|08-13-2001, 09:10 AM||#1|
Join Date: Jul 2001
Stem Cells: Now for the Hard Part
Now for the Hard Part
By Kristen Philipkoski
Aug 13, 2001 02:00 a.m. PDT
President Bush will allow the government to fund research on stem cell lines that already exist. Although that's not as good a deal as many researchers hoped for, they're not going to sit around and mope.
They'll take what they can get and they're eager the take the next step.
Research on embryonic stem cells using federal funds could begin before the end of this year under Bush's new guidelines.
Writing grant proposals will be daunting enough with patents and potential lawsuits complicating the process. But the science ahead is even more challenging.
Stem cells are taken from embryos, which are destroyed in the process, hence the opposition from those who believe that human life begins at conception. An embryonic stem cell has the ability to turn into almost any type of human cell. Researchers are trying to find ways to control this differentiation process so they can create cells to replace, for example, patients' damaged neurons or muscle cells.
At least scientists know how to write a research grant proposal. But no one is really sure how stem cells might eventually work to treat a disease such as diabetes, or if they will at all.
"This science is in it's infancy, so those are the questions that need to be answered," said Sean Tipton, a spokesman for the American Society for Reproductive Medicine.
Even if they see success, as Johns Hopkins researchers did recently in mice, they might not know how they did it.
John Gearhart, a stem cell researcher at Johns Hopkins University, led a group that injected stem cells (taken from voluntarily aborted fetuses in this case) into mice with induced spinal cord injury, rendering their back legs useless.
The mice regained some, but not all, movement in their hind legs. The problem is, the researchers have no idea how or why it worked.
"We don't always know what's going on," Gearhart said earlier this year.
But the hope is that undifferentiated stem cells will change into the type of stem cells they are surrounded by.
"In a mammalian embryo, a cell's fate is determined by its environment," Gearhart said.
When injected in to an injured site, such as a pancreas or heart, researchers hope the stem cells direct themselves to the injured area and replace the damaged tissue.
"We don't want them to migrate, which stem cells love to do," Gearhart said.
At this point in the research, Gearhart estimates that scientists can control the differentiation of the cells about 10 percent of the time.
Before the research comes the red tape, which could prove to be almost as complicated. But Tipton said the powers that be are doing what they can to make the process easier.
"The National Institutes of Health will have a registry of approved stem cell lines that meet the criteria the President laid out, and investigators will submit a grant proposal the same way as they submit one on anything else," said Tipton, who met with the two groups on Friday.
Bush said on Thursday that researchers, to be approved for a grant, must use one of 60 existing stem cell "lines." Stem cells can replicate themselves indefinitely, and millions of stem cells can be derived from just one embryo, creating one stem cell line.
But before the researchers can even apply for a grant, they must deal with a patent issue. In 1998 when University of Wisconsin researcher James Thompson isolated the first stem cells from an embryo, he also garnered an exclusive patent on how he did it for the university.
Since a company in Menlo Park, California, called Geron donated millions of dollars to Thompson's research, it was granted an exclusive license to this patent.
Since it wouldn't be fair to keep all of the goods to themselves, the Wisconsin Alumni Research Foundation set up the WiCell Research Institute to dole out the precious cells for a fee of $5,000 per cell line.
About 30 research centers have taken them up on their offer to date, and 100 more applications are being reviewed.
Some companies such as Bresagen of Athens, Georgia, have developed their own stem cells and say the Wisconsin patent is too broad. A patent dispute is likely to ensue, although no one has sued anyone yet.
Once the researcher could show that she had access to a line of stem cells, she could then apply for a grant from the government.
Grant writing is a daunting task in itself, but the good news is the NIH plans to allow researchers to append existing grants.
For example, a diabetes researcher might be using "adult" stem cells, which are taken from bone marrow, placentas, or skin (but thought to be less flexible than embryonic) to figure out how to create new pancreatic cells that would produce insulin.
He could simply resubmit his existing grant application and add a request for funds to use one of the 60 approved stem cell lines to pursue in tandem with his adult stem cell research.
"We are concerned about some of the restrictions, but on the other hand this may actually be a quicker way to get the work started," Tipton said