News Article | April 13, 2016
Researchers from Guangzhou Medical University said they used a gene-editing technique known as CRISPR to artificially induce a mutation in human cells and make them resistant to HIV, the virus that causes AIDS. Their paper, which appeared last week in the Journal of Assisted Reproduction and Genetics, is only the world's second published account of gene editing in human embryos. Critics said the study—intended as a proof-of-principle exercise—was unnecessary and lacked medical justification, and strongly cautioned against the broader ethical implications of the slippery slope of human genome modification. "This paper doesn't look like it offers much more than anecdotal evidence that (CRISPR) works in human embryos, which we already knew," George Daley, a stem-cell biologist at Children's Hospital Boston, told the prominent science journal Nature. It demonstrated that "the science is going forward before there's been the general consensus after deliberation that such an approach is medically warranted", he added. Tetsuya Ishii, a bioethicist at Japan's Hokkaido University, denounced the research as "just playing with human embryos", Nature said. In a statement issued by the hospital where they carried out their research, the Guangzhou team brushed aside such concerns, focusing instead on the "incalculable" size of the future market for disease treatments. "The assessments of those outside the field are not authoritative, and the research environment will continue to evolve," they said. "For us what is most important is that we diligently complete our research and stick to the path we believe in, acquiring independent intellectual property rights... so that we do not have to defer to others." Such perseverance, they said will ensure "our own position in the international community", adding: "The future market for the treatment of diseases through gene editing is incalculable." Speaking to China's state-run Global Times newspaper, the paper's lead author Fan Yong said: "It is the pioneers that will make the rules in this field." Han Bin, the director of China's National Center for Gene Research, told the paper—which often takes a nationalistic tone—that the technology's potential therapeutic benefits for all diseases caused by inherited variation, including cancer, should outweigh any qualms. Instead of following other countries' ethical stances, China should formulate its own standards and regulations, the Global Times cited him as saying. China is quickly cementing a reputation as a leader in the fields of genetic research and cloning, showing a willingness to forge ahead even as others hesitate over ethical issues. The world's biggest cloning factory is under construction in the northern port of Tianjin, with plans to churn out everything from pets to premium beef cattle. The chief executive of Boyalife Group, the Chinese firm behind it, told AFP his company had technology advanced enough to replicate humans. The head of its South Korean partner has been quoted as saying it preferred mainland locations to avoid bioethics laws elsewhere that would ban the use of human eggs. The Guangzhou Medical University study used flawed embryos not viable for fertility treatment, and had been approved by the university's ethics committee. Four out of the 26 embryos were successfully modified, while a number exhibited unexpected mutations. All of them were destroyed three days later. "The purpose of this study was to evaluate the technology and establish principles for the introduction of precise genetic modifications in early human embryos," the Journal of Assisted Reproduction and Genetics paper read. The legality of human embryo research varies by country, and there is no international consensus on what ought to be allowed. In the US, the influential National Institutes of Health are banned from funding such studies, while Britain's independent fertility regulator only issued its first licence for human embryo modification research in February, for a study on infertility and miscarriages.
News Article | April 13, 2016
Embryos edited Researchers at Guangzhou Medical University in China have reported editing the genes of non-viable human embryos to try to make them resistant to HIV infection. The team collected a total of 213 fertilized human eggs, donated by 87 patients, that were unsuitable for implantation as part of in vitro fertility therapy because they contained an extra set of chromosomes. The researchers then used the CRISPR–Cas9 genome-editing technique to introduce into some of the embryos a mutation that cripples an immune-cell gene called CCR5. Some people naturally carry this mutation, which alters the CCR5 protein in a way that prevents the HIV virus from entering the cells it tries to infect. Genetic analysis showed that 4 of 26 human embryos targeted were modified with the CCR5 mutation. But in some embryos, not all sets of chromosomes harboured the mutation; some contained the unmodified gene, whereas others had acquired different mutations. In April 2015, a different China-based team announced that it had modified a gene linked to a blood disease in non-viable human embryos, igniting a worldwide storm of ethics concerns. See go.nature.com/igymgu for more. SpaceX rocket touches down at sea SpaceX took a major step towards re-usable rockets when it flawlessly landed the first stage of its Falcon 9 rocket on an unmanned ship in the Atlantic Ocean, after an 8 April launch from Cape Canaveral, Florida. It was the first successful landing of the rocket at sea, following four attempts that resulted in crashes. The company, based in Hawthorne, California, returned an intact Falcon rocket to land in December last year. The latest flight delivered cargo to the International Space Station (ISS), including an expandable astronaut habitat designed by Bigelow Aerospace of North Las Vegas, Nevada. The previous SpaceX mission to the ISS failed when a Falcon 9 rocket broke apart after launch in June 2015. Kepler scare NASA mission managers were shocked to discover on 7 April that the exoplanet-hunting Kepler space telescope had entered emergency mode. Mission control was able to return it to normal operations three days later, but the cause of the malfunction remained a mystery as Nature went to press. This was the first software glitch in Kepler’s seven years in space, although it previously suffered hardware breakdowns. The spacecraft has lost at least the first several days of a planet-hunting campaign that it was scheduled to begin on 7 April and conduct until 1 July. See go.nature.com/mu7woc for more. China satellite lab China has launched its largest-ever suite of microgravity and life-science experiments into orbit. The country’s Shijian-10 probe left the Jiuquan Satellite Launch Center in Gansu province, northern China, on 7 April. It is carrying 19 experiments that include tests to assess the effects of radiation on genes as well as the influence of microgravity on materials, fluid physics and combustion. The early development of mouse embryos in microgravity will also be examined. After its 15-day mission, the bullet-shaped craft will re-enter Earth’s atmosphere to be recovered from a landing site in Inner Mongolia. Self-driving lorries Six squads of automated lorries successfully arrived in Rotterdam in the Netherlands on 6 April after having driven themselves from Sweden, Belgium and Germany, with one fleet travelling more than 2,000 kilometres from Stockholm. The trial was part of the Dutch-government-led European Truck Platooning Challenge and included lorries from six different manufacturers. ‘Truck platooning’ involves two or more lorries connected by WiFi and driving in a convoy, with the first vehicle determining the speed and route. The technology aims to save fuel by enabling lorries to travel closer together, which reduces air drag. Bank climate plan The World Bank announced a Climate Change Action Plan on 7 April to help countries to meet their commitments under the United Nations climate agreement signed in Paris in December 2015, and to prepare for unavoidable impacts of climate change. Under the plan, the bank will mobilize US$25 billion in private financing for clean energy by 2020. Among other actions, it will quadruple funding for clean transportation programmes and help to bring early-warning systems for natural disasters to 100 million people. Reef catastrophe Huge swathes of coral in Australia’s Great Barrier Reef are undergoing severe bleaching (pictured), according to aerial surveys. Many corals in the northern part of the reef are likely to die, because raised sea temperatures have caused them to expel the symbiotic algae that give them their colour. Researchers at the ARC Centre of Excellence for Coral Reef Studies in Townsville, Queensland, who are assessing the damage, say that more than 1,200 kilometres of the roughly 2,300-kilometre-long reef have bleached, and that the situation is substantially worse than in the two previous bleaching episodes in 1998 and 2002. See go.nature.com/ys7bau for more. Cambodia tiger loss Tigers are no longer breeding in Cambodia and the population there should be considered “functionally extinct”, the conservation group WWF announced on 6 April in Phnom Penh. The last wild tiger there was seen on a camera trap in 2007 in the Mondulkiri Protected Forest. But the WWF noted that national estimates and data compiled by the International Union for Conservation of Nature suggest that global tiger populations have rebounded to 3,890, from about 3,200 in 2010. Cambodia plans to bring eight young tigers from India into its dry forests in the Eastern Plains by 2019, as part of the global Tx2 initiative aiming to double wild tiger populations by the year 2022. Pharma merger off A marriage between two large pharmaceutical companies has been called off. Pfizer of New York City and Allergan of Dublin announced on 6 April that they had terminated a proposed merger process, which would have enabled the resulting company to take advantage of lower taxes in Ireland. The news came two days after the US Department of the Treasury unveiled stricter rules on companies that seek to move abroad to avoid US taxes. Pfizer pledged to announce by the end of the year whether it will spin off some parts of the company. NASA science chief Former astronaut John Grunsfeld, who has overseen NASA’s science portfolio since 2012, announced his retirement from the space agency on 5 April. The physicist and space-telescope expert flew five times on the space shuttle — including three visits to the Hubble Space Telescope — and was the lead spacewalker on the final flight to maintain and upgrade the telescope in 2009. As associate administrator for NASA’s Science Mission Directorate, he was responsible for more than 100 missions, such as the New Horizons spacecraft that visited Pluto last year. Grunsfeld’s deputy, Geoff Yoder, will take charge until a successor is chosen. Contracts with the International Seabed Authority (ISA), which regulates sea-bed mining in international waters, have picked up in recent years. Although commercial mining operations have not yet started, governments and corporations have signed contracts with the ISA to allow them to explore areas of the world’s oceans for materials including manganese nodules, copper, zinc, cobalt and platinum. Researchers have warned about the environmental impacts, saying that stricter regulation is needed. 16–20 April The American Association for Cancer Research holds its annual meeting in New Orleans, Louisiana. go.nature.com/q1t4fp 17–22 April The American Meteorological Society’s 32nd meeting on hurricanes and tropical meteorology convenes in San Juan, Puerto Rico. go.nature.com/pvszif
PubMed | University Hospitals Leuven, Sun Yat Sen University, the First Affiliated Hospital of Guangzhou Medical University, Chinese Institute of Clinical Medicine and 7 more.
Type: Journal Article | Journal: Journal of thoracic disease | Year: 2017
We aimed to summarize the diagnostic accuracy of white light bronchoscopy (WLB) and advanced techniques for airway pre-cancerous lesions and early cancer, such as autofluorescence bronchoscopy (AFB), AFB combined with WLB (AFB + WLB) and narrow-band imaging (NBI) bronchoscopy.We searched for eligible studies in seven electronic databases from their date of inception to Mar 20, 2015. In eligible studies, detected lesions should be confirmed by histopathology. We extracted and calculated the 22 data based on the pathological criteria of lung tumor, including high-grade lesions from moderate dysplasia (MOD) to invasive carcinoma (INV). Random-effect model was used to pool sensitivity, specificity, diagnostic odds ratio (DOR) and the area under the receiver-operating characteristic curve (AUC).In 53 eligible studies (39 WLB, 39 AFB, 17 AFB + WLB, 6 NBI), diagnostic performance for high-grade lesions was analyzed based on twelve studies (10 WLB, 7 AFB, 7 AFB + WLB, 1 NBI), involving with totally 2,880 patients and 8,830 biopsy specimens. The sensitivity, specificity, DOR and AUC of WLB were 51% (95% CI, 34-68%), 86% (95% CI, 73-84%), 6 (95% CI, 3-13) and 77% (95% CI, 73-81%). Those of AFB and AFB + WLB were 93% (95% CI, 77-98%) and 86% (95% CI, 75-97%), 52% (95% CI, 37-67%) and 71% (95% CI, 56-87%), 15 (95% CI, 4-57) and 16 (95% CI, 6-41), and 76% (95% CI, 72-79%) and 82% (95% CI, 78-85%), respectively. NBI presented 100% sensitivity and 43% specificity.With higher sensitivity, advanced bronchoscopy could be valuable to avoid missed diagnosis. Combining strategy of AFB and WLB may contribute preferable diagnosis rather than their alone use for high-grade lesions. Studies of NBI warrants further investigation for precancerous lesions.
News Article | December 14, 2016
Ketamine first attracted fans as a party drug, but it's quickly gaining clout as an ideal treatment for depression. A new study, published in the journal Science Signaling, reveals the much discussed key to ketamine's antidepressant powers. Researchers from Southern Illinois University School of Medicine, Guangzhou Medical University in China, Howard Hughes Medical Institute in Baltimore, and Johns Hopkins School of Medicine found that ketamine alters the presynaptic side of neurons or nerve cells, where the neurotransmitters are, in order to receive messages from another neuron. This mechanism alters the messages from one neuron to another, explained researcher Ke Zhang. "In our case, ketamine improved this 'message communication' between neurons," he told Motherboard. "The enhancement of neural activity benefits altering the depressing status of the patients." Clinical trials have shown that a single dose of ketamine (.5 to 10 milligrams/kilogram) significantly curbed depressive symptoms within 72 hours, corresponding author Xiang Cai told Motherboard. The results were measured by the Hamilton Depression Rating Scales, a standard evaluation for depression. "Compared with traditional antidepressants, the antidepressive-like actions of ketamine are persistent and fast," Cai said. In the study, the researchers combined electrophysiological recording, which measures the flow of ions in biological tissues, with analysis of rodent behavioral responses. They also looked for molecular changes, and tested the ketamine's effect in vivo. They tested ketamine on mice genetically adjusted to have certain genes, or to not have the genes out, to investigate the role of specific molecules in ketamine-induced fast antidepressant effects. Ketamine has been an FDA-approved anesthetic for half a century, Cai noted. It is already commonly used in clinics as a an antidepressant when other treatments have failed, as well as a "dissociative analgesic" for pain management, which means it induces a feeling of detachment and functions as a painkiller. But high amounts of ketamine have been associated with neurotoxicity and damage to other body systems. "Ketamine as a 'club drug' may also raise serious addictive problems," Cai said. Ketamine's antidepressant actions are also the subject of great controversy, but not because it's a recreational drug. "Before our study, there are different opinions about the molecular mechanism of how the antidepressant actions of ketamine," he said. One group holds that ketamine reduces the power of inhibition system in the brain and results in enhanced excitatory system, while another group thinks ketamine directly enhances excitatory system. Cai said his group's study shows that ketamine indeed enhances "excitatory synaptic transmission," in the hippocampus, which helps the brain with antidepressant actions and consolidating memories. Ketamine is gaining momentum and recognition has an effective antidepressant in cases where other treatments have failed. But, like marijuana or MDMT, it may take a while to be integrated into the larger health system. Get six of our favorite Motherboard stories every day by signing up for our newsletter.
PubMed | Guangzhou Medical University, Guangxi Medical University, Colby-Sawyer College and Soochow University of China
Type: | Journal: Respirology (Carlton, Vic.) | Year: 2017
A wide range of common loci have been extensively screened and evaluated for their associations with various complex diseases; however, the relevance of rare variants causing missense substitutions in the protein-coding genes in human diseases is still poorly understood.In this study, we conducted a two-stage retrospective study of a total of 1791 patients with COPD and 1940 controls in southern and eastern Chinese to test relevancies of five rare variants (i.e. p.Glu116Lys, p.Asn118Ser, p.Arg138Cys, p.Ala195Thr and p.Leu259Phe) of human mitogen-activated protein kinase kinase 7 (MAP2K7) to COPD susceptibility. The effects of these loci on lung function were further estimated.The p.Glu116Lys rare variant had significant associations with COPD risk. Compared to individuals with Glu/Glu wild-genotype, those with 116Lys rare variants (Lys/Glu+Lys/Lys) had an increased risk of COPD (OR=3.83, 95% CI: 2.64-5.56; P=1.4510Our data strongly suggest that the p.Glu116Lys rare variant in MAP2K7 predisposes its carriers to develop COPD, which would provide a useful genetic biomarker for COPD susceptibility in Chinese.
PubMed | Guangzhou Medical University, Amity University and Guangzhou Women and Childrens Medical Center
Type: | Journal: Brain research | Year: 2016
A considerable number of studies have demonstrated that nicotine, a 7-nicotinic acetylcholine receptor (7-nAChR) agonist, can dampen immune response through the cholinergic anti-inflammatory pathway. Evidence suggests that inflammation plays a critical role in eclampsia, which contributes to maternal and fetal morbidity and mortality. In the present study, possible anti-inflammation and neuro-protective effects of nicotine via 7-nAChRs have been investigated after inducing eclampsia-like seizures in rats.Rat eclampsia-like models were established by administering lipopolysaccharide (LPS) plus pentylenetetrazol (PTZ) in pregnant rats. Rats were given nicotine from gestation day (GD) 14-19. Then, clinical symptoms were detected. Seizure severity was recorded by behavioral tests, serum levels of inflammatory cytokines were measured by Luminex assays, microglia and astrocyte expressions were detected by immunofluorescence, and changes in neuronal number in the hippocampal CA1 region among different groups were detected by Nissl staining.Our results revealed that nicotine effectively improved fetal outcomes. Furthermore, it significantly decreased systolic blood pressure, and maternal serum levels of Th1 cytokines (TNF-, IL-1, IL-6 and IL-12P70) and an IL-17 cytokine (IL-17A), and dramatically increased eclampsia-like seizure threshold. Moreover, this attenuated neuronal loss and decreased the expression of microglial activation markers of the hippocampal CA1 region in the eclampsia-like group. Additionally, pretreatment with -bungarotoxin, a selective 7-nAChR antagonist could prevent the protective effects of nicotine in eclampsia-like model rats.Our findings indicate that the administration of nicotine may attenuate microglial activity and increase eclampsia-like seizure threshold in rat hippocampus through the 7 nicotinic receptor.
News Article | February 23, 2017
For decades, dentists have been strongly recommending that patients brush and floss daily to keep their teeth strong and healthy. A consistent dental hygiene routine also helps reduce the chances of chronic gum disease, or periodontitis, which is a common factor in adult tooth loss. However, since an article published on NetDoctor suggests a link between chronic gum disease and erectile dysfunction (ED), there appears to be another benefit to daily dental care for men. “Although more research is needed to determine if indeed there is a connection, I find these results intriguing,” said Dr. Michel, expert urologist and founder of the renowned Los Angeles urology practice Comprehensive Urology. “Heart disease has been tied to periodontitis, which has also been found to be associated with an increased risk of overall inflammation throughout the body. From there, we know that chronic inflammation can lead to a hardening of the arteries and increase one’s risk of a stroke, which are factors that are also linked to ED.” The study, conducted in association with China’s Guangzhou Medical University, was a review of data from five separate studies. The results from each study found that erectile dysfunction was more common in men with chronic gum disease. Interestingly, it was found to be more common in men under the age of 40 and over the age of 60. “Diabetes has been linked with both ED and gum disease, yet even when you take that into consideration, the results showed that ED is more than twice as likely in men with gum disease than it is in men who don’t have the disease,” Dr. Michel said. “However, this doesn’t mean that men with gum disease should suddenly be anxious about their sex life or that men with ED should necessarily see their dentist. We still need to determine the extent of the connection because there are similar risk factors for both ED and chronic gum diseases, such as smoking, alcohol consumption, and aging.” Erectile dysfunction affects men of all ages for a variety of reasons, be they physical or psychological. ED can adversely affect a man’s self-esteem as well as intimacy with his partner and should not be ignored. To learn more about this condition, including potential causes and treatment options, visit https://Comprehensive-Urology.com/Erectile-Dysfunction/. “Though the study did have limitations, the results should be considered further, particularly in light of a 2013 study that found ED symptoms improved in men after undergoing treatment for gum disease,” added Dr. Michel. “Accordingly, it’s our duty as urologists to make our patients aware of this possible connection between chronic periodontitis and erectile dysfunction. In general, before getting any type of treatment, I recommend men with ED adjust their diets and lifestyles, such as losing weight, maintaining a balanced diet, quitting smoking, and reducing stress.” Kia Michel, MD, earned his medical degree at the University of Washington School of Medicine and completed his residency at UCLA. He has also been recognized as a National Pfizer Scholar. As one of the founding members of the reputable Comprehensive Urology Medical Group, located in the Cedars-Sinai Medical Towers in Los Angeles, California, Dr. Michel treats a host of urological diseases. One of the few urologists who is both an acclaimed vaginal reconstructive and minimally invasive surgeon, Dr. Michel is a compassionate doctor who has dedicated his career to providing state-of-the-art care for his patients with a warm, nurturing touch. Comprehensive Urology is a renowned urological practice in Los Angeles that provides state of the art urological care in a personalized and compassionate environment. The physicians at Comprehensive Urology are board-certified urologists with specialty training in a number of different aspects of urology and provide tailored care for their patients with outstanding results. Call them today at (310) 499-2756 or visit: http://www.Comprehensive-Urology.com.
News Article | April 20, 2016
At the Karolinska Institute in Stockholm, Fredrik Lanner is preparing to edit genes in human embryos. It’s the kind of research that sparked an international frenzy in April last year, when a Chinese team revealed that it had done the world’s first such experiments1. But Lanner doesn’t expect his work, which will explore early human development, to cause such a fuss. A year of discussion about the ethics of embryo-editing research, and perhaps simply the passage of time, seems to have blunted its controversial edge — although such work remains subject to the same ethical anxieties that surround other reproductive-biology experiments. “At least in the scientific community, I sense more support for basic-research applications,” says Lanner, who gained approval for his experiments last June. His instinct seems to be borne out by the fairly muted reaction to a 6 April report2 of an experiment to edit human embryos — only the second to be published. A team led by Yong Fan at Guangzhou Medical University in China used the gene-editing technology CRISPR–Cas9 to try to introduce a mutation that makes humans resistant to HIV infection. “I don’t think there is anything wrong with what these scientists have done,” says Sarah Chan, a bioethicist at the University of Edinburgh, UK. “This work isn’t seeking to do what is still ethically in question. It’s not seeking to create genetically modified human beings.” The ethics committee of the university-affiliated hospital that approved Fan’s work says that it has green-lighted two other embryo-editing projects; such research is ethically sound because it will lead to improvements in gene-editing technology and could help to prevent diseases, a committee spokesperson says. Last December, an international summit of scientists and ethicists declared that gene editing should not be done in human embryos that are intended for use in establishing a pregnancy — but it endorsed basic research. “People are more understanding of this research,” says Fan, who points to UK fertility regulators’ approval in February of a proposal by developmental biologist Kathy Niakan to edit genes in healthy human embryos, at the Francis Crick Institute in London. Fan’s team began its experiments in early 2014 and originally submitted the paper to Cell Stem Cell, Fan says. By the time the manuscript ended up on the desk of David Albertini, editor-in-chief of the Journal of Assisted Reproduction and Genetics, a different Guanghzou-based team had become the first to report human-embryo-editing experiments. That paper1, which tried to correct a mutation that causes a blood disease, fed into a firestorm over the ethics of modifying human reproductive cells (or ‘germline’ modification). Some researchers called for a moratorium even on proof-of-principle research in non-viable embryos. Albertini, a reproductive biologist at the University of Kansas Medical Center in Kansas City, felt that it was important to publish Fan’s paper to educate scientists and clinicians. He says that the manuscript went through two rounds of review over eight months — twice as long as is normal for the journal — and that he urged the researchers to discuss the ethical issues surrounding germline editing in the paper. Fan’s paper should help to reassure international observers about the legitimacy of human-embryo-editing research in China, says Robin Lovell-Badge, a developmental biologist at the Crick. More such embryo-editing papers are likely to be published, he adds. “I know that there are papers floating around in review,” he says.“I’d much rather everything was out in the open.” (Fan says that his team is now focusing on improving the efficiency of CRISPR using human stem cells). Research involving the editing of human embryos will begin soon elsewhere in the world, if it hasn’t done so privately already. In a Cell paper published on 7 April3, Lanner’s team analysed gene expression in 88 early human embryos and is using those data to identify genes to disrupt in embryos using CRISPR–Cas9. Lanner will discuss the work at a meeting on human gene editing organized by the US National Academy of Sciences and National Academy of Medicine this month in Paris. He says that the experiments could begin in the coming months. Evan Snyder, a stem-cell scientist at the Sanford Burnham Prebys Medical Discovery Institute in La Jolla, California, says that he doesn’t know of anyone in the United States conducting human embryo editing. But he thinks that US scientists will inevitably take on such research, although federal funding of research on human embryos and germline modification is prohibited. It is important for such research to go forward, Snyder adds, to determine whether technical hurdles would prevent clinical applications. Norms for conducting and publishing human-embryo-editing work are still taking shape. Snyder says that whenever possible, researchers should use alternatives, such as embryos of non-human primates. And when it is not, they should use only surplus embryos that would ordinarily be discarded from in vitro fertilization clinics. Both Chinese teams used non-viable embryos, but Lovell-Badge says experiments in normal embryos are also important: to see, for instance, whether CRISPR–Cas9 is more or less effective in such cells. Some scientists contend that gene-editing experiments designed to probe human development, such as those planned by Lanner and Niakan, are more valuable than experiments that are intended to lay the groundwork for creating genetically modified humans. “At the moment, there seems little point in pursuing long-term clinical goals when there’s so much not known about the technique with human embryos,” says Lovell-Badge. But Chan thinks there should be ethical latitude for both kinds of research to proceed. “We should give the public the credit for being able to understand the difference between research into genetically modified embryos and genetically modifying human beings,” she says. “I think it’s a good thing if the hubbub dies down a bit.”
News Article | April 8, 2016
Researchers in China have edited the genes of human embryos to make cells resistant to HIV infection. It’s the second reported case of using molecular scissors called CRISPR/Cas9 to alter genes in human embryos. In the new work, published April 6 in the Journal of Assisted Reproduction and Genetics, the researchers snipped a gene called CCR5 to introduce a mutation that prevents HIV from entering cells. Just as in the first report, the researchers used embryos that have three copies of each chromosome and would not grow into a baby if implanted in a uterus. Few embryos in the study were altered in the desired way. Even embryos that contained the intended HIV-blocking mutation in one copy of CCR5 either had normal DNA or an unintended mutation in other copies of the gene. The study “demonstrates that significant technical issues remain to be addressed,” Yong Fan of Guangzhou Medical University and colleagues conclude. “Germline editing” — genetic modification of human cells, including embryos, eggs and sperm, that can be passed to future generations — has been controversial. Because these embryos are not viable, the gene alteration would not be considered germline editing according to guidelines issued after an international summit in December.
News Article | April 8, 2016
The attempt is another controversial test of whether gene-modified people are possible. Chinese fertility doctors have tried to make HIV-proof human embryos, but the experiments ended in a bust. The new report is the second time researchers in China revealed that they had a go at making genetically modified human embryos. The controversial experiments are, in effect, feasibility studies of whether it’s possible to make super-people engineered to avoid genetic disorders or resist disease. “It is foreseeable that a genetically modified human could be generated,” according to Yong Fan, a researcher at Guangzhou Medical University, who published the report. His team collected more than 200 one-cell embryos and attempted to alter their DNA to install a gene that protects against HIV infection. The study, published two days ago in an obscure reproductive journal, was first spotted by reporters at Nature. The scientists cautioned that they believe making actual genetically modified babies should be “strictly prohibited”—but perhaps only until the technology is perfected. “We believe that is necessary to keep developing and improving the technologies for precise genetic modification in humans,” Fan’s team said, since gene modification could “provide solutions for genetic diseases” and improve human health. The Chinese scientists tried to make human embryos resistant to HIV by editing a gene called CCR5. It’s known that some people possess versions of this gene which makes them immune to the virus, which causes AIDS. The reason is they no longer make a protein that HIV needs to enter and hijack immune cells. Doctors in Berlin demonstrated the effect after they gave a man sick from HIV a bone marrow transplant from a person with the protective gene mutation. The man—known since as the “Berlin patient”—was cured of HIV, too. Using the gene-editing method called CRISPR, Fan and his team tried to change the DNA in the embryos over to the protective version of the CCR5 gene in order to show, in principle, that they could make HIV-proof people. Almost exactly a year ago, in a world first, a separate group in Guangzhou said that it had altered embryos in an effort to repair the genetic defect that causes a blood disease beta thalassemia. That set off an ethical debate, and last December the U.S. National Academy of Sciences, along with British and some Chinese scientific leaders, said any attempt to make a gene-edited baby would be “irresponsible,” a message that in many ways seemed directed at IVF doctors in China. In February, U.S. officials went further, calling gene-editing a “weapon of mass destruction” and making a point of singling out the earlier Chinese research. One day endowing people with protective genes could become a real possibility. It would be like a vaccine, except one that is installed in a person’s genome from birth. And there’s a long list of genes people might demand for their children in addition to HIV resistance. One DNA change, for instance, seems to completely prevent Alzheimer’s. Another generates people with twice the muscle mass. But that’s a ways off, and Fan’s team said its experiments essentially flopped. They only managed to successfully edit a handful of embryos, and even these ended up as “mosaics,” or a mix of cells, some of which had the new gene, and some that didn’t.