RESUMEN
BACKGROUND & OBJECTIVE: Telomerase has been thought to play an important role in the carcinogenesis in recent years. Human telomerase reverse transcriptase (hTERT) is a limiting component for telomerase activity. This study was designed to explore the effect of transfection of the full-length cDNA of antisense hTERT on the malignant phenotype of human pulmonary giant cell carcinoma cell line (PLA-801D) and its potential role in the gene therapy for cancers. METHODS: An antisense hTERT cDNA eukaryotic expression vector pcDNA3.1(-)-hTERT including the full length of hTERT cDNA sequence was constructed using recombinant DNA technique and transfected into human pulmonary giant cell carcinoma cells (PLA-801D) with liposome. The effect of antisense hTERT on the cellular proliferation capacity of PLA-801D cells was analyzed by the growth curve. The expression of hTERT mRNA was examined by reverse transcription polymerase chain reaction (RT-PCR). The telomerase activity was determined by telomeric-repeat amplification protocol enzyme-linked immunoassay (TRAP-ELISA). RESULTS: Antisense pcDNA3.1 (-)-hTERT eukaryotic expression have been constructed and was successfully transfected into the PLA-801D cells. The growth speed of PLA-801D transfected with antisense hTERT was significantly inhibited compared with the control cells, and the hTERT mRNA expression was inhibited, the relatively expression was only 15.7% of control cells, and telomerase activity was down-regulated about 82.4%. CONCLUSION: Full-length antisense hTERT cDNA can suppress hTERT mRNA expression and telomerase activity, and restrict the growth speed of tumor cells.