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Bacteria In Tumors Can Inactivate Common Chemotherapy Drugs, Study Suggests (arstechnica.com)

Posted by BeauHD on from the caught-red-handed dept.

Researchers caught the bacteria Mycoplasma hyorhinis hiding out among cancer cells, thwarting chemotherapy drugs intended to treat the tumors they reside in. The findings have been published this week in Science. Ars Technica reports: Drug resistance among cancers is a "foremost challenge," according to the study's authors, led by Ravid Straussman at the Weizmann Institute of Science. Yet the new data suggest that certain types of drug-resistant cancers could be defeated with a simple dollop of antibiotics alongside a chemotherapy regimen. Dr. Straussman and his colleagues got a hunch to look for the bacteria after noticing that, when they grew certain types of human cancer cells together in lab, the cells all became more resistant to a chemotherapy drug called gemcitabine. This is a drug used to treat pancreatic, lung, breast, and bladder cancers and is often sold under the brand name Gemzar. The researchers suspected that some of the cells may secrete a drug-busting molecule. So they tried filtering the cell cultures to see if they could catch it. Instead, they found that the cell cultures lost their resistance after their liquid broth passed through a pretty large filter -- 0.45 micrometers. This would catch large particles -- like bacteria -- but not small molecules, as the researchers were expecting.

Looking closer, the researchers noticed that some of their cancer cells were contaminated with M. hyorhinis. And these bacteria could metabolize gemcitabine, rendering the drug useless. When the researchers transplanted treatable cancer cells into the flanks of mice -- some with and some without M. hyorhinis -- the bacteria-toting tumors were resistant to gemcitabine treatment.

19 of 38 comments (clear)

  1. no BS-detected alert? by Anonymous Coward · · Score: 1

    This seems actually kind of reasonable. I'm pleasantly surprised that it doesn't seem like wildly out of context pop-science clickbait.

  2. Deactivate by Anonymous Coward · · Score: 1, Informative

    Really get someone with proper English language skills to proof read these crap headlines at least. I know the text beneath it is obviously too much, but at least fix the titles.

    1. Re:Deactivate by Vermonter · · Score: 1

      Inactivate - verb - make inactive or inoperative.
      "household bleach does not inactivate the virus"

      But please, go on about how smart you are when it comes to the English language

  3. Symbiosis? by Viol8 · · Score: 4, Interesting

    I wonder if there's some sort of symbiosis going on between the cancer cells and the bacteria? Food supply in exchange for protection? Perhaps certain bacteria in the body prefer tumours over normal tissue.

    I've not idea, just putting it out there. Perhaps I'm talking utter BS, just curious.

    1. Re:Symbiosis? by cleavet · · Score: 3, Interesting

      That would be a valid avenue of research. My mother's myeloma has responded to chemotherapy much better since it was paired with an antibiotic. This allowed the oncologist to significantly reduce the dosage, with much less discomfort and lower cost.

    2. Re:Symbiosis? by Guppy · · Score: 1

      Perhaps certain bacteria in the body prefer tumours over normal tissue.

      Many successful cancers are now known to have immune-suppressing features -- a major focus of research now involved "Checkpoint Inhibitors" such as PD-1 which interfere with these suppression mechanisms. The bacteria would probably otherwise would be involved in a raging immune battle, if not for the local down-regulation.

  4. That's pretty scary by dwywit · · Score: 4, Insightful

    A bacteria species that can metabolize a drug designed to kill cells.

    Kill rapidly-dividing-and-growing cells of selected cancers, yes - but... it can drink a chemo concoction and just.... burp?

    That's almost scarier than the cancer itself.

    --
    They sentenced me to twenty years of boredom
    1. Re:That's pretty scary by Solandri · · Score: 4, Informative

      A bacteria species that can metabolize a drug designed to kill cells.

      The wiki page on how gemcitabine works is pretty fascinating. The drug as administered doesn't kill cells. It gets modified by enzymes in the cell into a form which interferes with DNA replication and blocks DNA repair. That's what kills the cell.

      Presumably the bacteria are just metabolizing it before these enzymes can convert it into its toxic form (or lack one of the needed enzymes). So no, not a superbug which digests a toxic material.

    2. Re: That's pretty scary by Rutulian · · Score: 1

      It's interesting...

      Another way to think about this is that standard drug pharmacokinetics studies are performed as part of determining dosage and clinical efficacy during clinical trials for (nearly) every pharmaceutical past and present on the market. The metabolic studies are usually performed using tissue cells, liver extracts, and mouse models, which covers the majority of degradation pathways that your drug is likely to encounter...from mammals. What's generally missing is any consideration for commensal or pathogenic microorganisms that might be present. Perhaps this is yet another avenue for the development of personalized therapies.

      It's not a surprising degradation pathway for the drug. It's been known for several decades at least, but because it is a bacterial pathway, it was not included in any of the testing phases.

  5. Can we use the bacteria for good? by Anonymous Coward · · Score: 1

    I wonder if there is a way to ensure that the bacteria only goes where we want? If so we could reduce many of the side effects of chemo by protecting the bone marrow and lymph systems.

  6. Yeah, those horrid vaccine things... by Viol8 · · Score: 2

    ... which have saved hundreds of millions of lives around the world since they were invented. Real, work of the devil they are.

    "this shit is everywhere i dont know what to do anymore"

    You could try educating yourself, then find out how to go and buy and cook fresh produce instead of dining at your local burger bar every day and drinking coke.

    1. Re:Yeah, those horrid vaccine things... by wyHunter · · Score: 1

      ARGH! You anti-anti-waxers don't listen either. Anti-vaxers for the most part do NOT mind vaccinations, they just don't like thimerosol (mercury) compounds in them AND the large number of vaccines given to tiny babies before they really have much of an immune system

  7. Potential upside? by king+neckbeard · · Score: 2

    If we've got bacteria that can shield cells from the effects of chemotherapy, then that could potentially be very useful. If we can get it to do the same thing for the rest of the body in a relatively benign way, then it might greatly improve outcomes for chemo patients.

    --
    This is my signature. There are many like it, but this one is mine.
    1. Re:Potential upside? by jafiwam · · Score: 1

      If we've got bacteria that can shield cells from the effects of chemotherapy, then that could potentially be very useful. If we can get it to do the same thing for the rest of the body in a relatively benign way, then it might greatly improve outcomes for chemo patients.

      Pre-infect kidneys and liver with the bacteria beforehand and help prevent the chemo from causing other problems, or allow for higher dosages.

    2. Re:Potential upside? by Binestar · · Score: 1

      Pre-infect kidneys and liver with the bacteria beforehand and help prevent the chemo from causing other problems, or allow for higher dosages.

      And when we're done we'll send rabbits down to eat the bacteria, and then foxes to eat the rabbits, then ...

      --
      Do you Gentoo!?
  8. Interesting by walterhpdx · · Score: 1

    I'm actually working on converting paper chemotherapy orders to electronic at the moment, and I'm wondering if we are going to need to make slight modifications to our regimens. This is a pretty interesting study. Methinks I'll share it with our lead pharmacist.

  9. Drug Resistant Bacteria by PPH · · Score: 1

    Pretty scary stuff. The human race isn't going to be wiped out by global warming. We are all going to catch something incurable from one of those little ankle-biters crawling around the floor at Starbucks.

    --
    Have gnu, will travel.
  10. Implications for New Drug Testing by rjune · · Score: 1

    If certain bacteria can inactivate chemotherapy drugs, that could skew the data as to how effective the treatment was. A new drug might seem to be less effective than it really is unless the testing protocol takes this into account.

  11. Re:No, you're not really an atheist by ChrisMaple · · Score: 1

    All conventional non-trivial definitions of god lead to contradictions. Things with contradictory properties cannot exist.

    The "conventional non-trivial" qualifier is there to prevent silliness like pantheism and "this rock is god".

    --
    Contribute to civilization: ari.aynrand.org/donate