Effect Of Telomerase Antisense Oligodeoxynucleotides On Telomerase Aitivity And Growth Of Eca-109 Cell Line

Objective Telomerase, a ribonucleoprotein, maintains telomeres by adding telom -ere repeat sequence using the RNA component of the enzyme as a template. Enzyme activity appears to be associated with cell immortality and malignant progression as telomerase activity has been found in the majority of human tumors. Human telomerase RNA(hTR) is the essential component that includes 445 nucleotides with the template region sequence targeted to telomere DNA. If designed antisense telomerase oligonucleotides inhibited telomrase activity, cells would stop proliferating. Telomerase has been proposed as a novel and potentially selective target for tumor treatment. The majority of esophagus cancers express high level of telomerase and even the expression of hTR is earlier than the activation of telomerase. In the present study here, we investigated the effect of phosphorothioate antisense oligonucleotide (PS-ASODN) on telomerase activity changes of cell proliferation in human esophagus cancer cell line Eca-109, aimed at exploring the treatment value of PS-ASODN for esophagus cancer.Methods PS-ASODN of 1 to 5 μ M was incubated with Eca-109 cell line for 1d, 3d, 5d and 7d, respectively. MTT assay was used to determine the cell growth inhibitory rate. Microscope was adopted to examine the morphologic changes of cell after treatment with 5 μ M PS-ASODN for 5d. Telomerase activity was detected by silver staining semi-quantitative TRAP assay.Results 1.PS-ASODN of 1 to 5 μ M inhibited the growth of Eca-109 cell line and inhibitory rate of more than 2 μ M PS-ASODN showed significant difference from control group(P<0.01). Cells were inhibited with an inhibitory rate of 55.9% after treatment of 5 μ M PS-ASODN for 5d. N-ASODN had no inhibitory effect on Eca-109 cell line, which suggesting that the efficacy depended on the dose of PS-ASODN, culture time and sequence selection. 2.The growth rate of cells after incubation with PS-ASODN was veduced in comparison with those of controls. Cells became round, suspended and small with treatment time. 3. Telomerase activity was slightly inhibited after treatment with 5 μ...