Bioaccumulation and viability of normal and cancerous human breast cells when are exposed to mercury

MARIÁNGELES ÁVILA MANIERO; JORGE SHORTREDE; MARIEL A. FANELLI; RODOLFO WUILLOUD

Congreso; SETAC Latin America 11th Biennial Meeting; 2015

Mercury is a widespread pollutant and one of the most toxic heavy metal, classified as 3th classcarcinogen by the International Agency for Research on Cancer (IARC). Mercury chloride (HgCl2),falling into the subclass of bivalent cationic metals, is considered a metalloestrogen because it mayactivate estrogens receptor (ER). Moreover, metallostrogen effects of Hg have not beeninvestigated as Cd. Since Hg remains a serious threat to human health, it is an important goal tostudy the effects of this metal on biological systems.The aims of this work were to determine theviability of ER positive MCF-7, and ER negative MDA-MB-231 and MCF-10A cells after a 3-htreatment with HgCl2, testing for possible differences in Hg uptake by these cells lines. Citotoxicityassay was carried out by MTT, and for protein assay there was chosen BCA method. IntracellularHg was measured by atomic fluorescence spectrometry (AFS). The results showed differencesbetween the cell lines concerning their sensitivity to Cd exposure; at 3 h and low Hgconcentrations, ER negative MDA-MB-231 and MCF-10A presented a higher Hg resistance than ERpositive MCF-7 cells, but at higher Hg concentration MCF-7 cells were more resistant.Furthermore, MCF-10A cells showed higher Hg bioaccumulation than MCF-7 and MDA-MB-231cells at higher metal exposure. These differences in Hg uptake in the cell lines may be due todifference in their origin, the presence of ER and different mechanisms of Hg uptake/effluxreflecting changes in the metal sensitivity. These findings open further opportunities andchallenges to understand specific molecular mechanisms of Hg toxicity in mammary cells