The Japan News / ANN

The Yomiuri Shimbun

This year’s Nobel Prize in Chemistry was awarded to two scientists who developed a method for genome editing, a tool that brought revolutionary changes to the life sciences and holds the promise of treating inherited diseases.

CRISPR/Cas9 “genetic scissors” have exploded in popularity due to their efficiency and ease in making genetic modifications. Yet despite these enormous benefits, this technology has also sparked concerns that human beings could too easily manipulate the genetic makeup of living things.

Until the CRISPR/Cas9 tool was developed by Emmanuelle Charpentier of France and Jennifer Doudna of the United States, modifying the genes of living things was cumbersome work requiring highly specialized technologies. According to Hiroshima University Prof. Takashi Yamamoto, who also is president of the Japanese Society for Genome Editing, CRISPR/Cas9 had a monumental impact on the life sciences.

“It’s efficient, simple to use and cheap. It’s become a technology that any researcher can use,” Yamamoto said.

The tool is close to practical application in the agriculture and fisheries fields. Using CRISPR/Cas9 allows selective breeding that previously took at least 10 years to now be completed in just a few years. In Japan, this technique has been used in research including a University of Tsukuba project to grow tomatoes rich in a compound that controls increases in blood pressure, an Osaka University project to create potatoes free from toxic compounds in their sprouts, and a Kyoto University project to develop red sea bream with more edible flesh.

It also is being used for research into treating genetic diseases and cancer. Conventional genetic treatments involved inserting regular genes from outside the body, but genome editing via CRISPR/Cas9 allows a disease’s genes to be rewritten. This has raised hopes for treating some incurable illnesses.

Akitsu Hotta, a junior associate professor at Kyoto University’s Center for iPS Cell Research and Application, created induced pluripotent stem (iPS) cells from the cells of patients with Duchenne muscular dystrophy, a genetic disease characterized by the gradual degeneration and weakening of the muscles. Hotta then successfully edited the genome of the iPS cells to create normal muscle cells using this tool. He hopes to develop a treatment through which genetic mutations can be corrected inside the patient’s body.

“Genome editing has been astoundingly simple. This breakthrough will lead to the development of various treatment methods,” Hotta said.

“This tool will have medical applications more quickly than other genetic engineering technologies will,” said University of Tokyo Prof. Osamu Nureki, a structural biology expert. He has been engaged in improving genome editing technologies.

“This will have an immeasurable impact on society, which is probably why it was awarded the Nobel Prize so soon,” Nureki added.

Bioethical concerns

In 2018, a Chinese researcher announced that he had used genome editing technology to alter the genes of a human fertilized egg and successfully produce twins. This triggered a barrage of criticism from around the world over concerns about bioethical and safety issues.

“While this technology might be acceptable for treating patients suffering from difficult diseases, using it at the embryo stage was going too far,” said Hokkaido University Prof. Tetsuya Ishii, an expert on bioethics. “Even this technology still has the risk that some off-target genetic information could be rewritten.”

Europe has moved forward with regulations on modifying human embryos, and the United States has essentially banned this practice. In Japan, guidelines prohibit research on returning a genetically modified embryo to the womb, and legislation on this issue is also being written up.

Using CRISPR/Cas9 for crops and foods also has sparked concerns about safety and the negative impact on the environment. The Health, Labor and Welfare Ministry has excluded using CRISPR/Cas9 technology from the examination of genetically modified foods, saying that if it only destroys part of the gene, it is “no different from variety improvement.”

In October 2019, the ministry introduced a voluntary notification system for food products made with the tochnology. However, as of Oct. 1 — one year after the system was launched — not a single developer has submitted a notification.

CRISPR/Cas9, which generates massive profits, is the subject of an ongoing patent dispute between the University of California, Berkeley, where Doudna works as a professor, and the Broad Institute in Cambridge, Mass., which showed the technology could be used in human and other cells.