Two papers in Nature publications have raised questions about whether reprogrammed adult cells, called iPS cells, are truly interchangeable with embryonic stem cells as many have been assuming. The papers found that iPS cells created from different adult tissues still bear some hallmarks of those starting blocks.
Stem cells in fat hold intrigue for scientists because most of us have excess to spare, and the cells seem to be quite versatile. Now a team at Stanford has found a way to transform them into induced pluripotent stem (iPS) cells without using potentially dangerous viruses to carry the reprogramming genes into the cells.
Induced pluripotent stem (iPS) cells have created excitement and head scratching ever since they were first created a little over two years ago. The excitement arises from their creation through reprogramming adult cells by manipulating their gene function, which does not require a human embryo and could potentially give a patient personalized replacement cells. But determining just how identical they are to embryonic stem cells in function has caused much consternation.
Researchers at the University of California, Los Angeles have found genetic differences that distinguish induced pluripotent stem (iPS) cells from embryonic stem cells. These differences diminish over time, but never disappear entirely. iPS cells are created when adult cells, such as those from the skin, are reprogrammed to look and behave like embryonic stem cells. But until now, scientists didn't know if the two types of stem cells were actually identical at a molecular level. This latest research shows that iPS and embryonic stem cells differ in which genes they have turned on or off.
Researchers at the University of California, San Francisco have designed a safer technique for reprogramming adult cells into a state that resembles embryonic stem cells. This method takes advantage of genetic molecules called microRNAs, which regulate the activity of genes. The original 2007 method for creating reprogrammed cells, called induced pluripotent stem (iPS) cells, relied on inserting four genes, some potentially tumor-causing, into the DNA of an adult cell such as a skin cell.