Stem Cell Research Progress Blog

Top NIH Scientist Goes to Private Sector

2006-04-11T12:21:00.000-07:00

Top NIH Scientist Goes to Private Sector

Dr. Mahendra Rao, the leader of the stem-cell unit at the National Institute on Aging, part of the National Institutes of Health, is leaving NIH to join the biotech company Invitrogen so that he can do embryonic stem cell research. In an interview with Wired Magazine, he said that he felt he needed to be working on a larger number of stem cell lines than those that were available through federal funding. He expressed concerns for the future of the field on the grounds that there was uncertainty about whether there would be funding for labs and research, leading to a lack of both facilities and to people willing to make stem cell research their career. I’d like to invite readers of this blog to read the whole interview (it’s not very long) to get a fuller picture of what one US scientist sees as the current state of affairs in stem cell research. Invitrogen also issued a press release on the hiring of Dr. Rao, which gives some of his background and experience.

Now, it’s hardly new for someone from the government to leave for the private sector, but when government funded research on science and health issues becomes divorced from other research to this extent, it’s bad news for knowledge and understanding.

Comprehensive stem cell article

2006-03-22T10:41:00.000-08:00

There's a good article on stem cell research, history, and policy called "Stem Cell Research: Medical Miracle or Moral Morass?" that appears in the Gotham Gazette. It focuses on stem cell research as it applies to the state of New York but it provides a good overview and links to other sources. It also has some really good images. If you are wanting to educate yourself a little more about stem cells, this is recommended reading.

HAPPY THANKSGIVING!

2005-11-23T10:07:00.000-08:00

I'm taking the rest of today (there are several posts below) and all of tomorrow off for Thanksgiving, I will be back on Friday. Also, next week I'm at a conference for a couple days on Tuesday and Wednesday, so blogging probably won't happen then. I'll catch things up later.

(Image is mine)

Reader Question

2005-12-02T16:15:00.000-08:00

A high school reader asked, What's the difference between stem cells and regular cells?

In really simple terms, I would say the answer is that regular cells already look like what they are. If you take a skin cell or a muscle cell or a heart cell and put it under a microscope, it will look like any other skin cell or muscle cell or heart cell. If you look at a stem cell, it will look different--it has the potential to be many kinds of cells.

Cells contain DNA, which makes up our genes. We have millions of genes which are not expressed--in other words, they are inactive. For example, I have a gene for blue eyes that I got from my mom, but it is not expressed; I have green eyes. However, my son has blue eyes--I passed that gene on to him. (He also got a blue-eye gene form his green-eyed dad, whose mother also has blue eyes, otherwise it wouldn't have been expressed since it's a recessive and needs two.) We have lots and lots of other genes which are not expressed.

A cell that has differentiated only expresses the genes for the kind of cell it is. When it divides (reproduces), it makes an exact copy of itself.

A stem cell has the capacity to express many more genes. An embryonic stem cell can theoretically express anything. When a stem cell divides, it creates a copy of itself and it also creates another cell which has the potential to be many different things. Proteins and enzymes and other chemicals in the environment (the body) tell it what to become.

Bottom line--if you put a skin cell in a culture and give it lots of different things that make it grow, it won't ever become a muscle cell. If you put an embryonic stem cell in a culture and give it things, you can make it either a skin cell or a muscle cell. If you put an umbilical cord or other adult stem cell in a culture and give it lots of things, you can make it become some things but not all--for example, a blood stem cell can't become cartilage although it can become a variety of types of blood cells.

On a theoretical level, since cells contain so much unexpressed, inactive DNA I suppose you could turn any cell into any other type of cell. The technology is nowhere close, though.

Weird Animal Modification of the Day

2006-01-13T12:25:00.000-08:00

Weird Animal Modification of the Day

Scientists in Taiwan have bred fluorescent green pigs with fluorescent internal organs. They say the fluorescence will make it easier to monitor the process of stem cell treatments—the stem cells will glow. The story is covered fairly broadly, including on the BBC, Reuters, and the Associated Press (see the Canadian Globe and Mail). The pigs have a gene from a jellyfish.

(Picture by me.)

Australian Scientists Want to Research Genetic Diseases in Stem Cells

2006-02-08T08:32:00.000-08:00

Australian Scientists Want to Research Genetic Diseases in Stem Cells

Scientists in Australia are seeking licenses to create stem cell lines from embryos with genetic abnormalities. One license would involve embryos with genetic diseases, such Huntington's, cystic fibrosis and muscular dystrophy. Another would involve research on embryos with chromosomal abnormalities or other mutations. The embryos would be obtained from IVF embryos that would otherwise be discarded because they are considered unsuitable for implantation—the embryos would have already undergone genetic testing to make this determination. The news is reported on ABC (Australian) Science (which also has a very cool image of DNA—they got it from NASA).

Some of the issues regard the use of fresh embryos or frozen ones. There are differing opinions as to what Australian law is on this. One researcher said that the freezing process destroys embryos. The article also quoted a feminist bioethicist, who said that there were potential issues if the embryos were obtained other than through the IVF process.

This seems to me to be one of the really important areas of embryonic stem cell research. To be able to observe the development of a disease is a key to finding out how to treat it.

Notch Protein Key in Neural Cells

2006-04-11T11:13:00.000-07:00

Notch Protein Key in Neural Cells

Researchers at the University of Edinburgh have discovered that activating the Notch protein in embryonic stem cells causes most of them to differentiate into neural cells. According to the press release (includes a nice image), the effect is observed in both human and mouse cells and only requires the presence of Notch activating signals in the stem cell culture. Once Notch is activated in one stem cell, the stem cell communicates with its neighbors and Notch is activated in them as well. Up to 90% of the stem cells in which Notch was activated became neural cells. The researchers want to move on to see what Notch is blocking in the stem cells so that they can start to control differentiation into other types of cells.

The study is in PLoS Biology, which is an open-access non-profit journal. The press release has a link to the article. PloS stands for Public Library of Science, and the journals are peer-reviewed. I’d like to encourage people to go to the site and look around in the interest of supporting open access to information. Open source may not have the prestige of established journals (in any field, not just the sciences) but I think it is crucial to the evolution of knowledge and knowledge paradigms.

This seems like an important finding to me, by the way, since there has been so much difficulty in producing or working with neural cells. It would be interesting to see what happens if Notch is activated in different kinds of adult stem cells.

Flatworm Gene For Stem Cell Differentiation Identified

2005-11-25T19:20:00.000-08:00

Flatworm Gene For Stem Cell Differentiation Identified

Researchers have identified a gene responsible for stem cell differentiation in a flatworm (planarian) which is frequently studied for its regenerative properties. The research was done at the University of Utah Health Sciences Center. According to the press release on EurekAlert,

Cut one of these animals in half, and a week later, two fully functional worms will have developed from the pieces. Cut a piece that is 1/279th the size of the animal, and it too will regrow into a complete worm. The process, scientists know, is dependent on stem cells in the adult planaria known as neoblasts.

The scientists, who had done a previous study turning off certain genes in the planaria, found in this study that the smedwi-2 gene, which is active in dividing neoblasts, is crucial to stem cell differentiation. They used RNA interference to turn the gene off. When a normal planarian is exposed to radiation that destroys the neoblasts, the animal begins to actually degenerate in a specific pattern and lose its ability to regenerate. The worms that had the smedwi-2 gene deactivated degenerated the same way the irradiated worms do.

The story as reported in Science Daily adds

The researchers postulated three theories why the worms could not regenerate or maintain cells after smedwi-2 was silenced:
The stem cells were not responding to tissue damage or homeostasis signals.
The stem cell division progeny failed to migrate to the appropriate tissues.
The daughter cells didn't know how to differentiate.
The team found that the stem cells were competent to robustly respond to amputation by significantly increasing their proliferation as well as to home to tissues undergoing homeostasis. But the researchers also found that once the daughter cells reach their target tissues, they were unable to properly differentiate.

The smedwi-2 gene is part of a protein family similar to PIWI genes, which have been shown to play a role in regulating stem cells. When neoblasts, like other stem cells, divide, they form a copy of the original and a daughter cell that has the capacity to become a different type of cell. The researchers speculated that the PIWI proteins are necessary for the daughter cells to differentiate and are not the mechanism required for the original stem cell itself to divide. It is not yet known if the PIWI proteins serve the same fuction in human stem cells, but the research is suggestive.

The story is also reported in the Salt Lake Tribune, with the press release also showing up with slight variations on RxPG News. The Howard Hughes Medical Institute has a cool picture of planaria with their report.

Recent Happenings There’s no way I can catch up o...

2007-01-10T15:50:00.000-08:00

Recent Happenings

There’s no way I can catch up on all the stories I missed over the last couple months (but I did get into law school!), so here are links to some of the ones I find more interesting, newest first (articles on money and politics are mostly not included, this is essentially just research):

1/10 BBC: British debate on hybrid cells (animal cells used as recipients of human DNA in cloning) taking place, research may be banned.

1/8: Press release from USC about stem cells causing cancer. An early, unrelated, story from CBC news discusses Canadian researchers’ findings that colon cancer is caused by cancer stem cells.

1/6 San Diego Tribune: Using stem cells to carry anti-cancer genes into the body. Similar story on press release 12/25 about neural stem cells.

12/22 UPI: Stem cells treat neuroblastomas in mice.

12/17 The Telegraph: Investigation into possible death of newborns in the Ukraine to obtain stem cells. (And people wonder why I am so firm on double-blind gov’t approved studies prior to treatment and wary of miracle cures from Kiev…)

12/15 AP (in The State): Researchers derive stem cells from unfertilized eggs. Related, more technical, article in The Scientist. Longer AP story on ABC News.

12/14 Press release: Mouse stem cells can help repair damaged brain tissue.

12/10 Boston Globe: Australia lifts ban on cloning.

12/10 Reuters: Scientists develop an “ink-jet” method of growing stem cells.

12/7 San Francisco Chronicle: Head of CIRM resigns for personal reasons, including age (69).

12/6 International Herald Tribune: Summary of laws about stem cell research around the world.

11/23 Boston Globe: Harvard researchers identify a cell that gives rise to all 3 kinds of heart tissue.

11/22 Reuters: Advanced Cell Technology clarifies its use of frozen embryos in a new technique for creating stem cells.

11/17 CNN: Iranian advances in stem cell research.

11/12 BBC: Stem cells from bone marrow help repair insulin-producing pancreatic cells. See also this related article.

11/9 The Independent: Stem cell transplantation repairs eyes in mice. Related story by Washington Post stem cell writer Rick Weiss in the Seattle Times.

11/9 CBS: Researchers develop potential lung cancer vaccine from mouse stem cells.

10/31 The Daily Record: Scientist in the UK grow miniature liver from umbilical stem cells.

10/23 The Age: Stem cells may cause brain tumors.

Other news includes using stem cells to regenerate teeth in pigs, a discovery that breast cancer stem cells may be resistant to radiation treatment, the possibility of using fat-derived stem cells in breast reconstruction, a stem cell heart trial in Britain, stem cell injections ease muscular dystrophy in dogs, heart damage repaired in pigs with stem cells, regrowth of neural stem cells in mice, additional risk of cancer after receiving allogeneic stem cell transplants, and heart valves grown from amniotic stem cells.

Well, that list by no means covers everything, but it should provide a decent swath of what’s been happening in the stem cell world.

Stem Cells in the New Year

2007-01-10T13:21:00.000-08:00

Stem Cells in the New Year

Well, 2006 has gone, and we have a new Congress. Stem cells are back on the political agenda now that Democrats control the House (and the Senate—maybe—depending on Tim Johnson’s recovery from stroke). Reuters reports that leaders of both parts of Congress intend to put forth the same bill that Bush vetoed last year; they predict it will again pass easily and that there may even be enough votes to over-ride a veto. AP reports on the same thing, but with a focus on the new research showing that stem cells obtained from amniotic fluid (see separate post on this) may be effective—according to an article in the Houston Chronicle (among may others), Congressional leaders are not embracing this research as a replacement for embryonic stem cell research right now, but it may present an additional argument on the side of people who are opposed to hESC research. However, the Boston Globe reports that the researcher who worked with the amniotic stem cells is telling Congress that his work is not a substitute for hESC research, and that appears to be the line stem-cell supporters will be following in Congress.

Amniotic Fluid a Source of Effective Stem Cells?

2007-01-10T13:26:00.000-08:00

Amniotic Fluid a Source of Effective Stem Cells?

A reader rightfully took me to task for not reporting on this—as it happens, I was on vacation when the news broke. I am now back from several days of skiing and making an effort to find out what happened in the world while I was on the mountaintop… You have probably already heard by now that scientists at Wake Forest University and colleagues from Harvard have been able to grow new tissue from stem cells obtained from amniotic fluid. The press release begins:

Scientists have discovered a new source of stems cells and have used them to create muscle, bone, fat, blood vessel, nerve and liver cells in the laboratory. The first report showing the isolation of broad potential stem cells from the amniotic fluid that surrounds developing embryos was published in Nature Biotechnology.

Needless to say, this is being hyped as an alternative to embryonic stem cell research. And perhaps it could be. According to the release,

Atala said a bank with 100,000 specimens theoretically could supply 99 percent of the U.S. population with perfect genetic matches for transplantation. There are more than 4 million live births each year in the United States. In addition to being easily obtainable, the AFS cells can be grown in large quantities because they typically double every 36 hours. They also do not require guidance from other cells (termed “feeders”) and they do not produce tumors, which can occur with certain other types of stem cells. The scientists noted that specialized cells generated from the AFS cells included all three classes of cells found in the developing embryo - termed ectoderm, mesoderm, and endoderm. In their high degree of flexibility and growth potential, the AFS cells resemble human embryonic stem cells, which are believed capable of generating every type of adult cell. “The full range of cells that AFS cells can give rise to remains to be determined,” said Atala. “So far, we’ve been successful with every cell type we’ve attempted to produce from these stem cells. The AFS cells can also produce mature cells that meet tests of function, which suggests their therapeutic value.”

This is obviously highly important research.

However, before jumping up and down with excitement or calling this a resolution to the stem cell dilemma (the Vatican has endorsed these new kinds of stem cells), there is still a lot that needs to happen. It took seven years of research for the researchers to get to this point (which, incidentally, gives an example of why people should not call embryonic stem cell research a dead end only nine years after the first human embryonic stem cell was isolated), and laboratory conditions are not the human body. Successful animal and human trials will have to take place for several years before any therapies can be approved by the FDA, so people in need of immediate help will not have this resource. It will be fabulous if this works, especially if the problems of rejection and tumor growth have been overcome, and I hope that trials can be expedited, but it’s not a proven therapy yet. One important issue to watch further is the long-term effects; do the cells survive and reproduce continuously, for example, or does the effect diminish after several months? Will they be effective in extremely rare genetic disorders or will an exact genetic match (e.g. cloning) be required in these cases? Another issue will be delivery of cells to the affected area—can these cells migrate or will they need to be injected into a specific location? None of these are insurmountable issues by any means—but they are areas where we don’t yet have answers and need more research. Procedures for collection of amniotic fluid will also have to be established—consent, timing, storage, etc.

Besides possibly offering an eventual solution to the dilemma of embryonic stem cell usage, it seems to me that this study probably has some other really important information for cell biology research in general—what is the controlling mechanism that enables them to act without guidance from other cells? What proteins are turning on or off what genes? Has the culture medium been significant? How do the cells interact with scaffolding devices used in tissue engineering? Do they interact with their niches in the way that some cells in the body seem to?

So, although I don’t think this is a wonder-cure yet, I hope the research continues and expands—both for therapies and for scientific knowledge.

Election Day Tidings

2006-11-08T08:37:00.000-08:00

Oh what a beautiful morning:

A good day for stem cell research supporters in several key elections:

First, the ballot initiative in Missouri:

St. Louis Post-Dispatch--here are the raw numbers.

Constitutional Amendment #2 Constitutional
amendment to allow any stem cell research that federal law
allows

98% of precincts
simple majority

1,057,930 Yes
1,012,164 No
Passing
Updated: 11/8/2006 6:48:01 AM

And here's a story:

Stem cell proposal wins, AP says
By Matt Franck
ST. LOUIS
POST-DISPATCH
11/08/2006

A Missouri ballot measure to protect embryonic stem cell research won slim voter approval Tuesday, narrowly surviving an opposition campaign that for weeks had eroded the measure’s popularity, according to the Associated Press, which called the measure shortly before 2:30 a.m. Wednesday.

In other state news, in Wisconsin, Jim Doyle has retained the governorship, and in Michigan Jennifer Granholm has also kept her post. Stem cell research has been a campaign issue in both states.

Umbilical Cord Stem Cells vs. Embryonic Stem Cells

2005-12-04T10:10:00.000-08:00

Umbilical Cord Stem Cells vs. Embryonic Stem Cells

Another reader question: “Dear Anne, Some of my associates are clearly opposed to embryonic stem cell research and are promoting umbilical stem cells as an alternative. Could you do a comparison of the two?”

So I poked around and found out that there are two basic disadvantages to umbilical cord stem cells: one is that there are actually very few of them in cord blood, so they are hard to isolate. The other is that they do not grow well in culture compared to embryonic stem cells. While umbilical cord stem cells appear to have the potential to differentiate into nearly as many kinds of cells as hESCs, they are significantly harder to work with.

Another issue with most kinds of stem cell treatments is immune system response. Stem cells from one’s own umbilical cord blood would not produce an immune system response. Great, for people who have banked their blood. But millions of us are too old to have done so. So we would need umbilical cord stem cells from someone else’s blood, which might provoke an immune system response. (The risk is less than with a straight bone marrow donation or organ transplant, but it is still an issue.) With hESC work, the cells that are produced could be a genetic copy of the patient’s own. This scenario assumes that the cells are specially created for the patient as part of a treatment plan. Getting someone else's hESC cells would presumably also create an immune system response. But the point here is that you can create an exact genetic copy with hESCs, which you can't with umbilical cord stem cells.

There are probably situations in which hESC treatment would not be ideal and it would be better to risk an immune system reponse; for example, what is the risk that the cloned stem cells contain the same conditions leading to cancer or a disease as the patient's original cells? hESC treatment might turn out to be appropriate for injury but not cancer, in which case umbilical cord stem cells could be perfect.

Umbilical cord stem cells certainly have great potential. But until their limitations are overcome, hESCs have more therapeutic advantages. Will this be true 10 years from now? Maybe not. The only way we will know is for research in both to continue.

Below are some sources that I consulted for this. I have highlighted the key points myself but otherwise these are copied directly from the web sites. Please go to those web sites for further information or any citation of the information. Thanks.

From the Stem Cell Research Foundation
http://www.stemcellresearchfoundation.org/About/FAQ.htm

Adult stem cells are undifferentiated cells that are found in small numbers in most adult tissues. However, they are also found in children and can be extracted from umbilical cord blood. A more accurate phrase is “somatic stem cells,” although this phrase has yet to be generally adopted. The primary roles of adult stem cells in the body are to maintain and repair the tissues in which they are found. They are usually thought of as multipotent cells, giving rise to a closely related family of cells within the tissue. An example is hematopoietic stem cells, which form all the various cells in the blood. Recent evidence, however, indicates that some adult stem cell types may be pluripotent, or at least able to differentiate into multiple cell types. For example, hematopoietic stem cells can differentiate into neurons, glia, skeletal muscle cells, heart muscle cells, and liver cells. Whether they actually do this ordinarily within the body is unknown. Blood from the placenta and umbilical cord that are left over after birth is a rich source of hematopoietic stem cells. These so-called umbilical cord stem cells have been shown to be able to differentiate into bone cells and neurons, as well as the cells lining the inside of blood vessels. A potential advantage of using adult stem cells from a patient is that the patient’s own cells could be expanded in culture, treated to differentiate into the desired cells, and then reintroduced into the patient. The use of the patient’s own cells would eliminate any possibility that they might be rejected by the immune system. Disadvantages of using adult stem cells are that they are rare in mature tissues and it is more difficult to expand their numbers in cell culture, compared with ESCs.

From the National Institute of Health
http://stemcells.nih.gov/info/faqs.asp

Why not use adult stem cells instead of using human embryonic stem cells in research?

Human embryonic stem cells are thought to have much greater developmental potential than adult stem cells. This means that embryonic stem cells may be pluripotent—that is, able to give rise to cells found in all tissues of the embryo except for germ cells rather than being merely multipotent—restricted to specific subpopulations of cell types, as adult stem cells are thought to be.

From the International Society for Stem Cell Research
http://www.isscr.org/public/adultstemcells.htm

Umbilical cord blood stem cells can be obtained from the umbilical cord immediately after birth. Like bone marrow, umbilical cord blood is another rich source of hematopoietic stem cells. These hematopoietic stem cells are usually referred to as neonatal stem cells and are less mature than those stem cells found in the bone marrow of adults or children.

The advantages of using cord blood as a source of stem cells are its non-invasive procurement and its vast abundance; thousands of babies are born each day. Until recently, umbilical cord blood was discarded after birth, along with the placenta. Now, in several countries around the world, cord blood is collected and either banked in public banks for general use, or stored by private companies for private use, in private cord blood banks.

Cord blood has recently emerged as an alternative source of hematopoietic stem cells for treatment of leukemia and other blood disorders. In these applications, umbilical cord blood has the notable advantage that despite its high content of immune cells, it does not produce strong graft-versus-host disease, a condition where the graft immune cells attack the patient's body cells. Therefore, cord blood grafts do not need to be as rigorously matched to a recipient as bone marrow grafts.

This expands the available donor pool for hematopoietic stem cell transplants considerably. However, a disadvantage of umbilical cord blood, and an argument against generalized use, is the limited number of stem cells in any given cord. This increases the risk of graft failure once transplanted into an adult.

The use of umbilical cord blood stem cells for other uses, such as organ and tissue repair, is under investigation. However, the stem cells themselves would be recognized as foreign and rejected the same way as a transplanted organ, unless the patient's immune system is strongly suppressed, or has been ablated before transplantation, such as is the case prior to bone marrow transplantations.

Also from the ISSCR:
8. What is unique about stem cells from baby teeth or umbilical cords? Stem cells from umbilical cord blood or the pulp under baby teeth are "younger" stem cells than those obtained from adults. They are able to divide for longer times in cell cultures than most adult stem cells, and may give rise to different tissues. Their potential to form many different cell types is currently being explored.

Umbilical cord blood stem cells are used for stem cell transplantation to reconstitute blood cell formation (the hematopoietic system) in patients that have been irradiated or treated with specific drugs for cancer or leukemia. Also, in some genetic diseases, where patients have a problem forming normal blood cells, a transplantation of matched umbilical cord blood cells can give them a new blood-forming system.

The new cells are infused into the vein of the patient and then they are able to find their way into the bone marrow, in a process called "stem cell homing."

And here is an article discussing the issue:

The Science Correspondent for the on-line magazine Reason wrote about umbilical cord stem cells a year ago. He wrote, “For example, one current problem with stem cells from umbilical cord blood is that they do not continually renew in culture without differentiating like human embryonic stem cells do.” His conclusion was one that I have also come to as I have read about stem cell cells, and in fact is very similar to the point I made above and in a previous post (Americans Support Stem Cell Research, 10/24/05):

However, only more research will tell whether the promise of adult umbilical cord and embryonic stem cells will be fulfilled. Various lines of research should be pursued simultaneously to insure the best chance of discovering effective future treatments. It may well turn out that adult stem cells are good treatments for certain diseases, umbilical ord stem cells work best for others, and embryonic stem cells are better at curing still different maladies. Contrary to the claims of ioconservatives, it is not either adult and umbilical cord stem cells or embryonic ones; for the sake of millions of suffering patients, it's necessary to forge ahead on all three fronts.

Here is the link to his full article:
http://www.reason.com/rb/rb120104.shtml

Stem Cell Quackery

2005-11-18T11:11:00.000-08:00

Stem Cell Quackery

In keeping with the trend this week of reporting on dubious results from stem cell treatments, I am blogging a little on this in general. A great site that anyone who is interested in finding out more about this is a page on Quackwatch by Dr. Stephen Barrett called “The Shady Side of Embryonic Stem Cell Therapy.” I want to high-light here that this is not a justification to stop embryonic stem cell research; it is a warning for people to beware being taken advantage of by scammers who prey on desperation and last hopes.

(To be fair, a person taking issue with what Barrett said about one company posted this quotation from the New Scientist on his site: ““Finally, some readers have taken us to task for our recent endorsement of the Quackwatch website (24 April). We should, we now realize, have made it clearer that while this site does an excellent job of debunking many phony and fraudulent therapy claims, it does so from a position of medical conservatism that dismisses all forms of therapy that fall outside the orthodox mainstream. This may delight some readers, but others find it unacceptably narrow. Be warned.” I tried to find the original information on the New Scientist site, but it is limited to subscribers. I do find the New Scientist to be a good publication from what I have seen. I am personally open to some alternative medicines, having had great experience with acupuncture, but I think well-designed and carefully supervised clinical trials are crucial to successful treatment with invasive procedures. The person who put this post up also has a link to one of the sites questioned by Quackwatch and does not disclose his own background or interest in defending the site.)

A reader has voiced some doubts to me about Medra, Inc, which is one of the companies discussed on the Quackwatch page. Barrett writes about Medra,

The chief American commercializer of embryonic stem cell therapy is William C. Rader, M.D., a psychiatrist in Malibu, California, who used to run Rader Institute clinics that specialized in treating eating disorders. For $25,000 (wired in advance), Rader will arrange for treatment at his Dominican Republic clinic. In the past, he has also done business under the names Mediquest Ltd., Czech Foundation, and Dulcinea Institute, Ltd. A message posted to the Yahoo StemCells group indicates that before he opened his own clinic (in 1997 in the Bahamas), Rader escorted patients to the Ukraine clinic.

(See Blog Post Ukrainian Stem Cell Treatment, 11/17/05, for more on the above-mentioned clinic, EmCell.)

So what does a psychiatrist know about biology? (Heck, I have a Ph.D., I could start a clinic and say it was run by Dr. Leonard.) A Los Angeles Times article “Outside the US, Businesses Run With Unproved Stem Cell Therapies,” posted on Stem Cell Research and reprinted on an ALS (Lou Gehrig’s disease) site says about Rader,

"I think there is a higher power," Rader said. "I feel that I am just simply a conduit."
Rader, 66, said he has not published anything about his therapy because that would open him to attack from a "conspiracy" of scientists, government authorities, pharmaceutical companies and abortion opponents.

In my opinion and experience, people who believe in their research will publish it in spite of what others might think. The article is important reading regarding other clinics, too, including EmCell and one in China.

A 2004 article in The Times (UK) by John Cornwell, which is long but important reading on this issue, says about Medra:

When I tracked down Dr William Rader, the medical director of Medra Inc, one of several stem-cell treatment centres, based in the Dominican Republic but run from an office in Malibu, he refused to tell me about the source or nature of the stem cells that the clinic used or the whereabouts and status of his Dominican clinic. He explained lamely: "It is becoming very difficult, legally, to give out any information about the use of stem cells in the United States."
Rader claims that his treatments relieve diseases such as "Alzheimer's, anaemia, autism, brain damage, cancer, cerebral palsy, chronic fatigue syndrome" and so forth, through to "systemic lupus erythematosus and hair loss". Neither Rader nor his "chief scientific investigator", Professor Albert Scheller, MD PhD, has any citations in the Medline list of publications appropriate for any of these diseases.

Cornwell's article should be read carefully by anyone considering stem cell therapy at a private clinic.

The Stem Cell Research Foundation site has this question and answer about Medra:

My son survived a near-drowning incident when he was 2 years old. He is now 5. He is severely brain damaged and also has cerebral palsy. I read about human embryonic stem cell (hESC) therapy being performed in the Dominican Republic by Medra INC. What are your comments about this? - YS
I would offer a serious note of caution about any company or organization that suggests that it has a human embryonic stem cell (hESC)-based therapy available at present. There are many of us in the field actively working towards being able to use hESC’s as platforms to derive cells for medical use. We are not there yet, and I would be vastly surprised if anyone else was either. I find the suggestion that anyone would offer such a therapy today to be most troubling. A short web search on the company you mention reveals some comments that I find very disturbing. It is unfortunate that there are individuals in our world that seek to take advantage of good people in need by offering them empty hopes and promises, especially for financial gain. Please, be careful and take care.

The Sacramento Bee apparently did a feature on stem cell clinics last January 9, but I was unable to find the article on the Bee's website, and the site that mentioned it did not have a link.

The only other information I found on my Google search for Medra was the company listing in directories, web pages where its ad was placed, and its own site. Bottom line: from what I have seen in the last few months while doing this blog, stem cell therapy, whether embryonic or adult, has promise for heart conditions and blood disease, but neurological and tissue treatment still has a lot of work to go. Researchers are still working on how to get stem cells to differentiate successfully, how to ensure that they migrate to the appropriate place, how to be sure they will not mutate or become malignant, and how to avoid immune system reactions. Most of this is still at the culture or laboratory animal stage and has not yet progressed to clinical safety trials, let alone large studies. If you are thinking about a new stem cell therapy, I suggest trying to find a trial you can participate in. See http://www.clinicaltrial.gov/ for the NIH list of active trials.

Got another company you want me to check out? Science, or science fiction? Let me know and I'll see what's been researched on it already. I don't have the resources to do major independent research, but I can poke around to see what's been done.

Lou Gehrig’s Disease Progress?

2006-10-17T09:43:00.000-07:00

A press release from Johns Hopkins reports that rats bred to have amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, had delayed onset and prolonged life when human stem cells were transplanted into their spinal cords. Onset was delayed by an average of 7 days and lifespan extended by 9 days. One of the things the research demonstrates is that the new cells were not themselves subject to the degeneration the surrounding cells suffered. Many of the cells developed into nerve cells and grew nerve endings to connect with other cells.

The next step in the research is to try grafting the cells along the length of the spinal cord; in this first study, the grafts only affected muscles and nerves below the waist and not those responsible for breathing. If the transplanted cells can be shown to have a significant effect in maintaining normal breathing, that would be a very important step forward. The study is also useful as a model of how stem cells change when transplanted. Human clinical studies are still far away.

There are more detailed articles on the study on Reuters, the Independent, and the BBC, among others.

Nasal Stem Cell Research

2006-03-09T10:38:00.000-08:00

Nasal Stem Cell Research

If you’re interested in spinal cord injury treatments with stem cells, you probably already know about the procedures in Portugal which transplant stem cells from the nasal cavity to the injured area of the spine. Now researchers at the University of Louisville in Kentucky have performed similar experiments on rats. The Louisville Courier has an extensive article on the procedure.

In the experiment, stem cells from the area known as the “olfactory neurosensory epithelium” were donated by patients undergoing sinus surgery. The cells were then coaxed into becoming neurons that can attach to muscle cells and also produce myelin, the protective sheathing for the nerves. The cells were then added to a biological jelly, which was injected into rats who had been subjected to a spinal injury that caused them to lose the use of their right paw. Twelve weeks later, the rats treated with the stem cells were using both front paws, while the rats in the control group were using their left front paw only and struggled to climb or walk across the rope.

One of the key differences between this study and other studies is that this was focusing on creating new neurons, rather that re-connecting existing neurons. The researchers said that clinical studies in people were probably 3-10 years away.

This seems like an exciting and important development. Among some of the other factors that are going to need to be followed up on are duration of recovery (12 weeks seems pretty long lasting for a rat, but let’s see), if the treatment works when the injury occurred a significant amount of time prior to the treatment (can they give it to the rats in the control group now and see if they improve?), finding out if the rats become cancer-prone after the treatment, and deriving effective methods for the differentiation to occur. This may already be well under way, but if there is excessive difficulty in controlling the differentiation, that will delay treatment options.

It also will be important to see if this kind of procedure is effective with neural degenerative disorders, or if it will only work in cases of injury.

Eyes and Stem Cells

2005-12-08T10:30:00.000-08:00

Eyes and Stem Cells

Two and a half years ago, Edward Bailey had a stem cell transplant to his left eye, which had been blinded in an industrial accident in 1993. His vision in the left eye is blurry, but he is able to see colors and shapes. Mr. Bailey told his story earlier this year on CNN. The operation that Edward Bailey had was one of several in Britain that involved taking naturally occurring limbal stem cells from donors’ eyes, growing them in culture, and then transplanting them into the patient. According to The Times, the doctors were “astonished at how the cells appeared to trigger the eye’s natural regeneration of its damaged surface.” There was no rejection issue, either. In these cases, the patients had all lost sight due to corneal injury, not to retinal damage. Similar work has been done at the Medical College of Wisconsin since at least 2001.

How common is this story? We hear about stem cells being used in trials for heart conditions and leukemia, and earlier this month I reported that they are being used in deafness. What’s the standing with stem cells and vision?

Over a year ago, Dr. Robert Lanza’s team at Advanced Cell Technology in Massachusetts was able to make embryonic stem cells differentiate into retinal cells. Lanza was quoted in the MSNBC story on this as saying, “They looked like little eyeballs. These things seem to be trying to assemble into primitive eyes.” Although the researchers were only clearly able to identify retinal cells, some of the cells resembled those that generate rods and cones. Lanza worked from cells which were not federally approved, and so was able to avoid the issue of contaminated lines; potentially, his cells could be transplanted into a human. He said that using cloning technology would ensure a genetic match and avoid rejection issues. The study was also reported by Wired News, and Lanza was quoted in that article as saying, “Embryonic stem cells like to do what they want to do, and one of the things they like to do is make neurons. They tend to be much easier to derive.” Retinal cells are actually a type of neuron. The Wired News article concluded,

Previous research has shown limited success in transplanting retinal cells derived from fetal or adult stem cells. Lanza and his colleagues are confident that their embryo-derived cells will work even better, because the cells are even more similar to natural retinal cells than those that were tested previously.

I checked the Advanced Cell Technology website and there are no press releases or published papers with any follow-up to this research, so I can’t tell you the current status of Lanza’s work in this area. In another study that was published in the journal Stem Cells on August 25, 2005, researchers from the University of Missouri demonstrated that embryonic stem cells transplanted into mice helped prevent retinal degeneration.

In 2004, researchers at Harvard's Schepens Eye Research Institute transplanted retinal stem cells from the eyes of healthy mice into mice who had retinal disease. After several weeks the transplanted cells had migrated into the damaged areas of the eyes and appeared to have become normal cells. (This study is reported on EurekAlert.)

The International Society for Stem Cell Research has a page devoted to the status of stem cell research on eyes.

It appears that for people with corneal injury, the potential for regaining sight through a limbal stem cell transplant is increasing. Stem cell treatment for retinal degeneration, disease, or injury is still a long way from actuality.

Retina Research

2006-08-15T14:48:00.000-07:00

Retina Research

Scientists at the University of Washington have successfully used human embryonic stem cells to treat diseased portions of the retina in mice, according to an article in the Seattle Times. The research was done with one of the federally approved lines. Stem cells derived from mice have previously been shown to have an effect upon retinal damage, but this is reported to be the first time human ESCs have done so. The MIT Technology Review also has a story on the subject.

The major challenge of the research was finding the right combination of growth factors. The scientists used growth factors that contribute to the development of the head in humans and mice, and also used a growth factor that contributes to a large eye size in frogs. With this combination of growth factors, the cells developed into retinal progenitor cells about twice as fast as they would in utero. The new cells replaced damaged rods, cones, and amacrine cells in the retina. Being able to create cells that developed into photoreceptors is a significant step forward in treating eye disease with stem cells, as it has been very difficult to reliably get stem cells to differentiate into the right kind and number of eye cells.

The researchers hope that this might lead to a treatment for human retinal diseases, such as macular degeneration, within two years. (It would be used for degenerative diseases and not—at least so far—as a treatment for blindness caused by other factors.) They are watching for the results of a California biotech company (ACT in Alameda) that is using the same ESC line as they did in similar research. ACT hopes to start human trials by the end of next year.

The next step will be to transplant the stem cells into blind animals and to see if the blindness can be reversed. Treatments of the eye with stem cells are really important, not only because vision is such a key sense to people, but also because they may provide information about how to treat the degeneration of other kinds of neural tissue. Since the retina is essentially an extension of the nerves in the brain, what works for the retina might work for brain or spinal degeneration.

In a somewhat related story, the Glasgow Daily Record reported that a young Scotsman is going to have umbilical-cord derived stem cell treatment to try to cure a rare degenerative disease of the eye called Lebers. The stem cells will be injected into his arm and his temples. The procedure will take place at a clinic in Rotterdam which has claimed success with using umbilical stem cells to treat multiple sclerosis. Most neurologists do not believe the MS treatment actually works, so it will be interesting to see if there is a success in the treatment for the nerve damage this man has sustained.

Lawsuit Against Stem Cell Transplant Program

2006-10-17T09:42:00.000-07:00

Lawsuit Against Stem Cell Transplant Program

A hospital, blood center, cancer center, and other institutions in Kansas City have been sued by a group of former patients and family members of deceased patients regarding stem cell transplants performed in the late 1990’s. The suit alleges that the various institutions were negligent in reviewing stem cell quality. The patients were apparently [I’m reading between the lines of the article here] given stem cell transplants as part of their treatment for cancer. About 25 % of the 40 people who received treatment died within a few months, and half were dead after two years. These are much higher mortality rates than those usually associated with stem cell transplants. The case is up for trial next March. Unsurprisingly, the defendants affirm the quality of their program.

Obviously there are a number of questions here the answers to which will probably only come out in court. Certainly the number of deaths raises concerns, but there could be many other factors: how were the patients selected for the program? How advanced was their cancer? What kind of cancer did they have? Were they told this was experimental and did they give informed consent to the risks? In at least one possible universe, the people who received the treatment may have been among those most likely to die from other causes. I’m only speculating here, and can certainly speculate the other way as well: Maybe someone in the lab cut corners, or perhaps the equipment was contaminated. The line between genuine error and negligence can be very blurry at times, and it’s quite possible that several things, any one of which alone would not have been problematic, combined to become deadly. If it goes to a jury, it will be interesting to see what happens. (I’m expecting pre-trial 11th hour settlements myself….)

Watch Stem Cell Videos

2006-05-06T15:30:00.000-07:00

I have to share this very cool website from the Exploratorium in San Francisco:

http://www.exploratorium.edu/imaging_station/gallery.php?Category=stemcells

You can see images and video of mouse embryonic stem cells, including a video of heart cells derived from stem cells beating. If you're not a researcher looking at these regularly, take a minute to explore these.

Fetal Stem Cell Transplants Help Huntington’s

2006-03-01T09:47:00.000-08:00

Fetal Stem Cell Transplants Help Huntington’s

A news release reports that French researchers have done a small study grafting neural cells from fetus that were electively aborted into the brains of patients with Huntington’s disease. This was a follow-up to an earlier report on the same study, which had looked at the patients after two years. At that point, three had motor and cognitive improvement and two did not. The three patients were examined again and, six years after the procedure, still had improvement. Because Huntington’s is a progressive disease (and invariably fatal), this is not a cure; the neural degeneration eventually continues. But the treatment did provide stability and was essentially remission. A story in The Independent reports that several hundred patients have received the transplant; this was the first long-term study.

The women who donated the fetal tissue were not asked to donate until they had already chosen to have an abortion.

Research Update

2006-10-06T12:33:00.000-07:00

Research Update

Well, I had no intent to write this infrequently but time sure slips away. I spent a lot of time studying for the LSAT (took it last week), which means that I got behind in all my work, and so it goes. So here are some very short synopses of research developments over the last few weeks.

Researchers at the University of Missouri have been able to derive five different types of cells from adult stem cells in pig blood, bone, blood vessel and nerve cells. The adult cells gave no indication of tumor formation. The technique involved isolating the stem cells and exposing them to different chemicals. The study also made use of a fluorescent gene marker to track the cells as they developed when they were re-inserted into a pig’s body. Press Release. In another study, researchers at Northwestern University were able to make a new cell from human blood stem cells: “human megakaryocytes (bone marrow cells that produce blood platelets that are responsible for blood clotting) derived from adult hematopoietic stem cells were, for the first time, reprogrammed into neutrophil-like cells similar to the white blood cells that are responsible for fighting infections.” Press Release.

The small heart stem cell trial taking place in Australia is showing success. Researchers said that patient have had improvement ranging from 10-60% in their heart functioning. The stem cells were separated from the patients’ blood and reinjected. Very short article on ABC. There were similar studies in Europe with different results, according to Forbes: a German team showed that patients who received the injections had 5.5% increase in function, compared to 3% for those who did not, and that they suffered fewer second heart attacks. Another German study had similar results. Both are notably less than what the Australians are claiming. Further, a Norwegian trial of 100 patients did not give any evidence of improvement. Researchers quoted said that research must go on, but this is not a therapy yet. See also the Mercury News.

Researchers have used human embryonic stem cells to slow vision loss in rats with a disease similar to of macular degeneration; the stem cells took the place of failing retinal cells, and the rats that received the stem cells had twice the visual acuity of the control group 40 days later. 18 different stem cell lines, including the federally approved ones and private ones, were used, with identical effects. This is good news for rats—it is less certain if this would work in people, since macular degeneration is a uniquely human disease. Washington Post.

The Batten Disease trial is about to get started, with one patient receiving treatment and the others receiving it thirty days later if there are no safety issues. This is a rare but horrible disease which slowly deprives children of motor function, speech, sight, communicative ability, and then they die. I really hope this works. Forbes.

You’ve probably already heard about this one, but researchers have been able to obtain stem cells from non-viable human embryos. Press release. This has of course not solved any ethical controversy—how do you know an embryo is dead? And even if it is, do you want to get cells from it? The chance of abnormality or genetic mutation is probably higher in an embryo that does not sustain itself. Seems to me that this might be useful for studying specific diseases but does not offer much that is not otherwise available. Houston Chronicle (Washington Post story).

Canadian researchers have used a monoclonal antibody developed in France to halt or cure acute myeloid leukemia in mice. The drug blocks a particular protein on the surface of a cancerous stem cell, thus preventing the cell from moving around and achoring itself anywhere in the body. Nowhere to settle, no more cancer cells to spawn. The researchers estimate it is at least 5-10 years before a trial could even be considered in humans. CBC. One should remember that the drug that caused the nearly fatal reaction in six British men last spring was also a monoclonal antibody.

Researchers at the Universities of Connecticut and of Pittsburgh have successfully cloned mice from a differentiated cell, using a type of specialized white blood cell called a granulocyte:

Surprisingly, the granulocytes were the most efficient donor cells for nuclear transfer among the different lineage cells, with 35 to 39 percent becoming a blastocyst, an early embryo consisting of about 100 to 150 cells, compared to 11 percent for the progenitor cells and only 4 percent for the stem cells. Only the granulocytes were able to produce two live cloned pups, although both died within a few hours of birth. As a control, the researchers performed nuclear transfer using embryonic stem cells; 49 percent developed to the blastocyst stage and 18 cloned pups were born.

Prior attempts to used different types of regular cells in cloning have failed. Any resulting blastocyst from a mature cell has had to be combined with a fertilized embryo. (Is any embryo unfertilized?) This research implies that the animal clones that have succeeded may be due to adult cells in the tissue environment. This is a pretty significant development, and obviously a lot more research is needed. It does confirm that the standard nuclear transfer procedure from ESCs is still more successful than any alternatives. The fact that the two mice that were cloned to birth died almost immediately suggests that something in the cloning process from regular cells is inhospitable to mammals. Press release. There has been a lot of media play on this one—the BBC has a decent article.

Researchers at the Howard Hughes Medical Institute have found an off-switch for skin stem cells; turning on the transcription factor gene Tcf3 blocked the differentiation of all three types of mature cells that a skin stem cell can develop into. The primary use for this knowledge will probably be in research, since it has been hard to keep stem cells from differentiating.

Possible bad news for breast cancer victims; researchers at the University of Southern California have found that almost all tumor cells in the bone marrow of women who have breast cancer are stem cells. This suggests that the likelihood of metastasis for women who have differentiated breast cancer—tumors in the bone marrow, not just the breast tissue—lasts longer than previously thought, perhaps for the rest of a lifetime. A lot more research still has to be done, and I expect will with this kind of finding.

Finally, this is not research, but it is important—the WARF will not collect royalties on any stem cell research done (by universities or non-profits) with its cells in the state of Wisconsin. Because of the way the WARF works, that’s a pretty strong incentive. Companies that relocate will also be eligible for grant money from the state. Governor Jim Doyle is working hard to make the state a desirable place for stem cell researchers. Milwaukee Business Journal. And the US Patent and Trademark Office has decided to review the WARF patents. This is no big surprise—they review about 90% of the patents requested. The executive director of a patent foundation said that 70% of the reviewed patents are revoked or modified. Mercury News (AP Wire).

And there you have it. I don’t see any particular theme to this research except that so much is still unknown.

Plant Stem Cells Discovery

2006-01-03T12:08:00.000-08:00

Plant Stem Cells Discovery

Although much of the focus and publicity on stem cell research is on animal cells, plants also have stem cells, which function similarly. Researchers at the Max Planck Society’s Institute for Developmental Biology in Germany have uncovered a feedback mechanism in plants which controls how many stem cells they have. A press release is available at the MPS site.

The parts of the plant which are above ground are generated by a tissue at the stop of the shoot called the “apical meristem,” which produces stem cells to make leaves, flowers, seeds, and yes, stems, throughout a plant’s life. Unlike animal stem cells, the stem cells produced by the apical meristem are capable of differentiating into any type of cell as long as the plant is growing. If the meristem produces too many stem cells, then there is uncontrolled growth, the plant equivalent of cancer; if too few, then the plant is stunted. The researchers wanted to find out how the plant regulated the number of its stem cells.

It was already known that growth hormones and a gene called WUSCHEL were involved, but it was unknown how the hormones and the gene worked together. The researchers found that the WUSCHEL gene restricts the activity of 4 other genes (ARRs) which “are part of a negative feedback loop, by which the growth-inducing plant hormone cytokinin limits its own influence.”

The hormone cytokinin is what causes the stem cells to multiply (by dividing), but it also activates the ARR genes, which then stop the cytokinin signaling and therefore stops growth. However, the WUSCHEL gene helps restrict the activity of the ARR genes, which means that more cytokinin can be produced. In other words, the WUSCHEL gene regulates how much growth hormone is produced by controlling the other genes that restrict it.

An earlier article about the discovery of the plant gene TCP20, which regulates cell growth and division, appeared on the BBC News site last September.

Understanding the role of growth hormones and cell division and regulation in plants can help give researchers understanding of similar processes in animals.

Cambridge University’s Plant Sciences Laboratory has some really cool pictures of plant cells. The images are copyrighted, so I will not reproduce them here, but poke around on their site if you are interested.

Breast Cancer Stem Cells Progress

2006-05-17T09:23:00.000-07:00

Breast Cancer Stem Cells Progress

Canadian researchers at the University of Calgary have developed a method to grow large quantities of breast cancer stem cells for laboratory research. The Regina Leader-Post says that the researchers are using a bioreactor that mimics the human body, similar to a technology which they previously used to grow large numbers of insulin-producing cells for diabetic patients. The Calgary Sun reports that the stem cells will initially come from mice. The bioreactor technology has previously been used for protein production.

One of the important things that seems to me to be happening in science is the ability to create research environments that are less artificial and more like what happens in the body. Simultaneously there’s also an improvement in computer programming that can analyze and predict reactions without as much need for an animal model. Both of these suggest to me that researchers are getting closer to understanding the cell as an organism in its own right and not as a component part that can be disassembled to see how it works. It’s not surprising that improvements in research technology lead to changes in understanding and thinking about the subject of the research, but it’s gratifying to see that progress being made.

Wisconsin and others

2006-09-14T14:32:00.000-07:00

Wow, it’s amazing how much time disappears when your kid comes home 2 1/2 hours earlier from school…

Anyway, just a little bit of interesting information related to WARF, the Wisconsin foundation connected with the University of Wisconsin Madison that handles the business side of stem cells. According to an article in Wisconsin Technology today, a review of the stem cell patents is expected after a legal challenge filed in July by a California group. The US Patent office will announce whether or not it will review next month. WARF expects a review and expects that the review will uphold the patent.

Also, the WiCell part of WARF has made an agreement with ACT in Alameda to distribute cells from the new so-called “ethical” stem cell lines. This could be interesting if ACT gets money from the CIRM, because of the profit sharing goals for the CIRM. It makes sense from a logistical stance for ACT to partner with WiCell, as WiCell already houses the national stem cell bank and distributes many other stem cell lines, both federally-approved and not, so researchers can get their material from a single source. But who collects any profit could be a legal knot.

It will also be interesting to see how much research gets done on these new stem cells, given all the negatives that have been voiced by scientists. Will there be sufficient interest in doing research for it to be worth it to produce them? With only two samples so far, there’s not much to work on comparatively.

Way Back When

Lost in the mists of my vanished time was a press release on EurekAlert saying that Harvard researchers have discovered a compound that increases the natural production of one’s own stem cells in the brain (at least, if one is a mouse). The research on the LTB4 compound also showed that when stem cells are stimulated to proliferate by the LTB4 compound, the cells have more LTB4 receptors. I presume this would make them more likely to proliferate further themselves when they are exposed to this molecule.

And in another story, European researchers have found out that when the cellular pathway known as “Wingless” is overactive—essentially, stuck in the on position—in hematopoietic stem cells, bizarre things happen—some cells disappeared, some occurred too frequently, some were unable to produce B or T cells or to develop into new kinds of cells. The key appears to be a protein called beta catenin, which kept the pathway open. This may be a clue as to what goes wrong in blood cancers.

And, in research you may have already heard about, three different papers on the aging of stem cells were published last week showing that a gene called Ink4a is key to the process by which stem cells shut themselves down. The suggestion is that this keeps them from accumulating and passing on mutations which could eventually lead to cancer. The gene was already known to be a tumor suppressor gene, but when scientists knocked it out in mice, the mice stem cells continued to repopulate. However, the mice developed cancer. While trading a short lifespan for a cancer-filled longer one doesn’t seem like a great deal, the research could give important directions to go in for cancer research and medicine.