Xenium Spatial Transcriptomics of Cisplatin-Resistant Head and Neck Tumors in Humanized Mice Treated with PI3K Inhibitor Gedatolisib

The therapeutic potential of the PI3K inhibitor gedatolisib on head and neck tumor progression, the tumor microenvironment, and immune cell infiltration was investigated using a humanized orthotopic mouse model implanted with cisplatin-resistant HN30R8 cells. HN30R8 human head and neck cancer cells were orthotopically implanted into the oral tongue of eight NOD humanized mice (HLA-A matched to the human cell line). Once tumors were established, mice were randomly assigned to two treatment groups: four received gedatolisib and four received saline as a control. Clinical-grade gedatolisib (Celcuity Inc., Minneapolis, MN, USA) was administered via tail vein injection at a dose of 16 mg/kg every three days. At the study endpoint, mice were humanely euthanized, and tumors were excised for analysis. Tumors were embedded in OCT compound and flash-frozen in an isopentane bath. Cryosections (10 µm) were mounted onto Xenium slides for spatial transcriptomic analysis using the 10x Genomics Xenium platform. The Xenium Prime 5K Human Pan-Tissue and Pathways Panel was used in combination with a custom 45-gene panel. This custom panel included select mouse genes (denoted in title case) and additional human genes of interest (denoted in uppercase).