蟾蜍灵在诱导HL-60细胞凋亡时对SYK和CBL家族蛋白的影响

为了探讨酪氨酸蛋白激酶SYK和CBL家族泛素连接酶在蟾蜍灵诱导HL-60细胞凋亡过程中的作用机制，采用台盼蓝染色检测细胞活力，采用流式细胞术检测细胞凋亡，采用Western blot和免疫沉降技术检测CBL、CBL—b表达和SYK的磷酸化。结果显示，蟾蜍灵以时间和剂量依赖方式抑制HL-60细胞增殖，24、48和72小时抑制细胞活力的IC50浓度分别约为26．3，7．8和2．0 nmol／L。高剂量蟾蜍灵从8小时即开始诱导HL-60细胞凋亡；与此同时蟾蜍灵快速活化SYK，并以时间依赖的方式下调CBL和CBL—b表达。结论：SYK活化及CBL家族蛋白表达下调可能参与蟾蜍灵对HL-60细胞的增殖抑制和凋亡诱导作用。

Effects of Bufalin on SYK and CBL Family Proteins in Induction of HL-60 cell Apoptosis

The study was aimed to explore the mechanism of SYK and CBL family of ubiquitin ligases in Bufalin-induced HL-60 cells apoptosis. Cell viability was tested by trypan blue staining and apoptosis was detected by using flow cytometery. The expressions of CBL and CBL-b and the phosphorylation of SYK were detected by using immunoprecipatation and Western blot. The results showed that Bufalin inhibited HL-60 cell proliferation in time- and dose-dependent manners. IC50 of suppressing cell viability at 24, 48 and 72 hours were about 26.3,7.8 and 2.0 nmol/L respectively. The high dose of bufalin already induced apoptosis of HL-60 cells at 8 hours. SYK was quickly phosphorylated, and the expressions of CBL and CBL-b were down-regulated after treatment with Bufalin. It is concluded that SYK activation and CBL protein down-regulation may be involved in Bufalin-induced HL-60 cell apoptosis.