Figure 4

GBGT1 methylation and RNA expression levels in The Cancer Genome Atlas (TCGA) ovarian cancer data. Methylation levels within the GBGT1 CpG island, detected at the (A) cg01169778 and (B) cg18089000 probes on the Illumina Infinium HumanMethylation27 BeadChip array in normal-adjacent ovarian tissue (n = 10), primary ovarian tumor (n = 528) and recurrent tumor (n = 33), do not show a difference among these three groups. (C) Box-plot showing a borderline significant difference in methylation between matched normal adjacent tissue and primary tumor pairs (n = 4 cases). (D) GBGT1 RNA expression, determined by the Illumina HiSeq RNA-Seq platform, stratified by GBGT1 methylation levels at the cg18089000 probe divided into quartiles, (n = Q1(lowest):67, Q2:64, Q3:64, Q4:70). (E) GBGT1 gene expression, determined by the Huex-1_0-st-V2 Affymetrix exon array, stratified by quartiles of methylation levels at the GBGT1 cg18089000 probe (n = Q1:141, Q2:145, Q3:144, Q4:141). **P-value (linear regression) <0.01, ***P < 0.001.