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

S Carcamo, CB Nguyen, E Grossi, D Filipescu… - Cell reports, 2022 - cell.com
Cell reports, 2022cell.com
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 …
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.
cell.com