雷公藤内酯醇对非霍奇金淋巴瘤基质细胞衍生因子-1及其特异性受体生物学轴效应的影响

Effects of triptolide on stromal cell derived factor-1/CXCR4 biological axis in non-Hodgkin lymphoma

目的研究雷公藤内酯醇对非霍奇金淋巴瘤(non-Hodgkin lymphoma,NHL)细胞系Raji增殖的抑制作用,并探讨雷公藤内酯醇体外抑制NHL肿瘤细胞通过淋巴结转移的作用及其分子机制。方法采用MTT法测定雷公藤内酯醇对Raji细胞增殖的影响;采用RT-PCR方法检测雷公藤内酯醇对NHL淋巴结基质细胞中基质细胞衍生因子-1α(SDF-1α)表达的影响;采用流式细胞术检测雷公藤内酯醇作用前后NHL淋巴结瘤细胞CXCR4受体表达水平的变化;采用Transwell微孔隔离室迁移实验观察雷公藤内酯醇对NHL淋巴结瘤细胞体外迁移的影响。结果MTT法表明低剂量雷公藤内酯醇(6.25～25nmol/L)即可以时间和剂量依赖方式明显抑制Raji细胞的生长;其作用24、36、48、60、72h的IC50值分别为43.06、25.08、7.32、2.66、0.58nmol/L。RT-PCR结果显示雷公藤内酯醇能抑制NHL淋巴结基质细胞SDF-1α的表达,其中较低剂量组(12.5nmol/L)与对照组相比有一定的降低,但差异无显著性(P>0.05),而较高剂量组(25、50nmol/L)则可明显抑制SDF-1α的表达(P<0.05),并具有量效关系。流式细胞术分析结果发现经不同浓度雷公藤内酯醇处理后,NHL淋巴结瘤细胞CXCR4表达率与对照组相比逐渐下降(P<0.01),此抑制效应呈剂量依赖性。Transwell趋化活性分析显示雷公藤内酯醇既能抑制重组人SDF-1α对NHL淋巴结瘤细胞的趋化作用,也能阻断NHL淋巴结基质细胞对瘤细胞的体外迁移,且雷公藤内酯醇对趋化作用的抑制具有剂量依赖关系。结论雷公藤内酯醇具有抗淋巴瘤细胞增殖的效应,并能阻断NHL淋巴结瘤细胞通过淋巴结的转移。其抗肿瘤机制及其抗细胞增殖作用与对NHLSDF-1/CXCR4生物学轴的抑制效应有关。

Objective To investigate the antiproliferative effect of triptolide on non-Hodgkin lymphoma （NHL） cell line Raji cells and to study the effects of triptolide on the lymph node metastasis in NHL and its molecular mechanism. Methods The effects of triptolide on the growth of Raji cells were studied by MTT assay. The effects of triptolide on stromal cell derived factor-1α （SDF-1α） mRNA expression in lymph node stromal cells from patients with NHL were determined by RT-PCR and the effects of triptolide on CXCR4 expression on lymphoma cells freshly isolated from the lymph nodes of these patients were studied by flow cytometric analysis. Transwell chemotaxis assay was used to observe the effect of triptolide on the migration of NHL tumor cells in vitro. Results Triptolide at low concentrations （6.25--25 nmol/L） inhibited the proliferation of Raji cells in a dose- and time-dependent manner with 24, 36, 48, 60, 72 h-IC50 value of 43.06, 25.08, 7.32, 2.66, and 0. 58 nmol/L. The RT-PCR results showed that triptolide could inhibit the expression of SDF-1α in NHL lymph node stromal cells at the concentration of 12.5 nmol/L with no significance （P〉0.05） while at the concentrations of 25 and 50 nmol/L with an obivious significance （P〈0. 05） and a dose-effect relationship. And triptolide with different concentrations could down-regulate the expression of CXCR4 on NHL lymph node tumor cells （P〈0.01） in a dose-dependent manner also. Moreover, Transwell chemotaxis assays suggested that triptolide could block the migration of freshly isolated lymphoma cells from NHL lymph node either to rhSDF-1α or NHL lymph node stromal cells in vitro in a dose-dependent manner. Conclusion Triptolide could inhibit both the proliferation of NHL cell line Raji cells and the migration of lymphoma cells via lymph node. The antitumor mechanisms of triptolide are related to the antiproliferative effect and the blockage of SDF-1/ CXCR4 biological axis.