Cyclin B1 and E2F-1 Expression Correlates with P16 in Head and Neck Squamous Cell Carcinomas
WU Todd, JF Silverman. Allegheny General Hospital, Pittsburgh, PA
Background: Cyclin B1 is a key molecule involved in the transition from G2 to M phase of the cell cycle and interacts with both pRB and p53. E2F-1 is a nuclear transcription factor that binds with pRB during the regulation of several genes needed for cell cycle entry and DNA synthesis. The expression of these cell cycle regulators in head and neck squamous cell carcinomas has not been previously reported.
Design: 64 cases of head and neck squamous cell carcinoma were retrieved for immunohistochemical analysis. The cases encompassed 20 laryngeal carcinomas, 21 tonsillar carcinomas and 21 tongue carcinomas. Immunohistochemical analysis was performed using antibodies directed against p16, E2F-1 and cyclin B1. Positive staining was quantitatively and qualitatively recorded. The fisher exact test and paired T-test were used to determine significance.
Results: p16 positive staining was seen in 2/20 laryngeal carcinomas, 13/21 tonsillar carcinomas, and 8/21 tongue carcinomas. Cyclin B1 staining and E2F-1 staining was increased in all p16 positive carcinomas compared with all p16 negative carcinomas (P<0.001). Staining for cyclin B1 and E2F-1 was also increased in p16 positive tonsillar tumors (P<0.01).
Conclusions: E2F-1 and cyclin B1 are expressed in oropharyngeal squamous cell carcinomas along with p16. This previously unreported finding may indicate a role for cyclin B1 and E2F-1 in Human Papilloma Virus associated carcinogenesis and possible targets for therapy.
Category: Head & Neck
Monday, March 22, 2010 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 173, Monday Morning