Project summary The incidence of HPV-associated (HPV+) head and neck squamous cell carcinoma (HNSCC) has dramatically increased over the last few decades and continues to rise. Despite the magnitude of this epidemic, mechanisms of HPV-driven carcinogenesis in HPV+ HNSCC have not been thoroughly investigated. Compared to patients with tobacco-associated HNSCC, those with HPV+ HNSCC have increased overall survival and higher response to treatment, which usually consists of chemo- and radiation therapy; however, survivors frequently suffer from treatment’s toxic side effects, such as swallowing and speech dysfunction. In addition, approximately 25% of HPV+ HNSCC patients develop recurrent or metastatic disease, for which there are limited treatment options. A pressing goal in head and neck oncology is to decrease the morbidity of therapy for HPV+ HNSCC through treatment de-escalation. However, biomarkers that identify HPV+ patients with good prognosis, who may be appropriate for de-escalation therapy, are lacking. Using three independent cohorts, we found that constitutively active NF-κB (usually arising from genetic defects in NF-κB regulators, including TRAF3 and CYLD) correlates with survival and should be explored as a prognostic biomarker in HPV+ HNSCC. Our preliminary data suggest that survival benefits of patients, whose tumors harbor overactive NF-κB, are attributed to better tumor response to therapy and that both, inherent NF-κB-driven tumor characteristics (e.g. downregulated expression of oxidative stress response, NRF2 target genes), as well as a distinct tumor microenvironment (e.g. elevated number of tumor infiltrating CD4+ T cells), may contribute to increased sensitivity of NF-κB active tumors to radiation. We previously reported that mutations in TRAF3 and CYLD were associated with a lack of HPV integration, leading us to hypothesize that NF-κB activation may enable cells to maintain HPV episomes. Since the canonical HPV carcinogenesis model depends on HPV integration, we also hypothesize that activation of NF-κB may be critical for an alternative mechanism of HPV carcinogenesis driven by HPV episomal maintenance. To explore our hypothesis, in Specific Aim 1, we will investigate the impact of NF-κB signaling on HPV gene expression and episomal maintenance. In Specific Aim 2, we will explore the significance of NF-κB pathway on cellular proliferation, survival, and cellular transformation in response to HPV. Finally, Specific Aim 3 will explore mechanisms of NF-κB mediated radiation sensitivity in HPV+ HNSCC.

Project Narrative In the past few decades, the human papilloma virus (HPV) has been driving an epidemic of head and neck squamous cell carcinoma (HNSCC) emphasizing the need for a clear understanding of HPV-driven carcinogenesis in these tumors. The goals of this proposal are to characterize a previously unrecognized subset of HPV-associated HNSCC that harbors somatic inactivating mutations in NF-κB regulators and to explore roles of NF-κB signaling in an alternative mechanism of HPV tumorigenesis. This work should help to define an alternative mechanism through which HPV causes cancer in the head and neck, personalize cancer care and de-escalate therapy to improve quality of life amongst survivors, while providing a basis for discovery and testing of novel therapies that may benefit patients at high risk of dying from HPV-associated cancer.