Cell Reports (Apr 2022)

Altered BAF occupancy and transcription factor dynamics in PBAF-deficient melanoma

  • Saul Carcamo,
  • Christie B. Nguyen,
  • Elena Grossi,
  • Dan Filipescu,
  • Aktan Alpsoy,
  • Alisha Dhiman,
  • Dan Sun,
  • Sonali Narang,
  • Jochen Imig,
  • Tiphaine C. Martin,
  • Ramon Parsons,
  • Iannis Aifantis,
  • Aristotelis Tsirigos,
  • Julio A. Aguirre-Ghiso,
  • Emily C. Dykhuizen,
  • Dan Hasson,
  • Emily Bernstein

Journal volume & issue
Vol. 39, no. 1
p. 110637

Abstract

Read online

Summary: ARID2 is the most recurrently mutated SWI/SNF complex member in melanoma; however, its tumor-suppressive mechanisms in the context of the chromatin landscape remain to be elucidated. Here, we model ARID2 deficiency in melanoma cells, which results in defective PBAF complex assembly with a concomitant genomic redistribution of the BAF complex. Upon ARID2 depletion, a subset of PBAF and shared BAF-PBAF-occupied regions displays diminished chromatin accessibility and associated gene expression, while BAF-occupied enhancers gain chromatin accessibility and expression of genes linked to the process of invasion. As a function of altered accessibility, the genomic occupancy of melanoma-relevant transcription factors is affected and significantly correlates with the observed transcriptional changes. We further demonstrate that ARID2-deficient cells acquire the ability to colonize distal organs in multiple animal models. Taken together, our results reveal a role for ARID2 in mediating BAF and PBAF subcomplex chromatin dynamics with consequences for melanoma metastasis.

Keywords