ABCB1 p.Leu662Arg
| Predicted by SNAP2: | A: N (66%), C: N (61%), D: N (57%), E: N (61%), F: N (93%), G: N (61%), H: N (78%), I: N (78%), K: N (78%), M: N (93%), N: N (72%), P: N (61%), Q: N (82%), R: N (72%), S: N (87%), T: N (82%), V: N (78%), W: N (61%), Y: N (57%), |
| Predicted by PROVEAN: | A: N, C: N, D: D, E: N, F: N, G: D, H: N, I: N, K: N, M: N, N: N, P: N, Q: N, R: N, S: N, T: N, V: N, W: D, Y: N, |
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[hide] Mechanisms of resistance to anticancer drugs: the ... Pharmacogenomics. 2005 Mar;6(2):115-38. Lepper ER, Nooter K, Verweij J, Acharya MR, Figg WD, Sparreboom A
Mechanisms of resistance to anticancer drugs: the role of the polymorphic ABC transporters ABCB1 and ABCG2.
Pharmacogenomics. 2005 Mar;6(2):115-38., [PMID:15882131]
Abstract [show]
ATP-binding cassette (ABC) genes play a role in the resistance of malignant cells to anticancer agents. The ABC gene products, including ABCB1 (P-glycoprotein) and ABCG2 (breast cancer-resistance protein [BCRP], mitoxantrone-resistance protein [MXR], or ABC transporter in placenta [ABCP]), are also known to influence oral absorption and disposition of a wide variety of drugs. As a result, the expression levels of these proteins in humans have important consequences for an individual's susceptibility to certain drug-induced side effects, interactions, and treatment efficacy. Naturally occurring variants in ABC transporter genes have been identified that might affect the function and expression of the protein. This review focuses on recent advances in the pharmacogenetics of the ABC transporters ABCB1 and ABCG2, and discusses potential implications of genetic variants for the chemotherapeutic treatment of cancer.
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106 Nonetheless, the association of the C3435T polymorphism with Table 2. Summary of common genetic variants in the ABCB1 gene cDNA position* Region‡ Wild-type allele Variant allele Amino acid Change§ -274 Intron -1 G A -223 Intron -1 C T -146 Intron -1 T C -60 Intron -1 A T -41 Intron -1 A G Non-coding -241 Exon 1 G A Non-coding -145 Exon 1 C G Non-coding -129 Exon 1 T C Non-coding -43 Exon 1 A G Non-coding +140 Intron 1 C A +237 Intron 1 G A -4 Exon 2 C T Non-coding -1 Exon 2 G A Non-coding 61 Exon 2 A G 21 Asn to Asp -8 Intron 3 C G 266 Exon 4 T C 89 Met to Thr 307 Exon 5 T C 103 Phe to Leu -25 Intron 4 G T +139 Intron 6 C T +145 Intron 6 C T 548 Exon 7 A G 183 Asn to Ser 729 Exon 8 A G 243 Syn 781 Exon 8 A G 261 Ile to Val -44 Intron 9 A G -41 Intron 10 T G 1199 Exon 11 G A 400 Ser to Asn -4 Intron 11 G A 1236¶ Exon 12 C T 412 Syn 1308 Exon 12 A G 436 Syn +17 Intron 12 G A +44 Intron 12 C T 1474 Exon 13 C T 492 Arg to Cys +24 Intron 13 C T 1617 Exon 14 C T 539 Syn +38 Intron 14 A G +38 Intron 15 G A 1985 Exon 16 T G 662 Leu to Arg 2005 Exon 16 C T 669 Arg to Cys -27 Intron 17 A G +8 Intron 20 C G *cDNA numbers are relative to the ATG site and based on the cDNA sequence from GenBank accession number M14758 with an A as the reference at position 43.
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ABCB1 p.Leu662Arg 15882131:106:1051
status: NEW[hide] Genetic polymorphisms of ATP-binding cassette tran... Expert Opin Pharmacother. 2005 Nov;6(14):2455-73. Sakurai A, Tamura A, Onishi Y, Ishikawa T
Genetic polymorphisms of ATP-binding cassette transporters ABCB1 and ABCG2: therapeutic implications.
Expert Opin Pharmacother. 2005 Nov;6(14):2455-73., [PMID:16259577]
Abstract [show]
Pharmacogenomics, the study of the influence of genetic factors on drug action, is increasingly important for predicting pharmacokinetics profiles and/or adverse reactions to drugs. Drug transporters, as well as drug metabolism play pivotal roles in determining the pharmacokinetic profiles of drugs and their overall pharmacological effects. There is an increasing number of reports addressing genetic polymorphisms of drug transporters. However, information regarding the functional impact of genetic polymorphisms in drug transporter genes is still limited. Detailed functional analysis in vitro may provide clear insight into the biochemical and therapeutic significance of genetic polymorphisms. This review addresses functional aspects of the genetic polymorphisms of human ATP-binding cassette transporters, ABCB1 and ABCG2, which are critically involved in the pharmacokinetics of drugs.
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106 Position Allele Amino acid Allele frequency in Caucasian populations Allele frequency in Japanese populatins Allele frequency in African populations n % n % n % 61 A G 21 Asn 21 Asp 799 89.7 10.3 193 100 0 100 97.5 2.5 266 T C 89 Met 89 Thr 100 99.5 0.5 145 100 0 100 100 0 307 T C 103 Phe 103 Leu 546 99.9 0.1 48 100 0 ND ND ND 325 G A 108 Glu 108 Lys ND ND ND 37 95.9 4.1 ND ND ND 781 A G 261 Ile 261 Val 100 100 0 145 100 0 100 98.5 1.5 1199 G A 400 Ser 400 Asn 696 95.0 5.0 193 100 0 100 99 1 1985 T G 662 Leu 662 Arg 100 99.5 0.5 145 100 0 100 100 0 2005 C T 669 Arg 669 Cys 100 100 0 145 100 0 100 99 1 2485 A G 829 Ile 829 Val 185 99.2 0.8 ND ND ND ND ND ND 2547 A G 849 Ile 849 Met 100 99.5 0.5 145 100 0 100 100 0 2677 G T A 893 Ala 893 Ser 893 Thr 611 55.1 42.1 2.8 241 40.0 41.1 18.9 100 90 10 0.5 2956 A G 986 Met 986 Val ND ND ND 100 99.5 0.5 ND ND ND 3151 C G 1051 Pro 1051 Ala 100 100 0 145 100 0 100 99.5 0.5 3320 A C 1107 Gln 1107 Pro 461 99.8 0.2 ND ND ND ND ND ND 3322 T C 1108 Trp 1108 Arg 100 100 0 145 100 0 100 99.5 0.5 3421 T A 1141 Ser 1141 Thr 100 100 0 145 100 0 100 88.9 11.1 3751 G A 1251 Val 1251 Ile 100 100 0 145 99 1 100 100 0 3767 C A 1256 Thr 1256 Lys 100 99.5 0.5 145 100 0 100 100 0 Data from [31-38, 203].
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ABCB1 p.Leu662Arg 16259577:106:510
status: NEW129 N21D M89T N44S H2N F103L E108K N183S G185V I261V S400N R492C A599T L662R R669C V801M A893S/T I829V I849M M986V A999T G1063A P1051A Q1107P W1108R I1145M S1141T V1251I T1256K COOH ATP-binding site ATP-binding site EXTRACELLULAR INTRACELLULAR A80E Figure 2.
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ABCB1 p.Leu662Arg 16259577:129:67
status: NEW[hide] Clinical pharmacogenetics and potential applicatio... Curr Drug Metab. 2008 Oct;9(8):738-84. Zhou SF, Di YM, Chan E, Du YM, Chow VD, Xue CC, Lai X, Wang JC, Li CG, Tian M, Duan W
Clinical pharmacogenetics and potential application in personalized medicine.
Curr Drug Metab. 2008 Oct;9(8):738-84., [PMID:18855611]
Abstract [show]
The current 'fixed-dosage strategy' approach to medicine, means there is much inter-individual variation in drug response. Pharmacogenetics is the study of how inter-individual variations in the DNA sequence of specific genes affect drug responses. This article will highlight current pharmacogenetic knowledge on important drug metabolizing enzymes, drug transporters and drug targets to understand interindividual variability in drug clearance and responses in clinical practice and potential use in personalized medicine. Polymorphisms in the cytochrome P450 (CYP) family may have had the most impact on the fate of pharmaceutical drugs. CYP2D6, CYP2C19 and CYP2C9 gene polymorphisms and gene duplications account for the most frequent variations in phase I metabolism of drugs since nearly 80% of drugs in use today are metabolised by these enzymes. Approximately 5% of Europeans and 1% of Asians lack CYP2D6 activity, and these individuals are known as poor metabolizers. CYP2C9 is another clinically significant drug metabolising enzyme that demonstrates genetic variants. Studies into CYP2C9 polymorphism have highlighted the importance of the CYP2C9*2 and CYP2C9*3 alleles. Extensive polymorphism also occurs in a majority of Phase II drug metabolizing enzymes. One of the most important polymorphisms is thiopurine S-methyl transferases (TPMT) that catalyzes the S-methylation of thiopurine drugs. With respect to drug transport polymorphism, the most extensively studied drug transporter is P-glycoprotein (P-gp/MDR1), but the current data on the clinical impact is limited. Polymorphisms in drug transporters may change drug's distribution, excretion and response. Recent advances in molecular research have revealed many of the genes that encode drug targets demonstrate genetic polymorphism. These variations, in many cases, have altered the targets sensitivity to the specific drug molecule and thus have a profound effect on drug efficacy and toxicity. For example, the beta (2)-adrenoreceptor, which is encoded by the ADRB2 gene, illustrates a clinically significant genetic variation in drug targets. The variable number tandem repeat polymorphisms in serotonin transporter (SERT/SLC6A4) gene are associated with response to antidepressants. The distribution of the common variant alleles of genes that encode drug metabolizing enzymes, drug transporters and drug targets has been found to vary among different populations. The promise of pharmacogenetics lies in its potential to identify the right drug at the right dose for the right individual. Drugs with a narrow therapeutic index are thought to benefit more from pharmacogenetic studies. For example, warfarin serves as a good practical example of how pharmacogenetics can be utilized prior to commencement of therapy in order to achieve maximum efficacy and minimum toxicity. As such, pharmacogenetics has the potential to achieve optimal quality use of medicines, and to improve the efficacy and safety of both prospective and licensed drugs.
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532 Nucleotide change rs number Amino acid change 49T>C rs28381804 F17L 61A>G rs61615398; rs9282564 N21D 131A>G rs1202183 N44S 178A>C rs41315618 I60L 239C>A rs9282565 A80E 266T>C Rs35810889 M89T 431T>C rs61607171 I144T 502G>A rs61122623 V168I 548A>G rs60419673 N183S 554G>T rs1128501 G185V 781A>G rs36008564 I261V 1199G>A rs2229109 S400N 1696G>A rs28381902 E566K 1777C>T rs28381914 R593C 1778G>A rs56107566 R593H 1795G>A rs2235036 A599T 1837G>T rs57001392 D613Y 1985T>G rs61762047 L662R 2005C>T rs35023033 R669C 2207A>T rs41316450 I736K 2398G>A rs41305517 D800N 2401G>A rs2235039 V801M 2485A>G rs2032581 I829V 2506A>G rs28381967 I836V 2547A>G rs36105130 I849M 2677T>A/G rs2032582 S893A/T 2975G>A rs56849127 S992N 3151C>G rs28401798 P1051A 3188G>C rs2707944 G1063A 3262G>A rs57521326 D1088N 3295A>G rs41309225 K1099E 3320A>C rs55852620 Q1107P 3322T>C rs35730308 W1108R 3410G>T rs41309228 S1137I 3421T>A rs2229107 S1141T 3502A>G rs59241388 K1168E 3669A>T rs41309231 E1223D 3751G>A rs28364274 V1251I 3767C>A r35721439 T1256K Data are from NCBI dbSNP (access date: 2 August 2008).
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ABCB1 p.Leu662Arg 18855611:532:477
status: NEW[hide] Sequence diversity and haplotype structure in the ... Pharmacogenetics. 2003 Aug;13(8):481-94. Kroetz DL, Pauli-Magnus C, Hodges LM, Huang CC, Kawamoto M, Johns SJ, Stryke D, Ferrin TE, DeYoung J, Taylor T, Carlson EJ, Herskowitz I, Giacomini KM, Clark AG
Sequence diversity and haplotype structure in the human ABCB1 (MDR1, multidrug resistance transporter) gene.
Pharmacogenetics. 2003 Aug;13(8):481-94., [PMID:12893986]
Abstract [show]
OBJECTIVES: There is increasing evidence that polymorphism of the ABCB1 (MDR1) gene contributes to interindividual variability in bioavailability and tissue distribution of P-glycoprotein substrates. The aim of the present study was to (1) identify and describe novel variants in the ABCB1 gene, (2) understand the extent of variation in ABCB1 at the population level, (3) analyze how variation in ABCB1 is structured in haplotypes, and (4) functionally characterize the effect of the most common amino acid change in P-glycoprotein. METHODS AND RESULTS: Forty-eight variant sites, including 30 novel variants and 13 coding for amino acid changes, were identified in a collection of 247 ethnically diverse DNA samples. These variants comprised 64 statistically inferred haplotypes, 33 of which accounted for 92% of chromosomes analyzed. The two most common haplotypes, ABCB1*1 and ABCB1*13, differed at six sites (three intronic, two synonymous, and one non-synonymous) and were present in 36% of all chromosomes. Significant population substructure was detected at both the nucleotide and haplotype level. Linkage disequilibrium was significant across the entire ABCB1 gene, especially between the variant sites found in ABCB1*13, and recombination was inferred. The Ala893Ser change found in the common ABCB1*13 haplotype did not affect P-glycoprotein function. CONCLUSION: This study represents a comprehensive analysis of ABCB1 nucleotide diversity and haplotype structure in different populations and illustrates the importance of haplotype considerations in characterizing the functional consequences of ABCB1 polymorphisms.
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103 A total of 30 segregating sites have not been previously described, including eight non-synonymous changes coding for the following amino acid changes: Met89Thr, Leu662Arg, Arg669Cys, Ile849Met, Pro1051Ala, Trp1108Arg, Val1251Ile, and Thr1256Lys.
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ABCB1 p.Leu662Arg 12893986:103:162
status: NEW111 These ten variants included five non-synonymous sites (Ile261Val, Leu662Arg, Pro1051Ala, Ser1141Thr, and Thr1256Lys).
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ABCB1 p.Leu662Arg 12893986:111:66
status: NEW141 Unauthorized reproduction of this article is prohibited. Table 1 Genetic variation in ABCB1 Allele frequencyd Variant cDNA NT DNA/AA AA Total CA AA AS ME PA No.a positionb changec position change (n ¼ 494) (n ¼ 200) (n ¼ 200) (n ¼ 60) (n ¼ 20) (n ¼ 14) 1.1Ã (À274) G to A Intron À1 0.006 0 0.016 0 0 0 1.2Ã (À223) C to T Intron À1 0.002 0.005 0 0 0 0 1.3Ã (À146) T to C Intron À1 0.002 0 0.005 0 0 0 1.4Ã (À60) A to T Intron À1 0.004 0 0.010 0 0 0 1.5 (À41) A to G Intron À1 0.002 0 0 0.017 0 0 1.6Ã À241 G to A Non-coding 0.002 0 0 0.017 0 0 1.7 À145 C to G Non-coding 0.002 0 0 0.017 0 0 1.8 À129 T to C Non-coding 0.060 0.051 0.071 0.036 0.100 0.071 1.9 À43 A to G Non-coding 0.012 0 0.020 0.036 0 0 1.10Ã (+140) C to A Intron 1 0.013 0.005 0.021 0 0 0.071 1.11Ã (+237) G to A Intron 1 0.004 0 0.010 0 0 0 2.1 À4 C to T Non-coding 0.004 0 0.010 0 0 0 2.2 À1 G to A Non-coding 0.036 0.080 0.005 0 0.050 0 2.3 61 A to G 21 Asn to Asp 0.045 0.080 0.025 0.017 0 0 4.1Ã (À8) C to G Intron 3 0.002 0.005 0 0 0 0 4.2Ã 266 T to C 89 Met to Thr 0.002 0.005 0 0 0 0 5.1 (À25) G to T Intron 4 0.210 0.158 0.300 0.067 0.200 0.286 8.1 729 A to G 243 Syn 0.002 0.005 0 0 0 0 8.2Ã 781 A to G 261 Ile to Val 0.006 0 0.015 0 0 0 10.1Ã (À44) A to G Intron 9 0.400 0.450 0.255 0.685 0.450 0.571 11.1Ã (À41) T to G Intron 10 0.002 0 0 0.017 0 0 11.2 1199 G to A 400 Ser to Asn 0.014 0.025 0.010 0 0 0 12.1Ã (À4) G to A Intron 11 0.002 0 0.005 0 0 0 12.2 1236 C to T 412 Syn 0.385 0.459 0.209 0.685 0.450 0.571 12.3Ã 1308 A to G 436 Syn 0.002 0 0.005 0 0 0 12.4Ã (+17) G to A Intron 12 0.008 0 0.020 0 0 0 12.5 (+44) C to T Intron 12 0.088 0.046 0.168 0 0 0 13.1 (+24) C to T Intron 13 0.530 0.521 0.542 0.540 0.450 0.571 14.1 1617 C to T 539 Syn 0.002 0.005 0 0 0 0 14.2 (+38) A to G Intron 14 0.540 0.505 0.540 0.683 0.450 0.500 15.1 (+38) G to A Intron 15 0.004 0.005 0.005 0 0 0 16.1Ã 1985 T to G 662 Leu to Arg 0.002 0.005 0 0 0 0 16.2Ã 2005 C to T 669 Arg to Cys 0.004 0 0.010 0 0 0 18.1Ã (À27) A to G Intron 17 0.008 0.010 0.005 0 0.050 0 20.1Ã (+8) C to G Intron 20 0.002 0 0.005 0 0 0 20.2 (+24) G to A Intron 20 0.126 0.121 0.150 0.067 0.200 0 20.3Ã (+40) C to T Intron 20 0.014 0 0.035 0 0 0 21.1Ã 2547 A to G 849 Ile to Met 0.002 0.005 0 0 0 0 21.2 2650 C to T 884 Syn 0.004 0.005 0.005 0 0 0 21.3a 2677 G to T 893 Ala to Ser 0.308 0.464 0.100 0.450 0.400 0.357 21.3b 2677 G to A 893 Ala to Thr 0.035 0.036 0.005 0.067 0 0.357 22.1 (+31) G to A Intron 22 0.002 0 0.005 0 0 0 25.1Ã 3151 C to G 1051 Pro to Ala 0.002 0 0.005 0 0 0 26.1Ã 3322 T to C 1108 Trp to Arg 0.002 0 0.005 0 0 0 26.2 3421 T to A 1141 Ser toThr 0.047 0 0.111 0 0.050 0 26.3 3435 C to T 1145 Syn 0.392 0.561 0.202 0.400 0.500 0.500 28.1 3751 G to A 1251 Val to Ile 0.002 0 0 0 0.050 0 28.2 3767 C to A 1256 Thr to Lys 0.002 0.005 0 0 0 0 28.3 (+21) T to C Intron 28 0.031 0 0.077 0 0 0 a Variants are numbered sequentially by exon.
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ABCB1 p.Leu662Arg 12893986:141:2098
status: NEW164 M89T I849M V1251I T1256K S1141TW1108R P1052AR669C A893S/T L662R Cytoplasm S400N I261V N21D Extracellular Fig. 1.
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ABCB1 p.Leu662Arg 12893986:164:58
status: NEW[hide] Functional implications of genetic polymorphisms i... Pharm Res. 2004 Jun;21(6):904-13. Pauli-Magnus C, Kroetz DL
Functional implications of genetic polymorphisms in the multidrug resistance gene MDR1 (ABCB1).
Pharm Res. 2004 Jun;21(6):904-13., [PMID:15212152]
Abstract [show]
The multidrug resistance (MDR1) gene product P-glycoprotein is a membrane protein that functions as an ATP-dependent efflux pump, transporting exogenous and endogenous substrates from the inside of cells to the outside. Physiological expression of P-glycoprotein in tissues with excretory or protective function is a major determinant of drug disposition and provides a cellular defense mechanism against potentially harmful compounds. Therefore, P-glycoprotein has significant impact on therapeutic efficacy and toxicity as it plays a key role in absorption of oral medications from the intestinal tract, excretion into bile and urine, and distribution into protected tissues such as the brain and testes. There is increasing interest in the possible role of genetic variation in MDR1 in drug therapy. Numerous genetic polymorphisms in MDR1 have been described, some of which have been shown to determine P-glycoprotein expression levels and substrate transport. Furthermore, some of these polymorphisms have an impact on pharmacokinetic and pharmacodynamic profiles of drug substrates and directly influence outcome and prognosis of certain diseases. This review will focus on the impact of genetic variation in MDR1 on expression and function of P-glycoprotein and the implications of this variation for drug therapy and disease risk.
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28 6, June 2004 ((c) 2004) 9040724-8741/04/0600-0904/0 (c) 2004 Plenum Publishing Corporation Table I. MDR1 Coding Variants cDNA positiona NT change DNA/AA position AA change Allele frequencyb Total (n ס 494) CA (n ס 200) AA (n ס 200) AS (n ס 60) ME (n ס 20) PA (n ס 14) 61 A to G 21 Asn to Asp 0.045 0.080 0.025 0.017 0 0 266 T to C 89 Met to Thr 0.002 0.005 0 0 0 0 729 A to G 243 Syn 0.002 0.005 0 0 0 0 781 A to G 261 Ile to Val 0.006 0 0.015 0 0 0 1199 G to A 400 Ser to Asn 0.014 0.025 0.010 0 0 0 1236 C to T 412 Syn 0.385 0.459 0.209 0.685 0.450 0.571 1308 A to G 436 Syn 0.002 0 0.005 0 0 0 1617 C to T 539 Syn 0.002 0.005 0 0 0 0 1985 T to G 662 Leu to Arg 0.002 0.005 0 0 0 0 2005 C to T 669 Arg to Cys 0.004 0 0.010 0 0 0 2547 A to G 849 Ile to Met 0.002 0.005 0 0 0 0 2650 C to T 884 Syn 0.004 0.005 0.005 0 0 0 2677 G to T 893 Ala to Ser 0.308 0.464 0.100 0.450 0.400 0.357 2677 G to A 893 Ala to Thr 0.035 0.036 0.005 0.067 0 0.357 3151 C to G 1051 Pro to Ala 0.002 0 0.005 0 0 0 3322 T to C 1108 Trp to Arg 0.002 0 0.005 0 0 0 3421 T to A 1141 Ser to Thr 0.047 0 0.111 0 0.050 0 3435 C to T 1145 Syn 0.392 0.561 0.202 0.400 0.500 0.500 3751 G to A 1251 Val to Ile 0.002 0 0 0 0.050 0 3767 C to A 1256 Thr to Lys 0.002 0.005 0 0 0 0 a cDNA numbers are relative to the ATG site and based on the cDNA sequence from GenBank accession number M14758.
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ABCB1 p.Leu662Arg 15212152:28:782
status: NEW[hide] Ethnic differences in genetic polymorphisms of CYP... Drug Metab Pharmacokinet. 2004 Apr;19(2):83-95. Ozawa S, Soyama A, Saeki M, Fukushima-Uesaka H, Itoda M, Koyano S, Sai K, Ohno Y, Saito Y, Sawada J
Ethnic differences in genetic polymorphisms of CYP2D6, CYP2C19, CYP3As and MDR1/ABCB1.
Drug Metab Pharmacokinet. 2004 Apr;19(2):83-95., [PMID:15499174]
Abstract [show]
Metabolic capacities for debrisoquin, sparteine, mephenytoin, nifedipine, and midazolam, which are substrates of polymorphic CYP2D6, CYP2C19, and CYP3A, have been reported to exhibit, in many cases, remarkable interindividual and ethnic differences. These ethnic differences are partly associated with genetic differences. In the case of the drug transporter ABCB1/MDR1, interindividual differences in its transporter activities toward various clinical drugs are also attributed to several ABCB1/MDR1 genetic polymorphisms. In this review, the existence and frequency of various low-activity alleles of drug metabolizing enzymes as well as populational drug metabolic capacities are compared among several different races or ethnicities. Distribution of nonsynonymous ABCB1/MDR1 SNPs and haplotype frequency in various races are summarized, with the association of nonsynonymous SNPs with large functional alterations as a rare event.
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85 Ethnic dierences in nonsynonymous SNPs of ABCB1W MDR1 cDNA positiona Position and amino acid change C AA AS J 61AÀG N21D 0.080 0.025 0.017 0 266TÀC M89T 0.005 0 0 0 781AÀG I261V 0 0.015 0 0 1199GÀA S400N 0.025 0.010 0 0 1985TÀG L662R 0.005 0 0 0 2005CÀT R669C 0 0.010 0 0 2547AÀG I849M 0.005 0 0 0 2677GÀT A893S 0.464 0.100 0.450 0.403 2677GÀA A893T 0.036 0.005 0.067 0.200 3151CÀG P1051A 0 0.005 0 0 3322TÀC W1108R 0 0.005 0 0 3421TÀA S1141T 0 0.111 0 0 3751GÀA V1251I 0 0 0 0.010 3767CÀA T1256K 0.005 0 0 0 C, 100 Caucasians; AA, 100 African-Americans; AS, 30 Asians; J, 145 Japanese (our study 116) ).
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ABCB1 p.Leu662Arg 15499174:85:259
status: NEW[hide] Function-altering SNPs in the human multidrug tran... PLoS Genet. 2007 Mar 9;3(3):e39. Jeong H, Herskowitz I, Kroetz DL, Rine J
Function-altering SNPs in the human multidrug transporter gene ABCB1 identified using a Saccharomyces-based assay.
PLoS Genet. 2007 Mar 9;3(3):e39., 2007-03-09 [PMID:17352537]
Abstract [show]
The human ABCB1 (MDR1)-encoded multidrug transporter P-glycoprotein (P-gp) plays a major role in disposition and efficacy of a broad range of drugs including anticancer agents. ABCB1 polymorphisms could therefore determine interindividual variability in resistance to these drugs. To test this hypothesis we developed a Saccharomyces-based assay for evaluating the functional significance of ABCB1 polymorphisms. The P-gp reference and nine variants carrying amino-acid-altering single nucleotide polymorphisms (SNPs) were tested on medium containing daunorubicin, doxorubicin, valinomycin, or actinomycin D, revealing SNPs that increased (M89T, L662R, R669C, and S1141T) or decreased (W1108R) drug resistance. The R669C allele's highly elevated resistance was compromised when in combination with W1108R. Protein level or subcellular location of each variant did not account for the observed phenotypes. The relative resistance profile of the variants differed with drug substrates. This study established a robust new methodology for identification of function-altering polymorphisms in human multidrug transporter genes, identified polymorphisms affecting P-gp function, and provided a step toward genotype-determined dosing of chemotherapeutics.
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3 The P-gp reference and nine variants carrying amino-acid-altering single nucleotide polymorphisms (SNPs) were tested on medium containing daunorubicin, doxorubicin, valinomycin, or actinomycin D, revealing SNPs that increased (M89T, L662R, R669C, and S1141T) or decreased (W1108R) drug resistance.
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ABCB1 p.Leu662Arg 17352537:3:233
status: NEW79 We first focused on the five SNPs with highest Grantham values (.80): M89T, L662R, R669C, A893S, and W1108R.
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ABCB1 p.Leu662Arg 17352537:79:76
status: NEW92 Features of the ABCB1 Variants Analyzed in This Study SNPa Evolutionary Conservationb Chemical Dissimilarity (Grantham Valuec ) Allele Count (out of 494 Alleles) M89T 0 81 1 L662R 3 102 1 R669C 2 180 2 A893S 2 99 151 P1051A 3 27 1 W1108R 3 101 1 S1141T 3 58 23 a Positions are relative to the transcription start site and based on the cDNA sequence from GenBank accession number M14758.1 with the change V185G, which is the most common haplotype in African Americans in the Pharmacogenetics of Membrane Transporters dataset.
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ABCB1 p.Leu662Arg 17352537:92:174
status: NEW109 Different P-gp variants displayed higher levels of resistance (A893S-M89T, L662R, and R669C) or lower levels of resistance (A893S, S1141T, A893S-R669C, A893S-P1051A, W1108R, and W1108R-R669C) relative to the P-gp reference (Figure 2A and 2B).
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ABCB1 p.Leu662Arg 17352537:109:75
status: NEW120 In the liquid assay, three variants for daunorubicin (A893S-R669C, A893S-M89T, and R669C) and five variants for doxorubicin (A893S, S1141T, A893S-M89T, L662R, and R669C) exhibited statistically significant increases in EC50 values (p , 0.05) (Figure 2C; Table S4).
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ABCB1 p.Leu662Arg 17352537:120:152
status: NEW129 The average 6 standard deviation of three measurements of relative protein levels is 103 6 19 for A893S, 83 6 17 for S1141T, 94 6 16 for A893S-R669C, 115 6 20 for A893S-M89T, 93 6 19 for L662R, 70 6 22 for A893S-P1051A, 134 6 25 for R669C, 102 6 18 for W1108R, 148 6 24 for R669C-W1108R, and 53 6 13 for frame-shifted, relative to the average of reference P-gp set to 100.
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ABCB1 p.Leu662Arg 17352537:129:187
status: NEW165 Five variants (S1141T, A893S-R669C, A893S-M89T, L662R, and R669C) exhibited a statistically significant increase in EC50 or EC30 values for two or more drugs.
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ABCB1 p.Leu662Arg 17352537:165:48
status: NEW174 The functional consequences of five ABCB1 polymorphisms were previously unknown: the M89T, L662R, R669C, and S1141T variants were associated with increased resistance to two or more drugs; and the W1108R variant strongly mitigated the impact of R669C on gain of P-gp function (Figures 2 and 4A).
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ABCB1 p.Leu662Arg 17352537:174:91
status: NEW194 Our data on functional consequences revealed that these predictions were sound: four functional SNPs (L662R, R669C, W1108R, and S1141T) scored highly on both criteria, while the two SNPs (A893S and P1051A) that showed no significant functional impact had lower scores on evolutionary conservation and chemical dissimilarity, respectively.
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ABCB1 p.Leu662Arg 17352537:194:102
status: NEW[hide] An update on ABCB1 pharmacogenetics: insights from... Pharmacogenomics J. 2011 Oct;11(5):315-25. doi: 10.1038/tpj.2011.16. Epub 2011 May 31. Wolf SJ, Bachtiar M, Wang J, Sim TS, Chong SS, Lee CG
An update on ABCB1 pharmacogenetics: insights from a 3D model into the location and evolutionary conservation of residues corresponding to SNPs associated with drug pharmacokinetics.
Pharmacogenomics J. 2011 Oct;11(5):315-25. doi: 10.1038/tpj.2011.16. Epub 2011 May 31., [PMID:21625253]
Abstract [show]
The human ABCB1 protein, (P-glycoprotein or MDR1) is a membrane-bound glycoprotein that harnesses the energy of ATP hydrolysis to drive the unidirectional transport of substrates from the cytoplasm to the extracellular space. As a large range of therapeutic agents are known substrates of ABCB1 protein, its role in the onset of multidrug resistance has been the focus of much research. This role has been of particular interest in the field of pharmacogenomics where genetic variation within the ABCB1 gene, particularly in the form of single nucleotide polymorphisms (SNPs), is believed to contribute to inter-individual variation in ABCB1 function and drug response. In this review we provide an update on the influence of coding region SNPs within the ABCB1 gene on drug pharmacokinetics. By utilizing the crystal structure of the mouse ABCB1 homolog (Abcb1a), which is 87% homologous to the human sequence, we accompany this discussion with a graphical representation of residue location for amino acids corresponding to human ABCB1 coding region SNPs. Also, an assessment of residue conservation, which is calculated following multiple sequence alignment of 11 confirmed sequences of ABCB1 homologs, is presented and discussed. Superimposing a 'heat map' of residue homology to the Abcb1a crystal structure has permitted additional insights into both the conservation of individual residues and the conservation of their immediate surroundings. Such graphical representation of residue location and conservation supplements this update of ABCB1 pharmacogenetics to help clarify the often confounding reports on the influence of ABCB1 polymorphisms on drug pharmacokinetics and response.
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No. Sentence Comment
131 These are E3/61A4G (N21D), E5/266C4T (M89T), E17/1985T4C (L662R), E17/2005C4T (R669C).
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ABCB1 p.Leu662Arg 21625253:131:58
status: NEW132 When in haplotype with the intensely studied SNPs E13/1236C4T (#s6), E22/2677G4T/A (#ns22) and E27/3435C4T (#s20), SNP E3/61A4G (N21D), which cannot be mapped to the 3D crystal structure, was reported to increase BODIPY-FL-paclitaxel accumulation and modulate the effect of cyclosporine A on the intracellular accumulation of BODIPY-FL-paclitaxel transport.50 However, the N21D substitution was found not to influence cyclosporine A pharmacokinetics in another study.51 In yet another study, the N21D polymorphism was reported to influence the trough but not the peak plasma levels concentration of methadone.52 Using a yeast-based assay, SNP E27/3421T4A (S1141T) (#ns33) and several SNPs that cannot be mapped to the crystal structure (E5/266C4T (M89T), E17/1985T4C (L662R), E17/2005C4T (R669C)) were reported to increase drug resistance to two or more drugs whereas SNP E27/ 3322T4C (W1108R) (#ns31) decreased drug resistance.49 Curiously, in another study, the E17/2005C4T (R669C) SNP was reported to be associated with decreased resistance to paclitaxel and etoposide in transfected LLC-PK1 cells.53 The increased resistance by SNP E17/2005C4T (R669C) was found to be reversed by SNP E27/3322T4C (W1108R) (#ns31).49 In another study using HEK293T cells, SNP E27/3421T4A (S1141T) (#ns33) was reported to be less sensitive to cyclosporine A inhibition of BODIPY-FL-paclitaxel transport.50 It was suggested that as the resistance profiles of SNPs E27/3421T4A (S1141T) (#ns33), E27/3322T4C (W1108R) (#ns31) and diplotype E27/3322T4C (W1108R)- E17/ 2005C4T (R669C)) display the largest variation across substrates, the region where S1141T (#ns33) and W1108R (#ns31) reside might contribute to the substrate discrimination activity of P-gp.49 The 3D crystal structure reveals that both S1141T (#ns33) and W1108R (#ns31) reside at the C-terminal NBD of the P-gp protein with S1141T (#ns33) residing on the outer surface and W1108R (#ns31) residing in the interior of the NBD (Figures 2b, 4d and 4e and flash movie http:// pfs.nus.edu.sg/demo_src/abcb1.html).
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ABCB1 p.Leu662Arg 21625253:132:768
status: NEW[hide] A synonymous polymorphism in a common MDR1 (ABCB1)... Biochim Biophys Acta. 2009 May;1794(5):860-71. Epub 2009 Mar 11. Fung KL, Gottesman MM
A synonymous polymorphism in a common MDR1 (ABCB1) haplotype shapes protein function.
Biochim Biophys Acta. 2009 May;1794(5):860-71. Epub 2009 Mar 11., [PMID:19285158]
Abstract [show]
The MDR1 (ABCB1) gene encodes a membrane-bound transporter that actively effluxes a wide range of compounds from cells. The overexpression of MDR1 by multidrug-resistant cancer cells is a serious impediment to chemotherapy. MDR1 is expressed in various tissues to protect them from the adverse effect of toxins. The pharmacokinetics of drugs that are also MDR1 substrates also influence disease outcome and treatment efficacy. Although MDR1 is a well-conserved gene, there is increasing evidence that its polymorphisms affect substrate specificity. Three single nucleotide polymorphisms (SNPs) occur frequently and have strong linkage, creating a common haplotype at positions 1236C>T (G412G), 2677G>T (A893S) and 3435C>T (I1145I). The frequency of the synonymous 3435C>T polymorphism has been shown to vary significantly according to ethnicity. Existing literature suggests that the haplotype plays a role in response to drugs and disease susceptibility. This review summarizes recent findings on the 3435C>T polymorphism of MDR1 and the haplotype to which it belongs. A possible molecular mechanism of action by ribosome stalling that can change protein structure and function by altering protein folding is discussed.
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153 A recent study by Gow et al. suggested that all of the SNPs they tested (N21D, S400N, R669C, A893S, A893T, S1141T, V1251I) produced small changes which in most cases are not statistically significant [59].
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ABCB1 p.Leu662Arg 19285158:153:67
status: NEW154 Another study using a yeast host to express human MDR1 SNPs (M89T, L662R, R669C, A893S, W1108R, S1141T) showed increased resistance to anthracyclines, actinomycin D and valinomycin.
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ABCB1 p.Leu662Arg 19285158:154:67
status: NEW[hide] Impact of Genetic Polymorphisms of ABCB1 (MDR1, P-... Clin Pharmacokinet. 2015 Jul;54(7):709-35. doi: 10.1007/s40262-015-0267-1. Wolking S, Schaeffeler E, Lerche H, Schwab M, Nies AT
Impact of Genetic Polymorphisms of ABCB1 (MDR1, P-Glycoprotein) on Drug Disposition and Potential Clinical Implications: Update of the Literature.
Clin Pharmacokinet. 2015 Jul;54(7):709-35. doi: 10.1007/s40262-015-0267-1., [PMID:25860377]
Abstract [show]
ATP-binding cassette transporter B1 (ABCB1; P-glycoprotein; multidrug resistance protein 1) is an adenosine triphosphate (ATP)-dependent efflux transporter located in the plasma membrane of many different cell types. Numerous structurally unrelated compounds, including drugs and environmental toxins, have been identified as substrates. ABCB1 limits the absorption of xenobiotics from the gut lumen, protects sensitive tissues (e.g. the brain, fetus and testes) from xenobiotics and is involved in biliary and renal secretion of its substrates. In recent years, a large number of polymorphisms of the ABCB1 [ATP-binding cassette, sub-family B (MDR/TAP), member 1] gene have been described. The variants 1236C>T (rs1128503, p.G412G), 2677G>T/A (rs2032582, p.A893S/T) and 3435C>T (rs1045642, p.I1145I) occur at high allele frequencies and create a common haplotype; therefore, they have been most widely studied. This review provides an overview of clinical studies published between 2002 and March 2015. In summary, the effect of ABCB1 variation on P-glycoprotein expression (messenger RNA and protein expression) and/or activity in various tissues (e.g. the liver, gut and heart) appears to be small. Although polymorphisms and haplotypes of ABCB1 have been associated with alterations in drug disposition and drug response, including adverse events with various ABCB1 substrates in different ethnic populations, the results have been majorly conflicting, with limited clinical relevance. Future research activities are warranted, considering a deep-sequencing approach, as well as well-designed clinical studies with appropriate sample sizes to elucidate the impact of rare ABCB1 variants and their potential consequences for effect sizes.
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No. Sentence Comment
67 Only a few reports have described the functional consequences of rare variants in cell models, e.g. variants 266T[C (rs35810889, p.M89T), 1199G[A/T/C (rs2229109, p.S400N/I/T), 1985T[G (rs35657960, p.L662R), 2005C[T (rs35023033, p.R669C), 3322T[C (rs35730308, p.T1108R) and 3751G[A (rs28364274, p.V1251I) [50-52].
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ABCB1 p.Leu662Arg 25860377:67:199
status: NEW