Fig. 2

RERG was down-regulated and hypermethylated in NPC cell lines, and restored by pharmacologic demethylation. a Gene expression was detected in tumor cell lines (HK1, C666-1, HK1_EBV) and an immortalized normal epithelia NP460 cells (n = 4) by qRT-PCR. GAPDH was used as an internal control. b RERG was highly methylated in NPC cell lines (HK1, C666-1, HK1_EBV) compared to NP460 (n = 3) by methyl qPCR. c Bisulfite genomic sequencing of the 25 CpG sites within the RERG promoter region in 2 NPC cell lines (HK1 and C666-1) and an immortalized epithelial cell line (NP460). Five clones were randomly selected and sequenced for each sample. Each row represents analysis of an individual promoter allele. Open circles indicate unmethylated cytosines, and filled circles indicate methylated cytosines. d RERG expression of NP460 and NPC cell lines (n = 3) treated with 5-aza-2’-deoxycytidine (Aza) alone or combined with trichostatin A (TSA) (A + T) were determined by qRT-PCR. GAPDH was used as an internal control. *: P < 0.05, **: P < 0.01, ***: P < 0.001 analyzed by Student’s t-test