Fig. 1

Differentially methylated microRNAs in prostate cancer. a Unsupervised hierarchical clustering of microRNAs’ promoters displaying significant alterations in DNA methylation as determined by Infinium HumanMethylation450 BeadChip in 25 prostate cancer (PCa) and 5 morphologically normal prostate tissue (MNPT) samples. Overall, 51 miRNA promoters were differentially methylated in PCa versus MNPT. b Validation of miR-130b~301b by pyrosequencing and (c) by RT-qPCR in 111 primary PCa and 14 MNPT cases, indicated that promoter hypermethylation was associated with miR-130b~301b downregulation. d LNCaP, DU145 and PC3 cell lines retain basal expression of miR-130b and miR-301b. e Reversal of DNA methylation in LNCaP cells using 5-aza-2-deoxycytidine (5-AZA-CdR) increased the expression of miR-130b and, in combination, with TSA augmented miR-301b expression. Mann-Whitney U test: *p < 0.05, **p < 0.01, ***p < 0.001