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The enzyme commonly used for gene editing is from a bacteria that is a common human pathogen. Bits of these bacteria (including their Cas9 protein) are recogniz
by virusduck 8y ago
The enzyme commonly used for gene editing is from a bacteria that is a common human pathogen. Bits of these bacteria (including their Cas9 protein) are recognized as foreign. Unfortunately, when gene-edited cells are expressing the Cas9 protein, bits of every protein in the cell, including Cas9, naturally get processed and presented on the surface of the cell. There are immune cells (T cells) that monitor for non-self protein bits on the surface of cells, and when non-self is detected, they kill that cell they perceive as infected.
There's a bit more nuance than this, but this makes it significantly more difficult to pull off gene editing in a human.
- TheSpiceIsLife 8y agoCould this be a potential cancer therapy?
- mjevans 8y agoI like your silver-lining take on this. It wouldn't be bad low-hanging fruit to look at if someone hasn't already done that study.
- deleted 8y ago[deleted]
- virusduck 8y agoIn a way, sure. A major roll of the immune system (especially T cells) is to monitor for unusual cells. Some pre-cancerous cells display unusual markers that are recognized and killed by T cells. Those that evade T cell recognition go on to be a problem. The major problem is still how do you target cancer cells? If you can find something that makes them unique, say a cell surface receptor, or an unusual metabolic process, there are lots of ways to target them for removal. It's just hard to uniquely identify cancer cells. Right now, most chemotherapy drugs target the phenotype of "fast replication" which really isn't too selective.
- amelius 8y ago> It's just hard to uniquely identify cancer cells. How about performing whole-genome sequencing on a tumor, and then targeting the differences with the patient's natural genome?
- bottled_poe 8y agoThat sounds way more complicated (expensive) than using a minimalist signature to identify cancerous cells.
- dogma1138 8y agoWith desktop gene sequencers becoming a near commodity product I’m not so sure. There are a companies that currently focus on this area specifically by leveraging the ever dropping costs and capabilities of gene sequencing by developing targeted immunotherapy solutions that can target the specific genetic makeup of a tumor from a biopsy.
- Izkata 8y agoWouldn't work reliably due to cases of genetic chimerism, though that could possibly be tested for. Though, in several cases I've read about, there was no consistent place to get samples to test for mismatched DNA.
- virusduck 8y ago
- subcosmos 8y agoMy thoughts exactly! Here's how it might work : Get a construct into the cell that is only transcribed if specific pathways are overly active, effectively testing that cells "cancer status". This is the hard part..... Then have it translate something pathogenic-looking that gets presented on the surface. So now the question is, how do you design some kind of promoter sequence that looks for, say, tp53 mutations or something similar?