This is an interesting new article on the potential hazards of using CRISPR to edit genes (see reference and abstract below).
As some of you may know, CRISPR cas-9 is the technology that is used to modify one's cells ex-vivo (outside of your body) in at least some (perhaps all, but I'm not sure) of the myeloma CAR T-cell therapies currently in trials. The article is very technical, but in a nut they are saying that they are now detecting large, unintended deletions and complex rearrangements of DNA in the lab when performing some types of gene editing using the CRISPR cas-9 technology.
Reference:
Kosicki, M, et al, "Repair of double-strand breaks induced by CRISPR–Cas9 leads to large deletions and complex rearrangements," Nature Biotechnology, July 16, 2018 (full text of article).
Abstract:
"CRISPR–Cas9 is poised to become the gene editing tool of choice in clinical contexts. Thus far, exploration of Cas9-induced genetic alterations has been limited to the immediate vicinity of the target site and distal off-target sequences, leading to the conclusion that CRISPR–Cas9 was reasonably specific. Here we report significant on-target mutagenesis, such as large deletions and more complex genomic rearrangements at the targeted sites in mouse embryonic stem cells, mouse hematopoietic progenitors and a human differentiated cell line. Using long-read sequencing and long-range PCR genotyping, we show that DNA breaks introduced by single-guide RNA/Cas9 frequently resolved into deletions extending over many kilobases. Furthermore, lesions distal to the cut site and crossover events were identified. The observed genomic damage in mitotically active cells caused by CRISPR–Cas9 editing may have pathogenic consequences."
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: Concerns with CRISPR method used in CAR T-cell therapies
I am totally confused. If you would be so kind, what is the point or conclusion of the article?
Thank you!
Thank you!
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Mank - Name: Mank
- Who do you know with myeloma?: Myself
- When were you/they diagnosed?: February 2017
- Age at diagnosis: 56
Re: Concerns with CRISPR method used in CAR T-cell therapies
Mank,
If you look at some of the current trials to treat myeloma, such as CAR-T cell therapy (which is discussed quite a bit on this forum, including this thread https://myelomabeacon.org/forum/post35339.html ) and other novel approaches such as this one https://clinicaltrials.gov/ct2/show/NCT03399448, you will note that these therapies are based on modifying one's T-cells (a type of white blood cell that is key to one's immune system) via editing the genes in the T-cells using the CRISPR cas9 technology.
The article states that there are circumstances where the CRISPR cas9 technology can introduce significant, unwanted changes to the DNA in the cells being modified that weren't discovered in previous studies. Reintroducing modified T-cells back into your body with significant, unwanted to changes to their DNA is clearly not something that one would want to do.
While these mutations are certainly concerning and need to be studied more, it is not clear to me that these types of unwanted mutations may actually be occurring in the various myeloma trials that are using the CRISPR cas9 technology. But it is a subject that one should be bringing up with the appropriate trial director if one is considering one of these new treatments.
If you look at some of the current trials to treat myeloma, such as CAR-T cell therapy (which is discussed quite a bit on this forum, including this thread https://myelomabeacon.org/forum/post35339.html ) and other novel approaches such as this one https://clinicaltrials.gov/ct2/show/NCT03399448, you will note that these therapies are based on modifying one's T-cells (a type of white blood cell that is key to one's immune system) via editing the genes in the T-cells using the CRISPR cas9 technology.
The article states that there are circumstances where the CRISPR cas9 technology can introduce significant, unwanted changes to the DNA in the cells being modified that weren't discovered in previous studies. Reintroducing modified T-cells back into your body with significant, unwanted to changes to their DNA is clearly not something that one would want to do.
While these mutations are certainly concerning and need to be studied more, it is not clear to me that these types of unwanted mutations may actually be occurring in the various myeloma trials that are using the CRISPR cas9 technology. But it is a subject that one should be bringing up with the appropriate trial director if one is considering one of these new treatments.
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: Concerns with CRISPR method used in CAR T-cell therapies
Very interesting article! I'm sure the folks who are working on the CAR-T cell therapies are paying attention, so I expect we'll hear more about this in regards to myeloma therapy somewhere down the road.
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Mike F - Name: Mike F
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: May 18, 2012
- Age at diagnosis: 53
Re: Concerns with CRISPR method used in CAR T-cell therapies
That is precisely why drugs go though such a thorough review by the FDA. If the CRISPER method introduces a high risk level of DNA malignancy, then it will have to be modified before any of the CAR T-cell therapies that rely on it receive final approval.
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Ron Harvot - Name: Ron Harvot
- Who do you know with myeloma?: Myself
- When were you/they diagnosed?: Feb 2009
- Age at diagnosis: 56
Re: Concerns with CRISPR method used in CAR T-cell therapies
Interesting follow up comments on this article can be found here:
http://www.sciencemediacentre.org/expert-reaction-to-study-looking-at-deletions-and-rearrangements-due-to-the-crispr-cas9-genome-editing-technique/
As suggested in the article, I have to believe that any of the clinical trials for myeloma using CRISPR technology do in fact perform a formidable amount of DNA sequencing tests to make sure that this problem does not occur in the modified T-Cells being used in the various trials.
http://www.sciencemediacentre.org/expert-reaction-to-study-looking-at-deletions-and-rearrangements-due-to-the-crispr-cas9-genome-editing-technique/
As suggested in the article, I have to believe that any of the clinical trials for myeloma using CRISPR technology do in fact perform a formidable amount of DNA sequencing tests to make sure that this problem does not occur in the modified T-Cells being used in the various trials.
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: Concerns with CRISPR method used in CAR T-cell therapies
Thank you Multibilly for posting these papers, which are a fascinating look into genomics and cell biology as it stands today in 'in vitro' research.
The consensus among the scientists interviewed seems to be that one should be cautious in using these sorts of techniques. Would you call this splicing of new DNA sequences into existing genomes? Considering that CAR T-cell therapy is already being used in clinical trials, I wonder how the 'in vivo' investigations are done in order to check the modified DNA from the patient's T cells.
The CAR T-cell therapy is not yet approved by Health Canada, but according to newspaper reports may be approved soon.
The consensus among the scientists interviewed seems to be that one should be cautious in using these sorts of techniques. Would you call this splicing of new DNA sequences into existing genomes? Considering that CAR T-cell therapy is already being used in clinical trials, I wonder how the 'in vivo' investigations are done in order to check the modified DNA from the patient's T cells.
The CAR T-cell therapy is not yet approved by Health Canada, but according to newspaper reports may be approved soon.
Last edited by Nancy Shamanna on Wed Aug 22, 2018 6:25 pm, edited 1 time in total.
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Nancy Shamanna - Name: Nancy Shamanna
- Who do you know with myeloma?: Self and others too
- When were you/they diagnosed?: July 2009
Re: Concerns with CRISPR method used in CAR T-cell therapies
Multibilly wrote:
If they weren't checking for these before, then they will be now.
CRISPR technology is potentially so valuable that I have to think that they'll find a way to get around these problems. But if not, then there are other ways to produce CAR-T cells.
As suggested in the article, I have to believe that any of the clinical trials for myeloma using CRISPR technology do in fact perform a formidable amount of DNA sequencing tests to make sure that this problem does not occur in the modified T-Cells being used in the various trials.
If they weren't checking for these before, then they will be now.
CRISPR technology is potentially so valuable that I have to think that they'll find a way to get around these problems. But if not, then there are other ways to produce CAR-T cells.
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Mike F - Name: Mike F
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: May 18, 2012
- Age at diagnosis: 53
Re: Concerns with CRISPR method used in CAR T-cell therapies
Thanks Multibilly. Greatly appreciate your taking time out to translate for me (as I head out the door and head over to my treatment center).
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Mank - Name: Mank
- Who do you know with myeloma?: Myself
- When were you/they diagnosed?: February 2017
- Age at diagnosis: 56
9 posts
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