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Thread: could adult stem cell therapy cause cancer ?

  1. #1

    could adult stem cell therapy cause cancer ?

    hi,

    i have done some searching about that, i would like others to share with me these links:

    articles about new studies about the posibility of adult stem cells to cause cancer:

    http://news.bbc.co.uk/1/hi/health/4465717.stm

    http://www.newscientist.com/channel/sex/stem-cells/mg19325852.400-cancer-warning-over-stem-cell-therapies.html

    http://www.newscientist.com/article.ns?id=mg18624965.200

    i was discussing these links with one of the representitives of a stem cell company, and he was saying that tumors could occur only if the stem cells were divided out of the body, but in his company ( xcell ) they don't do that actully, all they do is getting the cells from bone marrow, isolating them, then reinjecting.

    i am seriously thinking about having the therapy, but still worried about the cancer thing, and what i need to take the decision is more information..

    any one who can help please do so..

    thank you

  2. #2
    ttma,

    All cells have the potential to cause tumors. Some cells are more likely to produce cancer than others. A tumor is not necessarily a cancer and we should discuss that first. A tumor is a growth of cells that is an inappropriate amount or type of cells for the tissue. Thus, for example, a wart is a tumor. If a hair is growing int he spinal cord, that is a tumor. In contrast, a cancer is a cell that is growing out of control and that does not respond to most tissue factors, spreading across tissue boundaries and often into adjacent tissues and into blood of lymphatics to spread.

    Embryonic stem cells do have a propensity to grow without regard to their surroundings. They are in fact the only stem cells that do not need other cells in order to produce all the cells of the body. That is why they must be differentiated before tranplantation. Otherwise, they cause tumors called teratomas which have many types of cells in them, including hair and skin.

    Adult stem cells need other cells to interact with before they can produce cells that are tissue specific. The sites of these interactions are called niches. There has been much experience with transplantation of bone marrow stem cells. In order for bone marrow (or umbilical cord blood) cells to engraft, the cells occupying the niches must be removed. This is done chemo- or radiation therapy. Stem cells that settle into that niche then will make blood cells.

    The niches for the central nervous system are not known. However, a great deal of attention has been focused on the subventricular zone (SVZ) where adult neural stem cells are known to reside. The SVZ sends out a stream of migrating neural stem cells to the olfactory bulb and the hippocampus, called the rostral migratory stream. The spinal cord is also believed to be a site of neural stem cells. However, we don't know which they are. For some time, the neural stem cells of the spinal cord were believed to be ependymal cells. However, several studies suggest that the stem cells may be more scattered in the spinal cord. We don't have any easy way of displacing stem cells from the neural niches that they occupy.

    The study of Joanne Kurtzberg, showing beneficial effects of umbilical cord blood transfusion in children with Krabbés disease was very surprisng and encouraging. This is a deadly genetic disease where the brain has a mutated GalC gene, the brain demyelinates, and the kids usually end up severely retarded and dead after several years but early treatment with umbilical cord blood can save them and prevent further brain damage. The kids are not treated with any chemotherapy to open up the niches (Source). This raises the question whether it may be possible to transfused stem cells in situations where there is brain damage and “niches“ in the brain may be available for occupancy by cells that are just infused intravenously. This of course is the theory by which many clinical centers are not infusing cord blood or bone marrow cells intravenously for neurological disorders.

    Umbilical cord blood transplants is likely to become the treatment of choice for babies with rare neuorlogical genetic diseases. These include, for example, the disease adrenoleuodystrophy (the disease described in Lorenzo's oil), Hurler's syndrome, metachromatic leukodystrophy, Tay-Sachs disease, Sandhoffs disease, and others (Source). Umbilical cord blood has been used for many years to treat hematopoietic disorders. I believe that the first case of a cord blood transplant was done in the early 1990's for somebody who had Fanconi's anemia and received a unit of umbilical cord blood from a relative. He apparently was cured. There was an enormous struggle during the 1980's to get doctors to take umbilical cord blood seriously.

    I met a man recently at a New Jersey High Tech Hall of Fame induction by the name of Kenneth Moch (Source). He was the CEO of a company called Biocyte that pioneered umbilical cord blood cell transplants in the 1980's. The three scientists who founded the company were Gorden W. Douglas, Hal E. Broxmeyer, and Edward A. Boyce and they received patent 5,004,681 for their work (Source) Kenneth Moch reminded me that the word stem cell was really accepted by most doctors and cord blood was thought to be a scam in the 1980's. It took over 20 years for the field to reach respectability. It is still a struggle. Many fly-by-night clinics are trying cord blood cells on various diseases without doing rigorous trials to demonstrate efficacy.

    Probably over 10,000 people get bone marrow or cord blood cell transplants per year in the United States. While the mortality rate of such transplants is high, on the order of 5-10%, this is due to the nature of the disease for which the transplants are being done (leukemia, genetic anemia, autoimmune diseases) and the requirement of bone marrow ablation. Over 190,000 cord blood units are available for transplantation around the world (Source). The incidence of cancer associated with cord blood transplants is very low. It is actually quite hard to find the data because cord blood is frequently used to treat people with cancer. Cases where the cord blood actually caused the cancer is difficult and, to my knowledge, not reported. There are a major clinical trials studying this right now and I hope that the data will be available:
    http://clinicaltrials.gov/ct/show/NCT00008164?order=1

    In 2004, Laughlin, et al. published a very influential paper in the New England Journal of Medicine (Source). They found essentially that there was no differences in the outcomes after cord-blood transplantation and bone marrow transplants. They conclude that “HLA-mismatched cord blood should be considered an acceptable source of hematopoeitic adults in the absence of an HLA-matched adult donor“. While this might not sound very impressive, it is important to point out that this study is not a controlled study and there were major differences between the patient populations studied. First, cord blood recipients tended to be younger and more likely to have advnaced leukemia than bone marrow recipients. Second, they received lower doses of of nucleated cells and their hematopoietic recovery tended to be slower. Third, acute graft-versus-host disease (GVHD) was significantly greater in the bone marrow recipients. What the study did not compare were matched cord blood and matched bone marrow transplants. The reason is of course because matched bone marrow transplants (6/6 HLA antigens) are still considered the gold standard of the field and cord blood is used only when matched marrow iare not available (Source).

    Can bone marrow cells produce tumors? If the cells are unmanipulated, they are very unlikely to produce tumors after transplantation. Allografts (from another person) can cause GVHD (Graft versus Host disease) but this does not occur with autografts (from oneself). So, the risk of an autograft producing cancer or GVHD is low. However, you ask about the manipulation that the cells are undergoing and the FDA status of the cells. If the cells are manipulated either by growth factors or genetic modification, the US FDA requires safety tests for cancer and other problems before they will allow the treatment into clinical trial. European FDA's likely to require these as well.

    Wise.



    Quote Originally Posted by ttma
    hi,

    i have done some searching about that, i would like others to share with me these links:

    articles about new studies about the posibility of adult stem cells to cause cancer:

    http://news.bbc.co.uk/1/hi/health/4465717.stm

    http://www.newscientist.com/channel/sex/stem-cells/mg19325852.400-cancer-warning-over-stem-cell-therapies.html

    http://www.newscientist.com/article.ns?id=mg18624965.200

    i was discussing these links with one of the representitives of a stem cell company, and he was saying that tumors could occur only if the stem cells were divided out of the body, but in his company ( xcell ) they don't do that actully, all they do is getting the cells from bone marrow, isolating them, then reinjecting.

    i am seriously thinking about having the therapy, but still worried about the cancer thing, and what i need to take the decision is more information..

    any one who can help please do so..

    thank you

  3. #3
    thank you very much dr. wise, i am so glad i saw your respnse.

    i can't read every thing now cause it's late over her due to time difference, so i will come back later

    thank you again

  4. #4
    dr, wise

    i Benefited from what you have side, and understood many new things for me, so thank you very much

    in the first link that i posted before, it is stated that some of the adult stem cells in thier study (xtracted from fat tissue ) , which were grown for up to eight months and underwent between 90 and 140 divisions to multiply in number during this time, became cancerous by starting to make an enzyme, called telomerase, that enables them to continue dividing long after they would normally stop

    aren't high numbers of multiplication happening in some of today's clinical trials around the world? and could that be some thing to consider before involving in any therapy involving stem cells?

    in the second link it was claimed that stem cells can trigger cancer, but i couldn't relate what they have said with having adult stem cell therapy as a cause for it to occur

    pls. help me understand this more

  5. #5
    Quote Originally Posted by ttma
    dr, wise

    i Benefited from what you have side, and understood many new things for me, so thank you very much

    in the first link that i posted before, it is stated that some of the adult stem cells in thier study (xtracted from fat tissue ) , which were grown for up to eight months and underwent between 90 and 140 divisions to multiply in number during this time, became cancerous by starting to make an enzyme, called telomerase, that enables them to continue dividing long after they would normally stop

    aren't high numbers of multiplication happening in some of today's clinical trials around the world? and could that be some thing to consider before involving in any therapy involving stem cells?

    in the second link it was claimed that stem cells can trigger cancer, but i couldn't relate what they have said with having adult stem cell therapy as a cause for it to occur

    pls. help me understand this more
    ttma,

    Yes, any cell that is grown for long times in culture (particularly 80-90 passages) have the potential to be cancerous. Very few of the current adult stem cells that are being used for therapy are being grown as more than 5-10 passages.

    There is a theory that stem cells are responsible for cancer in our bodies. In other words, this theory posits that cancer cells do make more cancer cells. Instead, stem cells go into the tumors and they make more cancer cells. These are called "cancer stem cells" and these are the cells that chemotherapy is supposed to affect.

    In general, differentiated cells are less likely to cause cancer. Cells that are not grown for long times in culture are less become cancerous.

    Wise.

    Wise.

  6. #6
    dr wise, what you have said is Reassuring, but when i read the titles and some of the contents of these articles i feel that they give the impression that stem cell therapy is not safe and could be related to causing cancer, examples are:

    Cancer warning over stem cell therapies

    Old stem cells can turn cancerous

    IT is another obstacle for stem cell therapies to overcome

    EXCITEMENT about the potential of stem cells for curing all manner of ills is being tempered by two new studies

    ect.

    do you think they are Exaggerating or maybe i just didn't understand well?

  7. #7
    Quote Originally Posted by ttma
    dr wise, what you have said is Reassuring, but when i read the titles and some of the contents of these articles i feel that they give the impression that stem cell therapy is not safe and could be related to causing cancer, examples are:

    Cancer warning over stem cell therapies

    Old stem cells can turn cancerous

    IT is another obstacle for stem cell therapies to overcome

    EXCITEMENT about the potential of stem cells for curing all manner of ills is being tempered by two new studies

    ect.

    do you think they are Exaggerating or maybe i just didn't understand well?
    ttma,

    Are you considering stem cell therapy for yourself or a relative? If so, you need to let me know what kind of cells and how they will be applied. The details are very important and there is no blanket statement that can be made concerning risk.

    Wise.

  8. #8
    i am considering the therapy for my self dr wise, i had t-12 incomplete sci, walking with crutches with the help of an AFO, but still using the weel chair for most of the time

    i am considering the x-cell center in germany. and they use bone marrow stem cells, this is what i am realy considering

    i would like to know about the neurovita also, although i am more serious about the x-cell

    i agree wtih what you have said about not making blanket statements, but i think the writers of those article did, maybe because their not specialists

    anyway, thank you for your effort, i appreciate it

    ttma

  9. #9

  10. #10
    Quote Originally Posted by ttma
    i am considering the therapy for my self dr wise, i had t-12 incomplete sci, walking with crutches with the help of an AFO, but still using the weel chair for most of the time

    i am considering the x-cell center in germany. and they use bone marrow stem cells, this is what i am realy considering

    i would like to know about the neurovita also, although i am more serious about the x-cell

    i agree wtih what you have said about not making blanket statements, but i think the writers of those article did, maybe because their not specialists

    anyway, thank you for your effort, i appreciate it

    ttma
    TTMA,

    I don't think that there is any rationale for the neurovita, cells4health, or Beike group right now. None of these places have or are collecting convincing data. The latter is very concerning. If they were truly interested in seeing whether the treatment is effective, they would be doing long-term follwup studies. The fact that they are not does not give me confidence. In my opinion, all three places are likely to be scams, even though there are well-meaning people who believe the treatments are doing something for their patients.

    Wise.

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