Saturday, June 24, 2006

"Corrupted" Cells or Ethics?

The New Scientist is reporting the announcement (available by subscription here and the full, free version is here) by Pharmafrontiers (which is officially "Opexa Therapeutics.") that the company has successfully de-differentiated human blood cells into stem cells that are usually thought to be from other cell lineages. In other words, Pharmafrontiers,

"claims to have refined a way to produce stem cells from white blood cells called monocytes and develop them into many different tissue types including, crucially, insulin-producing cells."


This is exciting news. Pharmafrontiers is presenting a report at a scientific conference, where their research and results will presumably be subject to peer-review. The corporation is submitting a paper to a peer-reviewed journal and is applying for a patent on the technology to grow insulin-producing beta-islet cells from each patient's own white blood cells. The article notes several other labs in other parts of the world which have reported similar findings in peer-reviewed journals.

However, the bioethics story is the negative way in which The New Scientist has chosen to report the possibility that adult stem cells may provide therapies for diabetes and other diseases. There is an especially spurious comment about the amount of blood that would be needed from each patient - see the end of this post for more on that.


From the article:
Most mainstream stem cell researchers are sceptical, however, because the idea that specialised cells like monocytes can be "de-differentiated" back to more primitive stem cells remains heretical. "Let's see first how they perform functionally," says Stephen Minger of King's College London.

Pharmafrontiers, is to present its latest results at the end of this month in Toronto at the International Society for Stem Cell Research meeting. Deriving "stem cells" from monocytes was originally reported in 2003 in Proceedings of the National Academy of Sciences (vol 100, p 2426) by a team at Argonne National Laboratory in Illinois, but Pharmafrontiers bought up and refined the technology.

The company says it can de-differentiate monocytes into "multipotent" stem cells by exposing them to certain nutrients and growth factors. Such stem cells can give rise to many but not all tissue types like "pluripotent" embryonic stem cells (ESCs). Different combinations of growth factors can then turn the stem cells into a range of cell types.

Moreover, Pharmafrontiers says it is about to submit a patent application on a brew that turns the monocytes into pancreatic islet-like cells that produce insulin in response to high levels of glucose. "We now want to transplant these cultures into a diabetic mouse model," says Winnier, adding their results are being prepared for publication in a peer-reviewed journal.

Alan Colman of ES International, a company developing insulin-producing cells from human ESCs in Singapore, is also sceptical. He says it would take huge amounts of blood to produce enough islet cells for individual patients.

Chris Major of University College London says most stem cell researchers have neglected the idea of de-differentiating adult cells in favour of using embryonic stem cells. However, he warned there could be problems with using adult cells, because they have suffered years of genetic damage. "With embryonic cells, they're fresh, and not corrupted," he says.

Other teams are also experimenting with stem cells from blood. A team led by Bernat Soria of the Institute of Bioengineering at Miguel Hernández University in Alicante, Spain, last year reported reversing a mouse form of diabetes with insulin-producing cells developed from blood cells (Gastroenterology, vol 128, p 1774). And researchers at the University of Kiel in Germany led by Fred Fandrich report producing liver cells.
(emphases are mine)

The bug-a-boo about the volume of cells that would be necessary to treat any one patient is one of the arguments against the possiblity of using (destructive) embryonic stem cells. In the case of adult stem cells, however, we know the objection is falsified by the currently accepted procedure for collecting stem cells for complete bone marrow transplants. The donor is given a stimulating factor to cause him or her to produce larger than normal amounts of bone marrow-producing stem cells which are released into the circulating blood. The donor then undergoes a procedure called apheresis to collect the stem cells without loss of red blood cells, plasma, or platelets. Apheresis is a technique that allows the removal of specific cells or proteins from the patient's whole blood, with immediate return of most of the blood to the circulation. We've collected platelets and removed harmful antibodies from patients with this technology for decades. Here's a pdf from the University of Utah, explaining the procedure in more detail.

Perhaps The New Scientist should look at its own editorial staff to see whether they belong to the religion that "neglects" research on adult stem cells as "heretical." And why.

1 comment:

Suricou Raven said...

I dont see any systematic attempt to misrepresent here. They are just being cautious - noting its potential, but not being too optimistic, and listing the various reasons why it may turn out to be a false-alarm of a new treatment that will never be practical.