(from BBC.co.uk) – A boy treated [in Russia] with fetal stem cells for a rare genetic disease has developed benign tumors, raising questions about the therapy’s safety.
The boy, now 17, received the stem cells in 2001 at a Moscow hospital and four years later scans showed brain and spinal tumors, PLoS [Public Library of Science] Medicine reports.
Israeli doctors removed the abnormal growth from his spine and tests suggest it sprouted from the stem cells.
Critics say the finding is evidence against the controversial therapy.
Apart from the ethics of using cells taken from embryos, opponents say there are big safety concerns.
As well as the possibility that stem cells may turn cancerous, some researchers fear that it is possible that [embryonic] stem cell therapy could unwittingly pass viruses and other disease causing agents to people who receive cell transplants.
Experts are hopeful that [embryonic] stem cells, which have the ability to develop into other kinds of human cells, will eventually lead to treatments for some of the most intractable conditions.
The boy in question was treated for a condition called Ataxia Telangiectasia – a genetic disease that attacks the brain region controlling movement and speech.
He received three courses of fetal stem cell injections to the brain and the fluid surrounding the spine.
Four years after his first injection he was investigated for recurrent headaches and his doctors at the Sheba Medical Centre in Tel Aviv found two tumors – one in the spine and one in the brain at the same sites the injections had been given.
A year later, when the boy was 14, the doctors removed the non-cancerous tumor from his spine and it was found to contain cells that could not have arisen from the patient’s own tissue and had in all probability grown from the donated [embryonic] stem cells.
Although they were unable to sample the growth in the boy’s brain, the scientists believe this probably arose from the injected stem cells too.
Donor-derived cells might have been able to spark tumors in this patient because people with Ataxia Telangiectasia often have a weakened immune system, say the researchers. It is not clear whether the stem cell therapy helped his genetic condition.
They say the findings “do not imply that the research in stem cell therapeutics should be abandoned.”
Nonetheless, they say more work should be done to assess the safety of this therapy.
Josephine Quintavalle of the public interest group Comment on Reproductive Ethics said: “The risks of tumor formation in association with embryonic stem cells are widely acknowledged and one reason why there are very serious concerns about the proposed use of such cells in treating spinal cord injury in the US.
“It would appear from this report that fetal stem cells are similarly unstable. These are not areas of therapy we should be rushing into, whatever the ethical debates surrounding the use of embryo or fetal tissue per se.”
Stem cell scientist Dr Stephen Minger, of King’s College London, said it was clear that the tumors had arisen from the transplanted cells.
“This is worrying and we have to be cautious. We need to have long term monitoring and follow up of the patients given [embryonic] stem cells and rigorous regulation of centers providing cell therapy.
“Although this is just one case it does show that we need to be careful about the cell populations we are using.” He said not all clinics used good quality cells.
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Some definitions to help you when answering the questions:
- Adult Stem Cell: A stem cell from organs and tissues, usually after birth (including umbilical cord and placenta), that can renew itself and transform into other specialized cell types.
- Embryo: The earliest stage of human development, from the single cell zygote up to about 8 weeks.
- Fetus: The human being from 8 weeks after conception to birth.
- Blastocyst: Early stage of embryo, approximately 5-7 days after conception (50-250 cells.)
- Embryonic stem cell: A cell from the inner mass of cells of a blastocyst, with the potential to become most or all of the body tissues.
1. With what type of stem cells was a boy who has a rare genetic disease treated 8 years ago in Russia?
2. What problems did the boy develop from this treatment? Be specific.
3. In addition to causing tumors, what concern do researchers have about using embryonic stem cells?
4. Why do scientists say the boy’s tumors came from the fetal stem cell treatment he received?
5. Read the “Background” below and check out the links when considering this question.
Recently, Japanese scientists have discovered that they can transform adult human skin cells into cells that resemble embryonic stem cells. The converted cells have many of the physical and genetic features typically found in embryonic stem cells and can produce other tissue types, including neurons and heart tissue, according to the researchers.
Should the U.S. government fund embryonic stem cell research (as it is surrounded by such moral/ethical controversy), or only use taxpayer dollars to fund research using adult stem cells to cure disease? Explain your answer.
Adult stem cells vs. embryonic stem cells. (from njfpc.org/Articles/AdultStem.asp)
- Adult stem cell research has been on-going for 20-30 years, is not under any government restriction, and does not require the destruction of human life. These stem cells have already been used to treat spinal cord injuries, Leukemia, and even Parkinson’s disease . Adult stem cells are derived from umbilical cords, placentas, amniotic fluid, various tissues and organ systems like skin and the liver, and even fat obtained from liposuction.
- In contrast, embryonic stem cells are obtained by harvesting living embryos generally 5 to 7 days old, which are destroyed in the process. Most importantly, embryonic stem cells have never yet been successfully used to help cure disease. In fact, in animals they have caused tumors and other complications. Embryonic stem cells are also being touted by some as a possible treatment for repairing the brains of Alzheimer’s patients, but stem cell researchers confess that this is a distortion that is not being aggressively corrected by scientists.
- A new poll, conducted by International Communications Research, reveals that once Americans understand the difference between adult and embryonic stem cells, Americans strongly prefer funding adult stem cell research that does not destroy human life, by a margin of 61% to 23%. So, what is driving the biotech industry and many government officials to press for government money to subsidize embryonic stem cell research? Free money, and research without ethical limitations.
- Private industry has not been willing to put up any large sums of money on their own for embryonic stem cell research, because they are not sure it will yield the results they hope for. However, some drugmakers are getting into the field of research utilizing adult stem cells from umbilical cord blood and bone marrow . Investors are now taking notice that adult cells are actually working with human patients, and researchers are finding that these cells appear to be as flexible as the embryonic type.
The Adult stem cell technique named as Science Magazine’s “2008 Scientific Breakthrough of the Year” is a technique that allows stem cells to be created without the need to destroy embryos.
–The advance, which involves turning back the clock on adult tissue and “reprogramming” it with the properties of stem cells, could lead to new treatments for diseases including Parkinson’s and diabetes.
–The process allows for a potentially limitless numbers of “induced pluripotent stem” (IPS) cells to be made to order from a sick patient’s cells, meaning they do not risk rejection from the immune system when transplanted.
–The technique does not require stem calls to be harvested from embryos, making it more acceptable to religious groups.
–Dr Robert Coontz of the journal Science, which placed cellular reprogramming top of its list of the biggest scientific breakthroughs of 2008, said it “opened a new field of biology almost overnight and holds out hope of life-saving medical advances”. Three teams working in Japan and the United States made major advances with the technique over the last 12 months.
Watch a video and a podcast, and read additional information about the scientific breakthrough using
adult stem cells at sciencemag.org/btoy2008.
Watch a video on Adult Stem Cell vs Embryonic Stem Cell Research Ethics
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