Identification of human endogenous retroviruses working as enhancers in cancer cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE141141 | GEO | 2020/09/29
REPOSITORIES: GEO
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Project description:Purpose: In an HIV cure setting, Vorinostat may provide the “shock” capable of flushing HIV out of the persistent reservoir, while antiretroviral therapy is used to prevent new infections. However, this drug may modulate the expression of human endogenous retroviruses (HERVs). This study demonstrates significant modulation of HERVs and suggests that they should be considered as off-target effects of this drug treatment. Methods: Peripheral blood mononuclear cells were collected from 4 healthy donors. Naive CD4 T cells were isolated and utilized to assess HERV dysregulation after treatment with Vorinostat. Cells were collected for study and exposed to a dose of Vorinostat (10uM dose over a 24 hour period). After this, RNA was extracted from cells and their untreated paired counterparts for deep sequencing by Expression Analysis. Sequence reads that passed quality filters were mapped to the HERVd reference database using Bowtie and counted using HTSeq. Any HERV which did not achieve at least 1 count per million mapped and counted reads in at least 4 samples was discarded. Differential expression was performed upon the filtered dataset with edgeR and using TMM normalization. Results: Using an custom built data analysis pipeline, ~100 million reads per sample were mapped to the HERVd reference database and identified 10784 distinct dysregulated elements Bowtie/HTSeq workflow. Differential expression analysis was performed between vorinostat treated and untreated conditions which demonstrated 2102 dysregulated HERV elements with 1007 downregulated and 1095 upregulated (FDR < 0.05) with EdgeR. Results were further subset with a log2FC ± 3 which resulted in 451 upregulated and 363 downregulated HERV elements from 81 and 82 distinct families respectively. HERV elements from the LTR12 family were by far the most dramatically upregulated in family frequency and fold change magnitude. Further confirmation with droplet digital PCR confirmed upregulation of LTR12 elements and demonstrated an exponential dose response curve with HERV expression found at even moderate doses (334nM) of vorinostat treatment. Conclusions: This study represents the first detailed analysis of HERV dysregulation following vorinostat treatment using the untargeted approach of total RNA-Seq. These results demonstrate that vorinostat dysregulates multiple HERV families with a propensity to upregulate members of the LTR12 HERV family. This study also provides a methodology to analyze HERV dysregulation in future treatments with vorinostat or other drugs by providing a mechanism to choose primer and probe sets which will properly represent HERV dysregulation as expression across an HERV is not uniform or continuous. Finally, this work suggests that HERV dysregulation by vorinostat treatment should be considered an off-target effect of this drug and HERV elements, such as LTR12, should be monitored as biomarkers during shock and kill clinical trials with HDAC inhibitors and that trial subjects should be screened to explore further HIV:HERV interactions.
2018-05-01 | GSE102187 | GEO
Project description:Chronic lymphocytic leukemia (CLL) is one of the most diagnosed forms of leukemia worldwide and it is usually classified into two forms: indolent and aggressive. These two forms are characterized by distinct molecular features that drive different responses to treatment and clinical outcomes. In this context, a better understanding of the molecular landscape of the CLL forms may potentially lead to the development of new drugs or the identification of novel biomarkers. Human Endogenous Retroviruses (HERVs) are a class of transposable elements that have been associated with the development of different human cancers, including different forms of leukemias. However, no studies about HERVs in CLL have ever been reported so far. Here, we present the first locus-specific profiling of HERV expression in both the aggressive and indolent forms of CLL. Our analyses revealed several dysregulations in HERV expression occurring in CLL and some of them were specific for either the aggressive or indolent form of CLL. Such results were also validated by analyzing an external cohort of CLL patients and by RT-qPCR. Moreover, in-silico analyses have shown relevant signaling pathways associated with them suggesting a potential involvement of the dysregulated HERVs in these pathways and consequently in CLL development.
2024-04-17 | GSE233157 | GEO
Project description:Human endogenous retroviruses (HERVs) occupy a large portion of the human genome. Most HERVs are transcriptionally silent, but can be reactivated during pathological states such as viral infection and certain cancers. The HERV-K HML-2 clade includes elements that recently have integrated in the human germ line and often contain intact open reading frames (ORFs) that possibly support peptide and protein expression. Understanding HERV-K-host interactions and their potential as biomarkers is problematic due to the high similarity among different elements. Previously we described a long-read single molecule real-time sequencing (PacBio) strategy to analyze HERV-K RNA expression profiles in different cell types. However, identifying HERV-K HML-2 proteins accurately is difficult without robust and reliable methods and reagents. Here we present a new approach to characterize the HML-2 elements that (a) are being translated and (b) produce enough protein to be detected and identified by mass spectrometry. Our data reveal that RNA expression profiling alone cannot accurately predict which HML-2 elements are responsible for protein production, as we observe several differences between the highest expressed RNAs and the elements that are the predominant source of HERV-K HML-2 protein synthesis. These studies represent an important advance towards untangling the complexity of HERV-K-host interactions.
2025-01-08 | GSE283037 | GEO
Project description:Human endogenous retroviruses (HERVs) have received much attention for their implications in the etiology of many human diseases and their profound effect on evolution. Notably, recent studies have highlighted associations between HERVs expression and cancers [1], autoimmunity [2] and neurological [3] conditions. Their repetitive nature makes their study particularly challenging, where expression studies have largely focused on individual loci [4] or general trends within families [5, 6, 7]. To refine our understanding of HERVs activity, we introduce here a new microarray, HERV-V3, that offers an almost complete coverage of HERVs and their ancestors (mammalian apparent LTR-retrotransposons, MALRs) at the locus level. This was made possible by the careful detection and annotation of genomic HERVs/MALRs sequences as well as the development of a new hybridization model, allowing the optimization of probe performances and the control of cross-reactions. Although no gold standard in HERVs measurement exists to validate the array, HERV-V3 analytical performances were comparable to commercial Affymetrix arrays, and for a selection of tissue/pathological specific loci, the patterns of expression found on HERV-V3 were consistent with those reported in the literature.
2016-09-21 | GSE87134 | GEO
Project description:Human endogenous retroviruses (HERVs/MaLRs) are distributed among our 24 chromosomes and their long terminal repeats (LTRs) constitute putative regulatory sequences. HERVs have received much attention for their implication in cancer, autoimmunity and placental development. Herein, we used a recently described high-density microarray allowing the exploration of the whole HERVs/MaLRs transcriptome including 353,994 HERVs/MaLRs loci and also 1559 genes related to immunity. We obtained a first view of the HERV transcriptome in peripheral blood mononuclear cells (PBMCs) by using a composite panel of unstimulated, low dose and high dose LPS-stimulated PBMCs from healthy volunteers to mimic inflammatory response or monocyte anergy. About 5.6% of the HERVs/MaLRs repertoire is transcribed in PBMCs. Roughly, one tenth [5.7%-13.1%] of LTRs present a constitutive promoter or polyA function and a quarter [19.5%-27.6%] of LTRs may shift from silent to active LTRs, LTRs being broadly subjected to operational determinism. We provide evidence that some HERVs/MaLRs and genes share similar control of regulation upon LPS stimulation conditions, e.g. presenting a low dose LPS-dependent “tolerizable” profile which can be reversed by INF-g stimulation. Similarly to tissue tropism observed in solid tumors, stimulus-dependent response confirm that the expression of HERVs is tightly regulated in PBMCs. Altogether, these observations allow to integrate 62 HERVs/MaLRs and 26 genes in 11 canonical pathways. We highlight HERVs close to OAS2/3 and IFI44/IFI44L genes. HERV incorporation at the crossroads of immune response pathways, paves the way for further functional studies and analyses of HERV transcriptome in altered immune responses in vivo such as in sepsis.
2018-06-25 | GSE108239 | GEO
Project description:Background: The human genome consists of considerable portions derived from retroviruses inherited for millions of years. So-called human endogenous retroviruses (HERVs) are usually severely mutated, yet some coding-competent HERVs exist. The HERV-K(HML-2) group includes evolutionarily young proviruses that still encode typical retroviral proteins. HERV-K(HML-2) has been implicated in various human diseases because transcription is often upregulated and some of the encoded proteins are known to affect cell biology. HERV-K(HML-2) Protease (Pro) has received little attention so far, although it appears expressed in some disease contexts and other retroviral proteases are known to process cellular proteins. Results: We set out to identify human cellular proteins being substrates of HERV-K(HML-2) Pro employing a modified Terminal Amine Isotopic Labeling of Substrates (TAILS) procedure. Thousands of human proteins were identified as significantly processed by HERV-K(HML-2) Pro. Identified proteins locate to various cellular compartments and participate in diverse, often disease-relevant cellular processes. We verified cleavage of a majority of selected human proteins in vitro and in vivo. Conclusions: Hundreds, if not thousands of cellular proteins are potential substrates of HERV-K(HML-2) Pro. It is conceivable that even low-level expression of HERV-K(HML-2) Pro has a functional impact on cell biology and thus relevance for human diseases. Specific studies will be required to elucidate effects of HERV-K(HML-2) Pro expression regarding human substrate proteins, cell biology and disease. Endogenous retrovirus-encoded Pro activity may also be relevant for disease development in species other than human.
2019-09-02 | PXD013296 | Pride
Project description:Human Endogenous Retroviruses (HERVs) are exogenous viral elements that integrated into the germline millions of years ago. They comprise 8% of the human genome and play a critical role in cellular differentiation during development. HERV-K(HML-2) is the most recently integrated and actively transcribed HERV. It is found to be highly expressed in pluripotent stem cells and strongly downregulated during cellular differentiation. Moreover, expression of HERV-K in terminally differentiated neurons results in cytotoxicity. Expression of HERVs has been implicated in carcinogenesis and is suggested to confer stem cell like features important for cell growth. Atypical Teratoid / Rhabdoid Tumor (AT/RT) is a rare pediatric brain cancer that results from incomplete neuronal differentiation during embryonic development. In this paper, we investigated the cytopathic effect of Ouabain, a cardiac glycoside that induces cytotoxicity in stem cells, on AT/RT cells. We characterized four AT/RT cell lines by immunostaining and observed variable levels of stem cell, Oct4 and Pax6, and neuronal differentiation markers, TUBB3 and MAP2, as well as HERV-K envelope (env), polymerase (pol), and gag transcripts. We stained formalin-fixed brain tissues from 20 AT/RT patients and 5 unaffected controls for HERV-K ENV protein expression. 40% of AT/RT patient tissues showed ENV expression. In contrast, no ENV immunostaining was observed in all 5 control brain tissues. We used Ouabain, known to be cytotoxic to stem cells, observed up to 50% toxicity at 24 hr and 80% toxicity at 48 hr after treatment. While AT/RT primarily exist as large cell aggregates in suspension, Ouabain treatment downregulated HERV-K ENV protein and caused disruption of cell-to-cell interactions. Similarly, when AT/RT cells were transfected with a CRISPR/Cas9 construct designed to repress HERV-K promotor activity, cell aggregates separated and cell viability decreased significantly. Using a luciferase reporter construct under the control of a HERV-K promotor, we observed a significant decrease in HERV-K promotor activity at 8 to 72 hr post treatment with 0.5 uM Ouabain. Given that downregulation of HERV-K alone was sufficient to cause cytotoxicity in the cells, HERV-K expression may be essential for AT/RT growth and survival. Ouabain and other compounds that modulate HERV expression may provide an alternative or adjunctive therapeutic option for treatment of embryonal tumors.
2021-06-28 | GSE124210 | GEO
Project description:Neutrophil elastase (NE) is implicated in pulmonary arterial hypertension (PAH) but the role of neutrophils in the pathogenesis of PAH is unclear. Here we show that neutrophils from PAH vs. control subjects produce and release increased NE associated with enhanced extracellular trap formation. PAH neutrophils are highly adherent and show decreased migration consistent with increased vinculin, identified on proteomic analysis and previously linked to an antiviral response. This was substantiated by a transcriptomic interferon signature in PAH neutrophils and an increase in human endogenous retrovirus (HERV-K) envelope protein. NE and interferon genes are induced by HERV-K envelope and vinculin is increased by HERV-K dUTPase that is elevated in PAH plasma. Neutrophil exosomes from PAH plasma contain increased NE and HERV-K envelope and induce pulmonary hypertension in mice, that is mitigated by the NE inhibitor and antiviral agent, elafin. Thus elevated HERVs explain pathological neutrophils linked to PAH induction and progression.
2023-03-11 | PXD023134 | Pride
Project description:Background: Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. To date, no biomarker has shown sufficient evidence and ease of application in clinical routine to monitor the complexity of the sepsis-related immune alterations. Multiple levels of interaction of human endogenous retroviruses (HERVs) with the immune response led us to hypothesize that they may be relevant candidates both to contribute to the physiopathology of sepsis and to be part of a molecular signature. In this study, we used a recently described high-density microarray which allows exploring HERVs/MaLRs transcriptome in septic shock patients. Results: About 6.9% of the HERVs/MalRs repertoire is transcribed in whole blood. Concerning the functionality of LTRs, the majority of LTRs are silent (62.9%), 7.5% of LTRs present a putative constitutive promoter or polyA functions, while 20.4% of them may shift from silent to active. Evidence was given that a subset of HERVs/MaLRs and genes were modulated in septic shock patients according to the monocyte HLA-DR (mHLA-DR) expression level measured by flow cytometry, as a proxy of immunosuppression. We then identified a large signature consisting of 193 differentially expressed HERVs/MaLRs probesets further reduced to a smaller 10 HERVs/MaLRs signature. Both signatures, validated in an independent septic shock cohort, identified two groups of patients with different severity features including clinical criteria and the CD74 and CX3CR1 sepsis severity molecular markers. Conclusion: This microarray-based approach unveiled the expression of about 87,912 distinct HERV probesets and identified 764 putative promoter LTRs and 642 putative polyA LTRs in whole blood. HERV/MaLR expression was shown to be tightly modulated in septic shock patients according to mHLA-DR expression. We identified a set of potential molecular biomarkers in septic shock patients partially overlapping immunosuppression (mHLA-DR), and the risk of Health Care associated Infections (HAI) (CD74 ratio), complementary to existing molecular markers of a sepsis patients stratification. We identified a HERV/MaLR signature discriminating patients based on their immunosuppression state and severity.
2020-03-30 | GSE121349 | GEO
Project description:Background: Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. To date, no biomarker has shown sufficient evidence and ease of application in clinical routine to monitor the complexity of the sepsis-related immune alterations. Multiple levels of interaction of human endogenous retroviruses (HERVs) with the immune response led us to hypothesize that they may be relevant candidates both to contribute to the physiopathology of sepsis and to be part of a molecular signature. In this study, we used a recently described high-density microarray which allows exploring HERVs/MaLRs transcriptome in septic shock patients. Results: About 6.9% of the HERVs/MalRs repertoire is transcribed in whole blood. Concerning the functionality of LTRs, the majority of LTRs are silent (62.9%), 7.5% of LTRs present a putative constitutive promoter or polyA functions, while 20.4% of them may shift from silent to active. Evidence was given that a subset of HERVs/MaLRs and genes were modulated in septic shock patients according to the monocyte HLA-DR (mHLA-DR) expression level measured by flow cytometry, as a proxy of immunosuppression. We then identified a large signature consisting of 193 differentially expressed HERVs/MaLRs probesets further reduced to a smaller 10 HERVs/MaLRs signature. Both signatures, validated in an independent septic shock cohort, identified two groups of patients with different severity features including clinical criteria and the CD74 and CX3CR1 sepsis severity molecular markers. Conclusion: This microarray-based approach unveiled the expression of about 87,912 distinct HERV probesets and identified 764 putative promoter LTRs and 642 putative polyA LTRs in whole blood. HERV/MaLR expression was shown to be tightly modulated in septic shock patients according to mHLA-DR expression. We identified a set of potential molecular biomarkers in septic shock patients partially overlapping immunosuppression (mHLA-DR), and the risk of Health Care associated Infections (HAI) (CD74 ratio), complementary to existing molecular markers of a sepsis patients stratification. We identified a HERV/MaLR signature discriminating patients based on their immunosuppression state and severity.
2020-03-30 | GSE121350 | GEO