Bioengineered Tumor-Stroma Prostate Cancer In Vitro Models for Screening Therapeutics.

Cancer-associated fibroblasts are increasingly recognized to have a high impact on prostate tumor growth and drug resistance. Here, we bioengineered organotypic prostate cancer 3D in vitro models to better understand tumor-stroma interplay, the metabolomic profile underlying such interactions, and their impact on standard-of-care therapeutics performance. The assembly of robust and uniform spheroids was evaluated and compared in monotypic PC-3 and heterotypic microtumors comprised of either a healthy or malignant stroma and prostate cancer cells. Our findings demonstrate that the precise inclusion of prostate cancer stromal elements is crucial to generating robust PC-3 prostate cancer spheroids with reproducible morphology and size. The inclusion of cancer-associated fibroblasts promoted the establishment of more compact microtumors exhibiting characteristic expression of major proteins. Exometabolomic profile analysis also highlighted the impact of stromal cells on tumor models metabolism. The optimized heterotypic spheroids were additionally exploited for screening standard-of-care therapeutics, exhibiting a higher resistance when compared to their monotypic counterparts. Our findings demonstrate that including stromal elements in PC-3 prostate cancer models is crucial for their use as increasingly organotypic testing platforms, being relevant for screening candidate anti-cancer therapeutics and for the discovery of potential combinations with emerging anti-stroma therapies.