The Niche

Not so much a warning, but certainly bad news for Osiris. The mesenchymal stem cell drug Prochymal did not show efficacy in two large controlled study of graft versus host disease. ( Read that story here)

In more alarming news for at least some investors, Reuters is reporting that the US Securities and Exchange Commission has charged company CellCyte Genetics Corp has given false information to investors claiming that its stem cell technology was heading for human trials. Here’s more from Fierce Biotech

More seriously, a group called Bionet is calling for a clamp down on unregulated stem cell treatments, according to the BBC. The coalition of Chinese and European say patients are being subjected to a lot of hype and potential harm when they travel for these expensive treatments.
They are not the first:
See
Stick to the guidelines and fewer get hurt
Offshore stem cell therapies need sensitive regulation
Stem cell researchers face down stem cell tourism

On a philosophically lighter (though perhaps literally heavier note), mice fed the equivalent of the Atkins diet had fewer and less-active bone marrow and peripheral blood endothelial progenitor cells, compared to two other diet regimens. See the report in PNAS.
Here’s other work on how diet affects stem cells.

Posted by Monya Baker on September 09, 2009
Categories: Industry, Policy, Tissue-specific stem cells | Permalink | Comments (0) | TrackBacks (0)

Blood-forming stem cells have recently garnered some attention. Genzyme’s drug to boost circulating stem cells in patients with blood cancers won FDA approval on Monday. Here is Genzyme’s description of its small molecule chemokine receptor antagonist. Also, two research teams from Stanford have found ways to make artificial versions of the microenvironments where blood forms (See below), and a third team from Germany and Switzerland describes away to track individual blood-forming stem cells .

But it's not all bloody. Esophageal stem cells made the cover of the Journal of Clinical investigation. The cells lining your throat strike an “exquisite equilibrium between proliferation and differentiation.” Researchers led by Anil Rustgi at the University of Pennsylvania, used DNA-labeling to identify a population of slow-cycling, apparently self-renewing cells in the esophagus. Then they studied these cells in three-dimensional culture and found that they grew into esophageal structures. When these cells were placed in immunodeficient mice, they formed epithelial structures, and when they were placed in a mouse model of esophageal reflux disease, they migrated to the site of injury. Here’s the press release.

Continue reading "Blood-forming and esophageal stem cells: find, see, manipulate" »

Posted by Monya Baker on December 16, 2008
Categories: Blood stem cells, Tissue-specific stem cells | Permalink | Comments (0) | TrackBacks (0)

A bone marrow transplant seems to have suppressed HIV virus levels in blood. These results have been observed in a single patient and have not yet been reported in the peer-reviewed literature. According to news reports, a man infected with the AIDS virus received a bone marrow transplant as part of leukemia treatment. The donor of the bone marrow was naturally resistant to HIV infection because of a mutation in the CCR5 protein that the virus uses to gain entry into the cells it infects. Afterwards, the patient stopped taking his AIDS drugs. Twenty months later, though they cannot conclude that the virus has been vanquished, doctors cannot find evidence of leukemia or HIV in the 42-year-old patient.

See the reports in Reuters (shorter) and the Wall Street Journal online (more detailed.)

Continue reading "Stem-cell transplant seems to fend off HIV" »

Posted by Monya Baker on November 13, 2008
Categories: Tissue-specific stem cells | Permalink | Comments (1) | TrackBacks (0)

Two papers from the University of Michigan show how tissue-specific stem cells trade regenerative potential to control unwanted proliferation. One, in fly testes from Yukiko Yamasita, shows that cells halt their division if the daughter cells would be misoriented. The other, in mice brains, shows how gene expression changes with age to favor decreased regeneration with decreased risk for tumorigenesis.

I’ll put those research highlights below. If you’re interested in how stem-cell rigor declines with age, you’ll also be interested in A metasignalling network makes muscles age , which shows that muscle tissue doesn’t so much lose its regenerative potential as actively inhibit it.

Both these highlights will show up as formal article in Nature Reports Stem Cells next week. Already going live this week are two highlights that show just how many ways there are to be pluripotent. One features separate work by Azim Surani and Myriam Hemberger on how pluripotency is governed within the embryo. (See Plasticity of the pluripotent). The other highlight also combines coverage of two separate papers. Shinya Yamanaka and Konrad Hochedlinger show that reprogramming cultured mouse skin cells to pluripotency need not require genetic modification.

Continue reading "Aging stem cells: trade-offs between vigor and cancer" »

Posted by Monya Baker on October 16, 2008
Categories: Tissue-specific stem cells | Permalink | Comments (0) | TrackBacks (0)

Here's an account of a recent Nature paper. This will be an official article on Nature Reports on July 24.

Stretched out to its full length, your small intestine would be about five metres taller than you. It would take some 7,000 fruit flies, each standing on top of another, to reach that height.

That image is not quite as odd as it seems. Work led by Volker Hartenstein at the University of California, Los Angeles, shows that cell development within the hindgut of Drosophila is strikingly similar to that within the crypts and villi of the mammalian gut. Indeed, even the movement and differentiation of stem cells in the fly hindgut seem to mirror those seen within villi, the finger-like projections lining the small intestine. Thus, Drosophila could become a powerful model organism for studying this stem cell system.

Continue reading "Fly guts and lessons for humans" »

Posted by Monya Baker on July 18, 2008
Categories: Tissue-specific stem cells | Permalink | Comments (0) | TrackBacks (0)