TET2 Deficiency Causes Germinal Center Hyperplasia, Impairs Plasma Cell Differentiation, and Promotes B-cell Lymphomagenesis

Cancer Discov. 2018 Dec;8(12):1632-1653. doi: 10.1158/2159-8290.CD-18-0657. Epub 2018 Oct 1.


TET2 somatic mutations occur in ∼10% of diffuse large B-cell lymphomas (DLBCL) but are of unknown significance. Herein, we show that TET2 is required for the humoral immune response and is a DLBCL tumor suppressor. TET2 loss of function disrupts transit of B cells through germinal centers (GC), causing GC hyperplasia, impaired class switch recombination, blockade of plasma cell differentiation, and a preneoplastic phenotype. TET2 loss was linked to focal loss of enhancer hydroxymethylation and transcriptional repression of genes that mediate GC exit, such as PRDM1. Notably, these enhancers and genes are also repressed in CREBBP-mutant DLBCLs. Accordingly, TET2 mutation in patients yields a CREBBP-mutant gene-expression signature, CREBBP and TET2 mutations are generally mutually exclusive, and hydroxymethylation loss caused by TET2 deficiency impairs enhancer H3K27 acetylation. Hence, TET2 plays a critical role in the GC reaction, and its loss of function results in lymphomagenesis through failure to activate genes linked to GC exit signals. SIGNIFICANCE: We show that TET2 is required for exit of the GC, B-cell differentiation, and is a tumor suppressor for mature B cells. Loss of TET2 phenocopies CREBBP somatic mutation. These results advocate for sequencing TET2 in patients with lymphoma and for the testing of epigenetic therapies to treat these tumors.See related commentary by Shingleton and Dave, p. 1515.This article is highlighted in the In This Issue feature, p. 1494.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • CREB-Binding Protein / genetics
  • CREB-Binding Protein / metabolism
  • Cell Differentiation / genetics*
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Dioxygenases
  • Epigenesis, Genetic / genetics
  • Gene Expression Profiling / methods
  • Germinal Center / metabolism*
  • Germinal Center / pathology
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Hyperplasia
  • Lymphoma, Large B-Cell, Diffuse / genetics*
  • Lymphoma, Large B-Cell, Diffuse / metabolism
  • Lymphoma, Large B-Cell, Diffuse / pathology
  • Mice, Knockout
  • Mice, Transgenic
  • Mutation
  • Plasma Cells / metabolism*
  • Plasma Cells / pathology
  • Positive Regulatory Domain I-Binding Factor 1 / genetics
  • Positive Regulatory Domain I-Binding Factor 1 / metabolism
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins / metabolism


  • DNA-Binding Proteins
  • Proto-Oncogene Proteins
  • PRDM1 protein, human
  • Dioxygenases
  • TET2 protein, human
  • Positive Regulatory Domain I-Binding Factor 1
  • CREB-Binding Protein
  • CREBBP protein, human