Li Jun-e, Sun Guan-lin, Wu Ying-li, Wu Wei-li
Shanghai Institute of Hematology, Ruijin Hospital, Shanghai Second Medical University, Shanghai 200025, China.
Zhonghua Xue Ye Xue Za Zhi. 2003 Nov;24(11):580-3.
To investigate the synergistic effect of As(2)S(2) and STI 571 on K562 cells and its mechanism.
The inhibitive effect of As(2)S(2) on the proliferation of K562 cells was determined by cell number count. Cell apoptosis was assessed by flow cytometry, DNA fragmentation and morphology. Protein expression was determined by Western-blot and gene expression by RT-PCR.
As(2)S(2) could significantly inhibit the proliferation and induce apoptosis of K562 cells in a dose and time-dependent manner at concentrations from 1 micromol/L to 5 micromol/L for 24 approximately 72 h. 34.4%, 21.8% and 46.0% of the treated-cells displayed apoptosis at 3 micro mol/L for 72 h, 5 micromol/L for 48 h and 5 micromol/L for 72 h, respectively. Compared to treatment with STI571 (0.25 approximately 1.00 micromol/L) or As(2)S(2) (1 approximately 5 micromol/L) alone, treatment of K562 cells with As(2)S(2) and STI571 combination induced more cell apoptosis. (18.4 +/- 1.4)% and (15.8 +/- 1.2)% cells underwent apoptosis at 1 micromol/L STI571 for 48 h and 5 micromol/L As(2)S(2) for 48 h, respectively, and (40.6 +/- 2.0)% cells did in combination treatment (P < 0.05). For U937 cells, the percentages of apoptotic cells were (6.0 +/- 1.1)% at 1 micromol/L STI571 for 48 h, (4.5 +/- 1.2)% at 5 micromol/L As(2)S(2) for 48 h, and (7.3 +/- 1.0)% in combination treatment. As(2)S(2) decreased the bcr-abl fusion protein expression and PTK activity of c-abl and bcr-abl, but not for bcr-abl expression.
Combination treatment with As(2)S(2) and STI 571 induced more apoptosis of K562 cells. The reduction of PTK activity may be involved in the mechanisms.
探讨As₂S₂与STI 571对K562细胞的协同作用及其机制。
通过细胞计数法测定As₂S₂对K562细胞增殖的抑制作用。采用流式细胞术、DNA片段化分析及形态学观察评估细胞凋亡情况。通过蛋白质免疫印迹法检测蛋白质表达，逆转录聚合酶链反应检测基因表达。
在1微摩尔/升至5微摩尔/升浓度下作用24至72小时，As₂S₂能以剂量和时间依赖性方式显著抑制K562细胞增殖并诱导其凋亡。在3微摩尔/升作用72小时、5微摩尔/升作用48小时和5微摩尔/升作用72小时时，分别有34.4%、21.8%和46.0%的处理细胞发生凋亡。与单独使用STI571（0.25至1.00微摩尔/升）或As₂S₂（1至5微摩尔/升）处理相比，As₂S₂与STI571联合处理K562细胞诱导更多细胞凋亡。在1微摩尔/升STI571作用48小时和5微摩尔/升As₂S₂作用48小时时，分别有(18.4±1.4)%和(15.8±1.2)%的细胞发生凋亡，联合处理时有(40.6±2.0)%的细胞发生凋亡（P<0.05）。对于U937细胞，在1微摩尔/升STI571作用48小时时凋亡细胞百分比为(6.0±1.1)%，在5微摩尔/升As₂S₂作用48小时时为(4.5±1.2)%，联合处理时为(7.3±1.0)%。As₂S₂降低了bcr-abl融合蛋白表达以及c-abl和bcr-abl的蛋白酪氨酸激酶（PTK）活性，但对bcr-abl表达无影响。
As₂S₂与STI 571联合处理诱导K562细胞更多凋亡。PTK活性降低可能参与了其机制。
