SEMIQUANTITATIVE ANALYSIS OF TELOMERASE IN PANCREATIC DUCTAL ADENOCARCINOMA

Using a polymerase chain reaction-based amplification assay, we measur ed telomerase activity in surgically resected pancreatic ductal carcin omas (n = 16 cases) and normal ducts (n = 6), comparing findings with the telomerase activity of a human pancreatic cancer cell line, MIA Pa Ca-2, as a standard, i.e., relative telomerase activity was determined . Telomerase activity was expressed as the equivalent telomerase inten sity of the number of cells of MIA PaCa-2 per mu g protein of tissue s amples. The median value for telomerase activity in normal pancreatic ducts was 0.13 and the 25th and 75th percentile were 0.01 and 0.76. Th e median value for telomerase activity in pancreatic ductal adenocarci noma was 34.7 (25th percentile, 4.98; and 75th percentile, 296), signi ficantly higher than that of normal ducts (P < 0.001). When the cut-of f value was set at 1.0 and 3.0, the telomerase positivity rate of panc reatic ductal adenocarcinomas was 100% and 81.3%, respectively. Telome rase may be a specific marker for pancreatic ductal carcinomas.