STUDY ON TUMOR CELL LINES AND THEIR TELOMERASE ACTIVITY BY TELOMERASE INHIBITORS

Objective To study the potential anti-tumor effect of telomerase inhibitors. Methods Human colon cancer cell line HC8693, human lung cancer cell line A549, and human liver cancer cell line L7402 were used as target cells. The effects of 3′-azido-3′-deoxythymidine (AZT) and human antisense phosphorothioate deoxynucleotides (S-Oligos) aganist telomerase template on these cell lines were investigated. The cytotoxic effect of AZT and S-Oligos on tumor cells was quantified by using MTT colorimetric assay. Assay of 3H-TdR incorporation was undertaken to measure the cell replication. The changes of telomerase activity after treatment was detected and quantified by telomeric repeat amplification protocol (TRAP) semi-quantitative analysis.Results Both AZT and S-Oligos inhibited the growth of three tumor cell lines in a certain range of concentrations, meanwhile the telomerase activity was reduced after treatment. Moreover, 24 hours after removing AZT and S-Oligos from the media, the telomerase activity still maintain at the low level compared to control group. Among these three cell lines, HC8693 and L7402 were more sensitive to AZT and S-Oligos. Combined effect of AZT and S-Oligos was much stronger than either of the two reagents alone. Conclusion The results indicated that AZT and S-Oligos could be potentially used, alone or in combination, as anti-colon cancer,anti-liver cancer and anti-lung cancer agents or as an auxiliary in cancer treatment.