A new genetic engineering procedure holds the promise of fighting human diseases and revolutionizing agriculture.
Among other things, CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) can “edit” DNA (deoxyribonucleic acid, which has been called “the molecule of life”) to stop cancer cells from multiplying and also make cells resistant to the virus causing AIDS.
It could make crops pest-free, stop illnesses in livestock and provide a new plant-based source of ethanol.
In 2012, University of California researchers, working with a Swedish counterpart, published a study in Science detailing how CRISPR fought a species of bacteria (Streptococcus pyogenes) that causes strep throat and a flesh-eating disease by making two short strands of RNA (the ribonucleic acid present in all living cells), which Cas9, then a mysterious protein, latched onto.
“The sequence of the RNA strands corresponded to stretches of viral DNA and could home in on those segments like a genetic GPS,” WIRED reported. “And when the CRISPR-Cas9 complex arrives at its destination, Cas9 does something almost magical: It changes shape, grasping the DNA and slicing it with a precise molecular scalpel.”
In other words, a “microscopic multi-tool” could be programmed to edit the DNA of animals and plants in wondrous ways — turning genes off or substituting a new version.
It suddenly turned science fiction into reality, prompting ethical, legal and regulatory questions regarding editing species.
Last year an international team of researchers corrected a mutation in dozens of viable human embryos, targeting the MYBPC3 gene that causes the heart muscle to thicken later in life. The condition known as hypertrophic cardiomyopathy is the leading cause of sudden death in young athletes.
In July, the Nuffield Council on Bioethics — a British-based independent group — ruled that editing a human embryo, sperm or egg to influence characteristics is “morally permissible” if conducted in a way that is “ethically acceptable.”
The CRISPR revolution has some Iowa connections.
Feng Zhang, an Iowa-educated medical biologist leading the Broad Institute’s Massachusetts Institute of Technology-Harvard University team, received the first CRISPR patent after editing DNA on animals and plants. (Cal’s CRISPR editing took place in test tubes.)
Zhang’s family emigrated to the U.S. when he was 12. At 16, while attending Roosevelt High School in Des Moines, he earned an internship at the gene therapy research institute at Iowa Methodist Hospital.
University of Iowa doctors at the Wynn Institute for Vision Research used CRISPR in two mice to disrupt a mutant gene responsible for some forms of glaucoma, a leading cause of irreversible blindness.
Iowa State University is using CRISPR to create disease-resistant plants — with a funding assist from the Iowa Soybean Association — that repel pests, improve protein levels and are less susceptible to drought.
CRISPR also could prevent Porcine Reproductive and Respiratory Syndrome in hogs, a disease estimated to cost the U.S. livestock industry nearly $600 million annually.
In addition, according to WIRED, agronomists have used CRISPR to alter yeast DNA to consume plant matter and “excrete ethanol,” which could further reduce reliance on petroleum.
The U.S. Department of Agriculture “has allowed more than two dozen transgene-free plant products with knockout mutations to move forward without regulatory oversight,” according to Future Science.
However, that’s not the case in Europe.
A 2001 Court of Justice of the European Union (ECJ) ruling put stringent regulations on genetically modified organisms — species with entire genes or long stretches of DNA inserted into a plant. It made an exception for organisms when the DNA didn’t include a foreign genetic material or was modified by techniques such as irradiation.
That gave European scientists hope CRISPR would escape the GMO stigma that has prompted some consumer wariness. But in late July the ECJ held CRISPR to the GMO standard.
“It is an important judgment, and it’s a very rigid judgment,” Kai Purnhagen, a Dutch legal scholar specializing in European and international law, told Nature. “It means for all the new inventions such as CRISPR–Cas9 food, you would need to go through the lengthy approval process of the European Union.”
That gives non-European Union nations an agricultural research advantage.
Yet with all the exciting CRISPR possibilities, it’s still imperative to get things right, particularly regarding procedures on people.
For instance, last December U.S. researchers published a study in the Proceedings of the National Academy of Sciences “suggesting” that genetic differences between patients could complicate the design of CRISPR-based therapies.
In effect, they were addressing CRISPR accuracy. For all of CRISPR’s potential benefits, when splicing up an individual’s DNA, it’s a concern that should be heeded until more clinical studies are concluded.