人参皂苷Rg1诱导人白血病K562细胞复制性衰老的机制

目的 探讨人参皂苷Rg1(Rg1)诱导人白血病K562细胞复制性衰老特征性变化.方法 四甲基偶氮唑盐(MTT)法筛选Rg1对K562细胞增殖抑制的最佳浓度及时间,以此浓度和作用时间诱导K562细胞衰老.流式细胞术检测Rg1对细胞增殖周期的影响;衰老相关β-半乳糖苷酶(SA-β-Gal)染色检测阳性细胞百分率;Southern blotting检测端粒长度;Western blotting检测复制性衰老信号通路相关P21、P53与Rb蛋白表达;透射电镜观察人白血病K562细胞衰老超微形态学改变.结果 Rg1在体外能明显抑制K562细胞增殖,其最佳作用浓度为20 μmol/L,时间为48h;诱导后的K562细胞阻滞于G2/M期;SA-β-Gal染色阳性细胞百分率增加(P<0.05);复制性衰老通路相关蛋白P21、P53和Rb表达上调(P<0.05);端粒长度缩短加速(P<0.05);经诱导细胞呈现胞体增大,溶酶体体积增大、数目增多,线粒体体积增大等衰老形态学变化.结论 Rg1可能经由p53-p21-Rb信号通路诱导K562细胞呈现复制性衰老特征.

Replicative senescence characteristics of human leukemia cell line (K562) induced by ginsenoside Rg1

Objective To discuss the characteristic changes of leukemia cell line K562 on replicative senescence induced by ginsenoside Rg1. Methods The effect of Rg1 on the leukemia K562 cell line proliferation was detected by MTT colorimetric test in order to screen optimal time and drug concentration induced cells senescence. The flow cytometry method was used to analyze the cell’s cycle. The percentage of positive cells, the telomere length and the expression of the senescence -related proteins P21,P53,Rb were detected by SA-β-gal staining, southern blotting and western blotting methods, respectively. The ultrastructural senescence changes were observed under the a transmission electronic microscope. Results The optimal time and concentration in order to inhibit the proliferation of K562 cells were 48hours and 20mol/L respectively. The K562 cells arrested G2/M phase. The percentage of positive cells was increased (EM>P/EM> <0.05 ). The senescence -related proteins were up-regulated (EM>P/EM> <0.05). The telomere length became shorten quickly ( EM>P/EM> <0.05 ). Conclusion Rg1 may induce leukemia cell line K562 into the state of replicative senescence by the ce