Expression and regulation of Breast Cancer Resistance Protein in the human placenta and fetal membranes

Abstract

Breast Cancer Resistance Protein, BCRP, is highly expressed in many different tumor tissues conferring multi-drug resistance against many chemotherapy drugs. BCRP has also been reported to be present in normal tissues including the human placenta during pregnancy. It is believed that in the placenta, BCRP controls the levels of toxins, drugs and xenobiotics that may cross maternal circulation into fetal circulation. The expression of BCRP was examined in the human placenta and in placental membranes (amnion and chorion leave) and attached decidua. In addition, the effect of cytokines and hypoxia on BCRP expression in placental cells was examined in vitro. BCRP was found to be highly expressed in the placenta throughout pregnancy as well as in the amnion, chorion laeve and attached decidua. Our data suggest that increased cytokine expression and reduced oxygen levels may not have any effect on BCRP mRNA or protein levels in the placental syncytiotrophoblast cells. This may suggest that BCRP is stably expressed in the placenta, even under adverse conditions, and may imply that activity of this transporter protein is essential for normal placental function.