Circulating Horizontal Flow Bioreactor Using Tissue Engineering Scaffolds for Evaluating Prostate Cancer Metastasis to Bone.

The high mortality rates of prostate cancer correlate with patients who are diagnosed with bone metastasis. We have fabricated an innovative bioreactor with an injection port ideal for recapitulating the EMT (epithelial to mesenchymal transition) to MET (mesenchymal to epithelial transition) cascade of circulating prostate cancer cells. Further, the migration to bone by hypoxic cancer cells was evaluated under fluid flow. First, we demonstrated that hypoxia, an initiator of metastasis, activates αVβ3 integrins, leading to enhanced cell attachment and growth. We assessed the expression of αVβ3 and the MET biomarkers vimentin and E-cadherin to evaluate role of interstitial fluid flow on circulating prostate cancer cells. We observed upregulation of αV, β3, and E-cadherin expression in normoxic and hypoxic PC3 cells. Hypoxic PC3 cells expressed higher angiogenic markers such as VEGF (vascular endothelial growth factor), MMP-9 (matrix metalloproteinase protein-9), and FAK (focal adhesion kinase). We recapitulated the migration of clustered cells using hanging drop spheroids and observed different migratory pattern and that the crosstalk between PC3 cells and cancer-associated-fibroblasts alters the angiogenicity of cancer spheroids. Overall, this study showcases the ability of this bioreactor to mimic prostate cancer migration to bone under interstitial fluid flow. Understanding the migratory patterns of metastatic prostate cancer can help in predicting cancer progression and identifying appropriate therapies for patients with advanced-stage prostate cancer.