DIYbio - CRISPR injection sites for targeting the ABCC11 gene [closed]

Question

I've been researching into the biohacking world where people most notable Josiah Zayner and Tristan Roberts have used a CRISPR solution developed in their backyard for gene therapy.

There is even a CRISPR guide floating online for the curious, published by Zayner's startup.

However, the guide doesn't help us identify the injection sites in the human body to deliver the solution. Zayner injected Myostatin in his arm muscle.

Another biohacker's Youtube video describes making a pill for targeting stomach cells in a bid to cure lactose intolerance "Developing a Permanent Treatment for Lactose Intolerance Using Gene Therapy"

In general, how does one determine the most suitable site and or methodology for administering CRISPR in the human body that is appropriate for the gene and/or condition we are targeting?

EDIT: Personally, in my case, the gene of interest is ABCC11. I do note that most CRISPR (or any other gene therapy technique for that matter) attempts may target conditions involving more than one gene. However, why I think this gene and its associated conditions is unique is due to the fact much is written online about the effects of a single gene mutation in this particular gene. A paragraph on Wikipedia states:

Physical human traits that are controlled by a single gene are uncommon. Most human characteristics are controlled by multiple genes (polygenes) although ABCC11 is a peculiar example of a gene with unambiguous phenotypes that is controlled by a SNP. Additionally, it is considered a pleiotropic gene.

Official Pubmed documentation : A SNP in the ABCC11 gene is the determinant of human earwax type.

Answer 1

Creating changes in the genome in order to get your favorable results is not always as easy as it looks. Expression of a particular gene is not necessarily bound to its existence. There are other factors (mainly proteins) that have to be in the cell at the right time to make that gene expressed. Yet a trait is not always the result of one gene being expressed. So basically adding one gene will never give you bigger muscles and still, this is not really why performing gene editing in your garage is absurd. (Yes those videos are just hoaxes.)

In order to have a CRISPR/Cas9 system work, you gotta send both the Enzyme Cas9 and the guide RNA into the cell. You can't inject proteins or RNA directly to a cell or expecting cells to uptake them from the bloodstream. The gene constructs for both guide RNA and Enzyme have to be added to a vector which is mostly a virus. The virus had specific receptors on its envelope which help it to target the right cell to infect then viral genome will be inserted into the infected cells and thus they receive the genes that will express CRISPR/Cas system. Designing the gRNA, viral vector and engineering the virus for the specific target cells and applying the virus to the tissue requires precise and professional skill and a decent lab. By no means works done by those guys can lead to verified and trusted consequences. I recommend reading this if you are interested in gene therapy and CRISPR/Cas.

Answer 2

Okay, I didn't want to write an answer to this, because honestly - don't do try this at home.

You have to realise that what Zayner (who does incidentally have a PhD in biochemistry) does is not risk free, very likely not having actual effects besides editing the DNA in some of his cell$^{*1}$ and definitely just barely not illegal (in the US, it's very likely illegal in i.e. the EU).

The science behind gene therapy (which this essentially is) is not easy and trials are just starting to be performed, but mostly using viral vectors, because they are much more efficient and easier to target towards specific cells. While it's possible to target muscles by injecting into them, or cells in the ear by injecting there this always targets all cells in the given area and not just a specific cell type.

Also please note that the article about ABC11 you linked is anything but an 'official documentation': it's a research article published by a japanese research group that states they observed an correlation between earwax phenotype and a certain (SNP) genotype, which is also causative for a change in cGMP signalling of the protein it codes for.

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*1 from this article (which also links to this interview)

But Dana Carroll, a biochemist and CRISPR expert at the University of Utah, said the experiment is unlikely to work as Zayner suggests, pointing out that the gene is most influential when muscles are being developed early in life.

“When your muscles are already developed and you’re sitting there with mature muscles, there’s not a lot you can do to make them bigger and stronger other than exercise,” he told BuzzFeed News. “So he’d be better off exercising than injecting himself.”