2.6. Preparation of CAF Conditioned Medium (CM)

CAFs were plated into a 10 cm² dish, and a conventional culture was carried out for 24 h before Onco-P20 treatment. Subsequently, fresh DMEM + 10% FBS and treatment (or not for control cells) was replaced twice a week. After 2 weeks and an additional 48 h period without treatment, the medium was replaced with DMEM without FBS before CM harvesting. The supernatant was collected, centrifuged at 1000 rpm, and filtered with a 0.22-μm membrane for sterilization. CM of untreated proliferating fibroblasts was used as a control medium. Experiments were performed in duplicates.