Abstract 5514: Crosstalk between prostatic epithelial cells and the tumor microenvironment drives cancer progression and metastasis

Abstract Prostate cancer is a heterogeneous disease with a slow progression and a highly variable clinical outcome. Recent advances in the clinical handling of localized prostate cancers resulted in an almost 100% 10-year survival, but no curative treatment is currently available for metastatic disease. Thus, understanding the molecular mechanisms of progression of primary tumors to metastasis is crucial to develop new therapeutic strategies. While tumorigenesis initiates in prostatic epithelial cells, various cell types, including cancer associated fibroblasts (CAFs), immune and endothelial cells produce extra-cellular matrix and secrete signaling molecules that might contribute to tumor progression. However, the complex communication network driving tumor progression is poorly characterized. As the tumor suppressors PTEN and TP53 are among the most frequently altered genes in prostate cancer, we generated genetically engineered mice with Pten and Trp53 selective inactivation in prostatic epithelial cells at adulthood. Their analysis revealed that they develop precancerous lesions that progress to invasive and metastatic tumors. Spatial transcriptomic and single-cell analyses of Pten- and Trp53-deficient prostatic tumors identified the presence of a cancer cell population exhibiting cell plasticity driven by Jak/Stat3 signaling and induced by CAF-produced IL6. In addition, these tumors exhibit a hypoxic core and an immune infiltrate dominated by neutrophils. Inhibition of the hypoxic signaling reduced immune infiltration in primary tumors and their metastatic potential, but did not induce apoptosis of Pten- and Trp53- deficient epithelial cells, in contrast to those of Pten-deficient tumors. These results underline the importance of the tumor genomic background for therapeutic intervention. Taken together, our work highlights the key role of the tumor microenvironment in driving prostate cancer progression and uncovers new vulnerabilities of this disease. Citation Format: Darya Yanushko, Beatriz German Falcon, Céline Keime, Tao Ye, Christelle Thibault-Carpentier, Daniel Metzger, Gilles Laverny. Crosstalk between prostatic epithelial cells and the tumor microenvironment drives cancer progression and metastasis abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 5514.