Survivor. When mice with human tumors received doses of anti-CD47, which sets the immune system against tumor cells, the cancers shrank and disappeared.
Credit: Fotosearch
Posted on 05/31/2012 1:16:07 AM PDT by neverdem
Survivor. When mice with human tumors received doses of anti-CD47, which sets the immune system against tumor cells, the cancers shrank and disappeared.
A single drug can shrink or cure human breast, ovary, colon, bladder, brain, liver, and prostate tumors that have been transplanted into mice, researchers have found. The treatment, an antibody that blocks a "do not eat" signal normally displayed on tumor cells, coaxes the immune system to destroy the cancer cells.
A decade ago, biologist Irving Weissman of the Stanford University School of Medicine in Palo Alto, California, discovered that leukemia cells produce higher levels of a protein called CD47 than do healthy cells. CD47, he and other scientists found, is also displayed on healthy blood cells; it's a marker that blocks the immune system from destroying them as they circulate. Cancers take advantage of this flag to trick the immune system into ignoring them. In the past few years, Weissman's lab showed that blocking CD47 with an antibody cured some cases of lymphomas and leukemias in mice by stimulating the immune system to recognize the cancer cells as invaders. Now, he and colleagues have shown that the CD47-blocking antibody may have a far wider impact than just blood cancers.
"What we've shown is that CD47 isn't just important on leukemias and lymphomas," says Weissman. "It's on every single human primary tumor that we tested." Moreover, Weissman's lab found that cancer cells always had higher levels of CD47 than did healthy cells. How much CD47 a tumor made could predict the survival odds of a patient.
To determine whether blocking CD47 was beneficial, the scientists exposed tumor cells to macrophages, a type of immune cell, and anti-CD47 molecules in petri dishes. Without the drug, the macrophages ignored the cancerous cells. But when the CD47 (antibody) was present, the macrophages engulfed and destroyed cancer cells from all tumor types.
Next, the team transplanted human tumors into the feet of mice, where tumors can be easily monitored. When they treated the rodents with anti-CD47, the tumors shrank and did not spread to the rest of the body. In mice given human bladder cancer tumors, for example, 10 of 10 untreated mice had cancer that spread to their lymph nodes. Only one of 10 mice treated with anti-CD47 had a lymph node with signs of cancer. Moreover, the implanted tumor often got smaller after treatment -- colon cancers transplanted into the mice shrank to less than one-third of their original size, on average. And in five mice with breast cancer tumors, anti-CD47 eliminated all signs of the cancer cells, and the animals remained cancer-free 4 months after the treatment stopped.
"We showed that even after the tumor has taken hold, the antibody can either cure the tumor or slow its growth and prevent metastasis," says Weissman.
Although macrophages also attacked blood cells expressing CD47 when mice were given the antibody, the researchers found that the decrease in blood cells was short-lived; the animals turned up production of new blood cells to replace those they lost from the treatment, the team reports online today in the Proceedings of the National Academy of Sciences.
Cancer researcher Tyler Jacks of the Massachusetts Institute of Technology in Cambridge says that although the new study is promising, more research is needed to see whether the results hold true in humans. "The microenvironment of a real tumor is quite a bit more complicated than the microenvironment of a transplanted tumor," he notes, "and it's possible that a real tumor has additional immune suppressing effects."
Another important question, Jacks says, is how CD47 antibodies would complement existing treatments. "In what ways might they work together and in what ways might they be antagonistic?" Using anti-CD47 in addition to chemotherapy, for example, could be counterproductive if the stress from chemotherapy causes normal cells to produce more CD47 than usual.
Weissman's team has received a $20 million grant from the California Institute for Regenerative Medicine to move the findings from mouse studies to human safety tests. "We have enough data already," says Weissman, "that I can say I'm confident that this will move to phase I human trials."
If Dr. Weissman and his team were on to something that could possibly be a “cure”, you could rest assured his research would disapear along with Dr. Weissman and his team.
There is huge money in treating cancer, not in curing it.
Genetic programming has alwas been the solution to cancer. Turning off the CD47 “do not attack me” flag makes progress on that front.
“There is huge money in treating cancer, not in curing it.”
Isn’t it a shame and a sin that we live in a society that a statement like yours is true.
i would agree with CapnJack ... people have A LOT invested in ‘managing’ cancer.. not curing it.
i really hope Weissman and his team have the research spread across the net, just in case.
There is huge money in treating cancer, not in curing it.
Ohhhh, how right you are. I hate the ribbons and walks and cancer charities because the $ and attention airways goes in the wrong direction. Oncology can be barbaric today.
Cancer can’t be cured because it isn’t a disease. Its a catch-all term to describe a form of cell mutation that is far greater in its diversity than even cancer researchers thought until a few years ago.
Until then, genetics and “personalised therapy” was the holy grail.
That is, until evolution stepped in.
When they began sequencing the genomes of tumors they found that not only are different tumors entirely different animals genetically, but the same genetic diversity exists within different parts of the same tumor due to the fact that cancer evolves rapidly (makes sense when you consider the basic error is in speeded up DNA replication) as it grows.. even with the same tumor.
Thus, a needle biopsy of a tumor of clinically significant size is going to yield a genetic profile that is inconsistent with other parts of the tumor.
Once you add distant metastasis to the problem, the complexities multiply.
As for the foil hat nonsense.. there was tons of money in “managing” polio and TB too, yet I don’t recall hearing about sudden disappearances of vaccine researchers and people doing trials on antibiotic regimens.
Unfortunately its exactly because cancer is so difficult to treat that there is such a vast amount of misunderstanding, funding foolishness and blatant quackery in the field.
Thank God that I’m a 10 year cancer survivor, one day at a time. I have a wonderful Oncology doctor.
You cynics disgust me.
Okay, so now they have found a drug to kill cancer. It will probably be horribly expensive.
Google “ESSIAC”
Inexpensive, available without a prescription, and it kills cancer.
Neat! Thanks!
Yes. Fund research, get research. Reward cures, get cures.
All tax money dedicated to medical research should go into reward funds. Have a bunch of doctors define “cure,” and give out prizes for first, second and third place.
Google “ESSIAC”
Quack cancer cure. It has never been proven sucessful in any test.
essiac’s purported effect on cancer has been reviewed by several major medical and scientific bodies, including the U.S. Food and Drug Administration,[3] the National Cancer Institute,[2] and the American Cancer Society.[4] All have found no evidence that essiac has any effect against cancer. The U.S. FDA described essiac as a “Fake Cancer ‘Cure’ Consumers Should Avoid”.[3] Researchers at Memorial Sloan-Kettering Cancer Center wrote that essiac “has not been shown to treat or prevent cancer” and that its use should be avoided.[5]
^ Barrett, Stephen (July 27, 2010). “Questionable Cancer Therapies: Essiac”. Quackwatch. Retrieved July 5, 2011.
^ a b c d “Patient Information: Essiac/Flor Essence”. National Cancer Institute. July 21, 2010. Retrieved July 5, 2011.
^ a b “187 Fake Cancer “Cures” Consumers Should Avoid”. Guidance, Compliance & Regulatory Information. USFDA. Retrieved 24 May 2011.
^ “Essiac tea”. American Cancer Society - Complementary and Alternative Medicine. American Cancer Society. Retrieved 24 May 2011.
^ “Essiac”. Memorial Sloan-Kettering Cancer Center. March 10, 2011. Retrieved July 5, 2011.
the ‘one minute’ cure, i.e., hydrogen peroxide therapy has a decent record of fighting cancer, and can be done at home and is relatively inexpensive.....
No one is going to dispute that antioxidants like essiac, green/black/white tea are good for you and can have a cumulative positive effect on outcomes when combined with diet and lifestyle changes.
Quackery begins at the point people begin thinking this means the recommendations of oncologists and cancer surgeons should be discarded in favor of a jaunt down to the natural foods store.
It can be a fatal mistake.
Absolutely. WifeOfZeugma is 6 months free of a really nasty breast cancer. I am not sure that I'd submit to the treatment, having seen it up close. A hundred years from now, we'll look at today's chemo treatments, the same way we look at 18th century use of bloodletting and leeches.
P.S. The CD in CD47 stands for cluster of differentiation.
P.P.S. Just ignore the ignorant and cynical comments on the thread.
It should be promising!
The same methodology has been used in a clinic in Baja since the early ‘60s, although its probably not the same substance. The U.S. marshals burned their office down in San Francisco for doing it there.
ping
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