CRISPR-Cas9: Changing your DNA can actually be the cure to cancer and HIV?
If you could alter your DNA and change just one thing, what would it be? What if we told you that it is possible today and that by doing so you could alter your destiny forever? You could, for instance, prevent yourself from suffering potentially deadly diseases. If you knew the answer was yes to any of the aforementioned, would you do it? Would you have the guts to partake in an experimental therapy based on editing your genes? Intrigued? We are too. That's why today we want to talk about this fascinating new technology called CRISPR-Cas9. It is real and won't be leaving anytime soon.
What is CRISPR-Cas9 and How Does it Work?
Gene editing has become quite of a hot topic lately, specially when it comes to finding new ways of treating diseases. Also called genome editing, Gene Editing is a group of technologies that give scientists the ability to change the DNA of an organism. These change can add, remove or alter genetic material at particular locations in the genome. Sounds absurd? Not so much now that several approaches to genome editing have been already developed. The most recent, and probably most talked about, is the CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats - catch your breath - and CRISPR-associated protein 9).
The CRISPR-Cas9 system has generated a lot of excitement in the scientific community because it is faster, cheaper, more accurate, and more efficient than other existing genome editing methods. This type of gene editing process has a wide variety of applications including use as a basic biology research tool and development of biotechnology products. The genome editing system CRISPR has become a hugely important tool in medical research, and could ultimately have a significant impact in fields such as agriculture, bioenergy, and food security. The CRISPR-Cas9 was adapted from a naturally occurring genome editing system in bacteria by Francisco Mojica, a scientist at the University of Alicante in Spain. He proposed that CRISPRs serve as part of the bacterial immune system, defending against invading viruses.
Now researchers at the MIT Media Lab and the Center for Bits and Atoms have discovered a Cas9 enzyme that can target almost half of the locations on the genome, significantly widening its potential use. CRISPR is very accurate and specific, but the recents discoveries should allow CRISPR to target many disease-specific mutations that have previously been out of reach.
CRISPR-Cas9 and its Ethical Controversy
Currently, most research on genome editing is done to understand diseases using cells and animal models. Scientists are still working to determine whether this approach is safe and effective for use in people. There are some interesting research being made to explore CRISPR’s action on a wide variety of diseases, including hemophilia, cystic fibrosis and sickle cell disease. Some scientists hope it will be possible to treat even more complex diseases, such as cancer, heart disease, mental illness and HIV.
Ethical concerns arise when genome editing is used to alter human genomes, specially using technologies such as CRISPR-Cas9. Most of the changes introduced with genome editing are limited to somatic cells (cells that are not eggs or sperm cells). These changes affect only certain tissues and are not passed from one generation to the next. However, changes made to genes in egg or sperm cells or in the genes of an embryo could be passed to future generations. Germline cell and embryo genome editing bring up a number of ethical challenges, including whether it would be permissible to use this technology to enhance normal human traits (such as height or intelligence). Based on concerns about ethics and safety, this kind of genome editing is currently illegal in many countries.
The Bad News: A lot of People May be Immune to Cas9
Not everything is as bright as it seems though. A new research published this week in the peer-reviewed journal Nature Medicine suggests that the immune systems of a large majority of people could already be primed to attack and possibly even disable a key component of CRISPR-Cas9. A team of scientists in Germany exposed blood samples from 48 healthy volunteers to Cas9. The researchers found that 96 percent of the people in the study had T-cell based immunity against Cas9, and 85% had antibodies against it.
Michael Schmueck-Henneresse of Charité University Medicine Berlin, who led today’s study, said that he was initially surprised by the 96% finding. “It made sense because the Streptococcus pyogenes bacterium is one of the most common causes for bacterial infections in humans and we have all been through multiple infections and potentially even been colonized by it”.
Filling in the Safety Gaps of CRISPR-Cas9
No matter how controversial we feel about it right now, CRISPR-Cas9 certainly is a miracle method. Besides all the ethical and scientific concerns, this technique means the first real revolution to genetic engineering. And with the wide range of applications such as tackling fatal diseases or producing industrial bacteria, CRISPR has the strong potential to continue disrupting the science world.
On the other hand, there is so much more to learn about gene editing before we can reveal the dangers of CRISPR technology. Accidental activation of certain genes could lead to extinction of species and other unforeseen effects. The is why the Defense Advanced Research Projects Agency (DARPA) invested $65 million in a project called “safe genes,” a 4-year program that has been created to develop a safer CRISPR gene editing system. 'Safe Genes’ involves 7 selected researcher teams with a mission to refine the editing capabilities of the method by exploring safer ways to gene-engineering, providing tools to remove edited genes from environments and developing defense against possible bioterrorism threats. One thing is clear: CRISRP is here to stay, so we better learn to weigh the risks and benefits of its use.
What about you? Would you change your appearance if you could? Would you agree with changing characteristics on humans that are not even born yet? What would be the limit to the CRISPR-Cas9 potential?