Abstract 3564: SNAI2 enhances oncogenesis in malignant peripheral nerve sheath tumors

• Published in: Cancer research (Chicago, Ill.) Ill.), 2023-04, Vol.83 (7_Supplement), p.3564-3564
• Main Authors: Jafarah, Hilda, Murray, Béga, Shern, Jack, Zhang, Xiyuan
• Format: Article
• Language: English
• ISSN: 1538-7445; 1538-7445
• DOI: 10.1158/1538-7445.AM2023-3564

Background: MPNSTs are highly aggressive soft tissue sarcomas. Recurrent genetic mutations have been linked to its tumorigenesis, including the loss of functional polycomb repressive complex 2 (PRC2). This results in an altered transcription landscape characterized by the global loss of methylation on histone H3 lysine 27 (H3K27me3) and increased super-enhancer (SE) -associated histone acetylation. We have previously identified SNAI2 as a core SE-driven transcription factor (TF) that is essential for the growth of MPNST. Although SNAI2 is known to be critical for oncogenic processes, including epithelial-to-mesenchymal transition (EMT) and dedifferentiation, its role in maintaining MPNST survival through transcriptomic and epigenetic regulation has not been explored. Methods: Using CRISPR mediated knockout (KO), we targeted the SNAI2 DNA binding domain and confirmed KO via western blot, followed by in vitro phenotypic characterization, including 2D growth assays, anchorage-independent colony formation assays, and scratch assays. Additionally, an integrative analysis of SNAI2 genomic distribution and the transcriptomic effect of its KO was performed using chromatin immunoprecipitation coupled with DNA sequencing (ChIPseq) and RNA sequencing (RNAseq). Finally, an inducible re-expression system was employed to examine the effects on the chromatin landscape with SNAI2 rescue. Results: Genetic loss of SNAI2 slowed the growth of MPNST cells by 50% in comparison to the control. In vitro tumorigenic assays revealed that SNAI2 KO diminished the cells’ capacity in invasion but not in anchorage-independent cell growth. Analysis of the RNAseq results revealed that SNAI2 loss upregulated 790 genes and downregulated 1623 genes (log2fold change> 1, p