Bcl11b SWI/SNF-complex subunit modulates intestinal adenoma and regeneration after γ-irradiation through Wnt/β-catenin pathway

Carcinogenesis. 2015 Jun;36(6):622-31. doi: 10.1093/carcin/bgv044. Epub 2015 Mar 31.

Abstract

SWI/SNF chromatin remodeling complexes constitute a highly related family of multi-subunit complexes to modulate transcription, and SWI/SNF subunit genes are collectively mutated in 20% of all human cancers. Bcl11b is a SWI/SNF subunit and acts as a haploinsufficient tumor suppressor in leukemia/lymphomas. Here, we show expression of Bcl11b in intestinal crypt cells and promotion of intestinal tumorigenesis by Bcl11b attenuation in Apc (min/+) mice. Of importance, mutations or allelic loss of BCL11B was detected in one-third of human colon cancers. We also show that attenuated Bcl11b activity in the crypt base columnar (CBC) cells expressing the Lgr5 stem cell marker enhanced regeneration of intestinal epithelial cells after the radiation-induced injury. Interestingly, BCL11B introduction in human cell lines downregulated transcription of β-catenin target genes, whereas Bcl11b attenuation in Lgr5(+) CBCs increased expression of β-catenin targets including c-Myc and cyclin D1. Together, our results argue that Bcl11b impairment promotes tumor development in mouse and human intestine at least in part through deregulation of β-catenin pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / classification
  • Adenoma / genetics
  • Animals
  • Caco-2 Cells
  • Cell Line, Tumor
  • Cell Proliferation
  • Cell Transformation, Neoplastic / genetics*
  • Chromosomal Proteins, Non-Histone / genetics*
  • Colonic Neoplasms / classification
  • Colonic Neoplasms / genetics*
  • Cyclin D1 / biosynthesis
  • HCT116 Cells
  • HEK293 Cells
  • Humans
  • Intestinal Mucosa / metabolism
  • Intestinal Mucosa / radiation effects
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Polymorphism, Single Nucleotide
  • Proto-Oncogene Proteins c-myc / biosynthesis
  • Receptors, G-Protein-Coupled / biosynthesis
  • Repressor Proteins / biosynthesis
  • Repressor Proteins / genetics*
  • Transcription Factors / genetics*
  • Tumor Suppressor Proteins / biosynthesis
  • Tumor Suppressor Proteins / genetics*
  • Wnt Proteins / metabolism
  • Wnt Signaling Pathway
  • beta Catenin / biosynthesis
  • beta Catenin / genetics
  • beta Catenin / metabolism*

Substances

  • BCL11B protein, human
  • Chromosomal Proteins, Non-Histone
  • LGR5 protein, human
  • MYC protein, human
  • Proto-Oncogene Proteins c-myc
  • Receptors, G-Protein-Coupled
  • Repressor Proteins
  • SWI-SNF-B chromatin-remodeling complex
  • Transcription Factors
  • Tumor Suppressor Proteins
  • Wnt Proteins
  • beta Catenin
  • Cyclin D1