Open AccessSuppression of TET1-Dependent DNA Demethylation Is Essential for KRAS-Mediated Transformation
Author(s) -
Bo-Kuan Wu,
Charles Brenner
Publication year - 2014
Publication title -
cell reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.264
H-Index - 154
eISSN - 2639-1856
pISSN - 2211-1247
DOI - 10.1016/j.celrep.2014.10.063
Subject(s) - kras , dna demethylation , dna methylation , epigenetics , carcinogenesis , gene silencing , gene knockdown , ectopic expression , biology , cancer research , microbiology and biotechnology , gene expression , genetics , mutation , cell culture , cancer , gene
Hypermethylation-mediated tumor suppressor gene (TSG) silencing is a central epigenetic alteration in RAS-dependent tumorigenesis. Ten-eleven translocation (TET) enzymes can depress DNA methylation by hydroxylation of 5-methylcytosine (5mC) bases to 5-hydroxymethylcytosine (5hmC). Here, we report that suppression of TET1 is required for KRAS-induced DNA hypermethylation and cellular transformation. In distinct nonmalignant cell lines, oncogenic KRAS promotes transformation by inhibiting TET1 expression via the ERK-signaling pathway. This reduces chromatin occupancy of TET1 at TSG promoters, lowers levels of 5hmC, and increases levels of 5mC and 5mC-dependent transcriptional silencing. Restoration of TET1 expression by ERK pathway inhibition or ectopic TET1 reintroduction in KRAS-transformed cells reactivates TSGs and inhibits colony formation. KRAS knockdown increases TET1 expression and diminishes colony-forming ability, whereas KRAS/TET1 double knockdown bypasses the KRAS dependence of KRAS-addicted cancer cells. Thus, suppression of TET1-dependent DNA demethylation is critical for KRAS-mediated transformation.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom