Contributions of DEK oncogene activities to HPV-induced cellular metabolism and proliferation

About This Grant

Project Summary/Abstract I am a Ph.D. student at the University of Cincinnati College of Medicine in the laboratory of Dr. Susanne Wells at Cincinnati Children’s Hospital Medical Center. This proposal is designed to develop my training in metabolism, epigenetics, and bioinformatic analyses. The overall goal is to determine molecular mechanism(s) whereby HPV16 drives infected stratified squamous epithelium (SE) towards premalignancy and the contribution of the oncogene DEK to this process. HR-HPV infections are a significant risk factor for developing squamous cell carcinomas (SCCs) of the skin and mucosa. No antiviral options are available to treat HPV infections; thus, new therapeutics are desperately needed. Of the HR-HPV strains, HPV16 infection accounts for most HPV- associated SCCs and drives tumorigenesis by inhibiting critical tumor suppressors and inducing the expression of oncogenes like DEK. DEK is most highly expressed in SCCs associated with HR-HPV infection (i.e., head and neck, cervical) and promotes cellular proliferation and tumorigenesis. Previous studies have shown that HPV-induced tumorigenesis is dependent on DEK. Despite extensive knowledge of the pathological activities of HR-HPV and DEK in tumor biology, little is known about their activities in driving tissue into premalignancy. In laboratory-generated SE rafts, HPV16 infection induces early cancer phenotypes like aberrant proliferation, hyperplasia, and metabolic reprogramming, which are recapitulated to a similar extent in rafts generated from DEK overexpressing (DEK-OE) keratinocytes. However, the mechanism by which DEK regulates gene expression in SE is entirely unknown, and the extent to which HPV16 depends on DEK expression for its pathology remains unclear. To investigate these questions, I performed metabolomic and transcriptomic experiments showing that HPV16-infected SE rafts stimulate glutamine metabolism, which is also observed in DEK-OE rafts. Additionally, aberrant cellular proliferation was significantly reduced in DEK-OE SE rafts when I pharmacologically inhibited glutamine import. Thus, HPV16-induced DEK-OE may promote aberrant cellular proliferation and hyperplasia through stimulating glutamine metabolism. Aim 1 will define the extent to which proliferation and glutamine metabolism in HPV16-infected SE rafts depend on DEK expression. Furthermore, aim 1 will test the dependency of HPV16-induced cellular proliferation on glutamine metabolism. I expect DEK knockdown to decrease proliferation and glutamine metabolism in HPV16-infected SE. Similarly, I expect glutamine metabolism inhibition will reduce cellular proliferation and hyperplasia in HPV16-infected SE. Aim 2 will test whether DEK-OE in HPV16-infected SE rafts regulates glutamine metabolism gene expression through epigenetic reprogramming. I expect promoters/enhancers of glutamine metabolism genes to be directly bound by DEK and epigenetically modified with activating chromatin marks. Together, these experiments will define the extent to which HPV16 depends on DEK to promote early cancer phenotypes in normal SE and provide evidence for candidate therapeutic targets for developing critically needed HPV anti-virals and/or cancer preventatives.