April 23, 2014
Reprogrammed Cells Kept Bug-Free by SIRT1
(Genetic Engineering & Biotechnology News) – Regenerative medicine—the promise of rejuvenating or replacing damaged or diseased tissues—will most likely rely on the use of induced pluripotent stem (iPS) cells, which are obtained when adult cells are essentially thrown into evolutionary reverse. This abrupt change can be hard on cells, which may suffer chromosomal abnormalities and DNA damage. And so the bright vistas of regenerative medicine are shadowed by a stubborn cloud—the uncertainty thatstem cells that are derived from adult cells are really safe.
New Patenting Guidelines Are Needed for Biotechnology
(Phys.org) – Biotechnology scientists must be aware of the broad patent landscape and push for new patent and licensing guidelines, according to a new paper from Rice University’s Baker Institute for Public Policy. Published in the current issue of the journal Regenerative Medicine, the paper is based on the June 2013 U.S. Supreme Court ruling in the case Association for Molecular Pathology (AMP) v. Myriad Genetics that naturally occurring genes are unpatentable. The court case and rulings garnered discussion in the public about patenting biological materials.
A New Edition of Nursing for Women’s Health is Available
Nursing for Women’s Health (Volume 18, No. 2, April/May 2014) is now available online by subscription only.
- “Donor Motivations, Associated Risks and Ethical Considerations of Oocyte Donation” by Amy L. Boutelle
- “Fertility Preservation Options for Women Treated for Cancer” by Kelsea Lucas and Desiree Hensel
- “The Increasing Role of Genetics and Genomics in Women’s Health” by Elisabeth (Lisa) Z. Klein
A New Edition of Journal of Internal Medicine is Available
Journal of Internal Medicine (Volume 275, No. 5, May 2014) is now available online by subscription only.
- “Combined efforts in immunology and vaccinology will lead to effective vaccines against HIV, tuberculosis and malaria” by F. Chiodi and S. H. E. Kaufmann
- “The path of malaria vaccine development: challenges and perspectives” by C. Arama and M. Troye-Blomberg
- “The importance of validating proposed genetic profiles in IBD” by I. C. Lawrance
- “Assessment of the validity of a multigene analysis in the diagnostics of inflammatory bowel disease” by J. T. Bjerrum, et al.
A New Edition of JAMA Internal Medicine is Available
JAMA Internal Medicine (Volume 174, No. 4, April 2014) is now available online by subscription only.
- “23andMe, the Food and Drug Administration, and the Future of Genetic Testing” by Patricia J. Zettler, Jacob S. Sherkow, and Henry T. Greely
- “National Hospice Survey Results: For-Profit Status, Community Engagement, and Service” by Melissa D. Aldridge, et al.
- “The Changing Face of the Hospice Industry: What Really Matters?” by Kimberly S. Johnson
- “The Importance of Influenza Vaccination” by Hilary M. Babcock, John A. Jernigan, and David A. Relman
- “The Importance of Influenza Vaccination—Reply” by Peter Doshi
April 22, 2014
A New Edition of Genetics in Medicine is Available
Genetics in Medicine (Volume 16, No. 4, April 2014) is now available online by subscription only.
- “Noninvasive prenatal testing: limitations and unanswered questions” by Monica A. Lutgendorf, et al.
- “Communication of genetic test results to family and health-care providers following disclosure of research results” by Kristi D. Graves, et al.
- “Processes and factors involved in decisions regarding return of incidental genomic findings in research” by Robert Klitzman, et al.
A New Edition of Science, Technology & Human Values is Available
Science, Technology & Human Values (Volume 39, No. 3, May 2014) is now available online by subscription only.
- “Genetic Testing, Birth, and the Quest for Health” by Joëlle Vailly
- “Not Just Neoliberalism: Economization in US Science and Technology Policy” by Elizabeth Popp Berman
- “The World’s Not Ready for This: Globalizing Selective Technologies” by Lauren Jade Martin
Virtual Doctor Visits Gaining Steam in “Geneticist Deserts”
(Scientific American) – These “geneticist deserts” are prompting a small but growing tide of virtual patient visits. In an age when virtual chats are relatively commonplace, videoconferencing for genetic consultation—telegenetics —is becoming a logical extension of what people already do with their Webcams and smartphones. Telegenetics saves patients time, the cost and burden of transport and, oftentimes, the need to find day care or take time off from work. For doctors, the approach can expand their reach while limiting travel. Moreover, they can bill for their services as if they were seeing patients in their offices with just a slightly different billing code.
April 21, 2014
Pew: Drones, Eugenics Worry Public
(Union Times San Diego) – A majority of Americans believe that future changes in technology will generally improve people’s lives. But a survey of 1,001 adults by the Pew Research Center also found lots of public anxiety about the rise of personal drones, genetically altering children, and the idea of relying on robots to care for the elderly.
First Genetic Link Discovered to Difficult-to-Diagnose Breast Cancer Sub-Type
(Medical Xpress) – Scientists have identified the first genetic variant specifically associated with the risk of a difficult-to-diagnose cancer sub-type accounting for around 10-15 per cent of all breast cancer cases. The largest ever study of the breast cancer sub-type, called invasive lobular carcinoma, gives researchers important clues to the genetic causes of this particular kind of breast cancer, which can be missed through screening.
April 18, 2014
Broad Institute Gets Patent on Revolutionary Gene-Editing Method
(MIT Technology Review) – One of the most important genetic technologies developed in recent years is now patented, and researchers are wondering what they will and won’t be allowed to do with the powerful method for editing the genome. On Tuesday, the Broad Institute of MIT and Harvard announced that it had been granted a patent covering the components and methodology for CRISPR—a new way of making precise, targeted changes to the genome of a cell or an organism. CRISPR could revolutionize biomedical research by giving scientists a more efficient way of re-creating disease-related mutations in lab animals and cultured cells; it may also yield an unprecedented way of treating disease.
Research Brings Significant Improvement in Genetic Analysis of Tumors
(Medical Xpress) – Every tumour is unique and requires specific treatment. A thorough and complete analysis of the genetic activity in the tumour cells is necessary to determine the appropriate treatment. Researchers at TU Delft, in collaboration with researchers from Columbia University and the Antoni van Leeuwenhoek Hospital have achieved significant improvements in this type of analysis. The results were published on 4 and 10 April in the scientific journals PNAS and PLOS Genetics.
Cancer Drugs Targeted to Patient’s Own Genetics to Be Offered in New NHS Trial
(The Telegraph) – Cancer patients will be offered new drugs targeted to the specific genetic profile of their disease within ten years following research that promises to revolutionise the way tumours are treated. In a groundbreaking new venture, the NHS, Cancer Research UK and pharmaceutical companies are joining together to offer all cancer patients experimental new drugs that are honed to the specific genetics of their tumours.
Identical Twins, One Case of Down Syndrome: A Genetic Mystery
(Los Angeles Times) – A rare occurrence in the earliest days of a pregnancy produces an unusual and mystifying outcome: Identical twin fetuses are conceived of the same meeting of egg and sperm. And despite their shared DNA, one of the twins has Down syndrome (the most common genetic cause of intellectual impairment), but the other does not.
April 17, 2014
Modified Stem Cells May Offer Way to Treat Alzheimer’s Disease
(Medical News Today) – A new study suggests genetically modified stem cells may offer a new way to treat Alzheimer’s disease. When implanted in mice bred to have symptoms and brain hallmarks of Alzheimer’s, they increased connections between brain cells and reduced the amyloid-beta protein that accumulates to form plaques that clog up the brain.
Fertility Mystery Solved: Protein Discovered that Joins Sperm with Eggs
(The Guardian) – A fundamental key to fertility has been uncovered by British scientists with the discovery of an elusive protein that allows eggs and sperm to join together. The molecule – named Juno after the Roman goddess of fertility – sits on the egg surface and binds with a male partner on a fertilising sperm cell. Japanese researchers identified the sperm protein in 2005, sparking a decade-long hunt for its “mate”.
April 16, 2014
China Bans Genetic Testing
(Genetic Engineering & Biotechnology News) – For nearly a half-century, interrupted only by the Cultural Revolution, China promoted the growth of genetic testing to prevent and address birth defects through state-run hospitals, as well as charities and increasingly in recent years, private enterprises. Then in February, China reversed course. The China Food and Drug Administration posted a new regulation that immediately banned genetic testing—even previously approved services “including prenatal genetic testing, gene sequencing technology-related products, and cutting-edge products and technologies.”
April 15, 2014
Genetic Risk of Alzheimer’s Has Gender Bias
(New Scientist) – Carrying a copy of the “Alzheimer’s gene” doesn’t significantly raise a man’s risk of developing the disease. The gene does increase a woman’s risk, but women with one copy of the gene were as likely to develop the disease as men with no copies. The study – along with work suggesting that the gene is associated with educational achievement in young people – highlights how much remains to be done to untangle the genetics of Alzheimer’s.
Genetics Leader Reflects on 50th Anniversary of Discovery of Genetic Code
(Baylor College of Medicine) – In 1959, postdoctoral associate Dr. Thomas Caskey, participated in the Nobel Prize winning work of Dr. Marshall Nirenberg that helped unravel the genetic code of life. It was not just a “one-trick pony,” Caskey reflected. Nirenberg won the Nobel Prize for this work which unveiled the set of rules by which information encoded without genetic material (DNA or mRNA sequences) is translated into proteins by living cells.
April 14, 2014
Gene Editing Technology
What Is Gene Editing?
People sometimes express concerns over gene therapy, which is genetic engineering for therapeutic purposes, but what they are really concerned about is gene editing. Genetic engineering is a relatively straightforward procedure in the laboratory, and is the basis of the field of synthetic biology. Genes are made of DNA, and scientists are able to make any DNA sequence they want using a computer and laboratory equipment. Technically speaking, this is genetic engineering. While making a DNA sequence in a lab is relatively simple, inserting it into a cell and replacing the unwanted DNA, is an entirely different technique. The insertion or deletion of DNA may be more accurately described as gene editing.
Gene editing has been notoriously difficult to do. The best techniques have involved designing proteins that take a long time to make and are difficult to work with in the lab. Additionally, these gene editing techniques can only edit one segment of DNA at a time. This makes it difficult for scientists to study disease models (usually in mice) involving more than one genetic marker. Recently, however, several studies have touted a new gene editing technique called CRISPR (clustered regularly interspaced short palindromic repeats) that has already shown in animal models that it is easier to use and can change more than one portion of DNA at a time.
Gene therapy received a bad reputation in 1999 when 18-year-old Jesse Gelsinger, a clinical trial participant, died from a poor reaction to a technique involving the insertion of genetic material to potentially cure a rare genetic disease. This case was controversial for many reasons, including financial conflict-of-interest issues and proper informed consent. As a result of this case, as well as other cases that came to light upon investigation, gene therapy research and clinical trials decreased dramatically for a number of years. However, a recent Wired article entitled “The Fall and Rise of Gene Therapy” optimistically reported that improvements in gene insertion into cells have led to a resurgence of the field.
(It is notable that the Wired article was criticized for leaving out pertinent historical facts regarding the Gelsinger case and the ethical controversies surrounding the gene therapy field at the time. An informative response to the article can be found here.
Finding the right virus to target cells and insert DNA segments into those cells is only part of the story.
New Tools for Gene Editing
In order for scientists to determine what a gene actually does and whether it is the cause of a disease, they will do animal studies in which they remove the gene and see what changes occur in the animal, such as looking for disease symptoms. This is usually done in mouse models, and it usually takes many years to adequately remove or “silence” a gene. Using the CRISPR method scientists are now able to remove a gene in a matter of weeks. Additionally, with these techniques they are able to guide where the DNA is inserted, rather than just inserting it randomly into the cell.
Prior methods to delete and insert DNA were more cumbersome. In 1996, scientists developed a technique called zinc-finger nuclease (ZFN) in which scientists made a protein nuclease in the lab that targeted a specific portion of DNA that would then cut the DNA. But, scientists needed to make a new nuclease every time they wanted to investigate a different portion of DNA. This process was expensive and time consuming. It also was only good for one genetic modification at a time, making it difficult to investigate diseases that have more than one genetic marker.
In 2010, scientists developed a different nuclease technique that was easier to work with than ZFNs called TALEN (transcription activator-like effector nucleases). These nucleases are easier to design for a specific DNA target, but their large size presented practical problems in the lab.
Finally, in January 2013, scientists demonstrated that a method that bacteria use to inoculate themselves from viruses can also be used as a gene editing technique in humans. (See here for the research article.) This latest method is CRISPR. It requires a nuclease called CAS9 and a piece of RNA (similar to DNA) that scientists can make in the lab. Unlike prior methods for gene editing, the same nuclease can be used to edit any DNA target. The RNA segment tells the CRISPR/CAS9 system where to cut the DNA. Not only can it remove DNA, but it can also guide the cell’s DNA repair mechanisms to the precise location for inserting the edited DNA. ZFNs and TALENs also use the cell’s repair mechanisms to guide DNA, but CRISPR is much easier to work with and, importantly, much faster. Using CRISPR, several genes can be deleted and others inserted in mouse models in a matter of weeks rather than years. Several research groups and start-up companies are now studying CRISPR and refining the technique.
Use in Stem Cell Therapy
One way that scientists are hoping to use CRISPR is in stem cell therapy. For example, Susan Young in MIT Technology Review reports that Gang Boa’s group is looking into ways to overcome the immune response when a patient receives a donor’s stem cells. They are testing whether they can remove bone marrow stem cells from people with sickle cell disease, use CRISPR to edit out the offending gene sequence that causes sickle cell, and then re-insert the edited stem cells back into the patient. This is just one of several possibilities using CRISPR techniques. According to Young, “In little more than a year, CRISPR has begun reinventing genetic research.”
Many of the same concerns that have been mentioned on this site in regards to genetic engineering apply to gene therapy using CRISPR (See “Mighty Mitochondria and Assisted Reproductive Technology” and “Genetics in the News”. Not every trait or disease has a purely genetic basis. Also, if someone has a gene for a particular disease, in many cases, that only means he or she may get the disease. Pre-emptively removing a gene that has not been fully characterized may lead to unforeseen adverse effects. Sometimes genes have both “good” and “bad” effects. Additionally, sometimes the same gene may be recruited for different purposes. We, therefore, need to exercise caution when moving into areas in which our knowledge is still incomplete.
The most pressing bioethics issue is that of safety. CRISPR will not be in the clinic for a long time because, just as with its predecessors, ZFNs and TALENS, it sometimes cuts the DNA in the wrong spot. Off-target cutting can be lethal to cells. Much of the current research on CRISPR is finding ways to ensure accurate editing. Even being off by one nucleotide can wreak havoc on an organism, so until gene editing becomes more accurate, it will continue to be limited to studying model diseases or possibly for stem cell research.
Another ethical issued is raised by Harvard scientist George Church in Young’s MIT Technology Review article. He points out that once gene editing is able to cure diseases, “some scientists will be tempted to use it to engineer embryos during in vitro fertilization. Researchers have already shown that genome editing can rewrite DNA sequences in rat and mouse embryos, and in late January, researchers in China reported that they had created genetically modified monkeys using CRISPR. With such techniques, a person’s genome might be edited before birth—or, if changes were made to the eggs or sperm-producing cells of a prospective parent, even before conception.”
This brings up issues of autonomy and human dignity. Gene editing techniques could/might allow parents to make genetic decisions for their children. Furthermore, as we have seen with the American eugenics movement, fear of mental illness or other culturally driven preferences may lead some parents to decide to have their embryo’s genome edited without fully understanding the complex genetic basis, if there is a genetic basis, behind these traits. This delves into even more fundamental questions on the role that genetics plays in determining our traits.
The human genome is complex, and scientists are still learning the nuances of the genetic code and how genes are expressed. While using CRISPR technology to study disease in animal models seems to have a practical value, the consequences of editing certain genes in the human genome are still largely unknown. There are a small number of genetic diseases that are directly due to a particular error in the genetic code, but many diseases are due to a complexity of factors in which it’s unclear whether genetic editing would do more harm than good.
For an academic review article on ZFNs, TALENs, and CRISPR, see Trends in Biotechnology, Volume 31, Issue 7, 397-405, 09 May 2013. Subscription required.
Finding the Switch: Researchers Create Roadmap for Gene Expression
(Medical Xpress) – In a new study, researchers from North Carolina State University, UNC-Chapel Hill and other institutions have taken the first steps toward creating a roadmap that may help scientists narrow down the genetic cause of numerous diseases. Their work also sheds new light on how heredity and environment can affect gene expression.