Expression of p53 in oral squamous cell carcinoma is associated with the presence of IgG and IgA p53 autoantibodies in sera and saliva of the patients

Abstract

Around 50% of head and neck cancers are known to have aberrations of the p53 gene. Overexpression of the mutant p53 protein can induce a specific humoral response in cancer patients. Matched saliva, serum, and tissue samples from 26 patients with histologically confirmed oral squamous and verrucous carcinoma were investigated. p53 protein expression was evaluated by immunohistochemistry and antibodies specific for 53 protein were analysed in sera and whole mouth saliva by ELISA, immunoprecipitation, and competition assays; 16/25 (64%) samples demonstrated the stabilized p53 protein in tissues and 7/26 (27%) had a high level of p53 antibody in serum. In samples where matching saliva was available, p53 antibody was also present in saliva. In some tumours, only IgA-type p53 antibody was detected. p53 antibodies were found only in the serum and saliva of patients who showed p53 overexpression in their tumour tissues. These results demonstrate that detection of p53 antibodies can offer a specific and non-invasive method for the detection of a subset of tumours with p53 aberrations.