PDGFRA Defines the Mesenchymal Stem Cell Kaposi’s Sarcoma Progenitors by Enabling KSHV Oncogenesis in an Angiogenic Environment [RNA-seq]
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE141866 | GEO | 2019/12/12
REPOSITORIES: GEO
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Project description:Kaposi’s sarcoma (KS) is an AIDS-defining cancer caused by the KS-associated herpesvirus (KSHV). Unanswered questions regarding KS are its cellular ontology and the conditions conducive to viral oncogenesis. We identify PDGFRA(+)/SCA-1(+) bone marrow-derived mesenchymal stem cells (Pα(+)S MSCs) as KS spindle-cell progenitors and found that pro-angiogenic environmental conditions typical of KS are critical for KSHV sarcomagenesis. This is because growth in KS-like conditions generates a de-repressed KSHV epigenome allowing oncogenic KSHV gene expression in infected Pα(+)S MSCs. Furthermore, these growth conditions allow KSHV-infected Pα(+)S MSCs to overcome KSHV-driven oncogene-induced senescence and cell cycle arrest via a PDGFRA-signaling mechanism; thus identifying PDGFRA not only as a phenotypic determinant for KS-progenitors but also as a critical enabler for viral oncogenesis.
2019-12-12 | GSE141844 | GEO
Project description:Kaposi's sarcoma (KS), is an AIDS-associated neoplasm caused by the KS herpesvirus (KSHV/ HHV-8). KSHV-sarcomagenesis is the consequence of oncogenic viral gene expression as well as host genetic and epigenetic alterations. Although KSHV is invariably found in all KS lesions, the percentage of KSHV-infected (LANA+) spindle-cells of the lesion is variable, suggesting the existence of paracrine oncogenic mechanisms and/or spindle cells that have lost KSHV. A mouse model of KSHVBac36-driven tumorigenesis allowed us to induce KSHV-episome loss before and after tumor development. Although cells that lose the KSHV episome prior to tumor formation lose their tumorigenicity, explanted KSHV positive tumor cells that lost the KSHV episome remained tumorigenic. This pointed to the existence of virally-induced irreversible oncogenic alterations occurring during KSHV-tumor formation that support the possibility of hit and run viral sarcomagenesis. RNA sequencing and CpG-methylation analysis were performed on KSHV positive and negative cells, KSHV positive and KSHV negative tumors that developed following KSHV-episome loss from explanted tumor cells. When KSHV positive cells form KSHV-driven tumors, along with viral-gene upregulation there is a tendency for hypo-methylation in genes from oncogenic and differentiation pathways. In contrast, KSHV-negative tumors formed after KSHV-episome loss, show a tendency towards gene hyper-methylation when compared to KSHV-positive tumors. Regarding occurrence of host-mutations, we found the same set of innate-immunity related mutations undetected in KSHV-infected cells but present in all KSHV positive tumors, indicating that pre-existing host mutations that provide an in vivo growth advantage are clonally-selected and contribute to KSHV-tumorigenesis. In addition, KSHV negative tumors display de novo mutations related to cell proliferation that, together with the PDGFRAD842V, were responsible for driving tumorigenesis in absence of the KSHV-episomes. KSHV-induced irreversible genetic and epigenetic oncogenic alterations support the possibility of “hit and run” KSHV-sarcomagenesis consistent with the presence of LANA-negative spindle-cells in KS lesions.
2020-04-16 | GSE148741 | GEO
Project description:Kaposi's sarcoma (KS), is an AIDS-associated neoplasm caused by the KS herpesvirus (KSHV). A mouse model of KSHV-dependent tumorigenicity, allowed us to induce KSHV viral-episome loss following tumor development to test the plausibility of “hit and run” mechanism by KSHV. RNA-seq-transcriptome analysis and CpG-methylation were performed on KSHV positive cells, KSHV positive tumors and tumors that developed following viral-episome loss. During KSHV tumorigenesis, hypo-methylation was detected of oncogenic and differentiation pathways. In contrast, during tumorigenesis following KSHV-episome loss, a tendency towards hyper-methylation was detected. We found the same set of innate-immunity related mutations undetected in KSHV-infected cells but present in all KSHV-positive tumors, indicating that pre-existing host mutations that provide an in vivo growth advantage are clonally-selected and contribute to KSHV-tumorigenesis. We found de novo mutations related to cell proliferation that, together with the PDGFRAD842V, were responsible for driving tumorigenesis in absence of the KSHV-episomes. Virally-induced irreversible genetic and epigenetic oncogenic alteration supports the possibility of “hit and run” KSHV-sarcomagenesis consistent with the existence of LANA-negative spindle-cells in KS lesions.
2020-01-23 | GSE144101 | GEO
Project description:Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi’s sarcoma (KS) and multiple types of B cellmalignancies. Emerging evidence demonstrates that KSHV reprograms host-cell central carbon metabolic pathways, which contributesto viral persistence and tumorigenesis. However, the mechanisms underlying KSHV-mediated metabolic reprogramming remain poorlyunderstood. Carbamoyl-phosphate synthetase 2, aspartate transcarbamoylase, and dihydroorotase (CAD) is a key enzyme of the denovo pyrimidine synthesis, and was recently identified to deamidate the NF-κB subunit RelA to promote aerobic glycolysis and cellproliferation. Here we report that KSHV infection exploits CAD for nucleotide synthesis and glycolysis. Mechanistically, KSHV vCyclin binds to and hijacks cyclin-dependent kinase CDK6 to phosphorylate Ser-1900 on CAD, thereby activating CAD-mediatedpyrimidine synthesis and RelA-deamidation-mediated glycolytic reprogramming. Correspondingly, genetic depletion orpharmacological inhibition of CDK6 and CAD potently impeded KSHV lytic replication and thwarted tumorigenesis of primaryeffusion lymphoma (PEL) cells in vitro and in vivo. Altogether, our work defines a viral metabolic reprogramming mechanismunderpinning KSHV oncogenesis, which may spur the development of new strategies to treat KSHV-associated malignancies and otherdiseases.
2024-02-16 | PXD043435 | Pride
Project description:Purpose: To characterize genome-wide microRNA (miRNA) expression profiles in the context of Kaposi’s sarcoma-associated herpesvirus (KSHV)-induced oncogenesis using isogenic cell lines for a Kaposi's sarcoma (KS) xenograft model: KSHV-infected human endothelial cells (LTC) that form tumors with properties closely resembling KS lesions in nude mice and uninfected parental (TIVE) cells. Methods: miRNA expression profiles of LTC and TIVE cells were generated by deep sequencing using Illumina HiSeq 2500. The mappable reads were aligned to the human genome and miRBase using Bowtie. Results: We show, through global cellular miRNA transcriptome analysis, that KSHV infection has a profound impact on the host miRNA expression landscape, up-regulating multiple miRNAs with oncogenic roles while down-regulating many tumor suppressive miRNAs, thereby contributing to KS oncogenesis. In particular, we identify miR-127-3p as one of the most significantly down-regulated miRNAs in LTC and restoring this miRNA inhibits KSHV-induced transformation, proliferation and tumorigenesis. Conclusions: This study provides a detailed analysis of the cellular miRNA transcriptome in LTC and TIVE cells using small RNA sequencing technology. We identify significant dysregulation of cellular miRNAs with important oncogenic or tumor-suppressive functions that may be physiologically relevant to KSHV oncogenesis. Moreover, our results identify a previously unrecognized tumor suppressor function for miR-127-3p in KS, indicating that its restoration offers potential as a therapeutic intervention for KS.
2021-11-01 | GSE158936 | GEO
Project description:KS lesions consist of endothelial cells latently infected with KSHV which express the KSHV miRNAs. Identifying the targets of the KSHV miRNAs will help us understand their role in viral oncogenesis. Cross-Linking and Sequencing of Hybrids (CLASH) is a method for unambiguously identifying miRNA targetomes. We developed a streamlined version of CLASH, called quick CLASH (qCLASH). qCLASH requires a lower initial input of cells than its parent protocol. Additionally, a new fast-growing KSHV-negative endothelial cell line, named TIVE-EX-LTC cells, was established. qCLASH was performed on TIVE-EX-LTC cells latently infected with WT KSHV or a mutant virus lacking miR-K12-11/11*. A number of novel targets of the KSHV miRNAs were identified, including targets of miR-K12-11, the ortholog of cellular oncomiR miR-155. Many of the miRNA targets were involved in processes related to oncogenesis, such as glycolysis, angiogenesis, and cell cycle control.
2018-01-25 | GSE101978 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. Purpose: Kaposi’s sarcoma (KS)-associated herpesvirus (KSHV) causes several lymphoproliferative disorders, including KS, a common AIDS-associated malignancy. Cellular and viral microRNAs (miRNAs) have been shown to play important roles in regulating the expression of genes in oncogenesis. Herpesviruses, including KSHV, encode for miRNAs that are involved in angiogenesis, inflammation and apoptosis. A better knowledge of the miRNA-mediated pathways that regulate KSHV infection is therefore essential for an improved understanding of viral infection and pathogenesis. Methods: In this study, we used deep sequencing to analyze miRNA, both viral and human, and mRNA expression in KS tumor-derived human cells. Results: This approach revealed 153 differentially expressed human miRNAs between KSHV-positive and -negative cells. Differential expression of eight miRNAs was independently confirmed by qRT-PCR. We additionally showed that a majority (~73%) of KSHV-regulated miRNAs are down-regulated, including most members of the 14q32 miRNA cluster. Specifically, human miR-409-3p, which is known to target the pro-angiogenic growth factor angiogenin and the inflammation marker fibrinogen-beta, was significantly down-regulated in KSHV-infected cells based on deep sequencing and qRT-PCR. Despite this substantial down-regulation of cellular miRNAs, hsa-miR-708-5p was significantly up-regulated by KSHV and has been shown to directly inhibit pro-apoptotic protease Caspase-2. Finally, we evaluated to what extent there was an inverse correlation between miRNA and mRNA expression levels. Using filtered datasets, we identified relevant canonical pathways that were significantly enriched. Conclusion: Taken together, our data demonstrate that most human miRNAs affected by KSHV are repressed and our findings highlight the relevance of studying the post-transcriptional gene regulation of miRNAs for KSHV-associated malignancies.
2015-04-14 | GSE62829 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. Purpose: Kaposi’s sarcoma (KS)-associated herpesvirus (KSHV) causes several lymphoproliferative disorders, including KS, a common AIDS-associated malignancy. Cellular and viral microRNAs (miRNAs) have been shown to play important roles in regulating the expression of genes in oncogenesis. Herpesviruses, including KSHV, encode for miRNAs that are involved in angiogenesis, inflammation and apoptosis. A better knowledge of the miRNA-mediated pathways that regulate KSHV infection is therefore essential for an improved understanding of viral infection and pathogenesis. Methods: In this study, we used deep sequencing to analyze miRNA, both viral and human, and mRNA expression in KS tumor-derived human cells. Results: This approach revealed 153 differentially expressed human miRNAs between KSHV-positive and -negative cells. Differential expression of eight miRNAs was independently confirmed by qRT-PCR. We additionally showed that a majority (~73%) of KSHV-regulated miRNAs are down-regulated, including most members of the 14q32 miRNA cluster. Specifically, human miR-409-3p, which is known to target the pro-angiogenic growth factor angiogenin and the inflammation marker fibrinogen-beta, was significantly down-regulated in KSHV-infected cells based on deep sequencing and qRT-PCR. Despite this substantial down-regulation of cellular miRNAs, hsa-miR-708-5p was significantly up-regulated by KSHV and has been shown to directly inhibit pro-apoptotic protease Caspase-2. Finally, we evaluated to what extent there was an inverse correlation between miRNA and mRNA expression levels. Using filtered datasets, we identified relevant canonical pathways that were significantly enriched. Conclusion: Taken together, our data demonstrate that most human miRNAs affected by KSHV are repressed and our findings highlight the relevance of studying the post-transcriptional gene regulation of miRNAs for KSHV-associated malignancies.
2015-04-14 | GSE62828 | GEO
Project description:Kaposi's sarcoma (KS) may derive from Kaposi's Sarcoma Herpesvirus (KSHV)-infected human Mesenchymal Stem Cells (hMSCs) that migrate to sites characterized by inflammation and angiogenesis, promoting the initiation of KS. By analyzing the RNA sequences of KSHV-infected primary hMSCs, we have identified specific cell subpopulations, mechanisms, and conditions involved in the initial stages of KSHV-induced transformation and reprogramming of hMSCs into KS progenitor cells. Under pro-angiogenic environmental conditions, KSHV can reprogram hMSCs to exhibit gene expression profiles more similar to KS tumors, activating cell cycle progression, cytokine signaling pathways, and endothelial differentiation indicating the involvement of KSHV infection in inducing the Mesenchymal-to-Endothelial (MEndT) transition of hMSCs. This finding underscores the significance of this condition in facilitating KSHV-induced proliferation and reprogramming of hMSCs towards MEndT and closer to KS gene expression profiles, providing further evidence of these cell subpopulations as precursors of KS cells that thrive in a pro-angiogenic environment.
2024-07-08 | GSE260925 | GEO
Project description:Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi’s sarcoma (KS). In sub-Saharan Africa, the high prevalence of both HIV-1 and KSHV has made KS a leading cancer in the region, associated with poor prognosis and high mortality due to late medical presentation and advanced disease stages. A better understanding of the cellular and viral transcriptome profiles during neoplastic growth will aid in the definition of biomarkers and cellular functions associated with KS tumorigenesis and progression. Our approach is to examine the transcriptome profile in actual KS lesions versus non-cancer tissues from the same individual for a total of four male African epidemic KS patients. These patients have undetectable HIV-1 plasma viral load after successful anti-retroviral therapy. Our results capture the cellular complexity of in vivo lesion environment and provide a marked contrast to those derived from in vitro monoculture models. The findings demonstrate that latency and immune modulation related functions dominate the viral gene expression pattern. Moreover, KSHV significantly affected the cellular transcriptome profile with genes involved in lipid and glucose metabolism disorder pathways being the most substantially dysregulated. Despite the implied infiltration of immune cells into the lesions as predicted by CIBERSORT, KS tumor continued to progress, suggesting immunological dysfunction in these KS patients despite control of HIV-1 viremia. Lastly, there is limited overlap of our in vivo dataset with in vitro studies, suggesting a limitation of in vitro KS models.
2018-01-17 | GSE100684 | GEO