DOCSLIB.ORG

Dedifferentiation, Transdifferentiation, and Reprogramming: Future Directions in Regenerative Medicine

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

82 Dedifferentiation, Transdifferentiation, and Reprogramming: Future Directions in Regenerative Medicine Cristina Eguizabal, PhD1 Nuria Montserrat, PhD1 Anna Veiga, PhD1,2 Juan Carlos Izpisua Belmonte, PhD1,3 1 Center for Regenerative Medicine in Barcelona Address for correspondence and reprint requests Juan Carlos Izpisua 2 Reproductive Medicine Service, Institut Universitari Dexeus, Belmonte, PhD, Gene Expression Laboratory, The Salk Institute for Barcelona, Spain Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 93027 3 Gene Expression Laboratory, The Salk Institute for Biological Studies, (e-mail: [email protected]). La Jolla, California Semin Reprod Med 2013;31:82–94 Abstract The main goal of regenerative medicine is to replace damaged tissue. To do this it is Keywords necessary to understand in detail the whole regeneration process including differenti- ► regenerative ated cells that can be converted into progenitor cells (dedifferentiation), cells that can medicine switch into another cell type (transdifferentiation), and somatic cells that can be ► stem cells induced to become pluripotent cells (reprogramming). By studying the regenerative ► dedifferentiation processes in both nonmammal and mammal models, natural or artificial processes ► transdifferentiation could underscore the molecular and cellular mechanisms behind these phenomena and ► reprogramming be used to create future regenerative strategies for humans. To understand any regenerative system, it is crucial to find the potency and differentiate and how they can revert to pluri- cellular origins of renewed tissues. Using techniques like potency (reprogramming) or switch lineages (dedifferentia- genetic lineage tracing and single-cell transplantation helps tion and transdifferentiation). to identify the route of regenerative sources. These tools were We synthesize the studies of different model systems to developed first in nonmammal models (flies, amphibians, and highlight recent insights that are integrating the field. Where- fish) and then in mammal models like mice. The source of cells as previous reviews largely focused on specific animal mod- during regeneration in most cases is either stem cells or els, molecular pathways, or only on one regenerative route, progenitor cells, or the dedifferentiated or transdifferentiated our aim is to combine the three regenerative routes in several cells within the tissue of origin. Another process related to species and discuss future directions in regenerative regenerative therapies is reprogramming: somatic cells that medicine. can be converted into stem cells, known as induced pluripo- fi tent stem cells (iPSs). These arti cial stem cells are suitable for Dedifferentiation several purposes: basic research, drug screening, disease modeling, or autologous cell therapy. Dedifferentiation is the reverse developmental process in This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. The promising future of regenerative medicine is to re- which differentiated cells with specialized functions become place or regenerate tissues or organs to restore or reestablish undifferentiated progenitor cells. Dedifferentiation and sub- normal cell function. To do so, it is necessary to understand sequent proliferation provide the basis for tissue regeneration the three regenerative processes: dedifferentiation, trans- and the formation of new stem cell lineages. differentiation, and reprogramming. By using the model developed by Waddington1,2 (►Fig. 1), it is possible to In Vivo Dedifferentiation understand the epigenetic status and the developmental Historically, the first evidence of dedifferentiation during the potential of each cell during these processes. This modified regeneration process was found in plants.3 Basically, it can be schematic representation explains graphically how cells lose divided into different types: the regeneration of a tissue Issue Theme Stem Cells Helping Copyright © 2013 by Thieme Medical DOI http://dx.doi.org/ Reproductive Medicine; Guest Editor, Publishers, Inc., 333 Seventh Avenue, 10.1055/s-0032-1331802. Carlos Simón, MD, PhD New York, NY 10001, USA. ISSN 1526-8004. Tel: +1(212) 584-4662. Future Directions in Regenerative Medicine Eguizabal et al. 83 Figure 1 Dedifferentiation, transdifferentiation, and reprogramming processes in Waddington’s epigenetic landscape shows cell populations with different epigenetic and developmental potentials. A modification of the original and modified Waddington’s landscape.1,2 EG cells, embryonic germ cells; EC cells, embryonic carcinoma cells; ICM/ES cells, inner cell mass/embryonic stem cells; iPS cells, induced pluripotent stem cells; mGS cells, multipotent germline stem cells. structure lost after an injury, the de novo generation of a new lineage analysis revealed that the regenerating cells main- tissue structure not present before the injury, and the regen- taining the memory of the earlier cellular identity give rise to eration of the whole plant from a single somatic cell.4 Recent tissues only within their original lineage.15 A recent contro- studies on the generation of callus have shown that it versial study in Xenopus limb regeneration confirmed the regenerates due to a preexisting pluripotent stem cell popu- important role of SALL4 in the dedifferentiation and mainte- lation instead of a dedifferentiation process.5 More studies nance of the blastema cells in an undifferentiated state. More are still needed to evaluate this discrepancy. studies on limb regeneration are needed to elucidate the real In nonmammalian vertebrates, there are several examples mechanisms involved in limb regeneration in amphibians. of dedifferentiation; one of them is bone regeneration via In the case of tail regeneration in the axolotl, tracking dedifferentiation of the osteoblast in zebrafish fin.6 Knopf and fluorescent-labeled single muscle fibers and observing the colleagues monitored osteoblast differentiation in the regen- mononuclear state of muscle fiber cells as a “less differentiat- erating fin using a transgenic system expressing fluorescent ed” state, muscle cells confirmed the dedifferentiation of proteins under the control of promoters of early, intermedi- mature fibers. In the same manner, authors observed an ate, and late osteoblast-specific genes (RUNX2, SP7, and BGLAP increase of the transcription factor MSX-1, known to be – [osteocalcin]).7 9 Their elegant study showed that in a re- expressed in early development during epithelial-mesenchy- sponse to the amputation, mature osteoblasts dedifferentiate, mal transition. Taken together, all of this provides evidence become proliferative, and migrate distally to form outer that the terminally differentiated myotubes dedifferentiated – regions of the regeneration of blastema of fin rays. toward multipotent cells.16 19 Another example of dedifferentiation occurs during heart The dedifferentiation process has been shown to be related regeneration in zebrafish. Jopling and colleagues10 described to the entry of the regenerating cells into the cell cycle. It has that zebrafish heart can fully regenerate up to 20% after been observed that during regenerative dedifferentiation, the – This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. amputation in the ventricle.11 13 To explain these data, the tumor suppressor retinoblastoma protein (RB) plays a key authors generated induced green fluorescence protein (GFP) role in the reentry of the cells into cell cycle. Along these lines, transgenic zebrafish under cardiomyocyte-specificpro- it has been shown that Drosophila melanogaster mutants for moters (mlc2a and gata4). During this regeneration process, RB and Hippo (a member of the STE20 family of protein fully differentiated cardiomyocytes can dedifferentiate and kinases) maintain a normal neuronal differentiation program. proliferate, regenerating the missing part of the ventricle.10,14 However, the cells do not retain their differentiated status. GFP-labeled cells indicated that the newly generated cardio- They dedifferentiate to an earlier eye-precursor stage show- myocytes originated from existing GFP cardiomyocytes and ing unrestricted proliferation. So far, it seems that dediffer- not from a source of progenitors. entiation and the cell cycle processes are distinct from one Another good example of dedifferentiation is limb regen- another and that RB also plays an important role in main- eration in urodeles (salamander). At first the blastema (group taining the differentiated status of the cell.20,21 of cells that initiates the regenerative process) was regarded In mammals, the capacity of regeneration following the as a homogeneous cell population, but it was later demon- dedifferentiation strategy is limited. However, it has been strated to be a heterogeneous cell population containing observed that in the mouse model, Schwann cells possess the progenitor cells with restricted potential. A specificcell natural ability to regenerate. During development, Schwann Seminars in Reproductive Medicine Vol. 31 No. 1/2013 84 Future Directions in Regenerative Medicine Eguizabal et al. Figure 2 In vivo and in vitro dedifferentiation in mammals. (A) Schwann precursors dedifferentiate toward immature Schwann cells and then finally differentiate into mature myelinating or nonmyelinating Schwann cells. (B) Human tyroid follicular cells can be dedifferentiated into multilineage progenitor cells by culturing them in serum-free conditions. (C) Human epidermal
Recommended publications
  • Ascl1a/Dkk/Β-Catenin Signaling Pathway Is Necessary and Glycogen Synthase Kinase-3Β Inhibition Is Sufficient for Zebrafish Retina Regeneration

    Ascl1a/Dkk/Β-Catenin Signaling Pathway Is Necessary and Glycogen Synthase Kinase-3Β Inhibition Is Sufficient for Zebrafish Retina Regeneration

    Ascl1a/Dkk/β-catenin signaling pathway is necessary and glycogen synthase kinase-3β inhibition is sufficient for zebrafish retina regeneration Rajesh Ramachandran, Xiao-Feng Zhao, and Daniel Goldman1 Molecular and Behavioral Neuroscience Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109 Edited by David R. Hyde, University of Notre Dame, Notre Dame, IN, and accepted by the Editorial Board August 19, 2011 (received for review May 5, 2011) Key to successful retina regeneration in zebrafish are Müller glia necessary for proliferation of dedifferentiated MG in the injured (MG) that respond to retinal injury by dedifferentiating into a cy- retina and that glycogen synthase kinase-3β (GSK-3β) inhibition cling population of retinal progenitors. Although recent studies was sufficient to stimulate MG dedifferentiation into a pop- have identified several genes involved in retina regeneration, ulation of cycling multipotent progenitors in the uninjured ret- the signaling mechanisms underlying injury-dependent MG prolif- ina. Interestingly, Ascl1a knockdown limited the production of eration have remained elusive. Here we report that canonical Wnt neurons by progenitors in the GSK-3β inhibitor-treated retina. signaling controls the proliferation of MG-derived retinal progen- itors. We found that injury-dependent induction of Ascl1a sup- Results pressed expression of the Wnt signaling inhibitor, Dkk, and Ascl1a-Dependent Suppression of dkk Gene Expression in Injured induced expression of the Wnt ligand, Wnt4a. Genetic and phar- Retina. Wnt signaling is a conserved pathway that affects many macological inhibition of Wnt signaling suppressed injury-depen- fundamental developmental processes (18). Deregulated Wnt dent proliferation of MG-derived progenitors.
  • Mir-451A Suppresses Cell Proliferation, Metastasis and EMT Via Targeting YWHAZ in Hepatocellular Carcinoma

    Mir-451A Suppresses Cell Proliferation, Metastasis and EMT Via Targeting YWHAZ in Hepatocellular Carcinoma

    European Review for Medical and Pharmacological Sciences 2019; 23: 5158-5167 MiR-451a suppresses cell proliferation, metastasis and EMT via targeting YWHAZ in hepatocellular carcinoma G.-Y. WEI1, M. HU2, L. ZHAO1, W.-S. GUO1 1Department of General Surgery, Henan Traditional Chinese Medicine Hospital, Zhengzhou, China 2Department of Infection Management, Henan Traditional Chinese Medicine Hospital, Zhengzhou, China Abstract. – OBJECTIVE: MicroRNAs (miR- lines. Moreover, miR-451a inhibited the prolif- NAs) have been identified to participate in eration, invasion and migration of HCC cells via the progression of hepatocellular carcinoma targeting YWHAZ. Our findings indicated that (HCC). However, the function of miR-451a in miR-451a could serve as a novel target for HCC HCC remains unknown. The aim of this study diagnosis and biological therapy. was to determine the function of miR-451a by construction of several experiments in HCC tis- Key Words: sues and cells. MiR-451a, Hepatocellular carcinoma (HCC), Prolifer- PATIENTS AND METHODS: The expression ation, Metastasis, YWHAZ. level of miR-451a in 69 paired of HCC and ad- jacent normal tissue samples was detected us- ing quantitative Real-time polymerase chain re- Introduction action (qRT-PCR). MiR-451a expression in HCC derived cell lines was detected as well. By trans- fecting with miR-451a mimics or inhibitor, the Hepatocellular carcinoma (HCC) accounts expression level of miR-451a in HepG2 or Huh-7 for 85-90% of primary liver cancer. HCC is the cells was up- or down-regulated. MTT (3-(4,5-di- fifth most common morbidity and third most methylthiazol-2-yl)-2,5-diphenyl tetrazolium bro- common mortality cancer worldwide1.
  • Dedifferentiation-Associated Changes in Morphology and Gene Expression in Primary Human Articular Chondrocytes in Cell Culture M

    Dedifferentiation-Associated Changes in Morphology and Gene Expression in Primary Human Articular Chondrocytes in Cell Culture M

    Osteoarthritis and Cartilage (2002) 10, 62–70 © 2002 OsteoArthritis Research Society International 1063–4584/02/010062+09 $35.00/0 doi:10.1053/joca.2001.0482, available online at http://www.idealibrary.com on Dedifferentiation-associated changes in morphology and gene expression in primary human articular chondrocytes in cell culture M. Schnabel*, S. Marlovits†, G. Eckhoff*, I. Fichtel*, L. Gotzen*, V. Ve´csei† and J. Schlegel‡ *Department of Traumatology, Philipps-University of Marburg, Germany †Department of Traumatology, University of Vienna, Austria; Ludwig Boltzmann Institute of Biomechanics and Cell Biology, Vienna, Austria ‡Institute of Pathology, Munich Technical University, Germany Summary Objective: The aim of the present study was the investigation of differential gene expression in primary human articular chondrocytes (HACs) and in cultivated cells derived from HACs. Design: Primary human articular chondrocytes (HACs) isolated from non-arthritic human articular cartilage and monolayer cultures of HACs were investigated by immunohistochemistry, Northern analysis, RT-PCR and cDNA arrays. Results: By immunohistochemistry we detected expression of collagen II, protein S-100, chondroitin-4-sulphate and vimentin in freshly isolated HACs. Cultivated HACs, however, showed only collagen I and vimentin expression. These data were corroborated by the results of Northern analysis using specifc cDNA probes for collagens I, II and III and chondromodulin, respectively, demonstrating collagen II and chondromodulin expression in primary HACs but not in cultivated cells. Hybridization of mRNA from primary HACs and cultivated cells to cDNA arrays revealed additional transcriptional changes associated with dedifferentiation during propagation of chondrocytes in vitro.We found a more complex hybridization pattern for primary HACs than for cultivated cells.
  • Functional Skeletal Muscle Constructs from Transdifferentiated Human Fibroblasts

    Functional Skeletal Muscle Constructs from Transdifferentiated Human Fibroblasts

    www.nature.com/scientificreports OPEN Functional skeletal muscle constructs from transdiferentiated human fbroblasts Bin Xu1, Allison Siehr1 & Wei Shen1,2,3* Transdiferentiation of human non-muscle cells directly into myogenic cells by forced expression of MyoD represents one route to obtain highly desirable human myogenic cells. However, functional properties of the tissue constructs derived from these transdiferentiated cells have been rarely studied. Here, we report that three-dimensional (3D) tissue constructs engineered with iMyoD-hTERT- NHDFs, normal human dermal fbroblasts transduced with genes encoding human telomerase reverse transcriptase and doxycycline-inducible MyoD, generate detectable contractile forces in response to electrical stimuli upon MyoD expression. Withdrawal of doxycycline in the middle of 3D culture results in 3.05 and 2.28 times increases in twitch and tetanic forces, respectively, suggesting that temporally- controlled MyoD expression benefts functional myogenic diferentiation of transdiferentiated myoblast-like cells. Treatment with CHIR99021, a Wnt activator, and DAPT, a Notch inhibitor, leads to further enhanced contractile forces. The ability of these abundant and potentially patient-specifc and disease-specifc cells to develop into functional skeletal muscle constructs makes them highly valuable for many applications, such as disease modeling. Even though normal skeletal muscle has self-regenerative ability, it has remained a major challenge to treat genetic muscle diseases and volumetric muscle loss 1. Using human myogenic cells to develop cell-based thera- pies to repair or restore diseased or lost muscle tissue represents an important strategy to address this challenge. Human myogenic cells are also highly desirable for creating muscle tissue models or disease models, which can be used for fundamental studies of muscle physiology and pathology and for drug screening and validation.
  • Genomic Profiling Reveals High Frequency of DNA Repair Genetic

    Genomic Profiling Reveals High Frequency of DNA Repair Genetic

    www.nature.com/scientificreports OPEN Genomic profling reveals high frequency of DNA repair genetic aberrations in gallbladder cancer Reham Abdel‑Wahab1,9, Timothy A. Yap2, Russell Madison4, Shubham Pant1,2, Matthew Cooke4, Kai Wang4,5,7, Haitao Zhao8, Tanios Bekaii‑Saab6, Elif Karatas1, Lawrence N. Kwong3, Funda Meric‑Bernstam2, Mitesh Borad6 & Milind Javle1,10* DNA repair gene aberrations (GAs) occur in several cancers, may be prognostic and are actionable. We investigated the frequency of DNA repair GAs in gallbladder cancer (GBC), association with tumor mutational burden (TMB), microsatellite instability (MSI), programmed cell death protein 1 (PD‑1), and its ligand (PD‑L1) expression. Comprehensive genomic profling (CGP) of 760 GBC was performed. We investigated GAs in 19 DNA repair genes including direct DNA repair genes (ATM, ATR , BRCA1, BRCA2, FANCA, FANCD2, MLH1, MSH2, MSH6, PALB2, POLD1, POLE, PRKDC, and RAD50) and caretaker genes (BAP1, CDK12, MLL3, TP53, and BLM) and classifed patients into 3 groups based on TMB level: low (< 5.5 mutations/Mb), intermediate (5.5–19.5 mutations/Mb), and high (≥ 19.5 mutations/Mb). We assessed MSI status and PD‑1 & PD‑L1 expression. 658 (86.6%) had at least 1 actionable GA. Direct DNA repair gene GAs were identifed in 109 patients (14.2%), while 476 (62.6%) had GAs in caretaker genes. Both direct and caretaker DNA repair GAs were signifcantly associated with high TMB (P = 0.0005 and 0.0001, respectively). Tumor PD‑L1 expression was positive in 119 (15.6%), with 17 (2.2%) being moderate or high. DNA repair GAs are relatively frequent in GBC and associated with coexisting actionable mutations and a high TMB.
  • Mitosis Vs. Meiosis

    Mitosis Vs. Meiosis

    Mitosis vs. Meiosis In order for organisms to continue growing and/or replace cells that are dead or beyond repair, cells must replicate, or make identical copies of themselves. In order to do this and maintain the proper number of chromosomes, the cells of eukaryotes must undergo mitosis to divide up their DNA. The dividing of the DNA ensures that both the “old” cell (parent cell) and the “new” cells (daughter cells) have the same genetic makeup and both will be diploid, or containing the same number of chromosomes as the parent cell. For reproduction of an organism to occur, the original parent cell will undergo Meiosis to create 4 new daughter cells with a slightly different genetic makeup in order to ensure genetic diversity when fertilization occurs. The four daughter cells will be haploid, or containing half the number of chromosomes as the parent cell. The difference between the two processes is that mitosis occurs in non-reproductive cells, or somatic cells, and meiosis occurs in the cells that participate in sexual reproduction, or germ cells. The Somatic Cell Cycle (Mitosis) The somatic cell cycle consists of 3 phases: interphase, m phase, and cytokinesis. 1. Interphase: Interphase is considered the non-dividing phase of the cell cycle. It is not a part of the actual process of mitosis, but it readies the cell for mitosis. It is made up of 3 sub-phases: • G1 Phase: In G1, the cell is growing. In most organisms, the majority of the cell’s life span is spent in G1. • S Phase: In each human somatic cell, there are 23 pairs of chromosomes; one chromosome comes from the mother and one comes from the father.
  • Exploring the Interplay of Telomerase Reverse Transcriptase and Β-Catenin in Hepatocellular Carcinoma

    Exploring the Interplay of Telomerase Reverse Transcriptase and Β-Catenin in Hepatocellular Carcinoma

    cancers Review Exploring the Interplay of Telomerase Reverse Transcriptase and β-Catenin in Hepatocellular Carcinoma Srishti Kotiyal and Kimberley Jane Evason * Department of Oncological Sciences, Department of Pathology, and Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-801-587-4606 Simple Summary: Liver cancer is one of the deadliest human cancers. Two of the most common molecular aberrations in liver cancer are: (1) activating mutations in the gene encoding β-catenin (CTNNB1); and (2) promoter mutations in telomerase reverse transcriptase (TERT). Here, we review recent findings regarding the interplay between TERT and β-catenin in order to better understand their role in liver cancer. Abstract: Hepatocellular carcinoma (HCC) is one of the deadliest human cancers. Activating muta- tions in the telomerase reverse transcriptase (TERT) promoter (TERTp) and CTNNB1 gene encoding β-catenin are widespread in HCC (~50% and ~30%, respectively). TERTp mutations are predicted to increase TERT transcription and telomerase activity. This review focuses on exploring the role of TERT and β-catenin in HCC and the current findings regarding their interplay. TERT can have contradictory effects on tumorigenesis via both its canonical and non-canonical functions. As a critical regulator of proliferation and differentiation in progenitor and stem cells, activated β-catenin drives HCC; however, inhibiting endogenous β-catenin can also have pro-tumor effects. Clinical studies revealed a significant concordance between TERTp and CTNNB1 mutations in HCC. In Citation: Kotiyal, S.; Evason, K.J. stem cells, TERT acts as a co-factor in β-catenin transcriptional complexes driving the expression Exploring the Interplay of Telomerase of WNT/β-catenin target genes, and β-catenin can bind to the TERTp to drive its transcription.
  • Telomere and Telomerase in Oncology

    Telomere and Telomerase in Oncology

    Cell Research (2002); 12(1):1-7 http://www.cell-research.com REVIEW Telomere and telomerase in oncology JIAO MU*, LI XIN WEI International Joint Cancer Institute, Second Military Medical University, Shanghai 200433, China ABSTRACT Shortening of the telomeric DNA at the chromosome ends is presumed to limit the lifespan of human cells and elicit a signal for the onset of cellular senescence. To continually proliferate across the senescent checkpoint, cells must restore and preserve telomere length. This can be achieved by telomerase, which has the reverse transcriptase activity. Telomerase activity is negative in human normal somatic cells but can be detected in most tumor cells. The enzyme is proposed to be an essential factor in cell immortalization and cancer progression. In this review we discuss the structure and function of telomere and telomerase and their roles in cell immortalization and oncogenesis. Simultaneously the experimental studies of telomerase assays for cancer detection and diagnosis are reviewed. Finally, we discuss the potential use of inhibitors of telomerase in anti-cancer therapy. Key words: Telomere, telomerase, cancer, telomerase assay, inhibitor. Telomere and cell replicative senescence base pairs of the end of telomeric DNA with each Telomeres, which are located at the end of round of DNA replication. Hence, the continual chromosome, are crucial to protect chromosome cycles of cell growth and division bring on progress- against degeneration, rearrangment and end to end ing telomere shortening[4]. Now it is clear that te- fusion[1]. Human telomeres are tandemly repeated lomere shortening is responsible for inducing the units of the hexanucleotide TTAGGG. The estimated senescent phenotype that results from repeated cell length of telomeric DNA varies from 2 to 20 kilo division, but the mechanism how a short telomere base pairs, depending on factors such as tissue type induces the senescence is still unknown.
  • Crosstalk Between SOX2 and TGF-Β Signaling Regulates EGFR-TKI Tolerance and Lung Cancer Dissemination

    Crosstalk Between SOX2 and TGF-Β Signaling Regulates EGFR-TKI Tolerance and Lung Cancer Dissemination

    Author Manuscript Published OnlineFirst on August 19, 2020; DOI: 10.1158/0008-5472.CAN-19-3228 Author manuscripts have been peer reviewed and accepted for publication but have not yet been edited. Crosstalk between SOX2 and TGF-β signaling regulates EGFR-TKI tolerance and lung cancer dissemination Ming-Han Kuo1,10, An-Chun Lee1,10, Shih-Hsin Hsiao2,10, Sey-En Lin3,4, Yu-Fan Chiu1, Li-Hao Yang1, Chia-Cherng Yu5, Shih-Hwa Chiou6,7, Hsien-Neng Huang8, Jen-Chung Ko9*, Yu-Ting Chou1* 1Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan; 2Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan; 3Department of Pathology, Taipei Medical University Hospital, Taipei, Taiwan; 4Department of Pathology, Taipei Municipal Wan Fang Hospital, Taipei, Taiwan; 5Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan; 6Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan; 7Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan; 8Department of pathology, National Taiwan University Hospital, Hsin-Chu Branch, Hsinchu, Taiwan; 9Department of Internal Medicine, National Taiwan University Hospital, Hsin-Chu Branch, Hsinchu, Taiwan;10Co-first authors *Corresponding authors Jen-Chung Ko, National Taiwan University Hospital, Hsin-Chu Branch, No. 25, Lane 442, Sec. 1, Jingguo Rd., Hsinchu 30013, Taiwan. E-mail: [email protected] Yu-Ting Chou, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan. E-mail: [email protected] Running title: Interplay of SOX2 and TGF- on EGFR–TKI tolerance Conflicts of interest The authors disclose no potential conflicts of interest. This work was supported by National Tsing Hua University and Ministry of Science and Technology, Executive Yuan, Taiwan.
  • Tumor and Stem Cell Biology Research

    Tumor and Stem Cell Biology Research

    Cancer Tumor and Stem Cell Biology Research Coexpression of Oct4 and Nanog Enhances Malignancy in Lung Adenocarcinoma by Inducing Cancer Stem Cell–Like Properties and Epithelial–Mesenchymal Transdifferentiation Shih-Hwa Chiou1,2,3, Mong-Lien Wang2, Yu-Ting Chou4, Chi-Jen Chen4, Chun-Fu Hong4, Wang-Ju Hsieh5, Hsin-Tzu Chang2, Ying-Shan Chen4, Tzu-Wei Lin2, Han-Sui Hsu6,7, and Cheng-Wen Wu2,4,5,6 Abstract Epithelial–mesenchymal transition (EMT), a critical process of cancer invasion and metastasis, is associated with stemness property of cancer cells. Though Oct4 and Nanog are homebox transcription factors essential to the self-renewal of stem cells and are expressed in several cancers, the role of Oct4/Nanog signaling in tumorigenesis is still elusive. Here microarray and quantitative real-time PCR analysis showed a parallel, elevated expression of Oct4 and Nanog in lung adenocarcinoma (LAC). Ectopic expressions of Oct4 and Nanog in LACs increased the percentage of CD133-expressing subpopulation and sphere formation, enhanced drug resistance, and promoted EMT. Ectopic expressions of Oct4 and Nanog activated Slug and enhanced the tumor- initiating capability of LAC. Furthermore, double knockdown of Oct4 and Nanog suppressed the expression of Slug, reversed the EMT process, blocked the tumorigenic and metastatic ability, and greatly improved the mean survival time of transplanted immunocompromised mice. The immunohistochemical analysis demonstrated that expressions of Oct4, Nanog, and Slug were present in high-grade LAC, and triple positivity of Oct4/Nanog/ Slug indicated a worse prognostic value of LAC patients. Our results support the notion that the Oct4/Nanog signaling controls epithelial–mesenchymal transdifferentiation, regulates tumor-initiating ability, and promotes metastasis of LAC.
  • Mouse Digit Tip Regeneration Is Mediated by Fate-Restricted Progenitor Cells

    Mouse Digit Tip Regeneration Is Mediated by Fate-Restricted Progenitor Cells

    Mouse digit tip regeneration is mediated by fate-restricted progenitor cells Jessica A. Lehoczkya, Benoît Robertb, and Clifford J. Tabina,1 aDepartment of Genetics, Harvard Medical School, Boston, MA 02115; and bInstitut Pasteur, Génétique Moléculaire de la Morphogenèse, Centre National de la Recherche Scientifique, Unité de Recherche Associée 2578, F-75015 Paris, France Contributed by Clifford J. Tabin, November 1, 2011 (sent for review September 19, 2011) Regeneration of appendages is frequent among invertebrates as tation of both the axolotl limb and the zebrafish fin strongly well as some vertebrates. However, in mammals this has been suggest that transdifferentiation does not significantly contribute largely relegated to digit tip regeneration, as found in mice and to the regenerates, and that instead the blastemas are made up of humans. The regenerated structures are formed from a mound of lineage-restricted cell populations (9–11). undifferentiated cells called a blastema, found just below the site Digit tip regeneration has been reported in mammals including of amputation. The blastema ultimately gives rise to all of the mice and juvenile humans (12, 13). Amputations of the terminal tissues in the regenerate, excluding the epidermis, and has classi- phalanx through levels associated with the nail organ are capable cally been thought of as a homogenous pool of pluripotent stem of regeneration, whereas more proximal amputations are not. cells derived by dedifferentiation of stump tissue, although this Intriguingly, mesenchymal nail bed cells in neonatal mice and has never been directly tested in the context of mammalian digit tip humans express the transcription factor Msx1 (14, 15), which is regeneration.
  • Brief Demethylation Step Allows the Conversion of Adult Human Skin fibroblasts Into Insulin-Secreting Cells

    Brief Demethylation Step Allows the Conversion of Adult Human Skin fibroblasts Into Insulin-Secreting Cells

    Brief demethylation step allows the conversion of adult human skin fibroblasts into insulin-secreting cells Georgia Pennarossaa, Sara Maffeia, Marino Campagnola, Letizia Tarantinib,c, Fulvio Gandolfia, and Tiziana A. L. Brevinia,1 aLaboratory of Biomedical Embryology, UniStem, Center for Stem Cell Research, bDepartment of Clinical and Community Sciences, and cIstituto di Ricerca e Cura a Carattere Scientifico Maggiore Hospital, Mangiagalli and Regina Elena Foundation, Università degli Studi di Milano, Italy Edited by R. Michael Roberts, University of Missouri, Columbia, MO, and approved April 18, 2013 (received for review November 29, 2012) The differentiated state of mature cells of adult organisms is physiologically very stable. Differentiation is achieved and main- achieved and maintained through the epigenetic regulation of gene tained through the epigenetic regulation of gene expression, which expression, which consists of several mechanisms including DNA consists of different mechanisms including DNA methylation, methylation. The advent of induced pluripotent stem cell technol- histone modification, nucleosome packaging and rearrangements, ogy enabled the conversion of adult cells into any other cell type higher-order chromatin structures, and the interplay between passing through a stable pluripotency state. However, indefinite chromatin and nuclear lamina (8). For this reason, the complete reversal of this process requires extensive reprogramming that pluripotency is unphysiological, inherently labile, and makes cells fi prone to culture-induced alterations. The direct conversion of one makes it inef cient and prone to errors (9). cell type to another without an intermediate pluripotent stage is We reasoned that part of the problem may derive from consid- ering the achievement of a stable pluripotent state as an indispens- also possible but, at present, requires the viral transfection of able step, even if this does not occur during embryonic development, appropriate transcription factors, limiting its therapeutic potential.