AICAR对不同肿瘤细胞系c-Myc表达及细胞增殖影响的差异研究  

The differential effect of AICAR on c-Myc expression and proliferation in specific tumor cell lines

作　　者：赵艳丽 尚曼 王霆 傅源 ZHAO Yan-li;SHANG Man;WANG Ting;FU Yuan(Dept of Pharmacology,School of Basic Medical Sciences,Tianjin Medical University,Tianjin 300070,China)

机构地区：[1]天津医科大学基础医学院药理学系,天津300070

出　　处：《中国药理学通报》2023年第12期2288-2295,共8页Chinese Pharmacological Bulletin

基　　金：国家自然科学基金面上项目(No 82073051,32070711)。

摘　　要：目的探讨5-氨基咪唑-4-羧基酰胺核糖核苷(5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside,AICAR)在不同肿瘤细胞系内对促癌基因c-Myc的调节作用及对细胞增殖能力的影响。方法使用qRT-PCR法检测AICAR处理后c-Myc mRNA表达水平的变化。Western blot检测AICAR处理后c-Myc蛋白水平的变化。使用RNA干扰分析AICAR对c-Myc的调节作用是否依赖于AMPK和AICAR相关代谢酶。利用放线菌素D和放线菌酮研究AICAR对c-Myc的mRNA和蛋白质稳定性的影响。在多种肿瘤细胞中,用Western blot检测AICAR对不同肿瘤细胞c-Myc的调节作用,并用MTT法检测AICAR处理对细胞增殖的影响。结果AICAR明显提高c-Myc的mRNA和蛋白的表达。AICAR对c-Myc的上调效果在处理约12 h后达饱和。AICAR对c-Myc的调控不依赖于AMPK信号通路,也不是通过AICAR的代谢产物实现的。AICAR明显提高c-Myc mRNA的稳定性,但不影响蛋白的稳定性。AICAR对c-Myc的上调作用具有细胞特异性,在SW1990、786-O和A549细胞上调c-Myc表达,在HepG2、MCF-7和U2OS细胞下调c-Myc表达。在HepG2细胞中,AICAR处理明显降低细胞活力。而在SW1990和A549细胞中AICAR处理组的细胞活力与对照组差异无统计学意义。只有当c-Myc被敲低时,AICAR处理才会影响细胞活力。结论AICAR可以通过不依赖于AMPK的方式上调c-Myc的表达。AICAR对c-Myc表达调控的作用具有细胞选择性。AICAR对c-Myc的调控影响了其对肿瘤细胞增殖的抑制效果。Aim To investigate the effect of AICAR on the expression of the proto-oncogene c-Myc and cell proliferation rates in specific cancer cell lines.Methods The mRNA levels of c-Myc were evaluated using fluorescence-based qRT-PCR to examine the effect of AICAR treatment on c-Myc mRNA expression levels.Western blot was used to evaluate the protein levels of c-Myc following AICAR treatment.RNA interference was employed to determine whether the regulatory effect of AICAR on c-Myc was dependent on AMPK and the downstream metabolic enzymes relating to AICAR.Actinomycin D and cycloheximide were used to assess the effect of AICAR on the stability of cMyc mRNA and protein.Western blot was used to examine the regulatory effect of AICAR on c-Myc in various cancer cell lines.The MTT assay was used to determine the effect of AICAR on cell viability in these cell lines.Results AICAR significantly up-regulated c-Myc at both mRNA and protein levels.The protein level of c-Myc reached a plateau 12 h after the AICAR treatment.The up-regulatory effect of c-Myc induced by AICAR was not dependent on either the AMPK signaling pathway or the downstream metabolites of AICAR.AICAR could significantly enhance the mRNA stability of c-Myc but did not affect the protein stability.The up-regulation of c-Myc induced by AICAR was cell-type specific.AICAR up-regulated c-Myc in SW1990,786-O,and A549,while down-regulated c-Myc in HepG2,MCF7,and U2OS.In HepG2 cells,AICAR treatment decreased cell viability.However,in SW1990 and A549 cells,AICAR treatment did not lead to any significant difference in cell viability.AICAR decreased the cell viability only when c-Myc was knocked down in SW1990 and A549 cells.Conclusions AICAR directly up-regulates c-Myc expression in an AMPK-independent manner.The up-regulation effect is cell-type dependent.The regulation of c-Myc expression by AICAR is linked to the inhibitory effect of AICAR on tumor cell proliferation.

关 键 词：AICAR C-MYC AMPK 细胞增殖 肿瘤细胞异质性 抗癌化合物 

分 类 号：R329.28[医药卫生—人体解剖和组织胚胎学] R342.4[医药卫生—基础医学] R345.57R394.2R730.2