Pentraxin 3 accelerates lung injury in high tidal volume ventilation in mice.

Mechanical ventilation is the major cause of iatrogenic lung damage in intensive care units. Although inflammation is known to be involved in ventilator-induced lung injury (VILI), several aspects of this process are still unknown. Pentraxin 3 (PTX3) is an acute phase protein with important regulatory functions in inflammation which has been found elevated in patients with acute respiratory distress syndrome. This study aimed at investigating the direct effect of PTX3 production in the pathogenesis of VILI. Genetically modified mice deficient and that over express murine Ptx3 gene were subjected to high tidal volume ventilation (V(T)=45 mL/kg, PEEP(zero)). Morphological changes and time required for 50% increase in respiratory system elastance were evaluated. Gene expression profile in the lungs was also investigated in earlier times in Ptx3-overexpressing mice. Ptx3 knockout and wild-type mice developed same lung injury degree in similar times (156±42 min and 148±41 min, respectively; p=0.8173). However, Ptx3 over-expression led to a faster development of VILI in Ptx3-overexpressing mice (77±29 min vs 118±41 min, p=0.0225) which also displayed a faster kinetics of Il1b expression and elevated Ptx3, Cxcl1 and Ccl2 transcripts levels in comparison with wild-type mice assessed by quantitative real-time polymerase chain reaction. Ptx3 deficiency did not impacted the time for VILI induced by high tidal volume ventilation but Ptx3-overexpression increased inflammatory response and reflected in a faster VILI development.

Avaliação do papel funcional do gene NDRG4 na tumorigênese de mama / Evaluation of the functional role of gene NDRG4 in breast tumorigenesis

Em trabalho anterior realizado pelo nosso grupo, descrevemos que o gene NDRG4 se encontra silenciado em linhagens tumorais de mama devido a presença de metilação na sua região promotora. Neste trabalho, exploramos o papel do silenciamento do gene NDRG4 na tumorigênese da mama. Em um primeiro momento, investigamos a associação entre a presença de metilação na região promotora do gene NDRG4 em 61 amostras de tumores de mama e os dados clínico-patológicos das pacientes. Observamos uma associação estatisticamente significativa entre a presença de metilação do DNA na região promotora do gene NDRG4 e fatores de pior prognóstico, tais como: número de linfonodos positivos (p=0,025), níveis elevados da proteína p53 (p=0,014) e o tamanho do tumor (p=0,036); bem como com uma menor taxa de sobrevida livre de metástase em 10 anos (p=0,001). Em análise multivariada, a presença de metilação do DNA na região promotora do gene NDRG4 se mostrou um fator independente de prognóstico para sobrevida livre de mestástase (HR=5.5 e p=0.006). Paralelamente, realizamos o silenciamento do gene NDRG4 na linhagem de tumor de mama MCF7 utilizando a metodologia de shRNA. Variantes celulares, silenciadas para o gene NDRG4, apresentaram uma redução significativa na taxa de proliferação e na capacidade de formação de colônias isoladas e um aumento significativo na capacidade de migração. No entanto, não foram observadas diferenças significativas na capacidade de adesão e na susceptibilidade a taxanos dos clones silenciados

Correlation of MGMT promoter methylation status with gene and protein expression levels in glioblastoma.

OBJECTIVES: 1) To correlate the methylation status of the O6-methylguanine-DNA-methyltransferase (MGMT) promoter to its gene and protein expression levels in glioblastoma and 2) to determine the most reliable method for using MGMT to predict the response to adjuvant therapy in patients with glioblastoma. BACKGROUND: The MGMT gene is epigenetically silenced by promoter hypermethylation in gliomas, and this modification has emerged as a relevant predictor of therapeutic response. METHODS: Fifty-one cases of glioblastoma were analyzed for MGMT promoter methylation by methylation-specific PCR and pyrosequencing, gene expression by real time polymerase chain reaction, and protein expression by immunohistochemistry. RESULTS: MGMT promoter methylation was found in 43.1% of glioblastoma by methylation-specific PCR and 38.8% by pyrosequencing. A low level of MGMT gene expression was correlated with positive MGMT promoter methylation (p = 0.001). However, no correlation was found between promoter methylation and MGMT protein expression (p = 0.297). The mean survival time of glioblastoma patients submitted to adjuvant therapy was significantly higher among patients with MGMT promoter methylation (log rank = 0.025 by methylation-specific PCR and 0.004 by pyrosequencing), and methylation was an independent predictive factor that was associated with improved prognosis by multivariate analysis. DISCUSSION AND CONCLUSION: MGMT promoter methylation status was a more reliable predictor of susceptibility to adjuvant therapy and prognosis of glioblastoma than were MGMT protein or gene expression levels. Methylation-specific polymerase chain reaction and pyrosequencing methods were both sensitive methods for determining MGMT promoter methylation status using DNA extracted from frozen tissue.

Correlation of MGMT promoter methylation status with gene and protein expression levels in glioblastoma

OBJECTIVES: 1) To correlate the methylation status of the O6-methylguanine-DNA-methyltransferase (MGMT) promoter to its gene and protein expression levels in glioblastoma and 2) to determine the most reliable method for using MGMT to predict the response to adjuvant therapy in patients with glioblastoma. BACKGROUND: The MGMT gene is epigenetically silenced by promoter hypermethylation in gliomas, and this modification has emerged as a relevant predictor of therapeutic response. METHODS: Fifty-one cases of glioblastoma were analyzed for MGMT promoter methylation by methylation-specific PCR and pyrosequencing, gene expression by real time polymerase chain reaction, and protein expression by immunohistochemistry. RESULTS: MGMT promoter methylation was found in 43.1 percent of glioblastoma by methylation-specific PCR and 38.8 percent by pyrosequencing. A low level of MGMT gene expression was correlated with positive MGMT promoter methylation (p = 0.001). However, no correlation was found between promoter methylation and MGMT protein expression (p = 0.297). The mean survival time of glioblastoma patients submitted to adjuvant therapy was significantly higher among patients with MGMT promoter methylation (log rank = 0.025 by methylation-specific PCR and 0.004 by pyrosequencing), and methylation was an independent predictive factor that was associated with improved prognosis by multivariate analysis. DISCUSSION AND CONCLUSION: MGMT promoter methylation status was a more reliable predictor of susceptibility to adjuvant therapy and prognosis of glioblastoma than were MGMT protein or gene expression levels. Methylation-specific polymerase chain reaction and pyrosequencing methods were both sensitive methods for determining MGMT promoter methylation status using DNA extracted from frozen tissue.

Alcohol dehydrogenase 3 genotype as a risk factor for upper aerodigestive tract cancers.

OBJECTIVE: To assess alcohol dehydrogenase 3 (ADH3) polymorphism at position Ile349Val as indicator of risk factor for upper aerodigestive tract (UADT) cancer to verify its association with UADT cancer in nonalcoholic or nonsmoking individuals. DESIGN: Cross-sectional study. SETTING: Primary care or referral center. PATIENTS: The study group consisted of 141 consecutive patients with newly diagnosed squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx admitted for surgical treatment. The comparison group consisted of 94 inpatients without cancer from the A. C. Camargo or other São Paulo (Brazil) hospital and 40 healthy individuals. INTERVENTION: All participants were interviewed and data were collected using a structured questionnaire. After written informed consent was obtained, 20 mL of blood was collected in heparinized tubes. MAIN OUTCOME MEASURES: Odds ratio for ADH3 genotypes using logistic regression models. RESULTS: After adjustment for sex, age, tobacco use, and history of cancer in first-degree family relatives, a significantly higher odds ratio for UADT cancer was observed among individuals with AA genotype and low cumulative alcohol consumption (< or =100 kg of ethanol) (odds ratio = 3.8 [95% confidence interval, 1.5-9.7]). A 4-fold increase in odds ratio for UADT cancer among individuals with AA genotype and low tobacco consumption (< or =25 pack-years) was also found in the adjusted model. CONCLUSIONS: These results suggest that genotype AA may be a risk factor for UADT cancer, especially in individuals with low alcohol or tobacco consumption. However, further epidemiological case-control or cohort studies, preferably prospective, are needed to establish the exact role of ADH3 polymorphism and its association with the development of UADT cancers.