三叶青黄酮诱导髓系白血病NB-4细胞凋亡及信号通路的研究

目的:研究三叶青黄酮(RTHF)对人急性早幼粒细胞白血病NB-4细胞活力、凋亡及MAPK信号通路的影响。方法:采用CCK-8法及BrdU实验分别检测RTHF对NB-4细胞活力及增殖的影响;流式细胞术检测RTHF诱导细胞凋亡及阻滞细胞周期的作用。Western blot分析RTHF对细胞凋亡及MAPK信号通路相关蛋白表达的影响。结果:RTHF有效地抑制NB-4细胞的活力及增殖,呈时间和剂量依赖性,作用48 h的IC50为2.26 g/L。RTHF阻滞NB-4细胞进入增殖周期,停滞在G2期,并诱导其凋亡(P<0.01),呈剂量依赖性。RTHF下调抗凋亡蛋白Bcl-2的表达,上调促凋亡蛋白Bax、caspase-3和Cyt-C的表达,呈剂量依赖性(P<0.05)。RTHF对ERK1/2及JNK的表达无明显影响,但可降低ERK5蛋白表达,提高p38的表达水平(P<0.05)。结论:RTHF在体外有效地抑制白血病NB-4细胞活力及增殖,并诱导凋亡,其机制可能通过p38 MAPK信号通路及凋亡蛋白途径。

Effect of Radix Tetrastigma hemsleyani flavone on apoptosis and MAPK signaling pathway in myeloid leukemia NB-4 cells

AIM: To study the effects of Radix Tetrastigma hemsleyani flavone(RTHF) on the viability, apoptosis and MAPK signaling pathway in human acute promyelocytic leukemia NB-4 cells. METHODS: The inhibitory effects of RTHF on the viability and proliferation of NB-4 cells were measured by CCK-8 assay and BrdU test. Flow cytometry was used to analyze the apoptosis of NB-4 cells induced by RTHF, and the cell cycle distribution after RTHF treatment. The levels of apoptosis-and MAPK pathway-related proteins in the NB4 cells were determined by Western blot. RESULTS: RTHF inhibited the viability and proliferation of NB-4 cells in a time-and dose-dependent manner, and the IC50 at 48 h was 2.26 g/L. RTHF blocked NB-4 cells into the cell proliferation cycle, with stagnation in the G2 phase. Meanwhile, RTHF induced apoptosis of the cells, down-regulated the expression of anti-apoptotic protein Bcl-2, and up-regulated the expression of pro-apoptotic proteins Bax, caspase-3 and Cyt-C, in a dose-dependent manner(P<0.05). The expression of ERK5 was decreased, and p38 was increased induced after RTHF treatment. However, no obvious change of ERK1/2 and JNK after RTHF treatment was observed. CONCLUSION: RTHF effectively inhibits the viability and proliferation, and induces apoptosis of leukemic NB-4 cells in vitro. Its mechanism may be related to signaling pathways of p38 MAPK and apoptosis proteins.