A ‘clean-up’ procedure that may increase the safety of stem-cell-derived therapies is reported in Nature Communications this week. The technique exploits a cell-surface protein expressed exclusively on stem cells to eliminate undifferentiated cells from populations of mixed cells.
Stem cells can develop into all types of cells and hold great promise for regenerative therapies. However, cell populations created by conversion of stem cells often also contain small amounts of undifferentiated stem cells, which can cause the development of tumours.
Nissim Benvenisty and colleagues show that the tight-junction protein Claudin-6 is exclusively found on the surface of human pluripotent stem cells. They go on to show three different strategies - based on antibodies or a bacterial toxin - to recognise and kill Claudin-6-expressing cells. Application of these procedures efficiently removes Claudin-6-expressing cells from stem-cell-derived mixed cell populations and prevents tumour formation when such treated cells were subsequently injected into mice.