Inhibitory effect of silver nanoparticles on proliferation of estrogen-dependent MCF-7/BUS human breast cancer cells induced by butyl paraben or di-n-butyl phthalate
In this study the effect of silver nanoparticles (AgNPs) on proliferation of estrogen receptor (ER)-positive human breast cancer MCF-7/BUS cells was assessed by means of in vitro assay. The cells were exposed in the absence of estrogens to AgNPs alone or in combination with aluminum chloride (AlCl3), butyl paraben (BPB) and di-n-butyl phthalate (DBPh). The results revealed that AgNPs at the non-cytotoxic concentrations (up to 2 μg/mL) and AlCl3 (up to 500 μM) did not induce proliferation of MCF-7/BUS cells whereas BPB and DBPh showed strong estrogenic activity with the highest effect at 16 μM and 35 μM, respectively.
AgNPs inhibited the proliferation of the cells induced by DBPh, BPB or even with 17β-estradiol (E2) during 6-day incubation in the absence of estrogens. ICI 182,780 (10 nM), a known estrogen receptor (ER) antagonist, induced strong inhibitory effect. AgNPs also decreased transcription of the estrogen-responsive pS2 and progesterone receptor (PGR) genes but modulated expression neither of ERα nor ERβ in MCF-7/BUS cells exposed to BPB, DBPh or E2 for 6 h.
Our results indicate that AgNPs may inhibit growth of breast cancer cells stimulated by E2 or estrogenic chemicals, i.e. BPB and DBPh.