scholarly journals Global CpG DNA Methylation Footprint in Kaposi’s Sarcoma

Author(s):  
Guy Journo ◽  
Anuj Ahuja ◽  
David Dias-Polak ◽  
Yonatan Eran ◽  
Reuven Bergman ◽  
...  

Kaposi’s sarcoma-associated herpesvirus (KSHV), also familiar as human herpesvirus 8 (HHV-8), is one of the well-known human cancer-causing viruses. KSHV was originally discovered by its association with Kaposi’s sarcoma (KS), a common AIDS-related neoplasia. Additionally, KSHV is associated with two B-lymphocyte disorders; primary effusion lymphoma (PEL) and Multicentric Castlemans Disease (MCD). DNA methylation is an epigenetic modification that is essential for a properly functioning human genome through its roles in chromatin structure maintenance, chromosome stability and transcription regulation. Genomic studies show that expressed promoters tend to be un-methylated whereas methylated promoters tend to be inactive. We have previously revealed the global methylation footprint in PEL cells and found that many cellular gene promoters become differentially methylated and hence differentially expressed in KSHV chronically infected PEL cell lines. Here we present the cellular CpG DNA methylation footprint in KS, the most common malignancy associated with KSHV. We performed MethylationEPIC BeadChip to compare the global methylation status in normal skin compared to KS biopsies, and revealed dramatic global methylation alterations occurring in KS. Many of these changes were attributed to hyper-methylation of promoters and enhancers that regulate genes associated with abnormal skin morphology, a well-known hallmark of KS development. We observed six-fold increase in hypo-methylated CpGs between early stage of KS (plaque) and the more progressed stage (nodule). These observations suggest that hyper-methylation takes place early in KS while hypo-methylation is a later process that is more significant in nodule. Our findings add another layer to the understanding of the relationship between epigenetic changes caused by KSHV infection and tumorigenesis.

2003 ◽  
Vol 77 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Mark Cannon ◽  
Nicola J. Philpott ◽  
Ethel Cesarman

ABSTRACT Kaposi's sarcoma-associated herpesvirus (KSHV/human herpesvirus 8 [HHV-8]) is a gamma-2-herpesvirus responsible for Kaposi's sarcoma as well as primary effusion lymphoma (PEL). KSHV is a lymphotropic virus that has pirated many mammalian genes involved in inflammation, cell cycle control, and angiogenesis. Among these is the early lytic viral G protein-coupled receptor (vGPCR), a homologue of the human interleukin-8 (IL-8) receptor. When expressed, vGPCR is constitutively active and can signal via mitogen- and stress-activated kinases. In certain models it activates the transcriptional potential of NF-κB and activator protein 1 (AP-1) and induces vascular endothelial growth factor (VEGF) production. Despite its importance to the pathogenesis of all KSHV-mediated disease, little is known about vGPCR activity in hematopoietic cells. To study the signaling potential and downstream effects of vGPCR in such cells, we have developed PEL cell lines that express vGPCR under the control of an inducible promoter. The sequences required for tetracycline-mediated induction were cloned into a plasmid containing adeno-associated virus type 2 elements to enhance integration efficiency. This novel plasmid permitted studies of vGPCR activity in naturally infected KSHV-positive lymphocytes. We show that vGPCR activates ERK-2 and p38 in PEL cells. In addition, it increases the transcription of reporter genes under the control of AP-1, NF-κB, CREB, and NFAT, a Ca2+-dependent transcription factor important to KSHV lytic gene expression. vGPCR also increases the transcription of KSHV open reading frames 50 and 57, thereby displaying broad potential to affect viral transcription patterns. Finally, vGPCR signaling results in increased PEL cell elaboration of KSHV vIL-6 and VEGF, two growth factors involved in KSHV-mediated disease pathogenesis.


2002 ◽  
Vol 76 (5) ◽  
pp. 2551-2556 ◽  
Author(s):  
Isabelle Widmer ◽  
Marion Wernli ◽  
Felix Bachmann ◽  
Fred Gudat ◽  
Gieri Cathomas ◽  
...  

ABSTRACT Expression of human herpesvirus 8 viral Bcl-2 protein was demonstrated in spindle cells of late-stage Kaposi's sarcoma lesions but not in primary effusion lymphoma cell lines. In contrast, strong expression of human Bcl-2 was found in stimulated primary effusion lymphoma cells, whereas in Kaposi's sarcoma lesions preferential mononuclear cells, and to a lesser extent spindle cells, stained positive.


Blood ◽  
1999 ◽  
Vol 93 (12) ◽  
pp. 4034-4043 ◽  
Author(s):  
Yoshiyasu Aoki ◽  
Elaine S. Jaffe ◽  
Yuan Chang ◽  
Karen Jones ◽  
Julie Teruya-Feldstein ◽  
...  

Kaposi’s sarcoma-associated herpesvirus (KSHV; also known as human herpesvirus 8 [HHV-8]) is a herpesvirus linked to the development of Kaposi’s sarcoma (KS), primary effusion lymphoma, and a proportion of Castleman’s disease. KSHV encodes viral interleukin-6 (vIL-6), which is structurally homologous to human and murine IL-6. The biological activities of vIL-6 are largely unknown. To gain insight into the biology of vIL-6, we expressed vIL-6 in murine fibroblasts NIH3T3 cells and inoculated stable vIL-6–producing clones into athymic mice. vIL-6 was detected selectively in the blood of mice injected with vIL-6–expressing clones. Compared with controls, vIL-6–positive mice displayed increased hematopoiesis in the myeloid, erythroid, and megakaryocytic lineages; plasmacytosis in spleen and lymph nodes; hepatosplenomegaly; and polyclonal hypergammaglobulinemia. vIL-6–expressing NIH3T3 cells gave rise to tumors more rapidly than did control cells, and vIL-6–positive tumors were more vascularized than controls. Vascular endothelial growth factor (VEGF) was detected at higher levels in the culture supernatant of vIL-6–expressing cells compared with controls, and immunohistochemical staining detected VEGF in spleen, lymph nodes, and tumor tissues from mice bearing vIL-6–producing tumors but not control tumors. Thus, vIL-6 is a multifunctional cytokine that promotes hematopoiesis, plasmacytosis, and angiogenesis. Through these functions, vIL-6 may play an important role in the pathogenesis of certain KSHV-associated disorders.


2001 ◽  
Vol 75 (1) ◽  
pp. 429-438 ◽  
Author(s):  
Carmen Rivas ◽  
Ai-En Thlick ◽  
Carlo Parravicini ◽  
Patrick S. Moore ◽  
Yuan Chang

ABSTRACT Kaposi's sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8, is associated with three proliferative diseases ranging from viral cytokine-induced hyperplasia to monoclonal neoplasia: multicentric Castleman's disease (CD), Kaposi's sarcoma (KS), and primary effusion lymphoma (PEL). Here we report a new latency-associated 1,704-bp KSHV spliced gene belonging to a cluster of KSHV sequences having homology to the interferon regulatory factor (IRF) family of transcription factors. ORFK10.5 encodes a protein, latency-associated nuclear antigen 2 (LANA2), which is expressed in KSHV-infected hematopoietic tissues, including PEL and CD but not KS lesions. LANA2 is abundantly expressed in the nuclei of cultured KSHV-infected B cells. Transcription of K10.5 in PEL cell cultures is not inhibited by DNA polymerase inhibitors nor significantly induced by phorbol ester treatment. Unlike LANA1, LANA2 does not elicit a serologic response from patients with KS, PEL, or CD as measured by Western blot hybridization. Both KSHV vIRF1 (ORFK9) and LANA2 (ORFK10.5) appear to have arisen through gene duplication of a captured cellular IRF gene. LANA2 is a potent inhibitor of p53-induced transcription in reporter assays. LANA2 antagonizes apoptosis due to p53 overexpression in p53-null SAOS-2 cells and apoptosis due to doxorubicin treatment of wild-type p53 U2OS cells. While LANA2 specifically interacts with amino acids 290 to 393 of p53 in glutathione S-transferase pull-down assays, we were unable to demonstrate LANA2-p53 interaction in vivo by immunoprecipitation. These findings show that KSHV has tissue-specific latent gene expression programs and identify a new latent protein which may contribute to KSHV tumorigenesis in hematopoietic tissues via p53 inhibition.


2001 ◽  
Vol 75 (2) ◽  
pp. 891-902 ◽  
Author(s):  
Richard G. Jenner ◽  
M. Mar Albà ◽  
Chris Boshoff ◽  
Paul Kellam

ABSTRACT Kaposi's sarcoma-associated herpesvirus (KSHV; human herpesvirus 8) is associated with three human tumors, Kaposi's sarcoma, primary effusion lymphoma (PEL), and multicentric Castleman's disease. KSHV encodes a number of homologs of cellular proteins involved in the cell cycle, signal transduction, and modulation of the host immune response. Of the virus complement of over 85 open reading frames (ORFs), the expression of only a minority has been characterized individually. We have constructed a nylon membrane-based DNA array which allows the expression of almost every ORF of KSHV to be measured simultaneously. A PEL-derived cell line, BC-3, was used to study the expression of KSHV during latency and after the induction of lytic replication. Cluster analysis, which arranges genes according to their expression profile, revealed a correlation between expression and assigned gene function that is consistent with the known stages of the herpesvirus life cycle. Furthermore, latent and lytic genes thought to be functionally related cluster into groups. The correlation between gene expression and function also infers possible roles for KSHV genes yet to be characterized.


Blood ◽  
1999 ◽  
Vol 93 (12) ◽  
pp. 4034-4043 ◽  
Author(s):  
Yoshiyasu Aoki ◽  
Elaine S. Jaffe ◽  
Yuan Chang ◽  
Karen Jones ◽  
Julie Teruya-Feldstein ◽  
...  

Abstract Kaposi’s sarcoma-associated herpesvirus (KSHV; also known as human herpesvirus 8 [HHV-8]) is a herpesvirus linked to the development of Kaposi’s sarcoma (KS), primary effusion lymphoma, and a proportion of Castleman’s disease. KSHV encodes viral interleukin-6 (vIL-6), which is structurally homologous to human and murine IL-6. The biological activities of vIL-6 are largely unknown. To gain insight into the biology of vIL-6, we expressed vIL-6 in murine fibroblasts NIH3T3 cells and inoculated stable vIL-6–producing clones into athymic mice. vIL-6 was detected selectively in the blood of mice injected with vIL-6–expressing clones. Compared with controls, vIL-6–positive mice displayed increased hematopoiesis in the myeloid, erythroid, and megakaryocytic lineages; plasmacytosis in spleen and lymph nodes; hepatosplenomegaly; and polyclonal hypergammaglobulinemia. vIL-6–expressing NIH3T3 cells gave rise to tumors more rapidly than did control cells, and vIL-6–positive tumors were more vascularized than controls. Vascular endothelial growth factor (VEGF) was detected at higher levels in the culture supernatant of vIL-6–expressing cells compared with controls, and immunohistochemical staining detected VEGF in spleen, lymph nodes, and tumor tissues from mice bearing vIL-6–producing tumors but not control tumors. Thus, vIL-6 is a multifunctional cytokine that promotes hematopoiesis, plasmacytosis, and angiogenesis. Through these functions, vIL-6 may play an important role in the pathogenesis of certain KSHV-associated disorders.


2007 ◽  
Vol 88 (6) ◽  
pp. 1698-1707 ◽  
Author(s):  
Linding Wang ◽  
Melanie M. Brinkmann ◽  
Marcel Pietrek ◽  
Matthias Ottinger ◽  
Oliver Dittrich-Breiholz ◽  
...  

Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 is the causative agent of Kaposi's sarcoma, primary effusion lymphoma and the plasma-cell variant of multicentric Castleman's disease. Its alternatively spliced K15 gene encodes several membrane proteins with varying numbers of transmembrane domains. Two highly diverged alleles of the K15 gene, termed predominant (P) and minor (M), exist and share only 33 % amino acid identity with one another, but retain conserved putative src homology (SH) 2- and SH3-binding motifs. K15-M is thought to have entered the KSHV genome as the result of recombination with a related γ 2-herpesvirus. The more common K15-P allele has been shown to activate the mitogen-activated protein kinases Erk2 and JNK1 and the nuclear factor κB (NF-κB) pathway. To explore possible functional differences between K15-P and K15-M that might have influenced their spread in the KSHV population, here, the ability of the M form of K15 to activate these pathways was investigated. Similarly to K15-P, K15-M induces the activation of the Erk2 and JNK1 kinases, the NF-κB transcription factor and the expression of a similar range of cellular inflammatory genes, as assessed by gene-expression microarray studies and reporter assays. In epithelial cells, the activation of most K15-M target genes is impaired by mutagenesis of Y490 in its SH2-binding motif Y490EEV, although this motif appears less important in endothelial cells. Therefore, K15-M and K15-P can trigger similar intracellular signalling pathways, despite their extensive sequence divergence.


2001 ◽  
Vol 75 (10) ◽  
pp. 4843-4853 ◽  
Author(s):  
Mini Paulose-Murphy ◽  
Nguyen-Khoi Ha ◽  
Chunsheng Xiang ◽  
Yidong Chen ◽  
Laura Gillim ◽  
...  

ABSTRACT Human herpesvirus 8 (HHV-8), a gammaherpesvirus implicated in Kaposi's sarcoma, primary effusion lymphoma, and Castleman's disease, encodes several pathogenically important cellular homologs. To define the HHV-8 transcription program, RNA obtained from latently infected body cavity-based lymphoma 1 cells induced to undergo lytic replication was used to query a custom HHV-8 DNA microarray containing nearly every known viral open reading frame. The patterns of viral gene expression offer insights into the replication and pathogenic strategies of HHV-8.


F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 740 ◽  
Author(s):  
Nathan J. Dissinger ◽  
Blossom Damania

Kaposi’s sarcoma (KS)-associated herpesvirus (KSHV) is an oncogenic human herpesvirus. KSHV is associated with three cancers in the human population: KS, primary effusion lymphoma (PEL), and multicentric Castleman’s disease (MCD). KS is the leading cause of cancer in HIV-infected individuals. In this review, we discuss the most recent discoveries behind the mechanisms of KSHV latency maintenance and lytic replication. We also review current therapies for KSHV-associated cancers.


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