Methylthioadenosine phosphorylase expression in cutaneous squamous cell carcinoma

The methylthioadenosine phosphorylase (MTAP) gene is a tumour suppressor gene, located on chromosome 9p21, 100 kb telomeric of the p15 and p16 genes, which are often deleted in tumor cells. The role of MTAP protein expression in the genesis of cutaneous squamous cell carcinoma (SCC) is currently not known. In a previous study we have shown the frequent occurrence of allelic imbalance / loss of heterozygosity (AI/LOH) in cutaneous SCCs using AI/LOH markers flanking the p15, p16, and MTAP genes and demonstrated reduction in p15 and p16 protein expression in comparison to normal human skin. The present study is a continuation to our previous studies, aimed at determining possible roles played by MTAP protein expression in the genesis of cutaneous SCC. The expression of MTAP protein was detected using immunohistochemical approach in 109 micro array cutaneous SCC and 20 normal human skin tissue samples. The expression of MTAP was not significantly different in the cutaneous SCC cases as compared with normal human skin. This may indicate that MTAP protein expression does not contribute to the genesis of cutaneous SCC.