Proliferation study of GFP-GICs and organoids co-culture by Ki67. GIC7 and PG88-organoid co-cultures treated or not with PDT based on 5-ALA uptake after 5-ALA 50µg/mL treatment or medium alone. Fixed tissues were sliced at 12 µm to perform IF analysis with anti-Ki67 antibody (pink staining), scale bars 20 µm. Green fluorescent GICs infiltrated the organoid (green color), GIC7 (A) and PG88 (B) 5-ALA controls (left panels) show less positive pink nuclei (amplified in the small square at right) than PDT treated co-cultures (besides and amplified at right panels). Blue DAPI-stained nuclei were used to counterstain cells. Semiquantitative analysis of Ki67 positive cells was performed from: GIC7-5-ALA CNT, 7 fields from 1 sample; GIC7-PDT treated, 13 fields from 2 samples; PG88-5-ALA CNT, 8 fields from 1 sample and PG88-PDT treated, 11 fields from 2 samples. Results as a percentage average of positive cells are represented in (C,D) pictures: green color (GFP-GICs cells), blue DAPI-stained nuclei, and pink Ki67 positive cells; comparing controls (left part) and PDT samples (right part). Significant differences between GIC7-5-ALA CNT and GIC7-PDT-treatment (p = 0.0001) and between PG88-5-ALA CNT and PG88-PDT-treatment (p < 0.01) were found.