- Induced Pluripotent Stem (iPS) cells are reprogrammed adult skin cells that resemble embryonic stem cells, and may or may not have the same capabilities as embryonic stem cells.
- Human iPS cells were first created in November 2007 by Dr. James Thomson at the University of Wisconsin-Madison and Dr. Shinya Yamanaka in Japan. Research must still be done to prove the plasticity (ability to differentiate into all the different types of cells) of the iPS cell is equivalent to the human embryonic stem cell.
- The current technique involves use of a virus that literally “infects” a cell with four genes—including cancer genes—to trigger the reprogramming process. This process has been refined further to minimize the use of cancer genes by using simple compounds.
- Potential advantages of iPS cells:
- There may be no direct immune system rejection issues because these cells come from the patient; however, primary immune issues in autoimmune diseases would still have to be addressed.
- These cells are relatively easy to create in a sophisticated laboratory setting.
- Potential disadvantages of iPS cells:
- Economic costs of cells created for specific individuals would be high; iPS cell banks could be created, but that would re-introduce immune tolerance issues.
- This process creates potential for undesirable bits of genetic material from the virus to also invade the target cell. Because of this viral material and the use of cancer genes, the technique would need to be refined before it could be applied to human treatment. An approach published online in Science, 9-25-08 by Konrad Hochedlinger, Harvard University, used adenoviruses (believed not to integrate genes into the cell’s DNA) in place of viruses, a less-efficient procedure but a potential solution to the safety issue. However, the use of any such viruses to carry genes into cells must be carefully controlled and cautiously used.
|“But it would be premature to conclude that iPS cells can replace embryonic stem cells.”
Dr. Shinya Yamanaka, creator iPS cells, Stem Cell Research News,
November 20, 2007
|More study of the newly-made cells is required to ensure that the “cells do not differ from embryonic stem cells in a clinically significant or unexpected way, so it is hardly time to discontinue embryonic stem cell research.”
Dr. James Thomson,
creator of iPS cells and discoverer of Embryonic Stem Cells,
Stem Cell Research News, November 20, 2007
|“To choose…only one avenue of research or type of cell source, would — at this stage of regenerative medical research — be irresponsible, unreasonable, and premature. Promising and successful research exploring human stem cells should be supplemented with–not supplanted by — new and potentially exciting approaches, with all forms of research moving forward along multiple independent paths.”
Dr. William Brinkley,
Professor of Cell and Molecular Biology, and
Dean of the Graduate School of Houston’s
Baylor College of Medicine;
Houston Chronicle, November 24, 2007
The Alliance for Medical Research is an organization of scientists, physicians, health professionals, bioethicists, and educators who provide public education, awareness, and understanding of various and diverse sciences and research breakthroughs.
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