Biomarkers of effect of three pesticides on a human breast cell line

Agrochemicals, including acaricides, insecticides, herbicides and fungicides, are used on plant production against insects, weeds, fungi and rodents; however, the pesticide exposure can represent a risk for human health, mainly linked to neurological, respiratory and reproductive diseases. In children, the pesticides exposure can be associated with premature sexual maturation, including the premature thelarche, defined as breast development in girls below the age of eight years without other signs of sexual development. Indeed, several pesticides are considered as endocrine disrupting chemicals since they can interfere with the dysregulation of sexual, thyroid and neuro-endocrine hormones, acting via nuclear receptors. The present study aims to evaluate a panel of nuclear receptors as biomarkers of effect of three widely used pesticides such as glyphosate, imidacloprid and chlorpyrifos on a human breast cell line (MCF-7), representing the target organ of the idiopathic premature thelarche. Cytotoxic effects of the three pesticides were evaluated by the MTS and CyQuant assays at 48 and 72 hours(h), using five 10-fold dilutions spanning real exposure concentrations (100 pM –1μM). Proliferation was not affected whereas a dose-dependent decrease of metabolic activity was observed at 72h in all three pesticides, being statistically significant in imidacloprid treated cells. Three concentrations, including the real exposure level occurring in children, were selected for each pesticide to evaluate the gene expression of the estrogen receptor α (ERα), the estrogen receptor β (ERβ), the androgen receptor (AR), the aryl hydrocarbon receptor (AhR) and the progesterone receptor (PgR), by Real Time PCR (qPCR). Preliminary results will be shown. The project (RF-2016-02364628) is funded by the Italian Ministry of Health.