CRISPR Is Rapidly Ushering in a New Era in Science

A Battle Is Waged

A battle over CRISPR is raging through the halls of justice. Almost literally. Two of the key players in the development of the CRISPR technology, Jennifer Doudna and Feng Zhang, have turned to the court system to determine which of them should receive patents for the discovery of the technology. The fight went public in January and was amplified by the release of an article in Cell that many argued presented a one-sided version of the history of CRISPR research. Yet, among CRISPR’s most amazing feats is not its history, but how rapidly progress in the field is accelerating.

A CRISPR Explosion

CRISPR, which stands for clustered regularly-interspaced short palindromic repeats, is DNA used in the immune systems of prokaryotes. The system relies on the Cas9 enzyme* and guide RNA’s to find specific, problematic segments of a gene and cut them out. Just three years ago, researchers discovered that this same technique could be applied to humans. As the accuracy, efficiency, and cost-effectiveness of the system became more and more apparent, researchers and pharmaceutical companies jumped on the technique, modifying it, improving it, and testing it on different genetic issues.

Then, in 2015, CRISPR really exploded onto the scene, earning recognition as the top scientific breakthrough of the year by Science Magazine. But not only is the technology not slowing down, it appears to be speeding up. In just two months — from mid-November, 2015 to mid-January, 2016 — ten major CRISPR developments (including the patent war) have grabbed headlines. More importantly, each of these developments could play a crucial role in steering the course of genetics research.

Malaria

CRISPR made big headlines in late November of 2015, when researchers announced they could possibly eliminate malaria using the gene-editing technique to start a gene drive in mosquitos. A gene drive occurs when a preferred version of a gene replaces the unwanted version in every case of reproduction, overriding Mendelian genetics, which say that each two representations of a gene should have an equal chance of being passed on to the next generation. Gene drives had long been a theory, but there was no way to practically apply the theory. Then, along came CRISPR. With this new technology, researchers at UC campuses in Irvine and San Diego were able to create an effective gene drive against malaria in mosquitos in their labs. Because mosquitos are known to transmit malaria, a gene drive in the wild could potentially eradicate the disease very quickly. More research is necessary, though, to ensure effectiveness of the technique and to try to prevent any unanticipated negative effects that could occur if we permanently alter the genes of a species.

A few weeks later, just as 2015 was coming to an end, the New York Times reported that three different groups of researchers announced they’d successfully used CRISPR in mice to treat Duchenne muscular dystrophy (DMD), which, though rare, is among the most common fatal genetic diseases. With DMD, boys have a gene mutation that prevents the creation of a specific protein necessary to keep muscles from deteriorating. Patients are typically in wheel chairs by the time they’re ten, and they rarely live past their twenties due to heart failure. Scientists have often hoped this disease was one that would be well suited for gene therapy, but locating and removing the problematic DNA has proven difficult. In a new effort, researchers loaded CRISPR onto a harmless virus and either injected it into the mouse fetus or the diseased mice to remove the mutated section of the gene. While the DMD mice didn’t achieve the same levels of muscle mass seen in the control mice, they still showed significant improvement.

Writing for Gizmodo, George Dvorsky said, “For the first time ever, scientists have used the CRISPR gene-editing tool to successfully treat a genetic muscle disorder in a living adult mammal. It’s a promising medical breakthrough that could soon lead to human therapies.”

Blindness

Only a few days after the DMD story broke, researchers from the Cedars-Sinai Board of Governors Regenerative Medicine Institute announced progress they’d made treating retinitis pigmentosa, an inherited retinal degenerative disease that causes blindness. Using the CRISPR technology on affected rats, the researchers were able to clip the problematic gene, which, according to the abstract in Molecular Therapy, “prevented retinal degeneration and improved visual function.” As Shaomei Wang, one of the scientists involved in the project, explained in the press release, “Our data show that with further development, it may be possible to use this gene-editing technique to treat inherited retinitis pigmentosa in patients.” This is an important step toward using CRISPR  in people, and it follows soon on the heels of news that came out in November from the biotech startup, Editas Medicine, which hopes to use CRISPR in people by 2017 to treat another rare genetic condition, Leber congenital amaurosis, that also causes blindness.

January saw another major development as scientists announced that they’d moved beyond using CRISPR to edit genes and were now using the technique to control genes. In this case, the Cas9 enzyme is essentially dead, such that, rather than clipping the gene, it acts as a transport for other molecules that can manipulate the gene in question. This progress was written up in The Atlantic, which explained: “Now, instead of a precise and versatile set of scissors, which can cut any gene you want, you have a precise and versatile delivery system, which can control any gene you want. You don’t just have an editor. You have a stimulant, a muzzle, a dimmer switch, a tracker.” There are countless benefits this could have, from boosting immunity to improving heart muscles after a heart attack. Or perhaps we could finally cure cancer. What better solution to a cell that’s reproducing uncontrollably than a system that can just turn it off?