Abstract 1448: The YAP1/TEAD and NF-Kappa B transcription factors may cooperate to mediate prostate cancer progression

Abstract

Abstract Metastatic castration-resistant prostate cancer is morbid and lethal. The transcriptional coregulator YAP1 (Yes-associated protein 1) is a nuclear effector of the Hippo pathway. The Hippo pathway regulates cell growth, motility, and carcinogenesis. Here, we investigated biochemical and functional interactions between YAP1 and the nuclear factor (NF) kappa B/RELA subunit in prostate cancer cell models. We demonstrated that endogenous YAP1 and RELA form protein complexes in the cell, as revealed by co-immunoprecipitation and western blotting. Compared with control, we found that combined treatment of cells with androgen and SDF1a (stromal cell-derived factor-1 alpha) or RANKL (receptor activator of NF-kappa Β ligand) enhanced the protein-protein interaction between YAP1 and RELA, as showed by proximity ligation assay. Our confocal microscopy experiment further showed that combined SDF1a and androgen treatment augmented the YAP1 and RELA colocalization relative to single-agent. Moreover, our promoter-reporter and RNAi experiments showed that genetic silencing YAP1 or TEAD protein, a key mediator of the YAP1 transcription, significantly reduced the NF-Kappa B promoter-reporter gene activity. Also, disruption of YAP1 activity by genetic and small molecule attenuated endogenous protein-protein interaction between TEAD and RELA. Furthermore, controlled expression of MST1/STK4, a potent inhibitor of YAP1, suppressed the NF-Kappa B-promoter reporter activity. Additionally, our unbiased bioinformatics analysis of the exiting ChIP-seq (chromatin immunoprecipitation-sequencing) data identified several genes likely co-regulated by the TEAD1-4 and NF-Kappa B transcription factors. Besides, our computational analysis of the TCGA and Stand Up To Cancer (SU2C) prostate cancer data sets indicated that expression of YAP/TEAD and NF-kappa B/RELA correlates in clinical cases. These findings suggest that cooperative androgen and cytokine signaling regulates Hippo/YAP and NF-Kappa B interaction and their functions. These may have critical roles in advanced prostate cancer downstream of the Hippo pathway. Citation Format: Bekir Cinar, Marwah M. Al-Mathkour, Abdulrahman M. Dwead, Ava M. Boston, Michael S. Lewis, Carlos S. Moreno. The YAP1/TEAD and NF-Kappa B transcription factors may cooperate to mediate prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1448.