缺氧诱导因子-1抑制剂细胞筛选模型的 建立及抑制剂研究

目的:建立并应用2种缺氧诱导因子-1(HIF-1)抑制剂细胞筛选模型对雷公藤甲素和三白脂素-8活性进行评价,为HIF-1靶点抑制剂的研发提供基础。方法:建立基于报告基因的HIF-1抑制剂细胞筛选模型,U251-HRE和T47D-HRE细胞模型,分别对雷公藤甲素与三白脂素-8活性进行检测,观察其对下游关键调控基因VEGF表达的影响,并用MTT法比较2类抑制剂对多种实体瘤细胞的增殖抑制活性。结果:2种细胞模型在1%O2缺氧20 h,由HIF-1诱导的荧光素酶高表达,可用于抑制剂的活性评价。雷公藤甲素对U251-HRE细胞模型敏感,其HIF-1抑制活性IC50(3.4±0.5)×10-8mol.L-1,而三白脂素-8对T47D-HRE细胞模型敏感,其IC50(2.4±0.6)×10-8mol.L-1;雷公藤甲素和三白脂素-8在1×10-7mol.L-1都可对T47D细胞因缺氧所致的VEGF表达升高产生明显抑制作用,其抑制率分别为85.2%,62.6%;雷公藤甲素对所测肿瘤细胞株都有明显的增殖抑制活性,而三白脂素-8对乳腺癌、胰腺癌细胞株较为敏感。结论:针对不同类别的HIF-1抑制剂建立相应敏感的特异性细胞筛选模型至关重要。

Identification of two small molecule inhibitors of hypoxia-inducible factor 1 with different cell-based screening model

Objective: To investigate the inhibitory activity of HIF-1 by triptolide and manasaantin A, two cell-based models with luciferase report gene assay were established. Method: Two cell-based models of HIF-1 were used to evaluate HIF-1 inhibition activity of triptolide and manasaantin A. Secreted VEGF expression induced by hypoxia was detected by ELISA with two compounds. The growth inhibition of different solid tumor cell lines was measured by the MTT assay. Result: The expression of firefly luciferase was induced by hypoxia in U251-HRE and T47D-HRE cells. U251-HRE model was suitable for the detection of HIF-1 inhibition activity of triptolide. The IC₅₀ of triptolide on HIF-1 activity was (3.4±0.5)×10^-8 mol·L^-1. The report gene assay using T47D cells co-transfected with pGL2-TK-HRE and pRL-CMV showed more sensitive inhibition activity of HIF-1 on manassantin A than that of detected by U251-HRE model. The IC₅₀ of manassantin A on HIF-1 activity was (2.4±0.6)×10^-8 mol·L^-1. HIF-1 target gene VEGF was also inhibited by test compounds on protein level in T47D cells. Manasaantin A showed selective inhibition on the growth of human solid cancer cell lines, especially on breast cancer and pancreatic cancer cells. Meanwhile, triplotide showed strong proliferation inhibition activity on all tested cell lines. Conclusion: It is very important to select a suitable cell-based report gene assay of HIF-1 for screening of different kinds of inhibitor.