ABCMdb

ABCC1 p.Ala989Thr

Predicted by SNAP2:	C: N (82%), D: N (72%), E: N (66%), F: N (87%), G: N (87%), H: N (72%), I: N (82%), K: N (57%), L: N (78%), M: N (87%), N: N (87%), P: N (66%), Q: N (93%), R: N (61%), S: N (97%), T: N (87%), V: N (78%), W: D (53%), Y: N (93%),
Predicted by PROVEAN:	C: D, D: D, E: N, F: D, G: N, H: D, I: D, K: N, L: D, M: D, N: N, P: D, Q: N, R: D, S: N, T: N, V: D, W: D, Y: D,

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[hide] Role of pharmacogenetics of ATP-binding cassette t... Pharmacol Ther. 2006 Nov;112(2):457-73. Cascorbi I
Role of pharmacogenetics of ATP-binding cassette transporters in the pharmacokinetics of drugs.
Pharmacol Ther. 2006 Nov;112(2):457-73., [PMID:16766035]

Abstract [show]
Interindividual differences of drug response are an important cause of treatment failures and adverse drug reactions. The identification of polymorphisms explaining distinct phenotypes of drug metabolizing enzymes contributed in part to the understanding of individual variations of drug plasma levels. However, bioavailability also depends on a major extent from the expression and activity of drug transport across biomembranes. In particular efflux transporters of the ATP-binding cassette (ABC) family such as ABCB1 (P-glycoprotein, P-gp), the ABCC (multidrug resistance-related protein, MRP) family and ABCG2 (breast cancer resistance protein, BCRP) have been identified as major determinants of chemoresistance in tumor cells. They are expressed in the apical membranes of many barrier tissue such as the intestine, liver, blood-brain barrier, kidney, placenta, testis and in lymphocytes, thus contributing to plasma, liquor, but also intracellular drug disposition. Since expression and function exhibit a broad variability, it was hypothesized that hereditary variances in the genes of membrane transporters could explain at least in part interindividual differences of pharmacokinetics and clinical outcome of a variety of drugs. This review focuses on the functional significance of single nucleotide polymorphisms (SNP) of ABCB1, ABCC1, ABCC2, and ABCG2 in in vitro systems, in vivo tissues and drug disposition, as well as on the clinical outcome of major indications.

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830 A thorough investigation on the functional significance of 10 non-synonymous SNP, leading to amino acid changes C43S, T73I, S92F, T117; R230Q, R633Q, R723Q, A989T, C1047S. Login to comment
834 Lowest capacity was found for A989T, caused by a 2965G>A variant. Login to comment
852 Table 5 Frequency of ABCC1 genetic variants in different populations, position on DNA, putative effect, and frequencies (according to Le Saux et al., 2000; Ito et al., 2001; Moriya et al., 2002; Conrad et al., 2002; Oselin et al., 2003b; Wang et al., 2004) Position/ Nucleotide Aminoacid or effect Orientals Caucasians Function 128G>C C43S 0.01 - elevateda 218C>T T73I 0.00-0.04 - 257C>T S92F 0.00 0.00 decreaseda 350C>T T117M - 0.02 (decreased)a 689G>A R230N 0.00 0.00 (decreased)a 816G>A synonymous - 0.04 825T>C synonymous - 0.30 1057G>A V353M 0.00 0.005 elevateda 1299G>T R433S - 0.01 elevated Vmax of doxorubicin, decreased transport of LTC4 a,b 1684T>C synonymous - 0.80 1898G>A R633Q - 0.01 (decreased)a 2012G>T G671V - 0.03 doxorubicine-induced cardiomyopathyc 2168G>A R723Q 0.01-0.07 - decreaseda 2965G>A A989T 0.00 0.005 (decreased)a 3140G>C C1047S 0.00 0.00 3173G>A R1058Q 0.01 - 4002G>A synonymous - 0.28 4535C>T S1512L - 0.03 decreaseda a Letourneau et al. (2005). Login to comment

[hide] Pharmacogenetics/genomics of membrane transporters... Cancer Metastasis Rev. 2007 Mar;26(1):183-201. Huang Y
Pharmacogenetics/genomics of membrane transporters in cancer chemotherapy.
Cancer Metastasis Rev. 2007 Mar;26(1):183-201., [PMID:17323126]

Abstract [show]
Inter-individual variability in drug response and the emergence of adverse drug reactions are main causes of treatment failure in cancer therapy. Recently, membrane transporters have been recognized as an important determinant of drug disposition, thereby affecting chemosensitivity and -resistance. Genetic factors contribute to inter-individual variability in drug transport and targeting. Therefore, pharmacogenetic studies of membrane transporters can lead to new approaches for optimizing cancer therapy. This review discusses genetic variations in efflux transporters of the ATP-binding cassette (ABC) family such as ABCB1 (MDR1, P-glycoprotein), ABCC1 (MRP1), ABCC2 (MRP2) and ABCG2 (BCRP), and uptake transporters of the solute carrier (SLC) family such as SLC19A1 (RFC1) and SLCO1B1 (SLC21A6), and their relevance to cancer chemotherapy. Furthermore, a pharmacogenomic approach is outlined, which using correlations between the growth inhibitory potency of anticancer drugs and transporter gene expression in multiple human cancer cell lines, has shown promise for determining the relevant transporters for any given drugs and predicting anticancer drug response.

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124 Moreover, Letourneau et al. examined 10 non-synonymous ABCC1 SNPs to determine Table 2 Summary of genetic variants in ABC transporters ABCB1, ABCC1, ABCC2 and ABCG2 involved in cancer chemotherapy Variants (location, effect) Phenotype Drug Sample Reference ABCB1 +103T>C (5'flanking, non-coding) Increased transcription Doxorubicin vincristine osteosarcoma Stein et al., 1994 [19] +8T>C (5'flanking, non-coding) Unknown Leukemia Rund et al., 1999 [21] 1236C>T (exon12, synonymous) Higher expression AML blasts Illmer et al., 2002 [47] Lower clearance Irinotecan Cancer patients Sai et al., 2003 [44] Higher exposure Irinotecan, SN-38 Cancer patients Mathijssen et al., 2003 [45] 2677G>T/A (exon21, A893S/T) Lower expression placenta Tanabe et al., 2001 [42] Lower expression placenta Hitzl et al., 2004 [37] Higher expression AML blasts Illmer et al., 2002 [47] Allele specific expression Cell lines, lymphoma Mickley et al., 1998 [22] Lower clearance Irinotecan Cancer patients Sai et al., 2003 [44] Survival leukemia Illmer et al., 2002 [47] Survival leukemia van den Heuvel-Eibrink et al., 2001 [48] Worse survival AML blasts Kim et al., 2006 [10] Higher efficacy Paclitaxel Ovarian cancer Green et al., 2006 [50] 2995G>A (exon24, A999T) None Cell lines, lymphoma Mickley et al., 1998 [22] 3435C>T (exon26, synonymous) Lower expression Duodenal protein Hoffmeyer et al., 2000 [26] Lower expression placenta Hitzl et al., 2004 [37] Higher expression Intestine mRNA Nakamura et al., 2002 [32] Higher expression AML blasts Illmer et al., 2002 [47] Lower clearance Irinotecan Cancer patients Sai et al., 2003 [44] Lower efflux Digoxin CD56+ NK cells Hitzl et al., 2001 [27] Higher plasma level Digoxin Healthy volunteers Hoffmeyer et al., 2000 [26] Higher AUC Cyclosporin transplant patients Bonhomme-Faivre et al., 2004 [36] Lower CNS relapse Cancer patients Stanulla et al., 2005 [46] Better survival leukemia Illmer et al., 2002 [47] Higher efficacy Breast cancer Kafka et al., 2003 [49] Higher activity, worse survival AML Kim et al., 2006 [10] Better survival Platinums Esophageal cancer Wu et al., 2006 [43] No difference Docetaxel patients Puisset et al., 2004 [41] No difference Irinotecan Cancer patients Mathijssen et al., 2004 [39] No difference Vincristine patients Plasschaert et al., 2004 [40] No difference colon Taniguchi et al., 2003 [24] ABCC1 -260G>C (5'flanking, non-coding) Higher activity Transfected cell line Wang et al., 2005 [62] Table 2 (Continued) Variants (location, effect) Phenotype Drug Sample Reference 128G>C (exon2, C43S) Reduced resistance Vincristine, arsenite Transfected cell line Leslie et al., 2003 [60] 1299G>T (exon10, R433S) Reduced transport of LTC4, increased resistance to doxorubicin Leukotriene C4, doxorubicin Transfected cell line Conrad et al., 2002 [59] 2012G>T (exon16, G671V) No change in activityLeukotriene C4 Transfected cell line Conrad et al., 2001 [58] Heart toxicity Doxorubicin nLon-Hodgkin lymphoma Wojnowski et al., 2005 [63] 2965G>A (exon22, A989T) Reduced transport Estradiol 17β-glucuronide Transfected cell line Letourneau et al., 2005 [61] ABCC2 1271A>G (exon10, R421G) Reduced drug elimination, increased nephrotoxicity Methotrexate One lymphoma patient Hulot et al., 2005 [79] 3972C>T (exon28, nonsynonymous) Reduced drug clearance Irinotecan Cancer patients Innocenti et al., 2004 [80] ABCG2 376C>T (exon4, Q126stop) Reduced transport Porphyrin Trensfected cell Tamura et al., 2006 [104] 421C>A (exon5, Q141K) Lower expression Transfected cell lines Imai et al., 2002 [94] Lower expression Transfected cell lines Kondo et al., 2004 [95] Lower expression Placenta Kobayashi et al., 2005 [98] Reduced ATPase activity Trensfected cell lines Mizuarai et al., 2004 [97] Higher plasma levels Diflomotecan patients Sparreboom et al., 2004 [100] Increased bioavailability Topotecan patients Sparreboom et al., 2005 [101] Increased bioavailability 9-Aminocamptothecin patients Zamboni et al., 2006 [81] Increased drug accumulation Imatinib Transfected cell lines Gardner et al., 2006 [96] Increased drug accumulation Topotecan Trensfected cell lines Imai et al., 2002 [94] No difference Imatinib patients Gardner et al., 2006 [96] No difference intestine Zamber et al., 2003 [99] No difference MTX Trensfected cell lines Kondo et al., 2004 [95] the effects on expression and function of this transporter in transfected HEK293T cells [61]. Login to comment
125 None of the SNPs resulted in changed protein expression and function, except that the 2965G>A (Ala989Thr) caused a significant decrease in transport of one of the ABCC1 substrate estradiol 17β-glucuronide. Login to comment

[hide] Pharmacogenomics of MRP transporters (ABCC1-5) and... Drug Metab Rev. 2008;40(2):317-54. Gradhand U, Kim RB
Pharmacogenomics of MRP transporters (ABCC1-5) and BCRP (ABCG2).
Drug Metab Rev. 2008;40(2):317-54., [PMID:18464048]

Abstract [show]
Elucidation of the key mechanisms that confer interindividual differences in drug response remains an important focus of drug disposition and clinical pharmacology research. We now know both environmental and host genetic factors contribute to the apparent variability in drug efficacy or in some cases, toxicity. In addition to the widely studied and recognized genes involved in the metabolism of drugs in clinical use today, we now recognize that membrane-bound proteins, broadly referred to as transporters, may be equally as important to the disposition of a substrate drug, and that genetic variation in drug transporter genes may be a major contributor of the apparent intersubject variation in drug response, both in terms of attained plasma and tissue drug level at target sites of action. Of particular relevance to drug disposition are members of the ATP Binding Cassette (ABC) superfamily of efflux transporters. In this review a comprehensive assessment and annotation of recent findings in relation to genetic variation in the Multidrug Resistance Proteins 1-5 (ABCC1-5) and Breast Cancer Resistance Protein (ABCG2) are described, with particular emphasis on the impact of such transporter genetic variation to drug disposition or efficacy.

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71 Letourneau et al. (2005) studied the influence of 10 non-synonymous variations (Thr73Ile, Ser92Phe, Thr117Met, Arg230Gln, Arg633Gln, Arg723Gln, Ala989Thr, Cys1047Ser, Arg1056Gln, and Ser1512Leu) on MRP1 expression using membrane vesicles isolated from transfected cells and assesed transport activity for 3 known MRP1 substrates (LTC4, estradiol-17-β-glucuronide, and methotrexate). Login to comment
72 They found no significant effect of these variants on either expression or function, but did observe a 50% decrease in estradiol-17-β-glucuronide transport by the Ala989Thr variant (Letourneau et al., 2005) due to higher Km rather than decreased Vmax. Login to comment
81 MRP1 (ABCC1) NH2 NBD NBD in out Membrane Cys43Ser Ser92Phe Thr117Met Arg230Gln Val353Met Arg633Gln Gly671Val Arg723Gln Arg433Ser Ala989Thr Cys1047Ser Val1146Ile Arg1058Gln Thr1401Met Ser1512Leu Thr73Ile COOH NBD NBD COOH NBD COOH NBD NBD Table1MRP1(ABCC1)singlenucleotidepolymorphisms.Location,allelefrequencyandfunctionaleffects. Positionin codingsequence Aminoacid exchangeLocation Allelefrequency EffectNCBIIDReferenceAfCaJpothers 128G>CCys43SerExon2--1[1]-Decreaseinvincristineresistance[2]rs41395947 Disruptedplasmamembranetraffickingin transfectedcells[2] 218C>TThr73IleExon2--1[1]3.7Chinese[3]Noinfluenceonexpressionandtransportin membranevesicles[4] rs41494447 257C>TSer92PheExon30a 0a 0a 0Chinese[3]Noinfluenceonexpressionandtransportin membranevesicles[4] 350C>TThr117MetExon3-100[5]--Noinfluenceonexpressionandtransportin membranevesicles[4] 689G>AArg230GlnExon70a 0a 0a 0Chinese[3]Noinfluenceonexpressionandtransportin membranevesicles[4] 1057G>AVal353MetExon90a 0.5a 0a -- 1299G>TArg433SerExon10-1.4[6]--Changesintransportandresistance[7] 1898G>AArg633GlnExon13-[8]--Noinfluenceonexpressionandtransportin membranevesicles[4] 2012G>TGly671ValExon16-2.8[6]--Noinfluenceonexpressionandtransportin membranevesicles[6] Associatedwithanthracycline-induced cardiotoxicity[9] 2168G>AArg723GlnExon17--7.3[1]5.6Chinese[3]Noinfluenceonexpressionandtransportin membranevesicles[4]noinfluenceonmRNA expressioninenterocytes(n=1)[10] rs4148356 2965G>AAla989ThrExon220a 0.5a 0a -Noinfluenceonexpressionandtransportin membranevesicles(non-significantreduction inE17βGtransport)[4] 323 3140G>CCys1047SerExon234.5a 0a 0a -Noinfluenceonexpressionandtransportin membranevesicles[4] rs13337489 3173G>AArg1058GlnExon23--1[1]-Noinfluenceonexpressionandtransportin membranevesicles[4] rs41410450 3436G>AVal1146IleExon24-----rs28706727 4102C>TThr1401MetExon29-----rs8057331 4535C>TSer1512LeuExon31-[5]--Noinfluenceonexpressionandtransportin membranevesicles[4] ReferencewithoutfrequencymeansthatSNPwasdetectedbutnofrequencydetermined. Login to comment

[hide] Pharmacogenetics of ATP-binding cassette transport... Methods Mol Biol. 2010;596:95-121. Cascorbi I, Haenisch S
Pharmacogenetics of ATP-binding cassette transporters and clinical implications.
Methods Mol Biol. 2010;596:95-121., [PMID:19949922]

Abstract [show]
Drug resistance is a severe limitation of chemotherapy of various malignancies. In particular efflux transporters of the ATP-binding cassette family such as ABCB1 (P-glycoprotein), the ABCC (multidrug resistance-associated protein) family, and ABCG2 (breast cancer resistance protein) have been identified as major determinants of chemoresistance in tumor cells. Bioavailability depends not only on the activity of drug metabolizing enzymes but also to a major extent on the activity of drug transport across biomembranes. They are expressed in the apical membranes of many barrier tissues such as the intestine, liver, blood-brain barrier, kidney, placenta, testis, and in lymphocytes, thus contributing to plasma, liquor, but also intracellular drug disposition. Since expression and function exhibit a broad variability, it was hypothesized that hereditary variances in the genes of membrane transporters could explain at least in part interindividual differences of pharmacokinetics of a variety of anticancer drugs and many others contributing to the clinical outcome of certain leukemias and further malignancies.

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134 A thorough investigation on the functional significance of ten nonsynonymous SNPs, leading to amino acid changes C43S, T73I, S92F, T117; R230Q, R633Q, R723Q, A989T, C1047S. Login to comment
139 Lowest capacity was found for A989T, caused by a 2965G>A variant. Login to comment
155 ABCC2 (Multidrug Resistance-Associated Protein 2) Table 6.5 Frequency of ABCC1 genetic variants in different populations, position on DNA, putative effect, and frequencies (according to (33, 77-80, 136)) Position Amino acid or effect Orientals Caucasians Function c.128G>C C43S 0.01 - Elevateda c. 218C>T T73I 0.00-0.04 - c. 257C>T S92F 0.00 0.00 Decreaseda c. 350C>T T117M - 0.02 (Decreased)a c. 689G>A R230N 0.00 0.00 (Decreased)a c. 816G>A Synonymous - 0.04 c. 825T>C Synonymous - 0.30 c. 1057G>A V353M 0.00 0.005 Elevateda c. 1299G>T R433S - 0.01 Elevated vmax of doxorubicin, decreased transport of LTC4 a,b c. 1684T>C Synonymous - 0.80 c. 1898G>A R633Q - 0.01 (Decreased)a c. 2012G>T G671V - 0.03 Doxorubicine-induced cardiomyopathyc c. 2168G>A R723Q 0.01-0.07 - Decreaseda c. 2965G>A A989T 0.00 0.005 (Decreased)a c. 3140G>C C1047S 0.00 0.00 c. 3173G>A R1058Q 0.01 - c. 4002G>A Synonymous - 0.28 c. 4535C>T S1512L - 0.03 Decreaseda References: a [81], b [77], c [84] an inducible expression of ABCC2, which contributes also to the phenomenon of drug resistance. Login to comment

[hide] Pharmacogenetics of membrane transporters: an upda... Mol Biotechnol. 2010 Feb;44(2):152-67. Sissung TM, Baum CE, Kirkland CT, Gao R, Gardner ER, Figg WD
Pharmacogenetics of membrane transporters: an update on current approaches.
Mol Biotechnol. 2010 Feb;44(2):152-67., [PMID:19950006]

Abstract [show]
This review provides an overview of the pharmacogenetics of membrane transporters including selected ABC transporters (ABCB1, ABCC1, ABCC2, and ABCG2) and OATPs (OATP1B1 and OATP1B3). Membrane transporters are heavily involved in drug clearance and alters drug disposition by actively transporting substrate drugs between organs and tissues. As such, polymorphisms in the genes encoding these proteins may have significant effects on the absorption, distribution, metabolism and excretion of compounds, and may alter pharmacodynamics of many agents. This review discusses the techniques used to identify substrates and inhibitors of these proteins and subsequently to assess the effect of genetic mutation on transport, both in vitro and in vivo. A comprehensive list of substrates for the major drug transporters is included. Finally, studies linking transporter genotype with clinical outcomes are discussed.

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67 Those studied include C43S, T73I, S92F, T117M, R230Q, V353M, R433S, R633Q, G671V, R723Q, A989T, C1047S, R1058Q, A1337T, and S1512L. Login to comment
69 However, it has been noted that C43S, R433S, and A989T result in decreased ABCB1 function [43]. Login to comment

[hide] Polymorphisms of MRP1 (ABCC1) and related ATP-depe... Pharmacogenet Genomics. 2005 Aug;15(8):523-33. Conseil G, Deeley RG, Cole SP
Polymorphisms of MRP1 (ABCC1) and related ATP-dependent drug transporters.
Pharmacogenet Genomics. 2005 Aug;15(8):523-33., [PMID:16006996]

Abstract [show]
Genetic variations in drug metabolizing enzymes and targets are established determinants of adverse drug reactions and interactions, but less is known about the role of genetic polymorphisms in membrane transport proteins. MRP1 (ABCC1) is one of 13 polytopic membrane proteins that comprise the 'C' subfamily of the ATP-binding cassette (ABC) superfamily of transport proteins. MRP1 and related ABCC family members, including MRP2, 3, 4 and 5 (ABCC2, 3, 4 and 5), each have a distinctive pattern of tissue expression and substrate specificity. Together, these five transporters play important roles in the disposition and elimination of drugs and other organic anions, and in maintenance of blood-tissue barriers, as confirmed by enhanced chemosensitivity of respective knockout mice. Moreover, Mrp2 (Abcc2) deficient animals display mild conjugated hyperbilirubinemia, corresponding to a human condition known as Dubin-Johnson syndrome (DJS). Naturally occurring mutations in MRP/ABCC-related drug transporters have been reported, some of which are non-synonymous single nucleotide polymorphisms. The consequences of the resulting amino acid changes can sometimes be predicted from in vitro site-directed mutagenesis studies or from knowledge of mutations of analogous (conserved) residues in ABCC proteins that cause DJS, Pseudoxanthoma elasticum (ABCC6), cystic fibrosis (CFTR/ABCC7) or persistent hyperinsulinemic hypoglycemia of infancy (SUR1/ABCC8). Continual updating of databases of sequence variants and haplotype analysis, together with in vitro biochemical validation assays and pharmacological studies in knockout animals, should make it possible to determine how genetic variation in the MRP-related transporters contributes to the range of responses to drugs and chemicals observed in different human populations.

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148 Fig. 3 Exon 1 2 3 MSDMSD NBD1 MSD NBD2 C4535T(S1512L) G3173A (R1058Q) G3140C (C1047S) G2965A (A989T) G2168A (R723Q) G2012T(G671V) G1898A (R633Q) G1299T(R433S) G1057A (V353M) G689A (R230Q) C350T(T117M) C257T(S92F) C218T(T73I) C128C (C43S) (TM1-5) (TM6-11) (TM12-17) 4 5 6 7 8 9101112 1314 151617 1819 20 21 22 23 242526272829 30 31 Location of non-synonymous SNPs in the coding regions of the genes in the MRP1/ABCC1 gene. Login to comment

[hide] Functional characterization of non-synonymous sing... Pharmacogenet Genomics. 2005 Sep;15(9):647-57. Letourneau IJ, Deeley RG, Cole SP
Functional characterization of non-synonymous single nucleotide polymorphisms in the gene encoding human multidrug resistance protein 1 (MRP1/ABCC1).
Pharmacogenet Genomics. 2005 Sep;15(9):647-57., [PMID:16041243]

Abstract [show]
The 190-kDa ATP-binding cassette (ABC) multidrug resistance protein 1 (MRP1) encoded by the MRP1/ABCC1 gene mediates the active cellular efflux of glucuronide, glutathione and sulfate conjugates. It can also confer resistance to a diverse spectrum of chemotherapeutic agents and transport a variety of toxicants. In the present study, we examined 10 MRP1/ABCC1 missense genetic variants [non-synonymous single nucleotide polymorphisms (SNPs)] to determine whether or not they affect expression or function of the transporter. Variants 218C>T (Thr73Ile), 257C>T (Ser92Phe), 350C>T (Thr117Met), 689G>A (Arg230Gln), 1898G>A (Arg633Gln), 2168G>A (Arg723Gln), 2965G>A (Ala989Thr), 3140G>C (Cys1047Ser), 3173G>A (Arg1058Gln) and 4535C>T (Ser1512Leu) were recreated using site-directed mutagenesis and transfected into human embryonic kidney cells. Immunoblotting experiments showed that all mutant proteins were expressed at levels comparable to wild-type MRP1. Vesicular transport assays revealed that the Ala989Thr mutation caused a significant decrease in estradiol 17beta-glucuronide transport due to a decrease in apparent affinity (Km) for this organic anion. The transport properties of the other mutants were comparable to wild-type MRP1. When the MRP1/ABCC1 non-synonymous SNPs were evaluated by the SIFT algorithm using subsets of homologs and orthologs of MRP1/ABCC1, Arg230Gln, Val353Met, Arg433Ser, Gly671Val and Arg1058 mutations were predicted to be deleterious, whereas the PolyPhen algorithm predicted Ser92Phe and Gly671Val to be potentially damaging. Thus most predictions of these algorithms were not in accordance with our experimental results. In conclusion, our data suggest that none of the MRP1/ABCC1 variants studied are likely by themselves to have major deleterious effects in healthy individuals, and the SIFT and PolyPhen algorithms appear to be poor predictors of the phenotypic consequences of these MRP1 mutations at least in vitro.

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3 Variants 218C > T (Thr73Ile), 257C > T (Ser92Phe), 350C > T (Thr117Met), 689G > A (Arg230Gln), 1898G > A (Arg633Gln), 2168G > A (Arg723Gln), 2965G > A (Ala989Thr), 3140G > C (Cys1047Ser), 3173G > A (Arg1058Gln) and 4535C > T (Ser1512Leu) were recreated using site-directed mutagenesis and transfected into human embryonic kidney cells. Login to comment
5 Vesicular transport assays revealed that the Ala989Thr mutation caused a significant decrease in estradiol 17b-glucuronide transport due to a decrease in apparent affinity (Km) for this organic anion. Login to comment
28 Of these mutations, the Fig. 1 128G >C (C43S) 128G >T(T73I) 689G >A (R230Q)1057G >A (V353M) 1299G >T(R433S) 1898G >A (R633Q) 2012G >T(G671V) 2168G >A (R723Q) 3173G >A (R1058Q) 4535C >T(S1512L) 3140G >C (C1047S) 2965G >A (A989T) 350C >T(T117M) 257C >T(S92F) 313029282726252423222120181716151413121110987654321 19 MSD1 MSD1 MSD2 MSD3 MSD2 NBD1 MSD3 NBD2 TM 1 2 3 4 5 6 7 8 Val353Met Ala989Thr Cys1047Ser Arg1058Gln NBD2NBD1 Ser1512Leu Arg633Gln Arg433Ser Arg723Gln Thr73lle Thr117Met Arg230Gln Cys43Ser Ser92Phe Gly671Val 9 10 11 12 13 14 15 16 17 (a) (b) Location of reported non-synonymous single nucleotide polymorphisms (SNPs) in MRP1/ABCC1. Login to comment
46 The template for generating Table 1 Frequencies of non-synonymous single nucleotide polymorphisms in MRP1/ABCC1 Variant Amino acid substitution Allelic frequency Population References 128G > C Cys43Ser 0% (0/26) Japanese [16] 1% (1/96) Japanese [17] 218C > T Thr73Ile 0% (0/26) Japanese [16] 1% (1/96) Japanese [17] 3.7% (2/54) Chinese [37] 257C > T Ser92Phe 0% (0/220) Caucasian www.pharmGKB.org 0.5% (1/200) African-American 0% (0/60) Japanese 0% (0/14) Pacific-Islander 350C > T Thr117Met 1.6% (1/64) Caucasian [28] 689G > A Arg230Gln 0% (0/220) Caucasian www.pharmGKB.org 0.5% (1/200) African-American 0% (0/60) Japanese 0% (0/14) Pacific-Islander 1057G > A Val353Met 0.5% (1/220) Caucasian www.pharmGKB.org 0% (0/200) African-American 0% (0/60) Japanese 0% (0/14) Pacific-Islander 1299G > T Arg433Ser 1.4% (1/72) Caucasian [20] 0% (0/110) Caucasian [19] 1898G > A Arg633Gln 0.8% (2/234) Caucasian [29] 2012G > T Gly671Val 2.8% (2/72) Caucasian [20] 2.6% (6/234) Caucasian [29] 2168G > A Arg723Gln 3.8% (1/26) Japanese [16] 1% (1/96) Japanese [30] 7.3% (7/96) Japanese [17] 5.6% (3/54) Chinese [37] 2965G > A Ala989Thr 0.5% (1/220) Caucasian www.pharmGKB.org 0% (0/200) African-American 0% (0/60) Japanese 0% (0/14) Pacific-Islander 3140G > C Cys1047Ser 0% (0/220) Caucasian www.pharmGKB.org 4.5% (9/200) African-American 0% (0/60) Japanese 0% (0/14) Pacific-Islander 3173G > A Arg1058Gln 0% (0./26) Japanese [16] 1% (1/96) Japanese [17] 4535C > T Ser1512Leu 3.1% (2/24) Caucasian [28] Characterization of MRP1/ABCC1 variants in vitro Le´tourneau et al. 649 the Arg633Gln and Arg723Gln mutants was created by subcloning a HindIII fragment (1329 bp) encoding amino acids 517-959 into pGEM-3z [20]. Login to comment
47 The mutagenesis template for the Ala989Thr, Cys1047Ser and Arg1058Gln mutants was created by subcloning a 1986-bp XmaI fragment encoding amino acids 780-1440 from pcDNA3.1( - )MRP1k into pGEM-3z [21]. Login to comment
50 Mutagenesis was performed according to the manufacturer`s instructions with the following sense primers (substituted nucleotides for amino acid mutation are underlined, introduced or disrupted restriction sites are italicized and other silent substitutions are in lower case letters) as follows: Thr73Ile (50 -G ATG ACA CCT CTC AAC AAA ATC AAAACTGCCTTGGG-30 ); Ser92Phe (50 -GG GCA GAC CTG TTC TAC TTT TTC TGG GAA AG-30 ) (EarI); Thr117Met (50 -CTC TTG GGC ATC ACC ATG CTG CTT GCT ACC-30 ); Arg230Gln (50 -GG TTG ATT GTA CAG GGC TAC CGC C-30 ) (BsrGI); Arg633Gln (50 -GAC AGC ATC GAG CGA CAG CCT GTG AAA GAC GGC GG-30 ) (Eam1105I); Arg723Gln (50 -CAG AAT GAC TCT CTC CAA GAA AAt ATC CTT TTT GGA TGT CAG C-30 ) (PleI); Ala989Thr (50 -C ATG TGT AAC CAC GTG TCC ACG CTG GCT TCC-30 ) (PmlI); Cys1047Ser (50 - GCT TCC CGC TCT CTG CAT GTG GAC CTG C-30 ) (PmlI); Arg1058Gln (50 -CTG CTG CAC AGC ATC CTC CAG TCA CCC ATG AGC-30 ) (BstEII); and Ser1512Leu (50 -CAG GAG TAC GGA GCC CCA TTG GAC CTt CTG CAG CAG-30 ) (NarI). Login to comment
51 Following mutagenesis, the desired fragment was subcloned back into pcDNA3.1(-) MRP1k as a XbaI/BamHI fragment (865 bp) for the Thr73Ile, Ser92Phe, Thr117Met and Arg230Gln mutants; a Bsu36I/Esp3I fragment (721 bp) for the Arg633Gln and Arg723Gln mutants; a Esp3I/EcoRI fragment (1313 bp) for the Ala989Thr, Cys1047Ser, Arg1058Gln mutants; and a EcoRI/KpnI fragment (778 bp) for the Ser1512Leu mutant. Login to comment
87 The mutants were considered in four groups based on their location in the transporter: (a) MSD1/CL3 mutants Thr73Ile, Ser92Phe, Thr117Met and Arg230Gln; (b) NBD1 mutants Arg633Gln and Arg723Gln; (c) MSD3 mutants Ala989Thr, Cys1047Ser and Arg1058Gln; and (d) COOH-terminus mutant Ser1512Leu. Login to comment
98 The decrease in [3 H]E217bG uptake of approximately 50% by the Ala989Thr mutant was considered substantial enough to warrant further investigation (Fig. 3b). Login to comment
99 Kinetic parameters of [3 H]E217bG uptake by the MRP1 Ala989Thr mutant To further characterize the decrease in [3 H]E217bG transport by the Ala989Thr mutant protein, kinetic analysis was performed. Login to comment
100 A Michaelis-Menten plot of the data yielded a Km of 7.4 ± 1.6 mM and Vmax of 561 ± 34 pmol/mg protein/min for E217bG uptake by the Ala989Thr mutant protein compared to Km and Vmax values for E217bG uptake by WT-MRP1 of 3.1 ± 0.5 mM and 626 ± 22 pmol/mg protein/min, respectively. Login to comment
101 These results indicate that an increase in apparent Km for E217bG is primarily responsible for the decrease in transport of this conjugated oestrogen by the Ala989Thr mutant Fig. 4. Login to comment
102 Inhibition of [3 H]LTC4 and [3 H]MTX transport by E217bG To further characterize the interaction of E217bG with the Ala989Thr mutant protein, its ability to inhibit the transport of other organic anion substrates of MRP1 was investigated. Login to comment
103 The IC50 (E217bG) of [3 H]LTC4 transport for the Ala989Thr mutant was 31 mM whereas the IC50 (E217bG) for WT-MRP1 was 9 mM. Login to comment
106 Thus, the IC50 (E217bG) values were 3 mM and 2 mM for the Ala989Thr mutant and WT-MRP1, respectively Fig. 5. Login to comment
114 The effect of the SNPs (with the exception of Ala989Thr) on E217bG transport also ranged from none to moderate (< 40% decrease or increase). Login to comment
118 Because the Ala989Thr mutation caused the greatest decrease in E217bG uptake (50%), it was further characterized by kinetic analysis. Login to comment
120 Inhibition studies of LTC4 transport by E217bG yielded differences in IC50 values between the Ala989Thr mutant and wild-type 652 Pharmacogenetics and Genomics 2005, Vol 15 No 9 transporters that were in accordance with the approximate two-fold decrease in uptake affinity of the mutant for E217bG. Login to comment
121 By contrast, the IC50 values of E217bG for MTX uptake by the Ala989Thr mutant and wild-type MRP1 were similar. Login to comment
123 Previous mutagenesis and inhibition studies have Fig. 3 Cys43Ser Thr73lle Ser92Phe Thr117Met Arg230Gln Arg433Ser Arg633Gln Gly671Val Arg723Gln Ala989Thr Cys1047Ser Arg1058Gln Ser1512Leu Cys43Ser Thr73lle Ser92Phe Thr117Met Arg230Gln Arg433Ser Arg633Gln Gly671Val Arg723Gln Ala989Thr Cys1047Ser Arg1058Gln Ser1512Leu Thr73lle Ser92Phe Thr117Met Arg230Gln Arg633Gln Arg723Gln Ala989Thr Cys1047Ser Arg1058Gln Ser1512Leu LTC4 % WT-MRP1 uptake 0 25 50 75 100 125 E217βG % WT-MRP1 uptake 0 25 50 75 100 125 150 MTX % WT-MRP1 uptake 0 25 50 75 100 125 (b) (c) (a) ATP-dependent vesicular transport of organic anions by mutant MRP1 proteins. Login to comment
137 On the other hand, the Cys43Ser and Ala989Thr mutations were found by analysis in vitro to significantly modify MRP1 function, despite the fact that these effects were not predicted by the SIFT algorithm [18]. Login to comment
141 All the other MRP1/ABCC1 Fig. 4 500 250 0 0 25 50 75 100 [3 H]E217βGuptake(pmol/mg/min) [E217βG] (µM) Kinetic analysis of [3 H]E217bG transport by MRP1 mutant Ala989Thr. Login to comment
142 Membrane vesicles (2 mg protein per point) expressing wild-type (`) and Ala989Thr mutant (~) MRP1 were incubated with concentrations of E217bG ranging from 0.25 mM to 100 mM (40-120 nCi per point) for 1 min at 37 1C. Km and Vmax were determined from a Michaelis-Menten curve fitted by nonlinear regression. Login to comment
145 (a) E217bG-mediated inhibition of [3 H]LTC4 transport by wild-type (`) and Ala989Thr mutant (~) MRP1 was measured by incubating 2 mg of membrane vesicles with 50 nM [3 H]LTC4 (10 nCi) and concentrations of E217bG ranging from 2.5-50 mM for 1 min at 231C. Login to comment
146 (b) E217bG-mediated inhibition of [3 H]MTX transport by wild-type (`) and Ala989Thr mutant (~) MRP1 was measured by incubating 5 mg of membrane vesicle protein with 100 mM [3 H]MTX (125 nCi) and concentrations of E217bG ranging from 2.5-50 mM for 20 min at 371C. Results shown are those of a single experiment; each point represents the mean ± SD of triplicate determinations. Login to comment
158 This observation may be construed as being Table 2 Conservation of the amino acids substituted by non-synonymous SNP of human MRP1/ABCC1a Protein Speciesb C43S T73I S92F T117Mc R230Q V353M R433S R633Qc G671V R723Q A989T C1047S R1058Q S1512L MRP1 Human C T S T R V R R G R A C R S Monkey C T S M R V R R G Q A C R S Dog C T S M R V R R G R A R R S Cow C A S M Q V R R G R A R R S Rat C A S M Q V R W G R A R R S Mouse C T S M H V R R G R A R R S MRP2 Human L A V T K A K R G K A I R E Monkey L A V T K A K R G K A I R E Dog L A V T K A K R G K A I Q Q Rat L A A T K V K R G K A A R E Mouse L A A T K V K V G K A T R E Rabbit L A V T K V K R G K A I R E MRP3 Human C L S M Y I R K G Q A V R A Rat C L S M L L R K G Q A L R V MRP4 Human - - - - I F K R G R Y T K Y MRP5 Human - - - - V T R S G R T R R S MRP6 Human P A A M R I R S G V A L R A CFTR Human - - - - R Y K A G K L I Q Q SUR1 Human V L L A T V Q R G E L R L E SUR2 Human V L H T Q V Q R G E I N L P Pgp Human - - - - - E K S G A G R R Q YCF1 Saccharomyces cervisiae A I L V T V K L G K S Y R G Mrp1 Caenorhabditis elegans T L D F L I R T G R G L R K Mrp2 Caenorhabditis elegans T F D I L I K T G R G I R K AtMRP2 Arabidopsis thaliana Q L R W L M S P G R R K R E AtMRP1 Arabidopsis thaliana H T A V L M S P G R R K R E a Aligned using Clustal W (http://pbil.univ-lyon1.fr/). Login to comment
163 In addition, many of the variants have been found as singletons, including the mutation leading to Ala989Thr substitution. Login to comment

[hide] Structural and functional properties of human mult... Curr Med Chem. 2011;18(3):439-81. He SM, Li R, Kanwar JR, Zhou SF
Structural and functional properties of human multidrug resistance protein 1 (MRP1/ABCC1).
Curr Med Chem. 2011;18(3):439-81., [PMID:21143116]

Abstract [show]
Multidrug ABC transporters such as P-glycoprotein (P-gp/MDR1/ABCB1) and multidrug resistance protein 1 (MRP1/ABCC1) play an important role in the extrusion of drugs from the cell and their overexpression can be a cause of failure of anticancer and antimicrobial chemotherapy. Recently, the mouse P-gp/Abcb1a structure has been determined and this has significantly enhanced our understanding of the structure-activity relationship (SAR) of mammalian ABC transporters. This paper highlights our current knowledge on the structural and functional properties and the SAR of human MRP1/ABCC1. Although the crystal structure of MRP1/ABCC1 has yet to be resolved, the current topological model of MRP1/ABCC1 contains two transmembrane domains (TMD1 and TMD2) each followed by a nucleotide binding domain (NBD) plus a third NH2-terminal TMD0. MRP1/ABCC1 is expressed in the liver, kidney, intestine, brain and other tissues. MRP1/ABCC1 transports a structurally diverse array of important endogenous substances (e.g. leukotrienes and estrogen conjugates) and xenobiotics and their metabolites, including various conjugates, anticancer drugs, heavy metals, organic anions and lipids. Cells that highly express MRP1/ABCC1 confer resistance to a variety of natural product anticancer drugs such as vinca alkaloids (e.g. vincristine), anthracyclines (e.g. etoposide) and epipodophyllotoxins (e.g. doxorubicin and mitoxantrone). MRP1/ABCC1 is associated with tumor resistance which is often caused by an increased efflux and decreased intracellular accumulation of natural product anticancer drugs and other anticancer agents. However, most compounds that efficiently reverse P-gp/ABCB1-mediated multidrug resistance have only low affinity for MRP1/ABCC1 and there are only a few effective and relatively specific MRP1/ABCC1 inhibitors available. A number of site-directed mutagenesis studies, biophysical and photolabeling studies, SAR and QSAR, molecular docking and homology modeling studies have documented the role of multiple residues in determining the substrate specificity and inhibitor selectivity of MRP1/ABCC1. Most of these residues are located in the TMs of TMD1 and TMD2, in particular TMs 4, 6, 7, 8, 10, 11, 14, 16, and 17, or in close proximity to the membrane/cytosol interface of MRP1/ABCC1. The exact transporting mechanism of MRP1/ABCC1 is unclear. MRP1/ABCC1 and other multidrug transporters are front-line mediators of drug resistance in cancers and represent important therapeutic targets in future chemotherapy. The crystal structure of human MRP1/ABCC1 is expected to be resolved in the near future and this will provide an insight into the SAR of MRP1/ABCC1 and allow for rational design of anticancer drugs and potent and selective MRP1/ABCC1 inhibitors.

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816 There are at least 15 naturally occurring mutations identified in MRP1/ABCC1, including Cys43Ser in TM1, Thr73Ile in CL1, Ser92Phe in TM2, Arg230Asn in L0, Val353Met at TM6/TM7 interface, Arg433Ser in TM8, Gly671Val in TM11, Arg723Gln located between the Walker A and Walker B motifs of NBD1, Ala861Thr at NBD1/TM12 interface, Ala989Thr in TM12, Cys1047Ser in TM13, Arg1058Gln in CL7, Val1146Ile in CL7, Thr1337Ala between the Walker A and Walker B motifs of NBD2, and Thr1401Met, and many of them have been found to affect its transport activity [171, 362, 363, 366, 367, 377-384]. Login to comment

[hide] Xenobiotic, bile acid, and cholesterol transporter... Pharmacol Rev. 2010 Mar;62(1):1-96. Epub 2010 Jan 26. Klaassen CD, Aleksunes LM
Xenobiotic, bile acid, and cholesterol transporters: function and regulation.
Pharmacol Rev. 2010 Mar;62(1):1-96. Epub 2010 Jan 26., [PMID:20103563]

Abstract [show]
Transporters influence the disposition of chemicals within the body by participating in absorption, distribution, and elimination. Transporters of the solute carrier family (SLC) comprise a variety of proteins, including organic cation transporters (OCT) 1 to 3, organic cation/carnitine transporters (OCTN) 1 to 3, organic anion transporters (OAT) 1 to 7, various organic anion transporting polypeptide isoforms, sodium taurocholate cotransporting polypeptide, apical sodium-dependent bile acid transporter, peptide transporters (PEPT) 1 and 2, concentrative nucleoside transporters (CNT) 1 to 3, equilibrative nucleoside transporter (ENT) 1 to 3, and multidrug and toxin extrusion transporters (MATE) 1 and 2, which mediate the uptake (except MATEs) of organic anions and cations as well as peptides and nucleosides. Efflux transporters of the ATP-binding cassette superfamily, such as ATP-binding cassette transporter A1 (ABCA1), multidrug resistance proteins (MDR) 1 and 2, bile salt export pump, multidrug resistance-associated proteins (MRP) 1 to 9, breast cancer resistance protein, and ATP-binding cassette subfamily G members 5 and 8, are responsible for the unidirectional export of endogenous and exogenous substances. Other efflux transporters [ATPase copper-transporting beta polypeptide (ATP7B) and ATPase class I type 8B member 1 (ATP8B1) as well as organic solute transporters (OST) alpha and beta] also play major roles in the transport of some endogenous chemicals across biological membranes. This review article provides a comprehensive overview of these transporters (both rodent and human) with regard to tissue distribution, subcellular localization, and substrate preferences. Because uptake and efflux transporters are expressed in multiple cell types, the roles of transporters in a variety of tissues, including the liver, kidneys, intestine, brain, heart, placenta, mammary glands, immune cells, and testes are discussed. Attention is also placed upon a variety of regulatory factors that influence transporter expression and function, including transcriptional activation and post-translational modifications as well as subcellular trafficking. Sex differences, ontogeny, and pharmacological and toxicological regulation of transporters are also addressed. Transporters are important transmembrane proteins that mediate the cellular entry and exit of a wide range of substrates throughout the body and thereby play important roles in human physiology, pharmacology, pathology, and toxicology.

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7118 Nucleotide Change Amino Acid Change In Vitro Function Protein Expression/Localization ABCC1 MRP1 G128C C43S 1↔ Intracellular C218T T73I 1↔ Normal C257T S92F 2↔ Normal C350T T117M 2↔ Normal G689A R230Q ↔ Normal G1057A V353M N.D. N.D. G1299T R433S 2↔ Normal G1898A R633Q 2↔ Normal G2012T G671V ↔ Normal G2168A R723Q 2 Normal G2965A A989T 2↔ Normal G3140C C1047S 1↔ Normal G3173A R1058Q ↔ Normal C4535T S1512L ↔ Normal ABCC2 MRP2 C-24T N.D. N.D. G1058A R353H N.D. N.D. G1249A V417I ↔ Normal C2366T S789F 12 Intracellular T2780G L927R N.D. N.D. C3298T R1100C N.D. N.D. G3299A R1100H N.D. N.D. T3563A V1188E N.D. N.D. G4348A A1450T ↔ Normal/Intracellular G4544A C1515Y N.D. N.D. ABCC3 MRP3 G32A G11D ↔ Normal C202T H68Y N.D. N.D. G296A R99Q N.D. Normal C1037T S346F 2 Normal C1537A Q513K N.D. N.D. T1643A L548Q N.D. N.D. G1820A S607N 2 Normal C2221T Gln741STOP N.D. N.D. G2293C V765L ↔ Normal G2395A V799M N.D. N.D. C2758T P920S 1 Normal G2768A R923Q 1 Normal C3657A S1219R N.D. N.D. C3856G R1286G ↔ Normal G3890A R1297H N.D. N.D. C4042T R1348C 1 Normal A4094G Q1365R ↔ Normal C4141A R1381S ↔ Intracellular C4217T T1406M N.D. N.D. G4267A G1423R N.D. N.D. ABCC4 MRP4 C52A L18I N.D. N.D. C232G P78A 2↔ Normal T551C M184T N.D. N.D. G559T G187W 2 Reduced A877G K293E ↔ Normal G912T K304N ↔ Normal C1067T T356M N.D. N.D. C1208T P403L 2↔ Normal G1460A G487E 2 Normal A1492G K498E ↔ Normal A1875G I625M N.D. N.D. C2000T P667L N.D. N.D. A2230G M744V ↔ Normal G2269A E757K N.D. Intracellular G2459T R820I N.D. N.D. G2560T V854F N.D. N.D. G2698T V900L N.D. N.D. G2867C C956S 1↔ Normal G3211A V1071I ↔ Normal C3425T T1142M N.D. N.D. G3659A R1220Q N.D. N.D. A3941G Q1314R N.D. N.D. 2, reduced function; 1, increased function; ↔, no change in function; N.D. not determined. Login to comment
7115 Nucleotide Change Amino Acid Change In Vitro Function Protein Expression/Localization ABCC1 MRP1 G128C C43S 1࢒ Intracellular C218T T73I 1࢒ Normal C257T S92F 2࢒ Normal C350T T117M 2࢒ Normal G689A R230Q ࢒ Normal G1057A V353M N.D. N.D. G1299T R433S 2࢒ Normal G1898A R633Q 2࢒ Normal G2012T G671V ࢒ Normal G2168A R723Q 2 Normal G2965A A989T 2࢒ Normal G3140C C1047S 1࢒ Normal G3173A R1058Q ࢒ Normal C4535T S1512L ࢒ Normal ABCC2 MRP2 C-24T N.D. N.D. G1058A R353H N.D. N.D. G1249A V417I ࢒ Normal C2366T S789F 12 Intracellular T2780G L927R N.D. N.D. C3298T R1100C N.D. N.D. G3299A R1100H N.D. N.D. T3563A V1188E N.D. N.D. G4348A A1450T ࢒ Normal/Intracellular G4544A C1515Y N.D. N.D. ABCC3 MRP3 G32A G11D ࢒ Normal C202T H68Y N.D. N.D. G296A R99Q N.D. Normal C1037T S346F 2 Normal C1537A Q513K N.D. N.D. T1643A L548Q N.D. N.D. G1820A S607N 2 Normal C2221T Gln741STOP N.D. N.D. G2293C V765L ࢒ Normal G2395A V799M N.D. N.D. C2758T P920S 1 Normal G2768A R923Q 1 Normal C3657A S1219R N.D. N.D. C3856G R1286G ࢒ Normal G3890A R1297H N.D. N.D. C4042T R1348C 1 Normal A4094G Q1365R ࢒ Normal C4141A R1381S ࢒ Intracellular C4217T T1406M N.D. N.D. G4267A G1423R N.D. N.D. ABCC4 MRP4 C52A L18I N.D. N.D. C232G P78A 2࢒ Normal T551C M184T N.D. N.D. G559T G187W 2 Reduced A877G K293E ࢒ Normal G912T K304N ࢒ Normal C1067T T356M N.D. N.D. C1208T P403L 2࢒ Normal G1460A G487E 2 Normal A1492G K498E ࢒ Normal A1875G I625M N.D. N.D. C2000T P667L N.D. N.D. A2230G M744V ࢒ Normal G2269A E757K N.D. Intracellular G2459T R820I N.D. N.D. G2560T V854F N.D. N.D. G2698T V900L N.D. N.D. G2867C C956S 1࢒ Normal G3211A V1071I ࢒ Normal C3425T T1142M N.D. N.D. G3659A R1220Q N.D. N.D. A3941G Q1314R N.D. N.D. 2, reduced function; 1, increased function; ࢒, no change in function; N.D. not determined. Login to comment

[hide] Signatures of recent positive selection at the ATP... Hum Mol Genet. 2007 Jun 1;16(11):1367-80. Epub 2007 Apr 5. Wang Z, Wang J, Tantoso E, Wang B, Tai AY, Ooi LL, Chong SS, Lee CG
Signatures of recent positive selection at the ATP-binding cassette drug transporter superfamily gene loci.
Hum Mol Genet. 2007 Jun 1;16(11):1367-80. Epub 2007 Apr 5., [PMID:17412754]

Abstract [show]
Members of the ATP-binding cassette (ABC) superfamily of transporters have been implicated as major players in drug response. Single nucleotide polymorphisms (SNPs) in the ABC transporter genes may account for variation in drug response between individuals. Given the abundance of SNPs within the human genome, identification of functionally important SNPs is difficult. Here, we utilized signatures of recent positive selection (RPS) to identify SNPs in ABC genes that have potential functional significance by using the long-range-haplotype test to search for signatures of RPS at 18 ABC genes involved in drug transport. From the genotype data of these 18 ABC genes in four populations extracted from the HapMap database, at least one SNP in each of these genes displayed genomic signatures of RPS in at least one population. However, only 13 SNPs in 10 ABC genes from three populations retained statistical significance after Type I error reduction. The functional significance of six of these RPS SNPs, including those that failed multiple testing correction (MTC), has been reported previously. We experimentally confirmed a functional effect for two SNPs, including one that failed to show evidence of RPS after MTC. These observations suggest that Type I error reduction may inadvertently increase Type II error. Although the remaining positively selected SNPs have yet to be functionally validated, our study illustrates the feasibility of using this strategy to identify SNPs within 'adaptive' genes that may confer functional effect, prior to testing their roles in individual/population drug response variation or in complex disease susceptibility.

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184 Nonetheless, two very low frequency (,2%) non-synonymous ABCC1 SNPs, e22/G2965A (Ala989Thr) and e10/G1299GT (Arg433Ser), were reported experimentally to result in decreased estradiol 17b-glucoronide (53) and organic anion transport but increased doxorubicin resistance (54), respectively. Login to comment
183 Nonetheless, two very low frequency (,2%) non-synonymous ABCC1 SNPs, e22/G2965A (Ala989Thr) and e10/G1299GT (Arg433Ser), were reported experimentally to result in decreased estradiol 17b-glucoronide (53) and organic anion transport but increased doxorubicin resistance (54), respectively. Login to comment

[hide] ABC transporters in human lymphocytes: expression,... Expert Opin Drug Metab Toxicol. 2010 May;6(5):571-89. Giraud C, Manceau S, Treluyer JM
ABC transporters in human lymphocytes: expression, activity and role, modulating factors and consequences for antiretroviral therapies.
Expert Opin Drug Metab Toxicol. 2010 May;6(5):571-89., [PMID:20367109]

Abstract [show]
IMPORTANCE OF THE FIELD: ATP-binding cassette (ABC) transporters are a superfamily of efflux pumps that transport numerous compounds across cell membranes. These transporters are located in various human tissues including peripheral blood cells, in particular lymphocytes, and present a high variability of expression and activity. This variability may affect the intracellular concentrations and efficacy of drugs acting within lymphocytes, such as antiretroviral drugs. AREAS COVERED IN THIS REVIEW: This review focuses on the current knowledge about the expression, activity, roles and variability of ABC drug transporters in human lymphocytes. The identified modulating factors and their impact on the intracellular pharmacokinetics and efficacy of antiretroviral drugs are also detailed. WHAT THE READER WILL GAIN: Controversial data regarding the expression, activity and sources of variability of ABC transporters in lymphocytes are discussed. The modulating factors and their pharmacological consequences regarding antiretroviral therapies are also provided. TAKE HOME MESSAGE: Numerous studies have reported conflicting results regarding the expression and activity of ABC drug transporters in lymphocytes. Despite these discrepancies, which may partly result from heterogeneous analytical methods, ABCC1 appears to have the highest expression in lymphocytes and may thus play a predominant role in the resistance to antiretroviral drugs, particularly to protease inhibitors.

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183 Letourneau et al. showed that none of ten non-synonymous polymorphisms influenced significantly ABCC1 protein levels and that only one polymorphism, the A989T (2965 G > A) variant, affected ABCC1 activity [90]. Login to comment

[hide] Two polymorphic variants of ABCC1 selectively alte... Drug Metab Dispos. 2013 Dec;41(12):2187-96. doi: 10.1124/dmd.113.054213. Epub 2013 Sep 30. Conseil G, Cole SP
Two polymorphic variants of ABCC1 selectively alter drug resistance and inhibitor sensitivity of the multidrug and organic anion transporter multidrug resistance protein 1.
Drug Metab Dispos. 2013 Dec;41(12):2187-96. doi: 10.1124/dmd.113.054213. Epub 2013 Sep 30., [PMID:24080162]

Abstract [show]
In this study we compared the in silico predictions of the effect of ABCC1 nonsynonymous single nucleotide polymorphisms (nsSNPs) with experimental data on MRP1 transport function and response to chemotherapeutics and multidrug resistance protein 1 (MRP1) inhibitors. Vectors encoding seven ABCC1 nsSNPs were stably expressed in human embryonic kidney (HEK) cells, and levels and localization of the mutant MRP1 proteins were determined by confocal microscopy and immunoblotting. The function of five of the mutant proteins was determined using cell-based drug and inhibitor sensitivity and efflux assays, and membrane-based organic anion transport assays. Predicted consequences of the mutations were determined by multiple bioinformatic methods. Mutants C43S and S92F were correctly routed to the HEK cell plasma membrane, but the levels were too low to permit functional characterization. In contrast, levels and membrane trafficking of R633Q, G671V, R723Q, A989T, and C1047S were similar to wild-type MRP1. In cell-based assays, all five mutants were equally effective at effluxing calcein, but only two exhibited reduced resistance to etoposide (C1047S) and vincristine (A989T; C1047S). The GSH-dependent inhibitor LY465803 (LY465803 [N-[3-(9-chloro-3-methyl-4-oxo-4H-isoxazolo-[4,3-c]quinolin-5-yl)-cyclohexylmethy l]-benzamide)] was less effective at blocking calcein efflux by A989T, but in a membrane-based assay, organic anion transport by A989T and C1047S was inhibited by MRP1 modulators as well as wild-type MRP1. GSH accumulation assays suggest cellular GSH efflux by A989T and C1047S may be impaired. In conclusion, although six in silico analyses consistently predict deleterious consequences of ABCC1 nsSNPs G671V, changes in drug resistance and inhibitor sensitivity were only observed for A989T and C1047S, which may relate to GSH transport differences.

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5 In contrast, levels and membrane trafficking of R633Q, G671V, R723Q, A989T, and C1047S were similar to wild-type MRP1. Login to comment
6 In cell-based assays, all five mutants were equally effective at effluxing calcein, but only two exhibited reduced resistance to etoposide (C1047S) and vincristine (A989T; C1047S). Login to comment
7 The GSH-dependent inhibitor LY465803 (LY465803 [N-[3-(9-chloro-3-methyl-4-oxo-4H-isoxazolo- [4,3-c]quinolin-5-yl)-cyclohexylmethyl]-benzamide)] was less effective at blocking calcein efflux by A989T, but in a membrane-based assay, organic anion transport by A989T and C1047S was inhibited by MRP1 modulators as well as wild-type MRP1. Login to comment
8 GSH accumulation assays suggest cellular GSH efflux by A989T and C1047S may be impaired. Login to comment
9 In conclusion, although six in silico analyses consistently predict deleterious consequences of ABCC1 nsSNPs G671V, changes in drug resistance and inhibitor sensitivity were only observed for A989T and C1047S, which may relate to GSH transport differences. Login to comment
33 In a subsequent characterization of the organic anion transport activity of 10 additional ABCC1 nsSNPs, only one (rs35529209; 2965G.A; A989T) showed a significant reduction in E217bG transport (L&#e9;tourneau et al., 2005). Login to comment
34 In contrast to our experimental data, the predictive algorithms SIFT (Sorting Tolerant From Intolerant) and PolyPhen indicated that G671V would adversely affect MRP1 function but C43S and A989T were less likely to do so, whereas predictions for R433S were mixed (L&#e9;tourneau et al., 2005). Login to comment
40 Four (C43S, S92F, G671V, A989T) were mutants that our earlier studies showed had a phenotype discordant from that predicted by Polyphen and/or SIFT (L&#e9;tourneau et al., 2005). Login to comment
58 Lysates (10 mg protein per lane) prepared from HEK293 cell lines expressing wild-type (WT) and mutant (R633Q, G671V, R723Q, A989T, C1047S) MRP1 proteins and the untransfected control cell line (HEK) were immunoblotted, and MRP1 was detected with mAb QCRL-1. Login to comment
96 Total cellular glutathione in HEK293 wild-type, A989T and C1047S cells was measured using the enzymatic recycling method of Tietze (1969) and Brehe and Burch (1976). Login to comment
103 Tryptic fragmentation patterns of wild-type and A989T mutant MRP1 were determined as described previously elsewhere (Rothnie et al., 2006; Iram and Cole, 2012). Login to comment
104 Briefly, membrane vesicles (2 mg of protein per lane) enriched for wild-type or A989T mutant MRP1 were incubated in hypotonic buffer (50 mM HEPES, pH 7.4) in the absence or presence of S-methylGSH (10 mM) for 30 minutes on ice. Login to comment
117 The predicted effects of the nsSNPs A989T and C1047S located in TM12 and TM13 of MSD2, respectively, are also mixed. Login to comment
125 R723Q = A989T. Login to comment
126 nsSNPs R633Q, G671V, R723Q, A989T, and C1047S Have No Effect on Total on Plasma Membrane MRP1 Levels in HEK293 Cells. Login to comment
127 After we had isolated stably transfected HEK293 cell lines by G418 selection, cell lines expressing R633Q, G671V, R723Q, A989T, and C1047S and wild-type MRP1 were cloned to .90% homogeneity for MRP1 expression. Login to comment
128 Immunoblots of cell lysates showed that the levels of the five mutant proteins were comparable to (R633Q, A989T, C1047S) or somewhat (,50%) higher than (G671V, R723Q) wild-type MRP1, indicating that the mutations do not cause any major misfolding of MRP1 that would result in its degradation (Fig. 1B). Login to comment
132 Confocal fluorescence microscopy experiments showed that the R633Q, G671V, R723Q, A989T, and C1047S mutant proteins in the five clonal HEK cell lines were also routed correctly to the plasma membrane in a manner indistinguishable from wild-type MRP1 (Fig. 2). Login to comment
136 The HEK cell lines expressing R633Q, G671V, R723Q, A989T, and C1047S were tested for their levels of resistance to five xenobiotics for which human MRP1 is known to confer resistance, including the antineoplastic agents vincristine, etoposide (VP-16), doxorubicin, and the heavy metal oxyanions arsenite and antimony tartrate (Cole et al., 1994). Login to comment
138 Levels of vincristine resistance were the most variable, but the differences were only statistically significant (approximately 2.5-fold lower than wild-type MRP1, P , 0.05) in the cell lines expressing A989T and C1047S. Login to comment
140 Resistance of the A989T and C1047S cell lines to arsenite was comparable to the wild-type MRP1 cell line while resistance to antimony tartrate was reduced (1.7-fold and 3.0-fold, respectively). Login to comment
141 TABLE 1 Predicted effects of MRP1 nsSNPs examined in this study according to various in silico prediction methods nsSNP SIFT/SIFTBLink Probability Scoresa PolyPhen2 Classificationb (Score) I-Mutant Suite "Stability"c (DDG in kcal mol21 ) Grantham Value Difference (D)d Blosum50e PAM250f (Threshold) (,0.05) (.1.000) (,20.5; .0.5) (.50) (,0) (,0) C43S 0.51/0.08 possibly damaging (0.819) decrease (20.74) 112 21 0 S92F 0.11/0.05 possibly damaging (0.303) neutral (20.05) 155 23 23 NBD1-R633Q 0.66/0.57 benign (0.001) decrease (21.16) 43 1 1 NBD1-G671V 0.00/0.02 probably damaging (1.000) decrease (20.57) 109 24 21 NBD1-R723Q 0.49/0.39 benign(0.002) decrease (20.71) 43 1 1 A989T 0.53/0.12 benign (0.000) decrease (20.73) 58 0 1 C1047S 0.07/0.64 benign (0.001) decrease (20.67) 112 21 0 a SIFT (Sorting Intolerant From Tolerant) was used by manually entering a sequence alignment comprising only human homologs of MRP1, and SIFT-BLink probability scores were obtained using 100 aligned computer-selected sequences (threshold for nontolerated substitution set at ,0.05). Login to comment
153 To determine whether the five nsSNPs, R633Q, G671V, R723Q, A989T, and C1047S, affected the ability of MRP1 to mediate efflux of calcein, HEK293 cells stably expressing wild-type and mutant MRP1 as well as untransfected HEK cells were incubated with several concentrations of the cell permeable acetoxymethyl ester of calcein (calcein-AM) at 37&#b0;C; 3 hours later, the intracellular hydrolyzed calcein that had not been effluxed by MRP1 was measured. Login to comment
157 Thus, unlike the chemosensitivity assay, which showed that the drug-resistance patterns of A989T and C1047S were different from wild-type MRP1 (Table 2), the calcein efflux assay did not detect any differences (Fig. 3). Login to comment
158 nsSNPs A989T, But Not C1047S, Affects the Inhibition of MRP1-Mediated Calcein Efflux by LY465803. Login to comment
159 To further explore the selective effects of nsSNPs A989T and C1047S on their ability to recognize xenobiotics, we determined whether the two mutations affect the efficacy of MRP1 modulators. Login to comment
167 TABLE 2 Effect of nsSNP mutations on MRP1-mediated resistance to chemotherapeutic agents and metalloids in HEK293 cell lines Cell Line/ nsSNP Relative Resistancea Vincristine Doxorubicin Etoposide Na+ Arsenite K+ Antimony Tartrate Wild-type 12.2 6 0.6 3.9 6 1.6 7.1 6 0.6 1.4; 2.2 5.2; 6.4 R633Q 15.3 6 2.9 3.3 6 1.0 5.1 6 0.9 ND ND G671V 9.3 6 2.8 3.4 6 0.6 7.1 6 0.7 ND ND R723Q 21.3 6 7.2 2.5 6 0.1 6.9 6 0.5 ND ND A989T 4.4 6 1.1b ** 2.5 6 0.6 5.0 6 0.9 1.6; 2.3 3.1; 3.5 C1047S 5.1 6 0.5*** 1.8 6 0.2 4.5 6 0.7* 2.0; 1.8 2.2; 1.7 ND, not determined. Login to comment
173 However, the fluorescence levels in cells expressing A989T were decreased by 50%, indicating that the mutation had diminished the ability of LY465803 to inhibit MRP1. Similarly, in the converse experiment, when cells were preincubated with increasing concentrations of LY465803 before adding a single concentration of calcein-AM (6 mM), the fluorescence levels observed for the cells expressing the A989T mutant were consistently ;50% lower than the fluorescence levels in the control untransfected HEK293 cells as well as the cells expressing wild-type and C1047S mutant MRP1 at all LY465803 concentrations tested (Fig. 4B). Login to comment
174 nsSNPs A989T and C1047S Do Not Affect Inhibition of [3 H]E217bG Vesicular Transport by LY465803 and the Leukotriene Modifiers LY171883 and BAYu9773. Login to comment
175 To determine whether the nsSNP A989T also affected the sensitivity of MRP1 to the GSH-dependent LY465803 inhibitor in a vesicular transport assay, the ability of LY465803 to inhibit uptake of [3 H]E217bG into membrane vesicles prepared from the HEK cell line expressing A989T was examined; cell lines expressing the C1047S mutant and wild-type MRP1 were included as controls. Login to comment
176 Preliminary experiments confirmed that E217bG vesicular uptake by A989T was partially (50%) reduced in vesicles from the A989T HEK cell line, as it had been shown previously in vesicles prepared from transiently transfected A989T HEK cells (L&#e9;tourneau et al., 2005) (Supplemental Fig. 2). Login to comment
178 As can be seen in Table 3 from the data summary of multiple experiments, the IC50 values of LY465803 for A989T (0.05 6 0.01 mM) and C1047S (0.03 6 0.03 mM) were not significantly different from the IC50 for wild-type MRP1 (0.07 6 0.01 mM) although the difference approached statistical significance for C1047S (P = 0.07). Login to comment
180 BAYu9773, a nonselective antagonist of the CysLT receptors 1 and 2 and LY171883, a selective antagonist of CysLT receptor 1, inhibited E217bG transport by A989T with IC50 values of 0.32 6 0.19 mM and 19.58 6 6.15 mM, respectively. Login to comment
183 Effect of nsSNPs A989T and C1047S on [3 H]GSH Transport and Cellular GSH Levels. Login to comment
184 Because the A989T nsSNP was associated with a decreased inhibitory potency of the GSH-dependent LY465803 inhibitor in a cell-based (where its effects are dependent on intracellular GSH concentrations) but not in a membrane-based transport assay (where exogenous GSH is provided and is not limiting), it was of interest to determine whether vesicular transport of GSH and/or cellular levels of GSH were affected by this nsSNP. Login to comment
186 As shown in Fig. 6A, levels of apigenin-stimulated GSH uptake by A989T and C1047S were 16% and 26% lower than for wild-type MRP1, but in neither case were these differences statistically significant (P = 0.2 and 0.16, respectively). Login to comment
187 Thus, the difference in results obtained with LY465803 and the nsSNP A989T in the cell-based versus membrane-based Fig. 3. Login to comment
189 HEK293 cells stably expressing wild-type (WT-MRP1) and mutant (R633Q, G671V, R723Q, A989T, C1047S) MRP1 were incubated in the presence of increasing concentrations of calcein-AM (0-6mM), and the intracellular calcein remaining in the cells after 3 hours was measured by fluorometry as described in Materials and Methods. Login to comment
191 Effect of the MRP1 inhibitor LY465803 on calcein accumulation in HEK293 cells expressing wild-type and A989T and C1047S mutant MRP1 proteins. Login to comment
198 In contrast to the wild-type MRP1 cell line, the GSH levels present in the A989T and C1047S cell lines were comparable (106% and 94%, respectively) to those of the control untransfected cell line, suggesting that both nsSNPs adversely affect the ability of MRP1 to efflux GSH from intact cells (P = 0.08 and 0.02, respectively, for A989T and C1047S cells compared with wild-type MRP1 cells). Login to comment
199 nsSNPs A989T and C1047S Have No Major Impact on the Protease Susceptibility of MRP1. Login to comment
200 Because the functional changes detected for A989T and C1047S were the most significant among all the nsSNPs tested, we determined whether any of these changes were associated with any differences in protein conformation as reflected by a change in protease susceptibility. Login to comment
203 As shown in Supplemental Fig. 3A, when blots were probed with mAbs MRPr1 and 42.4 that detect epitopes in the NH2-half of MRP1, no differences in the tryptic fragment patterns obtained were observed between A989T (and C1047S, data not shown) and wild-type MRP1. Similarly, no differences were detected when the blots were probed with mAbs MRPm5, 897.2, and MRPm6, which detect epitopes located in the COOH-half of MRP1 (Supplemental Fig. 3B). Login to comment
210 Effect of MRP1 modulators on ATP-dependent vesicular uptake of [3 H]E217bG by wild-type and A989T and C1047S mutant MRP1. Login to comment
211 Membrane vesicles prepared from HEK293 cells expressing wild-type [WT (d)], A989T (s), and C1047S (m) mutant MRP1 were preincubated with a range of concentrations of (A) BAYu9773, (B) LY171883, and (C) LY465308 (+ GSH), and then ATP-dependent [3 H]E217bG uptake was measured after 5 minutes in the continued presence of the modulators as described in Materials and Methods. Login to comment
214 TABLE 3 Effect of MRP1 modulators on ATP-dependent vesicular uptake of E217bG by A989T and C1047S mutant MRP1 The values shown represents the mean IC50 values 6 S.D. obtained from three independent experiments performed using two different preparations of membrane vesicles. Login to comment
215 IC50 (mM) Wild-Type A989T C1047S LY465803 (+ GSH) 0.07 6 0.01 0.05 6 0.01 0.03 6 0.03 BAYu9773 0.62 6 0.16 0.32 6 0.19 0.69 6 0.18 LY171883 16.10 6 1.28 19.58 6 6.15 23.90 6 9.85 and compared the experimental data obtained with stable HEK cell lines with the consequences of the amino acid substitutions predicted by various in silico methods. Login to comment
245 Apigenin-stimulated vesicular transport of [3 H]GSH by A989T and C1047S mutant MRP1 and intracellular glutathione content. Login to comment
246 (A) ATP-dependent uptake of [3 H]GSH (100 mM/120 nCi) in the presence of apigenin (30 mM) was measured in membrane vesicles prepared from HEK293 cells expressing wild-type, A989T and C1047S MRP1 for 20 minutes at 37&#b0;C. Login to comment
258 The third and final category consists of A989T and C1047S which, despite the fact that most predictive methods indicated they were unlikely to affect MRP1 activity, exhibited altered phenotypes that distinguished them not only from wild-type MRP1 but to some degree from each other. Login to comment
259 Thus, HEK cells expressing A989T or C1047S differed in their drug-resistance profiles and their sensitivity to LY465803- mediated inhibition of calcein efflux, as well as their cellular GSH levels as detected in cell-based assays. Login to comment
260 The C1047S affected both vincristine and etoposide resistance while the A989T mutation affected only vincristine resistance. Login to comment
262 Inhibition of calcein efflux by the GSH-dependent LY465803 was also reduced in A989T cells but not C1047S cells. Login to comment
263 In contrast, membrane-based vesicular transport assays indicated that A989T and C1047S did not affect the ability of LY465803 to inhibit MRP1-mediated E217bG uptake. Login to comment

[hide] Importance of ABCC1 for cancer therapy and prognos... Drug Metab Rev. 2014 Aug;46(3):325-42. doi: 10.3109/03602532.2014.901348. Epub 2014 Mar 26. Kunicka T, Soucek P
Importance of ABCC1 for cancer therapy and prognosis.
Drug Metab Rev. 2014 Aug;46(3):325-42. doi: 10.3109/03602532.2014.901348. Epub 2014 Mar 26., [PMID:24670052]

Abstract [show]
Multidrug resistance presents one of the most important causes of cancer treatment failure. Numerous in vitro and in vivo data have made it clear that multidrug resistance is frequently caused by enhanced expression of ATP-binding cassette (ABC) transporters. ABC transporters are membrane-bound proteins involved in cellular defense mechanisms, namely, in outward transport of xenobiotics and physiological substrates. Their function thus prevents toxicity as carcinogenesis on one hand but may contribute to the resistance of tumor cells to a number of drugs including chemotherapeutics on the other. Within 48 members of the human ABC superfamily there are several multidrug resistance-associated transporters. Due to the well documented susceptibility of numerous drugs to efflux via ABC transporters it is highly desirable to assess the status of ABC transporters for individualization of treatment by their substrates. The multidrug resistance associated protein 1 (MRP1) encoded by ABCC1 gene is one of the most studied ABC transporters. Despite the fact that its structure and functions have already been explored in detail, there are significant gaps in knowledge which preclude clinical applications. Tissue-specific patterns of expression and broad genetic variability make ABCC1/MRP1 an optimal candidate for use as a marker or member of multi-marker panel for prediction of chemotherapy resistance. The purpose of this review was to summarize investigations about associations of gene and protein expression and genetic variability with prognosis and therapy outcome of major cancers. Major advances in the knowledge have been identified and future research directions are highlighted.

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134 Letourneau et al. (2005) studied the influence of 10 DOI: 10.3109/03602532.2014.901348 ABCC1 and cancer therapy and prognosis non-synonymous SNPs - Cys43Ser (G128C, rs41395947), Thr73Ile (C218T, rs41494447), Ser92Phe (C257T, rs8187844), Thr117Met (C350T, no rs number available), Arg230Gln (G689A, rs8187848), Arg633Gln (G1898A, rs112282109), Arg723Gln (G2168A, rs4148356), Ala989Thr (G2965A, rs35529209), Cys1047Ser (G3140C, rs13337489), Arg1058Gln (G3173A, rs41410450) and Ser1512Leu (C4535T, rs369410659) - on ABCC1 expression using membrane vesicles isolated from transfected cells and assessed transport activity for three known ABCC1 substrates. Login to comment
136 However, a 50% decrease in estradiol-17-b-glucuronide transport by the Ala989Thr variant due to higher Km was observed (Letourneau et al., 2005). Login to comment
159 NCBI ID Reference Amino acid exchange Nucleotide exchange Location Function MAFa rs41395947 Cys43Ser G128C Exon 2 Non-synonymous Unknown rs41494447 Thr73Ile C218T Exon 2 Non-synonymous T &#bc; 0.003 rs8187844 Ser92Phe C257T Exon 3 Non-synonymous T &#bc; 0.004 rs8187848 Arg230Gln G689A Exon 7 Non-synonymous A &#bc; 0.009 rs2230669 Pro272Pro G816A Exon 8 Synonymous A &#bc; 0.037 rs246221 Val275Val T825C Exon 8 Synonymous C &#bc; 0.301 rs35592 non-coding T-176C Intron 9 Non-coding C &#bc; 0.257 rs60782127 Arg433Ser G1299T Exon 10 Non-synonymous T &#bc; 0.004 rs35605 Leu562Leu T1684C Exon 13 Synonymous T &#bc; 0.173 rs112282109 Arg633Gln G1898A Exon 14 Non-synonymous A &#bc; 0.004 rs45511401 Gly671Val G2012T Exon 16 Non-synonymous T &#bc; 0.050 rs4148356 Arg723Gln G2168A Exon17 Non-synonymous A &#bc; 0.027 rs35529209 Ala989Thr G2965A Exon 22 Non-synonymous Unknown rs13337489 Cys1047Ser G3140C Exon 23 Non-synonymous C &#bc; 0.000 rs41410450 Arg1058Gln G3173A Exon 23 Non-synonymous Unknown rs2238476 non-coding G-1960A Intron 23 Non-coding T &#bc; 0.062 rs2230671 Ser1334Ser G4002A Exon 28 Synonymous T &#bc; 0.208 rs28364006 Thr1337Ala A4009G Exon 28 Non-synonymous Unknown rs369410659 Ser1512Leu C4535T Exon 31 Non-synonymous Unknown a Minor allele frequencies for Caucasinans in dbSNP based on HapMap-CEU population or 1000 genomes. Login to comment

[hide] Non-coding polymorphisms in nucleotide binding dom... PLoS One. 2014 Jul 31;9(7):e101740. doi: 10.1371/journal.pone.0101740. eCollection 2014. Kunicka T, Vaclavikova R, Hlavac V, Vrana D, Pecha V, Raus K, Trnkova M, Kubackova K, Ambrus M, Vodickova L, Vodicka P, Soucek P
Non-coding polymorphisms in nucleotide binding domain 1 in ABCC1 gene associate with transcript level and survival of patients with breast cancer.
PLoS One. 2014 Jul 31;9(7):e101740. doi: 10.1371/journal.pone.0101740. eCollection 2014., [PMID:25078270]

Abstract [show]
OBJECTIVES: ATP-Binding Cassette (ABC) transporters may cause treatment failure by transporting of anticancer drugs outside of the tumor cells. Multidrug resistance-associated protein 1 coded by the ABCC1 gene has recently been suggested as a potential prognostic marker in breast cancer patients. This study aimed to explore tagged haplotype covering nucleotide binding domain 1 of ABCC1 in relation with corresponding transcript levels in tissues and clinical phenotype of breast cancer patients. METHODS: The distribution of twelve ABCC1 polymorphisms was assessed by direct sequencing in peripheral blood DNA (n = 540). RESULTS: Tumors from carriers of the wild type genotype in rs35623 or rs35628 exhibited significantly lower levels of ABCC1 transcript than those from carriers of the minor allele (p = 0.003 and p = 0.004, respectively). The ABCC1 transcript levels significantly increased in the order CT-GT>CC-GT>CC-GG for the predicted rs35626-rs4148351 diplotype. Chemotherapy-treated patients carrying the T allele in rs4148353 had longer disease-free survival than those with the GG genotype (p = 0.043). On the other hand, hormonal therapy-treated patients with the AA genotype in rs35628 had significantly longer disease-free survival than carriers of the G allele (p = 0.012). CONCLUSIONS: Taken together, our study shows that genetic variability in the nucleotide binding domain 1 has a significant impact on the ABCC1 transcript level in the target tissue and may modify survival of breast cancer patients.

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215 Ten other non-synonymous SNPs leading to amino acid substitutions (Cys43Ser (G128C, rs41395947), Thr73Ile (C218T, rs41494447), Ser92Phe (C257T, rs8187844), Thr117Met (C350T, no rs number available), Arg230Gln (G689A, rs8187848), Arg633Gln (G1898A, rs112282109), Ala989Thr (G2965A, rs35529209), Cys1047Ser (G3140C, rs13337489), Arg1058Gln (G3173A, rs41410450), and Ser1512Leu (C4535T, rs369410659)) followed earlier had no effect on ABCC1 expression either, indicating that single amino acid substitutions may not necessarily influence the activity of the final protein [44]. Login to comment

[hide] Genetic variation of the ABC transporter gene ABCC... BMC Genet. 2015 Sep 23;16(1):114. doi: 10.1186/s12863-015-0271-3. Slomka M, Sobalska-Kwapis M, Korycka-Machala M, Bartosz G, Dziadek J, Strapagiel D
Genetic variation of the ABC transporter gene ABCC1 (Multidrug resistance protein 1-MRP1) in the Polish population.
BMC Genet. 2015 Sep 23;16(1):114. doi: 10.1186/s12863-015-0271-3., [PMID:26395522]

Abstract [show]
BACKGROUND: Multidrug resistance-associated protein 1 (MRP1), encoded by the ABCC1 gene, is an ATP-binding cassette transporter mediating efflux of organic anions and xenobiotics; its overexpression leads to multidrug resistance. In this study, 30 exons (from 31 in total) of the ABCC1 gene as well as and their flanking intron sequences were screened for genetic variation, using the High Resolution Melting (HRM) method, for 190 healthy volunteers representing the Polish population. Polymorphism screening is an indispensable step in personalized patient therapy. An additional targeted SNP verification study for ten variants was performed to verify sensitivity of the scanning method. RESULTS: During scanning, 46 polymorphisms, including seven novel ones, were found: one in 3' UTR, 21 in exons (11 of them non-synonymous) and 24 in introns, including one deletion variant. These results revealed some ethnic differences in frequency of several polymorphisms when compared to literature data for other populations. Based on linkage disequilibrium analysis, 4 haplotype blocks were determined for 9 detected polymorphisms and 12 haplotypes were defined. To capture the common haplotypes, haplotype-tagging single nucleotide polymorphisms were identified. CONCLUSIONS: Targeted genotyping results correlated well with scanning results; thus, HRM is a suitable method to study genetic variation in this model. HRM is an efficient and sensitive method for scanning and genotyping polymorphic variants. Ethnic differences were found for frequency of some variants in the Polish population compared to others. Thus, this study may be useful for pharmacogenetics of drugs affected by MRP1-mediated efflux.

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154 Bold variants signifies the ones which were validated by genotyping results Table 3 Summary of ABCC1 selected SNPs genotyping by HRM and comparing them with scanning results dbSNP ID Variant residue NM_004996.3: Intron/amino acid residue NP_004987.2: Observed genotypesa (n) HWE exact test P-valueb MAFc (genotyping) MAFc (scanning) Chi-square test P-valued R/R R/V V/V rs41395947 c.128G > C p.Cys43Se 380 0 0 1 - - - rs2230669 c.816G > A p.Pro272= 362 18 0 1 (A) 0.024 (A) 0.043 0.079 rs246221 c.825 T > C p.Val275 197 160 23 0.243 (C) 0.271 (C) 0.309 0.187 rs8187852 c.1057G > A p.Val353Met 379 0 0 1 - - - rs35587 c.1062 T > C p.Asn354= 204 142 33 0.247 (C) 0.274 (C) 0.332 0.044 rs35588 c.1218 + 8A > G Intron 190 160 30 0.709 (G) 0.289 (G) 0.325 0.214 rs60782127 c.1299G > T p.Arg433Ser 373 6 0 1 (T) 0.008 (T) 0.005 0.623 rs35605 c.1684 T > C p.Leu562= 13 105 262 0.588 (T) 0.172 (T) 0.130 0.063 rs8187858 c.1704C > T p.Tyr568= 325 55 0 0.242 (T) 0.072 (T) 0.087 0.374 rs45511401 c.2012G > T p.Gly671Val 346 28 3 0.007 (T) 0.045 (T) 0.077 0.038 rs4148356 c.2168G > A p.Arg723Gln 360 19 0 1 (A) 0.025 (A) 0.024 0.888 rs45517537 c.2581G > A p.Ala861Thr 380 0 0 1 - - - rs35529209 c.2965G > A p.Ala989Thr 378 0 0 1 - - - rs13337489 c.3140G > C p.Cys1047Ser 380 0 0 1 - - - rs28706727 c.3436G > A p.Val1146Ile 380 0 0 1 - - - rs2230671 c.4002G > A p.Ser1334= 204 140 32 0.296 (A) 0.271 (A) 0.277 0.850 rs28364006 c.4009A > G p.Thr1337Ala 380 0 0 1 - - - a Number of genotypes detected during this study, R - reference allele, V - variant allele. b P-value is consistent with Hardy-Weinberg equilibrium if P > 0.001. c Minor allele shown in brackets with its frequency. Login to comment