npg Cell Research (2013) 23:1-2. npg1 © 2013 IBCB, SIBS, CAS All rights reserved 1001-0602/13 $ 32.00 EDITORIAL

The 2013 special issue on biology Cell Research (2013) 23:1-2. doi:10.1038/cr.2013.4; published online 3 January 2013

Stem cells hold the remarkable ca- cial issue consists of two major parts. basic biology of stem cells as well as pacity of self-renewal and differentia- The first part of the issue presents a col- for engineering cell fate changes toward tion into more specialized cell lineages, lection of 5 review articles authored by desired cell types. and thus constitute a promising resource world-renowned scientists in the respec- The second half of the special issue in regenerative medicine for the gen- tive fields. Two reviews focus on the comprises 5 original research articles, eration of appropriate cell types in cell basic regulatory mechanisms in ES and among which three are related to iPS replacement therapy. Stem cell research, iPS cells: Huck-Hui Ng and colleague cells. Improving the quality of iPS cells accordingly, has become a highly review our current understanding of will be critical for their potential appli- vigorous and rapidly evolving field in the transcriptional regulatory principles cations in cell-based therapy. In their re- life sciences, highlighted by the 2012 underlying the state of pluripotency in search article, Jinsong Li and colleagues Nobel Prize in Physiology or Medicine ES cells and discuss how the control report that including a factor called awarded to Shinya Yamanaka and John of various signaling pathways could Zscan4 in the cocktail Gurdon, for their ground-breaking influence pluripotency; the article by could greatly improve the quality of the works in reprogramming cell fates [1]. Yi Zhang and colleague presents a resulting iPS cells, as demonstrated by As a general interest life science journal, comprehensive overview of both the the tetraploid complementation assay, Cell Research has enjoyed a phase of epigenetic landscapes of pluripotent and suggest that this factor likely acts rapid growth in the past several years, stem cells and epigenetic mechanisms to promote genomic stability during the as shown by the dramatic improve- involved in iPS cell generation. The reprogramming process. In two other ment in the scientific quality of papers article by George Daley and colleague articles, Xin Xie and colleagues report published in the journal as wells as its provides us a state-of-art analysis of the that a simple environmental stress, hy- broadening impact within the scientific current understanding on cell fate and perosmosis, could promote reprogram- community. Along the way, the field of cell fate conversions, covering diverse ming via p38 activation, while Jiuhong stem cell biology has naturally become aspects such as iPS cells and their dif- Kang and colleagues show that a mi- an important research area covered by ferentiation, direct conversion of cell croRNA called miR-29b, acts to mediate papers published in Cell Research [2]. fates between differentiated states, as the function of Sox2 in reprogramming, For instance, in the past year of 2012, well as facilitated lineage switching and that it does so via regulating DNA Cell Research has published a number through partial reprogramming. Much . Mesenchymal stem of important papers related to the stem of the excitement of the iPS cell tech- cells (MSCs) have been shown to pos- cell field, covering diverse aspects and nology stemmed from its potential use sess immunomodulatory properties. The topics such as induced pluripotent stem in regenerative medicine, and it is clear paper by Songtao Shi and colleagues (iPS) cells [3-7], mechanistic studies that significant research efforts are still reports the rather surprising finding of of pluripotency and differentiation [8- needed before this potential could be re- a subset of MSCs that express IL17, 11], modeling of human diseases using alized. In their article, Hideyuki Okano fail to execute immunomodulation, and stem cell-based systems [6, 12], direct and colleague review the progress from exhibit an inhibitory effect against an reprogramming of somatic cells to other pre-clinical studies that attempted to infectious fungus. Finally, the research cell types without passing through an treat spinal cord injury using neural article by Yi Zhang and colleagues pluripotent intermediate [13-16], as stem/progenitor cells derived from reveals novel roles of de- well as neural crest stem cells [17] and iPS cells, and discuss strategies and methylases KDM6A and KDM6B in stem cells [18-20]. safety issues related to iPS cell-based endoderm differentiation from human Reflecting our continued interest and therapies. Finally, Sheng Ding and col- ES cells via regulation of Wnt signaling. building on our existing strength in this leagues discuss chemical approaches The issue also includes two brief letters area, we are excited to present to our in the study of stem cell biology, which to the editor, which report new advances readers this 2013 Cell Research Special have proved to be a powerful tool for in generating functionally more mature Issue on “Stem cell biology”. This spe- improving our understanding of the hepatocytes from human ES cells, and | Cell Research npg 2 in the generation of cloned animals from curring in somatic cell reprogramming. kemic fusion gene reveals an impaired pig iPS cells, respectively. Cell Res 2012; 22:168-177. early hematopoietic-endothelial specifi- We would like to thank our Guest 5 Cao N, Liu Z, Chen Z, et al. Ascorbic cation. Cell Res 2012; 22:986-1002. acid enhances the cardiac differentia- 13 Sheng C, Zheng Q, Wu J, et al. Direct Editors, Linzhao Cheng, Hongkui tion of induced pluripotent stem cells reprogramming of Sertoli cells into Deng, Linheng Li, and Haifan Lin for through promoting the proliferation of multipotent neural stem cells by defined their help in the commissioning of the cardiac progenitor cells. Cell Res 2012; factors. Cell Res 2012; 22:208-218. review articles, and all of the authors 22:219-236. 14 Liu X, Li F, Stubblefield EA,et al. Direct for their contributions to this special 6 Wang Y, Zheng CG, Jiang Y, et al. reprogramming of human fibroblasts issue. We hope this exciting collection Genetic correction of β-thalassemia into dopaminergic neuron-like cells. of articles on stem cell biology will be patient-specific iPS cells and its use in Cell Res 2012; 22:321-332. an enjoyable read and will contribute to improving hemoglobin production in 15 Meng F, Chen S, Miao Q, et al. Induc- irradiated SCID mice. Cell Res 2012; tion of fibroblasts to neurons through the growth of the field in years to come. 22:637-648. adenoviral gene delivery. Cell Res 2012; 7 Wang F, Yin Y, Ye X, et al. Molecular in- 22:436-440. 1 Dangsheng Li sights into the heterogeneity of telomere 16 Sheng C, Zheng Q, Wu J, et al. Genera- reprogramming in induced pluripotent tion of dopaminergic neurons directly 1Deputy Editor-in-Chief, Cell Research, stem cells. Cell Res 2012; 22:757-768. from mouse fibroblasts and fibroblast- 8 Ding J, Xu H, Faiola F, Ma’ayan A, derived neural progenitors. Cell Res Shanghai Institutes for Biological Sci- Wang J. Oct4 links multiple epigenetic 2012; 22:769-772. ences, Chinese Academy of Sciences, pathways to the pluripotency network. 17 Achilleos A, Trainor PA. Neural crest Shanghai 200031, China Cell Res 2012; 22:155-167. stem cells: discovery, properties and [email protected] 9 Patterson M, Chan DN, Ha I, et al. potential for therapy. Cell Res 2012; Defining the nature of human pluripo- 22:288-304. References tent stem cell progeny. Cell Res 2012; 18 Tang DG. Understanding cancer stem 22:178-193. cell heterogeneity and plasticity. Cell 10 Wang C, Tang X, Sun X, et al. TGFβ Res 2012; 22:457-472. 1 Abbott A. Cell rewind wins medicine inhibition enhances the generation of 19 Chen T, Yang K, Yu J, et al. Identifica- Nobel. Nature 2012; 490:151-152. hematopoietic progenitors from human tion and expansion of cancer stem cells 2 Li D. A special issue on cell signaling, ES cell-derived hemogenic endothelial in tumor tissues and peripheral blood disease, and stem cells. Cell Res 2012; cells using a stepwise strategy. Cell Res derived from gastric adenocarcinoma 22:1-2. 2012; 22:194-207. patients. Cell Res 2012; 22:248-258. 3 Xu H, Yi BA, Wu H, et al. Highly ef- 11 Gwak J, Hwang SG, Park HS, et al. 20 Hou Y, Zou Q, Ge R, Shen F, Wang Y. ficient derivation of ventricular cardio- Small molecule-based disruption of The critical role of CD133+CD44+/high myocytes from induced pluripotent stem the Axin/β-catenin protein complex tumor cells in hematogenous metastasis cells with a distinct epigenetic signature. regulates mesenchymal stem cell dif- of liver . Cell Res 2012; 22:259- Cell Res 2012; 22:142-154. ferentiation. Cell Res 2012; 22:237-247. 272. 4 Panopoulos AD, Yanes O, Ruiz S, et al. 12 Bueno C, Montes R, Melen GJ, et al. A The metabolome of induced pluripotent human ESC model for MLL-AF4 leu- stem cells reveals metabolic changes oc-

Cell Research | Vol 23 No 1 | January 2013