Micro-vascularized Multicellular Pancreatic Ductal Adenocarcinoma (PDAC) spheroid: A novel 3D PDAC Research Model.

Aim

To establish a multicellular three-dimensional (3D) pancreatic ductal adenocarcinoma (PDAC) spheroid model in a pancreas-derived extracellular matrix environment and determine how cancer-associated fibroblasts (CAFs) and endothelial CD93 affect spheroid architecture and endothelial organization.

Methods

Porcine pancreatic decellularized extracellular matrix (dECM) was processed into a hydrogel and characterized. PANC-1 cells and mCherry-labelled human umbilical vein endothelial cells (HUVECs) were embedded with or without patient-derived CAFs. Microscopy, immunofluorescence staining, and image analysis were used to evaluate spheroid formation, cellular composition, HUVEC distribution, CD31/CD44 double-positive staining, and matrix-remodeling-associated proteins. CD93-overexpressing HUVECs were used to examine the effects of endothelial CD93.

Results

The dECM hydrogel retained major matrix components and supported PDAC spheroid formation. HUVECs exhibited elongated and interconnected network-like distributions around and within PANC-1 aggregates. Compared with PANC-1/HUVEC co-cultures, CAF-containing tri-cultures formed more spheroids and showed greater mean and total spheroid volumes, higher cell density, and increased estimated PANC-1 and HUVEC abundance. The CD31/CD44 double-positive signal was 1.46-fold higher in tri-cultures. Endothelial CD93 overexpression increased spheroid number and cell density and produced a more intermixed cellular distribution, but reduced the number of large spheroids, mean spheroid volume, total spheroid burden, estimated PANC-1 abundance, and MMP2 and MMP9 immunofluorescence signals. The CD31/CD44 double-positive signal increased by 1.3-fold without a significant change in estimated HUVEC abundance.

Conclusion

This model enables analysis of tumor-endothelial-stromal interactions in a pancreas-derived dECM environment. CAFs and endothelial CD93 differentially altered spheroid architecture and the CD44-associated endothelial phenotype. The formation of continuous and functional microvascular structures remains to be established.