A California “human biohacking” bill calls for warnings on do-it-yourself genetic-engineering kits.
HOUSTON — (July 30, 2019) One of the most extensively studied genes in cancer, TP53 is well known for its role as a tumor suppressor. It senses cellular stress or damage, and in response stops cell division or initiates cell death, thereby preventing a damaged cell from reproducing. Mutation of this gene eliminates a key cellular fail-safe mechanism and is a step leading to cancer. Researchers at Baylor College of Medicine have conducted the most comprehensive study of TP53 mutations to better understand the processes leading to the inactivation of this important gene. Their findings, published in the journal Cell Reports, shed light on how the gene becomes mutated and how those mutations can help predict clinical outlook.
The team, led by Dr. Larry Donehower, professor of molecular virology and microbiology at Baylor College of Medicine, studied 10,225 patient samples from 32 different cancers, from The Cancer Genome Atlas, and compared them to another 80,000 mutations in a database collected over three decades by Dr. Thierry Soussi, professor of molecular biology at Sorbonne University. After analyzing this large data sample, they have a more thorough understanding of how the TP53 gene mutation impacts cancer.
The team found that across all cancer types studied, TP53 mutations were more frequent in patients with poorer survival rates. But they also identified a way to more accurately predict prognosis. Donehower said he identified four upregulated genes in mutant TP53 tumors, whose expression correlated to patient outcome.
The black mouse on the screen sprawls on its belly, back hunched, blinking but otherwise motionless. Its organs are failing. It appears to be days away from death. It has progeria, a disease of accelerated aging, caused by a genetic mutation. It is only three months old.
I am in the laboratory of Juan Carlos Izpisúa Belmonte, a Spaniard who works at the Gene Expression Laboratory at San Diego’s Salk Institute for Biological Studies, and who next shows me something hard to believe. It’s the same mouse, lively and active, after being treated with an age-reversal mixture. “It completely rejuvenates,” Izpisúa Belmonte tells me with a mischievous grin. “If you look inside, obviously, all the organs, all the cells are younger.”
Izpisúa Belmonte, a shrewd and soft-spoken scientist, has access to an inconceivable power. These mice, it seems, have sipped from a fountain of youth. Izpisúa Belmonte can rejuvenate aging, dying animals. He can rewind time. But just as quickly as he blows my mind, he puts a damper on the excitement. So potent was the rejuvenating treatment used on the mice that they either died after three or four days from cell malfunction or developed tumors that killed them later. An overdose of youth, you could call it.
In addition to having access to large colonies of monkeys and other species, animal researchers in China face less public scrutiny than counterparts in the United States and Europe. Ji, who says his primate facility follows international ethical standards for animal care and use, notes that the Chinese public has long supported monkey research to help human health. “Our religion or our culture is different from that of the Western world,” he says. Yet he also recognizes that opinions in China are evolving. Before long, he says, “We’ll have the same situation as the Western world, and people will start to argue about why we’re using a monkey to do an experiment because the monkey is too smart, like human beings.”
This story, one in a series, was supported by the Pulitzer Center.
BEIJING, GUANGZHOU, JIANGMEN, KUNMING, AND SHANGHAI—Early one February morning, researchers harvest six eggs from a female rhesus macaque—one of 4000 monkeys chirping and clucking in a massive outdoor complex of metal cages here at the Yunnan Key Laboratory of Primate Biomedical Research. On today’s agenda at the busy facility, outside Kunming in southwest China: making monkey embryos with a gene mutated so that when the animals are born 5 months later, they will age unusually fast. The researchers first move the eggs to a laboratory bathed in red light to protect the fragile cells. Using high-powered microscopes, they examine the freshly gathered eggs and prepare to inject a single rhesus sperm into each one. If all goes well, the team will introduce the genome editor CRISPR before the resulting embryo begins to grow—early enough for the mutation for aging to show up in all cells of any offspring.
Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the CFTR gene. The 3272–26AG and 3849+10kbCT CFTR mutations alter the correct splicing of the CFTR gene, generating new acceptor and donor splice sites respectively. Here we develop a genome editing approach to permanently correct these genetic defects, using a single crRNA and the Acidaminococcus sp. BV3L6, AsCas12a. This genetic repair strategy is highly precise, showing very strong discrimination between the wild-type and mutant sequence and a complete absence of detectable off-targets. The efficacy of this gene correction strategy is verified in intestinal organoids and airway epithelial cells derived from CF patients carrying the 3272–26AG or 3849+10kbCT mutations, showing efficient repair and complete functional recovery of the CFTR channel. These results demonstrate that allele-specific genome editing with AsCas12a can correct aberrant CFTR splicing mutations, paving the way for a permanent splicing correction in genetic diseases.
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Genetics hold far more sway over the mouse microbiome than transient environmental exposures, researchers reported July 26 in Applied and Environmental Microbiology. The results appear to contradict previous studies in humans that have found environmental factors to be more influential than genetics, and they add to an ongoing dialogue in the microbiome research community over how much control we hold over the bacterial communities in our guts.
Hila Korach-Rechtman, a microbiologist at the Israel Institute of Technology in Haifa, set out to identify the microbes in mice that become a fixture in the gut after being introduced through the environment. “We really wanted to find these bacteria that can be transferred and remain in the host, even though they have different genetics,” she says.
Genetically Modified Bacteriophages Appear To Fight Off Resistant Bacteria : Shots — Health News Treatment with genetically altered bacteriophages — viruses that attack bacteria — may have halted a patient’s near-fatal infection, hinting at new ways to fight antibiotic-resistant bacteria.
A soft neural implant that can be controlled by a smartphone is capable of drug delivery and optogenetics. The technology could speed up efforts to uncover the causes of neurological and psychological disorders.
The trial is just one of a few underway to test the powerful CRISPR technology around the world. One of the most promising, for example, is studying whether gene editing can treat, and effectively cure, blood disorders such as beta thalassemia and sickle cell anemia.
In beta thalassemia, the hemoglobin part of red blood cells, which is supposed to pick up oxygen from the lungs and distribute it to the cells in the rest of the body, doesn’t work properly. Patients need to be transfused with donors blood regularly, and even with these transfusions, complications can occur if the dose isn’t right and iron levels in the blood cells spike, which can lead to organ damage and even death. In sickle cell disease, a mutation in the gene that makes hemoglobin causes the red blood cells to collapse into a sickle shape, which makes it more difficult for the cells to flow smoothly through the body’s arteries and veins. Blockages caused by the misshapen blood cells can lead to severe pain and strokes.
The biotech company CRISPR Therapeutics, founded by one of the technology’s co-developers, has engineered a solution to treat both conditions that relies on genetic modifications connected to the production of fetal hemoglobin. Normally fetal hemoglobin, which provides the developing fetus with oxygen via the blood while in utero, is shut off about six months after birth, and genes for adult hemoglobin are turned on. While it’s not clear why adult hemoglobin replaces the fetal version, researchers say that they have not seen any significant differences between the two types when it comes to the ability to transport oxygen to the body’s cells. However, since the genes for adult hemoglobin don’t produce healthy red blood cells in people with beta thalassemia and sickle cell disease, one treatment strategy is to introduce genetic changes that turn on fetal hemoglobin again.
