Protocol for generation of brain metastasis mouse model using stereotactic intracranial tumor-derived cells and modified intracarotid injection

Here, we present a protocol for establishing a reproducible mouse model of brain metastasis. We describe the steps for preparing and injecting tumor cells into the internal carotid artery to achieve direct cerebral circulation delivery. We detail procedures for monitoring and validating brain colonization using magnetic resonance imaging (MRI) and histological analysis (H&E staining) and provide guidance on stereotactically generating, harvesting, and re-injecting intracranial tumors via the intracarotid route. This approach enables modeling of brain metastasis and tumor adaptation in the brain microenvironment. • Instructions for stereotactic intracranial tumor-cell injection in mice • Steps to isolate and prepare intracranial tumor-derived cells for injection • Procedure for intracarotid cell delivery via ECA with temporary PPA ligation • Guidance for in vivo monitoring and validation of brain metastasis formation Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics. Here, we present a protocol for establishing a reproducible mouse model of brain metastasis. We describe the steps for preparing and injecting tumor cells into the internal carotid artery to achieve direct cerebral circulation delivery. We detail procedures for monitoring and validating brain colonization using magnetic resonance imaging (MRI) and histological analysis (H&E staining) and provide guidance on stereotactically generating, harvesting, and re-injecting intracranial tumors via the intracarotid route. This approach enables modeling of brain metastasis and tumor adaptation in the brain microenvironment.