Faculty Bibliography

PURPOSE:Human papillomavirus (HPV) infection drives the development of some head and neck squamous cell carcinomas (HNSCC). This disease is rapidly increasing in incidence worldwide. Although these tumors are sensitive to treatment, approximately 10% of patients fail therapy. However, the mechanisms that underlie treatment failure remain unclear. EXPERIMENTAL DESIGN:, (ii) oxidative phosphorylation (OXPHOS) inhibition using IACS-010759 on NRF2-dependent cells, and (iii) combination of cisplatin and OXPHOS inhibition. RESULTS:The OXPHOS pathway is enriched in recurrent HPV-associated HNSCC and may contribute to treatment failure. NRF2-enriched HNSCC samples from The Cancer Genome Atlas (TCGA) with enrichment in OXPHOS, fatty-acid metabolism, Myc, Mtor, reactive oxygen species (ROS), and glycolytic signaling networks exhibited worse survival. HPV-positive HNSCC cells demonstrated sensitivity to the OXPHOS inhibitor, in a NRF2-dependent manner. Further, using murine xenograft models, we identified NRF2 as a driver of tumor growth. Mechanistically, NRF2 drives ROS and mitochondrial respiration, and NRF2 is a critical regulator of redox homeostasis that can be crippled by disruption of OXPHOS. NRF2 also mediated cisplatin sensitivity in endogenously overexpressing primary HPV-related HNSCC cells. CONCLUSIONS:These results unveil a paradigm-shifting translational target harnessing NRF2-mediated metabolic reprogramming in HPV-related HNSCC.

Despite the success of immune checkpoint blockade therapy, few strategies sufficiently overcome immunosuppression within the tumor microenvironment (TME). Targeting regulatory T cells (T_regs) is challenging, because perturbing intratumoral T_reg function must be specific enough to avoid systemic inflammatory side effects. Thus, no T_reg-targeted agents have proven both safe and efficacious in patients with cancer. Neuropilin-1 (NRP1) is recognized for its role in supporting intratumoral T_reg function while being dispensable for peripheral homeostasis. Nonetheless, little is known about the biology of human NRP1⁺ T_regs and the signals that regulate NRP1 expression. Here, we report that NRP1 is preferentially expressed on intratumoral T_regs across six distinct cancer types compared to healthy donor peripheral blood [peripheral blood lymphocyte (PBL)] and site-matched, noncancer tissue. Furthermore, NRP1⁺ T_reg prevalence is associated with reduced progression-free survival in head and neck cancer. Human NRP1⁺ T_regs have broad activation programs and elevated suppressive function. Unlike mouse T_regs, we demonstrate that NRP1 identifies a transient activation state of human T_regs driven by continuous T cell receptor (TCR) signaling through the mitogen-activated protein kinase pathway and interleukin-2 exposure. The prevalence of NRP1⁺ T_regs in patient PBL correlates with the intratumoral abundance of NRP1⁺ T_regs and may indicate higher disease burden. These findings support further clinical evaluation of NRP1 as a suitable therapeutic target to enhance antitumor immunity by inhibiting T_reg function in the TME.

Head and neck squamous cell carcinoma (HNSCC) is characterized by complex relations between stromal, epithelial, and immune cells within the tumor microenvironment (TME). To enable the development of more efficacious therapies, we aim to study the heterogeneity, signatures of unique cell populations, and cell-cell interactions of non-immune and immune cell populations in 6 human papillomavirus (HPV)⁺ and 12 HPV^- HNSCC patient tumor and matched peripheral blood specimens using single-cell RNA sequencing. Using this dataset of 134,606 cells, we show cell type-specific signatures associated with inflammation and HPV status, describe the negative prognostic value of fibroblasts with elastic differentiation specifically in the HPV⁺ TME, predict therapeutically targetable checkpoint receptor-ligand interactions, and show that tumor-associated macrophages are dominant contributors of PD-L1 and other immune checkpoint ligands in the TME. We present a comprehensive single-cell view of cell-intrinsic mechanisms and cell-cell communication shaping the HNSCC microenvironment.

Current immunotherapy paradigms aim to reinvigorate CD8⁺ T cells, but the contribution of humoral immunity to antitumor immunity remains understudied. Here, we demonstrate that in head and neck squamous cell carcinoma (HNSCC) caused by human papillomavirus infection (HPV⁺), patients have transcriptional signatures of germinal center (GC) tumor infiltrating B cells (TIL-Bs) and spatial organization of immune cells consistent with tertiary lymphoid structures (TLS) with GCs, both of which correlate with favorable outcome. GC TIL-Bs in HPV⁺ HNSCC are characterized by distinct waves of gene expression consistent with dark zone, light zone and a transitional state of GC B cells. Semaphorin 4a expression is enhanced on GC TIL-Bs present in TLS of HPV⁺ HNSCC and during the differentiation of TIL-Bs. Our study suggests that therapeutics to enhance TIL-B responses in HNSCC should be prioritized in future studies to determine if they can complement current T cell mediated immunotherapies.

OBJECTIVE:The American Joint Committee on Cancer (AJCC) 8th edition introduced distinct clinical and pathological staging paradigms for human papilloma virus positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC). Treatment planning for OPSCC often utilizes positron emission tomography/computed tomography (PET/CT) to assess clinical stage. We hypothesize that PET/CT will accurately predict final pathologic AJCC 8th edition staging in patients with HPV+ OPSCC. METHODS:All patients with primary HPV+ OPSCC with preoperative PET/CT who underwent transoral robotic surgery and neck dissection between 2011 and 2017 were identified. Data were collected via chart review. Two neuroradiologists performed blinded re-evaluation of all scans. Primary tumor size and cervical nodal disease characteristics were recorded and TNM staging was extrapolated. Cohen's kappa statistic was used to assess interrater reliability. Test for symmetry was performed to analyze discordance between radiologic and pathologic staging. RESULTS:Forty-nine patients met inclusion criteria. Interrater reliability was substantial between radiologists for nodal (N) and overall staging (OS) (κ = 0.715 and 0.715). Radiologist A review resulted in identical OS for 67% of patients, overstaging for 31%, and understaging for 2%. Radiologist B review resulted in 61% identical OS, 39% overstaging, and 0% understaging. In misclassified cases, the test of symmetry shows strong bias toward overstaging N stage and OS (P < .001). Radiologic interpretation of extracapsular extension showed poor interrater reliability (κ = 0.403) and poor accuracy. CONCLUSION:PET/CT predicts a higher nodal and overall stage than pathologic staging. PET/CT should not be relied upon for initial tumor staging, as increased FDG uptake is not specific for nodal metastases. PET/CT is shown to be a poor predictor of ECE. LEVEL OF EVIDENCE:4 Laryngoscope, 131:1535-1541, 2021.

OBJECTIVE:To analyze the role of transoral robotic base-of-tongue mucosectomy in a cohort of patients with human papilloma virus negative unknown primary carcinoma. STUDY DESIGN:Retrospective database analysis. METHODS:A retrospective database review from 2012 to 2018 was performed at two large tertiary centers to study patients with human papilloma virus (HPV)-negative unknown primary carcinoma who underwent transoral robotic base-of-tongue mucosectomy. P16 testing was used as a surrogate for HPV status. Patients were included that had squamous cell carcinoma metastatic to the lateral neck based on fine needle aspiration or open biopsy. Preoperatively, all patients were classified as having an unknown primary based on normal clinical and flexible endoscopic exam, normal operative endoscopy, nonlocalizing imaging, and tonsillectomy. All patients underwent robotic base-of-tongue mucosectomy. The primary outcome measure was the incidence of pathologic identification of a mucosal primary. RESULTS:Twenty-three patients with p16-negative unknown primary carcinoma were identified and studied. All patients underwent transoral robotic base-of-tongue mucosectomy. Median age was 60 years at the time of diagnosis, and 18 of 23 (78.2%) were male. Pathologic analysis of the base-of-tongue specimens showed a primary tumor in only three of 23 (13.0%) of patients. CONCLUSION:Despite prior evidence suggesting a high rate of primary site identification in HPV-related disease, robotic base-of-tongue mucosectomy may not be indicated for HPV-negative unknown primary carcinoma based on a low likelihood of finding the primary. LEVEL OF EVIDENCE:4 Laryngoscope, 131:78-81, 2021.

Immune checkpoint blockade (ICB) therapy has revolutionized head and neck squamous cell carcinoma (HNSCC) treatment, but <20% of patients achieve durable responses. Persistent activation of the PI3K/AKT/mTOR signaling circuitry represents a key oncogenic driver in HNSCC; however, the potential immunosuppressive effects of PI3K/AKT/mTOR inhibitors may limit the benefit of their combination with ICB. Here we employ an unbiased kinome-wide siRNA screen to reveal that HER3, is essential for the proliferation of most HNSCC cells that do not harbor PIK3CA mutations. Indeed, we find that persistent tyrosine phosphorylation of HER3 and PI3K recruitment underlies aberrant PI3K/AKT/mTOR signaling in PIK3CA wild type HNSCCs. Remarkably, antibody-mediated HER3 blockade exerts a potent anti-tumor effect by suppressing HER3-PI3K-AKT-mTOR oncogenic signaling and concomitantly reversing the immune suppressive tumor microenvironment. Ultimately, we show that HER3 inhibition and PD-1 blockade may provide a multimodal precision immunotherapeutic approach for PIK3CA wild type HNSCC, aimed at achieving durable cancer remission.