Widespread transposable element-driven oncogene expression in cancers
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE113946 | GEO | 2019/02/05
REPOSITORIES: GEO
Similar Datasets
Project description:Widespread transposable element-driven oncogene expression in cancers
| PRJNA454575 | ENA
Project description:Transposable elements (TEs) are an abundant and rich genetic resource of regulatory sequences1-3. Cryptic regulatory elements within TEs can be epigenetically reactivated in cancer to influence oncogenesis in a process termed onco-exaptation4. However, the prevalence and impact of TE onco-exaptation events across cancer types are poorly characterized. Here, we analyzed 7,769 tumors and 625 normal datasets from 15 cancer types, identifying 129 TE cryptic promoter-activation events involving 106 oncogenes across 3,864 tumors. Furthermore, we interrogated the AluJb-LIN28B candidate: the genetic deletion of the TE eliminated oncogene expression, while dynamic DNA methylation modulated promoter activity, illustrating the necessity and sufficiency of a TE for oncogene activation. Collectively, our results characterize the global profile of TE onco-exaptation and highlight this prevalent phenomenon as an important mechanism for promiscuous oncogene activation and ultimately tumorigenesis.
| S-EPMC6443099 | biostudies-literature
Project description:Cryptic promoters within transposable elements (TEs) are transcriptionally reactivated in tumors to create novel TE-gene chimeric transcripts, which can produce immunogenic antigens. We performed the most comprehensive screen to date for these TE exaptation events in 33 TCGA tumor types, 675 cancer cell lines, and 11,686 GTEx adult tissue transcriptomes and identified 1,068 TE-exapted candidates with the potential to generate shared tumor-specific TE-chimeric antigens (TS-TEAs). Resultant whole lysate and HLA-pulldown mass spectrometry data confirmed that TS-TEAs are presented on cancer cell surfaces. In addition, we highlight the tumor-specific membrane proteins transcribed from TE promoters that can expose novel epitopes on the extracellular surface of cancer cells. Here, we showcase the high pan-cancer prevalence of TS-TEAs and atypical membrane proteins that can be therapeutically exploited through immunotherapy approaches.
2023-01-21 | PXD033351 | Pride
Project description:We charted the transcription start sites (TSSs) landscape globally to determine the expressed isoform of each gene and validate the precence of transposable element-derived transcript. Cryptic promoters within transposable elements (TEs) are transcriptionally reactivated in tumors to create novel TE-gene chimeric transcripts, which can produce immunogenic antigens. We performed the most comprehensive screen to date for these TE exaptation events in 33 TCGA tumortypes,675 cancer cell lines, and 11,686 GTEx adult tissue transcriptomes and identified 201,068 TE-exapted candidates with the potential to generate shared tumor-specific TE-chimeric antigens (TS-TEAs). Resultant whole lysate and HLA-pull down mass spectrometry data confirmed that TS-TEAs are presented on cancer cell surfaces. In addition, we highlight the tumor-specific membrane proteins transcribed from TE promoters that can expose novel epitopes on the extracellular surface of cancer cells. Here, we showcase the high pan-cancer prevalence of TS-TEAs and atypical membrane proteins that can be therapeutically exploited through immunotherapy approaches.
2023-01-20 | GSE201021 | GEO
Project description:PIWI proteins and PIWI-interacting RNAs (piRNAs) are part of a cellular pathway that has evolved to protect genomes against the proliferation of transposable elements (TEs). PIWIs and piRNAs assemble into complexes that are involved in epigenetic and post-transcriptional repression of TEs. Most of our understanding of the mechanisms of piRNA-mediated TE silencing comes from fruit fly and mouse models. However, even in these well-studied animals it is unclear how piRNA responses relate to variable TE expression and whether the strength of the piRNA response affects TE content over time. Here, we assessed the evolutionary interactions between TE and piRNAs in a statistical framework using three nonmodel laurasiatherian mammals as a study system: dog, horse, and a vesper bat. These three species diverged ?80 million years ago and have distinct genomic TE contents. By comparing species with distinct TE landscapes, we aimed to identify clear relationships among TE content, expression, and piRNAs. We found that the TE subfamilies that are the most transcribed appear to elicit the strongest "ping-pong" response. This was most evident among long interspersed elements, but the relationships between expression and ping-pong pilRNA (piRNA-like) expression were more complex among SINEs. SINE transcripts were equally abundant in the dog and horse yet new SINE insertions were relatively rare in the horse genome, where we identified a stronger piRNA response. Our analyses suggest that the piRNA response can have a strong impact on the TE composition of a genome. However, our results also suggest that the presence of a robust piRNA response is apparently not sufficient to stop TE mobilization and accumulation.
| S-EPMC4898795 | biostudies-literature
Project description:Background: The small RNAs that Transposable Elements generate are vastly different when they are transcriptionally silenced compared to when they are transcriptionally activated. We performed the deep sequencing of small RNAs in a number of small RNA biogenesis mutants in both Transposable Element-silenced and Transposable Element-active epigenome backgrounds. Results: We found that Transposable Elements generate large amounts of 21-22nt siRNAs only when they are transcriptionally active. These 21-22nt siRNAs are incorporated into the AGO6 protein. Conclusion: Ago6 is the key protein that bridges the post-transcriptional degradation of Transposable Element mRNAs and the establishment of DNA methylation. Examination of flower bud small RNAs from wild type and 5 single or double mutant combinations, many of which have biological replicates. In addition, IP purification of the AGO6 protein (and mock no-antigen controls) followed by sequencing of the incorporated small RNAs. Replicate A for Col and ddm1 are submitted in GSE41755
2014-11-14 | E-GEOD-57191 | biostudies-arrayexpress
Project description:The Dbl family of proteins represents a large group of proto-oncogenes involved in cell growth regulation. Alterations of the normal function of these proteins lead to pathological processes such as developmental disorders and neoplastic transformation. We have generated transgenic mice introducing the onco-Dbl cDNA sequences linked to the metallothionein promoter into the germ line of FVB mice and found that onco-Dbl expression affected proliferation, migration and differentiation of lens epithelial cells. We used high density oligonucleotide microarray to define the transcriptional profile induced by Dbl in the lenses of transgenic mice and observed modulation of genes encoding proteins promoting epithelial-mesenchymal transition (EMT). Moreover, genes encoding proteins involved in the positive regulation of apoptosis were markedly down regulated while anti-apoptotic genes were strongly up-regulated. Finally, several genes encoding proteins involved in the process of angiogenesis were up-regulated. These observations were validated by histological and immunohistochemical examination of the transgenic lenses, where vascularization can be readily observed. Thus, onco-Dbl expression in mouse lenses induces disruption of the lens architecture, epithelial cell proliferation, EMT, evasion from cell death, and aberrant angiogenesis. Whole lenses were removed from 2, 14, and 42 day old Dbl transgenic and wild type mice. 4 to 8 individual lenses were pooled . Three independent pools from each time and condition were used as replicates.
2009-06-01 | E-GEOD-15694 | biostudies-arrayexpress
Project description:Most common methods for inferring transposable element (TE) evolutionary relationships are based on dividing TEs into subfamilies using shared diagnostic nucleotides. Although originally justified based on the "master gene" model of TE evolution, computational and experimental work indicates that many of the subfamilies generated by these methods contain multiple source elements. This implies that subfamily-based methods give an incomplete picture of TE relationships. Studies on selection, functional exaptation, and predictions of horizontal transfer may all be affected. Here, we develop a Bayesian method for inferring TE ancestry that gives the probability that each sequence was replicative, its frequency of replication, and the probability that each extant TE sequence came from each possible ancestral sequence. Applying our method to 986 members of the newly-discovered LAVA family of TEs, we show that there were far more source elements in the history of LAVA expansion than subfamilies identified using the CoSeg subfamily-classification program. We also identify multiple replicative elements in the AluSc subfamily in humans. Our results strongly indicate that a reassessment of subfamily structures is necessary to obtain accurate estimates of mutation processes, phylogenetic relationships and historical times of activity.
| S-EPMC4133154 | biostudies-literature
Project description:Hybridization is a natural phenomenon that has been linked in several organismal groups to transposable element derepression and copy number amplification. A noteworthy example involves three diploid annual sunflower species from North America that have arisen via ancient hybridization between the same two parental taxa, Helianthus annuus and H. petiolaris. The genomes of the hybrid species have undergone large-scale increases in genome size attributable to long terminal repeat (LTR) retrotransposon proliferation. The parental species that gave rise to the hybrid taxa are widely distributed, often sympatric, and contemporary hybridization between them is common. Natural H. annuus × H. petiolaris hybrid populations likely served as source populations from which the hybrid species arose and, as such, represent excellent natural experiments for examining the potential role of hybridization in transposable element derepression and proliferation in this group. In the current report, we examine multiple H. annuus × H. petiolaris hybrid populations for evidence of genome expansion, LTR retrotransposon copy number increases, and LTR retrotransposon transcriptional activity. We demonstrate that genome expansion and LTR retrotransposon proliferation are rare in contemporary hybrid populations, despite independent proliferation events that took place in the genomes of the ancient hybrid species. Interestingly, LTR retrotransposon lineages that proliferated in the hybrid species genomes remain transcriptionally active in hybrid and nonhybrid genotypes across the entire sampling area. The finding of transcriptional activity but not copy number increases in hybrid genotypes suggests that proliferation and genome expansion in contemporary hybrid populations may be mitigated by posttranscriptional mechanisms of repression.
| S-EPMC3048363 | biostudies-literature
Project description:The Dbl family of proteins represents a large group of proto-oncogenes involved in cell growth regulation. Alterations of the normal function of these proteins lead to pathological processes such as developmental disorders and neoplastic transformation. We have generated transgenic mice introducing the onco-Dbl cDNA sequences linked to the metallothionein promoter into the germ line of FVB mice and found that onco-Dbl expression affected proliferation, migration and differentiation of lens epithelial cells. We used high density oligonucleotide microarray to define the transcriptional profile induced by Dbl in the lenses of transgenic mice and observed modulation of genes encoding proteins promoting epithelial-mesenchymal transition (EMT). Moreover, genes encoding proteins involved in the positive regulation of apoptosis were markedly down regulated while anti-apoptotic genes were strongly up-regulated. Finally, several genes encoding proteins involved in the process of angiogenesis were up-regulated. These observations were validated by histological and immunohistochemical examination of the transgenic lenses, where vascularization can be readily observed. Thus, onco-Dbl expression in mouse lenses induces disruption of the lens architecture, epithelial cell proliferation, EMT, evasion from cell death, and aberrant angiogenesis.
2009-06-01 | GSE15694 | GEO