Abstract 9595: Generation of Transgene-Free Induced Pluripotent Stem Cells from Fibroblasts by Small Molecule Chemicals

Abstract

Backgrounds: Reprogramming of somatic cells using viral- and non-viral vectors encoding defined transcription factors to generate induced pluripotent stem (iPS) cells has successfully been achieved over the past few years. However, the current established methods to create iPS cells require viral vectors or plasmids to deliver transgenes into the cells. Methods and Results: To obviate the putative problems of genetic contamination in the cells for future clinical application, it is highly demanded to develop new methods to create “safer” iPS cells without any genetic modifications. Here, we for the first time demonstrate successful generation of iPS cell line from mouse fibroblasts with only combinations of small-molecule chemicals such as GSK-3 beta inhibitor, histone deacetylase inhibitor, and G9a histone methyltransferase inhibitor, which act as epigenetic modulators and self-renewal activators. These chemical induced pluripotent stem (ChemiPS) cells have almost the same properties of embryonic stem cells in the expression patterns of pluripotency-related markers, epigenetic status in promoter regions of Oct4 and Nanog, spontaneous differentiation into three germ layers by in vitro embryoid body formation, and formation of teratoma in vivo after injection into mice. Conclusion: This study provides the first evidence that sole chemical combinations can reprogram somatic cells, resulting in transgene-free iPS cells. This method will advance the use of iPS cells in clinical application and disease investigation.