Fig. 2

TSPO promotor hypermethylation as uncovered by direct bisulfite sequencing is correlated to IDHmutation. Overview of methylation scores from direct bisulfite sequencing and qPCR expression values for TSPO in IDH-mut (R_DA01-R_AA05) and IDH-wt gliomas (R_GB01-R_GB12) in TSPO CpG island subarea chr22: 43,151,840 − 43,152,163 (a). Distribution of mean methylation scores reveals significant differences between IDH-mut and IDH-wt gliomas (Mann Whitney U, ***p < 0.001). Non-neoplastic brain shows weak/no methylation comparable to IDH-wt gliomas (b). Spearman correlation of methylation scores and qPCR expression values reveals a weak but significant inverse correlation (r = − 0.4404, *p = 0.0403) (c). Significances are displayed as follows: p > 0.05 = n.s., p < 0.05 = *, p < 0.01 = **, p < 0.001 = ***. Blood: unmethylated control, CpG: 5’-C-phosphate-G-3’, IDH: isocitrate dehydrogenase, HMC: hypermethylated control, IDH-wt: IDH-wildtype, IDH-mut: IDH-mutant, NB: non-neoplastic brain, TSS: transcription start site, qPCR: real-time quantitative polymerase chain reaction, R_DA: diffuse astrocytoma, R_AA: anaplastic astrocytoma, R_GB: glioblastoma