Abstract B043: The role of GATA2 and TWIST1 in disrupted differentiation during prostate cancer tumorigenesis

Abstract A healthy prostate gland consists of a bilayer of epithelial luminal and basal cells. Each cell type express unique cell-specific markers that allow us to identify them. In prostate development, we observe basal cells able to differentiate to luminal cells which forms the bilayer of epithelial cells we observe in prostate glands. However, in a prostate tumor the bilayer is lost and the cells instead form a monolayer of tumor cells that express both luminal and basal markers. This suggests a defect in the differentiation process. Previous research in our laboratory demonstrates that the transcription factor, CREB1, is aberrantly activated in prostate cancer cells and blocks differentiation. RNA sequencing results identified GATA2 and TWIST1 as possible CREB1 target genes in prostate cancer. ChIP assay results demonstrate the CREB1 could possibly regulate GATA2 and TWIST1 by binding to the CREB1 binding sites, CREs, within their respective promoters. Both genes have been shown to be elevated in human prostate cancers, but their role in preventing differentiation or driving prostate cancer oncogenesis is unclear. To determine how GATA2 and TWIST1 affect differentiation in prostate cancer, we are knocking them down in prostate cancer cells or overexpressing them in normal prostate cells and performing our differentiation protocol. We were able to knockdown GATA2 as validated by immunoblotting. We demonstrate that knocking down GATA2 allows prostate cancer cells to form a second layer of cells. Immunofluorescence results show prostate cancer cells colocalize both basal and luminal markers whereas prostate cancer cells with GATA2 knocked down have a separation of basal and luminal cells indicative of the bilayer. We demonstrate that the loss of GATA2 in prostate cancer cells decreases the migratory ability of these cells. Together this data suggest GATA2 is responsible for promoting oncogenesis. Previous research in our laboratory demonstrates the requirement of NOTCH3 in promoting prostate epithelial differentiation. To elucidate the mechanism that might be responsible for our findings we investigated if there is a GATA2-NOTCH3 interaction. Thus far, we have determined that prostate cancer cells with GATA2 knocked down have less NOTCH3 than prostate cancer cells. Citation Format: Carina Magdaleno, Kasturi Banerjee, Cindy Miranti. The role of GATA2 and TWIST1 in disrupted differentiation during prostate cancer tumorigenesis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Innovations in Prostate Cancer Research and Treatment; 2026 Jan 20-22; Philadelphia PA. Philadelphia (PA): AACR; Cancer Res 2026;86(2_Suppl):Abstract nr B043.