A study of cytokeratin 19 gene expression in erythroplakia

The expression of the cytokeratin (CK) 19 gene was investigated by reverse transcription-polymerase chain reaction (RT-PCR) and Northern blotting in two cases of erythroplakia, arising in the floor of the mouth of a 61-year-old man and the tongue of a 54-year-old man. Normal gingival tissue and squamous cell carcinomas were used as control. The results were as follows:1. Expression of CK19 mRNA on RT-PCR analysis. CK19 mRNA was moderately expressed in erythroplakia, slightly expressed in normal gingiva, and strongly expressed in squamous cell carcinomas.2. Expression of CK19 mRNA on Northern blotting analysis. CK19 mRNA was moderately expressed in erythroplakia and strongly expressed in squamous cell carcinomas. CK19 mRNA was slightly expressed in normal gingiva.These results indicate that epithelial dysplasia and carcinoma are abnormal processes of epithelial cell differentiation.