Downregulation of NANOG induces differentiation of human embryonic stem cells to extraembryonic lineages.
The homeobox transcription factor Nanog has been proposed to play a crucial role in the maintenance of the undifferentiated state of murine embryonic stem cells. A human counterpart, NANOG, has been identified, but its function and localization have not hitherto been described. We have used a combination of RNA interference and quantitative real-time polymerase chain reaction to study NANOG in human embryonic stem and embryonic carcinoma cells. Transfection of NANOG-specific small interfering RNAs reduced levels of NANOG transcript and protein and induced activation of the extraembryonic endoderm-associated genes GATA4, GATA6, LAMININ B1, and AFP as well as upregulation of trophectoderm-associated genes CDX2, GATA2, hCG-alpha, and hCG-beta. Immunostaining of preimplantation human embryos showed that NANOG was expressed in the inner cell mass of expanded blastocysts but not in earlier-stage embryos, consistent with a role in the maintenance of pluripotency. Taken together, our findings suggest that NANOG acts as a gatekeeper of pluripotency in human embryonic stem and carcinoma cells by preventing their differentiation to extraembryonic endoderm and trophectoderm lineages.
Hyslop
Louise
L
Centre for Stem Cell Biology and Developmental Genetics, University of Newcastle International Centre for Life, Newcastle NE1 3BZ, United Kingdom.
Stojkovic
Miodrag
M
Armstrong
Lyle
L
Walter
Theresia
T
Stojkovic
Petra
P
Przyborski
Stefan
S
Herbert
Mary
M
Murdoch
Alison
A
Strachan
Tom
T
Lako
Majlinda
M
D001755:Blastocyst / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D045744:Cell Line, Tumor; D019070:Cell Lineage / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D015536:Down-Regulation; D004622:Embryo, Mammalian / Q000166:cytology; D054278:Embryonal Carcinoma Stem Cells; D050991:GATA4 Transcription Factor / Q000378:metabolism; D050993:GATA6 Transcription Factor / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D005855:Germ Layers / Q000166:cytology / Q000378:metabolism; D049452:Green Fluorescent Proteins; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D006801:Humans; D000071317:Nanog Homeobox Protein; D014411:Neoplastic Stem Cells; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D014162:Transfection; D000509:alpha-Fetoproteins / Q000378:metabolism
D004268:DNA-Binding Proteins; D050991:GATA4 Transcription Factor; C484170:GATA4 protein, human; D050993:GATA6 Transcription Factor; C494759:GATA6 protein, human; D018398:Homeodomain Proteins; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D012333:RNA, Messenger; D000509:alpha-Fetoproteins; D049452:Green Fluorescent Proteins