【ノーベル賞技術】DNAを狙って切るCRISPR、もう病気の治療や食品に使われていた

DNA is like a long instruction book for living things. CRISPR is a tool that can find one place in DNA and change it. It works a little like "find and replace" on a computer. Two scientists who developed it won the Nobel Prize in 2020.

Today, CRISPR is used to treat a serious blood disease. In Japan, some foods made with this technology are already sold.

CRISPR is a technology that lets scientists cut DNA at a chosen spot and change it, a little like the "find and replace" function in a word processor. It comes from bacteria, which store pieces of virus DNA and later use a protein called Cas9 to cut the same virus when it attacks again.

In 2012, Emmanuelle Charpentier and Jennifer Doudna's team showed that this system could be used to cut any DNA simply by changing a guide RNA. They won the Nobel Prize in Chemistry in 2020. In 2023, a CRISPR treatment for sickle cell disease was approved in the UK and the US. In Japan, genome-edited tomatoes and fish are already on the market.

CRISPR-Cas9 has transformed biology by making it possible to cut DNA at a precisely chosen location. The system originated as a bacterial immune defense: bacteria store fragments of viral DNA and use the Cas9 protein to cut matching sequences during later infections. In 2012, Charpentier, Doudna and colleagues demonstrated in Science that the target could be reprogrammed simply by replacing the guide RNA, making genetic modification faster, cheaper and more accurate than earlier methods. The two scientists received the 2020 Nobel Prize in Chemistry. Within a few years, the technology reached patients and consumers.

In 2023, the UK and the US approved the first CRISPR-based therapy for inherited blood disorders such as sickle cell disease, in which patients' own blood-forming cells are edited and returned; in one trial, 29 of 30 patients were free of severe pain crises for over a year. In Japan, edited tomatoes and fish that only switch off or alter their own genes are sold after notification to the government. However, the therapy is extremely expensive and demanding, off-target cuts are still a concern, and the 2018 birth of gene-edited twins in China provoked international condemnation, underlining the need for strict limits on heritable editing.