[Detection of telomerase activity in bronchoscopic brush-off samples in patients with lung cancer]

Recent studies have shown that activation of telomerase plays an important role in carcinogenesis. However, there was few report on the level of telomerase activity in small samples from the patients with lung cancer. This study was designed to investigate the diagnostic significance of the detection of telomerase activity in bronchoscopic brush-off cells from the patients with lung cancer.

Telomeric repeat amplification protocol(TRAP)-based telomerase polymerase chain reaction(PCR)-enzyme-linked immunosorbent assay (ELISA) TRAP-PCR-silver staining were employed to detect telomerase activity in 56 samples of brushing cells from the patients with lung cancer and 10 samples with inflammation.

The positive rate of telomerase activity in 56 biopsy samples of lung cancer group was significantly higher than that in inflammation group (P < 0.001). The sensitivity, specificity, and accuracy of detection of telomerase activity was 87.5%, 83.3%, and 86.3%, respectively. There was no significant difference in the positive rate of telomerase activity between central lung cancer and peripheral lung cancer. Positive rate of detection of telomerase activity in bronchoscopic brush-off cells was 46.4%. The positive rate of telomerase activity detected in TRAP-PCR-ELISA was higher than that detected in TRAP-silver staining, but the significant difference was not found. It was found that samples with low absorbing value detected in the quantified way would show weak positive with less ladder bands or vague ladder bands if detected in the latter way.

The telomerase activity may be a good marker for diagnosis of lung cancer. Combined with cytologic measure, it is possible to raise the early diagnostic rate of lung cancer.