Hard cell

Human Life Review, Summer 2001 by Miniter, Richard

When President Bush meets the pope today, one of the issues they're sure to discuss is the controversy over embryonic stem-cell research. Mr. Bush is reportedly struggling with the decision of whether to accept a last-minute Clinton decision that would effectively lift the ban on federal funding of such research. During his campaign, Mr. Bush promised to uphold the ban.

Proponents of such research, and the media, frame the issue as one of religion vs. science, arguing that if the president keeps his promise, he will set back new medical advances and sacrifice potential cures for diseases like Parkinson's.

But science isn't on their side, and Mr. Bush doesn't have to choose between convictions and cures. While federal funding for embryo research is banned, the research itself is not. The private sector lavishly funds research on stem cells drawn from both embryos and adults. Yet research on embryonic stem cells is no more developed than the embryos themselves-while research on adult stem cells is close to delivering miraculous treatments.

Consider these recent advances:

Surgeons in Taiwan restored vision to patients with severe eye damage by using stem cells from the patients' own eyes. Their vision improved from 20/112 to 20/45, according to results published in the New England Journal of Medicine.

* British scientists found that adult stem cells in bone marrow can turn into liver tissue, a first step toward developing new treatments for liver damage. Their work was reported in the journal Nature.

* Two recent studies show that adult stem cells in bone marrow transplanted into the brain of mice can develop into neurons and have been reprogrammed into healthy brain cells in lab rats. Previous research had shown this transformation was possible in cultured cells, but these studies, one of which was published in the journal Science, show it can happen in living animals.

* Scientists found that adult stem cells in bone marrow injected into a damaged mouse heart could become functional heart muscle cells, and that these new cells partially restored the heart's pumping ability. One of the scientists predicted that after successful follow-up studies, human clinical trials could start in three years. The results were published in Nature.

These findings were all reported within the past year. And they are only a few examples of the breathtaking medical breakthroughs occurring after years of research on adult stem cells-stroke victims' brains repaired with adult stem cells becoming fully functional neurons connecting with existing brain cells, new cartilage grown to repair damaged knees.

We are on the verge of astounding human applications using adult stem cells. Embryonic stem cells, by contrast, have yet to save a single life.

Stem cells are unspecialized cells that have the ability to transform themselves, in varying degrees, into many other types of cells. Thus a single stem cell could become a skin cell, a hair cell, a liver cell and so on. All of us were once stem cells, and our bodies still hold many forms of these cells.

It appears that every organ and tissue in the body has undifferentiated stem cells. These cells may exist to repair organs when they are traumatized or damaged, but scientists are still puzzled by how they work and what exactly they are supposed to do. If scientists can improve this natural repair process with adult stem cells, people may be able to grow new livers from stem cells extracted from their own liver. Another source of adult stem cells is body fat. And umbilical cords provide a large supply of stem cells-without political or moral controversy.

A National Institutes of Health report, released just in time for last week's congressional hearings, argues that stem cells from embryos are better. But on closer examination, the evidence is shaky and speculative, while the unique drawbacks of embryo stem cells are becoming clearer.

The case for the superiority of embryo stem cells rests on three pillars: They are easier to harvest, there are more stem cells in embryos than in adults, and they can be more easily changed into every organ and tissue in the body.

The first two claims are misleading. Harvesting is a nonproblem. Scientists have been extracting some types of human adult stem cells for almost a decade, while human embryo stem cells weren't successfully isolated until 1998. Several biotech companies have developed proprietary methods to make adult-cell isolation and extraction even easier. "We've been here in the background while all the noise was going on, and there's been a pressure on us to provide a solution," John Wong, CEO of MorphoGen Pharmaceuticals, told BioWorld Today last August. "We believe we've provided that solution. The technology has just moved beyond stem cells from embryonic tissue."

While it's true that embryos have a higher ratio of stem to nonstem cells, that doesn't mean much. Scientists have discovered stem cells in adults in virtually every major organ, including the brain and body, and researchers last year identified conditions that would allow for the multiplication of adult stem cells in culture by a billion-fold in a few weeks.