Interesting way to fight Cancer
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05-09-2011, 09:31 PM
Interesting way to fight Cancer
These scientists have reprogrammed a bacterial cell that can grow in the body but only around cancer cells. There it releases a special enzyme. The patient is given a drug that is harmless in its normal state but kills cells when it comes in contact with the bacterial enzyme.

http://www.physorg.com/news/2011-09-harm...ancer.html

I really hope this works. It's the beginning of customizing bacterial dna to benefit humanity. We will find out in 2-3 years.

“Forget Jesus, the stars died so you could be born.” - Lawrence M. Krauss
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06-09-2011, 05:12 AM
RE: Interesting way to fight Cancer
This is great, until that bacteria mutates... Do I need to continue?

Smile

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07-09-2011, 02:22 AM (This post was last modified: 07-09-2011 02:58 AM by DeepThought.)
RE: Interesting way to fight Cancer
Bacteria don't mutate that quick and this particular species isn't your standard human pathogen. It would have to change allot before it could become a problem. Even then it would need to become resistant to antibiotics.

We could engineer a kill switch into it. A chemical vulnerability that would instantly kill it. Things like that have been done with other bacterial species modified in labs.
I think the anti-cancer drug kills the cancer cells and the bacteria which are releasing the enzyme simultaneously.

The bacteria would be bred in a controlled environment and it's DNA checked for changes periodically so every patient would get the same bacteria. All this stuff is old technology.

Now its getting cheaper/easier edit DNA. I want to switch to programming in that language myself. DNA readers/writers should be cheap/small enough to sit on my desk 20 years from now.
Within 10 years everyone can get their full DNA sequence for < $50 by visiting a doctor. GATTACA here we come!

The performance/cost of DNA readers is making exponential progress following Moore's Law.
EDIT: FASTER THAN MOORES LAW! Check out this: http://singularityhub.com/2011/03/05/cos...se-graphs/
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99.99% Accurate DIY testing kits are now available for many conditions from Tuberculosis to HIV. Soon a cheap diagnostic will be released that tests many conditions simultaneously (bacteria/virus/cancer) all with a little bit of blood.
Anyone that says the above is impossible is lacking imagination.

“Forget Jesus, the stars died so you could be born.” - Lawrence M. Krauss
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07-09-2011, 04:31 AM
RE: Interesting way to fight Cancer
The mutation of bacteria may not be a major concern. However, the uptake of DNA by the bacteria, transforming the bacteria can be another possible concern for some. The bacteria may take in segments of DNA from the human cells containing the malfunctioned gene, thus expressing said gene and become cancerous itself. Even so, the bacteria may not have the proper expression mechanism to express eukaryotic genes due to different gene expression mechanisms for prokaryotes. As long as the bacteria is harmless by not secreting toxins, and does not trigger an immune response when inside the body, there shouldn't be any major problems.

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07-09-2011, 07:55 AM (This post was last modified: 07-09-2011 09:07 AM by DeepThought.)
RE: Interesting way to fight Cancer
(07-09-2011 04:31 AM)robotworld Wrote:  The mutation of bacteria may not be a major concern. However, the uptake of DNA by the bacteria, transforming the bacteria can be another possible concern for some. The bacteria may take in segments of DNA from the human cells containing the malfunctioned gene, thus expressing said gene and become cancerous itself. Even so, the bacteria may not have the proper expression mechanism to express eukaryotic genes due to different gene expression mechanisms for prokaryotes. As long as the bacteria is harmless by not secreting toxins, and does not trigger an immune response when inside the body, there shouldn't be any major problems.

Usually plasmids would allow the a bacteria to acquire new traits like antibiotic resistance though horizontal gene transfer. Though like you said Human Cells will not accept bacterial DNA, and the immune system would instantly mark any exposed naked DNA for destruction. A plasmid looks like a virus to our immune system.

These bacteria are fresh from a lab so they shouldn't contain any hidden surprises. It's unlikely they can suddenly become a new species with entirely different behavior even if they acquired a new plasmid somehow. It didn't happen in the primate model so far.

Is there a way bacteria can steal DNA from our cell nucleus? Our cells have allot of defense mechanisms, and our chromosomes are different - they are wound around proteins and the ends are capped with telomere repeats instead of being circular.

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08-09-2011, 12:38 AM
RE: Interesting way to fight Cancer
(07-09-2011 07:55 AM)DeepThought Wrote:  Usually plasmids would allow the a bacteria to acquire new traits like antibiotic resistance though horizontal gene transfer. Though like you said Human Cells will not accept bacterial DNA, and the immune system would instantly mark any exposed naked DNA for destruction. A plasmid looks like a virus to our immune system.

These bacteria are fresh from a lab so they shouldn't contain any hidden surprises. It's unlikely they can suddenly become a new species with entirely different behavior even if they acquired a new plasmid somehow. It didn't happen in the primate model so far.

Is there a way bacteria can steal DNA from our cell nucleus? Our cells have allot of defense mechanisms, and our chromosomes are different - they are wound around proteins and the ends are capped with telomere repeats instead of being circular.

Naked DNA do not really trigger an immune response from the body since they do not produce toxins. That may be why naked DNA has an advantage in being used as a vector in gene therapy due to its inability to trigger an immune response. You have a point there in which bacteria will have difficulty obtaining DNA from our cell nucleus due to our compact DNA structure. However, how about other bacteria present in the body? The transfer of DNA from one bacteria to another through conjugation or transformation will confer traits such as antibiotic resistance to the bacteria. I think that can be a risk.

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08-09-2011, 02:04 AM
RE: Interesting way to fight Cancer
I think you are massively overplaying the risk. It's extremely unlikely, also this bacterial species is not a human pathogen.

Plasmids do create an immune response. Lookup DNA vaccination, and one example is in this study: http://www.ncbi.nlm.nih.gov/pubmed/20691019

So one of the bacteria gets resistant to antibiotics. It's still releases an enzyme that activates the anti-cancer drug that will kill it and the neighbouring cancer cells. Also the bacteria only likes low oxygen environments like solid tumours. It's not going to suddenly change it's metabolism and fundamental behaviour after a couple cell divisions is it? Even if you get some bacteria instantly becoming another species it will still have to deal with the anticancer drug and the bodies immune system once the cancer is gone.

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09-09-2011, 04:42 AM
RE: Interesting way to fight Cancer
Then that shouldn't be a problem any more! Big Grin
I was planning to use viral vectors to cure cancer in the future, but bacteria should be safer.

Welcome to science. You're gonna like it here - Phil Plait

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09-09-2011, 04:11 PM
RE: Interesting way to fight Cancer
Just goes to show how the most successful form of life on the planet may turn out to be the most useful thing mankind can use.

Behold the power of the force!
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