Technologia CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats), jeszcze do niedawna kojarzona z fantastyką naukową, dziś pozwala „edytować” ludzkie DNA i ratować życie. Umożliwia leczenie chorób genetycznych uznawanych dotąd za nieuleczalne, a nawet zapobieganie ich dziedziczeniu. Jednakże, w tym samym czasie, budzi ogromne kontrowersje, ponieważ ingeruje bezpośrednio w ludzki genom, co rodzi pytania o granice etyki, odpowiedzialność nauki oraz ryzyko „projektowania” przyszłych pokoleń. Artykuł Ani Żurek (4b) wyjaśnia, jak działa CRISPR, jakie przełomy już przyniósł i dlaczego jednych zachwyca, a innych głęboko niepokoi. Tekst ukaże się na łamach naszej anglojęzycznej gazetki szkolnej AimHigh Magazine. Zapraszamy do lektury!
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CRISPR-Cas9: How It Will Change Our Lives
Humanity is entering a new era, an era where we ourselves could control evolution, cure numerous diseases and even prevent others, all thanks to a microscopic technology called CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats). It’s a genetic engineering technique in molecular biology that enables us to edit our own DNA while we’re alive. I know it sounds like something straight out of a sci-fi movie, but believe me, it’s happening right now. We are already using this technology in medicine, agriculture, and even to create new species. But what we could achieve with CRISPR in the future and what we already achieved in the medical world might just blow your mind.
So what exactly is gene editing? To really understand how CRISPR works, we first have to take a look at what our DNA looks like. DNA is made out of specific molecules that carry information in a four-part code (a sequence of four chemical bases: A, T, C, G). This code is what we call: a gene. Our cells use this sequence as a kind of blueprint for how to make the proteins that build our bodies. So our DNA is basically an instruction for building us, what we look like, what we think like and also how we fight diseases. We’ve had this knowledge for over 150 years, and there were numerous attempts at gene editing, but only now have we really succeeded at it. And believe it or not, but we actually learned about genome editing from viruses. Some viruses called retroviruses (for example, the HIV virus) insert their own genetic material into the host’s genome. And by studying how viruses manipulate DNA and how they get into our DNA, scientists were able to understand how we could potentially change DNA sequences. And that’s what eventually led to the idea of developing the CRISPR method. So let’s dive into how it all works!
CRISPR gene editing is based on a version of the bacterial CRISPR-Cas9 antiviral defence system. To simplify this sentence, viruses and bacteria use proteins (like the Cas9 protein) that are directed by molecules of RNA (which are extremely similar to DNA, they are chemically their cousins) that interact with DNA sequences, they look at the genes on a letter by letter basis, so for example they find a dna sequence: ATTCGCAAG that matches their guide RNA. Then the enzyme cuts the DNA, which allows easy recoding. Once scientists understood how that recoding works, they could alter the sequences and develop the CRISPR method:
CRISPR consists of two components: the Cas9 protein, which is responsible for cutting the DNA, and a guide RNA, which recognises the sequences of DNA that we want to edit. But to be able to use CRISPR, scientists first have to analyse the DNA code and identify the sequence of the gene that is causing, e.g., a health problem. Then, in the lab, they create a specific guide RNA to recognise this gene. When that is done, scientists place the crafted RNA sequence in the Cas9 enzyme. And that’s when this complex is introduced to the target cells. When in our body, CRISPR-Cas9 is able to locate the defective gene and then cut our DNA. Next, scientists can alter the existing genome by modifying, deleting or inserting new sequences. So CRISPR is essentially a programmable tool that can be directed to any DNA sequence and make a change in a controlled way. In summary, we can think of CRISPR like a cut-and-paste text editor for DNA that helps us fix mistakes in our genes. This allows scientists to cure numerous genetic disorders which were thought to be incurable and/or terminal.
Now that we all understand what gene editing is and how it works, I want to talk a bit about how this technology can save and improve lives.
CRISPR can be used in various ways, from making crops resistant to pests to altering heritable genetic disorders that otherwise would be passed on to future generations. Countless people suffer from illnesses caused by genetic mutations, which until now were mostly incurable. The true tragedy of genetic disorders is the fact that they are often passed on from generation to generation. People suffering from them are terrified of having kids because they don’t want them to suffer the way they did, but now, thanks to CRISPR, the faulty gene can be fixed before the child of a sick mother is even born.
The first example of a genetic disorder that is treatable by CRISPR is Sickle cell disease. It’s a blood disorder, where red blood cells are sickle shaped and stiff, which can lead to them blocking blood vessels and cause strokes, anemia and organ damage. It’s caused by a mutated gene producing abnormal hemoglobin. And in this case, treatment is not just an “if” because in the fall of 2023, a CRISPR based therapy has been approved in the USA for sickle cell disease patients. This illness is perfect for a gene editing treatment because it’s caused by a single genetic mutation. In this case, CRISPR therapy doesn’t literally cure the disease, but it suppresses the effect of the mutation, so the patients don’t have to live in ongoing pain and fear anymore. It does so by activating the production of fetal haemoglobin, which is a protein normally made only when were still developing in the womb. When turned back on using CRISPR, it can suppress the effect of the mutation in adult haemoglobin. The first patient to receive this therapy is Victoria Gray, who volunteered for a clinical trial using CRISPR, and since receiving the treatment in 2019, she has not had another sickle cell crisis. Unfortunately, because this treatment is still new and complicated to perform, it’s very expensive, but scientists hope to make it more affordable in the future.
Curing / removing Huntington’s disease in our descendants is another way CRISPR could save lives. This illness causes severe degeneration of the brain over time, and it often runs in families. It usually begins once someone reaches mid life (20’s-40’s). Like sickle cell, it’s caused by a single gene, so it could be curable using CRISPR. The tragedy of this illness is the fact that if you’re a parent who carries this gene, and you pass it onto your children, you are aware of what horrors await your child, and there’s nothing you can do to prevent it. But with CRISPR, scientists could be able to remove this mutation from the embryo, so that the child that is born not only does not bear the Huntington’s trait but also doesn’t pass that trait onto their children, ending this horrible cycle. This has not yet been done, but researchers are actively working to make that possible.
Last but not least, I wanted to talk about an incredible case of a person being saved by CRISPR. A true miracle, a baby named KJ Muldoon who shaped science in 2025 by being the first person to receive a personalised CRISPR-based genome editing therapy. He’s the first person ever to get his genes custom-edited. KJ was born with an ultra-rare genetic condition, called carbamoyl-phosphate synthetase 1 (CPS1), which made his body unable to process protein. When the body breaks down proteins, it produces ammonia, which is usually processed by enzymes in the liver, but CPS1 Deficiency compromises one of these enzymes and causes ammonia to build up in the blood, which can be toxic to the brain-half of babies diagnosed with KJ’s disease die within their first week of life. When a group of researchers heard about this case, they knew that by editing a single broken gene in KJ’s genetic code-fixing the enzyme responsible for processing the ammonia, they could save his life. So using CRISPR, they located the exact gene that needed fixing, and pushed KJ’s cells to correct that DNA and create a new-functioning enzyme. This is so groundbreaking because previous gene-editing therapies, like the sickle cell treatment I talked about earlier, were designed to treat many tens of thousands of people but KJ’s therapy would work only for him. For now, KJ is doing great and scientists hope he won’t need any further treatments, but even if he does, his life was still saved.
Those are only a few examples of what we could achieve in the medical field thanks to CRISPR. Researchers think that maybe someday, thanks to this technology, we could even cure cancer, enhancing our immune system to fight tumour cells more aggressively. Scientists are confident that in the future CRISPR could be used to cure many more genetic disorders like cystic Fibrosis or Muscular Dystrophy, and by repairing broken genes in embryos, prevent dozens of others from even having the chance to ruin a child’s life or kill them. A lot of people are strictly against performing any kind of procedures on embryos, calling it unethical, but when it comes to ending human suffering, in my opinion, once we are capable of performing those procedures without any risks, it would be unethical not to do so. And to really emphasise it I want to use a quote from Jennifer Doudna’s book (who discovered this technology and has won a Nobel price for it), “As Charles Sabine, a victim of Huntington’s disease, put it, ‘Anyone who has to actually face the reality of one of these diseases is not going to have a remote compunction about thinking that there is any moral issue at all.’ Who are we to tell him otherwise?”
Ania Żurek (4b)
