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Drug testing and analysis2020; 13(1); 113-121; doi: 10.1002/dta.2907

A duplex qPCR assay for human erythropoietin (EPO) transgene to control gene doping in horses.

Abstract: The misuse of genetic manipulation technology to enhance athletic performance is termed gene doping which is prohibited in human sports, horseracing, and equestrian sports. Although many qPCR assays have been developed, most assays employ genomic DNA (gDNA) from humans, non-human primates, and mice as a background and they may not be applicable for testing horse samples. This study aimed to develop a qPCR assay for the detection of human erythropoietin (hEPO) transgene in horse blood cells where the viral vectors used in gene therapy can reside for months. For the detection of hEPO transgene, the performance of three sets of primers and a hydrolysis probe for hEPO were compared. One set showed adequate specificity, sensitivity, amplification efficiency, and a dynamic range of detection in the presence of horse gDNA. The assay was duplexed with the detection of horse tubulin α 4A (TUBA4A) gene as an endogenous internal control in order to prevent false-negative results due to poor recovery and storage of extracted DNA and/or qPCR experimental variation. For the extraction of hEPO-plasmid, the QIAGEN Gentra Puregene blood kit was shown to recover the majority (62%) of hEPO-plasmid from spiked horse blood cells. The specificity and limit of detection (LOD) of the duplex qPCR assay were determined in accordance with MIQE guidelines. These findings supported the application of this duplex qPCR assay to the detection of hEPO transgene in horse blood cells.
Publication Date: 2020-10-14 PubMed ID: 32762114DOI: 10.1002/dta.2907Google Scholar: Lookup
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  • Journal Article

Summary

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The researchers developed an effective duplex qPCR assay for detecting the human erythropoietin (hEPO) gene in horse blood cells, which could be used to prevent gene doping.

Understanding Key Concepts

  • Gene doping is a form of cheating in sports where athletes improve their performance by manipulating genetics, including use of the human erythropoietin (hEPO) gene. This gene has been known to enhance physical performance by promoting red blood cell production.
  • The technique being studied, duplex qPCR assay, is a method that can be used to detect specific genetic sequences – in this case, the hEPO gene. The ‘duplex’ refers to its ability to also measure a reference gene (in this case tubulin α 4A or TUBA4A) to ensure the test’s accuracy.

Research Methods

  • The research team tested three sets of primers and a hydrolysis probe for hEPO to compare their performance. Primers are used in qPCR assays to identify specific DNA sequences.
  • They selected the best-performing primer set based on specificity, sensitivity, amplification efficiency, and a dynamic range of detection in the presence of horse genomic DNA.
  • The duplex qPCR assay could detect both the hEPO transgene and horse TUBA4A gene. Including the TUBA4A gene allowed for an internal control to prevent false-negative results.
  • For the extraction of the hEPO-plasmid, researchers used the QIAGEN Gentra Puregene blood kit, which recovered the majority (62%) of hEPO-plasmid from spiked horse blood cells. The term ‘plasmid’ here refers to a small, circular piece of DNA that scientists insert into cells in gene doping.

Results

  • The specificity and limit of detection (LOD) of the duplex qPCR assay were determined according to the MIQE guidelines (Minimum Information for Publication of Quantitative Real-Time PCR Experiments) designed to ensure accuracy and reproducibility across different labs.
  • The results indicated that this duplex qPCR assay is precise and reliable for use in detecting the hEPO transgene in horse blood cells.

This research has significant implications for regulating human and equestrian sports and preventing fraudulent practices like gene doping.

Cite This Article

APA
Cheung HW, Wong KS, Lin VYC, Wan TSM, Ho ENM. (2020). A duplex qPCR assay for human erythropoietin (EPO) transgene to control gene doping in horses. Drug Test Anal, 13(1), 113-121. https://doi.org/10.1002/dta.2907

Publication

ISSN: 1942-7611
NlmUniqueID: 101483449
Country: England
Language: English
Volume: 13
Issue: 1
Pages: 113-121

Researcher Affiliations

Cheung, Hiu Wing
  • Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China.
Wong, Kin-Sing
  • Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China.
Lin, Venus Y C
  • Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China.
Wan, Terence S M
  • Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China.
Ho, Emmie N M
  • Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China.

MeSH Terms

  • Animals
  • Blood Cells / metabolism
  • DNA / blood
  • DNA / genetics
  • Doping in Sports
  • Erythropoietin / genetics
  • Horses / blood
  • Horses / genetics
  • Humans
  • Real-Time Polymerase Chain Reaction / methods
  • Transgenes

References

This article includes 32 references
  1. Li C, Samulski RJ. Engineering adeno-associated virus vectors for gene therapy.. Nat Rev Genet 2020;21(4):255-272.
  2. Shahryari A, Saghaeian Jazi M, Mohammadi S. Development and clinical translation of approved gene therapy products for genetic disorders.. Front Genet 2019;10:868.
  3. Baoutina A, Alexander IE, Rasko JE, Emslie KR. Potential use of gene transfer in athletic performance enhancement.. Mol Ther 2007;15(10):1751-1766.
  4. Wilkin T, Baoutina A, Hamilton N. Equine performance genes and the future of doping in horseracing.. Drug Test Anal 2017;9(9):1456-1471.
  5. International Federation of Horseracing Authorities. International agreement on breeding, racing and wagering and appendixes (January 2020).. 2020.
  6. Fédération Équestre Internationale. Equine prohibited substances list.. 2020.
  7. World Anti-Doping Agency. Prohibited list.. 2020.
  8. Chenuaud P, Larcher T, Rabinowitz JE. Autoimmune anemia in macaques following erythropoietin gene therapy.. Blood 2004;103(9):3303-3304.
  9. Gao G, Lebherz C, Weiner DJ. Erythropoietin gene therapy leads to autoimmune anemia in macaques.. Blood 2004;103(9):3300-3302.
  10. Favre D, Blouin V, Provost N. Lack of an immune response against the tetracycline-dependent transactivator correlates with long-term doxycycline-regulated transgene expression in nonhuman primates after intramuscular injection of recombinant adeno-associated virus.. J Virol 2002;76(22):11605-11611.
  11. Frisbie DD, Ghivizzani SC, Robbins PD, Evans CH, McIlwraith CW. Treatment of experimental equine osteoarthritis by in vivo delivery of the equine interleukin-1 receptor antagonist gene.. Gene Ther 2002;9(1):12-20.
  12. Ishihara A, Shields KM, Litsky AS. Osteogenic gene regulation and relative acceleration of healing by adenoviral-mediated transfer of human BMP-2 or -6 in equine osteotomy and ostectomy models.. J Orthop Res 2008;26(6):764-771.
  13. Kovac M, Litvin YA, Aliev RO. Gene therapy using plasmid DNA encoding vascular endothelial growth factor 164 and fibroblast growth factor 2 genes for the treatment of horse tendinitis and desmitis: case reports.. Front Vet Sci 2017;4:168.
  14. Mason JB, Gurda BL, Van Wettere A, Engiles JB, Wilson JM, Richardson DW. Delivery and evaluation of recombinant adeno-associated viral vectors in the equine distal extremity for the treatment of laminitis.. Equine Vet J 2017;49(1):79-86.
  15. Moss KL, Jiang Z, Dodson ME. Sustained interleukin-10 transgene expression following intra-articular AAV5-IL-10 administration to horses.. Hum Gene Ther 2020;31(1-2):110-118.
  16. Ortved K, Wagner B, Calcedo R, Wilson J, Schaefer D, Nixon A. Humoral and cell-mediated immune response, and growth factor synthesis after direct intraarticular injection of rAAV2-IGF-I and rAAV5-IGF-I in the equine middle carpal joint.. Hum Gene Ther 2015;26(3):161-171.
  17. Bustin SA, Benes V, Garson JA. The MIQE guidelines: minimum information for publication of quantitative real-time PCR experiments.. Clin Chem 2009;55(4):611-622.
  18. Johnson G, Nolan T, Bustin SA. Real-time quantitative PCR, pathogen detection and MIQE.. Methods Mol Biol 2013;943:1-16.
  19. Baoutina A, Coldham T, Bains GS, Emslie KR. Gene doping detection: evaluation of approach for direct detection of gene transfer using erythropoietin as a model system.. Gene Ther 2010;17(8):1022-1032.
  20. Perez IC, Le Guiner C, Ni W, Lyles J, Moullier P, Snyder RO. PCR-based detection of gene transfer vectors: application to gene doping surveillance.. Anal Bioanal Chem 2013;405(30):9641-9653.
  21. Ni W, Le Guiner C, Moullier P, Snyder RO. Development and utility of an internal threshold control (ITC) real-time PCR assay for exogenous DNA detection.. PLoS One 2012;7(5):e36461.
  22. Neuberger EW, Perez I, Le Guiner C. Establishment of two quantitative nested qPCR assays targeting the human EPO transgene.. Gene Ther 2016;23(4):330-339.
  23. Ni W, Le Guiner C, Gernoux G, Penaud-Budloo M, Moullier P, Snyder RO. Longevity of rAAV vector and plasmid DNA in blood after intramuscular injection in nonhuman primates: implications for gene doping.. Gene Ther 2011;18(7):709-718.
  24. Beiter T, Zimmermann M, Fragasso A. Direct and long-term detection of gene doping in conventional blood samples.. Gene Ther 2011;18(3):225-231.
  25. Moser DA, Braga L, Raso A, Zacchigna S, Giacca M, Simon P. Transgene detection by digital droplet PCR.. PLoS One 2014;9(11):e111781.
  26. Tozaki T, Ohnuma A, Takasu M. Droplet digital PCR detection of the erythropoietin transgene from horse plasma and urine for gene-doping control.. Genes (Basel) 2019;10(3):243.
  27. Tozaki T, Ohnuma A, Kikuchi M. Microfluidic quantitative PCR detection of 12 transgenes from horse plasma for gene doping control.. Genes 2020;11(4):475.
  28. Integrated DNA Technologies. Calculations: converting from nanograms to copy number.. 2013.
  29. Smits K, Goossens K, Van Soom A. Selection of reference genes for quantitative real-time PCR in equine in vivo and fresh and frozen-thawed in vitro blastocysts.. BMC Res Notes 2009;2(1):246.
  30. Rasmussen R. Quantification on the LightCycler.. 2001:21-34.
  31. Brunstein J. Interpretation of qPCR curve shapes.. MLO Med Lab Obs 2015;47(6):38. 40.
  32. Baoutina A, Coldham T, Fuller B, Emslie KR. Improved detection of transgene and nonviral vectors in blood.. Hum Gene Ther Methods 2013;24(6):345-354.

Citations

This article has been cited 7 times.
  1. Lu Y, Yan J, Ou G, Fu L. A Review of Recent Progress in Drug Doping and Gene Doping Control Analysis.. Molecules 2023 Jul 18;28(14).
    doi: 10.3390/molecules28145483pubmed: 37513354google scholar: lookup
  2. Tozaki T, Ohnuma A, Kikuchi M, Ishige T, Kakoi H, Hirota KI, Takahashi Y, Nagata SI. Investigation of optimal procedures for storage and use of plasma samples suitable for gene doping tests.. J Equine Sci 2023 Jun;34(2):21-27.
    doi: 10.1294/jes.34.21pubmed: 37405066google scholar: lookup
  3. Rooney MF, Neto NGB, Monaghan MG, Hill EW, Porter RK. Conditionally immortalised equine skeletal muscle cell lines for in vitro analysis.. Biochem Biophys Rep 2023 Mar;33:101391.
    doi: 10.1016/j.bbrep.2022.101391pubmed: 36504704google scholar: lookup
  4. Tozaki T, Ohnuma A, Nakamura K, Hano K, Takasu M, Takahashi Y, Tamura N, Sato F, Shimizu K, Kikuchi M, Ishige T, Kakoi H, Hirota KI, Hamilton NA, Nagata SI. Detection of Indiscriminate Genetic Manipulation in Thoroughbred Racehorses by Targeted Resequencing for Gene-Doping Control.. Genes (Basel) 2022 Sep 4;13(9).
    doi: 10.3390/genes13091589pubmed: 36140757google scholar: lookup
  5. Tozaki T, Ohnuma A, Kikuchi M, Ishige T, Kakoi H, Hirota KI, Kusano K, Nagata SI. Design and storage stability of reference materials for microfluidic quantitative PCR-based equine gene doping tests.. J Equine Sci 2021 Dec;32(4):125-134.
    doi: 10.1294/jes.32.125pubmed: 35023990google scholar: lookup
  6. Tozaki T, Ohnuma A, Kikuchi M, Ishige T, Kakoi H, Hirota KI, Kusano K, Nagata SI. Rare and common variant discovery by whole-genome sequencing of 101 Thoroughbred racehorses.. Sci Rep 2021 Aug 6;11(1):16057.
    doi: 10.1038/s41598-021-95669-1pubmed: 34362995google scholar: lookup
  7. Tozaki T, Hamilton NA. Control of gene doping in human and horse sports.. Gene Ther 2022 Apr;29(3-4):107-112.
    doi: 10.1038/s41434-021-00267-5pubmed: 34099895google scholar: lookup