Radioactive Bacteria Attack Cancer

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."

Comments

So how do I pass these radioactive bacteria?

[ackthpt]

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.

Re:So how do I pass these radioactive bacteria?

[MatthiasF]

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.

Re:So how do I pass these radioactive bacteria?

[plover]

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.

Re:So how do I pass these radioactive bacteria?

[ackthpt]

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.

Re:So how do I pass these radioactive bacteria?

[wisnoskij]

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.

Re:So how do I pass these radioactive bacteria?

[quantaman]

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.

Re:So how do I pass these radioactive bacteria?

[fuzzyfuzzyfungus]

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, every generation will be composed more of background-level atoms and less of the radioactive dopants.

Obviously, an injection of radiation isn't a good thing if it can be avoided; but the dose is fixed at the time of injection, and if the bacteria allow it to be targeted more efficiently, the damage to healthy tissues would be less severe. It sounds rather like a more sophisticated version of the 'radioactive seed' technique used on some localized tumors, where small pellets of (biologically inert, vitrified or coated in some way) radioactive material are injected directly into the tumor, so as to deliver a lethal dose of radiation without spreading throughout the body(as with an injection of soluble isotopes) or damaging tissue in the beampath(as with external radiation beams).

The use of bacteria and antibodies presumably allows targeting tumors that are too small, too numerous, or both, for a surgeon with a microscope and a needle to seed each one manually.

Re:So how do I pass these radioactive bacteria?

[ShanghaiBill]

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 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:So how do I pass these radioactive bacteria?

[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

Re:So how do I pass these radioactive bacteria?

[fragMasterFlash]

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.

Re:So how do I pass these radioactive bacteria?

[Ambassador Kosh]

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 make treatments because it is the best we can realistically do right now.

The plus side is our technology is getting better very quickly. A lot of developments are happening quicker than almost anyone ever predicted and things are looking very good long term. It is something that I hope to make a large difference in. So far things are looking very good for that.

Re:So how do I pass these radioactive bacteria?

[Ambassador Kosh]

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.

Re: So how do I pass these radioactive bacteria?

[viperidaenz]

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

Re:So how do I pass these radioactive bacteria?

[AcMNPV]

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!

Re: So how do I pass these radioactive bacteria?

[wisnoskij]

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.

Re:So how do I pass these radioactive bacteria?

[plover]

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 continue to attack the cancer cells until it decays or until the T-cells haul it away.

Remember, this is just the news announcing some promising experiments. It's not a packaged treatment yet. Perhaps they find a way to genetically modify the listeria to produce lower levels of toxins. Perhaps they splice in a weakening mutation that causes it to immediately die in the presence of a certain antibiotic, or when exposed to fairly low levels of RF. Maybe they add Terminator genes to prevent it from reproducing. I'm sure there 's a long list of potential kill-switches that they're already testing out.

Is it risky? Heck, yeah. But is the risk worse than that of pancreatic cancer?

Conclusion:

[EmagGeek]

The treated mice still had metastases of pancreatic cancer.

Re:Conclusion:

[xyourfacekillerx]

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

Re:Conclusion:

[pesho]

The treated mice still had metastases of pancreatic cancer.

Life unlike computers is analogue.

Re:Conclusion:

[Anonymous Coward]

USAsian, sorry...

Re:Conclusion:

[fuzzyfuzzyfungus]

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)

Re:Conclusion:

[fuzzyfuzzyfungus]

If that's the criterion, we might as well just order a bunch of Glock 'particle beam therapy' gear; because the patient is just going to die sooner or later anyway, so it might as well be cheap...

Re:Conclusion:

[Ambassador Kosh]

Except that in 18-20 months some of the cures being tested will be going into phase 1 and 2 trials and those patients can be given a try on that. So far some of them are showing about a 99% success rate in rates for complete eradication of cancer. From a societal perspective it is probably worth it to try and keep someone alive for 18-20 months if a cure is possible during that time. Society has invested a lot of resources in someone by the time they are an adult. If you let the person die you are basically writing that investment off. if there is a decent chance you can cure the person then the investment is not lost and they will probably contribute a lot more in their lifetime than what the treatment was worth.

Re:Conclusion:

[silentcoder]

At the rate we're discovering real and viable cures - 18-20 months is indeed worth it as there is a good chance of that being long enough to be around when a complete recovery becomes possible.
It's happened in my own life. About a year ago very good friend of mine started complaining about severe pain in her side, physio didn't help but the physio noticed something off and suggested she go for a scan. The scan revealed metathesized lymphatic melanoma - the biggest tumour was almost 15cm long, wrapped around her kidney arteries at that.
Initial prognosis: inoperable, incurable - 10 months to live, 18 if she's really lucky.

A surgeon however decided to operate, he knew he couldn't remove the tumor but as he said "I'll cut out as much as I can - and buy you time". He did just that - which turned out be only about 3cm that could be safely cut out, but it bought her a few more months.
4 Months later her oncologist called her to let her know about a drug trial for a new treatment (sorry, I don't know the name) which is a form of chemo based on gene-therapy, it specifically and exclusively targets cells with the specific mutation of the cancer she has, so they can use much higher doses than is usually safe with chemo (because it has almost no side-effects and doesn't affect other cells). He got her into the trial group.

Three weeks ago she announced that all the spread tumors were gone, and the main (original) tumor was down to about 2cm in size. It's likely that when the trial ends she'll still need surgery to get rid of the last bit -but her prognosis now is full recovery and cancer free before the end of this year.

That is why it's worth keeping them alive as long as possible - every DAY we buy them, massively increases their odds of a full recovery.

Re:Conclusion:

[Ambassador Kosh]

These are the stories I love to hear and why I went back to school to help turn those lab bench drugs into industrial scale drugs. We have the technology to cure many of these problems now or at least almost cure them to the point where a LOT of time is bought but making the drugs is very difficult. My goal is to work on making these drugs. A cure without a means of production is not much of a cure.

Re:Conclusion:

[EmagGeek]

I believe the term you are looking for is "high energy particle impact tissue disassociation therapy."

From the PNAS article title:

[Hartree]

"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?

Re:From the PNAS article title:

[pesho]

"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.

Re:From the PNAS article title:

[Hartree]

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

Welcome!

[linear a]

I for one welcome ...

Re:Welcome!

[wisnoskij]

... our radiative bacteria controlled super mutant overloards.

Re:One small problem

[Guido von Guido II]

All we have to do to treat you... ..is dose you with toxic, radioactive bacteria!

Compare it to chemo and radiation therapy. If they can deliver the bacteria safely (which is a big if) and if it ends up delivering less radioactivity to the patient than ordinary radiation therapy, it might end up being safer. Treating cancer is often about trade-offs.

Cue the spiderman theme!

[bferrell]

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

Re:Cue the spiderman theme!

[TuxWithoutPants]

Sure, some folks get spider powers, I have to make them inhale me...

Mutation danger?

[gmuslera]

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?

Re:Mutation danger?

[Ambassador Kosh]

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.

Re:Mutation danger?

[gmuslera]

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.

Re:One small problem

[mbstone]

But you have a choice. You can be implanted with the radioactive bacteria, or you can opt for the fecal transplant behind door #2 which Carol is pointing to down on the display floor.

Re:I'm torn

[mcvos]

The sci-fi fan in me - horrified about the inevitable result of injecting radioactive bacteria into people.

Horrified? What about the new breed of superheroes that will have the same powers as bacteria?

Re:If only....

[mcvos]

Didn't they have a treatment a few months ago that used modified HIV to fight cancer?

I get the impression that medical biologist are deep into mad scientist territory now.

The Problem: the mice died

[fygment]

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 comment on safety)

Re:If only....

[Ambassador Kosh]

Yes and that treatment is looking very promising. The problem is that when I last read up on it the issue is that it is very hard to make. We have an interesting problem right now. We are discovering some miracle level cures but not the miracle level abilities to make them at industrial scales. So some of these new things do work but take several people a year to make one dose so ... That is a major reason I am changing my profession. I plan to be working on turning this lab bench science into industrial work.