Human papillomavirus-associated head and neck squamous cell carcinoma (HPV+ HNSCC) is recognized as a distinct disease with unique etiology and clinical features. Current standard of care therapeutic modalities are identical for HPV+ and HPV− HNSCC and thus, there remains an opportunity to develop innovative pharmacologic approaches to exploit the inherent vulnerabilities of HPV+ HNSCC. In this study, using an inducible HPVE6E7 knockdown system, we found that HPV+ HNSCC cells are addicted to HPVE6E7, such that loss of these viral oncogenes impaired tumorigenicity in vitro and in vivo. A number of druggable pathways, including PPAR and Wnt, were modulated in response to HPVE6E7 loss. Fenofibrate showed significant anti-proliferative effects in a panel of HPV+ cancer cell lines. Additionally, fenofibrate impaired tumor growth as monotherapy and potentiated the activity of cisplatin in a pre-clinical HPV+ animal model. Systemic fenofibrate treatment induced p53 protein accumulation, and surprisingly, re-programmed the tumor-immune microenvironment to drive immune cell infiltration. Since fenofibrate is FDA-approved with a favorable long-term safety record, repositioning of this drug, as a single agent or in combination with cisplatin or checkpoint blockade, for the HPV+ HNSCC setting should be prioritized.

Abstract Background The incidence of p16+ oropharyngeal squamous cell carcinoma (OPSCC) has been increasing. The notion that p16+ OPSCC has a propensity for atypical and disseminating metastasis has gained traction. We compared treatment failure patterns in p16+ and p16− OPSCC and evaluated survival impact. Methods Retrospective analysis of patients with recurrent/metastatic OPSCC disease between 1/2009 and 12/2019. Results Thirty‐eight p16+ and 36 p16− patients were identified. Three distinct failure patterns (distant vs. locoregional, atypical vs. typical, and disseminating vs. non‐disseminating) were studied. No significant differences were found between p16+ and p16− patients. Multivariate analysis showed p16 status was an independent prognostic biomarker; p16+ patients have a favorable overall survival compared to p16− patients (HR 0.34, 95% CI 0.16–0.77; P = .005). Conclusions We challenge the view that p16+ OPSCC exhibits a distinctive treatment failure pattern and showed that p16 status impacts patient survival independent of disease progression.

In head and neck squamous cell carcinoma (HNSCC), anti-PD-1 inhibitors are approved for recurrent/metastatic (R/M) disease and anticipated to expand to other indications. The impact of p16 status and anatomical site on overall survival (OS) in immunotherapy-treated HNSCC patients remains unresolved. We performed a retrospective analysis of R/M HNSCC patients receiving anti-PD-1 immunotherapy at our academic medical center with an extensive community satellite network. Fifty-three R/M HNSCC patients were treated with anti-PD-1 immunotherapy and had a median OS of 6 months. Anatomical site was associated with distinct OS; oropharynx and larynx patients have superior OS compared to oral cavity patients. Analysis of the OPSCC subset showed p16+ status as a favorable, independent prognostic biomarker (HR 7.67 (1.23–47.8); p = 0.029). Further studies to assess the link between anatomical site, p16 status, and anti-PD-1 treatment outcomes in large cohorts of R/M HNSCC patients managed in real-world clinical practices and clinical trials should be prioritized.

BackgroundPatients with human papillomavirus (HPV+) head and neck squamous cell carcinoma (HNSCC) have superior prognoses compared with patients with HPV− HNSCC and strategies for treatment de-escalation are under investigation for the HPV+ setting. However, the survival advantage associated with HPV is not universal, and a subset of patients with HPV+ HNSCC fail definitive treatment and progress with metastatic/recurrent disease. Currently, no biomarker is available to distinguish aggressive from indolent HPV+ HNSCC. Immune dysfunction facilitates tumorigenesis and is associated with poor treatment response; therefore, we hypothesized that diminished intratumoral immune cell functionality may be attractive biomarkers to identify patients with HPV+ HNSCC at risk for early disease-specific mortality.MethodsThis is a retrospective analysis of The Cancer Genome Atlas (TCGA) HPV+ HNSCC cohort.ResultsImmunoglobulin J polypeptide (IGJ), uniquely expressed in plasma cells, showed a broad expression range in HPV+ HNSCC. Cox regression model, adjusting for clinical covariates, indicated that IGJ is an independent prognostic biomarker for disease-specific survival (DSS) and overall survival (OS). Patients with low IGJ had a 7.2-fold (p<0.001) increase in risk of disease-specific death with a median DSS of 13 months. Low IGJ showed an area under curve (AUC) of 0.89 with 91.0% sensitivity and 87.6% specificity to identify early disease-specific mortality (defined as DSS ≤12 months). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed a global dampening of immune pathways in low IGJ tumors.ConclusionsOur work showed that IGJ is a robust and independent prognostic biomarker for disease-specific mortality in HPV+ HNSCC. Patient with HPV+ HNSCC with limited adaptive immune functionality should not be candidates for treatment de-escalation modalities.

Objective: To determine the influence of high-risk HPV genotype on outcomes in HNSCC patients. Materials and Methods: This is a retrospective analysis of The Cancer Genome Atlas HNSCC cohort. Results: Using multivariate Cox regression analysis, we revealed that HPV33 + HNSCC patients have inferior overall survival compared to HPV16 + HNSCC patients independent of anatomical site (HR 3.59, 95% CI 1.58-8.12; p = 0.002). A host anti-viral immune response, apolipoprotein B mRNA editing enzyme, and catalytic polypeptide-like mutational signature, was under represented and, aneuploidy and 3p loss were more frequent in HPV33 + tumors. A deconvolution RNA-Seq algorithm to infer immune cell fractions revealed that CD8 + cytotoxic T-cell infiltration was reduced in HPV33+ compared to HPV16 + tumors (1.3% vs. 2.7%, p = 0.007). TGFB1, a negative modulator of T-cell infiltration and function, showed expression and pathway enrichment in HPV33 + tumors. Conclusions: Our work reveals that HPV genotype, in particular HPV33, has a powerful impact on HNSCC patient survival. We argue that p16 immunohistochemistry as a surrogate biomarker for HPV + status will lead to sub-optimal risk stratification and advocate HPV genotype testing as standard of care.

p53 and aldehyde dehydrogenase (ALDH) have been implicated in key tumorigenesis processes including cancer initiating cell (CIC) maintenance; however, the relationship between these two mediators remains poorly defined. In this study, ALDH isoform expression diversity was revealed in CICs with disparate p53 functional states: gain of function, high risk p53 mutation (p53HRmut) and wildtype p53 (p53WT) inactivated by the human papillomavirus 16 (HPV16) E6 oncogene. Interrogation of head and neck squamous cell carcinoma (HNSCC) cell lines and patient tumors showed that HPV16+/p53WT cases have higher ALDH variance score (AVS), a measure of tumor ALDH isoform expression diversity, compared to HPV−/p53HRmut cases (p = 0.03). AVS and several individual ALDH isoforms were associated with prognosis in HPV16+/p53WT HNSCC but not in HPV−/p53HRmut HNSCC. Knockdown of the dominant ALDH isoform in high AVS HNSCC depleted the CIC pool in vitro and in vivo . Our results demonstrate that p53 functional states are associated with distinct ALDH isoform transcriptomic signatures. Moreover, tumor ALDH profiling may provide insight on which ALDH isoform to target in high AVS HNSCC tumors to deplete the CIC population.

Human papillomavirus (HPV) insertions in cancer genomes have been linked to various forms of focal genomic instability and altered expression of neighboring genes. Here we tested the hypothesis that investigation of HPV insertions in a head and neck cancer squamous cell carcinoma (HNSCC) cell line would identify targetable driver genes contributing to oncogenesis of other HNSCC. In the cell line UPCI:SCC090 HPV16 integration amplified the PIM1 serine/threonine kinase gene ~16-fold, thereby increasing transcript and protein levels. We used genetic and pharmacological approaches to inhibit PIM kinases in this and other HNSCC cell lines. Knockdown of PIM1 transcripts by transfected short hairpin RNAs reduced UPCI:SCC090 viability. CRISPR/Cas9-mediated mutagenesis of PIM1 caused cell cycle arrest and apoptosis. Pharmacological inhibition of PIM family kinases decreased growth of UPCI:SCC090 and additional HNSCC cell lines in vitro and a xenograft UPCI:SCC090 model in vivo. Based on established interactions between intracellular signaling pathways and relatively high levels of gene expression in almost all HNSCC, we also evaluated combinations of PIM kinase and epidermal growth factor receptor (EGFR) inhibitors. Dual inhibition of these pathways resulted in supra-additive cell death. These data support clinical testing of PIM inhibitors alone or in combination in HNSCC.