Patterns of DNA methylation of the parathyroid hormone-related protein gene in human lung carcinoma

Humoral hypercalcaemia of malignancy often results from production of parathyroid hormone-related protein (PTHrP) by the tumour. We have investigated whether malignancy is associated with epigenetic changes in the PTHrP gene in lung. In normal and tumour tissue, there was a general background of nonmethylation in the PTHrP gene. In the 5' region, there appeared to be increased methylation of sites upstream of the promoter, P2. The extent of methylation increased from germ line to normal tissue to tumour tissue to tumour cell line, indicating that new methylation events in this region mark neoplastic change in lung cells.