Detection of telomerase activity in exfoliated cancer cells obtained from bile

Telomerase is detected by the telomeric repeat amplification protocol (TRAP ) assay in more than 85% of primary cancers. In the present study, we deter mined telomerase activity using exfoliated bile cells obtained from biliary tract neoplasia specimens. The aim of this study was to provide additional information regarding minimally invasive approaches to the detection of bi liary tract cancer in combination with routine cytologic examination. We an alyzed for telomerase activity bile juice from patients with gallbladder ca rcinoma, cholangiocarcinoma, cholecystitis and cholangitis. Semiquantitativ e determination of telomerase activity was performed using both a fluoresce nce-based TRAP assay on cell extracts and at the cellular level by an in si tu TRAP assay. The fluorescence-based TRAP assay detected bile telomerase a ctivity in samples from 4 of 10 patients with biliary tract cancer. In cont rast, the in situ TRAP assay detected telomerase positive cells in samples from 6 of 10 patients with biliary tract cancer. However, only one of these samples showed class V cytology. A combination of semiquantitative analysi s and an in situ TRAP assay to detect telomerase positive cells may improve the diagnosis of biliary tract cancers with the combination of routine cyt ologic examination.