Effect Of Antisense-oligodeoxynucleotide Aimed HTERT On Telomerase Activity And Cell Apoptosis In K562 Cell Line

Objective: Activation of telomerase plays an important role in the development of cellular immortalization and oncogenesis. Telmerase, a kind of reverse transcriptase, can use its own RNA template to synthesize the repeated sequence (5-TTAGGG-3)n of telomere DNA , adds it to the chromosome ends, maintain telomere length , and results in cellular immortalization and oncogenesis. Telomerase is composed of an RNA component (hTR), an associated protein (TP1) and a catalytic reverse transcriptase subunit (hTERT). It has been reported that high level expression of hTERT exists in 80-90% of cancer tissue and there is close correlation between hTERT and telomerase activation, it is a rate limiting factor of telomerase activation. In this study, K562 cell line was transfected with anti-sense phosphorothioate aoligonucletide (AS PS ODN) aimed directly to hTERT mRNA by lipofectamine, and observed its inhibiting effect on aimed gene and the influence on the telomerase activity and cell apoptosis ofK562 cells. The inhibiting mechanism was explored to provide the experimental base of hTERT as a target for antisense gene therapy in the leukemia.Method: Human leukemia cell line K562 was transfected with anti-sense oligonucleotide ASODN and SODN(sense phsophorothioate oligodeoxynucleotide) by liposome in three different concentrations (0.2μΜ,0.6μΜ,1.0μΜ). At the same time, blank control and liposome control were designed as comparement. Cells were collected to detect at 24 and 48 hours. RT-PCR was used to detect the expression of target gene hTERT mRNA, telomerase activation was detected by TRAP-PCR-ELISA...