title: Aza-deoxycytidine induces apoptosis or differentiation via DNMT3B and targets embryonal carcinoma cells but not their differentiated derivatives.
abstract: BACKGROUND
  Teratocarcinoma is a malignant male germ cell tumour, which contains stem cells and differentiated cancer tissues. DNMT3B has been shown to be highly expressed in human teratocarcinoma stem cells, and to mediate cytotoxicity of Aza-deoxycytidine (Aza-dC) in a pluripotent stem cell line NTERA2.
  
  
  METHODS
  We have established DNMT3B or POU5F1 (hereafter referred to as OCT4) knockdown in teratocarcinoma stem cells N2102Ep and TERA1 and in the pluripotent NTERA2 by a doxycycline-inducible system, and tested the cytotoxicity induced by Aza-dC.
  
  
  RESULTS
  Silencing of DNMT3B led to apoptosis of human teratocarcinoma stem cells N2102Ep and TERA1. Further, we found that induction of apoptosis or differentiation in NTERA2 and human embryonic stem cells by Aza-dC requires DNMT3B. To test whether Aza-dC inhibits proliferation of differentiated teratocarcinoma cells, we depleted OCT4 expression in N2102Ep and TERA1 cells treated with Aza-dC. Treatment with Aza-dC reduced cell number of differentiated cells to a lesser extent than their undifferentiated parental stem cells. Moreover, in contrast to the stem cells, Aza-dC failed to induce apoptosis of differentiated cells.
  
  
  CONCLUSIONS
  Our finding suggests that DNMT3B acts as an antiapoptotic gene in teratocarcinoma stem cells, and mediates apoptosis and differentiation of human pluripotent stem cells induced by Aza-dC, and that Aza-dC specifically induces apoptosis of teratocarcinoma stem cells.
authors.affiliation: Centre for Stem Cell Biology, University of Sheffield, Sheffield S10 2TN, UK.
authors.forename: P
authors.initials: P
authors.lastname: Wongtrakoongate
authors.affiliation: Centre for Stem Cell Biology, University of Sheffield, Sheffield S10 2TN, UK.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.affiliation: Centre for Stem Cell Biology, University of Sheffield, Sheffield S10 2TN, UK.
authors.forename: P W
authors.initials: PW
authors.lastname: Andrews
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000096:biosynthesis / Q000235:genetics*; D003841:Deoxycytidine / Q000494:pharmacology*; D054278:Embryonal Carcinoma Stem Cells / Q000187:drug effects; D006801:Humans; D039904:Pluripotent Stem Cells; D013234:Stem Cells / Q000166:cytology; D018243:Teratocarcinoma / Q000473:pathology; D000097584:DNA Methyltransferase 3B
chemical_list: D001374:Azacitidine; D004248:DNA (Cytosine-5-)-Methyltransferases; D003841:Deoxycytidine; D000097584:DNA Methyltransferase 3B