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. 2012 Oct 17;3(11):834–845. doi: 10.1007/s13238-012-2078-6

Overcoming barriers to the clinical utilization of iPSCs: reprogramming efficiency, safety and quality

Suying Cao 1, Kyle Loh 2, Yangli Pei 1, Wei Zhang 1, Jianyong Han 1,✉
PMCID: PMC4875458  PMID: 23073833

Abstract

Differentiated cells can be reprogrammed into pluripotent stem cells, known as “induced pluripotent stem cells” (iPSCs), through the overexpression of defined transcription factors. The creation of iPSC lines has opened new avenues for patient-specific cell replacement therapies for regenerative medicine. However, the clinical utilization of iPSCs is largely impeded by two limitations. The first limitation is the low efficiency of iPSCs generation from differentiated cells. The second limitation is that many iPSC lines are not authentically pluripotent, as many cell lines inefficiently differentiate into differentiated cell types when they are tested for their ability to complement embryonic development. Thus, the “quality” of iPSCs must be increased if they are to be differentiated into specialized cell types for cell replacement therapies. Overcoming these two limitations is paramount to facilitate the widespread employment of iPSCs for therapeutic purposes. Here, we summarize recent progress made in strategies enabling the efficient production of high-quality iPSCs, including choice of reprogramming factors, choice of target cell type, and strategies to improve iPSC quality.

Keywords: iPSCs, reprogramming, embryonic stem cells, efficiency and quality

References

  1. Aasen T., Raya A., Barrero M.J., Garreta E., Consiglio A., Gonzalez F., Vassena R., Bilic J., Pekarik V., Tiscornia G., et al. Efficient and rapid generation of induced pluripotent stem cells from human keratinocytes. Nat Biotechnol. 2008;26:1276–1284. doi: 10.1038/nbt.1503. [DOI] [PubMed] [Google Scholar]
  2. Aoi T., Yae K., Nakagawa M., Ichisaka T., Okita K., Takahashi K., Chiba T., Yamanaka S. Generation of pluripotent stem cells from adult mouse liver and stomach cells. Science. 2008;321:699–702. doi: 10.1126/science.1154884. [DOI] [PubMed] [Google Scholar]
  3. Blelloch R., Venere M., Yen J., Ramalho-Santos M. Generation of induced pluripotent stem cells in the absence of drug selection. Cell Stem Cell. 2007;1:245–247. doi: 10.1016/j.stem.2007.08.008. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bosnali M., Edenhofer F. Generation of transducible versions of transcription factors Oct4 and Sox2. Biol Chem. 2008;389:851–861. doi: 10.1515/BC.2008.106. [DOI] [PubMed] [Google Scholar]
  5. Brambrink T., Foreman R., Welstead G.G., Lengner C.J., Wernig M., Suh H., Jaenisch R. Sequential expression of pluripotency markers during direct reprogramming of mouse somatic cells. Cell Stem Cell. 2008;2:151–159. doi: 10.1016/j.stem.2008.01.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Carlson H., Ota S., Song Y., Chen Y., Hurlin P.J. Tbx3 impinges on the p53 pathway to suppress apoptosis, facilitate cell transformation and block myogenic differentiation. Oncogene. 2002;21:3827–3835. doi: 10.1038/sj.onc.1205476. [DOI] [PubMed] [Google Scholar]
  7. Chang C.W., Lai Y.S., Pawlik K.M., Liu K., Sun C.W., Li C., Schoeb T.R., Townes T.M. Polycistronic lentiviral vector for “hit and run” reprogramming of adult skin fibroblasts to induced pluripotent stem cells. Stem Cells. 2009;27:1042–1049. doi: 10.1002/stem.39. [DOI] [PubMed] [Google Scholar]
  8. Eminli S., Foudi A., Stadtfeld M., Maherali N., Ahfeldt T., Mostoslavsky G., Hock H., Hochedlinger K. Differentiation stage determines potential of hematopoietic cells for reprogramming into induced pluripotent stem cells. Nat Genet. 2009;41:968–976. doi: 10.1038/ng.428. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Eminli S., Utikal J., Arnold K., Jaenisch R., Hochedlinger K. Reprogramming of neural progenitor cells into induced pluripotent stem cells in the absence of exogenous Sox2 expression. Stem Cells. 2008;26:2467–2474. doi: 10.1634/stemcells.2008-0317. [DOI] [PubMed] [Google Scholar]
  10. Esteban M.A., Pei D. Vitamin C improves the quality of somatic cell reprogramming. Nat Genet. 2012;44:366–367. doi: 10.1038/ng.2222. [DOI] [PubMed] [Google Scholar]
  11. Esteban M.A., Wang T., Qin B., Yang J., Qin D., Cai J., Li W., Weng Z., Chen J., Ni S., et al. Vitamin C enhances the generation of mouse and human induced pluripotent stem cells. Cell Stem Cell. 2010;6:71–79. doi: 10.1016/j.stem.2009.12.001. [DOI] [PubMed] [Google Scholar]
  12. Esteban M.A., Xu J., Yang J., Peng M., Qin D., Li W., Jiang Z., Chen J., Deng K., Zhong M., et al. Generation of induced pluripotent stem cell lines from Tibetan miniature pig. J Biol Chem. 2009;284:17634–17640. doi: 10.1074/jbc.M109.008938. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Ezashi T., Telugu B.P., Alexenko A.P., Sachdev S., Sinha S., Roberts R.M. Derivation of induced pluripotent stem cells from pig somatic cells. Proc Natl Acad Sci U S A. 2009;106:10993–10998. doi: 10.1073/pnas.0905284106. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Feng B., Jiang J., Kraus P., Ng J.H., Heng J.C., Chan Y.S., Yaw L.P., Zhang W., Loh Y.H., Han J., et al. Reprogramming of fibroblasts into induced pluripotent stem cells with orphan nuclear receptor Esrrb. Nat Cell Biol. 2009;11:197–203. doi: 10.1038/ncb1827. [DOI] [PubMed] [Google Scholar]
  15. Feng B., Ng J.H., Heng J.C., Ng H.H. Molecules that promote or enhance reprogramming of somatic cells to induced pluripotent stem cells. Cell Stem Cell. 2009;4:301–312. doi: 10.1016/j.stem.2009.03.005. [DOI] [PubMed] [Google Scholar]
  16. Fusaki N., Ban H., Nishiyama A., Saeki K., Hasegawa M. Efficient induction of transgene-free human pluripotent stem cells using a vector based on Sendai virus, an RNA virus that does not integrate into the host genome. Proc Jpn Acad Ser B Phys Biol Sci. 2009;85:348–362. doi: 10.2183/pjab.85.348. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Gonzalez F., Barragan Monasterio M., Tiscornia G., Montserrat Pulido N., Vassena R., Batlle Morera L., Rodriguez Piza I., Izpisua Belmonte J.C. Generation of mouse-induced pluripotent stem cells by transient expression of a single nonviral polycistronic vector. Proc Natl Acad Sci U S A. 2009;106:8918–8922. doi: 10.1073/pnas.0901471106. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Gore A., Li Z., Fung H.L., Young J.E., Agarwal S., Antosiewicz-Bourget J., Canto I., Giorgetti A., Israel M.A., Kiskinis E., et al. Somatic coding mutations in human induced pluripotent stem cells. Nature. 2011;471:63–67. doi: 10.1038/nature09805. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Graf T., Enver T. Forcing cells to change lineages. Nature. 2009;462:587–594. doi: 10.1038/nature08533. [DOI] [PubMed] [Google Scholar]
  20. Han J., Yuan P., Yang H., Zhang J., Soh B.S., Li P., Lim S.L., Cao S., Tay J., Orlov Y.L., et al. Tbx3 improves the germ-line competency of induced pluripotent stem cells. Nature. 2010;463:1096–1100. doi: 10.1038/nature08735. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Hanna J., Markoulaki S., Schorderet P., Carey B.W., Beard C., Wernig M., Creyghton M.P., Steine E.J., Cassady J.P., Foreman R., et al. Direct reprogramming of terminally differentiated mature B lymphocytes to pluripotency. Cell. 2008;133:250–264. doi: 10.1016/j.cell.2008.03.028. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Heng J.C., Feng B., Han J., Jiang J., Kraus P., Ng J.H., Orlov Y.L., Huss M., Yang L., Lufkin T., et al. The nuclear receptor Nr5a2 can replace Oct4 in the reprogramming of murine somatic cells to pluripotent cells. Cell Stem Cell. 2010;6:167–174. doi: 10.1016/j.stem.2009.12.009. [DOI] [PubMed] [Google Scholar]
  23. Hochedlinger K., Jaenisch R. Nuclear reprogramming and pluripotency. Nature. 2006;441:1061–1067. doi: 10.1038/nature04955. [DOI] [PubMed] [Google Scholar]
  24. Hong H., Takahashi K., Ichisaka T., Aoi T., Kanagawa O., Nakagawa M., Okita K., Yamanaka S. Suppression of induced pluripotent stem cell generation by the p53-p21 pathway. Nature. 2009;460:1132–1135. doi: 10.1038/nature08235. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Huangfu D., Maehr R., Guo W., Eijkelenboom A., Snitow M., Chen A.E., Melton D.A. Induction of pluripotent stem cells by defined factors is greatly improved by small-molecule compounds. Nat Biotechnol. 2008;26:795–797. doi: 10.1038/nbt1418. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Huangfu D., Osafune K., Maehr R., Guo W., Eijkelenboom A., Chen S., Muhlestein W., Melton D.A. Induction of pluripotent stem cells from primary human fibroblasts with only Oct4 and Sox2. Nat Biotechnol. 2008;26:1269–1275. doi: 10.1038/nbt.1502. [DOI] [PubMed] [Google Scholar]
  27. Hussein S.M., Batada N.N., Vuoristo S., Ching R.W., Autio R., Narva E., Ng S., Sourour M., Hamalainen R., Olsson C., et al. Copy number variation and selection during reprogramming to pluripotency. Nature. 2011;471:58–62. doi: 10.1038/nature09871. [DOI] [PubMed] [Google Scholar]
  28. Ichida J.K., Blanchard J., Lam K., Son E.Y., Chung J.E., Egli D., Loh K.M., Carter A.C., Di Giorgio F.P., Koszka K., et al. A small-molecule inhibitor of tgf-Beta signaling replaces sox2 in reprogramming by inducing nanog. Cell Stem Cell. 2009;5:491–503. doi: 10.1016/j.stem.2009.09.012. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Ivanova N., Dobrin R., Lu R., Kotenko I., Levorse J., DeCoste C., Schafer X., Lun Y., Lemischka I.R. Dissecting self-renewal in stem cells with RNA interference. Nature. 2006;442:533–538. doi: 10.1038/nature04915. [DOI] [PubMed] [Google Scholar]
  30. Judson R.L., Babiarz J.E., Venere M., Blelloch R. Embryonic stem cell-specific microRNAs promote induced pluripotency. Nat Biotechnol. 2009;27:459–461. doi: 10.1038/nbt.1535. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Kaji K., Norrby K., Paca A., Mileikovsky M., Mohseni P., Woltjen K. Virus-free induction of pluripotency and subsequent excision of reprogramming factors. Nature. 2009;458:771–775. doi: 10.1038/nature07864. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Kawamura T., Suzuki J., Wang Y.V., Menendez S., Morera L.B., Raya A., Wahl G.M., Belmonte J.C. Linking the p53 tumour suppressor pathway to somatic cell reprogramming. Nature. 2009;460:1140–1144. doi: 10.1038/nature08311. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Keefer C.L., Pant D., Blomberg L., Talbot N.C. Challenges and prospects for the establishment of embryonic stem cell lines of domesticated ungulates. Anim Reprod Sci. 2007;98:147–168. doi: 10.1016/j.anireprosci.2006.10.009. [DOI] [PubMed] [Google Scholar]
  34. Kim J.B., Greber B., Arauzo-Bravo M.J., Meyer J., Park K.I., Zaehres H., Scholer H.R. Direct reprogramming of human neural stem cells by OCT4. Nature. 2009;461:649–643. doi: 10.1038/nature08436. [DOI] [PubMed] [Google Scholar]
  35. Kim J.B., Sebastiano V., Wu G., Arauzo-Bravo M.J., Sasse P., Gentile L., Ko K., Ruau D., Ehrich M., van den Boom D., et al. Oct4-induced pluripotency in adult neural stem cells. Cell. 2009;136:411–419. doi: 10.1016/j.cell.2009.01.023. [DOI] [PubMed] [Google Scholar]
  36. Kim J.B., Zaehres H., Wu G., Gentile L., Ko K., Sebastiano V., Arauzo-Bravo M.J., Ruau D., Han D.W., Zenke M., et al. Pluripotent stem cells induced from adult neural stem cells by reprogramming with two factors. Nature. 2008;454:646–650. doi: 10.1038/nature07061. [DOI] [PubMed] [Google Scholar]
  37. Kishigami S., Mizutani E., Ohta H., Hikichi T., Thuan N.V., Wakayama S., Bui H.T., Wakayama T. Significant improvement of mouse cloning technique by treatment with trichostatin A after somatic nuclear transfer. Biochem Biophys Res Commun. 2006;340:183–189. doi: 10.1016/j.bbrc.2005.11.164. [DOI] [PubMed] [Google Scholar]
  38. Krizhanovsky V., Lowe S.W. Stem cells: The promises and perils of p53. Nature. 2009;460:1085–1086. doi: 10.1038/4601085a. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Kustikova O., Fehse B., Modlich U., Yang M., Dullmann J., Kamino K., von Neuhoff N., Schlegelberger B., Li Z., Baum C. Clonal dominance of hematopoietic stem cells triggered by retroviral gene marking. Science. 2005;308:1171–1174. doi: 10.1126/science.1105063. [DOI] [PubMed] [Google Scholar]
  40. Li H., Collado M., Villasante A., Strati K., Ortega S., Canamero M., Blasco M.A., Serrano M. The Ink4/Arf locus is a barrier for iPS cell reprogramming. Nature. 2009;460:1136–1139. doi: 10.1038/nature08290. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Li W., Wei W., Zhu S., Zhu J., Shi Y., Lin T., Hao E., Hayek A., Deng H., Ding S. Generation of rat and human induced pluripotent stem cells by combining genetic reprogramming and chemical inhibitors. Cell Stem Cell. 2009;4:16–19. doi: 10.1016/j.stem.2008.11.014. [DOI] [PubMed] [Google Scholar]
  42. Liao J., Cui C., Chen S., Ren J., Chen J., Gao Y., Li H., Jia N., Cheng L., Xiao H., et al. Generation of induced pluripotent stem cell lines from adult rat cells. Cell Stem Cell. 2009;4:11–15. doi: 10.1016/j.stem.2008.11.013. [DOI] [PubMed] [Google Scholar]
  43. Lin S.L., Chang D.C., Chang-Lin S., Lin C.H., Wu D.T., Chen D.T., Ying S.Y. Mir-302 reprograms human skin cancer cells into a pluripotent ES-cell-like state. RNA. 2008;14:2115–2124. doi: 10.1261/rna.1162708. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Liu H., Zhu F., Yong J., Zhang P., Hou P., Li H., Jiang W., Cai J., Liu M., Cui K., et al. Generation of induced pluripotent stem cells from adult rhesus monkey fibroblasts. Cell Stem Cell. 2008;3:587–590. doi: 10.1016/j.stem.2008.10.014. [DOI] [PubMed] [Google Scholar]
  45. Lluis F., Pedone E., Pepe S., Cosma M.P. Periodic activation of Wnt/beta-catenin signaling enhances somatic cell reprogramming mediated by cell fusion. Cell Stem Cell. 2008;3:493–507. doi: 10.1016/j.stem.2008.08.017. [DOI] [PubMed] [Google Scholar]
  46. Loh Y.H., Agarwal S., Park I.H., Urbach A., Huo H., Heffner G.C., Kim K., Miller J.D., Ng K., Daley G.Q. Generation of induced pluripotent stem cells from human blood. Blood. 2009;113:5476–5479. doi: 10.1182/blood-2009-02-204800. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Lowry W.E., Richter L., Yachechko R., Pyle A.D., Tchieu J., Sridharan R., Clark A.T., Plath K. Generation of human induced pluripotent stem cells from dermal fibroblasts. Proc Natl Acad Sci U S A. 2008;105:2883–2888. doi: 10.1073/pnas.0711983105. [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. Lyssiotis C.A., Foreman R.K., Staerk J., Garcia M., Mathur D., Markoulaki S., Hanna J., Lairson L.L., Charette B.D., Bouchez L.C., et al. Reprogramming of murine fibroblasts to induced pluripotent stem cells with chemical complementation of Klf4. Proc Natl Acad Sci U S A. 2009;106:8912–8917. doi: 10.1073/pnas.0903860106. [DOI] [PMC free article] [PubMed] [Google Scholar]
  49. Maekawa M., Yamaguchi K., Nakamura T., Shibukawa R., Kodanaka I., Ichisaka T., Kawamura Y., Mochizuki H., Goshima N., Yamanaka S. Direct reprogramming of somatic cells is promoted by maternal transcription factor Glis1. Nature. 2011;474:225–229. doi: 10.1038/nature10106. [DOI] [PubMed] [Google Scholar]
  50. Maherali N., Hochedlinger K. Guidelines and techniques for the generation of induced pluripotent stem cells. Cell Stem Cell. 2008;3:595–605. doi: 10.1016/j.stem.2008.11.008. [DOI] [PubMed] [Google Scholar]
  51. Marion R.M., Strati K., Li H., Murga M., Blanco R., Ortega S., Fernandez-Capetillo O., Serrano M., Blasco M.A. A p53-mediated DNA damage response limits reprogramming to ensure iPS cell genomic integrity. Nature. 2009;460:1149–1153. doi: 10.1038/nature08287. [DOI] [PMC free article] [PubMed] [Google Scholar]
  52. Markoulaki S., Hanna J., Beard C., Carey B.W., Cheng A.W., Lengner C.J., Dausman J.A., Fu D., Gao Q., Wu S., et al. Transgenic mice with defined combinations of drug-inducible reprogramming factors. Nat Biotechnol. 2009;27:169–171. doi: 10.1038/nbt.1520. [DOI] [PMC free article] [PubMed] [Google Scholar]
  53. Marson A., Foreman R., Chevalier B., Bilodeau S., Kahn M., Young R.A., Jaenisch R. Wnt signaling promotes reprogramming of somatic cells to pluripotency. Cell Stem Cell. 2008;3:132–135. doi: 10.1016/j.stem.2008.06.019. [DOI] [PMC free article] [PubMed] [Google Scholar]
  54. Matsui T., Leung D., Miyashita H., Maksakova I.A., Miyachi H., Kimura H., Tachibana M., Lorincz M.C., Shinkai Y. Proviral silencing in embryonic stem cells requires the histone methyltransferase ESET. Nature. 2010;464:927–931. doi: 10.1038/nature08858. [DOI] [PubMed] [Google Scholar]
  55. Melton C., Judson R.L., Blelloch R. Opposing microRNA families regulate self-renewal in mouse embryonic stem cells. Nature. 2010;463:621–626. doi: 10.1038/nature08725. [DOI] [PMC free article] [PubMed] [Google Scholar]
  56. Miyabayashi T., Teo J.L., Yamamoto M., McMillan M., Nguyen C., Kahn M. Wnt/beta-catenin/CBP signaling maintains long-term murine embryonic stem cell pluripotency. Proc Natl Acad Sci U S A. 2007;104:5668–5673. doi: 10.1073/pnas.0701331104. [DOI] [PMC free article] [PubMed] [Google Scholar]
  57. Nakagawa M., Koyanagi M., Tanabe K., Takahashi K., Ichisaka T., Aoi T., Okita K., Mochiduki Y., Takizawa N., Yamanaka S. Generation of induced pluripotent stem cells without Myc from mouse and human fibroblasts. Nat Biotechnol. 2008;26:101–106. doi: 10.1038/nbt1374. [DOI] [PubMed] [Google Scholar]
  58. Okita K., Nakagawa M., Hyenjong H., Ichisaka T., Yamanaka S. Generation of mouse induced pluripotent stem cells without viral vectors. Science. 2008;322:949–953. doi: 10.1126/science.1164270. [DOI] [PubMed] [Google Scholar]
  59. Park I.H., Zhao R., West J.A., Yabuuchi A., Huo H., Ince T.A., Lerou P.H., Lensch M.W., Daley G.Q. Reprogramming of human somatic cells to pluripotency with defined factors. Nature. 2008;451:141–146. doi: 10.1038/nature06534. [DOI] [PubMed] [Google Scholar]
  60. Qin D., Gan Y., Shao K., Wang H., Li W., Wang T., He W., Xu J., Zhang Y., Kou Z., et al. Mouse meningiocytes express Sox2 and yield high efficiency of chimeras after nuclear reprogramming with exogenous factors. J Biol Chem. 2008;283:33730–33735. doi: 10.1074/jbc.M806788200. [DOI] [PMC free article] [PubMed] [Google Scholar]
  61. Shi Y., Desponts C., Do J.T., Hahm H.S., Scholer H.R., Ding S. Induction of pluripotent stem cells from mouse embryonic fibroblasts by Oct4 and Klf4 with small-molecule compounds. Cell Stem Cell. 2008;3:568–574. doi: 10.1016/j.stem.2008.10.004. [DOI] [PubMed] [Google Scholar]
  62. Shi Y., Do J.T., Desponts C., Hahm H.S., Scholer H.R., Ding S. A combined chemical and genetic approach for the generation of induced pluripotent stem cells. Cell Stem Cell. 2008;2:525–528. doi: 10.1016/j.stem.2008.05.011. [DOI] [PubMed] [Google Scholar]
  63. Shi Y., Zhao Y., Deng H. Powering reprogramming with vitamin C. Cell Stem Cell. 2010;6:1–2. doi: 10.1016/j.stem.2009.12.012. [DOI] [PubMed] [Google Scholar]
  64. Silva J., Barrandon O., Nichols J., Kawaguchi J., Theunissen T.W., Smith A. Promotion of reprogramming to ground state pluripotency by signal inhibition. PLoS Biol. 2008;6:e253. doi: 10.1371/journal.pbio.0060253. [DOI] [PMC free article] [PubMed] [Google Scholar]
  65. Soldner F., Hockemeyer D., Beard C., Gao Q., Bell G.W., Cook E.G., Hargus G., Blak A., Cooper O., Mitalipova M., et al. Parkinson’s disease patient-derived induced pluripotent stem cells free of viral reprogramming factors. Cell. 2009;136:964–977. doi: 10.1016/j.cell.2009.02.013. [DOI] [PMC free article] [PubMed] [Google Scholar]
  66. Stadtfeld M., Apostolou E., Akutsu H., Fukuda A., Follett P., Natesan S., Kono T., Shioda T., Hochedlinger K. Aberrant silencing of imprinted genes on chromosome 12qF1 in mouse induced pluripotent stem cells. Nature. 2010;465:175–181. doi: 10.1038/nature09017. [DOI] [PMC free article] [PubMed] [Google Scholar]
  67. Stadtfeld M., Brennand K., Hochedlinger K. Reprogramming of pancreatic beta cells into induced pluripotent stem cells. Curr Biol. 2008;18:890–894. doi: 10.1016/j.cub.2008.05.010. [DOI] [PMC free article] [PubMed] [Google Scholar]
  68. Stadtfeld M., Maherali N., Breault D.T., Hochedlinger K. Defining molecular cornerstones during fibroblast to iPS cell reprogramming in mouse. Cell Stem Cell. 2008;2:230–240. doi: 10.1016/j.stem.2008.02.001. [DOI] [PMC free article] [PubMed] [Google Scholar]
  69. Stadtfeld M., Nagaya M., Utikal J., Weir G., Hochedlinger K. Induced pluripotent stem cells generated without viral integration. Science. 2008;322:945–949. doi: 10.1126/science.1162494. [DOI] [PMC free article] [PubMed] [Google Scholar]
  70. Takahashi K., Tanabe K., Ohnuki M., Narita M., Ichisaka T., Tomoda K., Yamanaka S. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell. 2007;131:861–872. doi: 10.1016/j.cell.2007.11.019. [DOI] [PubMed] [Google Scholar]
  71. Takahashi K., Yamanaka S. Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell. 2006;126:663–676. doi: 10.1016/j.cell.2006.07.024. [DOI] [PubMed] [Google Scholar]
  72. Trounson A. Rats, cats, and elephants, but still no unicorn: induced pluripotent stem cells from new species. Cell Stem Cell. 2009;4:3–4. doi: 10.1016/j.stem.2008.12.002. [DOI] [PubMed] [Google Scholar]
  73. Utikal J., Polo J.M., Stadtfeld M., Maherali N., Kulalert W., Walsh R.M., Khalil A., Rheinwald J.G., Hochedlinger K. Immortalization eliminates a roadblock during cellular reprogramming into iPS cells. Nature. 2009;460:1145–1148. doi: 10.1038/nature08285. [DOI] [PMC free article] [PubMed] [Google Scholar]
  74. Varas F., Stadtfeld M., de Andres-Aguayo L., Maherali N., di Tullio A., Pantano L., Notredame C., Hochedlinger K., Graf T. Fibroblast-derived induced pluripotent stem cells show no common retroviral vector insertions. Stem Cells. 2009;27:300–306. doi: 10.1634/stemcells.2008-0696. [DOI] [PMC free article] [PubMed] [Google Scholar]
  75. Wernig M., Lengner C.J., Hanna J., Lodato M.A., Steine E., Foreman R., Staerk J., Markoulaki S., Jaenisch R. A drug-inducible transgenic system for direct reprogramming of multiple somatic cell types. Nat Biotechnol. 2008;26:916–924. doi: 10.1038/nbt1483. [DOI] [PMC free article] [PubMed] [Google Scholar]
  76. Wernig M., Meissner A., Foreman R., Brambrink T., Ku M., Hochedlinger K., Bernstein B.E., Jaenisch R. In vitro reprogramming of fibroblasts into a pluripotent ES-cell-like state. Nature. 2007;448:318–324. doi: 10.1038/nature05944. [DOI] [PubMed] [Google Scholar]
  77. West F.D., Terlouw S.L., Kwon D.J., Mumaw J.L., Dhara S.K., Hasneen K., Dobrinsky J.R., Stice S.L. Porcine induced pluripotent stem cells produce chimeric offspring. Stem Cells Dev. 2010;19:1211–1220. doi: 10.1089/scd.2009.0458. [DOI] [PubMed] [Google Scholar]
  78. Wobus A.M., Boheler K.R. Embryonic stem cells: prospects for developmental biology and cell therapy. Physiol Rev. 2005;85:635–678. doi: 10.1152/physrev.00054.2003. [DOI] [PubMed] [Google Scholar]
  79. Woltjen K., Michael I.P., Mohseni P., Desai R., Mileikovsky M., Hamalainen R., Cowling R., Wang W., Liu P., Gertsenstein M., et al. piggyBac transposition reprograms fibroblasts to induced pluripotent stem cells. Nature. 2009;458:766–770. doi: 10.1038/nature07863. [DOI] [PMC free article] [PubMed] [Google Scholar]
  80. Wu Z., Chen J., Ren J., Bao L., Liao J., Cui C., Rao L., Li H., Gu Y., Dai H., et al. Generation of pig induced pluripotent stem cells with a drug-inducible system. J Mol Cell Biol. 2009;1:46–54. doi: 10.1093/jmcb/mjp003. [DOI] [PubMed] [Google Scholar]
  81. Yamanaka S. Strategies and new developments in the generation of patient-specific pluripotent stem cells. Cell Stem Cell. 2007;1:39–49. doi: 10.1016/j.stem.2007.05.012. [DOI] [PubMed] [Google Scholar]
  82. Yu J., Hu K., Smuga-Otto K., Tian S., Stewart R., Slukvin I.I., Thomson J.A. Human induced pluripotent stem cells free of vector and transgene sequences. Science. 2009;324:797–801. doi: 10.1126/science.1172482. [DOI] [PMC free article] [PubMed] [Google Scholar]
  83. 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., et al. Induced pluripotent stem cell lines derived from human somatic cells. Science. 2007;318:1917–1920. doi: 10.1126/science.1151526. [DOI] [PubMed] [Google Scholar]
  84. Zhao Y., Yin X., Qin H., Zhu F., Liu H., Yang W., Zhang Q., Xiang C., Hou P., Song Z., et al. Two supporting factors greatly improve the efficiency of human iPSC generation. Cell Stem Cell. 2008;3:475–479. doi: 10.1016/j.stem.2008.10.002. [DOI] [PubMed] [Google Scholar]

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