Estrogen reduces HPV transcription and oncogene expression to target disease

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Project Summary / Abstract Human papillomaviruses (HPVs) are the most common sexually transmitted infection that affects nearly every sexually active individual at some point in their lives. A portion of these infections can result in cancer, and worldwide, as many as 5% of cancers are caused by this virus. There has been an increase in HPV-related head and neck cancer, and recently HPV has bypassed smoking as the main cause of this disease. The HPV vaccine protects against future infections but will not help anyone who already has HPV. As there are no treatments for this virus, this is a much needed area of research. Promising targets for anti-HPV therapeutics include viral replication and transcription. Here we present evidence that estrogen reduces HPV transcription through interactions with the viral long control region (LCR). Novel regulatory regions have also been discovered in the LCR that result in the loss of transcription. Reduced LCR transcription via estrogen translates to a reduction in early viral genes, including the oncogene E6. Lower levels of E6 allow for re-expression of the cellular tumor suppressor p53 and preliminary evidence suggests that this provides an HPV-specific loss in cell viability. The proposal seeks to expand upon these results to determine if the estrogenic effects are cytostatic or cytotoxic, and determine if these effects can be translated into an in vivo xenograft model. Data generated from these studies will generate the necessary data for a future R01 application to investigate the novel LCR regulatory regions, and possible sex related differences in the response to estrogen treatment to elucidate why the incidence of HPV-associated HNSCC is found at 3 fold higher levels in men than women, a currently understudied area. The ultimate goals of this proposal and future studies generated from this data is to limit viral load, cure infections, prevent downstream carcinogenesis, discover HPV-targeted cancer treatments, and to translate these approaches to the clinic.