Human Genome Editing and Ethical Considerations

The role of zygotic genome activation in genetic-related reproductive medicine: Technological perspective, religious and bioethical concerns, challenges and benefits

Zygotic Genome Activation (ZGA) is a crucial developmental milestone in early embryogenesis, marking the transition from maternal to embryonic control of development. This process, which varies in timing across species, involves the activation of the embryonic genome, paving the way for subsequent cell differentiation and organismal development. Recent advances in genomics and reproductive medicine have highlighted the potential of ZGA in the realm of genetic screening, providing a window into the genetic integrity of the developing embryo at its earliest stages. The intersection of ZGA and genetic screening primarily emerges in the context of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS). These techniques, often employed during assisted reproductive technologies, aim to detect potential genetic abnormalities or chromosomal imbalances before embryo implantation. Given that ZGA represents the onset of embryonic gene expression, understanding its intricacies can significantly enhance the accuracy and predictive power of these screening processes. With the advent of next-generation sequencing and other high-throughput genomic techniques, detailed mapping of the transcriptomic changes during ZGA has become feasible. Such advancements have deepened our insights into the dynamics of early embryonic development and the onset of genetic disorders. As our knowledge in this realm expands, it promises to revolutionize our capabilities in detecting, understanding, and potentially rectifying genetic anomalies at the earliest stages of human life, thereby optimizing reproductive outcomes.

Therapeutic Potential of CRISPR/Cas in Hashimoto's Thyroiditis: A Comprehensive Review

Hashimoto's thyroiditis (HT) is a commonly occurring illness of autoimmune endocrine origin. It is usually present in the pediatric age group along with other well-known diseases, such as type 1 insulin-dependent diabetes. The defining feature of this disease is the immune-- mediated attack on the thyroid gland resulting in the destruction of thyroid tissues and cells. Given that HT frequently affects family members, it is well-recognized that individuals are genetically predisposed to this disease. Patients with HT also display a significantly increased risk for several different cancers, justifying the eminent need for the development of therapies for managing and treating HT. Gene editing has made several advancements in the field of molecular biology and has turned out to become a promising approach to correct several autoimmune diseases. Currently, CRISPR/Cas, a nuclease-based editing technique, is publicized as a promising tool for curing several genetic diseases and cancers. However, very limited research has been conducted as of now on autoimmune disease management and cure via CRISPR/Cas technique. This review provides an account of the potential candidate genes associated with Hashimoto's thyroiditis, and only a few animal and human models have been generated via the CRISPR/Cas gene editing technique. Mouse models of autoimmune thyroiditis generated through the CRISPR/Cas gene editing technique by targeting the candidate genes will provide us with a deeper insight into the pathophysiology of HT and further pave the way for the immunomodulation of HT via 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.

Examining cultural structures and functions in biology

Scientific culture and structure organize biological sciences in many ways. We make choices concerning the systems and questions we study. Our research then amplifies these choices into factors that influence the directions of future research by shaping our hypotheses, data analyses, interpretation, publication venues, and dissemination via other methods. But our choices are shaped by more than objective curiosity-we are influenced by cultural paradigms reinforced by societal upbringing and scientific indoctrination during training. This extends to the systems and data that we consider to be ethically obtainable or available for study, and who is considered qualified to do research, ask questions, and communicate about research. It is also influenced by the profitability of concepts like open-access-a system designed to improve equity, but which enacts gatekeeping in unintended but foreseeable ways. Creating truly integrative biology programs will require more than intentionally developing departments or institutes that allow overlapping expertise in two or more subfields of biology. Interdisciplinary work requires the expertise of large and diverse teams of scientists working together-this is impossible without an authentic commitment to addressing, not denying, racism when practiced by individuals, institutions, and cultural aspects of academic science. We have identified starting points for remedying how our field has discouraged and caused harm, but we acknowledge there is a long path forward. This path must be paved with field-wide solutions and institutional buy-in: our solutions must match the scale of the problem. Together, we can integrate-not reintegrate-the nuances of biology into our field.

CRISPR-Cas and Its Wide-Ranging Applications: From Human Genome Editing to Environmental Implications, Technical Limitations, Hazards and Bioethical Issues

The CRISPR-Cas system is a powerful tool for in vivo editing the genome of most organisms, including man. During the years this technique has been applied in several fields, such as agriculture for crop upgrade and breeding including the creation of allergy-free foods, for eradicating pests, for the improvement of animal breeds, in the industry of bio-fuels and it can even be used as a basis for a cell-based recording apparatus. Possible applications in human health include the making of new medicines through the creation of genetically modified organisms, the treatment of viral infections, the control of pathogens, applications in clinical diagnostics and the cure of human genetic diseases, either caused by somatic (e.g., cancer) or inherited (mendelian disorders) mutations. One of the most divisive, possible uses of this system is the modification of human embryos, for the purpose of preventing or curing a human being before birth. However, the technology in this field is evolving faster than regulations and several concerns are raised by its enormous yet controversial potential. In this scenario, appropriate laws need to be issued and ethical guidelines must be developed, in order to properly assess advantages as well as risks of this approach. In this review, we summarize the potential of these genome editing techniques and their applications in human embryo treatment. We will analyze CRISPR-Cas limitations and the possible genome damage caused in the treated embryo. Finally, we will discuss how all this impacts the law, ethics and common sense.

What Do We (Not) Know About Global Views of Human Gene Editing? Insights and Blind Spots in the CRISPR Era

As research on human applications of CRISPR advances, researchers, advisory bodies, and other stakeholder organizations continue calling for global public discourses and engagement to shape the development of human gene editing (HGE). Research that captures public views and tests ways for engaging across viewpoints is vital for facilitating these discourses. Unfortunately, such research lags behind advances in HGE research and applications. Here, we provide the first review of nationally representative public-opinion surveys focused on HGE to discuss limitations and remaining gaps, illustrating how these gaps hinder interpretation of existing studies. Rigorous research with proper methods for capturing representative public opinion of HGE is limited, especially in countries outside of the United States and on a global scale. The result is severely restricted understanding of even the surface level of public views concerning HGE. We identify broad areas where we need more and better research capturing public views, and describe how future surveys can help collect insights necessary for discourse and decision making on HGE.

Deference and decision-making in science and society: How deference to scientific authority goes beyond confidence in science and scientists to become authoritarianism

Deference to scientific authority theoretically captures the belief that scientists and not publics should make decisions on science in society. Few studies examine deference, however, and none test this central theoretical claim. The result is deference is often conflated with concepts such as trust in scientists and belief in the authority of science. This study examines two claims key to conceptualizing deference: that deference (1) predicts anti-democratic views of decision-making and (2) relates to but is distinct from beliefs of science as authoritative knowledge. Analyzing US nationally representative data, we find deference to scientific authority does predict anti-democratic views, and this is its distinct conceptual value: trust in scientists and belief in science as authoritative knowledge strongly relate to deference, but both predict pro-democratic views, unlike deference. We discuss how these findings highlight deference as vital for understanding perceptions of science and societal decision-making and how we can better develop the concept.

CRISPR-Cas9 in genome editing: Its function and medical applications

The targeted genome modification using RNA-guided nucleases is associated with several advantages such as a rapid, easy, and efficient method that not only provides the manipulation and alteration of genes and functional studies for researchers, but also increases their awareness of the molecular basis of the disease and development of new and targeted therapeutic approaches. Different techniques have been emerged so far as the molecular scissors mediating targeted genome editing including zinc finger nuclease, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9). CRISPR-Cas9 is a bacterial immune system against viruses in which the single-strand RNA-guided Cas9 nuclease is linked to the targeted complementary sequences to apply changes. The advances made in the transfer, modification, and emergence of specific solutions have led to the creation of different classes of CRISPR-Cas9. Since this robust tool is capable of direct correction of disease-causing mutations, its ability to treat genetic disorders has attracted the tremendous attention of researchers. Considering the reported cases of nonspecific targeting of Cas9 proteins, many studies focused on enhancing the Cas9 features. In this regard, significant advances have been made in choosing guide RNA, new enzymes and methods for identifying misplaced targeting. Here, we highlighted the history and various direct aspects of CRISPR-Cas9, such as precision in genomic targeting, system transfer and its control over correction events with its applications in future biological studies, and modern treatment of diseases.

Genome-Editing Technologies: Concept, Pros, and Cons of Various Genome-Editing Techniques and Bioethical Concerns for Clinical Application

The traditional healthcare system is at the doorstep for entering into the arena of molecular medicine. The enormous knowledge and ongoing research have now been able to demonstrate methodologies that can alter DNA coding. The techniques used to edit or change the genome evolved from the earlier attempts like nuclease technologies, homing endonucleases, and certain chemical methods. Molecular techniques like meganuclease, transcription activator-like effector nucleases (TALENs), and zinc-finger nucleases (ZFNs) initially emerged as genome-editing technologies. These initial technologies suffer from lower specificity due to their off-targets side effects. Moreover, from biotechnology's perspective, the main obstacle was to develop simple but effective delivery methods for host cell entry. Later, small RNAs, including microRNA (miRNA) and small interfering RNA (siRNA), have been widely adopted in the research laboratories to replace lab animals and cell lines. The latest discovery of CRISPR/Cas9 technology seems more encouraging by providing better efficiency, feasibility, and multi-role clinical application. This later biotechnology seem to take genome-engineering techniques to the next level of molecular engineering. This review generally discusses the various gene-editing technologies in terms of the mechanisms of action, advantages, and side effects.

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.

Potential Value of Genomic Copy Number Variations in Schizophrenia

Schizophrenia is a devastating neuropsychiatric disorder affecting approximately 1% of the global population, and the disease has imposed a considerable burden on families and society. Although, the exact cause of schizophrenia remains unknown, several lines of scientific evidence have revealed that genetic variants are strongly correlated with the development and early onset of the disease. In fact, the heritability among patients suffering from schizophrenia is as high as 80%. Genomic copy number variations (CNVs) are one of the main forms of genomic variations, ubiquitously occurring in the human genome. An increasing number of studies have shown that CNVs account for population diversity and genetically related diseases, including schizophrenia. The last decade has witnessed rapid advances in the development of novel genomic technologies, which have led to the identification of schizophrenia-associated CNVs, insight into the roles of the affected genes in their intervals in schizophrenia, and successful manipulation of the target CNVs. In this review, we focus on the recent discoveries of important CNVs that are associated with schizophrenia and outline the potential values that the study of CNVs will bring to the areas of schizophrenia research, diagnosis, and therapy. Furthermore, with the help of the novel genetic tool known as the Clustered Regularly Interspaced Short Palindromic Repeats-associated nuclease 9 (CRISPR/Cas9) system, the pathogenic CNVs as genomic defects could be corrected. In conclusion, the recent novel findings of schizophrenia-associated CNVs offer an exciting opportunity for schizophrenia research to decipher the pathological mechanisms underlying the onset and development of schizophrenia as well as to provide potential clinical applications in genetic counseling, diagnosis, and therapy for this complex mental disease.

Genomic Editing of Non-Coding RNA Genes with CRISPR/Cas9 Ushers in a Potential Novel Approach to Study and Treat Schizophrenia

Schizophrenia is a genetically related mental illness, in which the majority of genetic alterations occur in the non-coding regions of the human genome. In the past decade, a growing number of regulatory non-coding RNAs (ncRNAs) including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have been identified to be strongly associated with schizophrenia. However, the studies of these ncRNAs in the pathophysiology of schizophrenia and the reverting of their genetic defects in restoration of the normal phenotype have been hampered by insufficient technology to manipulate these ncRNA genes effectively as well as a lack of appropriate animal models. Most recently, a revolutionary gene editing technology known as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated nuclease 9 (Cas9; CRISPR/Cas9) has been developed that enable researchers to overcome these challenges. In this review article, we mainly focus on the schizophrenia-related ncRNAs and the use of CRISPR/Cas9-mediated editing on the non-coding regions of the genomic DNA in proving causal relationship between the genetic defects and the pathophysiology of schizophrenia. We subsequently discuss the potential of translating this advanced technology into a clinical therapy for schizophrenia, although the CRISPR/Cas9 technology is currently still in its infancy and immature to put into use in the treatment of diseases. Furthermore, we suggest strategies to accelerate the pace from the bench to the bedside. This review describes the application of the powerful and feasible CRISPR/Cas9 technology to manipulate schizophrenia-associated ncRNA genes. This technology could help researchers tackle this complex health problem and perhaps other genetically related mental disorders due to the overlapping genetic alterations of schizophrenia with other mental illnesses.

Genome editing: the road of CRISPR/Cas9 from bench to clinic

Molecular scissors engineered for site-specific modification of the genome hold great promise for effective functional analyses of genes, genomes and epigenomes and could improve our understanding of the molecular underpinnings of disease states and facilitate novel therapeutic applications. Several platforms for molecular scissors that enable targeted genome engineering have been developed, including zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and, most recently, clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated-9 (Cas9). The CRISPR/Cas9 system's simplicity, facile engineering and amenability to multiplexing make it the system of choice for many applications. CRISPR/Cas9 has been used to generate disease models to study genetic diseases. Improvements are urgently needed for various aspects of the CRISPR/Cas9 system, including the system's precision, delivery and control over the outcome of the repair process. Here, we discuss the current status of genome engineering and its implications for the future of biological research and gene therapy.

Human Induced Pluripotent Stem Cells as a Platform for Personalized and Precision Cardiovascular Medicine

Human induced pluripotent stem cells (hiPSCs) have revolutionized the field of human disease modeling, with an enormous potential to serve as paradigm shifting platforms for preclinical trials, personalized clinical diagnosis, and drug treatment. In this review, we describe how hiPSCs could transition cardiac healthcare away from simple disease diagnosis to prediction and prevention, bridging the gap between basic and clinical research to bring the best science to every patient.

Ethical and regulatory aspects of genome editing

Gene editing is a rapidly developing area of biotechnology in which the nucleotide sequence of the genome of living cells is precisely changed. The use of genome-editing technologies to modify various types of blood cells, including hematopoietic stem cells, has emerged as an important field of therapeutic development for hematopoietic disease. Although these technologies offer the potential for generation of transformative therapies for patients suffering from myriad disorders of hematopoiesis, their application for therapeutic modification of primary human cells is still in its infancy. Consequently, development of ethical and regulatory frameworks that ensure their safe and effective use is an increasingly important consideration. Here, we review a number of issues that have the potential to impact the clinical implementation of genome-editing technologies, and suggest paths forward for resolving them such that new therapies can be safely and rapidly translated to the clinic.

A Broad Overview and Review of CRISPR-Cas Technology and Stem Cells

The pinnacle of four decades of research, induced pluripotent stem cells (iPSCs), and genome editing with the advent of clustered, regularly interspaced, short palindromic repeats (CRISPR) now promise to take drug development and regenerative medicine to new levels and to enable the interrogation of disease mechanisms with a hitherto unimaginable level of model fidelity. Autumn 2014 witnessed the first patient receiving iPSCs differentiated into retinal pigmented epithelium to treat macular degeneration. Technologies such as 3D bioprinting may now exploit these advances to manufacture organs in a dish. As enticing as these prospects are, these technologies demand a deeper understanding, which will lead to improvements in their safety and efficacy. For example, precise and more efficient reprogramming for iPSC production is a requisite for wider clinical adoption. Improving awareness of the roles of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) and genomic epigenetic status will contribute to the achievement of these aims. Similarly, increased efficiency, avoidance of off-target effects, and expansion of available target sequences are critical to the uptake of genome editing technology. In this review, we survey the historical development of genetic manipulation and stem cells. We explore the potential of genetic manipulation of iPSCs for in vitro disease modeling, generation of new animal models, and clinical applicability. We highlight the aspects that define CRISPR-Cas as a breakthrough technology, look at gene correction, and consider some important ethical and societal implications of this approach.

Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 Genetic Engineering: Robotic Genetic Surgery

As a novel technology that utilizes the endogenous immune defense system in bacteria, CRISPR/Cas9 has transcended DNA engineering into a more pragmatic and clinically efficacious field. Using programmable sgRNA sequences and nucleases, the system effectively introduces double strand breaks in target genes within an entire organism. The applications of CRISPR range from biomedicine to drug development and epigenetic modification. Studies have demonstrated CRISPR mediated targeting of various tumorigenic genes and effector proteins known to be involved in colon carcinomas. This technology significantly expands the scope of gene manipulation and allows for an enhanced modeling of colon cancers, as well as various other malignancies.