Ten years ago scientists came up with a way to produce stem cells by genetically modifying ordinary mature cells. Unfortunately they often formed tumors. Now they’ve discovered another way to produce them by confinement of ordinary cells to a restricted area.
This is similar to how different parts of the body confine specialized tissues to an area of space we call an “organ”. Scientists hypothesize that by replicating this specific geometric confinement they are somehow engaging natural mechanisms in a reverse order.
“The use of geometric constraints to reprogram mature cells may better reflect the process occurring naturally within the body…”
In other words – where embryonic stem cells slowly differentiate in to specialized tissue early in development by utilizing the shape of the fetus as a “blueprint”, scientists have figured out that the same thing can occur in reverse order when provided with the right geometric structure.
For this particular study they placed tendon cells called “fibroblasts” on to a rectangular surface. Over a ten day period they began to take the shape of a rectangle, which informed scientists that each cell was beginning to absorb morphogenetic cues from the environment.
By day 6 they began to lose the condensed form of DNA (chromatin) associated with specialized cells and by day 10 they had successfully formed spherical clusters of induced pluripotent stem cells. In order to confirm the transformation researchers continued to direct their growth in two other specialized cells, one of which transformed back in to a fibroblast.
“While it is well established that confining stem cells to defined geometric patterns and substrate properties can direct their differentiation into specialized cells, this study shows for the first time that mechanical cues can reset the genomic programs of mature cells and return them to a pluripotent state,” Shivashankar explains.
“…our findings allow researchers to generate stem cells from mature cells with high efficiency and without genetically modifying them.”