硫化砷诱导K562细胞凋亡中Bcl-2和Bax的表达

Expression of Bcl-2 and Bax in arsenic sulfide induced-apoptosis of K562 cell

目的 研究 Bcl- 2和 Bax在硫化砷诱导的 K5 6 2细胞凋亡中的表达 ,探讨其在硫化砷诱导的细胞凋亡中的作用 .方法 K5 6 2细胞经一定剂量硫化砷作用特定时间后 ,MTT法检测细胞生长、增殖状态 ,光镜及透射电镜下观察细胞形态及凋亡情况 ,S- P免疫组化染色检测 Bcl- 2、Bax的表达并进行图像分析 .结果 硫化砷对 K5 6 2细胞生长增殖有时间剂量依赖性抑制作用 ;175～ 14 0 0μg· L- 1 硫化砷作用 18～ 14 4 h后 ,K5 6 2细胞出现凋亡细胞的形态学改变 ;免疫组化染色表明 K5 6 2细胞低表达 Bcl- 2蛋白 (A值为 0 .15 2± 0 .0 2 3,阴性对照 A值 0 .10 8± 0 .0 12 ) ,硫化砷处理后对其表达无明显影响 (A值为 0 .138± 0 .0 2 8,P>0 .0 5 ) .硫化砷作用后 ,Bax蛋白的表达量 A值由 0 .2 4 0± 0 .0 13增加到 0 .316± 0 .0 2 1(P<0 .0 1) .结论 硫化砷可抑制 K5 6 2细胞的生长和增殖并诱导其发生凋亡 ,其机制可能与 Bax蛋白上调有关 .

AIM To study the expression and the effects of Bcl 2 and Bax protein in apoptosis of K562 cell induced by arsenic sulfide. METHODS After being incubated in culture medium containing variable levels of arsenic sulfide, cell growth and proliferation of K562 cell was analyzed with MTT assay; apoptosis was detected with cell morphology by light and transmission electron microscopy. The expression of Bcl 2 and Bax protein was determined with S P immunohistochemical stainning and imaging analysis. RESULTS After the treatment, cell growth and proliferation of K562 cell was inhibited in a dose and time dependent manner. Morphologically, after treatment with 175 to 1400 μg·L -1 of arsenic sulfide for 18 to 144 h, K562 cells presented some features of apoptosis. The baseline Bcl 2 expression of K562 cell was very low ( A : 0.152±0.023) while the absorbance (optical density) value ( A ) of negative control was 0.108±0.012. No significant difference was found after the treatment ( A : 0.138±0.028) ( P >0.05), but the expression of Bax protein in K562 cells co cultured with arsenic sulfide ( A : 0.316 ±0.021) was increased, compared with the untreated ( A : 0.240±0.013) ( P <0.01). CONCLUSION Arsenic sulfide could inhibit growth and proliferation of K562 cell and induce its apoptosis. These effects may be correlated with the up regulation of Bax protein.