RESUMO
In cancer, overactivation of poly (ADPribose) polymerases (PARP) plays a relevant role in DNA repair. We hypothesized that treatment with the PARP inhibitor rucaparib may reduce tumor burden via several biological mechanisms (apoptosis and oxidative stress) in mice. In lung tumors (LP07 lung adenocarcinoma) of mice treated/non-treated (control animals) with PARP inhibitor (rucaparib,150 mg/kg body weight/24 h for 20 day), PARP activity and expression, DNA damage, apoptotic nuclei, cell proliferation, and redox balance were measured using immunoblotting and immunohistochemistry. In lung tumors of rucaparib-treated mice compared to non-treated animals, tumor burden, PARP activity, and cell proliferation decreased, while DNA damage, TUNEL-positive nuclei, protein oxidation, and superoxide dismutase content (SOD)2 increased. In this experiment on lung adenocarcinoma, the pharmacological PARP inhibitor rucaparib elicited a significant improvement in tumor size, probably through a reduction in cell proliferation as a result of a rise in DNA damage and apoptosis. Oxidative stress and SOD2 also increased in response to treatment with rucaparib within the tumor cells of the treated mice. These results put the line forward to the contribution of PARP inhibitors to reduced tumor burden in lung adenocarcinoma. The potential implications of these findings should be tested in clinical settings of patients with lung tumors.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Animais , Camundongos , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Carga Tumoral , Linhagem Celular Tumoral , Adenocarcinoma de Pulmão/tratamento farmacológico , Poli(ADP-Ribose) Polimerases/metabolismo , Estresse Oxidativo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Dano ao DNA , ApoptoseRESUMO
BACKGROUND: Changes in the clinical subtype (CS) and intrinsic subtype (IS) between breast cancer (BC) metastases and corresponding primary tumours have been reported. However, their relationship with tumour genomic changes remains poorly characterised. Here, we analysed the association between genomic remodelling and subtype conversion in paired primary and metastatic BC samples. METHODS: A total of 57 paired primary and metastatic tumours from GEICAM/2009-03 (ConvertHER, NCT01377363) study participants with centrally assessed CS (n = 57) and IS (n = 46) were analysed. Targeted capture and next-generation sequencing of 202 genes on formalin-fixed paraffin-embedded samples was performed. The cancer cell fraction (CCF) of mutations in primary and metastatic pairs was estimated as a surrogate of tumour clonal architecture. Changes in mutation CCF between matched primary and metastatic tumours were analysed in the presence or absence of subtype conversion. FINDINGS: CS conversion occurred in 24.6% and IS conversion occurred in 36.9% of metastases. Primary tumours and metastases had a median of 11 (range, 3-29) and 9 (range, 1-38) mutations, respectively (P = 0.05). Overall, mutations in metastases showed a higher estimated CCF than in primary tumours (median CCF, 0.51 and 0.47, respectively; P = 0.042), consistent with increased clonal homogeneity. The increase in mutation CCF was significant in CS-converted (P = 0.04) but not in IS-converted (P = 0.48) metastases. Clonal remodelling was highest in metastases from hormone receptor-positive and human epidermal growth factor 2 (HER2)-positive tumours (P = 0.006). CONCLUSIONS: Mutations in BC metastases showed significantly higher estimated CCF than primary tumours. CCF changes were more prominent in metastases with CS conversion. Our findings suggest that changes in BC subtypes are linked to clonal remodelling during BC evolution.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias Ósseas/secundário , Neoplasias Encefálicas/secundário , Neoplasias da Mama/classificação , Neoplasias da Mama/patologia , Mutação , Neoplasias Cutâneas/secundário , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/genética , Neoplasias Encefálicas/genética , Neoplasias da Mama/genética , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Prognóstico , Estudos Prospectivos , Neoplasias Cutâneas/genéticaRESUMO
Acute Fibrinous and Organizing Pneumonitis (AFOP) is a disease with histopathological pattern characterized by the presence of intra-alveolar fibrin in the form of fibrin "balls" and organizing pneumonia represented by inflammatory myofibroblastic polyps. Symptoms of this rare interstitial pulmonary disease can be either acute or sub-acute and it can rapidly progress to death. Diagnosis should be considered in the Intensive Care Unit (ICU) if patients' symptomatology and radiology correlates with non-responding or progressive pneumonia and when morphology, on biopsies, encompasses criteria of diffuse alveolar damage (DAD) and organizing pneumonia (OP) balancing in between. Three clinical cases of patients presenting severe lung disease requiring mechanical ventilation and prolonged intensive care fitted on the variable spectra of AFOP histopathology and had poor outcome: a 23 year-old women had AFOP in the context of antiphospholipid syndrome pulmonary compromise; a 35 year-old man developed a letal intensive care pneumonia with AFOP pattern registered in post-mortem biopsy; and a 79 year-old man died 21 days after intensive care unit treatment of a sub-pleural organizing pneumonia with intra-alveolar fibrin, seen in post-mortem biopsy. The predominance of acute fibrin alveolar deposition pattern is helpful in raising AFOP differential diagnosis while organizing pneumonia pattern establishes a wider range of diagnosis that can go till solitary pulmonary nodule, remaining indefinite to suggest diagnosis. The performance time of biopsy in a larger number of clinical cases may be helpful in establishing the evolutionary morphological pattern, taking in mind the poor outcome of the disease, deserving rapid diagnosis to define treatment.
RESUMO
The endoplasmic reticulum (ER) of cancer cells needs to adapt to the enhanced proteotoxic stress associated with the accumulation of unfolded, misfolded and transformation-associated proteins. One way by which tumors thrive in the context of ER stress is by promoting ER-Associated Degradation (ERAD), although the mechanisms are poorly understood. Here, we show that the Small p97/VCP Interacting Protein (SVIP), an endogenous inhibitor of ERAD, undergoes DNA hypermethylation-associated silencing in tumorigenesis to achieve this goal. SVIP exhibits tumor suppressor features and its recovery is associated with increased ER stress and growth inhibition. Proteomic and metabolomic analyses show that cancer cells with epigenetic loss of SVIP are depleted in mitochondrial enzymes and oxidative respiration activity. This phenotype is reverted upon SVIP restoration. The dependence of SVIP hypermethylated cancer cells on aerobic glycolysis and glucose was also associated with sensitivity to an inhibitor of the glucose transporter GLUT1. This could be relevant to the management of tumors carrying SVIP epigenetic loss, because these occur in high-risk patients who manifest poor clinical outcomes. Overall, our study provides insights into how epigenetics helps deal with ER stress and how SVIP epigenetic loss in cancer may be amenable to therapies that target glucose transporters.
Assuntos
Reprogramação Celular/fisiologia , Degradação Associada com o Retículo Endoplasmático/fisiologia , Retículo Endoplasmático/metabolismo , Epigenômica , Proteínas de Membrana/metabolismo , Neoplasias/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Animais , Carcinogênese , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Reprogramação Celular/genética , Metilação de DNA , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Transportador de Glucose Tipo 1 , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/farmacologia , Camundongos , Camundongos Nus , Mitocôndrias/metabolismo , Neoplasias/genética , Fenótipo , Proteínas de Ligação a Fosfato/genética , Proteínas de Ligação a Fosfato/farmacologia , ProteômicaRESUMO
Acute fibrinous and organising pneumonia (AFOP) is a rare histological pattern of interstitial lung disease. The authors describe a 60-year-old woman admitted to the hospital for sustained fever, presenting with an alveolar opacity on chest X-ray, with the presumed diagnosis of community-acquired pneumonia and the onset of antibiotics. Since serological results suggested that Legionella pneumophila was the infectious agent, she was discharged on levofloxacin. A week later, she was again admitted with fever. CT scan showed opacities with crescentic morphology and a central ground-glass area suggestive of cryptogenic organising pneumonia. Microbiological, serological and autoimmunity tests were negative. She underwent surgical lung biopsy that revealed inflammatory infiltrate, macrophage desquamation, fibroblasts proliferation and fibrin deposition in the alveolar spaces, consistent with AFOP. She started corticotherapy with good response. Disease relapsed after prednisolone discontinuation, 10 months later. Currently, the patient is on prednisolone 5 mg/day without clinical and radiological recurrence.
Assuntos
Pneumonia em Organização Criptogênica/diagnóstico por imagem , Febre/diagnóstico , Pulmão/patologia , Pneumonia/diagnóstico por imagem , Prednisolona/uso terapêutico , Antibacterianos/uso terapêutico , Biópsia , Infecções Comunitárias Adquiridas/diagnóstico , Pneumonia em Organização Criptogênica/tratamento farmacológico , Diagnóstico Diferencial , Feminino , Febre/etiologia , Fibrina , Glucocorticoides/uso terapêutico , Humanos , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/tratamento farmacológico , Levofloxacino/administração & dosagem , Levofloxacino/uso terapêutico , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/tratamento farmacológico , Doenças Pulmonares Intersticiais/patologia , Pessoa de Meia-Idade , Pneumonia/microbiologia , Pneumonia/patologia , Prednisolona/administração & dosagem , Radiografia , Doenças Raras , Tomografia Computadorizada por Raios X/métodos , Resultado do TratamentoRESUMO
The CHL1 gene encodes a cell-adhesion molecule proposed as being a putative tumour-suppressor gene in breast cancer (BC). However, neither the underlying molecular mechanisms nor the clinical value of CHL1 downregulation in BC has been explored. The methylation status of three CpG sites in the CHL1 promoter was analysed by pyrosequencing in neoplastic biopsies from 142 patients with invasive BC and compared with that of non-neoplastic tissues. We found higher CHL1 methylation levels in breast tumours than in non-neoplastic tissues, either from mammoplasties or adjacent-to-tumour, which correlated with lower levels of protein expression in tumours measured by immunohistochemistry. A panel of five BC cell lines was treated with two epigenetic drugs, and restoration of CHL1 expression was observed, indicating in vitro dynamic epigenetic regulation. CHL1 was silenced by shRNA in immortalized but non-neoplastic mammary cells, and enhanced cell proliferation and migration, but not invasion, were found by real-time cell analysis. The prognostic value of CHL1 hypermethylation was assessed by the log-rank test and fitted in a Cox regression model. Importantly, CHL1 hypermethylation was very significantly associated with shorter progression-free survival in our BC patient series, independent of age and stage (p = 0.001). In conclusion, our results indicate that CHL1 is downregulated by hypermethylation and that this epigenetic alteration is an independent prognostic factor in BC.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Moléculas de Adesão Celular/genética , Metilação de DNA , Regiões Promotoras Genéticas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/metabolismo , Moléculas de Adesão Celular/biossíntese , Movimento Celular/genética , Proliferação de Células/genética , Ilhas de CpG/genética , Intervalo Livre de Doença , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Interferência de RNA , Análise de Sequência de DNA/métodos , Análise de Sequência de DNA/estatística & dados numéricosRESUMO
Long noncoding RNAs (lncRNAs) are important regulators of cellular homeostasis. However, their contribution to the cancer phenotype still needs to be established. Herein, we have identified a p53-induced lncRNA, TP53TG1, that undergoes cancer-specific promoter hypermethylation-associated silencing. In vitro and in vivo assays identify a tumor-suppressor activity for TP53TG1 and a role in the p53 response to DNA damage. Importantly, we show that TP53TG1 binds to the multifaceted DNA/RNA binding protein YBX1 to prevent its nuclear localization and thus the YBX1-mediated activation of oncogenes. TP53TG1 epigenetic inactivation in cancer cells releases the transcriptional repression of YBX1-targeted growth-promoting genes and creates a chemoresistant tumor. TP53TG1 hypermethylation in primary tumors is shown to be associated with poor outcome. The epigenetic loss of TP53TG1 therefore represents an altered event in an lncRNA that is linked to classical tumoral pathways, such as p53 signaling, but is also connected to regulatory networks of the cancer cell.
Assuntos
Proteínas de Ligação a DNA/genética , Neoplasias/genética , Neoplasias/patologia , Proteína Supressora de Tumor p53/metabolismo , Proteína 1 de Ligação a Y-Box/metabolismo , Animais , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Dano ao DNA , Metilação de DNA , Regulação para Baixo , Epigênese Genética , Células HCT116 , Humanos , Camundongos , Transplante de Neoplasias , Neoplasias/metabolismo , Prognóstico , Regiões Promotoras Genéticas , Transdução de Sinais , Proteína 1 de Ligação a Y-Box/genéticaRESUMO
BACKGROUND: Multi-drug resistant forms of Pseudomonas aeruginosa (MDRPA) are a major source of nosocomial infections and when discharged into streams and rivers from hospital wastewater treatment plants (HWWTP) they are known to be able to persist for extended periods. In the city of Manaus (Western Brazilian Amazon), the effluent of three HWWTPs feed into the urban Mindu stream which crosses the city from its rainforest source before draining into the Rio Negro. The stream is routinely used by Manaus residents for bathing and cleaning (of clothes as well as domestic utensils) and, during periods of flooding, can contaminate wells used for drinking water. RESULTS: 16S rRNA metagenomic sequence analysis of 293 cloned PCR fragments, detected an abundance of Pseudomonas aeruginosa (P. aeruginosa) at the stream's Rio Negro drainage site, but failed to detect it at the stream's source. An array of antimicrobial resistance profiles and resistance to all 14 tested antimicrobials was detected among P. aeruginosa cultures prepared from wastewater samples taken from water entering and being discharged from a Manaus HWWTP. Just one P. aeruginosa antimicrobial resistance profile, however, was detected from cultures made from Mindu stream isolates. Comparisons made between P. aeruginosa isolates' genomic DNA restriction enzyme digest fingerprints, failed to determine if any of the P. aeruginosa found in the Mindu stream were of HWWTP origin, but suggested that Mindu stream P. aeruginosa are from diverse origins. Culturing experiments also showed that P. aeruginosa biofilm formation and the extent of biofilm formation produced were both significantly higher in multi drug resistant forms of P. aeruginosa. CONCLUSIONS: Our results show that a diverse range of MDRPA are being discharged in an urban stream from a HWWTP in Manaus and that P. aeruginosa strains with ampicillin and amikacin can persist well within it.
Assuntos
Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Rios/microbiologia , Águas Residuárias/microbiologia , Amicacina/farmacologia , Ampicilina/farmacologia , Antibacterianos/farmacologia , Biodiversidade , Biofilmes , Brasil , Impressões Digitais de DNA , Farmacorresistência Bacteriana Múltipla , Eletroforese em Gel de Campo Pulsado , Hospitais , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/fisiologia , RNA Ribossômico 16S/genéticaRESUMO
PURPOSE: Autism spectrum disorders are associated with defects in social response and communication that often occur in the context of intellectual disability. Rett syndrome is one example in which epilepsy, motor impairment, and motor disturbance may co-occur. Mutations in histone demethylases are known to occur in several of these syndromes. Herein, we aimed to identify whether mutations in the candidate histone demethylase JMJD1C (jumonji domain containing 1C) are implicated in these disorders. METHODS: We performed the mutational and functional analysis of JMJD1C in 215 cases of autism spectrum disorders, intellectual disability, and Rett syndrome without a known genetic defect. RESULTS: We found seven JMJD1C variants that were not present in any control sample (~ 6,000) and caused an amino acid change involving a different functional group. From these, two de novo JMJD1C germline mutations were identified in a case of Rett syndrome and in a patient with intellectual disability. The functional study of the JMJD1C mutant Rett syndrome patient demonstrated that the altered protein had abnormal subcellular localization, diminished activity to demethylate the DNA damage-response protein MDC1, and reduced binding to MECP2. We confirmed that JMJD1C protein is widely expressed in brain regions and that its depletion compromises dendritic activity. CONCLUSIONS: Our findings indicate that mutations in JMJD1C contribute to the development of Rett syndrome and intellectual disability.Genet Med 18 1, 378-385.
Assuntos
Deficiência Intelectual/genética , Histona Desmetilases com o Domínio Jumonji/genética , Mutação , Oxirredutases N-Desmetilantes/genética , Síndrome de Rett/genética , Adulto , Motivos de Aminoácidos , Sequência de Aminoácidos , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/genética , Encéfalo/metabolismo , Encéfalo/patologia , Sequência Conservada , Análise Mutacional de DNA , Feminino , Expressão Gênica , Ordem dos Genes , Estudos de Associação Genética , Loci Gênicos , Humanos , Deficiência Intelectual/diagnóstico , Histona Desmetilases com o Domínio Jumonji/química , Histona Desmetilases com o Domínio Jumonji/metabolismo , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Neurônios/metabolismo , Oxirredutases N-Desmetilantes/química , Oxirredutases N-Desmetilantes/metabolismo , Matrizes de Pontuação de Posição Específica , Conformação Proteica , Transporte Proteico , Síndrome de Rett/diagnósticoRESUMO
Intestinal ganglioneuromatosis is a rare disorder of the enteric nervous system. It is often associated with neurofibromatosis type 1 and multiple endocrine neoplasia type 2b but, more rarely, it can present in a sporadic and isolated form. A 66-year-old man presented with a 14-year history of iron deficiency anaemia, with no visible bleeding, requiring occasional blood transfusions. Haematological causes of anaemia were thoroughly excluded, and conventional endoscopic and radiological examinations showed no lesions. Capsule enteroscopy identified an ulcerated stenosis in the small bowel, but the biopsies taken at balloon enteroscopy were inconclusive. The patient underwent a laparotomy, which revealed a stiff and ulcerated stenosis in the ileum. Histological analysis demonstrated the presence of diffuse intestinal ganglioneuromatosis. Three years after surgery, the patient is asymptomatic, with normal haemoglobin levels. This case demonstrates an isolated form of intestinal ganglioneuromatosis, with an atypical presentation, difficult to diagnose despite an exhaustive evaluation.
Assuntos
Anemia Ferropriva/diagnóstico , Ganglioneuroma/diagnóstico , Hemorragia Gastrointestinal/diagnóstico , Neoplasias do Íleo/diagnóstico , Íleo/patologia , Idoso , Anemia Ferropriva/etiologia , Constrição Patológica , Sistema Nervoso Entérico/patologia , Ganglioneuroma/complicações , Ganglioneuroma/patologia , Ganglioneuroma/cirurgia , Hemorragia Gastrointestinal/etiologia , Humanos , Neoplasias do Íleo/complicações , Masculino , Sangue Oculto , ÚlceraRESUMO
Metastasis is responsible for most cancer-related deaths, and, among common tumor types, melanoma is one with great potential to metastasize. Here we study the contribution of epigenetic changes to the dissemination process by analyzing the changes that occur at the DNA methylation level between primary cancer cells and metastases. We found a hypomethylation event that reactivates a cryptic transcript of the Rab GTPase activating protein TBC1D16 (TBC1D16-47 kDa; referred to hereafter as TBC1D16-47KD) to be a characteristic feature of the metastatic cascade. This short isoform of TBC1D16 exacerbates melanoma growth and metastasis both in vitro and in vivo. By combining immunoprecipitation and mass spectrometry, we identified RAB5C as a new TBC1D16 target and showed that it regulates EGFR in melanoma cells. We also found that epigenetic reactivation of TBC1D16-47KD is associated with poor clinical outcome in melanoma, while conferring greater sensitivity to BRAF and MEK inhibitors.
Assuntos
Progressão da Doença , Epigênese Genética , Receptores ErbB/metabolismo , Proteínas Ativadoras de GTPase/genética , Melanoma/genética , Melanoma/patologia , Animais , Linhagem Celular Tumoral , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/genética , Epigênese Genética/efeitos dos fármacos , Proteínas Ativadoras de GTPase/metabolismo , Imunoprecipitação , Camundongos Nus , Peso Molecular , Metástase Neoplásica , Prognóstico , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Inibidores de Proteínas Quinases/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética , Resultado do Tratamento , Proteínas rab de Ligação ao GTP/metabolismoRESUMO
Burkitt lymphoma is a fast-growing high grade B-cell neoplasm that rarely affects adults. Three clinical variants are described in the World Health Organization classification: endemic, sporadic, and immunodeficiency-associated. The non-endemic form typically presents as an abdominal mass in children. Symptoms usually occur due to mass effect or direct intestinal involvement. We describe a very unusual presentation of a sporadic Burkitt lymphoma case in a 61-year-old male with diffuse peritoneal and omental involvement, without lymphadenopathies, mimicking peritoneal carcinomatosis.
Assuntos
Linfoma de Burkitt/patologia , Carcinoma/diagnóstico , Omento/patologia , Neoplasias Peritoneais/diagnóstico , Peritônio/patologia , Tomografia Computadorizada por Raios X , Abdome/patologia , Protocolos de Quimioterapia Combinada Antineoplásica , Linfoma de Burkitt/tratamento farmacológico , Ciclofosfamida , Diagnóstico Diferencial , Doxorrubicina , Endoscopia do Sistema Digestório , Humanos , Laparotomia , Masculino , Metotrexato , Pessoa de Meia-Idade , Prednisona , VincristinaRESUMO
Shigellosis is a global human health problem and the incidence is highest among children. In the present work, main Shigella virulence genes was examined by PCR and compared to symptoms of pediatric shigellosis. Thirty Shigella isolates were identified from an etiologic study at which 1,339 children ranging 0-10 years old were enrolled. S. flexneri was the most frequent species reaching 60.0% of isolates, 22.2% were S. sonnei, and 6.6% were both S. dysenteriae and S. boydii. All Shigella infected children had diarrhea, but not all were accompanied by others symptoms of bacillary dysentery. Among major virulence genes, the PCR typing revealed ipaBCD was present in all isolates, followed by IpaH7.8, set-1A, set-1B, sen/ospD3, virF, and invE. The pathogenic potential of the ShET-1B subunit was observed in relation to dehydration (P < 0.001) and ShET-2 related to the intestinal injury (P = 0.033) evidenced by the presence of bloody diarrhea. Our results show associations among symptoms of shigellosis and virulence genes of clinical isolates of Shigella spp.
Assuntos
Disenteria Bacilar/epidemiologia , Disenteria Bacilar/genética , Shigella , Fatores de Virulência/genética , Animais , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Técnicas de Genotipagem , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Shigella/genética , Shigella/isolamento & purificação , Shigella/patogenicidadeRESUMO
Cancer cells possess aberrant proteomes that can arise by the disruption of genes involved in physiological protein degradation. Here we demonstrate the presence of promoter CpG island hypermethylation-linked inactivation of DERL3 (Derlin-3), a key gene in the endoplasmic reticulum-associated protein degradation pathway, in human tumours. The restoration of in vitro and in vivo DERL3 activity highlights the tumour suppressor features of the gene. Using the stable isotopic labelling of amino acids in cell culture workflow for differential proteome analysis, we identify SLC2A1 (glucose transporter 1, GLUT1) as a downstream target of DERL3. Most importantly, SLC2A1 overexpression mediated by DERL3 epigenetic loss contributes to the Warburg effect in the studied cells and pinpoints a subset of human tumours with greater vulnerability to drugs targeting glycolysis.
Assuntos
Transportador de Glucose Tipo 1/metabolismo , Neoplasias/metabolismo , Animais , Ilhas de CpG , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Transportador de Glucose Tipo 1/genética , Glicólise , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Nus , Neoplasias/genética , Oxigênio/metabolismo , Regiões Promotoras Genéticas , ProteóliseRESUMO
Performance evaluation of diagnostic tests is critical in the search for accurate diagnoses. A gold standard test is usually absent in parasitology, thus rendering satisfactory assessment of diagnostic accuracy difficult. Moreover, reliability (assessed by the study of repeatability) is a rarely studied characteristic of diagnostic tests. This study compared and evaluated the performance (repeatability, concordance and accuracy) of the spontaneous sedimentation technique (SST) and the Paratest for the diagnosis of Giardia lamblia, Entamoeba histolytica complex, Blastocystis spp., Ascaris lumbricoides, hookworm, Trichuris trichiura and Calodium hepaticum. Fecal samples of 143 individuals were separated into three replicates for each test. Concordance and homogeneity of the results between replicates of each test and between tests were evaluated. Proportions of positives, sensitivity and specificity were estimated using a Bayesian Latent Class Model. High repeatability of both tests was found for the detection of intestinal parasites, except for Blastocystis spp. and hookworm. Concordance between tests was generally high (concordance correlation coefficient, 0.72-0.88), except for Blastocystis spp., hookworm and T. trichiura. The Paratest detected more cases of Blastocystis spp. and fewer of hookworm than the SST. The tests were quite discordant in the detection of T. trichiura. A low sensitivity (39.4-49.2% for SST, 35.8-53.8% for Paratest) and a high specificity (93.2-97.2%) were found for both tests. The Paratest presented a slightly higher sensitivity for the diagnosis of Blastocystis spp. (53.8%), and SST did so for hookworm (49.2%). This is the first study on repeatability and accuracy (using a Bayesian approach) of two spontaneous sedimentation techniques. These results suggest underdiagnosis of little dense parasitic forms due to technical limitations in both tests. We conclude that the combined study of repeatability, concordance and accuracy is a key strategy for better evaluation of the performance of tests and is also useful for the identification of technical limitations.
Assuntos
Técnicas de Laboratório Clínico/normas , Enteropatias Parasitárias/diagnóstico , Intestinos/parasitologia , Ancylostomatoidea/isolamento & purificação , Animais , Ascaris lumbricoides/isolamento & purificação , Blastocystis/isolamento & purificação , Entamoeba histolytica/isolamento & purificação , Fezes/parasitologia , Giardia lamblia/isolamento & purificação , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Trichuris/isolamento & purificaçãoRESUMO
Unclassified sex cord testis tumor is an extremely rare tumor, especially in the adult. It is characterized histologically for a nonspecific combination of testis stromal and epithelial elements, with varying degree of differentiation. Treatment usually consists of radical orchiectomy followed by clinical and imaging surveillance. The available literature about this pathology relies almost exclusively on clinical cases. It's our aim to describe the case of a 37 years old man with an unclassified sex cord testis tumor, the first case described in Portugal, and to review the literature about this issue.
O tumor dos cordões sexuais nÉo classificável do testículo eÌ um tumor extremamente raro, particularmente na idade adulta. Caracteriza-se histologicamente pela conjugaçaÌo inespeciÌfica de elementos estromais e epiteliais do testículo, com grau de diferenciaçÉo variável. A sua abordagem consiste na orquidectomia radical, geralmente realizada antes do diagnóstico, e posterior vigil'ncia clínica e imagioloÌgica. A literatura disponível sobre esta patologia baseia-se quase exclusivamente na descriçÉo de casos clínicos. O nosso objetivo é apresentar o caso de um doente de 37 anos com um tumor dos cordões sexuais nÉo classificável do testículo, o primeiro descrito em Portugal, e fazer uma revisÉo da literatura sobre o tema.
Assuntos
Tumores do Estroma Gonadal e dos Cordões Sexuais/patologia , Neoplasias Testiculares/patologia , Adulto , Humanos , MasculinoRESUMO
OBJECTIVE: It is well defined that ovarian steroids play a role in the cardiovascular system, acting as vasoactive compounds. The aim of this study is to assess the endothelial function during the menstrual cycle using flow-mediated dilation of the brachial artery. METHODS: A total of 21 healthy premenopausal women, with regular menstrual cycles, were included in this observational, longitudinal, and prospective study. The endothelium function was assessed by ultrasound during four phases of the menstrual cycle: early follicular phase (EFP), late follicular phase (LFP), early luteal phase (ELP) and late luteal phase (LLP). RESULTS: We observed a significant variation among the vasodilatation response during the menstrual cycle phases (P<0.001). The result was higher during LFP than during ELP (P<0.001) or LLP (P<0.001). Late luteal phase had higher response than observed during ELP (P=0.003) and EFP was higher than LLP (P=0.003). There were no significant differences between the results observed during EFP and LFP (P=1.0), or EFP and ELP (P=0.137). CONCLUSION: Our results suggest that the ovarian steroids may play an important role in modulating endothelial function.
RESUMO
BACKGROUND: Calodium hepaticum (syn. Capillaria hepatica) is a worldwide helminth parasite of which several aspects of transmission still remain unclear. In the Amazon region, the mechanism of transmission based on the ingestion of eggs present in the liver of wild mammals has been suggested as the cause of the spurious infections described. We performed an epidemiological investigation to determine the incidence, risk of spurious infection and the dynamics of transmission of C. hepaticum in a community of the Brazilian Amazon. METHODOLOGY/PRINCIPAL FINDINGS: Stool samples of 135 individuals, two dog feces and liver tissue from a peccary (captured and eaten by the residents) were analyzed by conventional microscopy. Dog feces were collected from the gardens of households presenting human cases of spurious C. hepaticum infections. Community practices and feeding habits related to the transmission of the parasite were investigated. The individual incidence of spurious infection was 6.7% (95% CI: 2.08-11.24). Cases of spurious infection were observed in 7.5% of the families and the household incidence was from 50% to 83.3%. The risk of spurious infection was 10-fold greater in persons consuming the liver of wild mammals (pâ=â0.02). The liver tissue of a peccary and one feces sample of a dog presented eggs of C. hepaticum. The consumption of the infected liver was the cause of the spurious infections reported in one household. CONCLUSIONS/SIGNIFICANCE: This is the first identification of a source of spurious infection by C. hepaticum in humans and we describe a high rate of incidence in household clusters related to game liver alimentary habits. The finding of a dog feces contaminating peridomiciliary ground suggests the risk of new infections. We conclude that the mechanism of transmission based on the ingestion of liver is important for the dynamics of transmission of C. hepaticum in the studied area.
Assuntos
Capillaria/isolamento & purificação , Infecções por Enoplida/epidemiologia , Infecções por Enoplida/transmissão , Saúde da Família , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Brasil/epidemiologia , Criança , Pré-Escolar , Análise por Conglomerados , Cães , Infecções por Enoplida/parasitologia , Características da Família , Fezes/parasitologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Fígado/parasitologia , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Mammalian DNA methyltransferase 1 (DNMT1) is essential for maintaining DNA methylation patterns after cell division. Disruption of DNMT1 catalytic activity results in whole genome cytosine demethylation of CpG dinucleotides, promoting severe dysfunctions in somatic cells and during embryonic development. While these observations indicate that DNMT1-dependent DNA methylation is required for proper cell function, the possibility that DNMT1 has a role independent of its catalytic activity is a matter of controversy. Here, we provide evidence that DNMT1 can support cell functions that do not require the C-terminal catalytic domain. We report that PCNA and DMAP1 domains in the N-terminal region of DNMT1 are sufficient to modulate E-cadherin expression in the absence of noticeable changes in DNA methylation patterns in the gene promoters involved. Changes in E-cadherin expression are directly associated with regulation of ß-catenin-dependent transcription. Present evidence suggests that the DNMT1 acts on E-cadherin expression through its direct interaction with the E-cadherin transcriptional repressor SNAIL1.