Requirement of DNMT1 to orchestrate epigenomic reprogramming for NPM-ALK-driven lymphomagenesis.
Elisa RedlRaheleh Sheibani-TezerjiCrhistian de Jesus CardonaPatricia HammingerGerald TimelthalerMelanie Rosalia HasslerMaša ZrimšekSabine LaggerThomas DillingerLorena HofbauerKristina DraganićAndreas TiefenbacherMichael KothmayerCharles H DietzBernard H RamsahoyeLukas KennerChristoph BockChristian SeiserWilfried EllmeierGabriele SchweikertGerda EggerPublished in: Life science alliance (2020)
Malignant transformation depends on genetic and epigenetic events that result in a burst of deregulated gene expression and chromatin changes. To dissect the sequence of events in this process, we used a T-cell-specific lymphoma model based on the human oncogenic nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) translocation. We find that transformation of T cells shifts thymic cell populations to an undifferentiated immunophenotype, which occurs only after a period of latency, accompanied by induction of the MYC-NOTCH1 axis and deregulation of key epigenetic enzymes. We discover aberrant DNA methylation patterns, overlapping with regulatory regions, plus a high degree of epigenetic heterogeneity between individual tumors. In addition, ALK-positive tumors show a loss of associated methylation patterns of neighboring CpG sites. Notably, deletion of the maintenance DNA methyltransferase DNMT1 completely abrogates lymphomagenesis in this model, despite oncogenic signaling through NPM-ALK, suggesting that faithful maintenance of tumor-specific methylation through DNMT1 is essential for sustained proliferation and tumorigenesis.
Keyphrases
- dna methylation
- genome wide
- gene expression
- acute myeloid leukemia
- transcription factor
- advanced non small cell lung cancer
- diffuse large b cell lymphoma
- single cell
- copy number
- endothelial cells
- epidermal growth factor receptor
- stem cells
- cell therapy
- dna damage
- signaling pathway
- cell proliferation
- single molecule
- induced pluripotent stem cells
- mesenchymal stem cells
- circulating tumor
- high frequency
- cell free