Clonal Analysis of Oral Squamous Cell Carcinoma in Females by Analysis of X-Chromosome Inactivation

다국어 초록 (Multilingual Abstract)

The clonal origin of squamous cell carcinoma of the oral cavity in females was evaluated by analysis of the methylation pattern of the X-linked androgen receptor (HUMARA) gene. DNA extracted from paraffin embedded archival specimens was digested with Hpa Ⅱ, and PCR was performed to generate amplified DNA fragments of exon Ⅰ of the X-linked androgen receptor gene which contains a highly polymorphic trinucleotide repeat. Of a total of 8 tumors analyzed, 7 cases showed heterozygosity (86%) in the length of the amplification products and were therefore informative of clonal analysis. Clonal composition of the tumors was suggested by amplification of a single product band from Hpa Ⅱ treated genomic DNA. By contrast, PCR of Hpa Ⅱ treated DNA from normal tissue or lesional tissue of polyclonal composition resulted in amplified products of both maternally derived and paternally derived X-chromosomes. These observations indicate the clonal composition of squamous carcinoma of the oral mucous membrane in females. We conclude that analysis of the pattern of X-chromosome inactivation, targeting the AR gene by PCR, permits the determination of clonality in a high proportion of cases from archival tissues.