Kaposi's sarcoma (KS) is a multifocal tumor characterized by proliferating spindle cells of endothelial cell origin, erythrocyte-filled neovascular slits and an inflammatory cell infiltrate. KS is the most frequent cancer arising in HIV-infected individuals and is one of the most common neoplasms of children in developing countries. Kaposi's sarcoma-associated herpesvirus (KSHV or HHV-8) is the etiologic agent of KS, and drives tumor development via direct infection of lesional endothelial and spindle cells. Dermal microvascular endothelial cells (DMVEC) infected with KSHV in vitro harbor a primarily latent infection with a fraction of cells expressing lytic viral genes, a pattern that reflects viral gene expression patterns in vivo. KSHV-infected DMVEC develop a spindle morphology and a transformed phenotype and cellular gene expression profiling reveals viral induction of a number of potentially tumorigenic genes. One of these genes, the proto-oncogene c-Kit, was shown to play an essential role in DMVEC transformation in vitro and a preliminary analysis of KS tissue confirmed expression of c-Kit in KS tumors in vivo. The long-term goals of this project are to clarify the scope and temporal kinetics of c-Kit expression in KS tumors, and to clarify the viral and cellular mechanisms that lead to c-Kit expression and c-Kit-mediated cellular transformation.
Specific Aim 1 will use immunohistochemical and RT-PCR analysis to evaluate c-Kit expression in KS tumor tissue at early (patch and plaque) through late (nodular) stages of development in conjunction with serologic detection of latent or lytic KSHV infection.
Specific Aim 2 will use in vitro-infected DMVEC to identify the KSHV gene(s) responsible for c-Kit induction, and the molecular mechanisms involved.
Specific Aim 3 will use in vitro-infected DMVEC to elucidate downstream signaling pathways activated by c-Kit that lead ultimately to KSHV-induced transformation.
For Aims 2 and 3, adenovirus vectors will be used to overexpress viral and cellular genes of interest. Gene function will be validated with antisense oligonucleotides or pharmacologic inhibitors and appropriate functional assays, c-Kit has proven to be an effective therapeutic target for treatment of gastrointestinal stromal tumor (GIST). Clarification of the role of c-Kit in KSHV-associated endothelial transformation may suggest a similar approach for treatment of KS.
|Botto, Sara; Totonchy, Jennifer E; Gustin, Jean K et al. (2015) Kaposi Sarcoma Herpesvirus Induces HO-1 during De Novo Infection of Endothelial Cells via Viral miRNA-Dependent and -Independent Mechanisms. MBio 6:e00668|
|Totonchy, Jennifer E; Clepper, Lisa; Phillips, Kevin G et al. (2014) CXCR7 expression disrupts endothelial cell homeostasis and causes ligand-dependent invasion. Cell Adh Migr 8:165-76|
|Totonchy, Jennifer E; Osborn, Jessica M; Botto, Sara et al. (2013) Aberrant proliferation in CXCR7+ endothelial cells via degradation of the retinoblastoma protein. PLoS One 8:e69828|
|Sugaya, Makoto; Reed, Stacy; Rose, Patrick P et al. (2011) Kaposi's sarcoma and human dermal microvascular endothelial cells infected with Kaposi's sarcoma-associated herpesvirus express CCL21. J Dermatol Sci 61:139-42|
|Douglas, Janet L; Gustin, Jean K; Moses, Ashlee V et al. (2010) Kaposi Sarcoma Pathogenesis: A Triad of Viral Infection, Oncogenesis and Chronic Inflammation. Transl Biomed 1:|
|Douglas, Janet L; Whitford, Jill G; Moses, Ashlee V (2009) Characterization of c-Kit expression and activation in KSHV-infected endothelial cells. Virology 390:174-85|
|Mansouri, Mandana; Rose, Patrick P; Moses, Ashlee V et al. (2008) Remodeling of endothelial adherens junctions by Kaposi's sarcoma-associated herpesvirus. J Virol 82:9615-28|
|Rose, P P; Carroll, J M; Carroll, P A et al. (2007) The insulin receptor is essential for virus-induced tumorigenesis of Kaposi's sarcoma. Oncogene 26:1995-2005|
|Rose, Patrick P; Bogyo, Matthew; Moses, Ashlee V et al. (2007) Insulin-like growth factor II receptor-mediated intracellular retention of cathepsin B is essential for transformation of endothelial cells by Kaposi's sarcoma-associated herpesvirus. J Virol 81:8050-62|
|Mansouri, Mandana; Douglas, Janet; Rose, Patrick P et al. (2006) Kaposi sarcoma herpesvirus K5 removes CD31/PECAM from endothelial cells. Blood 108:1932-40|
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