Reprogramming of Cells
In November 2007, a Japanese and an American research groups published independently from each other the successful reprogramming of human skin and connective tissue cells into stem cells. The reprogramming is conducted by infiltrating specific genetic material into somatic cells so that they can show significant traits of embryonic stem cells. These traits include the capacity to differentiate into specific cell and tissue types under suitable conditions. Cells gained this way are called “induced pluripotent stem cells” (iPS). In due course, it is hoped that such stem cells will be able to be gained without the destruction of embryos.
Takahashi, Kazutoshi / Tanabe, Koji / Ohnuki, Mari / Narita, Megumi / Ichisaka, Tomoko / Tomoda, Kiichiro / Yamanaka, Shinya (2007): Induction of Pluripotent Stem Cells from Adult Human Fibroblasts by Defined Factors. In: Cell 131(4). Online Version
Yu, Junying / Vodyanik, Maxim A. / Smuga-Otto, Kim / Antosiewicz-Bourget, Jessica / Frane, Jennifer L. / Tian, Shulan / Nie, Jeff / Jonsdottir, Gudrun A. / Ruotti, Victor / Stewart, Ron / Slukvin, Igor I. / Thomson, James 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 However, the results could not be reproduced and the study has in the meantime been withdrawn by the institute.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, Haruko / Wakayama, Teruhiko / Sasai, Yoshiki / Kojima, Koji / Vacanti, Martin P. / Niwa, Hitoshi / Yamato, Masayuki / Vacanti, Charles 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, Alejandro / Ferrari, Francesco / Fujiwara, Yuko / Mathieu, Ronald / Lee, Soohyun / Lee, Semin / Tu, Ho-Chou / Ross, Samantha / Chou, Stephanie / Nguyen, Minh / Wu, Zhaoting / Theunissen, Thorold W. / Powell, Benjamin E. / Imsoonthornruksa, Sumeth / Chen, Jiekai / Borkent, Marti / Krupalnik, Vladislav / Lujan, Ernesto / Wernig, Marius / Hanna, Jacob H. / Hochedlinger, Konrad / Pei, Duanging / Jaenisch, Rudolf / Deng, Hongkui / Orkin, Stuart H. / Park, Peter J. / Daley, George G. 2015): Failure to replicate the STAP cell phenomenon. In: Nature 525, E6–E9. Online Version