Zhu Jiebin, Okumura Hirokazu, Ohtake Shigeki, Nakamura Shinobu, Nakao Shinji
Cellular Transplantation Biology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
Acta Haematol. 2003;110(1):1-10. doi: 10.1159/000072407.
The mechanisms of As(2)O(3)-induced apoptosis are very complex. In the present study, we investigated the molecular mechanism of As(2)O(3) in vitro at low concentration (0.25-2.0 micro M) on three human leukemia/lymphoma cell lines: HL-60, RL and K562. As(2)O(3) inhibited the growth of these cell lines significantly. During As(2)O(3) treatment, two forms of cell death, apoptosis in HL-60 and RL and oncosis in K562, were found by morphological study. In HL-60 and RL, cell cycle analysis showed, at a distinct SubG1 region, that CD95 and CD95 ligand (CD95L) expression was upregulated, caspase 8 and caspase 3 were activated, and Bcl-2 protein expression was downregulated. On the other hand, in K562, the cell cycle was arrested at the G2+M phase, CD95/CD95L expression was upregulated, caspase 8 and caspase 3 were activated, but Bcl-2 expression was not changed as compared with untreated cells. These findings suggest that the CD95/CD95L pathway is involved in cell killing by As(2)O(3). Using anti-CD95 IgG monoclonal antibody (anti-CD95 MoAb) or specific caspase inhibitor ZVAD-fmk to block the CD95 pathway, the cell death induced by As(2)O(3) was partially blocked in each cell line. These results suggest that As(2)O(3) inhibits the growth of these leukemia/lymphoma cell lines by inducing apoptosis or oncosis that is partially mediated by the CD95/CD95L pathway.
三氧化二砷诱导细胞凋亡的机制非常复杂。在本研究中，我们研究了低浓度（0.25 - 2.0微摩尔）的三氧化二砷在体外对三种人白血病/淋巴瘤细胞系HL - 60、RL和K562的分子机制。三氧化二砷显著抑制了这些细胞系的生长。在三氧化二砷处理过程中，通过形态学研究发现了两种细胞死亡形式，HL - 60和RL细胞发生凋亡，K562细胞发生胀亡。在HL - 60和RL细胞中，细胞周期分析显示，在一个明显的亚G1区域，CD95和CD95配体（CD95L）表达上调，半胱天冬酶8和半胱天冬酶3被激活，Bcl - 2蛋白表达下调。另一方面，在K562细胞中，细胞周期停滞在G2 + M期，CD95/CD95L表达上调，半胱天冬酶8和半胱天冬酶3被激活，但与未处理细胞相比，Bcl - 2表达没有变化。这些发现表明CD95/CD95L途径参与了三氧化二砷诱导的细胞杀伤。使用抗CD95 IgG单克隆抗体（抗CD95 MoAb）或特异性半胱天冬酶抑制剂ZVAD - fmk阻断CD95途径，三氧化二砷诱导的细胞死亡在每个细胞系中均被部分阻断。这些结果表明，三氧化二砷通过诱导部分由CD95/CD95L途径介导的凋亡或胀亡来抑制这些白血病/淋巴瘤细胞系的生长。
