Genomic instability is a hallmark of human cancers, including the 5% caused by human papillomavirus (HPV). Here we report a striking association between HPV integration and adjacent host genomic structural variation in human cancer cell lines and primary tumors. Whole-genome sequencing revealed HPV integrants flanking and bridging extensive host genomic amplifications and rearrangements, including deletions, inversions, and chromosomal translocations. We present a model of ''looping'' by which HPV integrant-mediated DNA replication and recombination may result in viral-host DNA concatemers, frequently disrupting genes involved in oncogenesis and amplifying HPV oncogenes E6 and E7. Our high-resolution results shed new light on a catastrophic process, distinct from chromothripsis and other mutational processes, by which HPV directly promotes genomic instability.
Purpose-To prospectively identify markers of response to therapy and outcome in an organsparing trial for advanced oropharyngeal cancer.Patients and Methods-Pretreatment biopsies were examined for expression of epidermal growth factor receptor (EGFR), p16, Bcl-xL, and p53 as well as for p53 mutation. These markers Authors' Disclosures of Potential Conflicts of Interest:Although all authors completed the disclosure declaration, the following author (s) indicated a financial or other interest that is relevant to the subject matter under consideration in this article. Certain relationships marked with a "U" are those for which no compensation was received; those relationships marked with a "C" were compensated. For a detailed description of the disclosure categories, or for more information about ASCO's conflict of interest policy, please refer to the Author Disclosure were assessed for association with high-risk human papillomavirus (HPV), response to therapy, and survival. Patient variables included smoking history, sex, age, primary site, tumor stage, and nodal status.Results-EGFR expression was inversely associated with response to induction chemotherapy (IC) (P = .01), chemotherapy/radiotherapy (CRT; P = .055), overall survival (OS; P = .001), and diseasespecific survival (DSS; P = .002) and was directly associated with current smoking (P = .04), female sex (P = .053), and lower HPV titer (P = .03). HPV titer was significantly associated with p16 expression (P < .0001); p16 was significantly associated with response to IC (P = .008), CRT (P = . 009), OS (P = .001), and DSS (P = .003). As combined markers, lower HPV titer and high EGFR expression were associated with worse OS (ρ EGFR = 0.008; ρ HPV = 0.03) and DSS (ρ EGFR = 0.01; ρ HPV = 0.016). In 36 of 42 biopsies, p53 was wild-type, and only one HPV-positive tumor had mutant p53. The combination of low p53 and high Bcl-xL expression was associated with poor OS (P = . 005) and DSS (P = .002).Conclusion-Low EGFR and high p16 (or higher HPV titer) expression are markers of good response to organ-sparing therapy and outcome, whereas high EGFR expression, combined low p53/ high Bcl-xL expression, female sex, and smoking are associated with a poor outcome. Smoking cessation and strategies to target EGFR and Bcl-xL are important adjuncts to the treatment of oropharyngeal cancer.
Epithelial-mesenchymal transition (EMT) is a key process in tumor metastatic cascade that is characterized by the loss of cell-cell junctions and cell polarity, resulting in the acquisition of migratory and invasive properties. However, the precise molecular events that initiate this complex EMT process in head and neck cancers are poorly understood. Increasing evidence suggests that tumor microenvironment plays an important role in promoting EMT in tumor cells. We have previously shown that head and neck tumors exhibit significantly higher Bcl-2 expression in tumor-associated endothelial cells and overexpression of Bcl-2 alone in tumor-associated endothelial cells was sufficient to enhance tumor metastasis of oral squamous cell carcinoma in a SCID mouse model. In this study, we show that endothelial cells expressing Bcl-2 (EC-Bcl-2), when co-cultured with head and neck tumor cells (CAL27), significantly enhance EMT-related changes in tumor cells predominantly by the secretion of IL-6. Treatment with recombinant IL-6 or stable IL-6 overexpression in CAL27 cells or immortalized oral epithelial cells (IOE) significantly induced the expression of mesenchymal marker, vimentin, while repressing E-cadherin expression via the JAK/STAT3/Snail signaling pathway. These EMT-related changes were further associated with enhanced tumor and IOE cell scattering and motility. STAT3 knock-down significantly reversed IL-6-mediated tumor and IOE cell motility by inhibiting FAK activation. Furthermore, tumor cells overexpressing IL-6 showed marked increase in lymph node and lung metastasis in a SCID mouse xenograft model. Taken together, these results demonstrate a novel function for IL-6 in mediating EMT in head and neck tumor cells and increasing their metastatic potential.
Purpose: The goal of this study was to examine the effect of tobacco use on disease recurrence (local/ regional recurrence, distant metastasis, or second primary) among patients with human papillomavirus (HPV)-positive squamous cell carcinoma of the oropharynx (SCCOP) following a complete response to chemoradiation therapy.Experimental Design: Between 1999 and 2007, 124 patients with advanced SCCOP (86% with stage IV) and adequate tumor tissue for HPV analysis who were enrolled in one of two consecutive University of Michigan treatment protocols were prospectively included in this study. Patients were categorized as never-, former, or current tobacco users. The primary end points were risk of disease recurrence and time to recurrence; secondary end points were disease-specific survival and overall survival.Results: One hundred and two patients (82.3%) had HPV-positive tumors. Over two thirds (68%) of patients with HPV-positive tumors were tobacco users. Among HPV-positive patients, current tobacco users were at significantly higher risk of disease recurrence than never-tobacco users (hazard ratio, 5.2; confidence interval, 1.1-24.4; P = 0.038). Thirty-five percent of HPV-positive ever tobacco users recurred compared with only 6% of HPV-positive never users and 50% of HPV-negative patients. All HPV-negative patients were tobacco users and had significantly shorter times to recurrence (P = 0.002), and had reduced disease-specific survival (P = 0.004) and overall survival (P < 0.001) compared with HPV-positive patients. Compared with HPV-positive never-tobacco users, those with a tobacco history showed a trend for reduced disease-specific survival (P = 0.064) but not overall survival (P = 0.221).Conclusions: Current tobacco users with advanced, HPV-positive SCCOP are at higher risk of disease recurrence compared with never-tobacco users. Clin Cancer Res; 16(4); 1226-35. ©2010 AACR.Head and neck squamous cell carcinoma is the eighth most common malignancy worldwide (1) and represents ∼5% of new cancer diagnoses worldwide annually (2). Over the past three decades, there has been a steady increase in the incidence of tonsil and tongue squamous cell carcinomas (3, 4). Recent evidence has identified high-risk human papillomavirus (HPV), particularly HPV-16, as a causative agent for a subset of head and neck squamous cell carcinomas, accounting for over 50% of squamous cell carcinomas of the oropharynx (SCCOP) in the United States (5-9). HPV-positive SCCOP has a distinct risk factor profile (6) and oncogenic mechanism (10, 11), and likely portends a more favorable prognosis than HPV-negative SCCOP (5,7,(12)(13)(14)(15)(16)(17). Despite its effect on prognosis, tumor HPV status has not yet been used to alter therapeutic management. The most popular current treatment for advanced SCCOP, regardless of HPV status, involves concurrent chemoradiation Authors' Affiliations:
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