What are stem cells?

“A stem cell is a cell that has the ability to divide (self replicate) for indefinite periods. Under the right conditions, or given the right signals, stem cells can give rise (differentiate) to the many different cell types that make up the organism. That is, stem cells have the potential to develop into mature cells that have characteristic shape and specialized functions, such as heart cells, skin cells, or nerve cells.” Scientists envision drawing from “lines” of stem cells – colonies of similar cells that can replicate for long periods – to create new specialized cells for transplant into patients, to repair or replace tissues that disease and disability have damages.¹

Where are stem cells found?

In the adult organism (“adult” referring to humans or animals any point after birth) stem cells are found in the bone marrow, blood stream, brain, spinal cord, dental pulp, skeletal muscle, skin, gastrointestinal tract, cornea, retina, liver and pancreas. Another rich source of stem cells is the blood within umbilical cords and placentas no longer needed by newborn babies.¹ New research shows human fat contains stem cells.² The stem cells receiving the most public attention are found within human embryos. researchers harvest these cells by pulling the “inner cell mass,” the 30-34 cells that will develop into the baby’s tissues and organs, from the center of a five-day-old embryo.¹

What is the problem with stem cell research?

Adult stem cell research is not controversial; no human being dies when these cells are collected. The moral problem arises because stem cell harvesting from embryos would destroy them.³ There is a very chilling similarity to the Jewish holocaust victims who were used as available sources solely for research purposes. Today, we can see such actions as crossing a critical moral line where human dignity is no longer the first priority. Once we approve killing one human being to save the life of another, where do we stop? Why not calculate an individual’s quality of life or projected social contribution and determine whether or not someone else is entitled to his or her organs? This kind of scientific progress is indeed a cold comfort for “spare parts.”

Is embryonic stem cell research justified?

Human emryonic stem cells (ESCs) have not yet successfully treated disease.⁴ Currently, the National Institutes of Health says that “any therapies based on the use of human ES cells are still hypothetical and highly experimental.” Scientists are still unsure how to induce the cells to change into the desirable types of cells needed for treatment. There are other problems including: the tendency of ESCs to form tumors when they are transplanted, unstable expression of traits contained in the cells’ genes, immune rejection and the risk of passing animal viruses to humans because formulas of animal cells are used to keep ESCs growing.^{1, 2}

What is the current state of research on adult stem cells?

Doctors already use adult stem cells to treat a host of human disease, including cancers, autoimmune diseases, stroke, cartilage and bone damage, and blood and liver disease. Scientists are continually discovering new capabilities of adult stem cells. There is also evidence of a universal adult stem cell that can change into any cell of the body.^1,4,5-6 Despite the reported “promise” of embryonic stem cells, stem cells from adults are the ones that have been delivering true therapy. Dr. Donald Orlic of the National Human Genome Research Institute states, “We are currently finding that these adult stem cells are functioning as well, perhaps even better than, embryonic stem cells.”⁷

Notes:

1. NIH, Stem Cells: Scientific Progress and Future Research Directions, 6/01
2. Weiss, Washington Post, 4/10/01; 7/6/01
3. National Bioethics Advisory Comm., Ethical Issues in Stem Cell Research, 9/99
4. Prentice Testimony, www.stemcellresearch.org
5. Goodman, Salt Lake Tribune, 7/1/01
6. Ramiya, Nature Medicine, 3/00