端粒酶抑制剂对肿瘤细胞及其端粒酶活性的影响

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

目的 探讨端粒酶抑制剂作为肿瘤治疗药物的可行性。方法 选择人结肠癌细胞株 HC86 93、人肺癌细胞株A5 49以及人肝癌细胞株 L740 2作为靶细胞 ,观察 3′-叠氮 -3′-脱氧胸腺核苷 (AZT)和人端粒酶模板区的硫代反义寡核苷酸 (S- Oligos)对上述几种肿瘤细胞株的作用 ,用 MTT试验测定细胞毒作用 ;3H - Td R掺入试验测定细胞增殖速度 ;用端粒重复序列扩增法 (TRAP)半定量方法测定细胞染毒前后端粒酶活性的变化。结果 反义核苷酸片段和 AZT在一定剂量范围内有抑制肿瘤细胞株繁殖的作用 ,在抑制细胞生长的同时 ,端粒酶活性降低 ,去除抑制剂 2 4h后 ,端粒酶活性仍然维持在较低水平。三种细胞中 ,HC86 93和 L740 2对两种抑制剂较 A5 49细胞株更加敏感 ,两种抑制剂联合应用比单独应用的效果好。结论 AZT和 S- Oligos单独或联合应用在体外有抗肿瘤细胞的作用 ,进一步深入的研究有助于新的抗癌药物的开发。

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.