Cell Genomics (Apr 2022)

Genome-wide functional perturbation of human microsatellite repeats using engineered zinc finger transcription factors

  • Y. Esther Tak,
  • Gaylor Boulay,
  • Lukuo Lee,
  • Sowmya Iyer,
  • Nicholas T. Perry,
  • Hayley T. Schultz,
  • Sara P. Garcia,
  • Liliane Broye,
  • Joy E. Horng,
  • Shruthi Rengarajan,
  • Beverly Naigles,
  • Angela Volorio,
  • Jeffry D. Sander,
  • Jingyi Gong,
  • Nicolò Riggi,
  • J. Keith Joung,
  • Miguel N. Rivera

Journal volume & issue
Vol. 2, no. 4
p. 100119

Abstract

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Summary: Repeat elements can be dysregulated at a genome-wide scale in human diseases. For example, in Ewing sarcoma, hundreds of inert GGAA repeats can be converted into active enhancers when bound by EWS-FLI1. Here we show that fusions between EWS and GGAA-repeat-targeted engineered zinc finger arrays (ZFAs) can function at least as efficiently as EWS-FLI1 for converting hundreds of GGAA repeats into active enhancers in a Ewing sarcoma precursor cell model. Furthermore, a fusion of a KRAB domain to a ZFA can silence GGAA microsatellite enhancers genome wide in Ewing sarcoma cells, thereby reducing expression of EWS-FLI1-activated genes. Remarkably, this KRAB-ZFA fusion showed selective toxicity against Ewing sarcoma cells compared with non-Ewing cancer cells, consistent with its Ewing sarcoma-specific impact on the transcriptome. These findings demonstrate the value of ZFAs for functional annotation of repeats and illustrate how aberrant microsatellite activities might be regulated for potential therapeutic applications.

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