3-溴代丙酰胺苯甲酰脲对人白血病和淋巴瘤的抗肿瘤作用机理

目的研究新型微管微丝抑制剂3-溴代丙酰胺苯甲酰脲（JIMB01）抗人白血病和淋巴瘤的作用机制。方法细胞毒测定用MTT法、细胞周期分析用流式细胞仪检测、DNA片断产生用琼脂糖凝胶电泳法、细胞Bcl-2蛋白磷酸化用Western blot法等。结果JIMB01体外对所测定的9株人白血病和淋巴瘤细胞系均具有较强的抗增殖活性；可以使人白血病细胞(CEM)阻滞于有丝分裂期（G₂/M期），并使细胞出现明显的凋亡形态变化和产生典型的DNA梯带；Western blot结果表明JIMB01处理的CEM细胞表达的Bcl-2蛋白发生磷酸化或高磷酸化；JIMB01可以激活CEM细胞caspase-3，8和9的催化活性，同时caspase-3抑制剂可以阻断JIMB01诱导CEM细胞凋亡。结论微管微丝抑制剂JIMB01抗肿瘤作用机制为阻滞肿瘤细胞于M期，并通过Bcl-2的蛋白磷酸化，继而经caspase通路诱导肿瘤细胞凋亡。

Antitumor mechanism of 3-bromopropionylamino benzoylurea on leukemia and lymphoma

AIM: To study the antitumor mechanism of 3-bromopropionylamino benzoylurea (JIMB01) on leukemia and lymphoma. METHODS: The antitumor effects of JIMB01 in cell culture was detected by MTT staining. JIMB01-induced apoptosis in leukemia and lymphoma cells was tested by Giemsa staining, fluorescent Hoechst33258 staining, as well as DNA gel electrophoresis. Cell cycle was analyzed by flow cytometry. JIMB01-induced Bcl-2 phosphorylation in CEM cell lines was detected by Western blot methods. The activities of caspase-3 and caspase-8 were determined by colorimetric protease assay and that of caspase-9 was determined by fluorescent intensity. RESULTS: This compound showed antiproliferative activities in a panel of nine human leukemia and lymphoma cell lines with IC50 values in the range of 0.25 micromol x L(-10 to 0. 51 micromol x L(-1). Morphological observation and cell cycle analysis indicated that CEM cells were blocked at mitosis phase by JIMB01. The fluorescent Hoechst33258 staining showed apoptotic nuclear degradation dispersed in the cytoplasm of CEM cells exposed to JIMB01 at 0. 80 micromol x L(-1) for 24 h. DNA degradation in the form of a multiple-unit DNA ladder was clearly demonstrated in CEM leukemia cells treated with JIMB01 at 0.15 micromol x L(-1) or higher for 24 h using agarose gel electrophoresis. Bcl-2 phosphorylation became visible, in Western blot, within 6 h in CEM cells treated with JIMB01 at 0.15 micromol x L(-1) or higher for 24 h. JIMB01 increased the activities of caspase-3, -8 and -9 in CEM cells; DEVD-fmk, a caspase-3 inhibitor, inhibited the cytotoxicity of JIMB01 in CEM leukemia cells. CONCLUSION: The antitumor mechanism of JIMB01 is that JIMB01 may induce tumor cell apoptosis through Bcl-2 phosphorylation and then caspase passway.