Abstract B004: Molecular crosstalk between NF-κB and NRF2 signaling affects prognosis in HPV-associated head and neck cancer
Authors: Kothari Aditi , Schrank Travis , Yarbrough Wendell , Isaeva Natalia 
Published: December 2023

The incidence of head and neck squamous cell carcinoma (HNSCC) is on the rise and is expected to increase by 50% by 2030. Around half of the patient population affected are diagnosed when the tumor is at a locally advanced stage. These patients are usually treated with intense radiotherapy, leading to severe side-effects. Precision medicine would revolutionize the treatment of head and neck cancer by accurately identifying patients that are at low risk of recurrence, reduce treatment related side-effects and aid in overall improvement in quality of life of patients after treatment. This generates the need to develop biomarkers to identify patients with less aggressive tumors as candidates for treatment de-escalation.  We applied an unbiased approach (weighted gene correlation network analysis (WGCNA)) that allows detection of autocorrelated gene sets on 3 independent cohorts of HPV+ HNSCC and created 22 consensus transcriptional modules by selecting genes that grouped together in WGCNA analyses from all 3 cohorts. Interestingly, only 1 module intrinsically divided HPV+ HNSCC into 2 subtypes, displaying different mutational profiles, mutational signatures, HPV gene expression patterns, HPV integration status, and patient survival. Gene set enrichment analysis revealed that this module was enriched in NF-kB genes and strongly associated with NF-κB signaling, confirming our prior findings that defined HPV+ HNSCC subtypes by presence or absence of NF-kB regulators, TRAF3 or CYLD defects and by the NF-κB activity classifier. We hypothesized that NF-kB-driven intrinsic tumor characteristics contribute to increased sensitivity of NF-kB active HPV+ head and neck tumors to radiation, providing patients survival benefits.  Indeed, TRAF3 or CYLD deletion dramatically increased radiation sensitivity of HPV+ head and neck cancer cells.  As we began to investigate mechanisms of radiation sensitization associated with TRAF3 and CYLD deletion, we found that activation of NF-κB significantly correlated with marked downregulation of nuclear factor erythroid 2-related factor 2 (NRF2) activity in tumors from 3 independent cohorts, as well as in HPV+ HNSCC cells that harbor constitutively active NF-kB due to deletion of TRAF3 or CYLD. Interestingly, TRAF3 CRISPR KO cells had lower NRF2 protein levels that were restored by MG132 treatment, indicating an involvement of KEAP1/CUL3 mediated proteasomal degradation of NRF2. In summary, our data showcases an inverse correlation between NF-kB and NRF2 pathways in HPV+ HNSCC. Currently, there are no prognostic biomarkers to distinguish patients who require aggressive therapy versus those that are appropriate for reduced intensity treatment. Identification of markers distinguishing the 2 subtypes of HPV+ HNSCC (high NF-kB and low NRF2 activity) may serve as prognostic biomarkers to help clinicians with therapeutic decisions.

Citation Format: Aditi Kothari, Travis Schrank, Wendell Yarbrough, Natalia Isaeva. Molecular crosstalk between NF-κB and NRF2 signaling affects prognosis in HPV-associated head and neck cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B004.