Notch信号通路抑制剂对原代耐药白血病干细胞生长分化的影响

  目的  探讨Notch信号通路在漆姑草（HSJ）醇提物诱导人急性早幼粒白血病细胞（NB4）分化中的作用。  方法  实验设对照组和低、中、高剂量漆姑草组（30、60、120 μg/mL）；作用NB4细胞48 h后，采用四甲基偶氮唑蓝（MTT）比色法检测NB4细胞增殖抑制率；Wright-Giemsa染色法观察NB4细胞形态；Real time-PCR检测Jagged1、Notch1、c-myc mRNA表达；Western blot法检测Jagged1、Notch1、c-myc蛋白表达。  结果  漆姑草作用NB4细胞后，细胞增殖受到明显抑制；与对照组比较，漆姑草组NB4细胞形态向成熟细胞改变，可见核/浆比例减小，核形呈肾形核或分叶核；与对照组比较，30、60、120 μg/mL漆姑草组NB4细胞中Jagged1 mRNA表达量[分别为（0.78 ± 0.10）、（0.32 ± 0.15）、（0.07 ± 0.02）]降低，Notch1 mRNA表达量[分别为（1.27 ± 0.14）、（1.39 ± 0.23）、（1.53 ± 0.30）]升高，c-myc mRNA表达量[分别为（0.88 ± 0.05）、（0.67 ± 0.02）、（0.47 ± 0.16）]降低，差异均有统计学意义（均P < 0.05）；与对照组比较，30、60、120 μg/mL漆姑草组NB4细胞中Jagged1蛋白表达量[分别为（0.95 ± 0.10）、（0.69 ± 0.02）、（0.59 ± 0.01）]降低，Notch1蛋白表达量[分别为（0.56 ± 0.08）、（0.81 ± 0.03）、（1.33 ± 0.14）]升高，c-myc蛋白表达量[分别为（0.82 ± 0.14）、（0.70 ± 0.07）、（0.65 ± 0.20）]降低，差异均有统计学意义（均P < 0.05）。  结论  漆姑草能诱导NB4细胞向成熟细胞方向分化，其分化诱导作用机制可能与Notch信号通路有关。

Molecular mechanisms of the antileukemia activities of retinoid and arsenic

  Objective  To study the effect of Notch signaling pathway on the differentiation of human acute promyelocytic leukemia cell line NB4 induced by Herba Saginae Japonicae ethanol extract (HSJ).  Methods  The NB4 cells were treated with low-, moderate-, high-dose (30, 60, 120 μg/mL) HSJ for 48 hours and a negative control group was also established. The inhibitive rate of NB4 cell′s proliferation was detected with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The morphology of the NB4 cells was observed with Wright-Giemsa staining. The mRNA and protein expressions of Jagged1, Notch1, and c-myc were detected with real time-PCR and Western blot, respectively.  Results  Compared with that of the control group, the proliferation of HSJ-treated NB4 cells was inhibited significantly, with the observed cells′ mature morphology as decreased nucleus/cytoplasm ratio and reniform and lobulated nuclei. In comparison to those of the control group, significantly decreased mRNA expressions of Jagged1 (0.78 ± 0.10, 0.32 ± 0.15, and 0.07 ± 0.02) and c-myc (0.88 ± 0.05, 0.67 ± 0.02, and 0.47 ± 0.16) and significantly increased mRNA expression of Notch1 (1.27 ± 0.14, 1.39 ± 0.23, and 1.53 ± 0.30) were observed for the NB4 cells treated with low-, moderate-, and high-dose HSJ (P < 0.05 for all); significantly decreased protein expressions of Jagged1 (0.95 ± 0.10, 0.69 ± 0.02, and 0.59 ± 0.01) and c-myc (0.82 ± 0.14, 0.70 ± 0.07, and 0.65 ± 0.20) and significantly increased protein expression of Notch1 (0.56 ± 0.08, 0.81 ± 0.03, and 1.33 ± 0.14) were also observed for the NB4 cells treated with low-, moderate-, and high-dose HSJ (all P < 0.05).  Conclusion  HSJ can induce mature differentiation of NB4 cells and the mechanism of the effect may be related to Notch signaling pathway.