Figure 2.

Novel Strategies for Directly and Specifically Eliminating Tumorigenic Cells

Two strategies that use virally transduced suicide genes (Figure 3) and oncolytic virus (Figure 4) specifically kill undifferentiated tumorigenic hPSCs. These systems not only prevent teratoma and cancer formation but also provide a safeguard against aberrant cells after transplantation. The latter represents a clinical advantage over other methods that do not involve viral vector manipulation. High-purity isolation of target cells improves their effectiveness and safety of the hPSC therapy, in part by decreasing the number of potentially tumorigenic cells. The adenoviral conditional targeting in stem cell (ACT-SC) method dramatically increases the homogeneity of transplanted cells (Figure 5).