You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Maturation, not initiation, is the major roadblock during reprogramming toward pluripotency from human fibroblasts
Koji Tanabe, Michiko Nakamura, Megumi Narita, Kazutoshi Takahashi and Shinya Yamanaka
Proceedings of the National Academy of Sciences of the United States of America
Vol. 110, No. 30 (July 23, 2013), pp. 12172-12179
Published by: National Academy of Sciences
Stable URL: http://www.jstor.org/stable/42712564
Page Count: 8
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Pluripotency can be induced in somatic cells by forced expression of POU domain, class 5, transcription factor 1 (OCT3/4), sex determining region Y-box 2 (SOX2), Kruppel-like factor 4 (KLF4), myelocytomatosis oncogene (c-MYC) (OSKM). However, factor-mediated direct reprogramming is generally regarded as an inefficient and stochastic event. Contrary to this notion, we herein demonstrate that most human adult dermal fibroblasts initiated the reprogramming process on receiving the OSKM transgenes. Within 7 d, ~20% of these transduced cells became positive for the TRA-1-60 antigen, one of the most specific markers of human pluripotent stem cells. However, only a small portion (~1%) of these nascent reprogrammed cells resulted in colonies of induced pluripotent stem cells after replating. We found that many of the TRA-1-60-positive cells turned back to be negative again during the subsequent culture. Among the factors that have previously been reported to enhance direct reprogramming, LIN28, but not Nanog homeobox (NANOG), Cyclin D1, or p53 shRNA, significantly inhibited the reversion of reprogramming. These data demonstrate that maturation, and not initiation, is the limiting step during the direct reprogramming of human fibroblasts toward pluripotency and that each proreprogramming factor has a different mode of action.
Proceedings of the National Academy of Sciences of the United States of America © 2013 National Academy of Sciences