共查询到20条相似文献，搜索用时 31 毫秒
1.
2.
Peilin Jia Quan Wang Qingxia Chen Katherine E Hutchinson William Pao Zhongming Zhao 《Genome biology》2014,15(10)
Many cancer genes form mutation hotspots that disrupt their functional domains or active sites, leading to gain- or loss-of-function. We propose a mutation set enrichment analysis (MSEA) implemented by two novel methods, MSEA-clust and MSEA-domain, to predict cancer genes based on mutation hotspot patterns. MSEA methods are evaluated by both simulated and real cancer data. We find approximately 51% of the eligible known cancer genes form detectable mutation hotspots. Application of MSEA in eight cancers reveals a total of 82 genes with mutation hotspots, including well-studied cancer genes, known cancer genes re-found in new cancer types, and novel cancer genes.
Electronic supplementary material
The online version of this article (doi:10.1186/s13059-014-0489-9) contains supplementary material, which is available to authorized users. 相似文献3.
BackgroundOne of the most important recent findings in cancer genomics is the identification of novel driver mutations which often target genes that regulate genome-wide chromatin and DNA methylation marks. Little is known, however, as to whether these genes exhibit patterns of epigenomic deregulation that transcend cancer types.ResultsHere we conduct an integrative pan-cancer-wide analysis of matched RNA-Seq and DNA methylation data across ten different cancer types. We identify seven tumor suppressor and eleven oncogenic epigenetic enzymes which display patterns of deregulation and association with genome-wide cancer DNA methylation patterns, which are largely independent of cancer type. In doing so, we provide evidence that genome-wide cancer hyper- and hypo- DNA methylation patterns are independent processes, controlled by distinct sets of epigenetic enzyme genes. Using causal network modeling, we predict a number of candidate drivers of cancer DNA hypermethylation and hypomethylation. Finally, we show that the genomic loci whose DNA methylation levels associate most strongly with expression of these putative drivers are highly consistent across cancer types.ConclusionsThis study demonstrates that there exist universal patterns of epigenomic deregulation that transcend cancer types, and that intra-tumor levels of genome-wide DNA hypomethylation and hypermethylation are controlled by distinct processes.
Electronic supplementary material
The online version of this article (doi:10.1186/s13059-015-0699-9) contains supplementary material, which is available to authorized users. 相似文献4.
Cancer is a heterogeneous disease with different combinations of genetic alterations driving its development in different individuals. We introduce CoMEt, an algorithm to identify combinations of alterations that exhibit a pattern of mutual exclusivity across individuals, often observed for alterations in the same pathway. CoMEt includes an exact statistical test for mutual exclusivity and techniques to perform simultaneous analysis of multiple sets of mutually exclusive and subtype-specific alterations. We demonstrate that CoMEt outperforms existing approaches on simulated and real data. We apply CoMEt to five different cancer types, identifying both known cancer genes and pathways, and novel putative cancer genes.
Electronic supplementary material
The online version of this article (doi:10.1186/s13059-015-0700-7) contains supplementary material, which is available to authorized users. 相似文献5.
6.
Jesse D Riordan Luke J Drury Ryan P Smith Benjamin T Brett Laura M Rogers Todd E Scheetz Adam J Dupuy 《BMC genomics》2014,15(1)
Background
Animal models of cancer are useful to generate complementary datasets for comparison to human tumor data. Insertional mutagenesis screens, such as those utilizing the Sleeping Beauty (SB) transposon system, provide a model that recapitulates the spontaneous development and progression of human disease. This approach has been widely used to model a variety of cancers in mice. Comprehensive mutation profiles are generated for individual tumors through amplification of transposon insertion sites followed by high-throughput sequencing. Subsequent statistical analyses identify common insertion sites (CISs), which are predicted to be functionally involved in tumorigenesis. Current methods utilized for SB insertion site analysis have some significant limitations. For one, they do not account for transposon footprints – a class of mutation generated following transposon remobilization. Existing methods also discard quantitative sequence data due to uncertainty regarding the extent to which it accurately reflects mutation abundance within a heterogeneous tumor. Additionally, computational analyses generally assume that all potential insertion sites have an equal probability of being detected under non-selective conditions, an assumption without sufficient relevant data. The goal of our study was to address these potential confounding factors in order to enhance functional interpretation of insertion site data from tumors.Results
We describe here a novel method to detect footprints generated by transposon remobilization, which revealed minimal evidence of positive selection in tumors. We also present extensive characterization data demonstrating an ability to reproducibly assign semi-quantitative information to individual insertion sites within a tumor sample. Finally, we identify apparent biases for detection of inserted transposons in several genomic regions that may lead to the identification of false positive CISs.Conclusion
The information we provide can be used to refine analyses of data from insertional mutagenesis screens, improving functional interpretation of results and facilitating the identification of genes important in cancer development and progression.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-1150) contains supplementary material, which is available to authorized users. 相似文献7.
8.
9.
10.
Background
N-linked protein glycosylation plays an important role in various biological processes, including protein folding and trafficking, and cell adhesion and signaling. The acquisition of a novel N-glycosylation site may have significant effect on protein structure and function, and therefore, on the phenotype.Results
We analyzed the human glycoproteome data set (2,534 N-glycosylation sites in 1,027 proteins) and identified 112 novel N-glycosylation sites in 91 proteins that arose in the human lineage since the last common ancestor of Euarchonta (primates and treeshrews). Three of them, Asn-196 in adipocyte plasma membrane-associated protein (APMAP), Asn-91 in cluster of differentiation 166 (CD166/ALCAM), and Asn-76 in thyroglobulin, are human-specific. Molecular evolutionary analysis suggested that these sites were under positive selection during human evolution. Notably, the Asn-76 of thyroglobulin might be involved in the increased production of thyroid hormones in humans, especially thyroxine (T4), because the removal of the glycan moiety from this site was reported to result in a significant decrease in T4 production.Conclusions
We propose that the novel N-glycosylation sites described in this study may be useful candidates for functional analyses to identify innovative genetic modifications for beneficial phenotypes acquired in the human lineage.Electronic supplementary material
The online version of this article (doi:10.1186/s12859-015-0468-5) contains supplementary material, which is available to authorized users. 相似文献11.
12.
13.
14.
15.
Background
The laying hen model of spontaneous epithelial ovarian cancer (EOC) is unique in that it is the only model that enables observations of early events in disease progression and is therefore also uniquely suited for chemoprevention trials. Previous studies on the effect of dietary flaxseed in laying hens have revealed the potential for both amelioration and prevention of ovarian cancer. The objective of this study was to assess the effect of flaxseed on genes and pathways that are dysregulated in tumors. We have used a bioinformatics approach to identify these genes, followed by qPCR validation, immunohistochemical localization, and in situ hybridization to visualize expression in normal ovaries and tumors from animals fed a control diet or a diet containing 10% flaxseed.Results
Bioinformatic analysis of ovarian tumors in hens led to the identification of a group of highly up-regulated genes that are involved in the embryonic process of branching morphogenesis. Expression of these genes coincides with expression of E-cadherin in the tumor epithelium. Levels of expression of these genes in tumors from flax-fed animals are reduced 40-60%. E-cadherin and miR200 are both up-regulated in tumors from control-fed hens, whereas their expression is decreased 60-75% in tumors from flax-fed hens. This does not appear to be due to an increase in ZEB1 as mRNA levels are increased five-fold in tumors, with no significant difference between control-fed and flax-fed hens.Conclusions
We suggest that nutritional intervention with flaxseed targets the pathways regulating branching morphogenesis and thereby alters the progression of ovarian cancer.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-709) contains supplementary material, which is available to authorized users. 相似文献16.
?zgün Babur Mithat G?nen Bülent Arman Aksoy Nikolaus Schultz Giovanni Ciriello Chris Sander Emek Demir 《Genome biology》2015,16(1)
We present a novel method for the identification of sets of mutually exclusive gene alterations in a given set of genomic profiles. We scan the groups of genes with a common downstream effect on the signaling network, using a mutual exclusivity criterion that ensures that each gene in the group significantly contributes to the mutual exclusivity pattern. We test the method on all available TCGA cancer genomics datasets, and detect multiple previously unreported alterations that show significant mutual exclusivity and are likely to be driver events.
Electronic supplementary material
The online version of this article (doi:10.1186/s13059-015-0612-6) contains supplementary material, which is available to authorized users. 相似文献17.
Duncan Sproul Robert R Kitchen Colm E Nestor J Michael Dixon Andrew H Sims David J Harrison Bernard H Ramsahoye Richard R Meehan 《Genome biology》2012,13(10):R84-16
Background
Aberrant CpG island promoter DNA hypermethylation is frequently observed in cancer and is believed to contribute to tumor progression by silencing the expression of tumor suppressor genes. Previously, we observed that promoter hypermethylation in breast cancer reflects cell lineage rather than tumor progression and occurs at genes that are already repressed in a lineage-specific manner. To investigate the generality of our observation we analyzed the methylation profiles of 1,154 cancers from 7 different tissue types.Results
We find that 1,009 genes are prone to hypermethylation in these 7 types of cancer. Nearly half of these genes varied in their susceptibility to hypermethylation between different cancer types. We show that the expression status of hypermethylation prone genes in the originator tissue determines their propensity to become hypermethylated in cancer; specifically, genes that are normally repressed in a tissue are prone to hypermethylation in cancers derived from that tissue. We also show that the promoter regions of hypermethylation-prone genes are depleted of repetitive elements and that DNA sequence around the same promoters is evolutionarily conserved. We propose that these two characteristics reflect tissue-specific gene promoter architecture regulating the expression of these hypermethylation prone genes in normal tissues.Conclusions
As aberrantly hypermethylated genes are already repressed in pre-cancerous tissue, we suggest that their hypermethylation does not directly contribute to cancer development via silencing. Instead aberrant hypermethylation reflects developmental history and the perturbation of epigenetic mechanisms maintaining these repressed promoters in a hypomethylated state in normal cells. 相似文献18.
19.
Steven H Lin Jing Wang Pierre Saintigny Chia-Chin Wu Uma Giri Jing Zhang Toshi Menju Lixia Diao Lauren Byers John N Weinstein Kevin R Coombes Luc Girard Ritsuko Komaki Ignacio I Wistuba Hiroshi Date John D Minna John V Heymach 《BMC genomics》2014,15(1)