OBJECTIVETo 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).

METHODSMCF-7 cells were exposed to different concentration of H(2)O(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(2)O(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.

RESULTSThe inhibitory effect on MCF-7 cells viability induced by H(2)O(2) was shown a dose-and time-dependent manner and MCF-7 cells proliferation, and was almost completely inhibited by the exposure of H(2)O(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.

CONCLUSIONJWA might enhance intracellular defenses against H(2)O(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.