CRISPR: Modernising Medicine

CRISPR: Modernising Medicine

  Sci-fi films often depict a boundless view of medicine, whereby one can step into a futuristic pod-like machine, several buttons can be pressed and an individual is almost instantly cured of any bodily ailment. Although medicine is most definitely not there yet, something has entered the forefront of scientific research for its ground-breaking possibilities. Crispr stands for Clustered Regularly Interspaced Short Palindromic Repeats, and it is the crux of genome editing technology.

  Crispr is used to make reference to CRISPR-Cas9 and other systems which can be employed to target specific sections of DNA along a selected portion of genetic code in order to alter them, and often lead to permanent modification within living cells. When mutations take place in a human genome that lead to disease, Crispr can be used to make the necessary changes so the disease does not take full effect.

So, how does Crispr work?

A Crisper ‘spacer’ sequence will be transcribed into an RNA sequence; this will act as a guide to a complementary section of DNA. Once the DNA has been located, Crispr will release an enzyme known as Cas9, which serves to cut the DNA so the selected gene is effectively shut off. Scientists have even been able to improve the system further by having Cas-9 activate gene expression as opposed to cutting the DNA, to enhance research into various diseases. Importantly, the Crispr-Cas9 technology is proving to be far more efficient than existing genome editing systems.

Crispr has proved to be already successful in its application in certain areas, with a study published by PNAS highlighting how researchers were able to remove a gene sequence present in mosquitoes and substitute in a separate gene causing it to become resistant to Plasmodium falciparum, which is the parasite which causes malaria. Here, Crispr is accelerating developments that will hopefully prevent the spread of malaria so focus can be transposed to treating and improving the lives of those already affected.

 The most recent advancement related to Crispr is that of growing human transplant organs in pigs. With the use of the technology, the notion is becoming far more feasible, as the editing process means scientists can remove life threatening viruses from the animals DNA, so xenotransplantation can take place (the transplantation of tissues and organs from an animal to a human). Within the pig genome, Porcine endogenous retroviruses are permanently integrated, causing great risk to humans, but if they can be removed a huge obstacle is overcome. Researchers in America were able to do this, completely deactivating the retroviruses from a line of pig DNA. Steps still need to be taken to bring this to fruition on a larger scale, but the technology is more than promising in helping to alleviate the shortage in donor organs.

  However, professionals warn that Crispr is not be exploited, and should only be used where necessary. The underlying problem of ‘designer babies’ and vanity projects are inherent to the advancements in genome editing, with people wishing to go further than freeing babies of disease, hoping to have free reign on features such as eye colour and complexion. Although the project is important to the realm of medicine, we must be careful to preserve integrity and the ethics of the field.

I hope you have found this post interesting, I’m sure there will be many more updates related to Crispr in the future and we will be sure to keep you posted!

By Vicale Czan Alfanti

Universal Medicine

https://www.broadinstitute.org/what-broad/areas-focus/project-spotlight/questions-and-answers-about-crispr
https://www.whatisepigenetics.com/gene-editing-crispr-cas9-designer-babies/

https://www.theguardian.com/science/2017/aug/10/gene-editing-to-remove-viruses-brings-transplant-organs-from-pigs-a-step-closer

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