Head and neck squamous cell carcinoma (HNSCC) is a common, morbid, and frequently lethal malignancy. To uncover its mutational spectrum, we analyzed whole-exome sequencing data from 74 tumor-normal pairs. The majority exhibited a mutational profile consistent with tobacco exposure; human papilloma virus was detectable by sequencing of DNA from infected tumors. In addition to identifying previously known HNSCC genes (TP53, CDKN2A, PTEN, PIK3CA, and HRAS), the analysis revealed many genes not previously implicated in this malignancy. At least 30% of cases harbored mutations in genes that regulate squamous differentiation (e.g., NOTCH1, IRF6, and TP63), implicating its dysregulation as a major driver of HNSCC carcinogenesis. More generally, the results indicate the ability of large-scale sequencing to reveal fundamental tumorigenic mechanisms.

Previous studies have established that a subset of head and neck tumors contains human papillomavirus (HPV) sequences and that HPV-driven head and neck cancers display distinct biological and clinical features. HPV is known to drive cancer by the actions of the E6 and E7 oncoproteins, but the molecular architecture of HPV infection and its interaction with the host genome in head and neck cancers have not been comprehensively described. We profiled a cohort of 279 head and neck cancers with next generation RNA and DNA sequencing and show that 35 (12.5%) tumors displayed evidence of high-risk HPV types 16, 33, or 35. Twentyfive cases had integration of the viral genome into one or more locations in the human genome with statistical enrichment for genic regions. Integrations had a marked impact on the human genome and were associated with alterations in DNA copy number, mRNA transcript abundance and splicing, and both inter-and intrachromosomal rearrangements. Many of these events involved genes with documented roles in cancer. Cancers with integrated vs. nonintegrated HPV displayed different patterns of DNA methylation and both human and viral gene expressions. Together, these data provide insight into the mechanisms by which HPV interacts with the human genome beyond expression of viral oncoproteins and suggest that specific integration events are an integral component of viral oncogenesis.cancer | head and neck | papilloma virus | genome rearrangement | integration sites H ead and neck cancer (HNC) is a heterogeneous group of tumors characterized by a common anatomic origin, and most such tumors develop from within the mucosa and are classified as head and neck squamous cell carcinomas (HNSCCs) (1). HNSCC, the sixth most common cancer diagnosed worldwide and the eighth most common cause of cancer death (2), is frequently associated with human papillomavirus (HPV) infection (3, 4). Depending on the anatomic site of the tumor, HPV prevalence is estimated at 23-36% (5). HPV-positive HNSCCs form a distinct subset of HNCs that differs from HPV-negative HNSCCs in tumor biology and clinical characteristics, including superior clinical outcomes (6-9).The molecular pathogenesis of HPV-driven HNSCC also seems distinct from HPV-negative tumors, with previous studies showing a divergent spectrum of alterations in gene expression, mutations, amplifications, and deletions as well as distinct epigenome alterations (10-15). HPV is known to drive tumorigenesis through the actions of its major oncoproteins E6 and E7, which target numerous cellular pathways, including inactivation of p53 and the retinoblastoma (Rb) protein (16-18). Together with E5, they also play an important role in immune evasion, being involved in both innate and adaptive immunity (19,20).Initially after infection, HPV is identified in circular extrachromosomal particles or episomes. A critical step in progression to cancer is the integration of viral DNA into the host cell Significance A significant proportion of head and neck cancer is driven by human papil...

Frequent gene amplification of the receptor-activated calcium-dependent chloride channel TMEM16A (TAOS2 or ANO1) has been reported in several malignancies. However, its involvement in human tumorigenesis has not been previously studied. Here, we show a functional role for TMEM16A in tumor growth. We found TMEM16A overexpression in 80% of head and neck squamous cell carcinoma (SCCHN), which correlated with decreased overall survival in patients with SCCHN. TMEM16A overexpression significantly promoted anchorage-independent growth in vitro, and loss of TMEM16A resulted in inhibition of tumor growth both in vitro and in vivo. Mechanistically, TMEM16A-induced cancer cell proliferation and tumor growth were accompanied by an increase in extracellular signal–regulated kinase (ERK)1/2 activation and cyclin D1 induction. Pharmacologic inhibition of MEK/ERK and genetic inactivation of ERK1/2 (using siRNA and dominant-negative constructs) abrogated the growth effect of TMEM16A, indicating a role for mitogen-activated protein kinase (MAPK) activation in TMEM16A-mediated proliferation. In addition, a developmental small-molecule inhibitor of TMEM16A, T16A-inh01 (A01), abrogated tumor cell proliferation in vitro. Together, our findings provide a mechanistic analysis of the tumorigenic properties of TMEM16A, which represents a potentially novel therapeutic target. The development of small-molecule inhibitors against TMEM16A may be clinically relevant for treatment of human cancers, including SCCHN.

Purpose We determined hepatocyte growth factor (HGF) and c-Met expression and signaling in human head and neck squamous cell carcinoma (HNSCC) cells and primary tissues and tested the ability of c-Met tyrosine kinase inhibitors (TKI) to block HGF-induced biological signaling. Experimental Design Expression and signaling were determined using immunoblotting, ELISA, and immunohistochemistry. Biological end points included wound healing, cell proliferation, and invasion. c-Met TKIs were tested for their ability to block HGF-induced signaling and biological effects in vitro and in xenografts established in nude mice. Results c-Met was expressed and functional in HNSCC cells. HGF was secreted by HNSCC tumor-derived fibroblasts, but not by HNSCC cells. Activation of c-Met promoted phosphorylation of AKT and mitogen-activated protein kinase as well as release of the inflammatory cytokine interleukin-8. Cell growth and wound healing were also stimulated by HGF. c-Met TKIs blocked HGF-induced signaling, interleukin-8 release, and wound healing. Enhanced invasion of HNSCC cells induced by the presence of tumor-derived fibroblasts was completely blocked with a HGF-neutralizing antibody. PF-2341066, a c-Met TKI, caused a 50% inhibition of HNSCC tumor growth in vivo with decreased proliferation and increased apoptosis within the tumors. In HNSCC tumor tissues, both HGF and c-Met protein were increased compared with expression in normal mucosa. Conclusions These results show that HGF acts mainly as a paracrine factor in HNSCC cells, the HGF/c-Met pathway is frequently up-regulated and functional in HNSCC, and a clinically relevant c-Met TKI shows antitumor activity in vivo. Blocking the HGF/c-Met pathway may be clinically useful for the treatment of HNSCC.

◥Purpose: Pembrolizumab improved survival in patients with recurrent or metastatic head and neck squamous-cell carcinoma (HNSCC). The aims of this study were to determine if pembrolizumab would be safe, result in pathologic tumor response (pTR), and lower the relapse rate in patients with resectable human papillomavirus (HPV)-unrelated HNSCC.Patients and Methods: Neoadjuvant pembrolizumab (200 mg) was administered and followed 2 to 3 weeks later by surgical tumor ablation. Postoperative (chemo)radiation was planned. Patients with high-risk pathology (positive margins and/or extranodal extension) received adjuvant pembrolizumab. pTR was quantified as the proportion of the resection bed with tumor necrosis, keratinous debris, and giant cells/histiocytes: pTR-0 (<10%), pTR-1 (10%-49%), and pTR-2 (≥50%). Coprimary endpoints were pTR-2 among all patients and 1-year relapse rate in patients with high-risk pathology (historical: 35%). Correlations of baseline PD-L1 and T-cell infiltration with pTR were assessed. Tumor clonal dynamics were evaluated (Clin-icalTrials.gov NCT02296684).Results: Thirty-six patients enrolled. After neoadjuvant pembrolizumab, serious (grades 3-4) adverse events and unexpected surgical delays/complications did not occur. pTR-2 occurred in eight patients (22%), and pTR-1 in eight other patients (22%). One-year relapse rate among 18 patients with high-risk pathology was 16.7% (95% confidence interval, 3.6%-41.4%). pTR ≥10% correlated with baseline tumor PD-L1, immune infiltrate, and IFNg activity. Matched samples showed upregulation of inhibitory checkpoints in patients with pTR-0 and confirmed clonal loss in some patients.Conclusions: Among patients with locally advanced, HPVunrelated HNSCC, pembrolizumab was safe, and any pathologic response was observed in 44% of patients with 0% pathologic complete responses. The 1-year relapse rate in patients with high-risk pathology was lower than historical.

Head and neck squamous cell carcinoma (HNSCC) is characterized by aggressive behavior with a propensity for metastasis and recurrence. Here we report a comprehensive analysis of the molecular and clinical features of HNSCC that govern patient survival. We find that TP53 mutation is frequently accompanied by loss of chromosome 3p, and that the combination of both events associates with a surprising decrease in survival rates (1.9 years versus >5 years for TP53 mutation alone). The TP53-3p interaction is specific to chromosome 3p, rather than a consequence of global genome instability, and validates in HNSCC and pan-cancer cohorts. In Human Papilloma Virus positive (HPV+) tumors, in which HPV inactivates TP53, 3p deletion is also common and associates with poor outcomes. The TP53-3p event is modified by mir-548k expression which decreases survival even further, while it is mutually exclusive with mutations to RAS signaling. Together, the identified markers underscore the molecular heterogeneity of HNSCC and enable a new multi-tiered classification of this disease.

Purpose Increased expression and/or activation of epidermal growth factor receptor (EGFR) is associated with tumor progression and poor prognosis in many cancers including head and neck squamous cell carcinoma (HNSCC). Src family kinases, including c-Src, mediate a variety of intra- or extracellular signals that contribute to tumor formation and progression. This study was undertaken to elucidate the role of c-Src in the growth and invasion of HNSCC and to determine the effects of combined targeting of EGFR and Src kinases in HNSCC cell lines. Experimental design HNSCC cells were engineered to stably express a dominant-active (DA) form of c-Src and investigated in cell growth and invasion assays. The biochemical effects of combined treatment with the Src inhibitor, AZD0530, a potent, orally active Src inhibitor with Bcr/Abl activity and the EGFR kinase inhibitor, gefitinib, were examined as well as the consequences of dual Src/EGFR targeting on the growth and invasion of a panel of HNSCC cell lines. Results HNSCC cells expressing DA c-Src demonstrated increased growth and invasion compared with vector-transfected controls. Combined treatment with AZD0530 and gefitinib resulted in greater inhibition of HNSCC cell growth and invasion compared with either agent alone. Conclusions These results suggest that increased expression and activation of c-Src promotes HNSCC progression where combined targeting of EGFR and c-Src may be an efficacious treatment approach.

Purpose: This study aimed to characterize estrogen receptor expression and signaling in head and neck squamous cell carcinoma (HNSCC) cell lines and patient tissues, and to evaluate estrogen receptor and epidermal growth factor (EGF) receptor (EGFR) cross-activation in HNSCC. Experimental Design: Estrogen receptor expression and signaling in HNSCC cell lines were assessed by immunoblotting. In vitro proliferation and invasion were evaluated in HNSCC cell lines in response to estrogen receptor and EGFR ligands or inhibitors. Estrogen receptor and EGFR protein expression in patient tissues was assessed by immunohistochemical staining. Results: Phospho-mitogen-activated protein kinase (P-MAPK) levels were significantly increased following combined estrogen and EGF treatment. Treatment of HNSCC cells with estrogen and EGF significantly increased cell invasion compared with either treatment alone, whereas inhibiting these two pathways resulted in reduced invasion compared with inhibiting either pathway alone. EGFR (P = 0.008) and nuclear estrogen receptor α (ERα nuc ; P < 0.001) levels were significantly increased in HNSCC tumors (n = 56) compared with adjacent mucosa (n = 30), whereas nuclear estrogen receptor β (ERβ nuc ) levels did not differ (P = 0.67). Patients with high ERα nuc and EGFR tumor levels had significantly reduced progression-free survival compared with patients with low tumor ERα nuc and EGFR levels (hazards ratio, 4.09; P = 0.01; Cox proportional hazards). In contrast, high ERβ nuc tumor levels were not associated with reduced progression-free survival alone or when combined with EGFR. Conclusions: ERα and ERβ were expressed in HNSCC, and stimulation with estrogen receptor ligands resulted in both cytoplasmic signal transduction and transcriptional activation. Estrogen receptor and EGFR cross-talk was observed. Collectively, these studies indicate that estrogen receptor and EGFR together may contribute to HNSCC development and disease progression. (Clin Cancer Res 2009;15(21):6529-40)