Expressão imunoistoquímica de P16, ciclina D1 e KI67 em lesões orais

Abstract

P16 is a tumor suppressor gene widely studied in lesions associated with human papillomavirus (HPV) since its overexpression is caused by viral protein E7. Furthermore, this molecule can interact with cyclin D1, an important regulator of cell cycle used a marker of tumor aggressiveness. The expression of the human Ki-67 protein is strictly associated with cell proliferation and consequently the degree of malignancy and prognosis of tumors. This study aimed to evaluate the immunohistochemical expression of p16, cyclin D1 and Ki67 in benign oral lesions showing Koilocytosis and squamous cell carcinoma (CEC) with or without microscopic evidence of viral infection. This is a retrospective study, quantitative and cross carried by lifting paraffin blocks performed in Oral Pathology Laboratory of the course of the Federal University of Ceará Dentistry, from 2008 to 2013. We selected 89 samples grouped in 25 fibroepithelial hyperplasia with Koilocytosis (HFE / Col); 16 oral squamous papillomas (PO); 28 oral squamous cell carcinomas (CEC), subdivided among patients younger than 50 years (CEC-50) and above 50 years (CEC + 50). Were used in 20 cases of fibroepithelial hyperplasia (HFE) as a negative control. In histological review of all groups, except for CEC + 50, cytological changes were found consistent with Koilocytosis (p <0.001). Females were the most prevalent in the whole sample is not, however, statistically significant (p = 0.830). The most affected age groups, in all groups, were the fourth and fifth decades of life, however, without statistical significance (p = 0701). The most common anatomical location in the HFE / Col was the alveolar ridge followed by buccal mucosa in the mouth floor PO and alveolar ridge, the CEC under age 50 the tongue and palate and in cases of CEC over 50 years the tongue, this last significantly (p = 0.015). All benign oral lesions and the group of CEC-50 showed high immunostaining for p16 and cyclin D1, which was statistically significant compared to the negative control (HFE) (p <0.001). The quantitative expression of Ki67 was significantly higher in CEC-50 in the control group (HFE) (p <0.001). We conclude that oral lesions with Koilocytosis (papilloma, HFE / Col and CEC-50) are positive for p16 and cyclin D1 suggests a possible association of pathogenesis with human papillomavirus.