Development of a 3D in vitro model to investigate tumour-stromal interactions in metastatic castration resistant prostate cancer

Prostate cancer (PCa) is among the most commonly diagnosed malignancies in men worldwide, with metastatic castration-resistant prostate cancer (mCRPC) representing its most aggressive and therapeutically challenging stage. Despite recent advancements in androgen deprivation therapy (ADT) and androgen receptor-targeted agents, mCRPC remains incurable due to the development of resistance and limited therapeutic response. Emerging evidence suggests that the tumour microenvironment (TME), particularly the interaction between tumour cells and mesenchymal stem cells (MSCs), plays a critical role in disease progression and metastasis. Tumour-secreted cytokines can reprogram MSCs into a pro-tumorigenic phenotype that enhances cancer cell invasion and migration. To better understand these interactions, we developed a 3D in vitro model using synthetic and biologically derived hydrogels to co-culture prostate cancer cells (DU145, LNCaP, and PC3) with healthy and patient-derived MSCs. Matrigel-based hydrogels enabled robust spheroid formation, with rheological and SEM characterization confirming optimal porosity and viscoelasticity conducive to nutrient diffusion and cellular remodelling. The incorporation of MSCs, particularly those derived from patient tissue and differentiated along adipogenic and osteogenic lineages, significantly promoted cancer cell migration, invasion, and epithelial-to-mesenchymal transition (EMT). Cytokine profiling revealed elevated expression of IL-6, IL-8, and IL-1β in co-cultures, supporting an inflammatory and metastatic niche. Importantly, therapeutic assessment demonstrated that combining STAT3 inhibitors (Niclosamide, STATTIC) with nitric oxide donors (DETA/NO) elicited synergistic cytotoxicity across both 2D and 3D platforms, effectively overcoming resistance to enzalutamide and docetaxel. PC3 cells, known for their metastatic potential, exhibited the highest invasiveness in response to osteogenic MSCs, further validating the model’s relevance to bone tropism in mCRPC. Overall, this 3D co-culture model recapitulates key features of the prostate TME and offers a translational platform to study tumour-stroma interactions and evaluate novel therapeutic strategies targeting the metastatic cascade. This system holds promise for advancing personalized therapy and preclinical drug screening in advanced PCa.

Publisher

University of Galway

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CC BY-NC-ND

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University of Galway Theses (PhD Theses)