Expression of breast cancer resistance protein (BCRP/ABCG2) in human placenta throughout gestation and at term before and after labor

• Published in: Canadian journal of physiology and pharmacology Vol. 84; no. 12; pp. 1251 - 1258
• Main Authors: Yeboah, D, Sun, M, Kingdom, J, Baczyk, D, Lye, S.J, Matthews, S.G, Gibb, W
• Format: Journal Article
• Language: English
• Published: Ottawa, ON National Research Council of Canada 01.12.2006; NRC Research Press; Canadian Science Publishing NRC Research Press
• Subjects: ATP Binding Cassette Transporter, Sub-Family G, Member 2; ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Biological and medical sciences; Blood Vessels - metabolism; Blotting, Western; Breast cancer; breast cancer resistance protein; Chemical properties; Drug resistance; Female; fetal blood vessels; Fundamental and applied biological sciences. Psychology; G proteins; Gene Expression; gestation; Gestational Age; human placenta; Humans; Labor, Obstetric - genetics; Labor, Obstetric - metabolism; multi-drug resistance; Neoplasm Proteins - genetics; Neoplasm Proteins - metabolism; Observations; Oncology; Placenta - blood supply; Placenta - metabolism; placenta humain; Polymerase chain reaction; Pregnancy; Proteins; protéine de résistance au cancer du sein; Reproductive system; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Rodents; résistance pléiotrope; Structure; syncytiotrophoblast; syncytiotrophoblaste; Trophoblasts - metabolism; vaisseaux sanguins foetaux; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Canada; Human; Fetal membrane; Breast cancer; Malignant tumor; Gene expression; Labor; Protein; Pregnancy; Mammary gland diseases; Vertebrata; Mammalia; Placenta; Blood vessel; Circulatory system
• ISSN: 0008-4212; 1205-7541
• DOI: 10.1139/y06-078

Breast cancer resistance protein, BCRP, is a multidrug resistance protein that is highly expressed in the human placenta. In cancer tissues, this protein actively extrudes a wide variety of chemically and structurally unrelated chemotherapeutic drugs and other compounds. Studies in mice have shown that in the absence of BCRP activity in the placenta, there is a 2-fold increase in the uptake in BCRP substrates into fetus. This suggests that in the placenta, BCRP extrudes compounds that would otherwise cross the syncytiotrophoblast cells into fetal circulation. The purpose of this study was to examine the expression and localization of BCRP in the human placenta throughout gestation. Tissues from 6-13, 16-19, 24-29, 32-35, and 38-41 weeks of gestation were used. Real time RT-PCR analysis demonstrated that the mRNA levels of BCRP in the placenta do not change significantly as gestation progressed. However, Western blot analysis revealed that the protein levels increased towards the end of gestation. We demonstrated that BCRP is localized to the syncytiotrophoblast of the placenta and in some fetal blood vessels within the placenta. Tissues from the early stages of pregnancy (6-13 weeks) showed fewer BCRP positive blood vessels than term tissues (38-41 weeks).