Direct, real-time PCR （MethyLight） assay for methylation of O6-methylguanine-DNA methyltransferase promoter in glioma

O6-Methylguanine-DNA methyltransferase （MGMT） is a cellular DNA repair protein that rapidly reverses alkylation （e.g. methylation） at the O6 position of guanine, thereby neutralizing the cytotoxic effects of alkylating agent therapy such as temozolomide （TMZ） and carmustine. It has been shown that epigenetic silencing of the MGMT gene by promoter methylation shuts down gene transcription and reflects a common alteration in primary human tumors leading to MGMT deficiency. Epigenetic silencing of the MGMT gene has been shown to correlate with improved survival in several studies of glioma patients treated with the alkylating agent therapy and has been substantiated in two clinical trials.