Loss of Expression of the p16 Gene Is Frequent in Malignant Skin Tumors

Expression of the p16 gene from 30 malignant skin tumors has been surveyed by immunohistochemical assay. Gene point mutations were detected by DNA direct sequencing and the mRNA level of gene expression was measured by RT-PCR. A silent point mutation of the p16 gene was found in only one patient. However, loss of expression of the p16 gene was noticed in 23 of 29 samples (79.3%). Correlation between loss of expression of the p16 gene and metastasis is significant (p = 0.0036). These findings suggest that loss of expression of the p16 gene may play a critical role in tumor progression of malignant skin tumors.