Reprogramming of the esophageal squamous carcinoma epigenome by SOX2 promotes ADAR1 dependence

Nat Genet. 2021 Jun;53(6):881-894. doi: 10.1038/s41588-021-00859-2. Epub 2021 May 10.

Abstract

Esophageal squamous cell carcinomas (ESCCs) harbor recurrent chromosome 3q amplifications that target the transcription factor SOX2. Beyond its role as an oncogene in ESCC, SOX2 acts in development of the squamous esophagus and maintenance of adult esophageal precursor cells. To compare Sox2 activity in normal and malignant tissue, we developed engineered murine esophageal organoids spanning normal esophagus to Sox2-induced squamous cell carcinoma and mapped Sox2 binding and the epigenetic and transcriptional landscape with evolution from normal to cancer. While oncogenic Sox2 largely maintains actions observed in normal tissue, Sox2 overexpression with p53 and p16 inactivation promotes chromatin remodeling and evolution of the Sox2 cistrome. With Klf5, oncogenic Sox2 acquires new binding sites and enhances activity of oncogenes such as Stat3. Moreover, oncogenic Sox2 activates endogenous retroviruses, inducing expression of double-stranded RNA and dependence on the RNA editing enzyme ADAR1. These data reveal SOX2 functions in ESCC, defining targetable vulnerabilities.

Publication types

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

MeSH terms

  • 3' Untranslated Regions / genetics
  • Adenosine Deaminase / metabolism*
  • Animals
  • Base Sequence
  • Carcinogenesis / genetics
  • Cell Line, Tumor
  • Cell Transformation, Neoplastic / genetics
  • Cyclin-Dependent Kinase Inhibitor p16 / metabolism
  • Endogenous Retroviruses / genetics
  • Enhancer Elements, Genetic / genetics
  • Epigenome*
  • Esophageal Neoplasms / genetics*
  • Esophageal Squamous Cell Carcinoma / genetics*
  • Gene Expression Regulation, Neoplastic
  • Genome, Human
  • Humans
  • Interferons / metabolism
  • Introns / genetics
  • Kruppel-Like Transcription Factors / genetics
  • Mice
  • Organoids / pathology
  • Protein Binding
  • RNA, Double-Stranded / metabolism
  • RNA-Binding Proteins / metabolism*
  • SOXB1 Transcription Factors / genetics
  • SOXB1 Transcription Factors / metabolism*
  • Tumor Suppressor Protein p53 / metabolism

Substances

  • 3' Untranslated Regions
  • CDKN2A protein, human
  • Cyclin-Dependent Kinase Inhibitor p16
  • KLF5 protein, human
  • Kruppel-Like Transcription Factors
  • RNA, Double-Stranded
  • RNA-Binding Proteins
  • SOX2 protein, human
  • SOXB1 Transcription Factors
  • Tumor Suppressor Protein p53
  • Interferons
  • ADAR protein, human
  • Adenosine Deaminase