Ethics and germline gene editing

CRISPR-Based Gene Editing: a Modern Approach for Study and Treatment of Cancer

The development and emergence of clustered regularly interspaced short palindromic repeats (CRISPR) as a genome-editing technology have created a plethora of opportunities in genetic engineering. The ability of sequence-specific addition or removal of DNA in an efficient and cost-effective manner has revolutionized modern research in the field of life science and healthcare. CRISPR is widely used as a genome engineering tool in clinical studies for observing gene expression and metabolic pathway regulations in detail. Even in the case of transgenic research and personalized gene manipulation studies, CRISPR-based technology is used extensively. To understand and even to correct the underlying genetic problem is of cancer, CRISPR-based technology can be used. Various kinds of work is going on throughout the world which are attempting to target different genes in order to discover novel and effective methodologies for the treatment of cancer. In this review, we provide a brief overview on the application of CRISPR gene editing technology in cancer treatment focusing on the key aspects of cancer screening, modelling and therapy techniques.

Exploring modified chitosan-based gene delivery technologies for therapeutic advancements

One of the critical steps in gene therapy is the successful delivery of the genes. Immunogenicity and toxicity are major issues for viral gene delivery systems. Thus, non-viral vectors are explored. A cationic polysaccharide like chitosan could be used as a nonviral gene delivery vector owing to its significant interaction with negatively charged nucleic acid and biomembrane, providing effective cellular uptake. However, the native chitosan has issues of targetability, unpacking ability, and solubility along with poor buffer capability, hence requiring modifications for effective use in gene delivery. Modified chitosan has shown that the "proton sponge effect" involved in buffering the endosomal pH results in osmotic swelling owing to the accumulation of a greater amount of proton and chloride along with water. The major challenges include limited exploration of chitosan as a gene carrier, the availability of high-purity chitosan for toxicity reduction, and its immunogenicity. The genetic drugs are in their infancy phase and require further exploration for effective delivery of nucleic acid molecules as FDA-approved marketed formulations soon.

Eight Strategies to Engineer Acceptance of Human Germline Modifications

Until recently, scientific consensus held firm that genetically manipulated embryos created through methods including Mitochondrial Replacement Therapy or human germline genome editing should not be used to initiate a pregnancy. In countries that have relevant laws pertaining to heritable human germline modifications, the vast majority prohibit or restrict this practice. In the last several years, scholars have observed a transformation of scientific and policy restrictions with insistent calls for creating a regulatory pathway. Multiple stakeholders highlight the role of social consensus and public engagement for governance of heritable human germline modifications. However, in the drive to gain public acceptance and lift restrictions, some proponents provide distorted or misleading narratives designed to influence public perception and incrementally shift the consensus. This article describes eight discrete strategies that proponents employ to influence framing, sway public opinion, and revise policymaking of human germline modifications in a manner that undermines honest engagement.

Responsible governance of human germline genome editing in China

Considerable improvements have been made to gene editing technology, which has been increasingly applied to research involving humans. Nevertheless, human heritable germline genome editing is associated with a series of potential ethical, legal, and social risks, which have generated major controversies and discussions worldwide, especially after the “gene-edited babies” incident. Influenced by this incident, China has realized the importance of ethical governance in the field of life science and technology, has accelerated legislative and policy efforts in this field, and has gradually moved toward the direction of “precautionary” ethical governance. Black letter analysis, big data public opinion analysis, and other research methods are used in this paper. This paper explores the scientific background, ethical debates, and latest developments regarding China’s regulatory framework for human germline gene editing after the “gene-edited babies” controversy and provides several recommendations on the future governance system of human germline gene editing in China. This paper argues that in recent years, the ethics governance of germline genome editing in China has been accelerated and great changes have been made. However, the regulatory system for germline genome editing requires further improvement in three aspects: coordination of legislation and agencies, establishment of an ethics review system at high levels, and public participation and education.

An Insight into Modern Targeted Genome-Editing Technologies with a Special Focus on CRISPR/Cas9 and its Applications

Genome-editing technology has enabled scientists to make changes in model organisms' DNA at the genomic level to get biotechnologically important products from them. Most commonly employed technologies for this purpose are transcription activator like effector nucleases (TALENs), homing-endonucleases or meganucleases, zinc finger nucleases (ZFNs), and clustered regularly interspaced short palindromic repeats (CRISPR) associated protein 9 (Cas9). Among these tools, CRISPR/Cas9 is most preferred because it's easy to use, has a small mutation rate, has great effectiveness, low cost of development, and decreased rate of advancement. CRISPR/Cas9 has a lot of applications in plants, animals, humans, and microbes. It also has applications in many fields such as horticulture, cancer, food biotechnology, and targeted human genome treatments. CRISPR technology has shown great potential for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic to provide early and easy detection methods, possible treatment, and vaccine development. In the present review, genome-editing tools with their basic assembly and features have been discussed. Exceptional notice has been paid to CRISPR technology on basis of its structure and significant applications in humans, plants, animals, and microbes such as bacteria, viruses, and fungi. The review has also shed a little light on current CRISPR challenges and future perspectives.

A review of COVID-19: Treatment strategies and CRISPR/Cas9 gene editing technology approaches to the coronavirus disease

The new coronavirus SARS-CoV-2 pandemic has put the world on lockdown for the first time in decades. This has wreaked havoc on the global economy, put additional burden on local and global public health resources, and, most importantly, jeopardised human health. CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats, and the CRISPR associated (Cas) protein (CRISPR/Cas) was identified to have structures in E. coli. The most modern of these systems is CRISPR/Cas. Editing the genomes of plants and animals took several years and cost hundreds of thousands of dollars until the CRISPR approach was discovered in 2012. As a result, CRISPR/Cas has piqued the scientific community's attention, particularly for disease diagnosis and treatment, because it is faster, less expensive, and more precise than previous genome editing technologies. Data from gene mutations in specific patients gathered using CRISPR/Cas can aid in the identification of the best treatment strategy for each patient, as well as other research domains such as coronavirus replication in cell culture, such as SARS-CoV2. The implications of the most prevalent driver mutations, on the other hand, are often unknown, making treatment interpretation difficult. For detecting a wide range of target genes, the CRISPR/Cas categories provide highly sensitive and selective tools. Genome-wide association studies are a relatively new strategy to discovering genes involved in human disease when it comes to the next steps in genomic research. Furthermore, CRISPR/Cas provides a method for modifying non-coding portions of the genome, which will help advance whole genome libraries by speeding up the analysis of these poorly defined parts of the genome.

Human embryo gene editing: God's scalpel or Pandora's box?

Gene editing refers to the site-specific modification of the genome, which mainly focuses on basic research, model organism construction and treatment and prevention of disease. Since the first application of CRISPR/Cas9 on the human embryo genome in 2015, the controversy over embryo gene editing (abbreviated as EGE in the following text) has never stopped. At present, the main contradictions focus on (1) ideal application prospects and immature technologies; (2) scientific progress and ethical supervision; and (3) definition of reasonable application scope. In fact, whether the EGE is 'God's scalpel' or 'Pandora's box' depends on the maturity of the technology and ethical supervision. This non-systematic review included English articles in NCBI, technical documents from the Human Fertilization and Embryology Authority as well as reports in the media, which performed from 1980 to 2018 with the following search terms: 'gene editing, human embryo, sequence-specific nuclease (SSN) (CRISPR/Cas, TALENT, ZFN), ethical consideration, gene therapy.' Based on the research status of EGE, this paper summarizes the technical defects and ethical controversies, enumerates the optimization measures and looks forward to the application prospect, aimed at providing some suggestions for the development trend. We should regard the research and development of EGE optimistically, improve and innovate the technology boldly and apply its clinical practice carefully.

Controlling CRISPR Through Law: Legal Regimes as Precautionary Principles

Since its advent in 2012, CRISPR has spawned a cottage industry of bioethics literature. One principal criticism of the technology is its virtually instant widespread adoption prior to deliberative bodies conducting a meaningful ethical review of its harms and benefits-a violation, to some, of bioethics' "precautionary principle." This view poorly considers, however, the role that the law can play-and does, in fact, play-in policing the introduction of ethically problematic uses of the technology. This Perspective recounts these legal regimes, including regulatory agencies and premarket approval, tort law and deterrence, patents and ethical licenses, funding agencies and review boards, as well as local politics. Identifying these legal regimes and connecting them to the precautionary principle should be instructive for bioethicists and policy makers who wish to conduct ethical reviews of new applications of CRISPR prior to their introduction.

CRISPR in the North American popular press

PURPOSE

CRISPR is often called one of the century's most important discoveries and is commonly discussed in terms of its momentous potential impacts. This study analyzed how CRISPR is discussed in the North American popular press, including how it is defined, and which benefits and risks/concerns are attributed to the technology.

METHODS

Using the Factiva database, we identified 228 relevant, nonduplicated articles containing either "CRISPR" or "C.R.I.S.P.R.," published in popular US and Canadian news sources between 1 January 2012 and 12 July 2017. Content analysis was performed on the articles.

RESULTS

CRISPR is most often discussed in the context of human health (83.8%), compared with animals (26.3%) and plants (20.6%). Nearly all articles (96.1%) presented CRISPR's potential benefits; 61.4% of articles presented CRISPR-related risks/concerns, the vast majority of which focused on the uncertainty surrounding CRISPR, specifically with respect to germline modifications.

CONCLUSIONS

Overall, the discourse suggests a strong promotion of CRISPR, but an element of caution is also evident. Technical as well as ethical, legal, and social risks/concerns play a prominent role. This media portrayal of CRISPR might help facilitate more sophisticated and balanced policy responses, where the scientific potential of the technology is highlighted alongside broader social considerations.

Women who suffer from schizophrenia: Critical issues

Many brain diseases, including schizophrenia, affect men and women unequally - either more or less frequently, or at different times in the life cycle, or to varied degrees of severity. With updates from recent findings, this paper reviews the work of my research group over the last 40 years and underscores issues that remain critical to the optimal care of women with schizophrenia, issues that overlap with, but are not identical to, the cares and concerns of men with the same diagnosis. Clinicians need to be alert not only to the overarching needs of diagnostic groups, but also to the often unique needs of women and men.

Implications of CRISPR-Based Germline Engineering for Cancer Survivors

Cancer survivors can carry germline mutations that will be transmitted to their progeny. Today, many of these mutations have been identified and can be tracked. With the recent development of genome-editing technologies and CRISPR (clustered regularly interspaced short palindromic repeats), the possibility of genetically modifying the human germline-gametes and embryos-has never been closer. This perspective has sparked a controversy within the scientific community with reactions ranging from calls for a ban on germline modification to cautious approval of further research. This Editorial analyzes the possible adoption of CRISPR-based germline engineering to prevent the spread of cancer predispositions in the human population. We discuss whether the genomic edition of human sperm and eggs would contribute to rectifying or altering the heritable genome. We anticipate the emergence of a new form of liberal eugenics fueled by a logic of offer and demand from stakeholders such as cancer survivors and their relatives and offspring, but also from fertility clinics, biotech firms, insurers, and clinicians. From a regulatory perspective, validating the clinical safety and utility of CRISPR-based germline engineering is an essential step. However, with time, gradually perfecting the technology and assessing the economic benefits for stakeholders could soften society's resistance and align opinions in support of genomic decontamination of human germlines. This progressive shift would be justified in the name of cancer prevention as well as a moral obligation to facilitate the conception of cancer-free children at a cost that is acceptable to individuals and health systems.

Carry on editing

INTRODUCTION OR BACKGROUND

Genome editing facilitates alterations to DNA, large or subtle, in a precise fashion. In its most popular form it uses the programmable endonuclease system, CRISPR/Cas9. Edits can be made to any genome, including the human genome. This raises the possibility of genome editing in human embryos in both a research and reproductive context.

SOURCES OF DATA

All reports of genome editing in human embryos are included here, along with key papers examining the science and ethics of human genome editing.

AREAS OF AGREEMENT

As a basic research tool, genome editing promises to accelerate our understanding of genome biology. It also shows great promise as a means of combatting disease through so-called somatic genome editing.

AREAS OF CONTROVERSY

Genome editing could be used to prevent human disease transmission in a reproductive context. Such germ line interventions are opposed by some, for a number of reasons. Some of these reasons are discussed and a comparison is made with preimplantation genetic diagnosis (PGD).

GROWING POINTS

It is important that scientists, clinicians, bioethicists and other stakeholders engage widely with all those with an interest in genome editing.

AREAS TIMELY FOR DEVELOPING RESEARCH

In addition to offering new insights into human biology, basic (fundamental) research will deliver expertise allowing ever more precise and controllable genome editing methodologies and allied technologies. A range of clear and accessible ethical frameworks must be developed and scrutinized as part of a wider societal debate about possible applications of genome editing. In the UK, human reproductive genome editing can only take place if a change to primary legislation occurs. Inclusive discussions and assessments, involving difficult scientific and ethical concepts, must form part of any democratic decision.

The ethics of clinical applications of germline genome modification: a systematic review of reasons

STUDY QUESTION

What are the reasons for or against the future clinical application of germline genome modification (GGM)?

SUMMARY ANSWER

A total of 169 reasons were identified, including 90 reasons for and 79 reasons against future clinical application of GGM.

WHAT IS KNOWN ALREADY

GGM is still unsafe and insufficiently effective for clinical purposes. However, the progress made using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)- CRISPR-associated system (Cas) has led scientists to expect to overcome the technical hurdles in the foreseeable future. This has invited a debate on the socio-ethical and legal implications and acceptability of clinical applications of GGM. However, an overview of the reasons presented in this debate is missing.

STUDY DESIGN, SIZE, DURATION

MEDLINE was systematically searched for articles published between January 2011 and June 2016. Articles covering reasons for or against clinical application of intentional modification of the nuclear DNA of the germline were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two researchers independently extracted the reported reasons from the articles and grouped them into categories through content analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

The systematic search yielded 1179 articles and 180 articles were included. Most papers were written by professionals in ethics, (science) journalism and biomedical sciences. Overall, 169 reasons were identified, including 90 reasons for, and 79 reasons against future clinical application of GGM. None of the included articles mentioned more than 60/169 reasons. The reasons could be categorized into: (i) quality of life of affected individuals; (ii) safety; (iii) effectiveness; (iv) existence of a clinical need or alternative; (v) costs; (vi) homo sapiens as a species (i.e. relating to effects on our species); (vii) social justice; (viii) potential for misuse; (ix) special interests exercising influence; (x) parental rights and duties; (xi) comparability to acceptable processes; (xii) rights of the unborn child; and (xiii) human life and dignity. Considerations relating to the implementation processes and regulation were reported.

LIMITATIONS, REASONS FOR CAUTION

We cannot ensure completeness as reasons may have been omitted in the reviewed literature and our search was limited to MEDLINE and a 5-year time period.

WIDER IMPLICATIONS OF THE FINDINGS

Besides needing (pre)clinical studies on safety and effectiveness, authors call for a sound pre-implementation process. This overview of reasons may assist a thorough evaluation of the responsible introduction of GGM.

STUDY FUNDING/COMPETING INTEREST(S)

University of Amsterdam, Alliance Grant of the Amsterdam Reproduction and Development Research Institute (I.D.), and Clinical Center, Department of Bioethics, National Institutes of Health Intramural Research Program (S.H.). There are no competing interests.

Trust in Science: CRISPR-Cas9 and the Ban on Human Germline Editing

In 2015 scientists called for a partial ban on genome editing in human germline cells. This call was a response to the rapid development of the CRISPR-Cas9 system, a molecular tool that allows researchers to modify genomic DNA in living organisms with high precision and ease of use. Importantly, the ban was meant to be a trust-building exercise that promises a 'prudent' way forward. The goal of this paper is to analyse whether the ban can deliver on this promise. To do so the focus will be put on the precedent on which the current ban is modelled, namely the Asilomar ban on recombinant DNA technology. The analysis of this case will show (a) that the Asilomar ban was successful because of a specific two-step containment strategy it employed and (b) that this two-step approach is also key to making the current ban work. It will be argued, however, that the Asilomar strategy cannot be transferred to human genome editing and that the current ban therefore fails to deliver on its promise. The paper will close with a reflection on the reasons for this failure and on what can be learned from it about the regulation of novel molecular tools.

Ethical issues in genetic modification and why application matters

Advances in genome editing techniques have generated renewed interest in the ethical implications of genetic modification. In this article, we review the recent literature and discuss in detail ethical issues pertaining to the application of this technology to five areas; human embryo research, organoid research, the prospect of genetically modified babies, mitochondrial replacement therapy and the creation of chimeric organisms. We point to a central issue which cuts through these different areas: the need to clearly frame how using the technology provides benefit that cannot be met by other means. Failure to provide reasonable justification, and address how risks-if any-will be mitigated, is likely to erode public trust and undermine progress in medical research and its clinical translation.

Responsible innovation in human germline gene editing: Background document to the recommendations of ESHG and ESHRE

Technological developments in gene editing raise high expectations for clinical applications, including editing of the germline. The European Society of Human Reproduction and Embryology (ESHRE) and the European Society of Human Genetics (ESHG) together developed a Background document and Recommendations to inform and stimulate ongoing societal debates. This document provides the background to the Recommendations. Germline gene editing is currently not allowed in many countries. This makes clinical applications in these countries impossible now, even if germline gene editing would become safe and effective. What were the arguments behind this legislation, and are they still convincing? If a technique could help to avoid serious genetic disorders, in a safe and effective way, would this be a reason to reconsider earlier standpoints? This Background document summarizes the scientific developments and expectations regarding germline gene editing, legal regulations at the European level, and ethics for three different settings (basic research, preclinical research and clinical applications). In ethical terms, we argue that the deontological objections (e.g., gene editing goes against nature) do not seem convincing while consequentialist objections (e.g., safety for the children thus conceived and following generations) require research, not all of which is allowed in the current legal situation in European countries. Development of this Background document and Recommendations reflects the responsibility to help society understand and debate the full range of possible implications of the new technologies, and to contribute to regulations that are adapted to the dynamics of the field while taking account of ethical considerations and societal concerns.

Responsible innovation in human germline gene editing. Background document to the recommendations of ESHG and ESHRE

Technological developments in gene editing raise high expectations for clinical applications, including editing of the germline. The European Society of Human Reproduction and Embryology (ESHRE) and the European Society of Human Genetics (ESHG) together developed a Background document and Recommendations to inform and stimulate ongoing societal debates. This document provides the background to the Recommendations. Germline gene editing is currently not allowed in many countries. This makes clinical applications in these countries impossible now, even if germline gene editing would become safe and effective. What were the arguments behind this legislation, and are they still convincing? If a technique could help to avoid serious genetic disorders, in a safe and effective way, would this be a reason to reconsider earlier standpoints? This Background document summarizes the scientific developments and expectations regarding germline gene editing, legal regulations at the European level, and ethics for three different settings (basic research, pre-clinical research and clinical applications). In ethical terms, we argue that the deontological objections (e.g. gene editing goes against nature) do not seem convincing while consequentialist objections (e.g. safety for the children thus conceived and following generations) require research, not all of which is allowed in the current legal situation in European countries. Development of this Background document and Recommendations reflects the responsibility to help society understand and debate the full range of possible implications of the new technologies, and to contribute to regulations that are adapted to the dynamics of the field while taking account of ethical considerations and societal concerns.

Parenting in the Age of Preimplantation Gene Editing

Medical science at its core aims to preserve health and eliminate disease, but a common theme in scientific discovery is the application of findings in ways that were not the primary intent. The development of diagnostic modalities to predict the health of resulting children has been a fundamental aim underpinning research into prenatal and preimplantation diagnostic modalities; however, the knowledge gained has in some cases been utilized for nonmedical purposes. As an example, amniocentesis developed to determine whether the pregnancy is chromosomally normal also provides information about the sex of the fetus, which normally does not affect health. The emerging gene-editing technologies that could be used to repair mutated disease-causing genes in an embryo will presumably also be able to be used to alter traits unrelated to disease. And yet, I will argue, the desire to preserve the mystery of reproduction remains a central value in humans' quest to reproduce. This yearning to maintain the mysteries will likely temper the development of strategies to alter our genome and affect the genetic identities of our offspring. In my experience as an obstetrician and reproductive endocrinology and infertility subspecialist, people want to have, not the best possible baby, but rather their own baby.

Genome engineering through CRISPR/Cas9 technology in the human germline and pluripotent stem cells

BACKGROUND

With the recent development of CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 genome editing technology, the possibility to genetically manipulate the human germline (gametes and embryos) has become a distinct technical possibility. Although many technical challenges still need to be overcome in order to achieve adequate efficiency and precision of the technology in human embryos, the path leading to genome editing has never been simpler, more affordable, and widespread.

OBJECTIVE AND RATIONALE

In this narrative review we seek to understand the possible impact of CRISR/Cas9 technology on human reproduction from the technical and ethical point of view, and suggest a course of action for the scientific community.

SEARCH METHODS

This non-systematic review was carried out using Medline articles in English, as well as technical documents from the Human Fertilisation and Embryology Authority and reports in the media. The technical possibilities of the CRISPR/Cas9 technology with regard to human reproduction are analysed based on results obtained in model systems such as large animals and laboratory rodents. Further, the possibility of CRISPR/Cas9 use in the context of human reproduction, to modify embryos, germline cells, and pluripotent stem cells is reviewed based on the authors' expert opinion. Finally, the possible uses and consequences of CRISPR/cas9 gene editing in reproduction are analysed from the ethical point of view.

OUTCOMES

We identify critical technical and ethical issues that should deter from employing CRISPR/Cas9 based technologies in human reproduction until they are clarified.

WIDER IMPLICATIONS

Overcoming the numerous technical limitations currently associated with CRISPR/Cas9 mediated editing of the human germline will depend on intensive research that needs to be transparent and widely disseminated. Rather than a call to a generalized moratorium, or banning, of this type of research, efforts should be placed on establishing an open, international, collaborative and regulated research framework. Equally important, a societal discussion on the risks, benefits, and preferred applications of the new technology, including all relevant stakeholders, is urgently needed and should be promoted, and ultimately guide research priorities in this area.

Genome editing in pluripotent stem cells: research and therapeutic applications

Recent progress in human pluripotent stem cell (hPSC) and genome editing technologies has opened up new avenues for the investigation of human biology in health and disease as well as the development of therapeutic applications. Gene editing approaches with programmable nucleases have been successfully established in hPSCs and applied to study gene function, develop novel animal models and perform genetic and chemical screens. Several studies now show the successful editing of disease-linked alleles in somatic and patient-derived induced pluripotent stem cells (iPSCs) as well as in animal models. Importantly, initial clinical trials have shown the safety of programmable nucleases for ex vivo somatic gene therapy. In this context, the unlimited proliferation potential and the pluripotent properties of iPSCs may offer advantages for gene targeting approaches. However, many technical and safety issues still need to be addressed before genome-edited iPSCs are translated into the clinical setting. Here, we provide an overview of the available genome editing systems and discuss opportunities and perspectives for their application in basic research and clinical practice, with a particular focus on hPSC based research and gene therapy approaches. Finally, we discuss recent research on human germline genome editing and its social and ethical implications.