A new study by Christine Chaffer of the Whitehead Institute for Biomedical Research seems to indicate that the journey from stem cell to specialized cell can also go backwards. Conventional thinking holds that stem cells can change into any specific body cell — liver cell, heart cell, etc., but sometimes, regular cells will imitate their transformable cousins.
Chaffer’s study began with the seemingly mundane observation that some healthy human breast cells were floating in a tube. Normally, healthy cells sink towards the bottom, while stem-cells are known to be free-floating. When Chaffer analyzed these floating cells she found that, among other indicators, an active CD44 gene which marked them being more like stem cells.
Looking at both cells in the body, Chaffer determined that about 1 in 300 cells had these traits. Amazingly, those that had weak expressions of the important CD44 gene produced offspring with stronger expressions of gene. As time progressed, Chaffer observed many cells spontaneously becoming more like stem cells.
This could prove hugely significant in the treatment of some degenerative diseases, which doctors are trying to cure through stem-cell therapies. Up to this point, scientists have sought to transform a patient’s cells into stem cells through means of genetic manipulation, which can carry many risks. Chaffer’s research — which still has to undergo thorough peer review — could open up whole new channels for creating stem cells using existing mechanisms apparently already in use within the body.
Though this may be great news for the field of stem cell research, it carries a major caveat. In the course of her research, Chaffer observed the same stem cell transformation in cancer cells as well. Cancer stem cells are a recent discovery, and are believed to allow to tumors to repair themselves and spread the cancer throughout the body. Moreover, cancer cells became high CD44 cells two to five times faster than normal healthy cells and created highly aggressive tumors.
As scary as that is, the discovery of spontaneously produced stem cells could slow the creation of cancer treatments that target cancer stem cells. Since normal cancer cells can become cancer stem cells, targeting the cancer stem cells may do little good since more will just be generated.
(via Discover)
Published: Apr 12, 2011 02:58 pm