Methylation profile of the promoter CpG islands of 14 “drug-resistance” genes in hepatocellular carcinoma

Figure 4 Methylation status of the promoter CpG Island correlated the expression state of the GSTpi gene in liver cancer cell lines. Both methylation status (panel 1) and mRNA level (panel 2) of the GSTpi gene in SMMC-7721 (lane 1), Hep3B (lane 2), HepG2 (Lane 3), HCCLM3 (lane 4) are determined and presented. *, size markers, the bands of 250 bp and 100 bp are shown. U, unmethylated; and M, the hypermethylated. The density of the bands (indicated in panel 3) for the intemal control β -actin and the GSTpi gene were densitometrically recorded, where the density of the β -actin in SMMC-7721 cells was arbitrarily taken as 100%. The band-ratio of the GSTpi over the β -actin genes were calculated and summarized in the table and plot (panel 3).