Methylome analysis for prediction of long and short survival in glioblastoma patients from the Nordic phase 3 trial

Genome wide DNA methylation profiling of glioblastoma tumor samples from the Nordic randomised, phase 3 trial. For this study samples were selected based on their good prognostic markers (type of surgery, performance status) from three treatment arms (temozolomide (TMZ) vs. hypofractionated radiation 34Gy vs. radiation 60Gy), and based on the MGMT methylation status. From each group half of the patients had short survival and the other half had long survival. 59 samples FFPE samples, histologically described as glioblastoma. DNA was extracted with Maxwell FFPE DNA Purification Kit (Promega) and quantified using Quantus (Promega), after which it was bisullfite converted with EZ DNA methylation kit (Zymo Research). The quality was assessed with the Illumina Infinium HD FFPE QC Assay Protocol and methylome analysis was done with the Infinium MethylationEPIC BeadChip Kit (Illumina) complemented by the Infinium HD FFPE DNA Restore Kit.