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1.
Sci Rep ; 10(1): 4749, 2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-32179816

RESUMO

Living cells are constantly exchanging momentum with their surroundings. So far, there is no consensus regarding how cells respond to such external stimuli, although it reveals much about their internal structures, motility as well as the emergence of disorders. Here, we report that twelve cell lines, ranging from healthy fibroblasts to cancer cells, hold a ubiquitous double power-law viscoelastic relaxation compatible with the fractional Kelvin-Voigt viscoelastic model. Atomic Force Microscopy measurements in time domain were employed to determine the mechanical parameters, namely, the fast and slow relaxation exponents, the crossover timescale between power law regimes, and the cell stiffness. These cell-dependent quantities show strong correlation with their collective migration and invasiveness properties. Beyond that, the crossover timescale sets the fastest timescale for cells to perform their biological functions.


Assuntos
Fenômenos Fisiológicos Celulares/fisiologia , Elasticidade , Viscosidade , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular , Fibroblastos/fisiologia , Humanos , Microscopia de Força Atômica , Modelos Biológicos , Imagem Molecular , Invasividade Neoplásica/patologia
2.
Oncogene ; 38(24): 4886, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31068665

RESUMO

The final sentence of the Acknowledgements should be as follows: This work was supported by grants from Instituto de Salud Carlos III (BA15/00092), Spanish Ministry of Economy and Competitiveness/EU-ERDF (SAF2016-80626-R, SAF2013-49149-R, BFU2014-51672-REDC), Fundación CajaCanarias (AP2015/008) to RF, and the Australian National Health and Medical Research (NHMRC program grant to SRL and KKK (APP1017028).

3.
Rev Gastroenterol Mex (Engl Ed) ; 84(3): 284-289, 2019.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30107945

RESUMO

INTRODUCTION AND AIMS: Interval colorectal cancer (iCRC) can occur due to missed lesions or to a newly developed lesion. The present study aimed to assess the iCRC rate and its characteristics in our population and find possible explanations. MATERIALS AND METHODS: A retrospective study was conducted on patients with colorectal cancer (CRC) diagnosed between January 2011 and January 2015 at our department. Demographics, endoscopic data, and tumor characteristics (location, histology, staging) were collected. We identified patients diagnosed with CCR who underwent colonoscopy at our department in the previous 10years and presented the disease (iCRC) before the date of their next recommended exam. The cases of iCRC were characterized and compared with other CRC cases. Possible explanations for the appearance of iCRC were analyzed. RESULTS: A total of 266 patients presented with CRC, 61.7% were men, and mean patient age was 70.7years. We identified 10 patients with iCRC: 6 were men, and mean patient age was 71.1years. Mean time for iCRC diagnosis after index colonoscopy was 3.5±1.84years. Tumor was located in the right colon in 50% of the patients with iCRC and in 24.5% of the patients without iCRC (P=.091). More patients with iCRC had a family history of CRC (50%) than the patients with reference CRC (3.1%) (P=.000). CONCLUSIONS: In our case series, 3.76% of all CRC were iCRC. There were no statistically significant differences between patients with or without iCRC, with the exception of family history of CRC.


Assuntos
Adenocarcinoma/diagnóstico , Colonoscopia/métodos , Neoplasias Colorretais/diagnóstico , Adenocarcinoma/epidemiologia , Adenocarcinoma/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/cirurgia , Detecção Precoce de Câncer , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Resultado do Tratamento
5.
Oncogene ; 36(33): 4802-4809, 2017 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-28288134

RESUMO

Correct control of DNA replication is crucial to maintain genomic stability in dividing cells. Inappropriate re-licensing of replicated origins is associated with chromosomal instability (CIN), a hallmark of cancer progression that at the same time provides potential opportunities for therapeutic intervention. Geminin is a critical inhibitor of the DNA replication licensing factor Cdt1. To properly achieve its functions, Geminin levels are tightly regulated through the cell cycle by ubiquitin-dependent proteasomal degradation, but the de-ubiquitinating enzymes (DUBs) involved had not been identified. Here we report that DUB3 and USP7 control human Geminin. Overexpression of either DUB3 or USP7 increases Geminin levels through reduced ubiquitination. Conversely, depletion of DUB3 or USP7 reduces Geminin levels, and DUB3 knockdown increases re-replication events, analogous to the effect of Geminin depletion. In exploring potential clinical implications, we found that USP7 and Geminin are strongly correlated in a cohort of invasive breast cancers (P<1.01E-08). As expected, Geminin expression is highly prognostic. Interestingly, we found a non-monotonic relationship between USP7 and breast cancer-specific survival, with both very low or high levels of USP7 associated with poor outcome, independent of estrogen receptor status. Altogether, our data identify DUB3 and USP7 as factors that regulate DNA replication by controlling Geminin protein stability, and suggest that USP7 may be involved in Geminin dysregulation during breast cancer progression.


Assuntos
Neoplasias da Mama/enzimologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Endopeptidases/metabolismo , Geminina/metabolismo , Ubiquitina Tiolesterase/metabolismo , Ubiquitina/metabolismo , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Ciclo Celular , Linhagem Celular Tumoral , Instabilidade Cromossômica , Replicação do DNA/fisiologia , Progressão da Doença , Endopeptidases/genética , Células HEK293 , Humanos , Estimativa de Kaplan-Meier , Invasividade Neoplásica , Prognóstico , Estabilidade Proteica , RNA Interferente Pequeno/genética , Ubiquitina Tiolesterase/genética , Peptidase 7 Específica de Ubiquitina , Ubiquitinação
6.
Oncogene ; 36(5): 678-686, 2017 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-27375025

RESUMO

Stresses such as hypoxia, nutrient deprivation and acidification disturb protein folding in the endoplasmic reticulum (ER) and activate the Unfolded Protein Response (UPR) to trigger adaptive responses through the effectors, PERK, IRE1 and ATF6. Most of these responses relate to ER homoeostasis; however, here we show that the PERK branch of the UPR also controls DNA replication. Treatment of cells with the non-genotoxic UPR agonist thapsigargin led to a rapid inhibition of DNA synthesis that was attributable to a combination of DNA replication fork slowing and reduced replication origin firing. DNA synthesis inhibition was dependent on the UPR effector PERK and was associated with phosphorylation of the checkpoint adaptor protein Claspin and activation of the Chk1 effector kinase, both of which occurred in the absence of detectable DNA damage. Remarkably, thapsigargin did not inhibit bulk DNA synthesis or activate Chk1 in cells depleted of Claspin, or when Chk1 was depleted or subject to chemical inhibition. In each case thapsigargin-resistant DNA synthesis was due to an increase in replication origin firing that compensated for reduced fork progression. Taken together, our results unveil a new aspect of PERK function and previously unknown roles for Claspin and Chk1 as negative regulators of DNA replication in the absence of genotoxic stress. Because tumour cells proliferate in suboptimal environments, and frequently show evidence of UPR activation, this pathway could modulate the response to DNA replication-targeted chemotherapies.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Quinase 1 do Ponto de Checagem/metabolismo , Replicação do DNA/fisiologia , Resposta a Proteínas não Dobradas/fisiologia , eIF-2 Quinase/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Linhagem Celular Tumoral , Quinase 1 do Ponto de Checagem/genética , Humanos , Transfecção , eIF-2 Quinase/genética
7.
Arq. bras. med. vet. zootec ; Arq. bras. med. vet. zootec. (Online);68(5): 1381-1389, set.-out. 2016. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-827895

RESUMO

Com o objetivo de avaliar o uso de diferentes fontes de ferro na prevenção da anemia ferropriva e no desempenho em leitões lactentes, dividiram-se 202 leitões em cinco tratamentos: FD - aplicação intramuscular de 200mg de ferro dextrano no terceiro dia de idade; T24 - terra à vontade fornecida aos leitões a cada 24 horas do terceiro ao 19º dia; T48 - terra à vontade fornecida aos leitões a cada 24 horas do terceiro ao 10º dia e do 11º ao 19º dia, com intervalo de 48 horas; T72 - terra à vontade fornecida aos leitões a cada 24 horas do terceiro ao 10º dia e do 11º ao 19º dia, com intervalo de 72 horas; SA - suplemento alimentar ultraprecoce rico em ferro quelatado em pó (SAUP) fornecido do terceiro ao 11º dia, com intervalo de 48 horas. O ferro dextrano aplicado no terceiro dia de vida e a suplementação com terra e SAUP foram eficientes para garantir o desempenho de leitões no período de aleitamento e não influenciaram no consumo de ração nem na taxa de viabilidade. As diferentes fontes de ferro estudadas não influenciaram o leucograma e foram eficientes na prevenção da anemia ferropriva e no desempenho dos leitões lactentes. Com relação às concentrações de hemoglobina e hematócrito, os animais suplementados com ferro dextrano apresentaram valores superiores quando comparados aos que recebem terra e SAUP.(AU)


In order to evaluate the use of different sources of iron to prevent iron deficiency anemia and to appraise the performance of suckling piglets, we sorted 202 piglets in five treatments. ID - intramuscular injection of 200mg of iron dextran on the third day of age; T24 - free daily access to land provided to piglets every 24 hours from the third to the nineteenth day; T48 - free daily access to land provided to piglets every 24 hours from the third to the tenth day and from day 11 to day 19 with an interval of 48 hours; T72 - free daily access to land provided to piglets every 24 hours from the third to the tenth day and from day 11 to day 19 with an interval of 72 hours; FS - Food supplement rich in iron-chelating powder (SAUP) available from the third to the eleventh day with an interval of 48 hours. The iron dextran applied on the third day of life as well as the supplementation with land and SAUP were effective to ensure the performance of piglets during the lactation period and did not affect feed intake or the viability rate. The different sources of iron studied did not influence the WBC (White Blood Cell) and succeded in preventing iron deficiency anemia and performance of suckling piglets. Regarding the concentrations of hemoglobin and hematocrit, the animals supplemented with iron dextran showed higher values when compared to those who receive land and SAUP.(AU)


Assuntos
Animais , Anemia Ferropriva/prevenção & controle , Animais Lactentes/crescimento & desenvolvimento , Quelantes de Ferro/administração & dosagem , Complexo Ferro-Dextran/administração & dosagem , Suínos/crescimento & desenvolvimento , Hematócrito/veterinária , Hemoglobinas/análise , Contagem de Leucócitos/veterinária
8.
Oncogenesis ; 5(8): e252, 2016 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-27526106

RESUMO

The forkhead box M1 (FOXM1) transcription factor has a central role in genotoxic agent response in breast cancer. FOXM1 is regulated at the post-translational level upon DNA damage, but the key mechanism involved remained enigmatic. RNF168 is a ubiquitination E3-ligase involved in DNA damage response. Western blot and gene promoter-reporter analyses showed that the expression level and transcriptional activity of FOXM1 reduced upon RNF168 overexpression and increased with RNF168 depletion by siRNA, suggesting that RNF168 negatively regulates FOXM1 expression. Co-immunoprecipitation studies in MCF-7 cells revealed that RNF168 interacted with FOXM1 and that upon epirubicin treatment FOXM1 downregulation was associated with an increase in RNF168 binding and conjugation to the protein degradation-associated K48-linked polyubiquitin chains. Consistently, RNF168 overexpression resulted in an increase in turnover of FOXM1 in MCF-7 cells treated with the protein synthesis inhibitor cycloheximide. Conversely, RNF168, knockdown significantly enhanced the half-life of FOXM1 in both absence and presence of epirubicin. Using a SUMOylation-defective FOXM1-5x(K>R) mutant, we demonstrated that SUMOylation is required for the recruitment of RNF168 to mediate FOXM1 degradation. In addition, clonogenic assays also showed that RNF168 mediates epirubicin action through targeting FOXM1, as RNF168 could synergise with epirubicin to repress clonal formation in wild-type but not in FOXM1-deficient mouse embryo fibroblasts (MEFs). The physiological relevance of RNF168-mediated FOXM1 repression is further emphasized by the significant inverse correlation between FOXM1 and RNF168 expression in breast cancer patient samples. Moreover, we also obtained evidence that RNF8 recruits RNF168 to FOXM1 upon epirubicin treatment and cooperates with RNF168 to catalyse FOXM1 ubiquitination and degradation. Collectively, these data suggest that RNF168 cooperates with RNF8 to mediate the ubiquitination and degradation of SUMOylated FOXM1 in breast cancer genotoxic response.

9.
Oncogene ; 35(11): 1433-44, 2016 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-26148240

RESUMO

The forkhead transcription factor FOXM1 has a key role in DNA damage response, and its deregulated overexpression is associated with genotoxic drug resistance in breast cancer. However, little is known about the posttranslational mechanisms by which FOXM1 expression is regulated by genotoxic agents and how they are deregulated in resistant cells. Initial co-immunoprecipitation studies verified previous proteomic analysis finding that the OTUB1 is a novel FOXM1-interacting protein. Western blot analysis showed that both OTUB1 and FOXM1 expression reduced upon genotoxic agent treatment in MCF-7 cells, but remained relatively constant in resistant cells. FOXM1 expression reduced upon OTUB1 depletion by siRNA and increased with OTUB1 overexpression in MCF-7 cells, arguing that OTUB1 positively regulates FOXM1 expression. In agreement, co-immunoprecipitation experiments demonstrated that FOXM1 expression is associated with OTUB1 binding but inversely correlates with conjugation to the protein degradation-associated Lys-48-linked ubiquitin-chains. Overexpression of wild-type (WT) OTUB1, but not the OTUB1(C91S) mutant, disrupted the formation of Lys48-linked ubiquitin-conjugates on FOXM1. Importantly, knockdown of OTUB1 by siRNA resulted in an increase in turnover of FOXM1 in MCF-7 cells treated with the protein synthesis inhibitor cycloheximide, whereas overexpression of WT OTUB1, but not the OTUB1(C91S) mutant, significantly enhances the half-life of FOXM1. In addition, proliferative and clonogenic assays also show that OTUB1 can enhance the proliferative rate and epirubicin resistance through targeting FOXM1, as OTUB1 has little effect on FOXM1-deficient cells. The physiological relevance of the regulation of FOXM1 by OTUB1 is further underscored by the significant correlations between FOXM1 and OTUB1 expression in breast cancer patient samples. Cox-regression survival analysis indicates that OTUB1 overexpression is linked to poorer outcome in particular in patients treated with chemotherapy. Collectively, these data suggest that OTUB1 limits the ubiquitination and degradation of FOXM1 in breast cancer and has a key role in genotoxic agent resistance.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Neoplasias da Mama/genética , Cisteína Endopeptidases/genética , Resistencia a Medicamentos Antineoplásicos/genética , Epirubicina/farmacologia , Fatores de Transcrição Forkhead/metabolismo , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cicloeximida/farmacologia , Dano ao DNA/genética , Reparo do DNA/genética , Enzimas Desubiquitinantes , Feminino , Proteína Forkhead Box M1 , Fatores de Transcrição Forkhead/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Células MCF-7 , Inibidores da Síntese de Proteínas/farmacologia , Interferência de RNA , RNA Interferente Pequeno/genética , Ubiquitinação/genética
10.
Int J Obes (Lond) ; 40(3): 479-86, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26443339

RESUMO

BACKGROUND/OBJECTIVES: The association between gluten and body weight is inconsistent. Previously, we showed that a gluten-free diet reduces weight gain without changing food intake in mice fed high-fat diets. In the present study, we investigated the effects of gluten intake on fat metabolism, thermogenesis and energy expenditure in mice fed a standard or high-fat diet. METHODS: Mice were fed four different experimental diets during 8 weeks: a control-standard diet (CD), a CD added with 4.5% of wheat gluten (CD-G), a high-fat diet (HFD) and a HFD added with 4.5% of wheat gluten (HFD-G). After 8 weeks, the mice received (99m)Tc-radiolabeled gluten orally to study gluten absorption and biodistribution or they underwent indirect calorimetry. After killing, subcutaneous and brown adipose tissues (SAT and BAT) were collected to assess thermogenesis-related protein expression. Lipid metabolism was studied in adipocyte cultures from the four groups. RESULTS: Despite having had the same energy intake, CD-G and HFD-G mice exhibited increased body weight and fat deposits compared with their respective controls. (99m)Tc-GLU or its peptides were detected in the blood, liver and visceral adipose tissue, suggesting that gluten can even reach extraintestinal organs. Uncoupling protein-1 expression was reduced in the BAT of HFD-G and in the SAT of CD-G and HFD-G mice. Indirect calorimetry showed lower oxygen volume consumption in CD-G and HFD-G groups compared with their controls. In HFD mice, daily energy expenditure was reduced with gluten intake. Gluten also reduced adiponectin, peroxisome proliferator-activated receptor (PPAR)-α and PPARγ and hormone-sensitive lipase in cultures of isolated adipocytes from HFD mice, whereas in the CD-G group, gluten intake increased interleukin-6 expression and tended to increase that of tumor necrosis factor. CONCLUSIONS: Wheat gluten promotes weight gain in animals on both HFD and CD, partly by reducing the thermogenic capacity of adipose tissues.


Assuntos
Metabolismo Energético/fisiologia , Glutens , Obesidade/metabolismo , Aumento de Peso/fisiologia , Adipogenia , Adiposidade , Animais , Modelos Animais de Doenças , Ingestão de Energia , Comportamento Alimentar , Regulação da Expressão Gênica , Metabolismo dos Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Termogênese
11.
Food Chem Toxicol ; 84: 74-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26271706

RESUMO

The aim of this study was to determine the presence of mycotoxins on dogs feed and to explore the potential association between mycotoxins exposure and the chance of mamary tumors in a case-control study. The study included 256 female dogs from a hospital population, 85 with mammary tumors (case group) and 171 without mammary tumors (control group). An epidemiological questionnaire was applied to both groups, and the data were analyzed by the EpiInfo statistical package. For the study, 168 samples of the feed offered to dogs were analyzed for the presence of aflatoxins, fumonisins and zearalenone by high-performance liquid chromatography. Mycotoxins were found in 79 samples (100%) in the case group and 87/89 (97.8%) in the control group. Mycotoxins were detected in all types of feed, regardless feed quality. Level of aflatoxin B1 (p = 0.0356, OR = 2.74, 95%, CI 1.13 to 6.60), aflatoxin G1 (AFG1) (p = 0.00007, OR = 4.60, 95%, CI = 2.16 to 9.79), and aflatoxin G2 (AFG2) (p = 0.0133, OR = 9.91, 95%, CI 1.21 to 81.15) were statistically higher in case of mammary cancer. In contrast, neutering was a protective factor for mammary cancer (p = 0.0004, OR = 0.32, 95%, CI = 0.17 to 0.60).


Assuntos
Aflatoxinas/toxicidade , Ração Animal/efeitos adversos , Carcinógenos Ambientais/toxicidade , Contaminação de Alimentos , Neoplasias Mamárias Animais/induzido quimicamente , Aflatoxina B1/análise , Aflatoxina B1/toxicidade , Aflatoxinas/análise , Ração Animal/análise , Animais , Brasil , Carcinógenos Ambientais/análise , Estudos de Casos e Controles , Cães , Feminino , Fumonisinas/análise , Fumonisinas/toxicidade , Hospitais Veterinários , Hospitais de Ensino , Neoplasias Mamárias Animais/prevenção & controle , Ovariectomia/veterinária , Zearalenona/análise , Zearalenona/toxicidade
12.
Oncogene ; 34(8): 1058-63, 2015 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-24632611

RESUMO

The DNA damage checkpoint is essential for the maintenance of genome integrity after genotoxic stress, and also for cell survival in eukaryotes. Claspin has a key role in the ATR (ATM and Rad3-related)-Chk1 branch of the DNA damage checkpoint and is also required for correct DNA replication. To achieve properly these functions, Claspin is tightly regulated by ubiquitinin-dependent proteasomal degradation, which controls Claspin levels in a DNA-damage- and cell-cycle-dependent manner. Here, we identified a new regulator of Claspin, the ubiquitin-specific peptidase 29, USP29. Downregulation of USP29 destabilizes Claspin, whereas its overexpression promotes an increase in Claspin levels. USP29 interacts with Claspin and is able to deubiquitinate it both in vivo and in vitro. Most importantly, USP29 knockdown results in an impaired phosphorylation of Chk1 after DNA damage and USP29-depleted cells show a major defect in the S-phase progression. With these results, we identified USP29 as a new player in the ATR-Chk1 pathway and the control of DNA replication.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteases Específicas de Ubiquitina/fisiologia , Ubiquitinação , Quinase 1 do Ponto de Checagem , Replicação do DNA/genética , Células HEK293 , Humanos , Proteínas Quinases/metabolismo , Processamento de Proteína Pós-Traducional/genética , Estabilidade Proteica , Proteólise , Células Tumorais Cultivadas , Ubiquitina Tiolesterase/metabolismo , Peptidase 7 Específica de Ubiquitina , Proteases Específicas de Ubiquitina/genética , Ubiquitinação/genética
13.
Oncogene ; 33(32): 4144-55, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24141789

RESUMO

FOXM1 is implicated in genotoxic drug resistance but its mechanism of action remains elusive. We show here that FOXM1-depletion can sensitize breast cancer cells and mouse embryonic fibroblasts (MEFs) into entering epirubicin-induced senescence, with the loss of long-term cell proliferation ability, the accumulation of γH2AX foci, and the induction of senescence-associated ß-galactosidase activity and cell morphology. Conversely, reconstitution of FOXM1 in FOXM1-deficient MEFs alleviates the accumulation of senescence-associated γH2AX foci. We also demonstrate that FOXM1 regulates NBS1 at the transcriptional level through an forkhead response element on its promoter. Like FOXM1, NBS1 is overexpressed in the epirubicin-resistant MCF-7Epi(R) cells and its expression level is low but inducible by epirubicin in MCF-7 cells. Consistently, overexpression of FOXM1 augmented and FOXM1 depletion reduced NBS1 expression and epirubicin-induced ataxia-telangiectasia mutated (ATM)phosphorylation in breast cancer cells. Together these findings suggest that FOXM1 increases NBS1 expression and ATM phosphorylation, possibly through increasing the levels of the MRN(MRE11/RAD50/NBS1) complex. Consistent with this idea, the loss of P-ATM induction by epirubicin in the NBS1-deficient NBS1-LBI fibroblasts can be rescued by NBS1 reconstitution. Resembling FOXM1, NBS1 depletion also rendered MCF-7 and MCF-7Epi(R) cells more sensitive to epirubicin-induced cellular senescence. In agreement, the DNA repair-defective and senescence phenotypes in FOXM1-deficent cells can be effectively rescued by overexpression of NBS1. Moreover, overexpression of NBS1 and FOXM1 similarly enhanced and their depletion downregulated homologous recombination (HR) DNA repair activity. Crucially, overexpression of FOXM1 failed to augment HR activity in the background of NBS1 depletion, demonstrating that NBS1 is indispensable for the HR function of FOXM1. The physiological relevance of the regulation of NBS1 expression by FOXM1 is further underscored by the strong and significant correlation between nuclear FOXM1 and total NBS1 expression in breast cancer patient samples, further suggesting that NBS1 as a key FOXM1 target gene involved in DNA damage response, genotoxic drug resistance and DNA damage-induced senescence.


Assuntos
Proteínas de Ciclo Celular/fisiologia , Senescência Celular , Dano ao DNA , Resistencia a Medicamentos Antineoplásicos , Epirubicina/química , Fatores de Transcrição Forkhead/fisiologia , Proteínas Nucleares/fisiologia , Animais , Antibióticos Antineoplásicos/química , Proteínas de Ciclo Celular/genética , Reparo do DNA , Proteínas de Ligação a DNA , Fibroblastos/citologia , Proteína Forkhead Box M1 , Fatores de Transcrição Forkhead/genética , Deleção de Genes , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Células MCF-7 , Camundongos , Proteínas Nucleares/genética , Fenótipo , Fosforilação , Regiões Promotoras Genéticas , Transdução de Sinais
14.
Oncogene ; 32(39): 4634-45, 2013 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-23108394

RESUMO

FOXM1 is implicated in genotoxic drug resistance but its role and mechanism of action remain unclear. Here, we establish that γH2AX foci, indicative of DNA double-strand breaks (DSBs), accumulate in a time-dependent manner in the drug-sensitive MCF-7 cells but not in the resistant counterparts in response to epirubicin. We find that FOXM1 expression is associated with epirubicin sensitivity and DSB repair. Ectopic expression of FOXM1 can increase cell viability and abrogate DSBs sustained by MCF-7 cells following epirubicin, owing to an enhancement in repair efficiency. Conversely, alkaline comet and γH2AX foci formation assays show that Foxm1-null cells are hypersensitive to DNA damage, epirubicin and γ-irradiation. Furthermore, we find that FOXM1 is required for DNA repair by homologous recombination (HR) but not non-homologous end joining (NHEJ), using HeLa cell lines harbouring an integrated direct repeat green fluorescent protein reporter for DSB repair. We also identify BRIP1 as a direct transcription target of FOXM1 by promoter analysis and chromatin-immunoprecipitation assay. In agreement, depletion of FOXM1 expression by small interfering RNA downregulates BRIP1 expression at the protein and mRNA levels in MCF-7 and the epirubicin-resistant MCF-7 Epi(R) cells. Remarkably, the requirement for FOXM1 for DSB repair can be circumvented by reintroduction of BRIP1, suggesting that BRIP1 is an important target of FOXM1 in DSB repair. Indeed, like FOXM1, BRIP1 is needed for HR. These data suggest that FOXM1 regulates BRIP1 expression to modulate epirubicin-induced DNA damage repair and drug resistance.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA/fisiologia , Resistencia a Medicamentos Antineoplásicos/fisiologia , Epirubicina/farmacologia , Fatores de Transcrição Forkhead/fisiologia , Proteínas de Neoplasias/fisiologia , RNA Helicases/fisiologia , Reparo de DNA por Recombinação/fisiologia , Animais , Dano ao DNA , DNA de Neoplasias/efeitos dos fármacos , DNA de Neoplasias/genética , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Proteínas de Grupos de Complementação da Anemia de Fanconi , Feminino , Fibroblastos , Proteína Forkhead Box M1 , Fatores de Transcrição Forkhead/antagonistas & inibidores , Raios gama , Histonas/análise , Humanos , Células MCF-7/efeitos dos fármacos , Células MCF-7/metabolismo , Células MCF-7/efeitos da radiação , Camundongos , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , RNA Helicases/biossíntese , RNA Helicases/genética , Interferência de RNA , RNA Mensageiro/biossíntese , RNA Neoplásico/biossíntese , RNA Interferente Pequeno/farmacologia , Tolerância a Radiação , Proteínas Recombinantes de Fusão/fisiologia
15.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;45(1): 38-42, Jan. 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-610541

RESUMO

Body stability is controlled by the postural system and can be affected by fear and anxiety. Few studies have addressed freezing posture in psychiatric disorders. The purpose of the present study was to assess posturographic behavior in 30 patients with social anxiety disorder (SAD) and 35 without SAD during presentation of blocks of pictures with different valences. Neutral images consisted of objects taken from a catalog of pictures, negative images were mutilation pictures and anxiogenic images were related to situations regarding SAD fears. While participants were standing on a force platform, similar to a balance, displacement of the center of pressure in the mediolateral and anteroposterior directions was measured. We found that the SAD group exhibited a lower sway area and a lower velocity of sway throughout the experiment independent of the visual stimuli, in which the phobic pictures, a stimulus associated with a defense response, were unable to evoke a significantly more rigid posture than the others. We hypothesize that patients with SAD when entering in a situation of exposure, from the moment the pictures are presented, tend to move less than controls, remaining this way until the experiment ends. This discrete body manifestation can provide additional data to the characterization of SAD and its differentiation from other anxiety disorders, especially in situations regarding facing fear.


Assuntos
Feminino , Humanos , Transtornos de Ansiedade/fisiopatologia , Equilíbrio Postural/fisiologia , Transtornos de Ansiedade/psicologia , Estudos de Casos e Controles , Medo/fisiologia , Medo/psicologia , Estimulação Luminosa
16.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;44(4): 366-373, Apr. 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-581489

RESUMO

The objective of the present randomized, open-label, naturalistic 8-week study was to compare the efficacy and safety of treatment with clonazepam (N = 63) and paroxetine (N = 57) in patients with panic disorder with or without agoraphobia. Efficacy assessment included number of panic attacks and clinician ratings of the global severity of panic disorders with the clinical global impression (CGI) improvement (CGI-I) and CGI severity (CGI-S) scales. Most patients were females (69.8 and 68.4 percent in the clonazepam and paroxetine groups, respectively) and age (mean ± SD) was 35.9 ± 9.6 years for the clonazepam group and 33.7 ± 8.8 years for the paroxetine group. Treatment with clonazepam versus paroxetine resulted in fewer weekly panic attacks at week 4 (0.1 vs 0.5, respectively; P < 0.01), and greater clinical improvements at week 8 (CGI-I: 1.6 vs 2.9; P = 0.04). Anxiety severity was significantly reduced with clonazepam versus paroxetine at weeks 1 and 2, with no difference in panic disorder severity. Patients treated with clonazepam had fewer adverse events than patients treated with paroxetine (73 vs 95 percent; P = 0.001). The most common adverse events were drowsiness/fatigue (57 percent), memory/concentration difficulties (24 percent), and sexual dysfunction (11 percent) in the clonazepam group and drowsiness/fatigue (81 percent), sexual dysfunction (70 percent), and nausea/vomiting (61 percent) in the paroxetine group. This naturalistic study confirms the efficacy and tolerability of clonazepam and paroxetine in the acute treatment of patients with panic disorder.


Assuntos
Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Agorafobia/tratamento farmacológico , Clonazepam/uso terapêutico , Transtorno de Pânico/tratamento farmacológico , Paroxetina/uso terapêutico , Clonazepam/efeitos adversos , Escalas de Graduação Psiquiátrica , Paroxetina/efeitos adversos , Resultado do Tratamento
17.
J Med Microbiol ; 60(Pt 8): 1146-1154, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21372182

RESUMO

Clostridium difficile is the major cause of antibiotic-associated colitis, a disease with significant morbidity and mortality. This study investigated the role of the haem oxygenase-1 (HO-1)/carbon monoxide (CO) pathway in C. difficile toxin A-induced enteritis in mice. The HO substrate haemin, zinc protoporphyrin IX (ZnPP IX), a specific HO-1 inhibitor, dimanganese decacarbonyl (DMDC), a CO donor, or an equivalent volume of their respective vehicles were injected subcutaneously 30 min prior to local challenge with toxin A (25 or 50 µg per ileal loop) or PBS. Intestinal ileal loop weight/length ratios were calculated 3 h later. Ileal tissues were collected for histological analysis and measurement of myeloperoxidase (MPO) activity, tumour necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ß) production by ELISA and immunohistochemistry for HO-1. Treatment of mice subjected to C. difficile toxin A (TcdA) with haemin or DMDC prevented oedema, mucosal disruption and neutrophil infiltration observed in histological analysis. It also decreased TcdA-induced MPO activity and TNF-α or IL-1ß production. In contrast, the specific HO-1 inhibitor (ZnPP IX) exacerbated all these evaluated parameters. TcdA increased HO-1 expression as seen by immunohistochemistry. These results suggest that the HO-1/CO pathway exerts a protective role in TcdA-induced enteritis and that its pharmacological modulation might be important for the management of C. difficile-associated disease.


Assuntos
Toxinas Bacterianas/toxicidade , Monóxido de Carbono/metabolismo , Enterite/induzido quimicamente , Enterotoxinas/toxicidade , Heme Oxigenase (Desciclizante)/metabolismo , Animais , Desoxiuridina/análogos & derivados , Desoxiuridina/farmacologia , Enterite/prevenção & controle , Heme Oxigenase (Desciclizante)/genética , Hemina/farmacologia , Íleo/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Protoporfirinas/farmacologia
18.
Rev. paul. pediatr ; 29(1): 126-129, jan.-mar. 2011. ilus
Artigo em Português | LILACS | ID: lil-582824

RESUMO

OBJETIVO: Os cistos aracnoides são achados raros. Em 10 por cento dos casos, sua localização é supraselar e ocorrem quase exclusivamente em crianças. Em geral, apresentam manifestações neurológicas e visuais, sendo incomum a puberdade precoce central como sinal clínico de sua presença. DESCRIÇÃO DO CASO: Menina avaliada aos dois anos e sete meses por telarca iniciada com um ano e oito meses e pubarca e axilarca com dois anos, com aumento da velocidade de crescimento (13cm/ano) e da idade óssea (sete anos e um mês). Ao exame, apresentou peso de 22,6kg (Z+4,0), estatura de 106cm (Z+3,5) e Tanner de M3P2. Exames realizados: teste de estímulo com GnRH (LH basal 8,3 UI/L, pico aos 30 minutos 94,3 UI/L; FSH basal=10,1 UI/L, pico aos 30 minutos 29,5 UI/L), ressonância nuclear magnética de crânio com cisto aracnoide supraselar e demais testes de função hipofisária normais. Foi iniciado tratamento com análogo de GnRH. Atualmente, aos quatro anos e três meses com estadio puberal M3P2, velocidade de crescimento e desenvolvimento neuropsicomotor normais para a idade. COMENTÁRIOS: A puberdade precoce central pode ser manifestação única de um cisto aracnoide, sendo essenciais o diagnóstico e o tratamento precoces, além de seguimento prolongado, uma vez que outras disfunções hipofisárias podem ocorrer tardiamente.


OBJECTIVE: Arachnoid cysts (AC) are a rare finding; 10 percent of them are suprasellar and occur almost exclusively in children. They are frequently associated with neurological and visual manifestations. Central precocious puberty as a sole manifestation is uncommon. CASE DESCRIPTION: Girl evaluated at the age of two years and seven months. She started breast development at the age of one year and eight months, pubic and axillary hair at the age of two years, with growth velocity acceleration (13cm/year) and increased bone age (seven years and one month). On exam: weight: 22.6kg (Z+4.0), height: 106cm (Z+3.5) and puberal stage of B3P2. The GnRH stimulus test was performed (basal LH 8.3 IU/L, at 30 minutes 94.3 IU/L; FSH basal=10.1 IU/L, at 30 minutes 29.5 IU/L). Nuclear Magnetic Resonance of the skull showed a suprasellar arachnoid cyst. Others stimulation tests were performed and excluded pituitary deficiencies. Treatment with a GnRH analog was started. At the age of four years and three months, she was B3P2, with normal growth velocity and neurologic development. COMMENTS: Central precocious puberty can be the only manifestation of AC. It is essential to establish early diagnosis and treatment. A prolonged follow up is recommended, since late pituitary dysfunctions can occur.


Assuntos
Humanos , Feminino , Pré-Escolar , Cistos Aracnóideos/complicações , Puberdade Precoce/etiologia
20.
Arq. bras. med. vet. zootec ; Arq. bras. med. vet. zootec. (Online);59(1): 30-34, fev. 2007. tab, ilus
Artigo em Inglês | LILACS | ID: lil-456410

RESUMO

The distribution of T. gondii in commercial cuts of pork (ham, tenderloin, spareribs and arm picnic) by PCR and bioassay from experimentally infected pigs, was evaluated. Eighteen mixed breed pigs were divided into two groups (G). The G1 animals (n=10) were infected with 4 x10(4) oocysts of the T. gondii VEG strain and the G2 animals (n=8) were used as control. Pigs of both groups were slaughtered at 59th day after infection, and meat samples were collected for bioassay and PCR. All animals from G1 were positive by at least one or both tests, and all control animals were negative. T. gondii was identified in pork by mouse bioassay and PCR in 27/40 (67.5 percent) and in 9/40 (22.5 percent) of the evaluated samples, respectively. There were no statistical differences in the distribution of tissue cysts from commercial cuts of pork by bioassay (P>0.05). However, statistical differences were observed when mouse bioassay and PCR were compared (P<0.01).


Avaliou-se a presença de T. gondii em cortes comerciais de carne suína (pernil, lombo, costela e paleta), por meio do bioensaio e PCR, em animais experimentalmente inoculados. Dois grupos (G) foram formados. Os animais do G1 (n=10) foram inoculados com 4 x10(4) oocistos da cepa VEG e os do G2 (n=8) permaneceram como grupo-controle, não inoculado. Todos os animais foram abatidos no dia 59 após a infecção, quando foram colhidas as amostras de carne para a realização das provas de bioensaio e da PCR. Todos os suínos do G1 apresentaram-se positivos a pelo menos um dos testes de diagnóstico ou a ambos, e os do grupo-controle permaneceram negativos. Não houve diferenças significativas em relação aos tipos de cortes comerciais e à presença do parasita no bioensaio (P>0,05). O bioensaio foi capaz de detectar T. gondii em 27/40 (67,5 por cento) amostras e a PCR em 9/40 (22,5 por cento). O estudo mostrou diferença entre o bioensaio e a PCR (P<0,01).


Assuntos
Bioensaio/métodos , Carne/análise , Camundongos , Reação em Cadeia da Polimerase/métodos , Toxoplasma/isolamento & purificação
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