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

AVILA MANIERO, MARIANGELES; SHORTREDE, JORGE; FANELLI, MARIEL; WUILLOUD, RODOLFO G.

Buenos Aires

Congreso; SETAC LATIN AMERICA 11th BIENNIAL MEETING; 2015

SETAC LATIN AMERICA

Mercury is a widespread pollutant and one of the most toxic heavy metal, classified as 3th class carcinogen 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 may activate estrogens receptor (ER). Moreover, metallostrogen effects of Hg have not been investigated as Cd. Since Hg remains a serious threat to human health, it is an important goal to study the effects of this metal on biological systems.The aims of this work were to determine the viability of ER positive MCF-7, and ER negative MDA-MB-231 and MCF-10A cells after a 3-h treatment with HgCl2, testing for possible differences in Hg uptake by these cells lines. Citotoxicity assay was carried out by MTT, and for protein assay there was chosen BCA method. Intracellular Hg was measured by atomic fluorescence spectrometry (AFS). The results showed differences between the cell lines concerning their sensitivity to Cd exposure; at 3 h and low Hg concentrations, ER negative MDA-MB-231 and MCF-10A presented a higher Hg resistance than ER positive 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-231 cells at higher metal exposure. These differences in Hg uptake in the cell lines may be due to difference in their origin, the presence of ER and different mechanisms of Hg uptake/efflux reflecting changes in the metal sensitivity. These findings open further opportunities and challenges to understand specific molecular mechanisms of Hg toxicity in mammary cells.