Abstract 2137: Differential gene expression identifies a transcriptional regulatory network involving ESR1and PITX1 in invasive epithelial ovarian cancer

Abstract

Abstract The heterogeneous subtypes and stages of epithelial ovarian cancer (EOC) differ in invasive processes, but the molecular factors that drive aggressive behavior remain nebulous. In this study, we analyzed two types of EOC at opposite ends of the invasiveness spectrum, high-grade serous ovarian cancers (HGSOCs) and serous borderline tumors (SBTs). We identified differentially expressed genes to guide follow on studies of regulatory networks. Initially, in a discovery sample set, we generated transcriptome sequences to identify 11 differentially expressed genes in SBTs and HGSOCs, and a nonoverlapping set of 17 differentially expressed genes stage II and stage III HGSOCs. We validated the classification performance of these gene expression signatures on a validation set of SBT and HGSOC with classification rates of 94 and 98% using the 11-gene and 17-gene sets, respectively. Transcription factor binding sites enriched in the differentially expressed gene promoter regions were examined by Chip-seq analysis in ovarian cancer and other cell lines. We identified a suite of transcription factors implicated in the differential regulation associated with invasiveness, including ERα, RARA, PITX1, FOXA1/FOXF1, and BHLHE41/E40. These data implicate estrogen responsive gene regulatory networks in ovarian cancers and suggest that dynamic regulatory interactions determine malignant EOC outcomes. Citation Format: Yichao Li, Sushil Kumar Jaiswal, Rupleen Kaur, Dana Alsaadi, Xiaoyu Liang, Frank Drews, Julie A. DeLoia, Thomas Krivak, Hanna M. Petrykowska, Valer Gotea, Lonnie Welch, Elnitski Laura. Differential gene expression identifies a transcriptional regulatory network involving ESR1and PITX1 in invasive epithelial ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2137.