Selective Elimination of Culture-Adapted Human Embryonic Stem Cells with BH3 Mimetics

Abstract

Summary: The selective survival advantage of culture-adapted human embryonic stem cells (hESCs) is a serious safety concern for their clinical application. With a set of hESCs with various passage numbers, we observed that a subpopulation of hESCs at late passage numbers was highly resistant to various cell death stimuli, such as YM155, a survivin inhibitor. Transcriptome analysis from YM155-sensitive (YM155S) and YM155-resistant (YM155R) hESCs demonstrated that BCL2L1 was highly expressed in YM155R hESCs. By matching the gene signature of YM155R hESCs with the Cancer Therapeutics Response Portal dataset, BH3 mimetics were predicted to selectively ablate these cells. Indeed, short-course treatment with a sub-optimal dose of BH3 mimetics induced the spontaneous death of YM155R, but not YM155S hESCs by disrupting the mitochondrial membrane potential. YM155S hESCs remained pluripotent following BH3 mimetics treatment. Therefore, the use of BH3 mimetics is a promising strategy to specifically eliminate hESCs with a selective survival advantage. : In this article, Cha and colleagues demonstrate that in culture-adapted hESCs, survival advantage toward several genotoxic stresses as well as YM155, a stemtoxic chemical, results from increased Bcl-xL expression. BH3 mimetics, predicted by a bioinformatics tool based on the gene expression signature of culture-adapted hESCs, induces selective cell death while normal hESCs remain functionally intact even after BH3 mimetics exposure. Keywords: culture adaptation, survival advantage, BCL2L1, BH3 mimetics, YM155, CTRP, BCL-xL