Thanks to the controversial new technology known as CRISPR, scientists are beginning to make headway in understanding and potentially curing some of the world's most intractable diseases.
Sickle-cell anemia, HIV, schizophrenia and autism -- essentially, anything involving bad DNA is now fair game. The latest example, from a study published earlier this month in the journal Molecular Therapy, focuses on Facioscapulohumeral muscular dystrophy, or FSHD, which is one of the most common forms of muscular dystrophy. The genetic disease causes the muscle fibers in the face, shoulders and upper arms to weaken over time -- and there is no known cure.
Enter CRISPR. This new gene-editing technique allows researchers to easily change, delete or replace genes in any plant or animal, including people. Picture the precision and ease of the find-and-replace function on a word document -- that’s how easy it now is to change the human genome. As an article in the MIT Technology Review put it last year, “This means they can rewrite the human genome at will.” Or, as one bioethicist told The Huffington Post last week, comparing what CRISPR can do to earlier attempts at genetic manipulation, “We used to have a butter knife, now we’ve got a scalpel.”
Biomedical researchers all over the world are now wondering how the technology might change their approach to all sorts of diseases. About a year ago, a team of FSHD researchers, led by Peter Jones at the University of Massachusetts Medical School, decided to give CRISPR a try. They already had a pretty good idea which of the thousands of genes in the human genome caused the disease, but until CRISPR came along therapeutic avenues were limited.
The acronym CRISPR, which stands for (take a deep breath) “clusters of regularly interspaced short palindromic repeats,” refers to both a technique and an actual thing, which is a macromolecular complex. The complex consists of a mix of two different types of biological material, protein and RNA. The RNA seeks out and binds to the targeted gene, like a hunting dog chasing down a fox, and the protein goes to work on it -- the hunter firing a shot.
Why would someone want to hunt down a gene? There’s no one answer to that question. Bad genes are like Tolstoy’s unhappy families -- they’re all bad in different ways. Sometimes a mutated gene doesn’t make the protein it’s supposed to make. When that’s the case, CRISPR can be used to replace this lazy gene with one that actually does its job.
Other times, the gene isn’t lazy, if you will, but is actively malicious -- it makes a protein that it’s not supposed to make, a toxin. That’s the story with FSHD. The U. Mass team figured they’d try to use CRISPR to shut down the gene, to “turn it off.” Until they got started on this study, no one had ever proved that CRISPR could be used to turn off a human disease gene, and the U. Mass researchers themselves weren’t sure it would work.
Well, it did.
The implications of this are pretty huge. The research could pave the way for other valuable studies, according to Charis Himeda, the lead author on the study. “I think progress for any disease is really progress for all diseases, because a lot of these therapies and technologies are going to turn out to be broadly applicable,” she said.
It’s important, however, not to get carried away. Himeda said she didn’t know specifically which other diseases could possibly be cured as a result of CRISPR inhibition, and she thinks it’s too soon to start testing any of the CRISPR techniques on people. ‘I think there’s reason to be really hopeful that some day it’ll actually lead to great therapies for genetic diseases as long as we’re not too eager to get this to the clinic right away,” she said.
Himeda’s use of CRISPR may be less risky than some of the other potential therapies. Replacing bad genes, as other scientists have done, involves cutting away pieces of DNA. To simply stop them from making stuff, as the U. Mass team has done, is less likely to cause the genes any permanent damage. But that doesn’t mean the technique is risk-free. Himeda points out that while they achieved a 50 percent reduction in expression of the FSHD disease gene, we still don’t know what the effects are on all the other genes in a cell. “There are things that we don’t understand yet that we need to characterize before we move forward,” Himeda said.
There’s a bigger ethical question at play here, too. Many people think it’s simply a bad idea to meddle with the human genome, no matter what technique you use or how good your intentions are. The fact that CRISPR is so easy to use makes it especially frightening. What happens if it ends up in the wrong hands? If sci-fi has taught us anything, it’s that it won’t end well. Think the 1997 futuristic thriller "Gattaca," where some children are conceived through genetic engineering to ensure a perfect -- and disease-free -- life, while others, known as "in-valids," are relegated to a brutal existence of menial labor.
Even Himeda worries about that. “People talk about it as a great tool, and it’s promising, but it’s also scary,” she noted. “We’re not ready for ‘Gattaca.’”
Lila Shapiro covers the science fiction of science, the imaginative ways scientists are trying to solve the world’s hardest problems. Tips? Email Lila@huffingtonpost.com