Project description:Tet1 is a hydroxylase known for its role in the conversion of 5-methylcytosines (5mC) to 5-hydroxymethylcytosines (5hmC) involved in the possible active demethylation process and gene expression regulation1-5.M-BM- As somatic cell reprogramming involves the re-activation of pluripotency genes and the silencing of somatic ones6, it remains unclear whether Tet1 plays a positive or negative role in the reprogramming process. Here we show that Tet1 deficiency enhances reprogramming and its overexpression impairs reprogramming. Mechanistically, we demonstrated that Tet1 represses the early obligatory process of mesenchymal to epithelial transition (MET) during reprogramming7,8. Thus, our findings not only define a negative role for Tet1 in somatic cell reprogramming, but also suggest that the Tet enzymes regulate cell fate through distinctive mechanisms. Examination of genome DNA hmC modifications in 2 conditions: individually overexpressed Tet1CD or Tet2CD during MEF reprogramming; Examination of mRNA levels in five different conditions: individually overexpressed DR or Tet1CD or Tet1CDmut or Tet2CD or Tet2CDmut, during MEF reprogrammig.
Project description:Tet1 is a hydroxylase known for its role in the conversion of 5-methylcytosines (5mC) to 5-hydroxymethylcytosines (5hmC) involved in the possible active demethylation process and gene expression regulation. As somatic cell reprogramming involves the re-activation of pluripotency genes and the silencing of somatic ones, it remains unclear the role of Tet1 in the reprogramming process. Here, we performed hMeDIP-seq and RNA-seq during somatic cells reprogramming with Tet1 over expression to invest the effect of Tet1.
Project description:Ten-eleven translocation (TET) family enzymes can convert 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) in DNA and have been proposed as potential DNA demethylase candidates1. Evidences from recent studies indicated that Tet1 is predominantly expressed in ES cells and plays dual functions in promoting transcription of pluripotency genes and as well as participating in the repression of developmental genes by facilitating recruitment of PRC21-5. These studies further raised the possibility that Tet1 might play a role in somatic cell reprogramming. Here, we provide evidence showing that Tet1 can substitute for pluripotent transcription factors in reprogramming differentiated somatic cells to pluripotent stem cells. Tet1 can replace any one of the four traditional transcription factors including Oct4, Sox2, Klf4 and c-Myc during somatic cell reprogramming. Subsequently, the chimeric mice with germline transmission capacity could be efficiently produced from all induced pluripotent stem (iPS) cell lines reprogrammed by OT (Oct4, Tet1), TSKM (Tet1, Sox2, Klf4, c-Myc), OTK, OTKM and OSTM combinations. Furthermore, the TSKM-reprogrammed iPS cells without using Oct4 could produce viable full-term iPS mice with normal fertility through tetraploid complementation and secondary iPS cells could be induced subsequently from the somatic cells retrieved from the iPS mice. Moreover, we demonstrated that conversion of 5mC into 5hmC in Nanog promoter occurred during reprogramming, which might account in part for the mechanism of Tet1 mediated reprogramming. To our knowledge, our study provides the first evidence demonstrating that DNA modifying enzyme Tet1 can replace the pluripotent transcription factors to reprogram differentiated somatic cells to iPS cells. Gene expression profile of iPS cells and ES cells were generated by Affymetrix Mouse Gene 1.0 ST Array. The Gene expression profile of ES cell R1 was used as control. Three biological repeats were included for each line.
Project description:Ten-eleven translocation methylcytosine dioxygenase-1, TET1, takes part in active DNA demethylation. This study showed that TET1 expression reprogramed ovarian cancer epigenome and correlated with poor survival in advanced-stage epithelial ovarian carcinoma (EOC).
Project description:This SuperSeries is composed of the following subset Series: GSE29870: Cancer-related epigenome changes associated with reprogramming to induced pluripotent stem cells (expression data) GSE29872: Cancer-related epigenome changes associated with reprogramming to induced pluripotent stem cells (methylation data) Refer to individual Series