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Gene Editing: Reinventing Humanity? Dennis M. Sullivan, MD, FACS, MA (Ethics) Director, Center for Bioethics Cedarville University www.cedarville.edu/bioethics E-mail: [email protected] Learning Outcomes: Participants will be able to: 1. Describe the new technologies for gene editing. 2. Explain the difference between somatic and germline genetic treatments. 3. Explore the major ethical concerns that these technologies raise. A GENETICS BREAKTHROUGH: CRISPR / CAS9 It’s Called CRISPR (Huh?) • • • Clustered regularly-interspaced short palindromic repeats Segments of prokaryotic DNA containing short repetitions of base sequences The short repetitions are palindromes (e.g., “Madam, I’m Adam”) • Part of a bacterial immune system CRISPR is a “Repurposed Tool” • Novel insight: – CRISPR is a defense mechanism in bacteria. – Repurposed as a gene-editing technique. • • By delivering the Cas9 protein and appropriate guide RNAs into a cell, the organism's genome can be cut at any desired location. Then new DNA can be added. Who Discovered All This? • • • • • (1987) Yoshizumi Ishino found the CRISPR gene. Eugene Koonin showed its purpose. Emmanuelle Charpentier identified Cas9 and guide RNA. (2014) Jennifer Doudna determined the mechanism and created the CRISPR/Cas9 system for gene editing. (Doudna may end up getting the Nobel Prize) GENE THERAPY IN THE PAST Somatic Cell Gene Therapies Alteration of genes of a diseased individual, using a viral vector: Candidate Diseases for Gene Therapy • Single gene defects more likely to respond • 1990s: gene therapy approved for: – Severe combined immune deficiency (SCID) – Familial hypercholesterolemia – Gaucher's disease – Cystic fibrosis Example of a Somatic Cell Therapy • Example: Cystic Fibrosis (CF) – CF is due to a malfunctioning gene that codes for a bronchial protein (in the lungs). – The protein is responsible for fluid balance. – Therefore, affected patients get think mucus plugs, eventually causing an early death. • Gene Therapy for CF – Insert a normal gene into the DNA of cells in order to compensate for the nonfunctioning defective gene. – Use a virus that normally causes colds. – Result: lungs function better for a few months. • Problems: – Treatment is dangerous, complicated, and expensive – If it works, benefit only temporary (altered cells are eventually replaced by the defective cells once again) THE ADVENT OF CRISPR/CAS9 A New Ballgame: Though not yet ready for clinical use, CRISPR / CAS9 allows direct editing of the human genome • Tested (so far) only in the lab • Much higher accuracy than viral vectors • Fewer risks of unwanted side effects • THE CONTROVERSY What Chinese Researchers Did: • • Used CRISPR/CAS9 on human embryos for the first time (with beta-thalassemia) “Tripronuclear zygotes” = polyspermic embryos (one ovum, two sperm), therefore non-implantable What Chinese Researchers Did (cont.) • • • • A completely unnecessary trial (no new knowledge gained) Because all of this had already been done in an animal model 86 human embryos 28 showed evidence of “splicing” only 4 had the desired changes (many “off target” effects) Therefore, the accuracy was < 5%. THE ETHICAL CONCERNS Utilitarian Concerns: • • • The technique is “not ready for prime time:” many errors, many possible bad outcomes. YET: Human Fertilization and Embryo Authority in the U.K. has approved using CRISPR in human embryos up to 14 days - as long as they are not implanted. Commodification of embryos BBC Interview • • • Kathy Niakan: Scientist makes case to edit embryos Wants to use the technique to study human fertility issues. (LINK) Germ-Line Interventions • • • • Alter an individual’s entire genome, including reproductive cells. These changes could be passed down to subsequent generations. Consent is impossible to obtain Unwanted and unpredictable side effects are likely Are we “playing God,” and meddling with human nature and human dignity? Stephen Pinker (Harvard Psychologist) Given this potential bonanza, the primary moral goal for today’s bioethics can be summarized in a single sentence: Stephen Pinker (Harvard Psychologist) Given this potential bonanza, the primary moral goal for today’s bioethics can be summarized in a single sentence: Get out of the way. Stephen Pinker (Harvard Psychologist) Given this potential bonanza, the primary moral goal for today’s bioethics can be summarized in a single sentence: Get out of the way. “A truly ethical bioethics should not bog down research in red tape, moratoria, or threats of prosecution based on nebulous but sweeping principles such as ‘dignity,’ ‘sacredness,’ or ‘social justice’” (Boston Globe, September 31, 2015). Therapy v. Enhancement: • • It seems reasonable to eliminate genetic diseases: – Sickle-cell anemia – Huntington’s Disease – Cystic Fibrosis But the new technology may permit human enhancement: – “Designer babies” selected for sex, eye color, or intelligence. – Is there a fixed human nature, or can we meddle with it? WHAT ABOUT GOD’S PERSPECTIVE? Psalm 139:13-14a For You formed my inward parts; You knitted me together in my mother's womb. I praise You, for I am fearfully and wonderfully made . . . Genesis 1:27 So God created man in his own image, in the image of God he created him; male and female he created them. How Should Christians Respond? • Be informed: – Be skeptical of new technologies – Some major advances come at a great cost • Get involved: – Advocate for the sanctity of human life – Especially help our younger generation, who are so used to modern technologies – Human life is precious, not a product • Pray Gene Editing: Reinventing Humanity? Dennis M. Sullivan, MD, FACS, MA (Ethics) Director, Center for Bioethics Cedarville University www.cedarville.edu/bioethics E-mail: [email protected]