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.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA177377-01
Application #
8546896
Study Section
Special Emphasis Panel (ZCA1-SRLB-1 (M1))
Program Officer
Read-Connole, Elizabeth Lee
Project Start
2013-09-01
Project End
2016-08-31
Budget Start
2013-09-01
Budget End
2014-08-31
Support Year
1
Fiscal Year
2013
Total Cost
$200,052
Indirect Cost
$78,130
Name
University of Southern California
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
072933393
City
Los Angeles
State
CA
Country
United States
Zip Code
90089
Liang, Deguang; Hu, Hao; Li, Shasha et al. (2014) Oncogenic herpesvirus KSHV Hijacks BMP-Smad1-Id signaling to promote tumorigenesis. PLoS Pathog 10:e1004253
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
Yan, Qin; Ma, Xinting; Shen, Chenyou et al. (2014) Inhibition of Kaposi's sarcoma-associated herpesvirus lytic replication by HIV-1 Nef and cellular microRNA hsa-miR-1258. J Virol 88:4987-5000
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
Zhu, Ying; Huang, Yufei; Jung, Jae U et al. (2014) Viral miRNA targeting of bicistronic and polycistronic transcripts. Curr Opin Virol 7:66-72
Jones, Tiffany; Ramos da Silva, Suzane; Bedolla, Roble et al. (2014) Viral cyclin promotes KSHV-induced cellular transformation and tumorigenesis by overriding contact inhibition. Cell Cycle 13:845-58
Li, Qiuhua; He, Meilan; Zhou, Fuchun et al. (2014) Activation of Kaposi's sarcoma-associated herpesvirus (KSHV) by inhibitors of class III histone deacetylases: identification of sirtuin 1 as a regulator of the KSHV life cycle. J Virol 88:6355-67
Lee, Myung-Shin; Jones, Tiffany; Song, Dae-Yong et al. (2014) Exploitation of the complement system by oncogenic Kaposi's sarcoma-associated herpesvirus for cell survival and persistent infection. PLoS Pathog 10:e1004412