Investigation of human papillomavirus infections and the expression of related genes in epithelial dysplasias and squamous cell carcinomas of the oral mucosa

Abstract

We studied the prevalence of human papillomavirus (HPV) infections in patients with epithelial dysplasia and squamous cell carcinoma of the oral mucosa, as well as the expression of p53, p53 (mutant type), Rb, p16, p21 and cyclin D1. The subjects were patients with irritation fibroma (IF), mild dysplasia (MiD), moderate dysplasia (MoD), severe dysplasia (SD), carcinoma in situ (CIS), well differentiated squamous cell carcinoma (WSCC) and poorly differentiated squamous cell carcinoma (PSCC) diagnosed at Osaka Dental University Hospital. Six patients, each with one of these conditions were examined. HPV was detected by in situ hybridization (ISH). Expression of p53, p53 (mutant type), Rb, p16, p21 and cyclin D1 was assessed by immunohistochemical staining (IHC). All cases were negative for HPV by ISH. For IHC, marked expression of p53 and mutant type p53 was seen in WSCC and PSCC. We could not detect expression of p21 in CIS, WSCC or PSCC. Marked expression of Rb and cyclin D1 was seen in CIS, WSCC and PSCC. We could not detect expression of p16 in WSCC or PSCC. The results suggested that HPV infections have low correlation with oral cancer. We found that p16 is a useful indicator of HPV infection.