Recently, we classified LINE-1 loci according to their methylation statuses and found that the percentage of hypomethylated LINE-1 loci ((u)C(u)C) can differentiate between the peripheral blood mononuclear cells (PBMCs) of oral cancer patients and normal controls with a higher specificity and sensitivity than overall methylation levels. Here, we evaluated the LINE-1 methylation levels and patterns in PBMCs from patients with cancers of the nasopharynx, lung, liver, bile duct, breast and colon.
METHODS:
Combined Bisulfite Restriction Analysis (COBRA) of LINE-1 loci was performed to examine the LINE-1 methylation statuses of PBMCs from 216 cancer patients with 6 different types of cancer compared with 144 normal controls.
RESULTS:
Only colorectal and nasopharyngeal cancer samples were found to have lower levels of overall LINE-1 methylation compared with normal controls (p