA on hepatic lipid accumulation is the inhibition of MFN2. As such, these mechanisms partly explain the development of hepatic steatosis in dairy cows.


Assuntos
Doenças dos Bovinos/metabolismo , Bovinos/metabolismo , Fígado Gorduroso/veterinária , GTP Fosfo-Hidrolases/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Ácido 3-Hidroxibutírico/metabolismo , Animais , Bovinos/genética , Doenças dos Bovinos/enzimologia , Doenças dos Bovinos/genética , Diacilglicerol O-Aciltransferase/genética , Diacilglicerol O-Aciltransferase/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Fígado Gorduroso/enzimologia , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Feminino , GTP Fosfo-Hidrolases/genética , Hepatócitos/enzimologia , Hepatócitos/metabolismo , Mitocôndrias/metabolismo , PPAR alfa/genética , PPAR alfa/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
8.
Arch Virol ; 164(8): 2091-2106, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31139938

RESUMO

Beak and feather disease virus (BFDV) belongs to the family Circoviridae. A rolling-circle replication strategy based on a replication-associated protein (Rep) has been proposed for BFDV. The Rep gene of BFDV was expressed and purified, and it was shown to cleave short oligonucleotides containing the conserved nonanucleotide sequence found in the replication origin of circoviruses. This endonuclease activity was most efficient in the presence of the divalent metal ions Mg2+ and Mn2+. Rep proteins containing mutation in the ATPase/GTPase motifs and the 14FTLNN18, 61KKRLS65, 89YCSK92, and 170GKS172 motifs lacked endonuclease activity. The endonuclease activity was not affected by ATPase inhibitors, with the exception of N-ethylmaleimide (NEM), or by GTPase inhibitors, but it was decreased by treatment with the endonuclease inhibitor L-742001. Both the ATPase and GTPase activities were decreased by site-directed mutagenesis and deletion of the ATPase/GTPase and endonuclease motifs. The Rep protein was able to bind a double-stranded DNA fragment of P36 (dsP36) containing the stem-loop structure of the replication origin of BFDV. All of the Rep mutant proteins showed reduced ability to bind this fragment, suggesting that all the ATPase/GTPase and endonuclease motifs are involved in the binding. Other than NEM, all ATPase, GTPase, and endonuclease inhibitors inhibited the binding of the Rep protein to the dsP36 fragment. This is the first report describing the endonuclease activity of the Rep protein of BFDV.


Assuntos
Circovirus/genética , Replicação do DNA/genética , Endonucleases/genética , Replicação Viral/genética , Adenosina Trifosfatases/genética , Infecções por Circoviridae/virologia , DNA Helicases/genética , DNA Viral/genética , GTP Fosfo-Hidrolases/genética , Origem de Replicação/genética , Transativadores/genética
9.
Zhonghua Bing Li Xue Za Zhi ; 48(5): 373-377, 2019 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-31104677

RESUMO

Objective: To analyze the concordance of KRAS, NRAS, BRAF and PIK3CA gene mutations detected in plasma and matched tumor tissues in colorectal cancer patients, in order to provide good evidences to support plasma could be a potential surrogate of tumor tissue for gene mutation test. Methods: One hundred and seventy-five cases of colorectal cancer were collected at the First Hospital of Jilin University, from October 2016 to October 2017.There were 101 males and 74 females, their ages ranged from 28 to 85 years,with median age of 59 years. The KRAS, NRAS, BRAF and PIK3CA gene mutations in the plasma and paired tumor specimens of all patients were detected by next generation sequencing. Results: The results of tissue samples test were gold standard. Comparison of the four genes showed that concordance rates between plasma and tissue samples were 81.1%(Kappa=0.543), 99.4%(Kappa=0.886), 99.4% (Kappa=0.886) and 97.7%(Kappa=0.714) respectively for KRAS, NRAS, BRAF and PIK3CA. The plasma detection rates of these genes were related to tumor stage(P=0.001), but not to gender(P=0.468) and age(P=1.000) of patients. Conclusions: The study shows a high concordance of KRAS, NRAS, BRAF and PIK3CA gene mutations in plasma against mutation status in tumor tissue. In colorectal cancer, tumor tissue remains the best specimen for gene detection. However, patients from tumor tissue specimens cannot be obtained, especially those with advanced metastases, plasma can be used instead of tissue to detect the mutation status of KRAS, NRAS, BRAF and PIK3CA to guide targeted therapy.


Assuntos
Classe I de Fosfatidilinositol 3-Quinases , Neoplasias Colorretais , GTP Fosfo-Hidrolases , Proteínas de Membrana , Mutação , Proteínas Proto-Oncogênicas B-raf , Proteínas Proto-Oncogênicas p21(ras) , Adulto , Idoso , Idoso de 80 Anos ou mais , Classe I de Fosfatidilinositol 3-Quinases/genética , Neoplasias Colorretais/genética , Feminino , GTP Fosfo-Hidrolases/genética , Humanos , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética
10.
Microbiol Res ; 222: 14-24, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30928026

RESUMO

Analysis of the Agrobacterium tumefaciens C58 genome revealed a potential Zur (zinc uptake regulator) binding site (5'-GATATGTTATTACATTAC-3', the underlined letters are the center of symmetry of the inverted palindrome) located in the upstream region of atu3184, whose gene product is a member of the COG0523 subfamily of G3E GTPases. The specific interaction of the Zur protein with the 18-bp inverted repeat operator motif in the presence of zinc was demonstrated in vitro by a DNA band shift assay and a DNase I footprinting assay. A LacZ reporter fusion assay further confirmed that Zur negatively regulates atu3184 promoter activity in vivo. The expression of atu3184 was upregulated in response to zinc limitation in the wild-type strain, but the zur mutant strain exhibited high-level constitutive expression of atu3184 under all conditions, irrespective of the zinc levels. It is likely that A. tumefaciens Zur senses zinc and directly regulates the atu3184 promoter by a molecular mechanism similar to that of Escherichia coli Zur, where the operator DNA is surrounded by four Zur monomers forming two dimers bound on the opposite sides of the DNA duplex. Disruption of atu3184 did not affect cell growth under metal-limited conditions and had no effect on the total cellular zinc content. Furthermore, an A. tumefaciens strain lacking atu3184 caused a tumor disease in a host plant.


Assuntos
Agrobacterium tumefaciens/genética , Proteínas de Bactérias/genética , Proteínas de Ligação a DNA/genética , Proteínas de Escherichia coli/genética , GTP Fosfo-Hidrolases/genética , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Agrobacterium tumefaciens/crescimento & desenvolvimento , Pegada de DNA , DNA Bacteriano , Escherichia coli , Regulação Bacteriana da Expressão Gênica , Chaperonas Moleculares , Óperon , Regiões Promotoras Genéticas , Proteínas Recombinantes , Virulência/genética , Zinco/metabolismo
11.
Cancer Discov ; 9(4): 469-471, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30936219

RESUMO

In this issue, Maertens and colleagues demonstrate that HDAC3 inhibition potentiates the effects of MAPK pathway inhibitors in melanoma, including difficult-to-treat NRAS- and NF1-driven tumors, with MGMT expression serving as a biomarker for responsiveness to the BRAF/MEK/HDAC inhibitor combination. Mechanistically, this triple cocktail suppresses expression of genes involved in DNA repair, leading to enhanced killing of melanoma cells.See related article by Maertens et al., p. 526.


Assuntos
Melanoma/genética , Proteínas Proto-Oncogênicas B-raf/genética , Reparo do DNA/efeitos dos fármacos , GTP Fosfo-Hidrolases/genética , Humanos , Proteínas de Membrana/genética , Inibidores de Proteínas Quinases
12.
Med Sci Monit ; 25: 2419-2428, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30940795

RESUMO

BACKGROUND Many studies have shown that hypertension may contribute to thoracic aortic dissection (TAD). Among the factors that modulate hypertension are endoplasmic reticulum stress and vascular smooth muscle cell proliferation which are in turn modulated by mitofusion-2 (Mfn2). Specifically, we determined, in the Han Chinese population, whether single nucleotide polymorphisms (SNPs) of Mfn2 influenced the occurrence of TAD. MATERIAL AND METHODS Six tagging SNPs of Mfn2 (rs2236057, rs3766741, rs2236058, rs17037564, rs2295281, and rs2336384) were genotyped using a TaqMan assay in 200 TAD patients and 451 health individuals from the Han Chinese population. RESULTS Logistic regression analysis indicated CC genotype of rs2295281 was highly linked to an increased risk of TAD (TT+CT versus CC, OR=0.540, 95% CI [0.320-0.911], P=0.021), implying that TT genotype and CT genotype of rs2295281 have a lower risk for TAD. Logistic regression analysis also indicated that rs2236058 was highly linked to the risk of TAD based on recessive genetic model, which indicated that the GG genotype was a protective factor against TAD (GG versus (CG+CC), OR=0.545, 95% CI [0.351-0.845], P=0.007). CG genotype and CC genotype of rs2236058 had a higher risk for TAD. In addition, rs2236058 was linked to the risk of TAD in the recessive genetic and homozygous models in the normotensive subgroup (GG versus (CG+CC), OR=0.298, 95% CI [0.112-0.792], P=0.015; GG versus CC, OR=0.528, 95% CI [0.302-0.925], P=0.026) but not in the hypertension subgroup. CONCLUSIONS Our findings showed that the occurrence of TAD in a Han Chinese population was influenced by Mfn2 polymorphisms.


Assuntos
Aneurisma Dissecante/genética , Aneurisma da Aorta Torácica/genética , GTP Fosfo-Hidrolases/genética , Proteínas Mitocondriais/genética , Adulto , Idoso , Alelos , Grupo com Ancestrais do Continente Asiático/genética , Estudos de Casos e Controles , China , Grupos Étnicos/genética , Feminino , GTP Fosfo-Hidrolases/fisiologia , Frequência do Gene/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Mitocondriais/fisiologia , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco
13.
Nucleic Acids Res ; 47(8): 4086-4110, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-30986824

RESUMO

Ataxia with oculomotor apraxia type 1 (AOA1) is an early onset progressive spinocerebellar ataxia caused by mutation in aprataxin (APTX). APTX removes 5'-AMP groups from DNA, a product of abortive ligation during DNA repair and replication. APTX deficiency has been suggested to compromise mitochondrial function; however, a detailed characterization of mitochondrial homeostasis in APTX-deficient cells is not available. Here, we show that cells lacking APTX undergo mitochondrial stress and display significant changes in the expression of the mitochondrial inner membrane fusion protein optic atrophy type 1, and components of the oxidative phosphorylation complexes. At the cellular level, APTX deficiency impairs mitochondrial morphology and network formation, and autophagic removal of damaged mitochondria by mitophagy. Thus, our results show that aberrant mitochondrial function is a key component of AOA1 pathology. This work corroborates the emerging evidence that impaired mitochondrial function is a characteristic of an increasing number of genetically diverse neurodegenerative disorders.


Assuntos
Proteínas de Ligação a DNA/genética , GTP Fosfo-Hidrolases/genética , Mitocôndrias/genética , Degradação Mitocondrial/genética , Proteínas Nucleares/genética , Ataxias Espinocerebelares/congênito , Linhagem Celular Transformada , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/deficiência , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , GTP Fosfo-Hidrolases/deficiência , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Homeostase/genética , Humanos , Linfócitos/metabolismo , Linfócitos/patologia , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Proteínas Nucleares/deficiência , Análise de Sequência com Séries de Oligonucleotídeos , Osteoblastos/metabolismo , Osteoblastos/patologia , Fosforilação Oxidativa , Transdução de Sinais , Ataxias Espinocerebelares/genética , Ataxias Espinocerebelares/metabolismo , Ataxias Espinocerebelares/patologia
14.
PLoS Genet ; 15(4): e1008059, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31022167

RESUMO

The ubiquitous second messenger c-di-GMP promotes bacterial biofilm formation by playing diverse roles in the underlying regulatory networks. This is reflected in the multiplicity of diguanylate cyclases (DGC) and phosphodiesterases (PDE) that synthesize and degrade c-di-GMP, respectively, in most bacterial species. One of the 12 DGCs of Escherichia coli, DgcE, serves as the top-level trigger for extracellular matrix production during macrocolony biofilm formation. Its multi-domain architecture-a N-terminal membrane-inserted MASE1 domain followed by three PAS, a GGDEF and a degenerate EAL domain-suggested complex signal integration and transmission through DgcE. Genetic dissection of DgcE revealed activating roles for the MASE1 domain and the dimerization-proficient PAS3 region, whereas the inhibitory EALdeg domain counteracts the formation of DgcE oligomers. The MASE1 domain is directly targeted by the GTPase RdcA (YjdA), a dimer or oligomer that together with its partner protein RdcB (YjcZ) activates DgcE, probably by aligning and promoting dimerization of the PAS3 and GGDEF domains. This activation and RdcA/DgcE interaction depend on GTP hydrolysis by RdcA, suggesting GTP as an inhibitor and the pronounced decrease of the cellular GTP pool during entry into stationary phase, which correlates with DgcE-dependent activation of matrix production, as a possible input signal sensed by RdcA. Furthermore, DgcE exhibits rapid, continuous and processive proteolytic turnover that also depends on the relatively disordered transmembrane MASE1 domain. Overall, our study reveals a novel GTP/c-di-GMP-connecting signaling pathway through the multi-domain DGC DgcE with a dual role for the previously uncharacterized MASE1 signaling domain.


Assuntos
Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Fósforo-Oxigênio Liases/genética , Fósforo-Oxigênio Liases/metabolismo , Proteínas de Escherichia coli/química , Matriz Extracelular/metabolismo , GTP Fosfo-Hidrolases/química , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Fósforo-Oxigênio Liases/química , Ligação Proteica , Domínios Proteicos , Domínios e Motivos de Interação entre Proteínas , Transdução de Sinais
15.
Oncol Rep ; 41(6): 3292-3304, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31002345

RESUMO

The ubiquitin­specific protease 9X (USP9X) is a conserved deubiquitinase that has been investigated in several types of human cancer. However, the clinical significance and the biological roles of USP9X in prostate cancer remain unexplored. In the present study, an investigation into the expression and clinical significance of USP9X in prostate cancer revealed that USP9X expression was downregulated in prostate cancer tissues compared with that in healthy tissues. In addition, decreased USP9X expression was associated with a higher Gleason score and local invasion. Depletion of USP9X in prostate cancer LNCaP and PC­3 cells by small interfering RNA promoted cell invasion and migration. Furthermore, USP9X depletion upregulated matrix metalloproteinase 9 (MMP9) and the phosphorylation of dynamin­related protein 1 (DRP1). Notably, a significant increase in phosphorylated extracellular signal­regulated kinase (ERK), an upstream activator of MMP9 and DRP1, was observed. To investigate whether ERK activation was able to increase MMP9 protein levels and induce DRP1 phosphorylation, an ERK inhibitor was used, demonstrating that ERK­mediated MMP9 production and change in mitochondrial function was critical for the biological function of USP9X in prostate cancer cells. In conclusion, the present study demonstrated that USP9X is downregulated in prostate cancer and functions as an inhibitor of tumor cell invasion, possibly through the regulation of the ERK signaling pathway.


Assuntos
GTP Fosfo-Hidrolases/genética , Metaloproteinase 9 da Matriz/genética , Proteínas Associadas aos Microtúbulos/genética , Proteínas Mitocondriais/genética , Neoplasias da Próstata/genética , Ubiquitina Tiolesterase/genética , Idoso , Movimento Celular/genética , Proliferação de Células/genética , Enzimas Desubiquitinantes/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Sistema de Sinalização das MAP Quinases/genética , Masculino , Pessoa de Meia-Idade , Dinâmica Mitocondrial/genética , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Fosforilação/genética , Neoplasias da Próstata/patologia
16.
Pathology ; 51(4): 399-404, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31023480

RESUMO

Partial regression is common in cutaneous melanoma; however, complete regression manifesting as tumoural melanosis is rare, conceptually challenging and under-reported. In this study we report on clinical, histological and molecular findings in four cases of completely regressed cutaneous melanoma with nodal or brain metastasis, followed by a comprehensive review of the literature. Our series included three women and one man with an average age of 60 years, and clinical presentation with hyper-pigmented cutaneous lesions. The main histological findings were expansile aggregates of melanophages with complete absence of malignant melanocytes on microscopic and immunohistochemical examination of the entire primary skin lesions, as well as substantial reduction in the number of junctional melanocytes in the overlying epidermis. NRAS mutant/BRAF wild type metastatic deposits were identified in three patients, with one patient having a BRAF V600E mutant metastatic tumour. Tumoural melanosis likely represents a partially effective immunological response to melanoma, with complete eradication of cutaneous disease and less effective systemic results. Patients with tumoural melanosis should be managed as potential completely regressed cutaneous melanoma, with comprehensive physical examination, imaging work up and close follow up.


Assuntos
GTP Fosfo-Hidrolases/genética , Melanoma/patologia , Melanose/patologia , Proteínas de Membrana/genética , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias Cutâneas/patologia , Idoso , Encéfalo/patologia , Feminino , GTP Fosfo-Hidrolases/metabolismo , Humanos , Linfonodos/patologia , Masculino , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Mutação , Metástase Neoplásica , Proteínas Proto-Oncogênicas B-raf/metabolismo
17.
Intern Med ; 58(14): 2091-2093, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30996168

RESUMO

A 33-year-old Japanese woman was referred for hoarseness. She had been diagnosed with Charcot-Marie-Tooth disease at age 3 and bilateral optic atrophy at age 15. Laryngoscopy revealed left vocal fold palsy. These findings suggested Charcot-Marie-Tooth disease type 2; the diagnosis was confirmed by a mitofusin 2 mutation analysis. Her symptoms remained stable for almost 10 years. Although vocal fold palsy and optic atrophy have been previously reported in patients with mitofusin 2 mutations, detailed clinical information and clinical course have never been documented. These data might contribute to the elucidation of the pathological conditions associated with mitofusin 2 mutations.


Assuntos
Doença de Charcot-Marie-Tooth/complicações , Doença de Charcot-Marie-Tooth/genética , GTP Fosfo-Hidrolases/genética , Proteínas Mitocondriais/genética , Atrofia Óptica/genética , Paralisia das Pregas Vocais/etiologia , Paralisia das Pregas Vocais/genética , Adolescente , Adulto , Doença de Charcot-Marie-Tooth/fisiopatologia , Pré-Escolar , Análise Mutacional de DNA , Feminino , Humanos , Atrofia Óptica/complicações , Atrofia Óptica/fisiopatologia , Paralisia das Pregas Vocais/fisiopatologia
18.
ACS Appl Mater Interfaces ; 11(17): 15322-15331, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30986029

RESUMO

Reactive oxygen species (ROS)-induced oxidative stress leads to neuron damage and is involved in the pathogenesis of chronic inflammation in neurodegenerative diseases (NDs), such as Alzheimer's, Parkinson's, and amyotrophic lateral sclerosis. Researchers, therefore, are looking for antiinflammatory drugs and gene therapy approaches to slow down or even prevent neurological disorders. Combining therapeutics has shown a synergistic effect in the treatment of human diseases. Many nanocarriers could be designed for the simultaneous codelivery of drugs with genes to fight diseases. However, only a few researches have been performed in NDs. In this study, we developed a mesoporous silica nanoparticle (MSN)-based approach for neurodegenerative therapy. This MSN-based platform involved multiple designs in the targeted codelivery of (1) curcumin, a natural antioxidant product, to protect ROS-induced cell damage and (2) plasmid RhoG-DsRed, which is associated with the formation of lamellipodia and filopodia for promoting neurite outgrowth. At the same time, TAT peptide was introduced to the plasmid RhoG-DsRed via electrostatic interaction to elevate the efficiency of nonendocytic pathways and the nuclear plasmid delivery of RhoG-DsRed in cells for enhanced gene expression. Besides, such a plasmid RhoG-DsRed/TAT complex could work as a noncovalent gatekeeper. The release of curcumin inside the channel of the MSN could be triggered when the complex was dissociated from the MSN surface. Taken together, this MSN-based platform combining genetic and pharmacological manipulations of an actin cytoskeleton as well as oxidative stress provides an attractive way for ND therapy.


Assuntos
Curcumina/farmacologia , Portadores de Fármacos/química , Nanopartículas/química , Crescimento Neuronal/efeitos dos fármacos , Plasmídeos/metabolismo , Dióxido de Silício/química , Citoesqueleto de Actina/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Curcumina/química , GTP Fosfo-Hidrolases/genética , Camundongos , Estresse Oxidativo , Tamanho da Partícula , Fragmentos de Peptídeos/química , Plasmídeos/química , Porosidade , Espécies Reativas de Oxigênio/metabolismo , Produtos do Gene tat do Vírus da Imunodeficiência Humana/química
19.
Cell Physiol Biochem ; 52(3): 435-438, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30873819

RESUMO

BACKGROUND/AIMS: Tachycardiomyopathy (TCM) is a largely reversible form of non-ischemic heart failure. The underlying mechanism are, however, still today poorly understood. Recent data indicate distinct changes in mitochondrial distribution in these patients, compared to other non-ischemic cardiomyopathies.This study investigated underlying mechanisms in mitochondrial dynamics in endomyocardial biopsy samples (EMB) from patients with TCM and compared them to patients with dilated cardiomyopathy (DCM), which show similar clinical features. METHODS: Focused mRNA analyses were performed on routinely obtained paraffinfixed EMB specimen from patients fulfilling TCM diagnosis criteria, as well as patients with DCM to elucidate regulatory changes in mitochondrial fusion, fission and mitophagy. RESULTS: In patients with TCM we were able to identify mRNA of Mitofusin 1 and 2, two effector proteins regulating mitochondrial fusion, to be strongly upregulated compared to patients with DCM. Conclusively, we did not find differences in the mRNA expression of mitochondrial fission regulators including DRP1, Fis1, MFF, MiD49, and MiD51. Furthermore, we did not find significant changes in PINK1 expression, an important mediator for mitochondrial autophagy. CONCLUSION: The mRNA upregulation of Mitofusin 1 and 2 provides first insight into the complex changes of mitochondrial dynamics in cardiomyocytes of patients with reversible heart failure due to TCM.


Assuntos
Cardiomiopatia Dilatada/genética , GTP Fosfo-Hidrolases/genética , Mitocôndrias/genética , Dinâmica Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas Mitocondriais/genética , RNA Mensageiro/genética , Biópsia , Cardiomiopatia Dilatada/classificação , Cardiomiopatia Dilatada/diagnóstico , Cardiomiopatia Dilatada/fisiopatologia , GTP Fosfo-Hidrolases/metabolismo , Regulação da Expressão Gênica , Frequência Cardíaca/fisiologia , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Degradação Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas Mitocondriais/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Fatores de Alongamento de Peptídeos/genética , Fatores de Alongamento de Peptídeos/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , RNA Mensageiro/metabolismo
20.
Mol Genet Genomic Med ; 7(5): e625, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30891959

RESUMO

BACKGROUND: Postzygotic KRAS, HRAS, NRAS, and FGFR1 mutations result in a group of mosaic RASopathies characterized by related developmental anomalies in eye, skin, heart, and brain. These oculocutaneous disorders include oculoectodermal syndrome (OES) encephalo-cranio-cutaneous lipomatosis (ECCL), and Schimmelpenning-Feuerstein-Mims syndrome (SFMS). Here, we report the results of the clinical and molecular characterization of a novel cohort of patients with oculocutaneous mosaic RASopathies. METHODS: Two OES, two ECCL, and two SFMS patients were ascertained in the study. In addition, two subjects with unilateral isolated epibulbar dermoids were also enrolled. Molecular analysis included PCR amplification and Sanger sequencing of KRAS, HRAS, NRAS, and FGFR1 genes in DNA obtained from biopsies (skin/epibulbar dermoids), buccal mucosa, and blood leukocytes. Massive parallel sequencing was employed in two cases with low-level mosaicism. RESULTS: In DNA from biopsies, mosaicism for pathogenic variants, including KRAS p.Ala146Thr in two OES subjects, FGFR1 p.Asn546Lys and KRAS p.Ala146Val in ECCL patients, and KRAS p.Gly12Asp in both SFMS patients, was demonstrated. No mutations were shown in DNA from conjunctival lesions in two subjects with isolated epibubar dermoids. CONCLUSION: Our study allowed the expansion of the clinical spectrum of mosaic RASopathies and supports that mosaicism for recurrent mutations in KRAS and FGFR1 is a commonly involved mechanism in these rare oculocutaneous anomalies.


Assuntos
Cisto Dermoide/genética , Displasia Ectodérmica/genética , Oftalmopatias/genética , Lipomatose/genética , Síndromes Neurocutâneas/genética , Nevo Sebáceo de Jadassohn/genética , Fenótipo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Cisto Dermoide/patologia , Displasia Ectodérmica/patologia , Oftalmopatias/patologia , GTP Fosfo-Hidrolases/genética , Humanos , Lipomatose/patologia , Proteínas de Membrana/genética , Mosaicismo , Síndromes Neurocutâneas/patologia , Nevo Sebáceo de Jadassohn/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA