Fig. 1

GR (NR3C1) expression and methylation in ER+ breast tumors and normal tissue from the TCGA breast cohort. a Relative GR mRNA expression levels in normal breast tissue and ER+ breast tumors from normalized RNAseq data. Black lines indicate mean GR expression. P value refers to Student’s t test. b Mean methylation of GR in normal tissue and ER+ tumor samples. Mean methylation calculated from beta-values for the 17 CpGs in the Illumina HumanMethylation450K array located within the GR proximal promoter CpG island. P value refers to Mann-Whitney U test. c Relative GR mRNA expression levels in ER+ tumors with (methylated ER+) and without (unmethylated ER+) GR CpG island methylation. ER+ tumors were divided into unmethylated versus methylated according to the highest mean GR CpG island methylation beta-value from normal breast tissue samples (β = 0.06). Black lines indicate mean expression. P value refers to Student’s t test. d Correlation of GR methylation and expression in ER+ tumors, at all 36 CpG sites across the GR gene included in the HM450K array. Methylation for all sites in the GR CpG island and proximal promoter region is correlated with reduced expression of GR mRNA levels, with Spearman correlation P < 0.05 unless otherwise indicated as not significant (ns)