IL-8 correlates with nonresponse to neoadjuvant nivolumab in HPV positive HNSCC via a potential extracellular vesicle miR-146a mediated mechanism

Therapy using anti-PD-1 immune checkpoint inhibitors (ICI) has revolutionized the treatment of many cancers including head and neck squamous cell carcinomas (HNSCC), but only a fraction of patients respond. To better understand the molecular mechanisms driving resistance, we performed extensive analysis of plasma and tumor tissues before and after a 4-week neoadjuvant trial in which HNSCC patients were treated with the anti-PD-1 inhibitor, nivolumab. Luminex cytokine analysis of patient plasma demonstrated that HPVpos nonresponders displayed high levels of the proinflammatory chemokine, interleukin-8 (IL-8), which decreased after ICI treatment, but remained higher than responders. miRNAseq analysis of tetraspanin-enriched small extracellular vesicles (sEV) purified from plasma of HPVpos nonresponders demonstrated significantly lower levels of seven miRNAs that target IL-8 including miR-146a. Levels of the pro-survival oncoprotein Dsg2, which has been to down-regulate miR-146a, are elevated with HPVpos tumors displaying higher levels than HPVneg tumors. Dsg2 levels decrease significantly following ICI in responders but not in nonresponders. In cultured HPVpos cells, restoration of miR-146a by forced expression or treatment with miR-146a-loaded sEV, reduced IL-8 level, blocked cell cycle progression, and promoted cell death. These findings identify Dsg2, miR-146a, and IL-8 as potential biomarkers for ICI response and suggest that the Dsg2/miR-146a/IL-8 signaling axis negatively impacts ICI treatment outcomes and could be targeted to improve ICI responsiveness in HPVpos HNSCC patients.

Abstract 3823: Viral transcript and tumor immune microenvironment-based transcriptomic profiling of HPV-associated head and neck cancer identifies subtypes associated with prognosis

Human papillomavirus (HPV)-associated Head and Neck Squamous Cell Carcinoma (HPV+HNSCC) is now the most common HPV-associated malignancy in the United States. Current treatments can be associated with severe side-effects or lack of efficacy yet prognostic biomarkers are limited, slowing efforts to personalize treatment in HPV+HNSCC. Here, we describe the use of a transcriptomic-based analytical platform to analyze expression patterns of viral transcripts, the tumor microenvironment (TME), and viral genome integration, and associate these features with overall survival.

Functional gene expression signatures were analyzed on publicly available HPV+HNSCC expression data (n=266). Unsupervised clustering analysis revealed 5 distinct and novel TME types across patients (immune-enriched non-fibrotic, immune-enriched fibrotic, fibrotic, immune-desert, immune-enriched luminal). These microenvironment subtypes were highly correlated with both overall survival and patient prognosis. Tumors with an immune-enriched microenvironment showed the highest survival rates, whereas fibrotic TME types were associated with poor survival (p < 0.05). Unsupervised clustering of a HPV+HNSCC cohort from The Cancer Genome Atlas (TCGA) (n=53), based on HPV transcript expression, revealed 4 HPV-related subtypes. Each subtype was enriched for distinct viral transcripts: E2/E5, E6/E7, E1/E4 and L1/L2. We then validated TME and HPV transcript-related classifications on an independent HPV+HNSCC cohort (n=132). Utilizing both viral transcript and TME subtypes, we found that the E2/E5 HPV subtype was associated with an immune-enriched TME and had a higher overall survival compared to the other subtypes. The E2/E5 subtype was also enriched for samples without HPV-genome integration, suggesting that HPV episomal DNA status and E2/E5 expression pattern may drive an inflamed microenvironment and improved prognosis. In contrast, E6/E7 subtype samples were associated with the fibrotic and depleted TME types, with lower values of T-cell and B-cell gene expression signatures and a lower survival rate. Both E1/E4 and L1/L2 subtypes were associated with the immune-enriched luminal TME types.

These findings suggest that HPV-transcript expression patterns may drive modulation of the TME, and hence impact prognosis. Further validation of the relationships between viral gene expression, TME, and prognosis is warranted to understand if such subtypes could aid in the development of prognostic biomarkers for treatment selection.

Citation Format: Daria Kiriy, Dmitry Tychinin, Nikita Kotlov, Olga Kudryashova, Anastasia Nikitina, Andrey Tyshevich, Naira Samarina, Ksenia Demina, Sandrine Degryse, Susan Raju Paul, Mark Poznansky, Krystle Lang Kuhs, James S. Lewis, Robert L. Ferris, Xiaowei Wang, Alexander Bagaev, Nathan Fowler, Lori Wirth, Daniel Faden. Viral transcript and tumor immune microenvironment-based transcriptomic profiling of HPV-associated head and neck cancer identifies subtypes associated with prognosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3823.