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Background: There is increasing evidence that folate, an important component of one-carbon metabolism, modulates the epigenome. Alcohol, which can disrupt folate absorption, is also known to affect the epigenome. We investigated the association of dietary folate and alcohol intake on leukocyte DNA methylation levels in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Leukocyte genome-wide DNA methylation profiles on approximately 450,000 CpG sites were acquired with Illumina HumanMethylation 450K BeadChip measured among 450 women control participants of a case-control study on breast cancer nested within the EPIC cohort. After data preprocessing using surrogate variable analysis to reduce systematic variation, associations of DNA methylation with dietary folate and alcohol intake, assessed with dietary questionnaires, were investigated using CpG site-specific linear models. Specific regions of the methylome were explored using differentially methylated region (DMR) analysis and fused lasso (FL) regressions. The DMR analysis combined results from the feature-specific analysis for a specific chromosome and using distances between features as weights whereas FL regression combined two penalties to encourage sparsity of single features and the difference between two consecutive features. Results: After correction for multiple testing, intake of dietary folate was not associated with methylation level at any DNA methylation site, while weak associations were observed between alcohol intake and methylation level at CpG sites cg03199996 and cg07382687, with q val = 0.029 and q val = 0.048, respectively. Interestingly, the DMR analysis revealed a total of 24 and 90 regions associated with dietary folate and alcohol, respectively. For alcohol intake, 6 of the 15 most significant DMRs were identified through FL. Conclusions: Alcohol intake was associated with methylation levels at two CpG sites. Evidence from DMR and FL analyses indicated that dietary folate and alcohol intake may be associated with genomic regions with tumor suppressor activity such as the GSDMD and HOXA5 genes. These results were in line with the hypothesis that epigenetic mechanisms play a role in the association between folate and alcohol, although further studies are warranted to clarify the importance of these mechanisms in cancer. © 2019 The Author(s).

Pulmonary grade-1 typical (TC) and grade-2 atypical (AC) carcinoids share molecular characteristics with grade-3 large-cell neuroendocrine carcinoma (LCNEC) despite the distinct clinical behaviors. Most carcinoids can be surgically resected, however, limited treatment options exist for metastatic disease, present in 10-23% of TC and 40-50% of AC. Comprehensive genomic studies could help identify better therapeutic opportunities, novel diagnostic markers, and provide insight on the mechanisms responsible for the increased aggressiveness of AC versus TC. Such studies are rare due to the limited availability of suitable material. We have established a multi-center collaboration that has given us access to a unique collection of samples. We have already characterized 40 TC and 60 LCNEC genomes/exomes, and 61 TC, 8 AC and 69 LCNEC trancriptomes (published data). In the present study, we have performed whole-exome and transcriptome sequencing on 20 AC patients. Methylation data from 850K Illumina arrays were also generated for these samples, and for a subset of 20 TC and 20 LCNEC previously mentioned. When comparing the mutational data on AC with that of TC and LCNEC, we have found that similar to TC, AC harbor recurrent alterations in chromatin remodeling genes (such as MEN1 and ARID1A). They also carry alterations in genes involved in other cancer-related pathways (based on STRING), such as cell motility and cell death explaining their more aggressive phenotype. Integrative clustering analysis (MOFA and iCLUSTER) based on expression and methylation data tends to classify carcinoids into four groups: groups 1 and 2 are mostly composed of females with TC, and differ by their age composition and smoking status (Fisher's exact test p=0.008 and 0.03, respectively). Groups 3 and 4 are mostly composed of males with AC (Fisher's exact test for tumor type p=8x10-5). When including the LCNEC data, the samples from group 3 cluster with LCNEC, suggesting that AC can display a variety of expression and methylation patterns that may be linked to aggressiveness. This result was supported by the better survival of groups 1 and 2 compared to groups 3 and 4 (log-rank p=0.02), for which survival was similar to that of patients with LCNEC. Here, we present for the first time: (i) a multi-omics study on AC; (ii) the methylome characterization of TC, AC, and LCNEC; and (iii) the results of a comparative analysis of TC, AC, and LCNEC based on their molecular characteristics. We have identified the genes and pathways that might explain the progression from low-grade TC to intermediate-grade AC. Our expression and methylation data also supports the existence of a “super-AC” group, which clusters with LCNEC. Finally, we have identified a panel of molecular alterations that may help pathologist distinguishing between these three entities. NL and NA contributed equally. LFC and MF jointly supervised this work. Citation Format: Noémie Leblay, Nicolas Alcala, David Hervás Marin, Tiffany M. Delhomme, Théo Giffon, Akram Ghantous, Amélie Chabrier, Cyrille Cuenin, Janine Altmueller, Geoffroy Durand, Catherine Voegele, Philippe Lorimier, Anne-Claire Toffart, Jules Derks, Odd Terje Brustugun, Joachim H. Clement, Joerg Saenger, John K. Field, Alex Soltermann, Gavin M. Wright, Luca Roz, Lucia Anna Muscarella, Paolo Graziano, Zdenko Herceg, Ernst-Jan Speel, Peter Nuernberg, James McKay, Nicolas Girard, Sylvie Lantuejoul, Juan Sandoval, Elisabeth Brambilla, Matthieu Foll, Lynnette Fernandez-Cuesta. Multi-omics comparative analyses of pulmonary typical carcinoids, atypical carcinoids, and large-cell neuroendocrine carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5358.

Cell-free circulating DNA isolated from the plasma of individuals with cancer has been shown to harbor cancer-associated changes in DNA methylation, and thus it represents an attractive target for biomarker discovery. However, the reliable detection of DNA methylation changes in body fluids has proven to be technically challenging. Here we describe a novel combination of methods that allows quantitative and sensitive detection of DNA methylation in minute amounts of DNA present in body fluids (quantitative Methylation Analysis of Minute DNA amounts after whole Bisulfitome Amplification, qMAMBA). This method involves genome-wide amplification of bisulphite-modified DNA template followed by quantitative methylation detection using pyrosequencing and allows analysis of multiple genes from a small amount of starting DNA. To validate our method we used qMAMBA assays for four genes and LINE1 repetitive sequences combined with plasma DNA samples as a model system. qMAMBA offered high efficacy in the analysis of methylation levels and patterns in plasma samples with extremely small amounts of DNA and low concentrations of methylated alleles. Therefore, qMAMBA will facilitate methylation studies aiming to discover epigenetic biomarkers, and should prove particularly valuable in profiling a large sample series of body fluids from molecular epidemiology studies as well as in tracking disease in early diagnostics.

Background: Pelvic actinomycosis is a chronic granulomatous suppurative disease caused by an anaerobic Gram positive organism Actinomyces israelii usually associated with intra-uterine devices. Pelvic actinomycosis can mimick pelvic or intra-abdominal malignancy leading to mutilating surgical exeresis. Results: We present a pelvic actinomycosis secondary to long-standing intra-uterine device use in a 50-year old European woman treated by intravenous antibiotic therapy, and then by a total abdominal hysterectomy and bilateral salpingoophorectomy to free the pelvis from abscess. We point out the difficulty in diagnosis, and the importance of high-dose intravenous antibiotic therapy to reduce the very high risk for nearby pelvic structure injuries, reported in the literature, leading to post-operative morbidity.

Cancers of the upper aerodigestive tract (UADT) are common forms of malignancy associated with tobacco and alcohol exposures, although human papillomavirus and nutritional deficiency are also important risk factors. While somatically acquired DNA methylation changes have been associated with UADT cancers, what triggers these events and precise epigenetic targets are poorly understood. In this study, we applied quantitative profiling of DNA methylation states in a panel of cancer-associated genes to a case-control study of UADT cancers. Our analyses revealed a high frequency of aberrant hypermethylation of several genes, including MYOD1, CHRNA3 and MTHFR in UADT tumors, whereas CDKN2A was moderately hypermethylated. Among differentially methylated genes, we identified a new gene (the nicotinic acetycholine receptor gene) as target of aberrant hypermethylation in UADT cancers, suggesting that epigenetic deregulation of nicotinic acetycholine receptors in non-neuronal tissues may promote the development of UADT cancers. Importantly, we found that sex and age is strongly associated with the methylation states, whereas tobacco smoking and alcohol intake may also influence the methylation levels in specific genes. This study identifies aberrant DNA methylation patterns in UADT cancers and suggests a potential mechanism by which environmental factors may deregulate key cellular genes involved in tumor suppression and contribute to UADT cancers. © 2012 Landes Bioscience.

Nicotinic acetylcholine receptor (nAChR) genes form a highly conserved gene cluster at the lung cancer susceptibility locus 15q25.1. In this study, we show that the CHRNα3 gene encoding the nAChRα3 subunit is a frequent target of aberrant DNA hypermethylation and silencing in lung cancer, whereas the adjacent CHRNβ4 and CHRNα5 genes exhibit moderate and no methylation, respectively. Treatment of cancer cells exhibiting CHRNα3 hypermethylation with DNA methylation inhibitors caused demethylation of the CHRNα3 promoter and gene reactivation. Restoring CHRNα3 levels through ectopic expression induced apoptotic cell death. Small hairpin RNA–mediated depletion of nAChRα3 in CHRNα3-expressing lung cancer cells elicited a dramatic Ca2+ influx response in the presence of nicotine, followed by activation of the Akt survival pathway. CHRNα3-depleted cells were resistant to apoptosis-inducing agents, underscoring the importance of epigenetic silencing of the CHRNα3 gene in human cancer. In defining a mechanism of epigenetic control of nAChR expression in nonneuronal tissues, our findings offer a functional link between susceptibility locus 15q25.1 and lung cancer, and suggest nAChRs to be theranostic targets for cancer detection and chemoprevention. Cancer Res; 70(7); 2779–88

The global increase in lung cancer burden, together with its poor survival and resistance to classical chemotherapy, underscores the need for identification of critical molecular events involved in lung carcinogenesis. Here, we have applied quantitative profiling of DNA methylation states in a panel of five cancer-associated genes (CDH1, CDKN2A, GSTP1, MTHFR, and RASSF1A) to a large case-control study of lung cancer. Our analyses revealed a high frequency of aberrant hypermethylation of MTHFR, RASSF1A, and CDKN2A in lung tumors as compared with control blood samples, whereas no significant increase in methylation levels of GSTP1 and CDH1 was observed, consistent with the notion that aberrant DNA methylation occurs in a tumor-specific and gene-specific manner. Importantly, we found that tobacco smoking, sex, and alcohol intake had a strong influence on the methylation levels of distinct genes (RASSF1A and MTHFR), whereas folate intake, age, and histologic subtype had no significant influence on methylation states. We observed a strong association between MTHFR hypermethylation in lung cancer and tobacco smoking, whereas methylation levels of CDH1, CDKN2A, GSTP1, and RASSF1A were not associated with smoking, indicating that tobacco smoke targets specific genes for hypermethylation. We also found that methylation levels in RASSF1A, but not the other genes under study, were influenced by sex, with males showing higher levels of methylation. Together, this study identifies aberrant DNA methylation patterns in lung cancer and thus exemplifies the mechanism by which environmental factors may interact with key genes involved in tumor suppression and contribute to lung cancer. [Cancer Res 2009;69(1):243–52]

Reproductive factors have been linked to both breast cancer and DNA methylation, suggesting methylation as an important mechanism by which reproductive factors impact on disease risk. However, few studies have investigated the link between reproductive factors and DNA methylation in humans. Genome-wide methylation in peripheral blood lymphocytes of 376 healthy women from the prospective EPIC study was investigated using LUminometric Methylation Assay (LUMA). Also, methylation of 458877 CpG sites was additionally investigated in an independent group of 332 participants of the EPIC-Italy sub-cohort, using the Infinium HumanMethylation 450 BeadChip. Multivariate logistic regression and linear models were used to investigate the association between reproductive risk factors and genome wide and CpG-specific DNA methylation, respectively. Menarcheal age was inversely associated with global DNA methylation as measured with LUMA. For each yearly increase in age at menarche, the risk of having genome wide methylation below median level was increased by 32% (OR:1.32, 95%CI:1.14-1.53). When age at menarche was treated as a categorical variable, there was an inverse dose-response relationship with LUMA methylation levels (OR(12-14 vs. ≤11 yrs):1.78, 95%CI:1.01-3.17 and OR(≥15 vs. ≤11 yrs):4.59, 95%CI:2.04-10.33; P for trend

The DOK1 gene is a putative tumour suppressor gene located on the human chromosome 2p13 which is frequently rearranged in leukaemia and other human tumours. We previously reported that the DOK1 gene can be mutated and its expression down-regulated in human malignancies. However, the mechanism underlying DOK1 silencing remains largely unknown. We show here that unscheduled silencing of DOK1 expression through aberrant hypermethylation is a frequent event in a variety of human malignancies. DOK1 was found to be silenced in nine head and neck cancer (HNC) cell lines studied and DOK1 CpG hypermethylation correlated with loss of gene expression in these cells. DOK1 expression could be restored via demethylating treatment using 5-aza-2'deoxycytidine. In addition, transduction of cancer cell lines with DOK1 impaired their proliferation, consistent with the critical role of epigenetic silencing of DOK1 in the development and maintenance of malignant cells. We further observed that DOK1 hypermethylation occurs frequently in a variety of primary human neoplasm including solid tumours (93% in HNC, 81% in lung cancer) and haematopoietic malignancy (64% in Burkitt's lymphoma). Control blood samples and exfoliated mouth epithelial cells from healthy individuals showed a low level of DOK1 methylation, suggesting that DOK1 hypermethylation is a tumour specific event. Finally, an inverse correlation was observed between the level of DOK1 gene methylation and its expression in tumour and adjacent non tumour tissues. Thus, hypermethylation of DOK1 is a potentially critical event in human carcinogenesis, and may be a potential cancer biomarker and an attractive target for epigenetic-based therapy. Copyright © 2011 UICC.

Udgivelsesdato: 2009-May-24 Cell-free circulating DNA isolated from the plasma of individuals with cancer has been shown to harbor cancer-associated changes in DNA methylation, and thus it represents an attractive target for biomarker discovery. However, the reliable detection of DNA methylation changes in body fluids has proven to be technically challenging. Here we describe a novel combination of methods that allows quantitative and sensitive detection of DNA methylation in minute amounts of DNA present in body fluids (quantitative Methylation Analysis of Minute DNA amounts after whole Bisulfitome Amplification, qMAMBA). This method involves genome-wide amplification of bisulphite-modified DNA template followed by quantitative methylation detection using pyrosequencing and allows analysis of multiple genes from a small amount of starting DNA. To validate our method we used qMAMBA assays for four genes and LINE1 repetitive sequences combined with plasma DNA samples as a model system. qMAMBA offered high efficacy in the analysis of methylation levels and patterns in plasma samples with extremely small amounts of DNA and low concentrations of methylated alleles. Therefore, qMAMBA will facilitate methylation studies aiming to discover epigenetic biomarkers, and should prove particularly valuable in profiling a large sample series of body fluids from molecular epidemiology studies as well as in tracking disease in early diagnostics.