Zhao Yan-min, Zhou Qian, Xu Yun, Lai Xiao-yu, Huang He
Bone Marrow Transplant Center, The First Affiliated Hospital of Zhejiang University Medical School, Hangzhou 310003, China.
Acta Pharmacol Sin. 2008 Apr;29(4):481-8. doi: 10.1111/j.1745-7254.2008.00767.x.
To examine the ability of rapamycin to suppress growth and regulate telomerase activity in the human T-cell leukemia cell line Jurkat.
Cell proliferation was assessed after exposure to rapamycin by 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide assay. Cell cycle progression and apoptosis were determined by flow cytometry. The proteins important for cell cycle progression and Akt/mammalian target of rapamycin signaling cascade were assessed by Western blotting. Telomerase activity was quantified by telomeric repeat amplication protocol assay. The human telomerase reverse transcriptase (hTERT) mRNA levels were determined by semi-quantitative RT-PCR.
Rapamycin inhibited the proliferation of Jurkat, induced G1 phase arrest, unregulated the protein level of p21 as well as p27, and downregulated cyclinD3, phospho-p70s6k, and phospho-s6, but had no effect on apoptosis. Treatment with rapamycin reduced telomerase activity, and reduced hTERT mRNA and protein expression.
Rapamycin displayed a potent antileukemic effect in the human Tcell leukemia cell line by inhibition of cell proliferation through G1 cell cycle arrest and also through the suppression of telomerase activity, suggesting that rapamycin may have potential clinical implications in the treatment of some leukemias.
研究雷帕霉素抑制人T细胞白血病细胞系Jurkat生长及调节端粒酶活性的能力。
通过3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐法评估雷帕霉素作用后细胞的增殖情况。采用流式细胞术检测细胞周期进程和凋亡情况。通过蛋白质印迹法评估对细胞周期进程及Akt/雷帕霉素哺乳动物靶标信号级联反应重要的蛋白质。采用端粒重复序列扩增法检测端粒酶活性。通过半定量逆转录聚合酶链反应测定人端粒酶逆转录酶（hTERT）mRNA水平。
雷帕霉素抑制Jurkat细胞增殖，诱导G1期阻滞，上调p21及p27蛋白水平，下调细胞周期蛋白D3、磷酸化p70s6k和磷酸化s6，但对凋亡无影响。雷帕霉素处理降低端粒酶活性，并降低hTERT mRNA和蛋白表达。
雷帕霉素通过G1期细胞周期阻滞抑制细胞增殖以及抑制端粒酶活性，在人T细胞白血病细胞系中显示出强大的抗白血病作用，提示雷帕霉素在某些白血病治疗中可能具有潜在的临床意义。
