Brief reports: Controlling the survival of human pluripotent stem cells by small molecule-based targeting of topoisomerase II alpha.
Pluripotent-specific inhibitors (PluriSIns) make a powerful tool to study the mechanisms controlling the survival of human pluripotent stem cells (hPSCs). Here, we characterize the mechanism of action of PluriSIn#2, a compound that selectively eliminates undifferentiated hPSCs, while sparing various other cell types derived from them. Toxicogenomic analysis predicts this compound to be a topoisomerase inhibitor. Gene expression analyses reveal that one of the human topoisomerase enzymes, topoisomerase II alpha (TOP2A), is uniquely expressed in hPSCs: TOP2A is highly expressed in undifferentiated cells, is downregulated during their differentiation, and its expression depends on the expression of core pluripotency transcription factors. Furthermore, siRNA-based knockdown of TOP2A in undifferentiated hPSCs results in their cell death, revealing that TOP2A expression is required for the survival of these cells. We find that PluriSIn#2 does not directly inhibit TOP2A enzymatic activity, but rather selectively represses its transcription, thereby significantly reducing TOP2A protein levels. As undifferentiated hPSCs require TOP2A activity for their survival, TOP2A inhibition by PluriSIn#2 thus causes their cell death. Therefore, TOP2A dependency can be harnessed for the selective elimination of tumorigenic hPSCs from culture.
Stem Cell Unit, Department of Genetics, Silberman Institute of Life Sciences, The Hebrew University, Jerusalem, Israel; Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA.
Uri
U
Ben-David
Ian G
IG
Cowell
Caroline A
CA
Austin
Nissim
N
Benvenisty
D000951:Antigens, Neoplasm / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D006801:Humans; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology; D000075223:Poly-ADP-Ribose Binding Proteins; D054852:Small Molecule Libraries / Q000494:pharmacology; D059003:Topoisomerase Inhibitors / Q000494:pharmacology*
D000951:Antigens, Neoplasm; D004268:DNA-Binding Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; D054852:Small Molecule Libraries; D059003:Topoisomerase Inhibitors; D004250:DNA Topoisomerases, Type II; C000618811:TOP2A protein, human
Cancer; Cell biology; Cell death; Embryonic stem cells; Induced pluripotent stem cells; Pluripotent stem cells; Tumorigenicity