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Biotech Medicine Science

Radioactive Bacteria Attack Cancer 53

Posted by Soulskill
from the incorporate-lasers-and-you've-got-yourself-a-customer dept.
ananyo writes "Two dangerous things together might make a medicine for one of the hardest cancers to treat. In a mouse model of pancreatic cancer, researchers have shown that bacteria can deliver deadly radiation to tumours — exploiting the immune suppression that normally makes the disease so intractable. The researchers coated the bacterium Listeria monocytogenes with radioactive antibodies and injected the bacterium into mice with pancreatic cancer that had spread to multiple sites. After several doses, the mice that had received the radioactive bacteria had 90% fewer metastases compared with mice that had received saline or radiation alone."
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Radioactive Bacteria Attack Cancer

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  • by ackthpt (218170) on Tuesday April 23, 2013 @06:25PM (#43530555) Homepage Journal

    Magically transport them to a parallel universe or pass them through me kidneys?

    I've already been nuked, lymphnodes on my lower left side, so I'm a little aware of side effects and long term prospects (so far so good, touch wood) maybe if we could train bacteria which do not require bringing in radiation we'd really be on to something.

    Still, it's progress.

    • I assume since they are covered in radioactive anti-bodies, that they cannot reproduce and would die eventually from the radiation exposure.

      And I highly doubt they would inject more than a safe limit into you if they did use these for treatment based on your level of kidney function.

      Probably ending up using a whole lot less radiation then the levels that nuked you.
      • by plover (150551)

        Even if the bacteria continue to reproduce in harmful rates, they can be treated later with antibiotics. First things first - target the cancer cells. Then you can worry about what the infection might have done to you.

        • by ackthpt (218170)

          I assume since they are covered in radioactive anti-bodies, that they cannot reproduce and would die eventually from the radiation exposure.

          And I highly doubt they would inject more than a safe limit into you if they did use these for treatment based on your level of kidney function.

          Probably ending up using a whole lot less radiation then the levels that nuked you.

          Yet with radiation which is resident rather than just in passing, via Radiation Therapy. Hmmm.

          Even if the bacteria continue to reproduce in harmful rates, they can be treated later with antibiotics. First things first - target the cancer cells. Then you can worry about what the infection might have done to you.

          One of the concerns every cancer patient will have is the potential of trading longer life later one for longer life now. Sure, back when I was treated it was about the best option available, but the idea of using radiation to kill something which has already mutated, with the potential to create a new mutation is something I'd love to see us move on from.

          • We are working on moving on from that. There are newer nanomedicines that are looking extremely effective. The problem is that those medicines are HARD to make. I mean really really HARD. Some of those things take a team of people a year to create one dosage. That is one reason that I decided to change from being a programmer to doing nanotech/biotech work. A lot of work is needed to turn the lab bench science into practical industrial scale cures. Until then we are going to be stuck with these simpler to m

        • A bacteria infection is a far more immediately lethal condition than cancer... And in some cases harder to treat.

          But I imagine this particular type is less so in both cases.

          • You could probably do some genetic modification to the bacteria to keep it from reproducing or even give it a termination time. Genetic engineering is getting pretty good at kill switches.

          • In the US, Listeria kills 500 people a year. Pancreatic cancer kills 37000. I'd rather have the food poisoning thanks.

            • Yes but the Listeria kills in a week and in severe cases has a 25% fatality rate.

              Pancreatic cancer also has a high mortality rate, but you will not be killed overnight with it.

              If yo had both, doctors could and would ignore the cancer which has a decent chance of killing you in a few months or years time, and focus on the Listeria, which has a decent chance of killing you in the next 8 hours.

          • by plover (150551)

            The bacteria only have to survive long enough to deliver the radiation to the cancer cells, which is a much shorter time frame than the lethality of the bacterial infection itself. Stick the patient in a PET scanner, inject him with the radioactive bacteria, wait a while, and watch until the little buggers to find their way to the tumor. Then begin treatment with cipro. If the bacteria die while inside the pancreas, that's even better - the radiation remains inside their stationary tiny corpses, and will

      • I assume since they are covered in radioactive anti-bodies, that they cannot reproduce and would die eventually from the radiation exposure..

        Even if they can reproduce, the only risk would be pathogenic(which you would want to be careful about in a sick and potentially immunoncompromised patient; but some bacterium can likely be found that is quite harmless). The bacteria themselves can't produce radioactive atoms, they just incorporated the ones that they were doped with before injection, and their descendants will have to be built largely from atoms that were inside your body to begin with... So, even if they establish a permanent population,

    • by quantaman (517394) on Tuesday April 23, 2013 @08:18PM (#43531555)

      From what I understand the bacteria themselves aren't attacking the cancer.

      The bacteria are being covered with radiation, most of the bacteria are quickly killed by the immune system and expelled from the body. But since the tumour suppresses immune activity the bacteria in the tumour last quite a bit longer and keep irradiating the tumour. So basically the bacteria are being used to deliver the radiation directly to the tumour.

      So it sounds like there's no real way of getting around the radiation or radiating your kidneys to some extent. But if you have pancreatic cancer long term prospects probably aren't your primary concern :(

      The other issue is that the other researchers in the article sounded a bit skeptical. It could be this is another example of a medical breakthrough in the headlines that doesn't pan out.

    • by ShanghaiBill (739463) * on Tuesday April 23, 2013 @08:33PM (#43531685)

      Magically transport them to a parallel universe or pass them through me kidneys?

      Many medical isotopes have a half-life of just a few days. So by the time the bacteria are done doing their job, the radioactive isotopes have decayed to a harmless level. Since the half-lives are so short, these isotopes cannot be stockpiled, and need to be generated in a reactor no more than a day or so before they are used. There are only a few reactors in the world configured to make these isotopes. The Chalk River Reactor [wikipedia.org] in Ontario makes most medical isotopes for North America, and there was a major shortage of these isotopes in 2007 when it had to shut for maintenance.

      • Re: (Score:2, Informative)

        by Anonymous Coward

        Half life of the isotope used in this experiment, Rhenium-188, is just under 17 hours.
        http://www.ncbi.nlm.nih.gov/pubmed/9169563

    • With the ability to target cells, specifically immunodeficient cancer cells, the total dosage of radioactive material needed should be greatly reduced. This would seem to be favorable to techniques that target all tissues in the vicinity of a tumor.
    • by AcMNPV (2347552)
      According to the article, this is one of the major concerns and was tested on non tumor cells in the mouse model. They showed that liver and spleen had elevated radiation levels for the first day but that dropped relativly fast and no radiation was detected after a week. They also checked the liver cells for radiation damage and couldn't find anything. Still, your concern is valid and cancer therapy induced tumors are just as bad as the tumors they are supposed to kill. Good luck with your treatment!
  • The treated mice still had metastases of pancreatic cancer.

    • Please, do expound as to why your stated fact is important here.

      • Please, do expound as to why your stated fact is important here.

        Well, it does mean that they aren't 'cured', and probably places a somewhat uncomfortable upper-probable-bound on how long it will take for the tumors to rally and start expanding again. That's a less than optimal outcome.

        On the plus side, there can be a real difference between "Yup, totally fucked, maybe 6 weeks?" and "Yup, totally fucked, 18-20 months, most likely."(especially if the treatment can be made not-terribly-debilitating)

    • by pesho (843750)

      The treated mice still had metastases of pancreatic cancer.

      Life unlike computers is analogue.

  • "Nontoxic radioactive Listeria is a highly effective therapy against metastatic pancreatic cancer"

    So, we're saying that we wasted lots of tumor cells via something nontoxic?

    Is that like saying nontoxic botox because we only let it get to the tissues we wanted paralyzed?

    • by pesho (843750)

      "Nontoxic radioactive Listeria is a highly effective therapy against metastatic pancreatic cancer"

      So, we're saying that we wasted lots of tumor cells via something nontoxic?

      Is that like saying nontoxic botox because we only let it get to the tissues we wanted paralyzed?

      They use an attenuated strain, so it is not going to give you an infection. They can probably charge double - once for cancer treatment and a second time for your Listeria vaccination. From table 2 in the article it appears that the bacteria are cleared from the normal tissue within a week.

      • by Hartree (191324)

        (Yeah, I realized that. It was just too good a straight line to pass up. Should have put a smiley. ;)

  • by bferrell (253291) on Tuesday April 23, 2013 @08:17PM (#43531545) Homepage Journal

    Spiderman, spiderman... Does whatever a spider can... :)

  • by gmuslera (3436) on Tuesday April 23, 2013 @09:31PM (#43532187) Homepage Journal
    If well those bacterias are targetting in a way or another tumours, their radiation they carry could cause on them random changes on the ADN that could lead to more dangerous diseases?
    • by Ambassador Kosh (18352) on Wednesday April 24, 2013 @12:08AM (#43533273)

      You could actually do the math for the mutation rate and the odds of a mutation being useful and weigh that against the odds of survival by the patient without the treatment. The math is probably not too bad and it is something that the scientists involved probably considered. Sure there is a non-zero chance of it happening but without this the odds of surviving pancreatic cancer is close to zero. I had a friend die from that one and it is definitely not the way you want to go. It is a very soft organ and VERY hard to treat with surgery, chemo or other drugs. It is one of the hardest to treat cancers we know of. So this kind of treatment is better than what we have even if it could mutate into something and kill you.

      • by gmuslera (3436)
        Nothing is "more dangerous" than something that will kill you for almost sure, unless it also could spread and kill others. But as you said, odds that turns into something viable and lethal are low, and adding that it should becoming contagious will make it far less likely.
  • Radiation is a cancer treatment.
  • the mice died and were dissected to see the effect on the metastases, that is, long before anything could determined about the radiation effects. So, still a lot of work to be done about how safe this is.

    Also from the article: the treatment does NOT work on the PRIMARY TUMOR. That's important. It likely means an indefinite number of repeat treatments need to follow because the primary tumor is still active. So the treatment might be able to stop the spread of, but not the root of, the cancer. (see co

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