High Specificity of Quantitative Methylation-Specific PCR Analysis for MGMT Promoter Hypermethylation Detection in Gliomas

Figure 3

Comparison of QMSP analysis MSP .   Representative results of Methylation-Specific PCR analysis and comparison with Quantitative Methylation-Specific PCR. As control of the bisulphite conversion the upper panels show PCR reactions specific for the ACTB gene promoter region not containing CpG; the middle panels show PCR reactions specific for the methylated sequence of the MGMT promoter; lower panels show results of QMSP. MW: Molecular weight marker. M, positive control (CpGenome Universal Methylated DNA); UM: Negative control (Universal Unmethylated DNA); N: Normal brain tissue; G: Glioma sample. Normal brain tissues N4, N7, N26 and snap-frozen tumour sample G43 show faint bands in the gel electrophoresis but MGMT/ACTB ratios below the cutoff value of 0.35 by QMSP, snap-frozen sample G45 show no methylated band by MSP but an MGMT/ACTB ratio above the cutoff value of 0.35 by QPCR.