[Effects of vinorelbine on apoptosis and expression of telomerase activity in human lung adenocarcinoma cells in vitro].

OBJECTIVE: To study the effect of vinorelbine on apoptosis, telomerase activity and expression of hTERT gene in human lung adenocarcinoma cell line Anip973 cells. METHODS: Anip973 cells were cocultured with Vinorelbine at different concentrations and collected at 24 h, 48 h and 72 h after treatment, respectively. The inhibition rate of cell growth was determined by methyl thiazolyl tetrazolium (MTT) assay to evaluate the effect of vinorelbine. The percentage of apoptosis was detected by flow cytometry. The cellular morphology was observed under inverted microscope and electron microscope. Telomerase activity of Anip973 cells was determined by the method of TRAP-PAGE-silver staining. RT-PCR was used to detect the expression of hTERT mRNA. RESULTS: Vinorelbine down-regulated the telomerase activity and expression of hTERT gene mRNA, inhibited the growth of Anip973 cells, and induced cell apoptosis in a time- and concentration-dependent manner. Annexin V-FITC assay showed 0.08 µg/ml NVB group could inhibited cell proliferation in 24 hour, and apoptosis rate was (7.37 ± 0.35)%, RT-PCR detection of hTERT mRNA expression in this group was (57.01 ± 1.71), and they were very significantly different from that in the control group (P < 0.01), but telomerase activity was (6.36 ± 0.06), compared with the control group showed no significant difference(P > 0.05). The change of hTERT mRNA expression is more sensitive than telomerase activity. The apoptosis rate, telomerase activity and hTERT mRNA expression of 0.4 µg/ml group and 2.0 µg/ml group were very significantly different from that in the control group (P < 0.01). The telomerase activity of 2.0 µg/ml at 72 hour group was (1.36 ± 0.27), basically completely inhibited, while the apoptosis rate was (74.87 ± 1.88)%, showed the cell apoptosis rate was in a negative correlation with the down-regulation of the hTERT mRNA (r = -0.96046, P < 0.01). CONCLUSIONS: Vinorelbine can induce apoptosis in Anip973 cells, and its mechanism of action is related to telomerase activity. The detection of telomerase activity and expression of hTERT gene is useful in predicting prognosis of patients with lung adenocarcinoma.