Re-expression of SMARCA4/BRG1 in small cell carcinoma of ovary, hypercalcemic type (SCCOHT) promotes an epithelial-like gene signature through an AP-1-dependent mechanism

• DOI: 10.7554/elife.59073
• Publication Date: 2020-12-23T13:00:31Z
• Authors: Krystal Ann Orlando; Amber K Douglas; Aierken Abudu; Yemin Wang; Basile Tessier-Cl...; Weiping Su; Alec Peters; Larry S Sherman; Rayvon Moore; Vinh Nguyen; Gian Luca Negri; Shane Colborne; Gregg B Morin; Friedrich Kommoss; Jessica D Lang; William PD Hendricks; Elizabeth A Raupach; Patrick Pirrotte; David G Huntsman; Jeffrey M Trent; Joel S Parker; Jesse R Raab; Bernard E Weissman
• Keywords: QH301-705.5; Science; 03 medical and health sciences; BRG1; Cell Line, Tumor; Biomarkers, Tumor; SCCOHT; Humans; Biology (General); Carcinoma, Small Cell; Cancer Biology; Ovarian Neoplasms; 0303 health sciences; Q; Ovary; R; DNA Helicases; Nuclear Proteins; multi-omics; AP-1; 3. Good health; SWI/SNF; Transcription Factor AP-1; Cell Transformation, Neoplastic; Mutation; Hypercalcemia; Medicine; Female; Epithelial; Transcription Factors

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare and aggressive form of ovarian cancer. SCCOHT tumors have inactivating mutations in SMARCA4 (BRG1), one of the two mutually exclusive ATPases of the SWI/SNF chromatin remodeling complex. To address the role that BRG1 loss plays in SCCOHT tumorigenesis, we performed integrative multi-omic analyses in SCCOHT cell lines +/- BRG1 reexpression. BRG1 reexpression induced a gene and protein signature similar to an epithelial cell and gained chromatin accessibility sites correlated with other epithelial originating TCGA tumors. Gained chromatin accessibility and BRG1 recruited sites were strongly enriched for transcription-factor-binding motifs of AP-1 family members. Furthermore, AP-1 motifs were enriched at the promoters of highly upregulated epithelial genes. Using a dominant-negative AP-1 cell line, we found that both AP-1 DNA-binding activity and BRG1 reexpression are necessary for the gene and protein expression of epithelial genes. Our study demonstrates that BRG1 reexpression drives an epithelial-like gene and protein signature in SCCOHT cells that depends upon by AP-1 activity.