earticle

영어

Somatic cells are known to be reprogrammed to induced pluripotent stem cells (iPSCs) by over-expressing a combination of defined transcription factors, consisting of Oct4 (O), Sox2 (S), Klf4 (K), and c-Myc. Here, we generated iPSCs from mouse embryonic fibroblasts (with Oct4-GFP reporter) by transfection of pCX-OSK-2A and pCX-cMyc vectors. However, iPSCs were found to have pCX-OSK-2A integration without pCX-cMyc. Established iPSCs showed mouse embryonic stem cell (mESC)-like characteristics. Moreover, we could generate partially reprogrammed cells (XiPS-7), which were cultured over 20 passages under mESC media maintaining partially reprogrammed state; Oct4-GFP negative, unsuccessful teratoma formation, distinct gene expression. Interestingly, however, when the cells were transferred to KOSR-based media containing bFGF, XiPS-7 cells converted to Oct4-GFPpositive iPSCs (XiPS-7c, fully reprogrammed cells) and XiPS-7c cells exhibited mESC-like properties. During the conversion of XiPS-7 to XiPS-7c, we found several cluster of slowly reprogrammed genes, which should be activated later stage of reprogramming. Our results suggest that partial reprogrammed cells induce to fully reprogramming status by KOSR-based media, which can be used to verify the mechanism of reprogramming.