Abstract Metastasis is the leading cause of melanoma-related deaths, yet its age-related mechanisms remain poorly understood. This gap stems partly from reliance on young mouse models (∼8 weeks old, equivalent to 20 human years) in most studies. Additionally, research has largely focused on lung metastasis, even though melanoma often spreads to other sites like the liver, which is notably more resistant to immune checkpoint inhibitors (ICIs).Using syngeneic melanoma cells, we optimized intravenous (IV) injections to model lung colonization and developed a novel liver colonization model using hydrodynamic tail vein injections. Tumor cells were injected into young (8 weeks) and aged (12-16 months) male C57BL/6 mice. Spleen, lungs, and liver were harvested to assess immune infiltration of lymphocyte and myeloid populations via flow cytometry. Hematoxylin and eosin (H Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 2078.
Burtseva et al. (2026) studied this question.