J Wang1, X Liu, W Jiang, L Liang. 1. Department of Internal Medicine, School of Oncology, Beijing University, Beijing 100036, China. Wangjie_CC@yahoo.com
Abstract
OBJECTIVE: To investigate the level of telomerase activation (TA) and telomerase catalytic subunit (hEST2) gene mRNA in patients with non-small cell lung cancer, and determine whether they are associated with tumor cell apoptosis, stage, and clinical outcome. METHODS: Primary tumor specimens from 58 patients untreated with chemotherapy and 10 cases of histologically benign and adjacent lung tissue were analyzed. TA and hEST2 were measured by means of a modified telomerase repeat amplification protocol (TRAP) assay and in situ hybridization (ISH), respectively. Terminal deoxynucleotidyl transferase (TdT)-mediated biotin dUTP nick end-labeling (TUNEL) was used to evaluate apoptotic cells. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect bcl-2 mRNA expression. RESULTS: TA and hEST2 were detected in 45 (77.6%) and 43 (74.1%) of 58 tumor specimens, respectively, and not detected in specimens of adjacent and benign lung tissue. One case expressed hEST2 as a weak positive. Statistically significant positive association was found between the level of TA and hEST2 (r = 0.85, P = 0.001). TA and hEST2 were associated with tumor stage, but not associated with tumor grade, gender and patient age. Positive rate of bcl-2 mRNA was 38 (65.5%) of 58 tumor specimens. The mean apoptotic index in the bcl-2 positive group (9.5 +/- 1.3) was lower than that in the bcl-2 negative one (19.8 +/- 2.1, P < 0.05), suggesting that apoptotic index may be inversely associated with bcl-2 expression (r = -0.48, P = 0.041). Bcl-2 expression in the TA and hEST2 positive group (92.1% and 89.4%) was higher than that in the negative one (50.0% and 45.0%, P = 0.043 and P = 0.032, respectively). The apoptotic index was lower in the TA or hEST2 positive group (8.2 +/- 1.4, 10.7 +/- 1.1) than in the negative one (20.5 +/- 1.6, 24.2 +/- 2.1, P < 0.05). A statistically significant inverse association was found between TA or hEST2 and apoptotic index (r = -0.45, P = 0.02 and r = -0.51, P = 0.001, respectively). Positive correlation was also detected between TA or hEST2 and bcl-2 expression (r = 0.86, P = 0.01 and r = 0.73, P = 0.024, respectively). The level of hEST2 mRNA and apoptotic index were associated with clinical outcome in a multivariate cox regression analysis. CONCLUSIONS: High TA and hEST2 were frequently detected in primary non-small cell lung cancer untreated with chemotherapy, having high bcl-2 expression and a low tumor cell apoptotic rate. This suggests that both TA and hEST2 are correlated with the deregulation of apoptosis. hEST2 and apoptotic index have prognostic significance in patients with non-small cell lung cancer.
OBJECTIVE: To investigate the level of telomerase activation (TA) and telomerase catalytic subunit (hEST2) gene mRNA in patients with non-small cell lung cancer, and determine whether they are associated with tumor cell apoptosis, stage, and clinical outcome. METHODS: Primary tumor specimens from 58 patients untreated with chemotherapy and 10 cases of histologically benign and adjacent lung tissue were analyzed. TA and hEST2 were measured by means of a modified telomerase repeat amplification protocol (TRAP) assay and in situ hybridization (ISH), respectively. Terminal deoxynucleotidyl transferase (TdT)-mediated biotin dUTP nick end-labeling (TUNEL) was used to evaluate apoptotic cells. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect bcl-2 mRNA expression. RESULTS: TA and hEST2 were detected in 45 (77.6%) and 43 (74.1%) of 58 tumor specimens, respectively, and not detected in specimens of adjacent and benign lung tissue. One case expressed hEST2 as a weak positive. Statistically significant positive association was found between the level of TA and hEST2 (r = 0.85, P = 0.001). TA and hEST2 were associated with tumor stage, but not associated with tumor grade, gender and patient age. Positive rate of bcl-2 mRNA was 38 (65.5%) of 58 tumor specimens. The mean apoptotic index in the bcl-2 positive group (9.5 +/- 1.3) was lower than that in the bcl-2 negative one (19.8 +/- 2.1, P < 0.05), suggesting that apoptotic index may be inversely associated with bcl-2 expression (r = -0.48, P = 0.041). Bcl-2 expression in the TA and hEST2 positive group (92.1% and 89.4%) was higher than that in the negative one (50.0% and 45.0%, P = 0.043 and P = 0.032, respectively). The apoptotic index was lower in the TA or hEST2 positive group (8.2 +/- 1.4, 10.7 +/- 1.1) than in the negative one (20.5 +/- 1.6, 24.2 +/- 2.1, P < 0.05). A statistically significant inverse association was found between TA or hEST2 and apoptotic index (r = -0.45, P = 0.02 and r = -0.51, P = 0.001, respectively). Positive correlation was also detected between TA or hEST2 and bcl-2 expression (r = 0.86, P = 0.01 and r = 0.73, P = 0.024, respectively). The level of hEST2 mRNA and apoptotic index were associated with clinical outcome in a multivariate cox regression analysis. CONCLUSIONS: High TA and hEST2 were frequently detected in primary non-small cell lung cancer untreated with chemotherapy, having high bcl-2 expression and a low tumor cell apoptotic rate. This suggests that both TA and hEST2 are correlated with the deregulation of apoptosis. hEST2 and apoptotic index have prognostic significance in patients with non-small cell lung cancer.
Authors: Katarzyna Dobija-Kubica; Marzena Zalewska-Ziob; Krzysztof Bruliński; Paweł Rogoziński; Andrzej Wiczkowski; Agata Gawrychowska; Jacek Gawrychowski Journal: Kardiochir Torakochirurgia Pol Date: 2016-03-30