Prevalence of High-Risk Human Papillomavirus in Tonsil Tissue in Healthy Adults and Colocalization in Biofilm of Tonsillar Crypts

IMPORTANCE

The pathogenesis of human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma is currently an important topic of elucidation. The presence of latent HPV infection in tonsil tissue of healthy adults may provide an explanation for a component of this process and contribute to the understanding of HPV-associated squamous cell carcinoma oncogenesis of the oropharynx.

OBJECTIVE

To determine the prevalence of oropharyngeal HPV and to determine the spatial relationship between the virus and crypt biofilm in tonsil tissue.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective, cross-sectional study was carried out using samples obtained from tonsils that were archived at a university hospital following elective nononcologic tonsillectomy from 2012 to 2015. Samples consisted of formalin-fixed paraffin embedded samples of tumor-free tonsil tissue from 102 adults between the ages of 20 and 39 years.

EXPOSURES

Human papillomavirus status was assessed by polymerase chain reaction, and high-risk subtypes 16 and 18 were assessed with quantitative polymerase chain reaction assay. Samples that demonstrated presence of HPV were then analyzed by in situ hybridization to localize the viral capsid protein. These samples were then stained with concanavalin A to establish biofilm presence and morphology. These samples were also stained with diamidino-phenylindole (DAPI) to visualize location of the virus in relation to cell nuclei. These data were then assembled for aggregate analysis to colocalize HPV in the biofilm of the tonsillar crypts.

MAIN OUTCOMES AND MEASURES

Outcome measurements were determined prior to data collection and include prevalence of high-risk HPV types 16 and 18 in tonsil tissue of otherwise healthy adults, as well as demonstration with immunohistochemistry of HPV in tonsillar crypt biofilm.

RESULTS

In 102 otherwise healthy adults (55 [53.9%] female; age range, 20-39 years), the overall prevalence of HPV in tonsils was 4.9% (n = 5); and high-risk type 16 or 18, 3.9% (n = 4). In this sample population, in situ hybridization colocalized HPV virus to the biofilm of the tonsillar crypts.

CONCLUSIONS AND RELEVANCE

Biofilm is present in the tonsillar crypts in a considerable proportion of tonsil tissues and may be reproducibly identified. Human papillomavirus is demonstrated to colocalize to the crypt biofilm. This has important implications with respect to the determination of HPV prevalence rates in the oropharynx. It may also play a role in the pathogenesis of HPV-related oropharyngeal carcinoma.

Disease-Specific Survival with Spindle Cell Carcinoma of the Head and Neck

Objectives

(1) Determine factors influencing survival in patients diagnosed with spindle cell carcinoma (SpCC), a rare variant of head and neck squamous cell carcinoma (SCC). (2) Compare survival of patients with SpCC to those with conventional SCC.

Study Design

Retrospective cohort study.

Setting

Surveillance, Epidemiology, and End Results 18 database (years 2004-2009).

Subjects and Methods

Among patients receiving treatment for a single primary in the oral cavity, oropharynx, hypopharynx, or larynx, 118 subjects with SpCC and 18,298 subjects with SCC were identified with complete data for the variables of age, sex, grade, tumor size, stage group, and TNM stage. Disease-specific survival curves were compared. Univariate and multivariate analyses were used to examine the effects of each factor on survival over all sites and within each of 3 sites.

Results

Univariate analysis of the combination of the 3 anatomic subsites showed survival with SpCC was worse than with conventional SCC ( P < .001). Three-year disease-specific survival with SpCC was 49.5%, and 5-year disease-specific survival was 40.2%. Compared with conventional SCC, survival was worse for SpCC of the oral cavity ( P < .001) and oropharynx ( P < .001) but no different for the larynx and hypopharynx site ( P = .15). Multivariate analysis identified age ( P = .02), tumor size ( P = .006), and M stage ( P < .001) as the only variables significantly affecting survival with SpCC. All variables significantly affected survival with conventional SCC.

Conclusions

Spindle cell carcinoma carries a worse prognosis than SCC. Larger tumor size, older age, and metastatic disease portend worse survival with SpCC of the head and neck.

Survival with Spindle Cell Carcinoma Compared to Conventional Squamous Cell Carcinoma

Objectives:

(1) Compare survival of patients with spindle cell carcinoma variant (SpCC) to survival of patients with conventional squamous cell carcinoma (SCC). (2) Describe the impact of patient demographics and tumor characteristics on survival with SpCC.

Methods:

A retrospective cohort study was conducted with 18,416 cases entered into the Surveillance, Epidemiology, and End Results Program database between 2004 and 2009. Variables including age, sex, race, tumor grade, size, stage group, TNM stage, and treatment modality of 18,298 SCC patients and 118 SpCC patients were extracted and combined into oral cavity, oropharynx, and larynx sites. Characteristics and survival of SpCC and SCC patients were compared in total and at each site. The effect of variables on survival with SpCC was assessed.

Results:

In total, SpCC patients experienced worse survival than conventional SCC patients ( P < .05). Overall, SpCC patient mortality was worse than SCC patients within the first 3 years ( P < .05) but was not different at 5 or 10 years. Of the 3 sites, survival was only significantly worse for SpCC patients within the oropharynx site ( P < .05). Survival of SpCC patients was worse with higher stage group and TNM stage (both P < .05), but did not differ by sex, race, or tumor grade.

Conclusions:

SpCC carries a worse prognosis than conventional SCC when located in the oropharynx. Survival with SpCC was associated with stage group and TNM stage, but was unaffected by sex, race, or grade.

Significance of HSPB1 expression in head and neck squamous cell carcinoma: a meta-analysis of published literatures

OBJECTIVE

HSPB1 functions to prevent stress-induced cellular damage and has is elevated in multiple cancer types. The significance of HSPB1 in HNSCC remains controversial. We sought to perform a meta-analysis of HSPB1 expression to clarify previous findings.

STUDY DESIGN

Meta-analysis of all published studies of HSPB1 in HNSCC patients using IHC techniques.

METHODS

A literature review was performed on PubMed and Google Scholar search engines using terms HSP27, HSPB1, Heat Shock Proteins, Cancer, Head and Neck Squamous Cell Carcinoma. Additional studies were added by review of manuscript bibliographies. Means and standard deviations for continuous data were obtained for overall HSPB1 expression (in cancer, normal and dysplasia), nodal status and TNM stage. Chi-square and Cochran's Q test were used to test statistical significance.

RESULTS

There were 77 studies identified in the context of HSPB1 and cancer in general. Of these, 7 studies (total patients n=347) met inclusion criteria and reported findings in HNSCC using IHC scoring techniques. For the mean difference in HSPB1 expression; cancer vs. normal, cancer vs. dysplasia, and dysplasia vs. normal all showed significance (p<0.0001) however the difference was not homogeneous across studies for cancer vs. dysplasia and normal. The difference was homogeneous for dysplasia vs. normal. There was no significant difference for HSPB1 expression by nodal status or stage.

CONCLUSION

HSPB1 is elevated in HNSCC and may be a useful biomarker for this disease.

Human papillomavirus-active head and neck cancer and ethnic health disparities

OBJECTIVES/HYPOTHESIS

Mortality for black males with head and neck squamous cell carcinoma (HNSCC) is twice that of white males or females. Human papillomavirus (HPV)-active HNSCC, defined by the concurrent presence of high-risk type HPV DNA and host cell p16(INK4a) expression, is associated with decreased mortality. We hypothesized that prevalence of this HPV-active disease class would be lower in black HNSCC patients compared to white patients.

STUDY DESIGN

Multi-institutional retrospective cohort analysis.

METHODS

Real-time polymerase chain reaction was used to evaluate for high-risk HPV DNA presence. Immunohistochemistry for p16(INK4a) protein was used as a surrogate marker for HPV oncoprotein activity. Patients were classified as HPV-negative (HPV DNA-negative, p16(INK4a) low), HPV-inactive (HPV DNA-positive, p16(INK4a) low), and HPV-active (HPV DNA-positive, p16(INK4a) high). Overall survival and recurrence rates were compared by Fisher exact test and Kaplan-Meier analysis.

RESULTS

There were 140 patients with HNSCC who met inclusion criteria. Self-reported ethnicity was white (115), black (25), and other (0). Amplifiable DNA was recovered from 102/140 patients. The presence of HPV DNA and the level of p16(INK4a) expression were determined, and the results were used to classify these patients as HPV-negative (44), HPV-inactive (33), and HPV-active (25). Patients with HPV-active HNSCC had improved overall 5-year survival (59.7%) compared to HPV-negative and HPV-inactive patients (16.9%) (P = .003). Black patients were less likely to have HPV-active disease (0%) compared to white patients (21%) (P = .017).

CONCLUSIONS

The favorable HPV-active disease class is less common in black than in white patients with HNSCC, which appears to partially explain observed ethnic health disparities.

Use of a microscope stage-mounted Nickel-63 microirradiator for real-time observation of the DNA double-strand break response

Eukaryotic cells begin to assemble discrete, nucleoplasmic repair foci within seconds after the onset of exposure to ionizing radiation. Real-time imaging of this assembly has the potential to further our understanding of the effects of medical and environmental radiation exposure. Here, we describe a microirradiation system for targeted delivery of ionizing radiation to individual cells without the need for specialized facilities. The system consists of a 25-micron diameter electroplated Nickel-63 electrode, enveloped in a glass capillary and mounted in a micromanipulator. Because of the low energy of the beta radiation and the minute total amount of isotope present on the tip, the device can be safely handled with minimum precautions. We demonstrate the use of this system for tracking assembly of individual repair foci in real time in live U2OS human osteosarcoma cells. Results indicate that there is a subset of foci that appear and disappear rapidly, before a plateau level is reached ∼30 min post-exposure. This subset of foci would not have been evident without real-time observation. The development of a microirradiation system that is compatible with a standard biomedical laboratory expands the potential for real-time investigation of the biological effects of ionizing radiation.

2D-DIGE proteomic characterization of head and neck squamous cell carcinoma

OBJECTIVE

Identify proteins that are differentially expressed between head and neck squamous cell cancer (HNSCC) and patient-matched normal adjacent tissue, and validate findings in a separate patient cohort.

STUDY DESIGN

Cross-sectional study of surgical specimens.

SETTING

Tertiary care academic medical center.

SUBJECTS AND METHODS

Laser capture microdissection and two-dimensional difference gel electrophoresis were used previously to establish proteomic profiles for tumor and normal adjacent tissue from 14 patients. Here, significance analysis of microarray was used to rank candidate biomarkers. Spots meeting statistical and biological criteria of significance were analyzed by liquid chromatography and tandem mass spectrometry to obtain protein identifications. The expression pattern of the highest-ranked candidate biomarker (cornulin) was validated in a larger, independent patient cohort (n = 68) by immunohistochemical staining of a tissue microarray.

RESULTS

Of 732 spots, 117 (15.9%) met criteria for significance. Identities were obtained for 39 spots, representing 17 different proteins. Four proteins were novel in the context of HNSCC: glutathione synthetase, which was upregulated; and cornulin (squamous epithelial heat shock protein 53), guanylate binding protein 6, and heat shock 70 kDa protein 5 (glucose-regulated protein, 78 kDa), which were downregulated. Cornulin functions in the stress response in normal squamous epithelium, and reduced expression has been proposed as a marker of susceptibility to laryngopharyngeal reflux and other stressors. Loss of cornulin expression was confirmed in an independent HNSCC patient cohort (P < 0.001).

CONCLUSIONS

Downregulation of cornulin is a prominent feature of the molecular signature of HNSCC identified by comparative proteomics. Cornulin may represent a link between HNSCC and other pathologies arising in stratified squamous epithelium.

Defining molecular phenotypes of human papillomavirus-associated oropharyngeal squamous cell carcinoma: validation of three-class hypothesis

OBJECTIVE

The purpose of this study was to determine if oropharyngeal squamous cell carcinoma (OSCC) classified into three groups based on human papillomavirus (HPV) 16 DNA presence and p16 expression display different protein expression patterns.

STUDY DESIGN

Cross-sectional study.

SETTING

A laboratory-based study of patients with OSCC treated at a tertiary care academic medical center.

SUBJECTS AND METHODS

Paraffin-embedded OSCC specimens from 77 patients classified into the three-class model (HPV negative, HPV inactive [HPV16+/p16-], and HPV active [HPV16+/p16+]) were queried for the expression of 14 tumor progression proteins using AQUA (HistoRx, New Haven CT). Protein expression between groups was assessed by analysis of variance. Global expression patterns were determined by unsupervised hierarchical clustering.

RESULTS

There were significant differences in expression of beta-catenin (P = 0.009), epidermal growth factor receptor (P = 0.009), and vascular endothelial growth factor (P = 0.028) between groups. HPV-active tumors had overexpression of beta-catenin. Hierarchical clustering showed HPV-negative and HPV-inactive tumors displayed association patterns distinct from HPV-active tumors.

CONCLUSIONS

Tumors classified by HPV DNA presence and p16 expression have different molecular phenotypes. This is the first demonstration of overexpression of beta-catenin (also found in HPV-caused cervical cancer) in HPV-active OSCC. HPV-active OSCC may share a similar ontogeny to HPV-caused cervical cancer.

Large-scale analysis of protein expression changes in human keratinocytes immortalized by human papilloma virus type 16 E6 and E7 oncogenes

Background

Infection with high-risk type human papilloma viruses (HPVs) is associated with cervical carcinomas and with a subset of head and neck squamous cell carcinomas. Viral E6 and E7 oncogenes cooperate to achieve cell immortalization by a mechanism that is not yet fully understood. Here, human keratinocytes were immortalized by long-term expression of HPV type 16 E6 or E7 oncoproteins, or both. Proteomic profiling was used to compare expression levels for 741 discrete protein features.

Results

Six replicate measurements were performed for each group using two-dimensional difference gel electrophoresis (2D-DIGE). The median within-group coefficient of variation was 19–21%. Significance of between-group differences was tested based on Significance Analysis of Microarray and fold change. Expression of 170 (23%) of the protein features changed significantly in immortalized cells compared to primary keratinocytes. Most of these changes were qualitatively similar in cells immortalized by E6, E7, or E6/7 expression, indicating convergence on a common phenotype, but fifteen proteins (~2%) were outliers in this regulatory pattern. Ten demonstrated opposite regulation in E6- and E7-expressing cells, including the cell cycle regulator p16^INK4a; the carbohydrate binding protein Galectin-7; two differentially migrating forms of the intermediate filament protein Cytokeratin-7; HSPA1A (Hsp70-1); and five unidentified proteins. Five others had a pattern of expression that suggested cooperativity between the co-expressed oncoproteins. Two of these were identified as forms of the small heat shock protein HSPB1 (Hsp27).

Conclusion

This large-scale analysis provides a framework for understanding the cooperation between E6 and E7 oncoproteins in HPV-driven carcinogenesis.

Characterization of Molecular Markers Indicative of Cervical Cancer Progression

Cervical cancer originates with human papillomavirus (HPV) infection and progresses via histologically-defined premalignant stages. Here we compare normal cervical epithelium and patient-matched high grade squamous intraepithelial lesions (HSIL) with cervical carcinoma tissue from the same patient population (n=10 per group). Specimens were analyzed by combined laser capture microdissection and 2D-DIGE. Significant expression changes were seen with 53 spots resulting in identification of 23 unique proteins at the molecular level. These include eight that uniquely distinguish normal epithelium and HSIL and four that uniquely distinguish HSIL and carcinoma. In addition, one protein, cornulin, distinguishes all three states. Other identified proteins included differentiation markers, oncogene DJ-1, serpins, stress and interferon-responsive proteins, detoxifying enzymes, and serum transporters. A literature review, performed for all identified proteins, allowed most changes to be assigned to one of three causes: direct or indirect HPV oncoprotein interactions, growth selection during latency, or interactions in the lesion microenvironment. Selected findings were confirmed by immunohistochemistry using either frozen sections from the same cohort or formalin fixed paraffin embedded samples from a tissue microarray. Novel markers described here have potential applications for increasing the predictive value of current screening methods.

Molecular Similarity of HNSCC from Different Subsites

Problem

Squamous cell carcinomas arising from various subsites within the head and neck (HNSCC), while histologically identical, have substantial differences in survival and recurrence rates. Controversy exists as to whether this reflects physical differences or fundamental molecular heterogeneity between subsites. In this study, we used two proteomics approaches to evaluate HNSCCs for differences in protein expression between subsites including oral cavity, oropharynx, larynx and hypopharynx.

Methods

Tumor tissue from a total of 85 patients with HNSCC was queried by two complementary proteomics techniques. Frozen tissue from 14 patients with histologically confirmed HNSCC was enriched for tumor and normal tissue by laser capture microdissection. Total protein was extracted, separated by 2D-difference gel electrophoresis (2D-DIGE), and evaluated for differential protein expression between subsites. A tissue microarray (TMA) was constructed consisting of 71 patients with HNSCC. This TMA was queried for expression of 4 cell-cycle and regulatory proteins chosen a priori for their known roles in cancer, using Automated Quantitative Analysis of protein expression (AQUA).

Results

From the first cohort, proteins from tumor and matched normal tissue were successfully isolated and 732 spots identified as matching across >90% of gels. After supervised statistical analysis, we identified no significant differences in protein expression between subsites. AQUA analysis of the second, larger cohort likewise revealed no difference between subsite for cyclin D1, p53, Rb, or p14 expression.

Conclusion

Using two validated, complementary proteomics methods we identified no significant differences between HNSCCs from different head and neck subsites.

Significance

It is possible that heterogeneity among HNSCCs may be based not on anatomic subsite, but rather on fundamentally different carcinogenic pathways – i.e. virally induced versus carcinogenic insult (tobacco, alcohol).

Support

NIHR33-CA-5941(WSD); AAO/HNSF Resident Research Grant 26357 (PMW).