多胺生物合成抑制剂对Hep-2细胞生长及端粒酶活性影响的研究

Effect of inhibition of polyamine biosynthesis on the growth and telomerase activity of human laryngeal carcinoma cells Hep-2

目的 观察多胺生物合成抑制剂二氟甲基鸟氨酸 (difluoromethylornithine,DFMO)对人喉鳞状细胞癌细胞Hep 2生长特性及端粒酶活性的影响 ,以期为抑制多胺生物合成逆转肿瘤恶性表型的分子机理寻找线索。方法 根据细胞形态、细胞生长曲线及流式细胞计 (flowcytometer)观察分析Hep 2细胞生长状况 ;用端粒酶重复序列扩增法 (telomeraserepeatamplificationprotocol,TRAP)检测Hep 2细胞端粒酶活性。结果 DFMO (2 .5mmol/L或 5mmol/L ,5d)处理Hep 2细胞 ,其生长受到明显抑制 ;G1期细胞增多 ,而S期细胞减少 ;细胞形态及FCM证明有细胞凋亡诱导 ;端粒酶活性受到明显抑制。当用腐胺与DFMO同时处理Hep 2细胞时可防止上述变化的发生。结论 多胺生物合成抑制剂可引起Hep 2细胞的增殖抑制及凋亡诱导 ,这些变化与端粒酶活性的抑制有关。

Objective To observe the effect of difluoromethylornithine (DFMO),an inhibitor of polyamine biosynthesis,on the growth and telomerase activity of human laryngeal carcinoma cells Hep 2, and try to find a new clue to search for the mechanism of reversion of tumor malignant phenotype via polyamine biosynthesis inhibition. Methods The growth characteristics of Hep 2 cells treated with DFMO were studied by morphological observation, cell growth curve and FCM analysis. Telomerase activity was detected by Telomerase Repeat Amplification Protocol (TRAP). Results The inhibition of cell proliferation, a marked increase in G 1 and a decrease in S phase populations in the cell cycle of 2.5 mmol/L or 5 mmol/L DFMO treated Hep-2 cells were demonstrated; The cell apoptosis was shown by cell morphology and apoptosis peak in FCM; The telomerase activity of the treated cells was suppressed, while these changes were prevented by provision of exogenous putrescine(Pu) along with DFMO. Conclusion Inhibition of polyamine biosynthesis could result in the proliferation inhibition and apoptosis induction of Hep 2 cells, which was associated with suppressed telomerase activity. It is suggested that inactivation of telomerase would be one of the important molecular events in reversion of tumor malignant phenotype via inhibition of polyamine biosynthesis.