By Janet Fang
Posting in Cancer
Solid tumor cells carry a "don't eat me" sign to escape attacks by the immune system. Disrupting this signal in mice with human cancer cells shrank the tumors and slowed their growth.
Solid tumor cells carry a “don’t eat me” signal to escape attacks by the immune system. Disrupting this tumor-protecting signal could mean developing a single drug that can fight at least 7 different types of cancer, a new study shows.
Tumor cells from a range of cancer types all express a protein called CD47 – the “don’t eat me” sign that prevents tumors from being chewed up by immune cells.
Solid tumors grow unchecked and metastasize to other sites by evading phagocytosis, the process of being engulfed and digested by immune cells. Years ago, Stanford scientists showed that drugs that block CD47 can eliminate tumors in mice with leukemia and lymphoma.
"What we've shown is that CD47 isn't just important on leukemias and lymphomas," says the new study’s lead author, Irving Weissman from Stanford. "It's on every single human primary tumor that we tested."
In particular, they looked at: ovarian, breast, colon, bladder, glioblastoma (brain), hepatocellular carcinoma (liver), and prostate tumor cells.
They exposed tumor cells to immune cells called macrophages and anti-CD47 molecules in a petri dish. They also transplanted human tumors into the feet of mice, and when they treated the mice with anti-CD47, the tumors shrank and didn’t spread to the rest of the body:
- Only one of 10 mice treated with anti-CD47 had a lymph node with signs of cancer.
- Colon cancers transplanted into the mice shrank to less than one-third of their original size on average.
- In 5 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," Weissman says.
They also found that, while many normal cells in the body also have CD47 to avoid being destroyed, cancer cells have higher levels of CD47 than healthy cells. How much CD47 a tumor made could predict the survival odds of a patient.
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.
A 2010 Weissman study showed that cancer cells also carried an “eat me” sign on them.
The new study was published in the Proceedings of the National Academy of Sciences this week.
Image: CD47 via Wikimedia
Mar 27, 2012
Some people are dubious that the pharmaceutical industry would be motivated to find and produce inexpensive treatments for cancer (as alternatives to current treatments which are lucrative), preferring that they wither on the vine for lack of development. Does that suspicion make it true? Nope. Others appear to be dubious that for-profit corporations could ever deliberately fail to develop effective treatments. Is it credible that an industry would fail to support potential treatments which had the potential of reducing their profits substantially? Probably; that's not outside the range of observed behaviors and does not stretch credulity. It doesn't need to be as dramatic as having taken a working treatment through all clinical trials and knowing it's safe and effective then suppressing it; it wouldn't get that far. More likely if this happened, it would be more subtle, like discounting and dropping any promising leads early if they did not show promise of increased profits. In which case we may not know if those would have panned out or not. It's not tinfoil hat time to suggest that an industry might be motivated by self interest (or even to suggest that it's their proper role to do so, safeguarding their shareholder's interests). All that means is not to dismiss the possibility out of hand, but neither should we believe it without further investigation. Notice that this can co-exist with the same companies also doing positive things in the world (and making a good profit thereby). They need not be all evil (ignore any positives) or all wonderful (ignore any negatives), and we can approve of some parts of the system as it is and disapprove of others. As an aside, we are talking about alleged "effective treatments" for some cancers. It's good to be careful about "cure"; and no one treatment is likely to be effective for all forms of cancer. It's not very credible that there are working alternative "cures for all cancers"; it is credible that there could be inexpensive and effective treatments for some cancers which are not receiving the support needed to become widely known and approved treatments, because of their potential for eroding profits.
Hi all... 1. Cancer treatment and all related treatments are a 1 trillion dollar a year business. 2. FDA has shown it's true colors by spending over 60 million dollars to prosecute Dr. Burznski... and they didn't win, the settlement including moving into 3rd stage human trials in over 70 different anti cancer protocols he has developed and tested. 3. Watch this documentary on Dr. Burzynski's anti neoplastin treatments http://www.burzynskimovie.com/index.php?option=com_content&view=article&id=110 4. There is likely more than one treatment for cancer... and certainly better than the current method. A friend said to me, the only thing big Pharma keeps in mind, is not killing you too quickly..... 5. Our diets and food supply are pretty bad... and that is what is driving our increased percentages of most diseases. 6. Let's keep the way we are going... and we will all die faster and poorer... mark
Don't forget DCA - DiChloroAcetate. This was all in the news just a few years ago. It was found by some Canadians that DCA actually CURED 70-80% of ALL cancers... that's right - ALL CANCERS. They were concerned that no one would put any money into clinical trials because DCA is cheap to manufacture, can't be patented and won't bring anyone a bundle of money. In fact, if a TRUE, LOW COST cure for cancer were indeed found - do you REALLY THINK it would see the light of day? Just look at how many oncology centers, cancer treatment centers, and people dealing with cancer there are in the US and they would almost ALL be out of job immediately. The AMA would NEVER let that happen. And NO, I don't have an aluminum foil hat, but, I AM being realistic!
Healing cancer was an issue about 50 years ago... If you talk to a qualified doctor who seriously wants to heal people and who knows the historical intrigues, he will confirm that effective cancer healing methods have been found back in the sixties. Now we're just "healing" the bank accounts of the pharma industry and supporting Rockefellers! Wake up, this aricle is just advertising expensive drugs! The effective cancer treatment is still surpressed and the same industry that financially supported Hitler is now selling drugs and chemotherapies to desperate people with only one goal, to reduce population.
Bloodroot (Sanguinaria Canadensis) is a Native American and Eastern medicine treatment for cancer that removes the protein coatings on cancer cells, causing cell apoptosis, or cell death. These CD47 proteins allow cancer cells to remain untouched by the immune system (the "don't eat me" sign). Below are two (out of many) cited works produced by respected medical research facilities that look at how Bloodroot (Sanguinaria Canadensis) works on cancer cells, but fall short of actually stating that it "cures" cancer. On the Memorial Sloan Kettering website, the publisher specifically posts a disclaimer on the first page that viewers must read and accept in order to gain access to information on natural herbs and their medical uses. In an article published on Memorial Sloan Kettering website (1) titled "Sanguinarine-induced apoptosis in human leukemia U937 cells via Bcl-2 downregulation and caspase-3 activation," the researchers discuss how leukemia cells die as a result of having the proteins removed or rearranged on the cell surfaces. This is a scientific study by doctors (Han MH, Yoo YH, Choi YH) in the Department of Biomaterial Control (BK21 Program) Dongeui University Graduate School, Busan, South Korea. In another article, this one published by the National Institute of Health ("PubMed") website, a research paper titled "Regulation of survival, proliferation, invasion, angiogenesis, and metastasis of tumor cells through modulation of inflammatory pathways by nutraceuticals" by the Cytokine Research Laboratory, Department of Experimental Therapeutics at The University of Texas MD Anderson Cancer Center in Houston, discusses how diet can affect the proliferation of inflammation, which can lead to the creation of an environment in the body that is conducive to growth and survival of cancer cells. The abstract: How our diet can prevent cancer is the focus of this review. Specifically, we will discuss how nutraceuticals, such as allicin, apigenin, berberine, butein, caffeic acid, capsaicin, catechin gallate, celastrol, curcumin, epigallocatechin gallate, fisetin, flavopiridol, gambogic acid, genistein, plumbagin, quercetin, resveratrol, sanguinarine, silibinin, sulforaphane, taxol, gamma-tocotrienol, and zerumbone, derived from spices, legumes, fruits, nuts, and vegetables, can modulate inflammatory pathways and thus affect the survival, proliferation, invasion, angiogenesis, and metastasis of the tumor. With medical research demonstrating the ability of natural herbs to fight cancer at the cellular level, it appears that a cure for cancer is still "shelved" until pharmaceutical manufacturers can patent and produce Bloodroot, or similar nutraceuticals, for profit. 1 http://www.mskcc.org/cancer-care/herb/bloodroot 2 http://www.ncbi.nlm.nih.gov/pubmed/20737283 - Cytokine Research Laboratory, Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
This is extremely encouraging. I wonder if combining it with some of the technology being developed for next-generation Chemotherapy would be a good next step? The so-called "smart transport" molecules carry a Chemo agent in relatively inert form, and bind with a specific protein found largely on tumors. If one substitutes the anti-CD47 tag for the Chemo agent, now we are (largely) targeting just the tumor, and not opening up the rest of the organism to semi-random attacks.
Normal cells would also no longer have the CD47 "don't eat me" marker molecule. So wouldn't macrophages start eating cells randomly?
when he showed up at the Canadian Cancer Society with a cancer cure, his data, and a number of his former patients (cured or in remission). He demonstrated the efficacy of concentrated hemp oil (uh-oh!) on various tumors. Unable to refute his research (or the human success-stories who came with him), they saw their industry--including their own positions--threatened(!), and threw him out of their office. Try a cursory web-search of 'Rick Simpson hemp oil cancer'....
since anyone can buy Bloodroot, how are the pharmaceutical manufacturers "shelving" the cure for cancer? Regardless, if Bloodroot really did "cure" cancer, i think there would be a lot of noise in the media and Internet of its efficacy. And, while I'm at it, if the big, evil, horrid pharmaceutical companies (who have created all kinds of life saving drugs over the years-and give (as in for free), millions of dollars worth of drugs for those that cannot afford it every year) spent billions in developing a cure for cancer, should they not be able to recoup that investment and sell it? One final thing, if you really want to be angry about something, it would be the FDA, which is responsible for killing people by not allowing those with serious or even terminal diseases to volunteer for these potentially life-saving or at least life-extending treatments that are in their early stages of development. I mean it's the height of stupidity to bar someone who is already dying from taking a drug that might be harmful to him or her. And you people want to turn all healthcare over to the government???
Introduce just enough poison to kill the bad stuff without killing the patient... Once the bad stuff has died, the patient heals and recovers and has basically survived/outlasted the same poison the bad stuff was not able to survive. The factor that defines a poison is the dosage at which it becomes lethal. If this new drug can shrink a tumor, there is a good chance the bulk of the tumor can be removed via surgery and the 2 treatments would work together to rid the patient of the cancer.
That's a good question, I wondered the same thing. According to the authors, anti-CD47 molecules failed to induce phagocytosis of noncancer cells in vitro. They inferred from this finding that normal healthy tissues lack a secondary prophagocytic 'eat me' signal. So, um, I guess it remains to be seen.
I understand your skepticism, but it may be partially misplaced. No, of course drug companies are not entirely evil - but neither are they necessarily entirely benevolent - both aspect can co-exist. Let's investigate without agenda and discover which is which. Suppose that Bloodroot and other non-patentable treatments were not a total miracle cure for all cancer, but were a cheap and effective alternative for some cancers. How would we know about it? Well, in the early stages of uncovering this effect, a small number of researchers or clinicians would be publishing interesting results, but that would be minor news until validated with expensive larger studies. Who's going to fund those studies? Following that line of thought, it would not be in the financial interest of the pharma companies and their shareholders to spend money on something which could substantially reduce profits. We're only talking about the market functioning exactly as it is intended to do here, not about evil intent or inflicting deliberate harm for no purpose. Spending shareholder money to reduce profits would not be due diligence. IF that had happened, what would we see? No, not "lots of noise in the media and Internet" because officially it's just some unproven treatments among many, since nobody funded the formal large scale testing. All we'd likely see is a small number of people, perhaps including the original researchers, saying that there was a cheap and useful treatment which never got developed. And that's what we do see, including right here. Does that mean it's true? Hardly! It's also possible that every proposed alternative treatment really *IS* ineffective but some researchers and patients refuse to give up hope and belief. But it does mean that the idea that "expected effects on net profits influence which treatments are allowed/supported to pass from promising to available", passes the "feasible" test, rather than being rejected out of hand. Suggesting that people should be mad at the FDA instead is (perhaps innocently) off topic, sort of "look over there, don't pay attention to the man behind the curtain". That is, your complaints about the FDA's policies on another issue, whether valid or not, have no bearing whatsoever on the current issue, and so come across as an attempt to distract our attention from the topic at hand.