Researchers at the University of Colorado Denver’s School of Medicine have announced a new way to convert human skin cells to stem cells. In late 2007, a Japanese team reported that they had inserted four human genes into ordinary human skin cells and re
Researchers at the University of Colorado Denver’s School of Medicine have announced a new way to convert human skin cells to stem cells. In late 2007, a Japanese team reported that they had inserted four human genes into ordinary human skin cells and reprogrammed those cells into stem cells—cells possessing the same properties as embryonic stem cells, that could then become almost any other cell in the body. While a remarkable achievement, the viruses and genes used in their study were incorporated into the chromosomes of the new cells, leading to a risk of cancer if the cells were used in the treatment of diseases.
In a paper released this week in the online version of Stem Cells, University of Colorado Denver’s School of Medicine researchers Wenbo Zhou, PhD, and Curt Freed, MD, have created “human induced pluripotent stem cells” (iPS cells)—reprogrammed to look and act like embryonic stem cells—from human skin fibroblasts using a common cold virus. The virus used is called adenovirus and has the advantage of not being incorporated into the DNA of the chromosomes, thereby producing stem cells that will be safer for use in human therapy. Freed and Zhou are the first to show that this method can be used to safely reprogram human cells.
“The previous research transformed mouse and human skin cells into stem cells which behave and function much like embryonic stem cells,” said Wenbo Zhou, PhD, assistant professor of Clinical Pharmacology and Toxicology in UC Denver’s School of Medicine and first author on the study. “Unfortunately, the cells were made with retroviruses which lead to malignant tumors. To be able to proceed with iPS cells for stem cell therapy in humans, cells must be free of the genes and viruses that were used to reprogram the cells.”
“Stem cell research offers great promise for understanding basic mechanisms of human development and differentiation, as well as the hope for new tr