Artikel
P16INK4A immunostaining patterns differentiate between the presence of high and low risk human papillomavirus types in head and neck dysplasias and papillomas
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Veröffentlicht: | 22. April 2010 |
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Gliederung
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Introduction: Human papillomavirus (HPV) is a risk factor for head and neck mucosa lesions, including HPV-16 in tonsillar squamous cell carcinomas (TSCC) and HPV-6/11 in laryngeal papillomas. The aim of this study was to determine whether expression of the HPV surrogate marker p16INK4A could predict the presence of high and low risk HPV types in head and neck dysplasias and papillomas.
Methods: P16INK4A immunostaining was performed on paraffin-embedded tissue sections of 8 laryngeal dysplasias (from 4 patients), 14 tonsillar dysplasias (12 patients), 27 laryngeal papillomas (14 patients) and 20 tonsillar papillomas (20 patients). Genomic DNA isolated from these tissues was examined for HPV type by PCR and enzyme-immunoassay analysis. FISH specific for HPV-types 6, 11 and 16 was performed to evaluate HPV physical status.
Results: A strong p16INK4A immunostaining was predominantly seen in tonsillar dysplasias and associated with integrated HPV-16, except for 1 case showing episomal HPV (9/11 cases). A predominantly intermediate p16INK4A expression level was associated with episomal HPV-6 or 11 in laryngeal dysplasias (3/4 cases) and papillomas (13/14). Low p16INK4A expression levels were detected in tonsillar papillomas, which were HPV-negative. Lesions harboring low-risk HPV-types more often showed a higher p16INK4A staining intensity in the nucleus than in the cytoplasm, whereas this pattern was not explicit in the lesions with high-risk HPV.
Conclusion: A strong p16INK4A overexpression predicts the presence of high-risk HPV-16 in tonsillar dysplasias. Less intense p16INK4A expression may be the result of an infection with low-risk HPV in laryngeal dysplasias and papillomas, or a HPV-unrelated mechanism in tonsillar papillomas.