International regulatory landscape and integration of corrective genome editing into in vitro fertilization

Methyl β-Cyclodextrin-sperm-mediated gene editing (MBCD-SMGE): a simple and efficient method for targeted mutant mouse production

BACKGROUND

Generating targeted mutant mice is a crucial technology in biomedical research. This study focuses on optimizing the CRISPR/Cas9 system uptake into sperm cells using the methyl β-cyclodextrin-sperm-mediated gene transfer (MBCD-SMGT) technique to generate targeted mutant blastocysts and mice efficiently. Additionally, the present study elucidates the roles of cholesterol and reactive oxygen species (ROS) in the exogenous DNA uptake by sperm.

RESULTS

In this study, B6D2F1 mouse sperm were incubated in the c-TYH medium with different concentrations of MBCD (0, 0.75, 1, and 2 mM) in the presence of 20 ng/µl pCAG-eCas9-GFP-U6-gRNA (pgRNA-Cas9) for 30 min. Functional parameters, extracellular ROS, and the copy numbers of internalized plasmid per sperm cell were evaluated. Subsequently, in vitro fertilization (IVF) was performed and fertilization rate, early embryonic development, and transfection rate were assessed. Finally, our study investigated the potential of the MBCD-SMGT technique in combination with the CRISPR-Cas9 system, referred to as MBCD-SMGE (MBCD-sperm-mediated gene editing), for generating targeted mutant blastocysts and mice. Results indicated that cholesterol removal from the sperm membrane using MBCD resulted in a premature acrosomal reaction, an increase in extracellular ROS levels, and a dose-dependent influence on the copy numbers of the internalized plasmids per sperm cell. Moreover, the MBCD-SMGT technique led to a larger population of transfected motile sperm and a higher production rate of GFP-positive blastocysts. Additionally, the current study validated the targeted indel in blastocyst and mouse derived from MBCD-SMGE technique.

CONCLUSION

Overall, this study highlights the significant potential of the MBCD-SMGE technique for generating targeted mutant mice. It holds enormous promise for modeling human diseases and improving desirable traits in animals.

Antioxidant effects of Bifidobacterium longum T37a in mice weight loss and aging model induced by D-galactose

BACKGROUND

Probiotics can reduce free radical scavenging rate and oxidative damage, and improve activity of crucial antioxidative enzymes in host cells. This study aimed to isolate Bifidobacterium spp. from faeces of babies, and investigate the antioxidant effects of the Bif. longum T37a in mice weight loss and aging model induced by D-galactose.

RESULTS

T37a have good antioxidant properties in the DPPH assay and anti-lipid peroxidation test. Compared with the model group, T37a low group significantly increased the thymus index and the levels of T-AOC and GSH-Px of mice. T37a high group significantly decreased the spleen and liver index of mice and the levels of MDA in liver, significantly increased in liver HDL-C levels, and decreased LDL-C in liver.

CONCLUSIONS

T37a may be an anti-aging and weight-loss probiotics for its antioxidant capacity, and it is necessary to study further the molecular mechanism of T37a as antioxidant.

Maternal spindle transfer for mitochondrial disease: lessons to be learnt before extending the method to other conditions?

Mitochondrial diseases are a group of conditions attributed to mutations of specific genes that regulate mitochondrial function. Maternal spindle transfer (MST) has been proposed as a method to prevent the transmission of these diseases and utilisation of the technique resulted in the birth of a baby free of disease in 2017 in Mexico. Potential flaws in research governance and the associated criticism emerged from the expansion of MST to provide a potentially new assisted reproductive technique to overcome infertility problems characterised by repeated in vitro embryo development arrest caused by mitochondrial dysfunction and cytoplasmic deficiencies of the oocyte. This applied technique represents a good example of the need to strike "a balance between taking appropriate precautions and hampering innovation". The purpose of this article is to explore, through a comprehensive literature search, whether and how this process can evolve from an experimental method to treat a medical condition to a standard of care solution for certain types of infertility. We argue that a number of key issues should be considered before applying the technique more broadly. These include regulatory oversight, safety and efficacy, cost, implications for research, essential laboratory skills and oversight, as well as the care needs of patients and egg donors.

An explainable deep learning-based algorithm with an attention mechanism for predicting the live birth potential of mouse embryos

In assisted reproductive technology (ART), embryos produced by in vitro fertilization (IVF) are graded according to their live birth potential, and high-grade embryos are preferentially transplanted. However, rates of live birth following clinical ART remain low worldwide. Grading is based on the embryo shape at a limited number of stages and does not consider the shape of embryos and intracellular structures, e.g., nuclei, at various stages important for normal embryogenesis. Here, we developed a Normalized Multi-View Attention Network (NVAN) that directly predicts live birth potential from the nuclear structure in live-cell fluorescence images of mouse embryos from zygote to across a wide range of stages. The input is morphological features of cell nuclei, which were extracted as multivariate time-series data by using the segmentation algorithm for mouse embryos. The classification accuracy of our method (83.87%) greatly exceeded that of existing machine-learning methods and that of visual inspection by embryo culture specialists. Our method also has a new attention mechanism that allows us to determine which values of multivariate time-series data, used to describe nuclear morphology, were the basis for the prediction. By visualizing the features that contributed most to the prediction of live birth potential, we found that the size and shape of the nucleus at the morula stage and at the time of cell division were important for live birth prediction. We anticipate that our method will help ART and developmental engineering as a new basic technology for IVF embryo selection.

A comprehensive overview of CRISPR/Cas 9 technology and application thereof in drug discovery

Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-Cas technology possesses revolutionary potential to positively affect various domains of drug discovery. It has initiated a rise in the area of genetic engineering and its advantages range from classical science to translational medicine. These genome editing systems have given a new dimension to our capabilities to alter, detect and annotate specified gene sequences. Moreover, the ease, robustness and adaptability of the CRISPR/Cas9 technology have led to its extensive utilization in research areas in such a short period of time. The applications include the development of model cell lines, understanding disease mechanisms, discovering disease targets, developing transgenic animals and plants, and transcriptional modulation. Further, the technology is rapidly growing; hence, an overlook of progressive success is crucial. This review presents the current status of the CRISPR-Cas technology in a tailor-made format from its discovery to several advancements for drug discovery alongwith future trends associated with possibilities and hurdles including ethical concerns.

CRISPR/Cas-Based Gene Editing Strategies for DOCK8 Immunodeficiency Syndrome

Defects in the DOCK8 gene causes combined immunodeficiency termed DOCK8 immunodeficiency syndrome (DIDS). DIDS previously belonged to the disease category of autosomal recessive hyper IgE syndrome (AR-HIES) but is now classified as a combined immunodeficiency (CID). This genetic disorder induces early onset of susceptibility to severe recurrent viral and bacterial infections, atopic diseases and malignancy resulting in high morbidity and mortality. This pathological state arises from impairment of actin polymerization and cytoskeletal rearrangement, which induces improper immune cell migration-, survival-, and effector functions. Owing to the severity of the disease, early allogenic hematopoietic stem cell transplantation is recommended even though it is associated with risk of unintended adverse effects, the need for compatible donors, and high expenses. So far, no alternative therapies have been developed, but the monogenic recessive nature of the disease suggests that gene therapy may be applied. The advent of the CRISPR/Cas gene editing system heralds a new era of possibilities in precision gene therapy, and positive results from clinical trials have already suggested that the tool may provide definitive cures for several genetic disorders. Here, we discuss the potential application of different CRISPR/Cas-mediated genetic therapies to correct the DOCK8 gene. Our findings encourage the pursuit of CRISPR/Cas-based gene editing approaches, which may constitute more precise, affordable, and low-risk definitive treatment options for DOCK8 deficiency.

Strategies to overcome the main challenges of the use of CRISPR/Cas9 as a replacement for cancer therapy

CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats-associated protein 9) shows the opportunity to treat a diverse array of untreated various genetic and complicated disorders. Therapeutic genome editing processes that target disease-causing genes or mutant genes have been greatly accelerated in recent years as a consequence of improvements in sequence-specific nuclease technology. However, the therapeutic promise of genome editing has yet to be explored entirely, many challenges persist that increase the risk of further mutations. Here, we highlighted the main challenges facing CRISPR/Cas9-based treatments and proposed strategies to overcome these limitations, for further enhancing this revolutionary novel therapeutics to improve long-term treatment outcome human health.

Human Germline Gene Editing from Maslahah Perspective: The Case of the World's First Gene Edited Babies

This paper describes maslahah, a fundamental concept in Islam and its application in deliberating permissibility of human germline gene editing from an Islamic perspective. This paper refers to He Jiankui's research that led to the birth of the world's first gene edited babies, who were edited to be protected from HIV. The objective, procedure, and output of the research were assessed against the conditions of maslahah. It can be concluded that the experiment did not meet the conditions; it is inconsistent with the objectives of shariah (maqasid al-shariah) and some fundamental Islamic teachings that it did not preserve greater benefit, hence it could be considered impermissible.

Before and after the Chinese gene-edited human babies: Multiple discourses of gene editing on social media

This study examines discourses in Chinese online discussions of gene editing by multiple social actors on Weibo before and after a significant scientific crisis, the 2018 scandal of Chinese gene-edited human babies. A content analysis of 2074 posts was done to identify frames, emotions, and metaphors. Findings reveal that Chinese social media have opened up new spaces for multiple social actors to generate multiple discourses. This has resulted in a more participatory public engagement with science and technology on Chinese social media, potentially influencing the online agenda and policy decisions on science and technology. Finally, findings indicate that a scientific crisis can serve as a trigger for significant changes in public attitudes and opinions regarding gene editing.

Procreative Non-Maleficence: A South African Human Rights Perspective on Heritable Human Genome Editing

If the safety and efficacy issues relating to heritable genome editing can be resolved, how should liberal democratic societies regulate the use of this technology by prospective parents who wish to effect edits to the genomes of their prospective children? We suggest that recent developments in South African law can be useful in this regard. The country's apex court recently recognized as a legal principle that the scope of possible reproductive decisions that parents may make when using new reproductive technologies excludes decisions that will cause harm to the prospective child—the principle of procreative non-maleficence. We suggest that the principle of procreative non-maleficence provides a mechanism for striking an equitable balance between two competing interests that are given legal recognition in most liberal democracies: the reproductive rights of prospective parents and the state's duty to protect child welfare.

Setting ethical limits on human gene editing after the fall of the somatic/germline barrier

The ethical debate about what is now called human gene editing (HGE) has gone on for more than 50 y. For nearly that entire time, there has been consensus that a moral divide exists between somatic and germline HGE. Conceptualizing this divide as a barrier on a slippery slope, in this paper, I first describe the slope, what makes it slippery, and describe strong barriers that arrest the slippage down to the dystopian bottom of pervasive eugenic enhancement. I then show how the somatic/germline barrier in the debate has been weakened to the level of ineffectiveness, with no replacement below. I examine a number of possible barriers on the slope below the somatic/germline barrier, most of which lack sufficient strength. With the exception of the minority of people in the HGE debate who see the eugenic society as utopia, the majority will need a barrier on the slope to stop the slide to dystopia.

Global Governance of Human Genome Editing: What Are the Rules?

Human gene editing, particularly using the new CRISPR/Cas9 technology, will greatly increase the capability to make precise changes to human genomes. Human gene editing can be broken into four major categories: somatic therapy, heritable gene editing, genetic enhancement, and basic and applied research. Somatic therapy is generally well governed by national regulatory systems, so the need for global governance is less urgent. All nations are in agreement that heritable gene editing should not proceed at this time, but there is likely to be divergence if and when such procedures are shown to be safe and effective. Gene editing for enhancement purposes is not feasible today but is more controversial with the public, and many nations do not have well-developed regulatory systems for addressing genetic enhancement. Finally, different nations treat research with human embryos very differently based on deeply embedded social, cultural, ethical, and legal traditions. Several international governance mechanisms are currently in operation for human gene editing, and several other governance mechanisms have been proposed. It is unlikely that any single mechanism will alone be effective for governing human gene editing; rather, a polycentric or ecosystem approach that includes several overlapping and interacting components is likely to be necessary.

Why human germline genome editing is incompatible with equality in an inclusive society

Human germline genome editing is increasingly being seen as acceptable provided certain conditions are satisfied. Accordingly, genetic modifications would take place on eggs or sperm (or their precursor cells) as well as very early embryos for the purpose of bringing children into existence with or without particular genetic traits. In this context, a number of already discussed and separate arguments, such as the (1) synecdoche, (2) non-identity (3) inherent equality and (4) expressivist arguments, can be brought together in the new context of examining, from an ethical perspective, some of the possible consequences of such germline genome editing. In so doing, it becomes clear that these novel procedures are incompatible with the concept of equality in value and in worth of all human beings in a genuinely inclusive society. Such equality is expressed in Article 1 of the United Nations' Universal Declaration of Human Rights which states that: 'All human beings are born … equal in dignity and rights.'

Future of Health Services: The Role of Physicians in the Disruptive Era

This article aimed to address the role of physicians in future health in the disruptive era. Physicians in this disruptive era must increase their capability and knowledge to compensate for this development. Advances in technology increase the impact on health care and the significance of disruption. Disruptive innovation encompasses several fields, such as physics, digital, and biology. Big data as one of the most important parts in clinical aspects encompass high-throughput cellular and protein-binding assays toward chemoinformatic-driven databases. Health status can be modified by changing epigenetic factor, such as lifestyle and environment. As a result, they affect human genetics and provide the insight of pathophysiology of disease, clinical treatment, and early preventive action. Disruptive innovations in health-care align with the development of artificial intelligence, machine learning, robotics, Internet of things, digitalization, and genomics. New paradigm shifting in physician–patient relationships is relevant to consumer health informatics.

Human genome editing: how to prevent rogue actors

BACKGROUND

Human genome editing technologies offer much potential benefit. However, central to any conversation relating to the application of such technologies are certain ethical, legal, and social difficulties around their application. The recent misuse, or inappropriate use, by certain Chinese actors of the application of genome editing technologies has been, of late, well noted and described. Consequently, caution is expressed by various policy experts, scientists, bioethicists, and members of the public with regard to the appropriate use of human germline genome editing and its possible future effect on future generations.

MAIN TEXT

As concerns about the applications of heritable genome editing have grown, so too have the questions around what is to be done to curtail 'rogue actors'. This paper explores various ways in which to regulate genomic editing that are socially beneficial, while being cognisant of legal and ethical principles and rights values. This is done by evolving regulatory frameworks across jurisdictions in an attempt to raise issues, address common principles, and set responsible standards for stewardship of the novel technology.

CONCLUSIONS

It is suggested that robust and concrete regulatory measures be introduced that are culturally and contextually sensitive, inclusive, appropriate, and trustworthy - and are based on public empowerment and human rights objectives. Doing so will ensure that we are perfectly positioned to harness and promote the benefits that novel technologies have to offer, while safeguarding public health and curtailing the ambitions of rogue actors. This it is acknowledged is no easy task, so, as a point of departure, this paper sets out a path forward by means of certain, practical recommendations - by constructing genome editing regulation in a manner that both fulfils the desire to better progress human health and that can withstand legal and ethical scrutiny. The following observations and recommendations are made: Firstly, that a solution of effective, legitimate governance should consist of a combination of national and supranational legislative regulation or 'hard' law, in combination with 'soft' ethics, firmly anchored in and underpinned by human rights values. Second, that efforts to support legal and ethical solutions should be rigorous, practical, and robust, contribute to a reaffirmation of human rights in a contextually sensitive manner, and be transnational in reach. Lastly, that greater harmonisation across jurisdictions and increased public engagement be sought. This it is proposed will address the question of how to implement a normative framework which in turn can prevent future rogue actors.

Attitudes of Members of Genetics Professional Societies Toward Human Gene Editing

Gene-editing technologies have improved in ease, efficiency, and precision. Although discussions are occurring around acceptable uses of human gene editing, limited data exist on the views of genetics-trained individuals. In 2017, we distributed an anonymous online survey to assess the attitudes of members of genetics professional societies toward gene editing (N = 500). Virtually all respondents were supportive of somatic editing in basic-science (99.2%) and clinical (87.4%) research on nonreproductive human cells. Only 57.2% were supportive of germline-editing basic-science research; 31.9% supported the transfer of viable embryos to humans for clinical research. While most favored future therapeutic uses of somatic (96.6%) and germline (77.8%) editing, there was little support for enhancement in somatic (13.0%) or germline (8.6%) cells. This study describes attitudes toward gene editing from genetics professionals worldwide and contributes to ongoing discourse and policy guidance in this domain.

Legal reflections on the case of genome-edited babies

Human genome-editing is banned by guidelines, laws and regulations in most countries. However, the first criminal case on genome-edited babies was sentenced in China in 2019. In this commentary we discuss our legal reflections on this case. Genome-editing on healthy embryos of human may lead to irreversible mutations and serious consequences on the heredity of future generations, while its long-term safety is unpredictable. A full set of laws, regulations along with the guidelines should be formulated to penalize genome-editing behaviors and prevent similar negative events in the future. More effective and binding mechanisms should be constructed and implemented among different countries. A collaborative network should be strengthened for better global registry and surveillance of human genome-editing technologies and research.

Ethical issues related to research on genome editing in human embryos

Although the potential advantages of clinical germline genome editing (GGE) over currently available methods are limited, the implementation of GGE in the clinic has been proposed and discussed. Ethical issues related to such an application have been extensively debated, meanwhile, seemingly less attention has been paid to ethical implications of studies which would have to be conducted in order to evaluate potential clinical uses of GGE. In this article, we first provide an overview of the debate on potential clinical uses of GGE. Then, we discuss questions and ethical issues related to the studies relevant to evaluation of potential clinical uses of GGE. In particular, we describe the problems related to the acceptable safety threshold, current technical hurdles in human GGE, the destruction of human embryos used in the experiments, involvement of egg donors, and genomic sequencing performed on the samples of the research participants. The technical and ethical problems related to studies on GGE should be acknowledged and carefully considered in the process of deciding to apply technology in such a way that will provide benefits and minimize harms.

Genetically Modified Babies and a First Application of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR-Cas9)

The world's first babies with CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats)-edited genes were born on November 25, 2018. Dr. Jiankui He of Southern University of Science and Technology in Shenzhen performed this gene editing. Dr. He's objectives and an assessment of how well they were achieved are discussed in the context of existing research in this area.

Germline Genome Editing Research: What Are Gamete Donors (Not) Informed About in Consent Forms?

The potential for using germline genome editing (GGE) in humans has garnered a lot of attention, both for its scientific possibilities as well as for the ethical, legal, and social challenges it ignites. The ethical debate has focused primarily on the suggestions of using GGE to establish a pregnancy (i.e., to offer it in a clinical setting), which is, to date, illegal in many jurisdictions. The use of GGE in research (where a pregnancy would not be established) has received much less attention, despite the fact that it raises serious ethical and social issues as well. Herein, we report on the analysis of informed consent forms for egg and sperm donation used in a widely publicized study where genome editing was used to correct a disease-causing genetic mutation in human embryos. Importantly, embryos were created using eggs and sperm obtained specifically for these experiments. The analysis indicates deficiencies in how the forms addressed various issues, including limited and potentially misleading information about the sensitive nature of the study, the lack of an explicit mention of genomic sequencing, as well as the poor readability of the forms. Furthermore, the arguably high compensation of U.S.$5,000 for egg donors raises questions about undue inducement to participate in research. Moreover, since the procurement of eggs involves serious health risks, it may be questioned whether research requiring such a procedure should be pursued. If such experiments are continued, donors should be informed about all relevant aspects in order to make informed decisions about participating.

Is selecting better than modifying? An investigation of arguments against germline gene editing as compared to preimplantation genetic diagnosis

BACKGROUND

Recent scientific advances in the field of gene editing have led to a renewed discussion on the moral acceptability of human germline modifications. Gene editing methods can be used on human embryos and gametes in order to change DNA sequences that are associated with diseases. Modifying the human germline, however, is currently illegal in many countries but has been suggested as a 'last resort' option in some reports. In contrast, preimplantation genetic (PGD) diagnosis is now a well-established practice within reproductive medicine. Both methods can be used to prevent children from being born with severe genetic diseases.

MAIN TEXT

This paper focuses on four moral concerns raised in the debate about germline gene editing (GGE) and applies them to the practice of PGD for comparison: Violation of human dignity, disrespect of the autonomy and the physical integrity of the future child, discrimination of people living with a disability and the fear of slippery slope towards immoral usage of the technology, e.g. designing children for specific third party interests. Our analysis did not reveal any fundamental differences with regard to the four concerns.

CONCLUSION

We argue that with regard to the four arguments analyzed in this paper germline gene editing should be considered morally (at least) as acceptable as the selection of genomes on the basis of PGD. However, we also argue that any application of GGE in reproductive medicine should be put on hold until thorough and comprehensive laws have been implemented to prevent the abuse of GGE for non-medical enhancement.

Societal and Ethical Impacts of Germline Genome Editing: How Can We Secure Human Rights?

Genome editing has opened up the possibility of heritable alteration of the human germline. The potential of this powerful tool has spurred a call for establishing robust regulatory frameworks to outline permissible uses of genome editing and to map a rational and ethical course. In response, major national scientific bodies and international organizations have convened and released comprehensive reports outlining recommendations for ethical regulatory frameworks. Significantly, these include an emphasis on public participation and the development of principles to guide future applications of genome editing. While essential, public input and principles are not sufficient to ensure ethical uses of this technology. We propose an approach that relies not only on agreed-upon principles and a democratic process but requires a Human Rights Impact Assessment to evaluate the potential burdens that such biomedical interventions may place on human rights.

Heritable Genome Editing in a Global Context: National and International Policy Challenges

A central problem for the international governance of heritable germline gene editing is that there are important differences in attitudes and values as well as ethical and health care considerations around the world. These differences are reflected in a complicated and diverse regulatory landscape. Several publications have discussed whether reproductive uses would be legally permissible in individual countries and whether clinical applications could emerge in the context of regulatory gaps and gray areas. Systematic comparative studies that explore issues related to the governance of this technology from different national and international perspectives are needed to address the lack of knowledge in this area. In this research report, we contribute to filling this gap by presenting views of stakeholders in the United Kingdom on challenges to the governance of heritable genome editing. We present findings from a multistakeholder study conducted in the United Kingdom between October 2016 and January 2018 and funded by the Wellcome Trust. This research included interviews, literature analysis, and a workshop. We involved leading U.K. scientists, in vitro fertilization clinicians, and representatives from regulatory bodies, patient organizations, and other civil societal organizations, as well as fertility companies. Part one of this article explores stakeholder perceptions of possible global developments in heritable genome editing and associated risks and governance challenges. Part two presents a range of policy options that were generated during the workshop in relation to the challenges discussed in part one.

Gene editing of stem cells for kidney disease modelling and therapeutic intervention

Recent developments in targeted gene editing have paved the way for the wide adoption of clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein-9 nucleases (Cas9) as an RNA-guided molecular tool to modify the genome of eukaryotic cells of animals. Theoretically, the translation of CRISPR-Cas9 can be applied to the treatment of inherited or acquired kidney disease, kidney transplantation and genetic corrections of somatic cells from kidneys with inherited mutations, such as polycystic kidney disease. Human pluripotent stem cells have been used to generate an unlimited source of kidney progenitor cells or, when spontaneously differentiated into three-dimensional kidney organoids, to model kidney organogenesis or the pathogenesis of disease. Gene editing now allows for the tagging and selection of specific kidney cell types or disease-specific gene knock in/out, which enables more precise understanding of kidney organogenesis and genetic diseases. This review discusses the mechanisms of action, in addition to the advantages and disadvantages, of the three major gene editing technologies, namely, CRISPR-Cas9, zinc finger nucleases and transcription activator-like effector nucleases. The implications of using gene editing to better understand kidney disease is reviewed in detail. In addition, the ethical issues of gene editing, which could be easily neglected in the modern, fast-paced research environment, are highlighted.

Efficiency Optimization of CRISPR/Cas9-Mediated Targeted Mutagenesis in Grape

Clustered regularly interspersed short palindromic repeats (CRISPR)/Cas system is an efficient targeted genome editing method. Although CRISPR/Cas9-mediated mutagenesis has been applied successfully in grape, few studies have examined the technique's efficiency. To optimize CRISPR/Cas9 editing efficiency in Vitis vinifera, we surveyed three key parameters: GC content of single guide RNA (sgRNA), variety of transformant cells used, and SpCas9 expression levels in transgenic cell mass. Four sgRNAs with differing GC content were designed to target exon sites of the V. vinifera phytoene desaturase gene. Suspension cells of 'Chardonnay' and '41B' varieties were used as the transgenic cell mass. Both T7EI and PCR/RE assays showed that CRISPR/Cas9 editing efficiency increases proportionally with sgRNA GC content with 65% GC content yielding highest editing efficiency in both varieties. Additionally, gene editing was more efficient in '41B' than in 'Chardonnay.' CRISPR/Cas9 systems with different editing efficiency showed different SpCas9 expression level, but compared with GC content of sgRNA, SpCas9 expression level has less influence on editing efficiency. Taken together, these results help optimize of CRISPR/Cas9 performance in grape.

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.

Germline Modification and Policymaking: The Relationship between Mitochondrial Replacement and Gene Editing

'Mitochondrial replacement' and 'germline gene editing' are relatively new techniques that represent a significant moral, technological, and legal threshold, as they would introduce permanent and heritable changes to the human gene pool. This article examines the close relationship between these two technologies over time, considering what regulatory lessons can be learned from the former as attention turns to the latter. It argues that the UK's 'mitochondrial replacement' approval process should not be taken as a model for the wider regulation of germline gene editing, and that policy-making needs to contend with a comprehensive picture of the social and political meaning of these technologies in the world.

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.

Chimeric Antigen Receptor T Cells: Extending Translation from Liquid to Solid Tumors

Successful translation of chimeric antigen receptor (CAR) T cells designed to target and eradicate CD19+ lymphomas has emboldened scientists and physicians worldwide to explore the possibility of applying CAR T-cell technology to other tumor entities, including solid tumors. Next-generation strategies such as fourth-generation CARs (CAR T cells redirected for universal cytokine killing, also known as TRUCKs) designed to deliver immunomodulatory cytokines to the tumor microenvironment, dual CAR designs to improve tumor control, inclusion of suicide genes as safety switches, and precision genome editing are currently being investigated. One major ongoing goal is to determine how best to generate CAR T cells that modulate the tumor microenvironment, overcome tumor survival mechanisms, and thus allow broader applicability as universal allogeneic T-cell therapeutics. Development of state-of-the-art and beyond viral vector systems to deliver designer CARs coupled with targeted genome editing is expected to generate more effective off-the-shelf CAR T cells with activity against a greater number of cancer types and importantly solid tumors.

Deliverable transgenics & gene therapy possibilities for the testes

Male infertility and hypogonadism are clinically prevalent conditions with a high socioeconomic burden and are both linked to an increased risk in cardiovascular-metabolic diseases and earlier mortality. Therefore, there is an urgent need to better understand the causes and develop new treatments for these conditions that affect millions of men. The accelerating advancement in gene editing and delivery technologies promises improvements in both diagnosis as well as affording the opportunity to develop bespoke treatment options which would both prove beneficial for the millions of individuals afflicted with these reproductive disorders. In this review, we summarise the systems developed and utilised for the delivery of gene therapy and discuss how each of these systems could be applied for the development of a gene therapy system in the testis and how they could be of use for the future diagnosis and repair of common male reproductive disorders.

Genome editing and assisted reproduction: curing embryos, society or prospective parents?

This paper explores the ethics of introducing genome-editing technologies as a new reproductive option. In particular, it focuses on whether genome editing can be considered a morally valuable alternative to preimplantation genetic diagnosis (PGD). Two arguments against the use of genome editing in reproduction are analysed, namely safety concerns and germline modification. These arguments are then contrasted with arguments in favour of genome editing, in particular with the argument of the child's welfare and the argument of parental reproductive autonomy. In addition to these two arguments, genome editing could be considered as a worthy alternative to PGD as it may not be subjected to some of the moral critiques moved against this technology. Even if these arguments offer sound reasons in favour of introducing genome editing as a new reproductive option, I conclude that these benefits should be balanced against other considerations. More specifically, I maintain that concerns regarding the equality of access to assisted reproduction and the allocation of scarce resources should be addressed prior to the adoption of genome editing as a new reproductive option.

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.

Everything in moderation, even hype: learning from vaccine controversies to strike a balance with CRISPR

The ease and applicability of CRISPR/Cas9--a new and precise gene editing and reproductive technology--have garnered hype and heightened concern about its potential 'unprecedented and horrific consequences' and have led many scientific leaders to call for a moratorium on its research and use. CRISPR appears distinctly more controversial than previous technological innovations (genetic or otherwise), with a greater reach and speed of human treatment and enhancement; however, we have seen similarly inflated hopes and fears in response to other medical innovations for well over a century. One intervention that has both historically and recently incited alarm--vaccines--serves as a pertinent example of what could go wrong if a technology's reach is shortened due to inflated fears. By comparing the vaccine controversy and the CRISPR debate, we can help separate the hype from the realistic potential of these technologies. How our society grapples with such innovations will determine the extent to which their impact on our individual and collective health will be beneficial. We must recognise the need for a tempered approach to CRISPR conversation leading to regulation and ethical application. Although CRISPR's reach will continue expanding with ongoing research, thus requiring continuous evaluation, the lessons we have learned from the vaccine controversy demonstrate that our approach must not be to shut down regulation and application now, but to thoughtfully conjoin productive debate and action so that therapeutic gene editing can alleviate suffering as soon as possible without precipitating social outcomes we would belatedly deplore.

Mitochondrial Replacement Techniques: Divergence in Global Policy

In 2015, the UK became the first country permitting the clinical application of mitochondrial replacement techniques (MRT). Here, we explore how MRT have led to diverging international policy. In response, we recommend focused regulatory efforts coupled with United Nations (UN) leadership to build international consensus on the future of MRT.

Genetic affinity and the right to 'three-parent IVF'

With the recent report of a live birth after use of mitochondrial replacement therapy, sometimes called 'three-parent IVF', the clinical application of the technique is fast becoming a reality. While the United Kingdom allows the procedure under regulatory scrutiny, it remains effectively outlawed in many other countries. We argue that such prohibitions may violate individuals' procreative rights, grounded in individuals' interest in genetic affinity. The interest in genetic affinity was recently endorsed by Singapore's highest court, reflecting an emphasis on the importance of biological ties found across the globe. We apply that reasoning to make the case for a right to 'three-parent IVF'.

Legal issues regarding gene editing at the beginning of life: an EU perspective

The development of clustered regularly interspaced short palindromic repeats (CRISPR)–Cas gene-modification technologies has opened impressive possibilities for the biomedical sciences. However, their application to human embryos and early fetuses has raised huge ethical and legal discussions because it affects the human germline. This paper provides a critical and in-depth analysis of the current legal framework on this topic in the EU context and at the national level in the member states. It also offers an alternative interpretation of the regulation, so as to help researchers, practitioners, policy makers and society as a whole to find efficient responses to challenges that cannot wait for a legally updated answer. As a final result, this paper will show that eugenic uses of CRISP–Cas and any kind of modification intended to alter the human germ line are generally banned in the EU context, while basic research on human embryos is mostly permitted. The legal status of therapeutic applications of CRISPR–Cas on early fetuses, however, has not been adequately addressed by the EU zone regulation.

Human Germline Genome Editing

With CRISPR/Cas9 and other genome-editing technologies, successful somatic and germline genome editing are becoming feasible. To respond, an American Society of Human Genetics (ASHG) workgroup developed this position statement, which was approved by the ASHG Board in March 2017. The workgroup included representatives from the UK Association of Genetic Nurses and Counsellors, Canadian Association of Genetic Counsellors, International Genetic Epidemiology Society, and US National Society of Genetic Counselors. These groups, as well as the American Society for Reproductive Medicine, Asia Pacific Society of Human Genetics, British Society for Genetic Medicine, Human Genetics Society of Australasia, Professional Society of Genetic Counselors in Asia, and Southern African Society for Human Genetics, endorsed the final statement. The statement includes the following positions. (1) At this time, given the nature and number of unanswered scientific, ethical, and policy questions, it is inappropriate to perform germline gene editing that culminates in human pregnancy. (2) Currently, there is no reason to prohibit in vitro germline genome editing on human embryos and gametes, with appropriate oversight and consent from donors, to facilitate research on the possible future clinical applications of gene editing. There should be no prohibition on making public funds available to support this research. (3) Future clinical application of human germline genome editing should not proceed unless, at a minimum, there is (a) a compelling medical rationale, (b) an evidence base that supports its clinical use, (c) an ethical justification, and (d) a transparent public process to solicit and incorporate stakeholder input.

Therapeutic gene editing: delivery and regulatory perspectives

Gene-editing technology is an emerging therapeutic modality for manipulating the eukaryotic genome by using target-sequence-specific engineered nucleases. Because of the exceptional advantages that gene-editing technology offers in facilitating the accurate correction of sequences in a genome, gene editing-based therapy is being aggressively developed as a next-generation therapeutic approach to treat a wide range of diseases. However, strategies for precise engineering and delivery of gene-editing nucleases, including zinc finger nucleases, transcription activator-like effector nuclease, and CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats-associated nuclease Cas9), present major obstacles to the development of gene-editing therapies, as with other gene-targeting therapeutics. Currently, viral and non-viral vectors are being studied for the delivery of these nucleases into cells in the form of DNA, mRNA, or proteins. Clinical trials are already ongoing, and in vivo studies are actively investigating the applicability of CRISPR/Cas9 techniques. However, the concept of correcting the genome poses major concerns from a regulatory perspective, especially in terms of safety. This review addresses current research trends and delivery strategies for gene editing-based therapeutics in non-clinical and clinical settings and considers the associated regulatory issues.