288 research outputs found
Evaluation of serum CEA, CYFRA21-1 and CA125 for the early detection of colorectal cancer using longitudinal preclinical samples
Blood-borne biomarkers for early detection of colorectal cancer (CRC) could markedly increase screening uptake. The aim of this study was to evaluate serum carcinoembryonic antigen (CEA), CYFRA21-1 and CA125 for the early detection of CRC in an asymptomatic cohort
RNAi screen for NRF2 inducers identifies targets that rescue primary lung epithelial cells from cigarette smoke induced radical stress
Chronic Obstructive Pulmonary Disease (COPD) is a highly prevalent condition characterized by inflammation and progressive obstruction of the airways. At present, there is no treatment that suppresses the chronic inflammation of the disease, and COPD patients often succumb to the condition. Excessive oxidative stress caused by smoke inhalation is a major driving force of the disease. The transcription factor NRF2 is a critical player in the battle against oxidative stress and its function is impaired in COPD. Increasing NRF2 activity may therefore be a viable therapeutic option for COPD treatment. We show that down regulation of KEAP1, a NRF2 inhibitor, protects primary human lung epithelial cells from cigarette-smoke-extract (CSE) induced cell death in an established in vitro model of radical stress. To identify new potential drug targets with a similar effect, we performed a siRNA screen of the 'druggable' genome using a NRF2 transcriptional reporter cell line. This screen identified multiple genes that when down regulated increased NRF2 transcriptional activity and provided a survival benefit in the in vitro model. Our results suggest that inhibiting components of the ubiquitin-proteasome system will have the strongest effects on NRF2 transcriptional activity by increasing NRF2 levels. We also find that down regulation of the small GTPase Rab28 or the Estrogen Receptor ESRRA provide a survival benefit. Rab28 knockdown increased NRF2 protein levels, indicating that Rab28 may regulate NRF2 proteolysis. Conversely ESRRA down regulation increased NRF2 transcriptional activity without affecting NRF2 levels, suggesting a proteasome-independent mechanism
Mutations in HYAL2, Encoding Hyaluronidase 2, Cause a Syndrome of Orofacial Clefting and Cor Triatriatum Sinister in Humans and Mice.
Orofacial clefting is amongst the most common of birth defects, with both genetic and environmental components. Although numerous studies have been undertaken to investigate the complexities of the genetic etiology of this heterogeneous condition, this factor remains incompletely understood. Here, we describe mutations in the HYAL2 gene as a cause of syndromic orofacial clefting. HYAL2, encoding hyaluronidase 2, degrades extracellular hyaluronan, a critical component of the developing heart and palatal shelf matrix. Transfection assays demonstrated that the gene mutations destabilize the molecule, dramatically reducing HYAL2 protein levels. Consistent with the clinical presentation in affected individuals, investigations of Hyal2-/- mice revealed craniofacial abnormalities, including submucosal cleft palate. In addition, cor triatriatum sinister and hearing loss, identified in a proportion of Hyal2-/- mice, were also found as incompletely penetrant features in affected humans. Taken together our findings identify a new genetic cause of orofacial clefting in humans and mice, and define the first molecular cause of human cor triatriatum sinister, illustrating the fundamental importance of HYAL2 and hyaluronan turnover for normal human and mouse development
Prognostic DNA methylation markers for sporadic colorectal cancer: a systematic review
Background Biomarkers that can predict the prognosis of colorectal cancer (CRC) patients and that can stratify high-risk early stage patients from low-risk early stage patients are urgently needed for better management of CRC. During the last decades, a large variety of prognostic DNA methylation markers has been published in the literature. However, to date, none of these markers are used in clinical practice. Methods To obtain an overview of the number of published prognostic methylation markers for CRC, the number of markers that was validated independently, and the current level of evidence (LoE), we conducted a systematic review of PubMed, EMBASE, and MEDLINE. In addition, we scored studies based on the REMARK guidelines that were established in order to attain more transparency and complete reporting of prognostic biomarker studies. Eighty-three studies reporting on 123 methylation markers fulfilled the study entry criteria and were scored according to REMARK. Results Sixty-three studies investigated single methylation markers, whereas 20 studies reported combinations of methylation markers. We observed substantial variation regarding the reporting of sample sizes and patient characteristics, statistical analyses, and methodology. The median (range) REMARK score for the studies was 10.7 points (4.5 to 17.5) out of a maximum of 20 possible points. The median REMARK score was lower in studies, which reported a p value below 0.05 versus those, which did not (p = 0.005). A borderline statistically significant association was observed between the reported p value of the survival analysis and the size of the study population (p = 0.051). Only 23 out of 123 markers (17%) were investigated in two or more study series. For 12 markers, and two multimarker panels, consistent results were reported in two or more study series. For four markers, the current LoE is level II, for all other markers, the LoE is lower. Conclusion This systematic review reflects that adequate reporting according to REMARK and validation of prognostic methylation markers is absent in the majority of CRC methylation marker studies. However, this systematic review provides a comprehensive overview of published prognostic methylation markers for CRC and highlights the most promising markers that have been published in the last two decades
Neutrinos
229 pages229 pages229 pagesThe Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms
Smoking Dose Modifies the Association between C242T Polymorphism and Prevalence of Metabolic Syndrome in a Chinese Population
Background: The C242T polymorphism of the CYBA gene that encodes p22phox, a component of NADPH oxidase, has been found to modulate superoxide production. Oxidase is a major source of the superoxide anion that contributes to individual components of metabolic syndrome. We examined the relationship of the C242T polymorphism with the prevalence of metabolic syndrome in a Chinese population, taking account of consumed cigarette amounts. Methodology/Principal Findings: In 870 participants, we collected biomarkers related to metabolic syndrome and detailed history of smoking and genotyped the C242T polymorphisms. After adjustment for covariates, the CT/TT genotypes were associated with a lower risk of metabolic syndrome (P = 0.0008). The odds of having metabolic syndrome in the CT/TT participants were 0.439 (95%CI: 0.265, 0.726), while for CC participants the odds were 1.110 (95%CI: 0.904, 1.362). There was significant (P = 0.014) interaction between the C242T polymorphism and smoking status in relation to the prevalence of metabolic syndrome. For smokers who smoke no less than 25 pack-years, those with CT/TT genotypes had lower risk of metabolic syndrome as compared with CC polymorphism carriers (P = 0.015). In the multiple regression analysis, the CT/TT genotypes were significantly associated with lower serum concentration of triglycerides both in all subjects and smokers; furthermore, the CT/TT genotypes were also related to smaller waist circumference in smokers. Conclusions: Our study suggests that the C242T gene polymorphism is indeed related to the prevalence of metaboli
Role of N-acetylcysteine in the management of COPD
The importance of the underlying local and systemic oxidative stress and inflammation in chronic obstructive pulmonary disease (COPD) has long been established. In view of the lack of therapy that might inhibit the progress of the disease, there is an urgent need for a successful therapeutic approach that, through affecting the pathological processes, will influence the subsequent issues in COPD management such as lung function, airway clearance, dyspnoea, exacerbation, and quality of life. N-acetylcysteine (NAC) is a mucolytic and antioxidant drug that may also influence several inflammatory pathways. It provides the sulfhydryl groups and acts both as a precursor of reduced glutathione and as a direct reactive oxygen species (ROS) scavenger, hence regulating the redox status in the cells. The changed redox status may, in turn, influence the inflammation-controlling pathways. Moreover, as a mucolytic drug, it may, by means of decreasing viscosity of the sputum, clean the bronchi leading to a decrease in dyspnoea and improved lung function. Nevertheless, as successful as it is in the in vitro studies and in vivo studies with high dosage, its actions at the dosages used in COPD management are debatable. It seems to influence exacerbation rate and limit the number of hospitalization days, however, with little or no influence on the lung function parameters. Despite these considerations and in view of the present lack of effective therapies to inhibit disease progression in COPD, NAC and its derivatives with their multiple molecular modes of action remain promising medication once doses and route of administration are optimized
Disparate oxidant gene expression of airway epithelium compared to alveolar macrophages in smokers
<p>Abstract</p> <p>Background</p> <p>The small airway epithelium and alveolar macrophages are exposed to oxidants in cigarette smoke leading to epithelial dysfunction and macrophage activation. In this context, we asked: what is the transcriptome of oxidant-related genes in small airway epithelium and alveolar macrophages, and does their response differ substantially to inhaled cigarette smoke?</p> <p>Methods</p> <p>Using microarray analysis, with TaqMan RT-PCR confirmation, we assessed oxidant-related gene expression in small airway epithelium and alveolar macrophages from the same healthy nonsmoker and smoker individuals.</p> <p>Results</p> <p>Of 155 genes surveyed, 87 (56%) were expressed in both cell populations in nonsmokers, with higher expression in alveolar macrophages (43%) compared to airway epithelium (24%). In smokers, there were 15 genes (10%) up-regulated and 7 genes (5%) down-regulated in airway epithelium, but only 3 (2%) up-regulated and 2 (1%) down-regulated in alveolar macrophages. Pathway analysis of airway epithelium showed oxidant pathways dominated, but in alveolar macrophages immune pathways dominated.</p> <p>Conclusion</p> <p>Thus, the response of different cell-types with an identical genome exposed to the same stress of smoking is different; responses of alveolar macrophages are more subdued than those of airway epithelium. These findings are consistent with the observation that, while the small airway epithelium is vulnerable, alveolar macrophages are not "diseased" in response to smoking.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov ID: NCT00224185 and NCT00224198</p
Mapping and phasing of structural variation in patient genomes using nanopore sequencing
Despite improvements in genomics technology, the detection of structural variants (SVs) from short-read sequencing still poses challenges, particularly for complex variation. Here we analyse the genomes of two patients with congenital abnormalities using the MinION nanopore sequencer and a novel computational pipeline—NanoSV. We demonstrate that nanopore long reads are superior to short reads with regard to detection of de novo chromothripsis rearrangements. The long reads also enable efficient phasing of genetic variations, which we leveraged to determine the parental origin of all de novo chromothripsis breakpoints and to resolve the structure of these complex rearrangements. Additionally, genome-wide surveillance of inherited SVs reveals novel variants, missed in short-read data sets, a large proportion of which are retrotransposon insertions. We provide a first exploration of patient genome sequencing with a nanopore sequencer and demonstrate the value of long-read sequencing in mapping and phasing of SVs for both clinical and research applications
Effects of cigarette smoke condensate on proliferation and wound closure of bronchial epithelial cells in vitro: role of glutathione
BACKGROUND: Increased airway epithelial proliferation is frequently observed in smokers. To elucidate the molecular mechanisms leading to these epithelial changes, we studied the effect of cigarette smoke condensate (CSC) on cell proliferation, wound closure and mitogen activated protein kinase (MAPK) activation. We also studied whether modulation of intracellular glutathione/thiol levels could attenuate CSC-induced cell proliferation. METHODS: Cells of the bronchial epithelial cell line NCI-H292 and subcultures of primary bronchial epithelial cells were used for the present study. The effect of CSC on epithelial proliferation was assessed using 5-bromo-2-deoxyuridine (BrdU) incorporation. Modulation of epithelial wound repair was studied by analysis of closure of 3 mm circular scrape wounds during 72 hours of culture. Wound closure was calculated from digital images obtained at 24 h intervals. Activation of mitogen-activated protein kinases was assessed by Western blotting using phospho-specific antibodies. RESULTS: At low concentrations CSC increased proliferation of NCI-H292 cells, whereas high concentrations were inhibitory as a result of cytotoxicity. Low concentrations of CSC also increased epithelial wound closure of both NCI-H292 and PBEC, whereas at high concentrations closure was inhibited. At low, mitogenic concentrations, CSC caused persistent activation of ERK1/2, a MAPK involved in cell proliferation. Inhibition of cell proliferation by high concentrations of CSC was associated with activation of the pro-apoptotic MAP kinases p38 and JNK. Modulation of intracellular glutathione (GSH)/thiol levels using N-acetyl-L-cysteine, GSH or buthionine sulphoximine (BSO), demonstrated that both the stimulatory and the inhibitory effects of CSC were regulated in part by intracellular GSH levels. CONCLUSION: These results indicate that CSC may increase cell proliferation and wound closure dependent on the local concentration of cigarette smoke and the anti-oxidant status. These findings are consistent with increased epithelial proliferation in smokers, and may provide further insight in the development of lung cancer
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