The use of a novel ELISA method for detection of antibodies against p63 in sera from patients diagnosed with oral and/or genital and skin lichen planus.

Lichen planus is a chronic inflammatory disease of mucosa and skin affecting approximately 1-2% of the adult population. Autoimmunity has been implicated in the etiology of this disease, and recently we detected antibodies directed against all six p63 isoforms in sera from 2 out of 20 patients diagnosed with oral lichen planus (OLP) using Western blot analysis. Here we have developed an ELISA method for screening sera for presence of autoantibodies directed against p63. Using the same sera as previously analysed, we show that the optical density ratios for sera from the two patients with known autoantibodies was considerably higher compared to mean optical density ratios for all samples as well as controls analysed. Applying this novel ELISA technique for screening of sera from an additional group of 46 patients with oral and/or genital or skin lichen and 43 matched controls, we detected another three patients with autoantibodies against the p63 proteins. These data are discussed together with the observation that all five patients with detectable p63 autoantibodies from our two studies had clinically severe disease symptoms.

Function and importance of p63 in normal oral mucosa and squamous cell carcinoma of the head and neck.

BACKGROUND/AIMS: Squamous cell carcinoma of the head and neck (HNSCC) is the 6th most common malignancy worldwide with a 5-year survival that has not improved over the last 20-25 years. Factors of prognostic significance for this tumour type include the presence of regional lymph node metastasis and amplification of chromosome 3q21-29, where the p63 gene is located. This gene encodes 6 proteins and is crucial for formation of the oral mucosa, teeth, salivary glands and skin. Each of the 6 different p63 proteins has different characteristics and functions, where some resemble the tumour suppressor protein p53, whilst others have functions that oppose p53. METHODS: To understand the function and importance of p63 in oral mucosa and tumour development we have studied protein as well as mRNA expression in normal oral mucosa and tumours. RESULTS/CONCLUSION: Expression of p63 proteins differs between the cell layers in normal oral mucosa, and primary HNSCC has a high expression level of p63 isoforms normally expressed in basal cells. Data suggest that p63 expression in HNSCC influences tumour cell differentiation.