Development of a Single-Cell Technique to Increase Yield and Use of Gastrointestinal Cancer Organoids for Personalized Medicine Application

Background: Organoids are excellent 3-dimensional in vitro models of gastrointestinal cancers. However, patient-derived organoids (PDOs) remain inconsistent and unreliable for rapid actionable drug sensitivity testing due to size variation and limited material. Study design: On day10/passage 2 after standard creation of organoids, half of PDOs were dissociated into single-cells with TrypLE Express Enzyme/DNase I and mechanical dissociation; and half of PDOs were expanded by the standard technique. Hematoxylin and eosin and immunohistochemistry with CK7 and CK20 were performed for characterization. Drug sensitivity testing was completed for single-cells and paired standard PDOs to assess reproducibility. Results: After 2 to 3 days, >50% of single-cells reformed uniform miniature PDOs (∼50 μm). We developed 10 PDO single-cell lines (n = 4, gastric cancer, [GC]; and n = 6, pancreatic ductal adenocarcinoma, [PDAC]), which formed epithelialized cystic structures and by IHC, exhibited CK7(high)/CK20(low) expression patterns mirroring parent tissues. Compared with paired standard PDOs, single-cells (n = 2, PDAC; = 2, GC) showed similar architecture, albeit smaller and more uniform. Importantly, single cells demonstrated similar sensitivity to cytotoxic drugs to matched PDOs. Conclusions: PDO single-cells are accurate for rapid clinical drug testing in gastrointestinal cancers. Using early passage PDO single-cells facilitates high-volume drug testing, decreasing time from tumor sampling to actionable clinical decisions, and provides a personalized medicine platform to optimally select drugs for gastrointestinal cancer patients.