RESUMEN
Objective To investigate the effects of quercetin on the growth of lung cancer cell line A549 and the expression of hTERT gene. Methods The number of viable cells was ascertained by trypan blue dye exclusion test. Morphological changes of apoptotic cells were observed by electronic microscopy and DNA ladder assay. The telomerase activity was analyzed by PCR-TRAP assay and hTERT mRNA expression was detected by quantitative RT-PCR. Results Quercetin had a significant inhibition on the proliferation of A549 cells in a dose-dependent manner. The IC50 was 22.5 ?mol/L after exposure to quercetin for 48 h. The results from electron microscopy and DNA ladder showed that apoptosis occurred in the A549 cells of treatment groups. The results of quantitative RT-PCR and PCR-TRAP revealed that the expression of hTERT mRNA was significantly inhibited by quercetin and telomerase activity was decreased. Conclusion Quercetin inhibits the growth of lung cancer cell line A549 in a dose-dependent manner,and induce their apoptosis. The down-regulated expression of hTERT,suppression of telomerase activity and destruction of telomere stability may all contribute to the mechanism of apoptosis induction.
RESUMEN
Objective To investigate the significance of the expression levels of humans telomerase reverse transcriptase(hTERT) gene in peripheral blood mononuclear cells with lung cancer patients. Methods From Mar.2002 to Feb.2005,the expression levels of hTERT were detected in 30 lung cancer patients and 15 normal humans by quantitative measurement with RT-PCR. Results The expression levels of hTERT mRNA in lung cancer patients (0.906?0.112) were significant as compared with those health controls(0.407?0.104). Conclusion It is effective to diagnose lung cancer by the quantitative measurement with RT-PCR for the expression levels of hTERT mRNA.