No abstract

Prostate cancer (PC) currently represents 7.5% of all new cancer cases; notably, the 5-year relative survival rate drops from 100% in localized cases to 30.2% in patients who present with metastases. There are no curative therapies for metastatic PC, and most men develop serial resistance to androgen suppression, resulting in a more aggressive disease state that is much more difficult to mitigate. Fibroblasts have been implicated in cancer progression and are thought to intravasate alongside circulating tumor cells and prime metastatic sites for tumor growth. Our understanding of the precise mechanisms by which they contribute to PC, however, is relatively underdeveloped in comparison to other solid cancer types. Here, we report a three-dimensional (3D) engineered prostate cancer tissue (EPCaT) model comprised of PC-3 castration-resistant (CRPC) or LNCaP androgen-dependent (ADPC) PC cell lines in direct coculture with BJ-5ta fibroblasts. By specifically isolating this cell-cell interaction within a bioinspired poly(ethylene glycol)-fibrinogen (PF) matrix, our EPCaT model introduces the ability to monitor coculture-driven changes at a tissue, cellular, and transcriptomic level. Temporal variations in EPCaT growth, cell and colony morphology, cell populations, and cell-mediated remodeling of the PF matrix were assessed. Changes in bulk transcriptomic expression were also quantified and differentially expressed genes (DEGs) were evaluated between CRPC and ADPC mono- and coculture conditions. Finally, to evaluate the clinical significance of our findings, EPCaTs were evaluated against normal and primary tumor tissue transcriptomic data acquired from the Cancer Genome Atlas (TCGA). In comparison to monoculture EPCaTs, both CRPC- and ADPC-fibroblast coculture conditions resulted in an increase in the number of proliferative cells, morphological features of cancer cell migration, and cell-mediated remodeling of the PF matrix, all of which suggest a more aggressive cell phenotype. DEG and gene ontology analysis revealed coculture-driven changes in genes associated with important tumorigenic processes including ECM organization, angiogenesis, and epithelial cell proliferation and migration. Interestingly, fibroblast coculture had a significantly larger impact on the ADPC transcriptome in comparison to CRPC, suggesting that fibroblasts could play an elevated role in less aggressive disease states. Notable DEGs in ADPC coculture that were also clinically significant in the TCGA tumor versus normal comparison included an overexpression of OR51E2 which has been shown to increase epithelial cell proliferation and participate in the ADPC to CRPC switch, thus exacerbating PC progression. Future studies will augment the pathophysiological relevance of our EPCaT model by including patient-isolated cancer-associated fibroblasts from recurring and non-recurring patients. Citation Format: Nicole L. Habbit, Benjamin Anbiah, Joshita Suresh, Yuan Tian, Luke S. Anderson, Megan L. Davies, Iman Hassani, Taraswi Mitra Ghosh, Balabhaskar Prabhakarpandian, Robert D. Arnold, Elizabeth A. Lipke. Elucidating the role of fibroblasts in CRPC and ADPC progression using 3D engineered prostate cancer tissues [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3856.

To investigate the ratiometric role of fibroblasts in prostate cancer (PCa) progression, this work establishes a matrix‐inclusive, three‐dimensional engineered prostate cancer tissue (EPCaT) model that enables direct coculture of neuroendocrine‐variant castration‐resistant (CPRC‐ne) or androgen‐dependent (ADPC) PCa cells with tumor‐supporting stromal cell types. Results show that the inclusion of fibroblasts within CRPC‐ne and ADPC EPCaTs drives PCa aggression through significant matrix remodeling and increased proliferative cell populations. Interestingly, this is observed to a much greater degree in EPCaTs formed with a small number of fibroblasts relative to the number of PCa cells. Fibroblast coculture also results in ADPC behavior more similar to the aggressive CRPC‐ne condition, suggesting fibroblasts play a role in elevating PCa disease state and may contribute to the ADPC to CRPC‐ne switch. Bulk transcriptomic analyses additionally elucidate fibroblast‐driven enrichment of hallmark gene sets associated with tumorigenic progression. Finally, the EPCaT model clinical relevancy is probed through a comparison to the Cancer Genome Atlas (TCGA) PCa patient cohort; notably, similar gene set enrichment is observed between EPCaT models and the patient primary tumor transcriptome. Taken together, study results demonstrate the potential of the EPCaT model to serve as a PCa‐mimetic tool in future therapeutic development efforts.This article is protected by copyright. All rights reserved

Throughout the tumorigenic process, locational heterogeneities in tumor tissue microarchitecture develop as a result of aberrant angiogenesis and a subsequently induced oxygen and nutrient gradient within the three-dimensional (3D) mass. This phenomenon often results in differential tissue stiffness between the necrotic, quiescent, and proliferative tumor regions. In vitro, strong correlations have been found to exist between cell culture platform stiffness and acquired chemoresistance and varied drug response. Therefore, to accurately recapitulate the tumor microenvironment, biomimetic models must provide a mechanically similar scaffold. This study reports novel quantification of the in vivo prostate tumor stiffness and the ensuing development of tunable 3D bioengineered tumor tissue (BioTT) to successfully recapitulate in vivo mechanical cues in vitro. In vivo samples were generated by subcutaneously injecting Matrigel-suspended metastatic prostate cancer cells (PC-3) into the flank of athymic NCr nude mice. Resultant tumors (300 – 1,500 mm3) were excised from the murine host and geometrically dissected to provide samples from the tumor core, midpoint, and periphery. The Young’s modulus was quantified via parallel plate compression under physiological conditions. The 3D BioTT model is comprised of poly(ethylene glycol)-fibrinogen (PF) with varying amounts of excess poly(ethylene glycol) diacrylate (PEGDA) to modulate the mechanical properties of the scaffold. PC-3 cancer cells and BJ-5ta human fibroblasts were encapsulated within the covalently crosslinkable biomaterial and co-cultured for 29 days in vitro. Cell viability was assessed by LIVE/DEAD staining and cellular morphology was visualized with Hoechst 33342, Phalloidin, and the anti-fibroblast immunomarker, TE-7. Temporal variations in cell populations were quantified by flow cytometry and mechanical stiffness characterization was again performed by parallel plate compression. In vivo prostate cancer tumors presented a wide range of tissue stiffness heterogeneity (200 – 5,750 Pa), characterized by an increasing modulus with respect to locational progression from the core to the periphery (n = 48 per tumor region). The BioTT model successfully recapitulated the full tumor stiffness range through biomaterial composition modulation; the addition of excess PEGDA significantly stiffened the PF scaffold (p ≤ 0.05, n = 3). PC-3 and BJ-5ta cells survived the encapsulation process and remained viable throughout long-term co-culture. Visualization of the 3D cellular microenvironment revealed both cancer and stromal cells maintained characteristic morphology. In future studies, the BioTT will be extended to a microfluidic chip platform, thus augmenting the physiological relevancy of the model by incorporating dynamic shear conditions and the ability to monitor cancer cell metastasis. Citation Format: Nicole L. Habbit, Benjamin Anbiah, Luke S. Anderson, Joshita Suresh, Iman Hassani, Matthew Eggert, Shanese L. Jasper, Balabhaskar Prabhakarpandian, Robert D. Arnold, Elizabeth A. Lipke. In vivo prostate tumor tissue stiffness differs by tumor region and can be recapitulated in bioengineered prostate tumor tissues [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1915.

No abstract