Open main menu

Homeobox protein NANOG is a transcriptional factor that helps embryonic stem cells (ESCs) maintain pluripotency by suppressing cell determination factors. Therefore NANOG deletion will trigger differentiation of ESCs. There are many different types of cancer that are associated with NANOG. In humans, this protein is encoded by the NANOG gene.[5][6]

NANOG
Available structures
PDBOrtholog search: PDBe RCSB
Identifiers
AliasesNANOG, entrez:79923, Nanog, Nanog homeobox
External IDsOMIM: 607937 MGI: 1919200 HomoloGene: 78027 GeneCards: NANOG
Gene location (Human)
Chromosome 12 (human)
Chr.Chromosome 12 (human)[1]
Chromosome 12 (human)
Genomic location for NANOG
Genomic location for NANOG
Band12p13.31Start7,787,794 bp[1]
End7,799,146 bp[1]
RNA expression pattern
PBB GE NANOG 220184 at fs.png
More reference expression data
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001297698
NM_024865

NM_028016
NM_001289828
NM_001289830
NM_001289831

RefSeq (protein)

NP_001284627
NP_079141

NP_001276757
NP_001276759
NP_001276760
NP_082292

Location (UCSC)Chr 12: 7.79 – 7.8 MbChr 6: 122.71 – 122.71 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

StructureEdit

The human NANOG protein coded by the NANOG1 gene, consists of 305 amino acids and possesses 3 functional domains: the N-terminal domain, the C- terminal domain, and the conserved homeodomain motif. The homeodomain region facilitates DNA binding. The human Nanog 1 gene is located on chromosome 12, and the mRNA contains a 915 bp open reading frame (ORF) with 4 exons and 3 introns.[7]

The N-terminal region of human NANOG is rich in serine, threonine and proline residues, and the C-terminus contains a tryptophan-rich domain. The homeodomain in hNANOG ranges from residues 95 to 155. There are also additional NANOG genes (NANOG2, NANOG p8) which potentially affect ESCs' differentiation. Scientists have shown that NANOG1 is fundamental for self-renewal and pluripotency, and NANOG p8 is highly expressed in cancer cells.[8]

FunctionEdit

 
Transcription programs in embryonic stem cells

NANOG is a transcription factor in embryonic stem cells (ESCs) and is thought to be a key factor in maintaining pluripotency. NANOG is thought to function in concert with other factors such as POU5F1 (Oct-4) and SOX2 to establish ESC identity. These cells offer an important area of study because of their ability to maintain pluripotency. In other words, these cells have the ability to become virtually any cell of any of the three germ layers (endoderm, ectoderm, mesoderm). It is for this reason that understanding the mechanisms that maintain a cell's pluripotency is critical for researchers to understand how stem cells work, and may lead to future advances in treating degenerative diseases.

Analysis of arrested embryos demonstrated that embryos express pluripotency marker genes such as POU5F1, NANOG and Rex1. Derived human ESC lines also expressed specific pluripotency markers:

  • TRA-1-60
  • TRA-1-81
  • SSEA4
  • alkaline phosphatase
  • TERT
  • Rex1

These markers allowed for the differentiation in vitro and in vivo conditions into derivatives of all three germ layers.[9]

POU5F1, TDGF1 (CRIPTO), SALL4, LECT1, and BUB1 are also related genes all responsible for self-renewal and pluripotent differentiation.[10]

The NANOG protein has been found to be a transcriptional activator for the Rex1 promoter, playing a key role in sustaining Rex1 expression. Knockdown of NANOG in embryonic stem cells results in a reduction of Rex1 expression, while forced expression of NANOG stimulates Rex1 expression.[11]

Besides the effects of NANOG in the embryonic stages of life, ectopic expression of NANOG in the adult stem cells can restore the proliferation and differentiation potential that is lost due to organismal aging or cellular senescence.[12][13][14][15][16]

Clinical significanceEdit

CancerEdit

NANOG is highly expressed in cancer stem cells and may thus function as an oncogene to promote carcinogenesis. High expression of NANOG correlates with poor survival in cancer patients.[17][18][19]

Recent researches has shown that the localization of NANOG and other transcription factors have potential consequences on cellular function. Experimental evidence has shown that the level of NANOG p8 expression is elevated specially in cancer cells, which mean that NANOG p8 gene is a critical member in (CSCs) Cancer stem cells, so knocking it down could reduce the cancer malignancy.[20]

DiagnosticsEdit

NANOG p8 gene has been evaluated as a prognostic and predictive cancer biomarker.[21]

Cancer stem cellsEdit

Nanog is a transcription factor that controls both self-renewal and pluripotency of embryonic stem cells. Similarly, the expression of Nanog family proteins is increased in many types of cancer and correlates with a worse prognosis.[22]

EvolutionEdit

Humans and chimpanzees share ten NANOG pseudogenes (NanogP2-P11) during evaluation, two of them are located on the X chromosome and they characterized by the 5’ promoter sequences and the absence of introns as a result of mRNA retrotransposition[23] all in the same places: one duplication pseudogene and nine retropseudogenes. Of the nine shared NANOG retropseudogenes, two lack the poly-(A) tails characteristic of most retropseudogenes, indicating that copying errors occurred during their creation. Due to the high improbability that the same pseudogenes (copying errors included) would exist in the same places in two unrelated genomes, evolutionary biologists point to NANOG and its pseudogenes as providing evidence of common descent between humans and chimpanzees.[24]

NameEdit

The name NANOG derives from Tír na nÓg (Irish for "Land of the Young"), a name given to the Celtic Otherworld in Irish and Scottish mythology.[25][26] Residents of Tír na nÓg are described as having eternal health and youth, hence the connection to the NANOG protein.

See alsoEdit

ReferencesEdit

  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000111704 - Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000012396 - Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Mitsui K, Tokuzawa Y, Itoh H, Segawa K, Murakami M, Takahashi K, Maruyama M, Maeda M, Yamanaka S (May 2003). "The homeoprotein Nanog is required for maintenance of pluripotency in mouse epiblast and ES cells". Cell. 113 (5): 631–42. doi:10.1016/S0092-8674(03)00393-3. PMID 12787504.
  6. ^ Chambers I, Colby D, Robertson M, Nichols J, Lee S, Tweedie S, Smith A (May 2003). "Functional expression cloning of Nanog, a pluripotency sustaining factor in embryonic stem cells". Cell. 113 (5): 643–55. doi:10.1016/S0092-8674(03)00392-1. PMID 12787505.
  7. ^ Gawlik-Rzemieniewska N, Bednarek I (2015-11-30). "The role of NANOG transcriptional factor in the development of malignant phenotype of cancer cells". Cancer Biology & Therapy. 17 (1): 1–10. doi:10.1080/15384047.2015.1121348. PMC 4848008. PMID 26618281.
  8. ^ Zhang W, Sui Y, Ni J, Yang T (2016). "Nanog gene: A propeller for stemness in primitive stem cells". International Journal of Biological Sciences. 12 (11): 1372–1381. doi:10.7150/ijbs.16349. PMC 5118783. PMID 27877089.
  9. ^ Zhang X, Stojkovic P, Przyborski S, Cooke M, Armstrong L, Lako M, Stojkovic M (December 2006). "Derivation of human embryonic stem cells from developing and arrested embryos". Stem Cells. 24 (12): 2669–76. doi:10.1634/stemcells.2006-0377. PMID 16990582.
  10. ^ Li SS, Liu YH, Tseng CN, Chung TL, Lee TY, Singh S (August 2006). "Characterization and gene expression profiling of five new human embryonic stem cell lines derived in Taiwan". Stem Cells and Development. 15 (4): 532–55. doi:10.1089/scd.2006.15.532. PMID 16978057.
  11. ^ Shi W, Wang H, Pan G, Geng Y, Guo Y, Pei D (August 2006). "Regulation of the pluripotency marker Rex-1 by Nanog and Sox2". The Journal of Biological Chemistry. 281 (33): 23319–25. doi:10.1074/jbc.M601811200. PMID 16714766.
  12. ^ Shahini A, Choudhury D, Asmani M, Zhao R, Lei P, Andreadis ST (January 2018). "NANOG restores the impaired myogenic differentiation potential of skeletal myoblasts after multiple population doublings". Stem Cell Research. 26: 55–66. doi:10.1016/j.scr.2017.11.018. PMID 29245050.
  13. ^ Shahini A, Mistriotis P, Asmani M, Zhao R, Andreadis ST (June 2017). "NANOG Restores Contractility of Mesenchymal Stem Cell-Based Senescent Microtissues". Tissue Engineering. Part A. 23 (11–12): 535–545. doi:10.1089/ten.TEA.2016.0494. PMC 5467120. PMID 28125933.
  14. ^ Mistriotis P, Bajpai VK, Wang X, Rong N, Shahini A, Asmani M, Liang MS, Wang J, Lei P, Liu S, Zhao R, Andreadis ST (January 2017). "NANOG Reverses the Myogenic Differentiation Potential of Senescent Stem Cells by Restoring ACTIN Filamentous Organization and SRF-Dependent Gene Expression". Stem Cells. 35 (1): 207–221. doi:10.1002/stem.2452. PMID 27350449.
  15. ^ Han J, Mistriotis P, Lei P, Wang D, Liu S, Andreadis ST (December 2012). "Nanog reverses the effects of organismal aging on mesenchymal stem cell proliferation and myogenic differentiation potential". Stem Cells. 30 (12): 2746–59. doi:10.1002/stem.1223. PMC 3508087. PMID 22949105.
  16. ^ Münst B, Thier MC, Winnemöller D, Helfen M, Thummer RP, Edenhofer F (March 2016). "Nanog induces suppression of senescence through downregulation of p27KIP1 expression". Journal of Cell Science. 129 (5): 912–20. doi:10.1242/jcs.167932. PMC 4813312. PMID 26795560.
  17. ^ Gong S, Li Q, Jeter CR, Fan Q, Tang DG, Liu B (September 2015). "Regulation of NANOG in cancer cells". Molecular Carcinogenesis. 54 (9): 679–87. doi:10.1002/mc.22340. PMC 4536084. PMID 26013997.
  18. ^ Jeter CR, Yang T, Wang J, Chao HP, Tang DG (August 2015). "Concise Review: NANOG in Cancer Stem Cells and Tumor Development: An Update and Outstanding Questions". Stem Cells. 33 (8): 2381–90. doi:10.1002/stem.2007. PMC 4509798. PMID 25821200.
  19. ^ Gawlik-Rzemieniewska N, Bednarek I (2016). "The role of NANOG transcriptional factor in the development of malignant phenotype of cancer cells". Cancer Biology & Therapy. 17 (1): 1–10. doi:10.1080/15384047.2015.1121348. PMC 4848008. PMID 26618281.
  20. ^ Zhang W, Sui Y, Ni J, Yang T (2016). "Nanog gene: A propeller for stemness in primitive stem cells". International Journal of Biological Sciences. 12 (11): 1372–1381. doi:10.7150/ijbs.16349. PMC 5118783. PMID 27877089.
  21. ^ Iv Santaliz-Ruiz LE, Xie X, Old M, Teknos TN, Pan Q (December 2014). "Emerging role of nanog in tumorigenesis and cancer stem cells". International Journal of Cancer. 135 (12): 2741–8. doi:10.1002/ijc.28690. PMC 4065638. PMID 24375318.
  22. ^ Zhang W, Sui Y, Ni J, Yang T (2016). "Nanog gene: A propeller for stemness in primitive stem cells". International Journal of Biological Sciences. 12 (11): 1372–1381. doi:10.7150/ijbs.16349. PMC 5118783. PMID 27877089.
  23. ^ Gawlik-Rzemieniewska N, Bednarek I (2015-11-30). "The role of NANOG transcriptional factor in the development of malignant phenotype of cancer cells". Cancer Biology & Therapy. 17 (1): 1–10. doi:10.1080/15384047.2015.1121348. PMC 4848008. PMID 26618281.
  24. ^ Daniel J. Fairbanks (2007). Relics of Eden: The Powerful Evidence of Evolution in Human DNA. Buffalo, N.Y: Prometheus Books. pp. 94–96, 177–182. ISBN 1-59102-564-8.
  25. ^ "ScienceDaily: Cells Of The Ever Young: Getting Closer To The Truth". Retrieved 2007-07-26.
  26. ^ Gawlik-Rzemieniewska N, Bednarek I (2015-11-30). "The role of NANOG transcriptional factor in the development of malignant phenotype of cancer cells". Cancer Biology & Therapy. 17 (1): 1–10. doi:10.1080/15384047.2015.1121348. PMC 4848008. PMID 26618281.

Further readingEdit

External linksEdit