Objective: To study telomerase activity (TA), telomerase RNA (hTR) and telomerase catalystic subunit (hTRT/hEST2) code gene expression in non-small cell lung cancer (NSCLC), their relationship and significance.
Methods: Telomerase repeat amplification protocol PCR (TRAP-PCR) for TA, RT-PCR for hTR and in situ hybridization for hTRT/hEST2 mRNA expression were performed.
Results: Positive rates of TA, hTR and hTRT/hEST2 were 68.4%(26/38), 51.7%(32/58) and 74.2%(43/58) in NSCLC. But, the adjacent and benign lung tissues were negative for expression of TA, hTR and hTRT/hEST2. A statistically significant positive correlation between TA and hTRT/hEST2 was observed(r = 0.84, P = 0.01), though there was no statistically significant positive association between TA and hTR (r = 0.16, P = 0.23). The median survivals of TA and hTRT/hEST2 positive groups (10.4 months, 7.5 months) were shorter than the negative ones (13.5 months, 14.7 months). However, only the hTRT/hEST2 group was found to show statistical significance to be an independent prognostic factor by multivariate Cox regression analysis.
Conclusion: Telomerase activity, hTR expression and hTRT/hEST2 are frequently detected at higher levels in NSCLC than the pericancerous normal tissues. There is a positive correlation between TA and hTRT/hEST2, both of which are markers of poor magnificent phenotype of NSCLC. The hTRT/hEST2 has an independent prognostic significance.