Figure 2. Cell-permeable OCT4, SOX2, KLF4, CMYC and NANOG induce iSC colonies (Protocol 1).
(A) Experimental timeline. Human dermal fibroblasts (HDF) were plated (day zero, D0), allowed to attach overnight and were treated daily with HDF media alone (no treatment), with 1 μM (each) recombinant OCT4, SOX2, KLF4, CMYC and NANOG proteins (RFs) or the same proteins containing MTD sequences to promote intracellular delivery (CP-RFs). The media was changed to hES media on day 7 (D7) and protein treatments (24 hrs/day) ended on day 16 (D16). (B) Colony morphologies. Photomicrographs of 4 representative iSC colonies induced by CP-RF treatment compared to a murine embryonic stem (mES) cell colony. (C) CP-RF induced colonies express alkaline phosphatase.