Bioethical issues in genome editing by CRISPR-Cas9 technology

Genome editing technologies have led to fundamental changes in genetic science. Among them, CRISPR-Cas9 technology particularly stands out due to its advantages such as easy handling, high accuracy, and low cost. It has made a quick introduction in fields related to humans, animals, and the environment, while raising difficult questions, applications, concerns, and bioethical issues to be discussed. Most concerns stem from the use of CRISPR-Cas9 to genetically alter human germline cells and embryos called germline genome editing . Germline genome editing leads to serial bioethical issues, such as the occurrence of undesirable changes in the genome, from whom and how informed consent is obtained, and the breeding of the human species eugenics . However, the bioethical issues that CRISPR-Cas9 technology could cause in the environment, agriculture and livestock should also not be forgotten. In order for CRISPR-Cas9 to be used safely in all areas and to solve potential issues, worldwide legislation should be prepared, taking into account the opinions of both life and social scientists, policy makers, and all other stakeholders of the sectors, and CRISPR-Cas9 applications should be implemented according to such legislations. However, these controls should not restrict scientific freedom. Here, various applications of CRISPR-Cas9 technology, especially in medicine and agriculture, are described and ethical issues related to genome editing using CRISPR-Cas9 technology are discussed. The social and bioethical concerns in relation to human beings, other organisms, and the environment are addressed.

___

  • Amoasii L, Hildyard JC, Li H, Sanchez-Ortiz E, Mireault A et al. (2018). Gene editing restores dystrophin expression in a canine model of Duchenne muscular dystrophy. Science 362 (6410): 86-91.
  • Amoroso PJ, Wenger LL (2003). The human volunteer in military biomedical research. In: Beam TE, Sparacino LR, Pellegrino ED, Hartle AE, Howe EG (editors). Military Medical Ethics. Volume 2. Washington, DC, USA: Walter Reed Army Medical Center, pp. 563-660.
  • Arévalo MT, Navarro A, Arico CD, Li J, Alkhatib O et al. (2014). Targeted silencing of anthrax toxin receptors protects against anthrax toxins. Journal of Biological Chemistry 289 (22): 15730-15738.
  • Baltimore D, Berg P, Botchan M, Carroll D, Charo RA et al. (2015). A prudent path forward for genomic engineering and germline gene modification. Science 348 (6230): 36-38.
  • Barrangou R, Fremaux C, Deveau H, Richards M, Boyaval P et al. (2007). CRISPR provides acquired resistance against viruses in prokaryotes. Science 315 (5819): 1709-1712.
  • Beriain IDM, del Cano AMM (2018). Gene editing in human embryos. A comment on the ethical issues involved. In: Soniewicka M (editor). The Ethics of Reproductive Genetics. Cham, Switzerland: Springer, pp. 173-187.
  • Black CK, Termanini KM, Aguirre O, Hawksworth JS, Sosin M (2018). Solid organ transplantation in the 21st century. Annals of Translational Medicine 6 (20): 409.
  • Brokowski C (2018). Do CRISPR germline ethics statements cut it? CRISPR Journal 1 (2): 115-125.
  • Cai L, Zheng LA, He L (2018). The forty years of medical genetics in China. Journal of Genetics and Genomics 45 (11): 569-582. Carroll D (2017). Focus: Genome editing: genome editing: past, present, and future. Yale Journal of Biology and Medicine 90 (4): 653.
  • Cathomen T, Schüle S, Schüßler-Lenz M, Abou-El-Enein M (2019). The human genome editing race: loosening regulatory standards for commercial advantage? Trends in Biotechnology 37 (2): 120-123.
  • Charlesworth CT, Deshpande PS, Dever DP, Camarena J, Lemgart VT et al. (2019). Identification of preexisting adaptive immunity to Cas9 proteins in humans. Nature Medicine 25 (2): 249.
  • Chen H, Kazemier HG, de Groote ML, Ruiters MH, Xu GL et al. (2013). Induced DNA demethylation by targeting ten-eleven translocation 2 to the human ICAM-1 promoter. Nucleic Acids Research 42 (3): 1563-1574.
  • Chin A (2015). CRISPR-Cas9 Therapeutics: A Technology Overview. Oxford, UK: Biostars.
  • Collins FS (2015). Statement on NIH Funding of Research Using Gene-Editing Technologies in Human Embryos. Bethesda, MD, USA: National Institutes of Health.
  • Cornelis MC, Nugent NR, Amstadter AB, Koenen KC (2010). Genetics of post-traumatic stress disorder: review and recommendations for genome-wide association studies. Current Psychiatry Reports 12 (4): 313-326.
  • Cyranoski D, Reardon S (2015). Chinese scientists genetically modify human embryos. Nature News 346: 1258096.
  • de Graeff N, Jongsma KR, Johnston J, Hartley S, Bredenoord AL (2019). The ethics of genome editing in non-human animals: a systematic review of reasons reported in the academic literature. Philosophical Transactions of the Royal Society B 374 (1772): 20180106.
  • Degrazia D (2019). Human-animal chimeras, “human” cognitive capacities, and moral status. Hastings Center Report 49 (5): 33- 34.
  • Doudna JA, Charpentier E (2014). The new frontier of genome engineering with CRISPR-Cas9. Science 346 (6213): 1258096. Duardo-Sanchez A (2017). CRISPR-Cas in medicinal chemistry: applications and regulatory concerns. Current Topics in Medicinal Chemistry 17 (30): 3308-3315.
  • Duchêne BL, Cherif K, Iyombe-Engembe JP, Guyon A, Rousseau J et al. (2018). CRISPR-induced deletion with saCas9 restores dystrophin expression in dystrophic models in vitro and in vivo. Molecular Therapy 26 (11): 2604-2616.
  • Eriksson S, Jonas E, Rydhmer L, Röcklinsberg H (2018). Invited review: Breeding and ethical perspectives on genetically modified and genome edited cattle. Journal of Dairy Science 101 (1): 1-17.
  • Esvelt KM, Smidler AL, Catteruccia F, Church GM (2014). Concerning RNA-guided gene drives for the alteration of wild populations. Elife 3: e03401.
  • Firth AL, Menon T, Parker GS, Qualls SJ, Lewis BM et al. 2015. Functional gene correction for cystic fibrosis in lung epithelial cells generated from patient iPSCs. Cell Reports 12 (9): 1385- 1390. doi: 10.1016/j.celrep.2015.07.062
  • Fung RKF, Kerridge IH (2016). Gene editing advance re-ignites debate on the merits and risks of animal to human transplantation. Internal Medicine Journal 46 (9): 1017-1022.
  • Gantz VM, Jasinskiene N, Tatarenkova O, Fazekas A, Macias VM et al. (2015). Highly efficient Cas9-mediated gene drive for population modification of the malaria vector mosquito Anopheles stephensi. Proceedings of the National Academy of Sciences of the USA 112 (49): E6736-E6743.
  • Gracheva EO, Ingolia NT, Kelly YM, Cordero-Morales JF, Hollopeter G et al. (2010). Molecular basis of infrared detection by snakes. Nature 464 (7291): 1006.
  • Greely HT (2019). Human germline genome editing: an assessment. CRISPR Journal 2 (5): 253-265.
  • Greene M, Master Z (2018). Ethical issues of using CRISPR technologies for research on military enhancement. Journal of Bioethical Inquiry 15 (3): 327-335.
  • Greenfield A (2017). Editing mammalian genomes: ethical considerations. Mammalian Genome 28 (7-8): 388-393. Guo X, Li XJ (2015). Targeted genome editing in primate embryos. Cell Research 25 (7): 767.
  • Halpern J, O’Hara SE, Doxzen KW, Witkowsky LB, Owen AL (2019). Societal and ethical impacts of germline genome editing: How can we secure human rights? CRISPR Journal 2 (5): 293-298.
  • Hammond A, Galizi R, Kyrou K, Simoni A, Siniscalchi C et al. (2016). A CRISPR-Cas9 gene drive system targeting female reproduction in the malaria mosquito vector Anopheles gambiae. Nature Biotechnology 34 (1): 78.
  • Heeger R (2015). Dignity only for humans? A controversy. In: Duwell M (editor). The Cambridge Handbook of Human Dignity: Interdisciplinary Perspectives. Cambridge, UK: Cambridge University Press, pp. 541-545.
  • Hermerén G (2015). Ethical considerations in chimera research. Development 142 (1): 3-5.
  • Hirsch F, Iphofen R, Koporc Z (2019). Ethics assessment in research proposals adopting CRISPR technology. Biochemia Medica 29 (2): 206-213.
  • Huisman C, van der Wijst MG, Falahi F, Overkamp J, Karsten G et al. (2015). Prolonged re-expression of the hypermethylated gene EPB41L3 using artificial transcription factors and epigenetic drugs. Epigenetics 10 (5): 384-396.
  • Ishii T (2017a). Genome-edited livestock: ethics and social acceptance. Animal Frontiers 7 (2): 24-32.
  • Ishii T (2017b). Germ line genome editing in clinics: the approaches, objectives and global society. Briefings in Functional Genomics 16 (1): 46-56.
  • Kim H, Kim JS (2014). A guide to genome engineering with programmable nucleases. Nature Reviews Genetics 15 (5): 321-334.
  • Kim S, Koo T, Jee HG, Cho HY, Lee G et al. (2018). CRISPR RNAs trigger innate immune responses in human cells. Genome Research 28 (3): 367-373.
  • Knoppers BM, Kleiderman E (2019). Heritable genome editing: Who speaks for “future” children? CRISPR Journal 2 (5): 285-292.
  • Koo T, Lu-Nguyen NB, Malerba A, Kim E, Kim D et al. (2018). Functional rescue of dystrophin deficiency in mice caused by frameshift mutations using campylobacter jejuni Cas9. Molecular Therapy 26 (6): 1529-1538.
  • Koplin JJ (2019). Human-animal chimeras: the moral insignificance of uniquely human capacities. Hastings Center Report 49 (5): 23-32.
  • Lanphier E, Urnov F, Haecker SE, Werner M, Smolenski J (2015). Don’t edit the human germ line. Nature News 519 (7544): 410.
  • Lau RW, Wang B, Ricardo SD (2018). Gene editing of stem cells for kidney disease modelling and therapeutic intervention. Nephrology 23 (11): 981-990.
  • Lau V, Davie JR (2016). The discovery and development of the CRISPR system in applications in genome manipulation. Biochemistry and Cell Biology 95 (2): 203-210.
  • Ledford H (2015). CRISPR, the disruptor. Nature 522 (7554): 20-24.
  • Li W, Teng F, Li T, Zhou Q (2013). Simultaneous generation and germline transmission of multiple gene mutations in rat using CRISPR-Cas systems. Nature Biotechnology 31 (8): 684.
  • Liang P, Xu Y, Zhang X, Ding C, Huang R et al. (2015). CRISPR/Cas9- mediated gene editing in human tripronuclear zygotes. Protein & Cell 6 (5): 363-372.
  • Liao J, Karnik R, Gu H, Ziller MJ, Clement K et al. (2015). Targeted disruption of DNMT1, DNMT3A and DNMT3B in human embryonic stem cells. Nature Genetics 47 (5): 469.
  • Long C, Li H, Tiburcy M, Rodriguez-Caycedo C, Kyrychenko V et al. (2018). Correction of diverse muscular dystrophy mutations in human engineered heart muscle by single-site genome editing. Science Advances 4 (1): eaap9004.
  • Macintosh KL (2019). Heritable genome editing and the downsides of a global moratorium. CRISPR Journal 2 (5): 272-279.
  • Manesh SB, Samani RO, Manesh SB (2014). Ethical issues of transplanting organs from transgenic animals into human beings. Cell Journal (Yakhteh) 16 (3): 353.
  • Marraffini LA, Sontheimer EJ (2008). CRISPR interference limits horizontal gene transfer in staphylococci by targeting DNA. Science 322 (5909): 1843-1845.
  • Martinelli L, Oksanen M, Siipi H (2014). De-extinction: a novel and remarkable case of bio-objectification. Croatian Medical Journal 55 (4): 423.
  • Mei Y, Wang Y, Chen H, Sun ZS, Ju XD (2016). Recent progress in CRISPR/Cas9 technology. Journal of Genetics and Genomics 43 (2): 63-75.
  • Memi F, Ntokou A, Papangeli I (2018). CRISPR/Cas9 gene-editing: Research technologies, clinical applications and ethical considerations. Seminars in Perinatology 42 (8): 487-500.
  • Mittal RD (2019). Gene editing in clinical practice: where are we? Indian Journal of Clinical Biochemistry 34 (1): 19-25.
  • Neuhaus CP, Zacharias RL (2018). Compassionate use of gene therapies in pediatrics: an ethical analysis. Seminars in Perinatology 42 (8): 508-514.
  • Niu YY, Shen B, Cui YQ, Chen YC, Wang JY et al. (2014). Generation of gene-modified cynomolgus monkey via Cas9/RNAmediated gene targeting in one-cell embryos. Cell 156 (4): 836- 843.
  • Olson S (editor) (2016). International Summit on Human Gene Editing: A Global Discussion. Washington, DC, USA: National Academies Press.
  • Ormond KE, Mortlock DP, Scholes DT, Bombard Y, Brody LC et al. (2017). Human germline genome editing. American Journal of Human Genetics 101 (2): 167-176.
  • Ota S, Hisano Y, Ikawa Y, Kawahara A (2014). Multiple genome modifications by the CRISPR/Cas9 system in zebrafish. Genes to Cells 19 (7): 555-564.
  • Otieno MO (2015). CRISPR-Cas9 human genome editing: challenges, ethical concerns and implications. Journal of Clinical Research and Bioethics 6 (6): 253-255.
  • Oye KA, Esvelt K, Appleton E, Catteruccia F, Church G et al. (2014). Regulating gene drives. Science 345 (6197): 626-628.
  • Polcz S, Lewis A (2016). CRISPR-Cas9 and the non-germline noncontroversy. Journal of Law and the Biosciences 3: 413-425. doi: 10.1093/jlb/lsw016
  • Ramanan V, Shlomai A, Cox DB, Schwartz RE, Michailidis E et al. (2015). CRISPR/Cas9 cleavage of viral DNA efficiently suppresses hepatitis B virus. Scientific Reports 5: 10833.
  • Rath D, Amlinger L, Rath A, Lundgren M (2015). The CRISPRCas immune system: biology, mechanisms and applications. Biochimie 117: 119-128.
  • Rodriguez E (2016). Ethical issues in genome editing using Crispr/ Cas9 system. Journal of Clinical Research and Bioethics 7 (2): 266.
  • Rodriguez E (2017). Ethical issues in genome editing for non-human organisms using CRISPR/Cas9 system. Journal of Clinical Research and Bioethics 8 (300): 10-4172.
  • Rodriguez E, Keiser M, McLoughlin H, Zhang F, Davidson BL (2014). AAV-CRISPR: a new therapeutic approach to nucleotide repeat diseases. Molecular Therapy 22: 94-94.
  • Roh DS, Li EBH, Liao EC (2018). CRISPR Craft: DNA editing the reconstructive ladder. Plastic and Reconstructive Surgery 142 (5): 1355-1364.
  • Rossant J (2018). Gene editing in human development: ethical concerns and practical applications. Development 145 (16): dev150888.
  • Schultz-Bergin M (2017). The dignity of diminished animals: Species norms and engineering to improve welfare. Ethical Theory and Moral Practice 20 (4): 843-856.
  • Schultz-Bergin M (2018). Is CRISPR an ethical game changer? Journal of Agricultural and Environmental Ethics 31 (2): 219-238.
  • Senis E, Fatouros C, Große S, Wiedtke E, Niopek D et al. (2014). CRISPR/Cas9-mediated genome engineering: an adenoassociated viral (AAV) vector toolbox. Biotechnology Journal 9 (11): 1402-1412.
  • Sherkow JS (2018). The CRISPR patent landscape: past, present, and future. CRISPR Journal 1 (1): 5-9. Shinwari ZK, Tanveer F, Khalil AT (2017). Ethical issues regarding CRISPR-mediated genome editing. Current Issues in Molecular Biology 26: 103-110. doi: 10.21775/9781910190630.09 Shriver A, McConnachie E (2018). Genetically modifying livestock for improved welfare: a path forward. Journal of Agricultural and Environmental Ethics 31 (2): 161-180.
  • Swiech L, Heidenreich M, Banerjee A, Habib N, Li Y et al. (2015). In vivo interrogation of gene function in the mammalian brain using CRISPR-Cas9. Nature Biotechnology 33 (1): 102.
  • Sýkora P (2018). Germline gene therapy in the era of precise genome editing: how far should we go? In: Soniewicka M (editor). The Ethics of Reproductive Genetics. Cham, Switzerland: Springer, pp. 157-171.
  • Urnov FD (2018). Genome Editing BC (before CRISPR): lasting lessons from the “old testament”. CRISPR Journal 1 (1): 34-46.
  • van Erp PB, Bloomer G, Wilkinson R, Wiedenheft B (2015). The history and market impact of CRISPR RNA-guided nucleases. Current Opinion in Virology 12: 85-90.
  • Wang ZP, Xing HL, Dong L, Zhang HY, Han CY et al. (2015). Egg cell-specific promoter-controlled CRISPR/Cas9 efficiently generates homozygous mutants for multiple target genes in Arabidopsis in a single generation. Genome Biology 16 (1): 144.
  • Wilson RC, Carroll D (2019). The daunting economics of therapeutic genome editing. CRISPR Journal 2 (5): 280-284.
  • Wu Y, Zhou H, Fan X, Zhang Y, Zhang M et al. (2015). Correction of a genetic disease by CRISPR-Cas9-mediated gene editing in mouse spermatogonial stem cells. Cell Research 25 (1): 67.
  • Xin L, Min L, Bing S (2016). Application of the genome editing tool CRISPR/Cas9 in non-human primates. Zoological Research 37 (4): 241.
  • Yang A (2015). Thinking Towards the Future of CRISPR/Cas9. London, UK: Brevia.
  • Yang W, Tu Z, Sun Q, Li XJ (2016). CRISPR/Cas9: implications for modeling and therapy of neurodegenerative diseases. Frontiers in Molecular Neuroscience 9: (30).
  • Yoshimi K, Kaneko T, Voigt B, Mashimo T (2014). Allele-specific genome editing and correction of disease-associated phenotypes in rats using the CRISPR–Cas platform. Nature Communications 5: 4240.
  • Yuan M, Gao X, Chard LS, Ali Z, Ahmed J et al. (2015). A markerfree system for highly efficient construction of vaccinia virus vectors using CRISPR Cas9. Molecular Therapy-Methods & Clinical Development 2: 15035.
  • Yumlu S, Bashir S, Stumm J, Kühn R (2019). Efficient gene editing of human induced pluripotent stem cells using CRISPR/Cas9. In: Luo Y (editor). CRISPR Gene Editing. New York, NY, USA: Humana Press, pp. 137-151.
  • Zhang F, Wen Y, Guo X (2014). CRISPR/Cas9 for genome editing: progress, implications and challenges. Human Molecular Genetics 23 (1): 40-46.
  • Zhang XL, Wei P, Xin-Tian H, Jia-Li L, Yong-Gang Y et al. (2014). Experimental primates and non-human primate (NHP) models of human diseases in China: current status and progress. Zoological Research 35 (6): 447.
  • Zou Q, Wang X, Liu Y, Ouyang Z, Long H et al. (2015). Generation of gene-target dogs using CRISPR/Cas9 system. Journal of Molecular Cell Biology 7 (6): 580-583.