Posted on 11/11/2006 7:20:07 PM PST by cryptical
Embryonic stem cells, the controversial and versatile cells that seem able to do just about anything, have now expanded their repertoire into cancer prevention. A vaccine made from these cells shields mice against developing lung cancer under conditions thought to mimic the effects of smoking.
Safety concerns about injecting stem cells into humans mean that regulatory agencies are unlikely to approve human tests of the vaccine, says lead researcher John Eaton at the University of Louisville in Kentucky.
Nevertheless, he thinks the vaccine is worth testing in people at high risk of developing cancer, such as heavy smokers or people with certain genetic mutations.
Other researchers are more cautious. Cancer vaccines, particularly vaccines made from cells, are notoriously more effective in mice than people, says Jeffrey Weber, an immunotherapist at the University of Southern California in Los Angeles. "The idea is interesting, but the execution may be impossible," he says.
But both Weber and Eaton agree that the finding could lead to new ways to prevent or treat cancer.
A lot in common
Eaton's approach was inspired by the similarities between embryos, embryonic stem cells and tumours. "Embryos and tumours both grow as balls, they derive nutrients from the host, and they both express peculiar proteins - some of them in common," he says.
These shared proteins made Eaton think that a vaccine prompting an immune response to embryonic stem cells would also trigger an attack against tumours.
He and his colleagues injected mice with stem cells and gave the mice a booster shot ten days later. The researchers then transplanted lung cancer cells under the animals' skin — a standard animal model for the disease.
The stem-cell injection protected 20 out of 25 mice from developing tumours, whereas tumours grew in all unvaccinated mice.
"We were absolutely shocked," Eaton says.
Even more effective was a mixture of stem cells and cells engineered to make a molecule that stimulates the immune system. None of the mice given this vaccine developed tumours when implanted with cancer cells.
Eight of nine animals given this treatment were also protected from lung cancer induced by chemicals thought to mimic the effects of cigarette smoke.
Eaton is now testing his approach against other types of cancer. The findings were reported on 8 November at a meeting in Prague on 'Molecular targets and cancer therapeutics', sponsored by a consortium of cancer-research organizations from Europe and the United States.
Weird protein
Although the mice seemed to suffer no ill effects from the vaccine, Eaton admits that injecting live stem cells into people raises safety issues — such as whether the vaccine would make the body attack its own stem cells.
Eaton's team is now looking for the molecules on the embryonic stem cells that give the vaccine its tumour-killing power. That could potentially lead to more effective cancer vaccines with specific components.
The researchers have already discovered one such protein — found mainly in embryos, placentas and tumours. As yet, Eaton is unwilling to say much about it, except: "It's weird."
Looking for such molecules holds more promise than injecting stem cells themselves, says Weber.
I thought so too. I don't get it.
Bingo. Too bad the gun-grabbers will never understand this concept.
Relax. Interferon was all the rage 30 years ago. Personally, I believe in research. My brother who died of leukenmia would be alive today if the research drugs were available 5 years sooner.
--did it depend on sacrificing a human embryo to find a cure.--
There are already about 60 strains of hESCs active when can generate countless more embryonic stem cells. There are probably over a hundred thousand frozen embryos that will eventually be destroyed or 'die' even if not used for medical research. I don't see that embryonic stem cell research requires any additional 'sacrifice' of a human embryo.
Ummm. Does everyone who has lung cancer smoked?
Bingo. I like your thought, reasoned and logical thinking. Not pessimism and hysteria.
--Ummm. Does everyone who has lung cancer smoked?--
Are you implying that smoking is safe?
Which diseases?
Alzheimers, Parkinson's, paralysis from spinal cord injuries, to name a few.
Researching penicillin and cipro, did it depend on sacrificing a human embryo to find a cure.
Which doesn't really have anything to do with the question you originally asked and I answered.
If this isn't to keep abortion rare and legal, what benefit is it for cloning.
I'm not sure I understand the question. Scientists and those who hope for cures from ESC do so for the obvious reasons: They want scientific progress in the area, and the cures it may bring. Also, for the researchers involved, you can add recognition, fame and money.
I do thank you for responding. I'll search it out to find the answers I need.
You're welcome. In your search, I encourage you to learn the scientific issues involved. When arguing the ethics, it will be more effective if you do so with understanding of the science.
Let me give you the bottom line so far: for ESC, the score is ZERO treatments and ZERO human clinical trials. For adult and cord blood, it is 60 treatments and 1,175 human clinical trials. I OPPOSE ESCs on both moral and scientific grounds. Why should we spend money and attention on ESCs when the other, non-ESCs are yielding great results. Makes no sense.
-A8
Nope. You seemed to have missed the point. Since i am not a doctor, nor a cancer research scientist; is all lung cancer caused by smoking?
Whether they mean it or not, the anti-ESC people come off as kind of creepy, because they look like they are rooting for cancer and for people to stay paralyzed
Their repertoire so far being:
1) Heavily rejected by the host.
2) Causing cancer.
3) No actual working treatments for humans.
Compared to adult stem cells which have them beat on the last point 70 to nothing.
The opening sentence is so misleading as to be a lie.
"No that wasn't my original question."
I responded to your example. That's an interesting idea. Ethics and science, in this current environment is that still possible?
I have to assume they had control mice that did not get the treatment that were compared against. This is normal practice, and the research is a total sham if they didn't.
"Embryonic stem cells, the controversial and versatile cells that seem able to do just about anything"
These types of stem cells have never cured anything. This is propaganda.
The stem-cell injection protected 20 out of 25 mice from developing tumours, whereas tumours grew in all unvaccinated mice.
--Their repertoire so far being:
1) Heavily rejected by the host.
2) Causing cancer.
3) No actual working treatments for humans.
But the science doesn't support embryonic research at this time. If it did as advertised, they wouldn't need the federal research dollars because the pharmaceutical companies would be all over it with their own bucks.
In the future--who knows? But such speculation is not science. This is all about hype for research grant money.
... and lots of cold, hard cash.
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