Ratiometric Inclusion of Fibroblasts Promotes Both Castration-resistant and Androgen-dependent Tumorigenic Progression in Engineered Prostate Cancer Tissues

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. Bulk RNAseq analysis of our CRPC and ADPC mono- and coculture EPCaTs on Day 15 of in vitro coculture (RNA isolated from n > 2 EPCaTs).

为探究成纤维细胞在前列腺癌（prostate cancer, PCa）进展中的比例调控作用，本研究构建了一种包含细胞外基质的三维工程化前列腺癌组织（engineered prostate cancer tissue, EPCaT）模型，该模型可实现神经内分泌变异型去势抵抗性前列腺癌（neuroendocrine-variant castration-resistant, CPRC-ne）或雄激素依赖性前列腺癌（androgen-dependent, ADPC）细胞与肿瘤支持性基质细胞的直接共培养。研究结果显示，在CRPC-ne和ADPC型EPCaT中引入成纤维细胞，可通过显著的基质重塑与增殖细胞群体扩增，促进前列腺癌侵袭性。值得注意的是，相较于前列腺癌细胞数量，成纤维细胞占比较低时构建的EPCaT中这一效应更为显著。成纤维细胞共培养还可使ADPC的生物学行为更接近侵袭性CRPC-ne表型，提示成纤维细胞可推动前列腺癌疾病进展，并可能参与ADPC向CRPC-ne的表型转化。批量转录组分析进一步阐明了成纤维细胞介导的与肿瘤发生进展相关的特征基因集富集现象。最后，本研究通过与癌症基因组图谱（Cancer Genome Atlas, TCGA）前列腺癌患者队列进行对比，验证了EPCaT模型的临床相关性；尤为关键的是，EPCaT模型与患者原发肿瘤转录组之间呈现出高度相似的基因集富集特征。综上，本研究结果证实EPCaT模型可作为前列腺癌模拟工具，应用于未来的治疗开发工作。本研究对体外共培养第15天的CRPC与ADPC单培养及共培养EPCaT样本开展了批量RNA测序分析（RNA提取自n>2个EPCaT样本）。