Science Saturday: An adult stem cell research "advance" that isn't

Apologies to Page, who rocks in every way imaginable, for piggybacking on her "Science Friday" series.

So I was browsing RedState this morning and noticed this RedHot item titled "Advance made in stem cell research".  Since I'm a grad student in immunology and scan the primary literature fairly regularly, I'm usually up on these things, so I was surprised to have missed this one.  The first alarm bells started going off when I moused over the link and found it was to the Washington Times.  Hmmm, a major advance in stem cell research that could render ES cells unnecessary, reported by the Washington Times and no other outlet.  

Blatant liberal media bias, or the right-wing press twisting the science to suit their purposes?  Read on...

First, here are the key grafs from the Wash Times article:

A team of Texas and British researchers says it has produced large amounts of embryoniclike stem cells from umbilical cord blood, potentially ending the ethical debate affecting stem-cell research -- the need to kill human embryos.

The international researchers said the cells -- called cord-blood-derived-embryoniclike stem cells, or CBEs -- have the ability to turn into any kind of body tissue, like embryonic stem cells do, and can be mass-produced using technology derived from NASA...

David Prentice, senior fellow for life sciences for the Family Research Council, which advocatescord-blood and other adult stem-cell research that does not require destruction of embryos, said the research sounds "real exciting."

Alrighty then.  No need for ES cell research.  Case closed.  Unless, that is, you actually do something anathema to conservatives and check out the actual data.

Fortunately, the writer of the Wash Times article was nice enough to name the study's lead author, making it easy to find the study with a PubMed search.  (Second set of alarm bells: The study is in the Journal of Cell Proliferation, an obscure journal I've never heard of.  Not that research published in obscure journals is necessarily had -- groundbreaking work often has trouble getting through peer review -- but you'd expect a finding of this magnitude to be in Cell, Science, or Nature.)  Even more fortunately, my institution has a subscription to said journal, allowing me to share it with you.

The first lines of the abstract:

When will embryonic stem cells reach the clinic? The answer is simple  not soon! To produce large quantities of homogeneous tissue for transplantation, without feeder layers, and with the appropriate recipient's immunological phenotype, is a significant scientific hindrance, although adult stem (ADS) cells provide an alternative, more ethically acceptable, source.

For those unfamiliar with the format of a scientific paper, the "abstract" is supposed to summarize the findings of the study and the relevant conclusions.  It is not supposed to make statements about ethics or clinical feasibility (the latter would be appropriate if it were the subject of the study, but in this case it isn't).  I've never seen a statement remotely like that in an abstract, and I've read a lot of them.

Reading through the rest of the paper (link won't work unless you have an institutional or individual subscription), the major findings are:

1. Stem cells can be isolated from cord blood and grown in culture.

2. They express certain cell surface markers characteristic of ES cells.

3. When grown in three-dimensional bioreactors and stimulated with factors that promote liver development, the cells took on some cell surface markers characteristic of liver cells.

First of all, none of these findings are new.  Even the headline finding, #3, is old hat -- in fact, this study from two years ago went even further.

More importantly, the study doesn't really address the heart of the ESC/ASC debate.  Embryonic stem cells are "totipotent" -- they can differentiate into ANY cell type in the body, which is why they have so much potential.  Adult stem cells -- whether from bone marrow, cord blood, or wherever -- are, as far as we know, "pluripotent".  They can differentiate into some cell types, mainly blood cells, but not all.  In particular, they can't differentiate into cells of non-blood lineages.  This is known as "transdifferentiation", and it's the holy grail of adult stem cell research.  

Unfortunately, that doesn't seem to happen.  A study from Irving Weissman's lab at Stanford (one of the top two stem cell labs in the USA, Doug Melton's lab at Harvard being the other) transplanted adult stem cells (which had been marked with a green fluorescent protein) into mice and looked at 15 million cells from various organs and tissues to see if they had the marker.  Guess how many did?  Eight.  And upon further review, all eight turned out to be the result of fusion with a blood cell. Here's the study, although you'll need a subscription to read that one, too.  

Oh, by the way, THAT study was published in Science.  And I'll bet you didn't read about it in the Washington Times.

So to summarize...

Washington Times: "The international researchers said the cells -- called cord-blood-derived-embryoniclike stem cells, or CBEs -- have the ability to turn into any kind of body tissue, like embryonic stem cells do..."

Reality: Some cells with an ES cell-like appearance turned on some liver cell markers when treated in a certain way in tissue culture.

Mmm hmmm.  It looks like ES cell research might have a future after all.  And it looks like when it comes to science, you can't always believe what you read in the media.