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24 result(s) for "Ouafik, L"
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Determination of 5-azacitidine in human plasma by LC–MS/MS: application to pharmacokinetics pilot study in MDS/AML patients
PurposeAzacitidine (Vidaza®, AZA) is a mainstay for treating acute myeloid leukemia (AML) in patients unfit for standard induction and other myelodysplastic syndromes (MDS). However, only half of the patients usually respond to this drug and almost all patients will eventually relapse. Predictive markers for response to AZA are yet to be identified. AZA is metabolized in the liver by a single enzyme, cytidine deaminase (CDA). CDA is a ubiquitous enzyme coded by a highly polymorphic gene, with subsequent great variability in resulting activities in the liver. The quantitative determination of AZA in plasma is challenging due the required sensitivity and because of the instability in the biological matrix upon sampling, possibly resulting in erratic values.MethodsWe have developed and validated following EMA standards a simple, rapid, and cost-effective liquid chromatography–tandem mass spectrometry method for the determination of azacitidine in human plasma.ResultsAfter a simple and rapid precipitation step, analytes were successfully separated and quantitated over a 5–500 ng/mL range. The performance and reliability of this method were tested as part of an investigational study in MDS/AML patients treated with standard azacitidine (75 mg/m2 for 7 days a week every 28 days).ConclusionOverall, this new method meets the requirements of current bioanalytical guidelines and could be used to monitor drug levels in MDS/AML patients.
Plasmatic MMP9 released from tumor-infiltrating neutrophils is predictive for bevacizumab efficacy in glioblastoma patients: an AVAglio ancillary study
We previously identified matrix metalloproteinase 2 (MMP2) and MMP9 plasma levels as candidate biomarkers of bevacizumab activity in patients with recurrent glioblastoma. The aim of this study was to assess the predictive value of MMP2 and MMP9 in a randomized phase III trial in patients with newly diagnosed glioblastoma and to explore their tumor source. In this post hoc analysis of the AVAglio trial (AVAGlio/NCT00943826), plasma samples from 577 patients (bevacizumab, n = 283; placebo, n = 294) were analyzed for plasma MMP9 and MMP2 levels by enzyme-linked immunosorbent assay. A prospective local cohort of 38 patients with newly diagnosed glioblastoma was developed for analysis of tumor characteristics by magnetic resonance imaging and measurement of plasma and tumor levels of MMP9 and MMP2. In this AVAglio study, MMP9, but not MMP2, was correlated with bevacizumab efficacy. Patients with low MMP9 derived a significant 5.2-month overall survival (OS) benefit with bevacizumab (HR 0.51, 95% CI 0.34–0.76, p  = 0.0009; median 13.6 vs. 18.8 months). In multivariate analysis, a significant interaction was seen between treatment and MMP9 ( p  = 0.03) for OS. In the local cohort, we showed that preoperative MMP9 plasma levels decreased after tumor resection and were correlated with tumor levels of MMP9 mRNA ( p  = 0.03). However, plasma MMP9 was not correlated with tumor size, invasive pattern, or angiogenesis. Using immunohistochemistry, we showed that MMP9 was expressed by inflammatory cells but not by tumor cells. After cell sorting, we showed that MMP9 was expressed by CD45+ immune cells. Finally, using flow cytometry, we showed that MMP9 was expressed by tumor-infiltrating neutrophils. In conclusion, circulating MMP9 is predictive of bevacizumab efficacy and is released by tumor-infiltrating neutrophils.
Epstein-Barr virus as a marker of biological aggressiveness in breast cancer
Purpose: Although a potential role of the Epstein-Barr virus (EBV) in the pathogenesis of breast cancer (BC) has been underlined, results remain conflicting. Particularly, the impact of EBV infection on biological markers of BC has received little investigation. Methods: In this study, we established the frequency of EBV-infected BC using real-time quantitative PCR (RT–PCR) in 196 BC specimens. Biological and pathological characteristics according to EBV status were evaluated. Results: EBV DNA was present in 65 of the 196 (33.2%) cases studied. EBV-positive BCs tended to be tumours with a more aggressive phenotype, more frequently oestrogen receptor negative ( P =0.05) and with high histological grade ( P =0.01). Overexpression of thymidine kinase activity was higher in EBV-infected BC ( P =0.007). The presence of EBV was weakly associated with HER2 gene amplification ( P =0.08). Conclusion: Our study provides evidence for EBV-associated BC undergoing distinct carcinogenic processes, with more aggressive features.
Identification of genes differentially expressed in glioblastoma versus pilocytic astrocytoma using Suppression Subtractive Hybridization
Glioblastoma (GBM) is a highly malignant glioma, which has the propensity to infiltrate throughout the brain in contrast to pilocytic astrocytoma (PA) of the posterior fossa, which does not spread and can be cured by surgery. We have used Suppression Subtractive Hybridization to define markers that better delineate the molecular basis of brain invasion and distinguish these tumor groups. We have identified 106 genes expressed in PA versus GBM and 80 genes expressed in GBM versus PA. Subsequent analysis identified a subset of 20 transcripts showing a common differential expression pattern for the two groups. GBM differs from PA by the expression of five genes involved in invasion and angiogenesis: fibronectin, osteopontin, chitinase-3-like-1 (YKL-40), keratoepithelin and fibromodulin. PA differs from GBM by the expression of genes related to metabolism (apolipoprotein D), proteolysis (protease-serine-11), receptor and signal transduction (PLEKHB1 for Pleckstrin-Homology-domain-containing-protein-family-B-member-1), transcription/translation (eukaryotic-translation-elongation-factor-1- α 1) processes and cell adhesion (SPOCK1 for SPARC/Osteonectin-CWCV-kazal-like-domains-proteoglycan). The expression of these genes was confirmed by real-time quantitative RT-PCR and immunohistochemistry. This study highlights the crucial role of brain invasion in GBM and identifies specific molecules involved in this process. In addition, it offers a restricted list of markers that accurately distinguish PA from GBM.
Routine molecular profiling of patients with advanced non-small-cell lung cancer: results of a 1-year nationwide programme of the French Cooperative Thoracic Intergroup (IFCT)
The molecular profiling of patients with advanced non-small-cell lung cancer (NSCLC) for known oncogenic drivers is recommended during routine care. Nationally, however, the feasibility and effects on outcomes of this policy are unknown. We aimed to assess the characteristics, molecular profiles, and clinical outcomes of patients who were screened during a 1-year period by a nationwide programme funded by the French National Cancer Institute. This study included patients with advanced NSCLC, who were routinely screened for EGFR mutations, ALK rearrangements, as well as HER2 (ERBB2), KRAS, BRAF, and PIK3CA mutations by 28 certified regional genetics centres in France. Patients were assessed consecutively during a 1-year period from April, 2012, to April, 2013. We measured the frequency of molecular alterations in the six routinely screened genes, the turnaround time in obtaining molecular results, and patients' clinical outcomes. This study is registered with ClinicalTrials.gov, number NCT01700582. 18 679 molecular analyses of 17 664 patients with NSCLC were done (of patients with known data, median age was 64·5 years [range 18–98], 65% were men, 81% were smokers or former smokers, and 76% had adenocarcinoma). The median interval between the initiation of analysis and provision of the written report was 11 days (IQR 7–16). A genetic alteration was recorded in about 50% of the analyses; EGFR mutations were reported in 1947 (11%) of 17 706 analyses for which data were available, HER2 mutations in 98 (1%) of 11 723, KRAS mutations in 4894 (29%) of 17 001, BRAF mutations in 262 (2%) of 13 906, and PIK3CA mutations in 252 (2%) of 10 678; ALK rearrangements were reported in 388 (5%) of 8134 analyses. The median duration of follow-up at the time of analysis was 24·9 months (95% CI 24·8–25·0). The presence of a genetic alteration affected first-line treatment for 4176 (51%) of 8147 patients and was associated with a significant improvement in the proportion of patients achieving an overall response in first-line treatment (37% [95% CI 34·7–38·2] for presence of a genetic alteration vs 33% [29·5–35·6] for absence of a genetic alteration; p=0·03) and in second-line treatment (17% [15·0–18·8] vs 9% [6·7–11·9]; p<0·0001). Presence of a genetic alteration was also associated with improved first-line progression-free survival (10·0 months [95% CI 9·2–10·7] vs 7·1 months [6·1–7·9]; p<0·0001) and overall survival (16·5 months [15·0–18·3] vs 11·8 months [10·1–13·5]; p<0·0001) compared with absence of a genetic alteration. Routine nationwide molecular profiling of patients with advanced NSCLC is feasible. The frequency of genetic alterations, acceptable turnaround times in obtaining analysis results, and the clinical advantage provided by detection of a genetic alteration suggest that this policy provides a clinical benefit. French National Cancer Institute (INCa).
Energy and greenhouse gas balance of bioenergy production from poplar and willow: a review
Short‐rotation woody crops (SRWC) such as poplar and willow are an important source of renewable energy. They can be converted into electricity and/or heat using conventional or modern biomass technologies. In recent years many studies have examined the energy and greenhouse gas (GHG) balance of bioenergy production from poplar and willow using various approaches. The outcomes of these studies have, however, generated controversy among scientists, policy makers, and the society. This paper reviews 26 studies on energy and GHG balance of bioenergy production from poplar and willow published between 1990 and 2009. The data published in the reviewed literature gave energy ratios (ER) between 13 and 79 for the cradle‐to‐farm gate and between 3 and 16 for cradle‐to‐plant assessments, whereas the intensity of GHG emissions ranged from 0.6 to 10.6 g CO2 Eq MJbiomass−1 and 39 to 132 g CO2 Eq kWh−1. These values vary substantially among the reviewed studies depending on the system boundaries and methodological assumptions. The lack of transparency hampers meaningful comparisons among studies. Although specific numerical results differ, our review revealed a general consensus on two points: SRWC yielded 14.1–85.9 times more energy than coal (ERcoal∼0.9) per unit of fossil energy input, and GHG emissions were 9–161 times lower than those of coal (GHGcoal∼96.8). To help to reduce the substantial variability in results, this review suggests a standardization of the assumptions about methodological issues. Likewise, the development of a widely accepted framework toward a reliable analysis of energy in bioenergy production systems is most needed.
Identification of secondary structure in the 5′-untranslated region of the human adrenomedullin mRNA with implications for the regulation of mRNA translation
Adrenomedullin (AM) is a multifunctional regulatory peptide with important angiogenic and mitogenic properties. Here we identify a region of stable secondary structure in the 5′-untranslated region (5′ UTR) of human AM mRNA. Reverse transcriptase–polymerase chain reaction of the 5′ UTR consistently resulted, in addition to the product with the expected size of 155 base pair (bp), in a second product with an ∼65-bp deletion from the central region of the 5′ UTR, suggesting the presence of a secondary structure. The presence of a stem–loop structure was confirmed by probing the 5′ UTR with RNases with selectivity for single- or double-stranded RNA. We investigated the role of this stem–loop structure in expression of luciferase reporter gene in cultured cell lines. Reporter assays using a chimeric mRNA that combined luciferase and the 5′ UTR of AM mRNA demonstrated a dramatic decrease of the reporter activity owing to a decreased translation, whereas the deletion of the stem–loop structure localized between nt +31 and +95 from the cap site led to the recovery of activity. Gel migration shift assays using cytosolic extracts from mammalian cell lines demonstrate a specific binding of a cytosolic protein to riboprobes containing the 5′ UTR of AM but not to riboprobes either corresponding to other areas of the message or containing the 5′ UTR but lacking the region of secondary structure. Although we conclude that the 5′ UTR of the human AM mRNA can modulate the translation of AM mRNA in vivo , and that the predicted stem–loop structure is necessary for this inhibition, the functional consequences of the cis element-binding activity remain to be determined.
Frequency and genome load of Epstein-Barr virus in 509 breast cancers from different geographical areas
Since the few data exploring a possible association between Epstein–Barr virus (EBV) and breast cancer are conflicting, we investigated this association together with the influences of geographical areas. 509 breast cancers were sampled from areas with varying risks of nasopharynx carcinoma (NPC) such as North Africa (Algeria and Tunisia, high-risk area); southern France (Marseille, intermediate-risk area); and northern Europe (northern France, the Netherlands and Denmark; low-risk areas). Polymerase chain reaction (PCR) of a subregion of EBV BamHIC encoding the EBERs demonstrated that 31.8% of the tumours contained the viral genome. No significant differences were observed among the geographical areas. However, positive samples showed higher loads of the EBV genome in the NPC high- and intermediate-risk areas than in the low-risk areas. EBV type 1 was the dominant strain. In situ hybridization studies using a 35 S-labelled riboprobe for EBER1 and a laser capture microdissection, combined with quantitative PCR, showed that EBV localization was restricted to some tumour epithelial cell clusters. EBV could not be detected in the stroma. Considering the whole population covered, the presence of the EBV genome was not correlated with age, menopausal status, tumour, size, nodal status or histological grade. © 2001 Cancer Research Campaign
Rapid deaminator status is associated with poor clinical outcome in pancreatic cancer patients treated with a gemcitabine-based regimen
Gemcitabine is a mainstay in the treatment of biliary and pancreatic cancers, with limited efficacy in most settings. The gemcitabine elimination pattern is primarily driven by deamination in the liver by CDA. CDA is affected by genetic polymorphisms, leading to marked variations in activity and, subsequently, to erratic drug plasma exposures in patients administered with standard dosage. CDA deficiency has been a rising concern with gemcitabine since several studies have proven that poor metabolizer patients experience life-threatening toxicities upon drug intake. In theory, ultrarapid metabolizer (UM) patients should be conversely at risk of treatment failure, although thus far few studies have addressed this issue in digestive oncology. A pilot study was conducted on 40 pancreatic cancer patients, all treated with gemcitabine-based therapy. CDA status was primarily established on a phenotypic basis determined by measurement of residual CDA enzymatic activity in serum. Additionally, a search for c208G>A and c79A>C polymorphisms was carried out. No patients carrying c208G>A polymorphisms were found, and only heterozygous c79A>C patients were observed. Eight out of the 40 patients (i.e., 20%) were identified as UM, with CDA activities over 6 U/mg. CDA activity was significantly different between progressive disease patients and patients with controlled disease (8.4 vs 3 U/mg; p < 0.001). Conversely, fewer gemcitabine-related severe toxicities were observed in UM patients. This pilot study strongly suggests that UM patients are nearly five-times more likely to have progressive disease than patients with normal or low CDA activities, and that beside molecular events at the tumor level, upstream deregulations affecting drug disposition should be taken into account. Original submitted 12 March 2013; Revision submitted 3 May 2013
RETRACTION: Expression of Adrenomedullin in Human Colorectal Tumors and Its Role in Cell Growth and Invasion In Vitro and in Xenograft Growth In Vivo
RETRACTION: E. Nouguerède, C. Berenguer, S. Garcia, B. Bennani, C. Delfino, I. Nanni, L. Dahan, M. Gasmi, J.‐F. Seitz, P.‐M. Martin and L. Ouafik, “Expression of Adrenomedullin in Human Colorectal Tumors and Its Role in Cell Growth and Invasion In vitro and in Xenograft Growth In Vivo,” Cancer Medicine 2, no. 2 (2013): 196‐207, https://doi.org/10.1002/cam4.51. The above article, published online on 29 January 2013 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the Journal Editor‐in‐Chief, Stephen Tait; and John Wiley & Sons Ltd. The retraction has been agreed due to duplication of elements found between Figure 2i and 2m and also between Figure 2c, 2g, and 2k. The authors provided a replacement Figure 2 to correct the duplications. However, the editors have lost confidence in the data and conclusions presented in this article as well as the new figure provided.