Oct3 Oct4 Sox2 Klf4 c-Myc

It is not near as easy as it looks; somewhere in the process p53 is stochastically activated (probably via the p38MAPK pathway?) - this impairs the conversion to IPSCs. It also might be one explanation of stem cell niche decay in ageing. I suspect you have to first select your raw material very carefully. You really don't want genomic integration of any material; so you have to expose the cell to totally extrinsic factors. This, btw, I think is what the niche stellite environment does. This might also be how ellagitannins work to regenerate beta cells in experimental alloxan induced type 1 diabetes - by enhancing the niche.

This is a hot topic; and there are already some 2010 papers. I can't pay for them, so I'll have to wait. Bryan do you have access? Once u r familiar with the signalling you can figure everything out - Google: "Oct3 Oct4 Sox2 Klf4 c-Myc"

The important thing is this work can be done in a kitchen; once you can get or make the immunoflourescent antibodies to the cell surface markers. Suppression of induced pluripotent stem cell generation by the p53–p21 pathway

Hyenjong Hong1,2, Kazutoshi Takahashi1, Tomoko Ichisaka1,3, Takashi Aoi1, Osami Kanagawa4, Masato Nakagawa1,2, Keisuke Okita1 & Shinya Yamanaka1,2,3,5

  1. . Center for iPS Cell Research and Application (CiRA), Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8507, Japan
  2. . Department of Stem Cell Biology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
  3. . Yamanaka iPS Cell Special Project, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
  4. . Laboratory for Autoimmune Regulation, RIKEN Center for Allergy and Immunology, RIKEN Yokohama Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
  5. . Gladstone Institute of Cardiovascular Disease, San Francisco, California 94158, USA

Correspondence to: Shinya Yamanaka1,2,3,5 Correspondence and requests for materials should be addressed to S.Y. (Email: yamanaka@frontier.kyoto-u.ac.jp).

Induced pluripotent stem (iPS) cells can be generated from somatic cells by the introduction of Oct3/4 (also known as Pou5f1), Sox2, Klf4 and c-Myc, in mouse1, 2, 3, 4 and in human5, 6, 7, 8. The efficiency of this process, however, is low9. Pluripotency can be induced without c-Myc, but with even lower efficiency10, 11. A p53 (also known as TP53 in humans and Trp53 in mice) short-interfering RNA (siRNA) was recently shown to promote human iPS cell generation12, but the specificity and mechanisms remain to be determined. Here we report that up to 10% of transduced mouse embryonic fibroblasts lacking p53 became iPS cells, even without the Myc retrovirus. The p53 deletion also promoted the induction of integration-free mouse iPS cells with plasmid transfection. Furthermore, in the p53-null background, iPS cells were generated from terminally differentiated T lymphocytes. The suppression of p53 also increased the efficiency of human iPS cell generation. DNA microarray analyses identified 34 p53-regulated genes that are common in mouse and human fibroblasts. Functional analyses of these genes demonstrate that the p53–p21 pathway serves as a barrier not only in tumorigenicity, but also in iPS cell generation.

  1. . Center for iPS Cell Research and Application (CiRA), Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8507, Japan
  2. . Department of Stem Cell Biology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
  3. . Yamanaka iPS Cell Special Project, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
  4. . Laboratory for Autoimmune Regulation, RIKEN Center for Allergy and Immunology, RIKEN Yokohama Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
  5. . Gladstone Institute of Cardiovascular Disease, San Francisco, California 94158, USA

Correspondence to: Shinya Yamanaka1,2,3,5 Correspondence and requests for materials should be addressed to S.Y. (Email: yamanaka@frontier.kyoto-u.ac.jp).