Allele-Specific Expression Analysis of PEG1/MEST in Head and Neck Squamous Cell Carcinomas

Genomic imprinting is an epigenetic feature that plays a significant role in carcinogenesis. In this study, we examined the expression status of an imprinted gene, paternally expressed gene 1/mesoderm-specific transcript PEG1/MEST, in 38 cases of head and neck squamous cell carcinomas (HNSCCs) and in 17 oral squamous cancer cell lines. Loss of imprinting (LOI) of PEG1/MEST was found in 8 of 10 (80%) in tumor specimens, and 6 of 10 (60%) informative cases even in the extracted normal tissue specimens. As for the oral squamous cancer cell lines, LOI was detected in 5 of 8 (62.5%) informative cases in PEG1/MEST. Thus, these data showed that abnormal expression of PEG1/MEST was found at a high frequency in the tumor, the extracted normal tissue specimens and the oral squamous cancer cell lines. PEG1/MEST LOI in extracted normal tissue specimens may have a potential individual cancer risk for HNSCC.