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

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.

Comments

Symbiosis?

[Viol8]

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.

Re:Symbiosis?

[cleavet]

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.

That's pretty scary

[dwywit]

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.

Re:That's pretty scary

[Solandri]

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.

Yeah, those horrid vaccine things...

[Viol8]

... 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.

Potential upside?

[king neckbeard]

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.