目的:探讨倍半萜烯内酯(sesquiterpene Iactones,SLs)类化合物对不同环氧合酶-2(cyclooxygenase-2,COX-2)表达水平的人鼻咽癌(nasopharyngeal carcinoma,NPC)细胞中癌干细胞(cancer stem cells,CSCs)转归的影响。方法:分别采用实时定量PCR(qRT-PCR)和Western blot检测人鼻咽癌高分化CNE1L和低分化CNE2L细胞株中COX-2 mRNA和蛋白本底表达水平。给予不同剂量SLs活性成分小白菊内酯(parthenolide,PN)处理2种细胞株后,再分别采用噻唑蓝(MTT)法测定细胞增殖活性;qRT-PCR检测细胞中干性相关基因COX-2、ABCG2、BMI1、OCT4 mRNA水平;流式细胞术分析干性侧群(side population,SP)细胞的相对含量;平板克隆集落形成实验检测干性细胞的自我更新和分化增殖能力。结果:CNE1L和CNE2L细胞中COX-2 mRNA和蛋白本底水平显著不同,在CNE1L细胞中明显高于CNE2L细胞(P〈0.05);与对照组比较,PN处理后,细胞增殖抑制率随PN浓度(10~100μmol/L)增加呈剂量依赖性增高(P〈0.05),细胞中COX-2 mRNA在CNE1L中升高、在CNE2L中降低,干性相关基因ABCG2、BMI1 mRNA在CNE1L细胞中升高、而OCT4 mRNA在两株细胞中均降低(P均〈0.05);SP细胞抑制率亦随PN浓度(2.5~40μmol/L作用24 h)增加呈剂量依赖性增高(P〈0.05);而细胞的集落形成能力随PN浓度(0.25~1.5μmol/L作用72 h)增加显著降低(P〈0.05);上述结果在CNE1L和CNE2L细胞株间差异均有统计学意义(P〈0.05),在CNE1L细胞中变化作用更强。结论:PN对不同NPC细胞株中的干性细胞功能具有抑制作用且存在明显差别,可能与不同细胞间COX-2表达的差异性有关。
OBJECTIVE:To investigate effects of the sesquiterpene lactones(SLs) compound on the induced outcomes of cancer stem cells(CSCs) in human nasopharyngeal carcinoma(NPC) cells with different levels of cyclooxygenase-2(COX-2).METHODS:The background levels of COX-2 mRNA and COX-2 protein were determined by the real time PCR(qRT-PCR) and Western blot in CNEIL and CNE2L cell lines.After treated with different doses of parthenolide(PN),proliferation of cells was determined by MTT assay,the transcription levels of COX-2,ABCG2, BMI1,OCT4 mRNA were determined by qRT-PCR,the relative content of side population(SP) cells was examined by flow cytometry,and the self-renewal and differentiation proliferation of stem-like cells were measured by colony formation assay.RESULTS:The background levels of COX-2 mRNA and protein were significantly higher in CNE1L compared with CNE2L cells(P〈0.05).Compared with control group,in PN-treated group the proliferation inhibition rate was increased in dose-dependent(10-100μmol/L for 24 h) manner(P〈0.05).The mRNA level of stemness relative genes,including COX-2,ABCG2,BMI1 mRNA was increased in CNEIL cells,but COX-2 mRNA was decreased in CNE2L cells,while the level of OCT4 mRNA was reduced in both cell lines.The SP inhibition rate(%) was also increased with dose-dependent pattern(2.5-40μmol/L for 24 h)(P〈0.05),and the colony formation was significantly lower(0.25- 1.5μmol/L for 72 h)(P〈0.05).All the results above were statistically different between CNE1L and CNE2L (P〈0.05),with effects in CNE1L cell more remarkable.CONCLUSION:There were significantly different effects of PN on the inhibition of CSCs function in different NPC cells.The varied expression of COX-2 between cell lines may be related to the susceptibility.