CRISPR Gene Editing Breakthrough could Treat many More Diseases

CRISPR gene editing already promises to fight diseases that were once thought unassailable, but techniques so far have required injecting the tools directly into affected cells. That’s not very practical for some conditions. However, there’s just been a breakthrough. NPR reports that researchers have published results showing that you can inject CRISPR-Cas9 into the bloodstream to make edits, opening the door to the use of gene editing for treating many common diseases.

The experimental treatment tackled a rare genetic disease, transthyretin amyloidosis. Scientists injected volunteers with CRISPR-loaded nanoparticles that were absorbed by the patients’ livers, editing a gene in the organ to disable production of a harmful protein. Levels of that protein plunged within weeks of the injection, saving patients from an illness that can rapidly destroy nerves and other tissues in their bodies.

The test involved just six people, and the research team still has to conduct long-term studies to check for possible negative effects. If this method proves viable on a large scale, though, it could be used to treat illnesses where existing CRISPR techniques aren’t practical, ranging from Alzheimer’s to heart disease.

There are some ethical considerations. Some are already wary about the potential for abusing CRISPR for ‘designer babies‘ and other less-than-altruistic purposes. Bloodstream injections would make it that much easier to perform dubious edits. If used properly, however, this new CRISPR method could avoid (or prevent) suffering that was once considered inevitable.


Gene-Editing: From Pigs To Humans

If any swine is fit to be an organ donor for people, then the dozens of pigs snuffling around Qihan Bio’s facility in Hangzhou, China, may be the best candidates so far. The Chinese company and its U.S. collaborators reported today that they have used the genome editor CRISPR to create the most extensively genetically engineered pigs to date—animals whose tissues, the researchers say, finally combine all the features necessary for a safe and successful transplant into humans.

This is the first prototype,” says Luhan Yang, a geneticist at Qihan Bio. In a preprint published today on bioRxiv, Qihan researchers and collaborators, including Cambridge, Massachusetts–based eGenesis—which Yang co-founded with Harvard University geneticist George Church—described the new generation of animals and various tests on their cells; the researchers have already begun to transplant the pigs’ organs into nonhuman primates, a key step toward human trials.

Qihan and eGenesis aren’t alone in their quest. Several academic and commercial research groups are racing to make up a shortage of life-saving human organs with the comparably sized hearts, kidneys, and livers of pigs. For these cross-species transplants, also known as xenotransplants, the pig’s genome must be re-engineered so that its organs will get along with the new host body. Pigs produce species-specific molecules that set off the human immune system, prompting rejection. Their tissue can also cause abnormal clotting and bleeding when it interacts with human blood. And the pig genome is littered with DNA sequences from viruses that infected the animals long ago and slipped genes into their chromosomes. These sequences, known as porcine endogenous retroviruses (PERVs), have been shown to produce potentially infectious viral particles, though their risk to humans is unclear.