Project description:Epigenetic pathways that regulate DNA methylation and chromatin modifications are frequently found to be dysregulated in human cancers. The TET methylcytosine dioxygenase 1 (TET1) enzyme is an important regulator of hydroxymethylcytosine (5hmC) in embryonic stem cells, neural progenitors,adult cells and reprogrammed cells. Decreased expression of TET proteins and loss of 5hmC has been reported in many tumors, suggesting a critical role for the maintenance of this epigenetic modification in normal cellular function. However, loss of TET1 function in the etiology of cancer has not been directly investigated. Here, we show that deletion of the Tet1 gene promotes the development of B cell lymphoma. Tet1 is required for maintaining normal levels of 5hmC, preventing aberrant DNA hypermethylation and for the regulation of transcriptional programs involved in B-cell lineage specification, chromosome maintenance, and DNA repair. Progenitor B cells in the absence of Tet1 accumulate DNA damage and whole-exome sequencing of Tet1-deficient tumors revealed a high correlation of mutations with those most frequently found in Non-Hodgkin B cell lymphoma (B-NHL) patients. In addition, we show that the TET1 gene is deleted, hypermethylated and transcriptionally silenced in B-NHL patients. These findings provide the first in vivo evidence of TET1 function as a tumor suppressor of hematopoietic malignancy. We did hydroxymethylation tests for two wild type mice and two Tet1 knockout mice.
Project description:Epigenetic pathways that regulate DNA methylation and chromatin modifications are frequently found to be dysregulated in human cancers. The TET methylcytosine dioxygenase 1 (TET1) enzyme is an important regulator of hydroxymethylcytosine (5hmC) in embryonic stem cells, neural progenitors,adult cells and reprogrammed cells. Decreased expression of TET proteins and loss of 5hmC has been reported in many tumors, suggesting a critical role for the maintenance of this epigenetic modification in normal cellular function. However, loss of TET1 function in the etiology of cancer has not been directly investigated. Here, we show that deletion of the Tet1 gene promotes the development of B cell lymphoma. Tet1 is required for maintaining normal levels of 5hmC, preventing aberrant DNA hypermethylation and for the regulation of transcriptional programs involved in B-cell lineage specification, chromosome maintenance, and DNA repair. Progenitor B cells in the absence of Tet1 accumulate DNA damage and whole-exome sequencing of Tet1-deficient tumors revealed a high correlation of mutations with those most frequently found in Non-Hodgkin B cell lymphoma (B-NHL) patients. In addition, we show that the TET1 gene is deleted, hypermethylated and transcriptionally silenced in B-NHL patients. These findings provide the first in vivo evidence of TET1 function as a tumor suppressor of hematopoietic malignancy.
Project description:Loss of Tet1 expression causes global 5mC and 5hmC changes in stem and progenitor cells in mice and causes enhanced Pro-B cell self-renewal, increased DNA damage and B-lymphomageneis. In this study we performed reduced representative bisulfite sequencing (RRBS) of DNA from WT and Tet1 KO LSK cells. DNA methylation sequencing was performed and analyzed using an enhanced reduced representation (ERRBS) methodology as previously described. DNA was extracted from purified LSK cells of 6-month old WT and Tet1 KO mice, Bisulphite treatment was performed using the EZ DNA Methylation Kit (Zymo Research). Libraries were amplified according to illumina protocols and sequenced on an Illumina HiSeq2500 machine DNA methylation profiling of LSK cells in WT and Tet1 KO mice.
Project description:Loss of Tet1 expression causes global 5mC and 5hmC changes in stem and progenitor cells in mice and causes enhanced Pro-B cell self-renewal, increased DNA damage and B-lymphomageneis. In this study we performed microarray analysis of total LSK cells from WT and Tet1 KO mice. These results revealed that genes regulated byTet1 in LSKs included Histones, DNA repair enzymes and B-lineage specific factors. LSK cells were purified from the bone marrow of 6-month old WT and Tet1 KO mice . RNA was extracted using RNeasy kit (Qiagen) and hybridized on Affymetrix microarrays. Microarray profiling of LSK cells in WT and Tet1 KO mice.
Project description:Loss of Tet1 expression causes global 5mC and 5hmC changes in stem and progenitor cells in mice and causes enhanced Pro-B cell self-renewal, increased DNA damage and B-lymphomageneis. In this study we performed reduced representative bisulfite sequencing (RRBS) of DNA from WT and Tet1 KO LSK cells.
Project description:Loss of Tet1 expression causes global 5mC and 5hmC changes in stem and progenitor cells in mice and causes enhanced Pro-B cell self-renewal, increased DNA damage and B-lymphomageneis. In this study we performed microarray analysis of total LSK cells from WT and Tet1 KO mice. These results revealed that genes regulated byTet1 in LSKs included Histones, DNA repair enzymes and B-lineage specific factors.
Project description:Loss of Tet1 expression causes global 5mC and 5hmC changes in stem and progenitor cells in mice and enhanced pro-B cell self-renewal, increased DNA damage and B-lymphomageneis. In this study we performed whole transciptome analysis using RNA-sequencing in purified long-term HSCs and MPPs. These results revealed that genes regulated byTet1 included Histones, DNA repair enzymes and B-lineage specific factors. Purified long-term HSCs and MPPs from WT and Tet1 KO mice were used for RNA isolation. RNA was extracted using RNeasy kit (Qiagen) and PolyA selection using oligo-dT beads (Life Technologies) was performed according to the manufacturer’s instructions. Libraries were generated as described before, including end-repair, A-tailing, adapter (Illumina Truseq system) ligation and PCR amplification. RNA libraries were then sequenced on the Illumina HiSeq 2000 using 50bp paired-end reads. Transcriptome profiling of LT-HSC and MPP cells in WT and Tet1 KO mice
Project description:Ten-Eleven Translocation 1 (TET1) is a member of methylcytosine dioxygenase, which catalyse 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC) that promote the demethylation process. The diminished expression of TET1 protein and 5-hmC in many tumors indicate a critical role for the maintenance of cell stability. However, role of TET1 in bladder cancer development remains unclear. Here we found that TET1 expression was downregulated in bladder cancer tissues compared with normal urothelium and was inversely related to patient overall survival. TET1 silencing in bladder cancer cells increase proliferation and inhibited cell migration and invasion while its re-expression inhibits their proliferation and the growth of tumor xenografts. Furthermore, we found that TET1 binds to the promoter of the TSG to maintain its hypomethylated which interacts with β-catenin and suppress its nuclear translocation, thus inhibiting β-catenin transcriptional activity and downstream genes. In conclusion, TET1 acts as a tumor suppressor gene in bladder cancer cells by suppressing β-catenin signaling. This study may facilitate efforts to therapeutic strategy for patients with bladder cancer.
Project description:Loss of Tet1 expression causes global 5mC and 5hmC changes in stem and progenitor cells in mice and enhanced pro-B cell self-renewal, increased DNA damage and B-lymphomageneis. In this study we performed whole transciptome analysis using RNA-sequencing in purified long-term HSCs and MPPs. These results revealed that genes regulated byTet1 included Histones, DNA repair enzymes and B-lineage specific factors.