Posted on 09/07/2005 8:20:16 PM PDT by Coleus
Stem Cell Research in Leech Underway at Rutgers-Camden
For Immediate Release
CAMDEN – Research underway at Rutgers University—Camden may provide an opportunity for medical and scientific advancements of stem cell knowledge without the current controversy.
Stem cell research in human embryos is highly controversial and isolating a human stem cell from hundreds of microscopically developing cells is extremely difficult. The aquatic leech offers an effective alternative to human stem cells, suggests Daniel Shain, an associate professor of biology at Rutgers-Camden.
A newly awarded $149,265 grant from the National Institutes of Health is allowing Shain and a team of Rutgers-Camden student researchers to map previously unknown genes involved in creating quite possibly the largest stem cells in the animal kingdom.
“We can approach in leeches what we can’t in humans. The leech embryo is hundreds of times bigger, almost like comparing a beach ball to a marble. And more than that, the leech presents its stem cell on the surface,” says the Rutgers-Camden researcher.
Stem cells are jumbled in human embryos, much like marbles in a bag. Finding those cells once is hard; finding them again in other samples is harder still. The leech embryo, however, presents its stem cells – only 10 of them, compared to hundreds in human embryos – on the surface, so there is no need to navigate through other cells and cell layers. Leech stem cells align in an asymmetrical pattern, with distinct size differences that allow scientists like Shain to identify them quickly again and again.
The ability to isolate the stem cells allows for more exciting discoveries, such as answering one key question in stem cell research: what makes a stem cell different from other cells?
“What makes stem cells different biochemically is a burning question for virtually every scientist in this field,” says Shain.
Shain and student researchers compared stem cells with leech precursor cells – cells in an earlier phase in development –and have identified genes that are activated when the stem cells are born.
“Like humans, leech have all genes present inside each cell, but only a select group of genes get turned on to specify what cell type it will be,” says Shain.
The difficulty in isolating human stem cells is a key reason why researchers have not determined what genes are turned on when that cell is created. By contrast, Shain has found that about 27 genes are turned on in the leech stem cells, and 29 are turned off. His team is researching the triggered genes, and has found a way of preventing gene K110 from being activated.
“When we stop it from turning on, the cell divides wildly out of control, as a tumor would divide, and it loses its ability to produce a stem cell,” says Shain, who points out that scientists have begun to further analyze a likely link between the molecular profile of stem cells and cancer cells.
In addition to gene K110, the Rutgers-Camden research team is working to characterize other genes associated with stem cell formation.
“The difference between a precursor (non-stem) cell and an embryonic stem cell is likely to be only a few key genes, and we think we may have them,” says Shain.
Shain teaches undergraduate and graduate courses in biology at Rutgers-Camden. where he joined the faculty in 1999. He has received numerous grants in support of his research into leech, ice worms, and other invertebrates.
A graduate of the University of New Hampshire, where he earned both his bachelor’s and master’s degrees, Shain earned his doctorate from Colorado State University and held a postdoctoral fellowship through the National Institute of Health at the University of California-Berkeley.
video, go to 19:55
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