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Sample records for quantitative mgmt promoter

  1. MGMT promoter methylation in gliomas-assessment by pyrosequencing and quantitative methylation-specific PCR

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    Håvik Annette

    2012-03-01

    Full Text Available Abstract Background Methylation of the O6-methylguanine-DNA methyltransferase (MGMT gene promoter is a favorable prognostic factor in glioblastoma patients. However, reported methylation frequencies vary significantly partly due to lack of consensus in the choice of analytical method. Method We examined 35 low- and 99 high-grade gliomas using quantitative methylation specific PCR (qMSP and pyrosequencing. Gene expression level of MGMT was analyzed by RT-PCR. Results When examined by qMSP, 26% of low-grade and 37% of high-grade gliomas were found to be methylated, whereas 97% of low-grade and 55% of high-grade gliomas were found methylated by pyrosequencing. The average MGMT gene expression level was significantly lower in the group of patients with a methylated promoter independent of method used for methylation detection. Primary glioblastoma patients with a methylated MGMT promoter (as evaluated by both methylation detection methods had approximately 5 months longer median survival compared to patients with an unmethylated promoter (log-rank test; pyrosequencing P = .02, qMSP P = .06. One third of the analyzed samples had conflicting methylation results when comparing the data from the qMSP and pyrosequencing. The overall survival analysis shows that these patients have an intermediate prognosis between the groups with concordant MGMT promoter methylation results when comparing the two methods. Conclusion In our opinion, MGMT promoter methylation analysis gives sufficient prognostic information to merit its inclusion in the standard management of patients with high-grade gliomas, and in this study pyrosequencing came across as the better analytical method.

  2. Detection of MGMT promoter methylation in glioblastoma using pyrosequencing.

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    Xie, Hao; Tubbs, Raymond; Yang, Bin

    2015-01-01

    Recent clinical trials on patients with glioblastoma revealed that O6-Methylguanine-DNA methyltransferase (MGMT) methylation status significantly predicts patient's response to alkylating agents. In this study, we sought to develop and validate a quantitative MGMT methylation assay using pyrosequencing on glioblastoma. We quantified promoter methylation of MGMT using pyrosequencing on paraffin-embedded fine needle aspiration biopsy tissues from 43 glioblastoma. Using a 10% cutoff, MGMT methylation was identified in 37% cases of glioblastoma and 0% of the non-neoplastic epileptic tissue. Methylation of any individual CpG island in MGMT promoter ranged between 33% and 95%, with a mean of 65%. By a serial dilution of genomic DNA of a homogenously methylated cancer cell line with an unmethylated cell line, the analytical sensitivity is at 5% for pyrosequencing to detect MGMT methylation. The minimal amount of genomic DNA required is 100 ng (approximately 3,000 cells) in small fine needle biopsy specimens. Compared with methylation-specific PCR, pyrosequencing is comparably sensitive, relatively specific, and also provides quantitative information for each CpG methylation.

  3. High Specificity of Quantitative Methylation-Specific PCR Analysis for MGMT Promoter Hypermethylation Detection in Gliomas

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    Paola Parrella

    2009-01-01

    Full Text Available Normal brain tissue from 28 individuals and 50 glioma samples were analyzed by real-time Quantitative Methylation-Specific PCR (QMSP. Data from this analysis were compared with results obtained on the same samples by MSP. QMSP analysis demonstrated a statistically significant difference in both methylation level (P=.000009 Mann Whitney Test and frequencies (P=.0000007, Z-test in tumour samples as compared with normal brain tissues. Although QMSP and MSP showed similar sensitivity, the specificity of QMSP analysis was significantly higher (93%; CI95%: 84%–100% as compared with MSP (64%; 95%CI: 46%–82%. Our results suggest that QMSP analysis may represent a powerful tool to identify glioma patients that will benefit from alkylating agents chemotherapy.

  4. Comprehensive analysis of MGMT promoter methylation: correlation with MGMT expression and clinical response in GBM.

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    Nameeta Shah

    Full Text Available O⁶-methylguanine DNA-methyltransferase (MGMT promoter methylation has been identified as a potential prognostic marker for glioblastoma patients. The relationship between the exact site of promoter methylation and its effect on gene silencing, and the patient's subsequent response to therapy, is still being defined. The aim of this study was to comprehensively characterize cytosine-guanine (CpG dinucleotide methylation across the entire MGMT promoter and to correlate individual CpG site methylation patterns to mRNA expression, protein expression, and progression-free survival. To best identify the specific MGMT promoter region most predictive of gene silencing and response to therapy, we determined the methylation status of all 97 CpG sites in the MGMT promoter in tumor samples from 70 GBM patients using quantitative bisulfite sequencing. We next identified the CpG site specific and regional methylation patterns most predictive of gene silencing and improved progression-free survival. Using this data, we propose a new classification scheme utilizing methylation data from across the entire promoter and show that an analysis based on this approach, which we call 3R classification, is predictive of progression-free survival (HR  = 5.23, 95% CI [2.089-13.097], p<0.0001. To adapt this approach to the clinical setting, we used a methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA test based on the 3R classification and show that this test is both feasible in the clinical setting and predictive of progression free survival (HR  = 3.076, 95% CI [1.301-7.27], p = 0.007. We discuss the potential advantages of a test based on this promoter-wide analysis and compare it to the commonly used methylation-specific PCR test. Further prospective validation of these two methods in a large independent patient cohort will be needed to confirm the added value of promoter wide analysis of MGMT methylation in the clinical

  5. Promoter Hypermethylation of DNA Repair Gene MGMT in Laryngeal Squamous Cell Carcinoma

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The relationship between hypermethylation of CpG islands in the promoter regions of O6methylguanine DNA methyltransferase (MGMT)genes and laryngeal squamous cell carcinoma was explored. Methylation-specific PCR and semi-quantitative RT-PCR were used to study the promoter methylation and mRNA expression of the MGMT gene in laryngeal carcinoma tissues, t issues adjacent to the tumor and normal laryngeal tissues. Hypermethylation of MGMT gene was detected in 16 samples of 46 (34.8 %) laryngeal squamous cell carcinoma samples. However, the MGMT hypermethylation was not detected in all tissues adjacent to the tumors and normal tissues. No significant difference in MGMT gene hypermethylation was found in samples with different histological grades (x2= 3. 130, P=0. 077) or in samples from patients with different TNM status (x2=3. 957, P=0. 138). No expression of MGMT mRNA was detected in all hypermethylated laryngeal carcinoma tissues. The expression of MGMT mRNA was detected in all unmethylated laryngeal carcinoma tissues, tissues adjacent to the tumors and normal tissues. It suggests that MGMT gene promoter hypermethylation is associated with MGMT gene transcription loss in laryngeal carcinoma tissues and possibly plays an important role in carcinogenesis of laryngeal tissues.

  6. Homogeneous MGMT immunoreactivity correlates with an unmethylated MGMT promoter status in brain metastases of various solid tumors.

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    Barbara Ingold

    Full Text Available The O(6-methylguanine-methyltransferase (MGMT promoter methylation status is a predictive parameter for the response of malignant gliomas to alkylating agents such as temozolomide. First clinical reports on treating brain metastases with temozolomide describe varying effects. This may be due to the fact that MGMT promoter methylation of brain metastases has not yet been explored in depth. Therefore, we assessed MGMT promoter methylation of various brain metastases including those derived from lung (n = 91, breast (n = 72 kidney (n = 49 and from malignant melanomas (n = 113 by methylation-specific polymerase chain reaction (MS-PCR and MGMT immunoreactivity. Fifty-nine of 199 brain metastases (29.6% revealed a methylated MGMT promoter. The methylation rate was the highest in brain metastases derived from lung carcinomas (46.5% followed by those from breast carcinoma (28.8%, malignant melanoma (24.7% and from renal carcinoma (20%. A significant correlation of homogeneous MGMT-immunoreactivity (>95% MGMT positive tumor cells and an unmethylated MGMT promoter was found. Promoter methylation was detected in 26 of 61 (43% tumors lacking MGMT immunoreactivity, in 17 of 63 (27% metastases with heterogeneous MGMT expression, but only in 5 of 54 brain metastases (9% showing a homogeneous MGMT immunoreactivity. Our results demonstrate that a significant number of brain metastases reveal a methylated MGMT-promoter. Based on an obvious correlation between homogeneous MGMT immunoreactivity and unmethylated MGMT promoter, we hypothesize that immunohistochemistry for MGMT may be a helpful diagnostic tool to identify those tumors that probably will not benefit from the use of alkylating agents. The discrepancy between promoter methylation and a lack of MGMT immunoreactivity argues for assessing MGMT promoter methylation both by immunohistochemical as well as by molecular approaches for diagnostic purposes.

  7. Assessment of Quantitative and Allelic MGMT Methylation Patterns as a Prognostic Marker in Glioblastoma.

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    Kristensen, Lasse S; Michaelsen, Signe R; Dyrbye, Henrik; Aslan, Derya; Grunnet, Kirsten; Christensen, Ib J; Poulsen, Hans S; Grønbæk, Kirsten; Broholm, Helle

    2016-03-01

    Methylation of the O(6)-methylguanine-DNA methyltransferase (MGMT) gene is a predictive and prognostic marker in newly diagnosed glioblastoma patients treated with temozolomide but how MGMT methylation should be assessed to ensure optimal detection accuracy is debated. We developed a novel quantitative methylation-specific PCR (qMSP) MGMT assay capable of providing allelic methylation data and analyzed 151 glioblastomas from patients receiving standard of care treatment (Stupp protocol). The samples were also analyzed by immunohistochemistry (IHC), standard bisulfite pyrosequencing, and genotyped for the rs1690252 MGMT promoter single nucleotide polymorphism. Monoallelic methylation was observed more frequently than biallelic methylation, and some cases with monoallelic methylation expressed the MGMT protein whereas others did not. The presence of MGMT methylation was associated with better overall survival (p = 0.006; qMSP and p = 0.002; standard pyrosequencing), and the presence of the protein was associated with worse overall survival (p = 0.009). Combined analyses of qMSP and standard pyrosequencing or IHC identified additional patients who benefited from temozolomide treatment. Finally, low methylation levels were also associated with better overall survival (p = 0.061; qMSP and p = 0.02; standard pyrosequencing). These data support the use of both MGMT methylation and MGMT IHC but not allelic methylation data as prognostic markers in patients with temozolomide-treated glioblastoma.

  8. Prognostic Relevance of Tumor Purity and TERT Promoter Mutations on MGMT Promoter Methylation in Glioblastoma.

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    Schulze Heuling, Eva; Knab, Felix; Radke, Josefine; Eskilsson, Eskil; Martinez-Ledesma, Emmanuel; Koch, Arend; Czabanka, Marcus; Dieterich, Christoph; Verhaak, Roel G; Harms, Christoph; Euskirchen, Philipp

    2017-02-01

    Promoter methylation status of O-6-methylguanine-DNA methyltransferase (MGMT), a DNA repair enzyme, is a critical biomarker in glioblastoma multiforme (GBM) as treatment decisions and clinical trial inclusion rely on its accurate assessment. However, interpretation of results is complicated by poor inter-assay reproducibility as well as weak a correlation between methylation status and expression levels of MGMT. The present study systematically investigates the influence of tumor purity on tissue subjected to MGMT analysis. A quantitative, allele-specific real-time PCR (qAS-PCR) assay was developed to determine genotype and mutant allele frequency of telomerase promoter (pTERT) mutations as a direct measure of tumor purity. We studied tumor purity, pTERT mutation by Sanger sequencing, MGMT methylation by pyrosequencing, IDH1 mutation status, and clinical parameters in a cohort of high-grade gliomas (n=97). The qAS-PCR reliably predicted pTERT genotype and tumor purity compared with independent methods. Tumor purity positively and significantly correlated with the extent of methylation in MGMT methylated GBMs. Extent of MGMT methylation differed significantly with respect to pTERT mutation hotspot (C228T vs. C250T). Interestingly, frontal lobe tumors showed greater tumor purity than those in other locations. Above all, tumor purity was identified as an independent prognostic factor in GBM. In conclusion, we determined mutual associations of tumor purity with MGMT methylation and pTERT mutations and found that the extent of MGMT methylation reflects tumor purity. In turn, tumor purity is prognostic in IDH1 wildtype GBM.

  9. Absence of MGMT promoter methylation in endometrial cancer.

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    Rimel, B J; Huettner, Phyllis; Powell, Matthew A; Mutch, David G; Goodfellow, Paul J

    2009-01-01

    O(6)-methylguanine-DNA methyltransferase (MGMT) acts to repair DNA damaged by alkylation of guanine residues. MGMT promoter methylation and gene silencing is seen in a variety of cancers and pre-cancerous changes [Ogino S, Meyerhardt JA, Kawasaki T, et al. CpG island methylation, response to combination chemotherapy, and patient survival in advanced microsatellite stable colorectal carcinoma. Virchows Arch 2007;450:529-37; Rodriguez MJ, Acha A, Ruesga MT, Rodriguez C, Rivera JM, Aguirre JM. Loss of expression of DNA repair enzyme MGMT in oral leukoplakia and early oral squamous cell carcinoma. A prognostic tool? Cancer Lett 2007;245:263-8; Ishii T, Murakami J, Notohara K, et al. Oesophageal squamous cell carcinoma may develop within a background of accumulating DNA methylation in normal and dysplastic mucosa. Gut 2007;56:13-9]. The loss of MGMT activity and promoter methylation is associated with increased sensitivity to alkylating agents and is a favorable prognostic indicator in gliomas [Weaver KD, Grossman SA, Herman JG. Methylated tumor-specific DNA as a plasma biomarker in patients with glioma. Cancer Invest 2006;24:35-40; Esteller M, Garcia-Foncillas J, Andion E, et al. Inactivation of the DNA-repair gene MGMT and the clinical response of gliomas to alkylating agents. N Engl J Med 2000;343:1350-4; Hegi ME, Diserens AC, Gorlia T, et al. MGMT gene silencing and benefit from temozolomide in glioblastoma. N Engl J Med 2005;352:997-1003]. We sought to determine if MGMT promoter methylation plays a role in endometrial cancer. One hundred and twenty primary endometrial cancers were analyzed for MGMT promoter methylation by combined bisulfite restriction analysis (COBRA). The cohort included 77 endometrioid endometrial cancers, 43 endometrial tumors of adverse histologic type, and 6 endometrial cancer cell lines. Twenty-one endometrioid and mixed endometrioid ovarian cancers were also analyzed. A subset of the primary tumors was analyzed for MGMT expression by

  10. Homogeneous MGMT Immunoreactivity Correlates with an Unmethylated MGMT Promoter Status in Brain Metastases of Various Solid Tumors

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    Barbara Ingold; Peter Schraml; Heppner, Frank L.; Holger Moch

    2009-01-01

    The O(6)-methylguanine-methyltransferase (MGMT) promoter methylation status is a predictive parameter for the response of malignant gliomas to alkylating agents such as temozolomide. First clinical reports on treating brain metastases with temozolomide describe varying effects. This may be due to the fact that MGMT promoter methylation of brain metastases has not yet been explored in depth. Therefore, we assessed MGMT promoter methylation of various brain metastases including those derived fr...

  11. Outcome in unresectable glioblastoma: MGMT promoter methylation makes the difference.

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    Thon, Niklas; Thorsteinsdottir, Jun; Eigenbrod, Sabina; Schüller, Ulrich; Lutz, Jürgen; Kreth, Simone; Belka, Claus; Tonn, Jörg-Christian; Niyazi, Maximilian; Kreth, Friedrich Wilhelm

    2017-02-01

    In 2011, we reported a predominant prognostic/predictive role of MGMT promoter methylation status on progression-free survival (PFS) in unresectable glioblastoma patients undergoing upfront radiotherapy plus concomitant and maintenance temozolomide (RTX/TMZ → TMZ). We, here, present the final results of this prospective study focussing on the prognostic/predictive value of MGMT promoter methylation status for death risk stratification. Overall, 56 adult patients with unresectable, biopsy proven glioblastoma were prospectively assigned to upfront RTX/TMZ → TMZ treatment between March 2006 and August 2008. Last follow-up was performed in June 2016. MGMT promoter methylation was determined using methylation-specific PCR (MSP) and sodium bisulfite sequencing. Analyses were done by intention to treat. Prognostic factors were obtained from proportional hazard models. At the time of the final analysis 55 patients showed progressive disease and 53 patients had died. MGMT promoter was methylated (unmethylated) in 30 (26) patients. Methylation of the MGMT promoter was the strongest favorable predictor for overall survival (OS, median: 20.3 vs. 7.3 months, p MGMT promoter methylation status is essential for patients' counseling, prognostic evaluation, and for the design of future trials dealing with unresectable glioblastomas.

  12. A five-miRNA signature with prognostic and predictive value for MGMT promoter-methylated glioblastoma patients.

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    Cheng, Wen; Ren, Xiufang; Cai, Jinquan; Zhang, Chuanbao; Li, Mingyang; Wang, Kuanyu; Liu, Yang; Han, Sheng; Wu, Anhua

    2015-10-06

    Although O(6)-methylguanine DNA methyltransferase (MGMT) promoter methylation status is an important marker for glioblastoma multiforme (GBM), there is considerable variability in the clinical outcome of patients with similar methylation profiles. The present study aimed to refine the prognostic and predictive value of MGMT promoter status in GBM by identifying a micro (mi)RNA risk signature. Data from The Cancer Genome Atlas was used for this study, with MGMT promoter-methylated samples randomly divided into training and internal validation sets. Data from The Chinese Glioma Genome Atlas was used for independent validation. A five miRNA-based risk signature was established for MGMT promoter-methylated GBM to distinguish cases as high- or low-risk with distinct prognoses, which was confirmed using internal and external validation sets. Importantly, the prognostic value of the signature was significant in different cohorts stratified by clinicopathologic factors and alkylating chemotherapy, and a multivariate Cox analysis found it to be an independent prognostic marker along with age and chemotherapy. Based on these three factors, we developed a quantitative model with greater accuracy for predicting the 1-year survival of patients with MGMT promoter-methylated GBM. These results indicate that the five-miRNA signature is an independent risk predictor for GBM with MGMT promoter methylation and can be used to identify patients at high risk of unfavorable outcome and resistant to alkylating chemotherapy, underscoring its potential for personalized GBM management.

  13. MGMT promoter methylation status and MGMT and CD133 immunohistochemical expression as prognostic markers in glioblastoma patients treated with temozolomide plus radiotherapy

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    Melguizo Consolación

    2012-12-01

    Full Text Available Abstract Background The CD133 antigen is a marker of radio- and chemo-resistant stem cell populations in glioblastoma (GBM. The O6-methylguanine DNA methyltransferase (MGMT enzyme is related with temozolomide (TMZ resistance. Our propose is to analyze the prognostic significance of the CD133 antigen and promoter methylation and protein expression of MGMT in a homogenous group of GBM patients uniformly treated with radiotherapy and TMZ. The possible connection between these GBM markers was also investigated. Methods Seventy-eight patients with GBM treated with radiotherapy combined with concomitant and adjuvant TMZ were analyzed for MGMT and CD133. MGMT gene promoter methylation was determined by methylation-specific polymerase chain reaction after bisulfite treatment. MGMT and CD133 expression was assessed immunohistochemically using an automatic quantification system. Overall and progression-free survival was calculated according to the Kaplan–Meier method. Results The MGMT gene promoter was found to be methylated in 34 patients (44.7% and unmethylated in 42 patients (55.3%. A significant correlation was observed between MGMT promoter methylation and patients’ survival. Among the unmethylated tumors, 52.4% showed low expression of MGMT and 47.6% showed high-expression. Among methylated tumors, 58.8% showed low-expression of MGMT and 41.2% showed high-expression. No correlation was found between MGMT promoter methylation and MGMT expression, or MGMT expression and survival. In contrast with recent results, CD133 expression was not a predictive marker in GBM patients. Analyses of possible correlation between CD133 expression and MGMT protein expression or MGMT promoter methylation were negative. Conclusions Our results support the hypothesis that MGMT promoter methylation status but not MGMT expression may be a predictive biomarker in the treatment of patients with GBM. In addition, CD133 should not be used for prognostic evaluation of these

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

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    Miyuki Uno

    2011-01-01

    Full Text Available 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.

  15. Identification of MGMT promoter methylation sites correlating with gene expression and IDH1 mutation in gliomas.

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    Zhang, Jie; Yang, Jian-Hui; Quan, Jia; Kang, Xing; Wang, Hui-Juan; Dai, Peng-Gao

    2016-10-01

    O(6)-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation was reported to be an independent prognostic and predictive factor in glioma patients who received temozolomide treatment. However, the predictive value of MGMT methylation was recently questioned by several large clinical studies. The purpose of this study is to identify MGMT gene promoter CpG sites or region whose methylation were closely correlated with its gene expression to elucidate this contradictory clinical observations. The methylation status for all CpG dinucleotides in MGMT promoter and first exon region were determined in 42 Chinese glioma patients, which were then correlated with MGMT gene expression, IDH1 mutation, and tumor grade. In whole 87 CpG dinucleotides analyzed, three distinct CpG regions covering 28 CpG dinucleotides were significantly correlated with MGMT gene expression; 10 CpG dinucleotides were significantly correlated with glioma classification (p MGMT gene hypermethylation significantly co-existed, but not for MGMT gene expression. The validation cohort of gliomas treated with standard of care and comparison of the CpGs we identified with the current CpGs used in clinical setting will be very important for gliomas individual medicine in the future.

  16. Prognosis value of MGMT promoter methylation for patients with lung cancer: a meta-analysis.

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    Chen, Chao; Hua, Haiqing; Han, Chenglong; Cheng, Yuan; Cheng, Yin; Wang, Zhen; Bao, Jutao

    2015-01-01

    The role of MGMT promoter methylation in lung cancer (LC) remains controversial. To clarify the association of MGMT promoter methylation with survival in LC, we performed a meta-analysis of the literature with meta-analysis. Trials were selected for further analysis if they provided an independent assessment of MGMT promoter methylation in LC and reported the survival data in the context of MGMT promoter methylation status. Subgroup analyses were conducted according to the study characteristic. A total of 9 trials, which comprised 859 patients, were included in the meta-analysis. The combined hazard ratio (HR) of 1.27 [95% CI 0.88-1.82; test for heterogeneity P = 0.027] suggests that MGMT promoter methylation has none impact on patient survival. In Stage I-III or younger populations, a significant association was found for MGMT promoter methylation in the prognosis of LC. In addition, the heterogeneity disappeared when the analysis was restricted to Stage I-III LC. Our analysis indicates that MGMT promoter methylation in stage I-III or younger patients was significantly correlated with wore survival. Further study is needed to determine these specific subgroups of LC patients.

  17. Relationships between MGMT promoter methylation and gastric cancer: a meta-analysis.

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    Yu, Dan; Cao, Tao; Han, Ya-Di; Huang, Fu-Sheng

    2016-01-01

    A DNA repair enzyme, O6-methylguanine-DNA methyltransferase (MGMT), plays an important role in the development of gastric cancers. However, the role of MGMT promoter methylation in the occurrence of gastric cancer and its relationships with clinicopathologic characteristics has not been fully clarified. Thus, we performed a meta-analysis to evaluate the associations between MGMT promoter methylation and gastric cancer. Electronic databases, including PubMed and Web of Science, were used to systematically search related clinical studies published in English until April 1, 2016. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to evaluate the associations between MGMT promoter methylation and gastric cancer risk or clinicopathologic characteristics. A total of 16 studies including 1,935 patients and 1,948 control persons were included in the analysis. Our study suggested that MGMT promoter methylation frequency was associated with gastric cancer (OR=3.46, 95% CI: 2.13-5.61, PMGMT promoter methylation in the no lymph node metastasis group was lower than that in lymph node metastasis group, with marginal significance (OR=0.65, 95% CI: 0.42-1.01, P=0.05). Additionally, the methylation rate of the MGMT promoter was much lower in patients without distant metastases than in those with metastases (OR=0.27, 95% CI: 0.18-0.40, PMGMT promoter methylation with Lauren classification, tumor location, tumor invasion, or Helicobacter pylori infection was found. In conclusion, the methylation status of the MGMT promoter was related to gastric cancer risk, distant metastasis, and lymph node metastasis, which indicates that MGMT promoter methylation may play an important role in gastric cancer development.

  18. The Correlation of MGMT Promoter Methylation and Clinicopathological Features in Gastric Cancer: A Systematic Review and Meta-Analysis.

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    Ding, Yong; Yang, Qihua; Wang, Bojun; Ye, Guoliang; Tong, Xiaoqiong

    2016-01-01

    The silencing of the tumor suppressor gene O-6-methylguanine-DNA methyltransferase (MGMT) by promoter methylation commonly occurs in human cancers. The relationship between MGMT promoter methylation and gastric cancer (GC) remains inconsistent. This study aimed to evaluate the potential value of MGMT promoter methylation in GC patients. Electronic databases were searched to identify eligible studies. The pooled odds ratio (OR) and the corresponding 95% confidence interval (95% CI) were used to evaluate the effects of MGMT methylation on GC risk and clinicopathological characteristics. In total, 31 eligible studies including 2988 GC patients and 2189 nonmalignant controls were involved in meta-analysis. In the pooled analysis, MGMT promoter methylation was significantly associated with GC risk (OR = 3.34, P MGMT methylation showed a trend associated with gender, and methylation is lower in males compared with females (OR = 0.76, 95% CI = 0.56-1.03). We did not find a significant association in relation to tumor types, clinical stage, age status or H. pylori status in cancer (all P > 0.1). MGMT promoter methylation may be correlated with the prognosis of GCs in disease free survival (DFS) or overall survival (OS) for univariate analysis. MGMT promoter methylation may play a crucial role in the carcinogenesis and prognosis of GC. MGMT methylation was not correlated with tumor types, clinical stage, age status, H. pylori status. However, the result of the association of MGMT methylation and gender should be considered with caution.

  19. Relationships between MGMT promoter methylation and gastric cancer: a meta-analysis

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    Yu D

    2016-10-01

    Full Text Available Dan Yu, Tao Cao, Ya-Di Han, Fu-Sheng Huang Department of Laboratory Medicine, Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan, People’s Republic of China Abstract: A DNA repair enzyme, O6-methylguanine-DNA methyltransferase (MGMT, plays an important role in the development of gastric cancers. However, the role of MGMT promoter methylation in the occurrence of gastric cancer and its relationships with clinicopathologic characteristics has not been fully clarified. Thus, we performed a meta-analysis to evaluate the associations between MGMT promoter methylation and gastric cancer. Electronic databases, including PubMed and Web of Science, were used to systematically search related clinical studies published in English until April 1, 2016. Odds ratios (ORs and 95% confidence intervals (95% CIs were calculated to evaluate the associations between MGMT promoter methylation and gastric cancer risk or clinicopathologic characteristics. A total of 16 studies including 1,935 patients and 1,948 control persons were included in the analysis. Our study suggested that MGMT promoter methylation frequency was associated with gastric cancer (OR=3.46, 95% CI: 2.13–5.61, P<0.001. Moreover, the frequency of MGMT promoter methylation in the no lymph node metastasis group was lower than that in lymph node metastasis group, with marginal significance (OR=0.65, 95% CI: 0.42–1.01, P=0.05. Additionally, the methylation rate of the MGMT promoter was much lower in patients without distant metastases than in those with metastases (OR=0.27, 95% CI: 0.18–0.40, P<0.001. No significant association of MGMT promoter methylation with Lauren classification, tumor location, tumor invasion, or Helicobacter pylori infection was found. In conclusion, the methylation status of the MGMT promoter was related to gastric cancer risk, distant metastasis, and lymph node metastasis, which indicates that MGMT promoter methylation may play an important role in

  20. MGMT promoter methylation and correlation with protein expression in primary central nervous system lymphoma.

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    Toffolatti, L; Scquizzato, E; Cavallin, S; Canal, F; Scarpa, M; Stefani, P M; Gherlinzoni, F; Dei Tos, A P

    2014-11-01

    The O (6)-methylguanine-DNA-methyltransferase (MGMT) gene encodes for a DNA repairing enzyme of which silencing by promoter methylation is involved in brain tumorigenesis. MGMT promoter methylation represents a favorable prognostic factor and has been associated with a better response to alkylating agents in glioma and systemic lymphoma. Primary central nervous system lymphoma (PCNSL) is a rare and aggressive extranodal malignant lymphoma. The current standard of care, based on high-dose methotrexate chemotherapy, has improved prognosis but outcome remains poor for a majority of patients. Therapeutic progress in this field is conditioned by limited biological and molecular knowledge about the disease. Temozolomide has recently emerged as an alternative option for PCNSL treatment. We aimed to analyze the MGMT gene methylation status in a series of 24 PCNSLs, to investigate the relationship between methylation status of the gene and immunohistochemical expression of MGMT protein and to evaluate the possible prognostic significance of these biomarkers. Our results confirm that methylation of the MGMT gene and loss of MGMT protein are frequent events in these lymphomas (54 % of our cases) and suggest that they are gender and age related. MGMT methylation showed high correlation with loss of protein expression (concordance correlation coefficient = -0.49; Fisher exact test: p MGMT promoter (n = 4), seems to be associated with a prolonged overall survival (>60 months in three of four patients). The prognostic significance of these molecular markers in PCNSL needs to be further studied in groups of patients treated in a homogeneous way.

  1. MGMT promoter methylation status and MGMT and CD133 immunohistochemical expression as prognostic markers in glioblastoma patients treated with temozolomide plus radiotherapy

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    Melguizo Consolación; Prados Jose; González Beatriz; Ortiz Raul; Concha Angel; Alvarez Pablo; Madeddu Roberto; Perazzoli Gloria; Oliver Jaime; López Rodrigo; Rodríguez-Serrano Fernando; Aránega Antonia

    2012-01-01

    Abstract Background The CD133 antigen is a marker of radio- and chemo-resistant stem cell populations in glioblastoma (GBM). The O6-methylguanine DNA methyltransferase (MGMT) enzyme is related with temozolomide (TMZ) resistance. Our propose is to analyze the prognostic significance of the CD133 antigen and promoter methylation and protein expression of MGMT in a homogenous group of GBM patients uniformly treated with radiotherapy and TMZ. The possible connection between these GBM markers was ...

  2. Defining the cutoff value of MGMT gene promoter methylation and its predictive capacity in glioblastoma.

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    Brigliadori, Giovanni; Foca, Flavia; Dall'Agata, Monia; Rengucci, Claudia; Melegari, Elisabetta; Cerasoli, Serenella; Amadori, Dino; Calistri, Daniele; Faedi, Marina

    2016-06-01

    Despite advances in the treatment of glioblastoma (GBM), median survival is 12-15 months. O6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation status is acknowledged as a predictive marker for temozolomide (TMZ) treatment. When MGMT promoter values fall into a "methylated" range, a better response to chemotherapy is expected. However, a cutoff that discriminates between "methylated" and "unmethylated" status has yet to be defined. We aimed to identify the best cutoff value and to find out whether variability in methylation profiles influences the predictive capacity of MGMT promoter methylation. Data from 105 GBM patients treated between 2008 and 2013 were analyzed. MGMT promoter methylation status was determined by analyzing 10 CpG islands by pyrosequencing. Patients were treated with radiotherapy followed by TMZ. MGMT promoter methylation status was classified into unmethylated 0-9 %, methylated 10-29 % and methylated 30-100 %. Statistical analysis showed that an assumed methylation cutoff of 9 % led to an overestimation of responders. All patients in the 10-29 % methylation group relapsed before the 18-month evaluation. Patients with a methylation status ≥30 % showed a median overall survival of 25.2 months compared to 15.2 months in all other patients, confirming this value as the best methylation cutoff. Despite wide variability among individual profiles, single CpG island analysis did not reveal any correlation between single CpG island methylation values and relapse or death. Specific CpG island methylation status did not influence the predictive value of MGMT. The predictive role of MGMT promoter methylation was maintained only with a cutoff value ≥30 %.

  3. Relationship between promoter methylation & tissue expression of MGMT gene in ovarian cancer

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    V Shilpa

    2014-01-01

    Full Text Available Background & objectives: Epigenetic alterations, in addition to multiple gene abnormalities, are involved in the genesis and progression of human cancers. Aberrant methylation of CpG islands within promoter regions is associated with transcriptional inactivation of various tumour suppressor genes. O 6 -methyguanine-DNA methyltransferase (MGMT is a DNA repair gene that removes mutagenic and cytotoxic adducts from the O 6 -position of guanine induced by alkylating agents. MGMT promoter hypermethylation and reduced expression has been found in some primary human carcinomas. We studied DNA methylation of CpG islands of the MGMT gene and its relation with MGMT protein expression in human epithelial ovarian carcinoma. Methods: A total of 88 epithelial ovarian cancer (EOC tissue samples, 14 low malignant potential (LMP tumours and 20 benign ovarian tissue samples were analysed for MGMT promoter methylation by nested methylation-specific polymerase chain reaction (MSP after bisulphite modification of DNA. A subset of 64 EOC samples, 10 LMP and benign tumours and five normal ovarian tissue samples were analysed for protein expression by immunohistochemistry. Results: The methylation frequencies of the MGMT gene promoter were found to be 29.5, 28.6 and 20 per cent for EOC samples, LMP tumours and benign cases, respectively. Positive protein expression was observed in 93.8 per cent of EOC and 100 per cent in LMP, benign tumours and normal ovarian tissue samples. Promoter hypermethylation with loss of protein expression was seen only in one case of EOC. Interpretation & conclusions: Our results suggest that MGMT promoter hypermethylation does not always reflect gene expression.

  4. Different diagnostic values of imaging parameters to predict pseudoprogression in glioblastoma subgroups stratified by MGMT promoter methylation

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ra Gyoung [Catholic Kwandong University International St. Mary' s Hospital, Department of Radiology, Catholic Kwandong University College of Medicine, Incheon (Korea, Republic of); Kim, Ho Sung; Shim, Woo Hyun; Kim, Sang Joon [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Paik, Wooyul [Dankook Unversity Hospital, Department of Radiology, Cheonan-si, Chungcheongnam-do (Korea, Republic of); Kim, Jeong Hoon [University of Ulsan College of Medicine, Asan Medical Center, Department of Neurosurgery, Seoul (Korea, Republic of)

    2017-01-15

    The aim of this study was to determine whether diffusion and perfusion imaging parameters demonstrate different diagnostic values for predicting pseudoprogression between glioblastoma subgroups stratified by O{sup 6}-mythylguanine-DNA methyltransferase (MGMT) promoter methylation status. We enrolled seventy-five glioblastoma patients that had presented with enlarged contrast-enhanced lesions on magnetic resonance imaging (MRI) one month after completing concurrent chemoradiotherapy and undergoing MGMT promoter methylation testing. The imaging parameters included 10 or 90 % histogram cutoffs of apparent diffusion coefficient (ADC10), normalized cerebral blood volume (nCBV90), and initial area under the time signal-intensity curve (IAUC90). The results of the areas under the receiver operating characteristic curve (AUCs) with cross-validation were compared between MGMT methylation and unmethylation groups. MR imaging parameters demonstrated a trend toward higher accuracy in the MGMT promoter methylation group than in the unmethylation group (cross-validated AUCs = 0.70-0.95 and 0.56-0.87, respectively). The combination of MGMT methylation status with imaging parameters improved the AUCs from 0.70 to 0.75-0.90 for both readers in comparison with MGMT methylation status alone. The probability of pseudoprogression was highest (95.7 %) when nCBV90 was below 4.02 in the MGMT promoter methylation group. MR imaging parameters could be stronger predictors of pseudoprogression in glioblastoma patients with the methylated MGMT promoter than in patients with the unmethylated MGMT promoter. (orig.)

  5. A three-gene signature for prognosis in patients with MGMT promoter-methylated glioblastoma.

    Science.gov (United States)

    Wang, Wen; Zhang, Lu; Wang, Zheng; Yang, Fan; Wang, Haoyuan; Liang, Tingyu; Wu, Fan; Lan, Qing; Wang, Jiangfei; Zhao, Jizong

    2016-10-25

    Glioblastoma is the most malignant tumor and has high mortality rate. The methylated prompter of MGMT results in chemotherapy sensitivity for these patients. However, there are still other factors that affected the prognosis for the glioblastoma patients with similar MGMT methylation status. We developed a signature with three genes screened from the whole genome mRNA expression profile from Chinese Glioma Genome Atlas (CGGA) and RNAseq data from The Cancer Genome Atlas (TCGA). Patients with MGMT methylation in low risk group had longer survival than those in high risk group (median overall survival 1074 vs. 372 days; P = 0.0033). Moreover, the prognostic value of the signature was significant difference in cohorts stratified by MGMT methylation and chemotherapy (P=0.0473), while there is no significant difference between low and high risk group or unmethylated MGMT patients without chemotherapy. Multivariate analysis indicated that the risk score was an independent prognosis factor (P = 0.004). In conclusion, our results showed that the signature has prognostic value for patients with MGMT promoter-methylated glioblastomas based on bioinformatics analysis.

  6. MGMT promoter methylation is associated with temozolomide response and prolonged progression-free survival in disseminated cutaneous melanoma.

    Science.gov (United States)

    Tuominen, Rainer; Jewell, Rosalyn; van den Oord, Joost J; Wolter, Pascal; Stierner, Ulrika; Lindholm, Christer; Hertzman Johansson, Carolina; Lindén, Diana; Johansson, Hemming; Frostvik Stolt, Marianne; Walker, Christy; Snowden, Helen; Newton-Bishop, Julia; Hansson, Johan; Egyházi Brage, Suzanne

    2015-06-15

    To investigate the predictive and prognostic value of O(6) -methylguanine DNA methyltransferase (MGMT) inactivation by analyses of promoter methylation in pretreatment tumor biopsies from patients with cutaneous melanoma treated with dacarbazine (DTIC) or temozolomide (TMZ) were performed. The patient cohorts consisted of Belgian and Swedish disseminated melanoma patients. Patients were subdivided into those receiving single-agent treatment with DTIC/TMZ (cohort S, n = 74) and those treated with combination chemotherapy including DTIC/TMZ (cohort C, n = 79). Median follow-up was 248 and 336 days for cohort S and cohort C, respectively. MGMT promoter methylation was assessed by three methods. The methylation-related transcriptional silencing of MGMT mRNA expression was assessed by real-time RT-PCR. Response to chemotherapy and progression-free survival (PFS) and overall survival were correlated to MGMT promoter methylation status. MGMT promoter methylation was detected in tumor biopsies from 21.5 % of the patients. MGMT mRNA was found to be significantly lower in tumors positive for MGMT promoter methylation compared to tumors without methylation in both treatment cohorts (p MGMT promoter methylation in cohort S (p = 0.0005), but did not reach significance in cohort C (p = 0.16). Significantly longer PFS was observed among patients with MGMT promoter-methylated tumors (p = 0.002). Multivariate Cox regression analysis identified presence of MGMT promoter methylation as an independent variable associated with longer PFS. Together, this implies that MGMT promoter methylation is associated with response to single-agent DTIC/TMZ and longer PFS in disseminated cutaneous melanoma.

  7. MGMT promoter methylation in serum and cerebrospinal fluid as a tumor-specific biomarker of glioma.

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    Wang, Zheng; Jiang, Wei; Wang, Yahong; Guo, Yang; Cong, Zheng; DU, Fangfang; Song, Bin

    2015-07-01

    O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation is a conventional technique to predict the prognosis or individualized treatment of glioma in tumor tissue following surgery or biopsy. However, the technique cannot be applied in those glioma patients with concomitant neurological dysfunctions or advanced age. The present study aimed to find a new minimally invasive and efficient alternative method for the detection of MGMT promoter methylation. The expression of MGMT promoter methylation was assessed in peripheral blood and cerebrospinal fluid (CSF), and compared to the corresponding tumor tissue from glioma patients. The 89 patients in the study [32 World Health Organization (WHO) grade II, 19 WHO grade III and 38 WHO grade IV) were pathologically-diagnosed glioma and received radiation therapy following sample collection. The resected glioma tumor tissue (89), corresponding serum (89) and CSF (78) samples were collected for the detection of MGMT promoter methylation using methylation-specific polymerase chain reaction. The sensitivity and specificity of detecting MGMT promoter methylation in CSF and serum were compared. Among the tumor tissue samples, 51/89 (57.3%) showed MGMT promoter methylation. The specificity of the detection in the CSF and serum samples reached 100%. The sensitivity of MGMT promoter methylation detection in CSF and serum were 26/40 (65.0%) and 19/51 (37.3%), respectively (PMGMT promoter methylation detection using CSF were 8/12 (66.7%), 11/18 (61.1%) and 7/10 (70.0%), respectively, which were significantly higher than the sensitivities using serum (7/21, 33.3%; 7/19, 36.8%; and 5/11, 45.5%, respectively PMGMT promoter methylation using CSF and serum were 18/25 (72.0%) and 10/24 (41.7%), respectively, both of which were significantly higher than the corresponding values for patients without residual tumors (8/15, 53.3% and 6/19, 31.6%, respectively; PMGMT promoter methylation in CSF specimens shows higher sensitivity

  8. Prognostic value of three different methods of MGMT promoter methylation analysis in a prospective trial on newly diagnosed glioblastoma.

    Directory of Open Access Journals (Sweden)

    Arne Christians

    Full Text Available Hypermethylation in the promoter region of the MGMT gene encoding the DNA repair protein O(6-methylguanine-DNA methyltransferase is among the most important prognostic factors for patients with glioblastoma and predicts response to treatment with alkylating agents like temozolomide. Hence, the MGMT status is widely determined in most clinical trials and frequently requested in routine diagnostics of glioblastoma. Since various different techniques are available for MGMT promoter methylation analysis, a generally accepted consensus as to the most suitable diagnostic method remains an unmet need. Here, we assessed methylation-specific polymerase chain reaction (MSP as a qualitative and semi-quantitative method, pyrosequencing (PSQ as a quantitative method, and methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA as a semi-quantitative method in a series of 35 formalin-fixed, paraffin-embedded glioblastoma tissues derived from patients treated in a prospective clinical phase II trial that tested up-front chemoradiotherapy with dose-intensified temozolomide (UKT-05. Our goal was to determine which of these three diagnostic methods provides the most accurate prediction of progression-free survival (PFS. The MGMT promoter methylation status was assessable by each method in almost all cases (n = 33/35 for MSP; n = 35/35 for PSQ; n = 34/35 for MS-MLPA. We were able to calculate significant cut-points for the continuous methylation signals at each CpG site analysed by PSQ (range, 11.5 to 44.9% and at one CpG site assessed by MS-MLPA (3.6% indicating that a dichotomisation of continuous methylation data as a prerequisite for comparative survival analyses is feasible. Our results show that, unlike MS-MLPA, MSP and PSQ provide a significant improvement of predicting PFS compared with established clinical prognostic factors alone (likelihood ratio tests: p<0.001. Conclusively, taking into consideration prognostic value

  9. MGMT, GATA6, CD81, DR4, and CASP8 gene promoter methylation in glioblastoma

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    Skiriute Daina

    2012-06-01

    Full Text Available Abstract Background Methylation of promoter region is the major mechanism affecting gene expression in tumors. Recent methylome studies of brain tumors revealed a list of new epigenetically modified genes. Our aim was to study promoter methylation of newly identified epigenetically silenced genes together with already known epigenetic markers and evaluate its separate and concomitant role in glioblastoma genesis and patient outcome. Methods The methylation status of MGMT, CD81, GATA6, DR4, and CASP8 in 76 patients with primary glioblastomas was investigated. Methylation-specific PCR reaction was performed using bisulfite treated DNA. Evaluating glioblastoma patient survival time after operation, patient data and gene methylation effect on survival was estimated using survival analysis. Results The overwhelming majority (97.3% of tumors were methylated in at least one of five genes tested. In glioblastoma specimens gene methylation was observed as follows: MGMT in 51.3%, GATA6 in 68.4%, CD81 in 46.1%, DR4 in 41.3% and CASP8 in 56.8% of tumors. Methylation of MGMT was associated with younger patient age (p CASP8 with older (p MGMT methylation was significantly more frequent event in patient group who survived longer than 36 months after operation (p CASP8 was more frequent in patients who survived shorter than 36 months (p MGMT, GATA6 and CASP8 as independent predictors for glioblastoma patient outcome (p MGMT and GATA6 were independent predictors for patient survival in younger patients’ group, while there were no significant associations observed in older patients’ group when adjusted for therapy. Conclusions High methylation frequency of tested genes shows heterogeneity of glioblastoma epigenome and the importance of MGMT, GATA6 and CASP8 genes methylation in glioblastoma patient outcome.

  10. Promoter methylation of DAPK1, FHIT, MGMT, and CDKN2A genes in cervical carcinoma.

    Science.gov (United States)

    Banzai, Chiaki; Nishino, Koji; Quan, Jinhua; Yoshihara, Kosuke; Sekine, Masayuki; Yahata, Tetsuro; Tanaka, Kenichi

    2014-02-01

    Aberrant DNA methylation contributes to the malignant phenotype in virtually all types of human cancer. This study explored the relationship between promoter methylation and inactivation of the DAPK1, FHIT, MGMT, and CDKN2A genes in cervical cancer. The promoter methylation of DAPK1, FHIT, MGMT, and CDKN2A was investigated by using a methylation-specific polymerase chain reaction in 53 specimens of cervical cancer (42 squamous cell carcinoma, 11 adenocarcinoma), 22 specimens of intraepithelial neoplasia tissues, and 24 control normal cervical tissue specimens. The correlation of promoter methylation with the clinicopathological features of cervical cancer was analyzed. The expressions of DAPK1, FHIT, MGMT, and CDKN2A were detected by measuring relative mRNA levels. The promoter methylation of DAPK1, FHIT, MGMT, and CDKN2A in cervical cancer vs. intraepithelial neoplasia vs. normal cervical tissue was 75.5 vs. 31.8 vs. 4.2 % (p promoter region significantly decreased the expression of only DAPK1 (p = 0.03). The methylation rate of the DAPK1 gene promoter was significantly higher in cervical cancer tissues than in cervical intraepithelial neoplasia and normal cervical tissues. Promoter methylation may therefore lead to the inactivation of the DAPK1 gene, and may be related to the progression of cervical oncogenesis.

  11. Meningeal hemangiopericytomas: a clinicopathological study with emphasis on MGMT (O(6) -methylguanine-DNA methyltransferase) promoter methylation status.

    Science.gov (United States)

    Kakkar, Aanchal; Kumar, Anupam; Jha, Prerana; Goyal, Nishant; Mallick, Supriya; Sharma, Mehar Chand; Suri, Ashish; Singh, Manmohan; Kale, Shashank S; Julka, Pramod Kumar; Sarkar, Chitra; Suri, Vaishali

    2014-08-01

    Meningeal hemangiopericytomas (HPCs) are aggressive dural-based tumors, for which no prognostic or predictive marker has been identified. Gross total resection is treatment of choice, but not easily achieved; hence, alkylating agents like temozolomide (TMZ) are now being tried. O(6) -methylguanine-DNA methyltransferase (MGMT) promoter methylation has proven prognostic and predictive value in glioblastomas. This study evaluates MGMT promoter methylation in meningeal HPCs to determine its role in HPC oncogenesis and its association with patient outcome. Meningeal HPCs diagnosed between 2002 and 2011 were retrieved and clinicopathological features reviewed. MGMT promoter methylation status was assessed by methylation-specific polymerase chain reaction (MSP) and immunohistochemistry (IHC) for MGMT protein. HPCs accounted for 1.1% of all CNS tumors. Forty cases were analyzed; the majority were adults (mean age = 41.4 years). Seventy percent were primary and 30% were recurrent tumors; 60% were grade II and 40% were grade III. MGMT promoter methylation was identified in 45% of cases, including Grade II (54.2%) and Grade III (31.3%) (P = 0.203). Promoter methylation was significantly (P = 0.035) more frequent in primary (57.1%) than in recurrent (16.7%) tumors. No correlation was noted between MGMT promoter methylation by MSP and MGMT protein expression by IHC, or with progression-free survival. Thus, a significant proportion of HPCs demonstrate MGMT promoter methylation, suggesting possible susceptibility to TMZ. As promoter methylation is more frequent in primary tumors, TMZ may serve as a therapeutic option in residual primary tumors. Epigenetic inactivation of MGMT in HPCs necessitates the assessment of prognostic and predictive value of MGMT promoter methylation in HPCs in larger clinical trials.

  12. MS-MLPA: an attractive alternative laboratory assay for robust, reliable, and semiquantitative detection of MGMT promoter hypermethylation in gliomas.

    NARCIS (Netherlands)

    Jeuken, J.W.M.; Cornelissen, S.J.B.; Vriezen, M.; Dekkers, M.M.G.; Errami, A.; Sijben, A.; Boots-Sprenger, S.H.E.; Wesseling, P.

    2007-01-01

    Expression of the DNA repair protein O6-alkylguanine-DNA-alkyltransferase (AGT), encoded by the O6-methylguanine (O6-mG) -DNA-methyltransferase (MGMT) DNA repair gene, results in resistance to alkylating agents, and hypermethylation of the MGMT promoter is associated with chemosensitivity as it prev

  13. MGMT promoter hypermethylation is a frequent, early, and consistent event in astrocytoma progression, and not correlated with TP53 mutation

    NARCIS (Netherlands)

    F.H. Groenendijk (Floris); W. Taal (Walter); H.J. Dubbink (Erik Jan); C.R. Haarloo (Cathleen); M.C.M. Kouwenhoven (Mathilde); M.J. van den Bent (Martin); J.M. Kros (Johan); W.N.M. Dinjens (Winand)

    2011-01-01

    textabstractHypermethylation of the MGMT gene promoter and mutation of the TP53 tumor-suppressor gene are frequently present in diffuse astrocytomas. However, there is only anecdotal information about MGMT methylation status and TP53 mutations during progression of low-grade diffuse astrocytoma (AII

  14. Promoter Hypermethylation and Its Impact on Expression of MGMT Gene in the GIT Malignant Patients of Kashmiri Origin.

    Science.gov (United States)

    Bhat, Arif Akbar; Wani, Hilal Ahmad; Ishaq, Shiekh; Waza, Ajaz Ahmad; Malik, Rawoof Ahmad; Shabir, Iram; Jeelani, Showkat; Kadla, Showkat; Qureshie, Waseem; Masood, Akbar; Majid, Sabhiya

    2017-02-07

    Epigenetic alterations, in addition to multiple gene abnormalities, are involved in the genesis and progression of human cancers. Gastrointestinal tract (GIT) cancer is a major medical and economic burden worldwide. Aberrant methylation of CpG islands within promoter regions is associated with transcriptional inactivation of various tumor suppressor genes. Although a number of cancer-associated genes have been found to be hypermethylated in GIT cancer, valuable methylation markers for early diagnosis and prognostic evaluation of this cancer remain largely unknown. O6-methyguanine DNA methyltransferase (MGMT) is a DNA-repair gene that removes mutagenic and cytotoxic adducts from the O6 position of guanine induced by alkylating agents. MGMT promoter hypermethylation and reduced expression have been found in some primary human carcinomas. We studied DNA methylation of CpG islands of the MGMT gene and its relation with MGMT protein expression in human GIT carcinomas. A total of 210 GIT tumor samples and 90 adjacent normal tissues were analyzed for MGMT promoter methylation by methylation-specific polymerase chain reaction after bisulfite modification of DNA and same samples were analyzed for MGMT protein expression by Western blotting. The methylation frequencies of MGMT gene promoter were 41.4%, 34.2%, and 44.2% in stomach, esophageal, and colorectal cancer cases while as 16.6, 13.3, and 13.3 in respective controls. MGMT protein was found downregulated in controls of all GIT. The results suggest that methylation at CpG islands of MGMT may be responsible for the downregulation of MGMT protein expression in GIT cancers.

  15. The Predictive but Not Prognostic Value of MGMT Promoter Methylation Status in Elderly Glioblastoma Patients: A Meta-Analysis

    OpenAIRE

    Yin, An-an; Zhang, Lu-hua; Cheng, Jin-xiang; Dong, Yu; Liu, Bo-Lin; Han, Ning; Zhang, Xiang

    2014-01-01

    Background The clinical implication of O6-methylguanine-DNA methyltransferase (MGMT) promoter status is ill-defined in elderly glioblastoma patients. Here we report a meta-analysis to seek valid evidence for its clinical relevance in this subpopulation. Methods Literature were searched and reviewed in a systematic manner using the PubMed, EMBASE and Cochrane databases. Studies investigating the association between MGMT promoter status and survival data of elderly patients (≥65 years) were eli...

  16. A combination of TERT promoter mutation and MGMT methylation status predicts clinically relevant subgroups of newly diagnosed glioblastomas.

    Science.gov (United States)

    Arita, Hideyuki; Yamasaki, Kai; Matsushita, Yuko; Nakamura, Taishi; Shimokawa, Asanao; Takami, Hirokazu; Tanaka, Shota; Mukasa, Akitake; Shirahata, Mitsuaki; Shimizu, Saki; Suzuki, Kaori; Saito, Kuniaki; Kobayashi, Keiichi; Higuchi, Fumi; Uzuka, Takeo; Otani, Ryohei; Tamura, Kaoru; Sumita, Kazutaka; Ohno, Makoto; Miyakita, Yasuji; Kagawa, Naoki; Hashimoto, Naoya; Hatae, Ryusuke; Yoshimoto, Koji; Shinojima, Naoki; Nakamura, Hideo; Kanemura, Yonehiro; Okita, Yoshiko; Kinoshita, Manabu; Ishibashi, Kenichi; Shofuda, Tomoko; Kodama, Yoshinori; Mori, Kanji; Tomogane, Yusuke; Fukai, Junya; Fujita, Koji; Terakawa, Yuzo; Tsuyuguchi, Naohiro; Moriuchi, Shusuke; Nonaka, Masahiro; Suzuki, Hiroyoshi; Shibuya, Makoto; Maehara, Taketoshi; Saito, Nobuhito; Nagane, Motoo; Kawahara, Nobutaka; Ueki, Keisuke; Yoshimine, Toshiki; Miyaoka, Etsuo; Nishikawa, Ryo; Komori, Takashi; Narita, Yoshitaka; Ichimura, Koichi

    2016-08-08

    The prognostic impact of TERT mutations has been controversial in IDH-wild tumors, particularly in glioblastomas (GBM). The controversy may be attributable to presence of potential confounding factors such as MGMT methylation status or patients' treatment. This study aimed to evaluate the impact of TERT status on patient outcome in association with various factors in a large series of adult diffuse gliomas. We analyzed a total of 951 adult diffuse gliomas from two cohorts (Cohort 1, n = 758; Cohort 2, n = 193) for IDH1/2, 1p/19q, and TERT promoter status. The combined IDH/TERT classification divided Cohort 1 into four molecular groups with distinct outcomes. The overall survival (OS) was the shortest in IDH wild-type/TERT mutated groups, which mostly consisted of GBMs (P MGMT methylation on survival of patients with GBM, samples from a combined cohort of 453 IDH-wild-type GBM cases treated with radiation and temozolomide were analyzed. A multivariate Cox regression model revealed that the interaction between TERT and MGMT was significant for OS (P = 0.0064). Compared with TERT mutant-MGMT unmethylated GBMs, the hazard ratio (HR) for OS incorporating the interaction was the lowest in the TERT mutant-MGMT methylated GBM (HR, 0.266), followed by the TERT wild-type-MGMT methylated (HR, 0.317) and the TERT wild-type-MGMT unmethylated GBMs (HR, 0.542). Thus, patients with TERT mutant-MGMT unmethylated GBM have the poorest prognosis. Our findings suggest that a combination of IDH, TERT, and MGMT refines the classification of grade II-IV diffuse gliomas.

  17. Promoter hypermethylation of MGMT gene may contribute to the pathogenesis of gastric cancer: A PRISMA-compliant meta-analysis.

    Science.gov (United States)

    Zhang, Zongxin; Xin, Shaojun; Gao, Min; Cai, Yunxiang

    2017-04-01

    The association of MGMT (O-methyguanine deoxyribonucleic acid methyltransferase) promoter hypermethylation with gastric cancer (GC) risk has been studied extensively, but the results remained unclear. Here, we performed a meta-analysis to evaluate whether promoter hypermethylation of the MGMT gene contributed to gastric pathogenesis. Relevant studies were identified by retrieving the PubMed, Web of Science, Embase, and China National Knowledge Infrastructure (CNKI) databases. The Newcastle-Ottawa Scale was applied to assess methodological quality of the included studies. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to evaluate the association of MGMT promoter hypermethylation with gastric pathogenesis. Moreover, STATA 12.0 software was used to summarize the extracted data in this meta-analysis. Seventeen studies, comprising 1736 cases and 1291 controls, were included in this meta-analysis. The frequency of MGMT promoter hypermethylation in the GC group (32.97%) was significantly higher than those in the control group (18.00%) (OR = 2.83, CI = 1.93-4.15, P < .05). When stratified by cancer subtype, the results indicated that the frequency of MGMT promoter hypermethylation was significantly higher in gastric adenocarcinoma than in control group (OR = 3.47, CI = 1.06-11.35, P < .05). In addition, MGMT promoter hypermethylation significantly promoted distant metastasis and lymph node (LN) metastasis of gastric tumor (for distant metastasis, OR = 4.22, CI = 2.42-7.37, P < .05; for LN metastasis, OR = 1.56, CI = 1.14-2.13, P < .05). A significant association between MGMT promoter hypermethylation and TNM-stage was also found in the present meta-analysis (OR = 2.70, CI = 1.79-4.08, P < .05). The results of this meta-analysis suggested that MGMT gene-promoter hypermethylation was significantly associated with an increased risk of GC, especially in Asians. Furthermore, MGMT gene-promoter

  18. Using the apparent diffusion coefficient to identifying MGMT promoter methylation status early in glioblastoma: importance of analytical method

    Energy Technology Data Exchange (ETDEWEB)

    Rundle-Thiele, Dayle [Centre for Clinical Research, University of Queensland, Brisbane, Queensland (Australia); Day, Bryan; Stringer, Brett [Brain Cancer Research Unit, Queensland Institute of Medical Research, Brisbane, Queensland (Australia); Fay, Michael [Department of Radiation Oncology, Royal Brisbane and Women' s Hospital, Brisbane, Queensland (Australia); Martin, Jennifer [Discipline of Clinical Pharmacology, School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales (Australia); Jeffree, Rosalind L [Department of Neurosurgery, Royal Brisbane and Women' s Hospital, Brisbane, Queensland (Australia); Thomas, Paul [Queensland PET Service, Royal Brisbane and Women' s Hospital, Brisbane, Queensland (Australia); Bell, Christopher [Centre for Clinical Research, University of Queensland, Brisbane, Queensland (Australia); Salvado, Olivier [CSIRO Digital Productivity Flagship, CSIRO, Herston, Queensland (Australia); Gal, Yaniv [Centre for Medical Diagnostic Technologies in Queensland, University of Queensland, Brisbane, Queensland (Australia); Coulthard, Alan [Discipline of Medical Imaging, University of Queensland, St Lucia, Queensland (Australia); Department of Medical Imaging, Royal Brisbane and Women' s Hospital, Brisbane, Queensland (Australia); Crozier, Stuart [Centre for Medical Diagnostic Technologies in Queensland, University of Queensland, Brisbane, Queensland (Australia); Rose, Stephen, E-mail: stephen.rose@csiro.au [CSIRO Digital Productivity Flagship, CSIRO, Herston, Queensland (Australia); Centre for Clinical Research, University of Queensland, Brisbane, Queensland (Australia)

    2015-06-15

    Accurate knowledge of O{sup 6}-methylguanine methyltransferase (MGMT) gene promoter subtype in patients with glioblastoma (GBM) is important for treatment. However, this test is not always available. Pre-operative diffusion MRI (dMRI) can be used to probe tumour biology using the apparent diffusion coefficient (ADC); however, its ability to act as a surrogate to predict MGMT status has shown mixed results. We investigated whether this was due to variations in the method used to analyse ADC. We undertook a retrospective study of 32 patients with GBM who had MGMT status measured. Matching pre-operative MRI data were used to calculate the ADC within contrast enhancing regions of tumour. The relationship between ADC and MGMT was examined using two published ADC methods. A strong trend between a measure of ‘minimum ADC’ and methylation status was seen. An elevated minimum ADC was more likely in the methylated compared to the unmethylated MGMT group (U = 56, P = 0.0561). In contrast, utilising a two-mixture model histogram approach, a significant reduction in mean measure of the ‘low ADC’ component within the histogram was associated with an MGMT promoter methylation subtype (P < 0.0246). This study shows that within the same patient cohort, the method selected to analyse ADC measures has a significant bearing on the use of that metric as a surrogate marker of MGMT status. Thus for dMRI data to be clinically useful, consistent methods of data analysis need to be established prior to establishing any relationship with genetic or epigenetic profiling.

  19. The predictive but not prognostic value of MGMT promoter methylation status in elderly glioblastoma patients: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    An-an Yin

    Full Text Available BACKGROUND: The clinical implication of O6-methylguanine-DNA methyltransferase (MGMT promoter status is ill-defined in elderly glioblastoma patients. Here we report a meta-analysis to seek valid evidence for its clinical relevance in this subpopulation. METHODS: Literature were searched and reviewed in a systematic manner using the PubMed, EMBASE and Cochrane databases. Studies investigating the association between MGMT promoter status and survival data of elderly patients (≥65 years were eligible for inclusion. RESULTS: Totally 16 studies were identified, with 13 studies included in the final analyses. The aggregate proportion of MGMT promoter methylation in elderly patients was 47% (95% confidence interval [CI]: 42-52%, which was similar to the value for younger patients. The analyses showed differential effects of MGMT status on overall survival (OS of elderly patients according to assigned treatments: methylated vs. unmethylated: (1 temozolomide (TMZ-containing therapies: hazard ratio [HR] 0.49, 95% CI 0.41-0.58; (2 TMZ-free therapies: HR 0.97, 95% CI 0.77-1.21. More importantly, a useful predictive value was observed by an interaction analysis: TMZ-containing therapies vs. RT alone: (1 methylated tumors: HR 0.48, 95% CI 0.36-0.65; (2 unmethylated tumors: HR 1.14; 95% CI 0.90-1.44. CONCLUSION: The meta-analysis reports an age-independent presence of MGMT promoter methylation. More importantly, the study encouraged routine testing of MGMT promoter status especially in elderly glioblastoma patients by indicating a direct linkage between biomarker test and individual treatment decision. Future studies are needed to justify the mandatory testing in younger patients.

  20. IDH1/2 Mutation and MGMT Promoter Methylation - the Relevant Survival Predictors in Czech Patients with Brain Gliomas.

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    Kramář, F; Minárik, M; Benešová, L; Halková, T; Netuka, D; Bradáč, O; Beneš, V

    2016-01-01

    Gliomas are a heterogeneous group of tumours varying in prognosis, treatment approach, and overall survival. Recently, novel markers have been identified which are linked to patient prognosis and therapeutic response. Especially the mutation of the enzyme isocitrate dehydrogenase 1 or 2 (IDH1/2) gene and the O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status seem to be the most important predictors of survival. From 2012 to 2015, 94 Czech patients with primary brain tumours were enrolled into the study. The IDH1/2 mutation was detected by denaturing capillary electrophores.The methylation status of the MGMT gene and other 46 genes was revealed by MS-MLPA. In all 94 patients, the clinical data were correlated with molecular markers by Kaplan-Meier analyses and Cox regression model. The MGMT promoter methylation status was established and compared to clinical data. In our study eight different probes were used to elucidate the MGMT methylation status; hypermethylation was proclaimed if four and more probes were positive. This 3 : 5 ratio was tested and confirmed by Kaplan-Meier and Cox analyses. The study confirmed the importance of the IDH1/2 mutation and hypermethylation of the MGMT gene promoter being present in tumour tissue. Both markers are independent positive survival predictors; in the Cox model the IDH hazard ratio was 0.10 and in the case of MGMT methylation it reached 0.32. The methylation analysis of the panel of additional 46 genes did not reveal any other significant epigenetic markers; none of the candidate genes have been confirmed in the Cox regression analyses as an independent prognostic factor.

  1. Assessment of Quantitative and Allelic MGMT Methylation Patterns as a Prognostic Marker in Glioblastoma

    DEFF Research Database (Denmark)

    Kristensen, Lasse S; Michaelsen, Signe R; Dyrbye, Henrik;

    2016-01-01

    Methylation of the O(6)-methylguanine-DNA methyltransferase (MGMT) gene is a predictive and prognostic marker in newly diagnosed glioblastoma patients treated with temozolomide but how MGMT methylation should be assessed to ensure optimal detection accuracy is debated. We developed a novel...... with better overall survival (p = 0.006; qMSP and p = 0.002; standard pyrosequencing), and the presence of the protein was associated with worse overall survival (p = 0.009). Combined analyses of qMSP and standard pyrosequencing or IHC identified additional patients who benefited from temozolomide treatment....... Finally, low methylation levels were also associated with better overall survival (p = 0.061; qMSP and p = 0.02; standard pyrosequencing). These data support the use of both MGMT methylation and MGMT IHC but not allelic methylation data as prognostic markers in patients with temozolomide...

  2. Lentiviral MGMT(P140K)-mediated in vivo selection employing a ubiquitous chromatin opening element (A2UCOE) linked to a cellular promoter.

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    Phaltane, Ruhi; Lachmann, Nico; Brennig, Sebastian; Ackermann, Mania; Modlich, Ute; Moritz, Thomas

    2014-08-01

    Notwithstanding recent successes, insertional mutagenesis as well as silencing and variegation of transgene expression still represent considerable obstacles to hematopoietic gene therapy. This also applies to O(6)-methylguanine DNA methyltransferase (MGMT)-mediated myeloprotection, a concept recently proven clinically effective in the context of glioblastoma therapy. To improve on this situation we here evaluate a SIN-lentiviral vector expressing the MGMT(P140K)-cDNA from a combined A2UCOE/PGK-promoter. In a murine in vivo chemoselection model the A2UCOE.PGK.MGMT construct allowed for significant myeloprotection as well as robust and stable selection of transgenic hematopoietic cells. In contrast, only transient enrichment and severe myelotoxicity was observed for a PGK.MGMT control vector. Selection of A2UCOE.PGK.MGMT-transduced myeloid and lymphoid mature and progenitor cells was demonstrated in the peripheral blood, bone marrow, spleen, and thymus. Unlike the PGK and SFFV promoters used as controls, the A2UCOE.PGK promoter allowed for sustained vector copy number-related transgene expression throughout the experiment indicating an increased resistance to silencing, which was further confirmed by CpG methylation studies of the PGK promoter. Thus, our data support a potential role of the A2UCOE.PGK.MGMT-vector in future MGMT-based myeloprotection and chemoselection strategies, and underlines the suitability of the A2UCOE element to stabilize lentiviral transgene expression in hematopoietic gene therapy.

  3. O6-Methylguanine-Methyltransferase (MGMT Promoter Methylation Status in Glioma Stem-Like Cells is Correlated to Temozolomide Sensitivity Under Differentiation-Promoting Conditions

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    Lucie Karayan-Tapon

    2012-06-01

    Full Text Available Glioblastoma (GBM is the most malignant type of primary brain tumor with a very poor prognosis. The actual standard protocol of treatment for GBM patients consists of radiotherapy and concomitant temozolomide (TMZ. However, the therapeutic efficacy of this treatment is limited due to tumor recurrence and TMZ resistance. Recently isolated, glioma stem-like cells (GSCs are thought to represent the population of tumorigenic cells responsible for GBM resistance and recurrence following surgery and chemotherapy. In addition, MGMT (O6-methylguanine-methyltransferase methylation is considered as one of the principal mechanisms contributing to TMZ sensitivity of GBM. In this study we have isolated GSCs from 10 adult GBM patients and investigated the relationship between MGMT methylation status and Temozolomide (TMZ sensitivity of these lines grown either in stem-like or differentiation promoting conditions. Sensitivity to TMZ was significantly associated with MGMT methylation status in cells committed to differentiation but not in stem-like cells. In addition, patients harboring highly methylated MGMT promoters had a longer overall survival. These results reveal the importance of the differentiation process when considering the predictive value of MGMT status in GSCs for clinical response to TMZ.

  4. MGMT inactivation and clinical response in newly diagnosed GBM patients treated with Gliadel.

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    Grossman, Rachel; Burger, Peter; Soudry, Ethan; Tyler, Betty; Chaichana, Kaisorn L; Weingart, Jon; Olivi, Alessandro; Gallia, Gary L; Sidransky, David; Quiñones-Hinojosa, Alfredo; Ye, Xiaobu; Brem, Henry

    2015-12-01

    We examined the relationship between the O(6)-methylguanine-methyltransferase (MGMT) methylation status and clinical outcomes in newly diagnosed glioblastoma multiforme (GBM) patients who were treated with Gliadel wafers (Eisai, Tokyo, Japan). MGMT promoter methylation has been associated with increased survival among patients with GBM who are treated with various alkylating agents. MGMT promoter methylation, in DNA from 122 of 160 newly diagnosed GBM patients treated with Gliadel, was determined by a quantitative methylation-specific polymerase chain reaction, and was correlated with overall survival (OS) and recurrence-free survival (RFS). The MGMT promoter was methylated in 40 (32.7%) of 122 patients. The median OS was 13.5 months (95% confidence interval [CI] 11.0-14.5) and RFS was 9.4 months (95% CI 7.8-10.2). After adjusting for age, Karnofsky performance score, extent of resection, temozolomide (TMZ) and radiation therapy (RT), the newly diagnosed GBM patients with MGMT methylation had a 15% reduced mortality risk, compared to patients with unmethylated MGMT (hazard ratio 0.85; 95% CI 0.56-1.31; p=0.46). The patients aged over 70 years with MGMT methylation had a significantly longer median OS of 13.5 months, compared to 7.6 months in patients with unmethylated MGMT (p=0.027). A significant difference was also found in older patients, with a median RFS of 13.1 versus 7.6 months for methylated and unmethylated MGMT groups, respectively (p=0.01). Methylation of the MGMT promoter in newly diagnosed GBM patients treated with Gliadel, RT and TMZ, was associated with significantly improved OS compared to the unmethylated population. In elderly patients, methylation of the MGMT promoter was associated with significantly better OS and RFS.

  5. Association between the methylation status of the MGMT promoter in bone marrow specimens and chemotherapy outcomes of patients with acute myeloid leukemia.

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    Hong, Qingxiao; Chen, Xiaoying; Ye, Huadan; Zhou, Annan; Gao, Yuting; Jiang, Danjie; Wu, Xiaodong; Tian, Bingru; Chen, Youfen; Wang, Ming; Xie, Jiping; Xia, Yongming; Duan, Shiwei

    2016-04-01

    The O(6)-methylguanine-DNA methyltransferase (MGMT) gene is a tumor suppressor gene that is associated with the risk of developing acute myeloid leukemia (AML). However, the association between the methylation status of the MGMT promoter and the chemotherapeutic outcomes of patients with AML remains unknown. In the present study, 30 bone marrow samples derived from patients with AML were collected prior and subsequent to chemotherapy. The methylation status of the MGMT promoter in the bone marrow specimens was determined by methylation-specific polymerase chain reaction. The results indicated that the methylation status of the MGMT promoter was influenced by different chemotherapeutic regimens. The MGMT methylation status of M4 patients (3 out of 6) were more chemosensitive, compared with that of patients with other AML subtypes (M1, 1 out of 3; M2, 0 out of 8; M3, 3 out of 7; M5, 0 out of 3; and M6, 1 out of 3). Age-based analysis revealed that the group aged ≤60 years (7 out of 24 patients) exhibited more methylation changes than patients aged >60 years (1 out of 6). Male patients (4 out of 13) were more susceptible to chemotherapy-induced methylation changes than female patients (4 out of 17). Thus, the methylation status of the MGMT promoter may serve as a potential biomarker to predict the therapeutic outcomes in male AML patients. However, further studies in larger sample sets are required to confirm the present findings.

  6. The Prognostic Value of Pyrosequencing-Detected MGMT Promoter Hypermethylation in Newly Diagnosed Patients with Glioblastoma

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    Veronica Villani

    2015-01-01

    Full Text Available O6-methylguanine-DNA-methyltransferase (MGMT has emerged as a relevant predictor of therapeutic response and good prognosis in patients with glioblastoma (GBM. Transcriptionally active MGMT rapidly removes the alkyl adducts, preventing the formation of cross-links and thereby causing resistance to alkylating drugs. Studies with pyrosequencing (PSQ showed that this technique has a higher reproducibility and sensitivity than other techniques. However, the definition of a prognostically relevant threshold for the percentage of MGMT methylation remains one of the most critical issues in the use of PSQ analysis. The aim of this study was to define the cut-off value correlated with good favourable prognostic outcomes. We retrospectively analyzed 51 patients (33 males, 18 females with GBM who underwent surgery or biopsy. The Receiver Operating Characteristics analysis showed that the best possible criteria for PSQ-detected percentage of MGMT methylation that predicted progression-free survival (PFS and overall survival (OS were 19% and 13%, respectively. Patients with ≤19% of PSQ-detected MGMT had a shorter PFS (HR: 0.24, p<0.01; those ones with ≤13% had a shorter OS (HR: 0.33, p<0.05. Our study reinforces the importance of MGMT in the management of GBM patients, but future studies with larger sample sizes are warranted to confirm our findings.

  7. The global DNA methylation surrogate LINE-1 methylation is correlated with MGMT promoter methylation and is a better prognostic factor for glioma.

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    Fumiharu Ohka

    Full Text Available Gliomas are the most frequently occurring primary brain tumor in the central nervous system of adults. Glioblastoma multiformes (GBMs, WHO grade 4 have a dismal prognosis despite the use of the alkylating agent, temozolomide (TMZ, and even low grade gliomas (LGGs, WHO grade 2 eventually transform to malignant secondary GBMs. Although GBM patients benefit from promoter hypermethylation of the O(6-methylguanine-DNA methyltransferase (MGMT that is the main determinant of resistance to TMZ, recent studies suggested that MGMT promoter methylation is of prognostic as well as predictive significance for the efficacy of TMZ. Glioma-CpG island methylator phenotype (G-CIMP in the global genome was shown to be a significant predictor of improved survival in patients with GBM. Collectively, we hypothesized that MGMT promoter methylation might reflect global DNA methylation. Additionally in LGGs, the significance of MGMT promoter methylation is still undetermined. In the current study, we aimed to determine the correlation between clinical, genetic, and epigenetic profiles including LINE-1 and different cancer-related genes and the clinical outcome in newly diagnosed 57 LGG and 54 GBM patients. Here, we demonstrated that (1 IDH1/2 mutation is closely correlated with MGMT promoter methylation and 1p/19q codeletion in LGGs, (2 LINE-1 methylation levels in primary and secondary GBMs are lower than those in LGGs and normal brain tissues, (3 LINE-1 methylation is proportional to MGMT promoter methylation in gliomas, and (4 higher LINE-1 methylation is a favorable prognostic factor in primary GBMs, even compared to MGMT promoter methylation. As a global DNA methylation marker, LINE-1 may be a promising marker in gliomas.

  8. Association between small heat shock protein B11 and the prognostic value of MGMT promoter methylation in patients with high-grade glioma.

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    Cheng, Wen; Li, Mingyang; Jiang, Yang; Zhang, Chuanbao; Cai, Jinquan; Wang, Kuanyu; Wu, Anhua

    2016-07-01

    OBJECT This study investigated the role and prognostic value of heat shock proteins (HSPs) in glioma. METHODS Data from 3 large databases of glioma samples (Chinese Glioma Genome Atlas, Repository for Molecular Brain Neoplasia Data, and GSE16011), which contained whole-genome messenger RNA microarray expression data and patients' clinical data, were analyzed. Immunohistochemical analysis was performed to validate protein expression in another set of 50 glioma specimens. RESULTS Of 28 HSPs, 11 were overexpressed in high-grade glioma (HGG) compared with low-grade glioma. A univariate Cox analysis revealed that HSPB11 has significant prognostic value for each glioma grade, which was validated by a Kaplan-Meier survival analysis. HSPB11 expression was associated with poor prognosis and was independently correlated with overall survival (OS) in HGG. This study further explored the combined role of HSPB11 and other molecular markers in HGG, such as isocitrate dehydrogenase 1 (IDH1) mutation and O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status. HSPB11 expression was able to refine the prognostic value of IDH1 mutation in patients with HGG. However, when combined with MGMT promoter methylation status, among patients with a methylated MGMT promoter, those with lower levels of HSPB11 expression had longer OS and progression-free survival than patients with higher levels of HSPB11 expression or with an unmethylated MGMT promoter. Moreover, within the MGMT promoter methylation group, patients with low levels of HSPB11 expression were more sensitive to combined radiochemotherapy than those with high levels of HSPB11 expression, which may explain why some patients with HGG with a methylated MGMT promoter show tolerance to radiochemotherapy. CONCLUSIONS HSPB11 was identified as a novel prognostic marker in patients with HGG. Together with MGMT promoter methylation status, HSPB11 expression can predict outcome for patients with HGG and identify those who

  9. MGMT Promoter Methylation and BRAF V600E Mutations Are Helpful Markers to Discriminate Pleomorphic Xanthoastrocytoma from Giant Cell Glioblastoma.

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    Laura-Nanna Lohkamp

    Full Text Available Giant Cell Glioblastoma (gcGBM and Pleomorphic Xanthoastrocytoma (PXA are rare astroglial tumors of the central nervous system. Although they share certain histomorphological and immunohistochemical features, they are characterized by different clinical behavior and prognosis. Nevertheless, few cases remain uncertain, as their histomorphological hallmarks and immunophenotypes do correspond to the typical pattern neither of gcGBM nor PXA. Therefore, in addition to the routinely used diagnostic histochemical and immunohistochemical markers like Gömöri, p53 and CD34, we analyzed if genetic variations like MGMT promoter methylation, mutations in the IDH1/2 genes, or BRAF mutations, which are actually used as diagnostic, prognostic and predictive molecular markers in anaplastic glial tumors, could be helpful in the differential diagnostic of both tumor entities. We analyzed 34 gcGBM and 20 PXA for genetic variations in the above-named genes and found distinct distributions between both groups. MGMT promoter hypermethylation was observed in 3 out of 20 PXA compared to 14 out of 34 gcGBM (15% vs. 41.2%, p-value 0.09. BRAF V600E mutations were detected in 50% of the PXA but not in any of the gcGBM (50% vs. 0%, p-value < 0.001. IDH1 R132 and IDH R172 mutations were not present in any of the PXA and gcGBM cases. Our data indicate, that in addition to the histological and immunohistochemical evaluation, investigation of MGMT promoter methylation and in particular BRAF V600E mutations represent reliable additional tools to sustain differentiation of gcGBM from PXA on a molecular basis. Based on these data specific BRAF kinase inhibitors could represent a promising agent in the therapy of PXA and their use should be emphasized.

  10. Long-term survival in glioblastoma: methyl guanine methyl transferase (MGMT) promoter methylation as independent favourable prognostic factor

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    Smrdel, Uros; Zwitter, Matjaz; Bostjancic, Emanuela; Zupan, Andrej; Kovac, Viljem; Glavac, Damjan; Bokal, Drago; Jerebic, Janja

    2016-01-01

    Abstract Background In spite of significant improvement after multi-modality treatment, prognosis of most patients with glioblastoma remains poor. Standard clinical prognostic factors (age, gender, extent of surgery and performance status) do not clearly predict long-term survival. The aim of this case-control study was to evaluate immuno-histochemical and genetic characteristics of the tumour as additional prognostic factors in glioblastoma. Patients and methods Long-term survivor group were 40 patients with glioblastoma with survival longer than 30 months. Control group were 40 patients with shorter survival and matched to the long-term survivor group according to the clinical prognostic factors. All patients underwent multimodality treatment with surgery, postoperative conformal radiotherapy and temozolomide during and after radiotherapy. Biopsy samples were tested for the methylation of MGMT promoter (with methylation specific polymerase chain reaction), IDH1 (with immunohistochemistry), IDH2, CDKN2A and CDKN2B (with multiplex ligation-dependent probe amplification), and 1p and 19q mutations (with fluorescent in situ hybridization). Results Methylation of MGMT promoter was found in 95% and in 36% in the long-term survivor and control groups, respectively (p < 0.001). IDH1 R132H mutated patients had a non-significant lower risk of dying from glioblastoma (p = 0.437), in comparison to patients without this mutation. Other mutations were rare, with no significant difference between the two groups. Conclusions Molecular and genetic testing offers additional prognostic and predictive information for patients with glioblastoma. The most important finding of our analysis is that in the absence of MGMT promoter methylation, longterm survival is very rare. For patients without this mutation, alternative treatments should be explored. PMID:27904447

  11. Promoter hypermethylation patterns of P16, DAPK and MGMT in oral squamous cell carcinoma: a systematic review and meta-analysis.

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    Don, K R; Ramani, Pratibha; Ramshankar, Vijayalakshmi; Sherlin, Herald Justin; Premkumar, Priya; Natesan, Anuja

    2014-01-01

    Oral squamous cell carcinoma (OSCC) is a common cancer world-wide that is highly lethal due to its recurrence and metastasis. Methylation is a common epigenetic mechanism that leads to gene silencing in tumors and could be a useful biomarker in OSCC. The prevalence of P16, death-associated protein kinase (DAPK) and O6-methylguanine-DNA-methyltransferase (MGMT) promoter hypermethylation in OSCC has been evaluated for several years while the results remain controversial. The aim of this systematic review is to critically analyze and perform a meta-analysis on the various studies in the literature that have reported the promoter hypermethylation of P16, DAPK and MGMT genes in OSCC. Articles were searched and selected through PubMed. Hand search from the relevant journals was also performed. Articles were reviewed and analyzed. The estimated prevalence of P16 methylation was 43%, DAPK methylation was 39.7% and MGMT methylation was 39.8%. Heterogeneity in methylation prevalences and correlations with the clinical outcomes of the disease prevailed in various studies. We can conclude from our systematic review that a higher prevalence of methylation of P16, DAPK and MGMT occur in OSCC. Further studies are required to substantiate the role of methylation of P16, DAPK and MGMT as a marker in OSCC.

  12. Correlation of chromosome damage and promoter methylation status of the DNA repair genes MGMT and hMLH1 in Chinese vinyl chloride monomer (VCM-exposed workers

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    Fen Wu

    2013-02-01

    Full Text Available Objective: To explore the association of the methylation status of MGMT and hMLH1 with chromosome damage induced by vinyl chloride monomer (VCM. Materials and Methods: Methylation of MGMT and hMLH1 was measured in 101 VCM-exposed workers by methylation-specifi c PCR. Chromosome damage in peripheral blood lymphocytes was measured by the cytokinesis-block micronucleus assay. The subjects were divided into chromosome damaged and non-damaged groups based on the normal reference value of micronuclei frequencies determined for two control groups. Results: MGMT promoter methylation was detectable in 5 out of 49 chromosome damaged subjects, but not in the chromosome non-damaged subjects; there was a signifi cant difference in MGMT methylation between the two groups (p < 0.05. Conclusions: We detected aberrant promoter methylation of MGMT in a small number of chromosome damaged VCM-exposed workers, but not in the chromosome non-damaged subjects. This preliminary observation warrants further investigation in a larger study.

  13. RESULTS OF THE INTERNATIONAL INTERLABORATORY COMPARISON OF MGMT PROMOTER METHYLATION ANALYSIS INVOLVING TWENTY-THREE ACADEMIC CENTERS IN GERMANY, AUSTRIA AND THE NETHERLANDS

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    Reifenberger, Guido; Malzkorn, B.; Acker, T.; Bettstetter, M.; Buslei, R.; von Deimling, A.; Dietmaier, W.; Dubbink, H.J.; Eigenbrod, S.; Garvalov, B.K.; Gerstenmaier, U.; Giese, A.; Haase, D.; Hasselblatt, M.; Kirches, E.; Koch, A.; Marienfeld, R.; Mittelbronn, M.; Montesinos-Rongen, M.; Pagenstecher, A.; Riemenschneider, M.J.; Prinz, M.; Romeike, B.; Roos, A.; Spiegl-Kreinecker, S.; Schittenhelm, J.; Schlegel, J.; Thal, D.R.; Tops, B.B.J.; Weis, J.; Westphal, G.; Worm, K.; Felsberg, J.

    2014-01-01

    BACKGROUND: Molecular testing for MGMT promoter methylation has become of clinical importance in the diagnostic assessment of malignant gliomas since test results may guide therapeutic decision making, in particular in elderly patients with glioblastoma. However, the patterns and extent of MGMT promoter methylation may vary from tumor to tumor, and standardized approaches for its routine diagnostic assessment are lacking. Thus, external quality assessment (EQA) measures are required to ensure accuracy and reproducibility of results across different laboratories. METHODS: We performed an interlaboratory comparison of MGMT promoter methylation analysis involving twenty-three academic institutions in Germany, Austria and the Netherlands. Two different test rounds were carried out, the first one using high molecular weight DNA extracted from frozen tissue samples of 20 tumors and the second one using formalin-fixed paraffin-embedded tissue sections of 16 tumors. All samples were centrally retrieved from the CNS tumor tissue bank at Heinrich Heine University Düsseldorf. Each participating center evaluated the same set of samples using the locally established methods. Results were centrally collected, together with information on the individual assays and the number of tests carried out per year. RESULTS: Methylation specific-PCR was the most commonly used method at the participating centers. Other less common techniques included pyrosequencing of bisulfite-modified DNA, MethyQESD (methylation-quantification of endonuclease-resistant DNA), MLPA (Multiplex Ligation-dependent Probe Amplification), and PCR-based fragment analysis. MGMT testing results showed a good overall concordance across the participating laboratories for those tumors that either had strongly methylated or clearly unmethylated MGMT promoter sequences. However, poor concordance was obtained for cases with only weak or partial MGMT promoter methylation. CONCLUSIONS: Our study provides an overview of the

  14. Kras gene mutation and RASSF1A, FHIT and MGMT gene promoter hypermethylation: indicators of tumor staging and metastasis in adenocarcinomatous sporadic colorectal cancer in Indian population.

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    Rupal Sinha

    Full Text Available OBJECTIVE: Colorectal cancer (CRC development involves underlying modifications at genetic/epigenetic level. This study evaluated the role of Kras gene mutation and RASSF1A, FHIT and MGMT gene promoter hypermethylation together/independently in sporadic CRC in Indian population and correlation with clinicopathological variables of the disease. METHODS: One hundred and twenty four consecutive surgically resected tissues (62 tumor and equal number of normal adjacent controls of primary sporadic CRC were included and patient details including demographic characteristics, lifestyle/food or drinking habits, clinical and histopathological profiles were recorded. Polymerase chain reaction - Restriction fragment length polymorphism and direct sequencing for Kras gene mutation and Methylation Specific-PCR for RASSF1A, FHIT and MGMT genes was performed. RESULTS: Kras gene mutation at codon 12 & 13 and methylated RASSF1A, FHIT and MGMT gene was observed in 47%, 19%, 47%, 37% and 47% cases, respectively. Alcohol intake and smoking were significantly associated with presence of Kras mutation (codon 12 and MGMT methylation (p-value <0.049. Tumor stage and metastasis correlated with presence of mutant Kras codon 12 (p-values 0.018, 0.044 and methylated RASSF1A (p-values 0.034, 0.044, FHIT (p-values 0.001, 0.047 and MGMT (p-values 0.018, 0.044 genes. Combinatorial effect of gene mutation/methylation was also observed (p-value <0.025. Overall, tumor stage 3, moderately differentiated tumors, presence of lymphatic invasion and absence of metastasis was more frequently observed in tumors with mutated Kras and/or methylated RASSF1A, FHIT and MGMT genes. CONCLUSION: Synergistic interrelationship between these genes in sporadic CRC may be used as diagnostic/prognostic markers in assessing the overall pathological status of CRC.

  15. Altered expression of MGMT in high-grade gliomas results from the combined effect of epigenetic and genetic aberrations.

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    João Ramalho-Carvalho

    Full Text Available MGMT downregulation in high-grade gliomas (HGG has been mostly attributed to aberrant promoter methylation and is associated with increased sensitivity to alkylating agent-based chemotherapy. However, HGG harboring 10q deletions also benefit from treatment with alkylating agents. Because the MGMT gene is mapped at 10q26, we hypothesized that both epigenetic and genetic alterations might affect its expression and predict response to chemotherapy. To test this hypothesis, promoter methylation and mRNA levels of MGMT were determined by quantitative methylation-specific PCR (qMSP or methylation-specific multiplex ligation dependent probe amplification (MS-MLPA and quantitative RT-PCR, respectively, in a retrospective series of 61 HGG. MGMT/chromosome 10 copy number variations were determined by FISH or MS-MLPA analysis. Molecular findings were correlated with clinical parameters to assess their predictive value. Overall, MGMT methylation ratios assessed by qMSP and MS-MLPA were inversely correlated with mRNA expression levels (best coefficient value obtained with MS-MLPA. By FISH analysis in 68.3% of the cases there was loss of 10q26.1 and in 15% of the cases polysomy was demonstrated; the latter displayed the highest levels of transcript. When genetic and epigenetic data were combined, cases with MGMT promoter methylation and MGMT loss depicted the lowest transcript levels, although an impact in response to alkylating agent chemotherapy was not apparent. Cooperation between epigenetic (promoter methylation and genetic (monosomy, locus deletion changes affecting MGMT in HGG is required for effective MGMT silencing. Hence, evaluation of copy number alterations might add relevant prognostic and predictive information concerning response to alkylating agent-based chemotherapy.

  16. Antineoplastic effect of decoy oligonucleotide derived from MGMT enhancer.

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    Tamar Canello

    Full Text Available Silencing of O(6-methylguanine-DNA-methyltransferase (MGMT in tumors, mainly through promoter methylation, correlates with a better therapeutic response and with increased survival. Therefore, it is conceivable to consider MGMT as a potential therapeutic target for the treatment of cancers. Our previous results demonstrated the pivotal role of NF-kappaB in MGMT expression, mediated mainly through p65/NF-kappaB homodimers. Here we show that the non-canonical NF-KappaB motif (MGMT-kappaB1 within MGMT enhancer is probably the major inducer of MGMT expression following NF-kappaB activation. Thus, in an attempt to attenuate the transcription activity of MGMT in tumors we designed locked nucleic acids (LNA modified decoy oligonucleotides corresponding to the specific sequence of MGMT-kappaB1 (MGMT-kB1-LODN. Following confirmation of the ability of MGMT-kB1-LODN to interfere with the binding of p65/NF-kappaB to the NF-KappaB motif within MGMT enhancer, the efficacy of the decoy was studied in-vitro and in-vivo. The results of these experiments show that the decoy MGMT-kB1-LODN have a substantial antineoplastic effect when used either in combination with temozolomide or as monotherapy. Our results suggest that MGMT-kB1-LODN may provide a novel strategy for cancer therapy.

  17. Antineoplastic effect of decoy oligonucleotide derived from MGMT enhancer.

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    Canello, Tamar; Ovadia, Haim; Refael, Miri; Zrihan, Daniel; Siegal, Tali; Lavon, Iris

    2014-01-01

    Silencing of O(6)-methylguanine-DNA-methyltransferase (MGMT) in tumors, mainly through promoter methylation, correlates with a better therapeutic response and with increased survival. Therefore, it is conceivable to consider MGMT as a potential therapeutic target for the treatment of cancers. Our previous results demonstrated the pivotal role of NF-kappaB in MGMT expression, mediated mainly through p65/NF-kappaB homodimers. Here we show that the non-canonical NF-KappaB motif (MGMT-kappaB1) within MGMT enhancer is probably the major inducer of MGMT expression following NF-kappaB activation. Thus, in an attempt to attenuate the transcription activity of MGMT in tumors we designed locked nucleic acids (LNA) modified decoy oligonucleotides corresponding to the specific sequence of MGMT-kappaB1 (MGMT-kB1-LODN). Following confirmation of the ability of MGMT-kB1-LODN to interfere with the binding of p65/NF-kappaB to the NF-KappaB motif within MGMT enhancer, the efficacy of the decoy was studied in-vitro and in-vivo. The results of these experiments show that the decoy MGMT-kB1-LODN have a substantial antineoplastic effect when used either in combination with temozolomide or as monotherapy. Our results suggest that MGMT-kB1-LODN may provide a novel strategy for cancer therapy.

  18. Clinical Neuropathology practice guide 5-2015: MGMT methylation pyrosequencing in glioblastoma: unresolved issues and open questions.

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    Bienkowski, Michal; Berghoff, Anna S; Marosi, Christine; Wöhrer, Adelheid; Heinzl, Harald; Hainfellner, Johannes A; Preusser, Matthias

    2015-01-01

    O6-methylguanine-methyltransferase (MGMT) promoter methylation status has prognostic and, in the subpopulation of elderly patients, predictive value in newly diagnosed glioblastoma. Therefore, knowledge of the MGMT promoter methylation status is important for clinical decision-making. So far, MGMT testing has been limited by the lack of a robust test with sufficiently high analytical performance. Recently, one of several available pyrosequencing protocols has been shown to be an accurate and robust method for MGMT testing in an intra- and interlaboratory ring trial. However, some uncertainties remain with regard to methodological issues, cut-off definitions, and optimal use in the clinical setting. In this article, we highlight and discuss several of these open questions. The main unresolved issues are the definition of the most relevant CpG sites to analyze for clinical purposes and the determination of a cut-off value for dichotomization of quantitative MGMT pyrosequencing results into "MGMT methylated" and "MGMT unmethylated" patient subgroups as a basis for further treatment decisions.

  19. Increased expression of the histone H3 lysine 4 methyltransferase MLL4 and the histone H3 lysine 27 demethylase UTX prolonging the overall survival of patients with glioblastoma and a methylated MGMT promoter.

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    Kim, Jinho; Lee, Sung-Hun; Jang, Ji Hwan; Kim, Mee-Seon; Lee, Eun Hee; Kim, Young Zoon

    2016-07-01

    OBJECTIVE The purpose of the present study was to investigate the epigenetic and prognostic roles of an H3K4 methyltransferase (mixed lineage leukemia 4 [MLL4]) and H3K27 demethylase (ubiquitously transcribed tetratricopeptide repeat gene on X chromosome [UTX]) in progression-free survival (PFS) and overall survival (OS) of patients with glioblastoma (GBM) who were treated with radiotherapy, chemotherapy, or both after resection. In addition, the authors examined methylation at the promoter of the O-6-methylguanine-DNA methyltransferase (MGMT) gene and other prognostic factors predicting length of PFS and OS in these patients. METHODS The medical records of 76 patients having a new diagnosis of histologically ascertained GBM in the period of January 2002 to December 2013 at the authors' institution were retrospectively reviewed. Immunohistochemical staining for MLL4 and UTX was performed on archived paraffin-embedded tissues obtained by biopsy or resection. The methylation status of the MGMT promoter in these tissues was determined by methylation-specific PCR analysis. RESULTS During the follow-up period (mean length 18.1 months, range 4.1-43.5 months), 68 (89.5%) of the patients died. The MGMT promoter was methylated in 49 patients (64.5%) and unmethylated in 27 (35.5%). The immunoreactivity pattern of UTX was identical to that of MLL4; increased expression of these 2 proteins was observed in samples from 34 patients (44.7%) and decreased expression in 42 patients (55.3%). The mean length of PFS was 9.2 months (95% CI 6.8-11.6 months). Extent of surgery, recursive partitioning analysis (RPA) class, and methylation status of the MGMT promoter were all associated with increased PFS in the multivariate analysis of factors predicting PFS. The mean length of OS was 18.6 months (95% CI 14.3-22.9 months). Patient age (p = 0.004), WHO performance status score (p = 0.019), extent of surgery (p = 0.007), RPA class (p = 0.036), methylation status of the MGMT promoter (p = 0

  20. The significance of MGMT promoter methylation and the expression of MGMT and NF-κB in glioma%MGMT基因启动子甲基化与MGMT蛋白和NF-κB在脑胶质瘤的表达及意义

    Institute of Scientific and Technical Information of China (English)

    程建杰; 赵妤; 李正金; 田林波; 王敏; 毕磊; 邵泽涛; 潘云

    2013-01-01

    目的 探讨MGMT和NF-κB在脑胶质瘤中的表达及两者的相关性和MGMT基因启动子甲基化与其蛋白表达的相关性分析.方法 采用免疫组化EnVision法检测MGMT和NF-κB在42例不同级别脑胶质瘤石蜡标本中的表达,运用MSP方法检测MGMT基因启动子甲基化状况.结果 (1)MGMT在低级别组胶质瘤中的表达率为73.7%;在高级别组中其表达率为21.7%.(2) NF-κB在低级别组胶质瘤中的表达率为52.6%,在高级别组中的表达率为60.9%.(3)42例胶质瘤中MGMT基因启动子甲基化发生率为50%,其中MGMT蛋白阳性的胶质瘤,启动子甲基化发生率为26.3%;MGMT蛋白表达阴性的胶质瘤,启动子甲基化发生率为69.6%;MGMT蛋白表达阳性率与其基因启动子甲基化呈负相关.(4)MGMT与NF-κB两者表达无相关性.结论 MGMT蛋白表达随胶质瘤的级别增高而下降,NF-κB与MGMT与胶质瘤级别无相关性.%Objective To investigate the expression of MGMT and NF-κB in glioma and correlation between MGMT and NF-κB,MGMT gene promoter methylation and its protein expression.Methods Immunohistochemistry assay was conducted to detect the expression of MGMT and NF-κB in gliomas;methylation specific PCR (MSP)was used to analyze the MGMT promoter methylation in glioma.Results (1)The ratio of MGMT expression was 73.7% in the low grade group glioma;its expression was 21.7% in the high grade group.(2)NF-κB expression rate was 52.6% in the low grade group glioma,expression of the high grade group was 60.9%.(3)In the 42 cases,the level of MGMT promoter methylaion was 50% ;it was in 19 cases that MGMT protein expresses positively,and among which 5 cases were methylated,so the positive expression rate was 26.3%.MGMT protein expression had negative correlation with its promoter methylation.(4) There was no correlation between MGMT and NF-κB expressions.Conclusions MGMT expression decrease following the level of glioma rise and there is no

  1. [Analysis of MGMT methylation with the therascreen(®) MGMT Pyro(®) Kit (Qiagen). A method verification].

    Science.gov (United States)

    Luquain, Alexandra; Magnin, Sandrine; Guenat, David; Prétet, Jean-Luc; Viennet, Gabriel; Valmary-Degano, Séverine; Mougin, Christiane

    2015-01-01

    Promoter methylation of the MGMT gene, encoding the enzyme O6-methylguanine-ubiquitous methyltransferase, is a theranostic good prognosis marker of glioblastomas treated with alkylating chemotherapy (temozolomide, Temodal(®)). Among the methylation analysis techniques, pyrosequencing is a reproducible and sensitive quantitative method. As part of the accreditation of the hospital platform of molecular genetics of cancer, Besançon, our objective was to verify the performance of the pyrosequencing commercial kit therascreen(®) MGMT Pyro(®) (Qiagen) in terms of repeatability, reproducibility, limit of blank (LOB), limit of detection (LOD), linearity and contamination by the guide SH GTA 04 delivered by the Cofrac. The repeatability tests show an average methylation of 3.22% [standard deviation (SD) = 0.41, coefficient of variation (CV) = 12.75%] for the unmethylated control and 70.16% (SD = 2.20, CV = 3.14%) for the methylated control. Reproducibility demontrates an average methylation of 1.39% (SD = 0.25, CV = 18.25%) for the unmethylated control and of 94.03% (SD = 2.56, CV = 2.73%) for the methylated control. The percentages of LOB and LOD are respectively 3.43% and 6.22% methylation. The regression coefficient of 0,983 confirms the linearity of the assay from 0% to 100% methylation. No contamination has been observed. Over 40% of glioblastomas studied in 2013 in our laboratory have shown a methylated MGMT gene. Our results confirms that the theraScreen(®) MGMT Pyro(®) kit (Qiagen) is performant in compliance with the quality requirements of the NF EN ISO 15189 for the routine analysis of methylation status of MGMT in glioblastomas.

  2. DNA修复基因MGMT启动子区过甲基化在胆管癌中的作用%Promoter Hypermethylation of DNA Repair Gene MGMT in Cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    刘小方; 孙宪春; 张翠生; 许政; 李绍军; 周先亭; 孙世杰

    2011-01-01

    Objective To explore the clinical significance of promoter hypermethylation of O6 -methylguanine-DNA methyltransferase (MGMT) in cholangiocarcinoma. Methods Promoter methylation status of MGMT gene and expression of MGMT protein were detected in cholangiocarcinoma by methylation-specific PCR and immunohis-tochemical staining, respectively. Results Aberrant methylation of MGMT gene was detected in 17 patients (47. 2%). Twenty-one cases showed negative immunoreactivities. Of 21 patients with negative MGMT expression, 14 patients had aberrant methylation of MGMT gene. In 15 patients with positive MGMT expression, aberrant methylation of MGMT gene was only found in three cases. There was a negative correlation between promoter methylation status of MGMT gene and the expression of MGMT protein (rs = - 0. 816, P0. 05). Conclusions Hypermethylation of MGMT promoter is a frequency molecular event in cholangiocarcinoma and may be involved in carcinogenesis. Methylation status of MGMT gene may be used to evaluate malignant degree of cholangiocarcinoma.%目的 探讨胆管癌组织中6-氧-甲基鸟嘌呤-DNA甲基转移酶(MGMT)基因的甲基化状态及其在胆管癌中的临床意义.方法 采用甲基化特异性PCR (MSP)和免疫组织化学法分析胆管癌组织中MGMT基因启动子甲基化状态及MGMT蛋白表达情况,并分析MGMT基因甲基化状态与临床病理特征的关系.结果 36例胆管癌组织中MGMT基因17例(47.2%)为甲基化阳性;MGMT蛋白阳性表达15例,阴性表达21例,21例MGMT蛋白阴性表达的胆管癌中MGMT甲基化阳性14例;15例MGMT蛋白阳性表达中MGMT甲基化阳性仅3例.MGMT蛋白表达与MGMT甲基化状态呈负相关(rs= -0.816,P<0.05).MGMT基因的甲基化状态与胆管癌患者的肿瘤浸润深度、分化程度及TNM分期有关(P<0.05),但与患者的年龄、性别、病理学类型、淋巴结转移均无关(P>0.05).结论 MGMT基因启动子过甲基化是胆管癌组织中常见的分

  3. Relationship between MGMT gene expression and promoter methylation and the clinical prognosis of patients with glioma%脑胶质瘤 MGMT 基因表达及启动子甲基化与患者临床预后关系的观察

    Institute of Scientific and Technical Information of China (English)

    袁强; 步星耀; 闫兆月; 周志龙; 孙彦熙; 周伟; 马春晓; 屈鸣麒

    2014-01-01

    Objective To investigate the influence of O 6-methylguanine-DNA methyltransferase ( MGMT) gene promoter methylation and expression in malignant glioma tissues and the clinical prognosis observation of malignant glioma patients .Methods A total of 78 postoperative patients who agreed to glioma individualized comprehensive treatment with complete clinical data were collected ,admitted to Department of Neurosurgery ,People′s Hospital of Zhengzhou University from April 2007 to April 2009 , all patients were grouped by detecting the glioma MGMT gene promoter methylation and protein expression .All patients received radiotherapy combined with chemotherapy treatment postoperation .The efficacy of two groups by observing short-term curative efficacy , survival time and the safety through the long-term follow-up were compared.The two groups of mean differences were compared by independent t-test, chi-square test was applied to count data R ×C table,and Kaplan-Meier method was used to draw survival curves ,survival curve was analyzed by Log-rank test .Results The status of MGMT gene promoter methylation demonstrate a negative correlation with MGMT protein expression ( r=-0.514 ,P<0.05 ) .The short-term curative efficacy in MGMT gene promoter methylation group was significantly superior to MGMT gene promoter unmethylation group(χ2 =47.890 ,P=0.000 ) ,and the short-term curative efficacy of low MGMT protein expression group was significantly superior to the high expression group (χ2 =30.032 ,P=0.000 ) .The survival time in MGMT gene promoter methylation group was significantly superior to the MGMT gene promoter unmethylation group (χ2 =21.405 , P <0.05 ) .And the survival efficacy time of low MGMT protein expression group was significantly superior to the high expression group (χ2 =18.643 , P<0.05 ) .The objective curative rate in MGMT gene promoter methylation group 81.0%( 34/42 ) was superior to the low MGMT protein expression group 74.4%( 29/39 ) .No adverse reaction

  4. MGMT expression predicts response to temozolomide in pancreatic neuroendocrine tumors.

    Science.gov (United States)

    Cros, J; Hentic, O; Rebours, V; Zappa, M; Gille, N; Theou-Anton, N; Vernerey, D; Maire, F; Lévy, P; Bedossa, P; Paradis, V; Hammel, P; Ruszniewski, P; Couvelard, A

    2016-08-01

    Temozolomide (TEM) showed encouraging results in well-differentiated pancreatic neuroendocrine tumors (WDPNETs). Low O(6)-methylguanine-DNA methyltransferase (MGMT) expression and MGMT promoter methylation within tumors correlate with a better outcome under TEM-based chemotherapy in glioblastoma. We aimed to assess whether MGMT expression and MGMT promoter methylation could help predict the efficacy of TEM-based chemotherapy in patients with WDPNET. Consecutive patients with progressive WDPNET and/or liver involvement over 50% who received TEM between 2006 and 2012 were retrospectively studied. Tumor response was assessed according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 guidelines. Nuclear expression of MGMT was assessed by immunochemistry (H-score, 0-300) and MGMT promoter methylation by pyrosequencing. Forty-three patients (21 men, 58years (27-84)) with grade 1 WDPNET (n=6) or 2 (n=36) were analyzed. Objective response, stable disease, and progression rates were seen in 17 patients (39.5%), 18 patients (41.9%), and 8 patients (18.6%), respectively. Low MGMT expression (≤50) was associated with radiological objective response (P=0.04) and better progression-free survival (PFS) (HR=0.35 (0.15-0.81), P=0.01). Disease control rate at 18months of treatment remained satisfying with an MGMT score up to 100 (74%) but dropped with a higher expression. High MGMT promoter methylation was associated with a low MGMT expression and longer PFS (HR=0.37 (0.29-1.08), P=0.05). Low MGMT score (≤50) appears to predict an objective tumor response, whereas an intermediate MGMT score (50-100) seems to be associated with prolonged stable disease.

  5. Antineoplastic Effect of Decoy Oligonucleotide Derived from MGMT Enhancer

    OpenAIRE

    Canello, Tamar; Ovadia, Haim; Refael, Miri; Zrihan, Daniel; Siegal, Tali; Lavon, Iris

    2014-01-01

    Silencing of O(6)-methylguanine-DNA-methyltransferase (MGMT) in tumors, mainly through promoter methylation, correlates with a better therapeutic response and with increased survival. Therefore, it is conceivable to consider MGMT as a potential therapeutic target for the treatment of cancers. Our previous results demonstrated the pivotal role of NF-kappaB in MGMT expression, mediated mainly through p65/NF-kappaB homodimers. Here we show that the non-canonical NF-KappaB motif (MGMT-kappaB1) wi...

  6. Promoter Region Hypermethylation and mRNA Expression of MGMT and p16 Genes in Tissue and Blood Samples of Human Premalignant Oral Lesions and Oral Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Vikram Bhatia

    2014-01-01

    Full Text Available Promoter methylation and relative gene expression of O6-methyguanine-DNA-methyltransferase (MGMT and p16 genes were examined in tissue and blood samples of patients with premalignant oral lesions (PMOLs and oral squamous cell carcinoma (OSCC. Methylation-specific PCR and reverse transcriptase PCR were performed in 146 tissue and blood samples from controls and patients with PMOLs and OSCC. In PMOL group, significant promoter methylation of MGMT and p16 genes was observed in 59% (P=0.0010 and 57% (P=0.0016 of tissue samples, respectively, and 39% (P=0.0135 and 33% (P=0.0074 of blood samples, respectively. Promoter methylation of both genes was more frequent in patients with OSCC, that is, 76% (P=0.0001 and 82% (P=0.0001 in tissue and 57% (P=0.0002 and 70% (P=0.0001 in blood, respectively. Significant downregulation of MGMT and p16 mRNA expression was observed in both tissue and blood samples from patients with PMOLs and OSCC. Hypermethylation-induced transcriptional silencing of MGMT and p16 genes in both precancer and cancer suggests important role of these changes in progression of premalignant state to malignancy. Results support use of blood as potential surrogate to tissue samples for screening or diagnosing PMOLs and early OSCC.

  7. Promoter region hypermethylation and mRNA expression of MGMT and p16 genes in tissue and blood samples of human premalignant oral lesions and oral squamous cell carcinoma.

    Science.gov (United States)

    Bhatia, Vikram; Goel, Madhu Mati; Makker, Annu; Tewari, Shikha; Yadu, Alka; Shilpi, Priyanka; Kumar, Sandeep; Agarwal, S P; Goel, Sudhir K

    2014-01-01

    Promoter methylation and relative gene expression of O(6)-methyguanine-DNA-methyltransferase (MGMT) and p16 genes were examined in tissue and blood samples of patients with premalignant oral lesions (PMOLs) and oral squamous cell carcinoma (OSCC). Methylation-specific PCR and reverse transcriptase PCR were performed in 146 tissue and blood samples from controls and patients with PMOLs and OSCC. In PMOL group, significant promoter methylation of MGMT and p16 genes was observed in 59% (P = 0.0010) and 57% (P = 0.0016) of tissue samples, respectively, and 39% (P = 0.0135) and 33% (P = 0.0074) of blood samples, respectively. Promoter methylation of both genes was more frequent in patients with OSCC, that is, 76% (P = 0.0001) and 82% (P = 0.0001) in tissue and 57% (P = 0.0002) and 70% (P = 0.0001) in blood, respectively. Significant downregulation of MGMT and p16 mRNA expression was observed in both tissue and blood samples from patients with PMOLs and OSCC. Hypermethylation-induced transcriptional silencing of MGMT and p16 genes in both precancer and cancer suggests important role of these changes in progression of premalignant state to malignancy. Results support use of blood as potential surrogate to tissue samples for screening or diagnosing PMOLs and early OSCC.

  8. Promoter Methylation of p16INK4A, hMLH1, and MGMT in Liquid-Based Cervical Cytology Samples Compared with Clinicopathological Findings and HPV Presence

    Directory of Open Access Journals (Sweden)

    Aris Spathis

    2011-01-01

    Full Text Available Cervical cancer is a common cancer inflicting women worldwide. Even though, persistent infection with oncogenic Human Papillomavirus (HPV types is considered the most important risk factor for cervical cancer development, less than 5% of women with HPV will eventually develop cervical cancer supporting that other molecular events, like methylation-dependent inactivation of tumor suppressor genes, may cocontribute in cervical carcinogenesis. We analyzed promoter methylation of three candidate genes (p16, MGMT, and hMLH1 in 403 liquid-based cytology samples. Methylation was commonly identified in both benign and pathologic samples and correlated with higher lesion grade determined by cytological, colposcopical, or histological findings, with HPV DNA and mRNA positivity of specific HPV types and p16INK4A protein expression. Overall accuracy of methylation is much lower than traditional diagnostic tests ranking it as an ancillary technique with more data needed to identify the exact value of methylation status in cervical carcinogenesis.

  9. NSCLC组织中MGMT过甲基化状况与临床病理特征的关系探讨%Investigation on the relationgship between the promoter hypermethylation of MGMT and clinicopathologic feature in NSCLC tissues

    Institute of Scientific and Technical Information of China (English)

    亢春彦; 陶志敏; 肖红; 张秀芝; 薛玉仙

    2011-01-01

    Objective To investigate the relationgship between the promoter hypermethylation of MGMT gene and clinicopathologic feature in NSCLC tissues .Methods Took 77 cases of NSCLC who were treated in Henan Chest Hospital from March 2006 to July 2009 as research subjects ,the other 20 cases with benign lung disease as the control group ,the methylation specific PCR (MSP) were used to test the methylation status of MGMT in two groups .Results 26 cases of study group had MGMT gene methylation ,the incidence rate was 33.8% ,while no case of control group occurred MGMT gene methylation ,the difference between groups was statistically significant ( P<0.05 ); The promoter hypermethylation of MGMT was correlated to the history of smoking ,lymph node metastasis,TNM stage was Ⅲ and low degree of tumor differation ( P<0.05 ) ,but not correlated to patient age ,gender and histological type( P>0.05 ) .Conclusion The promoter hypermethylation of MGMT gene may take part in lung carcinoma evolvement .%目的 探讨非小细胞肺癌(NSCLC)组织中DNA修复酶O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)过甲基化状况与临床病理特征的关系.方法 以2006年3月到2009年7月在河南省胸科医院胸外科手术治疗的77例NSCLC患者作为研究对象,另外选取20例肺良性病变患者作为对照组,采用甲基化特异性PCR(MSP)检测两组病例肺部病变组织中MGMT的甲基化状况.结果 研究组有26例出现MGMT基因甲基化,发生率为33.8%,对照组无1例出现MGMT基因甲基化,组间比较差异有统计学意义(P<0.05);NSCLC中MGMT过甲基化状态与有吸烟史、有淋巴结转移、TNM分期为Ⅲ期和分化程度为低分化有关,与患者年龄、性别和组织学类型无关.结论 NSCLC组织中的MGMT过甲基化状况可能与肺癌的发生、发展相关.

  10. Temozolomide Treatment for Pediatric Refractory Anaplastic Ependymoma with Low MGMT Protein Expression.

    Science.gov (United States)

    Komori, Kazutoshi; Yanagisawa, Ryu; Miyairi, Yosuke; Sakashita, Kazuo; Shiohara, Masaaki; Fujihara, Ikuko; Morita, Daisuke; Nakamura, Tomohiko; Ogiso, Yoshifumi; Sano, Kenji; Shirahata, Mitsuaki; Fukuoka, Kohei; Ichimura, Koichi; Shigeta, Hiroaki

    2016-01-01

    The benefit of postoperative chemotherapy for anaplastic ependymoma remains unknown. We report two pediatric patients with refractory anaplastic ependymoma treated with temozolomide (TMZ). We did not detect O(6) -methylguanine-DNA methyltransferase (MGMT) promoter methylation in tumor samples; however, MGMT protein expression was low. With TMZ treatment, one patient had a 7-month complete remission; the other, stable disease for 15 months. Three other patients did not respond to TMZ; two had high and one low MGMT expression, and two showed no MGMT promoter methylation. These findings suggest that TMZ may be effective for pediatric refractory anaplastic ependymoma with low MGMT protein expression.

  11. Promoter hypermethylation patterns of P16, DAPK and MGMT in Oral Squamous Cell Carcinoma: A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    K R Don

    2014-01-01

    Conclusion: We can conclude from our systematic review that a higher prevalence of methylation of P16, DAPK and MGMT occur in OSCC. Further studies are required to substantiate the role of methylation of P16, DAPK and MGMT as a marker in OSCC.

  12. Sensitivity Analysis of the MGMT-STP27 Model and Impact of Genetic and Epigenetic Context to Predict the MGMT Methylation Status in Gliomas and Other Tumors.

    Science.gov (United States)

    Bady, Pierre; Delorenzi, Mauro; Hegi, Monika E

    2016-05-01

    The methylation status of the O(6)-methylguanine-DNA methyltransferase (MGMT) gene is an important predictive biomarker for benefit from alkylating agent therapy in glioblastoma. Our model MGMT-STP27 allows prediction of the methylation status of the MGMT promoter using data from the Illumina's Human Methylation BeadChips (HM-27K and HM-450K) that is publically available for many cancer data sets. Here, we investigate the impact of the context of genetic and epigenetic alterations and tumor type on the classification and report on technical aspects, such as robustness of cutoff definition and preprocessing of the data. The association between gene copy number variation, predicted MGMT methylation, and MGMT expression revealed a gene dosage effect on MGMT expression in lower grade glioma (World Health Organization grade II/III) that in contrast to glioblastoma usually carry two copies of chromosome 10 on which MGMT resides (10q26.3). This implies some MGMT expression, potentially conferring residual repair function blunting the therapeutic effect of alkylating agents. A sensitivity analyses corroborated the performance of the original cutoff for various optimization criteria and for most data preprocessing methods. Finally, we propose an R package mgmtstp27 that allows prediction of the methylation status of the MGMT promoter and calculation of appropriate confidence and/or prediction intervals. Overall, MGMT-STP27 is a robust model for MGMT classification that is independent of tumor type and is adapted for single sample prediction.

  13. MGMT Gene Promoter Methylation as a Potent Prognostic Factor in Glioblastoma Treated With Temozolomide-Based Chemoradiotherapy: A Single-Institution Study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Suk [Department of Radiation Oncology, Yonsei University College of Medicine, Yonsei University Health System, Seoul (Korea, Republic of); Kim, Se Hoon [Department of Pathology, Yonsei University College of Medicine, Yonsei University Health System, Seoul (Korea, Republic of); Cho, Jaeho; Kim, Jun Won [Department of Radiation Oncology, Yonsei University College of Medicine, Yonsei University Health System, Seoul (Korea, Republic of); Chang, Jong Hee; Kim, Dong Suk; Lee, Kyu Sung [Department of Neurosurgery, Yonsei University College of Medicine, Yonsei University Health System, Seoul (Korea, Republic of); Suh, Chang-Ok, E-mail: cosuh317@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Yonsei University Health System, Seoul (Korea, Republic of)

    2012-11-01

    Purpose: Recently, cells deficient in O{sup 6}-methylguanine-DNA methyltransferase (MGMT) were found to show increased sensitivity to temozolomide (TMZ). We evaluated whether hypermethylation of MGMT was associated with survival in patients with glioblastoma multiforme (GBM). Methods and Materials: We retrospectively analyzed 93 patients with histologically confirmed GBM who received involved-field radiotherapy with TMZ from 2001 to 2008. The median age was 58 years (range, 24-78 years). Surgical resection was total in 39 patients (42%), subtotal in 30 patients (32%), and partial in 17 patients (18%); only a biopsy was performed in 7 patients (8%). Postoperative radiotherapy began within 3 weeks of surgery in 87% of the patients. Radiotherapy doses ranged from 50 to 74 Gy (median, 70 Gy). MGMT gene methylation was determined in 78 patients; MGMT was unmethylated in 43 patients (55%) and methylated in 35 patients (45%). The median follow-up period was 22 months (range, 3-88 months) for all patients. Results: The median overall survival (OS) was 22 months, and progression-free survival (PFS) was 11 months. MGMT gene methylation was an independently significant prognostic factor for both OS (p = 0.002) and PFS (p = 0.008) in multivariate analysis. The median OS was 29 months for the methylated group and 20 months for the unmethylated group. In 35 patients with methylated MGMT genes, the 2-year and 5-year OS rates were 54% and 31%, respectively. Six patients with combined prognostic factors of methylated MGMT genes, age {<=}50 years, and total/subtotal resections are all alive 38 to 77 months after operation, whereas the median OS in 8 patients with unmethylated MGMT genes, age >50 years, and less than subtotal resection was 13.2 months. Conclusion: We confirmed that MGMT gene methylation is a potent prognostic factor in patients with GBM. Our results suggest that early postoperative radiotherapy and a high total/subtotal resection rate might further improve the

  14. 视网膜母细胞瘤中MGMT启动子区甲基化状态及其产物表达%The MGMT promoter methylation status and its expression level in retinoblastoma

    Institute of Scientific and Technical Information of China (English)

    王怡琛; 李彬; 赵博文; 张浩; 高飞; 张志豹

    2012-01-01

    Objective To detect the methylation status of the promoter of O6 methylguanine DNA meghyltransferase {MGMT) gene and the expression level of MCMT mRNA and protein. Design Experimental Study. Participants 20 paraffin embedded RB tissues, 4 RB cell lines (Y79, SO-Rb50, SO-Rb50/VCR, WERI-RB1). Methods A series of 20 paraffin embedded RB tissue samples and 4 RB cell line were subjected to mehtylation-specific PCR (MSP) analysis to evaluate the methylation status of the MGMT promoter. Further, the expression of MGMT mRNA and protein were studied by Realtime PCR and Western Blot. The clinical data (e.g. Gender, age of onset) and pathological features (e.g. The realm of tumor encroachment, neovascularization in iris, NVI) were also collected. Main Outcome Measures Methylation status of the MGMT promoter, mRNA and protein expression level of MCMT, data of clinical and pathological features. Results Among the 20 paraffin embedded RB tissue samples, 12 cases (60%) were partially/completely methylated, the remaining 8 cases (40%) showed MGMT promoter unmethylated. As to the 4 RB cell lines, Y79, SO-Rb50, SO-Rb50/VCR were partially methylated, while WERI-RB1 was unmethylated. MGMT mRNA and protein were expressed in all 4 RB cell lines. The mRNA expression level of WERI-RBK 1.000±0.040) was higher than the other 3 cell lines( Y79,0.617±0.026;SO-Rb50,0.356±0.020 ;SO-Rb50/VCR, 0.389±0.017), the differences among which were statistically significant (P0.05). Conclusions There was a comparatively high MGMT promoter methylation rate in RB pathologic samples and cell lines, which had a corresponding effect to the expression level of MGMT mRNA and pro-tein. (Ophthalmol CHN, 2012, 21:121-126)%目的 检测视网膜母细胞瘤(RB)中,06-甲基鸟嘌呤DNA甲基转移酶(MGMT)基因启动子区甲基化状态及mRNA、蛋白产物的表达情况,并探讨其与RB临床、组织病理学特征的可能关系.设计 实验研究.研究对象 石蜡包埋RB组织20例,RB细胞系4

  15. MGMT testing-the challenges for biomarker-based glioma treatment

    OpenAIRE

    Wick, W; Weller, M; Van Den Bent, M.; Sanson, M; Weiler, M.; von Deimling, A.; Plass, C; Hegi, M.; Platten, M.; Reifenberger, G.

    2014-01-01

    Many patients with malignant gliomas do not respond to alkylating agent chemotherapy. Alkylator resistance of glioma cells is mainly mediated by the DNA repair enzyme O(6)-methylguanine-DNA methyltransferase (MGMT). Epigenetic silencing of the MGMT gene by promoter methylation in glioma cells compromises this DNA repair mechanism and increases chemosensitivity. MGMT promoter methylation is, therefore, a strong prognostic biomarker in paediatric and adult patients with glioblastoma treated wit...

  16. MGMT expression: insights into its regulation. 1. Epigenetic factors

    Directory of Open Access Journals (Sweden)

    Iatsyshyna A. P.

    2013-03-01

    Full Text Available O6-methylguanine-DNA methyltransferase (MGMT is the DNA repair enzyme responsible for removing of alkylation adducts from the O6-guanine in DNA. Despite MGMT prevents mutations and cell death, this enzyme can provide resistance of cancer cells to alkylating agents of chemotherapy. The high intra- and inter-individual variations in the human MGMT expression level have been observed indicating to a complicated regulation of this gene. This review is focused on the study of epigenetic factors which could be potentially involved in regulation of the human MGMT gene expression. These include chromatin remodeling via histone modifications and DNA methylation of promoter region and gene body, as well as RNA-based mechanisms, alternative splicing, protein post- translational modifications, and other.

  17. Glioblastoma and the significance of MGMT gene methylation

    Directory of Open Access Journals (Sweden)

    Payam Izadpanahi

    2014-08-01

    Full Text Available In this research Glioblastoma has been studied as one of the most common brain tumors and a short review of the available therapeutic methods have presented including surgery, radiotherapy, chemotherapy and particularly adjuvant chemotherapy with temozolomide, as the most effective developed treatment. Moreover, MGMT gene promoter methylation has been introduced as an important predictive factor of treatment response to temozolamide. The different mechanisms of methylation and the availableliterature on its association with patient survival and disease recurrence have been summarized. Taken together, Glioblastoma is a tumor in which the MGMT gene expression can potentially deliver the highest amount of data in comparison to other tumors; as almost every related study has emphasized on the direct association between MGMT methylation and patient survival. Regarding this debate, the pseudoprogression pattern in Glioblastoma patients and the laboratory methods studying MGMT gene methylation have been examined. At the end of this review, the obstacles to its development have been briefly mentioned.

  18. Implication of a Chromosome 15q15.2 Locus in Regulating UBR1 and Predisposing Smokers to MGMT Methylation in Lung.

    Science.gov (United States)

    Leng, Shuguang; Wu, Guodong; Collins, Leonard B; Thomas, Cynthia L; Tellez, Carmen S; Jauregui, Andrew R; Picchi, Maria A; Zhang, Xiequn; Juri, Daniel E; Desai, Dhimant; Amin, Shantu G; Crowell, Richard E; Stidley, Christine A; Liu, Yushi; Swenberg, James A; Lin, Yong; Wathelet, Marc G; Gilliland, Frank D; Belinsky, Steven A

    2015-08-01

    O(6)-Methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme that protects cells from carcinogenic effects of alkylating agents; however, MGMT is silenced by promoter hypermethylation during carcinogenesis. A single-nucleotide polymorphism (SNP) in an enhancer in the MGMT promoter was previously identified to be highly significantly associated with risk for MGMT methylation in lung cancer and sputum from smokers. To further genetic investigations, a genome-wide association and replication study was conducted in two smoker cohorts to identify novel loci for MGMT methylation in sputum that were independent of the MGMT enhancer polymorphism. Two novel trans-acting loci (15q15.2 and 17q24.3) that were identified acted together with the enhancer SNP to empower risk prediction for MGMT methylation. We found that the predisposition to MGMT methylation arising from the 15q15.2 locus involved regulation of the ubiquitin protein ligase E3 component UBR1. UBR1 attenuation reduced turnover of MGMT protein and increased repair of O6-methylguanine in nitrosomethylurea-treated human bronchial epithelial cells, while also reducing MGMT promoter activity and abolishing MGMT induction. Overall, our results substantiate reduced gene transcription as a major mechanism for predisposition to MGMT methylation in the lungs of smokers, and support the importance of UBR1 in regulating MGMT homeostasis and DNA repair of alkylated DNA adducts in cells.

  19. MGMT-Methylated Alleles Are Distributed Heterogeneously Within Glioma Samples Irrespective of IDH Status and Chromosome 10q Deletion.

    Science.gov (United States)

    Fontana, Laura; Tabano, Silvia; Bonaparte, Eleonora; Marfia, Giovanni; Pesenti, Chiara; Falcone, Rossella; Augello, Claudia; Carlessi, Nicole; Silipigni, Rosamaria; Guerneri, Silvana; Campanella, Rolando; Caroli, Manuela; Maria Sirchia, Silvia; Bosari, Silvano; Miozzo, Monica

    2016-06-26

    Several molecular markers drive diagnostic classification, prognostic stratification, and/or prediction of response to therapy in patients with gliomas. Among them, IDH gene mutations are valuable markers for defining subtypes and are strongly associated with epigenetic silencing of the methylguanine DNA methyltransferase (MGMT) gene. However, little is known about the percentage of MGMT-methylated alleles in IDH-mutated cells or the potential association between MGMT methylation and deletion of chromosome 10q, which encompasses the MGMT locus. Here, we quantitatively assessed MGMT methylation and IDH1 mutation in 208 primary glioma samples to explore possible differences associated with the IDH genotype. We also explored a potential association between MGMT methylation and loss of chromosome 10q. We observed that MGMT methylation was heterogeneously distributed within glioma samples irrespective of IDH status suggesting an incomplete overlap between IDH1-mutated and MGMT-methylated alleles and indicating a partial association between these two events. Moreover, loss of one MGMT allele did not affect the methylation level of the remaining allele. MGMT was methylated in about half of gliomas harboring a 10q deletion; in those cases, loss of heterozygosity might be considered a second hit leading to complete inactivation of MGMT and further contributing to tumor progression.

  20. Immunohistochemical Assessment of O(6)-Methylguanine-DNA Methyltransferase (MGMT) and Its Relationship with p53 Expression in Endometrial Cancers.

    Science.gov (United States)

    Lee, Kyung Eun

    2013-12-01

    O(6)-Methylguanine-DNA methyltransferase (MGMT) is a DNA repair protein, the loss of MGMT expression was commonly known due to hypermethylation of CpG islands in its promoter region. Overexpression of p53 protein may be associated with downregulated MGMT expression in brain tumors. The aims of this study were to investigate the role of MGMT expression loss and its correlation with p53 overexpression in endometrial cancers. MGMT and p53 expression was examined in formalin-fixed, paraffin-embedded tissues from 36 endometrial cancer cases using immnunohistochemical staining. The loss of MGMT expression was detected in 11 (30.6%) out of the 36 endometrial cancers and p53 immunoreactivity was detected in 23 (63.9%) out of the 36 endometrial cancers. Ten (90.9%) of the 11 cases with negative MGMT immunoreactivity showed positive p53 expression, so the loss of MGMT expression was significantly associated with the p53 overexpression (P=0.03). These findings suggest that the loss of MGMT expression may be one of factors capable of p53 overexpression in endometrial cancer. Further studies are needed to define the relation between MGMT and p53 for examining the mechanisms of tissue-specific MGMT expression.

  1. Prognostic value of MGMT methylation in colorectal cancer: a meta-analysis and literature review.

    Science.gov (United States)

    Li, Yanliang; Lyu, Zhongchuan; Zhao, Lixin; Cheng, Hong; Zhu, Dongyuan; Gao, Yongsheng; Shang, Xiuwan; Shi, Huaijie

    2015-03-01

    The development of colorectal cancer (CRC) spans about 5-10 years, making early detection and prevention beneficial to the survival of CRC patients. To address inconsistencies in evidence regarding O(6)-methylguanine-DNA-methyltransferase (MGMT) methylation as a potential prognostic factor in CRC, we conducted a meta-analysis to evaluate MGMT methylation in CRC patients. Fourteen studies were included in the meta-analysis after screening 120 articles. The following items were collected from each study: author, published year, country, patient gender, MGMT methylation status, and patients' disease progression. Pooled hazard ratios and odd ratios with 95% confidence intervals (CIs) were calculated using fixed or random effect models depending on the heterogeneity between studies. The overall survival of CRC patients was found not to be significantly associated with MGMT methylation. Further subgroup analysis showed that the frequency of MGMT methylation was significantly higher in CRC than in normal tissues (p MGMT promoter in CRC patients was more frequently methylated than in adenoma patients. In addition, MGMT methylation was significantly increased in adenoma than in normal tissues (p MGMT methylation is central to the development of cancer that involves a stepwise carcinogenesis of normal adenoma carcinoma cascade. However, MGMT methylation is not associated with the prognosis of CRC.

  2. Relationship between methylation of MGMT gene promoter and cervical carcinoma%宫颈癌及宫颈上皮内瘤变MGMT基因甲基化及其相关性研究

    Institute of Scientific and Technical Information of China (English)

    陆欢; 陈莹蓉; 孙立奇; 陶志梅; 张甦; 邓再兴; 戴利成

    2014-01-01

    目的:探讨宫颈癌和宫颈上皮内瘤变(CIN)患者宫颈脱落细胞中O6-甲基鸟嘌呤- DNA甲基转移酶(MGMT)基因启动子区甲基化状态在宫颈癌临床早期诊断和筛查中的作用。方法选取对照组20例,CINI、CINII、CINIII期患者各50例和宫颈癌患者50例,采用甲基化特异性PCR检测宫颈脱落细胞中MGMT基因启动子区甲基化状态并进行比较。结果宫颈癌和CINI、II、III期患者MGMT基因启动子区甲基化阳性率分别为82.0%(41/50)、24.0%(12/50)、50.0%(25/50)和80.0%(40/50),而对照组未检测到MGMT基因启动子区甲基化。与对照组比,宫颈癌组和CINI、II、III期组MGMT基因启动子区甲基化阳性率的差异均有统计学意义(均P<0.05)。宫颈癌组中MGMT基因启动子甲基化与其临床分期及组织分化程度有显著相关性(均P<0.05)。结论 MGMT基因启动子区甲基化可能参与宫颈癌的发生、发展,有助于宫颈癌的早期辅助诊断和筛查。%Objective To investigate the methylation status of MGMT gene promoter in cervical carcinoma and cervical intraepithelial neoplasia (CIN). Methods Methylation status of MGMT gene promoter was detected with methylation specific PCR (MSP) in cervical exfoliated cel s from patients with CINI (n=50), CINII (n=50), CINIII (n=50), cervical carcinoma (n=50) and non- cancer controls(n=20). Results The promoter methylation rates of MGMT were 82.0%(41/50), 24.0%(12/50), 50.0%(25/50) and 80.0%(40/50) in cervical carcinoma, CIN I, CINII and CINIII, while no methylation was detected in control group (P<0.05). The methylation of MGMT gene was correlated with the clinicopathological characteristics and tissue differentiation of cervical carcinoma (P<0.05). Conclusion The methylation of MGMT gene promoter region is associated with cervical carcinoma, which may be used as potential marker for early diagnosis of cervical carcinoma.

  3. Prognostic value of O-6-methylguanine-DNA methyltransferase (MGMT) protein expression in glioblastoma excluding nontumour cells from the analysis.

    Science.gov (United States)

    Dahlrot, R H; Dowsett, J; Fosmark, S; Malmström, A; Henriksson, R; Boldt, H; de Stricker, K; Sørensen, M D; Poulsen, H S; Lysiak, M; Söderkvist, P; Rosell, J; Hansen, S; Kristensen, B W

    2017-06-02

    It is important to predict response to treatment with temozolomide (TMZ) in glioblastoma (GBM) patients. Both MGMT protein expression and MGMT promoter methylation status have been reported to predict the response to TMZ. We investigated the prognostic value of quantified MGMT protein levels in tumour cells and the prognostic importance of combining information of MGMT protein level and MGMT promoter methylation status. MGMT protein expression was quantified in tumour cells in 171 GBMs from the population-based Region of Southern Denmark (RSD)-cohort using a double immunofluorescence approach. Pyrosequencing was performed in 157 patients. For validation we used GBM-patients from a Nordic Study (NS) investigating the effect of radiotherapy and different TMZ schedules. When divided at the median, patients with low expression of MGMT protein (AF-low) had the best prognosis (HR = 1.5, P = 0.01). Similar results were observed in the subgroup of patients receiving the Stupp regimen (HR = 2.0, P = 0.001). In the NS-cohort a trend towards superior survival (HR = 1.6, P = 0.08) was seen in patients with AF-low. Including MGMT promoter methylation status, we found for both cohorts that patients with methylated MGMT promoter and AF-low had the best outcome; median OS 23.1 and 20.0 months, respectively. Our data indicate that MGMT protein expression in tumour cells has an independent prognostic significance. Exclusion of nontumour cells contributed to a more exact analysis of tumour-specific MGMT protein expression. This should be incorporated in future studies evaluating MGMT status before potential integration into clinical practice. © 2017 British Neuropathological Society.

  4. Immunohistochemical evaluation of O6 -methylguanine DNA methyltransferase (MGMT) expression in 117 cases of glioblastoma.

    Science.gov (United States)

    Miyazaki, Masaya; Nishihara, Hiroshi; Terasaka, Shunsuke; Kobayashi, Hiroyuki; Yamaguchi, Shigeru; Ito, Tamio; Kamoshima, Yuuta; Fujimoto, Shin; Kaneko, Sadao; Katoh, Masahito; Ishii, Nobuaki; Mohri, Hiromi; Tanino, Mishie; Kimura, Taichi; Tanaka, Shinya

    2014-06-01

    Temozolomide (TMZ) is an oral alkylating agent which is widely used in the treatment of glioblastoma (GBM) and is composed of astrocytic and/or oligodendroglial tumors, and the evaluation of O(6) -methylguanine DNA methyltransferase (MGMT) expression is important to predict the response to TMZ therapy. In this study, we conducted immunohistochemical analysis of 117 cases of Japanese GBM including 19 cases of GBM with oligodendroglioma component (GBMO), using a scoring system for quantitative evaluation of staining intensity and proportion of MGMT, and performed survival analysis of these patients. Immunohistochemically, 55 cases (47%) were positive for MGMT with various intensities and proportions (total score (TS) ≥ 2), while 62 cases (53%) were negative (TS = 0). The distribution of MGMT expression pattern was not affected by any clinicopathological parameters such as the histological subtype (GBM vs. GBMO), age and gender. The survival analysis of these patients revealed that the minimal expression of MGMT (TS ≥ 2) was a significant unfavorable prognostic factor (P MGMT expression in GBM was the most potent independent predictor for progression free survival (P MGMT expression in GBM. In addition, our results emphases the clinicopathological values of the immunohistochemical approach for MGMT expression in glioma patients as a routine laboratory examination.

  5. MGMT gene silencing and benefit from temozolomide in glioblastoma

    NARCIS (Netherlands)

    Hegi, ME; Diserens, A; Gorlia, T; Hamou, M; de Tribolet, N; Weller, M; Kros, JM; Hainfellner, JA; Mason, W; Mariani, L; Bromberg, JEC; Hau, P; Mirimanoff, RO; Cairncross, JG; Janzer, RC; Stupp, R

    2005-01-01

    BACKGROUND: Epigenetic silencing of the MGMT (O(sup 6)-methylguanine-DNA methyltransferase) DNA-repair gene by promoter methylation compromises DNA repair and has been associated with longer survival in patients with glioblastoma who receive alkylating agents. METHODS: We tested the relationship bet

  6. O(6)-Methylguanine-DNA methyltransferase (MGMT): A drugable target in lung cancer?

    Science.gov (United States)

    Hiddinga, Birgitta I; Pauwels, Patrick; Janssens, Annelies; van Meerbeeck, Jan P

    2016-07-18

    This manuscript addresses the role of O(6)-methylguanine-DNA methyltransferase (MGMT) as a biomarker in the oncogenesis of cancer and the opportunity of turning this gene into a drugable target in neuroendocrine tumours of the lung. Studies in brain tumours conclude that MGMT promoter methylation is considered a strong predictive factor for a favourable outcome for treatment with temozolomide, e.g. alkylating agent. We conducted a systematic review of MGMT in non-small cell lung cancer (NSCLC), small-cell lung cancer (SCLC) and other pulmonary neuroendocrine tumours (NETs) to evaluate whether MGMT is a prognostic and/or predictive factor to select patients with lung cancer who can benefit from treatment with temozolomide. In NSCLC MGMT promoter methylation is not a prognostic and predictive factor, hence temozolomide has no place. In SCLC and NET patients with a MGMT promoter methylation benefit of temozolomide has to be confirmed.Temozolomide can be considered a 'personalized' treatment if the predictive role of MGMT is further confirmed.

  7. miRNA array screening reveals cooperative MGMT-regulation between miR-181d-5p and miR-409-3p in glioblastoma.

    Science.gov (United States)

    Khalil, Susanna; Fabbri, Enrica; Santangelo, Alessandra; Bezzerri, Valentino; Cantù, Cinzia; Di Gennaro, Gianfranco; Finotti, Alessia; Ghimenton, Claudio; Eccher, Albino; Dechecchi, Maria; Scarpa, Aldo; Hirshman, Brian; Chen, Clark; Ferracin, Manuela; Negrini, Massimo; Gambari, Roberto; Cabrini, Giulio

    2016-05-10

    The levels of expression of O6-methylguanine-DNA methyltransferase (MGMT) are relevant in predicting the response to the alkylating chemotherapy in patients affected by glioblastoma. MGMT promoter methylation and the published MGMT regulating microRNAs (miRNAs) do not completely explain the expression pattern of MGMT in clinical glioblastoma specimens. Here we used a genome-wide microarray-based approach to identify MGMT regulating miRNAs. Our screen unveiled three novel MGMT regulating miRNAs, miR-127-3p, miR-409-3p, and miR-124-3p, in addition to the previously identified miR-181d-5p. Transfection of these three novel miRNAs into the T98G glioblastoma cell line suppressed MGMT mRNA and protein expression. However, their MGMT- suppressive effects are 30-50% relative that seen with miR-181d-5p transfection. In silico analyses of The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) revealed that miR-181d-5p is the only miRNA that consistently exhibited inverse correlation with MGMT mRNA expression. However, statistical models incorporating both miR-181d-5p and miR-409-3p expression better predict MGMT expression relative to models involving either miRNA alone. Our results confirmed miR-181d-5p as the key MGMT-regulating miRNA. Other MGMT regulating miRNAs, including the miR-409-3p identified in this report, modify the effect of miR-181d-5p on MGMT expression. MGMT expression is, thus, regulated by cooperative interaction between key MGMT-regulating miRNAs.

  8. Digital PCR quantification of MGMT methylation refines prediction of clinical benefit from alkylating agents in glioblastoma and metastatic colorectal cancer

    NARCIS (Netherlands)

    Barault, L.; Amatu, A.; Bleeker, F.E.; Moutinho, C.; Falcomata, C.; Fiano, V.; Cassingena, A.; Siravegna, G.; Milione, M.; Cassoni, P.; Braud, F. De; Ruda, R.; Soffietti, R.; Venesio, T.; Bardelli, A.; Wesseling, P.; Hamer, P. de Witt; Pietrantonio, F.; Siena, S. Di; Esteller, M.; Sartore-Bianchi, A.; Nicolantonio, F. Di

    2015-01-01

    BACKGROUND: O(6)-methyl-guanine-methyl-transferase (MGMT) silencing by promoter methylation may identify cancer patients responding to the alkylating agents dacarbazine or temozolomide. PATIENTS AND METHODS: We evaluated the prognostic and predictive value of MGMT methylation testing both in tumor a

  9. Digital PCR quantification of MGMT methylation refines prediction of clinical benefit from alkylating agents in glioblastoma and metastatic colorectal cancer

    NARCIS (Netherlands)

    Barault, L.; Amatu, A.; Bleeker, F.E.; Moutinho, C.; Falcomata, C.; Fiano, V.; Cassingena, A.; Siravegna, G.; Milione, M.; Cassoni, P.; Braud, F. De; Ruda, R.; Soffietti, R.; Venesio, T.; Bardelli, A.; Wesseling, P.; Hamer, P. de Witt; Pietrantonio, F.; Siena, S. Di; Esteller, M.; Sartore-Bianchi, A.; Nicolantonio, F. Di

    2015-01-01

    BACKGROUND: O(6)-methyl-guanine-methyl-transferase (MGMT) silencing by promoter methylation may identify cancer patients responding to the alkylating agents dacarbazine or temozolomide. PATIENTS AND METHODS: We evaluated the prognostic and predictive value of MGMT methylation testing both in tumor a

  10. Digital PCR quantification of MGMT methylation refines prediction of clinical benefit from alkylating agents in glioblastoma and metastatic colorectal cancer

    NARCIS (Netherlands)

    Barault, L.; Amatu, A.; Bleeker, F.E.; Moutinho, C.; Falcomata, C.; Fiano, V.; Cassingena, A.; Siravegna, G.; Milione, M.; Cassoni, P.; Braud, F. De; Ruda, R.; Soffietti, R.; Venesio, T.; Bardelli, A.; Wesseling, P.; Hamer, P. de Witt; Pietrantonio, F.; Siena, S. Di; Esteller, M.; Sartore-Bianchi, A.; Nicolantonio, F. Di

    2015-01-01

    BACKGROUND: O(6)-methyl-guanine-methyl-transferase (MGMT) silencing by promoter methylation may identify cancer patients responding to the alkylating agents dacarbazine or temozolomide. PATIENTS AND METHODS: We evaluated the prognostic and predictive value of MGMT methylation testing both in tumor

  11. Digital PCR quantification of MGMT methylation refines prediction of clinical benefit from alkylating agents in glioblastoma and metastatic colorectal cancer

    NARCIS (Netherlands)

    Barault, L.; Amatu, A.; Bleeker, F. E.; Moutinho, C.; Falcomatà, C.; Fiano, V.; Cassingena, A.; Siravegna, G.; Milione, M.; Cassoni, P.; de Braud, F.; Rudà, R.; Soffietti, R.; Venesio, T.; Bardelli, A.; Wesseling, P.; de Witt Hamer, P.; Pietrantonio, F.; Siena, S.; Esteller, M.; Sartore-Bianchi, A.; di Nicolantonio, Federica

    2015-01-01

    Background: O6-methyl-guanine-methyl-transferase (MGMT) silencing by promoter methylation may identify cancer patients responding to the alkylating agents dacarbazine or temozolomide. Patients and methods: We evaluated the prognostic and predictive value of MGMT methylation testing both in tumor and

  12. MGMT — EDRN Public Portal

    Science.gov (United States)

    MGMT is involved in the cellular defense against the biological effects of O6-methylguanine (O6-MeG) in DNA. It repairs alkylated guanine in DNA by stoichiometrically transferring the alkyl group at the O-6 position to a cysteine residue in the enzyme. This is a suicide reaction: the enzyme is irreversibly inactivated.

  13. DNA修复基因MGMT启动子区过甲基化与脑胶质瘤%Promoter hypermethylation of DNA-repaired gene MGMT in gliomas

    Institute of Scientific and Technical Information of China (English)

    高薇; 王之敏; 周岱; 朱凤清

    2008-01-01

    目的 在许多肿瘤中发现启动子区过甲基化而导致O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)的转录失活,本研究拟从胶质瘤患者肿瘤组织和其对应血清中MGMT基因启动子过甲基化是否有一致性对MGMT基因启动子甲基化进行研究.方法 采用甲基化特异性PCR法(MSP)进行MGMT基因启动子区甲基化水平的检测.结果 27例胶质瘤组织中有14例(51.9%)MGMT甲基化扩增阳性,13例(48.1%)为MGMT去甲基化扩增阳性.相应的血清中有13例(48.1%)MGMT甲基化扩增阳性,14例(51.9%)MGMT去甲基化扩增阳性(P<0.05).结论 胶质瘤患者肿瘤组织和其对应的血清中MGMT基因启动子甲基化状态具有显著相关性.测定血清中MGMT基因启动子区的甲基化状态能反应胶质瘤组织中MGMT基因启动子区甲基化状态.MSP是检测MGMT基因启动子区甲基化灵敏和可靠的方法,可以指导临床脑胶质瘤的个体化化疗方案的设计.

  14. Chemoproteomics-Enabled Discovery of a Potent and Selective Inhibitor of the DNA Repair Protein MGMT.

    Science.gov (United States)

    Wang, Chao; Abegg, Daniel; Hoch, Dominic G; Adibekian, Alexander

    2016-02-18

    We present a novel chemical scaffold for cysteine-reactive covalent inhibitors. Chloromethyl triazoles (CMTs) are readily accessed in only two chemical steps, thus enabling the rapid optimization of the pharmacological properties of these inhibitors. We demonstrate the tunability of the CMTs towards a specific biological target by synthesizing AA-CW236 as the first potent non-pseudosubstrate inhibitor of the O(6) -alkylguanine DNA methyltransferase (MGMT), a protein of major clinical significance for the treatment of several severe cancer forms. Using quantitative proteomics profiling techniques, we show that AA-CW236 exhibits a high degree of selectivity towards MGMT. Finally, we validate the effectiveness of our MGMT inhibitor in combination with the DNA alkylating drug temozolomide in breast and colon cancer cells by fluorescence imaging and a cell-viability assay. Our results may open a new avenue towards the development of a clinically approved MGMT inhibitor.

  15. A Hypermethylated Phenotype Is a Better Predictor of Survival than MGMT Methylation in Anaplastic Oligodendroglial Brain Tumors: A Report from EORTC Study 26951

    NARCIS (Netherlands)

    Bent, M.J. van den; Gravendeel, L.A.; Gorlia, T.; Kros, J.M.; Lapre, L.; Wesseling, P.; Teepen, J.L.; Idbaih, A.; Sanson, M.; Smitt, P.A.; French, P.J.

    2011-01-01

    PURPOSE: The MGMT promoter methylation status has been suggested to be predictive for outcome to temozolomide chemotherapy in patients with glioblastoma (GBM). Subsequent studies indicated that MGMT promoter methylation is a prognostic marker even in patients treated with radiotherapy alone, both in

  16. A Hypermethylated Phenotype Is a Better Predictor of Survival than MGMT Methylation in Anaplastic Oligodendroglial Brain Tumors: A Report from EORTC Study 26951

    NARCIS (Netherlands)

    Bent, M.J. van den; Gravendeel, L.A.; Gorlia, T.; Kros, J.M.; Lapre, L.; Wesseling, P.; Teepen, J.L.; Idbaih, A.; Sanson, M.; Smitt, P.A.; French, P.J.

    2011-01-01

    PURPOSE: The MGMT promoter methylation status has been suggested to be predictive for outcome to temozolomide chemotherapy in patients with glioblastoma (GBM). Subsequent studies indicated that MGMT promoter methylation is a prognostic marker even in patients treated with radiotherapy alone, both in

  17. New insights into estrogenic regulation of O(6)-methylguanine DNA-methyltransferase (MGMT) in human breast cancer cells: Co-degradation of ER-α and MGMT proteins by fulvestrant or O(6)-benzylguanine indicates fresh avenues for therapy.

    Science.gov (United States)

    Paranjpe, Ameya; Bailey, Nathan I; Konduri, Santhi; Bobustuc, George C; Ali-Osman, Francis; Yusuf, Mohd A; Punganuru, Surendra R; Madala, Hanumantha Rao; Basak, Debasish; Mostofa, Agm; Srivenugopal, Kalkunte S

    2016-09-01

    Endocrine therapy using estrogen receptor-α (ER-α) antagonists for attenuating horm2one-driven cell proliferation is a major treatment modality for breast cancers. To exploit any DNA repair deficiencies associated with endocrine therapy, we investigated the functional and physical interactions of ER-α with O(6)-methylguanine DNA methyltransferase (MGMT), a unique DNA repair protein that confers tumor resistance to various anticancer alkylating agents. The ER-α -positive breast cancer cell lines (MCF-7, T47D) and ER- negative cell lines (MDAMB-468, MDAMB-231), and established inhibitors of ER-α and MGMT, namely, ICI-182,780 (Faslodex) and O(6)-benzylguanine, respectively, were used to study MGMT- ER interactions. The MGMT gene promoter was found to harbor one full and two half estrogen-responsive elements (EREs) and two antioxidant-responsive elements (AREs). MGMT expression was upregulated by estrogen, downregulated by tamoxifen in Western blot and promoter-linked reporter assays. Similarly, both transient and stable transfections of Nrf-2 (nuclear factor-erythroid 2-related factor-2) increased the levels of MGMT protein and activity 3 to 4-fold reflecting novel regulatory nodes for this drug-resistance determinant. Of the different ER-α antagonists tested, the pure anti-estrogen fulvestrant was most potent in inhibiting the MGMT activity in a dose, time and ER-α dependent manner, similar to O(6)-benzylguanine. Interestingly, fulvestrant exposure led to a degradation of both ER-α and MGMT proteins and O(6)-benzylguanine also induced a specific loss of ER-α and MGMT proteins in MCF-7 and T47D breast cancer cells with similar kinetics. Immunoprecipitation revealed a specific association of ER-α and MGMT proteins in breast cancer cells. Furthermore, silencing of MGMT gene expression triggered a decrease in the levels of both MGMT and ER-α proteins. The involvement of proteasome in the drug-induced degradation of both proteins was also demonstrated

  18. New insights into estrogenic regulation of O6-methylguanine DNA-methyltransferase (MGMT) in human breast cancer cells: Co-degradation of ER-α and MGMT proteins by fulvestrant or O6-benzylguanine indicates fresh avenues for therapy

    Science.gov (United States)

    Paranjpe, Ameya; Bailey, Nathan I.; Konduri, Santhi; Bobustuc, George C.; Ali-Osman, Francis; Yusuf, Mohd. A.; Punganuru, Surendra R.; Madala, Hanumantha Rao; Basak, Debasish; Mostofa, AGM; Srivenugopal, Kalkunte S.

    2016-01-01

    Abstract Endocrine therapy using estrogen receptor-α (ER-α) antagonists for attenuating horm2one-driven cell proliferation is a major treatment modality for breast cancers. To exploit any DNA repair deficiencies associated with endocrine therapy, we investigated the functional and physical interactions of ER-α with O6-methylguanine DNA methyltransferase (MGMT), a unique DNA repair protein that confers tumor resistance to various anticancer alkylating agents. The ER-α -positive breast cancer cell lines (MCF-7, T47D) and ER- negative cell lines (MDAMB-468, MDAMB-231), and established inhibitors of ER-α and MGMT, namely, ICI-182,780 (Faslodex) and O6-benzylguanine, respectively, were used to study MGMT- ER interactions. The MGMT gene promoter was found to harbor one full and two half estrogen-responsive elements (EREs) and two antioxidant-responsive elements (AREs). MGMT expression was upregulated by estrogen, downregulated by tamoxifen in Western blot and promoter-linked reporter assays. Similarly, both transient and stable transfections of Nrf-2 (nuclear factor-erythroid 2-related factor-2) increased the levels of MGMT protein and activity 3 to 4-fold reflecting novel regulatory nodes for this drug-resistance determinant. Of the different ER-α antagonists tested, the pure anti-estrogen fulvestrant was most potent in inhibiting the MGMT activity in a dose, time and ER-α dependent manner, similar to O6-benzylguanine. Interestingly, fulvestrant exposure led to a degradation of both ER-α and MGMT proteins and O6-benzylguanine also induced a specific loss of ER-α and MGMT proteins in MCF-7 and T47D breast cancer cells with similar kinetics. Immunoprecipitation revealed a specific association of ER-α and MGMT proteins in breast cancer cells. Furthermore, silencing of MGMT gene expression triggered a decrease in the levels of both MGMT and ER-α proteins. The involvement of proteasome in the drug-induced degradation of both proteins was also demonstrated

  19. MGMT 30100: Management Career Lectures

    OpenAIRE

    Landis, Maureen Huffer

    2014-01-01

    Abstract: Management Career Lectures (MGMT 30100) is designed to help undergraduate management students with their overall career/professional development whether that focus on internship/job search processes or graduate school attendance. The course also supports the development, refinement and enrichment of the competencies within the “Launching Business Leaders” initiative. Students develop skills useful for the internship/job search process, gain knowledge that benefits short and long-ter...

  20. Temozolomide Resistance in Glioblastoma Cell Lines: Implication of MGMT, MMR, P-Glycoprotein and CD133 Expression.

    Science.gov (United States)

    Perazzoli, Gloria; Prados, Jose; Ortiz, Raul; Caba, Octavio; Cabeza, Laura; Berdasco, Maria; Gónzalez, Beatriz; Melguizo, Consolación

    2015-01-01

    The use of temozolomide (TMZ) has improved the prognosis for glioblastoma multiforme patients. However, TMZ resistance may be one of the main reasons why treatment fails. Although this resistance has frequently been linked to the expression of O6-methylguanine-DNA methyltransferase (MGMT) it seems that this enzyme is not the only molecular mechanism that may account for the appearance of drug resistance in glioblastoma multiforme patients as the mismatch repair (MMR) complex, P-glycoprotein, and/or the presence of cancer stem cells may also be implicated. Four nervous system tumor cell lines were used to analyze the modulation of MGMT expression and MGMT promoter methylation by TMZ treatment. Furthermore, 5-aza-2'-deoxycytidine was used to demethylate the MGMT promoter and O(6)-benzylguanine to block GMT activity. In addition, MMR complex and P-glycoprotein expression were studied before and after TMZ exposure and correlated with MGMT expression. Finally, the effect of TMZ exposure on CD133 expression was analyzed. Our results showed two clearly differentiated groups of tumor cells characterized by low (A172 and LN229) and high (SF268 and SK-N-SH) basal MGMT expression. Interestingly, cell lines with no MGMT expression and low TMZ IC50 showed a high MMR complex expression, whereas cell lines with high MGMT expression and high TMZ IC50 did not express the MMR complex. In addition, modulation of MGMT expression in A172 and LN229 cell lines was accompanied by a significant increase in the TMZ IC50, whereas no differences were observed in SF268 and SK-N-SH cell lines. In contrast, P-glycoprotein and CD133 was found to be unrelated to TMZ resistance in these cell lines. These results may be relevant in understanding the phenomenon of TMZ resistance, especially in glioblastoma multiforme patients laking MGMT expression, and may also aid in the design of new therapeutic strategies to improve the efficacy of TMZ in glioblastoma multiforme patients.

  1. Silencing of MGMT with small interference RNA reversed resistance in human BCUN-resistant glioma cell lines

    Institute of Scientific and Technical Information of China (English)

    XIE Si-ming; FANG Mao; GUO Hui; ZHONG Xue-yun

    2011-01-01

    Background Our previous study had cloned two glioma cell lines SWOZ1 and SWOZ2 isolated from parental glioma cell line SWO38.The 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) resistance of SWOZ1 was higher than that of SWOZ2.Since O6-methylguanine-DNA methyltransferase (MGMT) was thought to be closely related to BCNU resistance in glioma,this study aimed to explore the function of MGMT in glioma resistant to BCNU.Methods A BCNU resistant glioma cell line SWOZ2-BCNU was established.The expression of MGMT was detected in SWOZ1,SWOZ2 and SWOZ2-BCNU.Small interferencing RNA targeting MGMT was used to silence the expression of MGMT in resistant cell lines SWOZ1 and SWOZ2-BCNU.The cytotoxicity of BCNU to these cells was measured using the cell counting kit-8 assay.Statistical analysis was carried out by one-way analysis of variance in statistical package SPSS 13.0.Results The resistance of SWOZ1 and SWOZ2-BCNU against BCNU was 4.9-fold and 5.3-fold higher than that of SWOZ2.The results of quantitative RT-PCR and Western blotting confirmed that MGMT was both significantly increased in SWOZ1 and SWOZ2-BCNU compared to SOWZ2.After transfection with small interferencing RNA targeting MGMT,a decreased level of MGMT mRNA expression in SWOZ1 and SWOZ2-BCNU for more than 75% compared to negative control was found and confirmed by Western blotting.As a result,the resistance against BCNU was reversed for about 50% both in the BCNU-resistant cell lines SWOZ1 and SWOZ2-BCNU.Conclusions Silencing MGMT with specific small interferencing RNA can reverse the BCNU resistant phenotype in these glioma cell lines.MGMT may play an important role both in intrinsic and acquired BCNU-resistance in glioma.

  2. Towards a molecular classification of colorectal cancer: The role of MGMT

    Directory of Open Access Journals (Sweden)

    Parham eMinoo

    2013-10-01

    Full Text Available O6-methylguanine DNA methyltransferase (MGMT is a DNA repair enzyme with the ability to protect cells from DNA mutations by removing alkyl groups from the O6 position of guanine. Colon mucosa is exposed to the direct effects of environmental carcinogens and therefore maintaining a proficient DNA repair system is very important to stay protected against DNA mutagenesis. Loss of MGMT expression is almost exclusively associated with methylation of CpG islands in the MGMT gene promoter region which is found in approximately 40% of colorectal cancers. The role of MGMT loss in colorectal tumorigenesis is complex but numerous studies have documented methylation of this gene even in the normal appearing mucosa as well as in aberrant crypt foci, suggesting that MGMT methylation can be regarded as an early event or field defect in colon cancer neoplasia. The focus of this perspective is the role of MGMT in different pathways of colorectal carcinogenesis as well as the implication of this molecule in treatment decisions in colorectal cancer patients.

  3. MiR-221/222 target the DNA methyltransferase MGMT in glioma cells.

    Directory of Open Access Journals (Sweden)

    Cristina Quintavalle

    Full Text Available Glioblastoma multiforme (GBM is one of the most deadly types of cancer. To date, the best clinical approach for treatment is based on administration of temozolomide (TMZ in combination with radiotherapy. Much evidence suggests that the intracellular level of the alkylating enzyme O(6-methylguanine-DNA methyltransferase (MGMT impacts response to TMZ in GBM patients. MGMT expression is regulated by the methylation of its promoter. However, evidence indicates that this is not the only regulatory mechanism present. Here, we describe a hitherto unknown microRNA-mediated mechanism of MGMT expression regulation. We show that miR-221 and miR-222 are upregulated in GMB patients and that these paralogues target MGMT mRNA, inducing greater TMZ-mediated cell death. However, miR-221/miR-222 also increase DNA damage and, thus, chromosomal rearrangements. Indeed, miR-221 overexpression in glioma cells led to an increase in markers of DNA damage, an effect rescued by re-expression of MGMT. Thus, chronic miR-221/222-mediated MGMT downregulation may render cells unable to repair genetic damage. This, associated also to miR-221/222 oncogenic potential, may poor GBM prognosis.

  4. Prognostic significance of IDH-1 and MGMT in patients with glioblastoma: One step forward, and one step back?

    Directory of Open Access Journals (Sweden)

    Combs Stephanie E

    2011-09-01

    Full Text Available Abstract A group of 160 patients with primary glioblastoma treated with radiotherapy and temozolomide was analyzed for the impact of O6-methly-guanly-methyl-transferase (MGMT-promoter methylation as well as isocitrate dehydrogenase (IDH1-mutational status. Unexpectedly, overall survival or progression-free survival were not longer in the group with methylated MGMT-promoter as compared to patients without that methylation. IDH-1 mutations were significantly associated with increased overall survival.

  5. The tumoral A genotype of the MGMT rs34180180 single-nucleotide polymorphism in aggressive gliomas is associated with shorter patients' survival.

    Science.gov (United States)

    Fogli, Anne; Chautard, Emmanuel; Vaurs-Barrière, Catherine; Pereira, Bruno; Müller-Barthélémy, Mélanie; Court, Franck; Biau, Julian; Pinto, Afonso Almeida; Kémény, Jean-Louis; Khalil, Toufic; Karayan-Tapon, Lucie; Verrelle, Pierre; Costa, Bruno Marques; Arnaud, Philippe

    2016-02-01

    Malignant gliomas are the most common primary brain tumors. Grade III and IV gliomas harboring wild-type IDH1/2 are the most aggressive. In addition to surgery and radiotherapy, concomitant and adjuvant chemotherapy with temozolomide (TMZ) significantly improves overall survival (OS). The methylation status of the O(6)-methylguanine-DNA methyltransferase (MGMT) promoter is predictive of TMZ response and a prognostic marker of cancer outcome. However, the promoter regions the methylation of which correlates best with survival in aggressive glioma and whether the promoter methylation status predictive value could be refined or improved by other MGMT-associated molecular markers are not precisely known. In a cohort of 87 malignant gliomas treated with radiotherapy and TMZ-based chemotherapy, we retrospectively determined the MGMT promoter methylation status, genotyped single nucleotide polymorphisms (SNPs) in the promoter region and quantified MGMT mRNA expression level. Each of these variables was correlated with each other and with the patients' OS. We found that methylation of the CpG sites within MGMT exon 1 best correlated with OS and MGMT expression levels, and confirmed MGMT methylation as a stronger independent prognostic factor compared to MGMT transcription levels. Our main finding is that the presence of only the A allele at the rs34180180 SNP in the tumor was significantly associated with shorter OS, independently of the MGMT methylation status. In conclusion, in the clinic, rs34180180 SNP genotyping could improve the prognostic value of the MGMT promoter methylation assay in patients with aggressive glioma treated with TMZ.

  6. DNA methylation and histone acetylation regulate the expression of MGMT and chemosensitivity to temozolomide in malignant melanoma cell lines.

    Science.gov (United States)

    Chen, Ya-Ping; Hou, Xiao-Yang; Yang, Chun-Sheng; Jiang, Xiao-Xiao; Yang, Ming; Xu, Xi-Feng; Feng, Shou-Xin; Liu, Yan-Qun; Jiang, Guan

    2016-08-01

    Malignant melanoma is an aggressive, highly lethal dermatological malignancy. Chemoresistance and rapid metastasis limit the curative effect of multimodal therapies like surgery or chemotherapy. The suicide enzyme O6-methylguanine-DNA methyltransferase (MGMT) removes adducts from the O6-position of guanine to repair DNA damage. High MGMT expression is associated with resistance to therapy in melanoma. However, it is unknown if MGMT is regulated by DNA methylation or histone acetylation in melanoma. We examined the effects of the DNA methylation inhibitor 5-Aza-2'-deoxycytidine and histone deacetylase inhibitor Trichostatin A alone or in combination on MGMT expression and promoter methylation and histone acetylation in A375, MV3, and M14 melanoma cells. This study demonstrates that MGMT expression, CpG island methylation, and histone acetylation vary between melanoma cell lines. Combined treatment with 5-Aza-2'-deoxycytidine and Trichostatin A led to reexpression of MGMT, indicating that DNA methylation and histone deacetylation are associated with silencing of MGMT in melanoma. This study provides information on the role of epigenetic modifications in malignant melanoma that may enable the development of new strategies for treating malignant melanoma.

  7. Volumetric and MGMT parameters in glioblastoma patients: Survival analysis

    Directory of Open Access Journals (Sweden)

    Iliadis Georgios

    2012-01-01

    Full Text Available Abstract Background In this study several tumor-related volumes were assessed by means of a computer-based application and a survival analysis was conducted to evaluate the prognostic significance of pre- and postoperative volumetric data in patients harboring glioblastomas. In addition, MGMT (O6-methylguanine methyltransferase related parameters were compared with those of volumetry in order to observe possible relevance of this molecule in tumor development. Methods We prospectively analyzed 65 patients suffering from glioblastoma (GBM who underwent radiotherapy with concomitant adjuvant temozolomide. For the purpose of volumetry T1 and T2-weighted magnetic resonance (MR sequences were used, acquired both pre- and postoperatively (pre-radiochemotherapy. The volumes measured on preoperative MR images were necrosis, enhancing tumor and edema (including the tumor and on postoperative ones, net-enhancing tumor. Age, sex, performance status (PS and type of operation were also included in the multivariate analysis. MGMT was assessed for promoter methylation with Multiplex Ligation-dependent Probe Amplification (MLPA, for RNA expression with real time PCR, and for protein expression with immunohistochemistry in a total of 44 cases with available histologic material. Results In the multivariate analysis a negative impact was shown for pre-radiochemotherapy net-enhancing tumor on the overall survival (OS (p = 0.023 and for preoperative necrosis on progression-free survival (PFS (p = 0.030. Furthermore, the multivariate analysis confirmed the importance of PS in PFS and OS of patients. MGMT promoter methylation was observed in 13/23 (43.5% evaluable tumors; complete methylation was observed in 3/13 methylated tumors only. High rate of MGMT protein positivity (> 20% positive neoplastic nuclei was inversely associated with pre-operative tumor necrosis (p = 0.021. Conclusions Our findings implicate that volumetric parameters may have a significant role in

  8. MGMT in colorectal cancer: a promising component of personalized treatment.

    Science.gov (United States)

    Zhang, Le; Zeng, Jing; Zeng, Zhaolei; Wang, Fenghua; Wang, Deshen; Chen, Cui; Li, Cong; An, Xin; Xu, Ruihua; Huang, Peng; Ba, Yi; Li, Yuhong

    2016-08-01

    The identification of new, effective drugs is a pressing need in colorectal cancer (CRC) rescue therapy. Data examining O (6)-methylguanine-DNA-methyl transferase (MGMT) and its predictive role in temozolomide (TMZ) treatment in CRC are scarce. In this study, the effect of MGMT status on the cytotoxic sensitivity caused by TMZ was analyzed using cytology proliferation assays in colon cancer cell lines. MGMT protein expression was assessed with immunohistochemistry in 385 patients. Concordance between primary and metastatic sites and the role of MGMT status on survival were statistically analyzed. TMZ sensitivity was significantly affected by the level of MGMT protein expression. Of 385 cases, 13 (3.4 %) demonstrated loss of MGMT expression. However, low MGMT expression levels were significantly more common in signet ring cell carcinomas (p = 0.011). In 111 of 385 cases, the overall concordance of MGMT status between primary tumor and metastatic sites was 66.67 % (κ = 0.271, p MGMT expression for the irinotecan-based regimen (p = 0.025), but MGMT protein expression was not observed to be a prognostic factor. In conclusion, MGMT was an important in vitro predictor of TMZ activity in CRC. The rate of MGMT protein loss was low in metastatic CRC patients from China, and MGMT might be more commonly lost in signet ring cell carcinoma. The MGMT status at primary and metastatic sites was consistent, but the power of concordance was poor. Further study into these topics is warranted.

  9. MGMT 520 FINAL EXAM Week 8

    OpenAIRE

    Laynebaril

    2017-01-01

    MGMT 520 FINAL EXAM Week 8       Click Link Below To Buy:     http://hwcampus.com/shop/mgmt-520-final-exam-week-8/             (TCOs G and I) In the 1930s, after immigrating to the U.S. from a region in central Europe threatened by the onset of World War II, Luigi and Maria Spongee opened a bakery in Chicago. They specialized in snack cakes. Spongee Cup Cakes became so popular in the area that the family stopped being actual bakers and becam...

  10. Temozolomide Resistance in Glioblastoma Cell Lines: Implication of MGMT, MMR, P-Glycoprotein and CD133 Expression.

    Directory of Open Access Journals (Sweden)

    Gloria Perazzoli

    Full Text Available The use of temozolomide (TMZ has improved the prognosis for glioblastoma multiforme patients. However, TMZ resistance may be one of the main reasons why treatment fails. Although this resistance has frequently been linked to the expression of O6-methylguanine-DNA methyltransferase (MGMT it seems that this enzyme is not the only molecular mechanism that may account for the appearance of drug resistance in glioblastoma multiforme patients as the mismatch repair (MMR complex, P-glycoprotein, and/or the presence of cancer stem cells may also be implicated.Four nervous system tumor cell lines were used to analyze the modulation of MGMT expression and MGMT promoter methylation by TMZ treatment. Furthermore, 5-aza-2'-deoxycytidine was used to demethylate the MGMT promoter and O(6-benzylguanine to block GMT activity. In addition, MMR complex and P-glycoprotein expression were studied before and after TMZ exposure and correlated with MGMT expression. Finally, the effect of TMZ exposure on CD133 expression was analyzed.Our results showed two clearly differentiated groups of tumor cells characterized by low (A172 and LN229 and high (SF268 and SK-N-SH basal MGMT expression. Interestingly, cell lines with no MGMT expression and low TMZ IC50 showed a high MMR complex expression, whereas cell lines with high MGMT expression and high TMZ IC50 did not express the MMR complex. In addition, modulation of MGMT expression in A172 and LN229 cell lines was accompanied by a significant increase in the TMZ IC50, whereas no differences were observed in SF268 and SK-N-SH cell lines. In contrast, P-glycoprotein and CD133 was found to be unrelated to TMZ resistance in these cell lines.These results may be relevant in understanding the phenomenon of TMZ resistance, especially in glioblastoma multiforme patients laking MGMT expression, and may also aid in the design of new therapeutic strategies to improve the efficacy of TMZ in glioblastoma multiforme patients.

  11. Impact on prognosis of the regional distribution of MGMT methylation with respect to the CpG island methylator phenotype and age in glioma patients.

    Science.gov (United States)

    Mur, Pilar; Rodríguez de Lope, Ángel; Díaz-Crespo, Francisco Javier; Hernández-Iglesias, Teresa; Ribalta, Teresa; Fiaño, Concepción; García, Juan Fernando; Rey, Juan Antonio; Mollejo, Manuela; Meléndez, Bárbara

    2015-05-01

    Clinical and molecular prognostic factors in gliomas include age, IDH mutation, the glioma CpG island methylator phenotype (G-CIMP+) and promoter methylation of the O(6)-methylguanine DNA-methyltransferase (MGMT) gene. Among these markers, a predictive value was reported in glioblastomas (GBM) for MGMT promoter methylation, in particular in elderly GBM patients. In this study, methylation data from 46 glioma samples with the Illumina 450K platform were obtained and extended using external data to include a total of 247 glioma samples. Methylation analysis of the whole MGMT gene with this platform revealed two strongly survival-associated CpG regions within the promoter and the gene body, which were confirmed in a reported dataset of high grade-gliomas. Methylation at the promoter (CpG 25, cg12981137 and the prognostic model MGMT-STP27) and at the gene body CpG 165 (cg07933035), were significantly associated with better overall survival, and strongly correlated with G-CIMP+ status. In this series, the prognostic value of MGMT methylation at the promoter was not observed in G-CIMP- cases, although around 50 % of them were MGMT-methylated. These results were also obtained in an homogeneously-treated series of chemoradiated G-CIMP- GBMs analyzed by MSP and qMSP, and confirmed in a reported pyrosequencing-analyzed series of gliomas. Interestingly, in contrast to the MGMT promoter, gene body methylation was of prognostic value in G-CIMP-patients older than 65 years. Our study highlights the relevance of the prognostic value of the different regions of methylation throughout the MGMT gene that could be affected by specific G-CIMP profiles and age groups.

  12. Prognostic value of MGMT protein expression in glioblastoma excluding non-tumour cells from the analysis

    DEFF Research Database (Denmark)

    Dahlrot, Rikke H; Dowsett, Joseph; Fosmark, Sigurd

    2017-01-01

    approach. Pyrosequencing was performed in 157 patients. For validation we used GBM-patients from a Nordic Study (NS) investigating the effect of radiotherapy and different TMZ schedules. RESULTS: When divided at the median, patients with low expression of MGMT protein (AF-low) had the best prognosis (HR 1.......5, P = 0.01). Similar results were observed in the subgroup of patients receiving the Stupp regimen (HR 2.0, P = 0.001). In the NS-cohort a trend towards superior survival (HR 1.6, P = 0.08) was seen in patients with AF-low. Including MGMT promoter methylation status, we found for both cohorts...... that patients with methylated MGMT promoter and AF-low had the best outcome; median OS 23.1 and 20.0 months, respectively. CONCLUSION: Our data indicate that MGMT protein expression in tumour cells has an independent prognostic significance. Exclusion of non-tumour cells contributed to a more exact analysis...

  13. High IFIT1 expression predicts improved clinical outcome, and IFIT1 along with MGMT more accurately predicts prognosis in newly diagnosed glioblastoma.

    Science.gov (United States)

    Zhang, Jin-Feng; Chen, Yao; Lin, Guo-Shi; Zhang, Jian-Dong; Tang, Wen-Long; Huang, Jian-Huang; Chen, Jin-Shou; Wang, Xing-Fu; Lin, Zhi-Xiong

    2016-06-01

    Interferon-induced protein with tetratricopeptide repeat 1 (IFIT1) plays a key role in growth suppression and apoptosis promotion in cancer cells. Interferon was reported to induce the expression of IFIT1 and inhibit the expression of O-6-methylguanine-DNA methyltransferase (MGMT).This study aimed to investigate the expression of IFIT1, the correlation between IFIT1 and MGMT, and their impact on the clinical outcome in newly diagnosed glioblastoma. The expression of IFIT1 and MGMT and their correlation were investigated in the tumor tissues from 70 patients with newly diagnosed glioblastoma. The effects on progression-free survival and overall survival were evaluated. Of 70 cases, 57 (81.4%) tissue samples showed high expression of IFIT1 by immunostaining. The χ(2) test indicated that the expression of IFIT1 and MGMT was negatively correlated (r = -0.288, P = .016). Univariate and multivariate analyses confirmed high IFIT1 expression as a favorable prognostic indicator for progression-free survival (P = .005 and .017) and overall survival (P = .001 and .001), respectively. Patients with 2 favorable factors (high IFIT1 and low MGMT) had an improved prognosis as compared with others. The results demonstrated significantly increased expression of IFIT1 in newly diagnosed glioblastoma tissue. The negative correlation between IFIT1 and MGMT expression may be triggered by interferon. High IFIT1 can be a predictive biomarker of favorable clinical outcome, and IFIT1 along with MGMT more accurately predicts prognosis in newly diagnosed glioblastoma.

  14. Protein expression and methylation of MGMT, a DNA repair gene and their correlation with clinicopathological parameters in invasive ductal carcinoma of the breast.

    Science.gov (United States)

    Asiaf, Asia; Ahmad, Shiekh Tanveer; Malik, Ajaz Ahmad; Aziz, Shiekh Aejaz; Rasool, Zubaida; Masood, Akbar; Zargar, Mohammad Afzal

    2015-08-01

    Epigenetic mechanisms such as DNA methylation are being increasingly recognized to play an important role in cancer and may serve as a cancer biomarker. The aim of this study was to evaluate the promoter methylation status of MGMT (O6-methylguanine-DNA methyltransferase) and a possible correlation with the expression of MGMT and standard clinicopathological parameters in invasive ductal breast carcinoma patients (IDC) of Kashmir. Methylation-specific PCR was carried out to investigate the promoter methylation status of MGMT in breast tumors paired with the corresponding normal tissue samples from 128 breast cancer patients. The effect of promoter methylation on protein expression in the primary breast cancer and adjacent normal tissues was evaluated by immunohistochemistry (n = 128) and western blotting (n = 30). The frequency of tumor hypermethylation was 39.8 % and a significant difference in methylation frequency among breast tumors were found (p MGMT in 68/128 (53.1 %) tumors. MGMT promoter methylation mediated gene silencing was associated with loss of its protein expression (rs = -0.285, p = 0.001, OR = 3.38, 95 % CI = 1.59-7.17). A significant correlation was seen between loss of MGMT and lymph node involvement (p = 0.030), tumor grade (p MGMT methylation was found to be associated with tumor grade (p = 0.011), tumor stage (p = 0.009), and loss of ER (p = 0.003) and PR receptors (p = 0.009). To our knowledge, our findings, for the first time, in Kashmiri population, indicate that MGMT is aberrantly methylated in breast cancer and promoter hypermethylation could be attributed to silencing of MGMT gene expression in breast cancer. Our data suggests that MGMT promoter hypermethylation could have a potential function as molecular biomarker of breast oncogenesis. Also, based on their predictive value of response to therapy, the immunohistochemical evaluation and interpretation of MGMT may also help in future to

  15. Diminished expression of MGMT & RASSF1A genes in gastric cancer in ethnic population of Kashmir

    Science.gov (United States)

    Bhat, Arif Akbar; Wani, Hilal Ahmad; Waza, Ajaz Ahmad; Malik, Rawoof Ahmad; Masood, Akbar; Jeelani, Showkat; Kadla, Showkat

    2016-01-01

    Background Cancer initiation and progression are accompanied by profound changes in DNA. DNA methylation that was the first epigenetic alterations identified in cancer. DNA hypermethylation at promoter sites is closely associated with down regulation of protein and as major participant in the development and progression of series of human tumors. Therefore we hypothesized that promoter hypermethylation of RASSF1A & MGMT gene could influence susceptibility to gastric cancer (GC) as well, and we conducted this study to test the hypothesis in Kashmiri population. Methods A hospital based case-control study; including 200 GC cases and 200 matched controls from patients who went surgical resection. Promoter hypermethylation was determined by Methylation Specific Polymerase chain reaction. The expression of MGMT & RASSF1A protein was examined by Western blotting technique. Results Frequency of promoter region hypermethylation of MGMT gene were 46.5% in cases and 5.5% in controls (PMGMT expression was found in 46.5% cases (P<0.05) while as loss of RASSF1A expression was found in 40.5% cases (P<0.05). In both genes a positive correlation was observed between promoter CpG island hypermethylation and down regulation of respective proteins. Conclusions These findings indicate that promoter hypermethylation at CpG island may be responsible for reduction of expression at protein level which may be an initial event in carcinogenesis and the progression of GC. PMID:28078123

  16. The Correlations between MGMT Promoter Methylation, NF-κB, TP53 and MGMT Protein Expression in Human Primary Glioblastomas%人原发胶质母细胞瘤组织中NF-κB、TP53及MGMT甲基化与MGMT蛋白表达的相关性研究

    Institute of Scientific and Technical Information of China (English)

    张钧; 滕颖; 齐雪岭; 李岩; 于春江; 张俊平

    2013-01-01

    背景与目的:胶质瘤化疗敏感性与一些分子表达相关.本研究检测和分析原发性胶质母细胞瘤(glioblastoma multiforme,GBM)患者肿瘤组织中核因子κB(NF-κB)、突变型P53(TP53)及O6甲基鸟嘌呤-DNA甲基转移酶(O6-methylguanine-DNA methyltransferase,MGMT)基因启动子区甲基化与MGMT蛋白表达的相关性,以探讨调控MGMT蛋白表达的作用机制.方法:采用甲基化特异性PCR方法(methylation specific PCR,MSP)检测我院收治的120例原发性GBM患者肿瘤组织标本MGMT基因启动子区甲基化;采用免疫组化方法检测NF-κB、TP53、MGMT蛋白表达情况.采用SPSS17.0软件及Spearman相关系数分析方法进行统计学分析.结果:免疫组化表明NF-κB、TP53表达与MGMT表达呈正相关(r=-0.244,r=-0.271,P均<0.05),NF-κB与TP53表达亦呈正相关(r=0.329,P<0.05).MSP结果显示MGMT基因启动子区甲基化率与MGMT蛋白表达强度无相关性.结论:转录因子NF-κB与TP53对原发性GBM肿瘤组织中MGMT蛋白表达可能存在正调控作用,而MGMT基因启动子区甲基化率与MGMT蛋白表达强度无相关性.

  17. Bifunctional alkylating agent-mediated MGMT-DNA cross-linking and its proteolytic cleavage in 16HBE cells.

    Science.gov (United States)

    Cheng, Jin; Ye, Feng; Dan, Guorong; Zhao, Yuanpeng; Wang, Bin; Zhao, Jiqing; Sai, Yan; Zou, Zhongmin

    2016-08-15

    Nitrogen mustard (NM), a bifunctional alkylating agent (BAA), contains two alkyl arms and can act as a cross-linking bridge between DNA and protein to form a DNA-protein cross-link (DPC). O(6)-methylguanine-DNA methyltransferase (MGMT), a DNA repair enzyme for alkyl adducts removal, is found to enhance cell sensitivity to BAAs and to promote damage, possibly due to its stable covalent cross-linking with DNA mediated by BAAs. To investigate MGMT-DNA cross-link (mDPC) formation and its possible dual roles in NM exposure, human bronchial epithelial cell line 16HBE was subjected to different concentrations of HN2, a kind of NM, and we found mDPC was induced by HN2 in a concentration-dependent manner, but the mRNA and total protein of MGMT were suppressed. As early as 1h after HN2 treatment, high mDPC was achieved and the level maintained for up to 24h. Quick total DPC (tDPC) and γ-H2AX accumulation were observed. To evaluate the effect of newly predicted protease DVC1 on DPC cleavage, we applied siRNA of MGMT and DVC1, MG132 (proteasome inhibitor), and NMS-873 (p97 inhibitor) and found that proteolysis plays a role. DVC1 was proven to be more important in the cleavage of mDPC than tDPC in a p97-dependent manner. HN2 exposure induced DVC1 upregulation, which was at least partially contributed to MGMT cleavage by proteolysis because HN2-induced mDPC level and DNA damage was closely related with DVC1 expression. Homologous recombination (HR) was also activated. Our findings demonstrated that MGMT might turn into a DNA damage promoter by forming DPC when exposed to HN2. Proteolysis, especially DVC1, plays a crucial role in mDPC repair.

  18. Comethylation of p16 and MGMT genes in colorectal carcinoma: Correlation with clinicopathological features and prognostic value

    Institute of Scientific and Technical Information of China (English)

    Koviljka Krtolica; Milena Krajnovic; Slavica Usaj-Knezevic; Dragan Babic; Dusan Jovanovic; Bogomir Dimitrijevic

    2007-01-01

    AIM: To investigate the significance of p16 and O6-methylguanine-DNA methyltransferase (MGMT) genes promoter hypermethylation and K-ras mutations on colorectal tumorigenesis and progression.METHODS: p16 and MGMT methylation status was examined on 47 tumor samples, and K-ras mutational status was examined on 85 tumor samples. For methylation analysis, a methylation specific PCR (MS-PCR)method was used.RESULTS: p16 and MGMT promoter methylation was found in 51% (24/47) and 43% (20/47) of CRCs,respectively, and the K-ras mutation was found in 44%(37/85) of CRCs. Comethylation ofp16 and MGMT genes was significantly associated with lower aggressiveness of the disease within a two-year period of observation.Only 27% of patients with simultaneous p16 and MGMT methylation showed the detectible occurrence of metastasis and/or death, compared to 67% of patients without double methylation or with no methylation (3/11vs 22/33, P < 0.05, x2-test). In addition, p16 and MGMT comethylation showed a trend toward an association with longer survival in patients with CRCs (35.5 ± 6.0 movs 23.1 ± 3.2 mo, P = 0.072, Log-rank test). Progression of the disease within a two-year period was observed in 66% of patients carrying the K-ras mutation, compared to only 19% of patients with wild type K-ras (29/44 vs7/37, P < 0.001, x2-test). The presence of the K-ras mutation significantly correlated to shortened overall survival (20.0 ± 1.9 mo vs 37.0 ± 1.8 mo, P < 0.001, Logrank test). The comethylation of p16 and MGMT genes was significantly associated with lower aggressiveness of the disease even when K-ras mutations were included in the analysis as an independent variable.CONCLUSION: Our data suggest that comethylation of promoters of p16 and MGMT genes could have a prognostic value in patients with CRC. Specifically,concurrent methylation of both genes correlates with better prognosis.

  19. Sensitivity to PRIMA-1MET is associated with decreased MGMT in human glioblastoma cells and glioblastoma stem cells irrespective of p53 status.

    Science.gov (United States)

    Patyka, Mariia; Sharifi, Zeinab; Petrecca, Kevin; Mansure, Jose; Jean-Claude, Bertrand; Sabri, Siham

    2016-09-13

    Alterations of the TP53 tumor suppressor gene occur in ~30% of primary glioblastoma (GBM) with a high frequency of missense mutations associated with the acquisition of oncogenic "gain-of-function" (GOF) mutant (mut)p53 activities. PRIMA-1MET/APR-246, emerged as a promising compound to rescue wild-type (wt)p53 function in different cancer types. Previous studies suggested the role of wtp53 in the negative regulation of the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT), a major determinant in resistance to therapy in GBM treatment. The potential role of MGMT in expression of p53 and the efficacy of PRIMA-1MET with respect to TP53 status and expression of MGMT in GBM remain unknown. We investigated response to PRIMA-1MET of wtp53/MGMT-negative (U87MG, A172), mutp53/MGMT-positive U138, LN-18, T98/Empty vector (T98/EV) and its isogenic MGMT/shRNA gene knockdown counterpart (T98/shRNA). We show that MGMT silencing decreased expression of mutp53/GOF in T98/shRNA. PRIMA-1MET further cleared T98/shRNA cells of mutp53, decreased proliferation and clonogenic potential, abrogated the G2 checkpoint control, increased susceptibility to apoptotic cell death, expression of GADD45A and sustained expression of phosphorylated Erk1/2. PRIMA-1MET increased expression of p21 protein in U87MG and A172 and promoted senescence in U87MG cell line. Importantly, PRIMA-1MET decreased relative cell numbers, disrupted the structure of neurospheres of patient-derived GBM stem cells (GSCs) and enabled activation of wtp53 with decreased expression of MGMT in MGMT-positive GSCs or decreased expression of mutp53. Our findings highlight the cell-context dependent effects of PRIMA-1MET irrespective of p53 status and suggest the role of MGMT as a potential molecular target of PRIMA-1MET in MGMT-positive GSCs.

  20. Multidrug Efflux Pumps Attenuate the Effect of MGMT Inhibitors.

    Science.gov (United States)

    Tomaszowski, Karl-Heinz; Schirrmacher, Ralf; Kaina, Bernd

    2015-11-02

    Various mechanisms of drug resistance attenuate the effectiveness of cancer therapeutics, including drug transport and DNA repair. The DNA repair protein O(6)-methylguanine-DNA methyltransferase (MGMT) is a key factor determining the resistance against alkylating anticancer drugs inducing the genotoxic DNA lesions O(6)-methylguanine and O(6)-chloroethylguanine, and MGMT inactivation or depletion renders cells more susceptible to treatment with methylating and chloroethylating agents. Highly specific and efficient inhibitors of the repair protein MGMT were designed, including O(6)-benzylguanine (O(6)BG) and O(6)-(4-bromothenyl)guanine (O(6)BTG) that are nontoxic on their own. Unfortunately, these inhibitors do not select between MGMT in normal and cancer cells, causing nontarget effects in the healthy tissue. Therefore, a targeting strategy for MGMT inhibitors is required. Here, we used O(6)BG and O(6)BTG conjugated to β-d-glucose (O(6)BG-Glu and O(6)BTG-Glu, respectively) in order to selectively inhibit MGMT in tumors, harnessing their high demand for glucose. Both glucose conjugates efficiently inhibited MGMT in several cancer cell lines, but with different extents of sensitization to DNA alkylating agents, with lomustine being more effective than temozolomide. We further show that the glucose conjugates are subject to ATP-binding cassette (ABC) transporter mediated efflux, involving P-glycoprotein, MRP1, and BCRP, which impacts the efficiency of MGMT inhibition. Surprisingly, also O(6)BG and O(6)BTG were subject to an active transport out of the cell. We also show that pharmacological inhibition of efflux transporters increases the induction of cell death following treatment with these MGMT inhibitors and temozolomide. We conclude that strategies of attenuating the efflux by ABC transporters are required for achieving successful MGMT targeting.

  1. A phase II study of bevacizumab and erlotinib after radiation and temozolomide in MGMT unmethylated GBM patients

    Science.gov (United States)

    Raizer, J. J.; Giglio, P.; Hu, J.; Groves, M.; Merrell, R.; Conrad, C.; Phuphanich, S.; Puduvalli, V. K.; Loghin, M.; Paleologos, N.; Yuan, Y.; Liu, D.; Rademaker, A.; Yung, W. K.; Vaillant, B.; Rudnick, J.; Chamberlain, M.; Vick, N.; Grimm, S.; Tremont-Lukats, I. W.; De Groot, J.; Aldape, K.; Gilbert, M. R.

    2016-01-01

    Survival for glioblastoma (GBM) patients with an unmethyated MGMT promoter in their tumor is generally worse than methylated MGMT tumors, as temozolomide (TMZ) response is limited. How to better treat patients with unmethylated MGMT is unknown. We performed a trial combining erlotinib and bevacizumab in unmethylated GBM patients after completion of radiation (RT) and TMZ. GBM patients with an unmethylated MGMT promoter were trial eligible. Patient received standard RT (60 Gy) and TMZ (75 mg/m2 × 6 weeks) after surgical resection of their tumor. After completion of RT they started erlotinib 150 mg daily and bevacizumab 10 mg/kg every 2 weeks until progression. Imaging evaluations occurred every 8 weeks. The primary endpoint was overall survival. Of the 48 unmethylated patients enrolled, 46 were evaluable (29 men and 17 women); median age was 55.5 years (29–75) and median KPS was 90 (70–100). All patients completed RT with TMZ. The median number of cycles (1 cycle was 4 weeks) was 8 (2–47). Forty-one patients either progressed or died with a median progression free survival of 9.2 months. At a follow up of 33 months the median overall survival was 13.2 months. There were no unexpected toxicities and most observed toxicities were categorized as CTC grade 1 or 2. The combination of erlotinib and bevacizumab is tolerable but did not meet our primary endpoint of increasing survival. Importantly, more trials are needed to find better therapies for GBM patients with an unmethylated MGMT promoter. PMID:26476729

  2. DGKI methylation status modulates the prognostic value of MGMT in glioblastoma patients treated with combined radio-chemotherapy with temozolomide.

    Directory of Open Access Journals (Sweden)

    Amandine Etcheverry

    Full Text Available BACKGROUND: Consistently reported prognostic factors for glioblastoma (GBM are age, extent of surgery, performance status, IDH1 mutational status, and MGMT promoter methylation status. We aimed to integrate biological and clinical prognostic factors into a nomogram intended to predict the survival time of an individual GBM patient treated with a standard regimen. In a previous study we showed that the methylation status of the DGKI promoter identified patients with MGMT-methylated tumors that responded poorly to the standard regimen. We further evaluated the potential prognostic value of DGKI methylation status. METHODS: 399 patients with newly diagnosed GBM and treated with a standard regimen were retrospectively included in this study. Survival modelling was performed on two patient populations: intention-to-treat population of all included patients (population 1 and MGMT-methylated patients (population 2. Cox proportional hazard models were fitted to identify the main prognostic factors. A nomogram was developed for population 1. The prognostic value of DGKI promoter methylation status was evaluated on population 1 and population 2. RESULTS: The nomogram-based stratification of the cohort identified two risk groups (high/low with significantly different median survival. We validated the prognostic value of DGKI methylation status for MGMT-methylated patients. We also demonstrated that the DGKI methylation status identified 22% of poorly responding patients in the low-risk group defined by the nomogram. CONCLUSIONS: Our results improve the conventional MGMT stratification of GBM patients receiving standard treatment. These results could help the interpretation of published or ongoing clinical trial outcomes and refine patient recruitment in the future.

  3. MGMT Expression Predicts PARP-Mediated Resistance to Temozolomide.

    Science.gov (United States)

    Erice, Oihane; Smith, Michael P; White, Rachel; Goicoechea, Ibai; Barriuso, Jorge; Jones, Chris; Margison, Geoffrey P; Acosta, Juan C; Wellbrock, Claudia; Arozarena, Imanol

    2015-05-01

    Melanoma and other solid cancers are frequently resistant to chemotherapies based on DNA alkylating agents such as dacarbazine and temozolomide. As a consequence, clinical responses are generally poor. Such resistance is partly due to the ability of cancer cells to use a variety of DNA repair enzymes to maintain cell viability. Particularly, the expression of MGMT has been linked to temozolomide resistance, but cotargeting MGMT has proven difficult due to dose-limiting toxicities. Here, we show that the MGMT-mediated resistance of cancer cells is profoundly dependent on the DNA repair enzyme PARP. Both in vitro and in vivo, we observe that MGMT-positive cancer cells strongly respond to the combination of temozolomide and PARP inhibitors (PARPi), whereas MGMT-deficient cells do not. In melanoma cells, temozolomide induced an antiproliferative senescent response, which was greatly enhanced by PARPi in MGMT-positive cells. In summary, we provide compelling evidence to suggest that the stratification of patients with cancer upon the MGMT status would enhance the success of combination treatments using temozolomide and PARPi.

  4. [Effects of 5-Aza-2'-deoxycytidine and trichostatin A on P16, hMLH1 and MGMT genes and DNA methylation in human gastric cancer cells].

    Science.gov (United States)

    Meng, Chun-feng; Zhu, Xin-jiang; Dai, Dong-qiu; Peng, Guo

    2009-09-01

    To investigate the effects of 5-Aza-2'-deoxycytidine (5-Aza-dC) and trichostatin A (TSA) on DNA methylation and expression of P16, hMLH1 and MGMT genes in the human gastric cancer cell line MGC-803, and to explore the mechanism of P16, hMLH1 and MGMT gene silencing in human gastric cancer cells. MGC-803 cells were cultured in RPMI-1640 medium and were treated with 5-Aza-dC or TSA. Methylation-specific polymerase chain reaction (MS-PCR) was used to detect the promoter methylation status of P16, hMLH1 and MGMT genes. RT-PCR was used to detect the mRNA expressions of P16, hMLH1 and MGMT. Promoter hypermethylation of P16, hMLH1 and MGMT genes were detected in MGC-803 cells, and mRNA expressions of P16, hMLH1 and MGMT were absent before treatment. After treatment with 5-Aza-dC, the promoter region of the P16, hMLH1 and MGMT gene exhibited a demethylation status, and their mRNA expressions were increased. The treatment with TSA had no effects on DNA demethylation or restoration of P16 or hMLH1 expression. P16, hMLH1 and MGMT mRNA relative expression levels after treatment with a combination of 5-Aza-dC and TSA were 0.412+/-0.030, 0.397+/-0.024 and 0.553+/-0.043 respectively, which were higher than those after 5-Aza-dC treatment alone (0.221+/-0.022, 0.214+/-0.018 and 0.156+/-0.017, all Pmechanism of P16, hMLH1 and MGMT gene silencing in human gastric cancer cells. Treatment with 5-Aza-dC alone or the combination of 5-Aza-dC and TSA can reactivate the expressions of these genes.

  5. Correlation of MLH1 and MGMT methylation levels between peripheral blood leukocytes and colorectal tissue DNA samples in colorectal cancer patients.

    Science.gov (United States)

    Li, Xia; Wang, Yibaina; Zhang, Zuoming; Yao, Xiaoping; Ge, Jie; Zhao, Yashuang

    2013-11-01

    CpG island methylation in the promoter regions of the DNA mismatch repair gene mutator L homologue 1 (MLH1) and DNA repair gene O(6)-methylguanine-DNA methyltransferase (MGMT) genes has been shown to occur in the leukocytes of peripheral blood and colorectal tissue. However, it is unclear whether the methylation levels in the blood leukocytes and colorectal tissue are correlated. The present study analyzed and compared the levels of MGMT and MLH1 gene methylation in the leukocytes of peripheral blood and colorectal tissues obtained from patients with colorectal cancer (CRC). The methylation levels of MGMT and MLH1 were examined using methylation-sensitive high-resolution melting (MS-HRM) analysis. A total of 44 patients with CRC were selected based on the MLH1 and MGMT gene methylation levels in the leukocytes of the peripheral blood. Corresponding colorectal tumor and normal tissues were obtained from each patient and the DNA methylation levels were determined. The correlation coefficients were evaluated using Spearman's rank test. Agreement was determined by generalized κ-statistics. Spearman's rank correlation coefficients (r) for the methylation levels of the MGMT and MLH1 genes in the leukocytes of the peripheral blood and normal colorectal tissue were 0.475 and 0.362, respectively (P=0.001 and 0.016, respectively). The agreement of the MGMT and MLH1 gene methylation levels in the leukocytes of the peripheral blood and normal colorectal tissue were graded as fair and poor (κ=0.299 and 0.126, respectively). The methylation levels of MGMT and MLH1 were moderately and weakly correlated between the patient-matched leukocytes and the normal colorectal tissue, respectively. Blood-derived DNA methylation measurements may not always represent the levels of normal colorectal tissue methylation.

  6. Promoting Quantitative Literacy in an Online College Algebra Course

    Science.gov (United States)

    Tunstall, Luke; Bossé, Michael J.

    2016-01-01

    College algebra (a university freshman level algebra course) fulfills the quantitative literacy requirement of many college's general education programs and is a terminal course for most who take it. An online problem-based learning environment provides a unique means of engaging students in quantitative discussions and research. This article…

  7. Expressions of MGMT and Survivin in Colorectal Carcinoma

    Institute of Scientific and Technical Information of China (English)

    QI Xiao-li; WANG Fa-liang; BO Ai-hua; HOU Jin-chao; NIU Shu-lei

    2008-01-01

    Objective:To investigate the expressions of O6-methyguanine-DNA methytransferase(MGMT) and Survivin in colorectal carcinoma and their clinical significance.Methods:Formalin-fixed,paraffin-embedded specimens from polypus and colorectal carcinoma were examined with streptavidin-biotin peroxidase(S-P)immunohistochemical technique for the expressions of MGMT and Survivin.Results:We found that there were significant differences in MGMT and Survivin between polypus and colorectal carcinoma.Expression of MGMT was correlated with ages and lymph node metastasis while Survivin was associated with lymph node metastasis only.Meanwhile,the expression of MGMT was correlated with Survivin (P<0.01,r=0.65).But there was no significant difference between male and female and the different depth of infiltration.Conclusion:It is concluded that the abnormal expressions of MGMT and Survivin were associated with the degree of malignancy of colorectal tumor.They possibly could be useful indexes for the primary screening and prognosis of colorectal carcinoma.ExaminatiOn of them may have an important guiding significance in the chemotherapy strategy.

  8. The effects of tumor treating fields and temozolomide in MGMT expressing and non-expressing patient-derived glioblastoma cells.

    Science.gov (United States)

    Clark, Paul A; Gaal, Jordan T; Strebe, Joslyn K; Pasch, Cheri A; Deming, Dustin A; Kuo, John S; Robins, H Ian

    2017-02-01

    A recent Phase 3 study of newly diagnosed glioblastoma (GBM) demonstrated the addition of tumor treating fields (TTFields) to temozolomide (TMZ) after combined radiation/TMZ significantly increased survival and progression free survival. Preliminary data suggested benefit with both methylated and unmethylated O-6-methylguanine-DNA methyl-transferase (MGMT) promoter status. To date, however, there have been no studies to address the potential interactions of TTFields and TMZ. Thus, the effects of TTFields and TMZ were studied in vitro using patient-derived GBM stem-like cells (GSCs) including MGMT expressing (TMZ resistant: 12.1 and 22GSC) and non-MGMT expressing (TMZ sensitive: 33 and 114GSC) lines. Dose-response curves were constructed using cell proliferation and sphere-forming assays. Results demonstrated a ⩾10-fold increase in TMZ resistance of MGMT-expressing (12.1GSCs: IC50=160μM; 22GSCs: IC50=44μM) compared to MGMT non-expressing (33GSCs: IC50=1.5μM; 114GSCs: IC50=5.2μM) lines. TTFields inhibited 12.1 GSC proliferation at all tested doses (50-500kHz) with an optimal frequency of 200kHz. At 200kHz, TTFields inhibited proliferation and tumor sphere formation of both MGMT GSC subtypes at comparable levels (12.1GSC: 74±2.9% and 38±3.2%, respectively; 22GSC: 61±11% and 38±2.6%, respectively; 33GSC: 56±9.5% and 60±7.1%, respectively; 114 GSC: 79±3.5% and 41±4.3%, respectively). In combination, TTFields (200kHz) and TMZ showed an additive anti-neoplastic effect with equal efficacy for TTFields in both cell types (i.e., ± MGMT expression) with no effect on TMZ resistance. This is the first demonstration of the effects of TTFields on cancer stem cells. The expansion of such studies may have clinical implications.

  9. Correlation of MGMT with Glioma:An Experimental Study%MGMT与脑胶质瘤相关性的实验研究

    Institute of Scientific and Technical Information of China (English)

    张露勇; 罗菲亚; 胡培丽; 单纯; 李锐

    2015-01-01

    目的:通过分析探讨O6-甲基鸟嘌呤-DNA甲基转移酶( MGMT)基因启动子甲基化与MGMT蛋白表达的情况,以期为脑胶质瘤的临床个体化治疗提供一定的理论基础。方法:收集45例脑胶质瘤和11例正常脑组织石蜡标本,采用免疫组化方法分别检测MGMT在56例标本中的表达情况,采用甲基化特异性PCR( MSP)方法检测45例脑胶质瘤中MGMT基因启动子甲基化情况。结果:脑胶质瘤组织与正常脑组织中MGMT的表达差异有统计学意义。不同级别胶质瘤之间的MGMT表达差异无统计学意义。胶质瘤中MGMT的表达与患者的性别及年龄之间的差异无统计学意义。胶质瘤中MGMT蛋白表达与MGMT基因启动子甲基化存在负相关。不同级别脑胶质瘤中MGMT基因启动子甲基化的表达差异无统计学意义。结论:MGMT的表达与肿瘤的恶性程度无相关性,但与烷化剂耐药有关。临床上为患者制订个性化治疗方案时,不能单独考虑性别、年龄的因素。使用烷化剂化疗前测定肿瘤细胞的MGMT活性具有一定的指导意义。%OBJECTIVE:To explore the O6-methylguanine DNA-methyltransferase ( MGMT ) gene promoter methylation and MGMT protein expression in order to provide a theoretical basis for clinical individualized treatment of glioma.METHODS:45 glioma tissue paraffin specimens and 11 normal brain tissue paraffin specimens were collected for measurement of MGMT expression by immunohistochemical assay.MGMT gene promoter methylation in the 45 glioma specimens was detected by methylation specific PCR ( MSP ) .RESULTS: The expression of MGMT was statistically significant between glioma tissue and normal brain tissue.MGMT expression level was not significantly different between the different grade of gliomas.MGMT expression was not associated with patient's sex and age differences.MGMT protein expression in gliomas was negatively associated with MGMT gene promoter

  10. MGMT-independent temozolomide resistance in pediatric glioblastoma cells associated with a PI3-kinase-mediated HOX/stem cell gene signature

    DEFF Research Database (Denmark)

    Gaspar, Nathalie; Marshall, Lynley; Perryman, Lara

    2010-01-01

    Sensitivity to temozolomide is restricted to a subset of glioblastoma patients, with the major determinant of resistance being a lack of promoter methylation of the gene encoding the repair protein DNA methyltransferase MGMT, although other mechanisms are thought to be active. There are, however,...

  11. DNA repair methyltransferase (Mgmt) knockout mice are sensitive to the lethal effects of chemotherapeutic alkylating agents.

    NARCIS (Netherlands)

    B.J. Glassner (Brian); G. Weeda (Geert); J.M. Allan (James); J.L.M. Broekhof (Jose'); N.H.E. Carls (Nick); I. Donker (Ingrid); B.P. Engelward (Bevin); R.J. Hampson (Richard); R. Hersmus (Remko); M.J. Hickman (Mark); R.B. Roth (Richard); H.B. Warren (Henry); M.M. Wu (Mavis); J.H.J. Hoeijmakers (Jan); L.D. Samson (Leona)

    1999-01-01

    textabstractWe have generated mice deficient in O6-methylguanine DNA methyltransferase activity encoded by the murine Mgmt gene using homologous recombination to delete the region encoding the Mgmt active site cysteine. Tissues from Mgmt null mice displayed very low O6-methylguanine DNA methyltransf

  12. Expression of O(6)-methylguanine DNA methyltransferase (MGMT) and its clinical significance in gastroenteropancreatic neuroendocrine neoplasm.

    Science.gov (United States)

    Yang, Qiu-Chen; Wang, Yu-Hong; Lin, Yuan; Xue, Ling; Chen, Yuan-Jia; Chen, Min-Hu; Chen, Jie

    2014-01-01

    O(6)-methylguanine-DNA methyltransferase (MGMT) is a widespread DNA repair enzyme defending against mutation caused by guanine O(6)-alkylating agents. Until now, we know only little about the expression of MGMT in gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN). To study the expression of MGMT and its clinical significance in GEP-NEN, 174 specimens of GEP-NEN were examined, of which 152 specimens came from The First Affiliated Hospital, Sun Yat-sen University during October 1995 to November 2013, 22 specimens came from Peking Union Medical College Hospital during September 2004 to April 2010. MGMT protein was detected with EnVision immunohistochemical staining method. Clinicopathological factors were also collected and analyzed. We observed that the overall expression rate of MGMT was 83.9%. Over expression of MGMT protein was not associated with sex, age, functional status, primary tumor location, grading, classification, TNM stage and metastasis (P > 0.05). Kaplan-Meier analysis revealed that there was no significant difference in survival between MGMT-positive and MGMT-negative tumors of GEP-NEN patients (χ(2) = 0.887, P = 0.346). In multivariate analyses carried out by Cox proportional hazards regression model, MGMT expression was also not an independent predictors of survival. These results demonstrated that MGMT protein was highly expressed in GEP-NEN. MGMT deficiency rate was similar in pancreatic NEN and in gastrointestinal NEN. MGMT expression was not correlated with prognosis of GEP-NEN.

  13. Quantitative correlation between promoter methylation and messenger RNA levels of the reduced folate carrier

    Directory of Open Access Journals (Sweden)

    Kheradpour Albert

    2008-05-01

    Full Text Available Abstract Background Methotrexate (MTX uptake is mediated by the reduced folate carrier (RFC. Defective drug uptake in association with decreased RFC expression is a common mechanism of MTX resistance in many tumor types. Heavy promoter methylation was previously identified as a basis for the complete silencing of RFC in MDA-MB-231 breast cancer cells, its role and prevalence in RFC transcription regulation are, however, not widely studied. Methods In the current study, RFC promoter methylation was assessed using methylation specific PCR in a panel of malignant cell lines (n = 8, including MDA-MB-231, and M805, a MTX resistant cell line directly established from the specimen of a patient with malignant fibrohistocytoma, whom received multiple doses of MTX. A quantitative approach of real-time PCR for measuring the extent of RFC promoter methylation was developed, and was validated by direct bisulfite genomic sequencing. RFC mRNA levels were determined by quantitative real-time RT-PCR and were related to the extent of promoter methylation in these cell lines. Results A partial promoter methylation and RFC mRNA down-regulation were observed in M805. Using the quantitative approach, a reverse correlation (correlation coefficient = -0.59, p Conclusion This study further suggests that promoter methylation is a potential basis for MTX resistance. The quantitative correlation identified in this study implies that promoter methylation is possibly a mechanism involved in the fine regulation of RFC transcription.

  14. Quantitative methods used in Australian health promotion research: a review of publications from 1992-2002.

    Science.gov (United States)

    Smith, Ben J; Zehle, Katharina; Bauman, Adrian E; Chau, Josephine; Hawkshaw, Barbara; Frost, Steven; Thomas, Margaret

    2006-04-01

    This study examined the use of quantitative methods in Australian health promotion research in order to identify methodological trends and priorities for strengthening the evidence base for health promotion. Australian health promotion articles were identified by hand searching publications from 1992-2002 in six journals: Health Promotion Journal of Australia, Australian and New Zealand journal of Public Health, Health Promotion International, Health Education Research, Health Education and Behavior and the American Journal of Health Promotion. The study designs and statistical methods used in articles presenting quantitative research were recorded. 591 (57.7%) of the 1,025 articles used quantitative methods. Cross-sectional designs were used in the majority (54.3%) of studies with pre- and post-test (14.6%) and post-test only (9.5%) the next most common designs. Bivariate statistical methods were used in 45.9% of papers, multivariate methods in 27.1% and simple numbers and proportions in 25.4%. Few studies used higher-level statistical techniques. While most studies used quantitative methods, the majority were descriptive in nature. The study designs and statistical methods used provided limited scope for demonstrating intervention effects or understanding the determinants of change.

  15. Expression Silence of DNA Repair Gene hMGMT Induced by RNA Interference

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-ying; LAI Yan-dong

    2007-01-01

    Objective: MGMT protein expression has been associated with tumor resistance to alkylating agents. The objective of this paper is to construct the RNA interference vector which can specifically induce the expression silence of human DNA repair gene hMGMT. Methods: The hMGMT specific siRNA expression cassette was made by two steps PCR, linked with pUC19 to get pU6-MGMTi, co-transfected with pEGFP-C1 into 16HBE and screened by G418. The MGMT mRNA and protein levels were detected by RT-PCR and Western Blot respectively. Results: hMGMT specific RNA interfere vector pU6-MGMTi was constructed successfully. In transfected 16HBE cells MGMT mRNA level could hardly be detected and the protein level was only 10% of control. Conclusion: MGMT specific RNAi expression cassette can effectively inhibit MGMT expression. MGMT silence cell line was built by co-transfection technology, which offered condition for studying the gene function of MGMT.

  16. Enhanced MGMT expression contributes to temozolomide resistance in glioma stem-like cells

    Institute of Scientific and Technical Information of China (English)

    Zhi-Kun Qiu; Dong Shen; Yin-Sheng Chen; Qun-Ying Yang; Cheng-Cheng Guo; Bing-Hong Feng; Zhong-Ping Chen

    2014-01-01

    O6-methylguanine DNA methyltransferase (MGMT) can remove DNA alkylation adducts, thereby repairing damaged DNA and contributing to the drug resistance of gliomas to alkylating agents. In addition, glioma stem-like cells (GSCs) have been demonstrated to be involved in the recurrence and treatment resistance of gliomas. In this study, we aimed to investigate MGMT expression and regulatory mechanisms in GSCs and the association of MGMT with temozolomide (TMZ) sensitivity. GSCs were enriched from one MGMT-positive cellline (SF-767) and 7 MGMT-negative celllines (U251, SKMG-4, SKMG-1, SF295, U87, MGR1, and MGR2) through serum-free clone culture. GSCs from the U251G, SKMG-4G, SF295G, and SKMG-1G cell lines became MGMT-positive, but those from the U87G, MGR1G, and MGR2G cell lines remained MGMT-negative. However, al the GSCs and their parental glioma celllines were positive for nuclear factor-κB (NF-κB). In addition, GSCs were more resistant to TMZ than their parental glioma cell lines (P 0.05). When we treated the MGMT-positive GSCs with TMZ plus MG-132 (an NF-κB inhibitor), the antitumor activity was significantly enhanced compared to that of GSCs treated with TMZ alone (P < 0.05). Furthermore, we found that MGMT expression decreased through the down-regulation of NF-κB expression by MG-132. Our results show that MG-132 may inhibit NF-κB expression and further decrease MGMT expression, resulting in a synergistic effect on MGMT-positive GSCs. These results indicate that enhanced MGMT expression contributes to TMZ resistance in MGMT-positive GSCs.

  17. Personalized care in neuro-oncology coming of age: why we need MGMT and 1p/19q testing for malignant glioma patients in clinical practice

    Science.gov (United States)

    Weller, Michael; Stupp, Roger; Hegi, Monika E.; van den Bent, Martin; Tonn, Joerg C.; Sanson, Marc; Wick, Wolfgang; Reifenberger, Guido

    2012-01-01

    Histological subtyping and grading by malignancy are the cornerstones of the World Health Organization (WHO) classification of tumors of the central nervous system. They shall provide clinicians with guidance as to the course of disease to be expected and the choices of treatment to be made. Nonetheless, patients with histologically identical tumors may have very different outcomes, notably in patients with astrocytic and oligodendroglial gliomas of WHO grades II and III. In gliomas of adulthood, 3 molecular markers have undergone extensive studies in recent years: 1p/19q chromosomal codeletion, O6-methylguanine methyltransferase (MGMT) promoter methylation, and mutations of isocitrate dehydrogenase (IDH) 1 and 2. However, the assessment of these molecular markers has so far not been implemented in clinical routine because of the lack of therapeutic implications. In fact, these markers were considered to be prognostic irrespective of whether patients were receiving radiotherapy (RT), chemotherapy, or both (1p/19q, IDH1/2), or of limited value because testing is too complex and no chemotherapy alternative to temozolomide was available (MGMT). In 2012, this situation has changed: long-term follow-up of the Radiation Therapy Oncology Group 9402 and European Organisation for Research and Treatment of Cancer 26951 trials demonstrated an overall survival benefit from the addition to RT of chemotherapy with procarbazine/CCNU/vincristine confined to patients with anaplastic oligodendroglial tumors with (vs without) 1p/19q codeletion. Furthermore, in elderly glioblastoma patients, the NOA-08 and the Nordic trial of RT alone versus temozolomide alone demonstrated a profound impact of MGMT promoter methylation on outcome by therapy and thus established MGMT as a predictive biomarker in this patient population. These recent results call for the routine implementation of 1p/19q and MGMT testing at least in subpopulations of malignant glioma patients and represent an encouraging

  18. SENSITIZATION OF ACNU KILLING EFFECTS ON HeLa S3 CELLS BY MGMT ANTISENSE RNA TRANSFECTION

    Institute of Scientific and Technical Information of China (English)

    季守平; 由英; 吴英; 陈建敏; 杨军; 章扬培

    1998-01-01

    O’-methylguanlne-DNA-msthybransferase(MGMT)plays a very important role in the ceUular resistsnce to uitrosoureas drugs. Inhibition of MGMT might be a useful approach in tumor chemotherapy. In this study, the depletlon vii MGMT activity hy retroviral-mediated antisense RNA transfectkm were reported. Three retroviral vectors expressing MGMT antisense RNA were constructed and transfected into HeLa S3 cells. The difference of MGMT mRNA, MGMT activity as well as cellular resistance to ACNU before and after transtecfion were ohserved. It was found that antisense RNA targeting 5''region and whole length of MGMT mRNA could partially deplete MGMT activity and enhance killing effects of ACNU.However, 3'' region antisense RNA had no effect on MGMT modulation.

  19. Analysis and Discussion about Quantitative Grading Standard for Salary Promotion of Agricultural Scientific Researchers

    Institute of Scientific and Technical Information of China (English)

    Xingquan; ZOU; Jia; ZHANG; Chengxing; YAN; Mingjing; QING

    2013-01-01

    The existing performance salary system has several grades in the same job title. When the number of workers qualified for promotion is more than the target,quantitative grading is usually adopted to determine salary promotion personnel. Scientific,fair and reasonable grading content and standard directly concern income and remuneration of scientific researchers,and also concern recognition and respect degree of contribution made by scientific researchers. Therefore,quantitative grading standard is of the utmost importance to keeping stability,arousing enthusiasm and creativity of scientific researchers,and promoting smooth development of scientific research. Achievements awarded,papers published and project research can reflect scientific research level,ability and working performance of agricultural scientific researchers. This paper takes these three items as examples,analyzes,discusses and compares the establishment and evaluation of quantitative grading standard. It states that " one yardstick" and " one vote veto system" should be adhered to when evaluating using the quantitative grading standard. It is expected to provide reference for organizations of the same trade in establishing quantitative grading standard and conducting evaluation.

  20. Quantitative Analyses of Core Promoters Enable Precise Engineering of Regulated Gene Expression in Mammalian Cells.

    Science.gov (United States)

    Ede, Christopher; Chen, Ximin; Lin, Meng-Yin; Chen, Yvonne Y

    2016-05-20

    Inducible transcription systems play a crucial role in a wide array of synthetic biology circuits. However, the majority of inducible promoters are constructed from a limited set of tried-and-true promoter parts, which are susceptible to common shortcomings such as high basal expression levels (i.e., leakiness). To expand the toolbox for regulated mammalian gene expression and facilitate the construction of mammalian genetic circuits with precise functionality, we quantitatively characterized a panel of eight core promoters, including sequences with mammalian, viral, and synthetic origins. We demonstrate that this selection of core promoters can provide a wide range of basal gene expression levels and achieve a gradient of fold-inductions spanning 2 orders of magnitude. Furthermore, commonly used parts such as minimal CMV and minimal SV40 promoters were shown to achieve robust gene expression upon induction, but also suffer from high levels of leakiness. In contrast, a synthetic promoter, YB_TATA, was shown to combine low basal expression with high transcription rate in the induced state to achieve significantly higher fold-induction ratios compared to all other promoters tested. These behaviors remain consistent when the promoters are coupled to different genetic outputs and different response elements, as well as across different host-cell types and DNA copy numbers. We apply this quantitative understanding of core promoter properties to the successful engineering of human T cells that respond to antigen stimulation via chimeric antigen receptor signaling specifically under hypoxic environments. Results presented in this study can facilitate the design and calibration of future mammalian synthetic biology systems capable of precisely programmed functionality.

  1. Methylation of discrete regions of the O6-methylguanine DNA methyltransferase (MGMT) CpG island is associated with heterochromatinization of the MGMT transcription start site and silencing of the gene.

    OpenAIRE

    Watts, G S; Pieper, R O; Costello, J F; Peng, Y M; Dalton, W S; Futscher, B.W.

    1997-01-01

    O6-Methylguanine DNA methyltransferase (MGMT) repairs the mutagenic and cytotoxic O6-alkylguanine lesions produced by environmental carcinogens and the chemotherapeutic nitrosoureas. As such, MGMT-mediated repair of O6-alkylguanine lesions constitutes a major form of resistance to nitrosourea chemotherapy and makes control of MGMT expression of clinical interest. The variability of expression in cell lines and tissues, along with the ease with which the MGMT phenotype reverts under various co...

  2. MGMT-INDEPENDENT TEMOZOLOMIDE RESISTANCE IN PAEDIATRIC GLIOBLASTOMA CELLS ASSOCIATED WITH A PI3-KINASE-MEDIATED HOX / STEM CELL GENE SIGNATURE

    OpenAIRE

    Gaspar, Nathalie; Marshall, Lynley; Perryman, Lara; Bax, Dorine A; Little, Suzanne E.; Viana-Pereira, Marta; Swee Y Sharp; Vassal, Gilles; Pearson, Andrew D. J.; Rui M. Reis; Hargrave, Darren; Workman, Paul; Jones, Chris

    2010-01-01

    Sensitivity to temozolomide (TMZ) is restricted to a subset of glioblastoma patients, with the major determinant of resistance being a lack of promoter methylation of the gene encoding the repair protein DNA methyltransferase MGMT, although other mechanisms are thought to be active. There are, however, limited preclinical data in model systems derived from paediatric glioma patients. We have screened a series of cell lines for TMZ efficacy in vitro, and have investigated the differential mech...

  3. Wnt/β-catenin pathway regulates MGMT gene expression in cancer and inhibition of Wnt signalling prevents chemoresistance.

    Science.gov (United States)

    Wickström, Malin; Dyberg, Cecilia; Milosevic, Jelena; Einvik, Christer; Calero, Raul; Sveinbjörnsson, Baldur; Sandén, Emma; Darabi, Anna; Siesjö, Peter; Kool, Marcel; Kogner, Per; Baryawno, Ninib; Johnsen, John Inge

    2015-11-25

    The DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) is commonly overexpressed in cancers and is implicated in the development of chemoresistance. The use of drugs inhibiting MGMT has been hindered by their haematologic toxicity and inefficiency. As a different strategy to inhibit MGMT we investigated cellular regulators of MGMT expression in multiple cancers. Here we show a significant correlation between Wnt signalling and MGMT expression in cancers with different origin and confirm the findings by bioinformatic analysis and immunofluorescence. We demonstrate Wnt-dependent MGMT gene expression and cellular co-localization between active β-catenin and MGMT. Pharmacological or genetic inhibition of Wnt activity downregulates MGMT expression and restores chemosensitivity of DNA-alkylating drugs in mouse models. These findings have potential therapeutic implications for chemoresistant cancers, especially of brain tumours where the use of temozolomide is frequently used in treatment.

  4. Quantitative analysis of DNA methylation in the promoter region of the methylguanine-O(6) -DNA-methyltransferase gene by COBRA and subsequent native capillary gel electrophoresis.

    Science.gov (United States)

    Goedecke, Simon; Mühlisch, Jörg; Hempel, Georg; Frühwald, Michael C; Wünsch, Bernhard

    2015-12-01

    Along with histone modifications, RNA interference and delayed replication timing, DNA methylation belongs to the key processes in epigenetic regulation of gene expression. Therefore, reliable information about the methylation level of particular DNA fragments is of major interest. Herein the methylation level at two positions of the promoter region of the gene methylguanine-O(6) -DNA-Methyltransferase (MGMT) was investigated. Previously, it was demonstrated that the epigenetic status of this DNA region correlates with response to alkylating anticancer agents. An automated CGE method with LIF detection was established to separate the six DNA fragments resulting from combined bisulfite restriction analysis of the methylated and non-methylated MGMT promoter. In COBRA, the DNA was treated with bisulfite converting cytosine into uracil. During PCR uracil pairs with adenine, which changes the original recognition site of the restriction enzyme Taql. Artificial probes generated by mixing appropriate amounts of DNA after bisulfite treatment and PCR amplification were used for validation of the method. The methylation levels of these samples could be determined with high accuracy and precision. DNA samples prepared by mixing the corresponding clones first and then performing PCR amplification led to non-linear correlation between the corrected peak areas and the methylation levels. This effect is explained by slightly different PCR amplification of DNA with different sequences present in the mixture. The superiority of CGE over PAGE was clearly demonstrated. Finally, the established method was used to analyze the methylation levels of human brain tumor tissue samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Identification of the Structural Features of Guanine Derivatives as MGMT Inhibitors Using 3D-QSAR Modeling Combined with Molecular Docking

    Directory of Open Access Journals (Sweden)

    Guohui Sun

    2016-06-01

    Full Text Available DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT, which plays an important role in inducing drug resistance against alkylating agents that modify the O6 position of guanine in DNA, is an attractive target for anti-tumor chemotherapy. A series of MGMT inhibitors have been synthesized over the past decades to improve the chemotherapeutic effects of O6-alkylating agents. In the present study, we performed a three-dimensional quantitative structure activity relationship (3D-QSAR study on 97 guanine derivatives as MGMT inhibitors using comparative molecular field analysis (CoMFA and comparative molecular similarity indices analysis (CoMSIA methods. Three different alignment methods (ligand-based, DFT optimization-based and docking-based alignment were employed to develop reliable 3D-QSAR models. Statistical parameters derived from the models using the above three alignment methods showed that the ligand-based CoMFA (Qcv2 = 0.672 and Rncv2 = 0.997 and CoMSIA (Qcv2 = 0.703 and Rncv2 = 0.946 models were better than the other two alignment methods-based CoMFA and CoMSIA models. The two ligand-based models were further confirmed by an external test-set validation and a Y-randomization examination. The ligand-based CoMFA model (Qext2 = 0.691, Rpred2 = 0.738 and slope k = 0.91 was observed with acceptable external test-set validation values rather than the CoMSIA model (Qext2 = 0.307, Rpred2 = 0.4 and slope k = 0.719. Docking studies were carried out to predict the binding modes of the inhibitors with MGMT. The results indicated that the obtained binding interactions were consistent with the 3D contour maps. Overall, the combined results of the 3D-QSAR and the docking obtained in this study provide an insight into the understanding of the interactions between guanine derivatives and MGMT protein, which will assist in designing novel MGMT inhibitors with desired activity.

  6. Identification of the Structural Features of Guanine Derivatives as MGMT Inhibitors Using 3D-QSAR Modeling Combined with Molecular Docking.

    Science.gov (United States)

    Sun, Guohui; Fan, Tengjiao; Zhang, Na; Ren, Ting; Zhao, Lijiao; Zhong, Rugang

    2016-06-23

    DNA repair enzyme O⁶-methylguanine-DNA methyltransferase (MGMT), which plays an important role in inducing drug resistance against alkylating agents that modify the O⁶ position of guanine in DNA, is an attractive target for anti-tumor chemotherapy. A series of MGMT inhibitors have been synthesized over the past decades to improve the chemotherapeutic effects of O⁶-alkylating agents. In the present study, we performed a three-dimensional quantitative structure activity relationship (3D-QSAR) study on 97 guanine derivatives as MGMT inhibitors using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. Three different alignment methods (ligand-based, DFT optimization-based and docking-based alignment) were employed to develop reliable 3D-QSAR models. Statistical parameters derived from the models using the above three alignment methods showed that the ligand-based CoMFA (Qcv² = 0.672 and Rncv² = 0.997) and CoMSIA (Qcv² = 0.703 and Rncv² = 0.946) models were better than the other two alignment methods-based CoMFA and CoMSIA models. The two ligand-based models were further confirmed by an external test-set validation and a Y-randomization examination. The ligand-based CoMFA model (Qext² = 0.691, Rpred² = 0.738 and slope k = 0.91) was observed with acceptable external test-set validation values rather than the CoMSIA model (Qext² = 0.307, Rpred² = 0.4 and slope k = 0.719). Docking studies were carried out to predict the binding modes of the inhibitors with MGMT. The results indicated that the obtained binding interactions were consistent with the 3D contour maps. Overall, the combined results of the 3D-QSAR and the docking obtained in this study provide an insight into the understanding of the interactions between guanine derivatives and MGMT protein, which will assist in designing novel MGMT inhibitors with desired activity.

  7. Quantitative Methylation Profiles for Multiple Tumor Suppressor Gene Promoters in Salivary Gland Tumors

    Science.gov (United States)

    Durr, Megan L.; Mydlarz, Wojciech K.; Shao, Chunbo; Zahurak, Marianna L.; Chuang, Alice Y.; Hoque, Mohammad O.; Westra, William H.; Liegeois, Nanette J.; Califano, Joseph A.; Sidransky, David; Ha, Patrick K.

    2010-01-01

    Background Methylation profiling of tumor suppressor gene (TSGs) promoters is quickly becoming a powerful diagnostic tool for the early detection, prognosis, and even prediction of clinical response to treatment. Few studies address this in salivary gland tumors (SGTs); hence the promoter methylation profile of various TSGs was quantitatively assessed in primary SGT tissue to determine if tumor-specific alterations could be detected. Methodology DNA isolated from 78 tumor and 17 normal parotid gland specimens was assayed for promoter methylation status of 19 TSGs by fluorescence-based, quantitative methylation-specific PCR (qMSP). The data were utilized in a binary fashion as well as quantitatively (using a methylation quotient) allowing for better profiling and interpretation of results. Principal Findings The average number of methylation events across the studied genes was highest in salivary duct carcinoma (SDC), with a methylation value of 9.6, compared to the normal 4.5 (p<0.0003). There was a variable frequency and individual methylation quotient detected, depending on the TSG and the tumor type. When comparing normal, benign, and malignant SGTs, there was a statistically significant trend for increasing methylation in APC, Mint 1, PGP9.5, RAR-β, and Timp3. Conclusions/Significance Screening promoter methylation profiles in SGTs showed considerable heterogeneity. The methylation status of certain markers was surprisingly high in even normal salivary tissue, confirming the need for such controls. Several TSGs were found to be associated with malignant SGTs, especially SDC. Further study is needed to evaluate the potential use of these associations in the detection, prognosis, and therapeutic outcome of these rare tumors. PMID:20520817

  8. MGMT-independent temozolomide resistance in pediatric glioblastoma cells associated with a PI3-kinase-mediated HOX/stem cell gene signature.

    Science.gov (United States)

    Gaspar, Nathalie; Marshall, Lynley; Perryman, Lara; Bax, Dorine A; Little, Suzanne E; Viana-Pereira, Marta; Sharp, Swee Y; Vassal, Gilles; Pearson, Andrew D J; Reis, Rui M; Hargrave, Darren; Workman, Paul; Jones, Chris

    2010-11-15

    Sensitivity to temozolomide is restricted to a subset of glioblastoma patients, with the major determinant of resistance being a lack of promoter methylation of the gene encoding the repair protein DNA methyltransferase MGMT, although other mechanisms are thought to be active. There are, however, limited preclinical data in model systems derived from pediatric glioma patients. We screened a series of cell lines for temozolomide efficacy in vitro, and investigated the differential mechanisms of resistance involved. In the majority of cell lines, a lack of MGMT promoter methylation and subsequent protein overexpression were linked to temozolomide resistance. An exception was the pediatric glioblastoma line KNS42. Expression profiling data revealed a coordinated upregulation of HOX gene expression in resistant lines, especially KNS42, which was reversed by phosphoinositide 3-kinase pathway inhibition. High levels of HOXA9/HOXA10 gene expression were associated with a shorter survival in pediatric high-grade glioma patient samples. Combination treatment in vitro of pathway inhibition and temozolomide resulted in a highly synergistic interaction in KNS42 cells. The resistance gene signature further included contiguous genes within the 12q13-q14 amplicon, including the Akt enhancer PIKE, significantly overexpressed in the KNS42 line. These cells were also highly enriched for CD133 and other stem cell markers. We have thus shown an in vitro link between phosphoinositide 3-kinase-mediated HOXA9/HOXA10 expression, and a drug-resistant, progenitor cell phenotype in MGMT-independent pediatric glioblastoma.

  9. Signal integration by the CYP1A1 promoter--a quantitative study.

    Science.gov (United States)

    Schulthess, Pascal; Löffler, Alexandra; Vetter, Silvia; Kreft, Luisa; Schwarz, Michael; Braeuning, Albert; Blüthgen, Nils

    2015-06-23

    Genes involved in detoxification of foreign compounds exhibit complex spatiotemporal expression patterns in liver. Cytochrome P450 1A1 (CYP1A1), for example, is restricted to the pericentral region of liver lobules in response to the interplay between aryl hydrocarbon receptor (AhR) and Wnt/β-catenin signaling pathways. However, the mechanisms by which the two pathways orchestrate gene expression are still poorly understood. With the help of 29 mutant constructs of the human CYP1A1 promoter and a mathematical model that combines Wnt/β-catenin and AhR signaling with the statistical mechanics of the promoter, we systematically quantified the regulatory influence of different transcription factor binding sites on gene induction within the promoter. The model unveils how different binding sites cooperate and how they establish the promoter logic; it quantitatively predicts two-dimensional stimulus-response curves. Furthermore, it shows that crosstalk between Wnt/β-catenin and AhR signaling is crucial to understand the complex zonated expression patterns found in liver lobules. This study exemplifies how statistical mechanical modeling together with combinatorial reporter assays has the capacity to disentangle the promoter logic that establishes physiological gene expression patterns. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. MGMT与恶性肿瘤%MGMT and cancer

    Institute of Scientific and Technical Information of China (English)

    崔灵芝; 章扬培; 宋三泰

    2004-01-01

    O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)是细胞中一种重要的DNA损伤修复酶,它在抵御烷化剂所致的细胞突变和死亡中起重要作用.本文综述了近年来关于MGMT的最新研究,内容包括MGMT的基因结构与功能,MGMT的分布及其影响因素,MGMT与肿瘤发生、发展及治疗的关系.

  11. Disruption of NF-κB signaling by fluoxetine attenuates MGMT expression in glioma cells

    Directory of Open Access Journals (Sweden)

    Song T

    2015-08-01

    Full Text Available Tao Song,1 Hui Li,2 Zhiliang Tian,3 Chaojiu Xu,4 Jingfang Liu,1 Yong Guo1 1Department of Neurosurgery, Xiangya Hospital, Central South University, 2Department of Immunology and Microbiology, Medical School of Jishou University, 3Department of Neurosurgery, 4Department of Oncology, The Hospital of Xiangxi Autonomous Prefecture, Jishou, People’s Republic of China Background: Resistance to temozolomide (TMZ in glioma is modulated by the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT. This study aimed to examine the effects of fluoxetine (FLT on MGMT expression in glioma cells and to investigate its underlying mechanisms.Materials and methods: Expression of MGMT, GluR1, or IκB kinase β (IKKβ was attenuated using short hairpin RNA-mediated gene knockdown. The 3-(4,5-dimethylthiazol -2-yl-2,5-diphenyltetrazolium bromide (MTT assay was used to evaluate the growth inhibition induced by FLT or TMZ. Terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling (TUNEL was conducted to detect apoptotic cells. Western blotting was conducted to analyze the protein expression of MGMT, IKKβ, and NF-κB/p65 following FLT treatment. The murine subcutaneous xenograft model was used to evaluate the combinational effect of TMZ and FLT.Results: FLT markedly reduced MGMT expression in glioma cells, which was independent of GluR1 receptor function. Further, FLT disrupted NF-κB/p65 signaling in glioma cells and consequently attenuated NF-κB/p65 activity in regulating MGMT expression. Importantly, FLT sensitized MGMT-expressing glioma cells to TMZ, as FLT enhanced TMZ’s ability to impair the in vitro tumorigenic potential and to induce apoptosis in glioma cells. Knockdown of MGMT or IKKβ expression abolished the synergistic effect of FLT with TMZ in glioma cells, which suggested that FLT might sensitize glioma cells to TMZ through down-regulation of MGMT expression. Consistently, TMZ combined with FLT markedly attenuated NF

  12. Flavonoids promoting HaCaT migration: I. Hologram quantitative structure-activity relationships.

    Science.gov (United States)

    Cho, Moonjae; Yoon, Hyuk; Park, Mijoo; Kim, Young Hwa; Lim, Yoongho

    2014-03-15

    Cell migration plays an important role in multicellular development and preservation. Because wound healing requires cell migration, compounds promoting cell migration can be used for wound repair therapy. Several plant-derived polyphenols are known to promote cell migration, which improves wound healing. Previous studies of flavonoids on cell lines have focused on their inhibitory effects and not on wound healing. In addition, studies of flavonoids on wound healing have been performed using mixtures. In this study, individual flavonoids were used for cellular migration measurements. Relationships between the cell migration effects of flavonoids and their structural properties have never been reported. Here, we investigated the migration of keratinocytes caused by 100 flavonoids and examined their relationships using hologram quantitative structure-activity relationships. The structural conditions responsible for efficient cell migration on keratinocyte cell lines determined from the current study will facilitate the design of flavonoids with improved activity.

  13. Quantitative promoter methylation analysis of multiple cancer-related genes in renal cell tumors

    Directory of Open Access Journals (Sweden)

    Oliveira Jorge

    2007-07-01

    Full Text Available Abstract Background Aberrant promoter hypermethylation of cancer-associated genes occurs frequently during carcinogenesis and may serve as a cancer biomarker. In this study we aimed at defining a quantitative gene promoter methylation panel that might identify the most prevalent types of renal cell tumors. Methods A panel of 18 gene promoters was assessed by quantitative methylation-specific PCR (QMSP in 85 primarily resected renal tumors representing the four major histologic subtypes (52 clear cell (ccRCC, 13 papillary (pRCC, 10 chromophobe (chRCC, and 10 oncocytomas and 62 paired normal tissue samples. After genomic DNA isolation and sodium bisulfite modification, methylation levels were determined and correlated with standard clinicopathological parameters. Results Significant differences in methylation levels among the four subtypes of renal tumors were found for CDH1 (p = 0.0007, PTGS2 (p = 0.002, and RASSF1A (p = 0.0001. CDH1 hypermethylation levels were significantly higher in ccRCC compared to chRCC and oncocytoma (p = 0.00016 and p = 0.0034, respectively, whereas PTGS2 methylation levels were significantly higher in ccRCC compared to pRCC (p = 0.004. RASSF1A methylation levels were significantly higher in pRCC than in normal tissue (p = 0.035. In pRCC, CDH1 and RASSF1A methylation levels were inversely correlated with tumor stage (p = 0.031 and nuclear grade (p = 0.022, respectively. Conclusion The major subtypes of renal epithelial neoplasms display differential aberrant CDH1, PTGS2, and RASSF1A promoter methylation levels. This gene panel might contribute to a more accurate discrimination among common renal tumors, improving preoperative assessment and therapeutic decision-making in patients harboring suspicious renal masses.

  14. Quantitative assessment of the relationship between RASSF1A gene promoter methylation and bladder cancer (PRISMA).

    Science.gov (United States)

    Zhan, Leyun; Zhang, Bingyi; Tan, Yaojun; Yang, Chengliang; Huang, Chenhong; Wu, Qiongya; Zhang, Yulin; Chen, Xiaobo; Zhou, Mi; Shu, Aihua

    2017-02-01

    Methylation of the Ras-association domain family 1 isoform A (RASSF1A) gene promoter region is thought to participate in the initiation and development of many different cancers. However, in bladder cancer the role of RASSF1A methylation was unclear. To evaluate the relationship between RASSF1A methylation and bladder cancer, a quantitative assessment of an independent meta-analysis was performed. In addition, a DNA methylation microarray database from the cancer genome atlas (TCGA) project was used to validate the results of the meta-analysis. We searched published articles from computerized databases, and DNA methylation data were extracted from TCGA project. All data were analyzed by R software. The results of the meta-analysis indicated that the frequency of RASSF1A gene methylation in bladder cancer patients is significantly higher than in healthy controls. The hazard ratio (HR) was 2.24 (95% CI = [1.45; 3.48], P = 0.0003) for overall survival (OS), and the RASSF1A gene promoter methylation status was strongly associated with the TNM stage and differentiation grade of the tumor. The similar results were also found by the data from TCGA project. There was a significant relationship between the methylation of the RASSF1A gene promoter and bladder cancer. Therefore, RASSF1A gene promoter methylation will be a potential biomarker for the clinical diagnosis of bladder cancer.

  15. Quantitative assessment of the relationship between RASSF1A gene promoter methylation and bladder cancer (PRISMA)

    Science.gov (United States)

    Zhan, Leyun; Zhang, Bingyi; Tan, Yaojun; Yang, Chengliang; Huang, Chenhong; Wu, Qiongya; Zhang, Yulin; Chen, Xiaobo; Zhou, Mi; Shu, Aihua

    2017-01-01

    Abstract Background: Methylation of the Ras-association domain family 1 isoform A (RASSF1A) gene promoter region is thought to participate in the initiation and development of many different cancers. However, in bladder cancer the role of RASSF1A methylation was unclear. To evaluate the relationship between RASSF1A methylation and bladder cancer, a quantitative assessment of an independent meta-analysis was performed. In addition, a DNA methylation microarray database from the cancer genome atlas (TCGA) project was used to validate the results of the meta-analysis. Methods: We searched published articles from computerized databases, and DNA methylation data were extracted from TCGA project. All data were analyzed by R software. Results: The results of the meta-analysis indicated that the frequency of RASSF1A gene methylation in bladder cancer patients is significantly higher than in healthy controls. The hazard ratio (HR) was 2.24 (95% CI = [1.45; 3.48], P = 0.0003) for overall survival (OS), and the RASSF1A gene promoter methylation status was strongly associated with the TNM stage and differentiation grade of the tumor. The similar results were also found by the data from TCGA project. Conclusion: There was a significant relationship between the methylation of the RASSF1A gene promoter and bladder cancer. Therefore, RASSF1A gene promoter methylation will be a potential biomarker for the clinical diagnosis of bladder cancer. PMID:28207521

  16. DNA repair by MGMT, but not AAG, causes a threshold in alkylation-induced colorectal carcinogenesis.

    Science.gov (United States)

    Fahrer, Jörg; Frisch, Janina; Nagel, Georg; Kraus, Alexander; Dörsam, Bastian; Thomas, Adam D; Reißig, Sonja; Waisman, Ari; Kaina, Bernd

    2015-10-01

    Epidemiological studies indicate that N-nitroso compounds (NOC) are causally linked to colorectal cancer (CRC). NOC induce DNA alkylations, including O (6)-methylguanine (O (6)-MeG) and N-methylated purines, which are repaired by O (6)-MeG-DNA methyltransferase (MGMT) and N-alkyladenine-DNA glycosylase (AAG)-initiated base excision repair, respectively. In view of recent evidence of nonlinear mutagenicity for NOC-like compounds, the question arises as to the existence of threshold doses in CRC formation. Here, we set out to determine the impact of DNA repair on the dose-response of alkylation-induced CRC. DNA repair proficient (WT) and deficient (Mgmt (-/-), Aag (-/-) and Mgmt (-/-)/Aag (-/-)) mice were treated with azoxymethane (AOM) and dextran sodium sulfate to trigger CRC. Tumors were quantified by non-invasive mini-endoscopy. A non-linear increase in CRC formation was observed in WT and Aag (-/-) mice. In contrast, a linear dose-dependent increase in tumor frequency was found in Mgmt (-/-) and Mgmt (-/-)/Aag (-/-) mice. The data were corroborated by hockey stick modeling, yielding similar carcinogenic thresholds for WT and Aag (-/-) and no threshold for MGMT lacking mice. O (6)-MeG levels and depletion of MGMT correlated well with the observed dose-response in CRC formation. AOM induced dose-dependently DNA double-strand breaks in colon crypts including Lgr5-positive colon stem cells, which coincided with ATR-Chk1-p53 signaling. Intriguingly, Mgmt (-/-) mice displayed significantly enhanced levels of γ-H2AX, suggesting the usefulness of γ-H2AX as an early genotoxicity marker in the colorectum. This study demonstrates for the first time a non-linear dose-response for alkylation-induced colorectal carcinogenesis and reveals DNA repair by MGMT, but not AAG, as a key node in determining a carcinogenic threshold.

  17. Expression and relevant research of MGMT and XRCC1 gene in differentgrades of brain glioma and normal brain tissues

    Institute of Scientific and Technical Information of China (English)

    Ya-Fei Zhang

    2015-01-01

    Objective: To explore and analyze expression and relevant research of MGMT and XRCC1 gene in different grades of brain glioma and normal brain tissues. Methods: 52 cases of patients with brain glioma treated in our hospital from December 2013 to December 2014, and 50 cases of normal brain-tissue patients with intracranial hypertension were selected, and proceeding test to the surgical resection of brain tissue of the above patients to determine its MGMT and XRCC1 protein content, sequentially to record the expression of MGMT and XRCC1 of both groups. Grading of tumors to brain glioma after operation was carried out, and the expression of MGMT and XRCC1 gene in brain tissues of different patients was analyzed and compared;finally the contingency tables of X2 test was used to analyze the correlation of XRCC1and MGMT. Results:Positive rate of MGMT expression in normal brain tissue was 2%,while positive rate of MGMT expression in brain glioma was 46.2%,which was obviously higher than that in normal brain tissues (χ2=26.85, P0.05), which had no statistical significance. There were 12 cases of patients whose MGMT protein expression was positive and XRCC1 protein expression was positive; there were 18 cases of patients whose MGMT protein expression was negative and XRCC1 protein expression was negative. Contingency tables of X2 test was used to analyze the correlation of XRCC1 and MGMT, which indicated that the expression of XRCCI and MGMT in brain glioma had no correlation (r=0.9%, P=0.353), relevancy of both was r=0.9%. Conclusions: Positive rate of the expression of MGMT and XRCC1 in brain glioma was obviously higher than that in normal brain tissues, but the distribution of different grades of brain glioma had no obvious difference, and MGMT and XRCC1 expression had no obvious correlation, which needed further research.

  18. Quantitative global and gene-specific promoter methylation in relation to biological properties of neuroblastomas

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    Kiss Nimrod B

    2012-09-01

    Full Text Available Abstract Background In this study we aimed to quantify tumor suppressor gene (TSG promoter methylation densities levels in primary neuroblastoma tumors and cell lines. A subset of these TSGs is associated with a CpG island methylator phenotype (CIMP in other tumor types. Methods The study panel consisted of 38 primary tumors, 7 established cell lines and 4 healthy references. Promoter methylation was determined by bisulphate Pyrosequencing for 14 TSGs; and LINE-1 repeat element methylation was used as an indicator of global methylation levels. Results Overall mean TSG Z-scores were significantly increased in cases with adverse outcome, but were unrelated to global LINE-1 methylation. CIMP with hypermethylation of three or more gene promoters was observed in 6/38 tumors and 7/7 cell lines. Hypermethylation of one or more TSG (comprising TSGs BLU, CASP8, DCR2, CDH1, RASSF1A and RASSF2 was evident in 30/38 tumors. By contrast only very low levels of promoter methylation were recorded for APC, DAPK1, NORE1A, P14, P16, TP73, PTEN and RARB. Similar involvements of methylation instability were revealed between cell line models and neuroblastoma tumors. Separate analysis of two proposed CASP8 regulatory regions revealed frequent and significant involvement of CpG sites between exon 4 and 5, but modest involvement of the exon 1 region. Conclusions/significance The results highlight the involvement of TSG methylation instability in neuroblastoma tumors and cell lines using quantitative methods, support the use of DNA methylation analyses as a prognostic tool for this tumor type, and underscore the relevance of developing demethylating therapies for its treatment.

  19. JNK contributes to temozolomide resistance of stem-like glioblastoma cells via regulation of MGMT expression.

    Science.gov (United States)

    Okada, Masashi; Sato, Atsushi; Shibuya, Keita; Watanabe, Eriko; Seino, Shizuka; Suzuki, Shuhei; Seino, Manabu; Narita, Yoshitaka; Shibui, Soichiro; Kayama, Takamasa; Kitanaka, Chifumi

    2014-02-01

    While elimination of the cancer stem cell population is increasingly recognized as a key to successful treatment of cancer, the high resistance of cancer stem cells to conventional chemoradiotherapy remains a therapeutic challenge. O6-methylguanine DNA methyltransferase (MGMT), which is frequently expressed in cancer stem cells of glioblastoma, has been implicated in their resistance to temozolomide, the first-line chemotherapeutic agent against newly diagnosed glioblastoma. However, much remains unknown about the molecular regulation that underlies MGMT expression and temozolomide resistance of glioblastoma cancer stem cells. Here, we identified JNK as a novel player in the control of MGMT expression and temozolomide resistance of glioblastoma cancer stem cells. We showed that inhibition of JNK, either pharmacologically or by RNA interference, in stem-like glioblastoma cells derived directly from glioblastoma tissues reduces their MGMT expression and temozolomide resistance. Importantly, sensitization of stem-like glioblastoma cells to temozolomide by JNK inhibition was dependent on MGMT expression, implying that JNK controls temozolomide resistance of stem-like glioblastoma cells through MGMT expression. Our findings suggest that concurrent use of JNK inhibitors with temozolomide may be a rational therapeutic approach to effectively target the cancer stem cell population in the treatment of glioblastoma.

  20. STAT-3 和 MGMT 在人胶质瘤中的表达及意义%Expression and significance of STAT-3 and MGMT in human gllomas

    Institute of Scientific and Technical Information of China (English)

    张龙洲; 王茂德

    2012-01-01

    目的:探讨STAT3和MGMT在人胶质瘤中的表达及其与肿瘤发生和病理分级之间的关系.方法:用免疫组化法检测并比较80例不同病理级别胶质瘤和15例正常脑组织中STAT3和MGMT的表达情况,并对二者表达做相关性分析.结果:STAT3和MGMT在正常脑组织中均未检测到阳性表达,在瘤组织中的表达均随肿瘤病理级别的升高而增高,相关性分析显示二者的表达存在正相关.结论:STAT3在胶质瘤的发生发展中起重要作用,其高表达可能与参与诱导MGMT的高表达有关.%Objective:To explore the expression of STAT —3 and MGMT in human gliomas and its relationship with tumorigenesis and the degrees of malignancy. Methods: Immunohistochemical SP method was employed to study the expression of STAT -3 and MGMT in 80 cases of glioma and 15 cases of normal cerebral tissue used as control group, the relationship of STAT - 3 and MGMT expression was analyzed. Results: Both the expression of STAT - 3 and MGMT increased as the malignant grade increased, at the same time the expression of STAT3 was positively related to that of MGMT. Conclusion: STAT3 may play a vital role in the progression of glioma through induction of MGMT.

  1. [MGMT expression in primary central nervous system diffuse large B cell lymphoma and its relationship with prognosis].

    Science.gov (United States)

    Shi, Q Y; Feng, X; Wang, J J; Wang, X; Bao, W; Ma, J; Shi, Q L

    2016-12-08

    Objective: To study the correlation between MGMT expression, clinicopathologic features and post-chemotherapy prognosis in patients with primary central nervous system lymphoma diffuse large B-cell lymphoma (PCNS-DLBCL). Methods: MGMT expression was detected in 76 cases of PCNS-DLBCL by EnVision method with immunohistochemical staining.Follow-up data including treatment response and overall survival time, were analyzed. Results: The rate of MGMT expression in PCNS-DLBCL was 67.1%(51/76). The MGMT expression rate in male patients was higher than that in female(PMGMT and aged over 60 years was shorter after chemotherapy than those without chemotherapy (P=0.022). In the patients aged over 60 years, the prognosis of MGMT-positive patients was significantly better than MGMT-negative patients (P=0.044). Conclusions: The expression of MGMT is more commonly found in male patients. In the patients aged over 60 years with the same therapy, the prognosis is better in the MGMT-negative ones. Detection of MGMT protein expression can provide some guidance in choice of treatment modalities in PCNS-DLBCL patients.

  2. The combination of IDH1 mutations and MGMT methylation status predicts survival in glioblastoma better than either IDH1 or MGMT alone

    NARCIS (Netherlands)

    Molenaar, R.J.; Verbaan, D.; Lamba, S.; Zanon, C.; Jeuken, J.W.M.; Boots-Sprenger, S.H.E.; Wesseling, P.; Hulsebos, T.J.M.; Troost, D.; Tilborg, A.A. Van; Leenstra, S.; Vandertop, W.P.; Bardelli, A.; Noorden, C.J.F. van; Bleeker, F.E.

    2014-01-01

    BACKGROUND: Genetic and epigenetic profiling of glioblastomas has provided a comprehensive list of altered cancer genes of which only O(6)-methylguanine-methyltransferase (MGMT) methylation is used thus far as a predictive marker in a clinical setting. We investigated the prognostic significance of

  3. The combination of IDH1 mutations and MGMT methylation status predicts survival in glioblastoma better than either IDH1 or MGMT alone

    NARCIS (Netherlands)

    R.J. Molenaar (Remco J.); D. Verbaan (Dagmar); S. Lamba (Simona); C. Zanon (Carlo); J. Jeuken (Judith); S.H.E. Boots-Sprenger (Sandra H. E.); P. Wesseling (Pieter); T. Hulsebos (Theo); D. Troost (Dirk); A.A.G. van Tilborg (Angela); S. Leenstra (Sieger); W.P. Vandertop (Peter); A. Bardelli (Alberto); C.J.F. van Noorden (Cornelis); F.E. Bleeker (Fonnet)

    2014-01-01

    textabstractBackground. Genetic and epigenetic profiling of glioblastomas has provided a comprehensive list of altered cancer genes of which only O6- methylguanine-methyltransferase (MGMT) methylation is used thus far as a predictive marker in a clinical setting. We investigated the prognostic signi

  4. Quantitative evaluation of the requirements for the promotion as associate professor at German medical faculties.

    Science.gov (United States)

    Sorg, Heiko; Knobloch, Karsten

    2012-01-01

    First quantitative evaluation of the requirements for the promotion as associate professor (AP) at German medical faculties. Analysis of the AP-regulations of German medical faculties according to a validated scoring system, which has been adapted to this study. The overall scoring for the AP-requirements at 35 German medical faculties was 13.5±0.6 of 20 possible scoring points (95% confidence interval 12.2-14.7). More than 88% of the AP-regulations demand sufficient performance in teaching and research with adequate scientific publication. Furthermore, 83% of the faculties expect an expert review of the candidate's performance. Conference presentations required as an assistant professor as well as the reduction of the minimum time as an assistant professor do only play minor roles. The requirements for assistant professors to get nominated as an associate professor at German medical faculties are high with an only small range. In detail, however, it can be seen that there still exists large heterogeneity, which hinders equal opportunities and career possibilities. These data might be used for the ongoing objective discussion.

  5. Alkylation and Carbamylation Effects of Lomustine and Its Major Metabolites and MGMT Expression in Canine Cells

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    Thushara Chakkath

    2015-04-01

    Full Text Available DNA Alkylation is thought to be the reason for the efficacy of lomustine while carbamylation has been implicated as the cause for the side effects seen with lomustine treatment such as hepatotoxicity. In the alkylation study we show that lomustine and its metabolites form similar levels of the DNA adducts N7 hydroxyethylguanine and O6 hydroxyethyldeoxyguanosine. In terms of carbamylation, lomustine showed greater extent of carbamylation in the canine hepatocytes and lymphoma cell lines. The DNA repair enzyme O6 methylguanine DNA methyltransferase (MGMT causes resistance of tumor cells to bifunctional nitrosourea, like lomustine. There is no data available regarding MGMT expression/activity in canine cells or tissues. Our study shows that there is low MGMT activity in the canine lymphoid cell line 17–71 while the GL-1 cells did not show any detectable enzyme activity or mRNA expression. The MGMT enzyme activity measured in canine hepatocytes is about 250–350 fmol/mg protein as compared to about 90 fmol/mg protein in 17–71 cells. We also show that MGMT mRNA expression in 17–71 cells and canine hepatocytes positively correlates with its enzyme activity in these cells.

  6. Expression of MGMT, hMLH1 and XRCC1 in Gastric Cancer Tissue and Their Clinical Signiifcance

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-feng; LIU Ai-yong; LI Jia

    2015-01-01

    Objective: To study the expression and their correlation of repair gene MGMT, hMLH1 and XRCC1 and to explore the relationship between their expressions and clinicopathologic features of gastric cancer. Methods: Immunohistochemical SP method was used to detect the expression of repair gene MGMT, hMLH1 and XRCC1 in 52 gastric cancer specimens. The relationship between MGMT, hMLH1, XRCC1 and clinicopathological features and the correlation between MGMT and hMLH1 and XRCC1 were analyzed. Results:The positive rates of MGMT, hMLH1 and XRCC1 proteins were 75.0%(39/52), 63.7%(33/52) and 76.8%(40/52), respectively. The expression MGMT protein was positively correlated to the expression of hM-LH1 (r=0.498, P0.05). The MGMT expression was associated with histological pattern, lymphatic metastasis, distant metastasis and postoperative recurrence (P 0.05). hMLH1 expression was related to histological pattern, lymphatic metastasis and postoperative recurrence (P0.05). XRCC1 expression was related to histological pattern, lymphatic metastasis, tumor staging and postoperative recurrence (P 0.05). Conclusion: MGMT, hMLH1 and XRCC1 expression is closely related to the occurrence of gastric cancer and has the effect against the development of gastric cancer.

  7. Screening_mgmt: a Python module for managing screening data.

    Science.gov (United States)

    Helfenstein, Andreas; Tammela, Päivi

    2015-02-01

    High-throughput screening is an established technique in drug discovery and, as such, has also found its way into academia. High-throughput screening generates a considerable amount of data, which is why specific software is used for its analysis and management. The commercially available software packages are often beyond the financial limits of small-scale academic laboratories and, furthermore, lack the flexibility to fulfill certain user-specific requirements. We have developed a Python module, screening_mgmt, which is a lightweight tool for flexible data retrieval, analysis, and storage for different screening assays in one central database. The module reads custom-made analysis scripts and plotting instructions, and it offers a graphical user interface to import, modify, and display the data in a uniform manner. During the test phase, we used this module for the management of 10,000 data points of various origins. It has provided a practical, user-friendly tool for sharing and exchanging information between researchers.

  8. Effects of 5-Aza-CdR on DNA methylation and expression of p16 and MGMT gene in lung cancer cell line SPC-A-1%5-氮杂-2'-脱氧胞苷对肺癌SPC-A-1细胞p16、MGMT基因甲基化及其表达的影响

    Institute of Scientific and Technical Information of China (English)

    方汉林; 于在诚; 金永堂; 薛绍礼; 陈首慧

    2011-01-01

    Objective To investigate the effects of 5-Aza-2'-deoxycytidine (5-Aza-CdR) on DNA methylation and expression of p16 and MGMT gene in the human lung cancer cell line SPC-A-1. Methods SPC-A-1 cells were cultured with RPMI 1640 medium and were treated with 5 μmol/L DNA methyltransferase inhibitor 5-Aza-CdR. Methylation-specific polymerase chain reaction(MSP) was used to detect the promoter methylation state of the p16 and MGMT gene. RT-PCR was used to detect the mRNA expression of p16 and MGMT before and after treatment with 5-Aza-CdR, respectively. Results Before treatment with 5-Aza-CdR,p16 and MGMT expressions were absent,and promoter hypermethylation of the p16 and MGMT gene were detected in SPC-A-1 cells, After treatment with 5-Aza-CdR, the promoter region of the p16 and MGMT gene exhibited a demethylation state, and their mRNA expressions were increased. Conclusion Promoter hypermethylation is a major mechanism of p16 and MGMT gene silencing in human lung cancer cells, and can be reversed by the demethylating agent 5-Aza-CdR, which can regulate the expressions of the p16 and MGMT gene.%目的 观察5-氮杂-2'-脱氧胞苷(5-Aza-CdR)对体外培养的肺癌SPC-A-1细胞p16、MGMT基因启动子区DNA甲基化状态及其表达的影响,探讨肺癌细胞p16、MGMT基因失活的机制及去甲基化制剂对p16、MGMT基因表达的调控.方法 5-Aza-CdR处理体外培养的肺癌SPC-A-1细胞,甲基化特异性PCR(MSP)法检测用药前后细胞p16、MGMT基因的甲基化状态,RT-PCR法检测用药前后细胞p16、MGMT mRNA.结果 加入5-Aza-CdR前,SPC-A-1细胞p16、MGMT mRNA表达缺失,其启动子区域表现为DNA甲基化.加入5-Aza-CdR后,SPC-A-1细胞中p16、MGMT基因呈现DNA去甲基化,而且表达缺失的p16、MGMT mRNA重新表达.结论 启动子区高甲基化是肺癌细胞p16、MGMT基因失活的主要原因之一,去甲基化制剂5-Aza-CdR能逆转p16、MGMT基因甲基化状态,从而调控p16、MGMT基因表达.

  9. Heterogeneity of MGMT promoter methylation and protein expression in glioma%脑胶质瘤O6-甲基鸟嘌呤-DNA甲基转移酶启动区甲基化及其表达异质性的研究

    Institute of Scientific and Technical Information of China (English)

    李杰飞; 孙彦辉; 刘福生; 金贵善; 柴奇; 张红波

    2011-01-01

    目的 研究脑胶质瘤组织不同部位O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)启动区甲基化状态及其表达的差异性.方法 在54例脑胶质瘤组织的中心和周边部位分别获取标本,共获得92份标本,采用巢式甲基化特异性PCR(MSP)进行MGMT启动区甲基化状态的检测,同时采用免疫组织化学方法进行MGMT蛋白表达的检测.结果 38例胶质瘤中获得了肿瘤两个不同部位MGMT启动区甲基化的状态,其中24例胶质瘤MGMT启动区甲基化的状态是一致的,占总数的63.2%(24/38).在29例胶质瘤患者中获得了肿瘤两个不同部位MGMT蛋白表达的情况,其中10例胶质瘤MGMT蛋白表达是一致的,占总数的34.5% (10/29).两总体一致性概率间差值的95%置信区间为(5.6%和51.8%),两者的差异有统计学意义.巢式MSP和免疫组化都获得检测结果的标本有77份,在61份MGMT启动区甲基化标本中,25份MGMT蛋白表达阴性,14份蛋白表达可疑阳性,18份蛋白表达阳性,4份蛋白表达强阳性.在16份MGMT启动区非甲基化标本中,2份MGMT蛋白表达阴性,2份蛋白表达可疑阳性,9份蛋白表达阳性,3份蛋白表达强阳性,MGMT启动区甲基化状态与蛋白表达呈负相关(r=-0.318,P=0.005).结论 脑胶质瘤MGMT蛋白表达在同一肿瘤的不同部位存在明显的异质性.虽然脑胶质瘤MGMT启动区甲基化的状态在同一肿瘤的不同部位存在一定的异质性,但是大多数脑胶质瘤MGMT启动区甲基化的状态在同一肿瘤的不同部位是一致的.脑胶质瘤MGMT启动区甲基化状态的一致性优于蛋白表达的一致性.脑胶质瘤MGMT启动区甲基化,MGMT蛋白表达较少,MGMT启动区非甲基化,MGMT蛋白表达较多.

  10. Aberrant gene promoter methylation associated with sporadic multiple colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Victoria Gonzalo

    Full Text Available BACKGROUND: Colorectal cancer (CRC multiplicity has been mainly related to polyposis and non-polyposis hereditary syndromes. In sporadic CRC, aberrant gene promoter methylation has been shown to play a key role in carcinogenesis, although little is known about its involvement in multiplicity. To assess the effect of methylation in tumor multiplicity in sporadic CRC, hypermethylation of key tumor suppressor genes was evaluated in patients with both multiple and solitary tumors, as a proof-of-concept of an underlying epigenetic defect. METHODOLOGY/PRINCIPAL FINDINGS: We examined a total of 47 synchronous/metachronous primary CRC from 41 patients, and 41 gender, age (5-year intervals and tumor location-paired patients with solitary tumors. Exclusion criteria were polyposis syndromes, Lynch syndrome and inflammatory bowel disease. DNA methylation at the promoter region of the MGMT, CDKN2A, SFRP1, TMEFF2, HS3ST2 (3OST2, RASSF1A and GATA4 genes was evaluated by quantitative methylation specific PCR in both tumor and corresponding normal appearing colorectal mucosa samples. Overall, patients with multiple lesions exhibited a higher degree of methylation in tumor samples than those with solitary tumors regarding all evaluated genes. After adjusting for age and gender, binomial logistic regression analysis identified methylation of MGMT2 (OR, 1.48; 95% CI, 1.10 to 1.97; p = 0.008 and RASSF1A (OR, 2.04; 95% CI, 1.01 to 4.13; p = 0.047 as variables independently associated with tumor multiplicity, being the risk related to methylation of any of these two genes 4.57 (95% CI, 1.53 to 13.61; p = 0.006. Moreover, in six patients in whom both tumors were available, we found a correlation in the methylation levels of MGMT2 (r = 0.64, p = 0.17, SFRP1 (r = 0.83, 0.06, HPP1 (r = 0.64, p = 0.17, 3OST2 (r = 0.83, p = 0.06 and GATA4 (r = 0.6, p = 0.24. Methylation in normal appearing colorectal mucosa from patients with multiple and solitary CRC showed no relevant

  11. Gene promoter hypermethylation in leukoplakia of the oral mucosa

    Directory of Open Access Journals (Sweden)

    Mingli Liu

    2010-07-01

    Full Text Available Mingli Liu1, Lei Feng2, Ximing Tang3, Shanchun Guo41Department of Physics, Tufts University School of Medicine, Boston, Massachussetts; 2Department of Thoracic/Head and Neck Medical Oncology, 3Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas; 4Sylvester Cancer Center, University of Miami School of Medicine, Florida, USAAbstract: To examine whether aberrant DNA methylation in the promoter region might occur earlier in tumorigenesis, particularly in premalignant lesions, we examined biopsies from 111 participants in a chemoprevention trial aimed at reversal of oral leukoplakia, using methylation-specific polymerase chain reaction for the promoter regions of the tumor suppressor gene CDKN2A (p16, the putative metastasis suppressor gene for death-associated protein kinase (DAP-K, the DNA repair gene O6-methyguanine-DNA-methyltransferase (MGMT, and the detoxification gene glutathione S-transferase p1(GSTP1. p16 promoter hypermethylation was detected in 21 of 82 (25.6%, DAP-K hypermethylation in 28 of 87 (32.2%, and MGMT hypermethylation in 32 of 106 (30.2% oral leukoplakia lesions analyzed. No aberrant methylation was found at the GSTP1 gene in 110 lesions examined. Among 68 biopsies analyzed for all three genes (p16, DAP-K, MGMT, 17 biopsies were detected with an abnormal methylation pattern at only one gene, 15 at two genes, and 8 at all three genes. Among clinical characteristics and their correlation with methylation, only alcohol consumption was correlated with DAP-K methylation (P = 0.027, while MGMT methylation was more frequent in females (P = 0.003 and nonsmokers (P = 0.0005. A significant correlation was found between p16 and DAP-K hypermethylation; p16 promoter was methylated in 14 (56% of 25 lesions with DAP-K methylation, and only 5 (11.1% of 45 DAP-K methylation-negative lesions (P = 0.0001. DAP-K aberrant methylation was also significantly correlated with MGMT methylation (16 of 31 in MGMT methylation

  12. O6-methylguanine-DNA methyltransferase (MGMT) immunohistochemistry as a predictor of resistance to temozolomide in primary CNS lymphoma.

    Science.gov (United States)

    Jiang, Xiaoyin; Reardon, David A; Desjardins, Annick; Vredenburgh, James J; Quinn, Jennifer A; Austin, Alan D; Herndon, James E; McLendon, Roger E; Friedman, Henry S

    2013-08-01

    Temozolomide, an alkylating agent, has shown promise in treating primary central nervous system lymphoma (PCNSL). The enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) repairs alkylating damage, such as that induced by temozolomide. We hypothesized that MGMT immunohistochemistry would predict resistance to temozolomide in PCNSL. A retrospective study of newly-diagnosed and recurrent PCNSL patients treated at our institution was conducted to study the predictive value of MGMT immunohistochemistry for response to temozolomide. 20 patients who were treated with temozolomide as a single agent were identified during the study time period. 6/20 patients demonstrated a response, corresponding to an objective response rate of 30 % (95 % CI 8-52). Five patients with low MGMT level (temozolomide. Only one of 10 patients (10 %) with high MGMT level (≥30 %) exhibited a response to temozolomide. Small sample numbers precluded formal statistical comparisons. Two patients with complete response remain alive without progressive disease 6.7 and 7.2 years after temozolomide initiation. Immunohistochemistry can be performed on small biopsies to selectively assess MGMT status in tumor versus surrounding inflammation. MGMT analysis by immunohistochemistry may predict response to temozolomide in PCNSL and should be prospectively investigated.

  13. Immunohistochemical profiles of IDH1, MGMT and P53: practical significance for prognostication of patients with diffuse gliomas.

    Science.gov (United States)

    Ogura, Ryosuke; Tsukamoto, Yoshihiro; Natsumeda, Manabu; Isogawa, Mizuho; Aoki, Hiroshi; Kobayashi, Tsutomu; Yoshida, Seiichi; Okamoto, Kouichiro; Takahashi, Hitoshi; Fujii, Yukihiko; Kakita, Akiyoshi

    2015-08-01

    Genetic and epigenetic status, including mutations of isocitrate dehydrogenase (IDH) and TP53 and methylation of O(6) -methylguanine-DNA methyltransferase (MGMT), are associated with the development of various types of glioma and are useful for prognostication. Here, using routinely available histology sections from 312 patients with diffuse gliomas, we performed immunohistochemistry using antibodies specific for IDH1 mutation, MGMT methylation status, and aberrant p53 expression to evaluate the possible prognostic significance of these features. With regard to overall survival (OS), univariate analysis indicated that an IDH1-positive profile in patients with glioblastoma (GBM), anaplastic astrocytoma (AA), anaplastic oligoastrocytoma and oligodendroglioma, or a MGMT-negative profile in patients with GBM and AA were significantly associated with a favorable outcome. Multivariate analysis revealed that both profiles were independent factors influencing prognosis. The OS of patients with IDH1-positive/MGMT-negative profiles was significantly longer than that of patients with negative/negative and negative/positive profiles. A p53 profile was not an independent prognostic factor. However, for GBM/AA patients with IDH1-negative/MGMT-negative profiles, p53 overexpression was significantly associated with an unfavorable outcome. Thus, the immunohistochemical profiles of IDH1 and MGMT are of considerable significance in gliomas, and a combination of IDH1, MGMT and p53 profiles may be useful for prognostication of GBM/AA.

  14. Posttranslational Regulation of O(6)-Methylguanine-DNA Methyltransferase (MGMT) and New Opportunities for Treatment of Brain Cancers.

    Science.gov (United States)

    Srivenugopal, Kalkunte S; Rawat, Amit; Niture, Suryakant K; Paranjpe, Ameya; Velu, Chinavenmani; Venugopal, Sanjay N; Madala, Hanumantha Rao; Basak, Debasish; Punganuru, Surendra R

    2016-01-01

    O(6)-Methylguanine-DNA-methyltransferase (MGMT) is an antimutagenic DNA repair protein highly expressed in human brain tumors. Because MGMT repairs the mutagenic, carcinogenic and cytotoxic O(6)-alkylguanine adducts, including those generated by the clinically used anticancer alkylating agents, it has emerged as a central and rational target for overcoming tumor resistance to alkylating agents. Although the pseudosubstrates for MGMT [O(6)-benzylguanine, O(6)-(4- bromothenyl)guanine] have gained attention as powerful and clinically-relevant inhibitors, bone marrow suppression due to excessive alkylation damage has diminished this strategy. Our laboratory has been working on various posttranslational modifications of MGMT that affect its protein stability, DNA repair activity and response to oxidative stress. While these modifications greatly impact the physiological regulation of MGMT, they also highlight the opportunities for inactivating DNA repair and new drug discovery in this specific area. This review briefly describes the newer aspects of MGMT posttranslational regulation by ubiquitination, sumoylation and glutathionylation and reveals how the reactivity of the active site Cys145 can be exploited for potent inhibition and depletion of MGMT by thiol-reacting drugs such as the disulfiram and various dithiocarbamate derivatives. The possible repurposing of these nontoxic and safe drugs for improved therapy of pediatric and adult brain tumors is discussed.

  15. Effectiveness of a systematic approach to promote intersectoral collaboration in comprehensive school health promotion-a multiple-case study using quantitative and qualitative data.

    Science.gov (United States)

    Pucher, Katharina K; Candel, Math J J M; Krumeich, Anja; Boot, Nicole M W M; De Vries, Nanne K

    2015-07-05

    We report on the longitudinal quantitative and qualitative data resulting from a two-year trajectory (2008-2011) based on the DIagnosis of Sustainable Collaboration (DISC) model. This trajectory aimed to support regional coordinators of comprehensive school health promotion (CSHP) in systematically developing change management and project management to establish intersectoral collaboration. Multilevel analyses of quantitative data on the determinants of collaborations according to the DISC model were done, with 90 respondents (response 57 %) at pretest and 69 respondents (52 %) at posttest. Nvivo analyses of the qualitative data collected during the trajectory included minutes of monthly/bimonthly personal/telephone interviews (N = 65) with regional coordinators, and documents they produced about their activities. Quantitative data showed major improvements in change management and project management. There were also improvements in consensus development, commitment formation, formalization of the CSHP, and alignment of policies, although organizational problems within the collaboration increased. Content analyses of qualitative data identified five main management styles, including (1) facilitating active involvement of relevant parties; (2) informing collaborating parties; (3) controlling and (4) supporting their task accomplishment; and (5) coordinating the collaborative processes. We have contributed to the fundamental understanding of the development of intersectoral collaboration by combining qualitative and quantitative data. Our results support a systematic approach to intersectoral collaboration using the DISC model. They also suggest five main management styles to improve intersectoral collaboration in the initial stage. The outcomes are useful for health professionals involved in similar ventures.

  16. Expression profiles of MGMT, p16, and APC genes in tumor and matching surgical margin from patients with oral squamous cell carcinoma.

    Science.gov (United States)

    Strzelczyk, Joanna Katarzyna; Gołąbek, Karolina; Krakowczyk, Łukasz; Owczarek, Aleksander J

    2016-01-01

    The aim of the study was to assess the expression of MGMT, p16, and APC genes in tumors and matching surgical margin samples from 56 patients with primary OSCC. We also analyzed the association of the clinical variables with the expression of the studied genes. After RNA isolation and cDNA synthesis gene expression levels were assessed by quantitative reverse transcription (qRT)-PCR. Two-sided parametrical Student's t-test for independent groups with equal/unequal variances showed no statistically significant differences in genes' expression in tumor compared to margin samples. No association was found between the genes' expression and clinical parameters, except for MGMT, whose low expression was probably associated with smoking (0.87 vs 1.34, p=0.065). 'Field cancerization' is an area with genetically or epigenetically altered cells and at the same time a risk factor for cancer. Disturbances in gene expression could also be the source of damages leading to cancerization. In conclusion, it is important to mention that the field remaining after a surgery may pose an increased risk of cancer development. It may be suggested that the diagnosis and treatment of cancers should not be concentrated only on the tumor itself, but also on the cancer field effect. Therefore, further molecular analysis on surgical margins and additional research regarding their assessment are required.

  17. Interferon-α/β enhances temozolomide activity against MGMT-positive glioma stem-like cells.

    Science.gov (United States)

    Shen, Dong; Guo, Cheng-Cheng; Wang, Jing; Qiu, Zhi-Kun; Sai, Ke; Yang, Qun-Ying; Chen, Yin-Sheng; Chen, Fu-Rong; Wang, Jie; Panasci, Lawrence; Chen, Zhong-Ping

    2015-11-01

    Glioma is one of the most common primary tumors of the central nervous system in adults. Glioblastoma (GBM) is the most lethal type of glioma, whose 5-year survival is 9.8% at best. Glioma stem-like cells (GSCs) play an important role in recurrence and treatment resistance. MGMT is a DNA repair protein that removes DNA adducts and therefore attenuates treatment efficiency. It has been reported that interferon-α/β (IFN-α/β) downregulates the level of MGMT and sensitizes glioma cells to temozolomide. In the present study, we assessed whether IFN-α/β is able to sensitize GSCs to temozolomide by modulating MGMT expression. Upon the treatment of IFN-α/β, the efficacy of temozolomide against MGMT‑positive GSCs was markedly enhanced by combination treatment with IFN-α/β when compared with the temozolomide single agent group, and MGMT expression was markedly decreased at the same time. Further mechanistic study showed that IFN-α/β suppressed the NF-κB activity, which further mediated the sensitization of MGMT‑positive GSCs to temozolomide. Our data therefore demonstrated that the application of IFN-α/β is a promising agent with which to enhance temozolomide efficiency and reduce drug resistance, and our findings shed light on improving clinical outcomes and prolonging the survival of patients with malignant gliomas.

  18. Quantitative evaluation of DNMT3B promoter methylation in breast cancer patients using differential high resolution melting analysis.

    Science.gov (United States)

    Naghitorabi, M; Mohammadi Asl, J; Mir Mohammad Sadeghi, H; Rabbani, M; Jafarian-Dehkordi, A; Javanmard, Haghjooye S

    2013-07-01

    DNA methylation plays an important role in carcinogenesis through epigenetic silencing of tumor suppressor genes. Aberrant methylation usually results from changes in the activity of DNA methyltransferases (DNMTs). Some studies show that the overexpression of the DNMTs may lead to aberrant methylation of tumor suppressor genes. Also the overexpression of DNMTs may be related to methylation status of their genes. Due to limited number of studies on DNMT3B promoter methylation, this study was performed to quantitatively measure the methylation level of DNMT3B gene in archival formalin fixed paraffin embedded (FFPE) tissues from breast cancer patients. Using differential high resolution melting analysis (D-HRMA) technology, the methylation level of DNMT3B gene promoter was quantified in 98 breast cancer FFPE tissues and also 10 fresh frozen normal tissue samples. Statistical analyses used for analyzing the correlation between the methylation and clinical variables. All the normal samples were found to be methylated at the DNMT3B promoter (the average methylation level 3.34%). Patients were identified as hypo-methylated (mean methylation level 0.8%), methylated (mean methylation level 2.48%) and hyper-methylated (mean methylation level 10.5%). Statistical analysis showed a significant correlation between the methylation status and the sample type, cancer type and tumor size. Also the methylation level was significantly associated with histologic grade. It is concluded that quantification of DNMT3B promoter methylation might be used as a reliable and sensitive diagnostic and prognostic tool in breast cancer. Also D-HRMA is demonstrated as a rapid and cost effective method for quantitative evaluation of promoter methylation.

  19. Expression of MGMT, hMLH1 and XRCC1 in Gastric Cancer Tissue and Their Clinical Significance

    Directory of Open Access Journals (Sweden)

    Xiao-feng LI

    2015-03-01

    Full Text Available Objective: To study the expression and their correlation of repair gene MGMT, hMLH1 and XRCC1 and to explore the relationship between their expressions and clinicopathologic features of gastric cancer.Methods: Immunohistochemical SP method was used to detect the expression of repair gene MGMT, hMLH1 and XRCC1 in 52 gastric cancer specimens. The relationship between MGMT, hMLH1, XRCC1 and clinicopathological features and the correlation between MGMT and hMLH1 and XRCC1 were analyzed. Results:The positive rates of MGMT, hMLH1 and XRCC1 proteins were 75.0% (39/52, 63.7% (33/52 and 76.8% (40/52, respectively. The expression MGMT protein was positively correlated to the expression of hM-LH1 (r=0.498, P<0.05, but no obvious correlation to the expression of XRCC1 (P>0.05. The MGMT expression was associated with histological pattern, lymphatic metastasis, distant metastasis and postoperative recurrence (P<0.05, orP<0.01 but not associated with gender, age, invasive depth and tumor staging (P>0.05. hMLH1 expression was related to histological pattern, lymphatic metastasis and postoperative recurrence (P<0.05, or P<0.01, but not related to gender, age, tumor staging, invasive depth and distant metastasis (P>0.05. XRCC1 expression was related to histological pattern, lymphatic metastasis, tumor staging and postoperative recurrence (P<0.05, or P<0.01, but not related to gender, age, invasive depth and distant metastasis (P>0.05. Conclusion: MGMT, hMLH1 and XRCC1 expression is closely related to the occurrence of gastric cancer and has the effect against the development of gastric cancer.

  20. Adenovirus-based strategies overcome temozolomide resistance by silencing the O6-methylguanine-DNA methyltransferase promoter.

    Science.gov (United States)

    Alonso, Marta M; Gomez-Manzano, Candelaria; Bekele, B Nebiyou; Yung, W K Alfred; Fueyo, Juan

    2007-12-15

    Currently, the most efficacious treatment for malignant gliomas is temozolomide; however, gliomas expressing the DNA repair enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) are resistant to this drug. Strong clinical evidence shows that gliomas with methylation and subsequent silencing of the MGMT promoter are sensitive to temozolomide. Based on the fact that adenoviral proteins directly target and inactivate key DNA repair genes, we hypothesized that the oncolytic adenovirus Delta-24-RGD could be successfully combined with temozolomide to overcome the reported MGMT-mediated resistance. Our studies showed that the combination of Delta-24-RGD and temozolomide induces a profound therapeutic synergy in glioma cells. We observed that Delta-24-RGD treatment overrides the temozolomide-mediated G(2)-M arrest. Furthermore, Delta-24-RGD infection was followed by down-modulation of the RNA levels of MGMT. Chromatin immunoprecipitation assays showed that Delta-24-RGD prevented the recruitment of p300 to the MGMT promoter. Importantly, using mutant adenoviruses and wild-type and dominant-negative forms of the p300 protein, we showed that Delta-24-RGD interaction with p300 was required to induce silencing of the MGMT gene. Of further clinical relevance, the combination of Delta-24-RGD and temozolomide significantly improved the survival of glioma-bearing mice. Collectively, our data provide a strong mechanistic rationale for the combination of oncolytic adenoviruses and temozolomide, and should propel the clinical testing of this therapy approach in patients with malignant gliomas.

  1. 喉癌细胞系中抑癌基因MGMT表达与DNA甲基化及组蛋白H3-K9甲基化的关系%Correlation between histone H3-K9 methylation, DNA methylation and expression of gene MGMT in Hep-2 cell line

    Institute of Scientific and Technical Information of China (English)

    杨静; 何丽霞; 季文樾; 金明珠; 赵旭东

    2012-01-01

    To explore the correlation between histone H3-K9 methylation, DNA methylation and expression of carcinoma suppressor gene MGMT in laryngeal carcinoma Hep-2 cell line. Method: 5-Aza-dC was used to deal with Hep-2 cell cultured in vitro. ChIP, MSP and Realtime- PCR were used to detect H3-K9 methylation, DNA methylation, of MGMT gene promoter region and MGMT gene expression before and after treatment with drugs. Result: In Hep-2 cell line,gene MGMT was characterized by DNA methylation and histone H3-K9 hypermethylation. 5-Aza-dC was able to reduce H3-K9 methylation of MGMT gene histone in Hep-2 cell line, 5-Aza-dC was able to reverse DNA methylation of MGMT gene histone in Hep-2 cell line,5-Aza-dC was able to up-regulate the down-regulated gene expression of tumor suppressor genes MGMT. Conclusion: Promoter methylation of cancer suppressor gene MGMT may induce the gene inactivity. DNA methylation may increase H3-K9 methylation. 5-Aza-dC can reduce H3-K9 methylation of tumor suppressor gene MGMT histone by reversing DNA methylation of tumor suppressor gene MGMT, and then the expression of tumor suppressor genes is increased and tumor development is inhibited.%目的:探讨喉癌Hep-2细胞中组蛋白H3-K9甲基化与DNA甲基化及抑癌基因MGMT表达的关系.方法:应用去甲基化制剂5-氮杂-2'-脱氧胞苷(5-Aza-dC)处理体外培养的Hep-2细胞.应用染色质免疫沉淀技术、甲基化特异性聚合酶链反应和实时定量逆转录聚合酶链反应分析药物作用前后MGMT基因启动子区组蛋白H3-K9甲基化、DNA甲基化和MGMT表达情况.结果:①在Hep-2细胞未经药物干预前,MGMT表现为DNA甲基化,组蛋白H3-K9高甲基化,MGMT低表达.②在5-Aza-dC的作用下,Hep-2细胞中MGMT的组蛋白H3-K9甲基化状态被降低;MGMT的DNA甲基化状态得到了逆转;原来低表达的MGMT表达上调.结论:喉癌细胞系中MGMT启动子区甲基化可能是导致其基因失活的主要原因.DNA甲

  2. Fluorogenic Real-Time Reporters of DNA Repair by MGMT, a Clinical Predictor of Antitumor Drug Response.

    Directory of Open Access Journals (Sweden)

    Andrew A Beharry

    Full Text Available Common alkylating antitumor drugs, such as temozolomide, trigger their cytotoxicity by methylating the O6-position of guanosine in DNA. However, the therapeutic effect of these drugs is dampened by elevated levels of the DNA repair enzyme, O6-methylguanine DNA methyltransferase (MGMT, which directly reverses this alkylation. As a result, assessing MGMT levels in patient samples provides an important predictor of therapeutic response; however, current methods available to measure this protein are indirect, complex and slow. Here we describe the design and synthesis of fluorescent chemosensors that report directly on MGMT activity in a single step within minutes. The chemosensors incorporate a fluorophore and quencher pair, which become separated by the MGMT dealkylation reaction, yielding light-up responses of up to 55-fold, directly reflecting repair activity. Experiments show that the best-performing probe retains near-native activity at mid-nanomolar concentrations. A nuclease-protected probe, NR-1, was prepared and tested in tumor cell lysates, demonstrating an ability to evaluate relative levels of MGMT repair activity in twenty minutes. In addition, a probe was employed to evaluate inhibitors of MGMT, suggesting utility for discovering new inhibitors in a high-throughput manner. Probe designs such as that of NR-1 may prove valuable to clinicians in selection of patients for alkylating drug therapies and in assessing resistance that arises during treatment.

  3. A novel temozolomide analog, NEO212, with enhanced activity against MGMT-positive melanoma in vitro and in vivo.

    Science.gov (United States)

    Chen, Thomas C; Cho, Hee-Yeon; Wang, Weijun; Nguyen, Jenny; Jhaveri, Niyati; Rosenstein-Sisson, Rachel; Hofman, Florence M; Schönthal, Axel H

    2015-03-28

    The alkylating agent temozolomide (TMZ) represents an important component of current melanoma therapy, but overexpression of O6-methyl-guanine DNA methyltransferase (MGMT) in tumor cells confers resistance to TMZ and impairs therapeutic outcome. We investigated a novel perillyl alcohol (POH)-conjugated analog of TMZ, NEO212, for its ability to exert anticancer activity against MGMT-positive melanoma cells. Human melanoma cells with variable MGMT expression levels were treated with NEO212, TMZ, or perillyl alcohol in vitro and in vivo, and markers of DNA damage and apoptosis, and tumor cell growth were investigated. NEO212 displayed substantially greater anticancer activity than any of the other treatments. It reduced colony formation of MGMT-positive cells up to eight times more effectively than TMZ, and much more potently induced DNA damage and cell death. In a nude mouse tumor model, NEO212 showed significant activity against MGMT-positive melanoma, whereas TMZ, or a mix of TMZ plus POH, was ineffective. At the same time, NEO212 was well tolerated. NEO212 may have potential as a more effective therapy for advanced melanoma, and should become particularly suitable for the treatment of patients with MGMT-positive tumors.

  4. Lipoic acid inhibits the DNA repair protein O 6-methylguanine-DNA methyltransferase (MGMT) and triggers its depletion in colorectal cancer cells with concomitant autophagy induction.

    Science.gov (United States)

    Göder, Anja; Nagel, Georg; Kraus, Alexander; Dörsam, Bastian; Seiwert, Nina; Kaina, Bernd; Fahrer, Jörg

    2015-08-01

    Alkylating agents are present in food and tobacco smoke, but are also used in cancer chemotherapy, inducing the DNA lesion O (6)-methylguanine. This critical adduct is repaired by O (6)-methylguanine-DNA methyltransferase (MGMT), resulting in MGMT inactivation and degradation. In the present study, we analyzed the effects of the natural disulfide compound lipoic acid (LA) on MGMT in vitro and in colorectal cancer cells. We show that LA, but not its reduced form dihydrolipoic acid, potently inhibits the activity of recombinant MGMT by interfering with its catalytic Cys-145 residue, which was partially reversible by N-acetyl cysteine. Incubation of HCT116 colorectal cancer cells with LA altered their glutathione pool and caused a decline in MGMT activity. This was mirrored by LA-induced depletion of MGMT protein, which was not attributable to changes in MGMT messenger RNA levels. Loss of MGMT protein coincided with LA-induced autophagy, a process resulting in lysosomal degradation of proteins, including presumably MGMT. LA-stimulated autophagy in a p53-independent manner as revealed by the response of isogenic HCT116 cell lines. Knockdown of the crucial autophagy component beclin-1 and chemical inhibitors blocked LA-induced autophagy, but did not abrogate LA-triggered MGMT degradation. Concomitant with MGMT depletion, LA pretreatment resulted in enhanced O (6)-methylguanine levels in DNA. It also increased the cytotoxicity of the alkylating anticancer drug temozolomide in temozolomide-resistant colorectal cancer cells. Taken together, our study showed that the natural compound LA inhibits MGMT and induces autophagy. Furthermore, LA enhanced the cytotoxic effects of temozolomide, which makes it a candidate for a supplement in cancer therapy.

  5. Quantitative analysis of promoter methylation in exfoliated epithelial cells isolated from breast milk of healthy women

    OpenAIRE

    Wong, Chung M; Anderton, Douglas L.; Smith-Schneider, Sallie; Wing, Megan A; Greven, Melissa C; Arcaro, Kathleen F.

    2010-01-01

    Promoter methylation analysis of genes frequently silenced in breast cancer is a promising indicator of breast cancer risk, as these methylation events are thought to occur long before presentation of disease. The numerous exfoliated epithelial cells present in breast milk may provide the breast epithelial DNA needed for detailed methylation analysis and assessment of breast cancer risk. Fresh breast milk samples and health, lifestyle and reproductive history questionnaires were collected fro...

  6. Quantitative analysis of promoter methylation in exfoliated epithelial cells isolated from breast milk of healthy women.

    Science.gov (United States)

    Wong, Chung M; Anderton, Douglas L; Smith-Schneider, Sallie; Wing, Megan A; Greven, Melissa C; Arcaro, Kathleen F

    2010-10-01

    Promoter methylation analysis of genes frequently silenced in breast cancer is a promising indicator of breast cancer risk, as these methylation events are thought to occur long before presentation of disease. The numerous exfoliated epithelial cells present in breast milk may provide the breast epithelial DNA needed for detailed methylation analysis and assessment of breast cancer risk. Fresh breast milk samples and health, lifestyle, and reproductive history questionnaires were collected from 111 women. Pyrosequencing analysis was conducted on DNA isolated from the exfoliated epithelial cells immunomagnetically separated from the total cell population in the breast milk of 102 women. A total of 65 CpG sites were examined in six tumor suppressor genes: PYCARD (also known as ASC or TMS1), CDH1, GSTP1, RBP1 (also known as CRBP1), SFRP1, and RASSF1. A sufficient quantity of DNA was obtained for meaningful analysis of promoter methylation; women donated an average of 86 ml of milk with a mean yield of 32,700 epithelial cells per ml. Methylation scores were in general low as expected of benign tissue, but analysis of outlier methylation scores revealed a significant relationship between breast cancer risk, as indicated by previous biopsy, and methylation score for several CpG sites in CDH1, GSTP1, SFRP1, and RBP1. Methylation of RASSF1 was positively correlated with women's age irrespective of her reproductive history. Promoter methylation patterns in DNA from breast milk epithelial cells can likely be used to assess breast cancer risk. Additional studies of women at high breast cancer risk are warranted.

  7. Effect of Plant Growth-Promoting Bacteria on Quantitative and Qualitative Yield of Forage Maize

    Directory of Open Access Journals (Sweden)

    R. Abasi

    2016-12-01

    Full Text Available This research was conducted to investigate the effect of growth-promoting bacteria on yield and some traits of maize. This experiment was performed as a factorial randomized complete block design with three replications at research farm of Islamic Azad University, Izeh branch, Iran. The experimental factors included four strains of plant growth-promoting bacteria: Pseudomonas fluorescent 169 (B1, Pseudomonas fluorescent 79 (B2, Pseudomonas putida 108 (B3, Pseudomonas putida 159 (B4 and without bacteria (control, B5 and two corn varieties namely sc 704 (A1 and Bolson (A2. Before planting corn seeds were soaked with liquid inoculation. Plant height, number of leaves per plant and ear, forage yield, dry matter and dry matter digestibility of leaf, stem and ear, crude protein and cell wall without hemicellulose in the leaf, stem and ear were evaluated. Analysis of variances showed that the effects of varieties, bacteria and their interaction on all traits were significant. Plant height, number of leaves per plant and ear, forage yield, dry matter and stem dry matter digestibility were higher in Bolson. Moreover, dry matter digestibility of leaf and ear, crude protein and cell wall without hemicellulose in the leaf, stem and ear of sc 704 were greater, compared to hybrid Bolson. Plant height, number of leaves per plant and ear, forage yield, dry matter and dry matter digestibility of stem and ear were greater in at the presence of fluorescent strains than those of putida strains. The results revealed that bacterial inoculation enhances the grain yield, yield components and quality of forage maize. Bolson seemed potent to outperform sc 704, though this proposition needs further examination in future field trials.

  8. Direct, real-time PCR (MethyLight) assay for methylation of O6-methylguanine-DNA methyltransferase promoter in glioma

    Institute of Scientific and Technical Information of China (English)

    CHEN Gong; WU Xing; YAO Yu; ZHOU Liang-fu; MAO Ying

    2009-01-01

    @@ O6-Methylguanine-DNA methyltransferase (MGMT) is a cellular DNA repair protein that rapidly reverses alkylation (e.g. methylation) at the O6 position of guanine,thereby neutralizing the cytotoxic effects of alkylating agent therapy such as temozolomide (TMZ) and carmustine.1It has been shown that epigenetic silencing of the MGMT gene by promoter methylation shuts down gene transcription2 and reflects a common alteration in primary human tumors leading to MGMT deficiency)Epigenetic silencing of the MGMT gene has been shown to correlate with improved survival in several studies of glioma" patients treated with the alkylating agent. 56therapy4 and has been substantiated in two clinical trials.5.6

  9. Quantitative proteomic analysis of the interaction between the endophytic plant-growth-promoting bacterium Gluconacetobacter diazotrophicus and sugarcane.

    Science.gov (United States)

    Lery, Letícia M S; Hemerly, Adriana S; Nogueira, Eduardo M; von Krüger, Wanda M A; Bisch, Paulo M

    2011-05-01

    Gluconacetobacter diazotrophicus is a plant-growth-promoting bacterium that colonizes sugarcane. In order to investigate molecular aspects of the G. diazotrophicus-sugarcane interaction, we performed a quantitative mass spectrometry-based proteomic analysis by (15)N metabolic labeling of bacteria, root samples, and co-cultures. Overall, more than 400 proteins were analyzed and 78 were differentially expressed between the plant-bacterium interaction model and control cultures. A comparative analysis of the G. diazotrophicus in interaction with two distinct genotypes of sugarcane, SP70-1143 and Chunee, revealed proteins with fundamental roles in cellular recognition. G. diazotrophicus presented proteins involved in adaptation to atypical conditions and signaling systems during the interaction with both genotypes. However, SP70-1143 and Chunee, sugarcane genotypes with high and low contribution of biological nitrogen fixation, showed divergent responses in contact with G. diazotrophicus. The SP70-1143 genotype overexpressed proteins from signaling cascades and one from a lipid metabolism pathway, whereas Chunee differentially synthesized proteins involved in chromatin remodeling and protein degradation pathways. In addition, we have identified 30 bacterial proteins in the roots of the plant samples; from those, nine were specifically induced by plant signals. This is the first quantitative proteomic analysis of a bacterium-plant interaction, which generated insights into early signaling of the G. diazotrophicus-sugarcane interaction.

  10. MGMT enrichment and second gene co-expression in hematopoietic progenitor cells using separate or dual-gene lentiviral vectors.

    Science.gov (United States)

    Roth, Justin C; Alberti, Michael O; Ismail, Mourad; Lingas, Karen T; Reese, Jane S; Gerson, Stanton L

    2015-01-22

    The DNA repair gene O(6)-methylguanine-DNA methyltransferase (MGMT) allows efficient in vivo enrichment of transduced hematopoietic stem cells (HSC). Thus, linking this selection strategy to therapeutic gene expression offers the potential to reconstitute diseased hematopoietic tissue with gene-corrected cells. However, different dual-gene expression vector strategies are limited by poor expression of one or both transgenes. To evaluate different co-expression strategies in the context of MGMT-mediated HSC enrichment, we compared selection and expression efficacies in cells cotransduced with separate single-gene MGMT and GFP lentivectors to those obtained with dual-gene vectors employing either encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) or foot and mouth disease virus (FMDV) 2A elements for co-expression strategies. Each strategy was evaluated in vitro and in vivo using equivalent multiplicities of infection (MOI) to transduce 5-fluorouracil (5-FU) or Lin(-)Sca-1(+)c-kit(+) (LSK)-enriched murine bone marrow cells (BMCs). The highest dual-gene expression (MGMT(+)GFP(+)) percentages were obtained with the FMDV-2A dual-gene vector, but half of the resulting gene products existed as fusion proteins. Following selection, dual-gene expression percentages in single-gene vector cotransduced and dual-gene vector transduced populations were similar. Equivalent MGMT expression levels were obtained with each strategy, but GFP expression levels derived from the IRES dual-gene vector were significantly lower. In mice, vector-insertion averages were similar among cells enriched after dual-gene vectors and those cotransduced with single-gene vectors. These data demonstrate the limitations and advantages of each strategy in the context of MGMT-mediated selection, and may provide insights into vector design with respect to a particular therapeutic gene or hematologic defect.

  11. BACH1 Promotes Temozolomide Resistance in Glioblastoma through Antagonizing the Function of p53

    Science.gov (United States)

    Nie, Er; Jin, Xin; Wu, Weining; Yu, Tianfu; Zhou, Xu; Zhi, Tongle; Shi, Zhumei; Zhang, Junxia; Liu, Ning; You, Yongping

    2016-01-01

    The acquisition of drug resistance is a persistent clinical problem limiting the successful treatment of glioblastoma (GBM). However, the molecular mechanisms by which initially chemoresponsive tumors develop therapeutic resistance remain poorly understood. In this study, we report that BACH1, a heme-binding protein that participates in transcriptional repression or activation, was significantly upregulated in glioblastoma tissues. Overexpression of BACH1 in GBM cells conferred resistance to temozolomide, whereas its inhibition markedly sensitized resistant cells to temozolomide in vitro and in vivo. Further investigation revealed that BACH1 activation significantly enhanced the expression of MGMT, and depletion of p53 disrupted the effects of BACH1 on MGMT and temozolomide resistance. P53 sequesters SP1 to prevent its binding to the MGMT promoter region and thus inhibits MGMT expression. Moreover, BACH1 overexpression impaired the association between p53 and SP1 via competitive binding p53, and antagonized the impact of p53 on MGMT expression. Finally, we found that BACH1 low expression correlated with better prognosis in GBM patients undergoing temozolomide therapy, especially in patients with wild-type TP53. Collectively, our findings identify a potential mechanism by which wild-type TP53 GBM cells develop resistance to temozolomide and suggest that targeting this pathway may be beneficial for overcoming resistance. PMID:28000777

  12. O 6 -methylguanine DNA methyltransferase gene promoter methylation in high-grade gliomas: A review of current status

    Directory of Open Access Journals (Sweden)

    Vaishali Suri

    2011-01-01

    Full Text Available Assessment of promoter methylation of the O 6 -methylguanine DNA methyltransferase (MGMT gene has recently gained importance in molecular profiling of high-grade gliomas. It has emerged not only as an important prognostic marker but also as a predictive marker for response to temozolomide in patients with newly diagnosed glioblastoma. Further, recent studies indicate that MGMT promoter methylation has strong prognostic relevance even in anaplastic (grade III gliomas, irrespective of therapy (chemotherapy or radiotherapy. This article provides an overview of its use as a predictive and prognostic biomarker, as well as the methods employed for its assessment and use in therapeutic decision making.

  13. Investigation of MGMT and DAPK1 methylation patterns in diffuse large B-cell lymphoma using allelic MSP-pyrosequencing

    DEFF Research Database (Denmark)

    Kristensen, Lasse Sommer; Treppendahl, Marianne Bach; Asmar, Fazila

    2013-01-01

    The tumor suppressor genes MGMT and DAPK1 become methylated in several cancers including diffuse large B-cell lymphoma (DLBCL). However, allelic methylation patterns have not been investigated in DLBCL. We developed a fast and cost-efficient method for the analysis of allelic methylation based...

  14. DNA修复酶(MGMT)在人胃肠癌中表达的临床意义%CLINICAL SIGNIFICANCE OF MGMT EXPRESSION IN HUMAN GASTROENTERIC CANCER

    Institute of Scientific and Technical Information of China (English)

    薄爱华; 邢立强; 卢广平; 孙素梅

    2006-01-01

    目的探讨MGMT在胃肠癌中表达的临床意义.方法93例胃肠癌(其中胃癌53例,大肠癌40例)利用SABC免疫组织化学方法检测MGMT.结果在胃肠癌中MGMT阳性率为49.46%(46/93),在胃癌和大肠癌中阳性率分别为45.28%(24/53)和55.00%(22/40).66岁以上老年组MGMT阳性率明显低于其他年龄组(P<0.05),癌组织浸润深度达浆膜组和有淋巴结转移组MGMT阳性率高.MGMT在胃肠癌中的表达与性别和癌组织类型、分化程度相关性不明显(P>0.05).结论MGMT在胃肠癌中的表达与年龄、浸润深度和淋巴结转移有关.

  15. Personal health promotion at US medical schools: a quantitative study and qualitative description of deans' and students' perceptions

    Directory of Open Access Journals (Sweden)

    Elon Lisa K

    2004-12-01

    Full Text Available Abstract Background Prior literature has shown that physicians with healthy personal habits are more likely to encourage patients to adopt similar habits. However, despite the possibility that promoting medical student health might therefore efficiently improve patient outcomes, no one has studied whether such promotion happens in medical school. We therefore wished to describe both typical and outstanding personal health promotion environments experienced by students in U.S. medical schools. Methods We collected information through four different modalities: a literature review, written surveys of medical school deans and students, student and dean focus groups, and site visits at and interviews with medical schools with reportedly outstanding student health promotion programs. Results We found strong correlations between deans' and students' perceptions of their schools' health promotion environments, including consistent support of the idea of schools' encouraging healthy student behaviors, with less consistent follow-through by schools on this concept. Though students seemed to have thought little about the relationships between their own personal and clinical health promotion practices, deans felt strongly that faculty members should model healthy behaviors. Conclusions Deans' support of the relationship between physicians' personal and clinical health practices, and concern about their institutions' acting on this relationship augurs well for the role of student health promotion in the future of medical education. Deans seem to understand their students' health environment, and believe it could and should be improved; if this is acted on, it could create important positive changes in medical education and in disease prevention.

  16. The Expression of P53, MGMT and EGFR in Glioma and Their Clinical Significance%脑胶质瘤中P53,MGMT,EGFR的表达及临床意义

    Institute of Scientific and Technical Information of China (English)

    骆竹媚; 周从明; 李平

    2014-01-01

    目的探讨P53,MGMT,EGFR在脑胶质瘤中的表达及临床意义。方法收集40例患者的临床特点,用免疫组化染色后,观察计算标本中P53,MGMT,EGFR的表达,分析其与脑胶质瘤的关系,及其两两间的关系。结果40例脑胶质瘤标本中,P53的阳性表达率是47.5%,其中高级别脑胶质瘤的表达高于低级别脑胶质瘤( P0.05);EGFR的阳性表达率是55%,其中高级别脑胶质瘤的表达高于低级别脑胶质瘤(P0.05).EGFR expression was detected with a 55% positive rate.The ex-pression rate of EGFR in gradeI/IIgliomas was higher than in gradeⅢ/Ⅳgliomas (P0.05).The expression of P53 was positively correlated with the expression of EGFR (P<0.05).The expression of P53 was negative correlated to the expression of MGMT (P<0.05). Con-clusion The expression of P53, MGMT, and EGFR may play an important role in the occurrence and development of glioma.

  17. Quantitation of 35S promoter in maize DNA extracts from genetically modified organisms using real-time polymerase chain reaction, part 2: interlaboratory study.

    Science.gov (United States)

    Feinberg, Max; Fernandez, Sophie; Cassard, Sylvanie; Bertheau, Yves

    2005-01-01

    The European Committee for Standardization (CEN) and the European Network of GMO Working Laboratories have proposed development of a modular strategy for stepwise validation of complex analytical techniques. When applied to the quantitation of genetically modified organisms (GMOs) in food products, the instrumental quantitation step of the technique is separately validated from the DNA extraction step to better control the sources of uncertainty and facilitate the validation of GMO-specific polymerase chain reaction (PCR) tests. This paper presents the results of an interlaboratory study on the quantitation step of the method standardized by CEN for the detection of a regulatory element commonly inserted in GMO maize-based foods. This is focused on the quantitation of P35S promoter through using the quantitative real-time PCR (QRT-PCR). Fifteen French laboratories participated in the interlaboratory study of the P35S quantitation operating procedure on DNA extract samples using either the thermal cycler ABI Prism 7700 (Applied Biosystems, Foster City, CA) or Light Cycler (Roche Diagnostics, Indianapolis, IN). Attention was focused on DNA extract samples used to calibrate the method and unknown extract samples. Data were processed according to the recommendations of ISO 5725 standard. Performance criteria, obtained using the robust algorithm, were compared to the classic data processing after rejection of outliers by the Cochran and Grubbs tests. Two laboratories were detected as outliers by the Grubbs test. The robust precision criteria gave values between the classical values estimated before and after rejection of the outliers. Using the robust method, the relative expanded uncertainty by the quantitation method is about 20% for a 1% Bt176 content, whereas it can reach 40% for a 0.1% Bt176. The performances of the quantitation assay are relevant to the application of the European regulation, which has an accepted tolerance interval of about +/-50%. These data

  18. Ursolic acid attenuates temozolomide resistance in glioblastoma cells by downregulating O6-methylguanine-DNA methyltransferase (MGMT) expression

    Science.gov (United States)

    Zhu, Zhongling; Du, Shuangshuang; Ding, Fengxia; Guo, Shanshan; Ying, Guoguang; Yan, Zhao

    2016-01-01

    The DNA-alkylating agent temozolomide (TMZ) is an effective chemotherapeutic agent against malignant glioma, including glioblastoma multiforme (GBM). However, the clinical efficacy of TMZ is limited in many patients because of O6-methylguanine-DNA methyltransferase (MGMT)-driven resistance. Thus, new strategies to overcome TMZ resistance are urgently needed. Ursolic acid (UA) is a naturally derived pentacyclic triterpene acid that exerts broad anticancer effects, and shows capability to cross the blood-brain barrier. In this study, we evaluated the possible synergistic effect of TMZ and UA in resistant GBM cell lines. The results showed that UA prevented the proliferation of resistant GBM cells in a concentration-dependent manner. Compared with TMZ or UA treatment alone, the combination treatment of TMZ and UA synergistically enhanced cytotoxicity and senescence in TMZ-resistant GBM cells. This effect was correlated with the downregulation of MGMT. Moreover, experimental results with an in vivo mouse xenograft model showed that the combination treatment of UA and TMZ reduced tumor volumes by depleting MGMT. Therefore, UA as both a monotherapy and a resensitizer, might be a candidate agent for patients with refractory malignant gliomas. PMID:27508051

  19. Quantitative assessment of the diagnostic role of FHIT promoter methylation in non-small cell lung cancer

    Science.gov (United States)

    Tan, Yulong; Lu, Zhouyi; Wang, An; Tan, Lixing; Chen, Sidi; Guo, Shicheng; Wang, Jiucun; Chen, Xiaofeng

    2017-01-01

    Aberrant methylation of CpG islands acquired in promoter regions plays an important role in carcinogenesis. Accumulated evidence demonstrates FHIT gene promoter hyper-methylation is involved in non-small cell lung cancer (NSCLC). To test the diagnostic ability of FHIT methylation status on NSCLC, thirteen studies, including 2,119 samples were included in our meta-analysis. Simultaneously, four independent DNA methylation datasets from TCGA and GEO database were analyzed for validation. The pooled odds ratio of FHIT promoter methylation in cancer samples was 3.43 (95% CI: 1.85 to 6.36) compared with that in controls. In subgroup analysis, significant difference of FHIT gene promoter methylation status in NSCLC and controls was found in Asians but not in Caucasian population. In validation stage, 950 Caucasian samples, including 126 paired samples from TCGA, 568 cancer tissues and 256 normal controls from GEO database were analyzed, and all 8 CpG sites near the promoter region of FHIT gene were not significantly differentially methylated. Thus the diagnostic role of FHIT gene in the lung cancer may be relatively limited in the Caucasian population but useful in the Asians. PMID:28036263

  20. A Quantitative Examination of Perceived Promotability of Information Security Professionals with Vendor-Specific Certifications versus Vendor-Neutral Certifications

    Science.gov (United States)

    Gleghorn, Gregory D.

    2011-01-01

    Human capital theory suggests the knowledge, skills, and abilities one obtains through experience, on-the-job training, or education enhances one's productivity. This research was based on human capital theory and promotability (i.e., upward mobility). The research offered in this dissertation shows what effect obtaining information security…

  1. Neoadjuvant cisplatin plus temozolomide versus standard treatment in patients with unresectable glioblastoma or anaplastic astrocytoma: a differential effect of MGMT methylation.

    Science.gov (United States)

    Capdevila, Laia; Cros, Sara; Ramirez, Jose-Luis; Sanz, Carolina; Carrato, Cristina; Romeo, Margarita; Etxaniz, Olatz; Hostalot, Cristina; Massuet, Ana; Cuadra, Jose Luis; Villà, Salvador; Balañà, Carmen

    2014-03-01

    Patients with unresectable glioblastoma or anaplastic astrocytoma have a dismal prognosis. The role of neoadjuvant chemotherapy prior to irradiation in these patients has been studied primarily in non-randomized studies. We have compared the effect of neoadjuvant chemotherapy plus radiotherapy versus concomitant radiotherapy plus temozolomide in a retrospective analysis of two consecutive series of patients in whom surgery consisted of biopsy only. From 2003 to 2005, 23 patients received two cycles of temozolomide plus cisplatin followed by radiotherapy (Cohort 1), and from 2006 to 2010, 23 additional patients received concomitant radiotherapy and temozolomide followed by adjuvant temozolomide (Cohort 2). In Cohort 1, 91.3 % of patients received all planned chemotherapy cycles. Progression-free and overall survival were 3.3 and 8.5 months, respectively. In Cohort 2, progression-free and overall survival were 5.1 and 11.2 months, respectively. No differences between the two groups were observed in rate of completion of radiotherapy, progression-free or overall survival. MGMT methylation was assessed in 91.3 % of patients. In Cohort 1, patients without MGMT methylation showed a trend towards shorter progression-free survival (P = 0.09), while in Cohort 2, patients without MGMT methylation had longer progression-free survival (P = 0.04). In the overall patient population, neoadjuvant temozolomide plus cisplatin had neither a positive nor negative influence on outcome. However, our findings indicate that patients with methylated MGMT may derive greater benefit from neoadjuvant temozolomide than those with unmethylated MGMT.

  2. The contrasting epigenetic role of RUNX3 when compared with that of MGMT and TIMP3 in glioblastoma multiforme clinical outcomes.

    Science.gov (United States)

    Saraiva-Esperón, Uxia; Ruibal, Alvaro; Herranz, Michel

    2014-12-15

    Glioblastoma multiforme (GBM) is the most frequent and malignant astrocytic glioma in the adult, with a survival rate at 5 years less than 5%. In the GBM pathogenesis, the importance of genes methylation involved in cell cycle, tumor suppression, DNA repair and genome integrity, as well as tumor invasion and apoptosis has been described. We analyzed epigenetic regulation involvement of two genes related with apoptosis: TIMP3 and RUNX3 in order to define a clinical profile and compare with the most studied gene in GBM: MGMT. Eighty samples from GBM patients were evaluated by methylation specific PCR (MSP). Data from each patient were collected from medical histories to relate survival rates with gene methylation patterns. Methylation percentages obtained were: MGMT 45%, RUNX3 30% and TIMP3 28%. The study of MGMT methylation had prognostic value in patients with glioblastoma multiforme because at 8 months, 28% of patients survived with the gene methylated, while none of them lived with the gene unmethylated (P=0.016). RUNX3 behavior was opposite to TIMP3 and MGMT. TIMP3action, in terms of patient's survival, was similar to that observed with MGMT, percentage of patients surviving at 8 months with the gene methylated was 27%, compared with 7% of those with the unmethylated gene; there being a tendency to statistical significance (p=0.09).

  3. MGMT methylation analysis of glioblastoma on the Infinium methylation BeadChip identifies two distinct CpG regions associated with gene silencing and outcome, yielding a prediction model for comparisons across datasets, tumor grades, and CIMP-status

    NARCIS (Netherlands)

    P. Bady (Pierre); D. Sciuscio (Davide); A.C. Diserens; J. Bloch (Jocelyne); M.J. van den Bent (Martin); C. Marosi (Christine); P-Y. Dietrich (Pierre Yves); M. Weller (Michael); L. Mariani (Luigi); F.L. Heppner (Frank ); D.R. Mcdonald (David ); D. Lacombe (Denis); R. Stupp (Roger); M. Delorenzi (Mauro); M.E. Hegi (Monika)

    2012-01-01

    textabstractThe methylation status of the O6-methylguanine- DNA methyltransferase (MGMT) gene is an important predictive biomarker for benefit from alkylating agent therapy in glioblastoma. Recent studies in anaplastic glioma suggest a prognostic value for MGMT methylation. Investigation of pathogen

  4. Valproic Acid Downregulates the Expression of MGMT and Sensitizes Temozolomide-Resistant Glioma Cells

    Directory of Open Access Journals (Sweden)

    Chung Heon Ryu

    2012-01-01

    Full Text Available Temozolomide (TMZ has become a key therapeutic agent in patients with malignant gliomas; however, its survival benefit remains unsatisfactory. Valproic acid (VPA has emerged as an anticancer drug via inhibition of histone deacetylases (HDACs, but the therapeutic advantages of a combination with VPA and TMZ remain poorly understood. The main aim of the present study was to determine whether an antitumor effect could be potentiated by a combination of VPA and TMZ, especially in TMZ-resistant cell lines. A combination of VPA and TMZ had a significantly enhanced antitumor effect in TMZ-resistant malignant glioma cells (T98 and U138. This enhanced antitumor effect correlated with VPA-mediated reduced O6-methylguanine-DNA methyltransferase (MGMT expression, which plays an important role in cellular resistance to alkylating agents. In vitro, the combination of these drugs enhanced the apoptotic and autophagic cell death, as well as suppressed the migratory activities in TMZ-resistant cell lines. Furthermore, in vivo efficacy experiment showed that treatment of combination of VPA and TMZ significantly inhibited tumor growth compared with the monotherapy groups of mice. These results suggest that the clinical efficacy of TMZ chemotherapy in TMZ-resistant malignant glioma may be improved by combination with VPA.

  5. Advances in the management of glioblastoma: the role of temozolomide and MGMT testing

    Directory of Open Access Journals (Sweden)

    Thomas RP

    2012-12-01

    Full Text Available Reena P Thomas, Lawrence Recht, Seema NagpalDepartment of Neurological Sciences, Stanford University Hospital, Stanford, CA, USAAbstract: Glioblastoma (GB is one of the most lethal forms of cancer, with an invasive growth pattern that requires the use of adjuvant therapies, including chemotherapy and radiation, to prolong survival. Temozolomide (TMZ is an oral chemotherapy with a limited side effect profile that has become the standard of care in GB treatment. While TMZ has made an impact on survival, tumor recurrence and TMZ resistance remain major challenges. Molecular markers, such as O6-methylguanine-DNA methyltransferase methylation status, can be helpful in predicting tumor response to TMZ, and therefore guides clinical decision making. This review will discuss the epidemiology and possible genetic underpinnings of GB, how TMZ became the standard of care for GB patients, the pharmacology of TMZ, the practical aspects of using TMZ in clinic, and how molecular diagnostics – particularly the use of O6-methylguanine-DNA methyltransferase status – affect clinical management.Keywords: glioblastoma, temozolomide, PredictMDx™, MGMT

  6. Support vector regression-guided unravelling: antioxidant capacity and quantitative structure-activity relationship predict reduction and promotion effects of flavonoids on acrylamide formation

    Science.gov (United States)

    Huang, Mengmeng; Wei, Yan; Wang, Jun; Zhang, Yu

    2016-09-01

    We used the support vector regression (SVR) approach to predict and unravel reduction/promotion effect of characteristic flavonoids on the acrylamide formation under a low-moisture Maillard reaction system. Results demonstrated the reduction/promotion effects by flavonoids at addition levels of 1-10000 μmol/L. The maximal inhibition rates (51.7%, 68.8% and 26.1%) and promote rates (57.7%, 178.8% and 27.5%) caused by flavones, flavonols and isoflavones were observed at addition levels of 100 μmol/L and 10000 μmol/L, respectively. The reduction/promotion effects were closely related to the change of trolox equivalent antioxidant capacity (ΔTEAC) and well predicted by triple ΔTEAC measurements via SVR models (R: 0.633-0.900). Flavonols exhibit stronger effects on the acrylamide formation than flavones and isoflavones as well as their O-glycosides derivatives, which may be attributed to the number and position of phenolic and 3-enolic hydroxyls. The reduction/promotion effects were well predicted by using optimized quantitative structure-activity relationship (QSAR) descriptors and SVR models (R: 0.926-0.994). Compared to artificial neural network and multi-linear regression models, SVR models exhibited better fitting performance for both TEAC-dependent and QSAR descriptor-dependent predicting work. These observations demonstrated that the SVR models are competent for predicting our understanding on the future use of natural antioxidants for decreasing the acrylamide formation.

  7. Feasibility of an implementation strategy for the integration of health promotion in routine primary care: a quantitative process evaluation.

    Science.gov (United States)

    Sanchez, Alvaro; Grandes, Gonzalo; Cortada, Josep M; Pombo, Haizea; Martinez, Catalina; Corrales, Mary Helen; de la Peña, Enrique; Mugica, Justo; Gorostiza, Esther

    2017-02-17

    Process evaluation is recommended to improve the understanding of underlying mechanisms related to clinicians, patients, context and intervention delivery that may impact on trial or program results, feasibility and transferability to practice. The aim of this study was to assess the feasibility of the Prescribe Healthy Life (PVS from the Spanish "Prescribe Vida Saludable") implementation strategy for enhancing the adoption and implementation of an evidence-based health promotion intervention in primary health care. A descriptive study of 2-year implementation indicators for the PVS clinical intervention was conducted in four primary health care centers. A multifaceted collaborative modeling implementation strategy was developed to enhance the integration of a clinical intervention to promote healthy lifestyles into clinical practice. Process indicators were assessed for intervention reach, adoption, implementation, sustainability and their variability at center, practice, and patient levels. Mean rates of adoption by means of active collaboration among the three main professional categories (family physicians, nurses and administrative personnel) were 75% in all centers. Just over half of the patients that attended (n = 11650; 51.9%) were reached in terms of having their lifestyle habits assessed, while more than a third (33.7%; n = 7433) and almost 10% (n = 2175) received advice or a printed prescription for at least one lifestyle change, respectively. Only 3.7% of the target population received a repeat prescription. These process indicators significantly (p < 0.001) varied by center, lifestyle habit and patient characteristics. Sustainability of intervention components changed thorough the implementation period within centers. The implementation strategy used showed moderate-to-good performance on process indicators related to adoption, reach, and implementation of the evidence-based healthy lifestyle promotion intervention in the context of

  8. Influence of EMAP II, IFN-α2b and its medicinal preparations on the MGMT protein amount in human cells in vitro

    Directory of Open Access Journals (Sweden)

    Lylo V. V.

    2014-11-01

    Full Text Available Aim. To study the effect of EMAP II, IFN-α2b and its medicinal preparations on the amount of O6-methylguanine-DNA methyltransferase (MGMT protein in human cells in vitro. Methods. The human cells of 4BL and Hep-2 lines were treated with the purified recombinant proteins EMAP II, IFN-α2b and its commercial me dicinal preparations. Changes in the MGMT gene expression were studied at a protein level by Western blot analysis. Results. Treatment of Hep-2 and 4BL cells with EMAP II at the concentrations of 0.02 mg/ml and 2 mg/ml respectively led to induction of the MGMT gene expression. EMAP II at the concentrations of 0.2–20 g/ml caused decrease of the MGMT protein amount in Hep-2 cells. The regulating activity of EMAP II was also observed for MARP (anti-Methyltransferase Antibody Recognizable Protein. IFN-α2b and Laferon-PharmBiotek with the activity of 200 and 2000 IU/ml were shown to cause an increase of the MGMT protein amount in Hep-2 cells. Conclusions. The purified recombinant proteins EMAP II and IFN-α2b which are substrates for the medicinal preparations influenced on the amount of MGMT protein in the human cell cultures in a concentration-dependent manner. At the same time the effect of medicinal preparations differs from that of the purified protein IFN-α2b. Possibly it depends on the presence of stabilizing components in their compositions.

  9. Quantitative proteomic analysis reveals effects of epidermal growth factor receptor (EGFR) on invasion-promoting proteins secreted by glioblastoma cells.

    Science.gov (United States)

    Sangar, Vineet; Funk, Cory C; Kusebauch, Ulrike; Campbell, David S; Moritz, Robert L; Price, Nathan D

    2014-10-01

    Glioblastoma multiforme is a highly invasive and aggressive brain tumor with an invariably poor prognosis. The overexpression of epidermal growth factor receptor (EGFR) is a primary influencer of invasion and proliferation in tumor cells and the constitutively active EGFRvIII mutant, found in 30-65% of Glioblastoma multiforme, confers more aggressive invasion. To better understand how EGFR contributes to tumor aggressiveness, we investigated the effect of EGFR on the secreted levels of 65 rationally selected proteins involved in invasion. We employed selected reaction monitoring targeted mass spectrometry using stable isotope labeled internal peptide standards to quantity proteins in the secretome from five GBM (U87) isogenic cell lines in which EGFR, EGFRvIII, and/or PTEN were expressed. Our results show that cell lines with EGFR overexpression and constitutive EGFRvIII expression differ remarkably in the expression profiles for both secreted and intracellular signaling proteins, and alterations in EGFR signaling result in reproducible changes in concentrations of secreted proteins. Furthermore, the EGFRvIII-expressing mutant cell line secretes the majority of the selected invasion-promoting proteins at higher levels than other cell lines tested. Additionally, the intracellular and extracellular protein measurements indicate elevated oxidative stress in the EGFRvIII-expressing cell line. In conclusion, the results of our study demonstrate that EGFR signaling has a significant effect on the levels of secreted invasion-promoting proteins, likely contributing to the aggressiveness of Glioblastoma multiforme. Further characterization of these proteins may provide candidates for new therapeutic strategies and targets as well as biomarkers for this aggressive disease. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Up-regulation of miR-370-3p restores glioblastoma multiforme sensitivity to temozolomide by influencing MGMT expression.

    Science.gov (United States)

    Gao, Yong-Tao; Chen, Xiao-Bing; Liu, Hong-Lin

    2016-01-01

    MicroRNAs (miRNA) are believed to play an important role in glioblastoma multiforme (GBM)chemotherapy. Our study aims to investigate potential miRNA biomarkers in GBM. Sixty GBM patients, which were given temozolomide (TMZ) chemotherapy and recurrent radiotherapy, were recruited. miRNA array was performed in cancerous and in paired normal tissues. Microarray results were further validated by a quantitative real-time PCR in selected tissues and GBM cell lines. TMZ resistance cells were developed and cell proliferation along with colony formation assays was determined. Our study employed H2AX formation and flow cytometry to analyse the role of miRNA in DNA damage and apoptosis. Our study illustrated 16 miRNA in which 9 were up-regulated and 7 down-regulated. and their differential expression were demonstrated in a recurrent GBM tissue. Among them, miRNA-370-3p demonstrated the highest level of down- regulation in tissues and in TMZ resistance cells. miRNA-370-3p mimic increased its expression and sensitivity of GBM cells to TMZ by suppressing the self-reparative ability of tumour cell DNA. O(6)-methylguanine-DNA methyltransferase (MGMT) was identified as the direct target gene of miR-370-3p, and it was found to be inversely correlated with miR-370-3p expression in tissue samples obtained. Thus, our study demonstrated a critical clinical role of an up-regulated miR-370-3p expression in glioblastoma multiforme chemotherapy sensitivity.

  11. A Luciferase Functional Quantitative Assay for Measuring NF-ĸB Promoter Transactivation Mediated by HTLV-1 and HTLV-2 Tax Proteins.

    Science.gov (United States)

    Bergamo, Elisa; Diani, Erica; Bertazzoni, Umberto; Romanelli, Maria Grazia

    2017-01-01

    HTLV-1 and HTLV-2 viruses express Tax transactivator proteins required for viral genome transcription and capable of transforming cells in vivo and in vitro. Although Tax oncogenic potential needs to be further elucidated, it is well established that Tax proteins activate, among others, transcription factors of the NF-ĸB family, which are involved in immune and inflammatory responses, cell growth, apoptosis, stress responses and oncogenesis. Here, we describe a reporter gene assay applied for quantitative analysis of Tax-dependent NF-ĸB activation. The procedure is based on co-transfection of two individual vectors containing the cDNA for firefly and Renilla luciferase enzymes and vectors expressing Tax proteins. The luciferase expression is driven by cis-NF-ĸB promoter regulatory elements responsive to Tax transactivating factor. This assay is particularly useful to investigate Tax influence on NF-ĸB activation mediated by viral or host factors.

  12. The nucleoside diphosphate kinase gene Nme3 acts as quantitative trait locus promoting non-Mendelian inheritance.

    Directory of Open Access Journals (Sweden)

    Hermann Bauer

    Full Text Available The t-haplotype, a variant form of the t-complex region on mouse chromosome 17, acts as selfish genetic element and is transmitted at high frequencies (> 95% from heterozygous (t/+ males to their offspring. This phenotype is termed transmission ratio distortion (TRD and is caused by the interaction of the t-complex responder (Tcr with several quantitative trait loci (QTL, the t-complex distorters (Tcd1 to Tcd4, all located within the t-haplotype region. Current data suggest that the distorters collectively impair motility of all sperm derived from t/+ males; t-sperm is rescued by the responder, whereas (+-sperm remains partially dysfunctional. Recently we have identified two distorters as regulators of RHO small G proteins. Here we show that the nucleoside diphosphate kinase gene Nme3 acts as a QTL on TRD. Reduction of the Nme3 dosage by gene targeting of the wild-type allele enhanced the transmission rate of the t-haplotype and phenocopied distorter function. Genetic and biochemical analysis showed that the t-allele of Nme3 harbors a mutation (P89S that compromises enzymatic activity of the protein and genetically acts as a hypomorph. Transgenic overexpression of the Nme3 t-allele reduced t-haplotype transmission, proving it to be a distorter. We propose that the NME3 protein interacts with RHO signaling cascades to impair sperm motility through hyperactivation of SMOK, the wild-type form of the responder. This deleterious effect of the distorters is counter-balanced by the responder, SMOK(Tcr, a dominant-negative protein kinase exclusively expressed in t-sperm, thus permitting selfish behaviour and preferential transmission of the t-haplotype. In addition, the previously reported association of NME family members with RHO signaling in somatic cell motility and metastasis, in conjunction with our data involving RHO signaling in sperm motility, suggests a functional conservation between mechanisms for motility control in somatic cells and

  13. Prognosis of Glioblastoma With Oligodendroglioma Component is Associated With the IDH1 Mutation and MGMT Methylation Status

    Directory of Open Access Journals (Sweden)

    Jae Kyung Myung

    2014-12-01

    Full Text Available Glioblastoma (GBM with oligodendroglioma component (GBMO is a newly described GBM subtype in the 2007 World Health Organization classification. However, its biological and genetic characteristics are largely unknown. We investigated the clinicopathological and molecular features of 34 GBMOs and compared the survival rate of these patients with those of patients with astrocytoma, oligodendroglioma, anaplastic oligoastrocytoma (AOA, and conventional GBMs in our hospital. GBMO could be divided into two groups based on the presence of an IDH1 mutation. The IDH1 mutation was more frequently found in secondary GBMO, which had lower frequencies of EGFR amplification but higher MGMT methylation than the wild type IDH1 group, and patients with mutant IDH1 GBMO were on average younger than those with wild-type IDH1. Therefore, GBMO is a clinically and molecularly heterogeneous subtype, largely belonging to a proneural and classical subtype of GBM. The survival rate of GBMO patients itself was worse than that of AOA patients but not significantly better than that of conventional GBM patients. GBMO survival was independent of the dominant histopathological subtype i.e., astrocyte-dominant or oligodendroglioma -dominant, but it was significantly associated with the IDH1 mutation and MGMT methylation status. Therefore, GBMO should be regarded as a separate entity from AOA and must be classified as a subtype of GBM. However, further study is needed to determine whether it is a pathologic variant or a pattern of GBM because GBMO has a similar prognosis to conventional GBMs.

  14. Disulfiram is a direct and potent inhibitor of human O6-methylguanine-DNA methyltransferase (MGMT) in brain tumor cells and mouse brain and markedly increases the alkylating DNA damage

    Science.gov (United States)

    Srivenugopal, Kalkunte S.

    2014-01-01

    The alcohol aversion drug disulfiram (DSF) reacts and conjugates with the protein-bound nucleophilic cysteines and is known to elicit anticancer effects alone or improve the efficacy of many cancer drugs. We investigated the effects of DSF on human O6-methylguanine-DNA methyltransferase (MGMT), a DNA repair protein and chemotherapy target that removes the mutagenic O6-akyl groups from guanines, and thus confers resistance to alkylating agents in brain tumors. We used DSF, copper-chelated DSF or CuCl2–DSF combination and found that all treatments inhibited the MGMT activity in two brain tumor cell lines in a rapid and dose-dependent manner. The drug treatments resulted in the loss of MGMT protein from tumor cells through the ubiquitin-proteasome pathway. Evidence showed that Cys145, a reactive cysteine, critical for DNA repair was the sole site of DSF modification in the MGMT protein. DSF was a weaker inhibitor of MGMT, compared with the established O6-benzylguanine; nevertheless, the 24–36h suppression of MGMT activity in cell cultures vastly increased the alkylation-induced DNA interstrand cross-linking, G2/M cell cycle blockade, cytotoxicity and the levels of apoptotic markers. Normal mice treated with DSF showed significantly attenuated levels of MGMT activity and protein in the liver and brain tissues. In nude mice bearing T98 glioblastoma xenografts, there was a preferential inhibition of tumor MGMT. Our studies demonstrate a strong and direct inhibition of MGMT by DSF and support the repurposing of this brain penetrating drug for glioma therapy. The findings also imply an increased risk for alkylation damage in alcoholic patients taking DSF. PMID:24193513

  15. Promoter methylation status of hMLH1,MGMT,and CDKN2A/p16 in colorectal adenomas

    Institute of Scientific and Technical Information of China (English)

    Vasiliki; Psofaki; Chryssoula; Kalogera; Nikolaos; Tzambouras; Dimitrios; Stephanou; Epameinondas; Tsianos; Konstantin; Seferiadis; Georgios; Kolios

    2010-01-01

    AIM:To investigate aberrant DNA methylation of CpG islands and subsequent low-or high-level DNA microsatellite instability(MSI)which is assumed to drive colon carcinogenesis. METHODS:DNA of healthy individuals,adenoma(tu-bular or villous/tubulovillous)patients,and colorectal carcinoma patients who underwent colonoscopy was used for assessing the prevalence of aberrant DNA methylation of human DNA mismatch repair gene mutator L homologue 1(hMLH1),Cyclin-dependent kinase inhibitor 2A(CDKN2A/p16),and O-6-methy...

  16. Long-term survival in glioblastoma: methyl guanine methyl transferase (MGMT promoter methylation as independent favourable prognostic factor

    Directory of Open Access Journals (Sweden)

    Smrdel Uros

    2016-12-01

    Full Text Available In spite of significant improvement after multi-modality treatment, prognosis of most patients with glioblastoma remains poor. Standard clinical prognostic factors (age, gender, extent of surgery and performance status do not clearly predict long-term survival. The aim of this case-control study was to evaluate immuno-histochemical and genetic characteristics of the tumour as additional prognostic factors in glioblastoma.

  17. MGMT和Survivin在乳腺癌中的表达及其临床意义%Expression of MGMT and Survivin in Breast Cancer and Its Clinical Significance

    Institute of Scientific and Technical Information of China (English)

    王发亮; 薄爱华; 芦广萍; 侯金超; 吴荣薇

    2008-01-01

    Objective:To investigate the expression of MGMT and Survivin in breast cancer and its clinical significance.Methods:Specimens from breast adenoma and breast cancer were taken and had been Formalin-fixed,paraffin-embedded.With Strept Avidin-Biotin Complex(SABC) immunohistochemical technique,the expression of MGMT and Survivin in these specimens was examined.Results:It was found that there were significant differences between MGMT and Survivin in breast adenoma and breast lymph node metastasis,while the expression of Survivin was associated with lymph node metastasis only.Meanwhile,the expression of MGMT was correlated with that of Survivin(r=0.34,P<0.01).Conclusion:It was concluded that the abnormal expressions of MGMT and Survivin were associated with lymph node metastasis.They possibly could be useful indexes for the primary screening and the prognosis of breast cancer.The examination of them may have an important guiding significance in the chemotherapy strategy.%目的:研究MGMT和Survivin在乳腺癌中的表达及其临床意义.方法:福尔马林固定,石蜡包埋乳腺癌和腺瘤标本,采用SABC免疫组织化学方法检测MGMT和Survivin在这些组织中的表达.结果:MGMT和Survivin在乳腺癌和乳腺腺瘤中的表达有显著性差异.MGMT在乳腺癌中的表达与患者的年龄、淋巴结转移有关,而Survivin仅与淋巴结转移有关.另外,MGMT和Survivin之间具有相关性(r=0.48,P<0.01).结论:MGMT和Survivin的异常表达与乳腺癌的淋巴结转移有关;MGMT和Survivin可以作为判断乳腺癌发生和预后的重要指标;检测它们的表达可以指导临床上化疗方案的制定.

  18. Avaliação da expressão do gene MGMT nos tecidos normal e neoplásico de doentes com câncer colorretal

    Directory of Open Access Journals (Sweden)

    Adriana Teixeira Cordeiro

    Full Text Available OBJETIVO: Avaliar a expressão tecidual do gene de reparo MGMT comparando a mucosa cólica normal e neoplásica em doentes com câncer colorretal. MÉTODOS: Foram estudados 44 portadores de adenocarcinoma colorretal confirmado por estudo histopatológico. Foram excluídos doentes suspeitos de pertencerem a famílias com câncer colorretal hereditário (HNPCC e PAF e os portadores de câncer do reto médio e inferior submetidos a tratamento quimioradioterápico neoadjuvante. A expressão do gene MGMT foi avaliada pela técnica da reação de polimerase em cadeia em tempo real (RT-PCR. A comparação dos resultados encontrados para expressão do gene MGMT entre tecidos normais e neoplásicos foi feita pelo teste t de Student pareado, adotando-se nível de significância de 5% (p <0,05. RESULTADOS: A expressão tecidual do gene MGMT em todos os doentes foi menor no tecido neoplásico quando comparada a do tecido normal (p=0,002. CONCLUSÃO: O gene de reparo MGMT encontra-se menos expresso no tecido neoplásico quando comparados aos tecidos normais em portadores de CCR esporádico.

  19. 人脑胶质瘤中MGMT、erbB2的表达及其意义%Expression and significance of MGMT and erbB2 in human glioma

    Institute of Scientific and Technical Information of China (English)

    孙春明; 王之敏; 周幽心; 左剑玲; 许期年; 王秀英; 周岱

    2009-01-01

    Objective To study the expression and significance of MGMT and erbB2 in human glioma. Methods RT-PCR method was used to determine the mRNA levels of MGMT and erbB2 gene in 42 clinical glioma specimens. Results The expression rates of MGMT and erbB2 in human glioma were 45. 2% and 61. 9%, respectively. The expression of MGMT was closely correlated to that of erbB2 (P<0. 01). Conclusion MGMT and erbB2 are all overexpressed in human gliomas, which is helpful to the drug selection for chemotherapy.%目的 探讨脑胶质瘤组织中耐药相关基因MGMT、erbB2的表达及临床意义.方法 采用RT-PCR法对42例脑胶质瘤标本中MGMT、erbB2 mRNA进行测定.结果 MGMT和erbB2在脑胶质瘤标本中的阳性表达率分别为45.2%和61.9%,两者有极显著相关性(P<0.01).结论 MGMT和erbB2在脑胶质瘤中均有较高表达,对合理选择胶质瘤化疗药物有一定临床意义.

  20. Complaints, Complainants, and Rulings Regarding Drug Promotion in the United Kingdom and Sweden 2004–2012: A Quantitative and Qualitative Study of Pharmaceutical Industry Self-Regulation

    OpenAIRE

    Anna V Zetterqvist; Juan Merlo; Shai Mulinari

    2015-01-01

    Editors' Summary Background Making and selling medicines is big business. In 2013, the global revenue of pharmaceutical companies was nearly US$1 trillion. And every year, a large proportion of this revenue—maybe as much as one-third—is spent on drug promotion. The pharmaceutical companies claim that drug promotion (for example, advertisements in journals and visits from pharmaceutical sales representatives) helps to inform and educate health care professionals about the risks and benefits of...

  1. Aberrant gene promoter methylation in sputum from individuals exposed to smoky coal emissions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.; Lan, Q.; Shen, M.; Jin, J.; Mumford, J.; Ren, D.X.; Keohavong, P. [University of Pittsburgh, Pittsburgh, PA (United States). Dept. of Environment and Occupational Health

    2008-07-15

    Recent studies suggested the potential for aberrant gene promoter methylation in sputum as a predictive marker for lung cancer. Here, the promoter methylation of p16, MGMT, RASSF1A and DAPK genes was investigated in sputum of individuals exposed to smoky coal emissions in Xuan Wei, China, where the lung cancer rate is more than 6 times the Chinese national average. Sputum DNA of 107 noncancer individuals and 58 lung cancer patients was screened for promoter methylation using methylation-specific PCR. Promoter methylation of the p16 gene was detected in about half (51.4% (551107)) of sputum DNA from noncancer individuals, a frequency higher than that observed for the RASSF1A (29.9%), MGMT (17.8%) and DAPK (15.9%) genes. Furthermore, the p16 gene was affected by promoter methylation at a frequency even higher among the lung cancer group, compared with the noncancer group (70.7% (41/58) versus 51.7% (55/107), p=0.017). Individuals exposed to smoky coal emissions in this region harbored frequent promoter methylation of these genes in their sputum and some of such alterations may be involved in lung tumor development.

  2. Oxidative cytotoxic agent withaferin A resensitizes temozolomide-resistant glioblastomas via MGMT depletion and induces apoptosis through Akt/mTOR pathway inhibitory modulation.

    Science.gov (United States)

    Grogan, Patrick T; Sarkaria, Jann N; Timmermann, Barbara N; Cohen, Mark S

    2014-08-01

    Temozolomide (TMZ) has remained the chemotherapy of choice in patients with glioblastoma multiforme (GBM) primarily due to the lack of more effective drugs. Tumors, however, quickly develop resistance to this line of treatment creating a critical need for alternative approaches and strategies to resensitize the cells. Withaferin A (WA), a steroidal lactone derived from several genera of the Solanaceae plant family has previously demonstrated potent anti-cancer activity in multiple tumor models. Here, we examine the effects of WA against TMZ-resistant GBM cells as a monotherapy and in combination with TMZ. WA prevented GBM cell proliferation by dose-dependent G2/M cell cycle arrest and cell death through both intrinsic and extrinsic apoptotic pathways. This effect correlated with depletion of principle proteins of the Akt/mTOR and MAPK survival and proliferation pathways with diminished phosphorylation of Akt, mTOR, and p70 S6K but compensatory activation of ERK1/2. Depletion of tyrosine kinase cell surface receptors c-Met, EGFR, and Her2 was also observed. WA demonstrated induction of N-acetyl-L-cysteine-repressible oxidative stress as measured directly and through a subsequent heat shock response with HSP32 and HSP70 upregulation and decreased HSF1. Finally, pretreatment of TMZ-resistant GBM cells with WA was associated with O6-methylguanine-DNA methyltransferase (MGMT) depletion which potentiated TMZ-mediated MGMT degradation. Combination treatment with both WA and TMZ resulted in resensitization of MGMT-mediated TMZ-resistance but not resistance through mismatch repair mutations. These studies suggest great clinical potential for the utilization of WA in TMZ-resistant GBM as both a monotherapy and a resensitizer in combination with the standard chemotherapeutic agent TMZ.

  3. Effect of Promoter Hypermethylation of DNA Repair Gene O6- methylguanine DNA Methyltransferase to the Treatment of Temozolomide in Glioblastoma%MGMT甲基化影响替莫唑胺对胶质母细胞瘤疗效的研究

    Institute of Scientific and Technical Information of China (English)

    李庆斌; 李瑞岩; 丛方方; 丁美娇; 李永利

    2012-01-01

    目的:探讨MGMT甲基化如何影响替莫唑胺对胶质母细胞瘤的治疗效果.方法:选取41个胶质母细胞瘤患者(根据相同替莫唑胺化疗方案治疗下临床结局的不同分为两组)的肿瘤组织,采用甲基化特异性聚合酶链反应分析胶质瘤组织中MGMT基因启动子区过甲基化状态,同时采用免疫组织化学法分析胶质瘤组织中MGMT蛋白表达情况.结果:临床结局不佳组中,以MGMT蛋白表达阳性的肿瘤为主(72.2%),而在结局相对良好组中,MGMT蛋白表达的阳性率仅为39.1%;在MGMT蛋白表达阳性的22例胶质母细胞瘤组织中,7例MGMT启动子甲基化,阳性率为31.8%,在MGMGT蛋白表达阴性的19例中,14例MGMT启动子甲基化,阳性率为73.7%(P<0.05).结论:MGMT基因启动子区的甲基化状态与MGMT蛋白的表达相关.MGMT基因启动子过甲基化,MGMT蛋白表达较低;MGMT基因启动子去甲基化,MGMT蛋白表达较高.MGMT启动子过甲基化通过抑制MGMT基因的表达而增加替莫唑胺的疗效.%Objective: To investigate the effect of the hypermethylation of MGMT promoter on the treatment of temozolomide to glioblastomas (GBM). Methods: Tumors were chosen (divided into two groups according to different clinical endings with the same treatment of lemozolomide); Methylalion-specific PCR was used to detect the promoter methylation of Ihe MGMT gene and loss of transcription in glioma tissues. MGMT expression was examined by immunohistochemistry method. Results: The majority(72.2%) of tumors' MGMT protein expressed positive in the group whose clinical endings are bad, but the positive rate is only 39.1% in the oClier group whose clinical endings are relatively good. Among the 41 GBM samples, MGMT expressed in 22 samples, in which hypermethylation was in 7 (31.7%) cases, while there was no MGMT expression in 19 samples, in which hypermethylation was detected in 14(73.7%) cases. Spearman correlation coefficient was used to analyze the

  4. Effects of formaldehyde on MGMT in mice organs%甲醛对小鼠脏器MGMT的影响

    Institute of Scientific and Technical Information of China (English)

    张全武; 孙少华; 王振全

    2004-01-01

    目的研究甲醛对小鼠脏器O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)表达的影响.方法选择健康昆明小鼠40只,随机分为4组:甲醛低剂量组(2.5 mg/m3)、中剂量组(5 mg/m3)、高剂量组(10 mg/m3)、对照组(无甲醛暴露),每组10只.除阴性对照组外,其余3组每日吸入甲醛1次,每次4 h,连续9周.应用链霉亲和素生物素-过氧化物酶(SABC)免疫组化法对小鼠脑、肺、肝及肾组织中MGMT进行检测.结果 3个染毒组小鼠肝和肺组织中MGMT表达降低,与对照组比较具有显著性差异(P<0.05或P<0.01);脑和肾组织MGMT表达各组之间无显著性差异(P>0.05).结论甲醛对小鼠肝和肺组织MGMT表达可能具有抑制作用.

  5. MAXIMIZATION OF DNA DAMAGE TO MGMT(+ EGFR(+ GBM CELLS USING OPTIMAL COMBINATION OF TEMOZOLOMIDE-ANTI EGFR MONOCLONAL ANTIBODY NIMOTUZUMAB

    Directory of Open Access Journals (Sweden)

    M. A. M. Inggas

    2015-09-01

    Full Text Available Background: Glioblastoma multiforme (GBM is the most aggressive primary brain tumor in adultswith dismal prognosis due to the unavailability of an effective therapy. Up to now, there had been no definitive studies published on EGFR inhibition therapy as a chemosensitizer for GBM therapy using Temozolomide (TMZ. This study aims to reveal the most effective method and timing to administer TMZ-anti EGFR targeted therapy which causes maximal DNA damage on GBM cells.Methods: Various regimens of anti EGFR monoclonal antibody Nimotuzumab (NMZ was administered in different combinations with TMZ, performed on U87MG MGMT(+ EGFR(+ cells. The effectiveness of the combinations were evaluated by measuring yH2AX levels which reflects the degree of DNA damage. One-way Anova and LSD tests were performed to determine the effects of each treatment with p<0.05. Results and discussion: the mean SD of yH2AX of each treatment was: 11,90±1,25 for the control group; 29.33±1.91 for NMZ alone; 28.13±1.58 for TMZ alone; 41.53±3.51 for concurrent use; 35.67 ±2.65 for NMZ after 24 hours TMZ; 31.87±2.94 for NMZ after 48 hours TMZ; 39.57±4.2 for TMZ after 24 hours NMZ; and 35.93 ±3.56 for TMZ after 48 hours NMZ. The administration of TMZ concurrent with or after 24 hours NMZ gives the highest amount of DNA damage to GBM cells. Conclusion: The administration of Nimotuzumab targeted therapy up to 24 hours before Temozolomide chemotherapy has been proven to be effective in maximizing the amount of DNA damage done to GBM cells in vitro. 

  6. 脑膜胶质瘤基因MGMT在胶质瘤组织中表达的临床研究%The clinical research of the MGMT expression levels in glioma pations

    Institute of Scientific and Technical Information of China (English)

    夏海成; 朱正权; 刘亮; 田海龙; 孙哲

    2011-01-01

    目的 探讨新疆维吾尔族胶质瘤患者肿瘤组织中0(6)-甲基鸟嘌呤DNA甲基转移酶(MGMT)表达水平与肿瘤病理级别之间的相关性以及种族因素对胶质瘤组织中MGMT表达水平的影响。方法 运用免疫组化法检测33例维吾尔族胶质瘤患者以及61例汉族胶质瘤患者肿瘤组织中的MGMT表达水平,对其与病理级别之间的相关性和种族因素对胶质瘤肿瘤组织中MGMT表达水平的影响进行分析。结果 61例胶质瘤患者中MGMT阳性率为45.90%,33例维族胶质瘤患者MGMT阳性率为30.30%,两个种族间差异无统计学意义(P>0.05)。对94例胶质瘤患者肿瘤组织MGMT表达水平与病理级别的相关性进行统计学分析,肿瘤组织MGMT表达水平与病理级别不相关(P>0.05)。结论 胶质瘤患者肿瘤组织MGMT表达水平与病理级别无明确相关;种族因素对胶质瘤肿瘤组织中MGMT表达水平无明显影响。%Objective To investigate the correlation between the expression of tumor O (6)-methylquanine DNA methyl-tranferase(MGMT) and pathological grade,and the influence of racial factors on tumor MGMT expression levels for glioma patients. Methods Compare and analysis the correlation between the pathological grade and MGMT levels and the racial factors on MGMT expression levels by the immunohistochemical staining on the tumor specimens of 33 Uygur and 61 Han. Results The positive rate of 61 Han gliomas pations with MGMT is 45.90% and 33 cases of the Uygur is 30. 30% , there's no clear correlation between the racial factors and the tumor MGMT levels. (P > 0. 05). Comparative the 94 patients with pathological level and tumor MGMT level, there is no clear correlation between pathologic level and MGMT pression in tumor tissues (P > 0. 05 ). ConclusionThere's no clear correlation of tumor MGMT expression and pathological levels; and there's no significant effect between racial factors and expression of glioma MGMT.

  7. Complaints, Complainants, and Rulings Regarding Drug Promotion in the United Kingdom and Sweden 2004–2012: A Quantitative and Qualitative Study of Pharmaceutical Industry Self-Regulation

    Science.gov (United States)

    Zetterqvist, Anna V.; Merlo, Juan; Mulinari, Shai

    2015-01-01

    Background In many European countries, medicines promotion is governed by voluntary codes of practice administered by the pharmaceutical industry under its own system of self-regulation. Involvement of industry organizations in policing promotion has been proposed to deter illicit conduct, but few detailed studies on self-regulation have been carried out to date. The objective of this study was to examine the evidence for promotion and self-regulation in the UK and Sweden, two countries frequently cited as examples of effective self-regulation. Methods and Findings We performed a qualitative content analysis of documents outlining the constitutions and procedures of these two systems. We also gathered data from self-regulatory bodies on complaints, complainants, and rulings for the period 2004–2012. The qualitative analysis revealed similarities and differences between the countries. For example, self-regulatory bodies in both countries are required to actively monitor promotional items and impose sanctions on violating companies, but the range of sanctions is greater in the UK where companies may, for instance, be audited or publicly reprimanded. In total, Swedish and UK bodies ruled that 536 and 597 cases, respectively, were in breach, equating to an average of more than one case/week for each country. In Sweden, 430 (47%) complaints resulted from active monitoring, compared with only two complaints (0.2%) in the UK. In both countries, a majority of violations concerned misleading promotion. Charges incurred on companies averaged €447,000 and €765,000 per year in Sweden and the UK, respectively, equivalent to about 0.014% and 0.0051% of annual sales revenues, respectively. One hundred cases in the UK (17% of total cases in breach) and 101 (19%) in Sweden were highlighted as particularly serious. A total of 46 companies were ruled in breach of code for a serious offence at least once in the two countries combined (n = 36 in the UK; n = 27 in Sweden); seven

  8. Complaints, complainants, and rulings regarding drug promotion in the United Kingdom and Sweden 2004-2012: a quantitative and qualitative study of pharmaceutical industry self-regulation.

    Directory of Open Access Journals (Sweden)

    Anna V Zetterqvist

    2015-02-01

    Full Text Available In many European countries, medicines promotion is governed by voluntary codes of practice administered by the pharmaceutical industry under its own system of self-regulation. Involvement of industry organizations in policing promotion has been proposed to deter illicit conduct, but few detailed studies on self-regulation have been carried out to date. The objective of this study was to examine the evidence for promotion and self-regulation in the UK and Sweden, two countries frequently cited as examples of effective self-regulation.We performed a qualitative content analysis of documents outlining the constitutions and procedures of these two systems. We also gathered data from self-regulatory bodies on complaints, complainants, and rulings for the period 2004-2012. The qualitative analysis revealed similarities and differences between the countries. For example, self-regulatory bodies in both countries are required to actively monitor promotional items and impose sanctions on violating companies, but the range of sanctions is greater in the UK where companies may, for instance, be audited or publicly reprimanded. In total, Swedish and UK bodies ruled that 536 and 597 cases, respectively, were in breach, equating to an average of more than one case/week for each country. In Sweden, 430 (47% complaints resulted from active monitoring, compared with only two complaints (0.2% in the UK. In both countries, a majority of violations concerned misleading promotion. Charges incurred on companies averaged €447,000 and €765,000 per year in Sweden and the UK, respectively, equivalent to about 0.014% and 0.0051% of annual sales revenues, respectively. One hundred cases in the UK (17% of total cases in breach and 101 (19% in Sweden were highlighted as particularly serious. A total of 46 companies were ruled in breach of code for a serious offence at least once in the two countries combined (n = 36 in the UK; n = 27 in Sweden; seven companies were in

  9. Construction of recombinant adenovirus vector containing MGMT gene%MGMT基因重组腺病毒载体的构建

    Institute of Scientific and Technical Information of China (English)

    郭鹏翔; 王季石

    2010-01-01

    目的:构建表达人O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)基因重组腺病毒载体.方法:提取人肝组织总RNA,利用反转录聚合酶链式反应(RT-PCR)克隆人肝细胞MGMT基因,将PCR产物连接入pBS-T原核载体,阳性重组子以双酶切及PCR鉴定.将目的基因MGMT片段亚克隆至腺病毒质粒pacAd5 CMVmcsIRES eGFP pA.构建重组腺病毒载体pacAd5 CMVmcs IRES eGFP pA-MGMT.结果:构建了人MGMT基因的重组腺病毒载体.结论:本研究成功构建了含MGMT基因的重组腺病毒载体,为进一步研究耐药基因MGMT在烷化剂治疗中对真核细胞的保护作用提供了有力的工具.

  10. Promoter Hypermethylation of the EMP3 Gene in a Series of 229 Human Gliomas

    Directory of Open Access Journals (Sweden)

    Marta Mellai

    2013-01-01

    Full Text Available The epithelial membrane protein 3 (EMP3 is a candidate tumor suppressor gene in the critical region 19q13.3 for several solid tumors, including tumors of the nervous systems. The aim of this study was to investigate the EMP3 promoter hypermethylation status in a series of 229 astrocytic and oligodendroglial tumors and in 16 GBM cell lines. The analysis was performed by methylation-specific PCR and capillary electrophoresis. Furthermore, the EMP3 expression at protein level was evaluated by immunohistochemistry and Western blotting analysis. Associations of EMP3 hypermethylation with total 1p/19q codeletion, MGMT promoter hypermethylation, IDH1/IDH2 and TP53 mutations, and EGFR amplification were studied, as well as its prognostic significance. The EMP3 promoter hypermethylation has been found in 39.5% of gliomas. It prevailed in low-grade tumors, especially in gliomas with an oligodendroglial component, and in sGBMs upon pGBMs. In oligodendroglial tumors, it was strongly associated with both IDH1/IDH2 mutations and total 1p/19q codeletion and inversely with EGFR gene amplification. No association was found with MGMT hypermethylation and TP53 mutations. In the whole series, the EMP3 hypermethylation status correlated with 19q13.3 loss and lack of EMP3 expression at protein level. A favorable prognostic significance on overall survival of the EMP3 promoter hypermethylation was found in patients with oligodendroglial tumors.

  11. Predictive value of MGMT, hMLH1, hMSH2 and BRCA1 protein expression for pathological complete response to neoadjuvant chemotherapy in basal-like breast cancer patients.

    Science.gov (United States)

    Nakai, Katsuya; Mitomi, Hiroyuki; Alkam, Yimit; Arakawa, Atsushi; Yao, Takashi; Tokuda, Emi; Saito, Mitsue; Kasumi, Fujio

    2012-04-01

    To evaluate the importance of biological markers to predict pathologic complete response (pCR) to neoadjuvant chemotherapy (NACT) in patients with locally advanced basal-like breast cancers (BLBCs). Thirty-two BLBC patients receiving NACT with an anthracycline-based regimen plus taxane were included in this study. The immunoreactivities of MGMT, MLH1, MSH2 and BRCA1 before and after NACT were evaluated. A pCR was obtained in 10 of 32 cases (31%). Cancer-related (P = 0.013) and disease-free (P = 0.023) survival rates were significantly higher in the pCR group than in the non-pCR group. In biopsy samples before NACT, attenuated expression of MGMT, MLH1, MSH2 and BRCA1 was observed in 12/32 (38%), 0/32 (0%), 5/32 (16%) and 28/32 (88%) cases, respectively. On evaluation of pCR, patients' characteristics (patients' age, menopausal status, or clinical and pathological stages) and immunohistochemical patterns, attenuated expression of MGMT was only found to be significantly predictive of a pCR (P = 0.018). Paired biopsy sample before NACT and a surgical tumor material after NACT were available for 19 cases of non-pCR. In these cases, decrease in expression during NACT were more frequently observed for MGMT as compared to MLH1, MSH2 or BRCA1 (P = 0.021). MGMT status is a predictive factor for pCR with neoadjuvant anthracycline-based plus taxane combination chemotherapy, which may be helpful in the selection of appropriate NACT for Japanese patients with BLBC.

  12. Quantitative analysis of liver GST-P foci promoted by a chemical mixture of hexachlorobenzene and PCB 126: implication of size-dependent cellular growth kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yasong [Colorado State University, Quantitative and Computational Toxicology Group, Department of Environmental and Radiological Health Sciences, Fort Collins, CO (United States); Translational Pharmacology Group, PDM, Pfizer Inc, Groton, CT (United States); Lohitnavy, Manupat; Lohitnavy, Ornrat; Eickman, Elizabeth; Gerjevic, Lisa; Yang, Raymond S.H. [Colorado State University, Quantitative and Computational Toxicology Group, Department of Environmental and Radiological Health Sciences, Fort Collins, CO (United States); Reddy, Micaela [DMPK Group, Preclinical Sciences, Roche Palo Alto LLC, CA (United States); Ashley, Amanda [Colorado State University, Department of Cell and Molecular Biology, Fort Collins, CO (United States); Xu, Yihua [University of Wisconsin, McArdle Laboratory for Cancer Research, Madison, WI (United States); Conolly, Rory B. [USEPA, National Center for Computational Toxicology, Research Triangle Park, NC (United States)

    2008-02-15

    The objectives of this study were twofold: (1) evaluating the carcinogenic potential of the mixture of two persistent environmental pollutants, hexachlorobenzene (HCB) and 3,3',4,4',5-pentachlorobiphenyl (PCB 126), in an initiation-promotion bioassay involving the development of {pi} glutathione S-transferase (GST-P) liver foci, and (2) analyzing the GST-P foci data using a biologically-based computer model (i.e., clonal growth model) with an emphasis on the effect of focal size on the growth kinetics of initiated cells. The 8-week bioassay involved a series of treatments of initiator, two-thirds partial hepatectomy, and daily oral gavage of the mixture of two doses in male F344 rats. The mixture treatment significantly increased liver GST-P foci development, indicating carcinogenic potential of this mixture. Our clonal growth model was developed to simulate the appearance and development of initiated GST-P cells in the liver over time. In the model, the initiated cells were partitioned into two subpopulations with the same division rate but different death rates. Each subpopulation was further categorized into single cells, mini- (2-11 cells), medium- (12-399 cells), and large-foci (>399 cells) with different growth kinetics. Our modeling suggested that the growth of GST-P foci is size-dependent; in general, the larger the foci, the higher the rate constants of division and death. In addition, the modeling implied that the two doses promoted foci development in different manners even though the experimental foci data appeared to be similar between the two doses. This study further illustrated how clonal growth modeling may facilitate our understanding in chemical carcinogenic process. (orig.)

  13. Design and application of quantitative evaluation for clinician' merit-based promotion%医师量化考核择优晋升的方案设计与实践

    Institute of Scientific and Technical Information of China (English)

    郝璐; 郑超; 曹秀堂

    2011-01-01

    Objective: based on the principles of fairness, objectiveness, and transparency, quantitative evaluation for clinician' ment-based promotion system will be established to give evidence for promotion and promote clinician s full development Methods: With clinical expert consultation and managers, four first-class performance appraisal index such as basic qualification, working attitude, working performance and professional capacity were set. Combined base value and extra point were used to evaluate clinician' s total performance. Results: performance appraisal should insist on medical treatment as the center and highlighted on working performance and professional capacity. Conclusion: The merit-based promotion is realized and incentive mechanism is led by implementation general evaluation.%目的:遵循公平、客观、透明的原则,探讨医师量化考核择优晋升的方案,为其晋升提供参考依据,并促进医师自身全面发展.方法:在广泛行F求管理者和临床专家的基础上,设立基本素质、丁作作风、工作业绩、业务水平4个一级评价指标,通过基础分和附加分对医师实行综合评价.结果:医师评价坚持以医疗为中心,注重工作业绩和业务水平.结论:通过综合评价和量化排序,实现择优晋升,效果显著,并对医师发展起到引导和激励的作用.

  14. Application of quantitative targeted absolute proteomics to profile protein expression changes of hepatic transporters and metabolizing enzymes during cholic acid-promoted liver regeneration.

    Science.gov (United States)

    Miura, Takayuki; Tachikawa, Masanori; Ohtsuka, Hideo; Fukase, Koji; Nakayama, Shun; Sakata, Naoaki; Motoi, Fuyuhiko; Naitoh, Takeshi; Katayose, Yu; Uchida, Yasuo; Ohtsuki, Sumio; Terasaki, Tetsuya; Unno, Michiaki

    2017-02-26

    Preoperative administration of cholic acid (CA) may be an option to increase the liver volume before elective liver resection surgery, so it is important to understand its effects on liver functionality for drug transport and metabolism. The purpose of this study was to clarify the absolute protein expression dynamics of transporters and metabolizing enzymes in the liver of mice fed CA-containing diet for 5 days (CA1) and mice fed CA-containing diet for 5 days followed by diet without CA for 7 days (CA2), in comparison with non CA-fed control mice. The CA1 group showed the increased liver weight, cell proliferation index, and oxidative stress, but no increase of apoptosis. Quantitative targeted absolute proteomics revealed (i) decreases in basolateral bile acid transporters ntcp, oatp1a1, oatp1b2, bile acid synthesis-related enzymes cyp7a1 and cyp8b1, and drug transporters bcrp, mrp6, ent1, oatp2b1, and (ii) increases in glutathione biosynthetic enzymes and drug-metabolizing enzyme cyp3a11. Liver concentrations of reduced and oxidized glutathione were both increased. In the CA2 group, the increased liver weight was maintained, while the biochemical features and protein profiles were restored to the non-CA-fed control levels. These findings suggest that CA administration alters liver functionality per body during liver regeneration and restoration.

  15. Achaete-scute complex homolog-1 promotes DNA repair in the lung carcinogenesis through matrix metalloproteinase-7 and O(6-methylguanine-DNA methyltransferase.

    Directory of Open Access Journals (Sweden)

    Xiao-Yang Wang

    Full Text Available Lung cancer is the leading cause of cancer-related deaths in the world. Achaete-scute complex homolog-1 (Ascl1 is a member of the basic helix-loop-helix (bHLH transcription factor family that has multiple functions in the normal and neoplastic lung such as the regulation of neuroendocrine differentiation, prevention of apoptosis and promotion of tumor-initiating cells. We now show that Ascl1 directly regulates matrix metalloproteinase-7 (MMP-7 and O(6-methylguanine-DNA methyltransferase (MGMT. Loss- and gain-of-function experiments in human bronchial epithelial and lung carcinoma cell lines revealed that Ascl1, MMP-7 and MGMT are able to protect cells from the tobacco-specific nitrosamine NNK-induced DNA damage and the alkylating agent cisplatin-induced apoptosis. We also examined the role of Ascl1 in NNK-induced lung tumorigenesis in vivo. Using transgenic mice which constitutively expressed human Ascl1 in airway lining cells, we found that there was a delay in lung tumorigenesis. We conclude that Ascl1 potentially enhances DNA repair through activation of MMP-7 and MGMT which may impact lung carcinogenesis and chemoresistance. The study has uncovered a novel and unexpected function of Ascl1 which will contribute to better understanding of lung carcinogenesis and the broad implications of transcription factors in tobacco-related carcinogenesis.

  16. Correlation between promoter methylation of O(6)-methylguanine-DNA-methyltransferase gene in malignant brain gliomas and clinical prognosis of these patients%恶性脑胶质瘤MGMT基因启动子甲基化状态与患者临床预后的相关性

    Institute of Scientific and Technical Information of China (English)

    罗敏捷; 张旺明; 王军; 郑伟新; 姜晓丹; 柯以铨

    2012-01-01

    Objective To study the correlations between O (6) -methylguanine-DNA-methyltransferase (MGMT) gene promoter methylation status in malignant glioma tissues and both MGMT protein expression and survival prognosis in these patients, and evaluate the significance of MGMT gene methylation status analyzing with methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) method in chemotherapy of brain glioma.Methods Thirty-nine patients with gliomas confirmed by pathology (WHO grade Ⅲ and grade Ⅳ)were collected in our study; the patient's overall survival (OS) after chemotherapy was tracked.MGMT protein expression of glioma tissues was detected by immunohistochemical staining,and MGMT promoter methylation status was detected by MS-MLPA method. Results Statistical difference of OS time was noted between patients with MGMT-negative and patients with MGMT-positive/-weak-positive (P=0.003).The prognosis in patients with positive MGMT protein expression was obviously poorer than that in patients with negative expression. In the groups of MGMT promoter un-methylation, mild hypermethylation, moderate hypermethylation and extensive hypermethylation, significant statistical difference of OS time was noted between each 2 groups (P<0.05); the higher degree of methylation,the better prognosis. Statistical correlation was noted between MGMT protein expression and promoter methylation status (r=0.697,P=0.000); the higher degree ofmethylation,the lower protein exression of MGMT. Conclusion Both MGMT protein expression and promoter methylation status can be regarded as prognostic indicator of OS in patients with malignant glioma accepted alkylating agent chemotherapy; MS-MLPA is a reliable method to detect MGMT gene promoter methylation status.%目的 探讨恶性脑胶质瘤组织O6-甲基鸟嘌呤-DNA-甲基转移酶(MGMT)基因启动子甲基化状态及MGMT蛋白表达与患者生存预后的关系,评价MS-MLPA技术检测MGMT基因启动子甲基化状

  17. MGMT在神经胶质瘤中表达的研究进展%Progress on Study of MGMT Expression in Human Gliomas

    Institute of Scientific and Technical Information of China (English)

    仇志坤; 冯冰虹; 陈忠平

    2010-01-01

    06-甲基鸟嘌呤DNA甲基转移酶(O6-methylguanine DNA methyltranferase,MGMT)是一种能将DNA上的加合物移除,并可修复损伤DNA的酶.其作用机制已逐渐被人们深入了解,但是MGMT在神经胶质瘤中表达调控依然有较多有待探讨之处.本文就MGMT表达调控、MGMT表达的意义、MGMT在肿瘤中表达的检测以及MGMT与胶质瘤化疗的新进展这几方面进行综述.

  18. Gene promoter methylation in colorectal cancer and healthy adjacent mucosa specimens: correlation with physiological and pathological characteristics, and with biomarkers of one-carbon metabolism.

    Science.gov (United States)

    Coppedè, Fabio; Migheli, Francesca; Lopomo, Angela; Failli, Alessandra; Legitimo, Annalisa; Consolini, Rita; Fontanini, Gabriella; Sensi, Elisa; Servadio, Adele; Seccia, Massimo; Zocco, Giuseppe; Chiarugi, Massimo; Spisni, Roberto; Migliore, Lucia

    2014-04-01

    We evaluated the promoter methylation levels of the APC, MGMT, hMLH1, RASSF1A and CDKN2A genes in 107 colorectal cancer (CRC) samples and 80 healthy adjacent tissues. We searched for correlation with both physical and pathological features, polymorphisms of folate metabolism pathway genes (MTHFR, MTRR, MTR, RFC1, TYMS, and DNMT3B), and data on circulating folate, vitamin B12 and homocysteine, which were available in a subgroup of the CRC patients. An increased number of methylated samples were found in CRC respect to adjacent healthy tissues, with the exception of APC, which was also frequently methylated in healthy colonic mucosa. Statistically significant associations were found between RASSF1A promoter methylation and tumor stage, and between hMLH1 promoter methylation and tumor location. Increasing age positively correlated with both hMLH1 and MGMT methylation levels in CRC tissues, and with APC methylation levels in the adjacent healthy mucosa. Concerning gender, females showed higher hMLH1 promoter methylation levels with respect to males. In CRC samples, the MTR 2756AG genotype correlated with higher methylation levels of RASSF1A, and the TYMS 1494 6bp ins/del polymorphism correlated with the methylation levels of both APC and hMLH1. In adjacent healthy tissues, MTR 2756AG and TYMS 1494 6bp del/del genotypes correlated with APC and MGMT promoter methylation, respectively. Low folate levels were associated with hMLH1 hypermethylation. Present results support the hypothesis that DNA methylation in CRC depends from both physiological and environmental factors, with one-carbon metabolism largely involved in this process.

  19. Expression and significance of EGFR and MGMT in primary and secondary glioblastomas%EGFR和MGMT在原发性与继发性胶质母细胞瘤中的表达及意义

    Institute of Scientific and Technical Information of China (English)

    胡新华; 张岩松; 邹元杰; 章文斌; 刘宏毅

    2012-01-01

    目的 探讨表皮生长因子受体(EGFR)与O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)在原发性与继发性胶质母细胞瘤(GBM)中的表达及意义.方法 应用免疫组织化学法检测32例原发性GBM和15例继发性GBM中EGFR和MGMT的表达情况;比较两者在原发性与继发性GBM中的表达差异,分析EGFR与MGMT表达的相关性及其与预后的关系.结果 原发性和继发性GBM中EGFR的阳性表达率和表达强度差异均有统计学意义(P<0.01);而MGMT在原发性和继发性GBM中的表达无明显差异(P>0.05).原发性和继发性GBM中,MGMT与EGFR表达无相关性(P>0.05).EGFR和MGMT均阳性和均阴性的GBM病人中位生存期分别为11个月和25个月,两者差异有统计学意义(P<0.05).结论 EGFR过表达多见于原发性GBM,MGMT表达与GBM分型和EGFR表达无相关性.联合检测EGFR和MGMT有助于预测GBM病人的预后.%Objective To study the expression and significance of epidermal growth factor receptor (EGFR) and O6-methylguanina-DNA methyltransferase (MGMT) in primary and secondary glioblastomas (GBM). Methods The expressions of EGFR and MGMT in 32 primary and 15 secondary GBM were detected by immunohistochemistry, and the differences in expressions were compared. The correlation of EGFR and MGMT expression between primary and secondary GBM and the relationship between correlation and prognosis were analyzed. Results There were significant differences in positive rate and expression intensity of EGFR between primary GBM and secondary GBM (P0.05). There was no correlation between MGMT and EGFR expression in primary and secondary GBM (P>0.05). The median survival times of GBM patients with both MGMT- and EGFR-positive or both negative expressions were 11 months and 25 months, indicating a significant difference (P<0.05). Conclusions EGFR overexpression is frequently found in primary GBM. There is no correlation between MGMT expression and both GBM typing and EGFR expression. Combined

  20. Mechanism by which interferon reduces the resistance of MGMT positive glioma stem cells to temozolomide%干扰素抗MGMT阳性胶质瘤干细胞替莫唑胺的耐药机制

    Institute of Scientific and Technical Information of China (English)

    苏辉; 刘兆玮; 杜红利; 乔艳梅

    2015-01-01

    OBJECTIVE:To investigate the role of interferon to increase the sensibilization of MGMT positive glioma stem cel s to temozolomide in vitro. METHODS:Glioma cel lines, U251 and SKMG-4, were induced by suspended cloning bal formation method to harvest MGMT positive glioma stem cel s, U251G and SKMG-4G. Cel counting kit-8 assay was used to detect the kil ing effect of interferonα/βcombined with temozolomide on MGMT positive glioma stem cel s. RT-PCR and western blot assay were employed to determine the expression of MGMT and nuclear factorκB in MGMT positive glioma stem cel s. RESULTS AND CONCLUSION:Western blot results showed positive expression of MGMT in U251G and SKMG-4G cel s at protein levels. After intervention with interferonα/β, the mRNA expression of MGMT and nuclear factorκB in SKMG-4G and U251G cel s was reduced significantly, and then further decreased after temozolomide treatment. These findings indicate that interferonα/βcan remarkably strengthen the kil ing effect of temozolomide on MGMT positive glioma stem cel s.%背景:临床对胶质瘤患者进行治疗的过程中容易出现耐药现象,研究发现,MGMT是胶质瘤表达的一种多药耐药基因。  目的:探讨干扰素增加替莫唑胺对MGMT阳性胶质瘤干细胞的增敏作用。  方法:采用“悬浮克隆球形成法”对胶质瘤细胞株U251、SKMG-4进行诱导,获得MGMT阳性的胶质瘤干细胞U251G、SKMG-4G。应用CCK-8法检测干扰素α/β联合替莫唑胺对MGMT阳性胶质瘤干细胞的杀伤效应;RT-PCR和Western blot检测预用干扰素α/β后MGMT阳性胶质瘤干细胞MGMT、NF-κB表达情况。结果与结论:经Western blot检测,胶质瘤干细胞U251G、SKMG-4G中MGMT蛋白呈阳性表达。采用预用干扰素α/β,然后添加替莫唑胺方式,提高了替莫唑胺的化疗敏感性,杀伤效应显著提高。使用干扰素α/β之后,SKMG-4G和U251G MGMT、NF-κB mRNA和蛋白表达均显著降低,联

  1. MGMT表达与恶性肿瘤化疗关系的研究现状%Research Status of Relationship Between O6 Methylguanine DNA Methyltransferose (MGMT) Expression and Chemotherapy in Malignancies

    Institute of Scientific and Technical Information of China (English)

    康马飞; 秦自科

    2008-01-01

    O6甲基鸟嘌呤DNA甲基转移酶(O6 methylguanine DNA methyltransferase,MGMT)是一种非常重要的DNA修复酶.肿瘤细胞对烷化剂耐药常与MGMT高表达有关.抑制MGMT的表达和活性,可能提高烷化剂疗效.文章就此进行综述.

  2. Abnormal promoter methylation of multiple genes in the malignant transformed PEP2D cells induced by alpha particles exposure

    Institute of Scientific and Technical Information of China (English)

    LiP; SuiJL

    2002-01-01

    The 5' promoter regions of some genes contain CpG-rich areas,known as CpG islands,Methylation of the cytosine in these dinuleotides has important regulatory effects on gene expression.The functional significance of promoter hypermethylation would play the same roles in carcinogenesis as gene mutations.The promoter methylations p14ARF,p16INK4a,MGMT,GSTP1,BUB3 and DAPK genes were analyzed with methylation specific PCR(MSP) in the transformed human bronchial epithelial cells(BEP2D) induced by α-particles.The results indicated that p14ARF gene was not methylated in BEP2D cells,but was methylated in the malignant transformed BERP35T-1 cells,and the level of its transcription was depressed remarkable in the latter.However p16INK4a gene,which shares two exons with p14ARF gene,was not methylated.MGMT gene was methylated in both BEP2D and BERP35T-1.DAPK gene was partially methylated in BEP2D cells and methylated completely in BERP35T1.GSTP1 was not methylated in BEP2D cells and was methylated partly in BERP35T-1.BUB3 gene was not methylated in BEP2D as well as BERP35T1 cells and was further proved by sequencing analysis.

  3. Promoter Methylation Precedes Chromosomal Alterations in Colorectal Cancer Development

    Directory of Open Access Journals (Sweden)

    Sarah Derks

    2006-01-01

    Full Text Available Background: Colorectal cancers are characterized by genetic and epigenetic alterations. This study aimed to explore the timing of promoter methylation and relationship with mutations and chromosomal alterations in colorectal carcinogenesis. Methods: In a series of 47 nonprogressed adenomas, 41 progressed adenomas (malignant polyps, 38 colorectal carcinomas and 18 paired normal tissues, we evaluated promoter methylation status of hMLH1, O6MGMT, APC, p14ARF, p16INK4A, RASSF1A, GATA-4, GATA-5, and CHFR using methylation-specific PCR. Mutation status of TP53, APC and KRAS were studied by p53 immunohistochemistry and sequencing of the APC and KRAS mutation cluster regions. Chromosomal alterations were evaluated by comparative genomic hybridization. Results: Our data demonstrate that nonprogressed adenomas, progressed adenomas and carcinomas show similar frequencies of promoter methylation for the majority of the genes. Normal tissues showed significantly lower frequencies of promoter methylation of APC, p16INK4A, GATA-4, and GATA-5 (P-values: 0.02, 0.02, 1.1×10−5 and 0.008 respectively. P53 immunopositivity and chromosomal abnormalities occur predominantly in carcinomas (P values: 1.1×10−5 and 4.1×10−10. Conclusions: Since promoter methylation was already present in nonprogressed adenomas without chromosomal alterations, we conclude that promoter methylation can be regarded as an early event preceding TP53 mutation and chromosomal abnormalities in colorectal cancer development.

  4. Promotion from qualitative to quantitative test is one of challenges of point-of-care testing development%从定性到定量的转变是 POCT 发展历程中的重要挑战

    Institute of Scientific and Technical Information of China (English)

    周蕾; 杨瑞馥

    2014-01-01

    With non-professional based on-site detection mode and miniature , portable and intelligent techniques as the basis , the potential of point-of-care testing ( POCT ) to feedback the result timely and help to make right decisions to handle emergencies has drawn the attention from extensive fields , including clinical investigation , disease control and prevention , quality control , environmental protection , forensic investigation, import and export inspection and so on.In this review, the definition, history and challenge of POCT promotion from qualitative detection to quantitative one were discussed .%POCT以“现场非专门训练人员”的操作模式与“微型、便携、智能”的检测技术为基础,以“事发现场快速获得检验结果进而指导科学处置”为目标,日益受到临床、疾控、质检、环保、法医、海关等广义检验领域的关注。在此,对POCT的定义、简史以及从定性到定量转变过程中面临的挑战进行阐述。

  5. Significance of complete 1p/19q co-deletion, IDH1 mutation and MGMT promoter methylation in gliomas: use with caution

    NARCIS (Netherlands)

    Boots-Sprenger, S.H.E.; Sijben, A.; Rijntjes, J.; Tops, B.B.J.; Idema, A.J.S.; Rivera, A.L.; Bleeker, F.E.; Gijtenbeek, A.; Diefes, K.; Heathcock, L.; Aldape, K.D.; Jeuken, J.W.M.; Wesseling, P.

    2013-01-01

    The histopathological diagnosis of diffuse gliomas often lacks the precision that is needed for tailored treatment of individual patients. Assessment of the molecular aberrations will probably allow more robust and prognostically relevant classification of these tumors. Markers that have gained a lo

  6. 胶质母细胞瘤MGMT基因启动子甲基化与蛋白表达%Heterogeneity of O6-methylguanine-DNA methyltransferase protein expression and gene promoter methylation in glioblastoma

    Institute of Scientific and Technical Information of China (English)

    潘强; 杨学军; 纪延伟; 孙健; 韩建国; 高松; 李罡; 张文高

    2010-01-01

    Objective To study the correlation of MGMT gene promoter methylation and protein expression and their regional variation in different specimens obtained from different regions within the tumor in patients with newly diagnosed glioblastoma. Methods Two to four samples in the same tumor were collected from different regions in 30 patients with newly diagnosed glioblastoma patients. In five patients among them,mutispecimens were obtained under assistance of neuronavigation system during the operation. In all samples,MGMT promoter profile were analyzed by Methylation - specific polymerase - Chain - reaction analysis, MSP ,while MGMT protein expression was detected in tissue sections by immunohistochemistry,IHC. Results MGMT promoter methylation was detected in 43. 56% (44/101) specimens. MGMT protein expression in tissue sections was assessed and scored:(1 :no or positive tumor cells 50%) ,The rate of MGMT staining with a score 1,2,3 in all of tumor sections was 32. 67% ,43.56% ,23. 76% respectively. No significant correlation between MGMT protein expression and promoter methylation(x2 =2. 905, P =0.088) was found. The regional heterogeneity of MGMT protein expression within the same tumor was in 57% (17/30) patients ;and the regional heterogeneity of gene promoter methylation was in37%(11/30)patients. Conclusions MGMT promoter methylation is probably not the only modulating element in MGMT protein expression. The heterogeneity of MGMT protein expression and its promoter methylation in the same tumor questions their guiding significance in making therapeutic scheme for individual patients with malignant glioma in clinical practice.%目的 研究新发胶质母细胞瘤中肿瘤不同部位MGMT基因启动子甲基化及其蛋白表达关系及区域差异性.方法 在30例新发胶质母细胞瘤肿瘤不同部位采取2~4块标本,其中5例在术中神经导航引导下采取.甲基化特异性PCR(MSP)法检测标本中MGMT基因启动子甲基化状况,免疫组

  7. The role of MGMT expression in predicting the effect of breast cancer chemotherapy%MGMT的表达在预测乳腺癌化疗效果中的应用

    Institute of Scientific and Technical Information of China (English)

    付爱芹; 张恩宁

    2016-01-01

    Objective To study the role of O6- methyl guanine-DNA methyl transferase (MGMT) expression in breast cancer and the correlation with the prognosis of breast cancer chemotherapy. Method Eighty-one patients with breast cancer who had surgical treatment and postoperative conventional chemotherapy were included in the study, and immunohistochemical assay was utilized to detect the MGMT in patient’s pathological tissue samples, and then the rela-tionship with clinical parameters and prognosis were investigated. Result Of the 81 patients, positive MGMT expression was observed in 58 (71.6%), and the positive rate of estrogen receptor was higher in those with positive MGMT expres-sion than those with negative expression, with significant differences observed (P<0.05);Positive MGMT expression is associated with lower overall response rate (P<0.05), while overall survival was of no significant difference in patients with positive or negative MGMT expression (P<0.05). Conclusion MGMT expression is useful in predicting the short-term efficacy of chemotherapy in breast cancer patients, though lacks power in respect of evaluating overall survival.%目的:探讨O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)在乳腺癌组织中的表达及其与乳腺癌化疗预后的关系。方法选取行手术治疗,术后接受常规化疗的乳腺癌患者81例为研究对象,采用免疫组化法检测患者病理组织MGMT水平,分析其与患者临床指标及预后的关系。结果81例患者病理组织中,MGMT阳性表达58例,占71.6%;阳性表达患者雌激素受体阳性率低于阴性表达患者,差异有统计学意义(P﹤0.05);MGMT阳性患者化疗总有效率低于阴性患者,差异有统计学意义(P﹤0.05);MGMT阳性患者与阴性患者总生存期对比,差异无统计学意义(P﹥0.05)。结论 MGMT对预测乳腺癌化疗患者近期疗效有一定价值,但对患者总生存期缺乏预测价值。

  8. Quantitative research.

    Science.gov (United States)

    Watson, Roger

    2015-04-01

    This article describes the basic tenets of quantitative research. The concepts of dependent and independent variables are addressed and the concept of measurement and its associated issues, such as error, reliability and validity, are explored. Experiments and surveys – the principal research designs in quantitative research – are described and key features explained. The importance of the double-blind randomised controlled trial is emphasised, alongside the importance of longitudinal surveys, as opposed to cross-sectional surveys. Essential features of data storage are covered, with an emphasis on safe, anonymous storage. Finally, the article explores the analysis of quantitative data, considering what may be analysed and the main uses of statistics in analysis.

  9. 卵巢癌组织中MGMT表达意义%Expression of MGMT and its clinicopathological significance in ovarian cancer

    Institute of Scientific and Technical Information of China (English)

    马琳; 刘芙蓉

    2006-01-01

    目的探讨6-氧-甲基鸟嘌呤-DNA甲基转移酶(MGMT)在卵巢癌中的表达及临床意义.方法应用免疫组化(SP)法对60例卵巢癌及癌旁正常组织中MGMT的表达进行检测.结果60例卵巢癌组织中MGMT的表达率为46.7%,癌旁正常组织MGMT的表达率为100%(P<0.05).MGMT的表达与卵巢癌的组织学类型和临床分期无关(P>0.05),但与卵巢癌的病理分级有关(P<0.05).结论卵巢癌组织中存在MGMT的表达缺失,MGMT的功能失活可能是卵巢癌发生的重要机制之一.

  10. 非小细胞肺癌组织MGMT蛋白的表达%Expression of MGMT in human non-small cell lung cancer tissues

    Institute of Scientific and Technical Information of China (English)

    刘莹; 王静; 吴逸明; 吴拥军

    2010-01-01

    目的:探讨DNA修复酶O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)在非小细胞肺癌(NSCLC)组织中的表达及其与肺癌发生、发展的关系.方法:免疫组化SABC法检测120例NSCLC及癌旁组织中和30例肺炎MGMT的表达.结果:120例NSCLC组织中,MGMT蛋白的阳性表达率(33%,40/120)显著低于癌旁正常组织(63%,76/120),χ2=21.624,P<0.05;亦显著低于30例肺炎症组织(60%,18/30),χ2=7.196,P<0.05;MGMT蛋白的阳性表达与患者吸烟史、分化程度和淋巴结转移相关,P(0.05.结论:MGMT蛋白的表达与NSCLC的发生、发展相关,监测MG-MT蛋白可能对肺癌的辅助诊断有一定意义.

  11. Expression and Significance of HSP70 and MGMT in Breast Neoplasms%HSP70和MGMT在乳腺肿瘤中的表达和意义

    Institute of Scientific and Technical Information of China (English)

    吴荣薇; 薄爱华; 王发亮; 芦广萍

    2008-01-01

    目的:探讨乳腺肿瘤组织中热休克蛋白HSP70和DNA修复酶O6-甲基鸟嘌呤-DNA甲基转移酶(O6-methyguanine-DNA methytransferase,MGMT)的表达及临床意义.方法:采用免疫组织化学SABC法检测65例乳腺肿瘤组织中HSP70和MGMT的表达情况.结果:乳腺肿瘤中HSP70的阳性率为80.00%(52/65),MGMT的阳性率为60.00%(39/65),二者呈中度相关性(r=0.46).其中,有淋巴结转移组的阳性率高于无转移组(P<0.05).结论:HSP70和MGMT的表达率与淋巴结转移情况有关.检测HSP70与MGMT对乳腺肿瘤预后和化疗方案的选择有指导意义.

  12. Association of Promoter Methylation of VGF and PGP9.5 with Ovarian Cancer Progression

    Science.gov (United States)

    Noordhuis, Maartje; Begum, Shahnaz; Loyo, Myriam; Poeta, Maria Luana; Barbosa, Alvaro; Fazio, Vito M.; Angioli, Roberto; Rabitti, Carla; Marchionni, Luigi; de Graeff, Pauline; J. van der Zee, Ate G.; Wisman, G. Bea A.; Sidransky, David; Hoque, Mohammad O.

    2013-01-01

    Purpose To elucidate the role of biological and clinical impact of aberrant promoter hypermethylation (PH) in ovarian cancer (OC). Experimental Design PH of PGP9.5, HIC1, AIM1, APC, PAK3, MGMT, KIF1A, CCNA1, ESR1, SSBP2, GSTP1, FKBP4 and VGF were assessed by quantitative methylation specific PCR (QMSP) in a training set. We selected two genes (VGF and PGP9.5) for further QMSP analysis in a larger independent validation (IV) set with available clinical data. Biologic relevance of VGF gene was also evaluated. Results PH frequency for PGP9.5 and VGF were 85% (316/372) and 43% (158/366) respectively in the IV set of samples while no PH was observed in controls. In 372 OC cases with available follow up, PGP9.5 and VGF PH were correlated with better patient survival [Hazard Ratios (HR) for overall survival (OS) were 0.59 (95% Confidence Intervals (CI)  = 0.42–0.84, p = 0.004), and 0.73 (95%CI = 0.55–0.97, p = 0.028) respectively, and for disease specific survival (DSS) were 0.57 (95%CI 0.39–0.82, p = 0.003) and 0.72 (95%CI 0.54–0.96, p = 0.027). In multivariate analysis, VGF PH remained an independent prognostic factor for OS (HR 0.61, 95%CI 0.43–0.86, p<0.005) and DSS (HR 0.58, 95%CI 0.41–0.83, p<0.003). Furthermore, PGP9.5 PH was significantly correlated with lower grade, early stage tumors, and with absence of residual disease. Forced expression of VGF in OC cell lines inhibited cell growth. Conclusions Our results indicate that VGF and PGP9.5 PH are potential biomarkers for ovarian carcinoma. Confirmatory cohorts with longitudinal follow-up are required in future studies to define the clinical impact of VGF and PGP9.5 PH before clinical application. PMID:24086249

  13. Association of promoter methylation of VGF and PGP9.5 with ovarian cancer progression.

    Directory of Open Access Journals (Sweden)

    Mariana Brait

    Full Text Available PURPOSE: To elucidate the role of biological and clinical impact of aberrant promoter hypermethylation (PH in ovarian cancer (OC. EXPERIMENTAL DESIGN: PH of PGP9.5, HIC1, AIM1, APC, PAK3, MGMT, KIF1A, CCNA1, ESR1, SSBP2, GSTP1, FKBP4 and VGF were assessed by quantitative methylation specific PCR (QMSP in a training set. We selected two genes (VGF and PGP9.5 for further QMSP analysis in a larger independent validation (IV set with available clinical data. Biologic relevance of VGF gene was also evaluated. RESULTS: PH frequency for PGP9.5 and VGF were 85% (316/372 and 43% (158/366 respectively in the IV set of samples while no PH was observed in controls. In 372 OC cases with available follow up, PGP9.5 and VGF PH were correlated with better patient survival [Hazard Ratios (HR for overall survival (OS were 0.59 (95% Confidence Intervals (CI  = 0.42-0.84, p = 0.004, and 0.73 (95%CI = 0.55-0.97, p = 0.028 respectively, and for disease specific survival (DSS were 0.57 (95%CI 0.39-0.82, p = 0.003 and 0.72 (95%CI 0.54-0.96, p = 0.027. In multivariate analysis, VGF PH remained an independent prognostic factor for OS (HR 0.61, 95%CI 0.43-0.86, p<0.005 and DSS (HR 0.58, 95%CI 0.41-0.83, p<0.003. Furthermore, PGP9.5 PH was significantly correlated with lower grade, early stage tumors, and with absence of residual disease. Forced expression of VGF in OC cell lines inhibited cell growth. CONCLUSIONS: Our results indicate that VGF and PGP9.5 PH are potential biomarkers for ovarian carcinoma. Confirmatory cohorts with longitudinal follow-up are required in future studies to define the clinical impact of VGF and PGP9.5 PH before clinical application.

  14. TERT promoter mutations and long telomere length predict poor survival and radiotherapy resistance in gliomas.

    Science.gov (United States)

    Gao, Ke; Li, Gang; Qu, Yiping; Wang, Maode; Cui, Bo; Ji, Meiju; Shi, Bingyin; Hou, Peng

    2016-02-23

    Increasing evidences have implicated somatic gain-of-function mutations at the telomerase reverse transcriptase (TERT) promoter as one of the major mechanisms that promote transcriptional activation of TERT and subsequently maintain telomere length in human cancers including glioma. To investigate the prognostic value of these mutations and telomere length, individually and their coexistence, in gliomas, we analyzed two somatic mutations C228T and C250T in the TERT promoter, relative telomere length (RTL), IDH1 mutation and MGMT methylation in 389 glioma patients, and explored their associations with patient characteristics and clinical outcomes. Our data showed that C228T and C250T mutations were found in 17.0% (66 of 389) and 11.8% (46 of 389) of gliomas, respectively, and these two mutations were mutually exclusive in this cancer. Moreover, they were significantly associated with WHO grade. We also found that the RTL was significant longer in gliomas than in meningiomas and normal brain tissues (Median, 0.89 vs. 0.44 and 0.50; P promoter mutations or long RTL caused a significantly poorer survival than TERT wild-type or short RTL. Coexisting TERT promoter mutations and long RTL were more commonly associated with poor patient survival than they were individually. Notably, the patients with TERT promoter mutations particularly C228T or long RTL were resistant to radiotherapy. Collectively, TERT promoter mutations and long RTL are not only prognostic factors for poor clinical outcomes, but also the predictors of radiotherapy resistance in gliomas.

  15. A Primer on Disseminating Applied Quantitative Research

    Science.gov (United States)

    Bell, Bethany A.; DiStefano, Christine; Morgan, Grant B.

    2010-01-01

    Transparency and replication are essential features of scientific inquiry, yet scientific communications of applied quantitative research are often lacking in much-needed procedural information. In an effort to promote researchers dissemination of their quantitative studies in a cohesive, detailed, and informative manner, the authors delineate…

  16. O6-甲基鸟嘌呤-DNA-甲基转移酶(MGMT)在乳腺癌中的表达及其临床意义%Expressions of O6 methylguanine-DNA methyltransferase(MGMT) in breast cancer and Its clinical significance

    Institute of Scientific and Technical Information of China (English)

    白金君; 王发亮; 薄爱华; 雷杰

    2008-01-01

    目的:研究DNA修复酶(O6-methylguanine-DNA methyltransferase,MGMT)在乳腺癌中的表达及其临床意义.方法:乳腺癌和腺瘤标本共计143例,10%福尔马林固定,石蜡包埋,采用SABC免疫组织化学方法检测MGMT表达.结果:MGMT在乳腺癌和乳腺腺瘤中的阳性率分别为57.85%和13.64%,组间比较具有显著性差异.MGMT在乳腺癌中的表达与患者的年龄、淋巴结转移有关.结论:MGMT的异常表达与乳腺癌的淋巴结转移有关;MGMT可以作为判断乳癌发生和预后的重要指标;检测其表达可以指导临床上化疗方案的制定.

  17. Comparison of ERCC2 and MGMT expression in human glioma and relation ERCC2,MGMT and relation that after preparing%人脑胶质瘤耐药基因ERCC2、MGMT表达之间的相关性及其与预后的关系研究

    Institute of Scientific and Technical Information of China (English)

    李登锦; 王如密; 王爱东; 黄强; 徐元宾

    2004-01-01

    目的探讨人脑胶质瘤组织中两种耐药基因ERCC2、MGMT表达之间的相关性及其与预后的关系.方法采用双管RT-PCR方法检测19例人脑胶质瘤组织中ERCC2和MGMT mRNA水平,并分析它们的相关性及其与患者生存时间的关系.结果 ERCC2、MGMT的表达量分别为(1.42±0.93),(2.89±1.82),ERCC2与MGMT之间具有极显著的相关性(P<0.01).与患者的生存时间具有显著的相关性(P<0.05).结论 ERCC2、MGMT基因表达之间具有内在的联系,共同参与细胞对DNA损伤的修复,并形成肿瘤耐药;与肿瘤的预后具有明显的相关性.

  18. The quantitative Morse theorem

    OpenAIRE

    Loi, Ta Le; Phien, Phan

    2013-01-01

    In this paper, we give a proof of the quantitative Morse theorem stated by {Y. Yomdin} in \\cite{Y1}. The proof is based on the quantitative Sard theorem, the quantitative inverse function theorem and the quantitative Morse lemma.

  19. Metazoan promoters

    DEFF Research Database (Denmark)

    Lenhard, Boris; Sandelin, Albin Gustav; Carninci, Piero

    2012-01-01

    Promoters are crucial for gene regulation. They vary greatly in terms of associated regulatory elements, sequence motifs, the choice of transcription start sites and other features. Several technologies that harness next-generation sequencing have enabled recent advances in identifying promoters...... and their features, helping researchers who are investigating functional categories of promoters and their modes of regulation. Additional features of promoters that are being characterized include types of histone modifications, nucleosome positioning, RNA polymerase pausing and novel small RNAs. In this Review, we...... discuss recent findings relating to metazoan promoters and how these findings are leading to a revised picture of what a gene promoter is and how it works....

  20. Quantitation of DNA methylation by melt curve analysis

    Directory of Open Access Journals (Sweden)

    Jones Michael E

    2009-04-01

    Full Text Available Abstract Background Methylation of DNA is a common mechanism for silencing genes, and aberrant methylation is increasingly being implicated in many diseases such as cancer. There is a need for robust, inexpensive methods to quantitate methylation across a region containing a number of CpGs. We describe and validate a rapid, in-tube method to quantitate DNA methylation using the melt data obtained following amplification of bisulfite modified DNA in a real-time thermocycler. Methods We first describe a mathematical method to normalise the raw fluorescence data generated by heating the amplified bisulfite modified DNA. From this normalised data the temperatures at which melting begins and finishes can be calculated, which reflect the less and more methylated template molecules present respectively. Also the T50, the temperature at which half the amplicons are melted, which represents the summative methylation of all the CpGs in the template mixture, can be calculated. These parameters describe the methylation characteristics of the region amplified in the original sample. Results For validation we used synthesized oligonucleotides and DNA from fresh cells and formalin fixed paraffin embedded tissue, each with known methylation. Using our quantitation we could distinguish between unmethylated, partially methylated and fully methylated oligonucleotides mixed in varying ratios. There was a linear relationship between T50 and the dilution of methylated into unmethylated DNA. We could quantitate the change in methylation over time in cell lines treated with the demethylating drug 5-aza-2'-deoxycytidine, and the differences in methylation associated with complete, clonal or no loss of MGMT expression in formalin fixed paraffin embedded tissues. Conclusion We have validated a rapid, simple in-tube method to quantify methylation which is robust and reproducible, utilizes easily designed primers and does not need proprietary algorithms or software. The

  1. Relationship of methylation of MGMT gene regulated by platinum-contained regimens in plasma and efficacy of chemotherapy in diffuse large B cell lymphoma patients%含铂方案调节弥漫大B细胞淋巴瘤患者血浆MGMT基因甲基化及与化疗疗效关系

    Institute of Scientific and Technical Information of China (English)

    康马飞; 廖漓漓; 刘瑛; 骆梅青; 陈莹

    2012-01-01

    Objective:To detect the methylation of the 06 - methylguanine DNA methyltransferase( MGMT )gene in peripheral plasma in diffuse large B cell lymphoma( DLBCL )patients who treated with platinum - contained regimen and to evaluate whether platinum - contained regimen regulate methylation of MGMT gene and to evaluate the relationship of methylation of MGMT gene and efficacy of chemotherapy in diffuse large B cell lymphoma. Methods: Before and after chemotherapy, a nested methylation - specific PCR( nMSP )was performed for the detection of methylation of MGMT gene in plasma from DLBCL patients who treated with platinum - contained regimens. Results: Thirty plasma samples, before treatment with DHAP regimen, MGMT gene methylation was found in 10. 0% ( 3/30 )of patients with DLBCL which resisted to CHOP regimen. The ratios of methylation, after 2 and 4 cycls of chemotherapy, were respectively 63. 3%( 19/30 )and 73. 3%( 22/30 ) and there was a significant different between pre - therapy group and post - therapy group( P = 0. 000 ). The response rates were respectively 100% ( 3/3 )and 92. 6% ( 25/ 27 )in patients with methylation and non - methylation of MGMT gene after 2 cycles of platinum - contained regimens and were respectively 86. 4%( 19/22 )and 75.0%( 6/8 )after 4 cycles and there was no significant difference between methylation group and non - methylation group. Conclusion: Platinum - contained regimens might regulate methylation of MGMT gene. Efficacy of chemotherapy with platinum - contained regimens was not related with methylation of MGMT gene.%目的 检测弥漫大B细胞淋巴瘤(DLBCL)患者用含铂方案化疗后外周血血浆中O6-甲基鸟嘌呤-DNA甲基转移酶(O6-methylguanine-DNA methyltransferase,MGMT)基因的甲基化状态,探讨含铂方案能否调节MGMT基因甲基化状态,并观察MGMT基因甲基化与含铂方案化疗疗效的关系.方法 利用巢式甲基化特异性聚合酶链反应法检测DLBCL患者含铂方案治疗前后

  2. 星形细胞瘤中IDH1突变、MGMT蛋白表达与放射治疗及预后的关系%IDH1 mutation and MGMT expression in astrocytoma and the relationship with prognosis after radiotherapy

    Institute of Scientific and Technical Information of China (English)

    蒋梦婉; 董祥慧; 李嘉瑶; 李婧琦; 戚基萍

    2014-01-01

    Objective To study the correlation between IDH1 mutation,MGMT expression,clinicopathologic features and post-radiotherapy prognosis in patients with astrocytoma.Methods Detection of IDH1 mutation and MGMT expression was carried out in 48 cases of astrocytoma (WHO grade Ⅱ to Ⅲ)by EnVision method with immunohistochemical staining.Follow-up data,including treatment response and overall survival time,were analyzed.Results The rates of IDH1 mutation and MGMT expression in astrocytomas were 62.7% (30/48) and 47.9% (23/48),respectively.There was a negative correlation between IDH1 mutation and MGMT expression (r =-0.641,P < 0.01).The age of patients with IDH1 mutation was younger at disease onset.The IDH1 mutation rate in patients with WHO grade Ⅱ astrocytoma was higher than that in patients with WHO grade Ⅲ tumor (P < 0.05).The age at onset was an independent factor affecting the expression of mutant IDH1.After radiotherapy,patients with IDH1 mutation +/MGMT-tumor carried a longer overall survival time than patients with IDH1 mutation-/MGMT + tumor (P < 0.05).Conclusions There is a correlation between IDH1 mutation and MGMT expression in WHO grade Ⅱ to Ⅲ astrocytoma.Age at onset is an independent factor affecting the expression of mutant IDH1.Tumors with IDH1 +/MGMT-pattern show better response to radiotherapy than tumors with IDH1-/MGMT + pattern.Detection of IDH1 mutation and MGMT protein expression can provide some guidance in choice of treatment modalities in patients with astrocytoma.%目的 探讨人脑星形细胞瘤中IDH1突变及MGMT蛋白的表达与临床病理特征之间的关系,以及不同表达类型在放疗条件下对预后的影响.方法 应用EnVision二步法进行免疫组织化学染色,观察48例星形细胞瘤(WHOⅡ~Ⅲ级)患者石蜡包埋组织中IDH1突变及MGMT蛋白表达情况,并对患者放化疗情况及生存时间进行随访.结果 星形细胞瘤中IDH1突变及MGMT蛋白表达率分别为62.7% (30

  3. Detection of the TWIST1 promoter methylation state through fluorescent quantitative PCR in urine sediments of bladder cancer%荧光定量PCR检测膀胱癌患者尿沉淀细胞TWIST1基因启动子甲基化状态的临床价值

    Institute of Scientific and Technical Information of China (English)

    陆明; 钱麟; 潘彬; 陈建刚; 赵枰

    2012-01-01

    目的:评估尿沉淀细胞TWIST1基因启动子甲基化状态在膀胱癌诊断中的价值.方法:用实时荧光定量PCR的方法,对50例临床确诊的膀胱癌患者、13例非肿瘤性尿路疾病患者、7例健康志愿者检测了尿沉淀细胞TWIST1基因启动子的甲基化状态;同时行尿脱落细胞学检查.结果:50例膀胱癌患者中尿脱落细胞TWIST1基因启动子甲基化阳性率为64.0%(32/50),对照组均未发现甲基化改变,两者比较差异有统计学意义(P<0.01).TWIST1基因启动子甲基化率有随组织分期升高的趋势,但在不同分级、分期膀胱癌中的差异无显著性.实时荧光定量PCR法检测尿液中TWIST1基因启动子甲基化的敏感性和特异性分别为64.0%、100.0%.而尿脱落细胞学检查阳性率为48.0%( 24/50),其敏感性和特异性分别为48.0%和100.0%.结论:尿脱落细胞TWIST1基因启动子的甲基化检测诊断膀胱癌敏感性和特异性均较高,且无创、无痛苦,可作为早期诊断膀胱癌的敏感指标.%Objective:To assess the TWIST1 promoter methylation state in urine sediments and evaluate their value in diagnosis of bladder cancer. Methods: Fifty patients with bladder cancer, 13 patients with non tumorous urinary disease and 7 healthy volunteers were recruited in the study. The TWIST1 promoter methylation state in urine sediments was determined by real-time fluorescent quantitative PCR. The urine exfoliative cytologic examination was also performed. Results: The positive rate of TWIST1 promoter methylation was 64.0% (32/50) in exfoliated urothelial cells of 50 patients with bladder cancer, no one showed positive TWIST1 promoter methylation in the control group. The difference in the positive rate of TWIST1 promoter methylation between two groups was significant(P < 0.01). TWIST1 promoter methylation status did not correlate with stage and grade of bladder cancer,though there was a trend that more frequent methylation was detected

  4. 弥漫性大 B 细胞淋巴瘤组织中 MGMT、hMLH1蛋白表达变化及其临床意义%Expression changes and clinical significance of MGMT and hMLH1 in diffuse large B-cell lymphoma

    Institute of Scientific and Technical Information of China (English)

    陈军; 廖小莉; 覃思繁; 林思彤

    2015-01-01

    目的:观察弥漫性大B细胞淋巴瘤( DLBCL)组织中O6-甲基鸟嘌呤-DNA甲基转移酶( MGMT)和人MutS同系物1( hMLH1)表达变化,并探讨其与DLBCL临床病理参数和化疗疗效的关系。方法采用免疫组织化学方法检测100例初治DLBCL患者肿瘤组织中的MGMT和hMLH1,分析两者表达的相关性及其与DLBC临床病理参数、化疗疗效的关系。结果本组患者肿瘤组织MGMT表达阳性42例,阴性58例,hMLH1表达阳性54例,阴性46例。 DLBCL患者肿瘤组织中MGMT与hMLH1表达无显著相关性。 MGMT表达与DLBCL临床分期、IPI评分、病理亚型有关(P均<0.05),与患者性别、年龄、血清LDH、全身症状、原发部位无关;hMLH1表达与DLBCL患者IPI评分、病理亚型有关( P均<0.05),与临床分期、性别、年龄、血清LDH、全身症状、原发部位无关。 MGMT阳性者CR率和化疗总有效率分别为28.6%、52.4%,均低于 MGMT阴性者的55.2%和75.9%( P均<0.05)。 hM-LH1阳性者CR率和化疗总有效率分别为75.9%,均高于hMLH1阴性者的28.3%和54.4%(P均<0.05)。结论DLBCL 组织中MGMT 和hMLH1表达率分别为42%和54%,MGMT 表达与临床分期、IPI 评分、病理亚型有关,hMLH1表达与IPI 评分、病理亚型有关,MGMT 表达阳性和hMLH1表达表达阴性者化疗效果较好。%Objective To observe the expression changes of O6-methylguanine DNA methyltransferase ( MGMT) and human MutL homolog 1 (hMLH1) in the diffuse large B-cell lymphoma (DLBCL) tissues and to investigate their correla-tions with DLBCL clinicopathological features and chemotherapeutic effect.Methods Immunohistochemisty was employed to determine the expression of MGMT and hMLH1 in the tumor tissues of 100 cases of newly diagnosed patients with DL-BCL, and their correlations with DLBCL clinical parameters and chemotherapeutic effect were analyzed.Results In the tumor

  5. Health Promotion

    DEFF Research Database (Denmark)

    Povlsen, Lene; Borup, I.

    2015-01-01

    In 1953 when the Nordic School of Public Health was founded, the aim of public health programmes was disease prevention more than health promotion. This was not unusual, since at this time health usually was seen as the opposite of disease and illness. However, with the Ottawa Charter of 1986......, the World Health Organization made a crucial change to view health not as a goal in itself but as the means to a full life. In this way, health promotion became a first priority and fundamental action for the modern society. This insight eventually reached NHV and in 2002 - 50 years after the foundation...... - an associate professorship was established with a focus on health promotion. Nevertheless, the concept of health promotion had been integrated with or mentioned in courses run prior to the new post. Subsequently, a wide spectrum of courses in health promotion was introduced, such as Empowerment for Child...

  6. Functional Screening of Core Promoter Activity.

    Science.gov (United States)

    Even, Dan Y; Kedmi, Adi; Ideses, Diana; Juven-Gershon, Tamar

    2017-01-01

    The core promoter is the DNA sequence that recruits the basal transcription machinery and directs accurate initiation of transcription. It is an active contributor to gene expression that can be rationally designed to manipulate the levels of expression. Core promoter function can be analyzed using different experimental approaches. Here, we describe the qualitative and quantitative analysis of engineered core promoter functions using the EGFP reporter gene that is driven by distinct core promoters. Expression plasmids are transfected into different mammalian cell lines, and the resulting fluorescence is monitored by live cell imaging , as well as by flow cytometry. In order to verify that the transcriptional activity of the examined core promoters is indeed a function of their activity, as opposed to differences in DNA uptake, real-time quantitative PCR analysis is performed. Importantly, the described methodology for functional screening of core promoter activity has enabled the analysis of engineered potent core promoters for extended time periods.

  7. Aberrant promoter hypermethylation in serum DNA from patients with silicosis.

    Science.gov (United States)

    Umemura, Shigeki; Fujimoto, Nobukazu; Hiraki, Akio; Gemba, Kenichi; Takigawa, Nagio; Fujiwara, Keiichi; Fujii, Masanori; Umemura, Hiroshi; Satoh, Mamoru; Tabata, Masahiro; Ueoka, Hiroshi; Kiura, Katsuyuki; Kishimoto, Takumi; Tanimoto, Mitsune

    2008-09-01

    It is well established that patients with silicosis are at high risk for lung cancer; however, it is difficult to detect lung cancer by chest radiography during follow-up treatment of patients with silicosis because of preexisting diffuse pulmonary shadows. The purpose of this study is to evaluate the usefulness of detection of serum DNA methylation for early detection of lung cancer in silicosis. Serum samples from healthy controls (n = 20) and silicosis patients with (n = 11) and without (n = 67) lung cancer were tested for aberrant hypermethylation at the promoters of the DNA repair gene O(6)-methylguanine-DNA methyltransferase (MGMT), p16(INK4a), ras association domain family 1A (RASSF1A), the apoptosis-related gene death-associated protein kinase (DAPK) and retinoic acid receptor beta (RARbeta) by methylation-specific polymerase chain reaction. Aberrant promoter methylation in at least one of five tumor suppressor genes was detected more frequently in the serum DNA of silicosis patients with lung cancer than in that of patients without it (P = 0.006). Furthermore, the odds ratio of having lung cancer was 9.77 (P = 0.009) for those silicosis patients with methylation of at least one gene. Extended exposure to silica (>30 years) was correlated with an increased methylation frequency (P = 0.017); however, methylation status did not correlate with age, smoking history or radiographic findings of silicosis. These results suggest that testing for aberrant promoter methylation of tumor suppressor genes using serum DNA may facilitate early detection of lung cancer in patients with silicosis.

  8. Reduction of in-source collision-induced dissociation and thermolysis of sulopenem prodrugs for quantitative liquid chromatography/electrospray ionization mass spectrometric analysis by promoting sodium adduct formation.

    Science.gov (United States)

    Wujcik, Chad E; Kadar, Eugene P

    2008-10-01

    Six chromatographically resolved sulopenem prodrugs were monitored for their potential to undergo both in-source collision-induced dissociation (CID) and thermolysis. Initial Q1 scans for each prodrug revealed the formation of intense [Prodrug2 + H]+, [Prodrug2 + Na]+, [Prodrug + Na]+, and [Sulopenem + Na]+ ions. Non-adduct-associated sulopenem ([Sulopenem + H]+) along with several additional lower mass ions were also observed. Product ion scans of [Prodrug3 + Na]+ showed the retention of the sodium adduct in the collision cell continuing down to opening of the beta-lactam ring. In-source CID and temperature experiments were conducted under chromatographic conditions while monitoring several of the latter ion transitions (i.e., adducts, dimers and degradants/fragments) for a given prodrug. The resulting ion profiles indicated the regions of greatest stability for temperature and declustering potential (DP) that provided the highest signal intensity for each prodrug and minimized in-source degradation. The heightened stability of adduct ions, relative to their appropriate counterpart (i.e., dimer to dimer adduct and prodrug to prodrug adduct ions), was observed under elevated temperature and DP conditions. The addition of 100 microM sodium to the mobile phase further enhanced the formation of these more stable adduct ions, yielding an optimal [Prodrug + Na]+ ion signal at temperatures from 400 to 600 degrees C. A clinical liquid chromatography/tandem mass spectrometry (LC/MS/MS) assay for sulopenem prodrug PF-04064900 in buffered whole blood was successfully validated using sodium-fortified mobile phase and the [PF-04064900 + Na]+ ion for quantitation. A conservative five-fold increase in sensitivity from previously validated preclinical assays using the [PF-04064900 + H]+ precursor ion was achieved.

  9. Quantitative lithofacies palaeogeography

    Institute of Scientific and Technical Information of China (English)

    Zeng-Zhao; Feng; Xiu-Juan; Zheng; Zhi-Dong; Bao; Zhen-Kui; Jin; Sheng-He; Wu; You-Bin; He; Yong-Min; Peng; Yu-Qing; Yang; Jia-Qiang; Zhang; Yong-Sheng; Zhang

    2014-01-01

    Quantitative lithofacies palaeogeography is an important discipline of palaeogeography.It is developed on the foundation of traditional lithofacies palaeogeography and palaeogeography,the core of which is the quantitative lithofacies palaeogeographic map.Quantity means that in the palaeogeographic map,the division and identification of each palaeogeographic unit are supported by quantitative data and quantitative fundamental maps.Our lithofacies palaeogeographic maps are quantitative or mainly quantitative.A great number of quantitative lithofacies palaeogeographic maps have been published,and articles and monographs of quantitative lithofacies palaeogeography have been published successively,thus the quantitative lithofacies palaeogeography was formed and established.It is an important development in lithofacies palaeogeography.In composing quantitative lithofacies palaeogeographic maps,the key measure is the single factor analysis and multifactor comprehensive mapping method—methodology of quantitative lithofacies palaeogeography.In this paper,the authors utilize two case studies,one from the Early Ordovician of South China and the other from the Early Ordovician of Ordos,North China,to explain how to use this methodology to compose the quantitative lithofacies palaeogeographic maps,and to discuss the palaeogeographic units in these maps.Finally,three characteristics,i.e.,quantification,multiple orders and multiple types,of quantitative lithofacies palaeogeographic maps are conclusively discussed.

  10. Quantitative investment analysis

    CERN Document Server

    DeFusco, Richard

    2007-01-01

    In the "Second Edition" of "Quantitative Investment Analysis," financial experts Richard DeFusco, Dennis McLeavey, Jerald Pinto, and David Runkle outline the tools and techniques needed to understand and apply quantitative methods to today's investment process.

  11. Rigour in quantitative research.

    Science.gov (United States)

    Claydon, Leica Sarah

    2015-07-22

    This article which forms part of the research series addresses scientific rigour in quantitative research. It explores the basis and use of quantitative research and the nature of scientific rigour. It examines how the reader may determine whether quantitative research results are accurate, the questions that should be asked to determine accuracy and the checklists that may be used in this process. Quantitative research has advantages in nursing, since it can provide numerical data to help answer questions encountered in everyday practice.

  12. Promoting Models

    Science.gov (United States)

    Li, Qin; Zhao, Yongxin; Wu, Xiaofeng; Liu, Si

    There can be multitudinous models specifying aspects of the same system. Each model has a bias towards one aspect. These models often override in specific aspects though they have different expressions. A specification written in one model can be refined by introducing additional information from other models. The paper proposes a concept of promoting models which is a methodology to obtain refinements with support from cooperating models. It refines a primary model by integrating the information from a secondary model. The promotion principle is not merely an academic point, but also a reliable and robust engineering technique which can be used to develop software and hardware systems. It can also check the consistency between two specifications from different models. A case of modeling a simple online shopping system with the cooperation of the guarded design model and CSP model illustrates the practicability of the promotion principle.

  13. Activities for Engaging Schools in Health Promotion

    Science.gov (United States)

    Bardi, Mohammad; Burbank, Andrea; Choi, Wayne; Chow, Lawrence; Jang, Wesley; Roccamatisi, Dawn; Timberley-Berg, Tonia; Sanghera, Mandeep; Zhang, Margaret; Macnab, Andrew J.

    2014-01-01

    Purpose: The purpose of this paper is to describe activities used to initiate health promotion in the school setting. Design/Methodology/Approach: Description of successful pilot Health Promoting School (HPS) initiatives in Canada and Uganda and the validated measures central to each program. Evaluation methodologies: quantitative data from the…

  14. 胶质瘤中MGMT、BRAF和EGFR的变化及其治疗的研究进展%Research Progress in Changes of MGMT, BRAF and EGFR in Gliomas and their Correlation with Treatment of Gliomas

    Institute of Scientific and Technical Information of China (English)

    高翔; 罗林

    2016-01-01

    With the development and progress of molecular biology techniques, the research of molecular markers for diagnosis, differential diagnosis and targeted drug therapy of gliomas has also made a great progress. The drugs developed on the base of molecular markers like O6-methylguanine-DNA methyltransferase (MGMT), murine sarcoma viral oncogenic homolog B1 (BRAF) gene and epidermal growth factor receptor (EGFR) also achieved some results in the treatment of glioma. Different types of gliomas have different pathogenesis, and the drugs based on different molecular markers provided a new re-search direction for individualized treatment and combination therapy of glioma patients. In this paper, the changes of EGFR, BRAF and MGMT in gliomas and the progress of glioma therapy were reviewed.%随着分子生物学技术的发展与进步,针对胶质瘤的诊断、鉴别诊断和靶向药物治疗的分子标志物的研究取得了很大的进展。其中,根据O6-甲基鸟嘌呤-DNA-甲基转移酶(MGMT)、鼠类肉瘤滤过性毒菌致癌同源体B1(BRAF)基因和表皮生长因子受体(EGFR)研发的药物也在脑胶质瘤治疗中取得了一定的效果。不同类型的胶质瘤有着不同的发病机制,基于不同分子标志物的药物为胶质瘤患者的个体化治疗或联合治疗提供了新的研究方向。本文就胶质瘤中MGMT、BRAF和EGFR的变化及其与胶质瘤治疗的研究进展进行了综述。

  15. 胶质瘤中MGMT、BRAF和EGFR的变化及其治疗的研究进展%Research Progress in Changes of MGMT, BRAF and EGFR in Gliomas and their Correlation with Treatment of Gliomas

    Institute of Scientific and Technical Information of China (English)

    高翔; 罗林

    2015-01-01

    With the development and progress of molecular biology techniques, the research of molecular markers for diagnosis, differential diagnosis and targeted drug therapy of gliomas has also made a great progress. The drugs developed on the base of mo-lecular markers like O6-methylguanine-DNA methyltransferase (MGMT), murine sarcoma viral oncogenic homolog B1 (BRAF) gene and epidermal growth factor receptor (EGFR) also achieved some results in the treatment of glioma. Different types of gliomas have different pathogenesis, and the drugs based on different molecular markers provided a new research direction for individualized treat-ment and combination therapy of glioma patients. In this paper, the changes of EGFR, BRAF and MGMT in gliomas and the progress of glioma therapy were reviewed.%随着分子生物学技术的发展与进步,针对胶质瘤的诊断、鉴别诊断和靶向药物治疗的分子标志物的研究取得了很大的进展。其中,根据O6-甲基鸟嘌呤-DNA-甲基转移酶(MGMT)、鼠类肉瘤滤过性毒菌致癌同源体B1(BRAF)基因和表皮生长因子受体(EGFR)研发的药物也在脑胶质瘤治疗中取得了一定的效果。不同类型的胶质瘤有着不同的发病机制,基于不同分子标志物的药物为胶质瘤患者的个体化治疗或联合治疗提供了新的研究方向。本文就胶质瘤中MGMT、BRAF和EGFR的变化及其与胶质瘤治疗的研究进展进行了综述。

  16. Interferon-α/β Enhance Temozolomide Activity against MGMT-positive Glioma Stem Cells in Vitro%干扰素-α/β体外增敏替莫唑胺对MGMT阳性胶质瘤干细胞作用

    Institute of Scientific and Technical Information of China (English)

    沈冬; 仇志坤; 陈银生; 陈芙蓉; 陈忠平

    2012-01-01

    [Objective] O6 methylguanine DNA methylbanferase (MGMT) is one of the main mechanisms of chemoresistance for alkylaling agents in malignant glioma. Recent studies showed that glioma stem cells (GSC) was the main cause for tumor recurrence and chemoresistance. This study aimed to explore the effects of interferon-a/β against MGMT-positive glioma stem cells, and to investigate whether Interferon-a/β can enhance the efficiency of temozolomide and the possible mechanism. [Methods] Glioma cell line U251 and SKMG-4, MCMT-negative in conventional culture, were induced through serum-free clone culture to get MGMT-positive GSC U2S1G and SKMG-4G. CCK-8 assay was used to test the growth inhibition effect of temozolomide with interferon-a/p against the MGMT-positive GSC. RT-PCR and Western blot analysis were applied to detect the MGMT and NF-KB expression in MGMT-positive GSC administered by interfenm-a/β. [Results] GSC were successfully obtained from two parental glioma cell lines U251 and SKMG-4, and MGMT expression in GSC was significantly increased determined by Western blot analysis. The chemotherapy sensitivity of temozolomide was significantly enhanced by using intederon-a/β in vitro. The expression of NF-KB and MCMT in MGMT-positive GSC decreased significantly in both mRNA and protein levels after using interferon-a/p through RT-PCR and Western-blot tests. [Conclusion] As to MGMT-positive GSC, interferoo-a/β can enhance the sensitivity of temozolomide, and down-regulate NF-KB expression, lower MGMT transcription expression and reverse the chemoresistance of temozolomide.%[目的]探讨干扰素是否能增加替莫唑胺(TMZ)对O6甲基鸟嘌呤DNA甲基转移酶(MGMT)阳性胶质瘤干细胞的抗肿瘤作用及其可能机制.[方法]采用“悬浮克隆球形成法”对常规培养条件下MGMT阴性表达的胶质瘤细胞株U251、SKMG-4进行诱导,获得MGMT阳性的胶质瘤干细胞U251G、SKMC-4G;应用CCK-8法检测干扰素-α和干扰素-β联合

  17. Vitamin and antioxidant rich diet increases MLH1 promoter DNA methylation in DMT2 subjects

    Directory of Open Access Journals (Sweden)

    Switzeny Olivier J

    2012-10-01

    Full Text Available Abstract Background Oxidative stress may lead to an increased level of unrepaired cellular DNA damage, which is discussed as one risk for tumor initiation. Mismatch repair (MMR enzymes act as proofreading complexes that maintain the genomic integrity and MMR-deficient cells show an increased mutation rate. One important gene in the MMR complex is the MutL homolog 1 (MLH1 gene. Since a diet rich in antioxidants has the potential to counteract harmful effects by reactive oxygen species (ROS, we investigated the impact of an antioxidant, folate, and vitamin rich diet on the epigenetic pattern of MLH1. These effects were analyzed in individuals with non-insulin depended diabetes mellitus type 2 (NIDDM2 and impaired fasting glucose (IFG. Methods In this post-hoc analysis of a randomized trial we analyzed DNA methylation of MLH1, MSH2, and MGMT at baseline and after 8 weeks of intervention, consisting of 300 g vegetables and 25 ml plant oil rich in polyunsaturated fatty acids per day. DNA methylation was quantified using combined bisulfite restriction enzyme analysis (COBRA and pyrosequencing. MLH1 and DNMT1 mRNA expression were investigated by qRT-PCR. DNA damage was assessed by COMET assay. Student’s two-tailed paired t test and one-way ANOVA with Scheffé corrected Post hoc test was used to determine significant methylation and expression differences. Two-tailed Pearson test was used to determine correlations between methylation level, gene expression, and DNA strand break amount. Results The intervention resulted in significantly higher CpG methylation in two particular MLH1 promoter regions and the MGMT promoter. DNA strand breaks and methylation levels correlated significantly. The expression of MLH1, DNMT1, and the promoter methylation of MSH2 remained stable. CpG methylation levels and gene expression did not correlate. Conclusion This vitamin and antioxidant rich diet affected the CpG methylation of MLH1. The higher methylation might be a

  18. 胶质瘤靶向MGMT增敏替莫唑胺治疗%Strategies to improve the sensibility of temozolomide in glioma treatment:Targeting the protein MGMT

    Institute of Scientific and Technical Information of China (English)

    江浩然; 荆国杰

    2016-01-01

    替莫唑胺(Temozolomide,TMZ)作为一种新型烷化剂药物对各种实体性肿瘤有着明显的抗肿瘤作用,其中在胶质瘤的治疗中,其作为一线用药更是有着不可取代的地位.替莫唑胺能够对基因组DNA造成损伤,从而杀伤肿瘤细胞,但是这种损伤能被O6-甲基鸟嘌呤-DNA甲基转移酶(O6-methylguanine DNA methyltranferase,MGMT)所修复,从而造成化疗耐药,直接影响替莫唑胺的杀伤肿瘤的作用.本综述主要叙述了近期在本领域中最新的针对MGMT增敏替莫唑胺的研究.

  19. DNA修复基因MGMT表达不足与胃癌细胞增殖的关系%Relationship between deficient expression of DNA repair gene MGMT and gastric carcinoma cell proliferation

    Institute of Scientific and Technical Information of China (English)

    雷晓华; 朱润庆

    2007-01-01

    目的 探讨DNA修复基因O6-甲基鸟嘌呤-DNA甲基转移酶(O6-met hylguanine-DNA methyltransferase, MGMT)异常表达与胃癌细胞增殖的关系及其临床意义.方法 采用免疫组织化学PV系列二步法检测80例人胃癌组织和12例正常胃黏膜组织中MGMT和PCNA的蛋白表达.结果 MGMT蛋白在胃癌中的阳性率为:52.50%,与正常胃黏膜组织中的阳性率(91.67%)相比,显著降低(P=0.012).MGMT的蛋白表达与胃癌病人的分化程度(P=0.001)、TNM分期(P=0.023)以及淋巴结转移(P=0.001)均密切相关.在80例人胃癌组织中,MGMT和PCNA蛋白表达之间呈显著负相关(P=0.015, r=0.283).结论 MGMT的表达不足促进了胃癌细胞的增殖.

  20. An Analysis on Expressions of MGMT and EGFR and Their Correlation in Breast Cancer%MGMT和EGFR在乳腺癌中的表达及其相关性分析

    Institute of Scientific and Technical Information of China (English)

    王发亮; 薄爱华; 吴力娟; 朱玉平; 张丽丽

    2008-01-01

    [目的] 研究乳腺癌组织中DNA修复酶O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)和表皮生长因子受体(EGFR)表达的相关性及其临床意义.[方法] 采用免疫组织化学SABC法,检测66例乳腺癌组织巾MGMT及EGFR的表达.[结果] 乳腺癌中MGMT的阳性率为57.58%,EGFR的阳性率为48.48%,MGMT与EGFR的表达具有中度相关性(r=0.403).有淋巴结转移患者MGMT与EGFR阳件率均高于无转移(P<0.05).[结论] 检测MGMT与EGFR的表达对乳腺癌患者的预后判断和制定化疗方案具有指导意义.

  1. Cigarette Smoking, BPDE-DNA Adducts, and Aberrant Promoter Methylations of Tumor Suppressor Genes (TSGs) in NSCLC from Chinese Population.

    Science.gov (United States)

    Jin, Yongtang; Xu, Peiwei; Liu, Xinneng; Zhang, Chunye; Tan, Cong; Chen, Chunmei; Sun, Xiaoyu; Xu, Yingchun

    2016-01-01

    Non-small cell lung cancer (NSCLC) is related to the genetic and epigenetic factors. The goal of this study was to determine association of cigarette smoking and BPDE-DNA adducts with promoter methylations of several genes in NSCLC. Methylation of the promoters of p16, RARβ, DAPK, MGMT, and TIMP-3 genes of tumor tissues from 199 lung cancer patients was analyzed with methylation-specific PCR (MSP), and BPDE-DNA adduct level in lung cancer tissue was obtained by ELISA. Level of BPDE-DNA adduct increased significantly in males, aged people (over 60 years), and smokers; however, no significant difference was found while comparing the BPDE-DNA adduct levels among different tumor types, locations, and stages. Cigarette smoking was also associated with increased BPDE-DNA adducts level (OR = 2.43, p > .05) and increased methylation level in at least 1 gene (OR = 5.22, p smoking also significantly increase the risk of p16 or DAPK methylation (OR = 3.02, p smoking for more than 40 pack-years (OR = 4.21, p smoking is significantly associated with the increase of BPDE-DNA adduct level, promoter hypermethylation of p16 and DAPK genes, while BPDE-DNA adduct was not significantly related to abnormal promoter hypermethylation in TSGs, suggesting that BPDE-DNA adducts and TSGs methylations play independent roles in NSCLC.

  2. Quantitative Autonomic Testing

    OpenAIRE

    Novak, Peter

    2011-01-01

    Disorders associated with dysfunction of autonomic nervous system are quite common yet frequently unrecognized. Quantitative autonomic testing can be invaluable tool for evaluation of these disorders, both in clinic and research. There are number of autonomic tests, however, only few were validated clinically or are quantitative. Here, fully quantitative and clinically validated protocol for testing of autonomic functions is presented. As a bare minimum the clinical autonomic laboratory shoul...

  3. Quantitative Algebraic Reasoning

    DEFF Research Database (Denmark)

    Mardare, Radu Iulian; Panangaden, Prakash; Plotkin, Gordon

    2016-01-01

    We develop a quantitative analogue of equational reasoning which we call quantitative algebra. We define an equality relation indexed by rationals: a =ε b which we think of as saying that “a is approximately equal to b up to an error of ε”. We have 4 interesting examples where we have a quantitative...... equational theory whose free algebras correspond to well known structures. In each case we have finitary and continuous versions. The four cases are: Hausdorff metrics from quantitive semilattices; pWasserstein metrics (hence also the Kantorovich metric) from barycentric algebras and also from pointed...

  4. Quantitative comparisons to promote inquiry in the introductory physics lab

    CERN Document Server

    Holmes, N G

    2015-01-01

    In a recent report, the American Association of Physics Teachers has developed an updated set of recommendations for curriculum of undergraduate physics labs.1 This document focuses on six major themes: constructing knowledge, modeling, designing experiments, developing technical and practical laboratory skills, analyzing and visualizing data, and communicating physics. These themes all tie together as a set of practical skills in scientific measurement, analysis, and experimentation. In addition to teaching students how to use these skills, it is important for students to know when to use them so that they can use them autonomously. This requires, especially in the case of analytical skills, high-levels of inquiry behaviours to reflect on data and iterate measurements, which students rarely do in lab experiments. In this paper, we describe a simple framework for structuring the critical thinking and inquiry behaviours relevant to lab work, which focuses on iterative cycles of comparisons between data sets. W...

  5. Quantitative Comparisons to Promote Inquiry in the Introductory Physics Lab

    Science.gov (United States)

    Holmes, N. G.; Bonn, D. A.

    2015-09-01

    In a recent report, the American Association of Physics Teachers has developed an updated set of recommendations for curriculum of undergraduate physics labs. This document focuses on six major themes: constructing knowledge, modeling, designing experiments, developing technical and practical laboratory skills, analyzing and visualizing data, and communicating physics. These themes all tie together as a set of practical skills in scientific measurement, analysis, and experimentation. In addition to teaching students how to use these skills, it is important for students to know when to use them so that they can use them autonomously. This requires, especially in the case of analytical skills, high levels of inquiry behaviors to reflect on data and iterate measurements, which students rarely do in lab experiments. Often, they perform lab experiments in a plug-and-chug frame, procedurally completing each activity with little to no sensemaking. An emphasis on obtaining true theoretical values or agreement on individual measurements also reinforces inauthentic behaviors such as retroactively inflating measurement uncertainties. This paper aims to offer a relatively simple pedagogical framework for engaging students authentically in experimentation and inquiry in physics labs.

  6. Mechanistic and quantitative aspects of liver tumour promotion in mice

    NARCIS (Netherlands)

    Ravenzwaay, van B.

    1988-01-01

    A variety of xenobiotic compounds is known to induce characteristic changes in the livers of laboratory animals. These changes include enlargement of the liver, usually as a result of cell enlargement (hypertrophy) or Increased cell replication (hyperplasia), induction of drugmetabolizing enzymes

  7. Correlation of MGMT gene promoter methylation with prognosis of papillary thyroid cancer%MGMT基因启动子甲基化与乳头状甲状腺癌预后的关系

    Institute of Scientific and Technical Information of China (English)

    沈樑; 张帅; 古维立; 黄迪; 陈绵龄; 梁柳森

    2014-01-01

    目的 检测乳头状甲状腺癌(PTC)组织和良性甲状腺肿瘤组织中MGMT基因启动子区甲基化状态,分析MGMT基因甲基化与PTC预后的关联,旨在为探索PTC预后提供依据.方法 采用甲基化特异PCR法检测60例PTC及60例良性甲状腺肿瘤组织的MGMT基因启动子区甲基化状态,比较两组的不同病理参数间MGMT基因甲基化状态,并分析其与PTC预后的关系.结果 病例组MGMT甲基化阳性率(51.7%)明显高于对照组(26.7%);病例组MGMT甲基化阳性率在有/无吸烟、有/无饮酒间差异显著(P<0.05);年龄越大、肿瘤直径越大、有淋巴结转移、临床分期越高、有MGMT基因甲基化是PTC较差预后的独立影响因素(P<0.05).结论 MGMT基因启动子区甲基化是PTC重要的早期事件,良性甲状腺肿瘤组织中虽然也可发生,但频率远低于PTC;MGMT基因启动子区甲基化对预后具有提示作用.

  8. Prognostic quality of activating TERT promoter mutations in glioblastoma: interaction with the rs2853669 polymorphism and patient age at diagnosis.

    Science.gov (United States)

    Spiegl-Kreinecker, Sabine; Lötsch, Daniela; Ghanim, Bahil; Pirker, Christine; Mohr, Thomas; Laaber, Magdalena; Weis, Serge; Olschowski, Alfred; Webersinke, Gerald; Pichler, Josef; Berger, Walter

    2015-09-01

    Expression of the telomerase reverse transcriptase (TERT) might be altered by activating mutations of the rs2853669 polymorphism within the promoter region. Here we investigate the impact of these genomic alterations on telomerase activation and dissect their prognostic potential in glioblastoma (GBM). The respective TERT promoter region was sequenced in 126 GBM tissues and compared with clinical parameters and glioma biomarkers MGMT promoter methylation and IDH1 mutation. TERT mRNA expression, telomerase activity, and telomere lengths were determined by reverse transcriptase PCR, TRAP assay, and real-time PCR, respectively. Seventy-three percent of GBM patients harbored TERT promoter mutations associated with enhanced telomerase activity and TERT mRNA expression but reduced telomere lengths (P < .001 for all). Patients with mutated tumors exhibited significantly shorter overall survival in the entire cohort (11.5 vs 23.1 months; P < .0001) and in the primary GBM patient subgroup lacking IDH1 mutations (n = 120; P = .0084). This prognostic impact was confined to younger patients (aged <65 years), while the negative prognostic power of enhanced age at diagnosis was limited to those patients lacking TERT promoter mutations. Presence of the common single nucleotide polymorphism rs2853669, disrupting an endogenous Ets2 transcription factor-binding site, was associated with improved survival exclusively in patients with a wild-type TERT promoter. On the contrary, the shortest mean overall survival was detected in those patients harboring both an activating TERT promoter mutation and homozygous rs2853669 alleles. In summary, TERT promoter mutations are powerful prognosticators for worse course of disease in human GBM patients but their prognostic value is influenced by the rs2853669 polymorphism and age at diagnosis. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e

  9. Quantitative imaging with fluorescent biosensors.

    Science.gov (United States)

    Okumoto, Sakiko; Jones, Alexander; Frommer, Wolf B

    2012-01-01

    Molecular activities are highly dynamic and can occur locally in subcellular domains or compartments. Neighboring cells in the same tissue can exist in different states. Therefore, quantitative information on the cellular and subcellular dynamics of ions, signaling molecules, and metabolites is critical for functional understanding of organisms. Mass spectrometry is generally used for monitoring ions and metabolites; however, its temporal and spatial resolution are limited. Fluorescent proteins have revolutionized many areas of biology-e.g., fluorescent proteins can report on gene expression or protein localization in real time-yet promoter-based reporters are often slow to report physiologically relevant changes such as calcium oscillations. Therefore, novel tools are required that can be deployed in specific cells and targeted to subcellular compartments in order to quantify target molecule dynamics directly. We require tools that can measure enzyme activities, protein dynamics, and biophysical processes (e.g., membrane potential or molecular tension) with subcellular resolution. Today, we have an extensive suite of tools at our disposal to address these challenges, including translocation sensors, fluorescence-intensity sensors, and Förster resonance energy transfer sensors. This review summarizes sensor design principles, provides a database of sensors for more than 70 different analytes/processes, and gives examples of applications in quantitative live cell imaging.

  10. MGMT和Ki-67抗原在肝细胞癌组织中的表达及意义%The Expressions and Clinical Significances of MGMT and Ki-67 Antigen in Human Hepatocellular Carcinoma

    Institute of Scientific and Technical Information of China (English)

    宋德霸; 赵龙栓; 王万鹏; 朱志杰; 黄修明; 谷渊

    2009-01-01

    目的 探讨O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)和细胞增殖核抗原Ki-67在原发性肝细胞肝癌(HCC)组织中的表达及意义.方法 应用免疫组化S-P法检测68例HCC组织及癌旁组织中MGMT及Ki-67抗原的表达.结果 MGMT、Ki-67抗原在HCc组织中的表达率分别为44.12%(30/68)和57.35%(39/68),MGMT的表达与Hcc组织病理分级有关(P0.05);Ki-67抗原的表达与HCC的肿瘤大小、包膜是否完整、脉管有无癌栓、病理分级有关(P0.05);并且随Ki-67抗原表达强度的增加,MGMT的表达强度明显下降,Ki-67抗原与MGMT表达呈负相关(γ=-0.301,P<0.05).结论 MGMT在HCC的发生发展中可能起抑制作用,MGMT的缺失是HCC发生的重要分子事件之一,检测Ki-67抗原有助于判断HCC恶性程度及复发转移的风险,联合检测MGMT和Ki-67抗原有助于预测HCC患者预后.

  11. Quantitative film radiography

    Energy Technology Data Exchange (ETDEWEB)

    Devine, G.; Dobie, D.; Fugina, J.; Hernandez, J.; Logan, C.; Mohr, P.; Moss, R.; Schumacher, B.; Updike, E.; Weirup, D.

    1991-02-26

    We have developed a system of quantitative radiography in order to produce quantitative images displaying homogeneity of parts. The materials that we characterize are synthetic composites and may contain important subtle density variations not discernible by examining a raw film x-radiograph. In order to quantitatively interpret film radiographs, it is necessary to digitize, interpret, and display the images. Our integrated system of quantitative radiography displays accurate, high-resolution pseudo-color images in units of density. We characterize approximately 10,000 parts per year in hundreds of different configurations and compositions with this system. This report discusses: the method; film processor monitoring and control; verifying film and processor performance; and correction of scatter effects.

  12. On Quantitative Rorschach Scales.

    Science.gov (United States)

    Haggard, Ernest A.

    1978-01-01

    Two types of quantitative Rorschach scales are discussed: first, those based on the response categories of content, location, and the determinants, and second, global scales based on the subject's responses to all ten stimulus cards. (Author/JKS)

  13. Multivariate Quantitative Chemical Analysis

    Science.gov (United States)

    Kinchen, David G.; Capezza, Mary

    1995-01-01

    Technique of multivariate quantitative chemical analysis devised for use in determining relative proportions of two components mixed and sprayed together onto object to form thermally insulating foam. Potentially adaptable to other materials, especially in process-monitoring applications in which necessary to know and control critical properties of products via quantitative chemical analyses of products. In addition to chemical composition, also used to determine such physical properties as densities and strengths.

  14. Multivariate Quantitative Chemical Analysis

    Science.gov (United States)

    Kinchen, David G.; Capezza, Mary

    1995-01-01

    Technique of multivariate quantitative chemical analysis devised for use in determining relative proportions of two components mixed and sprayed together onto object to form thermally insulating foam. Potentially adaptable to other materials, especially in process-monitoring applications in which necessary to know and control critical properties of products via quantitative chemical analyses of products. In addition to chemical composition, also used to determine such physical properties as densities and strengths.

  15. Detection of methylation in promoter sequences by melting curve analysis-based semiquantitative real time PCR

    Directory of Open Access Journals (Sweden)

    Lázcoz Paula

    2008-02-01

    Full Text Available Abstract Background We present two melting curve analysis (MCA-based semiquantitative real time PCR techniques to detect the promoter methylation status of genes. The first, MCA-MSP, follows the same principle as standard MSP but it is performed in a real time thermalcycler with results being visualized in a melting curve. The second, MCA-Meth, uses a single pair of primers designed with no CpGs in its sequence. These primers amplify both unmethylated and methylated sequences. In clinical applications the MSP technique has revolutionized methylation detection by simplifying the analysis to a PCR-based protocol. MCA-analysis based techniques may be able to further improve and simplify methylation analyses by reducing starting DNA amounts, by introducing an all-in-one tube reaction and by eliminating a final gel stage for visualization of the result. The current study aimed at investigating the feasibility of both MCA-MSP and MCA-Meth in the analysis of promoter methylation, and at defining potential advantages and shortcomings in comparison to currently implemented techniques, i.e. bisulfite sequencing and standard MSP. Methods The promoters of the RASSF1A (3p21.3, BLU (3p21.3 and MGMT (10q26 genes were analyzed by MCA-MSP and MCA-Meth in 13 astrocytoma samples, 6 high grade glioma cell lines and 4 neuroblastoma cell lines. The data were compared with standard MSP and validated by bisulfite sequencing. Results Both, MCA-MSP and MCA-Meth, successfully determined promoter methylation. MCA-MSP provided information similar to standard MSP analyses. However the analysis was possible in a single tube and avoided the gel stage. MCA-Meth proved to be useful in samples with intermediate methylation status, reflected by a melting curve position shift in dependence on methylation extent. Conclusion We propose MCA-MSP and MCA-Meth as alternative or supplementary techniques to MSP or bisulfite sequencing.

  16. Quantitative autonomic testing.

    Science.gov (United States)

    Novak, Peter

    2011-07-19

    Disorders associated with dysfunction of autonomic nervous system are quite common yet frequently unrecognized. Quantitative autonomic testing can be invaluable tool for evaluation of these disorders, both in clinic and research. There are number of autonomic tests, however, only few were validated clinically or are quantitative. Here, fully quantitative and clinically validated protocol for testing of autonomic functions is presented. As a bare minimum the clinical autonomic laboratory should have a tilt table, ECG monitor, continuous noninvasive blood pressure monitor, respiratory monitor and a mean for evaluation of sudomotor domain. The software for recording and evaluation of autonomic tests is critical for correct evaluation of data. The presented protocol evaluates 3 major autonomic domains: cardiovagal, adrenergic and sudomotor. The tests include deep breathing, Valsalva maneuver, head-up tilt, and quantitative sudomotor axon test (QSART). The severity and distribution of dysautonomia is quantitated using Composite Autonomic Severity Scores (CASS). Detailed protocol is provided highlighting essential aspects of testing with emphasis on proper data acquisition, obtaining the relevant parameters and unbiased evaluation of autonomic signals. The normative data and CASS algorithm for interpretation of results are provided as well.

  17. Quantitative Hydrocarbon Surface Analysis

    Science.gov (United States)

    Douglas, Vonnie M.

    2000-01-01

    The elimination of ozone depleting substances, such as carbon tetrachloride, has resulted in the use of new analytical techniques for cleanliness verification and contamination sampling. The last remaining application at Rocketdyne which required a replacement technique was the quantitative analysis of hydrocarbons by infrared spectrometry. This application, which previously utilized carbon tetrachloride, was successfully modified using the SOC-400, a compact portable FTIR manufactured by Surface Optics Corporation. This instrument can quantitatively measure and identify hydrocarbons from solvent flush of hardware as well as directly analyze the surface of metallic components without the use of ozone depleting chemicals. Several sampling accessories are utilized to perform analysis for various applications.

  18. Health Promotion as Part of a Holistic Approach to Community ...

    African Journals Online (AJOL)

    Health Promotion as Part of a Holistic Approach to Community Mental Health Care in Sierra Leone. ... of service is probably plagued by the strong stigma that prevails in society. Reliable quantitative data on mental illness is extremely minimal.

  19. Quantitative Decision Support Requires Quantitative User Guidance

    Science.gov (United States)

    Smith, L. A.

    2009-12-01

    Is it conceivable that models run on 2007 computer hardware could provide robust and credible probabilistic information for decision support and user guidance at the ZIP code level for sub-daily meteorological events in 2060? In 2090? Retrospectively, how informative would output from today’s models have proven in 2003? or the 1930’s? Consultancies in the United Kingdom, including the Met Office, are offering services to “future-proof” their customers from climate change. How is a US or European based user or policy maker to determine the extent to which exciting new Bayesian methods are relevant here? or when a commercial supplier is vastly overselling the insights of today’s climate science? How are policy makers and academic economists to make the closely related decisions facing them? How can we communicate deep uncertainty in the future at small length-scales without undermining the firm foundation established by climate science regarding global trends? Three distinct aspects of the communication of the uses of climate model output targeting users and policy makers, as well as other specialist adaptation scientists, are discussed. First, a brief scientific evaluation of the length and time scales at which climate model output is likely to become uninformative is provided, including a note on the applicability the latest Bayesian methodology to current state-of-the-art general circulation models output. Second, a critical evaluation of the language often employed in communication of climate model output, a language which accurately states that models are “better”, have “improved” and now “include” and “simulate” relevant meteorological processed, without clearly identifying where the current information is thought to be uninformative and misleads, both for the current climate and as a function of the state of the (each) climate simulation. And thirdly, a general approach for evaluating the relevance of quantitative climate model output

  20. Quantitative Intracerebral Hemorrhage Localization

    Science.gov (United States)

    Muschelli, John; Ullman, Natalie L.; Sweeney, Elizabeth M.; Eloyan, Ani; Martin, Neil; Vespa, Paul; Hanley, Daniel F.; Crainiceanu, Ciprian M.

    2015-01-01

    Background and Purpose The location of intracerebral hemorrhage (ICH) is currently described in a qualitative way; we provide a quantitative framework for estimating ICH engagement and its relevance to stroke outcomes. Methods We analyzed 111 patients with ICH from the MISTIE II clinical trial. We estimated ICH engagement at a population level using image registration of CT scans to a template and a previously labeled atlas. Predictive regions of NIHSS and GCS stroke severity scores, collected at enrollment, were estimated. Results The percent coverage of the ICH by these regions strongly outperformed the reader-labeled locations. The adjusted R2 almost doubled from 0.129 (reader-labeled model) to 0.254 (quantitative-location model) for NIHSS and more than tripled from 0.069 (reader-labeled model) to 0.214 (quantitative-location model). A permutation test confirmed that the new predictive regions are more predictive than chance: p<.001 for NIHSS and p<.01 for GCS. Conclusions Objective measures of ICH location and engagement using advanced CT imaging processing provide finer, objective, and more quantitative anatomic information than that provided by human readers. PMID:26451031

  1. Critical Quantitative Inquiry in Context

    Science.gov (United States)

    Stage, Frances K.; Wells, Ryan S.

    2014-01-01

    This chapter briefly traces the development of the concept of critical quantitative inquiry, provides an expanded conceptualization of the tasks of critical quantitative research, offers theoretical explanation and justification for critical research using quantitative methods, and previews the work of quantitative criticalists presented in this…

  2. Critical Quantitative Inquiry in Context

    Science.gov (United States)

    Stage, Frances K.; Wells, Ryan S.

    2014-01-01

    This chapter briefly traces the development of the concept of critical quantitative inquiry, provides an expanded conceptualization of the tasks of critical quantitative research, offers theoretical explanation and justification for critical research using quantitative methods, and previews the work of quantitative criticalists presented in this…

  3. Comparison of Different Promoter Methylation Assays in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Karijn P. M. Suijkerbuijk

    2010-01-01

    Full Text Available Background: Promoter hypermethylation has emerged as a promising cancer biomarker. Currently, a large variety of quantitative and non-quantitative techniques is used to measure methylation in clinical specimens. Here we directly compared three commonly used methylation assays and assessed the influence of tissue fixation, target sequence location and the amount of DNA on their performance.

  4. Applied quantitative finance

    CERN Document Server

    Chen, Cathy; Overbeck, Ludger

    2017-01-01

    This volume provides practical solutions and introduces recent theoretical developments in risk management, pricing of credit derivatives, quantification of volatility and copula modeling. This third edition is devoted to modern risk analysis based on quantitative methods and textual analytics to meet the current challenges in banking and finance. It includes 14 new contributions and presents a comprehensive, state-of-the-art treatment of cutting-edge methods and topics, such as collateralized debt obligations, the high-frequency analysis of market liquidity, and realized volatility. The book is divided into three parts: Part 1 revisits important market risk issues, while Part 2 introduces novel concepts in credit risk and its management along with updated quantitative methods. The third part discusses the dynamics of risk management and includes risk analysis of energy markets and for cryptocurrencies. Digital assets, such as blockchain-based currencies, have become popular b ut are theoretically challenging...

  5. Energy & Climate: Getting Quantitative

    Science.gov (United States)

    Wolfson, Richard

    2011-11-01

    A noted environmentalist claims that buying an SUV instead of a regular car is energetically equivalent to leaving your refrigerator door open for seven years. A fossil-fuel apologist argues that solar energy is a pie-in-the-sky dream promulgated by na"ive environmentalists, because there's nowhere near enough solar energy to meet humankind's energy demand. A group advocating shutdown of the Vermont Yankee nuclear plant claims that 70% of its electrical energy is lost in transmission lines. Around the world, thousands agitate for climate action, under the numerical banner ``350.'' Neither the environmentalist, the fossil-fuel apologist, the antinuclear activists, nor most of those marching under the ``350'' banner can back up their assertions with quantitative arguments. Yet questions about energy and its environmental impacts almost always require quantitative answers. Physics can help! This poster gives some cogent examples, based on the newly published 2^nd edition of the author's textbook Energy, Environment, and Climate.

  6. 胆囊腺癌及癌旁组织中MGMT、hMLH1、hMSH2基因的表达和临床意义%The clinical significance of MGMT, hMLH1 and hMSH2 gene expressions in gallbladder adenocarcinoma and adjacent tissues

    Institute of Scientific and Technical Information of China (English)

    曾毅; 杨竹林; 李代强; 邹琼; 刘子儒; 苗雄鹰; 杨乐平; 袁源

    2016-01-01

    目的 研究胆囊腺癌、癌旁组织和腺瘤性息肉中MGMT、hMLH1和hMSH2基因的表达水平及意义.方法 共收集80例腺癌、25例癌旁组织和25例腺瘤性息肉手术切除标本,常规石蜡包埋切片,EnVision免疫组化法检测MGMT、hMLH1和hMSH2表达水平.结果 胆囊腺癌组织中MGMT、hMLH1和hMSH2阳性表达率明显低于癌旁组织和腺瘤性息肉(P<0.01).癌旁组织与腺瘤性息肉MGMT、hMLH1和hMSH2的阳性表达率差异无统计学意义(P>0.05).高分化、肿块最大径≤3 cm、无淋巴结转移和未侵犯周围组织患者组织标本中MGMT、hMLH1和hMSH2的表达阳性率明显高于低分化、肿块最大径>3 cm、淋巴结转移和侵犯周围组织的患者(P<0.05).Kaplan-Meier生存分析显示MGMT、hMLH1和hMSH2表达阳性胆囊腺癌患者的平均生存期明显高于阴性患者(P<0.05).Cox多因素分析显示MGMT、hMLH1和hMSH2阳性表达与术后生存率呈正相关,与病死率呈负相关;组织中MGMT、hMLH1和hMSH2的阳性表达是胆囊腺癌术后的独立预后因子和保护性因素.结论 MGMT、hMLH1和hMSH2表达反映了胆囊腺癌的发生、进展和预后.MGMT、hMLH1和hMSH2阳性表达的腺癌患者预后较好.%Objective To investigate the gene expressions of MGMT,hMLH1 and hMSH2 in gallbladder adenocarcinoma,tumor adjacent tissues and adenomatous polyp,and to explore the clinicopathological significance.Methods The EnVision immunohistochemical method was used to detect the expressions of MGMT,hMLH1 and hMSH2 in routine paraffin-embedded sections of tissue samples of gallbladder adenocarcinoma (n =80),tumor adjacent tissues (n =25) and adenomatous polyp (n =25).Results The positive rates of MGMT,hMLH1 and hMSH2 were significantly lower in gallbladder adenocarcinoma than those in tumor adjacent tissues and adenomatous polyp (P < 0.05).The positive rates were significantly higherin specimens with well-differentiated adenocarcinoma,no lymph node

  7. Quantitation of signal transduction.

    Science.gov (United States)

    Krauss, S; Brand, M D

    2000-12-01

    Conventional qualitative approaches to signal transduction provide powerful ways to explore the architecture and function of signaling pathways. However, at the level of the complete system, they do not fully depict the interactions between signaling and metabolic pathways and fail to give a manageable overview of the complexity that is often a feature of cellular signal transduction. Here, we introduce a quantitative experimental approach to signal transduction that helps to overcome these difficulties. We present a quantitative analysis of signal transduction during early mitogen stimulation of lymphocytes, with steady-state respiration rate as a convenient marker of metabolic stimulation. First, by inhibiting various key signaling pathways, we measure their relative importance in regulating respiration. About 80% of the input signal is conveyed via identifiable routes: 50% through pathways sensitive to inhibitors of protein kinase C and MAP kinase and 30% through pathways sensitive to an inhibitor of calcineurin. Second, we quantify how each of these pathways differentially stimulates functional units of reactions that produce and consume a key intermediate in respiration: the mitochondrial membrane potential. Both the PKC and calcineurin routes stimulate consumption more strongly than production, whereas the unidentified signaling routes stimulate production more than consumption, leading to no change in membrane potential despite increased respiration rate. The approach allows a quantitative description of the relative importance of signal transduction pathways and the routes by which they activate a specific cellular process. It should be widely applicable.

  8. Quantitative traits and diversification.

    Science.gov (United States)

    FitzJohn, Richard G

    2010-12-01

    Quantitative traits have long been hypothesized to affect speciation and extinction rates. For example, smaller body size or increased specialization may be associated with increased rates of diversification. Here, I present a phylogenetic likelihood-based method (quantitative state speciation and extinction [QuaSSE]) that can be used to test such hypotheses using extant character distributions. This approach assumes that diversification follows a birth-death process where speciation and extinction rates may vary with one or more traits that evolve under a diffusion model. Speciation and extinction rates may be arbitrary functions of the character state, allowing much flexibility in testing models of trait-dependent diversification. I test the approach using simulated phylogenies and show that a known relationship between speciation and a quantitative character could be recovered in up to 80% of the cases on large trees (500 species). Consistent with other approaches, detecting shifts in diversification due to differences in extinction rates was harder than when due to differences in speciation rates. Finally, I demonstrate the application of QuaSSE to investigate the correlation between body size and diversification in primates, concluding that clade-specific differences in diversification may be more important than size-dependent diversification in shaping the patterns of diversity within this group.

  9. RICE SUCROSE SYNTHASE PROMOTER

    DEFF Research Database (Denmark)

    2000-01-01

    A promoter is described. The promoter comprises a nucleotide sequence corresponding to that shown as SEQ ID No. 1 or a variant, homologue or derivative thereof.......A promoter is described. The promoter comprises a nucleotide sequence corresponding to that shown as SEQ ID No. 1 or a variant, homologue or derivative thereof....

  10. Directional and quantitative phosphorylation networks

    DEFF Research Database (Denmark)

    Jørgensen, Claus; Linding, Rune

    2008-01-01

    for unravelling phosphorylation-mediated cellular interaction networks. In particular, we will discuss how the combination of new quantitative mass-spectrometric technologies and computational algorithms together are enhancing mapping of these largely uncharted dynamic networks. By combining quantitative...

  11. F# for quantitative finance

    CERN Document Server

    Astborg, Johan

    2013-01-01

    To develop your confidence in F#, this tutorial will first introduce you to simpler tasks such as curve fitting. You will then advance to more complex tasks such as implementing algorithms for trading semi-automation in a practical scenario-based format.If you are a data analyst or a practitioner in quantitative finance, economics, or mathematics and wish to learn how to use F# as a functional programming language, this book is for you. You should have a basic conceptual understanding of financial concepts and models. Elementary knowledge of the .NET framework would also be helpful.

  12. Designing quantitative telemedicine research.

    Science.gov (United States)

    Wade, Victoria; Barnett, Adrian G; Martin-Khan, Melinda; Russell, Trevor

    2016-10-27

    When designing quantitative trials and evaluation of telehealth interventions, researchers should think ahead to the intended way that the intervention could be implemented in routine care and consider how trial participants with similar characteristics to the target population can be included. The telehealth intervention and the context in which it is placed should be clearly described, and consideration given to conducting pragmatic trials in order to show the effect of telehealth in complex environments with rapidly changing technology. Types of research designs, comparators and outcome measures are discussed and common statistical issues are introduced. © The Author(s) 2016.

  13. Quantitative immunoglobulins in adulthood.

    Science.gov (United States)

    Crisp, Howard C; Quinn, James M

    2009-01-01

    Although age-related changes in serum immunoglobulins are well described in childhood, alterations in immunoglobulins in the elderly are less well described and published. This study was designed to better define expected immunoglobulin ranges and differences in adults of differing decades of life. Sera from 404 patients, aged 20-89 years old were analyzed for quantitative immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA). The patients with diagnoses or medications known to affect immunoglobulin levels were identified while blinded to their immunoglobulin levels. A two-factor ANOVA was performed using decade of life and gender on both the entire sample population as well as the subset without any disease or medication expected to alter immunoglobulin levels. A literature review was also performed on all English language articles evaluating quantitative immunoglobulin levels in adults >60 years old. For the entire population, IgM was found to be higher in women when compared with men (p immunoglobulin levels, the differences in IgM with gender and age were maintained (p immunoglobulin levels have higher serum IgA levels and lower serum IgM levels. Women have higher IgM levels than men throughout life. IgG levels are not significantly altered in an older population.

  14. Is quantitative electromyography reliable?

    Science.gov (United States)

    Cecere, F; Ruf, S; Pancherz, H

    1996-01-01

    The reliability of quantitative electromyography (EMG) of the masticatory muscles was investigated in 14 subjects without any signs or symptoms of temporomandibular disorders. Integrated EMG activity from the anterior temporalis and masseter muscles was recorded bilaterally by means of bipolar surface electrodes during chewing and biting activities. In the first experiment, the influence of electrode relocation was investigated. No influence of electrode relocation on the recorded EMG signal could be detected. In a second experiment, three sessions of EMG recordings during five different chewing and biting activities were performed in the morning (I); 1 hour later without intermediate removal of the electrodes (II); and in the afternoon, using new electrodes (III). The method errors for different time intervals (I-II and I-III errors) for each muscle and each function were calculated. Depending on the time interval between the EMG recordings, the muscles considered, and the function performed, the individual errors ranged from 5% to 63%. The method error increased significantly (P masseter (mean 27.2%) was higher than for the temporalis (mean 20.0%). The largest function error was found during maximal biting in intercuspal position (mean 23.1%). Based on the findings, quantitative electromyography of the masticatory muscles seems to have a limited value in diagnostics and in the evaluation of individual treatment results.

  15. Quantitative variations of CD4 + CD25 + cells in Peking duckwhite ...

    African Journals Online (AJOL)

    Quantitative variations of CD4 + CD25 + cells in Peking duckwhite leghorn chimeras based on bone marrow mesenchymal stem cells. ... PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN JOURNALS ONLINE (AJOL) · Journals ...

  16. 前列腺癌组织中DLC-1启动子甲基化定量检测的HRM方法建立及其应用意义%Establishment of HRM method for quantitative determination for methylation level of DLC-1 promoter in prostate cancer and its clinical significance

    Institute of Scientific and Technical Information of China (English)

    郭林; 张心菊; 关明; 刘瑞来; 顾小叶; 马玮哲

    2010-01-01

    Objective To establish quantitative method for detection of methylation level of DLC-1 promoter with HRM technology to analyze its association with pathological parameters in prostate cancer.Methods 89 prostate cancer tissue samples and 10 matched normal tissue samples were enrolled into this study.Prostate cancer cells were obtained by LCM.DNA was extracted and modified for methylation determination.CpGenome Universal Methylated DNA was chosen as 100% methylation sample.Then the calibrators representative of 100%,80%,50%,30%,10% and 0% methylation levels were prepared with dilution in a DNA sample of peripheral blood from healthy subjects(100% non-methylation).The DLC-1 methylation levels in prostate cancer tissue samples were detected with HRM.The associations of methylated level with age of patients,PSA value,TNM stage were investigated respectively.ResultsThe melting curves representing 100%,80%,50%,30%,10% and 0% methylation levels were aligned from right to left.The methylation levels of 10 adjacent normal samples and 35 prostate cancer samples were overlapped with 0% methylated calibrator.The methylation levels of 5 cancer samples ranged between 0% and 30%.The methylation levels of 29 cancer samples ranged between 31% and 80%.The methylation levels of 20 cancer samples ranged between 81% and 100%.HRM could be used to reliably detect the as low as 10% methylation for each assay,whereas methylation specific PCR(MSP) could be used to detect 30% methylation level.No significant association between methylation level and patients' age(X~2=3.29,P=0.19),PSA level(X~2=2.04,P=0.36) was found.However,DLC-1 methylation was higher in the prostate cancer tissues with advanced TNM stage(X~2=9.04,P=.01).Conclusions The quantitative method for DLC-1 methylation with HRM is successfully established.It is convenient with good reproducibility and high sensitivity.DLC-1 methylation could be used as the molecular marker for estimation of malignancy in prostate cancer.%目的

  17. Quantitative Risk Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Helms, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-10

    The US energy sector is vulnerable to multiple hazards including both natural disasters and malicious attacks from an intelligent adversary. The question that utility owners, operators and regulators face is how to prioritize their investments to mitigate the risks from a hazard that can have the most impact on the asset of interest. In order to be able to understand their risk landscape and develop a prioritized mitigation strategy, they must quantify risk in a consistent way across all hazards their asset is facing. Without being able to quantitatively measure risk, it is not possible to defensibly prioritize security investments or evaluate trade-offs between security and functionality. Development of a methodology that will consistently measure and quantify risk across different hazards is needed.

  18. Quantitative velocity modulation spectroscopy

    Science.gov (United States)

    Hodges, James N.; McCall, Benjamin J.

    2016-05-01

    Velocity Modulation Spectroscopy (VMS) is arguably the most important development in the 20th century for spectroscopic study of molecular ions. For decades, interpretation of VMS lineshapes has presented challenges due to the intrinsic covariance of fit parameters including velocity modulation amplitude, linewidth, and intensity. This limitation has stifled the growth of this technique into the quantitative realm. In this work, we show that subtle changes in the lineshape can be used to help address this complexity. This allows for determination of the linewidth, intensity relative to other transitions, velocity modulation amplitude, and electric field strength in the positive column of a glow discharge. Additionally, we explain the large homogeneous component of the linewidth that has been previously described. Using this component, the ion mobility can be determined.

  19. Quantitative metamaterial property extraction

    CERN Document Server

    Schurig, David

    2015-01-01

    We examine an extraction model for metamaterials, not previously reported, that gives precise, quantitative and causal representation of S parameter data over a broad frequency range, up to frequencies where the free space wavelength is only a modest factor larger than the unit cell dimension. The model is comprised of superposed, slab shaped response regions of finite thickness, one for each observed resonance. The resonance dispersion is Lorentzian and thus strictly causal. This new model is compared with previous models for correctness likelihood, including an appropriate Occam's factor for each fit parameter. We find that this new model is by far the most likely to be correct in a Bayesian analysis of model fits to S parameter simulation data for several classic metamaterial unit cells.

  20. Quantitative Hyperspectral Reflectance Imaging

    Directory of Open Access Journals (Sweden)

    Ted A.G. Steemers

    2008-09-01

    Full Text Available Hyperspectral imaging is a non-destructive optical analysis technique that can for instance be used to obtain information from cultural heritage objects unavailable with conventional colour or multi-spectral photography. This technique can be used to distinguish and recognize materials, to enhance the visibility of faint or obscured features, to detect signs of degradation and study the effect of environmental conditions on the object. We describe the basic concept, working principles, construction and performance of a laboratory instrument specifically developed for the analysis of historical documents. The instrument measures calibrated spectral reflectance images at 70 wavelengths ranging from 365 to 1100 nm (near-ultraviolet, visible and near-infrared. By using a wavelength tunable narrow-bandwidth light-source, the light energy used to illuminate the measured object is minimal, so that any light-induced degradation can be excluded. Basic analysis of the hyperspectral data includes a qualitative comparison of the spectral images and the extraction of quantitative data such as mean spectral reflectance curves and statistical information from user-defined regions-of-interest. More sophisticated mathematical feature extraction and classification techniques can be used to map areas on the document, where different types of ink had been applied or where one ink shows various degrees of degradation. The developed quantitative hyperspectral imager is currently in use by the Nationaal Archief (National Archives of The Netherlands to study degradation effects of artificial samples and original documents, exposed in their permanent exhibition area or stored in their deposit rooms.

  1. Tunable promoters in synthetic and systems biology

    DEFF Research Database (Denmark)

    Dehli, Tore; Solem, Christian; Jensen, Peter Ruhdal

    2012-01-01

    Synthetic and systems biologists need standardized, modular and orthogonal tools yielding predictable functions in vivo. In systems biology such tools are needed to quantitatively analyze the behavior of biological systems while the efficient engineering of artificial gene networks is central...... in synthetic biology. A number of tools exist to manipulate the steps in between gene sequence and functional protein in living cells, but out of these the most straight-forward approach is to alter the gene expression level by manipulating the promoter sequence. Some of the promoter tuning tools available...

  2. Tunable promoters in synthetic and systems biology

    DEFF Research Database (Denmark)

    Dehli, Tore; Solem, Christian; Jensen, Peter Ruhdal

    2012-01-01

    in synthetic biology. A number of tools exist to manipulate the steps in between gene sequence and functional protein in living cells, but out of these the most straight-forward approach is to alter the gene expression level by manipulating the promoter sequence. Some of the promoter tuning tools available......Synthetic and systems biologists need standardized, modular and orthogonal tools yielding predictable functions in vivo. In systems biology such tools are needed to quantitatively analyze the behavior of biological systems while the efficient engineering of artificial gene networks is central...

  3. Promoting preschool reading

    OpenAIRE

    2013-01-01

    The thesis titled Promoting preschool reading consists of a theoretiral and an empirical part. In the theoretical part I wrote about reading, the importance of reading, types of reading, about reading motivation, promoting reading motivation, internal and external motivation, influence of reading motivation on the child's reading activity, reading and familial literacy, the role of adults in promotion reading literacy, reading to a child and promoting reading in pre-school years, where I ...

  4. How Promotions Work

    OpenAIRE

    Robert C. Blattberg; Richard Briesch; Fox, Edward J.

    1995-01-01

    By synthesizing findings across the sales promotion literature, this article helps the reader understand how promotions work. We identify and explain empirical generalizations related to sales promotion; that is, effects that have been found consistently in multiple studies involving different researchers. We also identify issues which have generated conflicting findings in the research, as well as important sales promotion topics that have not yet been studied. This overview of the research ...

  5. Perceptions of health promoters about health promotion ...

    African Journals Online (AJOL)

    2013-02-11

    Feb 11, 2013 ... formal written health promotion guidelines for families with adolescents orphaned ..... community: '…What worries me is the fact that they still become pregnant .... to learn about HIV risk factors, testing, treatment choices and.

  6. Quantitative Techniques in Volumetric Analysis

    Science.gov (United States)

    Zimmerman, John; Jacobsen, Jerrold J.

    1996-12-01

    Quantitative Techniques in Volumetric Analysis is a visual library of techniques used in making volumetric measurements. This 40-minute VHS videotape is designed as a resource for introducing students to proper volumetric methods and procedures. The entire tape, or relevant segments of the tape, can also be used to review procedures used in subsequent experiments that rely on the traditional art of quantitative analysis laboratory practice. The techniques included are: Quantitative transfer of a solid with a weighing spoon Quantitative transfer of a solid with a finger held weighing bottle Quantitative transfer of a solid with a paper strap held bottle Quantitative transfer of a solid with a spatula Examples of common quantitative weighing errors Quantitative transfer of a solid from dish to beaker to volumetric flask Quantitative transfer of a solid from dish to volumetric flask Volumetric transfer pipet A complete acid-base titration Hand technique variations The conventional view of contemporary quantitative chemical measurement tends to focus on instrumental systems, computers, and robotics. In this view, the analyst is relegated to placing standards and samples on a tray. A robotic arm delivers a sample to the analysis center, while a computer controls the analysis conditions and records the results. In spite of this, it is rare to find an analysis process that does not rely on some aspect of more traditional quantitative analysis techniques, such as careful dilution to the mark of a volumetric flask. Figure 2. Transfer of a solid with a spatula. Clearly, errors in a classical step will affect the quality of the final analysis. Because of this, it is still important for students to master the key elements of the traditional art of quantitative chemical analysis laboratory practice. Some aspects of chemical analysis, like careful rinsing to insure quantitative transfer, are often an automated part of an instrumental process that must be understood by the

  7. Developing a Promotional Video

    Science.gov (United States)

    Epley, Hannah K.

    2014-01-01

    There is a need for Extension professionals to show clientele the benefits of their program. This article shares how promotional videos are one way of reaching audiences online. An example is given on how a promotional video has been used and developed using iMovie software. Tips are offered for how professionals can create a promotional video and…

  8. Quantitative goals for monetary policy

    OpenAIRE

    Fatás, Antonio; Mihov, Ilian; ROSE, Andrew K.

    2006-01-01

    We study empirically the macroeconomic effects of an explicit de jure quantitative goal for monetary policy. Quantitative goals take three forms: exchange rates, money growth rates, and inflation targets. We analyze the effects on inflation of both having a quantitative target, and of hitting a declared target; we also consider effects on output volatility. Our empirical work uses an annual data set covering 42 countries between 1960 and 2000, and takes account of other determinants of inflat...

  9. Quantitative Risk - Phases 1 & 2

    Science.gov (United States)

    2013-11-12

    quantitative risk characterization”, " Risk characterization of microbiological hazards in food ", Chapter 4, 2009 314...State University, July 9, 2013 213. Albert I, Grenier E, Denis JB, Rousseau J., “ Quantitative Risk Assessment from Farm to Fork and Beyond: a...MELHEM, G., “Conduct Effective Quantitative Risk Assessment (QRA) Studies”, ioMosaic Corporation, 2006 233. Anderson, J., Brown, R., “ Risk

  10. Quantitative Electron Nanodiffraction.

    Energy Technology Data Exchange (ETDEWEB)

    Spence, John [Arizona State Univ., Mesa, AZ (United States)

    2015-01-30

    This Final report summarizes progress under this award for the final reporting period 2002 - 2013 in our development of quantitive electron nanodiffraction to materials problems, especially devoted to atomistic processes in semiconductors and electronic oxides such as the new artificial oxide multilayers, where our microdiffraction is complemented with energy-loss spectroscopy (ELNES) and aberration-corrected STEM imaging (9). The method has also been used to map out the chemical bonds in the important GaN semiconductor (1) used for solid state lighting, and to understand the effects of stacking sequence variations and interfaces in digital oxide superlattices (8). Other projects include the development of a laser-beam Zernike phase plate for cryo-electron microscopy (5) (based on the Kapitza-Dirac effect), work on reconstruction of molecular images using the scattering from many identical molecules lying in random orientations (4), a review article on space-group determination for the International Tables on Crystallography (10), the observation of energy-loss spectra with millivolt energy resolution and sub-nanometer spatial resolution from individual point defects in an alkali halide, a review article for the Centenary of X-ray Diffration (17) and the development of a new method of electron-beam lithography (12). We briefly summarize here the work on GaN, on oxide superlattice ELNES, and on lithography by STEM.

  11. Programmable Quantitative DNA Nanothermometers.

    Science.gov (United States)

    Gareau, David; Desrosiers, Arnaud; Vallée-Bélisle, Alexis

    2016-07-13

    Developing molecules, switches, probes or nanomaterials that are able to respond to specific temperature changes should prove of utility for several applications in nanotechnology. Here, we describe bioinspired strategies to design DNA thermoswitches with programmable linear response ranges that can provide either a precise ultrasensitive response over a desired, small temperature interval (±0.05 °C) or an extended linear response over a wide temperature range (e.g., from 25 to 90 °C). Using structural modifications or inexpensive DNA stabilizers, we show that we can tune the transition midpoints of DNA thermometers from 30 to 85 °C. Using multimeric switch architectures, we are able to create ultrasensitive thermometers that display large quantitative fluorescence gains within small temperature variation (e.g., > 700% over 10 °C). Using a combination of thermoswitches of different stabilities or a mix of stabilizers of various strengths, we can create extended thermometers that respond linearly up to 50 °C in temperature range. Here, we demonstrate the reversibility, robustness, and efficiency of these programmable DNA thermometers by monitoring temperature change inside individual wells during polymerase chain reactions. We discuss the potential applications of these programmable DNA thermoswitches in various nanotechnology fields including cell imaging, nanofluidics, nanomedecine, nanoelectronics, nanomaterial, and synthetic biology.

  12. Quantitive DNA Fiber Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chun-Mei; Wang, Mei; Greulich-Bode, Karin M.; Weier, Jingly F.; Weier, Heinz-Ulli G.

    2008-01-28

    Several hybridization-based methods used to delineate single copy or repeated DNA sequences in larger genomic intervals take advantage of the increased resolution and sensitivity of free chromatin, i.e., chromatin released from interphase cell nuclei. Quantitative DNA fiber mapping (QDFM) differs from the majority of these methods in that it applies FISH to purified, clonal DNA molecules which have been bound with at least one end to a solid substrate. The DNA molecules are then stretched by the action of a receding meniscus at the water-air interface resulting in DNA molecules stretched homogeneously to about 2.3 kb/{micro}m. When non-isotopically, multicolor-labeled probes are hybridized to these stretched DNA fibers, their respective binding sites are visualized in the fluorescence microscope, their relative distance can be measured and converted into kilobase pairs (kb). The QDFM technique has found useful applications ranging from the detection and delineation of deletions or overlap between linked clones to the construction of high-resolution physical maps to studies of stalled DNA replication and transcription.

  13. 1, 2, 3, 4: infusing quantitative literacy into introductory biology.

    Science.gov (United States)

    Speth, Elena Bray; Momsen, Jennifer L; Moyerbrailean, Gregory A; Ebert-May, Diane; Long, Tammy M; Wyse, Sara; Linton, Debra

    2010-01-01

    Biology of the twenty-first century is an increasingly quantitative science. Undergraduate biology education therefore needs to provide opportunities for students to develop fluency in the tools and language of quantitative disciplines. Quantitative literacy (QL) is important for future scientists as well as for citizens, who need to interpret numeric information and data-based claims regarding nearly every aspect of daily life. To address the need for QL in biology education, we incorporated quantitative concepts throughout a semester-long introductory biology course at a large research university. Early in the course, we assessed the quantitative skills that students bring to the introductory biology classroom and found that students had difficulties in performing simple calculations, representing data graphically, and articulating data-driven arguments. In response to students' learning needs, we infused the course with quantitative concepts aligned with the existing course content and learning objectives. The effectiveness of this approach is demonstrated by significant improvement in the quality of students' graphical representations of biological data. Infusing QL in introductory biology presents challenges. Our study, however, supports the conclusion that it is feasible in the context of an existing course, consistent with the goals of college biology education, and promotes students' development of important quantitative skills.

  14. Health Promotion Education

    DEFF Research Database (Denmark)

    Lehn-Christiansen, Sine

    The paper discusses the implications of health promotion in education. The paper is based on my PhD project entitled “Health promotion education seen through a power/knowledge and subjectification perspective” (in prep). The PhD project explores how professional health promotion skills...... are conceived in a specific educational setting; namely the Danish social and health education programme. Here, health promotion is formally conceived as a qualification aimed at citizens and patients - and not at the students themselves. However, as the paper will demonstrate, conceptions of student...... health promotion workers should ideally act as health promotion role models. This claim leads to a series of educational and morally anchored dilemmas and challenges. Inspired by Foucault and others who have developed this line of thinking (eg. Signild Vallgårde) health promotion is viewed as a heartfelt...

  15. The frequent evolutionary birth and death of functional promoters in mouse and human

    DEFF Research Database (Denmark)

    Young, Robert S.; Hayashizaki, Yosihide; Andersson, Robin;

    2015-01-01

    sequence changes at promoters, we show that dramatic changes such as the complete gain and loss (collectively turnover) of functional promoters are common. Using quantitative measures of transcription initiation in both humans and mice across 52 matched tissues we discriminate promoter sequence gains from...... the same biological systems are similarly inclined to transcriptional rewiring. The genes affected by promoter turnover show evidence of adaptive evolution. In mice, promoters are primarily lost through deletion of the promoter containing sequence; whereas in humans, many promoters appear to be gradually...

  16. P04.24MUTATIONS OF THE TERT PROMOTER CORRELATE WITH ENHANCED TELOMERASE ACTIVATION AND PREDICT A WORSE PROGNOSIS IN PRIMARY GLIOBLASTOMA PATIENTS

    Science.gov (United States)

    Spiegl-Kreinecker, S.; Loetsch, D.; Laaber, M.; Pichler, J.; Weis, S.; Ghanim, B.; Webersinke, G.; Olschowski, A.; Berger, W.

    2014-01-01

    The stabilization of telomeres by upregulation of telomerase is compulsive for indefinite proliferation and cell immortalization therefore representing a main feature of malignant solid tumors, including gliomas. However, the mechanisms responsible for cancer-associated telomerase activation are not completely understood. Recently, defined mutations in the TERT promoter were identified in a variety of tumors, most frequent in primary glioblastomas (GBM). Presence of the mutations was associated with increased TERT expression. In the present study GBM derived tumor tissue from 126 patients operated at the Wagner Jauregg Hospital were screened for TERT promoter mutations. Subsequently the collected data were correlated with telomere associated parameters (telomerase activity, TERT mRNA expression, telomere lengths), the glioma biomarkers MGMT promoter methylation and IDH1 mutation as well as clinical parameters including patient survival. Using direct sequencing, the TERT promoter mutations (C228T, C250T) were found in 73% of tumors with predominance of C228T (72% of the mutated cases). Thirty-four (27%) samples contained none of the investigated TERT promoter mutations while mutations at both sites occurred in none of the investigated GBM cases. TERT promoter mutations were accompanied by a significant upregulation of telomerase activity (p = 0.0005) and TERT mRNA expression (p = 0.0004). Accordingly, telomere lengths of TERT promoter mutated tumors were significantly shorter compared to the TERT promoter wild-type subgroup (p = 0.001). Moreover, Kaplan-Meier survival analyses revealed a significantly shorter overall survival for GBM patients harbouring mutant tumors (p < 0.0001). In the multivariate Cox regression analysis TERT promoter mutation was found to have independent prognostic power (p = 0.049) but reached elevated significance in the interaction with age (p = 0.007). Accordingly, the prognostic quality of TERT promoter mutations was confined to the

  17. Quantitative Literacy: Geosciences and Beyond

    Science.gov (United States)

    Richardson, R. M.; McCallum, W. G.

    2002-12-01

    Quantitative literacy seems like such a natural for the geosciences, right? The field has gone from its origin as a largely descriptive discipline to one where it is hard to imagine failing to bring a full range of mathematical tools to the solution of geological problems. Although there are many definitions of quantitative literacy, we have proposed one that is analogous to the UNESCO definition of conventional literacy: "A quantitatively literate person is one who, with understanding, can both read and represent quantitative information arising in his or her everyday life." Central to this definition is the concept that a curriculum for quantitative literacy must go beyond the basic ability to "read and write" mathematics and develop conceptual understanding. It is also critical that a curriculum for quantitative literacy be engaged with a context, be it everyday life, humanities, geoscience or other sciences, business, engineering, or technology. Thus, our definition works both within and outside the sciences. What role do geoscience faculty have in helping students become quantitatively literate? Is it our role, or that of the mathematicians? How does quantitative literacy vary between different scientific and engineering fields? Or between science and nonscience fields? We will argue that successful quantitative literacy curricula must be an across-the-curriculum responsibility. We will share examples of how quantitative literacy can be developed within a geoscience curriculum, beginning with introductory classes for nonmajors (using the Mauna Loa CO2 data set) through graduate courses in inverse theory (using singular value decomposition). We will highlight six approaches to across-the curriculum efforts from national models: collaboration between mathematics and other faculty; gateway testing; intensive instructional support; workshops for nonmathematics faculty; quantitative reasoning requirement; and individual initiative by nonmathematics faculty.

  18. Deterministic quantitative risk assessment development

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, Jane; Colquhoun, Iain [PII Pipeline Solutions Business of GE Oil and Gas, Cramlington Northumberland (United Kingdom)

    2009-07-01

    Current risk assessment practice in pipeline integrity management is to use a semi-quantitative index-based or model based methodology. This approach has been found to be very flexible and provide useful results for identifying high risk areas and for prioritizing physical integrity assessments. However, as pipeline operators progressively adopt an operating strategy of continual risk reduction with a view to minimizing total expenditures within safety, environmental, and reliability constraints, the need for quantitative assessments of risk levels is becoming evident. Whereas reliability based quantitative risk assessments can be and are routinely carried out on a site-specific basis, they require significant amounts of quantitative data for the results to be meaningful. This need for detailed and reliable data tends to make these methods unwieldy for system-wide risk k assessment applications. This paper describes methods for estimating risk quantitatively through the calibration of semi-quantitative estimates to failure rates for peer pipeline systems. The methods involve the analysis of the failure rate distribution, and techniques for mapping the rate to the distribution of likelihoods available from currently available semi-quantitative programs. By applying point value probabilities to the failure rates, deterministic quantitative risk assessment (QRA) provides greater rigor and objectivity than can usually be achieved through the implementation of semi-quantitative risk assessment results. The method permits a fully quantitative approach or a mixture of QRA and semi-QRA to suit the operator's data availability and quality, and analysis needs. For example, consequence analysis can be quantitative or can address qualitative ranges for consequence categories. Likewise, failure likelihoods can be output as classical probabilities or as expected failure frequencies as required. (author)

  19. Quantitative luminescence imaging system

    Science.gov (United States)

    Batishko, C. R.; Stahl, K. A.; Fecht, B. A.

    The goal of the Measurement of Chemiluminescence project is to develop and deliver a suite of imaging radiometric instruments for measuring spatial distributions of chemiluminescence. Envisioned deliverables include instruments working at the microscopic, macroscopic, and life-sized scales. Both laboratory and field portable instruments are envisioned. The project also includes development of phantoms as enclosures for the diazoluminomelanin (DALM) chemiluminescent chemistry. A suite of either phantoms in a variety of typical poses, or phantoms that could be adjusted to a variety of poses, is envisioned. These are to include small mammals (rats), mid-sized mammals (monkeys), and human body parts. A complete human phantom that can be posed is a long-term goal of the development. Taken together, the chemistry and instrumentation provide a means for imaging rf dosimetry based on chemiluminescence induced by the heat resulting from rf energy absorption. The first delivered instrument, the Quantitative Luminescence Imaging System (QLIS), resulted in a patent, and an R&D Magazine 1991 R&D 100 award, recognizing it as one of the 100 most significant technological developments of 1991. The current status of the project is that three systems have been delivered, several related studies have been conducted, two preliminary human hand phantoms have been delivered, system upgrades have been implemented, and calibrations have been maintained. Current development includes sensitivity improvements to the microscope-based system; extension of the large-scale (potentially life-sized targets) system to field portable applications; extension of the 2-D large-scale system to 3-D measurement; imminent delivery of a more refined human hand phantom and a rat phantom; rf, thermal and imaging subsystem integration; and continued calibration and upgrade support.

  20. Integrating a quantitative risk appraisal in a health impact assessment

    DEFF Research Database (Denmark)

    Adám, Balázs; Molnár, Agnes; Gulis, Gabriel;

    2013-01-01

    BACKGROUND: Although the quantification of health outcomes in a health impact assessment (HIA) is scarce in practice, it is preferred by policymakers, as it assists various aspects of the decision-making process. This article provides an example of integrating a quantitative risk appraisal in an ...... a practical example of applying quantification in an HIA, thereby promoting its incorporation into political decision making.......BACKGROUND: Although the quantification of health outcomes in a health impact assessment (HIA) is scarce in practice, it is preferred by policymakers, as it assists various aspects of the decision-making process. This article provides an example of integrating a quantitative risk appraisal...

  1. Workshop on quantitative dynamic stratigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Cross, T.A.

    1988-04-01

    This document discusses the development of quantitative simulation models for the investigation of geologic systems. The selection of variables, model verification, evaluation, and future directions in quantitative dynamic stratigraphy (QDS) models are detailed. Interdisciplinary applications, integration, implementation, and transfer of QDS are also discussed. (FI)

  2. Mastering R for quantitative finance

    CERN Document Server

    Berlinger, Edina; Badics, Milán; Banai, Ádám; Daróczi, Gergely; Dömötör, Barbara; Gabler, Gergely; Havran, Dániel; Juhász, Péter; Margitai, István; Márkus, Balázs; Medvegyev, Péter; Molnár, Julia; Szucs, Balázs Árpád; Tuza, Ágnes; Vadász, Tamás; Váradi, Kata; Vidovics-Dancs, Ágnes

    2015-01-01

    This book is intended for those who want to learn how to use R's capabilities to build models in quantitative finance at a more advanced level. If you wish to perfectly take up the rhythm of the chapters, you need to be at an intermediate level in quantitative finance and you also need to have a reasonable knowledge of R.

  3. Understanding quantitative research: part 2

    OpenAIRE

    Hoare, Z.; Hoe, J.

    2013-01-01

    This article, which is the second in a two-part series, provides an introduction to understanding quantitative research, basic statistics and terminology used in research articles. Understanding statistical analysis will ensure that nurses can assess the credibility and significance of the evidence reported. This article focuses on explaining common statistical terms and the presentation of statistical data in quantitative research.

  4. What do health-promoting schools promote?

    DEFF Research Database (Denmark)

    Simovska, Venka

    2012-01-01

    Purpose – The editorial aims to provide a brief overview of the individual contributions to the special issue, and a commentary positioning the contributions within research relating to the health-promoting schools initiative in Europe. Design/methodology/approach – The members of the Schools...... for Health in Europe Research Group were invited to submit their work addressing processes and outcomes in school health promotion to this special issue of Health Education. Additionally, an open call for papers was published on the Health Education web site. Following the traditional double blind peer...... review process, nine submissions were accepted for publication. Five of these are selected to be published in this issue and the rest will be published in a future issue of the journal. Findings – The five articles in this issue take a comprehensive approach to health promotion in schools and reflect...

  5. Food Blogger Instagram: Promotion Through Social Media

    Directory of Open Access Journals (Sweden)

    M. Fariz Syahbani

    2017-04-01

    ABSTRACT Do promotions through food blogger account is the way that is currently being sought after by the culinary business operators to introduce their restaurant. Bloggers have a significant impact of people searching for information through social sites before making a purchase. In other words, the food blogger become a benchmark for people in considering whether or not a restaurant worth visiting. This research aims to determine of promotion through food blogger on social media instagram towards purchase intention of college student in Bandung. This research is a quantitative research. The method used is descriptive - causal. The sampling technique used is a non-probability sample of the type of incidental sampling. The data collection was distributed with questionnaires to 400 respondents who are collage students in Bandung was using instagram and recognizing the phenomenon of food bloggers as media promotion. Data analysis technique used is multiple linear regression analysis. The research results, food blogger promotion through social media on instagram be in good category. Purchase intention of college student at Bandung in good categories. Promotion through food blogger on social media instagram partial effect consisting of context, communication, collaboration and connection to the buying interest of collage students in Bandung and simultaneously influence the buying interest of collage students in Bandung. From this study, it appears that through the instagram as an effective media campaign can provide an explanation and the message delivered effectively and efficiently for displaying a variety of contexts with good multimedia features. Keyword : Promotion, Social Media Marketing, Food Blogger, Purchase Intention

  6. What do health-promoting schools promote?

    DEFF Research Database (Denmark)

    Simovska, Venka

    2012-01-01

    for Health in Europe Research Group were invited to submit their work addressing processes and outcomes in school health promotion to this special issue of Health Education. Additionally, an open call for papers was published on the Health Education web site. Following the traditional double blind peer......Purpose – The editorial aims to provide a brief overview of the individual contributions to the special issue, and a commentary positioning the contributions within research relating to the health-promoting schools initiative in Europe. Design/methodology/approach – The members of the Schools...

  7. Core promoter acetylation is not required for high transcription from the phosphoenolpyruvate carboxylase promoter in maize

    Directory of Open Access Journals (Sweden)

    Horst Ina

    2009-12-01

    suggest a central role of upstream promoter acetylation in the quantitative regulation of gene expression in this model gene. Induced core promoter acetylation is dispensable for the highest gene expression in the diurnal and circadian rhythm.

  8. SPORT PROMOTION STRATEGIES

    Directory of Open Access Journals (Sweden)

    Alexandru Lucian MIHAI

    2013-10-01

    Full Text Available In sport marketing, the word promotion covers a range of interrelated activities. All of these activities are designed to attract attention, stimulate the interest and awareness of consumers, and of course, encourage them to purchase a sport product. Promotion is about communicating with and educating consumers. The purpose of a sport promotional strategy is to build brand loyalty and product credibility, develop image, and position the brand. A promotional strategy is similar to a marketing strategy, but the promotional strategy seeks short-term objectives, both direct and indirect. Promotional objectives usually include increased sales, stimulate impulse buying, raise customer traffic, and present and reinforce image. It also provides information about products and services, publicizes new stores or websites, and creates and enhances customer satisfaction.

  9. Is Lamb Promotion Working?

    OpenAIRE

    Capps, Oral, Jr.; Williams, Gary W.

    2007-01-01

    This objective of this study is to determine whether the advertising and promotion dollars collected and spent by the American Lamb Board on lamb promotion since the inception of the Lamb Checkoff Program have effectively increased lamb consumption in the United States. The main conclusion is that program has resulted in roughly 7.6 additional pounds of total lamb consumption per dollar spent on advertising and promotion and $41.59 in additional lamb sales per dollar spent on advertising and ...

  10. Health promotion in Brazil.

    Science.gov (United States)

    Buss, Paulo Marchiori; de Carvalho, Antonio Ivo

    2007-01-01

    The evolution of health promotion within the Brazilian health system is examined, including an assessment of the intersectoral and development policies that have influenced the process. Particular attention is paid to the legal characteristics of the Unified Health System. Human resources formation and research initiatives in health promotion are outlined, with a summary of the obstacles that need to be overcome in order to ensure the effective implementation of health promotion in the future. Up to the end of the 20th Century health promotion was not used as a term in the Brazilian public heath context. Health promoting activities were concentrated in the area of health education, although targeting the social determinants of health and the principle of intersectoral action were part of the rhetoric. The situation has changed during the last decade, with the publication of a national policy of health promotion, issued by the Ministry of Health and jointly implemented with the States and Municipals Health Secretaries. More recently there has been a re-emergence of the discourse on the social determinants of health and the formation of intersectoral public policies as the basis of a comprehensive health promotion. Health promotion infrastructure, particularly around human resources and financing, requires strengthening in order to ensure capacity and sustainability in health promotion practice.

  11. Analysis of promotions

    Directory of Open Access Journals (Sweden)

    V.V. Bozhkova

    2011-03-01

    Full Text Available Article describes the classification of promotions and determining the effectiveness of specific measures to stimulate sales (which isnt possible practically in most advertising companies.

  12. Quantitative EPR A Practitioners Guide

    CERN Document Server

    Eaton, Gareth R; Barr, David P; Weber, Ralph T

    2010-01-01

    This is the first comprehensive yet practical guide for people who perform quantitative EPR measurements. No existing book provides this level of practical guidance to ensure the successful use of EPR. There is a growing need in both industrial and academic research to provide meaningful and accurate quantitative EPR results. This text discusses the various sample, instrument and software related aspects required for EPR quantitation. Specific topics include: choosing a reference standard, resonator considerations (Q, B1, Bm), power saturation characteristics, sample positioning, and finally, putting all the factors together to obtain an accurate spin concentration of a sample.

  13. Quantitative approaches in developmental biology.

    Science.gov (United States)

    Oates, Andrew C; Gorfinkiel, Nicole; González-Gaitán, Marcos; Heisenberg, Carl-Philipp

    2009-08-01

    The tissues of a developing embryo are simultaneously patterned, moved and differentiated according to an exchange of information between their constituent cells. We argue that these complex self-organizing phenomena can only be fully understood with quantitative mathematical frameworks that allow specific hypotheses to be formulated and tested. The quantitative and dynamic imaging of growing embryos at the molecular, cellular and tissue level is the key experimental advance required to achieve this interaction between theory and experiment. Here we describe how mathematical modelling has become an invaluable method to integrate quantitative biological information across temporal and spatial scales, serving to connect the activity of regulatory molecules with the morphological development of organisms.

  14. Understanding quantitative research: part 1.

    Science.gov (United States)

    Hoe, Juanita; Hoare, Zoë

    This article, which is the first in a two-part series, provides an introduction to understanding quantitative research, basic statistics and terminology used in research articles. Critical appraisal of research articles is essential to ensure that nurses remain up to date with evidence-based practice to provide consistent and high-quality nursing care. This article focuses on developing critical appraisal skills and understanding the use and implications of different quantitative approaches to research. Part two of this article will focus on explaining common statistical terms and the presentation of statistical data in quantitative research.

  15. Quantitative vs qualitative research methods.

    Science.gov (United States)

    Lakshman, M; Sinha, L; Biswas, M; Charles, M; Arora, N K

    2000-05-01

    Quantitative methods have been widely used because of the fact that things that can be measured or counted gain scientific credibility over the unmeasurable. But the extent of biological abnormality, severity, consequences and the impact of illness cannot be satisfactorily captured and answered by the quantitative research alone. In such situations qualitative methods take a holistic perspective preserving the complexities of human behavior by addressing the "why" and "how" questions. In this paper an attempt has been made to highlight the strengths and weaknesses of both the methods and also that a balanced mix of both qualitative as well as quantitative methods yield the most valid and reliable results.

  16. Promoter reuse in prokaryotes

    NARCIS (Netherlands)

    Nijveen, H.; Matus-Garcia, M.; Passel, van M.W.J.

    2012-01-01

    Anecdotal evidence shows promoters being reused separate from their downstream gene, thus providing a mechanism for the efficient and rapid rewiring of a gene’s transcriptional regulation. We have identified over 4000 groups of highly similar promoters using a conservative sequence similarity search

  17. Health-promoting schools

    DEFF Research Database (Denmark)

    Kwan, Stella Y L; Petersen, Poul Erik; Pine, Cynthia M

    2005-01-01

    Schools provide an important setting for promoting health, as they reach over 1 billion children worldwide and, through them, the school staff, families and the community as a whole. Health promotion messages can be reinforced throughout the most influential stages of children's lives, enabling...... them to develop lifelong sustainable attitudes and skills. Poor oral health can have a detrimental effect on children's quality of life, their performance at school and their success in later life. This paper examines the global need for promoting oral health through schools. The WHO Global School...... Health Initiative and the potential for setting up oral health programmes in schools using the health-promoting school framework are discussed. The challenges faced in promoting oral health in schools in both developed and developing countries are highlighted. The importance of using a validated...

  18. A Quantitative Assessment Approach to COTS Component Security

    Directory of Open Access Journals (Sweden)

    Jinfu Chen

    2013-01-01

    Full Text Available The vulnerability of software components hinders the development of component technology. An effective assessment approach to component security level can promote the development of component technology. Thus, the current paper proposes a quantitative assessment approach to COTS (commercial-off-the-shelf component security. The steps of interface fault injection and the assessment framework are given based on the internal factors of the tested component. The quantitative assessment algorithm and formula of component security level are also presented. The experiment results show that the approach not only can detect component security vulnerabilities effectively but also quantitatively assess the component security level. The score of component security can be accurately calculated, which represents the security level of the tested component.

  19. Developing Geoscience Students' Quantitative Skills

    Science.gov (United States)

    Manduca, C. A.; Hancock, G. S.

    2005-12-01

    Sophisticated quantitative skills are an essential tool for the professional geoscientist. While students learn many of these sophisticated skills in graduate school, it is increasingly important that they have a strong grounding in quantitative geoscience as undergraduates. Faculty have developed many strong approaches to teaching these skills in a wide variety of geoscience courses. A workshop in June 2005 brought together eight faculty teaching surface processes and climate change to discuss and refine activities they use and to publish them on the Teaching Quantitative Skills in the Geosciences website (serc.Carleton.edu/quantskills) for broader use. Workshop participants in consultation with two mathematics faculty who have expertise in math education developed six review criteria to guide discussion: 1) Are the quantitative and geologic goals central and important? (e.g. problem solving, mastery of important skill, modeling, relating theory to observation); 2) Does the activity lead to better problem solving? 3) Are the quantitative skills integrated with geoscience concepts in a way that makes sense for the learning environment and supports learning both quantitative skills and geoscience? 4) Does the methodology support learning? (e.g. motivate and engage students; use multiple representations, incorporate reflection, discussion and synthesis) 5) Are the materials complete and helpful to students? 6) How well has the activity worked when used? Workshop participants found that reviewing each others activities was very productive because they thought about new ways to teach and the experience of reviewing helped them think about their own activity from a different point of view. The review criteria focused their thinking about the activity and would be equally helpful in the design of a new activity. We invite a broad international discussion of the criteria(serc.Carleton.edu/quantskills/workshop05/review.html).The Teaching activities can be found on the

  20. 77 FR 47820 - Invention Promoters/Promotion Firms Complaints

    Science.gov (United States)

    2012-08-10

    ... United States Patent and Trademark Office Invention Promoters/Promotion Firms Complaints ACTION: Proposed... concerning invention promoters and responses from the invention promoters to these complaints. An individual may submit a complaint concerning an invention promoter to the USPTO, which will forward the complaint...

  1. Sexual Health Promotion Programme: Participants' Perspectives on Capacity Building

    Science.gov (United States)

    Keogh, Brian; Daly, Louise; Sharek, Danika; De Vries, Jan; McCann, Edward; Higgins, Agnes

    2016-01-01

    Objectives: The aim of this study was to evaluate a Health Service Executive (HSE) Foundation Programme in Sexual Health Promotion (FPSHP) with a specific emphasis on capacity building. Design: A mixed-method design using both quantitative and qualitative methods was used to collect the data. Setting: The FPSHP was delivered to staff working in…

  2. Assessing and Promoting Cultural Relativism in Students of Counseling

    Science.gov (United States)

    Mcauliffe, Garrett John; Grothaus, Tim; Jensen, Margaret; Michel, Rebecca

    2012-01-01

    Multicultural counseling is often promoted as a core element in counselor development. As such, educational efforts aim to increase counselors' cultural relativism, or their ability to recognize their own enculturation and to appreciate the value of other cultural norms. This mixed qualitative-quantitative study explored the relationship between…

  3. Oral Health Promotion in Schools: Rationale and Evaluation

    Science.gov (United States)

    Kizito, Alex; Caitlin, Meredith; Wang, Yili; Kasangaki, Arabat; Macnab, Andrew J.

    2014-01-01

    Purpose: The purpose of this paper is to explain the rationale and potential for the WHO health promoting schools (HPS) to improve children's oral health, and describe validated quantitative methodologies and qualitative approaches to measure program impact. Design/Methodology/Approach: Critical discussion of the impact of poor oral health and…

  4. Single-nucleotide polymorphisms of human O6-methylguanine -DNA methyltransferase(MGMT)gene in lung cancer patients from south China%肺癌患者O6-甲基鸟嘌呤-DNA甲基转移酶基因多态性研究

    Institute of Scientific and Technical Information of China (English)

    刘汝青; 庄志雄

    2002-01-01

    目的检测人类O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT) 基因5个外显子的单核苷酸多态(SNPs)及其与肺癌的关系.方法采用聚合酶链式反应(PCR)-单链构像多态性(SSCP)-DNA直接测序法对100例正常人和60例肺癌患者外周血白细胞进行MGMT基因SNPs研究.结果在正常人群和肺癌患者中检测到MGMT基因的第3、4外显子上存在着SNPs,即第3外显子上第250位碱基C被T所取代,导致错义突变(CTTTTT,使Leu84Phe);第4外显子上第280位碱基C被T取代,导致同义突变(T TCTTT,均编码Phe).这两个位点的SNPs在两组人群间的检出率差异无显著性(P>0. 05).结论 MGMT基因第3、4外显子上存在着SNPs,其多态改变与肺癌形成的关系较弱.

  5. Quantitative imaging methods in osteoporosis.

    Science.gov (United States)

    Oei, Ling; Koromani, Fjorda; Rivadeneira, Fernando; Zillikens, M Carola; Oei, Edwin H G

    2016-12-01

    Osteoporosis is characterized by a decreased bone mass and quality resulting in an increased fracture risk. Quantitative imaging methods are critical in the diagnosis and follow-up of treatment effects in osteoporosis. Prior radiographic vertebral fractures and bone mineral density (BMD) as a quantitative parameter derived from dual-energy X-ray absorptiometry (DXA) are among the strongest known predictors of future osteoporotic fractures. Therefore, current clinical decision making relies heavily on accurate assessment of these imaging features. Further, novel quantitative techniques are being developed to appraise additional characteristics of osteoporosis including three-dimensional bone architecture with quantitative computed tomography (QCT). Dedicated high-resolution (HR) CT equipment is available to enhance image quality. At the other end of the spectrum, by utilizing post-processing techniques such as the trabecular bone score (TBS) information on three-dimensional architecture can be derived from DXA images. Further developments in magnetic resonance imaging (MRI) seem promising to not only capture bone micro-architecture but also characterize processes at the molecular level. This review provides an overview of various quantitative imaging techniques based on different radiological modalities utilized in clinical osteoporosis care and research.

  6. Quantitative mass spectrometry: an overview

    Science.gov (United States)

    Urban, Pawel L.

    2016-10-01

    Mass spectrometry (MS) is a mainstream chemical analysis technique in the twenty-first century. It has contributed to numerous discoveries in chemistry, physics and biochemistry. Hundreds of research laboratories scattered all over the world use MS every day to investigate fundamental phenomena on the molecular level. MS is also widely used by industry-especially in drug discovery, quality control and food safety protocols. In some cases, mass spectrometers are indispensable and irreplaceable by any other metrological tools. The uniqueness of MS is due to the fact that it enables direct identification of molecules based on the mass-to-charge ratios as well as fragmentation patterns. Thus, for several decades now, MS has been used in qualitative chemical analysis. To address the pressing need for quantitative molecular measurements, a number of laboratories focused on technological and methodological improvements that could render MS a fully quantitative metrological platform. In this theme issue, the experts working for some of those laboratories share their knowledge and enthusiasm about quantitative MS. I hope this theme issue will benefit readers, and foster fundamental and applied research based on quantitative MS measurements. This article is part of the themed issue 'Quantitative mass spectrometry'.

  7. Quantitative mass spectrometry: an overview

    Science.gov (United States)

    2016-01-01

    Mass spectrometry (MS) is a mainstream chemical analysis technique in the twenty-first century. It has contributed to numerous discoveries in chemistry, physics and biochemistry. Hundreds of research laboratories scattered all over the world use MS every day to investigate fundamental phenomena on the molecular level. MS is also widely used by industry—especially in drug discovery, quality control and food safety protocols. In some cases, mass spectrometers are indispensable and irreplaceable by any other metrological tools. The uniqueness of MS is due to the fact that it enables direct identification of molecules based on the mass-to-charge ratios as well as fragmentation patterns. Thus, for several decades now, MS has been used in qualitative chemical analysis. To address the pressing need for quantitative molecular measurements, a number of laboratories focused on technological and methodological improvements that could render MS a fully quantitative metrological platform. In this theme issue, the experts working for some of those laboratories share their knowledge and enthusiasm about quantitative MS. I hope this theme issue will benefit readers, and foster fundamental and applied research based on quantitative MS measurements. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644965

  8. Promoting Renewable Energy Technologies

    DEFF Research Database (Denmark)

    Olsen, Ole Jess; Skytte, Klaus

    % of its annual electricity production. In this paper, we present and discuss the Danish experience as a case of promoting renewable energy technologies. The development path of the two technologies has been very different. Wind power is considered an outright success with fast deployment to decreasing...... technology and its particular context, it is possible to formulate some general principles that can help to create an effective and efficient policy for promoting new renewable energy technologies....

  9. Promoting Renewable Energy Technologies

    DEFF Research Database (Denmark)

    Olsen, Ole Jess; Skytte, Klaus

    % of its annual electricity production. In this paper, we present and discuss the Danish experience as a case of promoting renewable energy technologies. The development path of the two technologies has been very different. Wind power is considered an outright success with fast deployment to decreasing...... technology and its particular context, it is possible to formulate some general principles that can help to create an effective and efficient policy for promoting new renewable energy technologies....

  10. The Promoted Sibling

    DEFF Research Database (Denmark)

    Visholm, Steen

    PRESENTATION No 72 Steen Visholm Associate professor, M.Psych., Ph. D., Roskilde University Private adress: Krystalgade 6 II DK-1172 København K Denmark svisholm@ruc.dk THE PROMOTED SIBLING By their writings about sibling relations Mitchell and Coles has added fruitful complexity to the psychodyn......PRESENTATION No 72 Steen Visholm Associate professor, M.Psych., Ph. D., Roskilde University Private adress: Krystalgade 6 II DK-1172 København K Denmark svisholm@ruc.dk THE PROMOTED SIBLING By their writings about sibling relations Mitchell and Coles has added fruitful complexity...... to the psychodynamic understanding of families, groups and organisations. With a point of departure in a study of self-governing groups in a factory the paper introduces the concept: ‘the promoted sibling’ which provide quite some understanding of the middle managers challenges in his or her role and the challenges...... in democracy in general. The middle manager can be seen as ‘a sibling promoted from above’ and democracy can be seen as siblings promoting a sibling to be ‘a temporary parent’ (Winnicott) or ‘a sibling promoted from below’. The extension of the family dynamics with the sibling relations provides a way...

  11. Quantitative Proteome Mapping of Nitrotyrosines

    Energy Technology Data Exchange (ETDEWEB)

    Bigelow, Diana J.; Qian, Weijun

    2008-02-10

    An essential first step in the understanding disease and environmental perturbations is the early and quantitative detection of the increased levels of the inflammatory marker nitrotyrosine, as compared with its endogenous levels within the tissue or cellular proteome. Thus, methods that successfully address a proteome-wide quantitation of nitrotyrosine and related oxidative modifications can provide early biomarkers of risk and progression of disease as well as effective strategies for therapy. Multidimensional separations LC coupled with tandem mass spectrometry (LC-MS/MS) has, in recent years, significantly expanded our knowledge of human (and mammalian model system) proteomes including some nascent work in identification of post-translational modifications. In the following review, we discuss the application of LC-MS/MS for quantitation and identification of nitrotyrosine-modified proteins within the context of complex protein mixtures presented in mammalian proteomes.

  12. Semi-Quantitative Group Testing

    CERN Document Server

    Emad, Amin

    2012-01-01

    We consider a novel group testing procedure, termed semi-quantitative group testing, motivated by a class of problems arising in genome sequence processing. Semi-quantitative group testing (SQGT) is a non-binary pooling scheme that may be viewed as a combination of an adder model followed by a quantizer. For the new testing scheme we define the capacity and evaluate the capacity for some special choices of parameters using information theoretic methods. We also define a new class of disjunct codes suitable for SQGT, termed SQ-disjunct codes. We also provide both explicit and probabilistic code construction methods for SQGT with simple decoding algorithms.

  13. Quantitative two-qutrit entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Eltschka, Christopher [Institut fuer Theoretische Physik, Universitaet Regensburg, D-93040 Regensburg (Germany); Siewert, Jens [Departamento de Quimica Fisica, Universidad del Pais Vasco UPV/EHU, 48080 Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)

    2013-07-01

    We introduce the new concept of axisymmetric bipartite states. For d x d-dimensional systems these states form a two-parameter family of nontrivial mixed states that include the isotropic states. We present exact quantitative results for class-specific entanglement as well as for the negativity and I-concurrence of two-qutrit axisymmetric states. These results have interesting applications such as for quantitative witnesses of class-specific entanglement in arbitrary two-qutrit states and as device-independent witness for the number of entangled dimensions.

  14. When is Quantitative Easing effective?

    OpenAIRE

    Hoermann, Markus; Schabert, Andreas

    2011-01-01

    We present a simple macroeconomic model with open market operations that allows examining the effects of quantitative and credit easing. The central bank controls the policy rate, i.e. the price of money in open market operations, as well as the amount and the type of assets that are accepted as collateral for money. When the policy rate is sufficiently low, this set-up gives rise to an (il-)liquidity premium on non-eligible assets. Then, a quantitative easing policy, which increases the size...

  15. The Case for Infusing Quantitative Literacy into Introductory Geoscience Courses

    Directory of Open Access Journals (Sweden)

    Jennifer M. Wenner

    2009-01-01

    Full Text Available We present the case for introductory geoscience courses as model venues for increasing the quantitative literacy (QL of large numbers of the college-educated population. The geosciences provide meaningful context for a number of fundamental mathematical concepts that are revisited several times in a single course. Using some best practices from the mathematics education community surrounding problem solving, calculus reform, pre-college mathematics and five geoscience/math workshops, geoscience and mathematics faculty have identified five pedagogical ideas to increase the QL of the students who populate introductory geoscience courses. These five ideas include techniques such as: place mathematical concepts in context, use multiple representations, use technology appropriately, work in groups, and do multiple-day, in-depth problems that place quantitative skills in multiple contexts. We discuss the pedagogical underpinnings of these five ideas and illustrate some ways that the geosciences represent ideal places to use these techniques. However, the inclusion of QL in introductory courses is often met with resistance at all levels. Faculty who wish to include quantitative content must use creative means to break down barriers of public perception of geoscience as qualitative, administrative worry that enrollments will drop and faculty resistance to change. Novel ways to infuse QL into geoscience classrooms include use of web-based resources, shadow courses, setting clear expectations, and promoting quantitative geoscience to the general public. In order to help faculty increase the QL of geoscience students, a community-built faculty-centered web resource (Teaching Quantitative Skills in the Geosciences houses multiple examples that implement the five best practices of QL throughout the geoscience curriculum. We direct faculty to three portions of the web resource: Teaching Quantitative Literacy, QL activities, and the 2006 workshop website

  16. Compositional and Quantitative Model Checking

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand

    2010-01-01

    This paper gives a survey of a composition model checking methodology and its succesfull instantiation to the model checking of networks of finite-state, timed, hybrid and probabilistic systems with respect; to suitable quantitative versions of the modal mu-calculus [Koz82]. The method is based...

  17. Quantitative Reasoning in Problem Solving

    Science.gov (United States)

    Ramful, Ajay; Ho, Siew Yin

    2015-01-01

    In this article, Ajay Ramful and Siew Yin Ho explain the meaning of quantitative reasoning, describing how it is used in the to solve mathematical problems. They also describe a diagrammatic approach to represent relationships among quantities and provide examples of problems and their solutions.

  18. Time-resolved quantitative phosphoproteomics

    DEFF Research Database (Denmark)

    Verano-Braga, Thiago; Schwämmle, Veit; Sylvester, Marc

    2012-01-01

    proteins involved in the Ang-(1-7) signaling, we performed a mass spectrometry-based time-resolved quantitative phosphoproteome study of human aortic endothelial cells (HAEC) treated with Ang-(1-7). We identified 1288 unique phosphosites on 699 different proteins with 99% certainty of correct peptide...

  19. Quantitative Characterisation of Surface Texture

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Lonardo, P.M.; Trumpold, H.

    2000-01-01

    This paper reviews the different methods used to give a quantitative characterisation of surface texture. The paper contains a review of conventional 2D as well as 3D roughness parameters, with particular emphasis on recent international standards and developments. It presents new texture...

  20. GPC and quantitative phase imaging

    DEFF Research Database (Denmark)

    Palima, Darwin; Banas, Andrew Rafael; Villangca, Mark Jayson

    2016-01-01

    shaper followed by the potential of GPC for biomedical and multispectral applications where we experimentally demonstrate the active light shaping of a supercontinuum laser over most of the visible wavelength range. Finally, we discuss how GPC can be advantageously applied for Quantitative Phase Imaging...

  1. Quantitative risk assessment of CO

    NARCIS (Netherlands)

    Koornneef, J.; Spruijt, M.; Molag, M.; Ramírez, A.; Turkenburg, W.; Faaij, A.

    2010-01-01

    A systematic assessment, based on an extensive literature review, of the impact of gaps and uncertainties on the results of quantitative risk assessments (QRAs) for CO2 pipelines is presented. Sources of uncertainties that have been assessed are: failure rates, pipeline pressure, temperat

  2. Can we quantitatively assess security?

    NARCIS (Netherlands)

    Haverkort, Boudewijn R.

    2006-01-01

    This short note describes a number of methods for assessing security in a quantitative way. Next to describing a five existing approaches (where no completeness is claimed), a new assessment technique is proposed, that finds its roots in methods known from performability evaluation and stochastic mo

  3. La quantite en islandais modern

    Directory of Open Access Journals (Sweden)

    Magnús Pétursson

    1978-12-01

    Full Text Available La réalisation phonétique de la quantité en syllabe accentuée dans la lecture de deux textes continus. Le problème de la quantité est un des problèmes les plus étudiés dans la phonologie de l'islandais moderne. Du point de vue phonologique il semble qu'on ne peut pas espérer apporter du nouveau, les possibilités théoriques ayant été pratiquement épuisées comme nous 1'avons rappelé dans notre étude récente (Pétursson 1978, pp. 76-78. Le résultat le plus inattendu des recherches des dernières années est sans doute la découverte d'une différenciation quantitative entre le Nord et le Sud de l'Islande (Pétursson 1976a. Il est pourtant encore prématuré de parler de véritables zones quantitatives puisqu'on n' en connaît ni les limites ni l' étendue sur le plan géographique.

  4. Guarded Type Promotion

    DEFF Research Database (Denmark)

    Winther, Johnni

    2011-01-01

    conditional using the instanceof operator and thus the cast type is redundantly mentioned twice. We propose a new typing rule for Java called Guarded Type Promotion aimed at eliminating the need for the explicit casts when guarded. This new typing rule is backward compatible and has been fully implemented...... in a Java 6 compiler. Through our extensive testing of real-life code we show that guarded casts account for approximately one fourth of all casts and that Guarded Type Promotion can eliminate the need for 95 percent of these guarded casts....

  5. Quantitative disease resistance and quantitative resistance Loci in breeding.

    Science.gov (United States)

    St Clair, Dina A

    2010-01-01

    Quantitative disease resistance (QDR) has been observed within many crop plants but is not as well understood as qualitative (monogenic) disease resistance and has not been used as extensively in breeding. Mapping quantitative trait loci (QTLs) is a powerful tool for genetic dissection of QDR. DNA markers tightly linked to quantitative resistance loci (QRLs) controlling QDR can be used for marker-assisted selection (MAS) to incorporate these valuable traits. QDR confers a reduction, rather than lack, of disease and has diverse biological and molecular bases as revealed by cloning of QRLs and identification of the candidate gene(s) underlying QRLs. Increasing our biological knowledge of QDR and QRLs will enhance understanding of how QDR differs from qualitative resistance and provide the necessary information to better deploy these resources in breeding. Application of MAS for QRLs in breeding for QDR to diverse pathogens is illustrated by examples from wheat, barley, common bean, tomato, and pepper. Strategies for optimum deployment of QRLs require research to understand effects of QDR on pathogen populations over time.

  6. Promoting Linguistic Diversity

    DEFF Research Database (Denmark)

    Daryai-Hansen, Petra Gilliyard

    2005-01-01

    To face up to the omnipresence of ‘Anglo-American’, conferences on language policy today address the issue of promoting linguistic diversity. This especially applies to contemporary Europe. Nevertheless, these conferences, which can be regarded as a kind of laboratories or academic microcosm, do...

  7. Promoting La Cultura Hispana

    Science.gov (United States)

    Pluviose, David

    2007-01-01

    Launched in 1985 at Arizona State University, the Hispanic Research Center's (HRC) efforts to promote Latino and Chicano art and issues have flourished in recent years. In 2004, the HRC hosted the Arizona International Latina/o Arts Festival in collaboration with the Mesa Southwest Museum. The HRC has also founded a mentoring institute for…

  8. Promoting La Cultura Hispana

    Science.gov (United States)

    Pluviose, David

    2007-01-01

    Launched in 1985 at Arizona State University, the Hispanic Research Center's (HRC) efforts to promote Latino and Chicano art and issues have flourished in recent years. In 2004, the HRC hosted the Arizona International Latina/o Arts Festival in collaboration with the Mesa Southwest Museum. The HRC has also founded a mentoring institute for…

  9. Promoting Continuing Education Programs.

    Science.gov (United States)

    Hendrickson, Gayle A.

    This handbook is intended for use by institutions in marketing their continuing education programs. A section on "Devising Your Strategy" looks at identifying a target audience, determining the marketing approach, and developing a marketing plan and promotional techniques. A discussion of media options looks at the advantages and…

  10. Annual health promotion programmes in remote rural Sabah

    Directory of Open Access Journals (Sweden)

    Naing Oo Tha

    2014-12-01

    Full Text Available Health promotion programmes in remote rural areas are conducted annually in Sabah, Malaysia by Faculty of Medicine and Health Science, University Malaysia Sabah. *Objectives* - To understand the concepts and principles of health promotion, to acquire knowledge and skills relevant to the assessment of the community diagnosis by using qualitative and quantitative approaches, to identify the limitation and issues of health promotion and its solution, to formulate the strategic plan and able to conduct the health promotion programme, to empower the rural community to improve rural health through health promotion activities. *Targeted population* is remote rural community. *Stake holders engaged* are UMS, medical and nursing students, local health authorities and rural community. *Methods* - Students were trained by series of lectures for health promotion concepts, approaches and activities and exposed to rural areas in Sabah and conducted practical health promotion programs annually. Students helped empowering the local community to improve their health with multi-approaches Health promotion methods under supervision of a lecturer. Medical and nursing students conducted health promotion programme together in 2 weeks duration . Health and health related problems were identified in selected rural villages .Various types of health promotion activities were conducted in prevention of communicable disease and non-communicable diseases.*Sustainability* - By having sustainable financing , cooperation from stake holders and strong commitment from faculty leadership and team members ,the annual health promotion programmes are conducted effectively in the rural community in Sabah. Although the impact of these health promotion activities cannot be seen in short duration, health issues in the rural community were explained by the students and advise them with causes, risk factors and precautions which would be useful in reducing the occurrence of common health

  11. Applying Quantitative Approaches to the Formative Evaluation of Antismoking Campaign Messages.

    Science.gov (United States)

    Parvanta, Sarah; Gibson, Laura; Forquer, Heather; Shapiro-Luft, Dina; Dean, Lorraine; Freres, Derek; Lerman, Caryn; Mallya, Giridhar; Moldovan-Johnson, Mihaela; Tan, Andy; Cappella, Joseph; Hornik, Robert

    2013-12-01

    This article shares an in-depth summary of a formative evaluation that used quantitative data to inform the development and selection of promotional ads for the antismoking communication component of a social marketing campaign. A foundational survey provided cross-sectional data to identify beliefs about quitting smoking that campaign messages should target, as well as beliefs to avoid. Pretesting draft ads against quantitative indicators of message effectiveness further facilitated the selection and rejection of final campaign ads. Finally, we consider lessons learned from the process of balancing quantitative methods and judgment to make formative decisions about more and less promising persuasive messages for campaigns.

  12. Quantitative phase imaging of arthropods

    Science.gov (United States)

    Sridharan, Shamira; Katz, Aron; Soto-Adames, Felipe; Popescu, Gabriel

    2015-01-01

    Abstract. Classification of arthropods is performed by characterization of fine features such as setae and cuticles. An unstained whole arthropod specimen mounted on a slide can be preserved for many decades, but is difficult to study since current methods require sample manipulation or tedious image processing. Spatial light interference microscopy (SLIM) is a quantitative phase imaging (QPI) technique that is an add-on module to a commercial phase contrast microscope. We use SLIM to image a whole organism springtail Ceratophysella denticulata mounted on a slide. This is the first time, to our knowledge, that an entire organism has been imaged using QPI. We also demonstrate the ability of SLIM to image fine structures in addition to providing quantitative data that cannot be obtained by traditional bright field microscopy. PMID:26334858

  13. QUANTITATIVE CONFOCAL LASER SCANNING MICROSCOPY

    Directory of Open Access Journals (Sweden)

    Merete Krog Raarup

    2011-05-01

    Full Text Available This paper discusses recent advances in confocal laser scanning microscopy (CLSM for imaging of 3D structure as well as quantitative characterization of biomolecular interactions and diffusion behaviour by means of one- and two-photon excitation. The use of CLSM for improved stereological length estimation in thick (up to 0.5 mm tissue is proposed. The techniques of FRET (Fluorescence Resonance Energy Transfer, FLIM (Fluorescence Lifetime Imaging Microscopy, FCS (Fluorescence Correlation Spectroscopy and FRAP (Fluorescence Recovery After Photobleaching are introduced and their applicability for quantitative imaging of biomolecular (co-localization and trafficking in live cells described. The advantage of two-photon versus one-photon excitation in relation to these techniques is discussed.

  14. Quantitative wave-particle duality

    Science.gov (United States)

    Qureshi, Tabish

    2016-07-01

    The complementary wave and particle character of quantum objects (or quantons) was pointed out by Niels Bohr. This wave-particle duality, in the context of the two-slit experiment, is here described not just as two extreme cases of wave and particle characteristics, but in terms of quantitative measures of these characteristics, known to follow a duality relation. A very simple and intuitive derivation of a closely related duality relation is presented, which should be understandable to the introductory student.

  15. Quantitative spectroscopy of hot stars

    Science.gov (United States)

    Kudritzki, R. P.; Hummer, D. G.

    1990-01-01

    A review on the quantitative spectroscopy (QS) of hot stars is presented, with particular attention given to the study of photospheres, optically thin winds, unified model atmospheres, and stars with optically thick winds. It is concluded that the results presented here demonstrate the reliability of Qs as a unique source of accurate values of the global parameters (effective temperature, surface gravity, and elemental abundances) of hot stars.

  16. Controlled surface chemistries and quantitative cell response

    Science.gov (United States)

    Plant, Anne L.

    2002-03-01

    Living cells experience a large number of signaling cues from their extracellular matrix. As a result of these inputs, a variety of intracellular signaling pathways are apparently initiated simultaneously. The vast array of alternative responses that result from the integration of these inputs suggests that it may be reasonable to look for cellular response not as an 'on' or 'off' condition but as a distribution of responses. A difficult challenge is to determine whether variations in responses from individual cells arise from the complexity of intracellular signals or are due to variations in the cell culture environment. By controlling surface chemistry so that every cell 'sees' the same chemical and physical environment, we can begin to assess how the distribution of cell response is affected strictly by changes in the chemistry of the cell culture surface. Using the gene for green fluorescent protein linked to the gene for the promoter of the extracellular matrix protein, tenascin, we can easily probe the end product in a signaling pathway that is purported to be linked to surface protein chemistry and to cell shape. Cell response to well-controlled, well-characterized, and highly reproducible surfaces prepared using soft lithography techniques are compared with more conventional ways of preparing extracellular matrix proteins for cell culture. Using fluorescence microscopy and image analysis of populations of cells on these surfaces, we probe quantitatively the relationship between surface chemistry, cell shape and variations in gene expression endpoint.

  17. Quantitative measures for redox signaling.

    Science.gov (United States)

    Pillay, Ché S; Eagling, Beatrice D; Driscoll, Scott R E; Rohwer, Johann M

    2016-07-01

    Redox signaling is now recognized as an important regulatory mechanism for a number of cellular processes including the antioxidant response, phosphokinase signal transduction and redox metabolism. While there has been considerable progress in identifying the cellular machinery involved in redox signaling, quantitative measures of redox signals have been lacking, limiting efforts aimed at understanding and comparing redox signaling under normoxic and pathogenic conditions. Here we have outlined some of the accepted principles for redox signaling, including the description of hydrogen peroxide as a signaling molecule and the role of kinetics in conferring specificity to these signaling events. Based on these principles, we then develop a working definition for redox signaling and review a number of quantitative methods that have been employed to describe signaling in other systems. Using computational modeling and published data, we show how time- and concentration- dependent analyses, in particular, could be used to quantitatively describe redox signaling and therefore provide important insights into the functional organization of redox networks. Finally, we consider some of the key challenges with implementing these methods. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Quantitative characterisation of sedimentary grains

    Science.gov (United States)

    Tunwal, Mohit; Mulchrone, Kieran F.; Meere, Patrick A.

    2016-04-01

    Analysis of sedimentary texture helps in determining the formation, transportation and deposition processes of sedimentary rocks. Grain size analysis is traditionally quantitative, whereas grain shape analysis is largely qualitative. A semi-automated approach to quantitatively analyse shape and size of sand sized sedimentary grains is presented. Grain boundaries are manually traced from thin section microphotographs in the case of lithified samples and are automatically identified in the case of loose sediments. Shape and size paramters can then be estimated using a software package written on the Mathematica platform. While automated methodology already exists for loose sediment analysis, the available techniques for the case of lithified samples are limited to cases of high definition thin section microphotographs showing clear contrast between framework grains and matrix. Along with the size of grain, shape parameters such as roundness, angularity, circularity, irregularity and fractal dimension are measured. A new grain shape parameter developed using Fourier descriptors has also been developed. To test this new approach theoretical examples were analysed and produce high quality results supporting the accuracy of the algorithm. Furthermore sandstone samples from known aeolian and fluvial environments from the Dingle Basin, County Kerry, Ireland were collected and analysed. Modern loose sediments from glacial till from County Cork, Ireland and aeolian sediments from Rajasthan, India have also been collected and analysed. A graphical summary of the data is presented and allows for quantitative distinction between samples extracted from different sedimentary environments.

  19. Quantitative analysis of glycated proteins.

    Science.gov (United States)

    Priego-Capote, Feliciano; Ramírez-Boo, María; Finamore, Francesco; Gluck, Florent; Sanchez, Jean-Charles

    2014-02-07

    The proposed protocol presents a comprehensive approach for large-scale qualitative and quantitative analysis of glycated proteins (GP) in complex biological samples including biological fluids and cell lysates such as plasma and red blood cells. The method, named glycation isotopic labeling (GIL), is based on the differential labeling of proteins with isotopic [(13)C6]-glucose, which supports quantitation of the resulting glycated peptides after enzymatic digestion with endoproteinase Glu-C. The key principle of the GIL approach is the detection of doublet signals for each glycated peptide in MS precursor scanning (glycated peptide with in vivo [(12)C6]- and in vitro [(13)C6]-glucose). The mass shift of the doublet signals is +6, +3 or +2 Da depending on the peptide charge state and the number of glycation sites. The intensity ratio between doublet signals generates quantitative information of glycated proteins that can be related to the glycemic state of the studied samples. Tandem mass spectrometry with high-energy collisional dissociation (HCD-MS2) and data-dependent methods with collision-induced dissociation (CID-MS3 neutral loss scan) are used for qualitative analysis.

  20. Advances of IDH1 Mutation and MGMT Methylation in Diagnosis and Treatment of Brain Glioma%异柠檬酸脱氢酶-1突变及MGMT甲基化在脑胶质瘤的诊断及治疗研究进展

    Institute of Scientific and Technical Information of China (English)

    蒋梦婉; 刘琪; 李嘉瑶; 董祥慧; 戚基萍

    2016-01-01

    异柠檬酸脱氢酶-1 (Isocitrate dehydrogenase-l,IDHl)突变是脑胶质瘤中基因突变所导致的代谢物生成异常,突变型胶质瘤与普通型胶质瘤具有不同的分子生物学特征,并常与患者良好预后相关.MGMT(O6-methylguanine-DNA methyltransferase)启动子甲基化能够降低胶质瘤中DNA修复蛋白MGMT的表达,提高患者对化疗药物烷化剂治疗的敏感性.IDH1突变和MGMT启动子甲基化在胶质瘤的生长过程中存在关联,二者的联合检测对胶质瘤的预后及治疗方式具有一定的提示作用,在胶质瘤的分子病理学诊断方面具有很大的应用前景.目前IDH1突变和MGMT启动子甲基化的检测已逐渐应用于临床,但其诊断方式及治疗指导意义有待进一步研究探讨.本文就IDH1基因突变及MGMT启动子甲基化在胶质瘤诊断及治疗方面的研究进展进行综述.

  1. Advancement & Promotion Review: 2003

    CERN Multimedia

    2003-01-01

    Advancement, exceptional advancement and promotion decisions were made at the end of June, following the procedures published in Weekly Bulletin No. 13/2003. These decisions were included, where applicable, in the salaries for the month of July 2003. The award of the periodic step was communicated to staff by the salary shown on the July salary slip. All other decisions are communicated by separate notification. The names of staff receiving exceptional advancements or promotions are now published on the HR Division website and are accessible for consultation only at the following address: http://cern.ch/hr-div/internal/personnel/advlist_2003.asp It is recalled that change of career path proposals submitted to the Technical Engineers and Administrative Careers Committee (TEACC) or to Human Resources Division are being examined with a view to preparing the latters' recommendations by the end of September 2003. Final decisions will be applied retroactively to 1 July 2003. Human Resources Division Tel:...

  2. ADVANCEMENT & PROMOTION REVIEW: 2002

    CERN Multimedia

    2002-01-01

    Advancement, exceptional advancement and promotion decisions were made at the beginning of July, under the new career structure scheme and following the procedures published in Weekly Bulletin No. 11/2002. These decisions were included, where applicable, in the salaries for the month of July 2002. The award of the periodic step was communicated to staff by the salary shown on the July salary slip. All other decisions are communicated by separate notification. The names of staff receiving exceptional advancements or promotions will be published this year on the HR Division website and are accessible for consultation only at the following address : http://cern.ch/hr-div/internal/personnel/advlist.asp It is recalled that change of career path proposals submitted to the Technical Engineers and Administrative Careers Committee (TEACC) or to Human Resources Division are being examined with a view to preparing the latters' recommendations by the end of September 2002. Final decisions will be applied retroactivel...

  3. The quantitative side of the Repertory Grid Technique: some concerns

    CERN Document Server

    Karapanos, Evangelos

    2009-01-01

    User experience (UX) evaluation is gaining increased interest lately, both from academia and industry. In this paper we argue that UX evaluation needs to fulfill two important requirements: scalability, i.e. the ability to provide useful feedback in different stages of the design, and diversity, i.e. the ability to reflect the di-versity of opinions that may exist in different users. We promote the use of the Repertory Grid Technique as a promising UX evaluation technique and discuss some of our concerns regarding the quantitative side of its use.

  4. Promoting Health, Producing Moralisms?

    DEFF Research Database (Denmark)

    Brogaard Kristensen, Dorthe; Askegaard, Søren; Hauge Jeppesen, Lene

    2010-01-01

    Based on an ethnographic study of 25 Danish consumers, the aim of this paper is threefold. Firstly, based on a critique of traditional approaches to consumer health campaigning, it argues for a more socially diversified approach for understanding consumer construction and pursuit of healthy behav...... behaviour. Secondly, it presents a typology of discourses that are employed by consumers in constructing their (health oriented) food consumption. Thirdly, it addresses certain social and moral dilemmas inherent in consumer health promotional campaigns....

  5. Bicycle Promotion Plan

    Energy Technology Data Exchange (ETDEWEB)

    Simone, G. A.

    1981-03-09

    The objective of this Bicycle Promotion Plan is to outline a set of recommendations and supporting strategies for implementation by the US DOE toward increased use of the bicycle for energy conservation. The recommendations are designed in such a way as to function in concert with: (1) bicycle programs administered by other Federal government agencies; and (2) related programs and activities already sponsored by DOE. The approach to preparation of the Plan involved a review of all current and planned bicycle promotion programs at the Federal level as well as a review of the array of lierature on the subject. The UniWorld project staff also interacted with several DOE program offices, in order to determine the extent to which they might appropriately contribute to the implementation of bicycle promotional efforts. A synthesis of all the information gathered was published in January of 1981 as a part of the project (The Bicycle Program Review). Based upon this information and an examination of the barriers to bicycle use identified by bicycle transportation specialists in the field, UniWorld developed a series of the most potentially effective recommendations and program strategies for implementation by DOE. The recommendations address activities that could be undertaken in conjunction with existing DOE programs, new developments that might be considered to fulfill critical needs in the field, and interagency efforts that DOE could play a role in.

  6. The dynamics of mobile promoters: Enhanced stability in promoter regions.

    Science.gov (United States)

    Rabbani, Mahnaz; Wahl, Lindi M

    2016-10-21

    Mobile promoters are emerging as a new class of mobile genetic elements, first identified by examining prokaryote genome sequences, and more recently confirmed by experimental observations in bacteria. Recent datasets have identified over 40,000 putative mobile promoters in sequenced prokaryote genomes, however only one-third of these are in regions of the genome directly upstream from coding sequences, that is, in promoter regions. The presence of many promoter sequences in non-promoter regions is unexplained. Here we develop a general mathematical model for the dynamics of mobile promoters, extending previous work to capture the dynamics both within and outside promoter regions. From this general model, we apply rigorous model selection techniques to identify which parameters are statistically justified in describing the available mobile promoter data, and find best-fit values of these parameters. Our results suggest that high rates of horizontal gene transfer maintain the population of mobile promoters in promoter regions, and that once established at these sites, mobile promoters are rarely lost, but are commonly copied to other genomic regions. In contrast, mobile promoter copies in non-promoter regions are more numerous and more volatile, experiencing substantially higher rates of duplication, loss and diversification.

  7. 胶质瘤染色体1p和19q杂合性缺失与O6-甲基鸟嘌呤DNA甲基转移酶p53和Ki-67蛋白表达的关系%Correlation between loss of heterozygosity on chromosome 1p and 19q and expression of MGMT,p53 and Ki-67 proteins in gliomas

    Institute of Scientific and Technical Information of China (English)

    黄磊; 江涛; 袁芳; 李桂林; 徐立新; 崔云

    2011-01-01

    目的 探讨胶质瘤染色体1p和19q杂合性缺失(LOH)与O6-甲基鸟嘌呤DNA甲基转移酶(MGMT)、p53和Ki-67蛋白表达的关系.方法 采集146例胶质瘤(45例少突胶质细胞瘤、42例少突星形细胞瘤和59例星形细胞瘤)的肿瘤组织和血液标本,采用聚合酶链反应结合变性高效液相色谱技术检测染色体1p和19q LOH,免疫组化法检测肿瘤组织中MGMT、p53和Ki-67蛋白的表达,并进一步分析其与胶质瘤临床病理特征的关系.结果 少突胶质细胞肿瘤和星形细胞瘤中,1p LOH的发生率分别为59.8%和33.9%,差异有统计学意义(P=0.002);1p和19q LOH的发生率分别为42.5%和16.9%,差异有统计学意义(P=0.001).MGMT低表达和Ki-67高表达多发生于少突胶质细胞肿瘤中,发生率分别为65.5%和54.0%,而p53高表达多发生于星形细胞瘤和少突星形细胞瘤中,发生率为75.2%.在87例少突胶质细胞肿瘤中,1p LOH和MGMT蛋白低表达多发生于Ⅱ级少突胶质细胞肿瘤中,发生率分别为72.5%和87.5%,而p53和Ki-67蛋白高表达多发生于Ⅲ级少突胶质细胞肿瘤中,发生率分别为83.0%和76.6%.1p和19q LOH在非颞叶和颞叶肿瘤的发生率分别为55.6%和21.2%(P=0.002).1p LOH与19q LOH、MGMT蛋白表达与p53蛋白表达、MGMT蛋白表达与Ki-67蛋白表达、1p和19q LOH与p53蛋白表达、1p LOH与Ki-67蛋白表达均有关(均P<0.05).结论 1p和19q LOH及MGMT、p53和Ki-67的蛋白表达与胶质瘤的临床病理学特征有关,检测其LOH状态和表达水平对胶质瘤的诊断和治疗具有指导作用.%Objective To study the correlation of loss of heterozygosity(LOH)on chromosome 1 p and 19q with the expression of MGMT,p53 and Ki-67 proteins in gliomas.Methods One hundred and forty six cases of gliomas(45 oligodendrogliomas,42 oligodendroastrocytomas,and 59 astrocytomas)were included in this study.Their tissue and blood samples were retrospectively analyzed by PCR

  8. Non-manipulation quantitative designs.

    Science.gov (United States)

    Rumrill, Phillip D

    2004-01-01

    The article describes non-manipulation quantitative designs of two types, correlational and causal comparative studies. Both of these designs are characterized by the absence of random assignment of research participants to conditions or groups and non-manipulation of the independent variable. Without random selection or manipulation of the independent variable, no attempt is made to draw causal inferences regarding relationships between independent and dependent variables. Nonetheless, non-manipulation studies play an important role in rehabilitation research, as described in this article. Examples from the contemporary rehabilitation literature are included. Copyright 2004 IOS Press

  9. Quantitative relationships in delphinid neocortex

    DEFF Research Database (Denmark)

    Mortensen, Heidi S.; Pakkenberg, Bente; Dam, Maria

    2014-01-01

    total number of brain cells in cetaceans, and even fewer have used unbiased counting methods. In this study, using stereological methods, we estimated the total number of cells in the neocortex of the long-finned pilot whale (Globicephala melas) brain. For the first time, we show that a species...... density in long-finned pilot whales is lower than that in humans, their higher cell number appears to be due to their larger brain. Accordingly, our findings make an important contribution to the ongoing debate over quantitative relationships in the mammalian brain....

  10. cis Determinants of Promoter Threshold and Activation Timescale

    Directory of Open Access Journals (Sweden)

    Anders S. Hansen

    2015-08-01

    Full Text Available Although the relationship between DNA cis-regulatory sequences and gene expression has been extensively studied at steady state, how cis-regulatory sequences affect the dynamics of gene induction is not known. The dynamics of gene induction can be described by the promoter activation timescale (AcTime and amplitude threshold (AmpThr. Combining high-throughput microfluidics with quantitative time-lapse microscopy, we control the activation dynamics of the budding yeast transcription factor, Msn2, and reveal how cis-regulatory motifs in 20 promoter variants of the Msn2-target-gene SIP18 affect AcTime and AmpThr. By modulating Msn2 binding sites, we can decouple AmpThr from AcTime and switch the SIP18 promoter class from high AmpThr and slow AcTime to low AmpThr and either fast or slow AcTime. We present a model that quantitatively explains gene-induction dynamics on the basis of the Msn2-binding-site number, TATA box location, and promoter nucleosome organization. Overall, we elucidate the cis-regulatory logic underlying promoter decoding of TF dynamics.

  11. Quantitative graph theory mathematical foundations and applications

    CERN Document Server

    Dehmer, Matthias

    2014-01-01

    The first book devoted exclusively to quantitative graph theory, Quantitative Graph Theory: Mathematical Foundations and Applications presents and demonstrates existing and novel methods for analyzing graphs quantitatively. Incorporating interdisciplinary knowledge from graph theory, information theory, measurement theory, and statistical techniques, this book covers a wide range of quantitative-graph theoretical concepts and methods, including those pertaining to real and random graphs such as:Comparative approaches (graph similarity or distance)Graph measures to characterize graphs quantitat

  12. Can You Repeat That Please?: Using Monte Carlo Simulation in Graduate Quantitative Research Methods Classes

    Science.gov (United States)

    Carsey, Thomas M.; Harden, Jeffrey J.

    2015-01-01

    Graduate students in political science come to the discipline interested in exploring important political questions, such as "What causes war?" or "What policies promote economic growth?" However, they typically do not arrive prepared to address those questions using quantitative methods. Graduate methods instructors must…

  13. Can You Repeat That Please?: Using Monte Carlo Simulation in Graduate Quantitative Research Methods Classes

    Science.gov (United States)

    Carsey, Thomas M.; Harden, Jeffrey J.

    2015-01-01

    Graduate students in political science come to the discipline interested in exploring important political questions, such as "What causes war?" or "What policies promote economic growth?" However, they typically do not arrive prepared to address those questions using quantitative methods. Graduate methods instructors must…

  14. Strategies for quantitation of phosphoproteomic data

    DEFF Research Database (Denmark)

    Palmisano, Giuseppe; Thingholm, Tine Engberg

    2010-01-01

    Recent developments in phosphoproteomic sample-preparation techniques and sensitive mass spectrometry instrumentation have led to large-scale identifications of phosphoproteins and phosphorylation sites from highly complex samples. This has facilitated the implementation of different quantitation...... will be on different quantitation strategies. Methods for metabolic labeling, chemical modification and label-free quantitation and their applicability or inapplicability in phosphoproteomic studies are discussed....

  15. Digital radiography: a quantitative approach

    Energy Technology Data Exchange (ETDEWEB)

    Retraint, F. [Universite de Technologie de Troyes, Troyes (France)

    2004-07-01

    'Full-text:' In a radiograph the value of each pixel is related to the material thickness crossed by the x-rays. Using this relationship, an object can be characterized by parameters such as depth, surface and volume. Assuming a locally linear detector response and using a radiograph of reference object, the quantitative thickness map of object can be obtained by applying offset and gain corrections. However, for an acquisition system composed of cooled CCD camera optically coupled to a scintillator screen, the radiographic image formation process generates some bias which prevent from obtaining the quantitative information: non uniformity of the x-ray source, beam hardening, Compton scattering, scintillator screen, optical system response. In a first section, we propose a complete model of the radiographic image formation process taking account of these biases. In a second section, we present an inversion scheme of this model for a single material object, which enables to obtain the thickness map of the object crossed by the x-rays. (author)

  16. Quantitative ultrasonic phased array imaging

    Science.gov (United States)

    Engle, Brady J.; Schmerr, Lester W., Jr.; Sedov, Alexander

    2014-02-01

    When imaging with ultrasonic phased arrays, what do we actually image? What quantitative information is contained in the image? Ad-hoc delay-and-sum methods such as the synthetic aperture focusing technique (SAFT) and the total focusing method (TFM) fail to answer these questions. We have shown that a new quantitative approach allows the formation of flaw images by explicitly inverting the Thompson-Gray measurement model. To examine the above questions, we have set up a software simulation test bed that considers a 2-D scalar scattering problem of a cylindrical inclusion with the method of separation of variables. It is shown that in SAFT types of imaging the only part of the flaw properly imaged is the front surface specular response of the flaw. Other responses (back surface reflections, creeping waves, etc.) are improperly imaged and form artifacts in the image. In the case of TFM-like imaging the quantity being properly imaged is an angular integration of the front surface reflectivity. The other, improperly imaged responses are also averaged, leading to a reduction in some of the artifacts present. Our results have strong implications for flaw sizing and flaw characterization with delay-and-sum images.

  17. Quantitative Analysis of Face Symmetry.

    Science.gov (United States)

    Tamir, Abraham

    2015-06-01

    The major objective of this article was to report quantitatively the degree of human face symmetry for reported images taken from the Internet. From the original image of a certain person that appears in the center of each triplet, 2 symmetric combinations were constructed that are based on the left part of the image and its mirror image (left-left) and on the right part of the image and its mirror image (right-right). By applying a computer software that enables to determine length, surface area, and perimeter of any geometric shape, the following measurements were obtained for each triplet: face perimeter and area; distance between the pupils; mouth length; its perimeter and area; nose length and face length, usually below the ears; as well as the area and perimeter of the pupils. Then, for each of the above measurements, the value C, which characterizes the degree of symmetry of the real image with respect to the combinations right-right and left-left, was calculated. C appears on the right-hand side below each image. A high value of C indicates a low symmetry, and as the value is decreasing, the symmetry is increasing. The magnitude on the left relates to the pupils and compares the difference between the area and perimeter of the 2 pupils. The major conclusion arrived at here is that the human face is asymmetric to some degree; the degree of asymmetry is reported quantitatively under each portrait.

  18. Quantitative Characterization of Nanostructured Materials

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Frank (Bud) Bridges, University of California-Santa Cruz

    2010-08-05

    The two-and-a-half day symposium on the "Quantitative Characterization of Nanostructured Materials" will be the first comprehensive meeting on this topic held under the auspices of a major U.S. professional society. Spring MRS Meetings provide a natural venue for this symposium as they attract a broad audience of researchers that represents a cross-section of the state-of-the-art regarding synthesis, structure-property relations, and applications of nanostructured materials. Close interactions among the experts in local structure measurements and materials researchers will help both to identify measurement needs pertinent to real-world materials problems and to familiarize the materials research community with the state-of-the-art local structure measurement techniques. We have chosen invited speakers that reflect the multidisciplinary and international nature of this topic and the need to continually nurture productive interfaces among university, government and industrial laboratories. The intent of the symposium is to provide an interdisciplinary forum for discussion and exchange of ideas on the recent progress in quantitative characterization of structural order in nanomaterials using different experimental techniques and theory. The symposium is expected to facilitate discussions on optimal approaches for determining atomic structure at the nanoscale using combined inputs from multiple measurement techniques.

  19. Informatics methods to enable sharing of quantitative imaging research data.

    Science.gov (United States)

    Levy, Mia A; Freymann, John B; Kirby, Justin S; Fedorov, Andriy; Fennessy, Fiona M; Eschrich, Steven A; Berglund, Anders E; Fenstermacher, David A; Tan, Yongqiang; Guo, Xiaotao; Casavant, Thomas L; Brown, Bartley J; Braun, Terry A; Dekker, Andre; Roelofs, Erik; Mountz, James M; Boada, Fernando; Laymon, Charles; Oborski, Matt; Rubin, Daniel L

    2012-11-01

    The National Cancer Institute Quantitative Research Network (QIN) is a collaborative research network whose goal is to share data, algorithms and research tools to accelerate quantitative imaging research. A challenge is the variability in tools and analysis platforms used in quantitative imaging. Our goal was to understand the extent of this variation and to develop an approach to enable sharing data and to promote reuse of quantitative imaging data in the community. We performed a survey of the current tools in use by the QIN member sites for representation and storage of their QIN research data including images, image meta-data and clinical data. We identified existing systems and standards for data sharing and their gaps for the QIN use case. We then proposed a system architecture to enable data sharing and collaborative experimentation within the QIN. There are a variety of tools currently used by each QIN institution. We developed a general information system architecture to support the QIN goals. We also describe the remaining architecture gaps we are developing to enable members to share research images and image meta-data across the network. As a research network, the QIN will stimulate quantitative imaging research by pooling data, algorithms and research tools. However, there are gaps in current functional requirements that will need to be met by future informatics development. Special attention must be given to the technical requirements needed to translate these methods into the clinical research workflow to enable validation and qualification of these novel imaging biomarkers. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Quantitative basin evaluation, a tool for reducing exploration risks

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Over the last decade, the evaluation of the petroleum potential of sedimentary basins has shifted from a qualitative to a quantitative approach. This new perspective has led to the elaboration of basin simulators and a new discipline emerged: the basin modeling which is nowadays massively used by the oil industry. This methodology is an integration platform including geology, geochemistry and physics. Combined with uncertainty assessments, it is a powerful tool for reducing exploration risks. In this respect, IFP dedicates one of its IFP Sessions to 'Quantitative Basin Evaluation, a Tool for Reducing Exploration Risks'. This session was held on 18 June, 2001. The purpose of this workshop is to review the most modern advances used by professionals in the oil industry to improve the rate of hydrocarbon discovery and to lower exploration costs in frontier areas. IFP Sessions are conferences held for decision-makers and technical leaders to promote exchanges among involved parties: oil and gas companies, petroleum services and supply industries, engineering firms and research centers. Program: quantitative basin evaluation: the Berkine basin and its results; application of 2-D and 3-D basin modelling in the Gulf of Mexico; 2-D modelling in Brazilian sedimentary basins: lessons from recent case histories; quantitative modelling in the North Sea: towards a more confident assessment of the critical risks (*); uncertainties evaluation in petroleum system modelling (*); prediction of hydrocarbon type in the deep-water, Gulf of Mexico (*); constraining source and charge risk in deep-water areas - the Gulf of Mexico and offshore Angola (*); an overview of basin modelling and geochemistry activities in PDO; quantitative basin evaluation: how does it affect decision in exploration (*); panel discussion: evolution of the modelling tools. Abstracts are available only for 5 presentations (marked with (*)). (J.S.)

  1. PROMOTIONS: PROper MOTION Software

    Science.gov (United States)

    Caleb Wherry, John; Sahai, R.

    2009-05-01

    We report on the development of a software tool (PROMOTIONS) to streamline the process of measuring proper motions of material in expanding nebulae. Our tool makes use of IDL's widget programming capabilities to design a unique GUI that is used to compare images of the objects from two epochs. The software allows us to first orient and register the images to a common frame of reference and pixel scale, using field stars in each of the images. We then cross-correlate specific morphological features in order to determine their proper motions, which consist of the proper motion of the nebula as a whole (PM-neb), and expansion motions of the features relative to the center. If the central star is not visible (quite common in bipolar nebulae with dense dusty waists), point-symmetric expansion is assumed and we use the average motion of high-quality symmetric pairs of features on opposite sides of the nebular center to compute PM-neb. This is then subtracted out to determine the individual movements of these and additional features relative to the nebular center. PROMOTIONS should find wide applicability in measuring proper motions in astrophysical objects such as the expanding outflows/jets commonly seen around young and dying stars. We present first results from using PROMOTIONS to successfully measure proper motions in several pre-planetary nebulae (transition objects between the red giant and planetary nebula phases), using images taken 7-10 years apart with the WFPC2 and ACS instruments on board HST. The authors are grateful to NASA's Undergradute Scholars Research Program (USRP) for supporting this research.

  2. Exploring Australian health promotion and environmental sustainability initiatives.

    Science.gov (United States)

    Patrick, Rebecca; Kingsley, Jonathan

    2016-04-01

    Issue addressed Health promotion practitioners have important roles in applying ecosystem approaches to health and actively promoting environmental sustainability within community-level practice. The present study identified the nature and scope of health promotion activities across Australia that tackle environmental sustainability. Methods A mixed-method approach was used, with 82 participants undertaking a quantitative survey and 11 undertaking a qualitative interview. Purposeful sampling strategies were used to recruit practitioners who were delivering community-level health promotion and sustainability programs in Australia. The data were analysed thematically and interpretation was guided by the principles of triangulation. Results Study participants were at various stages of linking health promotion and environmental sustainability. Initiatives focused on healthy and sustainable food, active transport, energy efficiency, contact with nature and capacity building. Conclusion Capacity building approaches were perceived as essential to strengthening this field of practice. Healthy and sustainable food and active transport were suitable platforms for simultaneously promoting community health and sustainability. There was potential for expansion of programs that emphasise contact with nature and energy issues, as well as interventions that emphasise systems thinking and interdisciplinary approaches. So what? It was promising that Australian health promotion programs have started to address complexity rather than single issues, as evidenced by explicit engagement with environmental sustainability. However, more effort is required to enable a shift towards ecosystem approaches to health.

  3. Leadership Styles Promote Teamwork

    Directory of Open Access Journals (Sweden)

    Khater Aldoshan

    2015-08-01

    Full Text Available This paper will evaluate the importance of learning leadership styles and the explanation of when and how each one is used in the workforce. In this paper many experts have been cited that are well-known in the field of leadership. Also this paper will concentrate on the importance of teamwork in the workforce and there are many examples of how teamwork is effective for creating the best possible outcomes for creativity and productivity. In the television industry creativity is an essential component of the job description and inspirational leadership that promotes teamwork is essential.

  4. Promoting good practice.

    Science.gov (United States)

    2004-04-01

    Meanwhile, the Scottish Executive's Centre for Change and Innovation, which was set up to identify and promote good practice and increase the pace of change to benefit patients, has an informative website at www.cci.scot.nhs.uk which provides details of a range of innovative projects currently underway. The site has main sections focusing on, among other things, national and local programmes, best practice examples, feedback, advice on managing teams, and developing organisations. It also provides a link to the NHS Education for Scotland electronic library.

  5. CMV promoter is repressed by p53 and activated by JNK pathway.

    Science.gov (United States)

    Rodova, Marianna; Jayini, Renuka; Singasani, Reddy; Chipps, Elizabeth; Islam, M Rafiq

    2013-05-01

    Viral promoters are widely utilized in commercial and customized vectors to drive expression of genes of interest including reporter, effector and transfection control, because of their high transcription efficiency in a variety of primary and transformed cell lines. However, we observed altered rate of transcription for these promoters under conditions such as presence of an effector protein. These variations in viral promoter driven expressions can potentially lead to incorrect conclusion, especially in comparative and quantitative experiments. We found significantly reduced viral promoter activity in cells overexpressing tumor suppressor protein p53, whereas markedly induced transcription in cells overexpressing MAP/ERK kinase kinase 1 (Mekk 1). Using deletion constructs generated from the CMV promoter, we found the transcription reduction by p53 is possibly mediated through the TATA motif present in proximal CMV promoter. The activation of the CMV promoter by Mekk 1, on the other hand, is attributed to the proximal CRE binding site in the promoter. These findings may be of interest to investigators who use CMV (or other viral) promoter driven vectors for either comparative or quantitative gene expression, or effect on promoter activity. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Applications of microfluidics in quantitative biology.

    Science.gov (United States)

    Bai, Yang; Gao, Meng; Wen, Lingling; He, Caiyun; Chen, Yuan; Liu, Chenli; Fu, Xiongfei; Huang, Shuqiang

    2017-10-04

    Quantitative biology is dedicated to taking advantage of quantitative reasoning and advanced engineering technologies to make biology more predictable. Microfluidics, as an emerging technique, provides new approaches to precisely control fluidic conditions on small scales and collect data in high-throughput and quantitative manners. In this review, we present the relevant applications of microfluidics to quantitative biology based on two major categories (channel-based microfluidics and droplet-based microfluidics), and their typical features. We also envision some other microfluidic techniques that may not be employed in quantitative biology right now, but have great potential in the near future. This article is protected by copyright. All rights reserved.

  7. Analysis of aberrant methylation on promoter sequences of tumor suppressor genes and total DNA in sputum samples: a promising tool for early detection of COPD and lung cancer in smokers

    Directory of Open Access Journals (Sweden)

    Guzmán Leda

    2012-07-01

    Full Text Available Abstract Background Chronic obstructive pulmonary disease (COPD is a disorder associated to cigarette smoke and lung cancer (LC. Since epigenetic changes in oncogenes and tumor suppressor genes (TSGs are clearly important in the development of LC. In this study, we hypothesize that tobacco smokers are susceptible for methylation in the promoter region of TSGs in airway epithelial cells when compared with non-smoker subjects. The purpose of this study was to investigate the usefulness of detection of genes promoter methylation in sputum specimens, as a complementary tool to identify LC biomarkers among smokers with early COPD. Methods We determined the amount of DNA in induced sputum from patients with COPD (n = 23, LC (n = 26, as well as in healthy subjects (CTR (n = 33, using a commercial kit for DNA purification, followed by absorbance measurement at 260 nm. The frequency of CDKN2A, CDH1 and MGMT promoter methylation in the same groups was determined by methylation-specific polymerase chain reaction (MSP. The Fisher’s exact test was employed to compare frequency of results between different groups. Results DNA concentration was 7.4 and 5.8 times higher in LC and COPD compared to the (CTR (p  Conclusions We provide evidence that aberrant methylation of TSGs in samples of induced sputum is a useful tool for early diagnostic of lung diseases (LC and COPD in smoker subjects. Virtual slides The abstract MUST finish with the following text: Virtual Slides The virtual slide(s for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1127865005664160

  8. THE PROMOTION OF INNOVATIVE PRODUCTS

    OpenAIRE

    Alyabedeva, I.

    2012-01-01

    The article aims to consider the issues of the innovative products promotion. Peculiarities of innovative market and its future progress, key factors connected with the promotion of innovative products success are analyzed. Here are also suggested the successful marketing strategies variants of the innovative products promotion.

  9. The promotion of innovative products

    OpenAIRE

    Alyabedeva, I.

    2012-01-01

    The article aims to consider the issues of the innovative products promotion. Peculiarities of innovative market and its future progress, key factors connected with the promotion of innovative products success are analyzed. Here are also suggested the successful marketing strategies variants of the innovative products promotion.

  10. Towards Quantitative Ocean Precipitation Validation

    Science.gov (United States)

    Klepp, C.; Bakan, S.; Andersson, A.

    2009-04-01

    A thorough knowledge of global ocean precipitation is an indispensable prerequisite for the understanding and successful modelling of the global climate system as it is an important component of the water cycle. However, reliable detection of quantitative precipitation over the global oceans, especially at high latitudes during the cold season remains a challenging task for remote sensing and model based estimates. Quantitative ship validation data using reliable instruments for measuring rain and snowfall hardly exist but are highly demanded for ground validation of such products. The satellite based HOAPS (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data) climatology contains fields of precipitation, evaporation and the resulting freshwater flux along with 12 additional atmospheric parameters over the global ice-free ocean between 1987 and 2005. Except for the NOAA Pathfinder SST, all basic state variables are calculated from SSM/I passive microwave radiometer measurements. HOAPS contains three main data subsets that originate from one common pixel-level data source. Gridded 0.5 degree monthly, pentad and twice daily data products are freely available from www.hoaps.org. Especially for North Atlantic mid-latitude mix-phase precipitation, the HOAPS precipitation retrieval has been investigated in some depth. This analysis revealed that the HOAPS retrieval qualitatively well represents cyclonic and intense mesoscale precipitation in agreement with ship observations and Cloudsat data, while GPCP, ECMWF forecast, ERA-40 and regional model data miss mesoscale precipitation substantially. As the differences between the investigated data sets are already large under mix-phase precipitation conditions, further work is carried out on snowfall validation during the cold season at high-latitudes. A Norwegian Sea field campaign in winter 2005 was carried out using an optical disdrometer capable of measuring quantitative amounts of snowfall over the ocean

  11. ITALY: WEB TOURISM PROMOTION

    Directory of Open Access Journals (Sweden)

    Katarína Klimová

    2017-03-01

    Full Text Available Tourism, an important industry with a significant social and cultural dimensions, provides interesting stimuli for the study of communication, particularly in the search for adequate tools for persuading potential clients. Since the internet is an essential tool for self-promotion nowadays, specialists examine how tourist destinations are presented in different types of digital texts such as official tourism websites, which combine the informative function of guidebooks with the promotional function of brochures and leaflets. The purpose of this study is to analyse the rhetorical strategies used on the official homepages of nine Italian regions to catch the eye of potential clients and create an identity for a particular region as a tourist destination.   Il turismo, industria importante che ha una significativa dimensione sociale e culturale, costituisce un’area che fornisce stimoli interessanti per lo studio della comunicazione, in particolare nella ricerca di strumenti adeguati a persuadere potenziali clienti. Dal momento che oggi Internet è uno strumento essenziale per l’auto-promozione, molti specialisti si sono dedicati allo studio di come le destinazioni turistiche sono presentate in diversi tipi di testi digitali quali, ad esempio, i siti turistici ufficiali, che combinano la funzione informativa delle guide con quella promozionale di opuscoli e volantini. Scopo di questo studio è analizzare le strategie retoriche utilizzate nelle homepage ufficiali di nove regioni italiane per catturare l’attenzione dei potenziali clienti e per caratterizzare la regione come destinazione turistica.

  12. TWEAK Promotes Peritoneal Inflammation

    Science.gov (United States)

    Sanz, Ana Belen; Aroeira, Luiz Stark; Bellon, Teresa; del Peso, Gloria; Jimenez-Heffernan, Jose; Santamaria, Beatriz; Sanchez-Niño, Maria Dolores; Blanco-Colio, Luis Miguel; Lopez-Cabrera, Manuel; Ruiz-Ortega, Marta; Egido, Jesus; Selgas, Rafael; Ortiz, Alberto

    2014-01-01

    Peritoneal dialysis (PD) is complicated by peritonitis episodes that cause loss of mesothelium and eventually sclerosing peritonitis. An improved understanding of the molecular contributors to peritoneal injury and defense may increase the therapeutic armamentarium to optimize peritoneal defenses while minimizing peritoneal injury. There is no information on the expression and function of the cytokine TWEAK and its receptor Fn14 during peritoneal injury. Fn14 expression and soluble TWEAK levels were measured in human PD peritoneal effluent cells or fluids with or without peritonitis. Fn14 expression was also analyzed in peritoneal biopsies from PD patients. Actions of intraperitoneal TWEAK were studied in mice in vivo. sTWEAK levels were increased in peritoneal effluent in PD peritonitis. Effluent sTWEAK levels correlated with the number of peritoneal macrophages (r = 0.491, p = 0.002). Potential TWEAK targets that express the receptor Fn14 include mesothelial cells and macrophages, as demonstrated by flow cytometry of peritoneal effluents and by analysis of peritoneal biopsies. Peritoneal biopsy Fn14 correlated with mesothelial injury, fibrosis and inflammation, suggesting a potential deleterious effect of TWEAK/Fn14. In this regard, intraperitoneal TWEAK administration to mice promoted peritoneal inflammation characterized by increased peritoneal effluent MCP-1, Fn14 and Gr1+ macrophages, increased mesothelial Fn14, MCP-1 and CCL21 expression and submesothelial tissue macrophage recruitment. Taken together these data suggest that the TWEAK/Fn14 system may promote inflammation and tissue injury during peritonitis and PD. PMID:24599047

  13. Functional analysis of a reproductive organ predominant expressing promoter in cotton plants

    Institute of Scientific and Technical Information of China (English)

    REN Maozhi; CHEN Quanjia; LI Li; ZHANG Rui; GUO Sandui

    2005-01-01

    Transgenic Bt insect-resistant cotton plants have high insect resistance in the early stage of development, but relatively low resistance in the late stage. Substituting a reproductive organ-specific promoter for the CaMV35S promoter presently being used could be an ideal solution. For the first time, the promoter sequence of ADP-ribosylation factor 1 (arf1) gene was isolated from Gossypium hirsutumY18 by means of inverse PCR. The sequencing result discovered the unique structure of the arf1 promoter, including four promoter-specific elements, the initiator, TATA box, CAAT box and GC box, and also an intron in 5′-untranslation region. Four plant expression vectors were constructed for functional analysis of the promoter. Based on the pBI121 plant expression vector, four truncated arf1 promoters took the place of the CaMV35S promoter. These vectors were different only in their promoter regions. They were introduced into cotton plants via pollen tube pathway. Histochemical GUS staining and fluorescence quantitative analyses were performed to examine the expression patterns of the GUS gene driven by the 4 arf1 truncated promoters in transgenic cotton plants respectively. The results showed that the arf1 promoter was a typical reproductive organ-specific promoter. Hopefully, the arf1 promoter can be a regulatory element for designing cotton reproductive organs with desired characteristics.

  14. Functional analysis of a reproductive organ predominant expressing promoter in cotton plants.

    Science.gov (United States)

    Ren, Maozhi; Chen, Quanjia; Li, Li; Zhang, Rui; Guo, Sandui

    2005-10-01

    Transgenic Bt insect-resistant cotton plants have high insect resistance in the early stage of development, but relatively low resistance in the late stage. Substituting a reproductive organ-specific promoter for the CaMV35S promoter presently being used could be an ideal solution. For the first time, the promoter sequence of ADP-ribosylation factor 1 (arf1) gene was isolated from Gossypium hirsutumY18 by means of inverse PCR. The sequencing result discovered the unique structure of the arf1 promoter, including four promoter-specific elements, the initiator, TATA box, CAAT box and GC box, and also an intron in 5'-untranslation region. Four plant expression vectors were constructed for functional analysis of the promoter. Based on the pBl121 plant expression vector, four truncated arf1 promoters took the place of the CaMV35S promoter. These vectors were different only in their promoter regions. They were introduced into cotton plants via pollen tube pathway. Histochemical GUS staining and fluorescence quantitative analyses were performed to examine the expression patterns of the GUS gene driven by the 4 arf1 truncated promoters in transgenic cotton plants respectively. The results showed that the arf1 promoter was a typical reproductive organ-specific promoter. Hopefully, the arf1 promoter can be a regulatory element for designing cotton reproductive organs with desired characteristics.

  15. The sequence of spacers between the consensus sequences modulates the strength of procaryotic promoters

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Hammer, Karin

    1998-01-01

    than 2000 relative units, which is among the strongest promoters known for this organism. The ranking of the promoter activities was somewhat different when assayed in E. coli, but the promoters are efficient for modulating gene expression in this bacteria as well. DNA sequencing revealed...... the spacers, at least a 400 fold change in activity can be obtained. Interestingly, the entire range of promoter activities is covered in small steps of activity increase, which makes these promoters very suitable for quantitative physiological studies and for fine tuning of gene expression in industrial bio......A library of synthetic promoters for Lactococcus lactis was constructed, in which the known consensus sequences were kept constant while the sequences of the separating spacers were randomized. The library consists of 38 promoters which differ in strength from 0.3 relative units, and up to more...

  16. Quantitative patterns in drone wars

    Science.gov (United States)

    Garcia-Bernardo, Javier; Dodds, Peter Sheridan; Johnson, Neil F.

    2016-02-01

    Attacks by drones (i.e., unmanned combat air vehicles) continue to generate heated political and ethical debates. Here we examine the quantitative nature of drone attacks, focusing on how their intensity and frequency compare with that of other forms of human conflict. Instead of the power-law distribution found recently for insurgent and terrorist attacks, the severity of attacks is more akin to lognormal and exponential distributions, suggesting that the dynamics underlying drone attacks lie beyond these other forms of human conflict. We find that the pattern in the timing of attacks is consistent with one side having almost complete control, an important if expected result. We show that these novel features can be reproduced and understood using a generative mathematical model in which resource allocation to the dominant side is regulated through a feedback loop.

  17. Quantitative analysis of Boehm's GC

    Institute of Scientific and Technical Information of China (English)

    GUAN Xue-tao; ZHANG Yuan-rui; GOU Xiao-gang; CHENG Xu

    2003-01-01

    The term garbage collection describes the automated process of finding previously allocated memorythatis no longer in use in order to make the memory available to satisfy subsequent allocation requests. Wehave reviewed existing papers and implementations of GC, and especially analyzed Boehm' s C codes, which isa real-time mark-sweep GC running under Linux and ANSI C standard. In this paper, we will quantitatively an-alyze the performance of different configurations of Boehm' s collector subjected to different workloads. Reportedmeasurements demonstrate that a refined garbage collector is a viable alternative to traditional explicit memorymanagement techniques, even for low-level languages. It is more a trade-off for certain system than an all-or-nothing proposition.

  18. Quantitative genetics of disease traits.

    Science.gov (United States)

    Wray, N R; Visscher, P M

    2015-04-01

    John James authored two key papers on the theory of risk to relatives for binary disease traits and the relationship between parameters on the observed binary scale and an unobserved scale of liability (James Annals of Human Genetics, 1971; 35: 47; Reich, James and Morris Annals of Human Genetics, 1972; 36: 163). These two papers are John James' most cited papers (198 and 328 citations, November 2014). They have been influential in human genetics and have recently gained renewed popularity because of their relevance to the estimation of quantitative genetics parameters for disease traits using SNP data. In this review, we summarize the two early papers and put them into context. We show recent extensions of the theory for ascertained case-control data and review recent applications in human genetics.

  19. Qualitative and Quantitative Sentiment Proxies

    DEFF Research Database (Denmark)

    Zhao, Zeyan; Ahmad, Khurshid

    2015-01-01

    Sentiment analysis is a content-analytic investigative framework for researchers, traders and the general public involved in financial markets. This analysis is based on carefully sourced and elaborately constructed proxies for market sentiment and has emerged as a basis for analysing movements...... in stock prices and the associated traded volume. This approach is particularly helpful just before and after the onset of market volatility. We use an autoregressive framework for predicting the overall changes in stock prices by using investor sentiment together with lagged variables of prices...... and trading volumes. The case study we use is a small market index (Danish Stock Exchange Index, OMXC 20, together with prevailing sentiment in Denmark, to evaluate the impact of sentiment on OMXC 20. Furthermore, we introduce a rather novel and quantitative sentiment proxy, that is the use of the index...

  20. Quantitative photoacoustic elastography in humans

    Science.gov (United States)

    Hai, Pengfei; Zhou, Yong; Gong, Lei; Wang, Lihong V.

    2016-06-01

    We report quantitative photoacoustic elastography (QPAE) capable of measuring Young's modulus of biological tissue in vivo in humans. By combining conventional PAE with a stress sensor having known stress-strain behavior, QPAE can simultaneously measure strain and stress, from which Young's modulus is calculated. We first demonstrate the feasibility of QPAE in agar phantoms with different concentrations. The measured Young's modulus values fit well with both the empirical expectation based on the agar concentrations and those measured in an independent standard compression test. Next, QPAE was applied to quantify the Young's modulus of skeletal muscle in vivo in humans, showing a linear relationship between muscle stiffness and loading. The results demonstrated the capability of QPAE to assess the absolute elasticity of biological tissue noninvasively in vivo in humans, indicating its potential for tissue biomechanics studies and clinical applications.

  1. Quantitative analysis of qualitative images

    Science.gov (United States)

    Hockney, David; Falco, Charles M.

    2005-03-01

    We show optical evidence that demonstrates artists as early as Jan van Eyck and Robert Campin (c1425) used optical projections as aids for producing their paintings. We also have found optical evidence within works by later artists, including Bermejo (c1475), Lotto (c1525), Caravaggio (c1600), de la Tour (c1650), Chardin (c1750) and Ingres (c1825), demonstrating a continuum in the use of optical projections by artists, along with an evolution in the sophistication of that use. However, even for paintings where we have been able to extract unambiguous, quantitative evidence of the direct use of optical projections for producing certain of the features, this does not mean that paintings are effectively photographs. Because the hand and mind of the artist are intimately involved in the creation process, understanding these complex images requires more than can be obtained from only applying the equations of geometrical optics.

  2. Innovations in Quantitative Risk Management

    CERN Document Server

    Scherer, Matthias; Zagst, Rudi

    2015-01-01

    Quantitative models are omnipresent –but often controversially discussed– in todays risk management practice. New regulations, innovative financial products, and advances in valuation techniques provide a continuous flow of challenging problems for financial engineers and risk managers alike. Designing a sound stochastic model requires finding a careful balance between parsimonious model assumptions, mathematical viability, and interpretability of the output. Moreover, data requirements and the end-user training are to be considered as well. The KPMG Center of Excellence in Risk Management conference Risk Management Reloaded and this proceedings volume contribute to bridging the gap between academia –providing methodological advances– and practice –having a firm understanding of the economic conditions in which a given model is used. Discussed fields of application range from asset management, credit risk, and energy to risk management issues in insurance. Methodologically, dependence modeling...

  3. Quantitative Characterisation of Surface Texture

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Lonardo, P.M.; Trumpold, H.;

    2000-01-01

    This paper reviews the different methods used to give a quantitative characterisation of surface texture. The paper contains a review of conventional 2D as well as 3D roughness parameters, with particular emphasis on recent international standards and developments. It presents new texture...... characterisation methods, such as fractals, wavelets, change trees and others, including for each method a short review, the parameters that the new methods calculate, and applications of the methods to solve surface problems. The paper contains a discussion on the relevance of the different parameters...... and quantification methods in terms of functional correlations, and it addresses the need for reducing the large number of existing parameters. The review considers the present situation and gives suggestions for future activities....

  4. Quantitative evaluation of dermatological antiseptics.

    Science.gov (United States)

    Leitch, C S; Leitch, A E; Tidman, M J

    2015-12-01

    Topical antiseptics are frequently used in dermatological management, yet evidence for the efficacy of traditional generic formulations is often largely anecdotal. We tested the in vitro bactericidal activity of four commonly used topical antiseptics against Staphylococcus aureus, using a modified version of the European Standard EN 1276, a quantitative suspension test for evaluation of the bactericidal activity of chemical disinfectants and antiseptics. To meet the standard for antiseptic effectiveness of EN 1276, at least a 5 log10 reduction in bacterial count within 5 minutes of exposure is required. While 1% benzalkonium chloride and 6% hydrogen peroxide both achieved a 5 log10 reduction in S. aureus count, neither 2% aqueous eosin nor 1 : 10 000 potassium permanganate showed significant bactericidal activity compared with control at exposure periods of up to 1 h. Aqueous eosin and potassium permanganate may have desirable astringent properties, but these results suggest they lack effective antiseptic activity, at least against S. aureus.

  5. Quantitative measurements of inventory control.

    Science.gov (United States)

    Noel, M W

    1984-11-01

    The use of quantitative measurements for improving inventory management efficiency in hospital pharmacy is reviewed. Proper management of the pharmacy inventory affects the financial operation of the entire hospital. Problems associated with maintaining inadequate or excessive inventory investment are discussed, and the use of inventory valuation and turnover rate for assessing inventory control efficiency is described. Frequency of order placement has an important effect on inventory turnover, carrying costs, and ordering costs. Use of the ABC system of inventory classification for identifying products constituting the majority of inventory dollar investment is outlined, and the economic order value concept is explained. With increasing regulations aimed at controlling hospital costs, pharmacy managers must seek every possible means to improve efficiency. Reducing the amount of money obligated to inventory can substantially improve the financial position of the hospital without requiring a reduction in personnel or quality of service.

  6. GPC and quantitative phase imaging

    Science.gov (United States)

    Palima, Darwin; Bañas, Andrew Rafael; Villangca, Mark Jayson; Glückstad, Jesper

    2016-03-01

    Generalized Phase Contrast (GPC) is a light efficient method for generating speckle-free contiguous optical distributions using binary-only or analog phase levels. It has been used in applications such as optical trapping and manipulation, active microscopy, structured illumination, optical security, parallel laser marking and labelling and recently in contemporary biophotonics applications such as for adaptive and parallel two-photon optogenetics and neurophotonics. We will present our most recent GPC developments geared towards these applications. We first show a very compact static light shaper followed by the potential of GPC for biomedical and multispectral applications where we experimentally demonstrate the active light shaping of a supercontinuum laser over most of the visible wavelength range. Finally, we discuss how GPC can be advantageously applied for Quantitative Phase Imaging (QPI).

  7. Quantitative computation of RHEED patterns

    Science.gov (United States)

    Lordi, Scott Andrew

    This thesis is concerned with the general problem of performing quantitative RHEED computations for both flat and rough surfaces using the multislice method. Modifications to the RHEED multislice method which make it into a practical technique for performing RHEED computations are described. Computation of convergent-beam RHEED patterns using the RHEED multislice method is demonstrated by application to the case of MgO (001). Computed patterns are compared (based on the overall pattern geometry) to energy-filtered Tanaka and convergent-beam patterns recorded in a transmission electron microscope. The validity of the RHEED multislice method for convergent-beam computations is demonstrated by the level of agreement achieved. The application of the RHEED multislice method combined with the edge patching algorithm to the computation of RHEED streaks from rough surfaces is demonstrated by applying it to the case of rough Fe (001) surfaces. The computations are done using the column approximation and by neglecting the scattering from steps parallel to the incident beam. The computations are set up using STM images of the surfaces from which the experimental RHEED patterns were recorded. The shapes of the diffuse parts of the computed and experimental streaks agree well. There is a discrepancy between experiment and theory in the magnitudes of the flat surface spot position peaks relative to the diffuse parts of the streaks. The shapes of the diffuse parts of the computed streaks are shown to be insensitive to the computational and potential parameters. The magnitudes of the flat surface spot position peaks are at least weakly dependent on the potential parameters and the long range height variations of the surface. This agreement conclusively demonstrates that the RHEED multislice method can be used to perform quantitative computations of RHEED streaks from real rough surfaces. An approximation method (the patchwork approximation) for doing RHEED computations, exact in

  8. Health promotion and prevention strategies.

    Science.gov (United States)

    Bradbury-Golas, Kathleen

    2013-09-01

    Opiate dependency is a medical disorder that requires treatment intervention. Primary health care not only entails treatment of illness but also involves disease prevention and health promotion. Based on Pender's revised Health Promotion Model, a descriptive study comparing the health promoting behaviors/practices in abusing and recovering opiate-dependent drug users is analyzed. Using the Health Promoting Lifestyle Profile II, a comparative descriptive, exploratory, nonexperimental design study was conducted to identify key health-promoting behaviors in recovering opiate-dependent drug users. Prevention strategy recommendations are discussed, along with future research recommendations.

  9. Promoting Fair Food-to-Consumer Communication

    DEFF Research Database (Denmark)

    Barratt, Daniel; Hviid Madsen, Mai; Smith, Viktor

    2012-01-01

    with authoritative definitions (adding experts’ final judgments). The research is part of the cross-disciplinary research project “Spin or fair speak – when foods talk” which aims at providing new knowledge, tools, and experimental evidence for promoting fairness in food naming and labelling practices.......The line of research presented in this paper aims at shedding new light on the role of sensory elements in legal disputes concerning potentially misleading food naming and labelling. It presents selected results of a quantitative and qualitative review of 821 real-life cases on such issues......-up experiment are presented which targeted the limits for consumers’ acceptance of name-product combinations when exposed to taste samples alone (sensory product attributes), taste samples in combination with ingredients lists and nutrition facts (adding factual information), and both, in combination...

  10. Quantitative metal magnetic memory reliability modeling for welded joints

    Science.gov (United States)

    Xing, Haiyan; Dang, Yongbin; Wang, Ben; Leng, Jiancheng

    2016-03-01

    Metal magnetic memory(MMM) testing has been widely used to detect welded joints. However, load levels, environmental magnetic field, and measurement noises make the MMM data dispersive and bring difficulty to quantitative evaluation. In order to promote the development of quantitative MMM reliability assessment, a new MMM model is presented for welded joints. Steel Q235 welded specimens are tested along the longitudinal and horizontal lines by TSC-2M-8 instrument in the tensile fatigue experiments. The X-ray testing is carried out synchronously to verify the MMM results. It is found that MMM testing can detect the hidden crack earlier than X-ray testing. Moreover, the MMM gradient vector sum K vs is sensitive to the damage degree, especially at early and hidden damage stages. Considering the dispersion of MMM data, the K vs statistical law is investigated, which shows that K vs obeys Gaussian distribution. So K vs is the suitable MMM parameter to establish reliability model of welded joints. At last, the original quantitative MMM reliability model is first presented based on the improved stress strength interference theory. It is shown that the reliability degree R gradually decreases with the decreasing of the residual life ratio T, and the maximal error between prediction reliability degree R 1 and verification reliability degree R 2 is 9.15%. This presented method provides a novel tool of reliability testing and evaluating in practical engineering for welded joints.

  11. Methylation profiles of thirty four promoter-CpG islands and concordant methylation behaviours of sixteen genes that may contribute to carcinogenesis of astrocytoma

    Directory of Open Access Journals (Sweden)

    Wang Yifei

    2004-09-01

    Full Text Available Abstract Background Astrocytoma is a common aggressive intracranial tumor and presents a formidable challenge in the clinic. Association of altered DNA methylation patterns of the promoter CpG islands with the expression profile of cancer-related genes, has been found in many human tumors. Therefore, DNA methylation status as such may serve as an epigenetic biomarker for both diagnosis and prognosis of human tumors, including astrocytoma. Methods We used the methylation specific PCR in conjunction with sequencing verification to establish the methylation profile of the promoter CpG island of thirty four genes in astrocytoma tissues from fifty three patients (The WHO grading:. I: 14, II: 15, III: 12 and IV: 12 cases, respectively. In addition, compatible tissues (normal tissues distant from lesion from three non-astrocytoma patients were included as the control. Results Seventeen genes (ABL, APC, APAF1, BRCA1, CSPG2, DAPK1, hMLH1, LKB1, PTEN, p14ARF, p15INK4b, p27KIP1, p57KIP2, RASSF1C, RB1, SURVIVIN, and VHL displayed a uniformly unmethylated pattern in all the astrocytoma and non-astrocytoma tissues examined. However, the MAGEA1 gene that was inactivated and hypermethylated in non-astrocytoma tissues, was partially demethylated in 24.5% of the astrocytoma tissues (co-existence of the hypermethylated and demethylated alleles. Of the astrocytoma associated hypermethylated genes, the methylation pattern of the CDH13, cyclin a1, DBCCR1, EPO, MYOD1, and p16INK4a genes changed in no more than 5.66% (3/53 of astrocytoma tissues compared to non-astrocytoma controls, while the RASSF1A, p73, AR, MGMT, CDH1, OCT6,, MT1A, WT1, and IRF7 genes were more frequently hypermethylated in 69.8%, 47.2%, 41.5%, 35.8%, 32%, 30.2%, 30.2%, 30.2% and 26.4% of astrocytoma tissues, respectively. Demethylation mediated inducible expression of the CDH13, MAGEA1, MGMT, p73 and RASSF1A genes was established in an astrocytoma cell line (U251, demonstrating that expression of

  12. Buying time promotes happiness.

    Science.gov (United States)

    Whillans, Ashley V; Dunn, Elizabeth W; Smeets, Paul; Bekkers, Rene; Norton, Michael I

    2017-08-08

    Around the world, increases in wealth have produced an unintended consequence: a rising sense of time scarcity. We provide evidence that using money to buy time can provide a buffer against this time famine, thereby promoting happiness. Using large, diverse samples from the United States, Canada, Denmark, and The Netherlands (n = 6,271), we show that individuals who spend money on time-saving services report greater life satisfaction. A field experiment provides causal evidence that working adults report greater happiness after spending money on a time-saving purchase than on a material purchase. Together, these results suggest that using money to buy time can protect people from the detrimental effects of time pressure on life satisfaction.

  13. TRYPTOPHAN PROMOTES CHARITABLE DONATING

    Directory of Open Access Journals (Sweden)

    Laura eSteenbergen

    2014-12-01

    Full Text Available The link between serotonin (5-HT and one of the most important elements of prosocial behavior, charity, has remained largely uninvestigated. In the present study, we tested whether charitable donating can be promoted by administering the food supplement L-Tryptophan (TRP, the biochemical precursor of 5-HT. Participants were compared with respect to the amount of money they donated when given the opportunity to make a charitable donation. As expected, compared to a neutral placebo, TRP appears to increase the participants’ willingness to donate money to a charity. This result supports the idea that the food we eat may act as a cognitive enhancer modulating the way we think and perceive the world and others.

  14. Surface Protonics Promotes Catalysis

    Science.gov (United States)

    Manabe, R.; Okada, S.; Inagaki, R.; Oshima, K.; Ogo, S.; Sekine, Y.

    2016-12-01

    Catalytic steam reforming of methane for hydrogen production proceeds even at 473 K over 1 wt% Pd/CeO2 catalyst in an electric field, thanks to the surface protonics. Kinetic analyses demonstrated the synergetic effect between catalytic reaction and electric field, revealing strengthened water pressure dependence of the reaction rate when applying an electric field, with one-third the apparent activation energy at the lower reaction temperature range. Operando-IR measurements revealed that proton conduction via adsorbed water on the catalyst surface occurred during electric field application. Methane was activated by proton collision at the Pd-CeO2 interface, based on the inverse kinetic isotope effect. Proton conduction on the catalyst surface plays an important role in methane activation at low temperature. This report is the first describing promotion of the catalytic reaction by surface protonics.

  15. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  16. Recent trends in social systems quantitative theories and quantitative models

    CERN Document Server

    Hošková-Mayerová, Šárka; Soitu, Daniela-Tatiana; Kacprzyk, Janusz

    2017-01-01

    The papers collected in this volume focus on new perspectives on individuals, society, and science, specifically in the field of socio-economic systems. The book is the result of a scientific collaboration among experts from “Alexandru Ioan Cuza” University of Iaşi (Romania), “G. d’Annunzio” University of Chieti-Pescara (Italy), "University of Defence" of Brno (Czech Republic), and "Pablo de Olavide" University of Sevilla (Spain). The heterogeneity of the contributions presented in this volume reflects the variety and complexity of social phenomena. The book is divided in four Sections as follows. The first Section deals with recent trends in social decisions. Specifically, it aims to understand which are the driving forces of social decisions. The second Section focuses on the social and public sphere. Indeed, it is oriented on recent developments in social systems and control. Trends in quantitative theories and models are described in Section 3, where many new formal, mathematical-statistical to...

  17. 5-氮杂-2'-脱氧胞苷对宫颈癌细胞的基因表达调控%The regulatory effect of 5-aza-2,-deoxycytidine in cervical cancer cells

    Institute of Scientific and Technical Information of China (English)

    陈观娣; 范格英; 游可理; 钱德英; 岑坚敏; 舒焰红; 李志刚

    2016-01-01

    Objective To discuss the regulatory effect of 5-aza-2 ,-deoxycytidine on P16 and MGMT in cervical cancer cells. Methods After four kinds of cervical cancer cells (HeLa, SiHa, C33A and CaSki) were treated with 5-Aza-dC , MSP was used to detect the methylation variation of P16 and MGMT , and fluorogenic quantitative PCR and Western blot were employed for determination of P16 and MGMT expression. MTT and Annexin V-FITC/PI double staining were adopted for detection of cell proliferation and apoptosis. Results Both P16 and MGMT exhibited methylation in four kinds of cervical cancer cells , and after treatment with 5-Aza-dC ,their methylation levels were reversed. 5-Aza-dC was able to inhibit p16 and MGMT expression in the cervical cancer cells, and can also suppress cell proliferation and promote apoptosis. Conclusions Although methylation of P16 and MGMT are present in cervical cancer cells, their expression level was still high. Therefore, regulation of P16 and MGMT expression may be affected by other factors. 5-Aza-dC can suppress the growth of cervical cancer cells. Although 5-Aza-dC reverse the methylation levels of P16 and MGMT, it inhibits their gene expression. More experiments are needed to verify the hidden reasons and mechanisms.%目的:探讨5-氮杂-2'-脱氧胞苷(5-Aza-dC)对宫颈癌细胞p16和MGMT基因表达的调控作用。方法:用5-Aza-dC 处理4种宫颈癌细胞(HeLa、SiHa、C33A 和 CaSki)后,MSP 检测抑癌基因 P16和 MGMT的甲基化变化,并用荧光定量 PCR 和 Western blot 检测 P16和 MGMT 的表达情况,同时用 MTT 和 Annexin V-FITC/PI双染检测细胞增殖和凋亡。结果:P16和MGMT在4种宫颈癌细胞中均存在甲基化。用5-Aza-dC处理细胞后,甲基化程度均被逆转。5-Aza-dC抑制P16和MGMT在宫颈癌细胞中的表达。5-Aza-dC抑制宫颈癌细胞的增殖并促进其凋亡。结论:P16和MGMT虽在宫颈癌细胞中存在甲基化,但其表

  18. Quantitative imaging as cancer biomarker

    Science.gov (United States)

    Mankoff, David A.

    2015-03-01

    The ability to assay tumor biologic features and the impact of drugs on tumor biology is fundamental to drug development. Advances in our ability to measure genomics, gene expression, protein expression, and cellular biology have led to a host of new targets for anticancer drug therapy. In translating new drugs into clinical trials and clinical practice, these same assays serve to identify patients most likely to benefit from specific anticancer treatments. As cancer therapy becomes more individualized and targeted, there is an increasing need to characterize tumors and identify therapeutic targets to select therapy most likely to be successful in treating the individual patient's cancer. Thus far assays to identify cancer therapeutic targets or anticancer drug pharmacodynamics have been based upon in vitro assay of tissue or blood samples. Advances in molecular imaging, particularly PET, have led to the ability to perform quantitative non-invasive molecular assays. Imaging has traditionally relied on structural and anatomic features to detect cancer and determine its extent. More recently, imaging has expanded to include the ability to image regional biochemistry and molecular biology, often termed molecular imaging. Molecular imaging can be considered an in vivo assay technique, capable of measuring regional tumor biology without perturbing it. This makes molecular imaging a unique tool for cancer drug development, complementary to traditional assay methods, and a potentially powerful method for guiding targeted therapy in clinical trials and clinical practice. The ability to quantify, in absolute measures, regional in vivo biologic parameters strongly supports the use of molecular imaging as a tool to guide therapy. This review summarizes current and future applications of quantitative molecular imaging as a biomarker for cancer therapy, including the use of imaging to (1) identify patients whose tumors express a specific therapeutic target; (2) determine

  19. Detecting cervical cancer by quantitative promoter hypermethylation assay on cervical scrapings : A feasibility study

    NARCIS (Netherlands)

    Reesink-Peters, N; Wisman, G.B.A.; Jeronimo, C; Tokumaru, CY; Cohen, Y; Dong, SM; Klip, HG; Buikema, HJ; Suurmeijer, AJH; Hollema, H; Boezen, HM; Sidransky, D; van der Zee, AGJ

    2004-01-01

    Current morphology-based cervical cancer screening is associated with significant false-positive and false-negative results. Tumor suppressor gene hypermethylation is frequently present in cervical cancer. It is unknown whether a cervical scraping reflects the methylation status of the underlying ep

  20. Signal integration by the CYP1A1 promoter - a quantitative study

    NARCIS (Netherlands)

    Schulthess, P.; Löffler, A.; Vetter, S.; Kreft, L.; Schwarz, M.; Braeuning, A.; Blüthgen, N.

    2015-01-01

    Genes involved in detoxification of foreign compounds exhibit complex spatiotemporal expression patterns in liver. Cytochrome P450 1A1 (CYP1A1), for example, is restricted to the pericentral region of liver lobules in response to the interplay between aryl hydrocarbon receptor (AhR) and

  1. Detecting cervical cancer by quantitative promoter hypermethylation assay on cervical scrapings : A feasibility study

    NARCIS (Netherlands)

    Reesink-Peters, N; Wisman, G.B.A.; Jeronimo, C; Tokumaru, CY; Cohen, Y; Dong, SM; Klip, HG; Buikema, HJ; Suurmeijer, AJH; Hollema, H; Boezen, HM; Sidransky, D; van der Zee, AGJ

    Current morphology-based cervical cancer screening is associated with significant false-positive and false-negative results. Tumor suppressor gene hypermethylation is frequently present in cervical cancer. It is unknown whether a cervical scraping reflects the methylation status of the underlying

  2. Signal integration by the CYP1A1 promoter - a quantitative study

    NARCIS (Netherlands)

    Schulthess, P.; Löffler, A.; Vetter, S.; Kreft, L.; Schwarz, M.; Braeuning, A.; Blüthgen, N.

    2015-01-01

    Genes involved in detoxification of foreign compounds exhibit complex spatiotemporal expression patterns in liver. Cytochrome P450 1A1 (CYP1A1), for example, is restricted to the pericentral region of liver lobules in response to the interplay between aryl hydrocarbon receptor (AhR) and Wnt/β-cateni

  3. Detecting cervical cancer by quantitative promoter hypermethylation assay on cervical scrapings : A feasibility study

    NARCIS (Netherlands)

    Reesink-Peters, N; Wisman, G.B.A.; Jeronimo, C; Tokumaru, CY; Cohen, Y; Dong, SM; Klip, HG; Buikema, HJ; Suurmeijer, AJH; Hollema, H; Boezen, HM; Sidransky, D; van der Zee, AGJ

    2004-01-01

    Current morphology-based cervical cancer screening is associated with significant false-positive and false-negative results. Tumor suppressor gene hypermethylation is frequently present in cervical cancer. It is unknown whether a cervical scraping reflects the methylation status of the underlying ep

  4. Quantitative genetic bases of anthocyanin variation in grape (Vitis vinifera L. ssp. sativa) berry: a quantitative trait locus to quantitative trait nucleotide integrated study.

    Science.gov (United States)

    Fournier-Level, Alexandre; Le Cunff, Loïc; Gomez, Camila; Doligez, Agnès; Ageorges, Agnès; Roux, Catherine; Bertrand, Yves; Souquet, Jean-Marc; Cheynier, Véronique; This, Patrice

    2009-11-01

    The combination of QTL mapping studies of synthetic lines and association mapping studies of natural diversity represents an opportunity to throw light on the genetically based variation of quantitative traits. With the positional information provided through quantitative trait locus (QTL) mapping, which often leads to wide intervals encompassing numerous genes, it is now feasible to directly target candidate genes that are likely to be responsible for the observed variation in completely sequenced genomes and to test their effects through association genetics. This approach was performed in grape, a newly sequenced genome, to decipher the genetic architecture of anthocyanin content. Grapes may be either white or colored, ranging from the lightest pink to the darkest purple tones according to the amount of anthocyanin accumulated in the berry skin, which is a crucial trait for both wine quality and human nutrition. Although the determinism of the white phenotype has been fully identified, the genetic bases of the quantitative variation of anthocyanin content in berry skin remain unclear. A single QTL responsible for up to 62% of the variation in the anthocyanin content was mapped on a Syrah x Grenache F(1) pseudo-testcross. Among the 68 unigenes identified in the grape genome within the QTL interval, a cluster of four Myb-type genes was selected on the basis of physiological evidence (VvMybA1, VvMybA2, VvMybA3, and VvMybA4). From a core collection of natural resources (141 individuals), 32 polymorphisms revealed significant association, and extended linkage disequilibrium was observed. Using a multivariate regression method, we demonstrated that five polymorphisms in VvMybA genes except VvMybA4 (one retrotransposon, three single nucleotide polymorphisms and one 2-bp insertion/deletion) accounted for 84% of the observed variation. All these polymorphisms led to either structural changes in the MYB proteins or differences in the VvMybAs promoters. We concluded that

  5. Quantitative Ultrasound Measurements at the Heel

    DEFF Research Database (Denmark)

    Daugschies, M.; Brixen, K.; Hermann, P.

    2015-01-01

    Calcaneal quantitative ultrasound can be used to predict osteoporotic fracture risk, but its ability to monitor therapy is unclear possibly because of its limited precision. We developed a quantitative ultrasound device (foot ultrasound scanner) that measures the speed of sound at the heel...... with the foot ultrasound scanner reduced precision errors by half (p quantitative ultrasound measurements is feasible. (E-mail: m.daugschies@rad.uni-kiel.de) (C) 2015 World Federation for Ultrasound in Medicine & Biology....

  6. Clinical significance of Dmnt-1 expression and aberrant methylation of P16/MGMT gene promoter in uterine cervical neoplasm%子宫颈部肿瘤中DNA甲基化转移酶-1表达和P16/MGMT基因启动子甲基化的临床意义

    Institute of Scientific and Technical Information of China (English)

    林贞花; 李柱虎; 任香善; 刘双平; 赵祎玮

    2007-01-01

    目的 探讨子宫颈部肿瘤中Dnmt-1(DNA甲基化转移酶-1)表达和P16/MGMT基因启动子甲基化的临床意义.方法 用MS-PCR(Methylation Specific-PCR)和免疫组织化学染色方法研究Dnmt-1蛋白和P16/MGMT基因启动子甲基化在117例子宫颈部良、恶性病变组织中的表达意义.结果 Dnmt-1在浸润性鳞状上皮癌和腺癌中的表达明显高于慢性宫颈炎和宫颈上皮内瘤变.P16/MGMT基因启动区在慢性宫颈炎中全部表现为非甲基化,而在宫颈上皮内瘤变、浸润性鳞状上皮癌和腺癌中则表现为很高的异常甲基化水平.在子宫颈腺癌中,P16/MGMT基因启动子甲基化率在Dnmt-1表达阳性组明显高于Dnmt-1表达阴性组.结论 Dnmt-1蛋白表达和P16/MGMT基因启动子甲基化在宫颈癌进展过程中的早期就起着非常重要的作用,而且Dnmt-1蛋白表达和P16/MGMT甲基化检测对于恶性肿瘤的诊断有着重要的辅助意义.

  7. Advances in quantitative Kerr microscopy

    Science.gov (United States)

    Soldatov, I. V.; Schäfer, R.

    2017-01-01

    An advanced wide-field Kerr microscopy approach to the vector imaging of magnetic domains is demonstrated. Utilizing the light from eight monochrome light emitting diodes, guided to the microscope by glass fibers, and being properly switched in synchronization with the camera exposure, domain images with orthogonal in-plane sensitivity are obtained simultaneously at real time. After calibrating the Kerr contrast under the same orthogonal sensitivity conditions, the magnetization vector field of complete magnetization cycles along the hysteresis loop can be calculated and plotted as a coded color or vector image. In the pulsed mode also parasitic, magnetic field-dependent Faraday rotations in the microscope optics are eliminated, thus increasing the accuracy of the measured magnetization angles to better than 5∘. The method is applied to the investigation of the magnetization process in a patterned Permalloy film element. Furthermore it is shown that the effective magnetic anisotropy axes in a GaMnAs semiconducting film can be quantitatively measured by vectorial analysis of the domain structure.

  8. A quantitative philology of introspection

    Directory of Open Access Journals (Sweden)

    Carlos eDiuk

    2012-09-01

    Full Text Available The cultural evolution of introspective thought has been recognized to undergo a drastic change during the middle of the first millennium BC. This period, known as the ``Axial Age'', saw the birth of religions and philosophies still alive in modern culture, as well as the transition from orality to literacy - which led to the hypothesis of a link between introspection and literacy. Here we set out to examine the evolution of introspection in the Axial Age, studying the cultural record of the Greco-Roman and Judeo-Christian literary traditions. Using a statistical measure of semantic similarity, we identify a single ``arrow of time'' in the Old and New Testaments of the Bible, and a more complex non-monotonic dynamics in the Greco-Roman tradition reflecting the rise and fall of the respective societies. A comparable analysis of the 20th century cultural record shows a steady increase in the incidence of introspective topics, punctuated by abrupt declines during and preceding the First and Second World Wars. Our results show that (a it is possible to devise a consistent metric to quantify the history of a high-level concept such as introspection, cementing the path for a new quantitative philology and (b to the extent that it is captured in the cultural record, the increased ability of human thought for self-reflection that the Axial Age brought about is still heavily determined by societal contingencies beyond the orality-literacy nexus.

  9. Quantitative relationships in delphinid neocortex

    Directory of Open Access Journals (Sweden)

    Heidi S Mortensen

    2014-11-01

    Full Text Available Possessing large brains and complex behavioural patterns, cetaceans are believed to be highly intelligent. Their brains, which are the largest in the Animal Kingdom and have enormous gyrification compared with terrestrial mammals, have long been of scientific interest. Few studies, however, report total number of brain cells in cetaceans, and even fewer have used unbiased counting methods. In this study, using stereological methods, we estimated the total number of cells in the long-finned pilot whale (Globicephala melas brain. For the first time, we show that a species of dolphin has more neocortical neurons than in any mammal studied to date including humans. These cell numbers are compared across various mammals with different brain sizes, and the function of possessing many neurons is discussed. We found that the long-finned pilot whale neocortex has approximately 37.2 × 109 neurons, which is almost twice as many as humans, and 127 × 109 glial cells. Thus, the absolute number of neurons in the human neocortex is not correlated with the superior cognitive abilities of humans (at least compared to cetaceans as has previously been hypothesized. However, as neuron density in long-finned pilot whales is lower than that in humans, their higher cell number appears to be due to their larger brain. Accordingly, our findings make an important contribution to the ongoing debate over quantitative relationships in the mammalian brain.

  10. Quantitative ultrasound in cancer imaging.

    Science.gov (United States)

    Feleppa, Ernest J; Mamou, Jonathan; Porter, Christopher R; Machi, Junji

    2011-02-01

    Ultrasound is a relatively inexpensive, portable, and versatile imaging modality that has a broad range of clinical uses. It incorporates many imaging modes, such as conventional gray-scale "B-mode" imaging to display echo amplitude in a scanned plane; M-mode imaging to track motion at a given fixed location over time; duplex, color, and power Doppler imaging to display motion in a scanned plane; harmonic imaging to display nonlinear responses to incident ultrasound; elastographic imaging to display relative tissue stiffness; and contrast-agent imaging with simple contrast agents to display blood-filled spaces or with targeted agents to display specific agent-binding tissue types. These imaging modes have been well described in the scientific, engineering, and clinical literature. A less well-known ultrasonic imaging technology is based on quantitative ultrasound (QUS), which analyzes the distribution of power as a function of frequency in the original received echo signals from tissue and exploits the resulting spectral parameters to characterize and distinguish among tissues. This article discusses the attributes of QUS-based methods for imaging cancers and providing improved means of detecting and assessing tumors. The discussion will include applications to imaging primary prostate cancer and metastatic cancer in lymph nodes to illustrate the methods. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Submarine Pipeline Routing Risk Quantitative Analysis

    Institute of Scientific and Technical Information of China (English)

    徐慧; 于莉; 胡云昌; 王金英

    2004-01-01

    A new method for submarine pipeline routing risk quantitative analysis was provided, and the study was developed from qualitative analysis to quantitative analysis.The characteristics of the potential risk of the submarine pipeline system were considered, and grey-mode identification theory was used. The study process was composed of three parts: establishing the indexes system of routing risk quantitative analysis, establishing the model of grey-mode identification for routing risk quantitative analysis, and establishing the standard of mode identification result. It is shown that this model can directly and concisely reflect the hazard degree of the routing through computing example, and prepares the routing selection for the future.

  12. Oxytocin promotes human ethnocentrism.

    Science.gov (United States)

    De Dreu, Carsten K W; Greer, Lindred L; Van Kleef, Gerben A; Shalvi, Shaul; Handgraaf, Michel J J

    2011-01-25

    Human ethnocentrism--the tendency to view one's group as centrally important and superior to other groups--creates intergroup bias that fuels prejudice, xenophobia, and intergroup violence. Grounded in the idea that ethnocentrism also facilitates within-group trust, cooperation, and coordination, we conjecture that ethnocentrism may be modulated by brain oxytocin, a peptide shown to promote cooperation among in-group members. In double-blind, placebo-controlled designs, males self-administered oxytocin or placebo and privately performed computer-guided tasks to gauge different manifestations of ethnocentric in-group favoritism as well as out-group derogation. Experiments 1 and 2 used the Implicit Association Test to assess in-group favoritism and out-group derogation. Experiment 3 used the infrahumanization task to assess the extent to which humans ascribe secondary, uniquely human emotions to their in-group and to an out-group. Experiments 4 and 5 confronted participants with the option to save the life of a larger collective by sacrificing one individual, nominated as in-group or as out-group. Results show that oxytocin creates intergroup bias because oxytocin motivates in-group favoritism and, to a lesser extent, out-group derogation. These findings call into question the view of oxytocin as an indiscriminate "love drug" or "cuddle chemical" and suggest that oxytocin has a role in the emergence of intergroup conflict and violence.

  13. Ethnopoly promotes tolerance

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    On Friday 23 April, 225 primary school children from the eight schools in Meyrin-Cointrin and their accompanying adults took part in a big game of Ethnopoly. Private individuals, associations, administrations, shopkeepers and CERN all opened their doors to them to talk about their countries, their customs and what they are doing to promote tolerance and integration.   The CERN stand set up at ForumMeyrin for the Ethnopoly game. Scurrying from one place to another, the 10 and 11 year olds were made aware of the rich cultural diversity of their commune, which is home to 130 different nationalities. Physicists and engineers from CERN took up residence in the Forum Meyrin for the day in order to talk to the children about the advantages of international collaboration, a subject dear to the Organization's heart. They welcomed around fifty children in the course of the day, conveying to them a message of tolerance: despite their differences, the 10,000 scientists and other members of the CERN...

  14. Network modularity promotes cooperation.

    Science.gov (United States)

    Marcoux, Marianne; Lusseau, David

    2013-05-01

    Cooperation in animals and humans is widely observed even if evolutionary biology theories predict the evolution of selfish individuals. Previous game theory models have shown that cooperation can evolve when the game takes place in a structured population such as a social network because it limits interactions between individuals. Modularity, the natural division of a network into groups, is a key characteristic of all social networks but the influence of this crucial social feature on the evolution of cooperation has never been investigated. Here, we provide novel pieces of evidence that network modularity promotes the evolution of cooperation in 2-person prisoner's dilemma games. By simulating games on social networks of different structures, we show that modularity shapes interactions between individuals favouring the evolution of cooperation. Modularity provides a simple mechanism for the evolution of cooperation without having to invoke complicated mechanisms such as reputation or punishment, or requiring genetic similarity among individuals. Thus, cooperation can evolve over wider social contexts than previously reported.

  15. Artificial Promoters for Metabolic Optimization

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Hammer, Karin

    1998-01-01

    In this article, we review some of the expression systems that are available for Metabolic Control Analysis and Metabolic Engineering, and examine their advantages and disadvantages in different contexts. In a recent approach, artificial promoters for modulating gene expression in micro-organisms......In this article, we review some of the expression systems that are available for Metabolic Control Analysis and Metabolic Engineering, and examine their advantages and disadvantages in different contexts. In a recent approach, artificial promoters for modulating gene expression in micro......-organisms were constructed using synthetic degenerated oligonucleotides. From this work, a promoter library was obtained for Lactococcus lactis, containing numerous individual promoters and covering a wide range of promoter activities. Importantly, the range of promoter activities was covered in small steps...... of activity change. Promoter libraries generated by this approach allow for optimization of gene expression and for experimental control analysis in a wide range of biological systems by choosing from the promoter library promoters giving, e.g., 25%, 50%, 200%, and 400% of the normal expression level...

  16. Finding Signals for Plant Promoters

    Institute of Scientific and Technical Information of China (English)

    Weimou Zheng

    2003-01-01

    The strongest signal of plant promoter is searched with the model of single motif with two types. It turns out that the dominant type is the TATA-box. The other type may be called TATA-less signal, and may be used in gene finders for promoter recognition. While the TATA signals are very close for the monocot and the dicot, their TATA-less signals are significantly different. A general and flexible multi-motif model is also proposed for promoter analysis based on dynamic programming. By extending the Gibbs sampler to the dynamic programming and introducing temperature, an efficient algorithm is developed for searching signals in plant promoters.

  17. Sales promotions and food consumption.

    Science.gov (United States)

    Hawkes, Corinna

    2009-06-01

    Sales promotions are widely used to market food to adults, children, and youth. Yet, in contrast to advertising, practically no attention has been paid to their impacts on dietary behaviors, or to how they may be used more effectively to promote healthy eating. This review explores the available literature on the subject. The objective is to identify if and what literature exists, examine the nature of this literature, and analyze what can be learned from it about the effects of sales promotions on food consumption. The review finds that while sales promotions lead to significant sales increases over the short-term, this does not necessarily lead to changes in food-consumption patterns. Nevertheless, there is evidence from econometric modeling studies indicating that sales promotions can influence consumption patterns by influencing the purchasing choices of consumers and encouraging them to eat more. These effects depend on the characteristics of the food product, sales promotion, and consumer. The complexity of the effects means that sales promotions aiming to encourage consumption of nutritious foods need to be carefully designed. These conclusions are based on studies that use mainly sales data as a proxy for dietary intake. The nutrition (and economics) research communities should add to this existing body of research to provide evidence on the impact of sales promotions on dietary intake and related behaviors. This would help support the development of a sales promotion environment conducive to healthy eating.

  18. Pitfalls of Quantitative Surveys Online

    Directory of Open Access Journals (Sweden)

    Iva Pecáková

    2016-12-01

    Full Text Available With the development of the Internet in the last two decades, its use in all phases of field survey is growing very quickly. Indeed, it reduces costs while allowing exploration of relatively large files and enables effective use of a variety of research tools. The academic research is more reserved towards developing online surveys. Demands on the quality of data are the main cause; Internet surveys do not meet them and thus do not allow drawing objective conclusion about the populations surveyed. Unqualified use of the Internet may significantly influence data and information obtained from their analysis. The problematic definition of the population that is under investigation may result in a fault of its coverage. Its existence can be shown, for example, on a confrontation of the total and Internet population of the Czech Republic, the total and Internet population of the Czech households, etc. Representation of the population through an online panel may cause bias, depending on how the panel is created. A relatively new source of error in an online survey is the existence of “professional” respondents. The sampling method from a population or an online panel can lead to the emergence of such a sample that is not representative and does not allow inference to the population at all, or only in a very limited way. Even probability sampling, however, can be problematic if it is affected by a higher rate of non-responses. The aim of this paper is to summarise the possible sources of bias associated with any sample survey, but also to draw attention to those that are relatively new and are associated with the implementation of just quantitative surveys online.

  19. Traditions and Transitions in Quantitative Societal Culture Research in Organization Studies

    DEFF Research Database (Denmark)

    Peterson, Mark, F.; Søndergaard, Mikael

    2011-01-01

    Quantitative societal culture research (QSCR) in organization studies crystallizes a configuration of social science perspectives and methods that became prominent in the 1970s. We consider the qualities of and boundaries around cultural groups that this tradition emphasizes, and other...... characteristics of cultural groups that it does not emphasize. Current debates surrounding this tradition reflect both recent social science innovations and rediscoveries of early social science perspectives. Our analysis of quantitative cross-cultural societal research in organization studies considers...... this process of crystallization, innovation and rediscovery. We suggest ways to address current controversies and promote conversations with other research approaches....

  20. Quantitative and Qualitative Evaluations of the Enhanced Logo-autobiography Program for Korean-American Women.

    Science.gov (United States)

    Sung, Kyung Mi; Bernstein, Kunsook

    2017-09-05

    This study extends Bernstein et al.'s (2016) investigation of the effects of the Enhanced Logo-autobiography Program on Korean-American women's depressive symptoms, coping strategies, purpose in life, and posttraumatic growth by analyzing quantitative and qualitative data. This study's participants significantly improved on quantitative measures of depression, coping strategies, purpose in life, and post-traumatic growth at eight weeks post-intervention and follow-up. The qualitative content analysis revealed 17 themes with five essential themes. The program's activity to promote purpose in life through posttraumatic growth facilitated participants' recovery from traumatic experiences. Standardized guidelines are needed to conduct this program in Korean community centers.

  1. Quantitative Muscle Ultrasonography in Carpal Tunnel Syndrome.

    Science.gov (United States)

    Lee, Hyewon; Jee, Sungju; Park, Soo Ho; Ahn, Seung-Chan; Im, Juneho; Sohn, Min Kyun

    2016-12-01

    To assess the reliability of quantitative muscle ultrasonography (US) in healthy subjects and to evaluate the correlation between quantitative muscle US findings and electrodiagnostic study results in patients with carpal tunnel syndrome (CTS). The clinical significance of quantitative muscle US in CTS was also assessed. Twenty patients with CTS and 20 age-matched healthy volunteers were recruited. All control and CTS subjects underwent a bilateral median and ulnar nerve conduction study (NCS) and quantitative muscle US. Transverse US images of the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) were obtained to measure muscle cross-sectional area (CSA), thickness, and echo intensity (EI). EI was determined using computer-assisted, grayscale analysis. Inter-rater and intra-rater reliability for quantitative muscle US in control subjects, and differences in muscle thickness, CSA, and EI between the CTS patient and control groups were analyzed. Relationships between quantitative US parameters and electrodiagnostic study results were evaluated. Quantitative muscle US had high inter-rater and intra-rater reliability in the control group. Muscle thickness and CSA were significantly decreased, and EI was significantly increased in the APB of the CTS group (all pquantitative muscle US parameters may be useful for detecting muscle changes in CTS. Further study involving patients with other neuromuscular diseases is needed to evaluate peripheral muscle change using quantitative muscle US.

  2. Quantitative Relationships Involving Additive Differences: Numerical Resilience

    Science.gov (United States)

    Ramful, Ajay; Ho, Siew Yin

    2014-01-01

    This case study describes the ways in which problems involving additive differences with unknown starting quantities, constrain the problem solver in articulating the inherent quantitative relationship. It gives empirical evidence to show how numerical reasoning takes over as a Grade 6 student instantiates the quantitative relation by resorting to…

  3. Development and Measurement of Preschoolers' Quantitative Knowledge

    Science.gov (United States)

    Geary, David C.

    2015-01-01

    The collection of studies in this special issue make an important contribution to our understanding and measurement of the core cognitive and noncognitive factors that influence children's emerging quantitative competencies. The studies also illustrate how the field has matured, from a time when the quantitative competencies of infants and young…

  4. Quantitative analysis of saccadic search strategy

    NARCIS (Netherlands)

    Over, E.A.B.

    2007-01-01

    This thesis deals with the quantitative analysis of saccadic search strategy. The goal of the research presented was twofold: 1) to quantify overall characteristics of fixation location and saccade direction, and 2) to identify search strategies, with the use of a quantitative description of eye mov

  5. Evaluating quantitative research designs: Part 1.

    Science.gov (United States)

    Haughey, B P

    1994-10-01

    This article has provided an overview of the three major types of quantitative designs commonly used in nursing research, as well as some criteria for evaluating the designs of published research. The next column will include additional criteria for critiquing quantitative research designs.

  6. Using Popular Culture to Teach Quantitative Reasoning

    Science.gov (United States)

    Hillyard, Cinnamon

    2007-01-01

    Popular culture provides many opportunities to develop quantitative reasoning. This article describes a junior-level, interdisciplinary, quantitative reasoning course that uses examples from movies, cartoons, television, magazine advertisements, and children's literature. Some benefits from and cautions to using popular culture to teach…

  7. Quantitative analysis of saccadic search strategy

    NARCIS (Netherlands)

    Over, E.A.B.

    2007-01-01

    This thesis deals with the quantitative analysis of saccadic search strategy. The goal of the research presented was twofold: 1) to quantify overall characteristics of fixation location and saccade direction, and 2) to identify search strategies, with the use of a quantitative description of eye

  8. Applying Knowledge of Quantitative Design and Analysis

    Science.gov (United States)

    Baskas, Richard S.

    2011-01-01

    This study compared and contrasted two quantitative scholarly articles in relation to their research designs. Their designs were analyzed by the comparison of research references and research specific vocabulary to describe how various research methods were used. When researching and analyzing quantitative scholarly articles, it is imperative to…

  9. Quantitative Robust Control Engineering: Theory and Applications

    Science.gov (United States)

    2006-09-01

    1992). Discrete quantitative feedback technique, Capítulo 16 en el libro : Digital Control Systems: theory, hardware, software, 2ª edicion. McGraw...Rasmussen S.J., Garcia-Sanz, M. (2001, 2005), Software de diseño del libro Quantitative Feedback Theory: Fundamentals and Applications. Edición 2ª. CRCPress

  10. Development of Quantitative electron nano-diffraction

    NARCIS (Netherlands)

    Kumar, V.

    2009-01-01

    This thesis is a step towards development of quantitative parallel beam electron nano-diffraction (PBED). It is focused on the superstructure determination of zig-zag and zig-zig NaxCoO2 and analysis of charge distribution in the two polymorphs Nb12O29 using PBED. It has been shown that quantitative

  11. Trans activation of plasmid-borne promoters by adenovirus and several herpes group viruses.

    OpenAIRE

    Everett, R D; Dunlop, M

    1984-01-01

    This paper de