Stem Cells: One Step Back, Two Forward

Stem Cells

Science journals are very rarely retracted, but two recent publications regarding stem cells have joined the ranks of retracted journals. The studies in question were posted by Science in January, but had to be retracted this week due to external researchers not being able to recreate the outcome of the experiment. However, despite the negative press generated from taking back the findings of two stem cell studies, another breakthrough has occurred to help the field take steps forward again.

The retracted studies regarded the creation of STAP cells, specifically how those cells could be used to replicate placenta cells. Stimulus-triggered acquisition of pluripotency (STAP) describes how cells with the capability to become any cell in the body can be converted from specific cells. The first paper described a simple process in which bathing a newborn mouse’s spleen cells in acid could create pluripotent cells and how physical pressure could also be substituted for the acid exposure. The second paper described how STAP cells could be differentiated into placenta cells, something of which other pluripotent stem cells are incapable. Many inconsistencies by the RIKEN Institute, including duplicating, mislabeling, and manipulating photos as well as “inexplicable discrepancies” discredited the RIKEN institute, causing one of the scientists involved, Yoshiki Sasai, to now express his shame, saying it is hard to even consider STAP cells a promising enterprise anymore.

Though the study was mainly performed by the biochemist Haruko Obokata and her subordinates at the RIKEN institute in Kobe, the concept was first introduced by Charles Vacanti. Charles and his brother, Martin Vacanti, first started researching the idea at the University of Massachusetts Medical School over ten years ago. Charles Vacanti then met Obokata at Brigham and Women’s Hospital where she worked with him closely as a researcher in his laboratory. Brigham and Women’s Hospital is a subsidiary of Harvard, so both Harvard and Brigham have been looking into the research as well, though they have a policy of not publicly discussing their findings. However, Charles Vacanti claims that while he understands that it will be hard to convince skeptics after all of the negative press, he still believes in the STAP phenomenon.

While the two stem cell papers being retracted is a step back, supporters of stem cell research will be happy to know that there has also been forward progress. In a joint venture between four of Harvard’s affiliate hospitals, the Department of Defense, the National Cancer Institute, Howard Hughes Medical Institute, Harvard Stem Cell Institute, the National Institute of Neurological Disorders and Stroke, the Life Sciences Research Foundation, the National Institutes of Health, and the Veterans Administration, researchers have found a way to find illusive limbal stem cells. These cells have the potential to help victims of chemical injuries, burn victims, and various diseases of the eye.

The problem with limbal cells historically has been the fact that they were hard to find in the human body, but the study conducted discovered that they had a “marker molecule,” which is common in the intestine and skin cells, called ABCB5. Discovering that ABCB5 was in limbal cells allows doctors and scientists to find the cells and put them to good use. Scientists were even able to grow an anatomically correct human cornea in a mouse due to the breakthrough study. The study is one example of adult-derived stem cells being put to good use, and should be a large step forward after the two other journals were retracted.

By Eddie Mejia

Scientific American
Boston Globe
BBC News
Harvard Gazette

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