Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma (KS), a vascular cancer commonly found in AIDS patients. Despite extensive studies, the mechanism of KSHV-induced cellular transformation and tumorigenesis remains undefined. This critical gap of knowledge has impeded the development of effective intervention measures. We have shown that KSHV can efficiently infect and transform primary rat embryonic metanephric mesenchymal precursor cells (MM). KSHV-infected MM (KMM) induce KS-like tumors in nude mice. Using reverse genetics, we have found that a cluster of 10 KSHV pre-microRNAs (pre-miRs) is required for KSHV-induced cellular transformation and tumorigenesis. Encouraged by these findings, we have recently made significant progresses in infecting and transforming human primary cells with KSHV. Specifically, we have found that KSHV can also infect, immortalize and transform human primary mesenchymal stem cells (MSC), the human version of MM. This collaborative application between the University of Southern California and Nanjing Medical University proposes to extend these exciting paradigm-shifting discoveries with the objective to refine the MSC model, and use both the MM and MSC models to identify the specific miRs that mediate KSHV cellular transformation and tumorigenesis, and define the essential cellular genes and pathways that are targeted by these miRs. Based on our preliminary results, we have formulated a working hypothesis that KSHV can infect and transform MSC, and specific KSHV miRs manipulate essential cell growth and survival pathways, contributing critically to KSHV-induced cellular transformation and tumorigenesis. Therefore, the proposed project will refine the model of KSHV cellular transformation of human primary MSC (Aim 1);determine the contribution of individual viral pre-miRs and miRs to KSHV-induced cellular transformation and tumorigenesis by genetic complementation (Aim 2);determine the effect of individual viral pre-miRs and miRs on cellular transformation, and identify those that regulate cell growth, survival, angiogenesis and invasion (Aim 3);and delineate the mechanism of viral miRs- mediated KSHV-induced cellular transformation and tumorigenesis by identifying the essential direct targets (Aim 4). This collaborative project takes advantage of the expertise of the US and China laboratories. These works are significant and innovative because they will, for the first time, show that KSHV can truly transform human primary cells, define the functions and mechanisms of action of KSHV miRs in cellular transformation and tumorigenesis, and identify potential novel targets for developing innovative prognostic and therapeutic approaches. The study will also establish a novel paradigm of oncogenesis mediated by viral subversion of the miR pathway, thus providing insights into the oncogenesis of other cancers.

Public Health Relevance

Kaposi's sarcoma is a common malignancy in AIDS patients in US, China, and worldwide inflicting morbidity and mortality to the society. This project will investigate the mechanism underlining the development of Kaposi's sarcoma, and identify potential targets for the prevention and treatment of this disease.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Research Project (R01)
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Special Emphasis Panel (ZCA1)
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Read-Connole, Elizabeth Lee
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University of Southern California
Schools of Medicine
Los Angeles
United States
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Li, Wan; Jia, Xuemei; Shen, Chenyou et al. (2016) A KSHV microRNA enhances viral latency and induces angiogenesis by targeting GRK2 to activate the CXCR2/AKT pathway. Oncotarget 7:32286-305
Cheng, Fan; He, Meilan; Jung, Jae U et al. (2016) Suppression of Kaposi's Sarcoma-Associated Herpesvirus Infection and Replication by 5'-AMP-Activated Protein Kinase. J Virol 90:6515-25
Lee, Myung-Shin; Yuan, Hongfeng; Jeon, Hyungtaek et al. (2016) Human Mesenchymal Stem Cells of Diverse Origins Support Persistent Infection with Kaposi's Sarcoma-Associated Herpesvirus and Manifest Distinct Angiogenic, Invasive, and Transforming Phenotypes. MBio 7:e02109-15
Yao, Shuihong; Hu, Minmin; Hao, Tingting et al. (2015) MiRNA-891a-5p mediates HIV-1 Tat and KSHV Orf-K1 synergistic induction of angiogenesis by activating NF-κB signaling. Nucleic Acids Res 43:9362-78
Zhang, Junjie; Zhu, Lining; Lu, Xiaolu et al. (2015) Recombinant Murine Gamma Herpesvirus 68 Carrying KSHV G Protein-Coupled Receptor Induces Angiogenic Lesions in Mice. PLoS Pathog 11:e1005001
Brulois, Kevin; Wong, Lai-Yee; Lee, Hye-Ra et al. (2015) Association of Kaposi's Sarcoma-Associated Herpesvirus ORF31 with ORF34 and ORF24 Is Critical for Late Gene Expression. J Virol 89:6148-54
Cheng, Fan; Sawant, Tanvee Vinod; Lan, Ke et al. (2015) Screening of the Human Kinome Identifies MSK1/2-CREB1 as an Essential Pathway Mediating Kaposi's Sarcoma-Associated Herpesvirus Lytic Replication during Primary Infection. J Virol 89:9262-80
Hu, Minmin; Wang, Cong; Li, Wan et al. (2015) A KSHV microRNA Directly Targets G Protein-Coupled Receptor Kinase 2 to Promote the Migration and Invasion of Endothelial Cells by Inducing CXCR2 and Activating AKT Signaling. PLoS Pathog 11:e1005171
Bai, Zhiqiang; Huang, Yufei; Li, Wan et al. (2014) Genomewide mapping and screening of Kaposi's sarcoma-associated herpesvirus (KSHV) 3' untranslated regions identify bicistronic and polycistronic viral transcripts as frequent targets of KSHV microRNAs. J Virol 88:377-92
Brulois, Kevin; Toth, Zsolt; Wong, Lai-Yee et al. (2014) Kaposi's sarcoma-associated herpesvirus K3 and K5 ubiquitin E3 ligases have stage-specific immune evasion roles during lytic replication. J Virol 88:9335-49

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