Analysis of the correlation between methylation status and expression of MEG3 . (A) Analysis of MEG3 expression levels in NSCLC cell lines (A549, SPC-A1, NCI-H1650, NCI-H1299, NCI-358, NCI-H1975 and SK-MES-1) compared with the normal bronchial epithelial cell line (16HBE) by qRT-PCR. (B) The level of MEG3 expression in SPC-A1 cells following 5-aza-dC (0, 5, 10 μM) treatment. (C) The methylation status of the CpG island of MEG3 was assessed by bisulfite sequencing in NSCLC and normal tissues. Open and filled squares denote unmethylated and methylated CpG sites, respectively. Each row represents a single clone. *P < 0.05; **P < 0.01.