2 lines account for most human embryonic stem cell research, Stanford scholar finds

11-Aug-2009 - USA

For the past eight years, scientists who wanted to use federal funds for research on human embryonic stem cells had to restrict their studies to 21 cell lines approved by the National Institutes of Health. But an analysis by a researcher at the Stanford University School of medicine suggests that only two of those lines have been used routinely.

"I was surprised by these results," said Christopher Scott, director of Stanford's Program on Stem Cells in Society. "I never imagined that we would find that three-fourths of the requests would be for the same two cell lines."

On the one hand, the findings raise concerns about the reauthorization process of cell lines under way at the NIH — if these lines are now excluded from federal funding due to ethical considerations, researchers may abandon them, and their previous research, in favor of other lines. On the other hand, the findings draw attention to the possibility that these two lines may have abnormalities or characteristics that make them not as useful as newer lines.

"Not only are scientists asking for these lines, they are publishing on them," said Scott, a senior research scholar at Stanford's Center for Biomedical Ethics. "They have become the reference standards against which new embryonic and iPS cell lines are being compared."

Scott collaborated with researchers from the Mayo Clinic and the University of Michigan to conduct the research, which is published in Nature Biotechnology . Together they analyzed the number and timing of requests placed by scientists for human embryonic stem cell lines housed at the two largest stem cell banks in the country: the National Stem Cell Bank at the WiCell Research Institute in Madison, Wisc., and the Harvard Stem Cell Institute in Massachusetts.

Although the National Stem Cell Bank is meant to be the source of all NIH-approved lines, Scott and his colleagues found that at no time have all 21 lines been available for distribution; a maximum of 18 lines were available at the beginning of this year. Two cell lines, known as H1 and H9, made up the majority of requests — 941 out of 1,217, or 77 percent, since 1999. One other line, H7, was requested 111 times. In contrast, 13 of the previously approved lines were requested fewer than 10 times in the past decade.

Research on the three most-requested lines from the NSCB is prevalent in the scientific literature: 83 percent of 534 peer-reviewed publications from 1999 to 2008 discussed research on H9, 61 percent on H1 and 24 percent used H7 (the numbers exceed 100 percent because many studies used more than one cell line). In contrast, fewer than 36 percent of the publications used any of the other NSCB-curated cell lines.

https://www.bionity.com/en/news/104551/2-lines-account-for-most-human-embryonic-stem-cell-research-stanford-scholar-finds.html