Cancer protein transporter

Maliepaard M, Scheffer GL, Faneyte IF, van Gastelen MA, Pijnenborg AC, Schinkel AH et al. Subcellular localization and distribution of the breast cancer resistance protein transporter in normal human tissues. Cancer Res 2001 61(8)3458-3464. 

Huls M, Brown CD, Windass AS, Sayer R, van den Heuvel JJ, Heemskerk S, Russel FG, Masereeuw R.The breast cancer resistance protein transporter ABCG2 is expressed in the human kidney proximal tubule apical membrane. Kidney int 2007 73 220-225. Miller DS, Stewart DE, Pritchard JB. Intracellular compartmentation of organic anions within renal cells. Am J Physiol 1993 264 ... 

Subcellular localization and distribution of the breast cancer resistance protein transporter in normal human tissues. Cancer Research, 61. 3458-3464. 

The breast cancer resistance protein (BCRP) belongs to the G-branch of the ABC-transporter family (ABCG2). In contrast to most other ABC-proteins, BCRP consists of only one transmembrane domain (TDM) with one nucleotide binding fold (NBF) at its C-terminus. Because of this structural characteristic BCRP as well as other ABC-transporters with only one TMD are termed half transporters. To achieve functional activity these transporters have to form hetero- or homodimers. BCRP is involved in the multidrug resistance of certain tumors and transports endogenous compounds like cholesterol and steroid hormones. 

Both influx and efflux transporters are located in intestinal epithelial cells and can either increase or decrease oral absorption. Influx transporters such as human peptide transporter 1 (hPEPTl), apical sodium bile acid transporter (ASBT), and nucleoside transporters actively transport drugs that mimic their native substrates across the epithelial cell, whereas efflux transporters such as P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP), and breast cancer resistance protein (BCRP) actively pump absorbed drugs back into the intestinal lumen. 

Breast cancer resistance protein (BCRP) is another ATP-dependent efflux transporter that confers resistance to a variety of anticancer agents, including... 

Mao Q and Unadkat JD. Role of the breast cancer resistance protein (ABCG2) in drug transport. AAPS J 2005 7 E118-33. 

Borst, P., et al. A family of drug transporters the multidrug resistance-associated proteins. J. Natl. Cancer Inst. 2000, 92, 1295-1302. 

Zeng, H., et al. Transport of amphi-pathic anions by human multidrug resistance protein 3. Cancer Res. 2000, 60, 4779-4784. 

Breast Cancer Resistance Protein (BCRP, also known as MXR or ABCP), first cloned from mitoxantrone and anthracycline-resistant breast and colon cancer cells [188, 189] is a half-transporter efflux pump believed to function as a homo-or hetero-dimer. Following its identification, BCRP-mediated drug resistance was observed for topoisomerase inhibitors including camptothecins [190, 191] and in-dolocarbazoles [192]. In normal tissues, BCRP was detected in placental syncytio-trophoblasts, hepatocyte canalicular membrane, apical intestinal epithelia and vascular endothelial cells [193]. These findings support the important role BCRP plays in modulating topotecan bioavailability, fetal exposure and hepatic elimination [194]. Considering that the substrates and tissue distributions for BCRP overlap somewhat with MDR1 and MRPs [195], additional studies will be required to define the relative contribution of each of these transporters in the overall and tis-... 

Belinsky MG, Bain LJ, Balsara BB, Testa JR, Kruh GD. Characterization of MOAT-C and MOAT-D, new members of the MRP/cMOAT subfamily of transporter proteins. J Natl Cancer Inst 1998 90(22)7735-1741. 

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