As2S2与STI 571协同诱导K562细胞凋亡

目的　探索As2 S2 和STI 5 71联合使用对K5 6 2细胞的诱导凋亡作用及其机制。方法　用细胞计数法研究As2 S2 对K5 6 2细胞的生长抑制作用 ;细胞凋亡的检测用流式细胞术、基因组DNA电泳、细胞形态学观察等方法 ;蛋白表达的检测采用Western blot法 ;基因表达的变化用半定量RT PCR法。结果　As2 S2 1～ 5 μmol/L作用 2 4～ 72h ,即可明显抑制K5 6 2细胞增殖 ,3～ 5 μmol/L作用 4 8～ 72h即可诱导K5 6 2细胞凋亡。 3μmol/LAs2 S2 作用 72h ,细胞凋亡率达 34.4 % ;5 μmol/LAs2 S2 作用 4 8,72h ,细胞凋亡率分别达 2 1.8%和 4 6 .0 %。 1μmol/LSTI 5 71作用 4 8h ,细胞凋亡率为 (18.4± 1.4 ) % ;5 μmol/LAs2 S2 作用 4 8h ,细胞凋亡率为 (15 .8± 1.2 ) % ;而两者合用细胞凋亡率上升为 (40 .6± 2 .0 ) %。对于U937细胞 ,单用 1μmol/LSTI5 71作用 4 8h ,细胞凋亡率为 (4.5± 1.1) % ;单用 5 μmol/LAs2 S2 作用 4 8h ,细胞凋亡率为 (6 .0± 1.2 ) % ;而两者合用 ,细胞凋亡率为 (7.3± 1.0 ) % ,无明显协同作用。As2 S2 能降低K5 6 2细胞中Bcr Abl蛋白水平 ,并抑制c Abl和Bcr AblPTK活性 ,但As2 S2 并不调变bcr abl基因表达水平。结论　As2 S2 联合STI 5 71可增强诱导K5 6 2细胞凋亡的作用 ,其机制可能

Synergism of As2S2 and STI 571 in inducing apoptosis of K562 cells

OBJECTIVE: To investigate the synergistic effect of As(2)S(2) and STI 571 on K562 cells and its mechanism. METHODS: 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. RESULTS: 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. CONCLUSION: 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.