表没食子儿茶素没食子酸酯对星形神经胶质瘤U87MG细胞基质金属蛋白酶-2及核因子κB活性影响研究  

Epigallocatechin gallate inhibits activity of matrix metalloproteinase-2 and NF-κB in U87MG glioblastoma multiforme cells

作　　者：彭超[1] 罗祎敏[2] 陈延群[3] 

机构地区：[1]南华大学附属第一医院神经内科,湖南衡阳421001 [2]南华大学医学院,湖南衡阳421001 [3]南华大学附属南华医院肿瘤科,湖南衡阳421002

出　　处：《中国现代医学杂志》2015年第20期27-31,共5页China Journal of Modern Medicine

摘　　要：目的通过研究表没食子儿茶素没食子酸酯(EGCG)对星形神经胶质瘤(GBM)细胞系U87MG细胞基质金属蛋白酶-2(MMP-2)活性的抑制作用及对核因子κB(NF-κB)活性的影响,探讨EGCG对恶性胶质瘤细胞的作用机制。方法体外培养U87MG细胞,用EGCG预处理后,四氮唑盐酶还原法检测细胞的增殖及乳酸脱氢酶(LDH)的漏出率;明胶酶谱实验和实时定量逆转录-聚合酶链反应(RT-PCR)检测MMP-2的酶活性和m RNA表达水平;Western blot检测p65的核转位。为进一步探讨NF-κB与MMP-2基因表达的关系,U87MG细胞与EGCG孵育的同时,加入25μmol/L NF-κB特异性抑制剂二硫代氨基甲酸吡咯烷(PDTC)共同孵育,RT-PCR检测其对MMP-2表达的影响。结果 EGCG与佛波酯(PMA)诱导后的U87MG细胞共孵育后,当浓度<20μmol/L时,以剂量依赖性方式降低MMP-2 m RNA及其蛋白的表达。明胶酶谱实验显示,EGCG也能以剂量依赖性方式降低MMP-2的酶活性。PMA诱导后的U87MG细胞与EGCG共孵育后,转移至核内的p65蛋白随着EGCG浓度的增加而明显减少。NF-κB特异性抑制剂PDTC能协同EGCG下调MMP-2m RNA表达。结论 EGCG通过抑制NF-κB的转位,在基因和蛋白水平抑制PMA诱导的U87MG细胞MMP-2的表达及其酶活性。[Objective] To investigate the effects of Epigallocatechin gallate （EGCG） on the activity of matrix metalloproteinase （MMP）-2 and NF-κB in glioblastoma multiforme （GBM） cell line U87MG, so as to investigate its mechanism. [Methods] Cultured U87MG cells were incubated with EGCG, microculture tetrazolium test （MTr assay）, gelatin zymography, Western blot and RT-PCR were employed to evaluate the effect of EGCG on cell proliferation and lactate dehydrogenase （LDH） releasing rate, enzymatic activity and mRNA expression level of MMP-2, and the nuclear translocation of p65, respectively. In order to elucidate the effect of NF-κB on the abnormal expression of MMP-2, a specific inhibitor of NF-κB, pyrrolidine dithiocarbamate （PDTC, 25 μmol/L） was used when U87MG cells were cultured. The effect on the exprssion of MMP-2 was analyzed by RT-PCR. [Results] The expressions of MMP-2 mRNA and protein in U87MG cells induced by phorbol-12-myristate-13-acetate （PMA） cultured with ECGC were reduced within 0-40 μmol in an ECGC- dose-dependent manner. The enzymatic activity of MMP-2 was inhibited by ECGC. PMA induced U87MG cells co-cultured with ECGC showed a reduction of p65 protein within 0-40 μmol in an ECGC-dose-dependent manner. PDTC could assist EGCG to downregulate MMP-2 mRNA expression. [Conclusion] EGCG can inhibit the expression and enzymatic activity of MMP-2 in PMA-induced U87MG cells on gene and protein levels by inhibiting NF-κB translocation.

关 键 词：表没食子儿茶素没食子酸酯 星形神经胶质瘤 基质金属蛋白酶-2 核因子ΚB 

分 类 号：R730.264[医药卫生—肿瘤]