The most widely used human embryonic stem cell lines lack genetic diversity, a finding that raises social justice questions that must be addressed to ensure that all sectors of society benefit from stem cell advances, according to a U-M research team.
In the first published study of its kind, the team analyzed 47 embryonic stem cell lines, including most of the lines commonly used by stem cell researchers. The scientists determined the genetic ancestry of each line and found that most were derived from donors of northern and western European ancestry.
Several of the lines are of Middle Eastern or southern European ancestry. Two of the lines are of East Asian origin. None of the lines were derived from individuals of recent African ancestry, from Pacific Islanders, or from populations indigenous to the Americas.
In addition, U-M researchers identified several instances in which more than one cell line came from the same embryo donors, further reducing the overall genetic diversity of the most widely available lines.
“Embryonic stem cell research has the potential to change the future of medicine,” says Sean Morrison, director of the Center for Stem Cell Biology and one of the study leaders. “But there’s a lack of diversity among today’s most commonly used human embryonic stem cell lines, which highlights an important social justice issue.”
For the study, Morrison teamed up with two colleagues at the Life Sciences Institute: stem cell scientist Jack Mosher and population geneticist Noah Rosenberg. Their findings were published online in December in the New England Journal of Medicine.
A fundamental principle of medical research is that new therapies are tested on patients that mirror the diversity in society, because certain groups may respond to medications and treatments differently. By evaluating new therapies in diverse patients, researchers are more likely to detect the different effects these therapies might have.
Embryonic stem cell lines are being used to develop new cellular therapies for spinal cord injuries and various diseases, to screen for new drugs and to better understand inherited diseases. It’s crucial that diverse lines are available for this research to ensure that all patients benefit from the results, Morrison says.
“If that’s not done, we run the risk of leaving certain groups in our society behind,” says Morrison, who is a Howard Hughes Medical Institute investigator.
The U-M report comes as Michigan researchers launch new projects made possible by a recent state constitutional amendment allowing researchers in the state to derive new human embryonic stem cell lines using approaches already used in the rest of the country.
In Michigan, U-M researchers announced on Dec. 8 that they received approval from the Medical School’s Institutional Review Board and the university’s Human Pluripotent Stem Cell Research Oversight Committee to begin accepting donated embryos that will be used to derive the university’s first human embryonic stem cell lines. It is the first U-M project made possible by Proposal 2, the state constitutional amendment approved by Michigan voters in November 2008, easing restrictions on human embryonic stem cell research in the state.
In addition to Mosher, Morrison and Rosenberg, the paper’s U-M authors are Trevor Pemberton, Kristina Harter, Chaolong Wang and Erkan Buzbas.
