The
pyrethroid insecticide fenvalerate and the organophosphorus
insecticide phoxim are now the most widely used agents for indoor pest control in China.
Fenvalerate was shown to mimic estrogenic activity, whereas
phoxim did not induce similar effects. Our previous studies demonstrated that JWA, a novel
retinoic acid-inducible and cytoskeleton-associated gene, is also a potential environmental-responsive gene with increased expression to oxidative and heat-shock stresses. In the present study, the influence of both
fenvalerate and
phoxim was examined on the expression of JWA in MCF-7 (ER+) and MDA-MB-231 (ER-) human
breast carcinoma cell lines. Concentrations of 0.01, 1, and 100 micromol/L of
fenvalerate or
phoxim were selected to treat both MCF-7 and MDA-MB-231 cells at 1, 3, and 5 d, respectively. The MTT results only showed that
fenvalerate stimulated MCF-7 cell proliferation. Western blot assay was employed to detect the expressions of JWA and
heat-shock proteins (hsp27 and hsp70). The results showed that
after treatment with
fenvalerate, both JWA and hsp70 showed similar expression patterns in the both cell lines; however, all the expression patterns of JWA, hsp27, and hsp70 were evidently reversed between ER+ and ER- cells. In addition,
phoxim-treated cells showed a concentration-dependent relationship in JWA expression at all time points. These results suggest that JWA has similar functions with respect to hsp27 and hsp70, and might be a novel signal molecule in
estrogen receptor-related signal transduction pathways in mammalian cells.