Amniotic Fluid a Source of Effective Stem Cells?

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.