Nakagawa M, Koyanagi M, Tanabe K, Takahashi K, Ichisaka T, Aoi T, Okita K, Mochiduki Y, Takizawa N, Yamanaka SGeneration of induced pluripotent stem cells without Myc from mouse and human fibroblasts. Nat Biotechnol 26:101-106

Department of Stem Cell Biology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.
Nature Biotechnology (Impact Factor: 41.51). 02/2008; 26(1):101-6. DOI: 10.1038/nbt1374
Source: PubMed


Direct reprogramming of somatic cells provides an opportunity to generate patient- or disease-specific pluripotent stem cells. Such induced pluripotent stem (iPS) cells were generated from mouse fibroblasts by retroviral transduction of four transcription factors: Oct3/4, Sox2, Klf4 and c-Myc. Mouse iPS cells are indistinguishable from embryonic stem (ES) cells in many respects and produce germline-competent chimeras. Reactivation of the c-Myc retrovirus, however, increases tumorigenicity in the chimeras and progeny mice, hindering clinical applications. Here we describe a modified protocol for the generation of iPS cells that does not require the Myc retrovirus. With this protocol, we obtained significantly fewer non-iPS background cells, and the iPS cells generated were consistently of high quality. Mice derived from Myc(-) iPS cells did not develop tumors during the study period. The protocol also enabled efficient isolation of iPS cells without drug selection. Furthermore, we generated human iPS cells from adult dermal fibroblasts without MYC.

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    • "The 201B7 and 253G1 hiPSCs were cultured in mTeSR1 (STEM- CELL Technologies) on cell culture plates coated with Matrigel (BD Biosciences) (Nakagawa et al., 2008; Takahashi et al., 2007). "
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    ABSTRACT: The application of stem-cell-based therapies in regenerative medicine is hindered by the tumorigenic potential of residual human pluripotent stem cells. Previously, we identified a human pluripotent stem-cell-specific lectin probe, called rBC2LCN, by comprehensive glycome analysis using high-density lectin microarrays. Here we developed a recombinant lectin-toxin fusion protein of rBC2LCN with a catalytic domain of Pseudomonas aeruginosa exotoxin A, termed rBC2LCN-PE23, which could be expressed as a soluble form from the cytoplasm of Escherichia coli and purified to homogeneity by one-step affinity chromatography. rBC2LCN-PE23 bound to human pluripotent stem cells, followed by its internalization, allowing intracellular delivery of a cargo of cytotoxic protein. The addition of rBC2LCN-PE23 to the culture medium was sufficient to completely eliminate human pluripotent stem cells. Thus, rBC2LCN-PE23 has the potential to contribute to the safety of stem-cell-based therapies. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
    Full-text · Article · Apr 2015 · Stem Cell Reports
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    • "Induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs) share some similarities to cancer cells, including the capacity to bypass senescence and form tumors upon transplantation (Goding et al., 2014). Accordingly, some genes often associated with cancer, such as Myc (Nakagawa et al., 2008; Wernig et al., 2008), p53 (Krizhanovsky and Lowe, 2009), and telomerase (Batista et al., 2011; Park et al., 2008), have been implicated in cellular reprogramming. Additionally, two reprogramming factors, Oct4 and Sox2, can be oncogenic in some cellular contexts (Hochedlinger et al., 2005; Lu et al., 2010; Rudin et al., 2012; Sarkar and Hochedlinger, 2013). "
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    ABSTRACT: Mutations in the retinoblastoma tumor suppressor gene Rb are involved in many forms of human cancer. In this study, we investigated the early consequences of inactivating Rb in the context of cellular reprogramming. We found that Rb inactivation promotes the reprogramming of differentiated cells to a pluripotent state. Unexpectedly, this effect is cell cycle independent, and instead reflects direct binding of Rb to pluripotency genes, including Sox2 and Oct4, which leads to a repressed chromatin state. More broadly, this regulation of pluripotency networks and Sox2 in particular is critical for the initiation of tumors upon loss of Rb in mice. These studies therefore identify Rb as a global transcriptional repressor of pluripotency networks, providing a molecular basis for previous reports about its involvement in cell fate pliability, and implicate misregulation of pluripotency factors such as Sox2 in tumorigenesis related to loss of Rb function.
    Full-text · Article · Jan 2015 · Cell Stem Cell
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    • "However, it is possible to reprogram somatic cells with three transcription factors OCT4, SOX2 and KLF4, excluding c-MYC15 as it is naturally oncogenic (7,8). Although, the efficiency is reported to be low (7). "
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    ABSTRACT: Research related to induce pluripotent stem (iPS) cell generation has increased rapidly in recent years. Six transcription factors, namely OCT4, SOX2, C-MYC, KLF4, NANOG, and LIN28 have been widely used for iPS cell generation. As there is a lack of data on intra- and inter-networking among these six different transcription factors, the objective of this study is to analyze the intra- and inter-networks between them using bioinformatics. In this computational biology study, we used AminoNet, MATLAB to examine networking between the six different transcription factors. The directed network was constructed using MATLAB programming and the distance between nodes was estimated using a phylogram. The protein-protein interactions between the nuclear reprogramming factors was performed using the software STRING. The relationship between C-MYC and NANOG was depicted using a phylogenetic tree and the sequence analysis showed OCT4, C-MYC, NANOG, and SOX2 together share a common evolutionary origin. This study has shown an innovative rapid method for the analysis of intra and inter-networking among nuclear reprogramming factors. Data presented may aid researchers to understand the complex regulatory networks involving iPS cell generation.
    Full-text · Article · Dec 2014 · Cell Journal
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