Figure 1

Representative methylation-specific PCR (MSP) analyses of the MGMT promoter in GBM tissue from eleven patients (P). Note the presence of bands in both the unmethylated (U, 93 bp) and methylated (M, 81 bp) lanes for glioblastoma samples 21, 33 and 40, reflecting a methylated MGMT promoter. The lack of a band in the lane corresponding to methylation-specific primers for GBM in the rest of the samples reflects the absence of MGMT promoter methylation. In some samples, such as sample 23, no PCR products were observed (sample excluded).