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Gut bacteria from amphibians and reptiles achieve tumor elimination in mice

jaist.ac.jp

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Re: Gut bacteria from amphibians and reptiles achieve tumor elimination in mice

#71

Post by ajuc »

comp_bio wrote: post #45
kinj28 wrote: post #40

I have been working with my dad on his cancer treatment since last year. My interest in the topic has only peaked ever since. (Disclaimer- I am an engineer and not a microbiologist/doctor) Mutations and wrong copying of genome happens all the time in the body and some enzyme has the job of correcting the mutated genes so it doesn’t get into the system. Level 2 defence is T cells killing it as identified as foreign bo…

This is a fascinating niche of evolutionary biology that I have worked in for a while. The short answer is that yes, as far as we can tell all organisms evolve increasingly more efficient replication machinery, however at some point the strength of selection is no longer powerful enough to overcome the strength of genetic drift and some degree of error rate persists. As far as we can tell it seems like population siz…

If the organism is too efficient at preventing mutations - it would evolve slower, right?

Re: Gut bacteria from amphibians and reptiles achieve tumor elimination in mice

#73

Post by jjk166 »

kinj28 wrote: post #40

I have been working with my dad on his cancer treatment since last year. My interest in the topic has only peaked ever since. (Disclaimer- I am an engineer and not a microbiologist/doctor) Mutations and wrong copying of genome happens all the time in the body and some enzyme has the job of correcting the mutated genes so it doesn’t get into the system. Level 2 defence is T cells killing it as identified as foreign bo…

Our L1 defense is actually incredibly good. A human will undergo about 10^16 cell divisions over the course of their lifetime. Around 10^3 to 10^6 of those divisions will result in a mutation that gets past the L1 defenses and need to be eliminated by the T cells. It's not generally easy to make dramatic improvements to something with a 99.9999999% success rate.

The immune system is pretty good too, which means any given improvement to the replication system is, all else being equal, probably going to prevent mutations the T cells would already handle. If you need to do the research to figure out what's getting past the immune system anyways, and improving the immune system is lower hanging fruit, it's the logical place to start.

Re: Gut bacteria from amphibians and reptiles achieve tumor elimination in mice

#74

Post by 3eb7988a1663 »

colordrops wrote: post #66
3eb7988a1663 wrote: post #22

Earlier quoted context omitted.

Prevalence of the disease - if it only impacts 1/100 million, going to be hard to ever find sufficient patient population to test and recoup your investment. Existing quality of treatments - if there are already efficacious drugs on the market - how sure are you that this new therapy will be best in class? Only being as good as the status quo is not an ideal competitive position. Conversely, if there is an unmet need…

I guess I'm not being clear. Are these examples of "good" or "bad" reasons to not go to market? I assume "good"? If so, what would be an example of "bad"? Or vice versa if your meaning was opposite.

Ultimately most of these decisions come down to economics and not mustache twirling villains. The banality of evil.

Simplest "bad" reasons are the wealth of the patients. Malaria, river blindness, guinea worm, etc are terrible diseases that mostly impact poor people out of sight from Western eyes. Spending $X billion developing a drug for a population that can barely afford to feed themselves is not going to make a financial return on investment.

Re: Gut bacteria from amphibians and reptiles achieve tumor elimination in mice

#76

Post by kinj28 »

yes_man wrote: post #68
kinj28 wrote: post #40

I have been working with my dad on his cancer treatment since last year. My interest in the topic has only peaked ever since. (Disclaimer- I am an engineer and not a microbiologist/doctor) Mutations and wrong copying of genome happens all the time in the body and some enzyme has the job of correcting the mutated genes so it doesn’t get into the system. Level 2 defence is T cells killing it as identified as foreign bo…

Cancer sucks and I wish your father the best. Also not a doctor or microbiologist, but just wanted to share my layman’s guess on why fixing enzymes will not completely solve the issue: there’s 2 strands of DNA and to fix the broken (mutated) strand you need to have one correct template strand intact so you know what it should be fixed into. It could be the nucleotides swapped places between strands or are deleted com…

What I meant was there are collection of genes responsible for error correction. If there is a failure in duplication then these genes have not done their job.

Thought experiment, again as a layman, was to see if these genes responsible for error correction at the base level can be fixed or bolstered and that will act like a cancer vaccine. But looks like from other comments that this is even more harder!

Re: Gut bacteria from amphibians and reptiles achieve tumor elimination in mice

#77

Post by isolli »

sinnickal wrote: post #72

http://news.bbc.co.uk/1/hi/health/4155522.stm

In case people don't want to click on a random link, it is actually quite interesting:

Crocodile blood antibiotics hope

Scientists are catching crocodiles and sampling their blood in the hope of finding powerful new drugs to fight human infections.

Even horrific fighting wounds on the animal heal quickly

Re: Gut bacteria from amphibians and reptiles achieve tumor elimination in mice

#78

Post by anotherpaul »

Smileyferret wrote: post #63

Interesting article, but in the full paper their key figure (Fig 2) shows their treatment group of n=3 mice completely responded to the bacterial treatment, but their methods say they treated n=5 mice? Could be an honest mistake but that’s a little concerning for data manipulation. Also agree that using a PD-L1 mab feels like it’s for show especially considering the cancer model they’re using (Colon-26) was shown to…

Yes in figure 2 it's 3 mice, next figure 3 they also have 5 (panel e)

Re: Gut bacteria from amphibians and reptiles achieve tumor elimination in mice

#79

Post by mfld »

ajuc wrote: post #71
comp_bio wrote: post #45

Earlier quoted context omitted.

This is a fascinating niche of evolutionary biology that I have worked in for a while. The short answer is that yes, as far as we can tell all organisms evolve increasingly more efficient replication machinery, however at some point the strength of selection is no longer powerful enough to overcome the strength of genetic drift and some degree of error rate persists. As far as we can tell it seems like population siz…

If the organism is too efficient at preventing mutations - it would evolve slower, right?

Yes, but note the mutation rate of germline cells - that are passed to your offspring and hence influence evolution - is estimated to be two orders of magnitude lower than other (somatic) cells.
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