Some Hope on Stem Cells
Science may be on the cusp of changing the terms of the tormented debate over stem cell research, which holds such enormous promise for so many people. At first blush, the announcement that a small biochemical company in California had found a way to establish colonies of human embryonic stem cells without interfering with the potential for life of the original embryo was stunning. This would have been a key discovery because it would have addressed the ethical and religious objection that such research destroyed the embryo and was therefore an unconscionable destruction of human life. The disclosure afterward, that the California researchers may have overstated the implications of their work and that the 16 embryos used in the research were destroyed, is chastening. But the larger point should not be lost. Sooner rather than later, it seems clear, a way will be found to conduct this critical research without destroying the embryos, and at the point, the objections that have been raised about these efforts should be withdrawn.
We have trillions of tiny cells in our bodies, each with a unique function. How can one early cell among those others give hope for treatment of a whole range of maladies, from Alzheimer's to diabetes to spinal-cord damage and even cancer? The answer is in the word. Our many different cell types stem from a master cell, a stem cell. Stem cells have the ability to morph into all the subtypes of cells, from bone to muscle, to skin, blood, and nerve. If scientists can learn to control these stem cells and coax them into becoming specific cell types, they could grow replacements for tissues of organs and cells damaged by disease or time.
New vistas. Today, the greatest promise in cancer research arises from the fact that there are two kinds of cell populations. One group is composed of self-renewing, less differentiated stem cells. The other, more benign group is composed of differentiated, specialized cells that have little or no capacity to proliferate. Cancer treatment has centered previously on an undifferentiated attack on all the cells, reducing a tumor's size by destroying nonrenewable cells along with renewing cells.
Researchers now believe there are vast new possibilities for cancer therapies if they set their sights on eliminating the cancer stem cells rather than targeting the non-self-renewing cells. A number of cancer centers are studying this, including the Memorial Sloan-Kettering Cancer Center, the Dana-Farber Cancer Institute, and the Broad Institute, a joint effort by Harvard and MIT. In the interest of full disclosure, I should state that I have contributed to the funding of this program.
New vistas open all around us. Researchers at Johns Hopkins University have used embryonic stem cells on mice to regenerate their spinal columns so they could move again. It is a procedure that could one day realize the dream of the actor Christopher Reeve that people paralyzed like him would be able to walk again. From stem cells, scientists at UCLA have also created new cells to combat disease-a development that could lead to a cure for AIDS.
advertisement