ASSOCIATION OF PITUITARY TUMOR TRANSFORMING GENE EXPRESSION WITH EARLY ORAL TUMORIGENESIS AND MALIGNANT PROGRESSION OF PRECANCEROUS LESIONS

Background. Pituitary tumor transforming gene (PTTG1) is overexpressed in many types of human cancers and is involved in late-stage tumor progression. The role of PTTG1 in initiating tumorigenesis is unclear. Methods. PTTG1 expression was assessed in precancerous lesions and squamous cell carcinomas of the oral cavity (OSCC). The association between the protein expression and clinicopathologic parameters was analyzed. The expression level of PTTG1 upon carcinogen treatment was also investigated. Results. PTTG1 was overexpressed in both precancerous lesions and OSCC. The expression of PTTG1 was associated with carcinogen exposure in vivo and in vitro. PTTG1 overexpression was an independent factor for oral cancer development in precancerous lesions. Conclusions. This study provides the first evidence that PTTG1 is involved in the early stages of oral tumorigenesis. Carcinogen exposure may cause the initial induction of PTTG1 expression in oral precancerous lesions. PTTG1 overexpression is a potential prognosticator for malignant progression of oral precancerous lesions. (C) 2010 Wiley Periodicals, Inc. Head Neck 33: 719-726, 2011