Fig. 4

Establishment and validation of a novel human-originated PCP mouse model. A: Schematic representation of the steps involved in the establishment of the novel human-originated PCP mouse model. Fresh PCP tumor tissues were obtained during surgical resection, and the tumor tissue was cut into small, digestible fragments. Primary PCP cells were extracted by adding hyaluronidase and collagenase type I; finally, the primary cells were injected into the brains of the nude mice via stereotactic surgery or stored at -80 °C before pathological diagnosis. B: Validation of primary PCP cells: The tightly arranged squamous epithelial cells are shown under a light microscope. Beta-catenin and Pan-CK, which are markers for PCP, are expressed in the cytoplasm and/or membrane of primary PCP cells. C: Validation of the PCP mouse model: 8 weeks after stereotactic surgery, MRI-T2WI revealed mixed-density signals of PCP tumors in the mouse brain (n = 16), and the cystic cavity (high signal) and solid components of the tumors (equal signal) are shown in the yellow box. HE staining of the section corresponding to this MR image revealed that the tumor was located in the lateral hypothalamus. HE magnification revealed that the tumor cells formed tightly packed squamous epithelial structures and that a papillary-like projection inserted into the mouse brain tissue. The immunofluorescence image corresponds to the HE-stained image. Beta-catenin, Pan-CK and mutant BRAFv600e, which are classical biomarkers of PCPs, are expressed in the cytoplasm and/or cell membrane of mouse tumors (n = 16). Human PCP: MR-T2WI revealed mixed-density signals corresponding to the PCP tumors in the patient’s brain (n = 51); the cystic cavity (high signal) and solid tumor (equal signal) are indicated by yellow boxes. HE staining revealed that the tumor cells formed tightly packed squamous epithelial structures and papillary-like projections. The immunofluorescence image corresponds to the HE-stained image. Beta-catenin, Pan-CK and BRAFv600e mutations were expressed in the cytoplasm and/or cell membrane of the tumors (n = 51)