Genomic DNA from cell lines was isolated using the DNA Mini Preparation kit (Qiagen, Inc.). PCR assays were performed by using the promoter methylation PCR kit (Panomics, Redwood City, CA, USA) as described [14 (link)]. Briefly, 2 µg of genomic DNA were digested with 10 units Mse I (New England Biolabs, Boston, MA, USA) which recognizes the TTAA site to produce small fragments of DNA retaining the CpG islands. Following incubation with methylation binding protein (MBP) to form a protein/DNA complex, methylated DNA was isolated by centrifugation using a separation column and amplified at the following PCR program: 94°C for 5 min, 94°C for 1 min, 56°C for 1 min, and 72°C for 2 min for 35 cycles. PCR products were analyzed on 2.2% agarose gel. Based the TTAA site distribution in the LOX promoter, the primer pair including the forward (F) oligomer, 5’-TTCAGACACTGTGCGCTCTC-3’ and the reverse (R) oligomer, 5’-AGGAGGGAGACCTCTTCGAG-3’ was designed and used for amplification of the methylated LOX fragment on the promoter region (205 bp) containing 15 CpG islands.