Human breast cells are capable of mercury uptake, but they can show efflux?

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

Mendoza

Congreso; XXXIV REUNIÓN CIENTÍFICA DE LA SOCIEDAD DE BIOLOGÍA DE CUYO; 2016

Mercury (Hg) is a widespread pollutant and toxic element which enters into the body and may cause permanent changes. Thus, the mechanism of Hg transport across cell membranes is a key factor to elucidate mechanisms of toxicity. To examine the uptake and efflux of Hg2+, MCF 7, MDA MB 231 and MCF 10A (mammary human cell lines) were used. The viability of cell lines at different concentrations in μM range of Hg2+ was carried out by MTT assay. Cellular uptake and efflux of Hg were evaluated using cold vapor-atomic fluorescence spectrometry (CV-AFS) as an elemental detector. Efflux of Hg, was determined with a classical experiment, cells were treated during 3 hs with Hg, then washed and left with fresh medium by 3, 12 and 24 hs. The viability of three mammary cell lines was inversely proportional to the exposure time, being MCF 10A cells the most resistant ones. The uptake of Hg2+ was higher in MCF 10A cells at 3, 12 and 24 hs of treatment, while in MCF 7 and MCF 10A cells, the intracellular concentration of the metal diminished as the exposition time was increased. On the other hand, MDA MB 231 showed an opposite behavior, i.e., the intracellular concentration was higher for longer exposure time. After 3 hs of treatment, the levels of Hg2+ in the extracellular fresh medium increased, while the intracellular Hg concentration decreased. The same behavior was found in all the mammary cell lines used. Different types of transport membranes could be responsible for the mechanisms that regulate the entry and exit of Hg2+ in the mammary cell lines studied.