Specific detection and quantitation of SCC antigen 1 and SCC antigen 2 mRNAs by fluorescence-based asymmetric...

Squamous cell carcinoma antigen (SCCA) is expressed in normal squamous epithelia and malignant squamous cell tissues. The serum level of SCCA has been used to evaluate treatment efficacy, clinical course of disease, and recurrence. SCCA is produced by at least two genes (SCCA1 and SCCA2); both of them have been located on chromosome 18q21.3. It has been difficult to examine the expression levels of SCCA1 and SCCA2 mRNAs separately because of their high homology at nucleotide level. In the present study, asymmetric semi-nested reverse transcription PCR, based on the principle of fluorescence energy transfer, enabled to quantitate the copy numbers of both SCCA1 and SCCA2 mRNAs. Using this method, the expression levels of these mRNAs were evaluated in normal and malignant squamous tissues. The copy number of SCCA2 mRNA was higher in malignant tissues than in normal tissues, while those of SCCA1 mRNA did not significantly differ between normal and malignant tissues. These data indicate that specific quantitation of the expression level of SCCA2 mRNA may be useful for the diagnosis and management of patients with squamous cell carcinoma.