Like fine chefs, scientists are seemingly approaching a day when they will be able to make nearly any type of tissue from human embryonic stem cells. You need nerves or pancreas, bone or skin? With the right combination of growth factors, skill and patience, a laboratory tissue culture dish promises to yield therapeutic wonders. But within these batches of newly generated cells lurks a big potential problem: Any remaining embryonic stem cells, those that haven’t differentiated into the desired tissue can go on to become dangerous tumors called teratomas when transplanted into patients.
Now researchers at the Stanford University School of Medicine have developed a way to remove these pluripotent human embryonic stem cells ( ‘Pluripotent’ describes cells that are able to become all types of adult tissue.) from their progeny before the differentiated cells are used in humans.
The scientists believe the technique could also be used to remove residual tumor-initiating cells from populations of cells derived from induced pluripotent stem, or iPS, cells. These cells may also be useful for therapy but, unlike embryonic stem cells, iPS cells are created in the laboratory from adult tissue.