Close encounters with very small stem cells

 vsel small stem cell neostem vatican (

Interest in VSELs, or Very Small Embryonic-Like cells, has spiked again recently, driven by the penning of these largely negative pieces in Cell Stem Cell, Nature, Stem Cell Reports and Scientific American.

VSELs could be a game-changer for the stem cell field – the clichéd ‘Holy Grail'. As they are nonembryonic cells, if VSELs exist then they could replace the controversial embryonic stem cell in research and regenerative medicine. However, there-in lies the rub. Whether they exist is the issue of contention – and it's an issue which the Vatican City has entered into.

Back in 2006, a team led by Mariusz Ratajczak at the University of Louisville reported the discovery of small cells extracted from mouse bone marrow. The cells were about 3 microns in diameter and seemed capable of differentiating into all three germ layer lineages. Other studies since then have described cells with similar morphological and molecular profiles – but have people really seen a VSEL cell? Like a sighting of a UFO, sightings of VSELs remain mysterious and enshrouded in uncertainty. The Cell Stem Cell article, ‘VSELs: Is Ideology Overtaking Science', asks whether VSELs are cells at all, as opposed to debris or subcellular particles. Many researchers have been unable to reproduce the results seen by Ratajczak – and reproducibility is often cited as the key to good science.

However, at least two parties remain overtly positive about VSELs. One is Neostem, a New York-based biopharmaceutical company that has plans to carry out a first-in-man trial using VSELs to regenerate bone in dental patients. The second is the Vatican City. Aiming to support research that avoids the use of embryonic stem cells, the Vatican donated funds through the Stem For Life Foundation to support NeoStem's work on VSELs.

But Arthur Caplan, who is head of the Division of Medical Ethics at NYU Langone Medical Center wrote a pointed piece for NBC News, where he gave his opinion on the danger of mixing science with religion:

"Science and religion do not usually mix. But when they do and when the power of religion is used to cheer for a particular research strategy not because of evidence but because of morality that creates a huge potential for trouble…It is persuading one's scientific peers, not priests, rabbis, imams and ministers, that is the key to progress in medicine and science." 

Despite the controversy, proponents of VSELs remain resolute about their existence and potential. Ratajczak argues that other labs haven't been studying the same cell populations. "In studying rare populations of cells, one needs to compare apples to apples, which unfortunately was not done."

And Robin Smith, chief executive of NeoStem, compares the attacks on VSELs to the attacks suffered by Charles Darwin and Nicolaus Copernicus when their put forward their world-changing theories. Russell Taichman, who will be running the Neostem-backed VSEL dental trial, says: "I don't see the controversy — we have seen bone grow". Diane Krause, another researcher to have published evidence in support of VSELs, says "I can only say that we manage to see these cells. One of our postdocs went to the Ratajczak lab and learnt the technique properly."

If you want to read more about VSELs and make your own mind up, here are the recent interesting articles on the matter.

Nature: Doubt cast over tiny stem cells

Scientific American: Has Mariusz Ratajczak Found the Holy Grail of Stem Cells?

Stem Cell Reports: Do Pluripotent Stem Cells Exist in Adult Mice as Very Small Embryonic Stem Cells?

Cell Stem Cell: VSELs: Is Ideology Overtaking Science?

NBC News: Bioethicist: Failed search for controversial cells shows danger of mixing science, religion

What do you think? Do you think VSELs offer huge promise? Or do they not exist at all? Why not join our discussion on LinkedIn, or leave a comment below. Want more from Total BioPharma? Sign up to our newsletter – it doesn't cost anything and only takes a minute.

To learn more about research and development in the stem cell industry, attend the Stem Cells USA & Regenerative Medicine Congress, where Dr. Robin Smith's, Neostem's Chairman and Chief Executive Officer, will be speaking on the topic of capital formation strategies and obstacles necessary to narrow the access to large cap gap in the industry.

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