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Nobel Prize in Chemistry goes to the discoverers of CRISPR-Cas / "Discovery is an absolute stroke of luck for the life sciences" / Application of the technology at the Medical Center - University of Freiburg in preclinical studies

The 2020 Nobel Prize in Chemistry goes to Emmanuelle Charpentier and Jennifer Doudna for the discovery and development of the molecular gene scissors CRISPR-Cas. "The discovery of CRISPR-Cas is an absolute stroke of luck for the life sciences. It has triggered a revolution in fields as diverse as medicine, biotechnology and agriculture - and we are only at the beginning," says Prof. Dr. Toni Cathomen, Director of the Institute of Transfusional Medicine and Genetherapy at the Medical Center - University of Freiburg. "The discoverers are quite rightly receiving the Nobel Prize." Cathomen is currently leading preclinical studies on the use of gene scissor technology in patients with HIV or cancer. However, he also calls for clear boundaries. "We want to help patients and not design people according to our wishes," warns the geneticist.

Why is CRISPR-Cas worthy of a Nobel Prize?

Even before CRISPR-Cas, it was possible to edit genetic material at certain locations. However, the method, which was only discovered eight years ago, has major advantages over previous methods. "CRISPR-Cas is very simple, inexpensive and fast," says Cathomen, who was one of the first in the world to adapt gene scissors for human cells around 20 years ago. He is the co-editor of a recently published book that explains the function of CRISPR-Cas in an easy-to-understand way. "With CRISPR-Cas, researchers can carry out experiments in weeks that would otherwise have taken months or even years." The gene scissors can be used in human cells, animals, plants or bacteria.

How do CRISPR-Cas gene scissors work?

"CRISPR-Cas are gene scissors that work in a similar way to household scissors. Instead of paper, we can use them to cut genes," explains Cathomen. "By using gene scissors to cut the DNA at specific sections, we can specifically switch off disease-causing genes or even replace them with healthy genes," says the gene therapy expert. CRISPR-Cas is already being tested in clinical trials for aggressive forms of blood cancer, certain hereditary blood disorders and HIV therapy.

How should HIV therapy based on gene scissors work?

In order for HIV viruses to penetrate and multiply in immune cells, they need an entry portal, the surface protein CCR5. The Freiburg researchers therefore cut the gene for CCR5 out of the immune stem cells of HIV patients. The cells can no longer be infected. "The patients would then be permanently cured of HIV," says Cathomen.

What are the challenges of using CRISPR-Cas?

"Personally, I will never use gene scissors to intervene in the germline of humans. We still don't understand the effects sufficiently," says the Freiburg researcher. Interventions in the germline alter egg and sperm cells and are thus also passed on to later generations. Such interventions are prohibited in Germany, but not in other countries such as the UK, USA or China.

The insufficient precision of the method has been criticized several times. Incorrect cuts could lead to cancer or other serious diseases. "CRISPR-Cas is initially of immense importance for research. It is very important that we do not rush ahead with its use in humans. We must observe all the usual safety precautions in medicine here."

Contact:
Prof. Dr. Toni Cathomen
Director
Institute for Transfusion and Gene Therapy
Uniklinik Freiburg
Phone: 0761 270-34801
toni.cathomen@uniklinik-freiburg.de