Findings underscore need for screening methods to improve safety of promising experimental treatments.
A research team from the Harvard Stem Cell Institute (HSCI), Harvard Medical School (HMS), and the Stanley Center for Psychiatric Research at the Broad Institute of MIT and Harvard has found that as stem cell lines grow in a lab dish, they often acquire mutations in the TP53 (p53) gene, an important tumor suppressor responsible for controlling cell growth and division.

Their research suggests that genetic sequencing technologies should be used to screen for mutated cells in stem cell cultures, so that cultures with mutated cells can be excluded from scientific experiments and clinical therapies. If such methods are not employed it could lead to an elevated cancer risk in those receiving transplants.

The paper, published online in the journal Nature on April, 26, comes at just the right time, the researchers said, as experimental treatments using human pluripotent stem cells are ramping up across the country.

"Our results underscore the need for the field of regenerative medicine to proceed with care," said the study’s co–corresponding author Kevin Eggan, an HSCI Principal Faculty member and the director of stem cell biology for the Stanley Center. Eggan’s lab in Harvard University’s Department of Stem Cell and Regenerative Biology uses human stem cells to study the mechanisms of brain disorders, including amyotrophic lateral sclerosis, intellectual disability, and schizophrenia.

The research, the team said, should not discourage the pursuit of experimental treatments but instead be heeded as a call to screen rigorously all cell lines for mutations at various stages of development as well as immediately before transplantation.

"Our findings indicate that an additional series of quality control checks should be implemented during the production of stem cells and their downstream use in developing therapies," Eggan said. "Fortunately, these genetic checks can be readily performed with precise, sensitive, and increasingly inexpensive sequencing methods."

With human stem cells, researchers can recreate human tissue in the lab. This enables them to study the mechanisms by which certain genes can predispose an individual to a particular disease. Eggan has been working with Steve McCarroll, associate professor of genetics at Harvard Medical School and director of genetics at the Stanley Center, to study how genes shape the biology of neurons, which can be derived from these stem cells.