by Steven Ertelt
March 20, 2007
Los Angeles, CA (LifeNews.com) — Scientists may have discovered a molecule that might help the growth of embryonic stem cells without using mouse feeder cells that contaminate them. The feeder cells prevent embryonic stem cells from ever being used in medical transplants.
Researchers at the University of Southern California say the newly discovered small molecule IQ-1 can prevent embryonic stem cells from differentiating into various types of cells.
If they don’t sort themselves into a single cell type, the embryonic stem cells and continue to grow and divide indefinitely.
Embryonic stem cells are normally maintained on mouse embryonic fibroblast (MEFs) feeder layers. If the discovered molecule works as promised, scientists will no longer be required to use the mouse feeder cells to maintaining the "pluripotency" of embryonic stem cells.
Lead investigator Michael Kahn talked with UPI about the discovery and said the discovery is important if the cells are ever to be used in treating patients.
"Stem cells that grow on feeders are contaminated with mouse glycoproteins markers," said Kahn. "If you use them in humans, you’d potentially have a horrible immune response."
Despite the discovery, embryonic stem cell research is still nowhere close to being ready to help patients as it must still overcome rejection issues and other concerns.
The team has published their findings in the Proceedings of the National Academy of Sciences.
This isn’t the first time scientists have worked to grow embryonic stem cells without the mouse feeder cells used to spark the growth. A scientist in India last October, said he created embryonic stem cell lines without them.
Indira Hinduja, who created the country’s first test-tube baby, used human feeder cells to grow the embryonic stem cell lines so they would not be contaminated.
Hinduja and IVF specialist Kusum Zaveri developed three human embryonic stem cell lines without using the contaminating cells to grow them as most researchers have done around the world.
Using the human feeder cells to grow the lines will also help the embryonic stem cells to be able to be reimplanted up to 200 times as opposed to the limit of 75 times using mouse feeder cells.
Dr. Robert Lanza of Massachusetts-based Advanced Cell Technology, a biotech firm which came under intense scrutiny for false announcements about obtaining embryonic stem cells without destroying human embryos, claimed to have made mouse-free embryonic stem cells in march 2005.
"The science now exists to produce new lines that will be safe," he said at the time.
Lanza’s company worked with teams at the Harvard Medical School and the Howard Hughes Medical Institute and published an article in the medical journal Lancet.
Scientists at the University of Wisconsin claim to have been the first to get some of the embryonic stem cells separated from the mouse feeder cells.
ACT took this research a step further growing embryonic stem cells from scratch harvested by killing human embryos from fertility clinics.
However, Outi Hovatta of Sweden’s Karolinska Institutet and Heli Skottman of the Institute for Regenerative Medicine at Finland’s University of Tampere said ACT’s cells still contained some animal cells and that the new methods hadn’t fully erased contamination concerns.