CAJ | 학술논문

背景与目的:白血病是高度依赖NF-κB的恶性肿瘤,NF-κB与肿瘤的发生和转移以及肿瘤细胞的增殖、凋亡、耐药相关,现已证实NF-κB家族是Notch信号通路的一个靶基因.本研究探讨雷公藤红素对白血病U937细胞凋亡和细胞中Notch 1、NF-κB表达水平的影响.方法:以不同浓度雷公藤红素(0.25～16.0 μmol/L)分别作用于U937细胞12～60 h,MTT法检测细胞增殖活性,透射电子显微镜、流式细胞术观察雷公藤红素对U937细胞凋亡的影响,western blot、RT-PCR法分别检测雷公藤红素对U937细胞内Notch 1通路蛋白、基因表达水平的调控作用,激光共聚焦显微技术检测细胞凋亡时NF-κB的核浆分布变化.结果:雷公藤红素能明显抑制U937细胞增殖,具有浓度依赖和时间依赖性.此外,雷公藤红素以浓度依赖性方式诱导U937细胞凋亡,并伴随明显的凋亡细胞形态学改变,而雷公藤红素的凋亡诱导效应可能与其将细胞阻滞于G0/G1期有关.雷公藤红素对Notch 1通路蛋白及基因表达水平均有不同程度的抑制作用,该抑制作用呈明显的量效关系.NF-κB在胞核表达减少,胞浆表达增多.与对照组相比差异具有统计学意义(P<0.05).结论:雷公藤红素明显抑制U937细胞的增殖,并诱导其凋亡,其抗白血病效应可能与下调Notch 1信号通路以及NF-κB蛋白表达有关.
배경여목적:백혈병시고도의뢰NF-κB적악성종류,NF-κB여종류적발생화전이이급종류세포적증식、조망、내약상관,현이증실NF-κB가족시Notch신호통로적일개파기인.본연구탐토뢰공등홍소대백혈병U937세포조망화세포중Notch 1、NF-κB표체수평적영향.방법:이불동농도뢰공등홍소(0.25～16.0 μmol/L)분별작용우U937세포12～60 h,MTT법검측세포증식활성,투사전자현미경、류식세포술관찰뢰공등홍소대U937세포조망적영향,western blot、RT-PCR법분별검측뢰공등홍소대U937세포내Notch 1통로단백、기인표체수평적조공작용,격광공취초현미기술검측세포조망시NF-κB적핵장분포변화.결과:뢰공등홍소능명현억제U937세포증식,구유농도의뢰화시간의뢰성.차외,뢰공등홍소이농도의뢰성방식유도U937세포조망,병반수명현적조망세포형태학개변,이뢰공등홍소적조망유도효응가능여기장세포조체우G0/G1기유관.뢰공등홍소대Notch 1통로단백급기인표체수평균유불동정도적억제작용,해억제작용정명현적량효관계.NF-κB재포핵표체감소,포장표체증다.여대조조상비차이구유통계학의의(P<0.05).결론:뢰공등홍소명현억제U937세포적증식,병유도기조망,기항백혈병효응가능여하조Notch 1신호통로이급NF-κB단백표체유관.
Background and Objective: Leukemia is a malignant tumor highly dependent on nuclear factor kappa-light-chain-enhancer of activated B cells(NF-κB),which is relevant for the occurrence,metastasis,proliferation,apoptosis,and drug resistance of tumor cells.Research has confirmed that the NF-κB family is one of the target genes in the Notch signaling pathway.This study investigated the effects of Celastrol on the apoptosis of U937 cells and the expression levels of Notch1 and NF-κB in these cells.Methods: U937cells were treated with various concentrations Celastrol(0.5-16.0)μmol/L for 12-60 h.MTT assay was performed to examine the effect of Celastrol on growth inhibition of U937 cells.Cell apoptosis was detected through both Annexin-Ⅴ FITC/PI double-labeled cytometry and transmission electron microscopy(TEM).Cell cycle regulation was studied by propidium iodide.Western blot analysis and reverse transcription-polymerase chain reaction(RT-PCR)technologies were applied to assess the expression level of hERG in K562 cells and to assess the expression level of Notch1 in U937 cells.Subcellular distributions of NF-κB/p65 were detected through confocal microscopy.Results: Celastrol presented striking growth inhibition and apoptosis induction potency on U937 cells in vitro in a time-and dose-dependent manner.The IC50 value of Celastrol for 24 h was(6.21±0.24)μmol/L.Moreover,Celastrol induced apoptosis in U937 cells in a cell-cycle dependent manner,which means that Celastrol could arrest U937 cells in the G0/G1 phase.Through TEM,apoptotic bodies containing nuclear fragments were found in Celastrol-treated U937 cells.Overexpression of Notch1 was found in U937 cells,while Celastrol could downregulate it at both the protein and mRNA level in a dose-dependent manner,and expression of NF-κB decreased in nuclei and increased in the cytoplasm(P<0.05).Conclusions:Celastrol inhibited cell proliferation and induced apoptosis in U937 cells in a concentration-dependent manner.The possible mechanism might be involved in the regulation of a survival signaling pathway,such as Notch or Nκ-KB.