重组人肿瘤坏死因子调节端粒酶活性的体外研究

Regulation of the telomerase activity by recombinant human tumor necrosis factor in vitro

目的 研究重组人肿瘤坏死因子 (rhTNF)对端粒酶活性的调节作用。方法 将不同浓度rhTNF加入肝癌细胞株HepG2和HepG1 6细胞 ,以TRAP ELISA方法测定其端粒酶活性 ;采用Lipofect脂质体转染法将携带端粒酶催化亚单位—端粒酶逆转录酶 (hTERT)启动子的质粒转染至肝癌细胞株HepG2细胞 ,2h后加入不同浓度的rhTNF ,孵育 48h后 ,分别检测其报告基因萤虫素酶活性。 结果 在 10～ 10 0 0IU/ml浓度范围内 ,rhTNF可抑制端粒酶活性 ,同时在该浓度范围内 ,rhTNF可显著抑制hTERT启动子的表达 ,其抑制作用与rhTNF剂量呈正相关。结论 rhTNF杀伤肿瘤细胞的机制可能与其抑制hTERT的表达有关。

Objective To investigate the effect of recombinant human tumor necrosis factor (rhTNF) on telomerase activity in hepatoma cell line HepG2 cells and HepG1 6 cells. Methods TRAP ELISA method was used to determine the telomerase activity in HepG2 and HepG1 6 cells which were treated by different concentrations of rhTNF; plasmid which had been inserted 800 bp of the hTERT promoter was transiently transfected into HepG2 cells by Lipofect, and different concentrations of rhTNF were added into culture media 2 hours later, then the activity of the hTERT promoter was tested 48 hours after transfection. Results The telomerase activity of HepG2 was suppressed by rhTNF in a dose dependent manner. The expression of hTERT promoter was inhibited linearly with the dose of rhTNF within the range of 10～1 000 IU/ml. Conclusions Above results suggest that the anti tumor activity of rhTNF may attribute to its inhibitory effect on hTERT promoter expression.