Abstract A073: Human prostate-on-chip models to define stromal and epithelial interactions in normal and cancerous prostate
Authors: Tahsin Shekha K. , Jiang Linan , Sane Neha , Szewczyk Kailie , Khawaja Hunain , Zohar Yitshak , Miranti Cindy K. 
Published: June 2023

Abstract
Background: The secretion of morphogenic factors from the stroma, whose production is dependent on stromal androgen receptor (AR) action, is crucial for maintaining glandular structure and homeostatic function of the prostate gland. However, the precise nature of the factors involved, their regulation, and how they impact homeostasis in the human prostate is not clear. We hypothesize that loss of stromal AR function as seen in prostate cancer progression and during androgen-deprivation therapy likely contribute to tumor progression through disruption of this homeostasis. It is important to understand these interactions in the human context to better aid in improving patient outcomes. Approach: Microfluidic-based technology was used to develop the first human Prostate-on-Chip (PoC) where human prostate fibroblasts are co-cultured with human prostate basal epithelial cells under flow. Addition of androgen to the stromal cells is sufficient to induce luminal cell differentiation on top of the neighboring basal cells – recapitulating the cellular architecture of the human gland. To study prostate cancer in this context, we replaced the normal epithelial cells with tumor cells to interrogate the tumor-stromal interactions; thus, generating a human Prostate Cancer-on-Chip model (PCoC). Cytokine arrays and RT-qPCR was used to identify androgen-induced stromal morphogens and tumor cytokines involved in tumor/stromal interactions. Molecular biology approaches were used to identify the mechanisms involved. Results: Within the PCoC model, tumor cells invaded into the stroma and conversely stromal cells invaded into the tumors. This was accompanied by localized CAF conversion of the stroma. Invasion of tumor cells into the stroma could be blocked with an integrin-α6 binding peptide. Strikingly, the level of AR expression in the stroma was also reduced, recapitulating the loss of stromal AR expression seen in patients. A cytokine array identified TNFα and TGFβ as tumor secreted factors responsible for suppressing stromal AR protein and mRNA expression. TNFα suppressed stromal AR expression in the absence of CAF conversion via NF-κB binding to the AR promoter. On the other hand, p38-MAPK signaling suppressed AR expression independent of TNFα. FGF10 and Wnt16, but not KGF, were identified as androgen-induced stromal secreted morphogens. Loss of stromal AR expression, led to suppression of FGF10 and Wnt16, but not KGF expression. Thus, stromal AR inhibition by tumor secreted TNFα or p38-MAPK signaling suppresses the stromal morphogens required to maintain normal prostate homeostasis. Conclusions: We have developed the first human Prostate-on-Chip and Prostate Cancer-on-Chip models which recapitulate the biology of both the normal human prostate as well as prostate cancer stromal interactions. These models can be used to address a range of clinical problems in cancer development, drug response, and biomarker identification in the context of the tumor microenvironment. This model can easily be adapted for personalized medicine approaches.
Citation Format: Shekha K. Tahsin, Linan Jiang, Neha Sane, Kailie Szewczyk, Hunain Khawaja, Yitshak Zohar, Cindy K. Miranti. Human prostate-on-chip models to define stromal and epithelial interactions in normal and cancerous prostate [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr A073.