The breakthrough came in the form of a cardboard cut-out model. The mapping of the double helix structure of the DNA molecule and the consequent storage of genetic information is one of the most important scientific achievements of the 20th century. 70 years ago, on April 25, 1953, the American James Watson and the British Francis Crick published a one-page description in the scientific journal “Nature” that would change molecular biology and the world forever.

Today DNA analysis not only helps solve crimes committed decades ago through genetic fingerprints, but has also revolutionized fields such as agriculture and medicine. In the fight against cancer, great hopes are now being placed on approaches that would have been unthinkable without the discovery of the structure of DNA back then.

How the secret of life was discovered

The development of the coronavirus vaccine by Mainz-based BionTech, which is based on the molecule RNA, ribosucleic acid, would also have been impossible without the seminal discoveries of 1953. RNA is a single-stranded molecule, similar to double-stranded DNA. , which plays a key role in the translation of genetic information into proteins. Biontech is working on cancer vaccines.

One Saturday afternoon, Watson cut cardboard templates of the shape of the nucleic bases, adenine, thymine, guanine, and cytosine, components of DNA, side by side, as he later recounted. He wanted to find out how they were connected to each other. He suddenly recognized that adenine and thymine, guanine and cytosine, each join together to form base pairs, which in turn are arranged in a spiral staircase-like structure, ideally suited for storing vast amounts of information .

In a pub in Cambridge a short time later, the researchers announced that they had discovered the “secret of life,” Watson recalled. This discovery led to the realization that DNA is the carrier of genetic information. By discovering the structure of the double helix, Watson and Crick had already identified the basic features of the process by which DNA is replicated. Like a zipper the two chains can be separated and doubled by completing each with the corresponding building blocks.

“This is a simpler and more beautiful answer than we ever dared hope for,” Watson later said. The two researchers, then working at the University of Cambridge, along with Maurice Wilkins, of King’s College London, were awarded the Nobel Prize in Medicine in 1962. In contrast, the biochemist Rosalind Franklin and her collaborator Raymond Goslig, who died in 1958, were not honored for their contribution, even though they had both published a paper in the same issue of the journal Nature, which supported the findings of Watson and Crick, and with the X-ray diffraction images of DNA (Photo 51) led to the discovery of the DNA double helix.

Hopes for fighting cancers

What has been criticized, however, is that the three Nobel laureates did not recognize the importance of Franklin’s research, from which they had benefited, partly unknowingly. DNA research has made tremendous progress over the past 70 years. But even though the human genome is now considered almost completely decoded, scientists are still at the beginning, as John Diffley of the Francis Crick Institute in London reports in an interview with the German news agency dpa. “We still have a huge amount of work to do to understand how DNA sequences and differences in DNA sequences affect and result in different expressions in organisms and in humans,” explains the head of a group at the Francis Crick Institute in London that deals with reproduction of DNA.

This knowledge is necessary, among other things, for the use of methods, such as the so-called molecular scissor of Crispr/Cas genes. It can be used to switch off individual genes, for example to breed varieties of plants or animal species that are resistant to certain diseases. This method also promises hope for humans in the fight against diseases. For example, developing gene therapies for people with HIV or certain forms of cancer.

Hope for additional methods in the treatment of cancer are also given by other results from DNA research, as Sam Godfrey from the Cancer Research UK organization explains to dpa. For example, in the future tumors are to be genetically analyzed even more often for personalized treatment. One of the fundamental things to understand is that “cancer is not just one disease, it’s an incredible variety of genetic mistakes and other things that cause cells to lose the ability to follow instructions,” he explains. the diagnosis of cancer Increasingly important is the diagnosis of cancer through blood tests, with which the genetic characteristics of cancer cells can be detected much earlier than in the past.

“If it helps diagnose patients earlier, then patients have a much better chance of survival,” says Godfrey. The scientist also refers to recently published research from the Francis Crick Institute, which found remnants of ancient viruses in the human genome that cause an immune response in some people with cancer. This gives hope for an even greater therapeutic approach if these self-healing powers of the body can be activated in a targeted manner. Biontech’s cancer research also focuses on immunotherapy. To this end, the Mainz-based company wants to set up a research and development center in Great Britain, where up to 10,000 patients will be treated with personalized cancer treatments.