Methylated CpG Island Amplification of Representational Difference Analysis for Oral Cancer

CpG islands are G+C-rich regions approximately 1 kb long that are free of methylation and contain the promoters of many mammalian genes. It has been demonstrated that aberrant methylation of CpG islands is associated with gene silencing of tumor suppressor genes. To examine DNA methylation changes in oral squamous cell carcinoma (OSCC), we have applied a novel genome screening technique, methylated CpG island amplification coupled with representational difference analysis. Using DNA from an OSCC cell line as tester and DNA from normal tongue tissue as driver, DNA sequences aberrantly methylated in OSCC can be obtained. We therefore propose that MCA is a useful technique to study methylation and to isolate CpG islands differentially methylated in cancer.