title: Differences in the gene expression profiles of slow- and fast-forming preinduced pluripotent stem cell colonies.
abstract: Induced pluripotent stem cells (iPSCs) are generated through a gradual process in which somatic cells undergo a number of stochastic events. In this study, we examined whether two different doxycycline-inducible iPSCs, slow-forming 4F2A-iPSCs and fast-forming NGFP-iPSCs, have equivalent levels of pluripotency. Multiplex reverse-transcriptase PCR generated gene expression profiles (GEPs) of 13 pluripotency genes in single initially formed-iPSC (if-iPSC) colonies of NGFP and 4F2A group. Assessment of GEP difference using a weighted root mean square deviation (wRMSD) indicates that 4F2A if-iPSCs are more closely related to mESCs than NGFP if-iPSCs. Consistently, Nanog and Sox2 genes were more frequently derepressed in 4F2A if-iPSC group. We further examined 20 genes that are implicated in reprogramming. They were, overall, more highly expressed in NGFP if-iPSCs, differing from the pluripotency genes being more expressed in 4F2A if-iPSCs. wRMSD analysis for these reprogramming-related genes confirmed that the 4F2A if-iPSC colonies were less deviated from mESCs than the NGFP if-iPSC colonies. Our findings suggest that more important in attaining a better reprogramming is the mode of action by the given reprogramming factors, rather than the total activity of them exerting to the cells, as the thin-but-long-lasting mode of action in 4F2A if-iPSCs is shown to be more effective than its full-but-short-lasting mode in NGFP if-iPSCs.
authors.affiliation: Development and Differentiation Research Center, KRIBB, 111 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea ; Department of Functional Genomics, University of Science and Technology (UST), 113 Gwahang-ro, Yuseong-gu, Daejeon 305-333, Republic of Korea.
authors.forename: Sujin
authors.initials: S
authors.lastname: Kwon
authors.affiliation: Development and Differentiation Research Center, KRIBB, 111 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea.
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Park
authors.affiliation: Development and Differentiation Research Center, KRIBB, 111 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea ; Department of Functional Genomics, University of Science and Technology (UST), 113 Gwahang-ro, Yuseong-gu, Daejeon 305-333, Republic of Korea.
authors.forename: Byungkuk
authors.initials: B
authors.lastname: Min
authors.affiliation: Development and Differentiation Research Center, KRIBB, 111 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea ; Department of Functional Genomics, University of Science and Technology (UST), 113 Gwahang-ro, Yuseong-gu, Daejeon 305-333, Republic of Korea.
authors.forename: Yong-Kook
authors.initials: YK
authors.lastname: Kang