The CRISPR dilemma

In December 2015, Trends published an article on this revolutionary technique for modifying, deleting or replacing all types of genes. The report called "The Scientific Discussion of the Year" because the method could be used to design children to measure. One of the scientists who discovered this tool still fears that this will happen, as researchers are already conducting clinical trials to eradicate diseases in embryos and adult humans.

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Jennifer Doudna (54) grew up in the midst of exotic flora and fauna of Hawaii. His father taught literature at a local university and encouraged him from a very early age to read about science and mathematics. One day, when she was twelve, she left in her bed the book The Double Helix, written by James Watson, one of the discoverers of the structure of DNA in the 50s: "I read it a rainy afternoon and I was impressed. My head exploded when I realized that experiments could be done around the appearance of a molecule. That's when I started thinking, "Wow, it would be great to work on it," said the American biochemist last year with The Guardian .

Four decades later, the spark that ignited this book led her to be the co-discoverer of a revolutionary genetic editing tool that is now called CRISPR.The technique was developed by Doudna and the French microbiologist Emmanuelle Charpentier in 2012 and allows, roughly, the editing and editing of the genome of any cell, whether it be animal, plant or human. A real scalpel Biology, which in 2015 was described as the greatest discovery of the century in biotechnology, as it gave scientists the unprecedented ability to modify at will the genome of an organism, as does a writer when a scientist does not have a genome. he changes his word or corrects him for orthog raphe in a word processor

This power promised to contribute to the fight against a wide range of diseases such as schizophrenia, Alzheimer's disease and cancer, but it also raised fears. Three years ago, Doudna herself confessed to having had nightmares in which Adolf Hitler had asked her to learn more about her "awesome technology". Even the MIT magazine Technology Review said: "The fear is that this is a way to a future full of great people and baby designers for those who can afford it. blue-eyed, blonde-haired sons, why not create a group of extremely intelligent people who are tomorrow's leaders? "

That's why, three years ago, an academic of University of California at Berkeley had called for a total moratorium on the clinical use of CRISPR in the modification of embryos, ova and sperm. Today, his position has evolved: "We should not be using it today, but maybe in the future, it's a big change for me." early, I thought, why would anyone want to do it? Then, I started listening to people with genetic diseases in their families … Today, that 's all right. happens every day.Many send me pictures of their children.There was one that I could not forget.A mother told me that her young son had been diagnosed with neurodegenerative disease, caused by a sporadic and rare mutation.He sent me an image of this child.He was a lovely baby and he was so pretty in his car.I have a son and that's a good thing. broken heart, "added Doudna in The Guardian .

Fast Forward

Precisely, three years ago, the mistrust of Doudna and his colleagues was the main subject of the CRISPR test were mice whose genome is similar to that of human and non-reproductive cell cultures given by humans. Thanks to the technique of biochemistry, which is generally among the Nobel Prize candidates for medicine, with Charpentier, scientists had already corrected in 2015 the genetic errors of human cells responsible for anemia, leading to blindness and blindness. Heart failure. They also repaired the alterations causing cystic fibrosis, a lung disease whose patients have a life expectancy of 37 years, and replaced in rats the mutation responsible for ocular cataracts.

But China decided to go further. In 2016, his researchers were the first to insert CRISPR-modified white blood cells into an adult human to fight lung cancer. In addition, last year they were the first to use this method to successfully modify a genetic mutation in human embryos created by in vitro fertilization. Your goal? An alteration that causes Marfan syndrome, an incurable disorder that affects the skeleton, eyes, lungs and other body structures and affects one in five thousand people.

Given these advances and the possibility that in the future, they give rise to The children of the design, Doudna explained The Guardian that this was an essential dilemma for science: " What will be the social implications of permission for genetic modification? People will start saying, "I want a son who can measure five feet and has blue eyes? Are we really going to reach that point? Would you do things that are not medically necessary for some people? This is a difficult question. Shadow areas are numerous. "

In fact, the potential of CRISPR has influenced a change in public and societal perception.In the middle of this year, the Nuffield Council of Bioethics of the United Kingdom indicated that modification of the hereditary genome could be" ethically acceptable in certain circumstances. "At the same time, a report released late July by Pew showed that 72% of Americans think that altering the DNA of an unborn child to treat a critical illness is an appropriate use of genetic modification.

CRISPR continues to add promising effects in the fight against disease, and it is only in 2017 that advances such as those of American scientists from US Temple, who used this technique to cancel HIV in living organisms: thanks to CRISPR, they managed to eliminate the virus DNA in animals and they eliminated the infection. , experts at the University of Pittsburgh have succeeded in creating a gene that reduces the size and spread of tumors in mice bearing cells with prostate cancer and liver.

That's not all. Specialists from the American company Locus Biosciences have been able to activate the mechanisms of self-destruction of pathogens with resistance to antibiotics. Even researchers at Emory University have succeeded in modifying the genes for Huntington's disease in mice, reversing the symptoms of this deadly disease that degenerates nerve cells in the brain. And in terms of the environment, Synthetic Genomics has applied CRISPR to create algae that produce twice as much biofuel as their wild counterparts.

For example, we can now change a single letter in the three billion base pairs of the human genome. Since the discovery of the structure of DNA in the 1950s, scientists dreamed of being able to rewrite this code. What would happen if you could correct mutations that cause disease or introduce new beneficial traits into a species? We now have the tool that can do it. And it's getting cheaper and more accessible, "said Doudna in an interview in April 1945 to Foreign Affairs .

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