Reprogramming of cells
In November 2007 a Japanese as well as an American group of researchers published independently of each other techniques of successful reprogramming of human dermal and connective tissue cells into stem cells. When reprogramming the somatic cells, specific gen material is infiltrated so it shows essential characteristics of embryonic stem cells such as the trait to differentiate into certain cell or tissue types under certain circumstances. Stem cells which were derived this way are called "induced pluripotent stem cells" (iPS). In the long term it is the aim to derive stem cells by such techniques where embryos do not have to be destroyed.
Fig. 6: Schematic illustration of cell reprogramming. (Graphic reproduced by kind permission of Stem Cell Network.NRW)
Takahashi, K. / Tanabe, K. / Ohnuki, M. / Narita, M. / Ichisaka, T. / Tomoda, K. / Yamanaka, S. (2007): Induction of Pluripotent Stem Cells from Adult Human Fibroblasts by Defined Factors. In: Cell 131(4). Online Version
Yu, J. / Vodyanik, M. A. / Smuga-Otto, K. / Antosiewicz-Bourget, J. / Frane, J. L. / Tian, S. / Nie, J. / Jonsdottir, G. A. / Ruotti, V. / Stewart, R. / Slukvin, I. I. / Thomson, J. A. (2007): Induced Pluripotent Stem Cell Lines Derived from Human Somatic Cells. In: Science 318, 1917–1920. Online Version
In January 2014, a study published by the Japanese researcher Haruko Obokata in the scientific journal Nature caused a worldwide sensation. In this study she described an easy method involving citric acid and physical pressure to convert differentiated cells back into stem cells. However, the results could not be reproduced and the study has in the meantime been withdrawn by the institute. In addition, the discovery that data and pictures had been manipulated impaired the credibility of the study even more.
See here for the text of the study:
Obokata, H. / Wakayama, T. / Sasai, Y. / Kojima, K. / Vacanti, M. P. / Niwa, H. / Yamato, M. / Vacanti, C. A. (2014): Stimulus-triggered fate conversion of somatic cells into pluripotency. In: Nature 505, 641–647. Online Version
See here for a report and analysis of Obokatas study:
Los Angeles, A. / Ferrari, F. / Fujiwara, Y. / Mathieu, R. / Lee, S. / Lee, S. / Tu, H. / Ross, S. / Chou, S. / Nguyen, M. / Wu, Z. / Theunissen, T. W. / Powell, B. E. / Imsoonthornruksa, S. / Chen, J. / Borkent, M. / Krupalnik, V. / Lujan, E. / Wernig, M. / Hanna, J. H. / Hochedlinger, K. / Pei, D. / Jaenisch, R. / Deng, H. / Orkin, S. H. / Park, P. J. / Daley, G. G. (2015): Failure to replicate the STAP cell phenomenon. In: Nature 525, E6–E9. Online Version