ABCG2 Transports Sulfated Conjugates of Steroids and Xenobiotics*

The mechanism for the cellular extrusion of sulfated conjugates is still unknown. In the present study, we investigated whether human wild type ABCG2 transports estrone 3-sulfate (E1S) using membrane vesicles from cDNA-transfected mouse lymphoma cell line (P388 cells). The uptake of [3H]E1S into ABCG2-expressing membrane vesicles was stimulated by ATP, and the Km value for [3H]E1S was determined to be 16.6 μm. The ABCG2-mediated transport of [3H]E1S was potently inhibited by SN-38 and many sulfate conjugates but not by glucuronide and glutathione conjugates or other anionic compounds. Other sulfate conjugates such as [3H]dehydroepiandrosterone sulfate (DHEAS) and [35S]4-methylumbelliferone sulfate (Km = 12.9 μm) and [35S]6-hydroxy-5,7-dimethyl-2-methylamino-4-(3-pyridylmethyl)benzothiazole (E3040) sulfate (Km = 26.9 μm) were also transported by ABCG2. Although [3H]methotrexate, [3H]17β-estradiol-17β-D-glucuronide, [3H]2,4-dinitrophenyl-S-glutathione, and [14C]4-methylumbelliferone glucuronide were transported by ABCG2, this took place to a much lesser extent compared with [3H]E1S. It was suggested that ABCG2 preferentially transports sulfate conjugates and that E1S and DHEAS are the potential physiological substrates for this transporter.

[1]  J. Schellens,et al.  Overexpression of the BCRP/MXR/ABCP gene in a topotecan-selected ovarian tumor cell line. , 1999, Cancer research.

[2]  L. Doyle,et al.  A multidrug resistance transporter from human MCF-7 breast cancer cells. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[3]  J. Schellens,et al.  Breast cancer resistance protein is localized at the plasma membrane in mitoxantrone- and topotecan-resistant cell lines. , 2000, Cancer research.

[4]  T. Litman,et al.  Molecular cloning of cDNAs which are highly overexpressed in mitoxantrone-resistant cells: demonstration of homology to ABC transport genes. , 1999, Cancer research.

[5]  T. Tsuruo,et al.  Dominant‐negative inhibition of breast cancer resistance protein as drug efflux pump through the inhibition of S‐S dependent homodimerization , 2002, International journal of cancer.

[6]  D. Keppler,et al.  Hepatic Secretion of Conjugated Drugs and Endogenous Substances , 2000, Seminars in liver disease.

[7]  T. Litman,et al.  Acquired mutations in the MXR/BCRP/ABCP gene alter substrate specificity in MXR/BCRP/ABCP-overexpressing cells. , 2001, Cancer research.

[8]  S. Cole,et al.  Glutathione Stimulates Sulfated Estrogen Transport by Multidrug Resistance Protein 1* , 2001, The Journal of Biological Chemistry.

[9]  Y. Sugiyama,et al.  Excretion of GSSG and Glutathione Conjugates Mediated by MRP1 and CM0AT/MRP2 , 1998, Seminars in liver disease.

[10]  D. Keppler,et al.  Vectorial transport by double-transfected cells expressing the human uptake transporter SLC21A8 and the apical export pump ABCC2. , 2001, Molecular pharmacology.

[11]  J. Schuetz,et al.  Bcrp1 gene expression is required for normal numbers of side population stem cells in mice, and confers relative protection to mitoxantrone in hematopoietic cells in vivo , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[12]  Y. Sugiyama,et al.  Kinetic Analysis of Hepatobiliary Transport for Conjugated Metabolites in the Perfused Liver of Mutant Rats (EHBR) with Hereditary Conjugated Hyperbilirubinemia , 1995, Pharmaceutical Research.

[13]  H. Nakauchi,et al.  The ABC transporter Bcrp1/ABCG2 is expressed in a wide variety of stem cells and is a molecular determinant of the side-population phenotype , 2001, Nature Medicine.

[14]  J. Schellens,et al.  Role of breast cancer resistance protein in the bioavailability and fetal penetration of topotecan. , 2000, Journal of the National Cancer Institute.

[15]  Y. Sugiyama,et al.  Function and expression of multidrug resistance-associated protein family in human colon adenocarcinoma cells (Caco-2). , 2000, The Journal of pharmacology and experimental therapeutics.

[16]  T. Ishikawa,et al.  Transport of 7-ethyl-10-hydroxycamptothecin (SN-38) by breast cancer resistance protein ABCG2 in human lung cancer cells. , 2001, Biochemical and biophysical research communications.

[17]  M. J. van de Vijver,et al.  Subcellular localization and distribution of the breast cancer resistance protein transporter in normal human tissues. , 2001, Cancer research.

[18]  T. Litman,et al.  Functional characterization of the human multidrug transporter, ABCG2, expressed in insect cells. , 2001, Biochemical and biophysical research communications.

[19]  Vincenzo,et al.  A human placenta-specific ATP-binding cassette gene (ABCP) on chromosome 4q22 that is involved in multidrug resistance. , 1998, Cancer research.

[20]  K. Hayashi,et al.  Mechanism of glutathione S-conjugate transport in canalicular and basolateral rat liver plasma membranes. , 1990, The Journal of biological chemistry.

[21]  Y. Sugiyama,et al.  Role of metabolic enzymes and efflux transporters in the absorption of drugs from the small intestine. , 2000, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[22]  Hiroshi Suzuki,et al.  Characterization of the Transport Properties of Cloned Rat Multidrug Resistance-associated Protein 3 (MRP3)* , 1999, The Journal of Biological Chemistry.

[23]  E. Hudson,et al.  The multidrug-resistant phenotype associated with overexpression of the new ABC half-transporter, MXR (ABCG2). , 2000, Journal of cell science.

[24]  B. Sarkadi,et al.  Characterization of Drug Transport, ATP Hydrolysis, and Nucleotide Trapping by the Human ABCG2 Multidrug Transporter , 2002, The Journal of Biological Chemistry.

[25]  Y. Sugiyama,et al.  Characterization of bile acid transport mediated by multidrug resistance associated protein 2 and bile salt export pump. , 2001, Biochimica et biophysica acta.

[26]  M. Kool,et al.  A family of drug transporters: the multidrug resistance-associated proteins. , 2000, Journal of the National Cancer Institute.

[27]  T. Druley,et al.  From MDR to MXR: new understanding of multidrug resistance systems, their properties and clinical significance , 2001, Cellular and Molecular Life Sciences CMLS.

[28]  M. Kool,et al.  The multidrug resistance protein family. , 1999, Biochimica et biophysica acta.

[29]  Y. Sugiyama,et al.  Kinetic analysis of the primary active transport of conjugated metabolites across the bile canalicular membrane: comparative study of S-(2,4-dinitrophenyl)-glutathione and 6-hydroxy-5,7-dimethyl-2-methylamino-4-(3-pyridylmethyl)benzothiazole glucuronide. , 1997, The Journal of pharmacology and experimental therapeutics.

[30]  Fei Li,et al.  Overexpression of wild-type breast cancer resistance protein mediates methotrexate resistance. , 2002, Cancer Research.

[31]  D. Keppler,et al.  Conjugate export pumps of the multidrug resistance protein (MRP) family: localization, substrate specificity, and MRP2-mediated drug resistance. , 1999, Biochimica et biophysica acta.