新的环境应答蛋白JWA在MCF-7细胞应答氧化应激中的表达

目的研究氧化应激诱导MCF-7细胞氧化损伤过程中，JWA表达的调节规律及其作用，尤其是与热休克蛋白(HSPs)间的关系。方法以不同浓度的H202(0．01、0．10、1．00mmol／L)分别处理MCF-7细胞10、30、60、180min，建立MCF-7细胞氧化损伤模型并用DNA琼脂糖凝胶电泳鉴定；用四唑蓝(MTT)法分析H2O2对MCF-7细胞的相对细胞增殖率和细胞毒性的影响；采用Western-blot方法检测JWA、HSPT0、HSP27和热休克转录因子(HSF1)蛋白表达水平的变化。结果H202对MCF-7细胞的增殖抑制和细胞毒性呈时间和剂量依赖关系，MCF-7细胞在最高剂量、最长处理时间(1．00mmol／L、180min)时，细胞增殖几乎完全受抑制。H2Ch活跃地调节JWA的表达，氧化损伤使JWA、HSPT0和HSF1表达上调并呈剂量依赖关系，而且JWA、HSPT0和HSF1的表达规律相似，而HSP27表达似乎与氧化应激的信号调节无关。结论在H2O2致MCF-7细胞氧化应激时，JWA作为有效的环境应答蛋白．其与HSP70共同参与的信号通路可能受HSF1调控。

Expression of novel environmental responsive protein JWA involved in the oxidative stress responsiveness in MCF-7 cells

Objective To study the expression and the possible role of JWA protein in oxidative stress-induced damage of MCF-7 cells,especially the relationship between JWA and heat shock proteins(HSPs). Methods MCF-7 cells were exposed to different concentration of H 2O 2(0.01,0.10,1.00 mmol/L) for different time(10,30,60 and 180 min) respectively.DNA damage was detected by using DNA gel electrophoresis.The MTT assay was used to analyze the effect of H 2O 2 on the cytotoxicity and relative cell proliferation ratio of the cells.The expressions of JWA,HSP70,HSP27 and HSF1 were determined by Western-blot. Results The inhibitory effect on MCF-7 cells viability induced by H 2O 2 was shown a dose-and time-dependent manner and MCF-7 cells proliferation,and was almost completely inhibited by the exposure of H 2O 2 at 1.00 mmol/L for 180 min.Hydrogen peroxide treatment of MCF-7 cells caused oxidative stress which up-regulated the expressions of JWA,HSP70 and heat shock factor 1(HSF1) in a dose-dependent manner,and the expression pattern of JWA was very similar to those of HSP70 and HSF1 but not to HSP27. Conclusion JWA might enhance intracellular defenses against H 2O 2-induced oxidative damage in human breast carcinoma cells.JWA is determined functioning as an effective environmental responsive protein and as a parallel molecule of HSP70 actively participates in the signal pathways of oxidative damage which might be regulated by HSF1.